专业英语大作业样本

1、 7/7专业英语大作业样本 lesson 10 P1 P2 The mould designer is frequently confronted with a component design that incorporates a recess or projection which prevents the simple removal of the molding from the mould. The mould design for this type of component is inevitably more complex than for the in line of d

2、raw component, as it necessitates the removal of that part of the impression which forms the undercut prior to ejection . The splits can be incorporated in the mould design in several ways. The designer considers more complex systems where the splits are retained on the mould plate and actuated auto

3、matically. There are two basic designs: sliding and angled-lift splits. In both designs there are moving parts and it is necessary to arrange for (i) guiding the splits in the desired direction, (ii) actuating the splits, and (iii) securely locking the splits in position prior to the material being

4、injection into the moul d. 模具设计师经常面临的一个组成部分的设计，包括凹槽或投影，防止简单去除成型模具。因为脱模前要先抽出形成侧型芯的那部分型腔，这类零件的模具设计比直接脱模的零件复杂的多。 滑块可纳入模具设计的几种方法。设计师认为，更复杂的系统，滑块将自动保留并驱动在模板中。有两个个基本的设计思路：滑动和斜滑块。 在两者的设计中都有活动零件，而且有必要安排：沿着正确方向导向滑块，驱动滑块，在材料注射进模具之前安全地锁紧滑块。 Lesson 1 The injection molding and machine 1.1The injection molding 2I

5、njection molding is principally used for the production of the thermoplastic parts, although some progress has been made in developing a method for injection molding some thermosetting materials. The problem of injecting a melted plastic into a mold cavity from a reservoir of melted material has bee

6、n extremely difficult to solve for thermosetting plastics which cure and harden under such conditions within a few minute s. The principle of injection molding is quite similar to that of die-casting. The process consists of feeding a plastic compound in powdered or granular from a hopper through me

7、tering and melting stages and then injecting it into a mol d. After a brief cooling period, the mold is opened and the solidified part ejected. Injection-molding machines can be arranged for manual operation, automatic single-cycle operation, and full automatic operation. The advantage of injection

8、molding are: (i) a high molding speed adapted for mass production is possible; (ii) there is a wide choice of thermoplastic materials providing a variety of useful properties; (iii) it is possible to mold threads, undercuts, side holes, and large thin sections. 2.1 注塑成型主要用于生产热塑性塑料配件，虽然已经取得了一些进展，在发展中

9、国家的一些热固性材料注塑成型的方法。问题的注射熔融塑料在模腔的熔融材料的容器已极难处理热固性塑料固 化和硬化，在这种情况下，几分钟内。注塑成型原理很相似，压铸。这个过程包括喂养塑料复合粉末或颗粒从料斗通过计量和融化阶段，然后注射到模具。经过短暂的冷却时间，打开模 具和固化部分弹出。注塑机可设置为手工操作，自动循环操作，全自动操作。利用注射成型是：（一）高成形速度为适应大规模生产是可能的；（二）有多种可供选择的热塑性材料提供各种 有用的性质；（三）是有可能的模具，削弱，侧孔，和大的薄片。 Lesson2 Mould for threaded components 2.2 Stripping in

10、ternal threads The internally thread component may be stripped from the core using the basic stripper plate design providing the plastic material has sufficient elasticity during the ejection phase. The same principle applies here as to stripping any internal undercut, i.e. the molding must be free

11、to expand during ejection to permit the molded undercut to ride over the restriction on the core. This means that the outside form of the component must be such that it can be formed in a cavity which is fully contained in one half of the mould. Amould of this type is illustrated in Figure 2-1. This

12、 diagram shows a single impression mould for an internally threaded cap. The mould opens initially and, because of molding shrinkage and the undercut form, the molding is withdrawn from the cavity. During the latter stages of opening the stripper plates movement is checked, thereby causing the secon

13、d opening to occur at B. The molding is, therefore, progressively stripped as the core is withdrawn through the stripper plate. The aperture in the stripper plate must be slightly larger in diameter than the major diameter of the thread in order to prevent scoring of the thread. 内螺纹组件可能被剥夺的核心采用推板设计提

14、供塑料材料有足够的弹性在弹射阶段。同样的原则适用于这里作为剥离的任何内部削弱，即成型必须自由扩大在弹射允许成型凹穴通过限制的 核心。这意味着，外部组件形式必须是这样的：它可以形成一个腔是完全包含在一个半的模具。模具这种类型是说明了在图2 - 1。这个图显示了一个单一的印象模具内螺纹帽。模具打开了 最初，因为成型收缩和削弱形式，成型退出腔。在后期的开放料板检查，从而造成二开口发生在B成型，因此，逐步剥离为核心撤回通过卸料板。光圈在料板必须稍微比直径大的大直 为防止得分线。 Lesson 3 Basic underfeed mould P1 P2 P3 The moving half consis

