1、模具专业英语全册配套完整模具专业英语全册配套完整 教学课件教学课件 Unit1 Injection Molding Overview 1.1 The injection molding Injection molding is a method of producing plastic parts. This is done with an injection molding machine. The shape of the part to be injection molded is controlled by the geometry of the injection mold. The
2、 injection molding machine has two basic parts; the injection unit, which melts the plastic and then injects or moves it into the mold, and the clamping unit, which holds the injection mold. 注射成型是生产塑料部件的方法。他由注塑机来完成。注塑成型的部件形状受 到注塑模具的几何形状控制。注塑机有两个基本部分;注入装置,它可融化塑 料,然后把塑料注入或移动至模具中,锁模装置,它可夹住注塑模具。 Injecti
3、on 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 been extr
4、emely difficult to solve for thermosetting plastics which cure and harden under such conditions within a few minutes. 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 form from a hopper through mete
5、ring and melting stages and then injecting it into a mold. 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 mol
6、ding are: A high molding speed adapted for mass production is possible; There is a wide choice of thermoplastic materials providing a variety of useful properties; It is possible to mold threads, undercuts, side holes, and large thin sections. 尽管成型某些热固性材料的方法取得了一定进步,但注塑模主要还 是用来生产热塑性塑件。这主要是因为热固性塑料熔体在很
7、短的时间内 就会固化和硬化,在从料斗向模具型腔注入热固性塑料熔体的过程中, 也会出现这种情况,这个问题一直非常难解决。注塑成型原理和铸造十 分相似。注塑成型的工艺过程包括:首先把料斗中的粉状或粒状的塑料 混合物依次输送到计量区和熔化区,然后再注射到模具型腔中,经过 短时冷却后,开模,推出成型塑件。注塑机分为手动、半自动及全自动 操作。注塑模具有以下优点:较高的成型速度使大批量生产成为可能; 为成型具有不同使用性能的热塑性材料提供了较宽的选择;可以成型带 有螺纹的塑件、侧向凹陷的塑件、带有侧孔的塑件以及较大的薄壁件。 1.2 The injection-molding structure The
8、 injection mould is an assembly of parts containing within it an impression into which plastic material is injected and cooled. It is the impression which gives the moulding its form. The impression may, therefore, be defined as that part of the mould which imparts shape to the moulding. 注塑模具是由几部分组合
9、在一起形成成型腔,塑料熔体注入成型腔,并在成 型腔内冷却成型。是成型腔形成了塑件的形状。因此,成型腔被定义为模具 的成型部件。 The impression is formed by two mould members:the cavity, which is the female portion of the mould, gives the moulding its external form.The core, which is the male portion of the mould, forms the internal shape of the moulding. 成型腔由两部分
10、组成:型腔,即模具的母模部分,形成塑件的外部形状。 型芯,即模具的公模部分,形成塑件的内部形状。 1) Cavity and core plates The basic mould in this case consists of two plates. One plate is sunk into the cavity which shapes the outside form of the moulding and is therefore known as the cavity plate. Similarly, the core which projects from the core
11、 plate forms the inside shape of the moulding is closed, the two plates come together forming a space between the cavity and core which is the impression. 最简单的模具包括两块模板。一块模板下陷形成型腔,用于形成塑件的外 部形状,这块模板被称为型腔板。同理,型芯板上凸起的型芯加工塑件的 内部形状。这两块板拼合起来,在型腔和型芯之间形成的空间就是成型腔。 2) Sprue bush During the injection process pl
12、astic material is delivered to the nozzle of the machine as a melt; it is then transferred to the impression through a passage. The material in this passage is termed the sprue, and the bush is called a sprue bush. 注塑过程中,塑料以熔融状态从注塑机喷嘴射出,然后流过一通路进入 模具成型腔。熔体流过的通路称作主流道,其衬套被称作浇口套。 3) Runner and gate syst
13、ems The material may be directly injected into the impression through the sprue bush or for moulds containing several impressions it may pass from the sprue bush hole through a runner and gate system before entering the impression. 塑料熔体可能经过浇口套直接进入模具一个或几个型腔,或者熔体 从浇口套流出,经过分流道和浇口系统再进入型腔。 4) Registerrin
14、g If the material is to pass without hindrance into the mould, the nozzle and sprue must be correctly aligned. To ensure that this is so, the mould must be central to the machine and this can be achieved by including a register ring. 如果想让熔体没有任何阻碍地进入模具,注塑机的喷嘴和模具主流 道必须位于同一轴线上。为确保正确安装,模具必须安装在注塑机 的中心部位,
