机械毕业设计英文外文翻译204机电一体化

外文原文Options for micro-holemakingAs in the macroscale-machining world, holemaking is one of the most— if not the most—frequently performed operations for micromachining. Many options exist for how those holes are created. Each has its advantages and limitations, depending on the required hole diameter and depth, workpiece material and equipment requirements. This article covers holemaking with through-coolant drills and those without coolant holes, plunge milling, microdrilling using sinker EDMs and laser drilling.Helpful HolesGetting coolant to the drill tip while the tool is cutting helps reduce the amount of heat at the tool/workpiece interface and evacuate chips regardless of hole diameter. Butthrough-coolant capability is especially helpful when deep-hole microdrilling because the tools are delicate and prone to failure when experiencing recutting of chips, chip packing and too much exposure to carbide’s worst enemy—heat.When applying flood coolant, the drill itself blocks access to the cutting action. “Somewhere about 3 to 5 diameters deep, the coolant has trouble getting down to the tip,” said Jeff Davis, vice president of engineering for Harvey Tool Co., Rowley, Mass. “It becomes wise to use a coolant-fed drill at that point.”In addition, flood coolant can cause more harm than good when microholemaking. “The pressure from the flood coolant can sometimes snap fragile drills as they enter the part,” Davis said.The toolmaker offers a line of through-coolant drills with diameters from 0.039" to 0.125" that are able to produce holes up to 12 diameters deep, as well as microdrills without coolant holes from 0.002" to 0.020".Having through-coolant capacity isn’t enough, though. Coolant needs to flow at a rate that enables it to clear the chips out of the hole. Davis recommends, at a minimum, 600 to 800 psi of coolant pressure. “It works much better if you have higher pressure than that,” he added.To prevent those tiny coolant holes from becoming clogged with debris, Davis also recommends a 5μm or finer coolant filter.Another recommendation is to machine a pilot, or guide, hole to prevent the tool from wandering on top of the workpiece and aid in producing a straight hole. When applying a pilot drill, it’s important to select one with an included angle on its point that’s equal t o or larger than the included angle on the through-coolant drill that follows. The pilot drill’sdiameter should also be slightly larger. For example, if the pilot drill has a 120° included angle and a smaller diameter than a through-coolant drill with a 140° included angle, “then you’re catching the coolant-fed drill’s corners and knocking those corners off,” Davis said, which damages the drill.Although not mandatory, pecking is a good practice when microdrilling deep holes. Davis suggests a pecking cycle that is 30 to 50 percent of the diameter per peck depth, depending on the workpiece material. This clears the chips, preventing them from packing in the flute valleys.Lubricious ChillTo further aid chip evacuation, Davis recommends applying an oil-based metalworking fluid instead of a waterbased coolant because oil provides greater lubricity. But if a shop prefers using coolant, the fluid should include EP (extreme pressure) additives to increase lubricity and minimize foaming. “If you’ve got a lot of foam,” Davis noted, “the chips aren’t being pulled out the way they are supposed to be.”He added that another way to enhance a tool’s slipperiness while extending its life is with a coating, such as titanium aluminum nitride. TiAlN has a high hardness and is an effective coating for reducing heat’s impact when drilling difficult-to-machine materials, like stainless steel.David Burton, general manager of Performance Micro Tool, Janesville, Wis., disagrees with the idea of coating microtools on the sma ller end of the spectrum. “Coatings on tools below 0.020" typically have a negative effect on every machining aspect, from the quality of the initial cut to tool life,” he said. That’s because coatings are not thin enough and negatively alter the rake and relief angles when applied to tiny tools.However, work continues on the development of thinner coatings, and Burton indicated that Performance Micro Tool, which produces microendmills and microrouters and resells microdrills, is working on a project with others to create a submicron-thickness coating. “We’re probably 6 months to 1 year from testing it in the market,” Burton said.The microdrills Performance offers are basically circuit-board drills, which are also effective for cutting metal. All the tools are without through-coolant capability. “I had a customer drill a 0.004"-dia. hole in stainless steel, and he was amazed he could do it with a circuit-board drill,” Burton noted, adding that pecking and running at a high spindle speed increase the drill’s effectiveness.The requirements for how fast microtools should rotate depend on the type of CNC machines a shop uses and the tool diameter, with higher speeds needed as the diameter decreases. (Note: The equation for cutting speed is sfm = tool diameter × 0.26 × spindlecan go deeper because it’s de signed to place the load on its tip when drilling. This transfers the pressure into the shank, which absorbs it.Performance offers endmills as small as 5 microns (0.0002") but isn’t keen on increasing that line’s sales. “When people try to buy them, I ve ry seriously try to talk them out of it because we don’t like making them,” Burton said. Part of the problem with tools that small is the carbide grains not only need to be submicron in size but the size also needs to be consistent, in part because such a tool is comprised of fewer grains. “The 5-micron endmill probably has 10 grains holding the core together,” Burton noted.He added that he has seen carbide powder containing 0.2-micron grains, which is about half the size of what’s commercially available, but it also contained grains measuring 0.5 and 0.6 microns. “It just doesn’t help to have small grains if they’re not uniform.”MicrovaporizationElectrical discharge machining using a sinker EDM is another micro-holemaking option. Unlike , which create small holes for threading wire through the workpiece when wire EDMing, EDMs for producing microholes are considerably more sophisticated, accurate and, of course, expensive.For producing deep microholes, a tube is applied as the electrode. For EDMing smaller but shallower ho les, a solid electrode wire, or rod, is needed. “We try to use tubes as much as possible,” said Jeff Kiszonas, EDM product manager for Makino Inc., Auburn Hills, Mich. “But at some point, nobody can make a tube below a certain diameter.” He added that some suppliers offer tubes down to 0.003" in diameter for making holes as small as 0.0038". The tube’s flushing hole enables creating a hole with a high depth-to-diameter ratio and helps to evacuate debris from the bottom of the hole during machining.One suc h sinker EDM for producing holes as small as 0.00044" (11μm) is Makino’s Edge2 sinker EDM with fine-hole option. In Japan, the machine tool builder recently produced eight such holes in 2 minutes and 40 seconds through 0.0010"-thick tungsten carbide at the hole locations. The electrode was a silver-tungsten rod 0.00020" smaller than the hole being produced, to account for spark activity in the gap.When producing holes of that size, the rod, while rotating, is dressed with a charged EDM wire. The fine-hole option includes a W-axis attachment, which holds a die that guides the electrode, as well as a middle guide that prevents the electrode from bending or wobbling as it spins. With the option, the machine is appropriate for drilling hole diameters less than 0.005".Another sinker EDM for micro-holemaking is the Mitsubishi VA10 with a fine-hole哈尔滨理工大学2008届本科生毕业设计（论文）外文翻译jig attachment to chuck and guide the fine wire applied to erode the material. “It’s a standard EDM, but with that attachment fixed to the machine, we can do microhol e drilling,” said Dennis Powderly, sinker EDM product manager for MC Machinery Systems Inc., Wood Dale, Ill. He added that the EDM is also able to create holes down to 0.0004" using a wire that rotates at up to 2,000 rpm.Turn to TungstenEDMing is typically a slow process, and that holds true when it is used for microdrilling. “It’s very slow, and the finer the details, the slower it is,” said , president and owner of Optimation Inc. The Midvale, Utah, company builds Profile 24 Piezo EDMs for micromachining and also performs microEDMing on a contract-machining basis.Optimation produces tungsten electrodes using a reverse-polarity process and machines and ring-laps them to as small as 10μm in diameter with 0.000020" roundness. Applying a10μm-dia. electr ode produces a hole about 10.5μm to 11μm in diameter, and blind-holes are possible with the company’s EDM. The workpiece thickness for the smallest holes is up to 0.002", and the thickness can be up to 0.04" for 50μm holes.After working with lasers and then with a former EDM builder to find a better way to produce precise microholes, Jorgensen decided the best approach was DIY. “We literally started with a clean sheet of paper and did all the electronics, all the software and the whole machine from scratc h,” he said. Including the software, the machine costs in the neighborhood of $180,000 to $200,000.Much of the company’s contract work, which is provided at a shop rate of $100 per hour, involves microEDMing exotic metals, such as gold and platinum for X-ray apertures, stainless steel for optical applications and tantalum and tungsten for the electron-beam industry. Jorgensen said the process is also appropriate for EDMing partially electrically conductive materials, such as PCD.“The customer normally doesn’t care too much about the cost,” he said. “We’ve done parts where there’s $20,000 [in time and material] involved, and you can put the whole job underneath a fingernail. We do everything under a microscope.”Light CuttingBesides carbide and tungsten, light is an appropriate “tool material” formicro-holemaking. Although most laser drilling is performed in the infrared spectrum, the SuperPulse technology from The Ex One Co., Irwin, Pa., uses a green laser beam, said Randy Gilmore, the company’s director of laser technologies. Unlike the femtosecond variety, Super- Pulse is a nanosecond laser, and its green light operates at the 532-nanometer wavelength. The technology provides laser pulses of 4 to 5 nanoseconds in duration, and those pulses are sent in pairs with a delay of 50 to 100 nanoseconds between individual pulses. The benefits of this approach are twofold. “It greatly enhances material removal compared to1other nanosecond lasers,” Gilmore said, “and greatly reduces the amount of thermal damage don e to the workpiece material” because of the pulses’ short duration.The minimum diameter produced with the SuperPulse laser is 45 microns, but one of the most common applications is for producing 90μm to 110μm holes in diesel injector nozzles made of 1mm-t hick H series steel. Gilmore noted that those holes will need to be in the 50μm to 70μm range as emission standards tighten because smaller holes in injector nozzles atomize diesel fuel better for more efficient burning.In addition, the technology can produce negatively tapered holes, with a smaller entrance than exit diameter, to promote better fuel flow.Another common application is drilling holes in aircraft turbine blades for cooling. Although the turbine material might only be 1.5mm to 2mm thick, Gilmore explained that the holes are drilled at a 25° entry angle so the air, as it comes out of the holes, hugs the airfoil surface and drags the heat away. That means the hole traverses up to 5mm of material. “Temperature is everything in a turbine” he said, “because in an aircraft engine, the hotter you can run the turbine, the better the fuel economy and the more thrust you get.”To further enhance the technology’s competitiveness, Ex One developed apatent-pending material that is injected into a hollow-body component to block the laser beam and prevent back-wall strikes after it creates the needed hole. After laser machining, the end user removes the material without leaving remnants.“One of the bugaboos in getting lasers accepted in the diesel injector community is that light has a nasty habit of continuing to travel until it meets another object,” Gilmore said. “In a diesel injector nozzle, that damages the interior surface of the opposite wall.”Although the $650,000 to $800,000 price for a Super- Pulse laser is higher than amicro-holemaking EDM, Gilmore noted that laser drilling doesn’t require electrodes. “A laser system is using light to make holes,” he said, “so it doesn’t have a consumable.”Depending on the application, mechanical drilling and plunge milling, EDMing and laser machining all have their place in the expanding micromachining universe. “People want more packed into smaller spaces,” said Makino’s Kiszonas.哈尔滨理工大学2008届本科生毕业设计（论文）外文翻译中文翻译微孔的加工方法正如宏观加工一样，在微观加工中孔的加工也许也是最常用的加工之一。

机械类毕业设计外文翻译外文原文Options for micro-holemakingAs in the macroscale-machining world, holemaking is one of the most— if not the most—frequently performed operations for micromachining. Many options exist for how those holes are created. Each has its advantages and limitations, depending on the required hole diameter and depth, workpiece material and equipment requirements. This article covers holemaking with through-coolant drills and those without coolant holes, plunge milling, microdrilling using sinker EDMs and laser drilling.Helpful HolesGetting coolant to the drill tip while the tool is cutting helps reduce the amount of heat at the tool/workpiece interface and evacuate chips regardless of hole diameter. But through-coolant capability is especially helpful when deep-hole microdrilling because the tools are delicate and prone to failure when experiencing recutting of chips, chip packing and too much exposure to carbide’s worst enemy—heat.When applying flood coolant, the drill itself blocks access to the cutting action. “Somewhere about 3 to 5 diam eters deep, the coolant has trouble getting down to the tip,” said Jeff Davis, vice president of engineering for Harvey Tool Co., Rowley, Mass. “It becomes wise to use a coolant-fed drill at that point.”In addition, flood coolant can cause more harm than good when microholemaking. “The pressure from the flood coolant can sometimes snap fragile drills as they enter the part,” Davis said.The toolmaker offers a line of through-coolant drills with diameters from 0.039" to 0.125" that are able to produce holes up to 12 diameters deep, as well as microdrills without coolant holes from 0.002" to 0.020".Having through-coolant capacity isn’t enough, though. Coolant needs to flow at a rate that enables it to clear the chips out of the hole. Davis recommends, at a minimum, 600 to 800 psi of coolant pressure. “It works much better if you have higher pressure than that,” he added.To prevent those tiny coolant holes from becoming clogged with debris, Davis also recommends a 5μm or finer coolant filter.Another recommendation is to machine a pilot, or guide, hole to prevent the tool from wandering on top of the workpiece and aid in producing a straight hole. When applying a pilot drill, it’s important to select one with an included angle on its point that’s equal t o or larger than the included angle on the through-coolant drill that follows.The pilot drill’s diameter should also be slightly larger. For example, if the pilot drill has a 120° included angle and a smaller diameter than a through-coolant drill with a 140°included angle, “then you’re catching the coolant-fed drill’s corners and knocking those corners off,” Davis said, which damages the drill.Although not mandatory, pecking is a good practice when microdrilling deep holes. Davis suggests a pecking cycle that is 30 to 50 percent of the diameter per peck depth, depending on the workpiece material. This clears the chips, preventing them from packing in the flute valleys.Lubricious ChillTo further aid chip evacuation, Davis recommends applying an oil-based metalworking fluid instead of a waterbased coolant because oil provides greater lubricity. But if a shop prefers using coolant, the fluid should include EP (extreme pressure) additives to increase lubricity and minimize foaming. “If you’ve got a lot of foam,” Davis noted, “the chips aren’t being pulled out the way they are supposed to be.”He added that another way to enhance a tool’s slipperiness while extending its life is with a coating, such as titanium aluminum nitride. TiAlN has a high hardness and is an effective coating for reducing heat’s impact when drilling difficult-to-machine materials, like stainless steel.David Burton, general manager of Performance Micro Tool, Janesville, Wis., disagrees with the idea of coating microtools on the smaller end of the spectrum. “Coatings on tools below 0.020" typically have a negative effect on every machining aspect, from the quality of the initial cut to tool life,” he said. That’s because coatings are not thin enough and negatively alter the rake and relief angles when applied to tiny tools.However, work continues on the development of thinner coatings, and Burton indicated that Performance Micro Tool, which produces microendmills and microrouters and resells microdrills, is working on a project with others to create a submicron-thickness coating. “We’re probably 6 months to 1 year from testing it in the market,” Burton said.The microdrills Performance offers are basically circuit-board drills, which are also effective for cutting metal. All the tools are without through-coolant capability. “I had a customer drill a 0.004"-dia. hole in stainless steel, and he was amazed he could do it with a circuit-board drill,” Burton noted, adding that pecking and running at a high spindle speed increase the d rill’s effectiveness.The requirements for how fast microtools should rotate depend on the type of CNCmachines a shop uses and the tool diameter, with higher speeds needed as the diameter decreases. (Note: The equation for cutting speed is sfm = tool diameter × 0.26 × spindle speed.)Although relatively low, 5,000 rpm has been used successfully by Burton’s customers. “We recommend that our customers find the highest rpm at the lowest possible vibration—the sweet spot,” he said.In addition to minimizing vibration, a constant and adequate chip load is required to penetrate the workpiece while exerting low cutting forces and to allow the rake to remove the appropriate amount of material. If the drill takes too light of a chip load, the rake face wears quickly, becoming negative, and tool life suffers. This approach is often tempting when drilling with delicate tools.“If the customer decides he wants to baby the tool, he takes a lighter chip load,” Burton said, “and, typically, the cutting edge wears much quicker and creates a radius where the land of that radius is wider than the chip being cut. He ends up using it as a grinding tool, trying to bump material away.” For tools larger than 0.001", Burton considers a chip load under 0.0001" to be “babying.” If the drill doesn’t snap, premature wear can result in abysmal tool life.Too much runout can also be destructive, but how much is debatable. Burton pointed out that Performance purposely designed a machine to have 0.0003" TIR to conduct in-house, worst-case milling scenarios, adding that the company is still able to mill a 0.004"-wide slot “day in and day out.”He added: “You would think with 0.0003" runout and a chip load a third that, say, 0.0001" to 0.00015", the tool would break immediately because one flute would be taking the entire load and then the back end of the flute would be rubbing.When drilling, he indicated that up to 0.0003" TIR should be acceptable because once the drill is inside the hole, the cutting edges on the end of the drill continue cutting while the noncutting lands on the OD guide the tool in the same direction. Minimizing run out becomes more critical as the depth-to-diameter ratio increases. This is because the flutes are not able to absorb as much deflection as they become more engaged in the workpiece. Ultimately, too much runout causes the tool shank to orbit around the tool’s center while the tool tip is held steady, creating a stress point where the tool will eventually break.Taking a PlungeAlthough standard micro drills aren’t generally available below 0.002", microendmills that can be used to “plunge” a hole are. “When people want to drillsmaller than that, they use our endmills and are pretty successful,” Burton said. However, the holes can’t be very deep because the tools don’t have long aspect, or depth-to-diameter, ratios. Therefore, a 0.001"-dia. endmill might be able to only make a hole up to 0.020" deep whereas a drill of the same size can go deeper because it’s designed to place the load on its tip when drilling. This transfers the pressure into the shank, which absorbs it.Performance offers endmills as small as 5 microns (0.0002") but isn’t keen on increasing that line’s sales. “When people try to buy them, I very seriously try to talk them out of it bec ause we don’t like making them,” Burton said. Part of the problem with tools that small is the carbide grains not only need to be submicron in size but the size also needs to be consistent, in part because such a tool is comprised of fewer grains. “The 5-m icron endmill probably has 10 grains holding the core together,” Burton noted.He added that he has seen carbide powder containing 0.2-micron grains, which is about half the size of what’s commercially available, but it also contained grains measuring 0.5 and 0.6 microns. “It just doesn’t help to have small grains if they’re not uniform.”MicrovaporizationElectrical discharge machining using a sinker EDM is another micro-holemaking option. Unlike , which create small holes for threading wire through the workpiece when wire EDMing, EDMs for producing microholes are considerably more sophisticated, accurate and, of course, expensive.For producing deep microholes, a tube is applied as the electrode. For EDMing smaller but shallower holes, a solid electrode wire, or rod, is needed. “We try to use tubes as much as possible,” said Jeff Kiszonas, EDM product manager for Makino Inc., Auburn Hills, Mich. “But at some point, nobody can make a tube below a certain diameter.” He added that some suppliers offer tubes down to 0.003" in diameter for making holes as small as 0.0038". The tube’s flushing hole enables creating a hole with a high depth-to-diameter ratio and helps to evacuate debris from the bottom of the hole during machining.One such sinker EDM for produc ing holes as small as 0.00044" (11μm) is Makino’s Edge2 sinker EDM with fine-hole option. In Japan, the machine tool builder recently produced eight such holes in 2 minutes and 40 seconds through 0.0010"-thick tungsten carbide at the hole locations. The electrode was a silver-tungsten rod 0.00020" smaller than the hole being produced, to account for spark activity in the gap.When producing holes of that size, the rod, while rotating, is dressed with acharged EDM wire. The fine-hole option includes a W-axis attachment, which holds a die that guides the electrode, as well as a middle guide that prevents the electrode from bending or wobbling as it spins. With the option, the machine is appropriate for drilling hole diameters less than 0.005".Another sinker EDM for micro-holemaking is the Mitsubishi VA10 with afine-hole jig attachment to chuck and guide the fine wire applied to erode the material. “It’s a standard EDM, but with that attachment fixed to the machine, we can do microhole drilling,” said Dennis Powderly, sinker EDM product manager for MC Machinery Systems Inc., Wood Dale, Ill. He added that the EDM is also able to create holes down to 0.0004" using a wire that rotates at up to 2,000 rpm.Turn to TungstenEDMing is typically a slow process, and that holds true when it is used for microdrilling. “It’s very slow, and the finer the details, the slower it is,” said , president and owner of Optimation Inc. The Midvale, Utah, company builds Profile 24 Piezo EDMs for micromachining and also performs microEDMing on a contract-machining basis.Optimation produces tungsten electrodes using a reverse-polarity process and machines and ring-laps them to as small as 10μm in diameter with 0.000020" roundness. Applying a 10μm-dia. electrode produces a hole about 10.5μm to 11μm in diameter, and blind-holes are possible with the company’s EDM. The workpiece thickness for the smallest holes is up to 0.002", and the thickness can be up to 0.04" for 50μm holes.After working with lasers and then with a former EDM builder to find a better way to produce precise microholes, Jorgensen decided the best approach was DIY. “We literally started with a clean sheet of paper and did all the electronics, all the software and the whole machine from scratch,” he said. Including the software, the machine costs in the neighborhood of $180,000 to $200,000.Much of the company’s contract work, which is provided at a shop rate of $100 per hour, involves microEDMing exotic metals, such as gold and platinum for X-ray apertures, stainless steel for optical applications and tantalum and tungsten for the electron-beam industry. Jorgensen said the process is also appropriate for EDMing partially electrically conductive materials, such as PCD.“The customer normally doesn’t care too much about the cost,” he said. “We’ve done parts where there’s $20,000 [in time and material] involved, and you can put the whole job underneath a fingernail. We do everything under a microscope.”Light CuttingBesides carbide and tungsten, light is an a ppropriate “tool material” formicro-holemaking. Although most laser drilling is performed in the infrared spectrum, the SuperPulse technology from The Ex One Co., Irwin, Pa., uses a green laser beam, said Randy Gilmore, the company’s director of laser tec hnologies. Unlike the femtosecond variety, Super- Pulse is a nanosecond laser, and its green light operates at the 532-nanometer wavelength. The technology provides laser pulses of 4 to 5 nanoseconds in duration, and those pulses are sent in pairs with a delay of 50 to 100 nanoseconds between individual pulses. The benefits of this approach are twofold. “It greatly enhances material removal compared to other nanosecond lasers,” Gilmore said, “and greatly reduces the amount of thermal damage done to the workpiece material” because of the pulses’ short duration.The minimum diameter produced with the SuperPulse laser is 45 microns, but one of the most common applications is for producing 90μm to 110μm holes in diesel injector nozzles made of 1mm-thick H series steel. Gilmore noted that those holes will need to be in the 50μm to 70μm range as emission standards tighten because smaller holes in injector nozzles atomize diesel fuel better for more efficient burning.In addition, the technology can produce negatively tapered holes, with a smaller entrance than exit diameter, to promote better fuel flow.Another common application is drilling holes in aircraft turbine blades for cooling. Although the turbine material might only be 1.5mm to 2mm thick, Gilmore explained that the holes are drilled at a 25° entry angle so the air, as it comes out of the holes, hugs the airfoil surface and drags the heat away. That means the hole traverses up to 5mm of material. “Temperature is everything in a turbine” he said, “because in an aircraft engine, the hotter you can run the turbine, the better the fuel economy and the more thrust you get.”To further enhance the technology’s competitiveness, Ex One developed apatent-pending material that is injected into a hollow-body component to block the laser beam and prevent back-wall strikes after it creates the needed hole. After laser machining, the end user removes the material without leaving remnants.“One of the bugaboos in getting lasers accepted in the diesel injector community is that light has a nasty habit of continuing to travel until it meets another object,” Gilmore said. “In a diesel injector nozzle, that damages the interior surface of the opposite wall.”Although the $650,000 to $800,000 price for a Super- Pulse laser is higher than a micro-holemaking EDM, Gilmore noted that laser drilling doesn’t require electrodes. “A laser system is using light to make holes,” he said, “so it doesn’t have a consumable.”Depending on the application, mechanical drilling and plunge milling, EDMing and laser machining all have their place in the expanding micromachining universe. “People want more packed into smaller spaces,” said Makino’s Kiszonas.中文翻译微孔的加工方法正如宏观加工一样，在微观加工中孔的加工也许也是最常用的加工之一。

