往复螺杆式注塑机注射系统设计【说明书+CAD】
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青岛农业大学海都学院毕业论文（设计）任务书论文（设计）题目： 往复螺杆式注塑机注射系统设计 要求完成时间： 2011-06-18 论文（设计）内容（需明确列出研究的问题）： 设计一种往复螺杆式注塑机的注射系统，该注塑机的最大注射容量为，注射速度为，注射压力为。要求所设计的注射系统应结构合理，能够满足注塑机的工作要求。需解决的问题有： （1）总体结构设计； （2）传动装置设计； （3）塑化装置设计； （4）注射装置设计。 资料、数据、技术水平等方面的要求： 说明书要求内容充实，文字叙述条理清楚、重点突出。专业术语、计量单位、图表格式、文字书写以及引用文献，均应按正式出版物要求来表述。说明书应按要求格式打印，篇幅在8000字左右。 设计计算方法正确，数据来源可靠。相关分析计算要完整、结果正确。图表资料要完整、正确。 要求用CAD绘制出总装图和零件图，绘图应符合国家标准。 指导教师签名： 年 月 日青岛农业大学海都学院毕业论文（设计）立题表立题题目往复螺杆式注塑机注射系统设计题目来源来源于生产实际 来源于科研项目 其他 题目性质基础研究 应用研究 应用基础研究 其他题目完成形式毕业论文 毕业设计 申请立题教师吕宝君职称副教授从事专业机械设计与制造立题说明：课题要求设计往复螺杆式注塑机的主要工作部分注射系统。该注塑机的最大注射容量为，注射速度为，注射压力为。 往复螺杆式注塑机是注塑机中应用最多的一种，它的主要工作部分是注射系统。物料的塑化由注射系统来完成，主要作用是将胶料(或塑料)热炼和塑化，使其达到所要求的粘流状态，并以足够的压力和速度将其注入模腔内。注射成型的基本要求是塑化、注射和成型。塑化是保证成型制品质量的前提。为满足成型的要求，注射必须保证有足够的压力和速度。 教研室意见教研室主任签名： 年 月 日毕业论文（设计）领导工作小组意见： 主任签名： 年 月 日青岛农业大学海都学院本科生毕业论文（设计）题 目： 往复螺杆式注塑机注射系统设计 姓 名： 杨培旭 系 别： 工程系 专 业： 机械设计制造及其自动化 班 级： 07机制一 学 号： 200701004 指导教师： 吕宝君 2011年6月18日毕业论文（设计）诚信声明本人声明：所呈交的毕业论文（设计）是在导师指导下进行的研究工作及取得的研究成果，论文中引用他人的文献、数据、图表、资料均已作明确标注，论文中的结论和成果为本人独立完成，真实可靠，不包含他人成果及已获得青岛农业大学或其他教育机构的学位或证书使用过的材料。与我一同工作的同志对本研究所做的任何贡献均已在论文中作了明确的说明并表示了谢意。论文（设计）作者签名： 日期： 年 月 日 毕业论文（设计）版权使用授权书本毕业论文（设计）作者同意学校保留并向国家有关部门或机构送交论文（设计）的复印件和电子版，允许论文（设计）被查阅和借阅。本人授权青岛农业大学可以将本毕业论文（设计）全部或部分内容编入有关数据库进行检索，可以采用影印、缩印或扫描等复制手段保存和汇编本毕业论文（设计）。本人离校后发表或使用该毕业论文（设计）或与该论文（设计）直接相关的学术论文或成果时，单位署名为青岛农业大学。论文（设计）作者签名： 日期： 年 月 日指 导 教 师 签 名： 日期： 年 月 日 目 录摘要IAbstractII1 绪论11.1研究的目的及意义11.2研究内容11.3注塑机的现状11.4需要解决的问题22 总体方案设计42.1柱塞式注射装置42.2螺杆预塑式注射装置52.3往复螺杆式注射装置52.4方案的选定63主要零部件设计73.1塑化装置的设计73.1.1螺杆设计73.1.2料筒的设计103.2传动装置的设计113.2.1单级圆柱齿轮减速器的设计113.2.2轴的设计计算173.3注射装置的设计193.3.1喷嘴的设计193.3.2螺杆最大行程计算203.3.3液压油缸的直径计算203.3.4注射力计算204结论22参考文献23致谢24往复螺杆式注塑机注射系统设计摘要本文根据给定的设计参数介绍了一种往复螺杆式注射系统的设计，所设计的注射系统包括传动装置、塑化装置、注射装置三大部分。传动装置采用了单级齿轮减速器和三相异步电动机满足设计要求，塑化装置采用了三级变径螺杆与料筒结合完成对坯料的塑化，注射装置采用了单向液压缸与往复螺杆结合，由液压缸活塞推动螺杆完成注射过程并在下一循环的塑化过程中自动完成螺杆的退回。所设计的装置具有结构简单、性能可靠、制造容易的特点。关键词：注塑机；注射系统；往复螺杆式 Design of The Injection System of Reciprocating Screw Type Plastic Injection MachineAbstractThe design according to the given design parameters describes a reciprocating screw injection system design, the design of the injection system includes gear, plastics unit, injection unit of three parts. Transmission using a single-stage gear reducer and the three-phase induction motor to meet the design requirements, plasticizing device uses three adjustable screw and barrel combined with the completion of the blank plastics, injection device using one-way hydraulic cylinder and reciprocating Screw combination of hydraulic cylinder piston driven by the injection screw to complete the process and in the course of the next cycle of the plasticizing screw back automatically.The design of the device has a simple structure, reliable performance, easy to manufacture characteristics.Keywords: injection molding machine; injection system; reciprocating screwII青岛农业大学海都学院本科毕业论文（设计）1 绪论1.1研究的目的及意义目前注塑机发展的一个重要方向，是轻量化、节省资源、节省能源、高效率、低使用成本。往复螺杆式注塑机克服了传统注塑机结构庞大复杂，融料质量部均匀，效率低下等问题，集中体现了高新技术含量的特征1。往复螺杆式注塑机的应用，在锁模力只有传统技术三分之一时，仍可高质量的保证制品成型，使机器的体积和重量都大幅度降低，能大大提高注塑成型的效率，保证制品的精度，在节能和制品成本控制方面都具有重大意义。1.2研究内容本次设计要求从经济性、安全性、合理性几个方面考虑。以往复螺杆装置为此次的设计方案。通过所给的原始数据，以螺杆直径为出发点，采用类比设计的方法对料筒、喷嘴和减速器进行设计。所设计的装置要求结构简单、性能可靠、制造容易。本次设计主要围绕以下内容展开：传动装置设计、塑化装置设计、注射装置设计，并对设计的结构进行必要的强度设计。1.3注塑机的现状近年来，中国注塑机行业在改革开放的引导下，取得了长足的发展，也早已结束了注塑机设备基本依赖进口的时代，这主要体现在注塑机的产量以及生产厂家的数量上。国内注塑机的产量由几千台发展到十多万台，生产厂家由原来的四大金刚发展到现在华南、华东大小企业的百家争鸣。 从以上数据看，注塑机行业的增长速度已远远大于GDP的增速，这与老百姓生活水平的提高以及国内家电等行业的迅速壮大是密切相关的，而出口加工业飞速发展也是注塑行业高速增长的强劲推动力。从金额上看，国内注塑机的年产值数以百亿计，年出口过亿美元。全球注塑机产量最多的厂家也在中国。中国已成为名副其实的注塑机生产大国。2从注射机问世起，锁模力在1000-5000kN，注射量在50-2000g的中小型注射机占绝大多数。