模具设计与制造大学毕业论文外文文献翻译及原文

Injection MoldingThe basic concept of injection molding revolves around the ability of a thermoplastic material to be softened by heat and to harden when cooled .In most operations ,granular material (the plastic resin) is fed into one end of the cylinder (usually through a feeding device known as a hopper ),heated, and softened(plasticized or plasticized),forced out the other end of the cylinder, while it is still in the form of a melt, through a nozzle into a relatively cool mold held closed under pressure.Here,the melt cools and hardens until fully set-up. The mold is then opened, the piece ejected, and the sequence repeated.Thus, the significant elements of an injection molding machine become: 1) the way in which the melt is plasticized (softened) and forced into the mold (called the injection unit);2) the system for opening the mold and closing it under pressure (called the clamping unit);3) the type of mold used;4) the machine controls.The part of an injection-molding machine, which converts a plastic material from a sold phase to homogeneous seni-liguid phase by raising its temperature .This unit maintains the material at a present temperature and force it through the injection unit nozzle into a mold .The plunger is a combination of the injection and plasticizing device in which a heating chamber is mounted between the plunger and mold. This chamber heats the plastic material by conduction .The plunger, on each stroke; pushes unbelted plastic material into the chamber, which in turn forces plastic melt at the front of the chamber out through the nozzleThe part of an injection molding machine in which the mold is mounted, and which provides the motion and force to open and close the mold and to hold the mold close with force during injection .This unit can also provide other features necessary for the effective functioning of the molding operation .Movingplate is the member of the clamping unit, which is moved toward a stationary member. the moving section of the mold is bolted to this moving plate .This member usually includes the ejector holes and mold mounting pattern of blot holes or “T” slots .Stationary plate is the fixed member of the clamping unit on which the stationary section of the mold is bolted .This member usually includes a mold-mounting pattern of boles or “T” slots. Tie rods are member of the clamping force actuating mechanism that serve as the tension member of the clamp when it is holding the mold closed. They also serve as a gutted member for the movable plate .Ejector is a provision in the clamping unit that actuates a mechanism within the mold to eject the molded part(s) from the mold .The ejection actuating force may be applied hydraulically or pneumatically by a cylinder(s) attached to the moving plate, or mechanically by the opening stroke of the moving plate.Methods of melting and injecting the plastic differ from one machine to another and are constantly being implored .conventional machines use a cylinder and piston to do both jobs .This method simplifies machine construction but makes control of injection temperatures and pressures an inherently difficult problem .Other machines use a plasticizing extruder to melt the plastic and piston to inject it while some hare been designed to use a screw for both jobs :Nowadays, sixty percent of the machines use a reciprocating screw,35% a plunger (concentrated in the smaller machine size),and 5%a screw pot.Many of the problems connected with in ejection molding arise because the densities of polymers change so markedly with temperature and pressure. thigh temperatures, the density of a polymer is considerably cower than at room temperature, provided the pressure is the same.Therefore,if molds were filled at atmospheric pressure, “shrinkage” would make the molding deviate form the shape of the mold.To compensate for this poor effect, molds are filled at high pressure. The pressure compresses the polymer and allows more materials to flow into the mold, shrinkage is reduced and better quality moldings are produced.Cludes a mold-mounting pattern of bolt holes or “T” slots. Tie rods are members of the clamping force actuating mechanism that serve as the tension members of clamp when it is holding the mold closed. Ejector is a provision in the calming unit that actuates a mechanism within the mold to eject the molded part(s) form the mold. The ejection actuating force may be applied hydraulically or pneumatically by a cylinder(s) attached to the moving plate, or mechanically by the opening stroke of the moving plate.The function of a mold is twofold: imparting the desired shape to the plasticized polymer and cooling the injection molded part. It is basically made up of two sets of components: the cavities and cores and the base in which the cavities and cores are mounted. The mold ,which contains one or more cavities, consists of two basic parts :(1) a stationary molds half one the side where the plastic is injected,(2)Moving half on the closing or ejector side of the machine. The separation between the two mold halves is called the parting line. In some cases the cavity is partly in the stationary and partly in the moving section. The size and weight of the molded parts limit the number of cavities in the mold and also determine the machinery capacity required. The mold components and their functions are as following:(1)Mold Base-Hold cavity (cavities) in fixed, correctposition relative to machine nozzle.(2)Guide Pins-Maintain Proper alignment of entry into moldinterior.(3)Spree Bushing (spree)-Provide means of entry into moldinterior.(4)Runners-Conroy molten plastic from spree to cavities.(5)Gates-Control flow into cavities.(6)Cavity (female) and Force (male)-Control the size,shape and surface of mold article.(7)Water Channels-Control the temperature of mold surfacesto chill plastic to rigid state.(8)Side (actuated by came, gears or hydrauliccylinders)-Form side holes, slots, undercuts and threaded sections.(9)Vent-Allow the escape of trapped air and gas.(10)Ejector Mechanism (pins, blades, stripper plate)-Ejectrigid molded article form cavity or force.(11)Ejector Return Pins-Return ejector pins to retractedposition as mold closes for next cycle.The distance between the outer cavities and the primary spree must not be so long that the molten plastic loses too much heat in the runner to fill the outer cavities properly. The cavities should be so arranged around the primary spree that each receives its full and equal share of the total pressure available, through its own runner system (or the so-called balanced runner system).The requires the shortest possible distance between cavities and primary sprue, equal runner and gate dimension, and uniform culling.注射成型注射成型的基本概念是使热塑性材料在受热时熔融，冷却时硬化，在大部分加工中，粒状材料（即塑料树脂）从料筒的一端（通常通过一个叫做“料斗”的进料装置）送进，受热并熔融（即塑化或增塑），然后当材料还是溶体时，通过一个喷嘴从料筒的另一端挤到一个相对较冷的压和封闭的模子里。

模具设计与制造模具是制造业的重要工艺基础，在我国模具制造属于专用设备制造业。

中国虽然很早就开始制造模具和使用模具，但长期未形成产业。

直到20世纪80年代后期，中国模具工业才驶入发展的快车道。

近年，不仅国有模具企业有了很大发展，三资企业、乡镇（个体）模具企业的发展也相当迅速。

虽然中国模具工业发展迅速，但与需求相比，显然供不应求，其主要缺口集中于精密、大型、复杂、长寿命模具领域。

由于在模具精度、寿命、制造周期及生产能力等方面，中国与国际平均水平和发达国家仍有较大差距，因此，每年需要大量进口模具。

中国模具产业除了要继续提高生产能力，今后更要着重于行业内部结构的调整和技术发展水平的提高。

结构调整方面，主要是企业结构向专业化调整，产品结构向着中高档模具发展，向进出口结构的改进，中高档汽车覆盖件模具成形分析及结构改进、多功能复合模具和复合加工及激光技术在模具设计制造上的应用、高速切削、超精加工及抛光技术、信息化方向发展。

近年，模具行业结构调整和体制改革步伐加大，主要表现在，大型、精密、复杂、长寿命、中高档模具及模具标准件发展速度高于一般模具产品；塑料模和压铸模比例增大；专业模具厂数量及其生产能力增加；“三资”及私营企业发展迅速；股份制改造步伐加快等。

从地区分布来看，以珠江三角洲和长江三角洲为中心的东南沿海地区发展快于中西部地区，南方的发展快于北方。

目前发展最快、模具生产最为集中的省份是广东和浙江，江苏、上海、安徽和山东等地近几年也有较大发展。

虽然我国模具总量目前已达到相当规模，模具水平也有很大提高，但设计制造水平总体上落后于德、美、日、法、意等工业发达国家许多。

当前存在的问题和差距主要表现在以下几方面：（1）总量供不应求，国内模具自配率只有70%左右。

其中低档模具供过于求，中高档模具自配率只有50%左右。

（2）企业组织结构、产品结构、技术结构和进出口结构均不合理。

我国模具生产厂中多数是自产自配的工模具车间（分厂），自产自配比例高达60%左右，而国外模具超过70%属商品模具。

毕业设计（论文）外文文献翻译文献、资料中文题目：模具设计与制造文献、资料英文题目：Mold design and manufacture 文献、资料来源：文献、资料发表（出版）日期：院（部）：专业：班级：姓名：学号：指导教师：翻译日期： 2017.02.14Mold design and manufactureThe mold is the manufacturing industry important craft foundation in our country，the mold manufacture belongs to the special purpose equipment manufacturing industry. Although China very already starts to make the mold and the use mold but long-term has not formed the industry. Chinese mold industry only then drives into the development speed way. Recent years not only the state-owned mold enterprise had the very big development the three investments enterprise the villages and towns individual the mold enterprises development also quite rapid. Although the Chinese mold industrial development rapid but compares with the demand obviously falls short of demand its main gap concentrates precisely to large-scale is complex the long life mold domain. As a result of in aspect and so on mold precision life manufacture cycle and productivity。

本科毕业设计(论文)外文翻译（附外文原文）学院：机械与控制工程学院课题名称：复杂阶梯形圆筒件拉深有限元分析专业(方向)：机械设计制造及其自动化（模具设计与制造）班级：学生：指导教师：日期：拉伸模设计中拉伸壁起皱的分析摘要本文研究带有斜度的方形盒和带有阶梯的方形盒的拉深中发生的起皱现象。

