毕业设计外文资料 .doc

机电工程学院毕业设计外文资料翻译设计题目: 组合式醒发汽蒸装置 译文题目: 对微波炉校对面包面团的评价 学生姓名： 黄坤 学 号： 20064050604 专业班级： 机制F0607 指导教师： 朱克庆 正文：外文资料翻译译文 附件： 外文原文 指导教师评语： 签名： 年 月 日正文：外文资料翻译译文摘 要：本设计首先分析了洗发水瓶盖塑件的工艺特点，文中介绍了洗发水瓶盖塑件注塑成型模具设计要点及模具的工作过程。重点说明了洗发水瓶盖塑件结构的设计包括分析和阐述了洗发水瓶盖塑件的壁厚选择及工艺特点。该模具采用一模四腔、点浇口、三板模、模外定距分型、定模限位顶出,并针对塑件的工艺特点进行模具的设计包括模具型腔数目的确定，注塑机的选择，模具分型面、冷却系统、浇注系统、分型机构等的设计过程。还对注塑模具成型零件工作尺寸的计算并介绍了模具的主要零件加工工艺及模具的装配工艺。该模具结构紧凑，工作可靠，操作方便，生产效率高等。关键词：三板模；点浇口；模外定距分型；定模限位顶出；模具结构 1.1塑料所谓塑料是指该材料是可塑的。根据定义，塑料具有在任何方向上连续变形而不引起断裂的能力。按照这个定义，塑料可能包括玻璃，金属和蜡状物，因此，对塑料的命名造成误解和不确切的定义是很显然的。然而今天塑料的命名是和来源于人工合成的树脂混为一谈的。合成树脂是通过多种多样的化学过程制成的。塑料制造业是近期才发展起来的。今天在家电用品、汽车、不计其数的其它制品和机器中都能找到塑料的存在。一些用电的机器需要利用塑料的电绝缘性能进行隔电。塑料通常是以颗粒或粉末的方式运输到制品厂，并在成型之前使其融化（热塑性塑料）。塑料也可以板、平板、圆棒和管子等方式进行使用，这些便可加工成型各种各样的产品，液态塑料可以用来制成高强度塑料制品。塑料工业是当今世界上增长最快的工业门类之一，而注塑模具是其中发展较快的种类，因此，研究注塑模具对了解塑料产品的生产过程和提高产品质量有很大意义。塑料分类及应用 塑料或聚合物，通常称为塑料，可以分为两大类. 塑料一般可分为热塑性塑料和热固性塑料。 热塑性塑料 我们以前曾提到过，在无定形聚合物结构中，每一个分子的相邻长链分子作用力（次级作用力） 远远小于其共价键作用力（初级作用力）。因此，聚合物的强度是由次级作用力的强度决定的。线性和分支状的聚合物一般具有较弱的次级作用力。当这种聚合物的温度被加热到高于玻璃熔点时，我们就会发现它将变得更柔软，更具可塑性或更易浇铸成型。长分子的流动性（热振动）在甘油三酯的作用下将进一步加剧。当聚合物冷却下来后，它将恢复到其原来的硬度和强度。换句话说：这一过程是可逆的。 pllymers表现出的这种特性就被称之为热塑性塑料。像丙烯酸树脂、尼龙、聚乙烯和聚氯乙烯都是这方面的典型例子热固性塑料这类塑料包括诸如三聚氰胺-甲醛，可以用来制造比较硬的餐具，胶水中的合成树脂和加强型腔的产品，例如皮船和网球拍框。热固性塑料在成型前需经过先加热成粘性的液体，然后再浇注或注射到模具中，最后冷却成固体成型。对热固性塑料来说，交叉链接的化学键使它的熔化是不可逆的。热固性塑料一旦达到它的熔点便开始变软、熔化，在压力下它们可以充满模具型腔的各个角落。如果继续对它们进行加热，它们发生聚合或成型后成为永久的、难熔化的坚硬固体等一些化学变化。它们一旦固化成型后，便不能进一步的加热变软或熔化。1.2塑料模塑料件经过压力、转换和注射成型。其它方法还有压铸法，挤出法，层压法，拔丝法，薄模成型法，嵌入法，泡沫法和机械法。这其中的一些方法和另外一些适用于橡胶。有这么多不同工艺方法的原因是因为不同的材料必须按不同的方法制造。每种方法都有适用于一定材料的优越性。塑料产品的制造有两个主要步骤，第一步是制造树脂的化学过程，第二步是把所有的材料注入到成型的部件或零件中混合成型。1.3注射模虽然在研究用于热固性材料的工艺方面已经取得一定进展，但注射成形（即塑料注进一个所需形状的型腔里，然后冷却，并最终取出的过程。大多数消费产品如电话机，电脑机箱，和CD播放机等均是用注射成形方式生产的。）主要还是用于热塑性材料零件的生产。注射成形的问题是在几分钟之内解决热固性塑料的塑化和变硬，即从装有熔融塑料的储液槽内把熔融塑料注入到模具型腔内，这是非常困难的。注射成形的原理和压铸成形是很相似的，塑料粉被装到料斗中，当活塞后退的时候定量的料进入到加热容器内，塑料粉在加热容器内经过加热加压成为液体。当模具闭合时活塞向前移动，液体塑料在压力下进入到模具型腔内，当循环的冷却水把模具冷却掉，塑料变硬，当活塞后退时模具开模制件被顶出。注射机可以是人工操作，自动单循环操作和全自动操作。典型机器每分钟生产4次，塑件质量达到22盎司。在某些机器上可以获得每分钟6次的频率。该模具的使用和压铸机上的模具是类似的。注射成形的优点如下1.适用于大批量生产的高频率是可能的2.提供很多功能，热塑性塑料的选择广泛3.有能力生产带螺纹，螺旋线，侧孔和大而薄的制件2.1无合模线纺纱管锭塑料模具设计 该无合模线纺纱管锭塑料注塑模具设计的关键是该模具必须带有斜抽芯装置，并要准确确定合模方向，且保证合模线不能在管子的外表面。出于用途考虑，它是用于缠绕棉纱，这就要求管子外表面足够光滑，本文就解决以上设计问题给予说明。并通过对塑件材料，质量 体积的分析与计算，合理选用注塑机，并对各个参数进行了校核，设计出一副合理，经济，适用的塑料注塑模具2.2底切 底切是一种刻槽或一个结构部件，在简单的、刚性的两组合模具上难以或不能脱模（的难题）方面起作用。小型底切的零件柔韧的足以实现从模具上无损剥落，许多柔韧的可塑性材料在脱模时可以容许10的张力。大型底切就达不到要求了。尽管该工具设计者 非常聪明地考虑到了组合部件或可移动的侧孔的配置来实现成型过程中“extra flash”或分型线的可能性。在构思一个底切零件时，应当确认它是必要的。2.3塑料的新材料新材料的低固有的残余应力使设计一个新的水平自由创造的产品，提高美学和功能属性，作为产品设计，并不需要是有限的，以尽量减少影响的残余应力。这个功能可以让品牌能够区别其产品在零售和更好地满足消费者的需求，加强产品性能。 tritan提供更快的成型周期比许多其他透明塑料和可用于在注塑模具设计，传统的聚合物，包括聚碳酸酯。作为材料，并不需要额外的步骤，退火后成型，由于其较低的固有的残余应力，这些属性可能会导致重大的制造业优势，包括减少能源使用，改善加工时间，降低有关成本和提高生产率。 与二 ，密度较低，比聚碳酸酯， tritan也收益率，更多的零部件，每公斤的树脂，这可能有助于节省材料。这些节省下来的延长新共聚酯的耐久性，它可以帮助延长产品寿命并降低更换成本。 而tritan 提供更高的玻璃化转变温度（ Tg ）比传统的共聚酯，板制造的产品与新的聚合物不需要预干燥。耐用，重量轻的产品也可以热更快的速度和更低的温度比聚碳酸酯的资产负债表。这些独特的属性形成作出贡献卓越的物质分布特性和开放的窗口装饰时使用预先形式的装饰涂料，油墨和乙烯基。 “ tritan是一种革命性的一步，在塑料市场，是一个直接结果，足智多谋和技术专长来预期的伊士曼补充说： ”纳尔逊博士。 “这个新的一代将提供共聚酯塑胶业一个机会，以更好地应对不断变化的消费需求与有区别的，更高的性能的产品。3.1浇注系统在浇注模中，连接（注塑机）喷嘴和各个型腔的流动通道是十分必要的，这种进料通道称为浇注系统。通常，浇注系统由主流道，分流道和浇口组成。这些术语适用于相应的进料通道本身，以及取出塑件时从进料通道中一同取出的浇注系统凝料。图4-1所示为典型的两板式四腔模的浇注系统。从图中可以看出原料通过主流道，第一分流道，第二分流道和浇口注入到型腔中。