到了70年代后期，由于工程塑料的发展，特别是在汽车、船舶、宇航、机械以及大型家用电器方面的广泛应用，使大型注射机得到了迅速发展。美国最为明显。在1980年全美国约有140台10000kN以上锁模力的TodayHot大型注塑机投入巾场，到1985年增至500多台。日本名机公司已经成功地制造了当今世界最大的注塑机，其锁模力达到120000kN，注射量达到92000g。80年代以来，CAD/CAECAPPCAM计算机应用技术在塑机制造业的广泛采用，促进了我国注塑机研发和制造水平的高速发展3。以宁波海天股份有限公司为代表的一批国家级高新技术企业都相继引进美国U.G.S和PTC公司的计算机辅助设计和分析等软件，实现了三维立体参数化建模，机构运动仿真，对主关原件分析，对高应力区的应力分布、应力峰值、危险区域等进行准确的分析计算，帮助设计人员迅速地了解、评估和修改设计方案，保证重要零件结构合理性的可靠性达到完美结合。为了保证高质量的设计输出到高质量的产品输出，旧的加工方式已经很难适应技术、质量竞争的要求。海天公司在“八五”和“九五”规划中，HotTag按照滚动发展的科学方法，累积投资2亿元人民币组建了加工中心分厂。新建5万平方米的大型装配分厂，10万平方米的扳金和结构件加工分厂，新建了1万平方米的试验车间和实验室，新建了5928个库位的立体自动仓库。购置了德国OKUMA两条柔性加工线，加入到40多台加工中心组成的机群中。实施了国家863计划浙江海天CIMS工程，成功应用K3系统，实现了生产计划、物料、成本等计算机集成管理。引进IMAN系统实现了产品技术数据创建和跟踪，产品结构和版本，产品属性和关联数据的查询以及向K3系统的信息传递等计算机集成管理。1.4需要解决的问题注射成型（也称注射模塑，简称注塑）是指将注射用原料（粒状或粉状塑料）置于能加热的料筒内，受热、塑化后用螺杆或柱塞施加压力，使熔体经料筒末端的喷嘴注入到所需形状的模具中填满模腔，经冷却定型后脱模，即得到具有要求形状的制品4。注射成形的基本要求是塑化、注射和成形，为满足成形的要求，注射必须保证足够的压力和速度5。同时，由于注射压力很高，螺杆将受到很大的轴向力，因此，螺杆的设计要进行必要的强度校核；螺杆兼具传送物料与塑化的功能，因此要合理安排螺杆的结构以及不同功能段的螺槽深度。由于熔融树脂容易停滞在加热料筒内而发生热分解，因此要设计合理的塑化装置以保证熔融塑料能均匀受热，同时，为达到较大的注射压力，必须合理设计喷嘴的结构以减小压力损失。选用普通异步电动机做为驱动装置，要达到任务要求的转速，必须设计合理的传动装置，合理安排传动件的位置。为准确控制注射量，需设计计量装置，并通过行程开关完成计量的自动控制。222 总体方案设计注射装置是注射机中直接对塑料加热和加压的部分，塑料的塑化和注射都在这里进行。因此，注射装置是注射机的一个非常重要的组成部分。注射装置在注射成型工艺过程中，应能均匀加热和塑化一定数量的塑料；并以一定的压力和速度将熔料注入模腔；保压一段时间以防止模内熔料的反流，且向模内补充一部分熔料，补偿制件的冷却收缩6。注射装置主要形式有柱塞式、螺杆预塑式和往复螺杆式（简称螺杆式）。目前采用最多的是往复螺杆式，其次是柱塞式。2.1柱塞式注射装置柱塞式注射装置由定量加料装置、塑化部件、注射液压缸、注射座移动液压缸等组成。柱塞式注射装置具有以下特点：（1）塑化不均匀，提高料筒能力受到限制。由于料筒内塑料加热熔融塑化的热量来自于料筒的外部加热，且塑料导热性差，塑料在料筒内的运动呈“层流”状态，造成靠近料筒外壁的温度高，塑化快；而料筒中心的塑料温度低，塑化慢。料筒的直径越大，温度差越大，塑化越不均匀，甚至出现内层塑料尚未塑化好 ，而表层塑料已经过热分解变质的状况。对于热敏性塑料则更难于加工成型。（2）注射压力损失大。因为注射压力不能直接作用于熔料，需要经过未塑化的塑料传递，熔融塑料通过分流梭与料筒内壁的狭缝进入喷嘴，最后注入模腔，造成很大压力损失8。据实际测量，采用分流梭的柱塞式注射机，模腔压力仅为注射压力的25%50%，因此需要提高注射压力。 （3）不容易提高稳定的工艺条件。柱塞在注射时，首先加入料筒的加料区的塑料进行预先压缩，然后才将压力传递给塑化后的熔料，并将头部的熔料注入模腔。可见，即使柱塞等速移动，但熔料的充模速度却是先慢后快，直接影响到熔料在模内的流动状态。且每次加料量的不精确，对工艺条件的稳定和制品质量也会有影响。此外，料筒的清洗比较困难，但其结构简单，在注射量比较小时，仍不失其应用价值。因而，一般只用于注射量在60以下的小型注射机7。2.2螺杆预塑式注射装置螺杆预塑式注射装置是由两个料筒组成的，一个是螺杆预塑式料筒，另一个是注射料筒，两个料筒的连接处有单向阀。粒料通过螺杆预塑式料筒而塑化，熔料经过单向阀进入注射料筒8。当注射料筒中的熔料量达到预定量时，螺杆塑化停止，注射柱塞前进并将熔料注入模腔。预塑料筒中的螺杆在转动过程中不仅输送塑料，更重要的是对塑料产生剪切摩擦加热和搅拌混合作用。因此，这种注射装置的塑化质量和塑化效率比柱塞式注射装置有显著的提高。另外，由于料筒内取消了分流梭，而且进入注射料筒的是已经塑化的熔料，所以，注射时压力损失大大减小，注射速率也比较稳定，所以在连续注射或者大型注射装置上应用比较多。螺杆预塑式注射装置虽然解决了柱塞式注射装置在工作过程中的缺陷，扩大了注射量，减小了注射时的压力损失，但由于增加了一个料筒，结构比较复杂庞大。两个料筒的单向阀处容易引起塑料的停滞和分解。同时为了避免熔料泄露，注射料筒和柱塞间的配合要求比较高。因此，给制造和使用带来了一定的困难。为了克服这些缺点，在结构上做了进一步改进，产生了往复螺杆注射装置。2.3往复螺杆式注射装置往复螺杆注射装置也叫螺杆一线式（简称螺杆式）注射装置，主要由塑化部分、料斗、螺杆、传动装置 、注射座、注射座移动液压缸、注射液压缸等组成。塑化部件和螺杆传动装置等装在注射座上，注射座借助注射座移动液压缸可以沿底座的导轨往复运动使喷嘴撤离或者紧贴模具。 同时，为了便于拆换螺杆和 清洗料筒，在底座中部设有一个回转装置，使得注射座能够绕其转轴旋转一定角度。往复螺杆注射装置还有采用液压马达直接驱动型，可根据注射液压缸数目分为单缸式和双缸式两类结构 。对于双缸式液压马达随动式注射装置，螺杆和液压马达直接连接传递运动。双注射油缸放置在料筒两侧平行排列，注射时，液压马达随螺杆一起作轴向移动，故称随动式。这种形式注射装置结构紧凑，能耗低，它是恒定力矩驱动装置，当螺杆出现过载时，液压马达无法驱动，起到对螺杆的保护作用，而电动机驱动装置为恒定功率驱动装置，当螺杆过载时容易扭断螺杆9。目前普遍采用液压马达直接驱动的注射装置。2.4方案的选定往复螺杆式注射装置与柱塞式 注射装置比较有以下优点：（1）螺杆式注射装置塑化时不仅依靠外部加热器提供热量 ，而且螺杆的旋转运动不断地对塑料进行剪切摩擦，产生剪切摩擦热对塑料进行加热塑化 ，可以适当降低加热器的加热温度，因而在塑化效率和塑化质量上都优于柱塞式注射装置 。（2）注射压力损失少。因注射时，螺杆头部的塑料是 完全塑化的熔料，又没有分流梭造成的阻力，在其他条件相似的情况下，螺杆式注射装置可以采用比较小的注射压力。（3）塑化能力大，均匀性好，注射机的生产率高。螺杆还兼有对料筒壁的刮料作用，可减少塑料滞留而产生过热分解。（4）螺杆式注射装置可以对塑料就进行染色加工，而且料筒清洗比较方便。 不过，螺杆式注射装置的结构比柱塞式复杂，螺杆的设计和制造比较困难。尽管如此，因为其优点居多，所以应用十分广泛。经过比较，发现往复螺杆注射装置的优点居多，因此本次设计选用此类注射装置。3主要零部件设计3.1塑化装置的设计3.1.1螺杆设计1、螺杆的结构形式注塑机螺杆分为：渐变型螺杆、突变型螺杆、通用型螺杆。渐变型螺杆指螺槽深度由加料段深的螺槽向均化段的螺槽逐渐过度。主要用于加工具有宽的软化温度范围，高粘度非结晶性塑料，如聚氯乙烯等。突变型螺杆指螺杆槽深度由深变浅的过程是在一个较短的轴向距离内完成的主要用于加工粘度，熔点明显的结晶性塑料，如聚乙烯，聚丙烯等。通用型螺压缩段长度介于突变型螺杆与渐变型螺杆之间，以适应结晶性与非结晶塑料熔融塑料化的要求。通过比较，发现通用型的结构介于渐变型和突变型之间，兼有两者的特点，可以通过调节工艺条件来满足不同塑料的成型加工，扩大了适用范围，所以选用此结构的螺杆。螺杆的结构、形式和作用与挤出用螺杆基本相同，但也有某些差异。注射螺杆的长径比较小，一般为1620，压缩比较小，一般为25。常见注射螺杆压缩比的选择，见表3-1。表3-1 常见注射螺杆的压缩比塑料名称压缩比聚烯烃、聚苯乙烯、聚酰胺软聚氯乙烯硬聚氯乙烯2.53.5232注射螺杆均化段的螺槽深度一般偏大，因而具有较高的塑化能力，减小功率消耗，提高生产率。