注塑模具外文翻译原文

1、桂林电子科技大学毕业设计（论文）报告用纸编号： 毕业设计(论文)外文翻译（原文）院 （系）： 机电工程学院 专 业： 机械设计制造及其自动化 学生姓名： 莫 飞 学 号： 0801120436 姓 名： 吕汝金 职 称： 讲 师 2012 年 5 月 15 日21the injection moldingthe present situation that the mould makes at present and trendthe mold is at the core of a plastic manufacturing process because its cavity gives

2、a part its shape. this makes the mold at least as critical-and many cases more so-for the quality of the end product as, for example, the plasticiting unit or other components of the processing equipment.the mould is important handicraft equipment，occupies decisive position in industrid departments

3、such as consumer goods，electrical equipment electron，automobile , aircraft fabrication. the mould is important handicraft equipment , occupies decisive position in industrid departments such as consumer goods，electrical equipment electron，automobile , aircraft fabrication. industrial product part ro

4、ugh process 75%, the finish machining 50% and plastic part 90% will be completed from the mould. the chinese mould market demand already reaches scale of 500 hundred million yuan at present. the automobile mould , the annual growth rate covering piece of mould especially will exceed 20 %; also promp

5、t building material mould development，various heterotype material the mould，wall surface and floor mould become new mould growth point, plastic doors and windows and plastic drain-pipe increase to exceeding 30 by in the upcoming several years %; the home appliance mould annual growth rate will excee

6、d 10 %; the it industry year increases % speed equally exceeding 20，the need to the mould accounts for 20 of mould marketplace %.2004 annual chinese machine tools implements industry output value.will continue to increase. our country mould fabrication market potential is enormous. the basis data co

7、unts， in recent years，our country mould year gross output value reaches 3 billion u. s. dollar，entrance exceeds 1 billion u. s. dollar，exceed 100 million u. s. dollar outlet. increase by from 25% to increase to 2005 50% of 1995. the expert foretells that abroad: asia portion being occupied by in mou

8、ld fabrication in the whole world, will from 25% to increase to 2005 50% of 1995.chinese mould industry has been expanding by leaps and bounds，has formed east china and two big south china bases, and has expanded gradually arriving at other province. in 2002 (shandong，anhui，sichuan) in 1996，mould ma

9、nufacturing industry output value annual average growth 14% , grows by 25% in 2003. in 2003 our country mould output value is 45 billion rmb. the gross product place occupies the world the 3rd，exports a mould increases 33.5% compared to last year 336,800,000 u. s. dollar. but, contents low our count

10、ry technology moulds already pile up in excess of requirement，very most support of accurate，complicated top grade mould imports. every year the entrance mould exceeds 1 billion u. s. dollar. exceed 100 million u. s. dollar outlet.precise mould accuracy requires that 3 mu ms，large-scale moulds requir

11、e that 8000 satisfied kn agree well with model force injection machine request in 2 ；the minitype mould needs the request satisfying the diameter 1 mm silent stock tube. at present, adopt quick-cutting to produce a mould already becoming the general trend that the mould makes, a few moulds have prod

12、uced a manufacturer in abroad，high-speed machine tool large area has substituted the electric spark machine tool，quick-cutting has improved the mould efficacy greatly. machine tool enterprise aims at mould manufacturing enterprises，some treating centres 60% all above of the machine tool producing a

13、factory sells treating enterprise to a mould. the mould fabrication enterprise substituting the electric spark finish machining mould gradually in abroad has adopt quick-cutting already commonly , quick-cutting has produced a mould already becoming the general trend that the mould makes gradually，ha

14、s improved the mould efficacy and mass greatly. adopt quick-cutting to replace electric spark producing a mould , can get on the stick obviously , improves mould accuracy，life time growing.1. the introduction of injection moulds.plastic, which is one of the most versatile in the modern age, is widel

15、y used in many products throughout the world. due to its ability to produce complex-shape plastic parts with good dimensional accuracy and very short cycle times, injection moulding has become the most important process for manufacturing plastic parts in the plastic industry today. however, the curr

16、ent plastics industry is under great pressure, due to the globalization of the market, the short life cycle of product development, increasing product diversity, high demand of product quality. to meet such requirements, it is very important for this trade to adopt various advanced technologies whic

17、h include information and internet technology, cad/cae/cam integration technology, concurrent engineering, artificial intelligence, and so on, to effectively aid the development of injection-moulded product.in injection moulding, the design of a mould is of critical importance for product quality an

18、d efficient processing. in most cases, quality of mould is responsible for the economics of the entire process. injection mould design involves extensive empirical knowledge (heuristic knowledge) about the structure and functions of the components of the mould. nowadays, mould design faces with incr

