外文翻译材料制备机械设计理论中的新趋势和新问题
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步行机器人中英文对照外文翻译文献(文档含英文原文和中文翻译)图1 远程脑系统的硬件配置图2 两组机器人的身体结构图3 传感器的两个水银定位开关图4 层次分类图5 步行步态该输入处理器是作为参考程序块和一个图像搜索窗口形象该大小的搜索窗口取决于参考块的大小通常高达16 * 16且匹配。
该处理器计算价值块在搜索窗口,还找到最佳匹配块,这就是其中的最低当目标平移时块匹配是非常有力的。
然而,普通的块匹配方法当它旋转时无法跟踪目标。
为了克服这一困难,我们开发了一种新方法,跟随真正旋转目标的图6 双足步行图6 双足步行图7 双足步行实验图8 一系列滚动和站立运动通过集成传感器网络转型的综合为了使上述描述的基本动作成为一体,我们通过一种方法来描述一种被认为是根据传感器状况的网络转型。
图9显示了综合了基本动作机器人的状态转移图:两足行走,滚动,坐着和站立。
这种一体化提供了机器人保持行走甚至跌倒时的problems and advance the study of vision-based behaviors, we have adopted a new approach through building remote-brained robots. The body and the brain are connected by wireless links by using wireless cameras and remote-controlled actuators.As a robot body does not need computers on-board,it becomes easier to build a lightweight body with many DOFS in actuation.In this research, we developed a two-armed bipedal robot using the remote-brained robot environment and made it to perform balancing based on vision and getting up through cooperating arms and legs. The system and experimental results are described below.2 The Remote-Brained SystemThe remote-brained robot does not bring its own brain within the body. It leaves the brain in the mother environment and communicates with it by radio links. This allows us to build a robot with a free body and a heavy brain. The connection link between the body and the brain defines the interface between software and hardware. Bodies are designed to suit each research project and task. This enables us advance in performing research with a variety of real robot systems[10].A major advantage of remote-brained robots is that the robot can have a large and heavy brain based on super parallel computers. Although hardware technology for vision has advanced and produced powerful compact vision systems, the size of the hardware is still large. Wireless connection between the camera and the vision processor has been a research tool. The remote-brained approach allows us to progress in the study of a variety of experimental issues in vision-based robotics.Another advantage of remote-brained approach is that the robot bodies can be lightweight. This opens up the possibility of working with legged mobile robots. AsFigure 4 shows some of the classes in the programming environent for remote-brained robot written in Euslisp. The hierachy in the classes provides us with rich facilities for extending development of various robots.4 Vision-Based BalancingThe robot can stand up on two legs. As it can change the gravity center of its body by controling the ankle angles, it can perform static bipedal walks. During static walking the robot has to control its body balance if the ground is not flat and stable.In order to perform vision-based balancing it is re-quired to have high speed vision system to keep ob-serving moving schene. We have developed a tracking vision board using a correlation chip[l3]. The vision board consists of a transputer augmented with a special LSI chip(MEP[14] : Motion Estimation Processor) which performs local image block matching.The inputs to the processor MEP are an image as a reference block and an image for a search window.The size of the reference blsearch window depends on the size of the reference block is usually up to 32 by 32 pixels so that it can include 16 * 16 possible matches. The processor calculates 256 values of SAD (sum of absolute difference) between the reference block and 256 blocks in the search window and also finds the best matching block, that is, the one which has the minimum SAD value.Clock is up to 16 by 16 pixels.The size of the search window depends on the size of the reference block is usually up to 32 by 32 pixels so that it can include 16 * 16 possible matches. The processor calculates 256 values of SAD (sum of absolute difference) between the reference block and 256 blocks in the search window and also finds the best matching block, that is, the one which has the minimum SAD value.Block matching is very powerful when the target moves only in translation. However, the ordinary block matching method cannot track the target when it rotates. In order to overcome this difficulty, we developed a new method which follows up the candidate templates to real rotation of the target. The rotated template method first generates all the rotated target images in advance, and several adequate candidates of the reference template are selected and matched is tracking the scene in the front view. It remembers the vertical orientation of an object as the reference for visual tracking and generates several rotated images of the reference image. If the vision tracks the reference object using the rotated images, it can measures the body rotation. In order to keep the body balance, the robot feedback controls its body rotation to control the center of the body gravity. The rotational visual tracker[l5] can track the image at video rate.5 Biped WalkingIf a bipedal robot can control the center of gravity freely, it can perform biped walk. As the robot shown in Figure 2 has the degrees to left and right directions at the ankle position, it can perform bipedal walking in static way.The motion sequence of one cycle in biped walking consists of eight phases as shown in Figure 6. One step consists of four phases; move-gravity-center-on-foot,lift-leg, move-forward-leg, place-leg. As the body is described in solid model, the robot can generate a body configuration for move-gravity-center-on-foot according to the parameter of the hight of the gravity center. After this movement, the robot can lift the other leg and move it forward. In lifting leg, the robot has to control the configuration in order to keep the center of gravity above the supporting foot. As the stability in balance depends on the hight of the gravity center, the robot selects suitable angles of the knees.Figure 7 shows a sequence of experiments of the robot in biped walking6 Rolling Over and Standing UpFigure 8 shows the sequence of rolling over, sitting and standing up. This motion requires coordination between arms and legs.As the robot foot consists of a battery, the robot can make use of the weight of the battery for the roll-over motion. When the robot throws up the left leg and moves the left arm back and the right arm forward, it can get rotary moment around the body. If the body starts turning, the right leg moves back and the left foot returns its position to lie on the face. This rollover motion changes the body orientation from face up to face down. It canbe verified by the orientation sensor.After getting face down orientation, the robot moves the arms down to sit on two feet. This motion causes slip movement between hands and the ground. If the length of the arm is not enough to carry the center of gravity of the body onto feet, this sitting motion requires dynamic pushing motion by arms. The standing motion is controlled in order to keep the balance.7 Integration through Building Sensor-Based Transition NetIn order to integrate the basic actions described above, we adopted a method to describe a sensor-based transition network in which transition is considered according to sensor status. Figure 9 shows a state transition diagram of the robot which integrates basic actions: biped walking, rolling over, sitting, and standing up. This integration provides the robot with capability of keeping walking even when it falls down.The ordinary biped walk is composed by taking two states, Left-leg Fore and Right-leg Fore, successively.The poses in ‘Lie on the Back’ and ‘Lie on the Face’are as same as one in ‘Stand’. That is, the shape ofthe robot body is same but the orientation is different.The robot can detect whether the robot lies on the back or the face using the orientation sensor. When the robot detects falls down, it changes the state to ‘Lie on the Back’ or ‘Lie on the Front’ by moving to the neutral pose. If the robot gets up from ‘Lie on the Back’, the motion sequence is planned to exe cute Roll-over, Sit and Stand-up motions. If the state is ‘Lie on the Face’, it does not execute Roll-over but moves arms up to perform the sitting motion.8 Concluding RemarksThis paper has presented a two-armed bipedal robot which can perform statically biped walk, rolling over and standing up motions. The key to build such behaviors is the remote-brained approach. As the experiments have shown, wireless technologies permit robot bodies free movement. It also seems to change the way we conceptualize robotics. In our laboratory it has enabled the development of a new research environment, better suited to robotics and real-world AI.The robot presented here is a legged robot. As legged locomotion requires dynamic visual feedback control, its vision-based behaviors can prove the effectiveness of the vision system and the remote-brained system. Our vision system is based on high speed block matching function implemented with motion estimation LSI. The vision system provides the mechanical bodies with dynamic and adaptive capabilities in interaction with human. The mechanical dog has shown adaptive behaviors based on distance。