注射螺杆因有轴向位移，故加料段应较长，约为螺杆长度的一半，而压缩段和计量段则各为螺杆长度的1/4。典型的注射。螺杆如图3-1所示。为使螺杆注射时不致出现熔料积存或沿螺槽回流，应考虑螺杆头部结构。熔融粘度大的塑料，通常采用锥形尖头的注射螺杆，如图3-2所示。采用该螺杆，不仅可减少塑料降解，同时使排料比较干净。2、螺杆的尺寸图3-1 注射用螺杆DS-料筒外径 hm-计量段螺槽深度 Ds-螺杆公称直径L/D-螺杆总长度 S-螺距 L/D-长径比 hf-进料段螺槽深度 hf/hm-压缩比 a=1/4L图3-2 锥形螺杆头（1）长度L的确定原始数据已经给出螺杆的直径Ds=40mm。由塑性成型加工入门可知注射机螺杆仅作预塑用所以(L/Ds)小于挤出机的(L/Ds),一般取1822. 常采用20：1。那么由此可以得出螺杆的长度L=4020=800mm。对于通用螺杆，其加料段、压缩段和均化段的长度L1、L2和L3占总长的百分比为5060%、2030%、2030%。在此次设计中，分别取50%、25%、25%。那么对应的长度为400mm、200mm和200mm。（2）均化段螺槽深度h3和压缩比i的确定均化段螺槽深度是螺杆性能的重要参数之一，螺槽深度与塑化之间的关系：螺槽深度与剪切效果：螺槽浅，剪切热大，螺杆消耗功率大。浅的螺槽与长均化段的螺杆是稳定挤出的重要条件。注射机的h3越大，塑化能力越大。一般 h3=(0.040.07)Ds。 （3-1）此处取h3=0.065Ds=2.6mm压缩比是螺杆加料段的螺槽深度h1与h3的比值。即i=h1/h3对注射机而言，小的压缩比有利于提高塑化能力。 对结晶性塑料（PP、PE、聚酰胺及复合塑料）i=3.03.5对高粘度塑料（硬PVC、AS、聚甲醛）i=1.42.5通用型 i=2.02.8此处取i=2.1。那么h1=i*h3=2.12.6=5.4mm （3-2）螺纹升角、螺距s和螺棱宽度e的确定当s=Ds时，=18，e=0.080.12Ds。此处取e=0.1Ds=4mm。（3）螺杆材料的选用注塑机螺杆工作恶劣，要承受高的注射压力，在加上频繁启动。要求螺杆材料具有：高的强度，表面耐腐蚀耐磨损，其表面硬度不低于HV950，螺杆工作表面的粗糙度要求不低于Ra0.4um,国内一般选用40Cr 或其它合金钢材,为提高螺杆表面耐磨能力,螺杆表面氮化、喷涂合金、镀铬或镀钛。此处选用40Cr。3、螺杆的强度校核当注射机液压系统选用30MPa的规格时由 p=（D2/Ds2）P0 （3-3）其中：p注射压力（MPa） D-注射油缸直径(cm) Ds螺杆直径（cm） P0 注射油压（MPa）可以计算得到D=80mm压缩应力:c=(D/d1)P0=(80/29.2)30 MPa=82.2 MPa （3-4）其中：d1-螺杆加料段螺纹根径（cm）剪切应力:=Mt/Ws （3-5）Mt=9549(p/n)=954912/180=212.2Nm （3-6）Ip=D14/32=3.144/32=25.12cm4 （3-7）Ws=Ip/R=D13/16=12.56cm3 （3-8）=(212.2/12.56)106=17MPa其中： Mt螺杆扭矩（Nm） Ip极惯性矩（cm） D1加料段螺纹直径（cm） p电动机功率（KW） n-螺杆转速（r/min） Ws抗扭截面系数（cm3）合成应力:r=(c+4)=(82.210+41710)=83MPa （3-9）由于r=y/n=539/3=179MPa那么螺杆可以安全工作。其中：y-40Cr的屈服强度（MPa） n安全系数，取2.53 许用应力3.1.2料筒的设计1、料筒内径和壁厚的确定机筒壁厚既要满足强度要求，又要注意机筒结构及其对成型工艺条件的影响。壁厚过小：机筒升温快，但热容量小；壁厚过大：升温慢，热惯性大，调节温度后。根据经验一般取料筒的外径和内径之比K为22.5 螺杆与料筒内径的间隙一般取0.150.3mm。此处取0.2mm那么料筒的内径为40.4mm。当取K=2时，得到料筒的外径为80.8mm。料筒的长度应该按照螺杆的具体长度而选定。2、料筒材料的选取料筒与螺杆一起完成塑料的塑化和注射，要求其耐温、耐热、耐磨和耐腐蚀。那么材料可以取45钢内表面镀铬、氮化钢（38CrMoAl）内表面氮化处理，氮化层深度0.5 mm、碳钢内表面浇铸Xaloy合金衬里。HRC65。此处选用45钢。3、料筒强度校核应力 r=pk/(k-1)=126102/(2-1)=259MPa （3-10）=t/n=400/1.5=267MPa （3-11）r 其中：r-料筒的工作应力 （MPa） p注射压力（MPa） k料筒内外径之比，取22.5 许用应力（MPa） n安全系数，取1.52 t-45钢屈服强度（MPa）所以料筒能够安全工作3.2传动装置的设计3.2.1单级圆柱齿轮减速器的设计1、电动机的选择（1） 类型和结构构型式 在选择合适的异步电动机时，应本着实用、经济和安全的基本原则，要考虑类型、额定功率、额定电压、额定转速等四个因素。往复螺杆式注塑机在不同条件下需要选择不同的转速，同时，在注塑机启动时容易瞬间超载，故电动机功率需略大于螺杆的工作功率；根据以上条件选择Y系列三相异步电动机。（2）电动机的功率 计算电机所需功率： 查得：联轴器传动效率：0.99每对轴承传动效率：0.99圆柱齿轮的传动效率：0.97总传动效率 = （3-12）电动机所需功率 （3-13）查机械设计手册13得：单级圆柱齿轮减速器传动比则电动机转速由p=12.05kw和，选择Y180L-6电动机各参数如下：额定功率15kw满载转速970r/min额定电流31.4A,功率因数102、减速器的设计计算基本传动数据计算 电动机型号为Y180L-4，满载转速为970r/min则传动比 （3-14）计算机构各轴的转速及动力参数 （1）各轴的转速 电动机轴轴 轴 轴 （2）各轴的输入功率 轴 轴 （3）各轴的输入转矩 电机输出转矩 （3-15） 轴 轴 齿轮传动设计图3-3齿轮传动简图（1）选定齿轮类型、精度等级、材料及齿数12按图3.2所示的传动方案，选用直齿圆柱齿轮传动。注塑机为一般工作机器，速度不高，故选用7级精度（GB 10095-88）。材料选择。由表10-1（机械设计）选择小齿轮材料为40Cr（调质），硬度为280HBS，大齿轮材料为45钢（调质），硬度为240HBS，二者材料硬度差为40HBS。选小齿轮齿数z1=24，则大齿轮齿数z2=120。（2）按齿面接触强度设计由设计计算公式进行试算，即 （3-16）1）确定公式内的各计算数值试选载荷系数Kt=1.3。计算小齿轮传递的转矩T1=选取齿宽系数=1。查表得材料的弹性影响系数ZE=1.89.8。由图齿轮的接触疲劳强度极限，查得小齿轮的接触疲劳强度极限；大齿轮的接触疲劳强度极限。计算应力循环次数N1=60n1jLh= （3-17）N2=取接触疲劳寿命系数KHN1=0.95；KHN2=1.15。计算接触疲劳许用应力。取失效概率为1%，安全系数S=1，由计算公式得 2）计算试算小齿轮分度圆直径d1t，将中较小的值代入公式（4-17）中。=67.98mm计算圆周速度v。V=计算齿宽b。计算齿宽与齿高之比。模数：齿高：计算载荷系数根据v=3.45m/s,7级精度，由图10-8（机械设计）查得动载系数Kv=1.05；直齿轮，;查得使用系数.5；用插值法查得7级精度、小齿轮相对支承非对称布置时，。由=10.68，查图得；故载荷系数校正所算得的分度圆直径，由计算公式得mm计算模数m。（3）按齿根弯曲强度设计弯曲强度的设计公式为 （3-18）1）确定公式内的各计算数值查图得小齿轮的弯曲疲劳强度极限；大齿轮的弯曲强度极限；取弯曲疲劳寿命系数,;计算弯曲疲劳许用应力取弯曲疲劳安全系数S=1.4；计算载荷系数K。查取齿形系数。 查得齿形系数；。查取应力校正系数。 查表得;。计算大、小齿轮的并加以比较。经比较：大齿轮的数值大。2）设计计算对于计算结果，由齿面接触疲劳强度计算的模数m大于由齿根弯曲疲劳强度计算的模数，由于齿轮模数m的大小主要取决于弯曲强度所决定的承载能力，而齿面接触疲劳强度所决定的承载能力，仅与齿轮直径（即模数与齿数的乘积）有关，可取由弯曲强度算得模数2.54并就近圆整为标准值m=3.0mm，按接触强度算得的分度圆直径d1=81.456mm，算出小轮齿数大齿轮齿数取3、几何尺寸计算（1）计算分度圆直径（2）计算中心距（3）计算齿轮宽度取B1=85mm,B2=81mm。4、结构设计及绘制齿轮零件图如图3-4所示图3-4齿轮传动示意图3.2.2轴的设计计算因本设计中减速器并非主要设计部件所以此处只设计高速轴。