15、ts of the moving mould plate assembly, support blocks, backing plate, ejector assembly and the pin ejection system. Thus the moving half in this design is identical with the moving half of basic moulds. The floating cavity plate, which may be of the integer or insert-bolster design, is located on su

16、bstantial guide pillars (not shown) fitted in the feed plate. These guide pillars must be of sufficient length to support the floating cavity plate over its full movement and still project to perform the function of alignment between the cavity and core when the mould is being close d. Guide bushes

17、are fitted into the moving mould plate and the floating cavity plate respectively. The maximum movement of the floating cavity plate is controlled by stop bolts or similar devices. The moving mould plate is suitably bored to provide a clearance for the stop bolt assembly. The stop bolts must be long

18、 enough to provide sufficient space between the feed plate and the floating cavity plate for easy removal of the feed system. The minimum space provided for should be 65mm just sufficient for an operator to remove the feed system by hand if necessary. 一个简单的模具，这种类型是显示在图3 - 1，并说明设计和开放序列如下。模具由三个基本部分组成，

19、即：移动一半，浮动型腔板和板的饲料，分别。移动一半由动模板组件，支持块，底板 ，喷射器装配和针弹射系统。因此，移动一半在这设计相同的移动半年基本模。浮动型腔板，这可能是整数或insert-bolster设计，位于大幅度的导柱（未显示）安装在饲料盘。这些导柱必 须有足够的长度支持浮动型腔板在其充分的运动和仍然项目履行的职能，调整之间的型腔和型芯的模具时关闭。导衬套安装到移动模具板和浮动型腔板分别。 Lesson 4 Feed system Gate A gate is an entrance through which molten plastic enters the cavity.The g

20、ate has the following functions: restricts the flow and the direction of molten plastic; simplifies cutting of a runner and moldings to simplify finishing of parts; quickly cools and solidifies to avoid backflow after molten plastic has filled up in the cavity. 浇口是一个入口通过它熔融塑料进入型腔。浇口有以下功能：限制流量和方向的熔融塑

21、料；简化了切割的亚军和造型简化零件精加工；快速冷却并固化，避免回流后，熔融塑料填补了 Cold slug well The purpose of the cold slug well, shown opposite the sprue, is theoretically to receive the material that has chilled at the front of the nozzle during the cooling and ejection phase . Perhaps of greater importance is the fact that it provid

22、es positive means whereby the sprue can be pulled from the sprue bush for ejection purposes. 冷料口的作用，正对浇口，理论上得到冷料喷嘴前端在冷却和射血期。也许更重要的事实是，它提供了积极的手段，使浇口可以被从浇口套弹射的目的。 Lesson5 Sprue bush and Register ring P1 P2 P3 The sprue bush is defined as that part if the mould in which the sprue is formed. In practice

23、 the sprue bush is the connecting member between the machine nozzle and the mould face, and provides suitable aperture through which the material can travel on its way to the impressions or to the start of the runner system in multi-impression moulds. The sprue bush is fairly highly stressed in some

24、 applications and should therefore be made from a %2 11 nickel chrome steel and should always be hardened. Note that while initially the nozzle may have been set up correctly, an increase in the injection cylinder temperature will cause a fairly high force to be applied to the sprue bush because of

25、the expansion of the injection cylinde r . The internal aperture of the sprue bush has between 2and 4included taper, which facilitates removal of the sprue from the mould at the end of molding cycle. For reference, 2; 2.6; 3 and 4 are the included tapers adopted by various standard parts suppliers.

26、浇口套的定义是部分的模具中，流道形成。在实践中，浇道衬套连接成员之间的喷嘴和模具，并提供合适的光圈通过它可以旅行的道路上的印象或开始的多型腔模具浇注系统。 浇口套相当高度强调在一些应用程序，因此应该从镍铬钢和应始终硬化。注意，虽然最初的喷嘴可能被正确设置，增加了注射温度会产生相当高的力量适用于主流道衬套因为膨胀的注射 筒。 Lesson6 RUNNER Runner cross-section shape The cross-sectional shape of the runner used in a mould is usually one of four forms (Figure 6-

27、1): fully round (a), trapezoidal (b), modified trapezoidal(c) and hexagonal (d). The criterion of efficient runner design is that the runner should provide a maximum cross-section area from the standpoint of pressure transfer and a minimum contact on the periphery from the standpoint of heat transfe

28、 r. The ratio of cross-sectional area to periphery will, therefore, give a direct indication of the efficiency of the runner design; the higher the value the greater the efficiency. Ratios for various types of runner section are given in Figure 6-2 . As can be seen, the round and square types of run