机械设计外文文献翻译、中英文翻译unavailable。

The first step in the design process is to define the problem and XXX are defined。

the designer can begin toXXX evaluated。

and the best one is XXX。

XXX.Mechanical DesignA XXX machines include engines。

turbines。

vehicles。

hoists。

printing presses。

washing machines。

and XXX and methods of design that apply to XXXXXX。

cams。

valves。

vessels。

and mixers.Design ProcessThe design process begins with a real need。

Existing apparatus may require XXX。

efficiency。

weight。

speed。

or cost。

while new apparatus may be XXX。

To start。

the designer must define the problem and XXX。

ideas and concepts are generated。

evaluated。

and refined until the best one is XXX。

XXX.XXX。

assembly。

XXX.During the preliminary design stage。

it is important to allow design XXX if some ideas may seem impractical。

they can be corrected early on in the design process。

英语原文：CAD/CAM is the technical expression, indicates the computer-aided design and the computer aided manufacturing.This is one item in the design and the production, carries out certain function technology about the use computer data.This technology is completing the design and the production direction to the place develops.In these two traditions was considered is in the production process out of the ordinary, independent function.In brief, CAD/CAM will be able to provide the technology base for the future complete computer production.Looked from the computer science angle that, the design and the manufacture process is one has, processing, the exchange and the management process about the product information.The people use the computer to take the main technical method, from forms in one's mind to the product to put in the market in the entire process information to carry on the analysis and processing, produces and utilizes each kind of numerical information and the graph information, carries on the product the design and the manufacture.The CAD/CAM technology is not the traditional design, the manufacture flow method simple reflection, also is not limits in the partial use computer takes the tool in the individual step or the link, but is unifies the computer science and the project domain specialized technology as well as human's wisdom and the experience take the modern scientific method as the instruction, in the design, in the manufacture entire process each completely manager, as far as possible use computer system completes the work which these duplication high, the labor big, the computation complex as well as depends on purely artificially completes with difficulty, but assists must replaces the engineers and technicians to complete the entire process, obtains the desired effec The CAD/CAM system as well as plans the hardware, the software for supports the environment, (subsystem) realizes through each function module to the product description, the computation, the analysis, optimized, the cartography, the technological process design, the simulation as well as the NC processing.But the generalized CAD/CAM integrative system also should include aspects and so on production plan, management, quality control.Since 1946 first electronic accounting machine has been born in US, people on unceasing computer technology Introduces the machine design? Manufacture domain.As early as in the 50's, for the first time develops successfully the numerical control engine bed, may realize through the different numerical control procedure to the different components processing Afterwards, Massachusetts Institute of Technology's servo laboratory succeeds with the computer manufacture numerical control paper tape, has realized the NC programming automation.In this foundation, the people proposed the following tentative plan: The APT software is feeds the path method realization computer assistance programming through the description, that, can not describe feeds the path, but is direct description components itself? From this has had the CAD initial concept.The entire 50's, the electronic accounting machine also is in the electron tube time, uses the machine language programming, the computer mainly uses in thescience computation, also only has the output function for it disposition graph equipment.CADCAM system basic compositionCAD/CAM system hardware dispositionCAD/CAM system software compositionCAD/CAM system software dispositionComputer aided manufacturing (CAM) may define for uses the computer system to design, to manage and controls a productive plan the movement, through direct or indirect planned production resources computer contact surface.If defines states, the computer aided manufacturing application has 2 big aspects:1) computer supervisory control.This is the direct application, the computer with the production process connection, uses in supervising directly and the control production process2) produces the support application.This is the indirect application, middle the productive plan, the computer uses in supporting the production operation, but is not the computer and the production process links directly.Charting productive forces increaseThe CAD/CAM system may undertake the one whole set new charting theory to be able to strengthen the productivity.Again completes next step, keeps firmly in mind the entire design to be possible to store up the system.When the planner receives one with has saved the blueprint specification similar work piece, he only must recollect, and adjusts it the work storage place, revises in the original blueprint not to conform to a new work piece request part, productivity enhances.The original work piece efficiency enhances, but this can enhance the next step working efficiency.This is a complete at times renewal database support, can facilitate the user to use Improve mapping analysisThe charting analysis is another important work, it can by certain synthesize the CAD/CAM system automatic operation.This in pipeline design, in particular an important application.The pipeline design paper very is usually complex moreover must conform to the precise industry specification.The other giftedCAD/CAM also can affect a company in other aspects the project system.It can enhance the entire physical process the efficiency, the permission present project plan and the report procedure appraisal.CAD/CAM can improve improves the quality of the product the guarantee technology.It can automatic accurate and the integrity document material, the maintenance partial data accurate and bill of materials accurate.DeficiencyCAD/CAM insufficient spot not that obvious, but they can destroy even the most perfect design, the biggest shortcoming is only can directly skips from the manual charting and the recordpreservation to CAD/CAM, the elephant installs a set of jet engine in the populace automobile.The automobile possibly can run quick somewhat, but if the foundation enhancement has not coordinated the heavy pressure, the entire automobile can disperse the frame.CAD/CAM applicationSKETCHPAD, the CAD/CAM technology has passed through very long chi.It is already applied in the middle of each widespread industry.It uses in each aspect, controls from the airplane to the weapon research, manufactures from the map to the movement medical service, from circuit analysis to building steel analysis.CAD/CAM is being applied in each kind of charting and the production, installs the schematic diagram from the movie to the large-scale long-distance monitoring direct set battleship, its application to is developing variously.Now CAD/CAM market.Now in the market has four kind of different CAD/CAM sellers.First is some subordinate companies sells comes from a big enterprise part or the branch CAD/CAM technology.The IBM CAD/CAM branch is an example.If belongs to Mc-Donnell-Douglas McAuto; Belongs to General Electric Lalma, with belongs to Schlumberger Applican, if the multi-large number CAD/CAM subordinate company the main corporation has the massive service intercourse, not only sale supervisory system moreover when one's position is lowly one's words carry no weight service office.When they control the massive accounts also with provides the service, these companies on in optimum condition, because they may extract the massive profits.But they must undertake the complex administrative chain of command, this obstructs in them makes the fast response to the market tendency, or their itself studies and outside the development department, the merge improves on again their new production line the new technical developmentCAD/CAM technology and the product development road of futureAfter many year promotions, the CAD technology already widely applied in professions and so on machinery, electron, astronautics, chemical industry, building.Played using the CAD technology enhanced the enterprise the rated capacity, the optimization design proposal, reduces technical personnel's labor intensity, reduction design cycle, beefed-up design roles and so on standardization.In recent years, our country CAD technology development and the application have obtained the considerable development, besides has carried on sinicizing and the re-development to many overseas softwares, but also was born many had the independent copyright CAD system, If high Chinese CAD, opens item CAD and so on, because these software price is cheap, conforms to our country national condition and the standard, therefore has received widespread welcome, has won the more and more big market share. But, our country CAD/CAM software no matter is from the product development level from the commercialization, the marketability degree all has not the small disparity with the developed country.Because the overseas CAD/CAM software appears early, the development and the application time is also long,therefore they develop quite maturely, now basically already has seized the international market.These overseas software company uses its technical and the fund superiority, starts vigorously to our country market march At present, the overseas some outstanding softwares, like UG, SolidWorks, Pro/Engineer, CATIA and so on, already have seized part of domestic markets.Therefore, our country CAD/CAM software prospect is unoptimistic.But, we also should see clearly own superiority, for instance understood our country market, provides the technical support to be convenient, price small advantage and so on.Not only under these premises, we importantly with the trend of the times, the track international newest tendency, observe each international standard, in international domestic forms the oneself unique superiority, must base the home, the union national condition, face the domestic economic development need，develops has oneself characteristic, conforms to CAD/CAM software which the Chinese is familiar with.。