1、轴的结构形式及尺寸高速轴（1轴）：（1）作用在齿轮上的力（2）初步确定轴的最小直径，估算轴最小直径，轴材料为45#钢（调质），查表得=97，于是有输出轴需要安装联轴器取 查手册选用型号为HX2的弹性柱销联轴器。公称转矩为560轴孔直径为22mm,L=52mm（3）轴的结构设计1） 轴上零件的装配方案如图3-53-5 轴上零件装配方案示意图确定各段直径：2）为了满足半联轴器轴向定位要求，-轴端左侧需制出一轴肩，故取-段的直径=24mm,右端用轴端挡圈定位，按轴端直径取挡圈直径D=28mm。半联轴器与轴配合长度52mm，-长度应小于，现取50mm3）初步选择滚动轴承由=24mm,选择深沟球轴承6205 其参数=25mm ， =15mm左端滚动轴承采用轴肩定位。6205定位轴间高度h=4mm,因此取4）取安装齿轮处轴段-V的直径 =32mm, 右端与右轴承间采用套筒定位。已知齿轮宽85mm为可靠定位取左端采用轴肩定位，h0.07d，故取h=3mm 则轴环处=38mm,轴环宽b1.4h,取=5mm5）轴承端盖的总宽度20mm 取外端面与半联轴器左端距离l=20mm 故40mm6）齿轮距箱体内壁距离a=16mm,轴承距箱体内壁一段距离s，取s=6mm，轴承宽T=15mm,则 = T+s+a+（85-81）=15+6+16+4=41mm=a+s=6+16=22mm2、轴强度的校核（1）求轴上的载荷根据轴的结构图做出轴的结构简图，确定各支撑点位置，求得：L1=75mm，L2=29.5mm，L3=65mm。根据轴的计算简图做出弯矩图和扭矩图，如图3-6。图3-6 轴的弯矩图和扭矩图从图中我们可以发现截面D是危险截面。现将计算出的截面C处的及M值列于表3-2。表3-2载荷水平面H垂直面V支反力F=1008.9N,=2564.9N=367.2N,=933.6N弯矩M=75665.4Nmm=27540.9Nmm总弯矩M=80521.8Nmm扭矩TT=Nmm（2）按弯扭合成应力校核轴的强度D截面是危险截面，因此只校核D截面的强度，根据选定材料45 钢，调质处理，查表得取=0.6，轴的计算应力，故安全。143.3注射装置的设计3.3.1喷嘴的设计1尺寸的确定由文献11可知，喷嘴直径 d=kQ1/3 （3-19）k由塑料的性能决定，对热敏性和高粘度的塑料k取0.680.8。一般性塑料k取0.350.4。Q注射速率（/s）此处k取0.8由原始数据可以知道注射速率Q=110g/s。这是相对Ps而言的。Ps的密度是1.05g/cm3。那么可以得d=0.8（110/1.05）1/3=3.8mm又由塑性成型设备9可知，可以取喷嘴的球面半径SR=15mm。2材料的选用由于喷嘴和料筒配合着工作，其所要求的性能与料筒相似。因此，在材料的选择上可以与料筒相同，即也选用45钢。3.3.2螺杆最大行程计算由 Vc=（/4）DsS （3-20）其中：Vc注射量（cm）Ds螺杆直径（mm）S-螺杆最大行程（cm）可以计算得到S=10cm3.3.3液压油缸的直径计算当注射机液压系统选用30MPa的规格时由 p=（D2/Ds2）P0 （3-21）其中：p注射压力（MPa） D-注射油缸直径(cm) Ds螺杆直径（cm） P0 注射油压（MPa）可以计算得到D=80mm3.3.4注射力计算F=(/4)Dsp (3-22)其中：F注射力（KN） Ds螺杆直径（mm） p注射压力（MPa）可以计算得到F=158.3KN4结论本文根据给定的设计参数介绍了一种往复螺杆式注射系统的设计，所设计的注射系统包括传动装置、塑化装置、注射装置三大部分。传动装置采用了单级齿轮减速器和三相异步电动机满足设计要求，电动机的输出的转速经减速减速到要求转速后传递到螺杆上，带动螺杆转动。塑化装置采用了三级变径螺杆与料筒结合完成对坯料的塑化，螺杆转动完成了坯料的疏松，同时起到剪切和混炼的作用，能提高塑化效率，改善熔融物的质量。注射装置采用了单向液压缸与往复螺杆结合，由液压缸活塞推动螺杆完成注射过程并在下一循环的塑化过程中自动完成螺杆的退回，随着螺杆的转动，熔融塑料在料筒前端累积增多，在融料的压力下螺杆沿轴向后退，待到回退到融料量满足需求时，螺杆停转，并在注射液压缸的推力下完成注射过程。所设计的装置具有结构简单、性能可靠、制造容易的特点。通过此次的毕业设计，加深了对所学课本知识的理解，并能够与此次的设计相结合，提高了理论联系实际的能力，也体会到了在实际工作中设计工作的重要性。此次的毕业设计既是对之前所学知识的复习与运用，同时也是毕业生上岗就业前的一次实习。使自己对以后的工作又有了更深的理解参考文献1 赵银章. 旧型往复螺杆式注塑机的改造. 现代塑料加工应用, 19992 王卫卫.金属与塑性成型设备.机械工业出版社，19963 项钢. 高效精密注塑机规划和选型. 工程建设与设计, 20104 马海舟,潘晓铭,潘道波. 塑料注塑机快速注射部分设计与应用. 液压与气动, 20075 雄戈. 智能化全电动注塑机. 国外塑料, 20096 陈仲成. 革新注塑机成型条件及调整方式探讨. 现代商贸工业, 20097 向鹏,李绣峰,杜遥雪. 全电动注塑机的特点及应用领域. 现代塑料加工应用, 20078 吴红. 小型注塑机液压系统优化设计研究. 南宁职业技术学院学报, 20099 刘向东.塑性成型设备机械工业出版社，200210吴宗泽.机械设计课程设计手册第三版.清华大学出版社2004,311陆萍主编，机械设计基础，山东科技大学出版社，200312成大先.机械设计手册M.化学工业出版社；200513机械设计手册联合编写组编机械设计手册北京：机械工业出版社，199814濮良贵，纪名刚.机械设计，高等教育出版社，2006致谢24英文原文Injection molding machineInjection molding machine is plastic machine for short. It uses the thermal physical properties of plastics, the material from the hopper into the barrel, is barreled by heating coil heat, so the material will be melted, which is arranged by the external force under the action of the motor driving the rotation of the screw in the barrel. The material in the screw under the action of the screw groove, along the forward delivery and compaction, dual role the material in the heating and shear under gradually plasticizing, melted and homogenized, when the screw rotates, the material in the screw channel friction and shear force, the molten material is pushed to the screw head. At the same time, the screw with backward in the material, the screw head forming material storage space, completing the plasticizing process, then, screw in the injection cylinder piston thrust under the action of high speed, high pressure, in the material storage chamber, the melt through the nozzle to the mold cavity injection, cavity melt after pressing, cooling, solidification, mold in the mold closing mechanism of action next, open mold, and through the ejection device to finalize the design good products fall from