15、(我们可以)通过使用定位圈达到这一目的。 5) Guide pillars and bushes To mould an even-walled article, it is necessary to ensure that the cavity and core are kept in alignmemt. This is done by incorporating guide pillars on one mould plate which then enter corresponding guide bushes in the other mould plate as the mould
16、 closes. 若加工具有均匀壁厚的塑件,必须确保型腔和型芯在同一轴线上,这可以依靠 导柱和导套实现。导柱安装在一块模板上,合模时进入安装在另一块模板上对 应的导套里。 6) Fixed half and moving half The various mould parts fall naturally into two sections or halves. Hence, that half attached to the stationary platen of the machine (indicated by the chain dotted line) is termed the
17、 fixed half. The other half of the mould attached to the moving platen of the machine is known simply as the moving half. Now it has to be decided in which of the two halves the cavity or core is to be situated. Generally the core is situated in the moving half and the overriding reason why this is
18、so, is as follows: 各种模具结构(虽然不同,但均)可以划分为两个部分或部件。因此, 固定在注塑机固定板的部分称为定模部分,同理,固定在注塑机移动板 的部分即为动模部分。这样,模具被安装在注塑机上。通常型芯安装在 动模部分,其原理如下: The moulding, as it cools, will shrink on to the core and remain with it as the mould opens. This will occur irrespective of whether the core is in the fixed half or the mov
19、ing half. However, this shrinkage on to the core means that some form of ejector system is almost certainly necessary. (塑件)冷却后开模,由于熔体的收缩作用使塑件紧紧地包在型芯上,这与型 芯是安装在定模部分还是安装在动模部分无关。然而,塑件包紧在型芯上意味 着必需使用某种形式的推出系统。如果型芯安装在动模部分,推出系统运动的 动力很容易获得,此外,单型腔模具中,熔体直接进入模具内部,型腔必须固 定在定模部分,型芯必须安装在动模部分。 1.3 Injection-molding
20、 machine Several methods are used to force or inject the melted plastic into the mold. The most commonly used system in the larger machines (as shown in Figure 1.1) is the in-line reciprocating screw, as shown in Figure 1.2. The screw acts as a combination injection and plasticizing unit. As the pla
21、stic is fed to the rotating screw, it passes through three zones as shown: feed, compression, and metering. After the feed zone, the screw-flight depth is gradually reduced, forcing the plastic tocompress. The work is converted to heat by shearing the plastic, making it a semifluid mass. In the mete
22、ring zone, additional heat is applied by conduction from the barrel surface. As the chamber in front of the screw becomes filled, it forces the screw back, tripping a limit switch that activates a hydraulic cylinder that forces the screw forward and injects the fluidplastic into theclosed mold. An a
23、ntiflowback valve prevents plastic under pressure from escaping back into the screw flights. Figure 1.1 The injection-molding machine 熔融塑料注入模具中通常有几种方式。在大型注塑机(如图1.1所示)上常采用 往复式螺旋注塑的注入方式,如图1.2所示。螺杆同时具有注射和塑化的功能。 树脂原料进入旋转的螺杆时,要经过图示的三个区域:喂入区、压实区和计量 区。经过喂入区后,为压实树脂原料,螺杆螺旋部分的深度逐渐降低,同时传 递树脂原料间因剪切作用而产生的热量,使原料呈
24、半流动状态。在计量区,螺 缸表面的加热装置对熔体进一步加热。当熔体充满螺杆前部区域时,螺杆在熔 体压力的作用下后退,触动限位开关使液压缸工作,在液压力的作用下推动螺 杆向前运动,将熔融塑料注射到闭合的模具型腔中。防倒流阀能够阻止受压熔 体倒流进螺杆的螺旋区。 The clamping force that a machine is capable of exerting is part of the size designation and is measured in tons. A rule-of-thumb can be used to determine the tonnage req
25、uired for a particular job. It is based on two tons of clamp force per square inch of projected area. If the flow pattern is difficult and the parts are thin, this may have to go to three or four tons. 注塑机的锁模系统所提供的锁模力由(塑件在分型面的投影)尺寸决定, 锁模力以吨为单位。通常靠经验来决定塑件所需要的锁模力总吨数,一 般在塑件投影面积上每平方英寸需要作用两吨锁模力。如果熔体流动困 难
26、或塑件较薄,锁模力应提高到三到四吨。 Many reciprocating-screw machines are capable of handing thermosetting plastic materials. Previously these materials were handled by compression or transfer molding. Thermosetting materials cure or polymerize in the mold and are ejected hot in the range of 375410. Thermoplastic pa