机械专业中英文对照英语词汇瓷ceramics合成纤维synthetic fibre电化学腐蚀electrochemical corrosion车架automotive chassis悬架suspension转向器redirector变速器speed changer板料冲压sheet metal parts加工spot facing machining车间workshop工程技术人员engineer气动夹紧pneuma lock数学模型mathematical model画法几descriptive geometry机械制图Mechanical drawing投影projection视图view剖视图profile chart标准件standard component零件图part drawing装配图assembly drawing尺寸标注size marking技术要求technical requirements刚度rigidity力internal force位移displacement截面section疲劳极限fatigue limit断裂fracture塑性变形plastic distortion脆性材料brittleness material刚度准则rigidity criterion垫圈washer垫片spacer直齿圆柱齿轮straight toothed spur gear斜齿圆柱齿轮helical-spur gear直齿锥齿轮straight bevel gear运动简图kinematic sketch齿轮齿条pinion and rack蜗杆蜗轮worm and worm gear虚约束passive constraint曲柄crank摇杆racker凸轮cams共轭曲线conjugate curve成法generation method定义域definitional domain值域range导数\\微分differential coefficient求导derivation定积分definite integral不定积分indefinite integral曲率curvature偏微分partial differential毛坯rough游标卡尺slide caliper千分尺micrometer calipers攻丝tap二阶行列式second order determinant逆矩阵inverse matrix线性程组linear equations概率probability随机变量random variable排列组合permutation and combination气体状态程equation of state of gas动能kinetic energy势能potential energy机械能守恒conservation of mechanical energy动量momentum桁架truss轴线axes余子式cofactor逻辑电路logic circuit触发器flip-flop脉冲波形pulse shape数模digital analogy液压传动机构fluid drive mechanism机械零件mechanical parts淬火冷却quench淬火hardening回火tempering调质hardening and tempering磨粒abrasive grain结合剂bonding agent砂轮grinding wheel后角clearance angle龙门刨削planing主轴spindle主轴箱headstock卡盘chuck加工中心machining center车刀lathe tool车床lathe钻削镗削bore车削turning磨床grinder基准benchmark钳工locksmith锻forge压模stamping焊weld拉床broaching machine拉broaching装配assembling铸造found流体动力学fluid dynamics流体力学fluid mechanics加工machining液压hydraulic pressure切线tangent机电一体化mechanotronics mechanical-electrical integration 气压air pressure pneumatic pressure稳定性stability介质medium液压驱动泵fluid clutch液压泵hydraulic pump阀门valve失效invalidation强度intensity载荷load应力stress安全系数safty factor可靠性reliability螺纹thread螺旋helix键spline销pin 滚动轴承rolling bearing滑动轴承sliding bearing弹簧spring制动器arrester brake十字结联轴节crosshead联轴器coupling链chain皮带strap精加工finish machining粗加工rough machining变速箱体gearbox casing腐蚀rust氧化oxidation磨损wear耐用度durability随机信号random signal离散信号discrete signal超声传感器ultrasonic sensor集成电路integrate circuit挡板orifice plate残余应力residual stress套筒sleeve扭力torsion冷加工cold machining电动机electromotor汽缸cylinder过盈配合interference fit热加工hotwork摄像头CCD camera倒角rounding chamfer优化设计optimal design工业造型设计industrial moulding design有限元finite element滚齿hobbing插齿gear shaping伺服电机actuating motor铣床milling machine钻床drill machine镗床boring machine步进电机stepper motor丝杠screw rod导轨lead rail组件subassembly可编程序逻辑控制器Programmable Logic Controller PLC电火花加工electric spark machining电火花线切割加工electrical discharge wire - cutting 相图phase diagram热处理heat treatment固态相变solid state phase changes有色金属nonferrous metal瓷ceramics合成纤维synthetic fibre电化学腐蚀electrochemical corrosion车架automotive chassis悬架suspension转向器redirector变速器speed changer板料冲压sheet metal parts加工spot facing machining车间workshop工程技术人员engineer气动夹紧pneuma lock数学模型mathematical model画法几descriptive geometry机械制图Mechanical drawing投影projection视图view剖视图profile chart标准件standard component零件图part drawing装配图assembly drawing尺寸标注size marking技术要求technical requirements刚度rigidity力internal force位移displacement截面section疲劳极限fatigue limit断裂fracture塑性变形plastic distortion脆性材料brittleness material刚度准则rigidity criterion垫圈washer垫片spacer直齿圆柱齿轮straight toothed spur gear斜齿圆柱齿轮helical-spur gear直齿锥齿轮straight bevel gear运动简图kinematic sketch 齿轮齿条pinion and rack蜗杆蜗轮worm and worm gear虚约束passive constraint曲柄crank摇杆racker凸轮cams共轭曲线conjugate curve成法generation method定义域definitional domain值域range导数\\微分differential coefficient求导derivation定积分definite integral不定积分indefinite integral曲率curvature偏微分partial differential毛坯rough游标卡尺slide caliper千分尺micrometer calipers攻丝tap二阶行列式second order determinant逆矩阵inverse matrix线性程组linear equations概率probability随机变量random variable排列组合permutation and combination气体状态程equation of state of gas动能kinetic energy势能potential energy机械能守恒conservation of mechanical energy 动量momentum桁架truss轴线axes余子式cofactor逻辑电路logic circuit触发器flip-flop脉冲波形pulse shape数模digital analogy液压传动机构fluid drive mechanism机械零件mechanical parts淬火冷却quench淬火hardening回火tempering调质hardening and tempering磨粒abrasive grain结合剂bonding agent砂轮grinding wheelAssembly line 组装线Layout 布置图Conveyer 流水线物料板Rivet table 拉钉机Rivet gun 拉钉枪Screw driver 起子Pneumatic screw driver 气动起子worktable 工作桌OOBA 开箱检查fit together 组装在一起fasten 锁紧(螺丝)fixture 夹具(治具)pallet 栈板barcode 条码barcode scanner 条码扫描器fuse together 熔合fuse machine热熔机repair修理operator作业员QC品管supervisor 课长ME 制造工程师MT 制造生技cosmetic inspect 外观检查inner parts inspect 部检查thumb screw 大头螺丝lbs. inch 镑、英寸EMI gasket 导电条front plate 前板rear plate 后板chassis 基座bezel panel 面板power button 电源按键reset button 重置键Hi-pot test of SPS 高源高压测试Voltage switch of SPS 电源电压接拉键sheet metal parts 冲件plastic parts 塑胶件SOP 制造作业程序material check list 物料检查表work cell 工作间trolley 台车carton 纸箱sub-line 支线left fork 叉车personnel resource department 人力资源部production department生产部门planning department企划部QC Section品管科stamping factory冲压厂painting factory烤漆厂molding factory成型厂common equipment常用设备uncoiler and straightener整平机punching machine 冲床robot机械手hydraulic machine油压机lathe车床planer |plein|刨床miller铣床grinder磨床linear cutting线切割electrical sparkle电火花welder电焊机staker=reviting machine铆合机position职务president董事长general manager总经理special assistant manager特助factory director厂长department director部长deputy manager | =vice manager副理section supervisor课长deputy section supervisor =vice section superisor副课长group leader/supervisor组长line supervisor线长assistant manager助理to move, to carry, to handle搬运be put in storage入库pack packing包装to apply oil擦油to file burr 锉毛刺final inspection终检to connect material接料to reverse material 翻料wet station沾湿台Tiana天那水cleaning cloth抹布to load material上料to unload material卸料to return material/stock to退料scraped |\\'skr?pid|报废scrape ..v.刮;削deficient purchase来料不良manufacture procedure制程deficient manufacturing procedure制程不良oxidation |\\' ksi\\'dei?n|氧化scratch刮伤dents压痕defective upsiding down抽芽不良defective to staking铆合不良embedded lump镶块feeding is not in place送料不到位stamping-missing漏冲production capacity生产力education and training教育与训练proposal improvement提案改善spare parts=buffer备件forklift叉车trailer=long vehicle拖板车compound die合模die locker锁模器pressure plate=plate pinch压板bolt螺栓administration/general affairs dept总务部automatic screwdriver电动启子thickness gauge厚薄规gauge(or jig)治具power wire电源线buzzle蜂鸣器defective product label不良标签identifying sheet list标示单location地点present members出席人员subject主题conclusion结论decision items决议事项responsible department负责单位pre-fixed finishing date预定完成日approved by / checked by / prepared by核准/审核/承办PCE assembly production schedule sheet PCE组装厂生产排配表model机锺work order工令revision版次remark备注production control confirmation生产确认checked by初审approved by核准department部门stock age analysis sheet 库存货龄分析表on-hand inventory现有库存available material良品可使用obsolete material良品已呆滞to be inspected or reworked 待验或重工total合计cause description原因说明part number/ P/N 料号type形态item/group/class类别quality品质prepared by制表notes说明year-end physical inventory difference analysis sheet 年终盘点差异分析表physical inventory盘点数量physical count quantity帐面数量difference quantity差异量cause analysis原因分析raw materials原料materials物料finished product成品semi-finished product半成品packing materials包材good product/accepted goods/ accepted parts/good parts良品defective product/non-good parts不良品disposed goods处理品warehouse/hub仓库on way location在途仓oversea location海外仓spare parts physical inventory list备品盘点清单spare molds location模具备品仓skid/pallet栈板tox machine自铆机wire EDM线割EDM放电机coil stock卷料sheet stock片料tolerance工差score=groove压线cam block滑块pilot导正筒trim剪外边pierce剪边drag form压锻差pocket for the punch head挂钩槽slug hole废料feature die公母模expansion dwg展开图radius半径shim(wedge)楔子torch-flame cut火焰切割set screw止付螺丝form block折刀stop pin定位销round pierce punch=die button圆冲子shape punch=die insert异形子stock locater block定位块under cut=scrap chopper清角active plate活动板baffle plate挡块cover plate盖板male die公模female die母模groove punch压线冲子air-cushion eject-rod气垫顶杆spring-box eject-plate弹簧箱顶板bushing block衬套insert 入块club car高尔夫球车capability能力parameter参数factor系数phosphate皮膜化成viscosity涂料粘度alkalidipping脱脂main manifold主集流脉bezel斜视规blanking穿落模dejecting顶固模demagnetization去磁;消磁high-speed transmission高速传递heat dissipation热传rack上料degrease脱脂rinse水洗alkaline etch龄咬desmut剥黑膜D.I. rinse纯水次Chromate铬酸处理Anodize阳性处理seal封revision版次part number/P/N料号good products良品scraped products报放心品defective products不良品finished products成品disposed products处理品barcode条码flow chart流程表单assembly组装stamping冲压molding成型spare parts=buffer备品coordinate座标dismantle the die折模auxiliary fuction辅助功能poly-line多义线heater band 加热片thermocouple热电偶sand blasting喷沙grit 砂砾derusting machine除锈机degate打浇口dryer烘干机induction感应induction light感应光response=reaction=interaction感应ram连杆edge finder巡边器concave凸convex凹short射料不足nick缺口speck瑕??shine亮班splay 银纹gas mark焦痕delamination起鳞cold slug冷块blush 导色gouge沟槽;凿槽satin texture段面咬花witness line证示线patent专利grit沙砾granule=peuet=grain细粒grit maker抽粒机cushion缓冲magnalium镁铝合金magnesium镁金metal plate钣金lathe车mill锉plane刨grind磨drill铝boring镗blinster气泡fillet镶;嵌边through-hole form通形式voller pin formality滚针形式cam driver铡楔shank摸柄crank shaft曲柄轴augular offset角度偏差velocity速度production tempo生产进度现状torque扭矩spline=the multiple keys花键quenching淬火tempering回火annealing退火carbonization碳化tungsten high speed steel钨高速的moly high speed steel钼高速的organic solvent有机溶剂bracket小磁导liaison联络单volatile挥发性resistance电阻ion离子titrator滴定仪beacon警示灯coolant冷却液crusher破碎机阿基米德蜗杆Archimedes worm安全系数safety factor; factor of safety安全载荷safe load凹面、凹度concavity扳手wrench板簧flat leaf spring半圆键woodruff key变形deformation摆杆oscillating bar摆动从动件oscillating follower摆动从动件凸轮机构cam with oscillating follower 摆动导杆机构oscillating guide-bar mechanism 摆线齿轮cycloidal gear摆线齿形cycloidal tooth profile摆线运动规律cycloidal motion摆线针轮cycloidal-pin wheel包角angle of contact保持架cage背对背安装back-to-back arrangement背锥back cone ；normal cone背锥角back angle背锥距back cone distance比例尺scale比热容specific heat capacity闭式链closed kinematic chain闭链机构closed chain mechanism臂部arm变频器frequency converters变频调速frequency control of motor speed变速speed change变速齿轮change gear change wheel变位齿轮modified gear变位系数modification coefficient标准齿轮standard gear标准直齿轮standard spur gear表面质量系数superficial mass factor表面传热系数surface coefficient of heat transfer表面粗糙度surface roughness并联式组合combination in parallel并联机构parallel mechanism并联组合机构parallel combined mechanism并行工程concurrent engineering并行设计concurred design, CD不平衡相位phase angle of unbalance不平衡imbalance (or unbalance)不平衡量amount of unbalance不完全齿轮机构intermittent gearing波发生器wave generator波数number of waves补偿compensation参数化设计parameterization design, PD残余应力residual stress操纵及控制装置operation control device槽轮Geneva wheel槽轮机构Geneva mechanism ；Maltese cross槽数Geneva numerate槽凸轮groove cam侧隙backlash差动轮系differential gear train差动螺旋机构differential screw mechanism差速器differential常用机构conventional mechanism; mechanism in common use 车床lathe承载量系数bearing capacity factor承载能力bearing capacity成对安装paired mounting尺寸系列dimension series齿槽tooth space齿槽宽spacewidth齿侧间隙backlash齿顶高addendum齿顶圆addendum circle齿根高dedendum齿根圆dedendum circle齿厚tooth thickness齿距circular pitch齿宽face width齿廓tooth profile齿廓曲线tooth curve齿轮gear齿轮变速箱speed-changing gear boxes 齿轮齿条机构pinion and rack齿轮插刀pinion cutter; pinion-shaped shaper cutter 齿轮滚刀hob ,hobbing cutter齿轮机构gear齿轮轮坯blank齿轮传动系pinion unit齿轮联轴器gear coupling齿条传动rack gear齿数tooth number齿数比gear ratio齿条rack齿条插刀rack cutter; rack-shaped shaper cutter齿形链、无声链silent chain齿形系数form factor齿式棘轮机构tooth ratchet mechanism插齿机gear shaper重合点coincident points重合度contact ratio冲床punch传动比transmission ratio, speed ratio传动装置gearing; transmission gear传动系统driven system传动角transmission angle传动轴transmission shaft串联式组合combination in series串联式组合机构series combined mechanism串级调速cascade speed control创新innovation creation创新设计creation design垂直载荷、法向载荷normal load唇形橡胶密封lip rubber seal磁流体轴承magnetic fluid bearing从动带轮driven pulley从动件driven link, follower从动件平底宽度width of flat-face从动件停歇follower dwell从动件运动规律follower motion从动轮driven gear粗线bold line粗牙螺纹coarse thread大齿轮gear wheel打包机packer打滑slipping带传动belt driving带轮belt pulley带式制动器band brake单列轴承single row bearing单向推力轴承single-direction thrust bearing单万向联轴节single universal joint单位矢量unit vector当量齿轮equivalent spur gear; virtual gear当量齿数equivalent teeth number; virtual number of teeth当量摩擦系数equivalent coefficient of friction当量载荷equivalent load刀具cutter导数derivative倒角chamfer导热性conduction of heat导程lead导程角lead angle等加等减速运动规律parabolic motion; constant acceleration and deceleration motion等速运动规律uniform motion; constant velocity motion等径凸轮conjugate yoke radial cam等宽凸轮constant-breadth cam等效构件equivalent link等效力equivalent force等效力矩equivalent moment of force等效量equivalent等效质量equivalent mass等效转动惯量equivalent moment of inertia等效动力学模型dynamically equivalent model底座chassis低副lower pair点划线chain dotted line（疲劳）点蚀pitting垫圈gasket垫片密封gasket seal碟形弹簧belleville spring顶隙bottom clearance定轴轮系ordinary gear train; gear train with fixed axes动力学dynamics动密封kinematical seal动能dynamic energy动力粘度dynamic viscosity动力润滑dynamic lubrication动平衡dynamic balance动平衡机dynamic balancing machine 动态特性dynamic characteristics动态分析设计dynamic analysis design动压力dynamic reaction动载荷dynamic load端面transverse plane端面参数transverse parameters端面齿距transverse circular pitch端面齿廓transverse tooth profile端面重合度transverse contact ratio端面模数transverse module端面压力角transverse pressure angle锻造forge对称循环应力symmetry circulating stress对心滚子从动件radial (or in-line ) roller follower对心直动从动件radial (or in-line ) translating follower对心移动从动件radial reciprocating follower对心曲柄滑块机构in-line slider-crank (or crank-slider) mechanism 多列轴承multi-row bearing多楔带poly V-belt多项式运动规律polynomial motion多质量转子rotor with several masses惰轮idle gear额定寿命rating life额定载荷load ratingII 级杆组dyad发生线generating line发生面generating plane法面normal plane法面参数normal parameters法面齿距normal circular pitch法面模数normal module法面压力角normal pressure angle法向齿距normal pitch法向齿廓normal tooth profile法向直廓蜗杆straight sided normal worm法向力normal force反馈式组合feedback combining反向运动学inverse ( or backward) kinematics反转法kinematic inversion反正切Arctan成法generating cutting仿形法form cutting案设计、概念设计concept design, CD防振装置shockproof device飞轮flywheel飞轮矩moment of flywheel非标准齿轮nonstandard gear非接触式密封non-contact seal非期性速度波动aperiodic speed fluctuation非圆齿轮non-circular gear粉末合金powder metallurgy分度线reference line; standard pitch line分度圆reference circle; standard (cutting) pitch circle 分度圆柱导程角lead angle at reference cylinder分度圆柱螺旋角helix angle at reference cylinder分母denominator分子numerator分度圆锥reference cone; standard pitch cone分析法analytical method封闭差动轮系planetary differential复合铰链compound hinge复合式组合compound combining复合轮系compound (or combined) gear train复合平带compound flat belt复合应力combined stress复式螺旋机构Compound screw mechanism复杂机构complex mechanism杆组Assur group干涉interference刚度系数stiffness coefficient刚轮rigid circular spline钢丝软轴wire soft shaft刚体导引机构body guidance mechanism刚性冲击rigid impulse (shock)刚性转子rigid rotor刚性轴承rigid bearing刚性联轴器rigid coupling高度系列height series高速带high speed belt高副higher pair格拉晓夫定理Grashoff`s law根切undercutting公称直径nominal diameter高度系列height series功work工况系数application factor工艺设计technological design工作循环图working cycle diagram 工作机构operation mechanism工作载荷external loads工作空间working space工作应力working stress工作阻力effective resistance工作阻力矩effective resistance moment公法线common normal line公共约束general constraint公制齿轮metric gears功率power功能分析设计function analyses design共轭齿廓conjugate profiles共轭凸轮conjugate cam构件link鼓风机blower固定构件fixed link; frame固体润滑剂solid lubricant关节型操作器jointed manipulator惯性力inertia force惯性力矩moment of inertia ,shaking moment 惯性力平衡balance of shaking force惯性力完全平衡full balance of shaking force惯性力部分平衡partial balance of shaking force 惯性主矩resultant moment of inertia惯性主失resultant vector of inertia冠轮crown gear广义机构generation mechanism广义坐标generalized coordinate轨迹生成path generation轨迹发生器path generator滚刀hob滚道raceway滚动体rolling element滚动轴承rolling bearing滚动轴承代号rolling bearing identification code 滚针needle roller滚针轴承needle roller bearing滚子roller滚子轴承roller bearing滚子半径radius of roller滚子从动件roller follower滚子链roller chain滚子链联轴器double roller chain coupling滚珠丝杆ball screw滚柱式单向超越离合器roller clutch过度切割undercutting函数发生器function generator函数生成function generation含油轴承oil bearing耗油量oil consumption耗油量系数oil consumption factor赫兹公式H. Hertz equation合成弯矩resultant bending moment合力resultant force合力矩resultant moment of force黑箱black box横坐标abscissa互换性齿轮interchangeable gears花键spline滑键、导键feather key滑动轴承sliding bearing滑动率sliding ratio滑块slider环面蜗杆toroid helicoids worm环形弹簧annular spring缓冲装置shocks; shock-absorber灰铸铁grey cast iron回程return回转体平衡balance of rotors混合轮系compound gear train积分integrate机电一体化系统设计mechanical-electrical integration system design 机构mechanism机构分析analysis of mechanism机构平衡balance of mechanism机构学mechanism机构运动设计kinematic design of mechanism机构运动简图kinematic sketch of mechanism机构综合synthesis of mechanism机构组成constitution of mechanism机架frame, fixed link机架变换kinematic inversion机器machine机器人robot机器人操作器manipulator机器人学robotics技术过程technique process技术经济评价technical and economic evaluation 技术系统technique system机械machinery机械创新设计mechanical creation design, MCD机械系统设计mechanical system design, MSD机械动力分析dynamic analysis of machinery机械动力设计dynamic design of machinery机械动力学dynamics of machinery机械的现代设计modern machine design机械系统mechanical system机械利益mechanical advantage机械平衡balance of machinery机械手manipulator机械设计machine design; mechanical design机械特性mechanical behavior机械调速mechanical speed governors机械效率mechanical efficiency机械原理theory of machines and mechanisms机械运转不均匀系数coefficient of speed fluctuation机械无级变速mechanical stepless speed changes基础机构fundamental mechanism基本额定寿命basic rating life基于实例设计case-based design,CBD基圆base circle基圆半径radius of base circle基圆齿距base pitch基圆压力角pressure angle of base circle基圆柱base cylinder基圆锥base cone急回机构quick-return mechanism急回特性quick-return characteristics急回系数advance-to return-time ratio急回运动quick-return motion棘轮ratchet棘轮机构ratchet mechanism棘爪pawl极限位置extreme (or limiting) position极位夹角crank angle between extreme (or limiting) positions计算机辅助设计computer aided design, CAD计算机辅助制造computer aided manufacturing, CAM计算机集成制造系统computer integrated manufacturing system, CIMS 计算力矩factored moment; calculation moment计算弯矩calculated bending moment加权系数weighting efficient加速度acceleration加速度分析acceleration analysis加速度曲线acceleration diagram尖点pointing; cusp尖底从动件knife-edge follower间隙backlash间歇运动机构intermittent motion mechanism 减速比reduction ratio减速齿轮、减速装置reduction gear减速器speed reducer减摩性anti-friction quality渐开螺旋面involute helicoid渐开线involute渐开线齿廓involute profile渐开线齿轮involute gear渐开线发生线generating line of involute渐开线程involute equation渐开线函数involute function渐开线蜗杆involute worm渐开线压力角pressure angle of involute渐开线花键involute spline简谐运动simple harmonic motion键key键槽keyway交变应力repeated stress交变载荷repeated fluctuating load交叉带传动cross-belt drive交错轴斜齿轮crossed helical gears胶合scoring角加速度angular acceleration角速度angular velocity角速比angular velocity ratio角接触球轴承angular contact ball bearing角接触推力轴承angular contact thrust bearing 角接触向心轴承angular contact radial bearing 角接触轴承angular contact bearing铰链、枢纽hinge校正平面correcting plane接触应力contact stress接触式密封contact seal阶梯轴multi-diameter shaft结构structure结构设计structural design截面section节点pitch point 节距circular pitch; pitch of teeth节线pitch line节圆pitch circle节圆齿厚thickness on pitch circle节圆直径pitch diameter节圆锥pitch cone节圆锥角pitch cone angle解析设计analytical design紧边tight-side紧固件fastener径节diametral pitch径向radial direction径向当量动载荷dynamic equivalent radial load径向当量静载荷static equivalent radial load径向基本额定动载荷basic dynamic radial load rating 径向基本额定静载荷basic static radial load tating径向接触轴承radial contact bearing径向平面radial plane径向游隙radial internal clearance径向载荷radial load径向载荷系数radial load factor径向间隙clearance静力static force静平衡static balance静载荷static load静密封static seal局部自由度passive degree of freedom矩阵matrix矩形螺纹square threaded form锯齿形螺纹buttress thread form矩形牙嵌式离合器square-jaw positive-contact clutch 绝对尺寸系数absolute dimensional factor绝对运动absolute motion绝对速度absolute velocity均衡装置load balancing mechanism抗压强度compression strength开口传动open-belt drive开式链open kinematic chain开链机构open chain mechanism可靠度degree of reliability可靠性reliability可靠性设计reliability design, RD空气弹簧air spring空间机构spatial mechanism空间连杆机构spatial linkage空间凸轮机构spatial cam空间运动副spatial kinematic pair空间运动链spatial kinematic chain空转idle宽度系列width series框图block diagram雷诺程Reynolds‘s equation离心力centrifugal force离心应力centrifugal stress离合器clutch离心密封centrifugal seal理论廓线pitch curve理论啮合线theoretical line of action隶属度membership力force力多边形force polygon力封闭型凸轮机构force-drive (or force-closed) cam mechanism 力矩moment力平衡equilibrium力偶couple力偶矩moment of couple连杆connecting rod, coupler连杆机构linkage连杆曲线coupler-curve连心线line of centers链chain链传动装置chain gearing链轮sprocket sprocket-wheel sprocket gear chain wheel联组V 带tight-up V belt联轴器coupling shaft coupling两维凸轮two-dimensional cam临界转速critical speed六杆机构six-bar linkage龙门刨床double Haas planer轮坯blank轮系gear train螺杆screw螺距thread pitch螺母screw nut螺旋锥齿轮helical bevel gear螺钉screws螺栓bolts螺纹导程lead 螺纹效率screw efficiency螺旋传动power screw螺旋密封spiral seal螺纹thread (of a screw)螺旋副helical pair螺旋机构screw mechanism螺旋角helix angle螺旋线helix ,helical line绿色设计green design design for environment马耳他机构Geneva wheel Geneva gear马耳他十字Maltese cross脉动无级变速pulsating stepless speed changes脉动循环应力fluctuating circulating stress脉动载荷fluctuating load铆钉rivet迷宫密封labyrinth seal密封seal密封带seal belt密封胶seal gum密封元件potted component密封装置sealing arrangement面对面安装face-to-face arrangement面向产品生命期设计design for product`s life cycle, DPLC 名义应力、公称应力nominal stress模块化设计modular design, MD模块式传动系统modular system模幅箱morphology box模糊集fuzzy set模糊评价fuzzy evaluation模数module摩擦friction摩擦角friction angle摩擦力friction force摩擦学设计tribology design, TD摩擦阻力frictional resistance摩擦力矩friction moment摩擦系数coefficient of friction摩擦圆friction circle磨损abrasion wear; scratching末端执行器end-effector目标函数objective function耐腐蚀性corrosion resistance耐磨性wear resistance挠性机构mechanism with flexible elements挠性转子flexible rotor齿轮internal gear齿圈ring gear力internal force圈inner ring能量energy能量指示图viscosity逆时针counterclockwise (or anticlockwise)啮出engaging-out啮合engagement, mesh, gearing啮合点contact points啮合角working pressure angle啮合线line of action啮合线长度length of line of action啮入engaging-in牛头刨床shaper凝固点freezing point; solidifying point扭转应力torsion stress扭矩moment of torque扭簧helical torsion spring诺模图NomogramO 形密封圈密封O ring seal盘形凸轮disk cam盘形转子disk-like rotor抛物线运动parabolic motion疲劳极限fatigue limit疲劳强度fatigue strength偏置式offset偏( 心) 距offset distance偏心率eccentricity ratio偏心质量eccentric mass偏距圆offset circle偏心盘eccentric偏置滚子从动件offset roller follower偏置尖底从动件offset knife-edge follower偏置曲柄滑块机构offset slider-crank mechanism 拼接matching评价与决策evaluation and decision频率frequency平带flat belt平带传动flat belt driving平底从动件flat-face follower平底宽度face width平分线bisector 平均应力average stress平均中径mean screw diameter平均速度average velocity平衡balance平衡机balancing machine平衡品质balancing quality平衡平面correcting plane平衡质量balancing mass平衡重counterweight平衡转速balancing speed平面副planar pair, flat pair平面机构planar mechanism平面运动副planar kinematic pair平面连杆机构planar linkage平面凸轮planar cam平面凸轮机构planar cam mechanism平面轴斜齿轮parallel helical gears普通平键parallel key其他常用机构other mechanism in common use起动阶段starting period启动力矩starting torque气动机构pneumatic mechanism奇异位置singular position起始啮合点initial contact , beginning of contact气体轴承gas bearing千斤顶jack嵌入键sunk key强迫振动forced vibration切齿深度depth of cut曲柄crank曲柄存在条件Grashoff`s law曲柄导杆机构crank shaper (guide-bar) mechanism曲柄滑块机构slider-crank (or crank-slider) mechanism 曲柄摇杆机构crank-rocker mechanism曲齿锥齿轮spiral bevel gear曲率curvature曲率半径radius of curvature曲面从动件curved-shoe follower曲线拼接curve matching曲线运动curvilinear motion曲轴crank shaft驱动力driving force驱动力矩driving moment (torque)全齿高whole depth。