熔融塑料通过主流道和分流道是温度降低而使熔体粘度升高，然而，熔体通过浇口填充型腔时，由于剪切作用产生的热量又使黏度降低。浇注系统要保持适当长度，使熔体的压力减少和热量的损失降到最低。因此，设计时必须充分考虑型腔布局和浇口形式。主流道主流道是将熔融塑料从注射剂喷嘴传递到模具型腔的通道。主流道是浇口套的一部分，浇口套是独立于模具的单独零件。分流道分流道是引导熔融塑料进入模具型腔的通道。浇口浇口是熔融塑料进入型腔的入口。浇口有以下作用：约束熔体流动，引导熔体的流动方向，使分流道和塑件末端易于分离，快速冷却固化防止熔融塑料充满型腔后倒流。冷料井冷料井正对着主流道。理论上，冷料井的作用是用来储存在（塑件）冷却和推出的过程中注塑机喷嘴处所形成的熔体前锋冷料也许冷料井更重要的作用是（开模时）帮助浇道凝料脱出浇道口。塑件成型后，主流道，分流道和浇口部分凝料将被废弃。但是，分流道和浇口在塑料质量和成本方面有着重要影响。3.2分流道分流道位于模板内，是连接主流道和型腔入口的通道。分流道必须光滑，以防止对熔体流动产生阻力。另外，加工分流道时，分流到不能留有加工痕迹，否则将会导致流道凝料难以脱模。为满足上述条件，模具设计者必须指明分流道的抛光方式是“沿脱模方向抛光”。设计分流道时还应考虑其他因素：(i)分流道截面形状；(ii)分流道尺寸；(iii)分流道布局。分流道截面形状常用的四种分流道截面形状如图6-1所示：圆形分流道(a)；梯形分流道(b)；U分流道(c)；六边形分流道(d)。高效率的流道设计标准是：从压力传递角度来看，分流道应该提供最大的截面面积，从热传递来看，分流道分流道应该提供最小的表面积。因此，横截面与周长的比率直接体现了分流道的效率，比率越大，效率越高。不同横截面分流道的比率如图6-2所示。由图可知，依据这两个标准，圆形和正方形截面的分流道效率最高，反之，半圆形和矩形截面的效率较低，通常设计时不采用这两种形式。分流道尺寸确定分流道尺寸必须考虑以下因素：(i)塑件的体积和壁厚；(ii)型腔与主要分流道或主流道的距离；(iii)分流道的冷却状态；(iv)所能提供的模具加工手段；(iv)所使用的树脂原料。分流道布局分流道系统的布局取决于以下因素：(i)型腔分流道；(ii)组件形状；(iii)模具种类（例如，两模板或多模板）；(iv)浇口类型。设计分流道系统时主要考虑以下两个方面。分流道长度应该最短，以减少压力损失；分流道系统应该保持平衡。分流道平衡布置意味着，对于（多腔模具的）每个塑件，塑料熔体从主流道到浇口所流经的距离应该相等。如果浇口位置和注塑区域也相同，这种平衡式布局能够确保所有的型腔具有相同的填充形式，（且在填充过程中）不会中断。图6-3(a)(b)(c)给出了模具分流道均为平衡式布局的例子。然而，采用平衡式分流道系统并不是完全可行的，尤其是具有不同型腔的多腔模具中，如图6-3(d)所示。这时，需要采用不同尺寸的浇口来平衡型腔充模状态，即通过平衡浇口来平衡分流道系统。3.3浇口浇口是连接分流道和模具型腔的通道或入口。与浇注系统其他部分相比，浇口截面较小。浇口的截面积必须小，原因如下：(i) 型腔充满后，浇口处迅速凝固，可防止注塑机螺杆后退时（引起压力变化）造成塑件的熔体回流。(ii) 浇口去除方便，在某些模具中浇口可以自动拉断。(iii) 去除浇口后残留痕迹小。(iv) 多腔填充易于控制。(v) 填充塑件收缩所形成的浇口处凹陷所需的熔体量降到最小。应该考虑（或依据）浇口截面、浇口长度以及后面提到的浇口位置来确定浇口尺寸。浇口最佳尺寸受以下因素影响：(i)注塑熔体的流动特性；(ii)塑件壁厚；(iii)注入型腔的熔体体积；(iv)熔体温度；(v)模具温度。理想浇口的理论尺寸并不存在。生产中通常凭借设计经验选择浇口尺寸。然而，读者可能没有设计经验可供借鉴，为此，我们给出每种类型浇口的经验尺寸。不考虑其他因素，浇口经验值适用于壁厚为0.75mm-4mm的塑件。浇口类型为获得最佳填充条件，应慎重选择接口类型。然而，多数情况下，只有一种形式能满足所有塑件的要求，这时选择就比较容易。浇口类型（如图7-1）通常有以下几种：直浇口(f)，侧浇口(j)，搭接浇口(a)，扇形浇口(b)，盘形浇口(g)，环形浇口(h)，薄膜浇口(c)，点浇口(d)，潜伏式浇口(i)和护耳浇口(e)。附件：外文原文文献出处：模具专业英语MAbstract：The injection technological characteristics of shampoo bottle cover and analyzed, and the design main points and working process are also introduced. The design method of shampoo bottle cover plastic structure is mainly introduced .The mould is four-cavity and feature the pointed gate, three-plate mold, mold ranging parting, restricted ejector of fixed-die, The selection of the sidewall thickness, the decision of the mold cavity number, the selection of injection machine, and the designing process of the parting plane, the exhaust system, cool material cave and pin gate are stated. The design structure characteristics of shampoo bottle cover and parting plane with pin gate style, and side core-drawing structure. Analysis of the calculating the working dimensions of the forming parts of injection mold and the conventional manufacturing processes of the main parts of the injection mold . The mold is compact in construction, easy and reliable in operation ,high efficiency in production and keeps the tolerance of part been accurate. Key words： Three-plate mold；Pointed gate；Mold ranging parting；Restricted ejector of fixed-die；Mold structure1.1 Plastics Plastic means pliable or impressionable. it is defined as the capability of being deformed continuously in any direction without breaking apart. Following this definition, plastics could include glass, metals, and