19、easing deadline pressures and the design itself is predominantly based upon experience of the mould designer. mould designers are required to possess thorough and broad experience, because detailed decisions require the knowledge of the interaction among various parameters. unfortunately, it is pres

20、ently impossible to cover the growing demand for such experienced designers. therefore, intelligent cad tools that can assist in the various tasks of the mould design process are very important to the productivity of the mould -making industry.the growing trend in global manufacturing is to a large

21、extent supported by internet, information technologies and global marketing. nowadays, it is common to see that design, manufacturing and final assembly of a product are made in companies located in different parts of the world. the various parties concerned would need to share their expertise and e

22、xperiences during the product development process. the current progress of internet and information technologies can provide a solution to support and facilitate collaborative product developments among different geographically distributed enterprises. developing an internet-based intelligent mould

23、design system as one of the module of a collaborative product development system can provide an effective and feasible tool to aid the collaborative development of injection moulds in the small- and medium-sized enterprises to satisfy the stringent requirements of nowadays competitive global market.

24、this paper presents an internet-based intelligent mould design system using internet technology and knowledge-based approach. the system can shorten the design cycle of injection mould and can effectively aid the design and development works of injection moulds in the small-and medium-sized enterpri

25、ses to meet the increasing pressure of the current competitive world market. the rest of the paper is organized as follows. section 2 gives a brief introduction of injection mould design. section 3 introduces earlier research works on mould design and related fields. the architecture of the internet

26、-based mould design system is presented in section 4. the knowledge-based part of the mould design system is described in section 5. section 6 discusses the development of the system. 2. injection mould design the basic features of an injection mould consist of cavity number and layout, feed system,

27、 cooling system, ejection system and mould construction. 2.1. design rules there are many rules for designing molds. these rules and standard practices are based on logic, past experience, convenience, and economy. for designing, mold making, and molding, it is usually of advantage to follow the rul

28、es. but occasionally, it may work out better if a rule is ignored and an alternative way is selected. in this text, the most common rules are noted, but the designer will learn only from experience which way to go. the designer must ever be open to new ideas and methods, to new molding and mold mate

29、rials that may affect these rules.a mould design project normally starts with economic considerations, namely the question of how many parts can and should be produced in one mould in one shot in order to meet the delivery date and other requirements. this is follow by consideration of the arrangeme

30、nts of the cavities in the mould frame, which might directly include thoughts on the ease of ejection and subsequently, the connection between mouldings and runners and part quality (number, position and shape of gates). the feed system accommodates the molten plastic material coming from the inject

31、ion nozzle of the moulding machine and distributes it into each cavity. to remove the heat from the moulding, it is necessary to provide the mould with a cooling system. after the moulding has solidified and cooled down, it has to be removed from the mould by the ejection system. mould is normally c

32、onstructed by stacking several metal plates to form a rigid body. it has to house various mould components in correct positions for the proper functioning of the mould. mould construction normally involves the selection of mould bases and standard mould parts. for complicated plastic parts, some oth

33、er mechanisms such as slides, unscrewing device, etc, might also be involved in the whole mould structure.2.2. mold materialdepending on the processing parameters for the various processing methods as well as the length of the production run, the number of finished products to be produced, molds for

34、 plastics processing must satisfy a great variety of requirements. it is therefore not surprising that molds can be made from a very broad spectrum of materials, including-from a technical standpoint-such exotic materials as paper matched and plaster. however, because most processes require high pre

35、ssures, often combined with high temperatures, metals still represent by far the most important material group, with steel being the predominant metal. it is interesting in this regard that, in many cases, the selection of the mold material is not only a question of material properties and an optimu

36、m price-to-performance ratio but also that the methods used to produce the mold, and thus the entire design, can be influenced.a typical example can be seen in the choice between cast metal molds, with their very different cooling systems, compared to machined molds. in addition, the production tech

37、nique can also have an effect; for instance, it is often reported that, for the sake of simplicity, a prototype mold is frequently machined from solid stock with the aid of the latest technology such as computer-aided (cad) and computer-integrated manufacturing (cim). in contrast to the previously u

38、sed methods based on the use of patterns, the use of cad and cam often represents the more economical solution today, not only because this production capability is available pin-house but also because with any other technique an order would have to be placed with an outside supplier.overall, althou

39、gh high-grade materials are often used, as a rule standard materials are used in mold making. new, state-of-the art (high-performance) materials, such as ceramics, for instance, are almost completely absent. this may be related to the fact that their desirable characteristics, such as constant prope