毕业设计论文外文资料原文及译文学院：机电工程学院专业：机械设计制造及其自动化班级：学号：姓名：Mechanical engineering1.The porfile of mechanical engineeringEngingeering is a branch of mechanical engineerig,it studies mechanical and power generation especially power and movement.2.The history of mechanical engineering18th century later periods,the steam engine invention has provided a main power fountainhead for the industrial revolution,enormously impelled each kind of mechznical biting.Thus,an important branch of a new Engineering – separated from the civil engineering tools and machines on the branch-developed together with Birmingham and the establishment of the Associantion of Mechanical Engineers in 1847 had been officially recognized.The mechanical engineering already mainly used in by trial and error method mechanic application technological development into professional engineer the scientific method of which in the research,the design and the realm of production used .From the most broad perspective,the demend continuously to enhance the efficiencey of mechanical engineers improve the quality ofwork,and asked him to accept the history of the high degree of education and training.Machine operation to stress not only economic but also infrastructure costs to an absolute minimun.3.The field of mechanical engineeringThe commodity machinery development in the develop country,in the high level material life very great degree is decided each kind of which can realize in the mechanical engineering.Mechanical engineers unceasingly will invent the machine next life to produce the commodity,unceasingly will develop the accuracy and the complexity more and more high machine tools produces the machine.The main clues of the mechanical development is:In order to enhance the excellent in quality and reasonable in price produce to increase the precision as well as to reduce the production cost.This three requirements promoted the complex control system development.The most successful machine manufacture is its machine and the control system close fusion,whether such control system is essentially mechanical or electronic.The modernized car engin production transmission line(conveyer belt)is a series of complex productions craft mechanizationvery good example.The people are in the process of development in order to enable further automation of the production machinery ,the use of a computer to store and handle large volumes of data,the data is a multifunctional machine tools necessary for the production of spare parts.One of the objectives is to fully automated production workshop,three rotation,but only one officer per day to operate.The development of production for mechanical machinery must have adequate power supply.Steam engine first provided the heat to generate power using practical methods in the old human,wind and hydropower,an increase of engin .New mechanical engineering industry is one of the challenges faced by the initial increase thermal effciency and power,which is as big steam turbine and the development of joint steam boilers basically achieved.20th century,turbine generators to provide impetus has been sustained and rapid growth,while thermal efficiency is steady growth,and large power plants per kW capital consumption is also declining.Finally,mechanical engineers have nuclear energy.This requires the application of nuclear energy particularly high reliability and security,which requires solving many new rge power plants and the nuclear power plant control systems have become highly complex electroonics,fluid,electricity,water and mechanical parts networks All in all areas related to the mechanical engineers.Small internal combustion engine,both to the type (petrol and diesel machines)or rotary-type(gas turbines and Mong Kerr machine),as well as their broad application in the field of transport should also due to mechanical enginerrs.Throughout the transport,both in the air and space,or in the terrestrial and marine,mechanial engineers created a variety of equipment and power devices to their increasing cooperation with electrical engineers,especially in the development of appropration control systems.Mechanical engineers in the development of military weapons technology and civil war ,needs a similar,though its purpose is to enhance rather than destroy their productivity.However.War needs a lot of resources to make the area of techonlogy,many have a far-reaching development in peacetime efficiency.Jet aircraft and nuclear reactors are well known examples.The Biological engineering,mechanical engineering biotechnology is a relatively new and different areas,it provides for the replacement of the machine or increase thebody functions as well as for medical equipment.Artficial limbs have been developed and have such a strong movement and touch response function of the human body.In the development of artificial organ transplant is rapid,complex cardiac machines and similar equipment to enable increasingly complex surgery,and injuries and ill patients life functions can be sustained.Some enviromental control mechanical engineers through the initial efforts to drainage or irrigation pumping to the land and to mine and ventilation to control the human environment.Modern refrigeration and air-conditioning plant commonaly used reverse heat engine,where the heat from the engine from cold places to more external heat.Many mechanical engineering products,as well as other leading technology development city have side effects on the environment,producing noise,water and air pollution caused,destroyed land and landscape.Improve productivity and diver too fast in the commodity,that the renewable naturalforces keep pace.For mechanical engineers and others,environmental control is rapidly developing area,which includes a possible development and production of small quantities of pollutants machine sequnce,and the development of new equipment and teachnology has been to reduce and eliminate pollution.4.The role of mechanical engineeringThere are four generic mechanical engineers in common to the above all domains function.The 1st function is the understanding and the research mechanical science foundation.It includes the power and movement of the relationship dynamics For example,in the vibration and movement of the relationship;Automatic control;Study of the various forms of heart,energy,power relations between the thermodynamic;Fluidflows; Heat transfer; Lubricant;And material properties.The 2nd function will be conducts the research,the desing and the development,this function in turn attempts to carry on the essential change to satisfy current and the future needs.This not only calls for a clear understanding of mechanical science,and have to breakdown into basic elements of a complex system capacity.But also the need for synthetic and innovative inventions.The 3rd function is produces the product and the power,include plan,operation and maintenance.Its goal lies in the maintenance eitherenhances the enterprise or the organization longer-tern and survivabilaty prestige at the same time,produces the greatest value by the least investments and the consumption.The 4th function is mechanical engineer’s coordinated function,including the management,the consultation,as well as carries on the market marking in certain situation.In all these function,one kind unceasingly to use the science for a long time the method,but is not traditional or the intuition method tendency,this is a mechanical engineering skill aspect which unceasingly grows.These new rationalization means typical names include:The operations research,the engineering economics,the logical law problem analysis(is called PABLA) However,creativity is not rationalization.As in other areas,in mechanical engineering,to take unexpected and important way to bring about a new capacity,still has a personal,marked characteristice.5.The design of mechanical engineeringThe design of mechanical is the design has the mechanical property the thing or the system,such as:the instrument and the measuring appliance in very many situations,the machine design must use the knowledge of discipline the and so on mathematics,materials science and mechanics.Mechanical engineering desgin includeing all mechanical desgin,but it was a study,because it also includes all the branches of mechsnical engineering,such as thermodynamics all hydrodynamics in the basic disciplines needed,in the mechanical engineering design of the initial stude or mechanical design.Design stages.The entire desgin process from start to finish,in the process,a demand that is designed for it and decided to do the start.After a lot of repetition,the final meet this demand by the end of the design procees and the plan.Design considerations.Sometimes in a system is to decide which parts needs intensity parts of geometric shapesand size an important factor in this context that we must consider that the intensity is an important factor in the design.When we use expression design considerations,we design parts that may affect the entire system design features.In the circumstances specified in the design,usually for a series of such functions must be taken into account.Howeever,to correct purposes,we should recognize that,in many cases thedesign of important design considerations are not calculated or test can determine the components or systems.Especially students,wheen in need to make important decisions in the design and conduct of any operation that can not be the case,they are often confused.These are not special,they occur every day,imagine,for example,a medical laboratory in the mechanical design,from marketing perspective,people have high expectations from the strength and relevance of impression.Thick,and heavy parts installed together:to produce a solid impression machines.And sometimes machinery and spare parts from the design style is the point and not the other point of view.Our purpose is to make those you do not be misled to believe that every design decision will needreasonable mathematical methods.Manufacturing refers to the raw meterials into finished products in the enterprise.Create three distinct phases.They are:input,processing exprot.The first phase includes the production of all products in line with market needs essential.First there must be the demand for the product,the necessary materials,while also needs such as energy,time,human knowledge and technology resourcess .Finall,the need for funds to obtain all the other resources. Lose one stage after the second phase of the resources of the processes to be distributed.Processing of raw materials into finished products of these processes.To complete the design,based on the design,and then develop plans.Plan implemented through various production processes.Management of resources and processes to ensure efficiency and productivity.For example,we must carefully manage resources to ensure proper use of funds.Finally,people are talking about the product market was cast.Stage is the final stage of exporting finished or stage.Once finished just purchased,it must be delivered to the users.According to product performance,installation and may have to conduct further debugging in addition,some products,especially those very complex products User training is necessary.6.The processes of materials and maunfacturingHere said engineering materials into two main categories:metals and non-ferrous,high-performance alloys and power metals.Non-metallic futher divided into plastice,synthetic rubber,composite materials and ceramics.It said the productionproccess is divided into several major process,includingshape,forging,casting/ founding,heat treatment,fixed/connections ,measurement/ quality control and materal cutting.These processes can be further divide into each other’s craft.Various stages of the development of the manufacturing industry Over the years,the manufacturing process has four distinct stages of development, despite the overlap.These stages are:The first phase is artisanal,the second Phase is mechanization.The third phase is automation the forth Phase is integrated.When mankind initial processing of raw materials into finished products will be,they use manual processes.Each with their hands and what are the tools manuslly produced.This is totally integrated production take shape.A person needs indentification,collection materials,the design of a product to meet that demand,the production of such products and use it.From beginning to end,everything is focused on doing the work of the human ter in the industrial revolution introduced mechanized production process,people began to use machines to complete the work accomplished previously manual. This led to the specialization.Specialization in turn reduce the manufacture of integrated factors.In this stage of development,manufacturing workers can see their production as a whole represent a specific piece of the part of the production process.One can not say that their work is how to cope with the entire production process,or how they were loaded onto a production of parts finished.Development of manufacting processes is the next phase of the selection process automation.This is a computer-controlled machinery and processes.At this stage,automation island began to emerge in the workshop lane.Each island represents a clear production process or a group of processes.Although these automated isolated island within the island did raise the productivity of indivdual processes,but the overall productivity are often not change.This is because the island is not caught in other automated production process middle,but not synchronous with them .The ultimate result is the efficient working fast parked through automated processes,but is part of the stagnation in wages down,causing bottlenecks.To better understand this problem,you can imagine the traffic in the peak driving a red light from the red Service Department to the next scene. Occasionally you will find a lot less cars,more than being slow-moving vehicles,but the results can be found by thenext red light Brance.In short you real effect was to accelerate the speed of a red Department obstruction offset.If you and other drivers can change your speed and red light simultaneously.Will advance faster.Then,all cars will be consistent,sommth operation,the final everyone forward faster.In the workshop where the demand for stable synchronization of streamlined production,and promoted integration of manufacturing development.This is a still evolving technology.Fully integrated in the circumstances,is a computer-controllrd machinery and processing.integrated is completed through computer.For example in the preceding paragraph simulation problems,the computer will allow all road vehicles compatible with the change in red.So that everyone can steady traffic.Scientific analysis of movement,timing and mechanics of the disciplines is that it is composed of two pater:statics and dynamics.Statics analyzed static system that is in the system,the time is not taken into account,research and analysis over time and dynamics of the system change.Dynameics from the two componets.Euler in 1775 will be the first time two different branches: Rigid body movement studies can conveniently divided into two parts:geometric and mechanics.The first part is without taking into account the reasons for the downward movement study rigid body from a designated location to another point of the movement,and must use the formula to reflect the actual,the formula would determine the rigid body every point position. Therefore,this study only on the geometry and,more specifically,on the entities from excision.Obviously,the first part of the school and was part of a mechanical separation from the principles of dynamics to study movement,which is more than the two parts together into a lot easier.Dynamics of the two parts are subsequently divided into two separate disciplines,kinematic and dynamics,a study of movement and the movement strength.Therefore,the primary issue is the design of mechanical systems understand its kinematic.Kinematic studies movement,rather than a study of its impact.In a more precise kinematic studies position,displacement,rotation, speed,velocity and acceleration of disciplines,for esample,or planets orbiting research campaing is a paradigm.In the above quotation content should be pay attention that the content of the Euler dynamics into kinematic and rigid body dynamics is based on the assumptionthat they are based on research.In this very important basis to allow for the treatment of two separate disciplines.For soft body,soft body shape and even their own soft objects in the campaign depends on the role of power in their possession.In such cases,should also study the power and movement,and therefore to a large extent the analysis of the increased complexity.Fortunately, despite the real machine parts may be involved are more or less the design of machines,usually with heavy material designed to bend down to the lowest parts.Therefore,when the kinematic analysis of the performance of machines,it is often assumed that bend is negligible,spare parts are hard,but when the load is known,in the end analysis engine,re-engineering parts to confirm this assnmption.机械工程1.机械工程简介机械工程是工程学的一个分支，它研究机械和动力的产，尤其是力和动力。