wax. Thus, it is evident that name plastixs is identified with the products which are derived from synthetic resins. The synthetic resins are made by various chemical processes. Plastics manufacturing is of comparatively recent date.Today plastics are commonly found in homes, automobiles, numerous other products, and machines. Some machines which utilize electricity require plastic parts with electrical insulating properties.Plastics are ususlly shipped to manfacturing plants as pellets or powders, and they are melted（for thermoplastics) just before the shaping process. Plastics are also available as sheet, plate, rod, and tubing , which may be formed into a variety of products. Liquid plastics are used especially in the making of reinforced-plastic parts. Plastics industry is one of the industry that develop fastest nowadays in the world. Injection mould is the faster one, hence it is very important to study injection mould on order to know the production process of plastics production and improve the product quality.Classification and Application of Plasstics Plastics are generally divided into the categories of thermoplastics and thermosets plastics.Thermoplastics We noted earlier that,in the amorphous structure of a polymer,the bonds between adjacent long-chain molecules(secondary bonds)are much weaker than the covalent bonds(primary bonds)within each molecule.Hence it is the strength of the seondary bonds that determines the overall strength of the polymer.Linear and branched polymers have weak secondary bonds. If we now raise the temperature of this polymer above the glass-transition temperature,we find that it becomes softer and easier to form or to mold into a shape.The mobility of the long molecules (thermal vibrations)increases at Tgand above.If this polymer is now cooled,it returns to its original hardness and strength.In other words,the process is reversible. Pllymers that exhibit this behavior are known as thermoplastics.Typical examples are acrylics,nylon,polyethylene,and polyvinyl chloride.Thermosetting molding materialsThese include the melamine-formaldehyde used in hard plastic tableware and the eqoxy resins used for glus and rein-forced cast products such as kayaks and tennid racket frames. Thermosetting products are heated until they become a viscous liquid, poured or injected into a mold, and then allowed to solidify.As thermosetting materials, chemical cross-linking occurs to create an irreversible, infusible mass. Upon the application of initial heat the thermosetting plastics soften and melt, and under pressure they will every crevice of a mold cavity. Upon contionued application of heat they polymerize, or undergo a chemical change, which hardens them into a permanently hard, infusiblem and insoluble state. After this they cannot again be softened or melted by further heating.1.2 Plastics Material Molding Plastic objects are formed by compression, transfer, and injection molding.Other oprocesses are casting,extrusion and laminating, filament winding, sheet forming, joining, foaming, and machining. Some of these and still others are used for rubber. A reason for a variety of processes is that different materials must be worked in different ways. Also, each methods is advantageous for certain kinds of products .