the top die.Configuration according to the clamping member and the injection component type has horizontal, vertical, angle type three(1) Horizontal injection molding machine: horizontal injection molding machine is the most common type. Its characteristic is the center line injection assembly and clamping assembly center line of concentric or consistent, also with the parallel to the mounting surface. It has the advantages of low center of gravity, steady work, mold installation, operation and repair, which are convenient, the mold opening big, small occupied space height; but covers an area of large. (2) Vertical injection molding machine: its characteristic is clamping device and injection device of the axis line arrangement and perpendicular to the ground. It also has the advantages of small occupied area, convenient assembly and disassembly of insert mold, easy installation, since the bucket into the material plasticization is evenly, easy to realize automation and machine automation line management. The disadvantage of it is the top product is not easy to fall off automatically, it often needs manual or other method to take out, and is not easy to realize full automatic operation and large products injection; machine height, feeding, inconvenient repair.(3) Angle type injection molding machine: injection device and a molding device axis are arranged vertically. According to the injection assembly center lines are vertical, horizontal and relative position of the vertical and horizontal installation, recumbent points: horizontal vertical, injection assembly line and plane parallel, and mold assembly center line and the base of vertical and horizontal, vertical; injection assembly center line and the surface vertical, and die assembly center line and the reference surface. The advantages of angle type injection machine has the advantages of both horizontal and vertical injection molding machine, special apply to the mold opening side gate asymmetric geometry products.At present, the injection device are common cylinder form and double cylinder form, I plant the injection molding machine is double cylinder form, and is directly driven by a hydraulic motor of screw in injection molding. Because of different manufacturers, different types of machine components are not the same; the following will make a concrete analysis of our factory with machine.The working principle is: the plastic, screw in plastic parts in the drive the main shaft to rotate through the hydraulic motor, spindle end is connected with the screw, and the other end of the hydraulic motor key connection, screw rotation, plasticity and melt classified pushed to the storage chamber cylinder front, at the same time, screw back in the reaction material, and through the thrust bearing the thrust seat back, pulling the piston rod through the nut straight back. To complete the measurement, injection, the injection cylinder rod chamber oil inlet through the bearing to push the piston rod to complete the action, the rod chamber piston oil inlet to push the piston rod and screw and finish the injection.The work principle of screw plasticizing components: performs, screw rotation, from the material inlet into the screw groove material advancing continuously forward, heating ring through the barrel wall of the heat transfer to the spiral groove material, solid material in the dual role of external heating and screw rotational shear, and through the thermal process functional section of screw, achieving the plasticizing and melting, melting away the check ring around the screw head, front end through the channel into the screw, and