这两种类型的起皱现象有一个共同的特征：全都发生在相对无支撑、无压边的拉深壁处。

在带有斜度的方形盒的拉深中，常受到工序参数的影响，例如：模具的间隙值和压边力等，所以常用有限元模拟的方法来研究分析起皱的发生。

模拟的结果表明模具的间隙值越大，起皱现象就越严重，而且增加压边力也不能抑制和消除起皱现象的发生。

在带有阶梯的方形盒拉深的起皱现象分析中，常通过实际生产中一种近似的几何结构来研究、试验。

当凸模与阶梯边缘之间的金属板料在拉深时分布并不均衡，就会在侧壁发生起皱现象。

为了消除起皱现象的发生，一个最优的模具设计常采用有限元的方法进行分析。

模拟的结果和起皱试验论证了有限元分析的准确性，并且表明了在拉深模具设计中使用有限元方法分析的优越性。

关键词:侧壁起皱；拉深模；带有阶梯的方形盒；带有斜度的方形盒1 引言起皱是金属板料成形中常见的失效形式之一。

由于功能和视觉效果的原因，起皱通常是不能为零件制品所能接受的。

在金属板料成形加工中通常存在三种类型的起皱现象：法兰起皱；侧壁起皱和由于残余压应力在未变形区产生的弹性变形。

在冲压复杂形状的时候，拉深壁起皱就是在模具型腔中形成的褶皱。

由于金属板料在拉深壁区域内相对无支撑，因此，消除拉深壁起皱比抑制法兰起皱要难得多。

我们知道在不被支撑的拉深壁区域中材料的外力拉深可以防止起皱，这可以在实践中通过增加压边力而实现，但是运用过大的拉深力会引起破裂失效。

因此，压边力必须控制在一定的范围内，一方面可以抑制起皱，另一方面也可以防止破裂失效。

合适的压边力范围是很难确定的，因为起皱在拉深零件的中心区域以一个复杂的形状形成，甚至根本不存在一个合适的压边力范围。

英文翻译The Science of Die MakingThe traditional method of making large automotive sheet metal dies by model building and tracing has been replaced by CAD/CAM terminals that convert mathematical descriptions of body panel shapes into cutter paths.Teledyne Specialty Equipment’s Efficient Die and Mold facility is one of the companies on the leading edge of this transformation.by Associate EditorOnly a few years ago,the huge steel dies requited for stamping sheet metal auto body panels were built by starting with a detailed blueprint and an accurate full-scale master model of the part. The model was the source from which the tooling was designed and produced.The dies,machined from castings,were prepared from patterns made by the die manutacturers or somethimes supplied bythe car maker.Secondary scale models called”tracing aids”were made from the master model for use on duplicating machines with tracers.These machines traced the contour of the scale model with a stylus,and the information derived guided a milling cutter that carved away unwanted metal to duplicate the shape of the model in the steel casting.All that is changing.Now,companies such as Teledyne Specialty Equipment’s Effi cient Die and Mold operation in Independence,OH,work from CAD data supplied by customers to generate cutter paths for milling machines,which then automatically cut the sheetmetal dies and SMC compression molds.Although the process is uesd to make both surfaces of the tool, the draw die still requires a tryout and “benching” process.Also, the CAD data typically encompasses just the orimary surface of the tool,and some machined surfaces, such as the hosts and wear pads, are typically part of the math surface.William Nordby,vice president and business manager of dies and molds at Teledyne,says that “although no one has taken CAD/CAM to the point of building the entire tool,it will eventually go in that direction because the “big thrdd”want to compress cycle times and are trying to cut the amount of time that it takes to build the tooling.Tryout, because of the lack of development on the design end,is still a very time-consuming art,and vety much a trial-and-error process.”No More Models and Tracing AidsThe results to this new technology are impressive. For example, tolerances are tighter and hand finishing of the primary die surface with grinders has all but been eliminated. The big difference, says Gary Kral, Teledyne’s director of engineering, is that the dimensional control has radically improved. Conventional methods of making plaster molds just couldn’t hold tolerances because of day-to-day temperature and humidity variations.”For SMC molds the process is so accurate , and because there is no spring back like there is when stamping sheet metal, tryouts are not always required.SMC molds are approved by customers on a regulate basis without ever running a part .Such approvals are possible because of Teledyne’s ability to check the toolsurface based on mathematical analysis and guarantee that it is made exactly to the original design data.Because manual trials and processes have been eliminated, Teledyne has been able to consider foreign markets.” The ability to get a tool approved based on the mathe gives us the opportunity to compete in places we wouldn’t have otherwise,” says Nordby.According to Jim Church, systems manager at Teledyne, the company used to have lots of pattern makers ,and still has one model maker.” But 99.9 percent of the company’s work now is from CAD data. Instead of model makers, engineers work in front of computer monitors.”He says that improvenents in tool quality and reduction in manufacturing time are significant. Capabilities of the process were demonstrated by producing two identical tools. One was cut using conventional patterns and tracing mills, and the other tool was machined using computer generated cutting paths. Although machining time was 14 percent greater with the CAM-generated path, polishing hours were cut by 33 percent. In all ,manufacturing time decreased 16.5 percent and tool quality increased 12 percent.Teledyne’s CAD/CAM system uses state-of-the-art software that allows engineers to design dies and molds, develop CNC milling cutter paths and incorporate design changes easily. The system supports full-color, shaded three-dimensional modeling on its monitors to enhance its design and analysis capabilities. The CAD/CAM system also provides finite element analysis that can be used to improve the quality of castings , and to analyze the thermal properties of molds. Inputs virtually from any customer database can be used either directly or through translation.CMM Is CriticalTeledyne’s coordinate measuring machine(CMM),says’ Church,”is what has made a difference in terms of being able to move from the traditional manual processes of mold and die making to the automated system that Teledyne uses today.”The CMM precisely locates any point in a volume of space measuring 128 in, by 80 in, by 54 in, to an accuracy of 0.0007 in. It can measure parts, dies and molds weighing up to 40 tons. For maximum accuracy,the machine is housed in an environmentally isolated room where temperature is maintained within 2 deg.F of optimum. To isolate the CMM from vibration, it is mounted on a 100-ton concrete block supported on art cushions.According to Nordby, the CMM is used not only as a quality tool, but also as a process checking tool. “ As a tool goes through the shop, it is checked several times to validate the previous operation that was performed.” For example, after the initial surface of a mold is machined and before any finish work is done, it is run through the CMM for a complete data check to determine how close the surface is to the required geometry.The mold is checked with a very dense pattern based on flow lines of the part. Each mold is checked twice, once before benching and again after benching. Measurements taken from both halves of the mold are used to calculate theoretical stock thickness at full closure of the mold to verify its accuracy with the CAD design data.Sheet Metal Dies Are Different“Sheet metal is a different ballgame,” says Nordby, “because you have the issue of material springback and the way the metal forms in the die. What happens in the sheet metal is that you do the same kinds of things for the male punch as you would with SMC molds and you ensure that it is 100 percent to math data. But due to machined surface tolerance variations, the female half becomes the working side of the tool. And there is still a lot of development required after the tool goes into the press. The math generated surfaces apply primarily to the part surface of the tool.”EMS Tracks the Manufacturing ProcessTeledyne’s business operations also are computerized and carried over a network consisting of a V AX server and PC terminals. IMS (Effective Management Systems) software tracks orders, jobs in progress, location of arts, purchasing, receiving, and is now being upgraded to include accounting functions.Overall capabilities of the EMS system include bill-of-material planning and control, inventory management, standard costing, material history, master production scheduling, material requirements planning, customer order processing, booking and sales history, accounts receivable, labor history, shop floor control, scheduling, estimating, standard routings, capacity requirements planning, job costing, purchasing and receiving, requisitions, purchasing and receiving, requisitions, purchasing history and accounts payable.According to Frank Zugaro, Teledyne’s scheduling manager, the EMS software was chosen because of its capabilities in scheduling time and resources in a job shop environment. All information about a job is entered into inventory management to generate a structured bill of material. Then routes are attached to it and work orders are generated.The system provides daily updates of data by operator hour as well as a material log by shop order and word order. Since the database is interactive, tracking of materials received and their flow through the build procedure can be documented and cost data sent to accounting and purchasing.Gary Kral, Teledyne’s director of engineering, says that EMS is really a tracking device, and one of the systems greatest benefits is that it provides a documented record of everything involving a job and eliminates problems that could arise from verbal instructions and promises. Kral says that as the system is used more, they are finding that it pays to document more things to make it part of the permanent record. It helps keep them focused.模具制造科学传统的通过制造模具加工大型板材的方法已经被可以把实体的形状信息转换为切削路径的CAD/CAM所取代了。

冲压模具设计毕业外文翻译中英文翻译外文文献翻译毕业设计(论文)外文资料翻译系部:专业:姓名:学号:外文出处: The Pofessional English of DesignManufacture for Dies & Moulds附件: 1.外文资料翻译译文,2.外文原文。

指导教师评语:签名:年月日附件1:外文资料翻译译文冲压模具设计对于汽车行业与电子行业，各种各样的板料零件都是有各种不同的成型工艺所生产出来的，这些均可以列入一般种类“板料成形”的范畴。

板料成形(也称为冲压或压力成形)经常在厂区面积非常大的公司中进行。

如果自己没有去这些大公司访问，没有站在巨大的机器旁，没有感受到地面的震颤，没有看巨大型的机器人的手臂吧零件从一个机器移动到另一个机器，那么厂区的范围与价值真是难以想象的。

当然，一盘录像带或一部电视专题片不能反映出汽车冲压流水线的宏大规模。

站在这样的流水线旁观看的另一个因素是观看大量的汽车板类零件被进行不同类型的板料成形加工。

落料是简单的剪切完成的，然后进行不同类型的加工，诸如:弯曲、拉深、拉延、切断、剪切等，每一种情况均要求特殊的、专门的模具。

而且还有大量后续的加工工艺，在每一种情况下，均可以通过诸如拉深、拉延与弯曲等工艺不同的成形方法得到所希望的得到的形状。

根据板料平面的各种各样的受应力状态的小板单元体所可以考虑到的变形情形描述三种成形，原理图1描述的是一个简单的从圆坯料拉深成一个圆柱水杯的成形过程。

图1 板料成形一个简单的水杯拉深是从凸缘型坯料考虑的，即通过模具上冲头的向下作用使材料被水平拉深。

一个凸缘板料上的单元体在半径方向上被限定，而板厚保持几乎不变。

板料成形的原理如图2所示。

拉延通常是用来描述在板料平面上的两个互相垂直的方向被拉长的板料的单元体的变形原理的术语。

拉延的一种特殊形式，可以在大多数成形加工中遇到，即平面张力拉延。

在这种情况下，一个板料的单元体仅在一个方向上进行拉延，在拉长的方向上宽度没有发生变化，但是在厚度上有明确的变化，即变薄。

2 Injection molding machineFrom Plastics Wiki, free encyclopediaInjection molding machines consist of two basic parts, an injection unit and a clamping unit. Injection molding machines differ in both injection unit and clamping unit. The name of the injection molding machine is generally based on the type of injection unit used.2.1Types of injection molding machinesMachines are classified primarily by the type of driving systems they use: hydraulic, electric, or hybrid.2.1.1HydraulicHydraulic presses have historically been the only option available to molders until Nissei Plastic Industrial Co., LTD introduced the first all-electric injection molding machine in 1983. The electric press, also known as Electric Machine Technology (EMT), reduces operation costs by cutting energy consumption and also addresses some of the environmental concerns surrounding the hydraulic press.2.1.2ElectricElectric presses have been shown to be quieter, faster, and have a higher accuracy, however the machines are more expensive.2.1.3HybridHybrid injection molding machines take advantage of the best features of both hydraulic and electric systems. Hydraulic machines are the predominant type in most of the world, with the exception of Japan.2.2Injection unitThe injection unit melts the polymer resin and injects the polymer melt into the mold. The unit may be: ram fed or screw fed.The ram fed injection molding machine uses a hydraulically operated plunger to push the plastic through a heated region. The high viscosity melt is then spread into a thin layer by a "torpedo" to allow for better contact with the heated surfaces. The melt converges at a nozzle and is injected into the mold.Reciprocating screw A combination melting, softening, and injection unit in an injection molding machine. Another term for the injection screw. Reciprocating screws are capable of turning as they move back and forth.The reciprocating screw is used to compress, melt, and convey the material. The reciprocating screw consists of three zones (illustrated below):•feeding zone•compressing zone•metering zoneWhile the outside diameter of the screw remains constant, the depth of the flights on the reciprocating screw decreases from the feed zone to the beginning of the metering zone. These flights compress the material against the inside diameter of the barrel, which creates viscous (shear) heat. This shear heat is mainly responsible for melting the material. The heater bands outside the barrel help maintain the material in the molten state. Typically, a molding machine can have three or more heater bands or zones with different temperature settings.Injection molding reciprocating screw An extruder-type screw rotates within a cylinder, which is typically driven by a hydraulic drive mechanism. Plastic material is moved through the heated cylinder via the screw flights and the material becomes fluid. The injection nozzle is blocked by the previous shot, and this action causes the screw to pump itself backward through the cylinder. (During this step, material is plasticated and accumulated for the next shot.) When the mold clamp has locked, the injection phase takes place. At this time, the screw advances, acting as a ram. Simultaneously, the non-return valve closes off the escape passages in the screw and the screw serves as a solid plunger, moving the plastic ahead into the mold. When the injection stroke and holding cycle is completed, the screw is energized to return and the non-return valve opens, allowing plastic to flow forward from the cylinder again, thus repeating the cycle.2.2.1Feed hopperThe container holding a supply molding material to be fed to the screw. The hopper located over the barrel and the feed throat connects them.2.2.2Injection ramThe ram or screw that applies pressure on the molten plastic material to force it into the mold cavities.2.2.3Injection screwThe reciprocating-screw machine is the most common. This design uses the same barrel for melting and injection of plastic.The alternative unit involves the use of separate barrels for plasticizing and injecting the polymer. This type is called a screw-preplasticizer machine or two-stage machine. Plastic pellets are fed from a hopper into the first stage, which uses a screw to drive the polymer forward and melt it. This barrel feeds a second barrel, which uses a plunger to inject the melt into the mold. Older machines used one plunger-driven barrel to melt and inject the plastic. These machines are referred to as plunger-type injection molding machines.2.2.4BarrelBarrel is a major part that melts resins transmitted from hopper through screws and structured in a way that can heat up resins to the proper temperature. A band heater, which can control temper atures in five sections, is attached outside the barrel. Melted resins are supplied to the mold passing through barrel head, shot-off nozzle, and one-touch nozzle.2.2.5Injection cylinderHydraulic motor located inside bearing box, which is connected to injection cylinder load, rotates screw, and the melted resins are measures at the nose of screw. There are many types of injection cylinders that supply necessary power to inject resins according to the characteristics of resins and product types at appropriate speed and pressure. This model employs the double cylinder type. Injection cylinder is composed of cylinder body, piston, and piston load.2.3Clamping unitThe clamping unit holds the mold together, opens and closes it automatically, and ejects the finished part. The mechanism may be of several designs, either mechanical, hydraulic or hydromechanical.Toggle clamps - a type clamping unit include various designs. An actuator moves the crosshead forward, extending the toggle links to push the moving platen toward a closed position. At the beginning of the movement, mechanical advantage is low and speed is high; but near the end of the stroke, the reverse is true. Thus, toggle clamps provide both high speed and high force at different points in the cycle when they are desirable. They are actuated either by hydraulic cylinders or ball screws driven by electric motors. Toggle-clamp units seem most suited to relatively low-tonnage machines.Two clamping designs: (a) one possible toggle clamp design (1) open and (2) closed; and (b) hydraulic clamping (1) open and (2) closed. Tie rods used to guide movuing platens not shown.Hydraulic clamps are used on higher-tonnage injection molding machines, typically in the range 1300 to 8900 kN (150 to 1000 tons). These units are also more flexible than toggle clamps in terms of setting the tonnage at given positions during the stroke.Hydraulic Clamping System is using the direct hydraulic clamp of which the tolerance is still and below 1 %, of course, better than the toggle system. In addition, the Low Pressure Protection Device is higher than the toggle system for 10 times so that the protection for the precision and expensive mold is very good. The clamping force is focus on the central for evenly distribution that can make the adjustment of the mold flatness in automatically. Hydromechanical clamps -clamping units are designed for large tonnages, usually above 8900 kN (1000 tons); they operate by (1) using hydraulic cylinders to rapidly move the mold toward closing position, (2) locking the position by mechanical means, and (3) using high pressure hydraulic cylinders to finally close the mold and build tonnage.2.3.1Injection moldThere are two main types of injection molds: cold runner (two plate and three plate designs) and hot runner– the more common of the runnerless molds.2.3.2Injection platensSteel plates on a molding machine to which the mold is attached. Generally, two platens are used; one being stationary and the other moveable, actuated hydraulically to open and close the mold. It actually provide place to mount the mould. It contains threaded holes on which mould can be mounted using clamps.2.3.3Clamping cylinderA device that actuates the chuck through the aid of pneumatic or hydraulic energy.2.3.4Tie BarTie bars support clamping power, and 4 tie bars are located between the fixing platen and the support platen.3 Injection mouldFrom Wikipedia, the free encyclopediaMold A hollow form or cavity into which molten plastic is forced to give the shape of the required component. The term generally refers to the whole assembly of parts that make up the section of the molding equipment in which the parts are formed. Also called a tool or die. Moulds separate into at least two halves (called the core and the cavity) to permit the part to be extracted; in general the shape of a part must be such that it will not be locked into the mould. For example, sides of objects typically cannot be parallel with the direction of draw (the direction in which the core and cavity separate from each other). They are angled slightly; examination of most household objects made from plastic will show this aspect of design, known as draft. Parts that are "bucket-like" tend to shrink onto the core while cooling and, after the cavity is pulled away, are typically ejected using pins. Parts can be easily welded together after moulding to allow for a hollow part (like a water jug or doll's head) that couldn't physically be designed as one mould.More complex parts are formed using more complex moulds, which may require moveable sections, called slides, which are inserted into the mould to form particular features that cannot be formed using only a core and a cavity, but are then withdrawn to allow the part to be released. Some moulds even allow previously moulded parts to be re-inserted to allow a new plastic layer to form around the first part. This system can allow for production of fully tyred wheels.Traditionally, moulds have been very expensive to manufacture; therefore, they were usually only used in mass production where thousands of parts are being produced.Molds require: Engineering and design, special materials, machinery and highly skilled personnel to manufacture, assemble and test them.Cold-runner moldCold-runner mold Developed to provide for injection of thermoset material either directly into the cavity or through a small sub-runner and gate into the cavity. It may be compared to the hot-runner molds with the exception that the manifold section is cooled rather than heated to maintain softened but uncured material. The cavity and core plates are electrically heated to normal molding temperature and insulated from the cooler manifold section.3.1.1Types of Cold Runner MoldsThere are two major types of cold runner molds: two plate and three plate.3.1.2Two plate moldA two plate cold runner mold is the simplest type of mold. It is called a two plate mold because there is one parting plane, and the mold splits into two halves. The runner system must be located on this parting plane; thus the part can only be gated on its perimeter.3.1.3Three plate moldA three plate mold differs from a two plate in that it has two parting planes, and the mold splits into three sections every time the part is ejected. Since the mold has two parting planes, the runner system can be located on one, and the part on the other. Three plate molds are used because of their flexibility in gating location. A part can be gated virtually anywhere along its surface.3.1.4AdvantagesThe mold design is very simple, and much cheaper than a hot runner system. The mold requires less maintenance and less skill to set up and operate. Color changes are also very easy, since all of the plastic in the mold is ejected with each cycle.3.1.5DisadvantagesThe obvious disadvantage of this system is the waste plastic generated. The runners are either disposed of, or reground and reprocessed with the original material. This adds a step in the manufacturing process. Also, regrind will increase variation in the injection molding process, and could decrease the plastic's mechanical properties.3.1.6Hot runner moldHot-runner mold -injection mold in which the runners are kept hot and insulated from the chilled cavities. Plastic freezeoff occurs at gate of cavity; runners are in a separate plate so they are not, as is the case usually, ejected with the piece.Hot runner molds are two plate molds with a heated runner system inside one half of the mold.A hot runner system is divided into two parts: the manifold and the drops. The manifold has channels that convey the plastic on a single plane, parallel to the parting line, to a point abovethe cavity. The drops, situated perpendicular to the manifold, convey the plastic from the manifold to the part.3.1.7Types of Hot Runner MoldsThere are many variations of hot runner systems. Generally, hot runner systems are designated by how the plastic is heated. There are internally and externally heated drops and manifolds.3.1.8Externally heated hot runnersExternally heated hot runner channels have the lowest pressure drop of any runner system (because there is no heater obstructing flow and all the plastic is molten), and they are better for color changes none of the plastic in the runner system freezes. There are no places for material to hang up and degrade, so externally heated systems are good for thermally sensitive materials.3.1.9Internally heated hot runnersInternally heated runner systems require higher molding pressures, and color changes are very difficult. There are many places for material to hang up and degrade, so thermally sensitive materials should not be used. Internally heated drops offer better gate tip control. Internally heated systems also better separate runner heat from the mold because an insulating frozen layer is formed against the steel wall on the inside of the flow channels.3.1.10 insulated hot runnersA special type of hot runner system is an insulated runner. An insulated runner is not heated; the runner channels are extremely thick and stay molten during constant cycling. This system is very inexpensive, and offers the flexible gating advantages of other hot runners and the elimination of gates without the added cost of the manifold and drops of a heated hot runner system. Color changes are very easy. Unfortunately, these runner systems offer no control, and only commodity plastics like PP and PE can be used. If the mold stops cycling for some reason, the runner system will freeze and the mold has to be split to remove it. Insulated runners are usually used to make low tolerance parts like cups and frisbees.3.1.11 DisadvantagesHot-runner mold is much more expensive than a cold runner, it requires costly maintenance, and requires more skill to operate. Color changes with hot runner molds can be difficult, since it is virtually impossible to remove all of the plastic from an internal runner system.3.1.12 AdvantagesThey can completely eliminate runner scrap, so there are no runners to sort from the parts, and no runners to throw away or regrind and remix into the original material. Hot runners are popular in high production parts, especially with a lot of cavities.Advantages Hot Runner System Over a Cold Runner System include:•no runners to disconnect from the molded parts•no runners to remove or regrind, thus no need for process/ robotics to remove them•having no runners reduces the possibility of contamination•lower injection pressures•lower clamping pressure•consistent heat at processing temperature within the cavity•cooling time is actually shorter (as there is no need for thicker, longer-cycle runners)•shot size is reduced by runner weight•cleaner molding process (no regrinding necessary)•nozzle freeze and sprue sticking issues eliminated中文翻译注塑模具设计与制造2 注射机选自《维基百科》注射机由两个基本部分组成，注射装置和夹紧装置。