New Tools Maximize New Machine Designs The primary tooling concerns when machining aluminum are: minimizing the tendency of aluminum to stick to the tool cutting edges; ensuring there is good chip evacuation form the cutting edge; and ensuring the core strength of the tools is sufficient to withstand the cutting forces without breaking.Technological developments such as the Makino MAG-Series machines have made tooling vendors rethink the any state-of-the-art machine technology. It is vital to apply the right tooling and programming concepts.Materials coatings and geometry are the three elements in tool design that interrelate to minimize these concerns. If these three elements do not work together, successful high-speed milling is not possible. It is imperative to understand all three of these elements in order to be successful in the high-speed machining of aluminum.Minimize Built-Up EdgeWhen machining aluminum, one of the major failure modes of cutting tools the material being machined adheres to the tool cutting edge. This condition rapidly degrades the cutting ability of the tool. The built-up edge that is generated by the adhering aluminum dulls the tool so it can no longer cut through the material. Tool material selection and tool coating selection are the two primary techniques used by tool designers to reduce occurrence of the built-up edge.The sub-micron grain carbide material requires a high cobalt concentration to achieve the fine grain structure and the material’s strength properties. Cobalt re acts with aluminum at elevated temperatures, which causes the aluminum to chemically bond to the exposed cobalt of the tool material. Once the aluminum starts to adhere to the tool, it quickly forms a built-up edge on the tool rendering it ineffective.The secret is to find the right balance of cobalt to provide adequate material strength, while minimizing the exposed cobalt in the tools for aluminum adherence during the cutting process. This balance is achieved using coarse-grained carbide that provides a tool of sufficient hardness so as to not dull quickly when machining aluminum while minimizing adherence.Tool CoatingsThe second tool design element that must be considered when trying to minimize the built-up edge is the tool coating. Tool coating choices include TiN, TiAIN, AITiN, chrome nitrides, zirconium nitrides, diamond, and diamond-like coatings(DLC). Withso many choices, aerospace milling shops need to know which one works best in an aluminum high-speed machining application.The Physical Vapor Deposition (PVD) coating application process on TiN, TiCN, TiAIN, and AITiN tools makes them unsuitable for an aluminum application. The PVD coating process creates two modes for aluminum to bond to the tools――the surface roughness and the chemical reactivity between the aluminum and the tool coating.The PVD process results in surface that is rougher that the substrate material to which it is applied. The surface”peaks and valleys” created by this process causes aluminum to rapidly collect in the valleys on the tool. In addition, the PVD coating is chemically reactive to the aluminum due to its metallic crystal and ionic crystal features. A TiAIN coating actually contains aluminum, which easily bonds with a cutting surface of the same material. The surface roughness and chemical reactivity attributes will cause the tool and work piece to stick together, thus creating the built-up edge.In testing performed by OSG Tap and Die, it was discovered that when machining aluminum at very high speeds, the performance of an uncoated coarse-grained carbide tool was superior to that of one coated with TiN, Ticn, TiAIN, or ALTiN. This testing does not mean that all tool coatings will reduce the tool performance. The diamond and DLC coatings result in a very smooth chemically inert surface. These coatings have been found to significantly improve tool life when cutting aluminum materials.The diamond coatings were found to be the best performing coatings, but there is a considerable cost related to this type of coating. The DLC coatings provide the best cost for performance value, adding about 20%-25%to the total tool cost. But, this coating extends the tool life significantly as compared to an uncoated coarse-grained carbide tool.GeometryThe rule of thumb for high-speed aluminum machining tooling designs is to maximize space for chip evacuation. This is because aluminum is a very soft material, and the federate is usually increased which creates more and bigger chips.The Makino MAG-Series aerospace milling machines, such as the MAG4, require an additional consideration for tool geometry-tool strength. The MAG-Series machines with their powerful 80-hp spindles will snap the tools if they are not designed with sufficient core strength.In general, sharp cutting edges should always be used to avoid aluminumelongation. A sharp cutting edge will create high shearing and also high surface clearance, creating a better surface finish and finish and minimizing chatter or surface vibration. The issue is that it is possible to achieve a sharper cutting edge with the fine-grained carbide material than the coarse grained material. But due to aluminum adherence to the fine-grained material, it is not possible to maintain that edge for very long.Coarse CompromiseThe coarse grained material appears to be the best compromise. It is a strong material that can have a reasonable cutting edge. Test results show it is able to achieve a very long tool life with good surface finish. The maintenance of the cutting edge is improved using an oil mist coolant through the tool. Misting gradually cools down the tools, eliminating thermal shock problems.The helix angle is an additional tool geometry consideration. Traditionally when machining aluminum a fool with a high helix angle has been used. A high helix angle lifts the chip away from the part more quickly, but increases the friction and heat generated as result of the cutting action. A high helix angle is typically used on a tool with a higher number of flutes to quickly evacuate the chip from the part.When machining aluminum at very high speeds the heat created by the increased friction may cause the chips to weld to the tool. In addition, a cutting surface with a high helix angle will chip more rapidly that a tool with a low helix angle. A tool design that utilizes only two flutes enables both a low helix angle and sufficient chip evacuation area. This is the approach that has proven to be the most successful in extensive testing performed by OSG when developing the new tooling line, the maxal.新工具使新机器设计最优当加工铝时,我们主要关心的是:铝粘住加工切削边缘的倾向;保证有好的碎片排屑形成切削边缘;和保证工具有足够的中心强度来承受切削力而不被破坏。
外文原文:Mechanical Design and Manufacturing ProcessesMechanical design is the application of science and technology to devise new or improved products for the purpose of satisfying human needs. It is a vast field of engineering technology which not only concerns itself with the original conception of the product in terms of its size, shape and construction details, but also considers the various factors involved in the manufacture, marketing and use of the product.People who perform the various functions of mechanical design are typically called designers, or design engineers. Mechanical design is basically a creative activity. However, in addition to being innovative, a design engineer must also have a solid background in the areas of mechanical drawing, kinematics,dynamics, materials engineering, strength ofmaterials and manufacturing processes.As stated previously, the purpose of mechanical design is to produce a product which will serve a need for man. Inventions, discoveries and scientific knowledge by themselves do not necessarily benefit people; only if they are incorporated into a designed product will a benefit be derived. It should berecognized,therefore, that a human need must be identified before a particular product is designed.Mechanical design should be considered to be an opportunity to use innovative talents to envision a design of a product, to analyze the system and then make sound judgments on how the product is to be manufactured. It is important to understand the fundamentals of engineering rather than memorize mere facts and equations. There are no facts or equations which alone can be used to provide all the correct decisions required to produce a good design.On the other hand, any calculations made must be done with the utmost care and precision. For example, if a decimal point is misplaced, an otherwise acceptable design may not function.Good designs require trying new ideas and being willing to take a certain amount of risk, knowing that if the new idea does not work the existing method can be reinstated. Thus a designer must have patience, since there is no assurance of success for the time and effort expended. Creating a completely new design generally requires that many old and well-established methods be thrust aside. This is not easy sincemany people cling to familiar ideas, techniques and attitudes. A design engineer should constantly search for ways to improve an existing product and must decide what old, proven concepts should be used and what new, untried ideas should be incorporated.New designs generally have "bugs" or unforeseen problems which must be worked out before the superior characteristics of the new designs can be enjoyed. Thus there is a chance for a superior product, but only at higher risk.It should be emphasized that,if a design does not warrant radical new methods, such methods should not be applied merely for the sake of change.During the beginning stages of design, creativity should be allowed to flourish without a great number of constraints.Even though many impractical ideas may arise, it is usually easy to eliminate them in the earlystages of design before firm details are required by manufac-turing. In this way, innovative ideas are not inhibited. Quite often, more than one design is developed, up to the point where they can be compared against each other.It is entirely possible that the design which is ultimately accepted will use ideas existing in one of the rejected designs that did not show as much overall promise.Psychologists frequently talk about trying to fit people to the machines they operate. It is essentially the responsibility of the design engineer to strive to fit machines to people. This is not an easy task, since there is really no average person for which certain operating dimensions and procedures are optimum.Another important point which should be recognized is that a design engineer must be able to communicate ideas to other people if they are to be incorporated. Communicating the design to others is the final, vital step in the design process. Undoubtedly many great designs, inventions, and creative works have been lost to mankind simply because the originators were unable or unwilling to explain their accomplishments to others. Presentation is a selling job. The engineer, when presenting a new solution to administrative, management, or supervisory persons, is attempting to sell or to prove to them that this solution is a better one. Unless this can be done successfully, the time and effort spent on obtaining the solution have been largely wasted.Basically, there are only three means of communication available to us. Theseare the written, the oral, and the graphical forms. Therefore the successful engineer will be technically competent and versatile in all three forms of communication. A technically competent person who lacks ability in any one of these forms is severely handicapped.If ability in all three forms is lacking, no one will ever know how competent that person is!The competent engineer should not be afraid of the possibility of not succeeding in a presentation. In fact, occasional failure should be expected because failure or criticism seems to accompany every really creative idea. There is a great deal to be learned from a failure,and the greatest gains are obtained by those willing to risk defeat. In the final analysis, the real failure would lie in deciding not to make the presentation at all. To communicate effectively, the following questions must be answered:(1) Does the design really serve a human need?