generates backpressure, push the screw after the shift measurement complete melt, at the time of injection screw up, piston effect, with rapid advancement, in the cylinder, will melt reservoir material in the chamber through the nozzle into the mold.Screw plasticizing components generally have the following characteristics:The screw has two functions of plasticizing and injection;The screw in plastic, only for the plasticThe plastics in plasticizing process, thermal process through than extrusion;The screw on the plasticizing and injection were to occur, axial displacement, and screw in working state of intermittent when to stop, thus forming a non - stability of screw plasticizing process.(1) ScrewScrew is a key component of plastic parts, direct contact with plastic, plastic through the effective length of the screw channel, after the heat for a long time, must go through 3 states (glass, behavior, viscous state) transformation, geometric parameters, geometry, length of functional section of screw will directly affect the transmission efficiency and the plasticizing quality of plastic, will ultimately affect the quality of injection molding cycle and product.Compared with the extrusion screw, plastic screw has the following characteristics:The injection screw length-diameter ratio and compression ratio is small;Screw groove of injection screw is section of the deep;The injection screws feeding sections is longer, and are short;The injection screw work, plasticizing capacity and melt temperature will vary with the axial displacement screw and change.(I) classification, screwInjection screw according to the plastic adaptability, can be divided into general and special screw, general also called conventional screw, can be processed with low viscosity, most of the thermoplastic, civil plastic crystalline and amorphous and engineering plastics, is the most basic form of the screw, and the corresponding and special screw, is used to process with ordinary screw processing hard plastic; according to the screw structure and geometry characteristics, can be divided into conventional screw and screw, the conventional screw is also known as the three section screw, is the basic form of the screw, screw form has many kinds, such as separation screw, screw, wavy shunt screw, no metering section of screw.The conventional screw thread effective length is usually divided into feeding sections (conveying), the compression section (Plastics segment), and metering section (averaging period), according to the plastic properties of different, can be divided into gradual, mutation type and general type screw.The tapered screw: compression long, plasticizing energy transfer for PVC relaxation, poor thermal stability of plastic.The mutant compression screw: short, plasticizing energy conversion is more acuteness, used for polyolefin, PA crystalline plastics.The general purpose screw: adaptability is strong, and can be suitable for processing a variety of plastic, avoid frequent replacement of the screw, increase production efficiency.DS screw diameter, screw diameter directly affect the plasticizing capacity, will directly affect the injection volume, therefore, injection volume of injection molding machine the screw diameter is large.L/ds - screw length to diameter ratio. L is the effective length of screw thread part of the screw, the ratio of length to diameter is larger, the length of that thread, directly affect the thermal process of material in the screw, the ability to influence the absorption of energy, while the energy source has two parts: one part is the external heating coil to the barrel, and