附录外文资料与中文翻译外文资料：China's mold industry and its development trend The mold is the manufacturing industry important craft foundation, in our country, the mold manufacture belongs to the special purpose equipment manufacturing industry. China although very already starts to make the mold and the use mold, but long-term has not formed the industry. Straight stabs 0 centuries 80's later periods, the Chinese mold industry only then drives into the development speedway. Recent years, not only the state-owned mold enterprise had the very big development, the three investments enterprise, the villages and towns (individual) the mold enterprise's development also quite rapid .Although the Chinese mold industrial development rapid, but compares with the demand, obviously falls short of demand, its main gap concentrates precisely to, large-scale,complex, the long life mold domain. As a result of in aspect and so on mold precision, life, manufacture cycle and productivity, China and the international average horizontal and the developed country still had a bigger disparity, therefore, needed massively to import the mold every year .The Chinese mold industry except must continue to sharpen the productivity, from now on will have emphatically to the profession internal structure adjustment and the state-of-art enhancement. The structure adjustment aspect, mainly is the enterprise structure to the specialized adjustment, the product structure to center the upscale mold development, to the import and export structure improvement, center the upscale automobile cover mold forming analysis and the structure improvement, the multi-purpose compound mold and the compound processing and the laser technology in the mold design manufacture application, the high-speed cutting, the superfinishing and polished the technology, the information direction develops .The recent years, the mold profession structure adjustment and the organizational reform step enlarges, mainly displayed in, large-scale, precise, complex, the long life, center the upscale mold and the mold standard letter development speed is higher than the common mold product; The plastic mold and the compression casting mold proportion increases; Specialized mold factory quantity and its productivity increase; "The three investments" and the private enterprise develops rapidly; The joint stock system transformation step speeds up and so on. Distributes from the area looked, take Zhujiang Delta and Yangtze River delta as central southeast coastal area development quickly to mid-west area, south development quickly to north. At present develops quickest, the mold produces the most centralized province is Guangdong and Zhejiang, places such as Jiangsu, Shanghai, Anhui and Shandong also has a bigger development in recent years .Although our country mold total quantity had at present achieved the suitable scale, the mold level also has the very big enhancement, after but design manufacture horizontal overall rise and fall industry developed country and so on Yu De, America, date, France, Italy many. The current existence question and the disparity mainly display in following several aspects:(1) The total quantity falls short of demandDomestic mold assembling oneself rate only ,about 70%. Low-grade mold , center upscale mold assembling oneself rate only has 50% about .(2) The enterprise organizational structure, the product structure, the technical structure and the import and export structure does not gather In our country mold production factory to be most is from the labor mold workshop which produces assembles oneself (branch factory), from produces assembles oneself the proportion to reach as high as about 60%, but the overseas mold ultra 70% is the commodity mold. The specialized mold factory mostly is "large and complete", "small and entire" organization form, but overseas mostly is "small but", "is specially small and fine". Domestic large-scale, precise, complex, the long life mold accounts for the total quantity proportion to be insufficient 30%, but overseas in 50% above 2004 years, ratio of the mold import and export is 3.7:1, the importand export balances the after net import volume to amount to 1.32 billion US dollars, is world mold net import quantity biggest country .(3) The mold product level greatly is lower than the international standardThe production cycle actually is higher than the international water broad product level low mainly to display in the mold precision, cavity aspect and so on surface roughness, life and structure .(4) Develops the ability badly, economic efficiency unsatisfactory.Our country mold enterprise technical personnel proportion low the level is lower, also does not take the product development, frequently is in the passive position in the market. Our country each mold staff average year creation output value approximately ,ten thousand US dollars, overseas mold industry developed country mostly 15 to 20 thousand US dollars, some reach as high as 25 to 30 thousand US dollars, relative is our country quite part of molds enterprises also continues to use the workshop type management with it, truly realizes the enterprise which the modernized enterprise manages fewTo create the above disparity the reason to be very many, the mold long-term has not obtained the value besides the history in as the product which should have, as well as the most state-owned enterprises mechanism cannot adapt the market economy, but also has the following several reasons: .(1) Country to mold industry policy support dynamics also insufficientlyAlthough the country already was clear about has promulgated the mold profession industrial policy, but necessary policy few, carried out dynamics to be weak. At present enjoyed the mold product increment duty enterprise nation 185, the majority enterprise still the tax burden is only overweight. The mold enterprise carries on the technological transformations introduction equipment to have to pay the considerable amount the tax money, affects the technology advancement, moreover privately operated enterprise loan extremely difficult .(2) Talented person serious insufficient, the scientific research development and the technical attack investment too urineMold profession is the technology, the fund, the work crowded industry, along with the time progress and the technical development, grasps the talented person which and skilled utilizes the new technology exceptionally short, the high-quality mold fitter and the enterprise management talent extremely is also anxious. Because the mold enterprise benefit unsatisfactory and takes insufficiently the scientific research development and the technical attack, the scientific research unit and the universities, colleges and institutes eye stares at is creating income, causes the mold profession invests too few in the scientific research development and the technical attack aspect, causes the mold technological development step not to be big, progresses not quick .(3) The craft equipment level to be low, also necessary is not good, the use factor lowrecent years our country engine bed profession progressed quickly, has been able to provide the quite complete precision work equipment, but compared with the overseas equipment, still had a bigger disparity. Although the domestic many enterprises have introduced many overseas advanced equipment, but the overall equipment level low are very more than the overseas many enterprises. As a result of aspect the and so on system and fund reason, introduces the equipment not not necessary, the equipment and the appendix not necessary phenomenon are extremely common, the equipment utilization rate low question cannot obtain the comparatively properly solution for a long time .(4) Specialization, standardization, commercialized degree low, the cooperation abilityBecause receives "large and complete" "small and entire" the influence since long ago, mold specialization level low, the specialized labor division is not careful, the commercialized degree is low. At present domestic every year produces mold, commodity mold minister 40% About, other for from produce uses for oneself. Between the mold enterprise cooperates impeded, completes the comparatively large-scale mold complete task with difficulty. Mold standardization level low, moldstandard letter use cave rare is low also to the mold quality, the cost has a more tremendous influence, specially has very tremendous influence .(5) To the mold manufacture cycle) the mold material and the mold correlation technology fallsThe mold material performance, the quality and the variety question often can affect the mold quality, the life and the cost, the domestically produced molding tool steel and overseas imports the steel products to compare has a bigger disparity. Plastic, plate, equipment energy balance, also direct influence mold level enhancement .At present, our country economy still was at the high speed development phase, on the international economical globalization development tendency is day by day obvious, this has provided the good condition and the opportunity for the our country mold industry high speed development. On the one hand, the domestic mold market will continue high speed to develop, on the other hand, the mold manufacture also gradually will shift as well as the transnational group to our country carries on the mold purchase trend to our country extremely to be also obvious. Therefore, will take a broad view the future, international, the domestic mold market overall development tendency prospect will favor, estimated the Chinese mold will obtain the high speed development under the good market environment, our country not only can become the mold great nation, moreover certainly gradually will make the powerful nation to the mold the ranks to make great strides forward. "15" period, the Chinese mold industry level not only has the very big enhancement in the quantity and the archery target aspect, moreover the profession structure, the product level, the development innovation ability, enterprise's system and the mechanism as well as the technology advancement aspect also can obtain a bigger development .The mold technology has gathered the machinery, the electron, chemistry, optics, the material, the computer, the precise monitor and the information network and so on many disciplines, is a comprehensive nature multi-disciplinary systems engineering. The mold technology development tendency mainly is the mold product to larger-scale, preciser, more complex and a more economical direction develops,the mold product technical content unceasingly enhances, the mold manufacture cycle unceasingly reduces, the mold production faces the information, is not having the chart, is fine, the automated direction develops, the mold enterprise to the technical integration, the equipment excellent, is producing approves the brand, the management information, the management internationalization direction develops. Our country mold profession still will have to enhance from now on the general character technology had :(1) To establish in the CAD/CAE platform the advanced mold design technology, enhances modernization which the mold designed, information, intellectualization, standardized level .(2) Establishes in the CAM/CAPP foundation the advanced mold processing technology and the advanced manufacture technology unifies, raises the automated level and the production efficiency which the mold processes .(3) The mold production enterprise's information management technology. For example PDM (product data management), ERP (enterprise resource management), MIS (mold manufacture management information system) and information network technology the and so on INTERMET platform application, the promotion and the development .(4) Are high speed, Gao Jing, the compound mold processing technology research and the application. For example the ultra fine ramming mold manufacture technology, the precise plastic and the compression casting mold manufacture technology and so on .(5) Enhances the mold production efficiency, reduces the cost and reduces the mold production cycle each kind of fast economical mold manufacture technology .(6) The advanced manufacture technology application. For example hot technology and so on flow channel technology, gas auxiliary technology, hypothesized technology, nanotechnology, rapid scanning technology, reversion project, parallel project in the mold research, the development, the processing process application .(7) The raw material the simulation technology which forms in the mold .(8) The advanced mold processing and the appropriation equipment research and the development .(9) The mold and the mold standard letter, the important auxiliary standardizedtechnology .(10) The mold and its the product examination technology.(11) High quality, the new mold material research and the development and itsthe correct application .(12) The mold production enterprise's modern management technology □Mold profession in "十15" period needs to solve the key essential technologyshould be the mold information, the digitized technology and precise, ultra fine,high speed, the highly effective manufacture technology aspect breakthrough Along with the national economy total quantity and the industry producttechnology unceasing development, all the various trades and occupations to the molddemand quantity more and more big, the specification more and more is also high.Although mold type many, but its development should be with emphasis both canmeet the massive needs, and has the comparatively high-tech content, specially atpresent domestic still could not be self-sufficient, needs the massive imports themold and can represent the development direction large-scale, precise, is complex,the long life mold. The mold standard letter type, the quantity, the level, theproduction a and so on have the significant influence to the entire mold professiondevelopment. Therefore, some important mold standard letters also must theprioritize, moreover its development speed should quickly to the mold developmentspeed, like this be able unceasingly to raise our country mold standardization level,thus improves the mold quality, reduces the mold production cycle, reduces the cost.Because our country mold product holds the bigger price superiority in theinternational market, therefore regarding the exportation prospect good moldproduct also should take key develops. According to the above required quantity big,the technical content is high, represents the development direction, the exportprospect good principle choice prioritize product, moreover chooses the product tohave at present to have the certain technology base, belongs has the condition, hasthe product which the possibility develops .According to "十15" the mold profession development plan, "十15" the period mold product development mainly has following several kind of the automobile cover mold(1)Ramming mold to occupyThe mold total quantity dish with emphasis above 40%. Automobile cover mold mainly for automobile necessary, also includes for the agriculture with the vehicle, the project machinery and the farm machinery necessary cover mold, it has the very big representation in the ramming mold, the mold mostly is large and middle scale, structure complex, the specification is high. For the passenger vehicle necessary cover mold, the request is in particular higher, may represent the ramming mold the level. This kind of mold our country had the certain technology base, already for middle-grade passenger vehicle necessary, but the level is not high, the ability is insufficient, at present satisfying rate only has one about the half. Center the upscale passenger vehicle cover mold main dependence import, has become the bottleneck which the automobile develops, enormous influence vehicle type development .(2)The precise ramming moldMulti- locations level was entering the mold and fine represents the ramming mold development direction, the precision request life request has been extremely high, mainly for the electronics industry, the automobile, the instrument measuring appliance, the electrical machinery electric appliance and so on formed a complete set. These two kind of molds, domestic had the suitable foundation, and has introduced the overseas technology and the equipment, the individual enterprise produces the product has achieved the world level, but the majority of enterprises still had a bigger disparity, the supply total quantity insufficient, the import were very many(3) The large-scale precise plastic moldPlastic mold accounts for the mold total quantity 10%, moreover this proportion also is rising. In the plastic mold necessary large-scale casts the mold for the automobile and the electrical appliances, necessary models for the integratedcircuit seals the mold, for the electronic information industry and the machinery and the packing necessary multilayer, the multi- cavities, the multi- material qualities, the multicolor precise note , and saves water the agricultural necessary plastic different molding for the new building materials to squeeze out the mold and the pipeline and the nozzle mold and so on, at present although had the suitable technology base and fast is developing, but the technical level and overseas still had a bigger disparity, the total quantity falls short of demand, Every year import amount reaches several hundred million US dollar.(4) The main mold standard to imitateeAt present domestically to have an greater output the mold standard letter mainly is the mold frame, the guidance, the throwout lever pushes the tube, the elastic part and so on. These products not only the domestic necessary massive need, the exportation prospect very is also good, should continue vigorously to develop. The nitrogen cylinder and the hot flow channel part main dependence import, should raise the level in the existing foundation, forms the standard and organization scale production.(5) The other high-tech content moldsOccupiesin the mold total quantity green 8% compression casting mold, large-scale thin wall precise compression casting technology content high, the difficulty is big. The magnesium alloy compression casting mold at present although just started, but the prospects for development were good, have the representation. The meridian rubber tire mold also is the development direction, detachable mold technology difficulty is biggest. With fast takes shape some fast pattern making technologies and the corresponding fast economical mold which the technology unifies has the very good prospects for development. These high-tech content molds in "十15" period also should the prioritize .中文翻译：我国模具工业现状及发展趋势模具是制造业的重要工艺基础，在我国，模具制造属于专用设备制造业。