40、rties up to very high temperatures, are not required on molds, whereas their negative characteristics, e. g. low tensile strength and poor thermal conductivity, have a clearly related to ceramics, such as sintered material, is found in mild making only to a limited degree. this refers less to the mo

41、dern materials and components produced by powder metallurgy, and possibly by hot isocratic pressing, than to sintered metals in the sense of porous, air-permeable materials.removal of air from the cavity of a mold is necessary with many different processing methods, and it has been proposed many tim

42、es that this can be accomplished using porous metallic materials. the advantages over specially fabricated venting devices, particularly in areas where melt flow fronts meet, i, e, at weld lines, are as obvious as the potential problem areas: on one hand, preventing the texture of such surfaces from

43、 becoming visible on the finished product, and on the other hand, preventing the microspores from quickly becoming clogged with residues (broken off flash, deposits from the molding material, so-called plate out, etc.). it is also interesting in this case that completely new possibilities with regar

44、d to mold design and processing technique result from the use of such materials. 2.3. the basic mold2.3.1. mold cavity space the mold cavity space is a shape inside the mold, “excavated” in such a manner that when the molding material is forced into this space it will take on the shape of the cavity

45、 space and, therefore, the desired product. the principle of a mold is almost as old as human civilization. molds have metals into sand forms. such molds, which are still used today in foundries, can be used only once because the mold is destroyed to release the product after it has solidified. toda

46、y, we are looking for permanent molds that can be used over and over. now molds are made from strong, durable materials, such as steel, or from softer aluminum or metal alloys and even from certain plastics where a long mold life is not required because the planned production is small. in injection

47、molding the plastic is injected into the cavity space with high pressure, so the mold must be strong enough to resist the injection pressure without deforming.2.3.2. number of cavities many molds, particularly molds for larger products, are built for only cavity space, but many molds, especially lar

48、ge production molds, are built with 2 or more cavities. the reason for this is purely economical. it takes only little more time to inject several cavities than to inject one. for example, a 4-cavity mold requires only one-fourth of the machine time of a single-cavity mold. conversely, the productio

49、n increases in proportion to the number of cavities. a mold with more cavities is more expensive to build than a single-cavity mold, but not necessarily 4 times as much as a single-cavity mold. but it may also require a larger machine with larger platen area and more clamping capacity, and because i

50、t will use 4 times the amount of plastic, it may need a large injection unit, so the machine hour cost will be higher than for a machine large enough for the smaller mold.2.3.3. cavity shape and shrinkage the shape of the cavity is essentially the “negative” of the shape of the desired product, with

51、 dimensional allowance added to allow for shrinking of the plastic. the shape of the cavity is usually created with chip-removing machine tools, or with electric discharge machining, with chemical etching, or by any new method that may be available to remove metal or build it up, such as galvanic pr

52、ocesses. it may also be created by casting certain metals in plaster molds created from models of the product to be made, or by casting some suitable hard plastics. the cavity shape can be either cut directly into the mold plates or formed by putting inserts into the plates.2.4. cavity and core by c

53、onvention, the hollow portion of the cavity space is called the cavity. the matching, often raised portion of the cavity space is called the core. most plastic products are cup-shaped. this does not mean that they look like a cup, but they do have an inside and an outside. the outside of the product

54、 is formed by the cavity, the inside by the core. the alternative to the cup shape is the flat shape. in this case, there is no specific convex portion, and sometimes, the core looks like a mirror image of the cavity. typical examples for this are plastic knives, game chips, or round disks such as r

55、ecords. while these items are simple in appearance, they often present serious molding problems for ejection of the product. the reason for this is that all injection molding machines provide an ejection mechanism on the moving platen and the products tend to shrink onto and cling to the core, from

56、where they are then ejected. most injection molding machines do not provide ejection mechanisms on the injection side.2.5. polymer processing polymer processing, in its most general context, involves the transformation of a solid (sometimes liquid) polymeric resin, which is in a random form (e.g., p

57、owder, pellets, beads), to a solid plastics product of specified shape, dimensions, and properties. this is achieved by means of a transformation process: extrusion, molding, calendaring, coating, thermoforming, etc. the process, in order to achieve the above objective, usually involves the followin

58、g operations: solid transport, compression, heating, melting, mixing, shaping, cooling, solidification, and finishing. obviously, these operations do not necessarily occur in sequence, and many of them take place simultaneously. shaping is required in order to impart to the material the desired geom

59、etry and dimensions. it involves combinations of viscoelastic deformations and heat transfer, which are generally associated with solidification of the product from the melt. shaping includes: two-dimensional operations, e.g. die forming, calendaring and coating; three-dimensional molding and forming operations. two-dimensional proce