another part is friction thermal and shear heat generated by the rotation of the screw, the external mechanical energy conversion, therefore, L/ds directly affect the melting effect of material and melt, but if L/ds is too large, the transmission torque increase, increased energy consumption.L1 - feeding length. The feeding section is also called conveying or feed section, in order to improve the transport capacity, screw groove surface must be smooth, the length of the L1 shall ensure that the material conveying length too short enough, because L1 will lead to premature melting material, thus it is difficult to guarantee the transportation conditions of stabilizing pressure, will be difficult to ensure the screw later. Plastic under their own gravity from the hopper to slip into the screw, screw rotation, the thrust surface friction in the barrel and screw groove under the action of the material is compressed into a solid, nut intensive, the relative motion along the direction of the thread, this section, plastic solid state, namely the glass state.The depth of screw channel H1 - feed section. H1 deep, is receiving materials, improving the feeding quantity and plasticizing capacity, but will affect the shear strength of material plasticization and screw root, general H1 (0.12 0.16) ds.L3 - melting length. Melting section called homogeneous section or the measuring section, melt further homogenization, uniform temperature in the channel of L3 segment, uniform composition, the formation of good quality of melt, the length of L3 is helpful to melt in the screw groove fluctuations, stable pressure, causes the material to feed evenly extruded from the screw head, so it is also called the metering section. L3 short time, help to improve the general screw plasticizing capacity, L3= (4 5)ds.H3 - melting section of spiral groove depth, H3 small, shallow groove, improves the plasticizing effect of plastic melt, to melt homogenization, but H3 is too small will lead to higher shear rate, and shear heat is too large, causing degradation of the molecular chain, the effect of melt quality,; conversely, if the H3 is too large, the perform, enhanced flow screw back pressure generated, will reduce the plasticizing capacity.L2 - plasticizing period (compression) length of thread. The tapered space material continuously under compression, shear and mixing effect, material from the L2 point, molten pool increased, to the point of weld pool has been occupying the entire screw groove, the material from the glass state through viscoelastic state transition to a viscous state, namely this segment, the plastic is state of coexistence in the particles with a molten body. The length of L2 will affect the transformation of the material from the glassy to viscous flow state, is too short will not change, plugging in the terminal segment of the L2 formation of high pressure, torque or axial force of solid material; too long will increase the screw torque and unnecessary consumption, general L2= (6 8) ds. For the crystalline plastics, material melting point, melting a narrow range, L2 can be shorter, generally (3 4) ds, for heat-sensitive plastic, this section Kvetching.S - Pitch, the size effect of helix angle, thus affecting the transport efficiency of screw, general S ds.E - Compression ratio. =h1/h3, namely the feeding section of spiral groove depth H1 and the melting section of spiral groove depth ratio of h3. E, will enhance the shear effect, but will weaken the plasticizing capacity, generally speaking, slightly smaller as well, to help improve the plasticizing capacity and increase the adaptability to raw materials, for crystalline plastics, the compression ratio is 2.63.0. For low viscosity and thermal stability of plastic, can choose the high compression ratio and high viscosity; thermal sensitivity plastic, should choose low compression rate.