(2) Will it be competitive with existing products of rival companies?(3) Is it economical to produce?(4) Can it be readily maintained?(5) Will it sell and make a profit?Only time will provide the true answers to the preceding questions, but the product should be designed, manufactured and marketed only with initial affirmative answers. The design engineer also must communicate the finalized design to manufacturing through the use of detail and assembly drawings.Quite often, a problem will occur during the manufacturing cycle[3]. It may be that a change is required in the dimensioning or tolerancing of a part so that it can be more readily produced. This fails in the category of engineering changes which must be approved by the design engineer so that the product functionwill not be adversely affected. In other cases, a deficiency in the design may appear during assembly or testing just prior to shipping. These realities simply bear out the fact that design is a living process. There is always a better way to do it and the designer should constantly strive towards finding that better way.Designing starts with a need,real or imagined.Existing apparatus may need improvements in durability, efficiently, weight, speed, or cost. New apparatus maybe needed to perform a function previously done by men, such as computation, assembly, or servicing. With the obj ective wholly or partly defined, the next step in design is the conception of mechanisms and their arrangements that will perform the needed functions.For this, freehand sketching is of great value, not only as a record of one's thoughts and as an aid in discussion with others, but particularly for communication with one's own mind, as a stimulant for creative ideas. to fluctuating stress, particular attention is given to a reduction in stress concentration, and to an increase of strength at fillets, threads, holes, and fits. Stress reduction are made by modification in shape, and strengthening may be done by prestressing treatments such as surface rolling and shallow hardening. Hollow shafts and tubing, and box sections give a favorable stress distribution, together with stiffness and minimum weight. Sufficient stiffness to maintain alignment and uniform pressure between contacting surfaces should be provided for crank, cam, and gear shafts, and for enclosures and frames containing bearing supports. The stiffness of shafts and other components must be suitable to avoid resonant vibrations.e &zsic equations to calculate and optimize dimensions.The fundamental equations of mechanics and the other sciences are the accepted bases for calculations. They are sometimes rearranged in special forms to facilitate the determination or optimization of dimensions, such as the beam and surface stress equations for determining gear-tooth size. Factors may be added to a fundamental equation for conditions not analytically determinable, e. g. , on thin steel tubes, an allowance for corrosion added to the thickness based on pressure. When it is necessary to apply a fundamental equation to shapes, materials, or conditions which only approximate the assumptions for its derivation, it is done in a manner which gives results "on the safe side".In situations where data are incomplete, equations of the sciences may be used as proportioning guides to extend a satisfactory design to new capacities.4.Choose materials for a combination of properties.Materials should be chosen fora combination of pertinent properties, not only for strengths, hardness, and weight, but sometimes for resistance to impact, corrosion, and low or high temperatures. Cost and fabrication properties are factors, such as weldability, machinability, sensitivity to variation in heat-treating temperatures, and required coating.5.Select carefully between stock and integral components. A previously developed components is frequently selected by a designer and his company from the stocks of parts manufacturers, if the component meet the performance and reliability requirements and is adaptable without additional development costs to the particular machine being designed.However, its selection should be carefully made wi'th a full knowledge of its propcrties, since the reputation and liability of the company suffer if there is a failure in any one of the machine's parts. In other eases the strength, reliability, and cost requirements are better met if the designer of the machine also designs the component, with the particular advantage of compactness if it is designs integral with other components, e. g., gears to be forged in clusters or integral with a shaft.6. Provide for accurate location and non interference of parts in assembly. A good design provides for the correct locating of parts and for easy assembly and repair.Shoulders and pilot surfaces give accurate location without measurement during assembly. Shapes can be designed so that parts cannot be assembled backwards or in the wrong place. Interferences, as between screws in tapped holes, and between linkages must he foreseen and prevended.Inaccurate alignment and positioning between such assemblies must be avoided, or provision must be made to minimize any resulting detrimental displacements and stresses.The human race has distinguished itself from all other forms of life by using tools and intelligence to create items that serve to make life easier and more enjoyable. Through the centuries, both the tools and theenergy sources to power these tools have evolved to meet the increasing sophistication and complexity ofmankind's ideas.In their earliest forms, tools primarily consisted of stone instruments. Considering tile relative simplicity of the items being made and the materials being shaped, stone was adequate. When iron tools were invented, durable metals and more sophisticated articles could be produced. The twentieth century has seen the creation of products made from the most durable and,consequently, the most unmachinable materials in history. In an effort to meet the manufacturing challenges created by these materials, tools have now evolved to include materials such as alloy steel, carbide, diamond, and ceramics.A similar evolution has taken place with the methods used to power our tools. Initially,tools were powered by muscles; either human or animal. However as the powers of water, wind, steam, and electricity were harnessed, mankind was able tofurther extended manufacturing capabilities with new machines, greater accuracy, and faster machining rates.Every time new tools, tool materials, and power sources are utilized, the efficiency and capabilities of manufacturers are greatly enhanced. However as old problems are solved, new problems and challenges arise so that the manufacturers of today are faced with tough questions such as the following: How do you drill a 2 mm diameter hole 670 mm deep without experiencing taper or runout? Is there a way to efficiently deburr passageways inside complex castings and guarantee 100 % that no burrs were missed? Is there a welding process that can eliminate the thermal damage now occurring to my product?Since the 1940s, a revolution in manufacturing has been taking place that once again allows manufacturers to meet the demands imposed by increasingly sophisticated designs and durable, but in many cases nearly unmachinable, materials. This manufacturing revolution is now, as it has been in the past, centered on the use of new tools and new forms of energy.The result has been the introduction of new manufacturing processes used for material removal, forming, and joining, known today as nontraditional manufacturing processes.The conventional manufacturing processes in use today for material removal primarily rely on electric motors and hard tool materials to perform tasks such as sawing, drilling, an broaching. Conventional forming operations are performed with the energy from electric motors, hydraulics, and gravity. Likewise, material joining is conventionally accomplished with thermal energy sources such as burning gases and electric arcs.In contrast, nontraditional manufacturing processes harness energy sources considered unconventional by yesterday's standards. Material removal can now be accomplished with electrochemical reactions, high-temperature plasmas, and high-velocity jets of liquids and abrasives. Materials that in the past have been extremely difficult to form, are now formed with magnetic fields, explosives, and the shock waves from powerful electric sparks. Material-joining capabilities have been expanded with the use of high-frequency sound waves and beams of electrons.In the past 50 years, over 20 different nontraditional manufacturing processes have been invented andsuccessfully implemented into production. The reason there are such a large number of nontraditional processes is the same reason there aresuch a large number of conventional processes; each process has its own characteristic attributes and limitations, hence no one process is best for all manufacturing situations.For example, nontraditional process are sometimes applied to increase productivity either by reducing the number of overall manufacturing operations required to produce a product or by performing operations faster than the previously used method.In other cases, nontraditional processes are used to reduce the number of rejects experienced by the old manufacturing method by increasing repeatability, reducing in-process breakage of fragile workpieces, or by minimizing detrimental effects on workpiece properties.Because of the aforementioned attributes, nontraditional manufacturing processes have experienced steady growth since their introduction. An increasing growth rate for these processes in the future is assured for the following reasons:1.Currently, nontraditional processes possess virtually unlimited capabilities when compared with conventional processes, except for volumetric material removal rates. Great advances have been made in the past few years in increasing the removal rates of some of these processes, and there is no reason to believe that this trend will not continue into the future.2. Approximately one half of the nontraditional manufacturing processes are available with computer control of the process parameters. The use of computers lends simplicity to processes that people may be unfamiliar with, and thereby accelerates acceptance.Additionally, computer control assures reliability and repeatability[s], which also accelerates acceptance and implementation.3.Most nontraditional processes are capable of being