可行成形图在汽车覆盖件冲压工艺高效设计的应用Dae-Cheol Ko a，Seung-Hoon Cha b，Sang-Kon Lee c，Chan-Joo Lee b，Byung-Min Kim d,*a ILIC, Pusan National University, 30 Jangjeon-Dong, Kumjeong-Gu, Busan609-735, South Koreab Precision Manufacturing Systems Division, Pusan National University, 30Jangjeon-Dong, Kumjeong-Gu, Busan 609-735, South Koreac PNU-IFAM, Joint Research Center, Pusan National University, 30Jangjeon-Dong, Kumjeong-Gu, Busan 609-735, South Koread School of Mechanical Engineering, Pusan National University, 30 Jangjeon-Dong, Kumjeong-Gu, Busan 609-735, South Korea摘要：本文提出使用可行的成形图来表示无断裂和起皱的安全区域，进而有效和快速地设计冲压工艺方法。

要确定可行的成形图，有限元分析对应于正交实验设计的过程变量组合。

随后，基于成形极限图的有限元分析，确定断裂和起皱的特征值。

所有组合的特征值在整个过程中，通过人工神经网络训练进行了一系列预测。

可行的成形图从所有组合的过程变量中最终确定。

以汽车覆盖件如转动架和车轮毂的冲压工艺作为实例来验证利用成形图的进行过程设计有效性。

有限元模拟结果与实验模拟结果比较表明，利用可行的成形图来进行冲压工艺的设计是有效的并适用于实际的过程。

外文翻译-模具类注塑机模具设计外文翻译毕业设计题目:操纵机构及其面板凸轮机构模具设计原文1:Plastic Material Molding译文1:塑料成型原文2:The Injection-molding Maching 译文2:注塑机Plastic Material MoldingPlastic objects are formed by comperssion,transfer,and injection molding.Other processes arecasting, extrusion and laminating, filament winding, sheet forming, jointing, foaming, andmaching. Some of these and still otherrs are used for rubber. A reason for a variety of processes isthat different materials must be worked in differentways. Also, each methods is advantageous for certain kind of product(Table 1)Table 1 Characteristics of Forming and Shaping Processesfor Plastics and Composite Materialsprocess CharacteristicsExtrusion Long, uniform, solid or hollow complex cross-sections;high production rates; low tooling costs; widetolerrances.Injection molding Complex shapes of various sizes, eliminating assembly;high production rates; costly tooling; good dimensionalaccurancy.Structural foam molding Large parts with high stiffness-to-weight ratio; lessexpensive tooling than in injection molding; lowproduction rates.Blow molding Hollow thin-walled parts of various sizes; highproduction rates and low cost for making containers.Rotational molding Large hollow shapes of relatively simple shape;lowtooling cost; low production rates.Thermoforming Shallow or relatively deep cavities; low tooling costs;medium production rates.Compression molding Parts similar to impression-die forging;relativelyinpensive tooling; medium production rates.Transfer molding More complex parts than compression molding andhigher production rates; some scrap loss; mediumtooling cost.1Casting Simple or intricate shapes made with flexible molds;low production rates.Processing of composite materials Long cycle time; tolerances and tooling cost depend onprocess.There are two main steps in the manufacture of plastic products. The first is a chemical process to create the resin. The second is to mixand shape all the material into the finished article or product.1.1 Compression MoldingIn compression molding, a preshaped charge of material, a premeasured volume of powder, or a viscous mixture of liquid redin and filler material is placed directly into a heated mold cavity. Forming is done under pressure from a plug or from the upper half of the die (Figer 1). Compression molding results in the formation of flash (if additional plastic is forced between the mold halves, because of a poor mold fit or wear, it is called flash.), which is subsequently removed by trimming or other means.Typical parts made are dishes, handles, container caps, fittings, electrical and electronic components, washing-machine agitators, and housings. Fiber-reinforced parts with long chopped fibers are formed by this process exclusively.Compression molding is used mainly with thermosetting plastics, with the original material being in a partially ploymerized state. Cross-linking (in these ploymers, additional element link one chain to another. The best example is the use of sulfur to cross-link elastomers to create automobile tires) is completed in the heated die; curing times rang from0.5 to 5 minutes, depending on the material and on part thickness and geometry. The thicker the material is, the longer it will take to cure. Elastomers are also shaped by compression molding.Three types of compression molds are available as follows:2Figuer 1 Typres of compression moldinga. flash-type, for shallow or flat parts,b. positive, for high density parts,c. semipositive, for quality production.1.2 Transfer MoldingTransfer molding represents a further development of compression molding. The uncured thermosetting material is placed in a heatedtransfer pot or chamber (Figer 2). After the materialis heated, it is injected into heated closed molds. A ram, a plunger, or a rotating-screw feeder (depending on the type of machine used)forces the material to flow through the narrow channels into the mold cavity.Typical parts made by transfer molding are electrical and electronic components and rubber and silicone parts. This process is particularly suitable for intricate parts with varying wall thickness.1.3 Injection MoldingInjection molding (injection of plastic into a catity of desired shape. The plastic is then cooled and ejected in its final form. Most consumer productions such as telephones, computer casings, and CD players are injection molded. ) is principally used for the production of thermoplastic parts, although some process has been made in developing a method for injection molding some3thermosetting materials.Figure 2 Sequence of operations in transfer molding forthermosetting plastics The problem of injection a melted plastic into a mold cavity from a reservoir melted material has been extremelydifficult to solve for thermosetting plastics which cure and harden such conditions within a few minutes. The principle of injection molding is quite similar to that of die-casting. Plastic powder is loaded into thefeed hopper and a certain amount feeds into the heating chamber when the plunger draws back. The plastic powder under heat and pressures in the heating chamber becomes a fluid. After the mold is closed, the plunger moves forward, forcing some of the fluid plastic into the mold cavity under pressures. Since the mold in cooled by circulating cold water, the plastic hardens and the part may be ejected when the plunger draws back and the mold opens. Injection-molding machines can be arranged for manual operation, automatic single-cycle operation, and ful automatic operation. Typical machines produce molded parts weighing up to 22 ounces at the rate of four shots per minute, and it is possible on molded parts machines to obtain a rate of six shots per minute. The molds used are similar to the dies of a die-casting machine. The advantages of injection molding are as follows:1. A high molding speed adapted for mass production is possible,2. There is a wide choice of thermoplastic materials providing a variety of usefulproperties,3. It is possible to mold threads,(“sideways” racesses or projections of the molded part thatprevent its removal from the mold along the parting direction. They can accommodated4by specialized mold design such as sliders.), side holes, and large thin sections. 1.4 Thermoplastic Mold DesignBasically, there are two types of transfer mold: the conventional sprue type and the positive plunger type. In the sprue type the plastic performs are placed in a separate loading chamber above the mold cavity. One or more sprues (the runway between the injection machine's nozzle and the runners or the gate) lead down to the parting surface of the mold where they connect with gates to the mold cavity or cavities (Figer 3). Special press with a floating intermediate platen are especially useful for accommodating the two parting surface molds. The plunger acts directly on the plastic material, forcing it through the sprues and gates into the mold cavities. Heat and pressure must be maintained for a definite time for curing. When the part is cured the press is opened, breaking the sprues from the gates. The cull and sprues and raised upward, being held by a tapered, dovetailed projection machine on the end ofFigure 3 Schematic illustration of transfer moldingthe plunger. They can easily be removed from the dovetail by pushing horizontally. In a positive plunger-type transfer mold the sprue is eliminated so that the loading chamber extends through to the mold parting surface and connects directly with the gates (the entrance to the mold cavity). The positive plunger type is preferred, because themold is less complicated, and less material is wasted. Parts made by transfer molding have greater strength, more uniform densities, closer dimensional tolerances, and the parting plane (the separation plane of the two mold halves) requires less cleaning as compression molding.The following figure shows a typical two-plate mold and indicates the structure of mold and the arrangement of all parts in mold (Figure4).5Figure 4 The typical structure of two-plate mold作者:Yijun Huang国籍:china出处:Qinghua university press6塑料成型塑料制品一般是由压缩，传递和注塑成型等方法形成的。