A NOVEL INTEGRATED SYSTEM FOR RAPID PRODUCT DEVELOPMENTThis paper presents a novel integrated system of rapid product development for reducing the time and cost of product development. The system is composed of four building blocks —digital prototype, virtual prototype, physical prototype and rapid tooling manufacturing system. It can aid effectively in product design, analysis, prototype, mould, and manufacturing process development by integrating closely the various advanced manufacturing technologies which involve the 3D CAD, CAE, reverse engineering, rapid prototyping and rapid tooling. Furthermore, two actual examples are provided to illustrate the application of this integrated system. The results indicate that the system has a high potential to reduce further the cycle and cost of product development.Keywords: Rapid product development; rapid prototyping; integrated system.1. IntroductionDue to the pressure of international competition and market globalization in the 21st century, there continues to be strong driving forces in industry to compete effectively by reducing manufacturing times and costs while assuring high quality products and services. Current industries are facing the new challenges: quick response to business opportunity has been considered as one of the most important factors to ensure company competitiveness; manufacturing industry is evolving toward digitalization, network and globalization. Therefore, new products must be more quickly and cheaply developed, manufactured and introduced to the market. In order to meet the demand of rapid product development, the various new technologies such as reverse engineering (RE), 3D CAD, rapid prototyping (RP), and rapid tooling (RT) have emerged and are regarded as key enabling tools with the ability to shorten the product development and manufacturing time. For example, it has been claimed that RP can cut new product development costs by up to 70% and the time to market by 90%.1 In the form of a better design, more design possibilities, a 3D CAD model can be shown to the customer for approval and prevents misunderstandings. A virtual prototyping is employed to guide in optimizationof the product design and manufacturing process planning, which may result in the accurate determination of the process parameters, and reduce the number of costly physical prototype iterations. Rapid tooling technique offers a fast and low cost method to produce moulds, and shows a high potential for faster response to market demands. When properly integrated among 3D CAD, CAE, RE, RP and RT, these technologies will play a much more important role to reduce further the development cycle and cost of the product production. On the basis of above technologies, a novel integrated system of rapid product development is to be founded so as to meet the requirement of rapid product development.2. Architecture of the Integrated Development SystemThe development process from initial conceptual design to commercial product is an iterative process which includes: product design; analysis of performance, safety and reliability; product prototyping for experimental evaluation; and design modification. Therefore, any step of the new product development process has a direct and strong influence on time-to-market in short order. A good product development system must enable designers or design teams to consider all aspects of product design, manufacturing, selling and recycling at the early stage of the design cycle. So that design iteration and changes can be made easily and effectively. The more fluent the feedback is the higher possibility of success the system has. Design for manufacturing (DFM) and concurrent engineering (CE) necessitate that product and process design be developed simultaneously rather than sequentially.The integrated system of rapid product development is composed of four modules: digital prototype, virtual prototype, physical prototype and rapid tooling.The product development starts from the creation of a 3D CAD model using a CAD software package. At that stage, the product geometry is defined and its aesthetic and dimensional characteristics are verified. The main function of digital prototype is to perform 3D CAD modelling. The CAD model is regarded as a central component of the whole system or project information base which means that in all design, analysis and manufacturing activities the same data is utilized. The product and its components are directly designed on a 3D CAD system (e.g.Pro/Engineer, Unigraphics, CATIA, IDEAS, etc.) during the creative design. If a physical partis ready, the model can be constructed by the reverse engineering technique. RE is a methodology for constructing CAD models of physical parts by digitizing an existing part, creating a digital model and then using it to manufacture components. RE can reduce the development cycle when redesigns become necessary for improved product quality. Preexisting parts with features for improved performance can be readily incorporated into the desired part design. Therefore, it is very useful in creating the CAD model of an existing part when the engineering design is lost or has gone through many design changes. When a designer creates a new design using mock-up, it is also necessary to construct the CAD model of the mock-up for further use of the design data in analysis and manufacturing. The three primary steps in RE process are part digitization, features extraction, and CAD modelling. Part digitization is accomplished by a variety of contact or non-contact digitizers. There are various commercial systems available for part digitization. These systems range from coordinate measuring machine (CMM), laser scanners to ultrasonic digitizers. They can be classified into two broad categories: contact and non-contact. Laser triangulation scanner (LTS), magnetic resonance images (MRI), and computer tomography (CT) are commonly used as non-contact devices. Contact digitizers mainly have CMM and cross-sectional imaging measurement (CIM). Feature extraction is normally achieved by segmenting the digitized data and capturing surface features such as edges. Part modelling is fulfiled through fitting a variety of surfaces to the segmented data points.In order to reduce the iterations of design-prototype-test cycles, increase the product process and manufacturing reliability, it is necessary to guide in optimizing the product design and manufacturing process through virtual prototype (VP). VP is a process of using 3D CAD model, in lieu of a physical prototype, for testing and evaluation of specific characteristics of a product or a manufacturing process. It is often carried out by CAE and virtual manufacturing system. Computer aided engineering (CAE) analysis is an integral part of time-compression technologies. Various software tools available (i.e. ANSYS, MARC, I-DEAS, AUTOFORM, DYNAFORM, etc.) can speed up the development of new products by initiating design optimization before physical prototypes are built. The CAD models can be transferred to a CAE environment for an analysis of the product functional performance and of the manufacturing processes for producing the product’s components. It has also proven to be ofgreat value in the design optimization of part geometry, to determine its dimensions and to control warpage and shrinkage while minimizing process-induced residual stresses and deformations. Virtual manufacturing system (VM) is the natural extension of CAE. It simulates the product functionality and the processes for producing it prior to the development of physical prototypes. VM enables a designer to visualize and optimize a product process with a set of process parameters. The visualization of a virtually simulated part prior to physical fabrication helps to reduce unwanted prototype iterations. Therefore, a product virtual manufacturing system may result in accurate determination of the process parameters, and reduce the number of costly physical prototype iterations. 3D CAD model and VP allow most problems with unfitting to become obvious early in the product development process. Assemblies can be verified for interference as VP can be exercised through a range of tasks. Structure and thermal analysis can be performed on the same model employing CAE applications as well as simulating down-stream manufacturing processes. It is clear that VP increases process and product reliability. Although VP is intended to ensure that unsuitable designs are rejected or modified, in many cases, a visual and physical evaluation of the real component is needed. This often requires physical prototype to be produced. Hence, once the VP is finished, the model may often be sent directly to physical fabrication.The CAD model can be directly converted to the physical prototype using a RP technique or high-speed machining (HSM) process. The 3D CAD model is to be exported not only in the STL format which is considered the de facto standard for interfacing CAD and RP systems, but also in the NC coding which can be used by HSM. HSM has a potential for rapid producing plaster or wooden pattern for RT. RP is a new forming process which fabricates physical parts layer by layer under computer control directly from 3D CAD models in a very short time. In contrast to traditional machining methods, the majority of rapid prototyping systems tend to fabricate parts based on additive manufacturing process, rather than subtraction or removal of material. Therefore, this type of fabrication is unconstrained by the limitations attributed to conventional machining approaches. The application of RP technique as a useful tool can provide benefits throughout the process of developing new products. Specifically, there are serious benefits that RP can bring in the areas of market research, sales support, promotionalmaterial, and the ever-important product launch. Physical RP can also become a powerful communications tool to ensure that everyone involved in the development process fully understands and appreciates the product being developed. Hence, it can help to reduce substantially the inevitable risks in the route from product concept to commercial success, and help shorten time-to-market, improve quality and reduce cost. Over the last 20 years, RP machines have been widely used in industry. The RP methods commercially available include Stereolithgraphy (SLA), Selective Laser Sintering (SLS), Fused Deposition Manufacturing (FDM), Laminated Object Manufacturing (LOM), Ballistic Particle Manufacturing (BMP), and Three-Dimensional Printing (3D printing), etc.Once the design has been accepted, the realization of the production line represents a major task with a long lead time before any product can be put to the market. In particular, the preparation of complex tooling is usually in the critical path of a project and has therefore a direct and strong influence on time-to-market. In order to reduce the product development time and cost, the new technique of RT has been developed. RT is a technique that can transform the RP patterns into functional parts, especially metal parts. It offers a fast and low cost method to produce moulds and functional parts. Furthermore, the integration of both RP and RT in development strategy promotes the implementation of concurrent engineering in companies. Numerous processes have been developed for producing dies from RP system. The RT methods can generally be divided into direct and indirect tooling categories, and also soft (firm) and hard tooling subgroups. Indirect RT requires some kinds of master patterns, which can be made by conventional methods (e.g. HSM), or more commonly by an RP process such as SLA or SLS. Direct RT, as the name suggests, involves the manufacturing of a tool cavity directly on a RP system, hence eliminating the intermediate step of generating a pattern. Soft tooling can be obtained via replication from a positive pattern or master. Soft tooling is associated with low costs; used for low volume production and uses materials that have low hardness levels such as silicones, epoxies, low melting point alloys, etc. RTV silicone rubber moulds, epoxy moulds, metal spraying moulds, etc. are some of these typical soft moldings. Hard tooling is associated with higher volume of production, and the use of materials of greater hardness. Keltool process, Quickcast process, and the ExpressTool process are some of these hard toolings. Electrical discharge machining (EDM) seemsto be an interesting area in which rapid tooling finds a potential application. Some methods of making EDM electrodes based on RP technique have developed, such as abrading process, copper electroforming and net shape casting, etc. On the basis of the above techniques, a novel integrated system of rapid product development is to be proposed. Its overall architecture is shown in Fig. 1.3. Case Studies3.1. Case study 1: ImpellerA total of thirty plastic impellers, with a relatively complex geometry, were required by acustomer within fifteen working days from the receipt of a 2D CAD model. There were many factors to be considered in deciding the most appropriate route for producing the impellers. These factors mainly involved cost, lead-time, the number of parts required, the final material for the parts, and the part geometry. In order to maximize the benefits in terms of time and cost reduction for the parts, it was decided to use silicon rubber mould and the parts were eventually produced by vacuum casting process. Silicon rubber mould is an easy, relatively inexpensive and fast way to fabricate prototype or pre-production tools. It can be utilized for moulding parts in wax, polyurethane, ABS, and a few epoxy materials. The process is best suited for projects where form, fit, or functional testing can be done with a material which mimics the characteristics of the production material. The casting parts with fine details and very thin walls can be easily and rapidly produced. The whole process flow involved the 3D CAD modelling, producing master pattern (RP prototype), silicon rubber mould, and casting green parts. The time sequence for the fabrication of impellers was described as follows. Due to the complexity of the impeller, the task of generating the 3D CAD model using Pro/Engineer software package took almost 3 calendar days. The master pattern for this project was built on a SPS 600 machine in 2 calendar days. SL process was chosen because it was cost effective and the surface finish was good. The next step involved creating a roomtemperature vulcanized (RTV) silicone rubber mold which was completed within an additional 3 calendar days. Finally, the ABS materials were cast into silicon rubber mould under the vacuum casting condition, and the green parts were achieved in 4 calendar days. The required 30 components were produced successfully and completed in 12 calendar days. The primary process stages are illustrated in Fig. 2. These impellers only cost about 5 thousand RMB and took 12 working days. Consequently, in contrast to the traditional development mode, the impellers developed using the integrated system can cut cost by up to 50% and the time-to-market by 75%. When evaluated against satisfying urgent requirement with respect to time, the procedure is clearly worth pursuing, as indicated by the case study described above. Gong from a 3D CAD solid modeling to fully functional production impellers in less than 12 working days is certainly extraordinary.With proper implementation of the process by qualified personnel, working within the scope of the constraints noted, the acceptance and advancement of the integrated manufacturing methodis likely to grow.3.2. Case study 2: MannequinTen plastic mannequins were required by a client in three months from the receipt of the plaster model of the emulational body. This component was an ideal candidate for using integrated system to development, with a very complex surface and a requirement for only 10 parts. In order to produce the plastic mannequin, the various technologies including reverse engineering, 3D CAD, rapid prototyping and rapid tooling were used to complete model measuring, surfaces reconstructing, 3D CAD modelling, prototype and mould building. The whole development work was presented below. The first step of the project was to construct a CAD model of the emulational body by RE process. ATOS measuring equipment made in GOM Inc. which has a high scanning (10,000 points/sec) and can measure models in a wide range from 500mm to 10mm, was employed to capture the digitized data of the plaster mold. Figure 3(a) shows the point clouds of the body model. The subsequent process was to perform surfaces reconstructing. To speed this process, a special reverse engineering program, called CopyCAD (DelcamInc.), was used to create quickly and easily the CAD surfaces from the digitized data. After surfaces reconstructing, many errors in the original model and the joints must be modified by PowerShape software package (another software of Delcam Inc.). The surfaces model of the body is represented in Fig. 3(b). To fabricate easily, the surface model was divided into 11 individual components which included the head, body, upper arms, forearms, tights, shanks and feet using Pro/Engineer software package. Subsequently, every surface model was converted to a solid model, and many holes and slots needed to be designed for fixing joints such as shoulder, knees, etc. Then, the solid parts and joints were assembled to form the solid model of the emulational body. Figure 3(c) illustrates the completed CAD solid model. The RP prototypes of these components were built on a LPS 600 machine. The assembly RP body model is shown in Fig. 3(d). In addition, silicon rubber moulds of these components were fabricated for producing the green parts. Finally, the required 10 plastic mannequins were produced successfully and the project was completed in about 12 weeks. Figures 3(e) and (f) describe respectively the silicon rubber mould of half head and the green product. The case indicates the rapid development of large product and complex surfaces can be realized quickly following the integrated development mode.4. ConclusionIn this paper, we have presented an integrated system based on RP for rapid product developing. The system consists of four modules: digital prototype, virtual prototype, physical prototype and rapid tooling. It employs fully and integrates closely the various advanced manufacturing technologies which involve the 3D CAD, RE, CAE, RP, and RT. In this system, the procedure of development from design to end product is worked step by step: design, analysis, rapid prototype and tooling. By evaluating the whole process and its various components, and comparing them with traditional process, it has been clear that one can reap benefits in various ways. The system can effectively compress the design and manufacturing cycle time and reduce the development cost, which is an important factor in competition. Using this integrated system to develop new product shows a high potential for faster response to market and customers’ demands. As a result, it will play a more and more important role to reduce the manufacturing cycle and cost of product development in the future. AcknowledgementsThis research was supported by The National High Technology Research and Development Program (863 Program) under the project “The integrated manufacturing technology and equipments of rapid tooling for rapid product development”(No.2023AA421270), and “Tenth Five-Year” National Key T echnologies R&D Program of China under the project “Research and demonstrator of rapid manufacturing integrated system based on rapid prototyping” (No. 2023BA205B10- CMTT1001).。