adaptively-controlled through the use of vision systems, laser gages, and other in-process inspection techniques. If, for example, the in-process inspection system determines that the size of holes being produced in a product are becoming smaller, the size can be modified without changing hard tools, such as drills.4.The implementation of nontraditional manufacturing processes will continus to increase as manufacturing engineers, product designers, and metallurgical engineers become increasingly aware of the unique capabilties and benefits that nontraditional manufacturing processes provide.The high speed milling processing is more and more high to the numericalcontrol programming system request, the price expensive high speed processing equipment proposed a higher secure and the valid request to the software. The high-speed cutting has compared to the traditional cutting special technological requirement, besides must have the high-speed cutting engine bed and the high-speed cutting cutting tool, has the appropriate CAM programming software also is very important. The numerical control processing numerical control instruction has contained all technological process, outstanding high speed processes the CAM programming system to be supposed to have the very high computation speed, strong inserts makes up the function, the entire journey is automatic has cut the inspection and the handling ability, the automatic hilt and the jig interference inspection, enters for rate the optimized processing function, treats the processing path monitoring function, the cutting tool path edition optimization function and the processing remaining analysis function and so on. The high-speed cutting programming first must pay attention to the processing method the security and the validity; Next, must guarantee with utmost effort the cutting tool path smooth is steady, this can affect components the directly and so on processing quality and engine bed main axle life; Finally, must cause the cutting tool load to be even as far as possible, this can affect the cutting tool directly the life.1. The CAM system should have the very high computation programming speedIn the high speed processing uses extremely small entering and cuts the depth for the quantity, its NC procedure must be much bigger than to the traditional numerical control processing procedure, thus requests the software computation speed to have to be quick, by saves the cutting tool path edition and the optimized programming time.2. The entire journey automatically guards against has cut the handling ability and the automatic hilt interference inspection abilityThe high speed processing processes the nearly 10 time of cuttings speeds by the tradition to carry on the processing, once will occur has cut to the engine bed, the product and the cutting tool has the calamity consequence, therefore will request its CAM system to have to have the entire journey automatically to guard against has cut processing the ability and the automatic hilt and the jig interference inspection, circles evades the function. The system can automatically prompt short supports on both sides the cutting tool length, and automatically carries on the cutting tool interference inspection.3. Rich high-speed cutting cutting tool path strategyThe high speed processing to processes the craft to feed the way to have the special request compared to the traditional way, in order to can guarantee the maximum cutting efficiency, also guaranteed when high-speed cutting processes the security, the CAM system ought to be able to act according to processes the instantaneous remainder the size automatically to enter for rate carries on optimized processing, can automatically carry on the cutting tool path edition to optimize, the processing remaining analysis and the treatment processing path monitoring, by guarantees the high speed processing cutting tool stressful condition the stability, enhances the cutting tool the service life.After uses the high speed processing equipment, will be able to increase to programmers' demand, because high speed will process the technological requirement strictly, has cut the protection to be more important, therefore will have to spend the much time to carry on the simulation examination to the NC instruction. In the ordinary circumstances, high speed processes the programming time the to be ordinary than processing programming time to have to be much longer. In order to guarantee the high speed processing equipment enough utilization ratio, must dispose the more CAM personnel. The existing CAM software, like PowerMILL, MasterCAM, UnigraphicsNX, Cimatron and so on have all provided the correlation function high speed milling cutting tool path strategy.中文译文:机械设计及加工工艺机械设计是一门通过设计新产品或者改进老产品,满足人类需求的应用技术科学。
机械类毕业设计外文翻译、毕业设计(论文)外译文题目:轴承的摩擦与润滑10 月 15 日外文文献原文:Friction , Lubrication of BearingIn many of the problem thus far , the student has been asked to disregard or neglect friction . Actually , friction is present to some degree whenever two parts are in contact and move on each other. The term friction refers to the resistance of two or more parts to movement.Friction is harmful or valuable depending upon where it occurs. friction is necessary for fastening devices such as screws and rivets which depend upon friction to hold the fastener andthe parts together. Belt drivers, brakes, and tires are additional applications where friction is necessary.The friction of moving parts in a machine is harmful because it reduces the mechanical advantage of the device. The heat produced by friction is lost energy because no work takes place. Also , greater power is required to overcome the increased friction. Heat is destructive in that it causes expansion. Expansion may cause a bearing or sliding surface to fit tighter. If a great enough pressure builds up because made from low temperature materials may melt.There are three types of friction which must be overcome in moving parts: (1)starting, (2)sliding, and(3)rolling. Starting friction is the friction between two solids that tend to resist movement. When two parts are at a state of rest, the surface irregularities of both parts tend to interlock and form a wedging action. T o produce motion in these parts, the wedge-shaped peaks and valleys of the stationary surfaces must be made to slide out and over each other. The rougher the two surfaces, the greater is starting friction resulting from their movement .Since there is usually no fixed pattern between the peaks and valleys of two mating parts, the irregularities do not interlock once the parts are in motion but slide over each other. The friction of the two surfaces is known as sliding friction. As shown in figure ,starting friction is always greater than sliding friction .Rolling friction occurs when roller devces are subjected to tremendous stress which cause the parts to change shape or deform. Under these conditions, the material in front of a roller tends to pile up and forces the object to roll slightly uphill. This changing of shape , known as deformation, causes a movement of molecules. As a result ,heat is produced from the addedenergy required to keep the parts turning and overcome friction.The friction caused by the wedging action of surface irregularities can be overcome partly by the precision machining of the surfaces. However, even these smooth surfaces may require the use of a substance between them to reduce the friction still more. This substance is usually a lubricant which provides a fine, thin oil film. The film keeps the surfaces apart and prevents the cohesive forces of the surfaces from coming in close contact and producing heat .Another way to reduce friction is to use different materials for the bearing surfaces and rotating parts. This explains why bronze bearings, soft alloys, and copper and tin iolite bearings are used with both soft and hardened steel shaft. The iolite bearing is porous. Thus, when the bearing is dipped in oil, capillary action carries the oil through the spaces of the bearing. This type of bearing carries its own lubricant to the points where the pressures are the greatest.Moving parts are lubricated to reduce friction, wear, and heat. The most commonly used lubricants are oils, greases, and graphite compounds. Each lubricant serves a different purpose. The conditions under which two moving surfaces are to work determine the type of lubricant to be used and the system selected for distributing the lubricant.On slow moving parts with a minimum of pressure, an oil groove is usually sufficient to distribute the required quantity of lubricant to the surfaces moving on each other .A second common method of lubrication is the splash system in which parts moving in a reservoir of lubricant pick up sufficient oil which is then distributed to all moving parts during each cycle. This system is used in the crankcase of lawn-mower engines to lubricate the crankshaft, connecting rod ,and parts of the piston.A lubrication system commonly used in industrial plants is the pressure system. In this system, a pump on a machine carries the lubricant to all of the bearing surfaces at a constant rate and quantity.There are numerous other systems of lubrication and a considerable number of lubricants available for any given set of operating conditions. Modern industry pays greater attention to the use of the proper lubricants than at previous time because of the increased speeds, pressures, and operating demands placed on equipment and devices.Although one of the main purposes of lubrication is reduce friction, any substance-liquid , solid , or gaseous-capable of controlling friction and wear between sliding surfaces can be classed as a lubricant.V arieties of lubricationUnlubricated sliding. Metals that have been carefully treated to remove all foreign materials seize and weld to one another when slid together. In the absence of such a high degree of cleanliness, adsorbed gases, water vapor ,oxides, and contaminants reduce frictio9n and the tendency to seize but usually result in severe wear; this is called “unlubricated ”or dry sliding.Fluid-film lubrication. Interposing a fluid film that completely separates the sliding surfaces results in fluid-film lubrication. The fluid may be introduced intentionally as the oil in the main bearing of an automobile, or unintentionally, as in the case of water between a smooth tuber tire and a wet pavement. Although the fluid is usually a liquid such as oil, water, and a wide。