Mold design and manufactureThe mold is the manufacturing industry important craft foundation, in our country, the mold manufacture belongs to the special purpose equipment manufacturing industry. China although very already starts to make the mold and the use mold, but long-term has not formed the industry. Straight stabs 0 centuries 80's later periods, the Chinese mold industry only then drives into the development speedway. Recent years, not only the state-owned mold enterprise had the very big development, the three investments enterprise, the villages and towns (individual) the mold enterprise's development also quite rapid .Although the Chinese mold industrial development rapid, but compares with the demand, obviously falls short of demand, its main gap concentrates precisely to, large-scale, is complex, the long life mold domain. As a result of in aspect and so on mold precision, life, manufacture cycle and productivity, China and the international average horizontal and the developed country still had a bigger disparity, therefore, needed massively to import the mold every year .The Chinese mold industry except must continue to sharpen the productivity, from now on will have emphatically to the profession internal structure adjustment and the state-of-art enhancement. The structure adjustment aspect, mainly is the enterprise structure to the specialized adjustment, the product structure to center the upscale mold development, to the import and export structure improvement, center the upscale automobile cover mold forming analysis and the structure improvement, the multi-purpose compound mold and the compound processing and the laser technology in the mold design manufacture application, the high-speed cutting, the superfinishing and polished the technology, the information direction develops .The recent years, the mold profession structure adjustment and the organizational reform step enlarges, mainly displayed in, large-scale, precise, was complex, the long life, center the upscale mold and the mold standard letter development speed is higher than the common mold product; The plastic mold and the compression casting mold proportion increases; Specialized mold factory quantity and its productivity increase; "The three investments" and the private enterprise develops rapidly; The joint stock system transformation step speeds up and so on. Distributes from the area looked, take Zhujiang Delta and Yangtze River delta as central southeast coastal area development quickly to mid-west area, south development quickly to north. At present develops quickest, the mold produces the most centralized province is Guangdong and Zhejiang, places such as Jiangsu, Shanghai, Anhui and Shandong also has a bigger development in recent years .Although our country mold total quantity had at present achieved the suitable scale, the mold level also has the very big enhancement, after but design manufacture horizontal overall rise and fall industry developed country and so on Yu De, America, date, France, Italy many. The current existence question and the disparity mainly display in following several aspects:(1) the total quantity falls short of demanddomestic mold assembling oneself rate only ,about 70%. Low-grade mold , center upscale mold assembling oneself rate only has 50% about .(2) the enterprise organizational structure, the product structure, the technical structure and the import and export structure does not gatherin our country mold production factory to be most is from the labor mold workshop which produces assembles oneself (branch factory), from produces assembles oneself the proportion to reach as high as about 60%, but the overseas mold ultra 70% is the commodity mold. The specialized mold factory mostly is "large and complete", "small and entire"organization form, but overseas mostly is "small but", "is specially small and fine". Domestic large-scale, precise, complex, the long life mold accounts for the total quantity proportion to be insufficient 30%, but overseas in 50% above 2004 years, ratio of the mold import and export is 3.7:1, the import and export balances the after net import volume to amount to 1.32 billion US dollars, is world mold net import quantity biggest country .(3) the mold product level greatly is lower than the international standardthe production cycle actually is higher than the international water broad product level low mainly to display in the mold precision, cavity aspect and so on surface roughness, life and structure .(4) develops the ability badly, economic efficiency unsatisfactory our country mold enterprise technical personnel proportion lowthe level is lower, also does not take the product development, frequently is in the passive position in the market. Our country each mold staff average year creation output value approximately ,ten thousand US dollars, overseas mold industry developed country mostly 15 to10,000 US dollars, some reach as high as 25 to10,000 US dollars, relative is our country quite part of molds enterprises also continues to use the workshop type management with it, truly realizes the enterprise which the modernized enterprise manages fewTo create the above disparity the reason to be very many, the mold long-term has not obtained the value besides the history in as the product which should have, as well as the most state-owned enterprises mechanism cannot adapt the market economy, but also has the following several reasons: .(1) country to mold industry policy support dynamics also insufficientlyalthough the country already was clear about has promulgated the mold profession industrial policy, but necessary policy few, carried out dynamics to be weak. At present enjoyed the mold product increment duty enterprise nation 185, the majority enterprise still the tax burden is only overweight. The mold enterprise carries on the technological transformations introduction equipment to have to pay the considerable amount the tax money, affects the technology advancement, moreover privately operated enterprise loan extremely difficult .(2) talented person serious insufficient, the scientific research development and the technical attack investment too urinemold profession is the technology, the fund, the work crowded industry, along with the time progress and the technical development, grasps the talented person which and skilled utilizes the new technology exceptionally short, the high-quality mold fitter and the enterprise management talent extremely is also anxious. Because the mold enterprise benefit unsatisfactory and takes insufficiently the scientific research development and the technical attack, the scientific research unit and the universities, colleges and institutes eye stares at is creating income, causes the mold profession invests too few in the scientific research development and the technical attack aspect, causes the mold technological development step not to be big, progresses not quick . (3) the craft equipment level to be low, also necessary is not good, the use factor lowrecent years our country engine bed profession progressed quickly, has been able to provide the quite complete precision work equipment, but compared with the overseas equipment, still had a bigger disparity. Although the domestic many enterprises have introduced many overseas advanced equipment, but the overall equipment level low are very more than the overseas many enterprises. As a result of aspect the and so on system and fund reason, introduces the equipment not not necessary, theequipment and the appendix not necessary phenomenon are extremely common, the equipment utilization rate low question cannot obtain the comparatively properly solution for a long time .(4) specialization, standardization, commercialized degree low, the cooperation abilitybecause receives "large and complete" "small and entire" the influence since long ago, mold specialization level low, the specialized labor division is not careful, the commercialized degree is low. At present domestic every year produces mold, commodity mold minister 40% About, other for from produce uses for oneself. Between the mold enterprise cooperates impeded, completes the comparatively large-scale mold complete task with difficulty. Mold standardization level low, mold standard letter use cave rare is low also to the mold quality, the cost has a more tremendous influence, specially has very tremendous influence . (5) to the mold manufacture cycle) the mold material and the mold correlation technology fallsthe mold material performance, the quality and the variety question often can affect the mold quality, the life and the cost, the domestically produced molding tool steel and overseas imports the steel products to compare has a bigger disparity. Plastic, plate, equipment energy balance, also direct influence mold level enhancement .At present, our country economy still was at the high speed development phase, on the international economical globalization development tendency is day by day obvious, this has provided the good condition and the opportunity for the our country mold industry high speed development. On the one hand, the domestic mold market will continue high speed to develop, on the other hand, the mold manufacture also gradually will shift as well as the transnational group to our country carries on the mold purchase trend to our country extremely to be also obvious. Therefore, will take a broad view the future, international, thedomestic mold market overall development tendency prospect will favor, estimated the Chinese mold will obtain the high speed development under the good market environment, our country not only can become the mold great nation, moreover certainly gradually will make the powerful nation to the mold the ranks to make great strides forward. "15" period, the Chinese mold industry level not only has the very big enhancement in the quantity and the archery target aspect, moreover the profession structure, the product level, the development innovation ability, enterprise's system and the mechanism as well as the technology advancement aspect also can obtain a bigger development .The mold technology has gathered the machinery, the electron, chemistry, optics, the material, the computer, the precise monitor and the information network and so on many disciplines, is a comprehensive nature multi-disciplinary systems engineering. The mold technology development tendency mainly is the mold product to larger-scale, preciser, more complex and a more economical direction develops, the mold product technical content unceasingly enhances, the mold manufacture cycle unceasingly reduces, the mold production faces the information, is not having the chart, is fine, the automated direction develops, the mold enterprise to the technical integration, the equipment excellent, is producing approves the brand, the management information, the management internationalization direction develops. Our country mold profession still will have to enhance from now on the general character technology had :(1) to establish in the CAD/CAE platform the advanced mold design technology, enhances modernization which the mold designed, information, intellectualization, standardized level .(2) establishes in the CAM/CAPP foundation the advanced mold processing technology and the advanced manufacture technology unifies,raises the automated level and the production efficiency which the mold processes .(3) the mold production enterprise's information management technology. For example PDM (product data management), ERP (enterprise resource management), MIS (mold manufacture management information system) and information network technology the and so on INTERMET platform application, the promotion and the development .(4) are high speed, Gao Jing, the compound mold processing technology research and the application. For example the ultra fine ramming mold manufacture technology, the precise plastic and the compression casting mold manufacture technology and so on .(5) enhances the mold production efficiency, reduces the cost and reduces the mold production cycle each kind of fast economical mold manufacture technology .(6) the advanced manufacture technology application. For example hot technology and so on flow channel technology, gas auxiliary technology, hypothesized technology, nanotechnology, rapid scanning technology, reversion project, parallel project in the mold research, the development, the processing process application .(7) the raw material the simulation technology which forms in the mold .(8) the advanced mold processing and the appropriation equipment research and the development .(9) the mold and the mold standard letter, the important auxiliary standardized technology .(10) the mold and its the product examination technology.(11) high quality, the new mold material research and the development and its the correct application .(12) the mold production enterprise's modern management technology □Mold profession in "十15" period needs to solve the key essential technology should be the mold information, the digitized technology and precise, ultra fine, high speed, the highly effective manufacture technology aspect breakthroughAlong with the national economy total quantity and the industry product technology unceasing development, all the various trades and occupations to the mold demand quantity more and more big, the specification more and more is also high.Although mold type many, but its development should be with emphasis both can meet the massive needs, and has the comparatively high-tech content, specially at present domestic still could not beself-sufficient, needs the massive imports the mold and can represent the development direction large-scale, precise, is complex, the long life mold. The mold standard letter type, the quantity, the level, the production a and so on have the significant influence to the entire mold profession development. Therefore, some important mold standard letters also must the prioritize, moreover its development speed should quickly to the mold development speed, like this be able unceasingly to raise our country mold standardization level, thus improves the mold quality, reduces the mold production cycle, reduces the cost. Because our country mold product holds the bigger price superiority in the international market, therefore regarding the exportation prospect good mold product also should take key develops. According to the above required quantity big, the technical content is high, represents the development direction, the export prospect good principle choice prioritize product, moreover chooses the product to have at present to have the certain technology base, belongs has the condition, has the product which the possibility develops .According to "十15" the mold profession development plan, "十15" the period mold product development mainly has following several kind of the automobile cover mold(1) ramming mold to occupythe mold total quantity dish with emphasis above 40%. Automobile cover mold mainly for automobile necessary, also includes for the agriculture with the vehicle, the project machinery and the farm machinery necessary cover mold, it has the very big representation in the ramming mold, the mold mostly is large and middle scale, structure complex, the specification is high. For the passenger vehicle necessary cover mold, the request is in particular higher, may represent the ramming mold the level. This kind of mold our country had the certain technology base, already for middle-grade passenger vehicle necessary, but the level is not high, the ability is insufficient, at present satisfying rate only has one about the half. Center the upscale passenger vehicle cover mold main dependence import, has become the bottleneck which the automobile develops, enormous influence vehicle type development .(2)the precise ramming moldmulti- locations level was entering the mold and fine represents the ramming mold development direction, the precision request life request has been extremely high, mainly for the electronics industry, the automobile, the instrument measuring appliance, the electrical machinery electric appliance and so on formed a complete set. These two kind of molds, domestic had the suitable foundation, and has introduced the overseas technology and the equipment, the individual enterprise produces the product has achieved the world level, but the majority of enterprises still had a bigger disparity, the supply total quantity insufficient, the import were very many(3) the large-scale precise plastic moldplastic mold accounts for the mold total quantity 10%, moreover this proportion also is rising. In the plastic mold necessary large-scale casts the mold for the automobile and the electrical appliances, necessary models for the integrated circuit seals the mold, for the electronic information industry and the machinery and the packing necessary multilayer, the multi- cavities, the multi- material qualities, the multicolor precise note , and saves water the agricultural necessary plastic different molding for the new building materials to squeeze out the mold and the pipeline and the nozzle mold and so on, at present although had the suitable technology base and fast is developing, but the technical level and overseas still had a bigger disparity, the total quantity falls short of demand, Every year import amount reaches several hundred million US dollar.(4) the main mold standard to imitateeat present domestically to have an greater output the mold standard letter mainly is the mold frame, the guidance, the throwout lever pushes the tube, the elastic part and so on. These products not only the domestic necessary massive need, the exportation prospect very is also good, should continue vigorously to develop. The nitrogen cylinder and the hot flow channel part main dependence import, should raise the level in the existing foundation, forms the standard and organization scale production.(5) the other high-tech content moldsoccupiesin the mold total quantity green 8% compression casting mold, large-scale thin wall precise compression casting technology content high, the difficulty is big. The magnesium alloy compression casting mold at present although just started, but the prospects for development were good, have the representation. The meridian rubber tire mold also is the development direction, detachable mold technology difficulty is biggest. With fast takes shape some fast pattern making technologies and thecorresponding fast economical mold which the technology unifies has the very good prospects for development. These high-tech content molds in "十15" period also should the prioritize .模具设计与制造模具是制造业的重要工艺基础，在我国，模具制造属于专用设备制造业。