27、rts must be allowed to cool in the mold in order to remove them without distortion. Thus thermosetting cycles can be faster. Of course the mold must be heated rather than chilled, as with thermoplastics. 许多往复螺杆式注塑机能生产热固性塑料。以前,热固性塑料由挤出模具或 传递模具生产。热固性塑料熔体在模具内固化或发生聚合反应,并在温度为 375410范围内推出。热塑性塑料熔体必须在模具内冷却成
28、型,以保证 推出时不发生变形。这种热固性循环速度很快。当然,生产热塑性塑件时, 模具必须被加热,而不是冷却。 Injection-molding machines can be arranged for manual operation, automatic single-cycle operation, and full automatic operation. The advantage of injection molding are: 1) a high molding speed adapted for mass production is possible; 2) there is
29、 a wide choice of thermoplastic materials providing a variety of useful properties; 3) it is possible to mold threads, undercuts, side holes, and large thin sections 注塑机分为手动、半自动及全自动操作。注塑模具有以下优点:较高的成 型速度使大批量生产成为可能;为成型具有不同使用性能的热塑性材料提 供了较宽的选择;可以成型带有螺纹的塑件、侧向凹陷的塑件、带有侧孔 的塑件以及较大的薄壁件。 EXERCISE Questions 1 W
30、hat are the components of injection- molding? 2 How does the reciprocating-screw injection system work? 3. What are the advantage of injection molding ? Reading Material:Basics of Injection Molding Injection molding is a manufacturing technique for making parts from both thermoplastic and thermosett
31、ing plastic materials in production. Molten plastic is injected at high pressure into a mold, which is the inverse of the products shape. After a product is designed, usually by an industrial designer or an engineer, molds are made by a moldmaker (or toolmaker) from metal, usually either steel or al
32、uminium, and precision-machined to form the features of the desired part. Injection molding is widely used for manufacturing a variety of parts, from the smallest component to entirebody panels of cars. Injection molding is the most common method of production, with some commonly made items includin
33、g bottle caps and outdoor furniture. 注塑成型是一种制造技术,在生产中用于制造由热塑性和热固性塑料材料组成 的零部件。熔化的塑料以高压被注入到了模具中,此过程是形成了产品的相反 形状。通常情况下,在由工业设计师或工程师设计完成产品后,由模具制造商 (或工具商) 制造由金属(通常是钢或铝)组成的模具,然后经过精密加工塑造所期望部 件的特征。注塑成型广泛用于制造各种零部件,从最小的零部件到整个汽车 的车身壁板。注塑成型是最常见的生产方法,还通常用于制造某些物品包括 瓶盖和室外家具。 1)Ejector Stopper A block that stops an
34、ejector plate from going forward stop pin 1.顶出板制动装置 它是阻止顶出板向前运动的障碍物。 2)Ejector Plate Ejector Plate is also called a push plate. A plate supports an edge of an ejector pin or a push back pin to eject a part from a mold. It is ejected by an ejector device of a molding machine, and returned to the orig
35、inal position when the edge of a push back pin collides with a cavity plate during mold clamping. 2.顶出板 顶出板也被称为推出板。此板支撑推顶杆的边缘或回推销使零部件从模具 中推出。 3)Stop Pin A stopper installed to keep an ejector plate horizontal or prevent the ejector plate from retreating too far and damaging a core adaptor plate. 3.止
36、动销 已安装的制动装置使顶出板保持水平或防止推出器模板退离过远并破坏型 芯安装板。 4)Push Rods A shaft linked to the force (hydraulic or mechanical) of the molding machine in order to get the ejector plate to work. 4.推杆 连接在注塑机上的轴可产生力使顶出板工作。 5) Ejector Guide Pins / Ejector Guide Bush An ejector guide pin is also called a push plate guide pi
37、n and functions as a guide for sliding of an ejector plate. Because an ejector guide bush slides, a hard material is used. An ejector guide bush is also called a push plate guide bush. It is a cylindrical part used to determine the position by matching the ejector guide pin. 5.顶出导销/顶出导套 顶出导销也被称为推板导销
38、,起到顶出板的导轨槽作用。 因为顶出导套滑动,所以使用较硬的材料。顶出导套也被称为推板导套。它是 一个确定与顶出导销匹配位置的圆柱形部件。 6)Gas Spring / Gas Spring Holder A gas spring forcibly pushes back an ejector plate. The strength of the spring is adjusted by adjusting the filling pressure. When using a gas spring, make sure to avoid high temperature (heat may