附录A 外文文献The present situation of theory research on Drive axle design and analysisWith the development of testing technology and improved driving axle in the design process to test the introduction of new technology and a variety of test equipment dedicated to carry out scientific experiments, all aspects of product structure, performance and strength of parts and components, life testing At the same time, extensive use of modern mathematical physics analysis, and assembly of products, parts and components to carry out a full technical analysis, research, and thus drive the development of bridge design theory to scientific experiments and technical analysis is based on the stage.(1) Computer Supported drive axle design and analysis of the theoretical innovation:Computer in the engineering design of the popularization and application, so that the bridge design theory-driven and technology leap in the development of completely different design process. Drive axle structure parameters and the optimization of performance parameters such as selection and matching, the intensity of components accounting and life prediction, simulation of the relevant products or simulation analysis of the art form that is more so on the choice of design and shape, design drawings Drawing will be conducted on the computer. The use of computer tools for analysis, because of its fast computing and large data capacity, we can use more accurate mathematical model of multi-degree of freedom to simulate the driving axle of the campaign in a variety of conditions, the use of modern advanced mathematics methods of analysis, can be obtained more accurate results, which analyzed for a variety of programs designed to work creatively to provide a great convenience. At present, due to the external computer equipment and the achievements of human-computer links, can be the computer's rapid calculation and logic to determine the capacity, high-capacity data storage and efficient data-processing capacity, the calculation results of dynamic image display function and creativity thinking ability and experience, the realization ofhuman-computer dialogue-style semi-automatic design, or product design expert systems, design automation. The design process can be computer-related products on a large amount of data, data retrieval, on the design of the design of high-speed computing, computer screen displays graphics and design calculations; designers can also be used up pen and direct man-machine dialogue language graphic changes to achieve the best design options, and then by computer graphics equipment line drawings drawn products. This use of computers and external devices product design methods, collectively referred to as computer-aided design. CAD and CAM will be the future into CADMAT system will show the usefulness of its huge.(2) basic studies to support the drive axle design and analysis of the theoretical innovation:With the computer design of drive axle in the popularization and application, a number of modern methods of mathematical physics and the basis for new theoretical achievements in the automotive design has become more widely used. The design of modern drive axle, in addition to traditional methods, computer-aided design methods, but also the introduction of the most optimal design, reliability, design, finite element analysis of computer simulation or simulation analysis, modal analysis and other modern design methods and analytical tools. Bridge design and analysis of drive to achieve the current high level of theory, especially the past three decades is more than a century of basic science, applied technology, materials and manufacturing processes result of continuous development and progress as well as design, production and use of long-term accumulation of experience. It is based on the production of large-scale practice, the basis of the theory as a guide to reflect the achievements of contemporary science and technology-driven bridge design software and hardware as a means to meet the needs of society for the purpose, through the use of materials, technology, equipment, tools, testing equipment, test the technical and business achievements in the field of management, continuous development and progress.(3) reverse engineering theory and methods widely used:Driving axle in the field of automated manufacturing, and often involve an enormous amount of complex design and manufacturing and testing surface. Under normal circumstances, first of all applications on the computer computer-aided design and manufacturing technology for the design of product model, and thengenerate code for processing. With the traditional processing model, compared to reverse engineering a CAD model of characterization of non-existing methods of product design, but through a variety of ways from the physical model was taken from the data re-engineering development models of a product amend. Drive the design and manufacture of axle housing is a very typical reverse engineering methods.(4) the application of rapid prototyping technology :Product innovation is designed to give full play to the designer's creative imagination, using the technical knowledge and skills to carry out the innovative ideas that the principle of a practice, its aim is to creatively design a rich and advanced new products. In the development of traditional design, the process is divided into program design, technical design, process design and product manufacturing. With the development of information technology, product design and development of the scope of the content from the traditional extended to product planning, manufacturing, testing, testing , marketing, as well as the whole process of recovery. Traditional design, the extension of the product development cycle. Rapid prototyping technology is the complete CAD model solid model layer by layer manufacturing technology, rapid prototyping technology to rid itself of the traditional processing methods, the growth of a new processing method to the complex three-dimensional processing is decomposed into a simple combination of two-dimensional processing. Therefore it does not need the use of traditional machine tools and processing tool, and only 10% of traditional processing methods of a 30% and 20% of the working hours of a 30% of the cost of products will be able to directly create and mold samples. Product innovation in the design and development application of rapid prototyping technology, with modern high-tech tools and technology to transform traditional methods of product design and development, to promote design innovation, product innovation, process innovation and management innovation to form a digital, virtual and intelligent , integrated in order to bring about a revolution in product design and development.(5) the application of concurrent engineering to product management and development:Drive Axle Industries has launched a worldwide competition designed to shorten a new product development time, reduce costs, improve quality, increasemarket competitiveness, manufacturers are increasingly becoming the most important issue to consider. Concurrent Engineering as a modern, advanced product design and development model to address these problems is a good way for countries to the automotive industry has been used. The so-called concurrent engineering, is the integrated, concurrent design of products and related processes of systems engineering, it takes from concept to product design, shape design, manufacture, use, maintenance of the entire process until the end of life of all the relevant factors that can solve the out of touch the design and manufacturing process design changes caused by frequent and long development time, cost of Higher contradictions can be designed to maximize the quality and development efficiency, and increase market competitiveness. Concurrent engineering, the key is the process of the product and its associated parallel implementation of integrated design, manufacturing and assembly-oriented design is an important aspect of concurrent engineering in product development throughout the entire process of design is the key. Innate quality of the product design decisions. Statistics show that products, including raw materials, manufacture, use, maintenance and other costs that 70% of the generalized cost is a decision from the design stage. The objectives of concurrent engineering is as much as possible early in the design stage on the introduction of the manufacture and assembly of the binding process, such as material selection, manufacturing processes, and assembly of such constraints, design changes to make as much as possible in the early stage of product development, and from manufacturing to assembly to reduce the occurrence of adverse situations, when to make a successful product design, product development to avoid the late change in design due to the enormous waste, which on the drive axle design and subAnalysis of the objectives of the theory put forward more demands.附录B外文文献的中文翻译驱动桥设计与分析的理论研究现状随着测试技术的发展与完善,在驱动桥设计过程中引进新的测试技术和各种专用的试验设备,进行科学实验,从各方面对产品的结构、性能和零部件的强度、寿命进行测试,同时广泛采用近代数学物理分析方法,对产品及其总成、零部件进行全面的技术分析、研究,这样就使驱动桥设计理论发展到以科学实验和技术分析为基础的阶段。