外文翻译：Injection moulding for Mold Design and ManufactureThe mold is the manufacturing industry important craft foundation, in our country, the mold manufacture belongs to the special purpose equipment manufacturing industry. China although very already starts to make the mold and the use mold, but long-term has not formed the industry. Straight stabs 0 centuries 80's later periods, the Chinese mold industry only then drives into the development speedway. Recent years, not only the state-owned mold enterprise had the very big development, the three investments enterprise, the villages and towns (individual) the mold enterprise's development also quite rapidly.Although the Chinese mold industrial development rapid, but compares with the demand, obviously falls short of demand, its main gap concentrates precisely to, large-scale, is complex, the long life mold domain. As a result of in aspect and so on mold precision, life, manufacture cycle and productivity, China and the international average horizontal and the developed country still had a bigger disparity, therefore, needed massively to import the mold every year .The Chinese mold industry except must continue to sharpen the productivity; from now on will have emphatically to the profession internal structure adjustment and the state-of-art enhancement. The structure adjustment aspect, mainly is the enterprise structure to the specialized adjustment, the product structure to center the upscale mold development, to the import and export structure improvement, center the upscale automobile cover mold forming analysis and the structure improvement, the multi-purpose compound mold and the compound processing and the laser technology in the mold design manufacture application, the high-speed cutting, the super finishing and polished the technology, the information direction develops .The recent years, the mold profession structure adjustment and the organizational reform step enlarges, mainly displayed in, large-scale, precise, was complex, the long life, center the upscale mold and the mold standard letter development speed is higher than the common mold product; The plastic mold and the compression casting moldproportion increases; Specialized mold factory quantity and its productivity increase; "The three investments" and the private enterprise develops rapidly; The joint stock system transformation step speeds up and so on. Distributes from the area looked, take Zhujiang Delta and Yangtze River delta as central southeast coastal area development quickly to mid-west area, south development quickly to north. At present develops quickest, the mold produces the most centralized province is Guangdong and Zhejiang, places such as Jiangsu, Shanghai, Anhui and Shandong also has a bigger development in recent years.Although our country mold total quantity had at present achieved the suitable scale, the mold level also has the very big enhancement, after but design manufacture horizontal overall rise and fall industry developed country and so on Yu De, America, date, France, Italy many. The current existence question and the disparity mainly display in following several aspects:(1) The total quantity falls short of demandDomestic mold assembling one rate only, about 70%. Low-grade mold, center upscale mold assembling oneself rate only has 50% about.(2) The enterprise organizational structure, the product structure, the technical structure and the import and export structure does not gatherIn our country mold production factory to be most is from the labor mold workshop which produces assembles oneself (branch factory), from produces assembles oneself the proportion to reach as high as about 60%, but the overseas mold ultra 70% is the commodity mold. The specialized mold factory mostly is "large and complete", "small and entire" organization form, but overseas mostly is "small but", "is specially small and fine". Domestic large-scale, precise, complex, the long life mold accounts for the total quantity proportion to be insufficient 30%, but overseas in 50% above 2004 years, ratio of the mold import and export is 3.7:1, the import and export balances the after net import volume to amount to 1.32 billion US dollars, is world mold net import quantity biggest country .(3) The mold product level greatly is lower than the international standardThe production cycle actually is higher than the international water broadproduct level low mainly to display in the mold precision, cavity aspect and so on surface roughness, life and structure.(4) Develops the ability badly, economic efficiency unsatisfactory our country mold enterprise technical personnel proportion lowThe level is lower, also does not take the product development, and frequently is in the passive position in the market. Our country each mold staff average year creation output value approximately, ten thousand US dollars, overseas mold industry developed country mostly 15 to10, 000 US dollars, some reach as high as 25 to10, 000 US dollars, relative is our country quite part of molds enterprises also continues to use the workshop type management with it, truly realizes the enterprise which the modernized enterprise manages fewTo create the above disparity the reason to be very many, the mold long-term has not obtained the value besides the history in as the product which should have, as well as the most state-owned enterprises mechanism cannot adapt the market economy, but also has the following several reasons: .The mold material performance, the quality and the variety question often can affect the mold quality, the life and the cost, the domestically produced molding tool steel and overseas imports the steel products to compare has a bigger disparity. Plastic,plate, equipment energy balance, also direct influence mold level enhancement.RSP ToolingRapid Solidification Process (RSP) Tooling, is a spray forming technology tailored for producing molds and dies [2-4]. The approach combines rapid solidification processing and netshape materials processing in a single step. The general concept involves converting a mold design described by a CAD file to a tooling master using a suitable rapid prototyping (RP) technology such as stereolithography. A pattern transfer is made to a castable ceramic, typically alumina or fused silica. This is followed by spray forming a thick deposit of tool steel (or other alloy) on the pattern to capture the desired shape, surface texture and detail. The resultant metal block is cooled to room temperature and separated from the pattern. Typically, the deposit’s exterior walls are machined square, allowing it to be used as an insert in a holding block such as a MUD frame [5]. The overall turnaround time for tooling is about three days, stating with a master. Molds and dies produced in this way have been used for prototype and production runs in plastic injection molding and die casting.An important benefit of RSP Tooling is that it allows molds and dies to be made early in the design cycle for a component. True prototype parts can be manufactured to assess form, fit, and function using the same process planned for production. If the part is qualified, the tooling can be run in production as conventional tooling would. Use of a digital database and RP technology allows design modifications to be easily made.Experimental ProcedureAn alumina-base ceramic (Cotronics 780 [6]) was slurry cast using a silicone rubber master die, or freeze cast using a stereolithography master. After setting up, ceramic patterns were demolded, fired in a kiln, and cooled to room temperature. H13 tool steel was induction melted under a nitrogen atmosphere, superheated about100︒C, and pressure-fed into a bench-scale converging/diverging spray nozzle, designed and constructed in-house. An inert gas atmosphere within the spray apparatus minimized in-flight oxidation of the atomized droplets as they deposited onto the tool pattern at a rate of about 200 kg/h. Gas-to-metal mass flow ratio was approximately 0.5.For tensile property and hardness evaluation, the spray-formed material was sectioned using a wire EDM and surface ground to remove a 0.05 mm thickheat-affected zone. Samples were heat treated in a furnace that was purged with nitrogen. Each sample was coated with BN and placed in a sealed metal foil packet as a precautionary measure to prevent decarburization.Artificially aged samples were soaked for 1 hour at temperatures ranging from 400 to 700︒C, and air cooled. Conventionally heat treated H13 was austenitized at 1010︒C for 30 min., air quenched, and double tempered (2 hr plus 2 hr) at 538︒C.Microhardness was measured at room temperature using a Shimadzu Type M Vickers Hardness Tester by averaging ten microindentation readings. Microstructure of the etched (3% nital) tool steel was evaluated optically using an Olympus Model PME-3 metallograph and an Amray Model 1830 scanning electron microscope. Phase composition was analyzed via energy-dispersive spectroscopy (EDS). The size distribution of overspray powder was analyzed using a Microtrac Full Range Particle Analyzer after powder samples were sieved at 200 μm to remove coarse flakes. Sample density was evaluated by water displacement using Archimedes’ principle and a Mettler balance (Model AE100).A quasi 1-D computer code developed at INEEL was used to evaluate multiphase flow behavior inside the nozzle and free jet regions. The code's basic numerical technique solves the steadystate gas flow field through an adaptive grid, conservative variables approach and treats the droplet phase in a Lagrangian manner with full aerodynamic and energetic coupling between the droplets and transport gas. The liquid metal injection system is coupled to the throat gas dynamics, and effects of heat transfer and wall friction are included. The code also includes a nonequilibriumsolidification model that permits droplet undercooling and recalescence. The code was used to map out the temperature and velocity profile of the gas and atomized droplets within the nozzle and free jet regions.Results and DiscussionSpray forming is a robust rapid tooling technology that allows tool steel molds and dies to be produced in a straightforward manner. Each was spray formed using a ceramic pattern generated from a RP master.Particle and Gas BehaviorParticle mass frequency and cumulative mass distribution plots for H13 tool steel sprays are given in Figure 1. The mass median diameter was determined to be 56 μm by interpolation of size corresponding to 50% cumulative mass. The area mean diameter and volume mean diameter were calculated to be 53 μm and 139 μm, respectively. Geometric standard deviation, d=(d84/d16)½ , is 1.8, where d84 and d16 are particle diameters corresponding to 84% and 16% cumulative mass in Figure 1.Figure1. Cumulative mass and mass frequency plots of particles in H13 tool stepsprays.Figure2 gives computational results for the multiphase velocity flow field (Figure 2a), and H13 tool steel solid fraction (Figure2b), inside the nozzle and free jetregions. Gas velocity increases until reaching the location of the shock front, at which point it precipitously decreases, eventually decaying exponentially outside the nozzle. Small droplets are easily perturbed by the velocity field, accelerating inside the nozzle and decelerating outside. After reaching their terminal velocity, larger droplets (〜150 μm) are less perturbed by the flow field due to their greater momentum.It is well known that high particle cooling rates in the spray jet (103-106 K/s) and bulk deposit (1-100 K/min) are present during spray forming [7]. Most of the particles in the spray have undergone recalescence, resulting in a solid fraction of about 0.75. Calculated solid fraction profiles of small (〜30 μm) and large (〜150 μm) droplets with distance from the nozzle inlet, are shown in Figure 2b.Spray-Formed DepositsThis high heat extraction rate reduces erosion effects at the surface of the tool pattern. This allows relatively soft, castable ceramic pattern materials to be used that would not be satisfactory candidates for conventional metal casting processes. With suitable processing conditions, fine surface detail can be successfully transferred from the pattern to spray-formed mold. Surface roughness at the molding surface is pattern dependent. Slurry-cast commercial ceramics yield a surface roughness of about 1 μm Ra, suitable for many molding applications. Deposition of tool steel onto glass plates has yielded a specular surface finish of about 0.076 μm Ra. At the current state of development, dimensional repeatability of spray-formed molds, starting with a common master, is about ±0.2%.Figure 2. Calculated particle and gas behavior in nozzle and free jet regions.(a) Velocity profile.(b) Solid fraction.ChemistryThe chemistry of H13 tool steel is designed to allow the material to withstand the temperature, pressure, abrasion, and thermal cycling associated with demanding applications such as die casting. It is the most popular die casting alloy worldwide and second most popular tool steel for plastic injection molding. The steel has low carbon content (0.4 wt.%) to promote toughness, medium chromium content (5 wt.%) to provide good resistance to high temperature softening, 1 wt% Si to improve high temperature oxidation resistance, and small molybdenum and vanadium additions (about 1%) that form stable carbides to increase resistance to erosive wear[8]. Composition analysis was performed on H13 tool steel before and after spray forming.Results, summarized in Table 1, indicate no significant variation in alloy additions.MicrostructureThe size, shape, type, and distribution of carbides found in H13 tool steel is dictated by the processing method and heat treatment. Normally the commercial steel is machined in the mill annealed condition and heat treated(austenitized/quenched/tempered) prior to use. It is typically austenitized at about 1010︒C, quenched in air or oil, and carefully tempered two or three times at 540 to 650︒C to obtain the required combination of hardness, thermal fatigue resistance, and toughness.Commercial, forged, ferritic tool steels cannot be precipitation hardened becauseafter electroslag remelting at the steel mill, ingots are cast that cool slowly and formcoarse carbides. In contrast, rapid solidification of H13 tool steel causes alloying additions to remain largely in solution and to be more uniformly distributed in the matrix [9-11]. Properties can be tailored by artificial aging or conventional heat treatment.A benefit of artificial aging is that it bypasses the specific volume changes that occur during conventional heat treatment that can lead to tool distortion. These specific volume changes occur as the matrix phase transforms from ferrite to austenite to tempered martensite and must be accounted for in the original mold design. However, they cannot always be reliably predicted. Thin sections in the insert, which may be desirable from a design and production standpoint, are oftentimes not included as the material has a tendency to slump during austenitization or distort during quenching. Tool distortion is not observed during artificial aging ofspray-formed tool steels because there is no phase transformation.注塑模具之模具设计与制造模具是制造业的重要工艺基础，在我国，模具制造属于专用设备制造业。