39、expand gas, deteriorating the original functions of a gas spring). Calculating Filling Pressure To figure out filling pressure (P) from early load (Wo): P = 100 * Wo /C (C: constant) To figure out corresponding spring constant (K) from filling pressure (P) and gas spring constant (G): K =G * P / 100
40、 To figure out force by displacement (x) from the top of the piston rod (W): W = P (Gx + C) See the catalog of each manufacturer for constant (C) and gas spring constant (G). 6.气压弹簧/气压弹簧支架 气压弹簧可用力推回顶出板。弹簧的强度可通过充气压力调节。 当使用气压弹簧时,一定要避免高温。 计算充气压力 由最初负荷计算充气压力: P = 100 * Wo /G 由充气压力和气压弹簧常数计算相应的弹簧常数: K =G
41、* P / 100 由距离活塞杆顶部的位移计算力: W = P (Gx + C) 7)Gas Spring Holder A gas spring holder is a block used to fix a gas spring to an ejector plate. Counter bore process for a bolt installation hole, for it also functions as a push rod. 7.气压弹簧支架 气压弹簧支架是用于把气压弹簧固定到顶出板的部件。 因为它也起着推杆作用,所以具有用于螺栓连接的沉孔工艺。 8)Sprue Lock
42、 Pins A pin has the edge of which is undercut to pull a part in mold opening and remove a sprue from a sprue bush. After mold opening, this pin will function as an ejector pin and ejects the sprue from a aprue bush. Also it releases gas contained in molten plastic. 8.浇口锁销 浇口锁销有一个侧向分型的边,这样在模具打开时可拉出零部
43、件,并可从浇 口套中除去一个浇口。 模具打开后,锁销将起到顶出销的作用并从浇口套中推出浇口。同时也释放 了已熔化塑料中的气体。 For Reference: Glance at the Structure of the Die The following is the Structure Diagram of the Die and Mold Sample 1. Adjust pin (Knock-out bar): A pin or bar typically attached to the upper portion of the die set that forces the finis
44、hed piece out. 2. Punch holder: Another term used for the upper die shoe. 3. Backing plate:A plate used to support the hardware for the cavity used in plastics injection molding. 4. Punch plate: A metal plate onto which the various punches are mounted. 5. Stripper fixing type: A fixed plate designed
45、 to remove sheet metal stock from the punch as it pulls away from the die during the operation 6. Trimming die: 7. Die holder: Another term used for the lower die shoe. 8. Pressure pin: A pin used in conjunction with an air cushion that transfers pressure from the air cushion to the bottom of the di
46、e. 9. Pad: Anything made of or stuffed with soft material to fill out a shape, protect against friction, pressure, jarring, or blows, etc. 10. Drawing punch: A punch especially adapted to form holes in sheet metal material includes an elongate draw rod formed with a partially threaded. 11. Knock-out
47、 pin (Straight punch): A die block that removes the finished pieces off the die cavity. 12. Blanking stretching beyond the elastic limited occurs, then plastic deformation, reduction in area, and finally, fracturing starts through cleavage planes in the reduced area and becomes complete. 金属承受拉应力和压应力
48、。在超出弹性极限时发生伸长,然后进入塑性变形, 断面减小,最终裂纹沿不断减小的断面上的撕裂带扩展,从而实现完全分离。 The fundamental steps in shearing or cutting are shown in Figure 2.1. The pressure applied by the punch on the metal tends to deform it into the die opening. When the elastic limit is exceeded by further loading, a portion of the metal will
49、be forced into the die opening in the form of an embossed pad on the lower face of the material. A corresponding depression results on the upper face, as indicated at Figure 2.1a. As the load is further increased, the punch will penetrate the metal to a certain depth and force an equal portion of metal thickness into the die, as indicated at Figure 2.1b. This penetration occurs before fracturing starts and reduces the cross-sectional area of me
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