外文资料翻译原文(二)Machine design theoryThe machine design is through designs the new product or improves the old product to meet the human need the application technical science. It involves the project technology each domain, mainly studies the product the size, the shape and the detailed structure basic idea, but also must study the product the personnel which in aspect the and so on manufacture, sale and use question. Carries on each kind of machine design work to be usually called designs the personnel or machine design engineer. The machine design is a creative work. Project engineer not only must have the creativity in the work, but also must in aspect and so on mechanical drawing, kinematics, engineerig material, materials mechanics and machine manufacture technology has the deep elementary knowledge.If front sues, the machine design goal is the production can meet the human need the product. The invention, the discovery and technical knowledge itself certainly not necessarily can bring the advantage to the humanity, only has when they are applied can produce on the product the benefit. Thus, should realize to carries on before the design in a specific product, must first determine whether the people do need this kind of productMust regard as the machine design is the machine design personnel carries on using creative ability the product design, the system analysis and a formulation product manufacture technology good opportunity. Grasps the project elementary knowledge to have to memorize some data and the formula is more important than. The merely service data and the formula is insufficient to the completely decision which makes in a good design needs. On the other hand, should be earnest precisely carries on all operations. For example, even if places wrong a decimal point position, also can cause the correct design to turn wrongly.A good design personnel should dare to propose the new idea, moreover is willing to undertake the certain risk, when the new method is not suitable, use original method. Therefore, designs the personnel to have to have to have the patience, because spends the time and the endeavor certainly cannot guarantee brings successfully. A brand-new design, the request screen abandons obsoletely many, knows very well the method for the people. Because many person of conservativeness, does this certainly is not an easy matter. A mechanical designer should unceasingly explore the improvement existing product the method, should earnestly choose originally, the process confirmation principle of design in this process, with has not unified it after the confirmation new idea.Newly designs itself can have the question occurrence which many flaws and has not been able to expect, only has after these flaws and the question are solved, can manifest new goods come into the market the product superiority. Therefore, a performance superior product is born at the same time, also is following a higher risk. Should emphasize, if designs itself does not request to use the brand-new method, is not unnecessary merely for the goal which transform to use the new method.In the design preliminary stage, should allow to design the personnel fully to display the creativity, not each kind of restraint. Even if has had many impractical ideas, also can in the design early time, namely in front of the plan blueprint is corrected. Only then, only then does not send to stops up the innovation the mentality. Usually, must propose several sets of design proposals, then perform the comparison. Has the possibility very much in the plan which finally designated, has used certain not in plan some ideas which accepts.How does the psychologist frequently discuss causes the machine which the people adapts them to operate. Designs personnel''s basic responsibility is diligently causes the machine to adapt the people. This certainly is not an easy work, because certainly doesnot have to all people to say in fact all is the most superior operating area and the operating process.Another important question, project engineer must be able to carry on the exchange and the consultation with other concerned personnel. In the initial stage, designs the personnel to have to carry on the exchange and the consultation on the preliminary design with the administrative personnel, and is approved. This generally is through the oral discussion, the schematic diagram and the writing material carries on. In order to carry on the effective exchange, needs to solve the following problem:(1) designs whether this product truly does need for the people? Whether there is competitive ability(2) does this product compare with other companies'' existing similar products?(3) produces this kind of product is whether economical?(4) product service is whether convenient?(5) product whether there is sale? Whether may gain?Only has the time to be able to produce the correct answer to above question. But, the product design, the manufacture and the sale only can in carry on to the above question preliminary affirmation answer foundation in. Project engineer also should through the detail drawing and the assembly drawing, carries onthe consultation together with the branch of manufacture to the finally design proposal.Usually, can have some problem in the manufacture process. Possibly can request to some components size or the common difference makes some changes, causes the components the production to change easily. But, in the project change must have to pass through designs the personnel to authorize, guaranteed cannot damage the product the function. Sometimes, when in front of product assembly or in the packing foreign shipment experiment only then discovers in the design some kind of flaw. These instances exactly showed the design is a dynamic process. Always has a better method to complete the design work, designs the personnel to be supposed unceasingly diligently, seeks these better method. Recent year, the engineerig material choice already appeared importantly. In addition, the choice process should be to the material continuously the unceasing again appraisal process. The new material unceasingly appears, but some original materials can obtain the quantity possibly can reduce. The environmental pollution, material recycling aspect and so on use, worker''s health and security frequently can attach the new limiting condition to the choice of material. In order to reduce the weight or saves the energy, possibly can request the use different material. Comes fromdomestic and international competition, to product service maintenance convenience request enhancement and customer''s aspect the and so on feedback pressure, can urge the people to carry on to the material reappraises. Because the material does not select when created the product responsibility lawsuit, has already had the profound influence. In addition, the material and between the material processing interdependence is already known by the people clearly. Therefore, in order to can and guarantees the quality in the reasonable cost under the premise to obtain satisfaction the result, project engineer makes engineers all to have earnestly carefully to choose, the determination and the use material.Makes any product the first step of work all is designs. Designs usually may divide into several explicit stages: (a) preliminary design; (b) functional design; (c) production design. In the preliminary design stage, the designer emphatically considered the product should have function. Usually must conceive and consider several plans, then decided this kind of thought is whether feasible; If is feasible, then should makes the further improvement to or several plans. In this stage, the question which only must consider about the choice of material is: Whether has the performance to conform to the request material to be possible to supply the choice;If no, whether has a bigger assurance all permits in the cost and the time in the limit develops one kind of new material.In the functional design and the engineering design stage, needs to make a practical feasible design. Must draw up the quite complete blueprint in this stage, chooses and determines each kind of components the material. Usually must make the prototype or the working model, and carries on the experiment to it, the appraisal product function, the reliability, the outward appearance and the service maintenance and so on. Although this kind of experiment possibly can indicate, enters in the product to the production base in front of, should replace certain materials, but, absolutely cannot this point take not earnestly chooses the material the excuse. Should unify the product the function, earnestly carefully considers the product the outward appearance, the cost and the reliability. Has the achievement very much the company when manufacture all prototypes, selects the material should the material which uses with its production in be same, and uses the similar manufacture technology as far as possible. Like this has the advantage very much to the company. The function complete prototype if cannot act according to the anticipated sales volume economically to make, or is prototypical and the official production installment has in the quality and the reliable aspect is very greatly different, then thiskind of prototype does not have the great value. Project engineer is best can completely complete the material in this stage the analysis, the choice and the determination work, but is not remains it to the production design stage does. Because, is carries on in the production design stage material replacement by other people, these people are inferior to project engineer to the product all functions understanding. In the production design stage, is should completely determine with the material related main question the material, causes them to adapt with the existing equipment, can use the existing equipment economically to carry on the processing, moreover the material quantity can quite be easy to guarantee the supply.In the manufacture process, inevitably can appear to uses the material to make some changes the situation. The experience indicated that, may use certain cheap materials to take the substitute. However, in the majority situation, in will carry on the production later to change the material to have in to start before the production to change the price which the material will spend to have to be higher than. Completes the choice of material work in the design stage, may avoid the most such situations. Started after the production manufacture to appear has been possible to supply the use the new material is replaces the material the most commonreason. Certainly, these new materials possibly reduce the cost, the improvement product performance. But, must carry on the earnest appraisal to the new material, guarantees its all performance all to answer the purpose. Must remember that, the new material performance and the reliable very few pictures materials on hand such understood for the people. The majority of products expiration and the product accident caused by negligence case is because in selects the new material to take in front of substitution material, not truly understood their long-term operational performance causes.The product responsibility lawsuit forces designs the personnel and the company when the choice material, uses the best procedure. In the material process, five most common questions are: (a) did not understand or cannot use about the material application aspect most newly the best information paper; (b) has not been able to foresee and to consider the dusk year possible reasonable use (for example to have the possibility, designs the personnel also to be supposed further to forecast and the consideration because product application method not when creates consequence. ecent years many products responsibilities lawsuit case, because wrongly uses the plaintiff which the product receives the injury to accuse produces the factory, and wins the decision); (c) uses the materialdata not entire perhaps some data are indefinite, works as its long-term performance data is the like this time in particular; (d) the quality control method is not suitable and not after the confirmation; (e) the personnel which completely is not competent for the post by some chooses the material.Through to the above five questions analysis, may obtain these questions is does not have the sufficient reason existence the conclusion. May for avoid these questions to these questions research analyses the appearance indicating the direction. Although uses the best choice of material method not to be able to avoid having the product responsibility lawsuit, designs the personnel and the industry carries on the choice of material according to the suitable procedure, may greatly reduce the lawsuit the quantity. May see from the above discussion, the choice material people should to the material nature, the characteristic and the processing method have comprehensive and the basic understanding.外文资料翻译译文(二)机械设计理论机械设计是一门通过设计新产品或者改进老产品来满足人类需求的应用技术科学。