英文文献Mould designOVERVIEWWhile discussing the differences among engineers, scientists, and mathematicians in Chapter 1, we saw that the word engineering is related to both ingenious and devise .Creative design lies at the center of the mechanical engineering profession, and an engineer’s ultimate goal is to produce new hardware that solves one of society’s technical problems. Beginning either from a blank sheet of paper or from existing hardware that is being modified, the product development process oft en forms the focus of an engineer’s activities. I n keeping with their profession’s title, many engineers truly are ingenious, and they possess the vision and skill to make such lasting contributions as those described in the top ten list of Section 1.3 Formal education in engineering is not a prerequisite to having a good for a new or improved product. Your interest in studying mechanical engineering, in fact, may have been sparked by your own ideas for building hardware. The elements of mechanical engineering that we have examined up to this point-machine components and tools, forces in structures and fluids, materials and stresses, thermal and energy systems, and the motion of machinery-are intended to have set a foundation that will enable you to approach mechanical design in a more effective and systematic manner .IN that respect, approach the taken in this textbook is a condensed analog of the traditional engineering curriculum: Approximation, mathematics, and science are applied to design problems in order to increase performance and reduce trial and error. By applying the resources of Chapter2-7, you can select certain machine components and perform back-of-the-envelope calculation to guide design decisions. Such analyses are not made for their sake alone; rather, they enable you to design better and fast.Effective mechanical design is a broad area, and the creative and technical processes behind it cannot be set forth fully in one chapter-or even one textbook for that matter. Indeed, with this material as a starting point, you should continue to develop hands-on experience and design skills throughout your entire professional career. Even the most seasoned grapples with the procedure for transforming an idea into manufactured hardware that can be sold at a reasonable cost.After first discussing the hierarchy of steps that engineers take when they transform a new idea intoreality, we explore the subject of mechanical design through three case studies in the fields of conceptual design, computer-aided design, and detailed machine design. We will also discuss mechanical design from a business perspective and describe how patents protect newly developed technology. After completing this chapter, you should be able to:1)Outline the major steps and iteration in points in the high-level mechanical design procedure.2)Give an example of the processes for brainstorming and for identifying the advantages anddisadvantages of various design options3)Understand the role played by computer-aided engineering tools in mechanical design, anddescribe how such tools can be seamlessly integrated with one another.4)By using a sketch as a guide, describe the operation of an automobile automatic transmission, acomplex machine design that incorporates mechanical, electronic, computer, and hydraulic components.5)Explain what patents are, and discuss their importance to engineering’s business environment HIGH-LEVEL DESIGN PEOCEDUREIn this section, we outline the steps that engineers take when they develop new products and hardware. From the broadest viewpoint, design is defined as the systematic process for devising a mechanical system to meet one of society’s technical needs. The specific motivation could lie in the areas of transportation, communication, or security, for instance. The prospective product is expected to solve a particular problem so well, or offer such a new capability, that other will pay for it. Early on, a company’s marketing department will collaborate with engineers and managers to identify, in a general sense, new opportunities for products. Together, they define the new product’s concept by drawing upon feedback from potential customers and from user of related product. Designers will subsequently develop those concepts, work out the details, and bring the functioning hardware to realization. Many approximations, trade-offs, and choices are made along the way, and mechanical engineers are mindful that the level of precision that is need will naturally and gradually grow as the design matures. For instance, it does not make sense for an engineer to resolve specific details (should a grade 1020 or 1045 steel alloy be used? Are ball or roller bearings most appropriate? What must be the viscosity of the oil?) until the design＇s overall concept has taken firm shape. After all, at an early stage of the design cycle, the specifications for the product’s size, weight, power, or performance could still change. Design engineers are comfortablewith such ambiguity, and they are able to develop product even in the presence of requirements and constraints that can change.The formal procedure by which a marketing concept evolves into manufactured hardware is based upon many principles and attributes. Most engineers would probably agree that creativity, simplicity, and iteration are key factors in any successful endeavor. Innovation begins with a good idea, but also implies starting from a blank sheet of paper. Nevertheless, engineers must still take the first, perhaps uncertain, step for transforming that formative idea into concrete reality. Early design decisions are made by drawing upon a variety of source: personal experience, knowledge of mathematics and science, laboratory and field testing, and trial and error guided by good judgment. Generally speaking, simpler design concepts are better than complex ones, and the adage “keep it simple, stupid”has a well-deserved reputation among engineers for guiding decisions. Iteration is also important for improving a design and for refining hardware that works into hardware that works well. The first idea that you have, just like the first prototype that you construct, will probably not be the best ones that can be realized. With the gradual improvement of each iteration, however, the design will perform better, more efficiently, and more elegantly.From a macroscopic perspective, the mechanical design procedure can be broken down into four major steps, which are outlined with greater detail in Figure 8.1.1. Define and research objectives.Initially, a designer describes the new product’s requirements in terms of its function, weight, strength, cost, safety, reliability, and so forth. At this first stage, constraints that the design must satisfy are also established. Those constraints might be of a technical nature-say, a restriction on size or power consumption. Alternatively, the constraints could be related to business or marketing concerns, such as the product’s appearance, cost, or ease of use. When faced with a new technical challenge, engineers will conduct research and gather background information that is expected to be useful when concepts and details are later evaluated. Engineers read patents that have been issued for related technologies, consult with vendors of components or subsystems that might be used in the product, attend expositions and trade shows, and meet with potential customers to better understand the application. Early in the design process, engineers define the problem, set the objective, and gather pertinent information for the foundation of a good design.2. Generate concepts.In this stage, designers generally work in teams with the goal of devising a wide range of potential solutions to the problem at hand. This creative effort involves conceiving new ideas and combining previous ones to be greater than the sum of their parts. Hardware solutions are conceptualized and composed, and both good and not-so-good ideas are tossed about. Results from the brainstorming sessions are systematically recorded, the advantages and disadvantages of various solutions are identified, and trade-offs among the differing approaches are made. To document the suite of ideas that emerges from this synthesis stage, engineers sketch concepts, make notes, and prepare lists of “pros and cons”in their design notebooks. No particular idea is evaluated in depth, nor is any idea viewed with too critical an eye. Instead, you should focus on cataloging multiple approaches and devising a wide rang of design concepts, not necessarily all conventional ones. Even though a particular solution might not seem feasible at this early stage, should the product’s requirements or constraints change in the future (which is likely), the idea might in fact resurface as a leading contender.3. Narrow down the options.The design team further evaluates the concepts with a view toward reducing them to a promising few. For instance, engineers make preliminary calculations to compare strength, safety, cost, and reliability, and they will begin to discard the less feasible concepts. Sample hardware could also be produced at this stage. Just as a picture is worth a thousand words, a physical prototype is often useful for engineers to visualize complex machine components and to explain their assembly to others. The prototype can also be tested so that trade-off decisions are made based on the results of both measurements and analyses. One method for producing such components is called rapid prototyping, and its key capability is that complex, three-dimensional can be fabricated directly from is called fused deposition modeling, and it enables durables durable and fully functional prototypes to be fabricated from plastics and polycarbonates. As an example, Figure 8.2 depicts a computer-aided design drawing of an engine block and a physical prototype developed with the system show in Figure 8.34. Develop a detailed design.To reach this point of the high-level procedure, the design team will have brainstormed, tested, analyzed, and converged its way to what it perceives as the best concept. The implementation of the design, construction of a final prototype, and development of the manufacturing process each remain. Detailedtechnical issues are solved by applying mathematical, scientific, laboratory, and computer-aided engineering tools. Completed drawings and parts lists are prepared. The designers conduct engineering analysis and experiments to verify performance over a range of operating conditions. If necessary, changes to shape, dimensions, materials, and components will be made until all requirements and constraints are met. The design is documented through engineering drawings and written reports so that able to understand the reasons behind each of the many decisions that the designers made. Such documentation is also useful for future design teams to teams to learn from and build upon the present team’s experiences.At the most fundamental level, the final design must all of its requirements and constraints. You might thing that an engineer’s tasks are completed once the working prototype has been delivered or after the finishing touches have been applied to the drawings. However, mechanical engineers today work in a broader environment, and their hardware is viewed with a critical eye beyond the criterion of whether or not it functions as intended. For a product be successful, it must also be safe to use, reliable, environmentally sound in its use and disposal, and affordable to manufacture. After all, if the product is technically superb but it requires expensive materials and manufacturing operations, customers may avoid the product and select one that is more balanced in cost and performance. In the end, engineering is a business venture that must meet the needs of its customers.模具设计概况当我们在第1章讨论工程师,科学家和数学家之间不同的时候，我们看到工程学这个涉及到创意和设计两方面内容。