本科毕业论文(设计)外文翻译学院：机电工程学院专业：机械工程及自动化姓名：高峰指导教师：李延胜2011年 05 月 10日教育部办公厅Failure Analysis，Dimensional Determination And Analysis，Applications Of Cams INTRODUCTIONIt is absolutely essential that a design engineer know how and why parts fail so that reliable machines that require minimum maintenance can be designed．Sometimes a failure can be serious，such as when a tire blows out on an automobile traveling at high speed．On the other hand，a failure may be no more than a nuisance．An example is the loosening of the radiator hose in an automobile cooling system．The consequence of this latter failure is usually the loss of some radiator coolant，a condition that is readily detected and corrected．The type of load a part absorbs is just as significant as the magnitude．Generally speaking，dynamic loads with direction reversals cause greater difficulty than static loads，and therefore，fatigue strength must be considered．Another concern is whether the material is ductile or brittle．For example，brittle materials are considered to be unacceptable where fatigue is involved．Many people mistakingly interpret the word failure to mean the actualbreakage of a part．However，a design engineer must consider a broader understanding of what appreciable deformation occurs．A ductile material，however will deform a large amount prior to rupture．Excessive deformation，without fracture，may cause a machine to fail because the deformed part interferes with a moving second part．Therefore，a part fails(even if it has not physically broken)whenever it no longer fulfills its required function．Sometimes failure may be due to abnormal friction or vibration between two mating parts．Failure also may be due to a phenomenon called creep，which is the plastic flow of a material under load at elevated temperatures．In addition，the actual shape of a part may be responsible for failure．For example，stress concentrations due to sudden changes in contour must be taken into account．Evaluation of stress considerations is especially important when there are dynamic loads with direction reversals and the material is not very ductile． In general，the design engineer must consider all possible modes of failure，which include the following．——Stress——Deformation——Wear——Corrosion——Vibration——Environmental damage——Loosening of fastening devicesThe part sizes and shapes selected also must take into account many dimensional factors that produce external load effects，such as geometric discontinuities，residual stresses due to forming of desired contours，and the application of interference fit joints．Cams are among the most versatile mechanisms available．A cam is a simple two-member device．The input member is the cam itself，while the output member is called the follower．Through the use of cams，a simple input motion can be modified into almost any conceivable output motion that is desired．Some of the common applications of cams are ——Camshaft and distributor shaft of automotive engine ——Production machine tools——Automatic record players——Printing machines——Automatic washing machines——Automatic dishwashersThe contour of high-speed cams (cam speed in excess of 1000 rpm) must be determined mathematically．However，the vast majority of cams operate at low speeds(less than 500 rpm) or medium-speed cams can be determined graphically using a large-scale layout．In general，the greater the cam speed and output load，the greater must be the precision with which the cam contour is machined．DESIGN PROPERTIES OF MATERIALSThe following design properties of materials are defined as they relate to the tensile test．FigureStatic Strength．The strength of a part is the maximum stress that the part can sustain without losing its ability to perform its required function．Thus the static strength may be considered to be approximately equal to the proportional limit，since no plastic deformation takes place and no damage theoretically is done to the material．Stiffness．Stiffness is the deformation-resisting property of a material．The slope of the modulus line and，hence，the modulus of elasticity are measures of the stiffness of a material．Resilience．Resilience is the property of a material that permits it to absorb energy without permanent deformation．The amount of energy absorbed is represented by the area underneath the stress-strain diagram within the elastic region．Toughness．Resilience and toughness are similar properties．However，toughness is the ability to absorb energy without rupture．Thus toughness is represented by the total area underneath the stress-strain diagram，as depicted in Figure 2．8b．Obviously，the toughness and resilience of brittle materials are very low and are approximately equal．Brittleness． A brittle material is one that ruptures before any appreciable plastic deformation takes place．Brittle materials are generally considered undesirable for machine components because they are unable to yield locally at locations of high stress because of geometric stress raisers such as shoulders，holes，notches，or keyways．Ductility． A ductility material exhibits a large amount of plastic deformation prior to rupture．Ductility is measured by the percent of areaand percent elongation of a part loaded to rupture．A 5%elongation at rupture is considered to be the dividing line between ductile and brittle materials．Malleability．M alleability is essentially a measure of the compressive ductility of a material and，as such，is an important characteristic of metals that are to be rolled into sheets．Hardness．The hardness of a material is its ability to resist indentation or scratching．Generally speaking，the harder a material，the more brittle it is and，hence，the less resilient．Also，the ultimate strength of a material is roughly proportional to its hardness．Machinability．Machinability is a measure of the relative ease with which a material can be machined．In general，the harder the material，the more difficult it is to machine．FigureCOMPRESSION AND SHEAR STATIC STRENGTHIn addition to the tensile tests，there are other types of static load testing that provide valuable information．Compression Testing．M ost ductile materials have approximately the same properties in compression as in tension．The ultimate strength，however，can not be evaluated for compression．As a ductile specimen flows plastically in compression，the material bulges out，but there is no physical rupture as is the case in tension．Therefore，a ductile material fails in compression as a result of deformation，not stress．Shear Testing．Shafts，bolts，rivets，and welds are located in such a way that shear stresses are produced．A plot of the tensile test．The ultimate shearing strength is defined as the stress at which failure occurs．The ultimate strength in shear，however，does not equal the ultimate strength in tension．For example，in the case of steel，the ultimate shear strength is approximately 75% of the ultimate strength in tension．This difference must be taken into account when shear stresses are encountered in machine components．DYNAMIC LOADSAn applied force that does not vary in any manner is called a static or steady load．It is also common practice to consider applied forces that seldom vary to be static loads．The force that is gradually applied during a tensile test is therefore a static load．On the other hand，forces that vary frequently in magnitude and direction are called dynamic loads．Dynamic loads can be subdivided to the following three categories．Varying Load．W ith varying loads，the magnitude changes，but the direction does not．For example，the load may produce high and low tensile stresses but no compressive stresses．Reversing Load．In this case，both the magnitude and direction change．These load reversals produce alternately varying tensile and compressive stresses that are commonly referred to as stress reversals．Shock Load．This type of load is due to impact．One example is an elevator dropping on a nest of springs at the bottom of a chute．The resulting maximum spring force can be many times greater than the weight of the elevator，The same type of shock load occurs in automobile springs when a tire hits a bump or hole in the road．FATIGUE FAILURE-THE ENDURANCE LIMIT DIAGRAMThe test specimen in Figure ．，after a given number of stress reversals will experience a crack at the outer surface where the stress is greatest．The initial crack starts where the stress exceeds the strength of the grain on which it acts．This is usually where there is a small surface defect，such as a material flaw or a tiny scratch．As the number of cycles increases，the initial crack begins to propagate into a continuous series of cracks all around the periphery of the shaft．The conception of the initial crack is itself a stress concentration that accelerates the crack propagation phenomenon．Once the entire periphery becomes cracked，the cracks start to move toward the center of the shaft．Finally，when the remaining solid inner area becomes small enough，the stress exceeds the ultimate strength and the shaft suddenly breaks．Inspection of the break reveals a very interesting pattern，as shown in Figure ．The outer annular area is relatively smooth because mating cracked surfaces had rubbed against each other．However，the center portion is rough，indicating a sudden rupture similar to that experienced with the fracture of brittle materials．This brings out an interesting fact．When actual machine parts fail as a result of static loads，they normally deform appreciably because of the ductility of the material．FigureThus many static failures can be avoided by making frequent visual observations and replacing all deformed parts．However，fatigue failures give to warning．Fatigue fail mated that over 90% of broken automobile parts have failed through fatigue．The fatigue strength of a material is its ability to resist the propagation of cracks under stress reversals．Endurance limit is a parameter used to measure the fatigue strength of a material．By definition，the endurance limit is the stress value below which an infinite number of cycles will not cause failure．Let us return our attention to the fatigue testing machine in Figure ．The test is run as follows：A small weight is inserted and the motor is turned on．At failure of the test specimen，the counter registers the number of cycles N，and the corresponding maximum bending stress is calculated from Equation ．The broken specimen is then replaced by an identical one，and an additional weight is inserted to increase the load．A new value of stress is calculated，and the procedure is repeated until failure requires only one complete cycle．A plot is then made of stress versus number of cycles to failure．Figure shows the plot，which is called the endurance limit or S-N curve．Since it would take forever to achieve an infinite number of cycles，1 million cycles is used as a reference．Hence the endurance limit can be found from Figure by noting that it is the stress level below which the material can sustain 1 million cycles without failure．The relationship depicted in Figure is typical for steel，because the curve becomes horizontal as N approaches a very large number．Thus the endurance limit equals the stress level where the curve approaches a horizontal tangent．Owing to the large number of cycles involved，N is usually plotted on a logarithmic scale，as shown in Figure ．When this is done，the endurance limit value can be readily detected by the horizontal straight line．For steel，the endurance limit equals approximately 50% of the ultimate strength．However，if the surface finish is not of polished equality，the value of the endurance limit will be lower．For example，for steel parts with a machined surface finish of 63 microinches ( μin．)，the percentage drops to about 40%．For rough surfaces (300μin．or greater)，the percentage may be as low as 25%．The most common type of fatigue is that due to bending．The next mostfrequent is torsion failure，whereas fatigue due to axial loads occurs very seldom．Spring materials are usually tested by applying variable shear stresses that alternate from zero to a maximum value，simulating the actual stress patterns．In the case of some nonferrous metals，the fatigue curve does not level off as the number of cycles becomes very large．This continuing toward zero stress means that a large number of stress reversals will cause failure regardless of how small the value of stress is．Such a material is said to have no endurance limit．For most nonferrous metals having an endurance limit，the value is about 25% of the ultimate strength．EFFECTS OF TEMPERATURE ON YIELD STRENGTH AND MODULUS OF ELASTICITY Generally speaking，when stating that a material possesses specified values of properties such as modulus of elasticity and yield strength，it is implied that these values exist at room temperature．At low or elevated temperatures，the properties of materials may be drastically different．For example，many metals are more brittle at low temperatures．In addition，the modulus of elasticity and yield strength deteriorate as the temperature increases．Figure shows that the yield strength for mild steel is reduced by about 70% in going from room temperature to 1000o F．Figure shows the reduction in the modulus of elasticity E for mild steel as the temperature increases．As can be seen from the graph，a 30% reduction in modulus of elasticity occurs in going from room temperature to 1000o F．In this figure，we also can see that a part loaded below the proportional limit at room temperature can be permanently deformed under the same load at elevated temperatures．FigureCREEP: A PLASTIC PHENOMENONTemperature effects bring us to a phenomenon called creep，which is the increasing plastic deformation of a part under constant load as a function of time．Creep also occurs at room temperature，but the process is so slow that it rarely becomes significant during the expected life of the temperature is raised to 300o C or more，the increasing plastic deformation can become significant within a relatively short period of time．The creep strength of a material is its ability to resist creep，and creep strength data can be obtained by conducting long-time creep tests simulating actual part operating conditions．During the test，theplastic strain is monitored for given material at specified temperatures．Since creep is a plastic deformation phenomenon，the dimensions of a part experiencing creep are permanently altered．Thus，if a part operates with tight clearances，the design engineer must accurately predict the amount of creep that will occur during the life of the machine．Otherwise，problems such binding or interference can occur．Creep also can be a problem in the case where bolts are used to clamp tow parts together at elevated temperatures．The bolts，under tension，will creep as a function of time．Since the deformation is plastic，loss of clamping force will result in an undesirable loosening of the bolted joint．The extent of this particular phenomenon，called relaxation，can be determined by running appropriate creep strength tests．Figure shows typical creep curves for three samples of a mild steel part under a constant tensile load．Notice that for the high-temperature case the creep tends to accelerate until the part fails．The time line in the graph (the x-axis) may represent a period of 10 years，the anticipated life of the product．FigureSUMMARYThe machine designer must understand the purpose of the static tensile strength test．This test determines a number of mechanical properties of metals that are used in design equations．Such terms as modulus of elasticity，proportional limit，yield strength，ultimate strength，resilience，and ductility define properties that can be determined from the tensile test．Dynamic loads are those which vary in magnitude and direction and may require an investigation of the machine part’s resistance to failure．Stress reversals may require that the allowable design stress be based on the endurance limit of the material rather than on the yield strength or ultimate strength．Stress concentration occurs at locations where a machine part changes size，such as a hole in a flat plate or a sudden change in width of a flat plate or a groove or fillet on a circular shaft．Note that for the case of a hole in a flat or bar，the value of the maximum stress becomes much larger in relation to the average stress as the size of the hole decreases．Methods of reducing the effect of stress concentration usuallyinvolve making the shape change more gradual．Machine parts are designed to operate at some allowable stress below the yield strength or ultimate strength．This approach is used to take care of such unknown factors as material property variations and residual stresses produced during manufacture and the fact that the equations used may be approximate rather that exact．The factor of safety is applied to the yield strength or the ultimate strength to determine the allowable stress．Temperature can affect the mechanical properties of metals．Increases in temperature may cause a metal to expand and creep and may reduce its yield strength and its modulus of elasticity．If most metals are not allowed to expand or contract with a change in temperature，then stresses are set up that may be added to the stresses from the load．This phenomenon is useful in assembling parts by means of interference fits．A hub or ring has an inside diameter slightly smaller than the mating shaft or post．The hub is then heated so that it expands enough to slip over the shaft．When it cools，it exerts a pressure on the shaft resulting in a strong frictional force that prevents loosening．TYPES OF CAM CONFIGURATIONSPlate Cams．This type of cam is the most popular type because it is easy to design and manufacture．Figure 6．1 shows a plate cam．Notice that the follower moves perpendicular to the axis of rotation of the camshaft．All cams operate on the principle that no two objects can occupy the same space at the same time．Thus，as the cam rotates ( in this case，counterclockwise )，the follower must either move upward or bind inside the guide．We will focus our attention on the prevention of binding and attainment of the desired output follower motion．The spring is required to maintain contact between the roller of the follower and the cam contour when the follower is moving downward．The roller is used to reduce friction and hence wear at the contact surface．For each revolution of the cam，the follower moves through two strokes-bottom dead center to top dead center (BDC to TDC) and TDC to BDC．Figure illustrates a plate cam with a pointed follower．Complex motions can be produced with this type of follower because the point can follow precisely any sudden changes in cam contour．However，this design is limited to applications in which the loads are very light；otherwisethe contact point of both members will wear prematurely，with subsequent failure．Two additional variations of the plate cam are the pivoted follower and the offset sliding follower，which are illustrated in Figure ．A pivoted follower is used when rotary output motion is desired．Referring to the offset follower，note that the amount of offset used depends on such parameters as pressure angle and cam profile flatness，which will be covered later．A follower that has no offset is called an in-line follower．Figure 6..3Translation Cams．Figure depicts a translation cam．The follower slides up and down as the cam translates motion in the horizontal direction．Note that a pivoted follower can be used as well as a sliding-type follower．This type of action is used in certain production machines in which the pattern of the product is used as the cam．A variation on this design would be a three-dimensional cam that rotates as well as translates．For example，a hand-constructed rifle stock is placed in a special lathe．This stock is the pattern，and it performs the function of a cam．As it rotates and translates，the follower controls a tool bit that machines the production stock from a block of wood．FigurePositive-Motion Cams．In the foregoing cam designs，the contact between the cam and the follower is ensured by the action of the spring forces during the return stroke．However，in high-speed cams，the spring force required to maintain contact may become excessive when added to the dynamic forces generated as a result of accelerations．This situation can result in unacceptably large stress at the contact surface，which in turn can result in premature wear．Positive-motion cams require no spring because the follower is forced to contact the cam in two directions．Thereare four basic types of positive-motion cams: the cylindrical cam，the grooved-plate cam ( also called a face cam ) ，the matched-plate cam，and the scotch yoke cam．Cylindrical Cam．The cylindrical cam shown in Figure produces reciprocating follower motion，whereas the one shown in Figure illustrates the application of a pivoted follower．The cam groove can be designed such that several camshaft revolutions are required to produce one complete follower cycle．Grooved-plate Cam．In Figure we see a matched-plate cam with a pivoted follower，although the design also can be used with a translation follower．Cams E and F rotate together about the camshaft B．Cam E is always in contact with roller C，while cam F maintains contact with roller D．Rollers C and D are mounted on a bell-crank lever，which is the follower oscillating about point A．Cam E is designed to provide the desired motion of roller C，while cam F provides the desired motion of roller D．Scotch Yoke Cam．This type of cam，which is depicted in Figure ，consists of a circular cam mounted eccentrically on its camshaft．The stroke of the follower equals two times the eccentricity e of the cam．This cam produces simple harmonic motion with no dwell times．Refer to Section for further discussion．CAM TERMINOLOGYBefore we become involved with the design of cams，it is desirable to know the various terms used to identify important cam design parameters．The following terms refer to Figure ．The descriptions will be more understandable if you visualize the cam as stationary and the follower as moving around the cam．Trace Point．The end point of a knife-edge follower or the center of the roller of a roller-type follower．Cam Contour．The actual shape of the cam．Base Circle．The smallest circle that can be drawn tangent to the cam contour．Its center is also the center of the camshaft．The smallest radial size of the cam stars at the base circle．Pitch Curve．The path of the trace point，assuming the cam is stationary and the follower rotates about the cam．Prime Circle．The smallest circle that can be drawn tangent to the pitch curve．Its center is also the center of the camshaft．Pressure Angle．The angle between the direction of motion of the follower and the normal to the pitch curve at the point where the center of the roller lies．Cam Profile．Same as cam contour．BDC．Bottom Dead Center，the position of the follower at its closest point to the cam hub．Stroke．The displacement of the follower in its travel between BDC and TDC．Rise．The displacement of the follower as it travels from BDC to TDC．Return．The displacement of the follower as it travels from TDC or BDC．Ewell．The action of the follower when it remains at a constant distance from the cam hub while the cam turns．A clearer understanding of the significance of the pressure angle can be gained by referring to Figure ．Here FTis the total force acting on the roller．It must be normal to the surfaces at the contact point．Its direction is obviously not parallel to the direction of motion of the follower．Instead，it is indicated by the angle α，the pressure angle，measured from the line representing the direction of motion of thefollower．Therefore，the force FT has a horizontal component FHand avertical component FV．The vertical component is the one that drives thefollower upward and，therefore，neglecting guide friction，equals thefollower Fload．The horizontal component has no useful purpose but it is unavoidable．In fact，it attempts to bend the follower about its guide．This can damage the follower or cause it to bind inside its guide．Obviously，we want the pressure angle to be as possible to minimize the side thrustFH．A practical rule of thumb is to design the cam contour so that the pressure angle does not exceed 30o．The pressure angle，in general，depends on the following four parameters:——Size of base circle——Amount of offset of follower——Size of roller——Flatness of cam contour ( which depends on follower stroke and type of follower motion used )Some of the preceding parameters cannot be changed without altering the cam requirements，such as space limitations．After we have learned how to design a cam，we will discuss the various methods available to reducethe pressure angle．故障的分析、尺寸的决定以及凸轮的分析和应用前言介绍：作为一名设计工程师有必要知道零件如何发生和为什么会发生故障，以便通过进行最低限度的维修以保证机器的可靠性。