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 mix and shape all the material into the finished article or product.1.3 Injection MoldingInjection molding (injection of plastic into a cavity of desired shape. The plastic is then cooled and ejected in its final form. Most consumer products 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 some thermosetting materialsm. The problem of injecting a melted plastic into a mold cavity from a reservoir melted material has been extremely 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. Plastic powder is loaded into the feed hopper and a certain amount feeds into the heating chamber when the plunger draws back. The plastic powder under heat and pressure 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 is 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 full 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 some 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 useful properties3. It is possible to mold threads, undercuts (sideways recesses or projections of the molded part that prevent its removal from the mold along the parting direction. They can accommodated by specialized mold design such as sliders. ) , side holes, and large thin sections.2.1 No mold line of spindles spinning plastic mold design The nil-ray tube spindles spinning plastic injection mold design, the key is to die with the ramp-pumping device and to accurately determine the direction of mold and mold guarantee Line is not in the external surface of the tubes. For purposes consider that it is used for winding yarn, which calls for the tubes outer surface smooth enough, This article solve design problems to provide an explanation. And pieces of plastic materials, the quality of analysis and volume calculation, a reasonable selection of injection molding machinery, as well as various parameters of the check, design a reasonable, affordable, suitable plastic injection mold.2.2 Undercuts An udetcut is an indentation or a projection on a part which has the effect of making it difficult or inpossible to eject the part from asimple, rigid, two-part mold. Some parts with minor undercuts may be flexible enough to be stripped from the mold without damage;many flexible thermoplastic materials can tolerate a 10% strain during the mold ejection. Larger undercuts are undesirable. Even if the tool designer is sufficiently ingenious to conceive of arrangements involving multipart tools or movables side cores to accomplish the possibility of extra flash or parting lines being apparent on the molding. Before committing oneself to an undercut part, one should be sure that it is necessary.2.3 The new material of platicThe new materials lower inherent residual stress gives designers a new level of freedom to create products with enhanced aesthetics and functionality attributes, as product designs do not need to be limited to minimize the effects of residual stress. This feature can allow brands to differentiate their products at retail and better meet consumer demand for enhanced product performance. Tritan provides faster molding cycles than many other transparent plastics and