英文原文名《English for Die Mould Design and Manufacturing》中文译名《模具设计与制造专业英语》英文原文版出处:《模具设计与制造专业英语》,刘建雄王家惠廖丕博主编,北京大学出版社2006年3月第1版译文:3.3压铸压铸是通过压力作用下使熔融金属进入金属模具,是快速生产精密产品的一部分。
这个术语同时适用于所得的铸件。
压铸件因为具有有良好的表面而可以经济地应用于批量和大批量生产中。
只需要相对小的加工,就可以实现很好的公差保证,这些原则在一些压铸操作中都得到了很好的检验。
压铸模具是永久性的,不会由于金属的引入而影响到他们,除正常磨损或损耗。
在相同的大小和形状的条件下,压铸模通常比塑料模和永久铸造更昂贵。
这种快速成型依靠快速把金属注入模具、冷却、开模、铸件取出和模具下次压铸的准备。
3.3.1模具压铸周期在铸造周期里,首先模具闭合并且锁紧,熔化的金属在一个特定温度的熔炉中,然后进入注射缸,根据合金的类型,用于热压室或者冷压室金属浇注系统,这些将在后面描述。
在注射阶段的压铸过程中,熔融金属在压力的作用下,快速通过模具浇注系统进入模具并排出模具里的空气,金属量必须足够大以充满型腔和溢流井,溢流井的设计是用来储存接收溢流出来的融溶金属液的,因为接触到模具型腔的空气容易氧化,同时也最先接触到模具其也可以快速冷却以便可以接下来进行第二次的压铸。
一旦这模具型腔填满了,作用于金属液的压力会增大,保压一定的时间以便金属液凝固,模具的分离、工件的取出通常通过机器自动操作完成,打开模具进行必要的清理和润滑,然后下一轮压铸继续循环。
从模具取下的工件冷却后,操作工切除金属浇注填充时产生的披锋,同时去除溢流井和分型线,接着能进行二次加工和表面后处理。
3.3.2压铸合金四类主要的压铸模具合金为锌、铝、镁和铜基合金,压铸工艺发展于19世纪铅/锡合金零件的制作,然而,铅和锡由于力学性能差,现在很少用来压铸。
附录现代工程机械行业的技术进步大型机械式挖掘机在目前国际国内在矿山开采及工程施工中有着广泛的应用,其性能的优劣对生产率有很大的影响.在国际市场竟争日趋激烈的今天,如何提高产品的质量是提高其市场竞争力的关键。
目前,我国的大型机械式挖掘机在设计水平,设计手段及产品质量上与国外同类产品相比尚有较大差距.国外已经将人一机一环境作为一个系统统一考虑,提倡低振动、低噪音的绿色设计,将现代设计方法(电子模拟理论、动态设计、可靠性设计等)普遍地应用于挖掘机设计,使产品设计现代化,性能可靠。
而我国仍然主要采用传统的仿型设计,而近年来才将现代设计方法逐步应用到挖掘机的设计上,但在这方面工作开展的不得力,主要表现在自行设计开发能力不够,基础工作做得不完善,尤其在挖掘机动力学方面。
挖掘机结构非常复杂,往往是多发动机同时驱动,同时工作环境恶劣,外载荷成随机性变化,因此在设计大型矿用挖掘机的新产品时,为了使其作业安全,工作顺畅,除必要的理论分析和静强度计算外,还必须要进行动力学分析和计算,以在设计之初保证机械的动强度和可靠性。
在进行这种分析时,土壤的力学特性必须考虑,而且是重要因素。
通过进行动力学研究,才能确定挖掘机各部件的载荷特性,设计出质量可靠的产品。
Modern construction machinery industry of technical progress Large-size mechanical mining excavator is used widely in international and domestic engineering construction and mining performance, and its property defines the efficiency much.Now because the international market is opened step step, how to promote the quality of excavator is the key that a factory reinforces its competing force.In our country,the designing elevation and production quality on excavator can not keep up with international advanced technology applying on excavator.Now the advanced technology has already applied advanced designing method on excavator designing,such as electronic simulating theory,dynamic design, reliability design and so on.But in our country ,the most excavator design has still applied the traditional design method ,the modern design method has not began to be actually applied .The prime display is that the capability of self-design is not enough and the basic work has not done perfectly especially the excavator kinetics .The construct of excavator is very complex and the multiple movers often work simultaneously.at the same time its working environment is very bad and the eternal load varies randomly.As a result ,when designing the new product of excavator ,in order to ensure the performance safety,the designer not only has the basic theory analysis on static load computing ,but also do necessary work about the kinetics of mechanism to qualify the dynamic reliability in the period of designing .Trough the kinetic analysis ,the load property of all the elements in excavator can be decided so as to design reliable product .。
附录附录A 外文资料A. market situation analysis and research trendA. is half hanged tractor, dump truck, car, tank car, van, the special structure of hoisting lift car, store house bar car, and other special vehicles. From abroad, the development of the car industry, the development trend of auto specialty. In the 20th century 70, 80 time, the main functions of the developed countries of specialized automobile vehicles is 50% of the quantities, now has been increased to 80 %. China's current below 25 %. China has joined the WTO, developing automobile industry is facing a great challenge, special vehicle is an important part of automobile industry, affected is inevitable. With the development of economy and the construction of infrastructure, China will need a lot of special automobile, therefore the tenth-five period in China will be truly special development into "fast track". Special automobile market analysis.In recent years, China's special automobile industry. In 1990, the production of specialized automobile enterprises about 500, 2000, has 756 home auto production enterprise of total 884 85.5 per cent. In 1998, our special automobile production of 14.95 million vehicles, the total of the auto production, 1999 respectively 21.2% 17.41 million vehicles and achieve 17.28 million vehicles. In 2001, and special markets are almost the entire automotive market occupation deodorants.Currently our special automobile market has the following five basic features:1.Special-purpose automobile production and demand truly reflects many varieties, small batch. Special automobile refitting enterprise development and production has many varieties, seriation, pluralism characteristics in different periods, market, adjust the different needs of different products production scale. This feature in cars and ordinary greatly vehicles. Generally speaking, the box truck, traction semi-trailer, etc, in demand more than tipper, alone can reach up to 10 million, most special vehicle demand to hundreds of thousands of cars only cars, and some even several dozens or car.2.Our special automobile recent price advantage, part of a product is competitive. Domestic main varieties, such as special automobile, refrigerator, semi-trailers concrete pump truck, car, transport and accessory part oilfield as lifting transporter through cooperation, technology or imported special device, approaching or partial reached international advanced level, price competition with the ability of foreign products. To demand greater products, such as heavy, medium dump truck, car, tank truck and van car etc, have a stable domestic market.3.Special-purpose automobile service fields, market prospect is anacreontic, different period of different, but can appear more hot hot exists. In 2001, for example, the country increased infrastructure investment, especially in infrastructure, increasing investment in the construction of the Midwest, plus such as "west-east gas transmission" and "electricity", "water", the qinghai-tibet railway and highway construction of domestic several large project startup, heavy exclusive up year-on-year, the 84.5 %, Meanwhile, the development of the highway road cargo further specialization, intensive, various box truck, half hanged tractor and special carriers of the social demand had the very big enhancement, only half hanged tractor, year-on-year growth of about 90% by the car industry, become a black horse.4.Market calls stronger technical content, specificity of special products, but higher market supply capacity. Because China's most exclusive enterprise development abilityweak, capital, technology appear quite a number of domestic enterprises do not have enough to eat, a. a. market and pretty much on imports to fill the position. A. as heavy, domestic production, and the market more than 70 species to 200 types, 500 cultivars, can satisfy the market companies within 30%. In addition, because many industries for special automobile technology, high performance requirements to achieve a domestic product requirements, such as airport special automobile, highway maintenance management, senior medical ambulance etc. Car, And as YunChaoChe domestic market capacity and products of domestic enterprises can rarely grade C bulletproof requirements.5.Special-purpose automobile production enterprises, the market management of the good and bad are intermingled. A. industry various mechanisms, organization form is diversified. There, the state-run private, There are limited liability company, joint stock limited company is, Also belong to different industries, mode of production and management by truck chassis refitting, market, easy to interference. Illegally assembled and selling product certification phenomenon in all, which seriously interfere with special automobile market. Special automobile manufacturing enterprise, mostly for small and medium-sized enterprise, the difference between. According to the modified enterprise 1999 annual 530 home, more than 1000 production enterprises only 47, accounting for 8.9%, Production of enterprises under 100 $229, accounting for 43.2 percent. There are 45 yield less than 10 bus. In recent years, the government to strengthen the management of specialized automobile market, increase the reorganization and crack, market environment is greatly improved, to gradually regularized.Although our special automobile industry development prospects and success, but compared with special automobile enterprises abroad, there are still great difference.1.The labor productivity significantly lower. In 1999, special production enterprises, the output value per person for 0.98 million yuan, the profit for 11.13 0.015 yuan per person. And the three indexes, Japan in early 1990 to 12.5 million cars, and the period 37.5 million.2.Product technical level is relatively backward. Mainly displays in: (1) the utilization coefficient, low quality of same type, with more than 20 foreign heavy vehicle tonnage; % ~ 30 % 2 special function satisfaction than the same products abroad backward 5 ~ 10 years, 3 man-computer engineering application, adaptive performance is not strong, high technology USES less, 4 vehicle reliability, sealing and durability, and noise pollution emission.3.Product development ability is poor. Our special automobile varieties are mostly through a generic, and high technology products through introducing technology or product to make appropriate improvement "and" localization, the lack of real independent innovation products development.The international competition ability is weak. Our special cars with low coefficient of international competitiveness, import and export trade, and the import value difference of specialized automobile mainly from Europe and Japan and other developed countries, mainly exports