29、ner are the two most satisfactory designs from this standpoint; whereas the ratios exhibited by the semicircular and rectangular types make their use generally undesirable. 流道横截面形状用于模具通常是四种形式之一（图1）：全圆（一），（二）修正梯形梯形，（三）和（四）。有效率的流道设计标准是运动员应该提供最大横截面积从压力传递和最低的接触 从热传递。比例横断面地区周边将，因此，给予直接说明效率的流道设计；较高的价值更大的效

30、率。比率为各类亚军部分是由于在图6 - 2。可以看出，该圆形和方形类型的运动员是最满意 的设计，从这个角度；而比展出的半圆形和矩形类型，使它们的使用一般不良。 Lesson7 GATES Type of gate前两段 The size of the gate can be consideredin terms of the gate cross-sectional area and the gate length, the latter being known as gate land. The optimum size for a gate will depend on a number

31、of factors including (i) the flow characteristics of the material to be molded (ii) the wall section of the molding,(iii)the volume of material to be injected into the impression, (iv)the temperature of the melt, and(v) the temperature of the mould. No theoretical size exists for the ideal gate. The

32、 gate size chosen in practice for a particular component is normally based on past experience. However, the reader may not have this experience upon which to base a decision and, therefore, a guide to the dimensions for each gate type is given. The guide applies, except where otherwise stared, to th

33、e general case of a molding with a wall section between 0.75mmand 4 mm. 浇口可被视为在该门横截面积和栅极长度，后者被称为门的土地。最佳尺寸为栅将取决于若干因素，包括（一）流动特性的模制材料（二）的壁部分成型，（三）材料的数量被注入的印象， （四）熔体的温度，和（五）的模温。 没有理论大小存在的理想大门。门的大小选择在实践中的特定组件通常是根据过去的经验。然而，读者可能没有这方面的经验为基础的决策，因此，指导的规模每个门式是。本指南适用，除 非另有凝视，在一般情况下一个成型的一段围墙0.75毫米和4毫米之间。 Lesson8

34、 Parting surface FLAT PARTING SURFACE The mature of the parting surface depends entirely on the shape of the component. For instance, the parting surface of the rectangular molding is shown in Figure 8-1(a). The cavity for this article can be die-sunk into one mould plate. The position of the partin

35、g surface will therefore be at the top of the molding, the parting surface itself being perfectly flat. For appearance this is the ideal arrangement as the parting line is not noticeable unless flash develops. A further consideration is that the parting surface must be chosen so that the molding can

36、 be removed from the mould. Figure 8-1(b) shows the parting surface of a flat rectangular molding which incorporates a double-bevel edge. The suitable choice for the parting line is on the centre of the double-bevel which allows for half of the required form to be die-sunk into each of the two mould

37、 halves. The parting line must occur along the line round the position of maximum dimension when viewed in the draw direction. Then is this line lies on a plane the parting surface will be flat. 完整的分型面完全取决于形状的部件。例如，分型面成型的矩形显示在图8 - 1（一）。腔为这篇文章可以die-sunk到一个模具板。位置的分型面，因此将在顶部的模，分型面本身是完全持平 。外观这是理想的安排分模线并

38、不明显，除非快速发展。另一个考虑是，分型面必须选择，使成型可以从模具中删除。图8 - 1（乙）显示，分别表面的平面矩形，采用了双边缘。选择适合的 分模线的中心的双允许一半所需的形式是die-sunk成一个半模。分模线必须发生沿线的位置附近的最大尺寸时，在拉伸方向。然后这是位于一个平面分型面是平。 Lesson9 MOULD CAVITIES AND CORES 8.1 Integer cavity and core plates When the cavity or core is machined from a large plate or block of steel, or is cas

39、t in one piece, and used without bolstering as one of the mould plates, it is termed an integer cavity plate or integer core plate. This design is preferred for single-impression moulds because of the strength, smaller size and lower cost characteristics. It is not used as much for multi-impression

40、moulds as there are other factors such as alignment which must be taken into consideration. Of the many manufacturing processes available for preparing moulds only two are normally used in this case. These are (a) a direct machining operation on a rough steel forging or blank using the conventional

41、machine tools, or (b) the precision investment casting technique in which a master pattern is made of the cavity and core. The pattern is then used to prepare a casting of the cavity or core by a special process. A 4.25% nickel-chrome-molybdenum steel (BS 970-835 M30) is normally specified for integ

42、er mould plates which are to be made by the direct machining method. The precision investment casting method usually utilizes a high-chrome steel. 当腔或核心是从加工大型板或钢块，或是投在一片，使用不支持为一体的模具板，它被称为整数或整数的腔板芯板。这种设计是首选的single-impression模具因为实力，更小的尺寸和更低成 本的特点。它不使用过多型腔的模具有等其他因素，必须考虑到。在众多的制造工艺可用于 制备模2通常在这种情况下使用。这是（一）直接加工操作粗钢锻或空白使用传统工具机，或（乙） 精密熔模铸造技