can be used in injection molds designed for traditional polymers, including polycarbonate. As the material does not require an additional annealing step after molding, due to its lower inherent residual stress, these attributes may result in significant manufacturing advantages, including reducing energy use, improving processing times, lowering associated costs and increasing production rates. With a two percent lower density than polycarbonate, Tritan also yields more parts per kilogram of resin, which may contribute to material savings. These savings are extended by the new copolyesters durability, which can help to lengthen product lifetime and lower replacement costs. While Tritan offers a higher glass transition temperature (Tg) than traditional copolyesters, sheet products manufactured with the new polymer do not require pre-drying. The durable and lightweight products can also be thermoformed faster and at lower temperatures than polycarbonate sheet. These unique forming attributes contribute to superior material distribution properties and open the decorating window when using pre-form decorative paints, inks and vinyl. “Tritan is a revolutionary step forward in the plastics marketplace and is a direct result of the ingenuity and technical expertise that has come to be expected of Eastman,” adds Dr. Nelson. “This new-generation copolyester will provide the plastics industry with an opportunity to better address evolving consumer needs with differentiated, higher performance products.”3.1 Feed SystemIt is necessary to provide a flow-way in the injection mould to connect the nozzle (of the injection machine) to each impression. This flow-way is termed the feed system. Normally the feed system comprises a sprue, runner and gate. These terms apply equally to the flow-way itself, and to the molded material which is removed from the flow-way itself in the process of extracting the molding.A typical feed system for a four-impression, two plate-type mould is shown in Figure 4.1. It is seen that the material passes through the sprue, main runner, branch runners and gate before entering the impression. As the temperature of molten plastic is lowered while going through the sprue and runner, the viscosity will rise; therefore, the viscosity is lowered by shear heat generated when going through the gate to fill the cavity. It is desirable to keep the distance that the material has to travel down to a minimum to reduce pressure and heat losses. It is for this reason that careful consideration must be given to the impression layout and gates design. Figure 4-1 Feed system: (a) typical shot of consisting of moldings with sprue, runner and gates attached; (b) section through feed portion of mouldSprueA sprue is a channel through which to transfer molten plastic injected from the nozzle of the injector into the mold. It is a part of sprue bush, which is a separate part from the mold.RunnerA runner is a channel that guides molten plastic into the cavity of a mold.GateA gate is an entrance through which molten plastic enters the cavityThe gate 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 cavityCold slug wellThe 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 durin