southeast Asia and Africa is the object of the developing countries.In the tenth-five period special-purpose automobile development trend.Along with the national "tenth five-year plan" period, the steady development of the national economy and the market economic system, and the improvement of electronic and information and automation technology in the automotive industry, the development of domestic special-purpose automobile will appear as follows:1."The special market demand growth, and the market will be more competitive, special production enterprises gradually to the polarization. According to the country "special" tenth five-year plan "period", "tenth-five period special-purpose automobile needs to 10% annual growth rate increases, in 2005, our various special automobile market demand for 34 million cars, trucks of production equipments, including the 35 million, 41.814.1 %, Tractor semi-trailer 4.8 million vehicles, 14%, Van car 85,000, 25% of the time, 3.3 million cars, car tank of 9.5%, 135 million cars lifting lifters, 4%, The special structure of 1.7 million cars, 5%, Store house bar 0.2 million cars, car type 0.7%. "Tenth-five", is expected to end the special automobile ownership will reach 275.3 million vehicles. Facing such opportunities, coupled with the "wto" brings more foreign products, special vehicle production enterprise competition intensifies, domestic car again production enterprise stronger who will appear the weak, the weak, the enterprise will be further, exclusive joint, merger, reorganization and leasing, private car will also become one of the enterprise reform mode.2.The special demand more diversified and some special function, special products will ChongXingHua, special function to high technical content, the direction of development. Large-tonnage heavy vehicle transportation safety, high, low cost, and transportation units in some developed countries of the main highway transportation of container trailer is heavy, tank truck and various special semi-trailer, the special production and heavy mainly are the total quantities of 80 %. Our special cars by road conditions and production of special chassis, has been to limit, heavy mid-size car obviously low proportion. Along with our country economy and the traffic environment improvement, industry of specialized automobile especially heavy special-purpose automobile demand is bigger and bigger, heavy dump truck, bulk cement concrete mixer, car and truck, high compression garbage truck, sprayer, municipal transport, a. a. heavy oil will win customers. To the degree of specialization and special requirements are increasingly high technical content, born out of many new special type. By 2005, heavy, medium and small proportion is 1:6 by now, 3 evolved for 3:4:3 reasonable composition. By 1998 will breed varieties, 223 1372 cultivars, increased to 300 kinds of 2005, 3 000 varieties.3.Car production flexibility, automation, professional to produce and coordination network development, design and development of CAD technology of virtual technology is widely used to test technology, intelligent, systematic development direction. A. "many varieties, small batch, short cycle" characteristics, product updates faster, market demand diversity, personalized towards the direction of development, the traditional pattern of all-round enterprise competitiveness, will lose all forms of cooperative development, production and marketing, fast response to market demands, flexible production, design, manufacturing and adopted by many enterprises. CAD technology for shortening exclusive product development cycle, improve product quality and reduce cost will play a positive role in promoting. At the same time, with special automobile production and technology development, and special automobile test coverage is more and more wide, from the traditional measuring instrument to various special test equipment, from a single test to the comprehensive test, from hardware to software are put forward higher request, and more complex, will promote the technique and method of special test. Combined with the application of computer software technology, special test technical trend intelligent and systematized.附录B 外文资料中文翻译专用车市场现状分析及趋势研究专用车是自卸车、半挂牵引车、厢式车、罐式车、起重举升车、特种结构车、仓栅车等专用载货汽车的统称。
机械工程摄政出版公司,1998机械设计查尔斯.比尔兹利摘要:机器是机构与其他零件的组合,为了有益的用途而转换、传递或利用能量、力或者运动实例有发动机、涡轮、车辆、卷扬机、印刷机、洗衣机和电影摄影机.许多适用于机器设计的原理和力法也适用于不是真正机器的制成品,从轮毂盖和档案橱柜到仪表和核压力容器。
“机械设计”这一术语比“机器设计”更为广义,它包括机器设计。
而对于某些仪器,如用以确定热、流动线路和体积的热力以及流体方面的问题要单独考虑。
但是,在机械设计时要考虑运动和结构方面的问题以及保存和封装的规定。
在机械工程领域以及其他工程领域应用机械设计,都需要诸如开关、凸轮、阀门、容器和搅拌器等机械装置。
关键字:机械设计、机构设计,工程工差设计过程设计开始于一种真实的或想像的需要。
现有的仪器需要在耐用性、效率、重量、速度或成本上有所改善。
新的工具也许要用来做那些以前需要人来完成的工作,例如计算、汇编或服务。
整体宗旨或部分定义,设计的下一个步骤是机制的构想和一些必要职能的安排。
对于此,徒手画图是很重要的,不仅作为一个人的想法而纪录,而且可以在与别人的讨论中作为一种援助,但是最重要的是与自己的思想交流,充当一种创造性思维的兴奋剂。
并且,由于一种新的机器通常包含一些知名的构件类型的新的组装或替代,也或许是在大小上和材料上有所改变,因此,丰富的组件知识是十分有用的。
无论是在设计的过程中或之后,设计师都要做快速或粗略的计算与分析,以确定此项设计的整体大小和可行性。
当获得一些所需要的或可用的相关空间量时,规模布局图就可以做了。
当机器的几个组成部分的基本形状和一些尺寸规格都确定时,认真分析就可以开始了。
分析将主要围绕该机器的客观满意度和性能优越性展开,并要增加安全性和保证耐用性的同时降低机器重量,还要研究确定每个受重载的构件的尺寸,连同这些构件之间的受力平衡。
材料和加工工艺也要选择。
这些重要目标的实现必须依靠基于力学原理的分析,例如那些静态反作用力和摩擦力的最佳利用,动力学中的惯性力、加速度和功,弹性材料的强度、应力和挠度,材料的物理特性,水力驱动器的润滑和流体力学。
郑州航空工业管理学院 英 文 翻 译
2012届机械设计制造及其在自动化专业1006962班级
姓 名 郝振兴 学号 100696208 指导教师 贺红霞 职称 教授
二О一 二年 三 月 十二 日 - 2 -
New Trends and Problems in Material Processing Machine Design Theory
Abstract : Based on reviewing the historical background, prospecting for the development trend ,analyzing the complicacy and mechanism and summing up some achievements and experiences in scientific research , several new problems and the possible direction of development in material processing technology and machine are proposed ,such as ,producing new concept materials possessing some specific and extraovdinary properties by means of integrating and coalescing conelative frontier science and technology ;and thereafter a brief discussion is given.
Keywords: interface; extraordinary physical field; procession machine ; function material - 3 -
1 The Time Background of Material Processing Machine In the long span of history of human progress ,many tools ,machines and methods were created and a variety of materials with different properties were processed. Materials and its processing have become one of pillar and driving force of mankind progress. In pace with multi - polar competition in current world and people’s striving perseveringly for happier life ,material function goes beyond unceasingly men’s knowledge and imagination ,for example ,cryptic function material ,semiconductor material ,energy material ,vibration - absorptive material , super - strength aluminum alloy accounting for 70 percent of application of aeronautics and space ,metal foil of 4~5μm ,deep drawing plate with anisotropy below 1 percent ,electronic aluminum foil with micro - orientation up to 95 percent ,heat resisting aluminum alloy with super strong specific strength used in aeronautics ,space and deep sea ,etc. Thus several important development trends with distinct time features in material processing domain are shaped up as follows : (1) Creating material processing machine with extraordinary physical field for processing material with special texture structures and functions. For example ,applications of thermal energy and mechanical energy are breaking through unceasingly technology limit ,and some non - tradition energy ,such as microwave ,chemical energy , bioenergy , etc. , are introduced into material processing procedure one after another ,so that some material processing machines with extraordinary energy circumstance are produced. (2) Breaking through traditional physical limits and integrating melting ,solidifying ,plastic deformation and heat treatment to obtain special function of material and cut down expenses[3 ] . For example ,near - net shaping material processing technology , such as fast rolling , spraying deposition ,over - plastic molding , injection molding , high energy beam ,etc ,is applied. (3) Material processing process is forged ahead in the direction of high speed ,heavy - duty and high accuracy online control ,for instance , the rolling speed goes up to 130 m·s - 1 ,the deformation pressure rises up to 300 MPa ,accuracy of dimension up to 0.1μm ,accuracy of shape up to 0. 1 I ,strength accuracy comes up to 0.1 MPa. For these reasons ,it is necessary for material processing machine design theory to integrate and coalesce ingeniously correlative frontier science and technology to create and produce some new concept material processing machine with following functions. - 4 -
2 Due Functions of New Concept Material Processing Machine
(1) To have the ability to produce and bear extraordinary physical field and transmit extraordinary energy flow with the aim of providing extraordinary physical circumstances necessary for new concept material processing. For example ,high gradient temperature field with the speed of cool - down of work interface which exceeds 104~106 K·s - 1 , line wave and pulse complex exerted in solidifying - deforming area , super - strength contact stress field of material forming interface ,turbulent flow field of molten metal with very big flakiness ratio ,low frequency magnetic field with random frequency ,microwave field for powder metal heating ,ultrasonic field for large volume solidifying ,etc. [4 ] ,are applied. (2) To have the ability to work in critical state so that high stability and ideal performance of processing machine is ensured under the circumstance of reinforced technological condition and multi - field coupling operation. For example ,chatter suppressing capability of fast ultra - thin rolling under the condition of boundary lubricating state[5 ] ,the capability of self - excited vibration suppressing under the condition of special friction state ,synergism stability and disturbance stability of flexible connecting parallel shaft with multi - driving system ,etc. [4 ] ,are ensured. (3) To have the ability to accurately control the material processing in order to obtain low loss ,high efficiency and high quality of material processing. For example , super - high accuracy on - line monitor of products form ,on – line monitor and on - line adjustment of products texture and properties ,precision coordination control of multi - procedure , on - line monitor of micro - orientation of metal plastic deformation ,etc. [4 ] ,are ensured. Some products accuracy index may be enumerated as follows : dimensional accuracy coming to 0.1μm , microstructure uniformity to crystal lattice ,strength error to 0.1 MPa ,etc. [4 ] In short ,only by new concept material processing machine with