机械类毕业设计外文翻译外文原文Options for micro-holemakingAs in the macroscale-machining world, holemaking is one of the most— if not the most—frequently performed operations for micromachining. Many options exist for how those holes are created. Each has its advantages and limitations, depending on the required hole diameter and depth, workpiece material and equipment requirements. This article covers holemaking with through-coolant drills and those without coolant holes, plunge milling, microdrilling using sinker EDMs and laser drilling.Helpful HolesGetting coolant to the drill tip while the tool is cutting helps reduce the amount of heat at the tool/workpiece interface and evacuate chips regardless of hole diameter. But through-coolant capability is especially helpful when deep-hole microdrilling because the tools are delicate and prone to failure when experiencing recutting of chips, chip packing and too much exposure to carbide’s worst enemy—heat.When applying flood coolant, the drill itself blocks access to the cutting action. “Somewhere about 3 to 5 diam eters deep, the coolant has trouble getting down to the tip,” said Jeff Davis, vice president of engineering for Harvey Tool Co., Rowley, Mass. “It becomes wise to use a coolant-fed drill at that point.”In addition, flood coolant can cause more harm than good when microholemaking. “The pressure from the flood coolant can sometimes snap fragile drills as they enter the part,” Davis said.The toolmaker offers a line of through-coolant drills with diameters from 0.039" to 0.125" that are able to produce holes up to 12 diameters deep, as well as microdrills without coolant holes from 0.002" to 0.020".Having through-coolant capacity isn’t enough, though. Coolant needs to flow at a rate that enables it to clear the chips out of the hole. Davis recommends, at a minimum, 600 to 800 psi of coolant pressure. “It works much better if you have higher pressure than that,” he added.To prevent those tiny coolant holes from becoming clogged with debris, Davis also recommends a 5μm or finer coolant filter.Another recommendation is to machine a pilot, or guide, hole to prevent the tool from wandering on top of the workpiece and aid in producing a straight hole. When applying a pilot drill, it’s important to select one with an included angle on its point that’s equal t o or larger than the included angle on the through-coolant drill that follows.The pilot drill’s diameter should also be slightly larger. For example, if the pilot drill has a 120° included angle and a smaller diameter than a through-coolant drill with a 140°included angle, “then you’re catching the coolant-fed drill’s corners and knocking those corners off,” Davis said, which damages the drill.Although not mandatory, pecking is a good practice when microdrilling deep holes. Davis suggests a pecking cycle that is 30 to 50 percent of the diameter per peck depth, depending on the workpiece material. This clears the chips, preventing them from packing in the flute valleys.Lubricious ChillTo further aid chip evacuation, Davis recommends applying an oil-based metalworking fluid instead of a waterbased coolant because oil provides greater lubricity. But if a shop prefers using coolant, the fluid should include EP (extreme pressure) additives to increase lubricity and minimize foaming. “If you’ve got a lot of foam,” Davis noted, “the chips aren’t being pulled out the way they are supposed to be.”He added that another way to enhance a tool’s slipperiness while extending its life is with a coating, such as titanium aluminum nitride. TiAlN has a high hardness and is an effective coating for reducing heat’s impact when drilling difficult-to-machine materials, like stainless steel.David Burton, general manager of Performance Micro Tool, Janesville, Wis., disagrees with the idea of coating microtools on the smaller end of the spectrum. “Coatings on tools below 0.020" typically have a negative effect on every machining aspect, from the quality of the initial cut to tool life,” he said. That’s becaus e coatings are not thin enough and negatively alter the rake and relief angles when applied to tiny tools.However, work continues on the development of thinner coatings, and Burton indicated that Performance Micro Tool, which produces microendmills and microrouters and resells microdrills, is working on a project with others to create a submicron-thickness coating. “We’re probably 6 months to 1 year from testing it in the market,” Burton said.The microdrills Performance offers are basically circuit-board drills, which are also effective for cutting metal. All the tools are without through-coolant capability. “I had a customer drill a 0.004"-dia. hole in stainless steel, and he was amazed he could do it with a circuit-board drill,” Burton noted, adding th at pecking and running at a high spindle speed increase the drill’s effectiveness.The requirements for how fast microtools should rotate depend on the type ofCNCcharged EDM wire. The fine-hole option includes a W-axis attachment, which holds a die that guides the electrode, as well as a middle guide that prevents the electrode from bending or wobbling as it spins. With the option, the machine is appropriate for drilling hole diameters less than 0.005".Another sinker EDM for micro-holemaking is the Mitsubishi VA10 with afine-hole jig attachment to chuck and guide the fine wire applied to erode the material. “It’s a standard EDM, but with that attachment fixed to the machine, we can do microhole drilling,” said Dennis Powderly, sinker EDM product manager for MC Machinery Systems Inc., Wood Dale, Ill. He added that the EDM is also able to create holes down to 0.0004" using a wire that rotates at up to 2,000 rpm.Turn to TungstenEDMing is typically a slow process, and that holds true when it is used for microdrilling. “It’s very slow, and the finer the details, the slower it is,” said , president and owner of Optimation Inc. The Midvale, Utah, company builds Profile 24 Piezo EDMs for micromachining and also performs microEDMing on a contract-machining basis.Optimation produces tungsten electrodes using a reverse-polarity process and machines and ring-laps them to as small as 10μm in diameter with 0.000020" roundness. Applying a 10μm-dia. electrode produces a hole about 10.5μm to 11μm in diameter, and blind-holes are possible with th e company’s EDM. The workpiece thickness for the smallest holes is up to 0.002", and the thickness can be up to 0.04" for 50μm holes.After working with lasers and then with a former EDM builder to find a better way to produce precise microholes, Jorgense n decided the best approach was DIY. “We literally started with a clean sheet of paper and did all the electronics, all the software and the whole machine from scratch,” he said. Including the software, the machine costs in the neighborhood of $180,000 to $200,000.Much of the company’s contract work, which is provided at a shop rate of $100 per hour, involves microEDMing exotic metals, such as gold and platinum for X-ray apertures, stainless steel for optical applications and tantalum and tungsten for the electron-beam industry. Jorgensen said the process is also appropriate for EDMing partially electrically conductive materials, such as PCD.“The customer normally doesn’t care too much about the cost,” he said. “We’ve done parts where there’s $20,000 [in time and material] involved, and you can put the whole job underneath a fingernail. We do everything under a microscope.”Light CuttingBesides carbide and tungsten, light is an appropriate “tool material” formicro-holemaking. Although most laser drilling is performed in the infrared spectrum, the SuperPulse technology from The Ex One Co., Irwin, Pa., uses a green laser beam, said Randy Gilmore, the company’s director of laser technologies. Unlike the femtosecond variety, Super- Pulse is a nanosecond laser, and its green light operates at the 532-nanometer wavelength. The technology provides laser pulses of 4 to 5 nanoseconds in duration, and those pulses are sent in pairs with a delay of 50 to 100 nanoseconds between individual pulses. The benefits of this approach are twofold. “It greatly enhances material removal compared to other nanosecond lasers,” Gilmore said, “and greatly reduces the amount of thermal damage done to the workpiece material” because of the pulses’ short duration.The minimum diameter produced with the SuperPulse laser is 45 microns, but one of the most common applications is for producing 90μm to 110μm holes in diesel injector nozzles made of 1mm-thick H series steel. Gilmore noted that those holes will need to be in the 50μm to 70μm ra nge as emission standards tighten because smaller holes in injector nozzles atomize diesel fuel better for more efficient burning.In addition, the technology can produce negatively tapered holes, with a smaller entrance than exit diameter, to promote better fuel flow.Another common application is drilling holes in aircraft turbine blades for cooling. Although the turbine material might only be 1.5mm to 2mm thick, Gilmore explained that the holes are drilled at a 25° entry angle so the air, as it comes out of the holes, hugs the airfoil surface and drags the heat away. That means the hole traverses up to 5mm of material. “Temperature is everything in a turbine” he said, “because in an aircraft engine, the hotter you can run the turbine, the better the fuel economy and the more thrust you get.”To further enhance the technology’s competitiveness, Ex One developed apatent-pending material that is injected into a hollow-body component to block the laser beam and prevent back-wall strikes after it creates the needed hole. After laser machining, the end user removes the material without leaving remnants.“One of the bugaboos in getting lasers accepted in the diesel injector community is that light has a nasty habit of continuing to travel until it meets anothe r object,” Gilmore said. “In a diesel injector nozzle, that damages the interior surface of the opposite wall.”Although the $650,000 to $800,000 price for a Super- Pulse laser is higher than a micro-holemaking EDM, Gilmore noted that laser drilling doesn’t require electrodes. “A laser system is using light to make holes,” he said, “so it doesn’t have a consumable.”Depending on the application, mechanical drilling and plunge milling, EDMing and laser machining all have their place in the expanding microm achining universe. “People want more packed into smaller spaces,” said Makino’s Kiszonas.中文翻译微孔的加工方法正如宏观加工一样，在微观加工中孔的加工也许也是最常用的加工之一。

English translationThe E- Behind EverythingElectricity and magnetism run nearly everything we plug in or turn on. Although it’s something we take for granted, it has taken hundreds of years of experimentation and research to reach the point where we flick a switch and the lights go on.People knew about electricity for a long time. Ancient Greeks noticed that if they rubbed a piece of amber, feathers would stick to it. You’ve experienced a similar thing if you’ve ever had your hair stick up straight after you combed it, or had your socks stick together when you removed them from the drier. This is called static electricity, but back then nobody knew how to explain it or what to do with it.Experiments using friction to generate static electricity led to machines that could produce large amounts of static electricity on demand. In 1660 German Otto von made the first electrostatic generator with a ball of sulfur and some cloth. The ball symbolized the earth, and he believed that this little replica of the e arth would shed part of its electric “soul” when rubbed. It worked, and now scientists could study electric shocks and sparks whenever they wanted.As scientists continued to study electricity, they began thinking of it as an invisible fluid and tried to capture and store it. One of the first to do this was Pieter van, Holland. In 1746 he wrapped a water-filled jar with metal foil and discovered that this simple device could store the energy produced by an electrostatic generator. This device became known as the jar. were very important in other people’s experiments, such as Benjamin Franklin’s famous kite experiment. Many people suspected that lightning and static electricity were the same thing, since both crackled and produced bright sparks. In 1752 Franklin attached a key to a kite and flew it in a storm-threatened sky. (NOTE that Franklin did not fly a kite in an actual storm. NEVER do that!) When a thundercloud moved by, the key sparked. This spark charged the jars and proved that lightning was really electricity. Like many experimenters and scientists Franklin used one discovery to make another. Franklin was not the only scientist inspired to conduct experiments with electricity. In the 1780s, the Italian scientist Luigi m ade a dead frog’s leg move by means of an electric current. called this “animal electricity.” He thought that the wet animal tissue generated electricity when it came in contact with metal probes. He even suggested that the soul was actually Italian Alessandro Volta was skeptical of con clusions. In 1799 he discovered that it wasn’t animal tissue alone producing the electric current at all. Volta believed that the current was actually caused by the interaction of water and chemicals in the animal tissue with the metal probes. Volta stacked metal disks separated by layers of cardboard soaked in salt water. This so-called voltaic pile produced an electric current without needing to be charged like a jar. This invention is still around today, but we call it the battery.Volta’s pile was a lot different from the batteries you put in your Discman. It was big, ugly, and messy, but it worked, making Volta the first person to generate electricity with a chemical reaction. His work was so important that the term volt—the unit of electrical tension or pr—is named in his honor. As for Galvani, although he was proven wrong, his work stimulated research on electricity and the body. That research eventually proved that nerves do carry electrical impulses, an important medical discovery. Like electricity, magnetism was baffling to the earliest researchers. Today manufactured magnets are common, but in earlier timesthe only available magnets were rare and mysterious rocks with an unexplainable attraction for bits of iron. Explanations of the way they work sound strange today. For example, in the 1600, English doctor William Gilbert published a book on magnetism. He thought that these strange substances, called “lodestones,” had a soul that accounted for the attraction of a lodestone to iron and steel. The only real use for lodestones was to make compasses, and many thought the compass needle’s movement was in response to its attraction to the earth’s “soul.” By 1800, after many years of study, scientists began wondering if these two mysterious forces—electricity and magnetism—were related. In 1820 Danish physicist Hans Oersted showed that whenever an electric current flows through a wire, it produces a magnetic field around the wire. French mathematician André-Marie used algebra to come up with a mathematical formula to describe this relationship between electricity and magnetism. He was one of the first to develop measuring techniques for electricity. The unit for current, the ampere, abbreviated as amp or as A, is named in his honor. Groundbreaking experiments in electromagnetism were conducted by British scientist Michael Faraday. He showed that when you move a loop of a wire in a magnetic field, a little bit of current flows through the loop for just a moment. This is called induction. Faraday constructed a different version of it called the induction ring. In later years, engineers would use the principle of the induction ring to build electrical transformers, which are used today in thousands of electrical and electronic devices. Faraday also invented a machine that kept a loop of wire rotating near a magnet continuously. By touching two wires to the rotating loop, he could detect the small flow electric current. This machine used induction to produce a flow of current as long as it was in motion, and so it was an electromagnetic generator. However, the amount of electricity it produced was very tiny. There was still another use for induction. Faraday also created a tiny electric motor—too small to do the work of a steam engine but still quite promising. For thousands of years electricity and magnetism were subjects of interest only to experimenters and scientists. Nobody thought of a practical way of using electricity before the 1800s and it was of little interest to most people. But by Faraday’s time invento rs and engineers were gearing up to transform scientific concepts into practical machines.Telegraphs and TelephonesOne of the most important ways that electricity and magnetism have been put to use is making communication faster and easier. In this day o f instant messaging, cell phones, and pagers, it’s hard to imagine a time when messages had to be written and might spend weeks or even months reaching their destination. They had to be carried great distances by ships, wagon, or even by horseback—you coul dn’t just call somebody up to say hello. That all changed when inventors began using electricity and magnetism to find better ways for people to talk to each other. The telegraph was first conceived of in the 1700s, but few people pursued it. By the 1830s, however, advancements in the field of electromagnetism, such as those made by Alessandro Volta and Joseph Henry, created new interest in electromagnetic communication. In 1837, English scientist Charles Wheatstone opened the first com telegraph line between London and Camden Town, a distance of 1.5 miles. Building on, Samuel Morse, an American artist and inventor, designed a line to connect Washington, DC and Baltimore, Maryland in 1844. Morse’s telegraph was a simple device that used a battery, a switch, and a small electromagnet, but it allowed people miles apart to communicate instantly. Although Morse is often credited with inventing the telegraph, his greatest contribution was actually Morse, a special language designed for the telegraph. Morse'scommercialization of the telegraph spread the technology quickly. In 1861 California was connected to the rest of the United States with the first transcontinental telegraph line. Five years later, engineers found a way of spanning the Atlantic Ocean with telegraph lines, thus connecting the United States and Europe. This was an enormous and challenging job. To do it engineers had to use a huge ship called The Great Eastern to lay the cable across the ocean. It was the only ship with enough room to store all that cable. The world was connected by wire before the nation was connected by rail—the transcontinental railroad wasn’t completed until 1869! The telegraph was the key to fast, efficient railroad service. The railroads and the telegraph expanded side-by-side, crisscrossing every continent, except Anta, in the late 1800s. In the late 19th and early 20th centuries, telegraphy became a very lucrative business for companies such as Western Union. It also provided women with new career options. As convenient as the telegraph was, people dreamt of hearing the voices of loved ones who lived far away. Pretty soon, another instrument to communicate across distances was invented. Alexander Graham Bell, a teacher and inventor, worked with the deaf and became fascinated with studying sound. In 1875, Bell discovered a way to convert sound waves to an undulating current that could be carried along wires. This helped him invent the telephone. The first phone conversation was an inadvertent one between Bell and Watson, his ass istant in the next room. After spilling some acid, Bell said “Mr. Watson, come here.I want you.” He patented his device the same year. Early phone service wasn’t as portable and convenient as today’s. At first, telephones we connected in pairs. You could call only one person, and they could only call you. The telephone exchange changed all that. The first exchange was in New Haven, Connecticut in 1878. It allowed people who subscribed to it to call one another. Operators had to connect the calls, but in 1891 an automatic exchange was invented. Some problems had to be solved, though, before long-distance telephoning could work. The main one was that the signal weakened with distance, disappearing if the telephone lines were too long. A solution was found in 1912 with a way to amplify electrical signals, and transcontinental phone calls were possible. A test took place in 1914, and the next year, Bell, who was in New York, called Watson, who was in San Francisco. He said the same thing he had said during the first phone conversation. Watson’s answer? “It will take me five days to get there now!”Plc development1.1 MotivationProgrammable Logic Controllers (PLC), a computing device invented by Richard E. Morley in 1968, have been widely used in industry including manufacturing systems, transportation systems, chemical process facilities, and many others. At that time, the PLC replaced the hardwired logic with soft-wired logic or so-called relay ladder logic (RLL), a programming language visually resembling the hardwired logic, and reduced thereby the configuration time from 6 months down to 6 days [Moody and Morley, 1999].Although PC based control has started to come into place, PLC based control will remain the technique to which the majority of industrial applications will adhere due to its higher performance, lower price, and superior reliability in harsh environments. Moreover, according to a study on the PLC market of Frost and Sullivan [1995], an increase of the annual sales volume to 15 million PLCs per year with the hardware value of more than 8 billion US dollars has been predicted, though the prices of computing hardware is steadily dropping. The inventor of the PLC, Richard E Morley, fairly considers the PLC market as a 5-billion industry at the present time.Though PLCs are widely used in industrial practice, the programming of PLC based control systems is still very much relying on trial-and-error. Alike software engineering, PLC software design is facing the software dilemma or crisis in a similar way. Morley himself emphasized this aspect most forcefully by indicating [Moody and Morley, 1999, p. 110]:`If houses were built like software projects, a single woodpecker could destroy civilization.” Particularly, practical problems in PLC programming are to eliminate software bugs and to reduce the maintenance costs of old ladder logic programs. Though the hardware costs of PLCs are dropping continuously, reducing the scan time of the ladder logic is still an issue in industry so that low-cost PLCs can be used.In general, the productivity in generating PLC is far behind compared to other domains, for instance, VLSI design, where efficient computer aided design tools are in practice. Existent software engineering methodologies are not necessarily applicable to the PLC based software design because PLC-programming requires a simultaneous consideration of hardware and software. The software design becomes, thereby, more and more the major cost driver. In many industrial design projects, more than SO0/a of the manpower allocated for the control system design and installation is scheduled for testing and debugging PLC programs [Rockwell, 1999].In addition, current PLC based control systems are not properly designed to support the growing demand for flexibility and reconfigurability of manufacturing systems. A further problem, impelling the need for a systematic design methodology, is the increasing software complexity in large-scale projects.1.2 Objective and Significance of the ThesisThe objective of this thesis is to develop a systematic software design methodology for PLC operated automation systems. The design methodology involves high-level description based on state transition models that treat automation control systems as discrete event systems, a stepwise design process, and set of design rules providing guidance and measurements to achieve a successful design. The tangible outcome of this research is to find a way to reduce the uncertainty in managing the control software development process, that is, reducing programming and debugging time and their variation, increasing flexibility of the automation systems, and enabling software reusability through modularity. The goal is to overcome shortcomings of current programming strategies that are based on the experience of the individual software developer.A systematic approach to designing PLC software can overcome deficiencies in the traditional way of programming manufacturing control systems, and can have wide ramifications in several industrial applications. Automation control systems are modeled by formal languages or, equivalently, by state machines. Formal representations provide a high-level description of the behavior of the system to be controlled. State machines can be analytically evaluated as to whether or not they meet the desired goals. Secondly, a state machine description provides a structured representation to convey the logical requirements and constraints such as detailed safety rules. Thirdly, well-defined control systems design outcomes are conducive to automatic code generation- An ability to produce control software executable on commercial distinct logic controllers can reduce programming lead-time and labor cost. In particular, the thesis is relevant with respect to the following aspects.Customer-Driven ManufacturingIn modern manufacturing, systems are characterized by product and process innovation, become customer-driven and thus have to respond quickly to changing system requirements. A majorchallenge is therefore to provide enabling technologies that can economically reconfigure automation control systems in response to changing needs and new opportunities. Design and operational knowledge can be reused in real-time, therefore, giving a significant competitive edge in industrial practice.Higher Degree of Design Automation and Software QualityStudies have shown that programming methodologies in automation systems have not been able to match rapid increase in use of computing resources. For instance, the programming of PLCs still relies on a conventional programming style with ladder logic diagrams. As a result, the delays and resources in programming are a major stumbling stone for the progress of manufacturing industry. Testing and debugging may consume over 50% of the manpower allocated for the PLC program design. Standards [IEC 60848, 1999; IEC-61131-3, 1993; IEC 61499, 1998; ISO 15745-1, 1999] have been formed to fix and disseminate state-of-the-art design methods, but they normally cannot participate in advancing the knowledge of efficient program and system design.A systematic approach will increase the level of design automation through reusing existing software components, and will provide methods to make large-scale system design manageable. Likewise, it will improve software quality and reliability and will be relevant to systems high security standards, especially those having hazardous impact on the environment such as airport control, and public railroads.System ComplexityThe software industry is regarded as a performance destructor and complexity generator. Steadily shrinking hardware prices spoils the need for software performance in terms of code optimization and efficiency. The result is that massive and less efficient software code on one hand outpaces the gains in hardware performance on the other hand. Secondly, software proliferates into complexity of unmanageable dimensions; software redesign and maintenance-essential in modern automation systems-becomes nearly impossible. Particularly, PLC programs have evolved from a couple lines of code 25 years ago to thousands of lines of code with a similar number of 1/O points. Increased safety, for instance new policies on fire protection, and the flexibility of modern automation systems add complexity to the program design process. Consequently, the life-cycle cost of software is a permanently growing fraction of the total cost. 80-90% of these costs are going into software maintenance, debugging, adaptation and expansion to meet changing needs [Simmons et al., 1998].Design Theory DevelopmentToday, the primary focus of most design research is based on mechanical or electrical products. One of the by-products of this proposed research is to enhance our fundamental understanding of design theory and methodology by extending it to the field of engineering systems design. A system design theory for large-scale and complex system is not yet fully developed. Particularly, the question of how to simplify a complicated or complex design task has not been tackled in a scientific way. Furthermore, building a bridge between design theory and the latest epistemological outcomes of formal representations in computer sciences and operations research, such as discrete event system modeling, can advance future development in engineering design. Application in Logical Hardware DesignFrom a logical perspective, PLC software design is similar to the hardware design of integrated circuits. Modern VLSI designs are extremely complex with several million parts and a product development time of 3 years [Whitney, 1996]. The design process is normally separated into acomponent design and a system design stage. At component design stage, single functions are designed and verified. At system design stage, components are aggregated and the whole system behavior and functionality is tested through simulation. In general, a complete verification is impossible. Hence, a systematic approach as exemplified for the PLC program design may impact the logical hardware design.1.3 Structure of the ThesisFigure 1.1 illustrates the outline of the following thesis. Chapter 2 clarifies the major challenges and research issues, and discourses the relevant background and terminology. It will be argued that a systematic design of PLC software can contribute to higher flexibility and reconfigurability of manufacturing systems. The important issue of how to deal with complexity in engineering design with respect to designing and operating a system will be debated. The research approach applied in this thesis is introduced starting from a discussion of design theory and methodology and what can be learnt from that field.Chapter 3 covers the state-of-the-art of control technology and the current practice in designing and programming PLC software. The influences of electrical and software engineering are revealed as well as the potentially applicable methods from computer science are discussed. Pros and cons are evaluated and will lead to the conclusion that a new methodology is required that suffices the increasing complexity of PLC software design.Chapter 4 represents the main body of the thesis and captures the essential features of the design methodology. Though design theory is regarded as being in a pre- scientific stage it has advanced in mechanical, software and system engineering with respect to a number of proposed design models and their evaluation throughout real-world examples. Based on a literature review in Chapter 2 and 3 potential applicable design concepts and approaches are selected and applied to context of PLC software design. Axiomatic design is chosen as underlying design concept since it provides guidance for the designer without restriction to a particular design context. To advance the design concept to PLC software design, a formal notation based on statechart formalism is introduced. Furthermore, a design process is developed that arranges the activities needed in a sequential order and shows the related design outcomes.In Chapter 5, a number of case studies are given to demonstrate the applicability of the developed design methodology. The examples are derived from a complex reference system, a flexible assembly system. The achieved insights are evaluated in a concluding paragraph.Chapter 6 presents the developed computerized design tool for PLC software design on a conceptual level. The software is written in Visual Basic by using ActiveX controls to provide modularity and reuse in a web-based collaborative programming environment. Main components of the PLC software are modeling editors for the structural (modular) and the behavioral design, a layout specification interface and a simulation engine that can validate the developed model. Chapter 7 is concluding this thesis. It addresses the achievements with respect to the research objectives and questions. A critical evaluation is given alongside with an outlook for future research issues.电力的故事当我们插上电源,打开旋钮,电和磁差不多在每样东西上都运行着,今天我们知道这是什么,这一些花了人们上百年时间的实验和研究来达到这一点—当我们按下按钮时,光亮已经开始，人们对电的了解已经有很长一段时间了.古希腊人注意到,摩擦一块琥珀,羽毛将能被吸住.你已经经历过相类似的事情,当你梳头时,头发将垂直竖起,当你从干燥机中拿袜子时,袜子也会粘在一起.这被称作静电.但是在以前人们不知道如何解释此类现象或如何应用这种现象，使用摩擦产生的静电来带动机器的实验可以产生大量所需要的静电.在1660年,德国人Otto von Guericke用一个硫磺球和一些布制造了第一台静电发电机.硫磺球象征大地,他深信这种小型地球复制品被摩擦时将流出电的灵魂,他成功了,现在的科学家可以在任何想要的时候来研究电击和电火花.随着科学家们持续对电的研究,他们开始认为它以一种看不见的方式流动,并试图去捕获并储存.第一次去做这项研究的是荷兰Leyden的Pieter van Musschenbroek.1746,他用一个金属箔片包一个装满水的罐子,发现这种简单的设备能储存由静电发电机产生的能量.这个设备后来著名的莱顿瓶.莱顿瓶在其他人的实验中有非常重要的作用.如Benjamin Franklin著名的风筝实验.许多人认为闪电和静电是同一种东西,由于双方碰撞产生明亮的电火花.1752年, Franklin将一把钥匙绑在风筝上,在一个暴风即将来临的天气里放飞(请记住Franklin不是在一个真正的暴风寸中放飞的,永远不要这样做),当一块雷雨云经过时,钥匙被闪电击中,闪电充满莱顿瓶,由此证明闪电实际也是一种电力.同其他实验人和科学家一样, Franklin用一个发现来做另外一个. Franklin并不是唯一的在电力实验方面灵光突现的科学家.18世纪80年代,意大利的科学家Luigi Galvani用电流让一只切断的青蛙的腿移动. Galvani称之为生物电.他认为当潮湿的动物组织同金属探测针接触时产生电能.他甚至大胆预测精神也是一种电能。