外文资料翻译资料来源：《模具设计与制造专业英语》文章名：Chapter 3 Casting Dies书刊名：《English for Die & Mould Design and Manufacturing》作者：刘建雄王家惠廖丕博主编出版社：北京大学出版社，2002章节：Chapter 3 Casting Dies页码：P51~P60文章译名：铸造模具Chapter 3 Casting Dies3.1CastingThe first castings were made during the period 4000~3000 B.C., using stone and metal molds for casting copper. Various casting processes have been developed over a long period of time, each with its own characteristics and applications, to meet specific engineering and service requirements. Many parts and components are made by casting, including cameras, carburetors, engine blocks, crankshafts, automotive components, agricultural and railroad equipment, pipes and plumbing fixtures, power tools, gun barrels, frying pans, and very large components for hydraulic turbines.Casting can be done in several ways. The two major ones are sand casting, in which the molds used are disposable after each cycle, and die casting, or permanent molding, in which the same metallic die is used thousands or even millions of times. Both types of molds have three common features. They both have a “plumbing” system to channel molten alloy into the mold cavity. These channels are called sprues, runners, and gates (Fig. 3-1). Molds may be modified by cores which form holes and undercuts or inserts that become an integral part of the casting. Inserts strengthen and reduce friction, and they may be more machinable than the surrounding metal. For example, a steel shaft when properly inserted into a die cavity results in an assembled aluminum step gear after the shot.After pouring or injection, the resulting castings require subsequent operations such trim-ming, inspection, grinding, and repairs to a greater or lesser extent prior to shipping. Premium-quality castings from alloys of aluminum or steel require x-ray soundness that will be acceptable by the customer.Certain special casting processes are precision-investment casting, low-pressure casting, and centrifugal casting.3.2Sand CastingThe traditional method of casting metals is in sand molds and has been used for millennia. Simply stated, sand casting consists of (a) placing a pattern having the shape of the desired casting in sand to make an imprint, (b) incorporating a gating system, (c) filling the resulting cavity with molten metal, (d) allowing the metal to cool until it solidifies, (e) breaking away the sand mold, and (f) removing the casting (Fig. 3-2). The production steps for a typical sand-casting operation are shown in Fig. 3-3.Although the origins of sand casting date to ancient times, it is still the most prevalent form of casting. In the United States alone, about 15 million tons of metal are cast by this method each year.Open riser Vent Pouring basin (cup)CopeBlind FlaskriserSprueCore(sand)SandParting lineDragMoldcavityChokeRunner GateSandFig. 3-2 Schematic illustration of a sand mold33.2.1SandsMost sand casting operations use silica sand (SiO2), which is the product of the dis- integration of rocks over extremely long periods of time. Sand is inexpensive and is suitable as mold material because of its resistance to high temperatures. There are two general types of sand: naturally bonded (bank sand) and synthetic (lake sand). Because its composition can be controlled more accurately, synthetic sand is preferred by most foundries.Several factors are important in the selection of sand for molds. Sand having fine, round grains can be closely packed and forms a smooth mold surface. Although fine-grained sand enhances mold strength, the fine grains also lower mold permeability. Good permeability of molds and cores allows gases and steam evolved during casting to escape easily.3.2.2Types of Sand MoldsSand molds are characterized by the types of sand that comprise them and by the methods used to produce them. There are three basic types of sand molds: greensand, cold-box, and no-bake molds.The most common mold material is green molding sand, which is a mixture of sand, clay, and water. The term “green” refers to the fact that the sand in the mold is moist or damp while the metal is being poured into it. Greensand molding is the least expensive method of makingmolds.In the skin-dried method, the mold surfaces are dried, either by storing the mold in air or by drying it with torches. These molds are generally used for large castings because of their higher strength.Sand molds are also oven dried (baked) prior to pouring the molten metal; they are stronger than greensand molds and impart better dimensional accuracy and surface finish to the casting. However, this method has drawbacks: distortion of the mold is greater; the castings are more susceptible to hot tearing because of the lower collapsibility of the mold; and the production rate is slower because of the drying time required.In the cold-box mold process, various organic and inorganic binders are blended into the sand to bond the grains chemically for greater strength. These molds are dimensionally more accurate than greensand molds but are more expensive.In the no-bake mold process, a synthetic liquid resin is mixed with the sand; the mixture hardens at room temperature. Because bonding of the mold in this and in thecold-box process takes place without heat, they are called cold-setting processes.The following are the major components of sand molds (Fig. 3-2):(1)The mold itself, which is supported by a flask. Two-piece molds consist of a cope on top and a drag on the bottom. The seam between them is the parting line. When more than two pieces are used, the additional parts are called cheeks.(2)A pouring basin or pouring cup, into which the molten metal is poured.(3)A sprue, through which the molten metal flows downward.(4)The runner system, which has channels that carry the molten metal from the sprue to the mold cavity. Gates are the inlets into the mold cavity.(5)Risers, which supply additional metal to the casting as it shrinks during solidification. Fig. 3-2 shows two different types of risers: a blind riser and an open riser.(6)Cores, which are inserts made from sand. They are placed in the mold to form hollow regions or otherwise define the interior surface of the casting. Cores are also used on the outside of the casting to form features such as lettering on the surface of a casting or deep external pockets.(7)Vents, which are placed in molds to carry off gases produced when the molten metal comes into contact with the sand in the mold and core. They also exhaust air from the mold cavity as the molten metal flows into the mold.3.2.3PatternsPatterns are used to mold the sand mixture into the shape of the casting. They may be made of wood, plastic, or metal. The selection of a pattern material depends on the size and shape of the casting, the dimensional accuracy, the quantity of castings required, and the molding process.Because patterns are used repeatedly to make molds, the strength and durability of the material selected for patterns must reflect thenumber of castings that the mold will produce.They may be made of a combination of materials to reduce wear in critical regions. Patterns are usually coated with a parting agent to facilitate their removal from the molds.Patterns can be designed with a variety of features to fit application and economic requirements. One-piece patterns, also called loose or solid patterns, are generally used for simpler shapes and low-quantity production. They are generally made of wood and are inexpensive. Split patterns are two-piece patterns made such that each part forms a portion of the cavity for the casting; in this way, castings with complicated shapes can be produced.Match-plate patterns are a popular type of mounted pattern in which two-piece patterns are constructed by securing each half of one or more split patterns to the opposite sides of a single plate (Fig.3-4). In such constructions, the gating system can be mounted on the drag side of the pattern. This type of pattern is used most often in conjunction with molding machines and large production runs to produce smaller castings.Cope sidePlateDrag sideFig. 3-4 A typical metal match-plate pattern used in sand castingAn important recent development is the application of rapid prototyping to moldand pattern making. In sand casting, for example, a pattern can be fabricated in arapid prototyping machine and fastened to a backing plate at a fraction of the timeand cost of machining a pattern. There are several rapid prototyping techniques withwhich these tools can be produced quickly.Pattern design is a crucial aspect of the total casting operation. The design should provide for metal shrinkage, case of removal from the sand mold by means of a taper or draft (Fig.3-5), and proper metal flow in the mold cavity.Pattern Draft angleDamageFlaskSand moldPoor GoodFig. 3-5 Taper on patterns for case of removal from the sand mold3.2.4CoresFor castings with internal cavities or passages, such as those found in an automotive engine block or a valve body, cores are utilized. Cores are placed in themold cavity before casting to form the interior surfaces of the casting and are removed from the finished part during shakeout and further processing. Like molds,cores must possess strength, permeability, ability to withstand heat, and collapsibility; therefore, cores are made of sand aggregates.The core is anchored by core prints. These are recesses that are added to the pattern to support the core and to provide vents for the escape of gases (Fig. 3-6). A common problem with cores is that for some casting requirements, as in the casewhere a recess is required, they may lack sufficient structural support in the cavity.To keep the core from shifting, metal supports (chaplets) may be used to anchor thecore in place (Fig. 3-6).ChapletCore CoreCoreprintsCavity PartinglineMoldCavity CoreprintsFig. 3-6 Examples of sand cores showing core prints and chaplets to support cores8Cores are generally made in a manner similar to that used in making molds; the majority are made with shell, no-bake, or cold-box processes. Cores are formed in core boxes, which are used in much the same way that patterns are used to form sand molds. The sand can be packed into the boxes with sweeps, or blown into the box by compressed air from core blowers. The latter have the advantages of producing uniform cores and operating at very high production rates.3.2.5Sand-Molding MachinesThe oldest known method of molding, which is still used for simple castings, is to compact the sand by hand hammering (tamping) or ramming it around the pattern. For most operations, however, the sand mixture is compacted around the pattern by molding machines (Fig.3-7). These machines eliminate arduous labor, offer high-quality casting by improving the application and distribution of forces, manipulate the mold in a carefully controlled manner, and increase production rate.Squeeze head(a)(c) Equalizing pistons Pressurized air(b)(d)DiaphragmHydraulic cylinderFig. 3-7 Various designs of squeeze heads for mold making(a)conventional flat head (b) profile head (c) equalizing squeeze pistons (d) flexible diaphragmMechanization of the molding process can be further assisted by jolting the assembly. The flask, molding sand, and pattern are first placed on a pattern plate mounted on an anvil, and then jolted upward by air pressure at rapid intervals. The inertial forces compact the sand around the pattern. Jolting produces the highest compaction at the horizontal parting line, whereas in squeezing, compaction is highest at the squeezing head (Fig. 3-7). Thus, more uniform com- paction can be obtained by combining squeezing and jolting.In vertical flaskless molding, the halves of the pattern form a vertical chamber wall against which sand is blown and compacted (Fig. 3-8). Then, the mold haves are packed horizontally, with the parting line oriented vertically and moved along a pouring conveyor. This operation is simple and eliminates the need to handle flasks, allowing for very high production rates, particularly when other aspects of the operation (such as coring and pouring) are automated.Ram forceBoxSandPatternMetal poured here(a)(b)Fig. 3-8 Vertical flaskless molding(a)sand is squeezed between two halves of the pattern(b)assembled molds pass along an assembly line for pouringSandslingers fill the flask uniformly with sand under high-pressure stream. They are used to fill large flasks and are typically operated by machine. An impeller in the machine throws sand from its blades or cups at such high speeds that the machine not only places the sand but also rams it appropriately.In impact molding, the sand is compacted by controlled explosion or instantaneous release of compressed gases. This method produces molds withuniform strength and good permeability.In vacuum molding, also known as the “V” process, the pattern is covered tightly by a thin sheet of plastic. A flask is placed over the coated pattern and is filled with dry binderless sand. A second sheet of plastic is then placed on top of the sand, and a vacuum action hardens the sand so that the pattern can be withdrawn. Both halves of the mold are made this way and assembled.During pouring, the mold remains under a vacuum but the casting cavity does not. When the metal has solidified, the vacuum is turned off and the sand falls away, releasing the casting. Vacuum molding produces castings with high-quality detail and dimensional accuracy. It is especially well suited for large, relatively flat castings.113.2.6The Sand Casting OperationAfter the mold has been shaped and the cores have been placed in position, the two halves (cope and drag) are closed, clamped, and weighted down. They are weighted to prevent the separation of the mold sections under the pressure exerted when the molten metal is poured into the mold cavity.The design of the gating system is important for proper delivery of the molten metal into the mold cavity. As described, turbulence must be minimized, air and gases must be allowed to escape by such means as vents, and proper temperature gradients must be established and maintained to minimize shrinkage and porosity. The design of risers is also important in order to supply the necessary molten metal during solidification of the casting. The pouring basin may also serve as a riser. A complete sequence of operations in sand casting is shown in Fig. 3-9. In Fig. 3-9(a), a mechanical drawing of the part is used to generate a design for the pattern. Considerations such as part shrinkage and draft must be built into the drawing. In (b)~(c), patterns have been mounted on plates equipped with pins for alignment. Note the presence of core prints designed to hold the core in place. In (d)~(e), core boxes produce core halves, which are pasted together. The cores will be used to produce the hollow area of the part shown in (a). In (f), the cope half of the mold is assembled by securing the cope pattern plate to the flask with aligning pins, and attaching inserts to form the sprue and risers. In (g), the flask is rammed with sand and the plate and inserts are removed. In (h), the drag half is produced in a similar manner, with the pattern inserted. A bottom board is placed below the drag and aligned with pins. In (i), the pattern, flask, and bottom board are inverted, and the pattern is withdrawn, leaving the appropriate imprint. In (j), the core is set in place within the drag cavity. In (k), the mold is closed by placing the cope on top of the drag and securing the assembly with pins. The flasks are then subjected to pressure to counteract buoyant forces in the liquid, which might lift the cope. In (l), after the metal solidifies, the casting is removed from the mold. In (m), the sprue and risers are cut off and recycled, and the casting is cleaned, inspected, and heat treated (when necessary).After solidification, the casting is shaken out of its mold, and the sand and oxide layers adhering to the casting are removed by vibration (using a shaker) or by sand blasting. Ferrous castings are also cleaned by blasting with steel shot (shot blasting) or grit. The risers and gates are cut off by oxyfuel-gas cutting, sawing, shearing, andabrasive wheels, or they are trimmed in dies. Gates and risers on steel castings are also removed with air carbon-arc or powder-injection torches. Castings may be cleaned by electrochemical means or by pickling with chemicals to remove surface oxides.(a) (b) (c) Core printsMechanical drawing of part (d) (e)Core boxesCore printsCope pattern plateCore halvespasted together(f)FlaskGateDrag pattern plateRisers SprueCope ready for sand(g) (h) (i)Cope after ramming withsand and removing pattern, sprue, and risers Drag ready for sandDrag afterremoving pattern(j)CopeDrag (k)(l)(m)Drag with core set in place ClosingpinsCope and dragassembled readyfor pouringCasting asremoved frommold; heat treatedCasting readyfor shipmentFig. 3-9 Schematic illustration of the sequence of operations for sand castingAlmost all commercially-used metals can be sand cast. The surface finish obtained is largely a function of the materials used in making the mold. Dimensional accuracy is not as good as that of other casting processes. However, intricate shapes can be cast by this process, such as cast-iron engine blocks and very large propellers for ocean liners. Sand casting can be economical for relatively small production runs, and equipment costs are generally low.The surface of castings is important in subsequent machining operations, because machi- nability can be adversely affected if the castings are not cleaned properly and sand particles remain on the surface. If regions of the casting have not formed properly or have formedincompletely, the defects may be repaired by filling them with weld metal. Sand-mold castings generally have rough, grainy surfaces, depending on the quality of the mold and the materials used.The casting may subsequently be heat-treated to improve certain properties needed for its intended service use; these processes are particularly important for steel castings. Finishing operations may involve machining straightening, or forging with dies to obtain final dimensions.Minor surface imperfections may also be filled with a metal-filled epoxy, especially for cast-iron castings because they are difficult to weld. Inspection is an important final step and is carried out to ensure that the casting meets all design and quality control requirements.第三章铸造模具3.1 铸造第一批铸件是在公元前4000年至公元前3000年制造的。

模具设计与制造外文翻译参考文献(文档含中英文对照即英文原文和中文翻译)译文：模具设计与制造模具是制造业的重要工艺基础，在我国模具制造属于专用设备制造业。

中国虽然很早就开始制造模具和使用模具，但长期未形成产业。

直到20世纪80年代后期，中国模具工业才驶入发展的快车道。

近年，不仅国有模具企业有了很大发展，三资企业、乡镇（个体）模具企业的发展也相当迅速。

虽然中国模具工业发展迅速，但与需求相比，显然供不应求，其主要缺口集中于精密、大型、复杂、长寿命模具领域。

由于在模具精度、寿命、制造周期及生产能力等方面，中国与国际平均水平和发达国家仍有较大差距，因此，每年需要大量进口模具。

中国模具产业除了要继续提高生产能力，今后更要着重于行业内部结构的调整和技术发展水平的提高。

结构调整方面，主要是企业结构向专业化调整，产品结构向着中高档模具发展，向进出口结构的改进，中高档汽车覆盖件模具成形分析及结构改进、多功能复合模具和复合加工及激光技术在模具设计制造上的应用、高速切削、超精加工及抛光技术、信息化方向发展。

近年，模具行业结构调整和体制改革步伐加大，主要表现在，大型、精密、复杂、长寿命、中高档模具及模具标准件发展速度高于一般模具产品；塑料模和压铸模比例增大；专业模具厂数量及其生产能力增加；“三资”及私营企业发展迅速；股份制改造步伐加快等。

从地区分布来看，以珠江三角洲和长江三角洲为中心的东南沿海地区发展快于中西部地区，南方的发展快于北方。

目前发展最快、模具生产最为集中的省份是广东和浙江，江苏、上海、安徽和山东等地近几年也有较大发展。

虽然我国模具总量目前已达到相当规模，模具水平也有很大提高，但设计制造水平总体上落后于德、美、日、法、意等工业发达国家许多。

当前存在的问题和差距主要表现在以下几方面：（1）总量供不应求，国内模具自配率只有70%左右。

其中低档模具供过于求，中高档模具自配率只有50%左右。

（2）企业组织结构、产品结构、技术结构和进出口结构均不合理。