Design, Invention, CreativityThese are all familiar terms but may mean different things to different people. These terms can encompass a wide range of activities from styling the newest look in clothing, to creating impressive architecture, to engineering a machine for the manufacture of facial tissues. Engineering design, which we are concerned with here, embodies all three of these activities as well as many others. The word design is derived from the Latin designate, which means “to designate, or mark out.” Webster's gives several definitions, the most applicable being “to outline, plot, or plan, as action or work..., to conceive, invent - contrive.” Engineering design has been defined as “... the process of applying the various techniques and scientific principles for the purpose of defining a device, a process or a system in sufficient detail to permit its realization... Design may be simple or enormously complex, easy or difficult, mathematical or nonmathematical; it may involve a trivial problem or on e of great importance.” Design is a universal constituent of engineering practice. But the complexity of engineering subjects usually requires that the student be served with a collection of structured, set-piece problems designed to elucidate a particular concept or concepts related to the particular topic. These textbook problems typically take the form of “given A, B, C, and D find E.” Unfortunately, real-life engineering problems are almost never so structured. Real design problems more often take the form of "What we need is a frame to stuff this widget into that hole within the time allocated to the transfer of this other gizmo.” The new engineering graduate will search in vain among his or her textbooks for much guidance to solve such a problem. This unstructured problem statement usually leads to what is commonly called “blank paper syndrome.” Engineers often find themselves staring at a blank sheet of paper pondering how to begin solving such an ill-defined problem.Much of engineering education deals with topics of analysis, which means to decompose, to take apart, to resolve into its constituent parts. This is quite necessary. The engineer must know how to analyze systems of various types, mechanical, electrical, thermal, or fluid. Analysis requires a thorough understanding of both theappropriate mathematical techniques and the fundamental physics of the system's function. But, before any system can be analyzed, it must exist, and a blank sheet of paper provides little substance for analysis. Thus the first step in any engineering design exercise is that of synthesis, which mean~ putting together.The design engineer, in practice, regardless of discipline, continuously faces the challenge of structuring the unstructured problem. Inevitably, the problem as posed to the engineer is ill-defined and incomplete. Before any attempt can be made to analyze the situation he or she must first carefully define the problem, using an engineering approach, to ensure that any proposed solution will solve the right problem. Many examples exist of excellent engineering solutions which were ultimately rejected because they solved the wrong problem, i.e., a different one than the client really had.Much research has been devoted to the definition of various “design processes” in tended to provide means to structure the unstructured problem and lead to a viable solution. Some of these processes present dozens of steps, others only a few. The one presented in Table 1-1 contains 10 steps and has, in the author's experience, proven successful in over 30 years of practice in engineering design.Table 1-1 A design processITERATION Before discussing each of these steps in detail it is necessary topoint out that this is not a process in which one proceeds from step one through ten in a linear fashion. Rather it is, by its nature, an iterative process in which progress is made haltingly, two steps forward and one step back. It is inherently circular. To iterate means to repeat, to return to a previous state. If, for example, your apparently great idea, upon analysis, turns out to violate the second law of thermodynamics, you can return to the ideation step and get a better idea! Or, if necessary, you can return to an earlier step in the process, perhaps the background research, and learn more about the problem.Mechanical System1) AxleThe structure appearance of the axle depends on the axle erection site and form on the case body mainly, axle part decorate and fix way , receive strength situation and processing technology ,etc..Structure designing requirement of the axle : ①The part should have accurate , firm job positions on the axle and axle; ②The part is installed and dismantled, adjusted conveniently on the axle; ③The axle should have good manufacturing engineering ,etc. . ④Try one's best to prevent the stress from being centralized2) Worm transmissionThe sport transmission interlocking among the axles for the implementation space, generally interlock in the angle. Characteristic its structure compactness, than heavy, transmission steady, apt lock since transmission. The shortcoming rubs and is worn and torn largely, the caloric value is big, ηis low, ∴suitable for the transmission of the power of centre.3) Rolling bearingBecause rolling bearing is the rolling friction, ∴it is small to rub obstruction, the caloric value is small , with high efficiency, start sensitively, safeguard it conveniently, and already standardization, easy to select for use and change, it is very extensive so use.The invalid form of the rolling bearing and calculation criterion:Main invalid form:(1) Lose a bit more tiredly --Installation lubricates and safeguards the normal invalid form under the good situation--Basis of calculating in main invalid form and life-span of bearing(2)Plasticity is out of shape --The rotational speed is very low and doing the main invalid form when the intermittence is swung--Cause the vibration , noise , rub the moment to increase, operate the precision to reduce(3) Wearing and tearing --Under lubricating badly and sealing the situation not tight, or the main invalid form of bearing working under many dust condition.Wear and tear the consequence: The bearing swims in the crack and strengthens, the precision of movement is reduced, vibration and noise increase.Calculate criterion : The general bearing ①carry on fatigue life and calculate (to clicking losing ); ②The quiet intensity is checked.Low-speed bearing: Only go on ②(quiet intensity is checked) .High-speed bearing: ①Calculate fatigue life ; ②Rotational speed of check-up limit.。

MS Access MRP Manufacturing Resource PlanningSmall Business MRP - Small Business ERPMicrosoft Access Database ERP MRP ProgramERP / MRP Manufacturing Software ProgramPEDYN specializes in Small Business Manufacturing Operations, Engineering Management, and Document Control Software. See the all in one P2000 Enterprise Resource Planning (ERP / MRP) program that uses Microsoft Access as the program platform. The P2000 is a powerful Low Cost solution for your complete business operations, from design concept, project management and documentations control to purchasing, material control, manufacturing, and order entry. It's graphical design and drill down navigation make the P2000 very easy to learn and use. Since the program is completely written using Microsoft Access, it interfaces well with other products, and can be easily customized to fit your ever changing business requirements. The program can be used along with other ERP / MRP programs that your company may be using by activating only the modules that you require. The P2000 is expandable, flexible and provides the perfect low cost solutions for small to mid size engineering and manufacturing companies. Why spend a fortune on expensive complicated system programs that are not easily adaptable to your specific needs. Using Microsoft Access as a front-end operating system means that you havefull control and flexibility. Create new forms and reports as you need them. Expand your operating system anyway you choose.ERP software Categories and Features1.Manufacturing and Operations Modules:Manufacturing Software, Manufacturing Program, Operations Software, Operations Program, Manufacturing Solutions, Production Management Program, Production Control Management, Discrete Manufacturing, Production Planning, Material Requirement Planning （MRP）， Manufacturing Resource Planning （MRP II）, Enterprise Resource Planning, ERP Software, MIS, Stock Replenishment Systems, Production Workflow Management, Product Management, Supply Chain Management, SCM, Supply Management, Materials Management, Business Management, Planning and Scheduling Enterprise, Multi-User Manufacturing Control Software, Inventory Management, Inventory Control, Product Management, Stock Control software, Small Business Soluitions, Small Business MRP, Small Business ERP2.Engineering Modules:Engineering Management Software, Engineering Software, Engineering Program, Engineering Project Management Software Programs, Design Management Software Engineer Task Management, Engineering Task Management, Daily Task Management, Tasking,Engineering Change Notice, Engineering Change Request, Engineering Change Order, Engineering Change Orders, ECN, ECO, DCO, DCN, ECR, DCR, Engineering Operations, Engineering Project Planning and Scheduling, Online Task Management3.Documentation Modules:Documentation Control software, Document Control Management, Drawing Control, Configuration Control Management, Configuration Management Software, Configuration Control Software, Drafting Management, Document Change Order, Change Orders, BOM software, Bill Of Materials, Indented Multi Level, Reference Designators, Drafting Task Management,Draftsman,CAD, AUTOCAD, Configuration Management, Electronic Document Management, Enterprise Document Management Systems, Specification Management, Release Control, Revision Control, Workflow Systems, Specification Control Drawings, Source Control Drawings, SCD, Fabrication Drawing, Assembly Drawings, Online Sign-off and Approval Forms, Engineering Change Orders, ECN, ECO, DCO, DCN, ECR, DCR, BOM, bom, PDM Product Data Management, PDM Software, PDM Access Database4.Processes:Make To Order, Assemble To Order, Build To Order, Configure To Order, Cellular Manufacturing, , Forecasting, Standard Costing,Material Receiving, Shipping, Resources, Master Scheduling, Production Capacity, Shop Loading and Capacity Planning, Business Processes, Job Shop, Routing, Electronic Order Processing, Demand, Scheduling, Scrap, Product Cost, Labor, WIP, Finished Goods, Stock Control, Inventory Control, Standard Cost, Standard Costing, Average Costing, Average cost, Forecasting, Delivery, Pick List, Vendor List, Components, Sub Assemblies, Material Planning, Demand Planning, Forecasting, Sales Planning, Distribution Planning, Production Planning, Work Order Management, Customer Order Management, Order Entry, Pricing, Shipping, Load Building, Routing, Item Master, Parts List, Parts Book, Purchase Order, Purchase Orders, PO, Purchasing, Work Order, Sales Order, Order Entry, Customer Order Processing, Shop Order, Back Order, Shipping Order, Parts Allocation, Allocations, Product Costing, Master ProductionScheduling, Dock-to-Stock, Inspection, Testing, ISO 9000 Compliant, ISO 9001 Compliance, Finance and Accounting Interface, Accounts Payable, Accounts Receivable, General Ledger, Invoicing, Cost Management, Financial Control, Cash Flow Forecasting, Financial Forecasting, Planning System, Invoice, Tracking, Time, Analysis, Human Resources, Payroll, Time, Personnel5.Platform:MS Access Database Platform, Microsoft Access Database, MS Access97, MS Access2000, MS Access 97, MS Access 2000, Access XP 2002 2003, MSAccess Forms, MSAccess Reports, Microsoft Windows 98, Microsoft Windows 2000, Microsoft NT, Microsoft XP, Excel, SQL, MySQL, ACCESS PEDYNE, PEDYNAMICS, P2000, Software, Program, Custom, Customized, Access Programming, Custom Database, Low Cost, LOW COST, Free Demo, Free Trial6.Other:PDM Product Data Management, Repetitive Production Management, Business Planning, Sales and Operations Planning, Distribution Requirements Planning, Capacity Requirements Planning, CRP, Process Management, Product Data Management, Information Management Systems, Warehousing, Distribution Center Operations, Warehouse Management Systems, WMS, Electronic Data Interchange, EDI, Customer Relationship Management, CRM, Company Solutions, QRM, Quick Response Manufacturing, Supply Chain Planning, Vendor Managed Inventory, VMI, Site Location Planning, Distribution Resource Planning, DRP, Resource Monitoring, Administrative Management, JIT, Demand Planning, Demand Chain, Business Intelligence, Intelligent Enterprise, Flow Techniques, Business Solutions, Agile E-Business, QuickBooks, PeachTree, Quality ManagementMaterial Requirements Planning OverviewMaterial Requirements Planning (MRP) is designed to assist manufacturers in inventory and production management. Using MRP helps ensure that materials will be available in sufficient quantity and at the proper time for production to occur, without incurring excess costs by having the materials on hand too early. MRP assists in generating and (as needed) revising production plans to meet expected demands and replenishment plans to assure the timely availability of raw materials and all levels of product components.MRP begins by compiling a Bill of Materials (BOM) for each end product or component of interest. This is a listing of the components and quantities that are needed to manufacture the end product or component. Theoretically, the compilation of BOMs continues recursively, enumerating the subcomponents that are needed to manufacture each component, until only raw materials appear in the generated BOMs. In practice, a manufacturer may prefer to extend the BOM enumeration for only a specified number of levels and to assume that components and/or raw materials beneath that level are available on demand.Next, MRP requires information on the lead times associated with each manufacturing or assembly procedure that is required to produce the components and end products. Lead time is the time required toassemble or manufacture the needed components into the end product (or higher-level component), and thus is the time elapsed between the point at which all needed components are present and the end of assembly or manufacturing. These lead times may be compiled per unit of each component/product or may be based on predetermined batch sizes.MRP combines the BOMs, the lead times, and estimates of demand for end products to generate the Master Production Schedule, which details a schedule of assembly and production that enables the manufacturer to meet the estimated demand. This schedule addresses only the final level of assembly or production (resulting in end products), and includes both the timing and quantities of production. The Master Production Schedule serves as the basis for all further output information from MRP.Using the Master Production Schedule as a starting point, it is a conceptually simple (but computationally demanding) task to combine it with the data on lead times and BOMs to derive a schedule of component (and possibly raw materials) requirements, through as many levels of assembly and production as the manufacturer chooses. This schedule can account for such factors as work-in-progress, current inventory of and pending orders for materials and components, and direct demand for components as service items. Using this schedule ofrequirements, the manufacturer must determine a material replenishment strategy that satisfies these requirements. A wide variety of ordering rules and heuristics can be incorporated intocomputer-based MRP models.In addition to the material requirements, other useful data can be generated from the Master Production Schedule. These include the projected inventory levels for any end product, the projected schedule for any assembly or production process, and the projected utilization of capacity for a particular production operation. Any of this information should aid in evaluating current or potential materials replenishment strategies.Computers are instrumental in any real-world implementation of MRP, due to the large amount of data processing required to generate initial material requirements. Additionally, it's probable that the entire analysis will have to be repeated several times in response to changing conditions (for example, changes in demand, manufacturing processes, or material supply). This makes the need for computers even clearer. This example illustrates the use of SAS/OR software (specifically, PROC CPM and PROC GANTT) in a SAS/AF application that performs Material Requirements Planning for a hypothetical clothing manufacturer. A small number of data steps and relatively simple procedure calls from SAS/OR, Base SAS, and SAS/GRAPHaccomplish all the computational work needed to support this application. The few simplifying assumptions made to limit the scope of this sample application could in practice be relaxed to make the application useful in a more complex and more realistic MRP setting. This application could also serve as an MRP module in a broader production and inventory control system.MS Access MRP(制造资源计划)小企业的MRP——小企业的ERP基于微软的Access数据库ERP/MRPERP /MRP 制造软件项目PEDYN是一家专门针对开发小企业的生产操作系统、工程管理和文件控制软件的公司。