(2) The screw headIn the injection screw, screw head is: the plastic, can be good plastic melt and releasing to the storage chamber, and in high pressure injection, and can effectively close the melt front screw head, prevent backflow.The screw head is divided into two categories, with check ring and not the inverse ring with the check, the check ring, a plastic screw, melt homogenizing section will check ring away, through the gap formation and the screw head, into the storage chamber, injection pressure, melt screw the head of the formation of thrust, the non-return valve return channel plugging, prevent backflow.For some high viscosity materials such as PMMA, PC, AC or poor thermal stability of PVC material, in order to reduce the retention time of shearing and material, can not check ring, but this injection will produce reflux, prolonging holding time.On the screw head requirements:The screw head to be flexible smooth;The check ring and the cylinder to be suitable with the gap, to prevent melt flow, and flexible;The existing flow section is enough, but also to ensure the check ring face a return force, making fast closed at the time of injection;The structure should be easy disassembly, convenient cleaning;The direction of the screw thread screw and screw in screw head instead, prevent a plastic screw head loose.(3) Cylinder(I), the barrel structureCylinder is an important part of plastic parts; interior screw is arranged outside the heating coil, under complex stress and thermal stress.(II), the feeding portStructure feeding port directly affects feed effect and plastic parts of the feeding ability, injection molding machine most by gravity feed material in hopper, simple manufacture, but feed the negative; the feed material and the screw contact angle, contact area is large, can improve the feed efficiency, is not easy in the hopper into bridge hole.(III), cylinder wall thicknessCylinder wall thickness is of sufficient strength and stiffness, because the barrel to melt and gas pressure, and the barrel length to diameter ratio, cylinder requires enough heat capacity, so the cylinder walls have a certain thickness, otherwise it is difficult to ensure that the temperature stability; but if it is too thick, barrel bulky, waste material, the thermal inertia of large, slow temperature rise, temperature regulation of delay larger.(IV), cylinder clearanceCylinder gap refers to the single gap barrel wall and screw diameter, the gap is too large, plasticizing capacity is reduced, injected back into the discharge increases, injection time, causing material degradation in the process; if it is too small, the thermal expansion effect on the screw and barrel friction, energy consumption increased, even death card, this gap delta = (0.0020.005) ds.(V), the material heating and cooling tubeInjection molding machine barrel heating with electric resistance, ceramic heating, cast aluminum heating, should be reasonably arranged according to the application and processing of materials, commonly used has the resistance heating and ceramic heating, to comply with the requirements of injection molding process, the barrel to subsection control, small 3, large machine 5.Cooling refers to the feeding mouth is cooling, because the feeding mouth if the temperature is too high, the solid in the feeding mouth bridge, blocking the outlet, thus affecting the transport efficiency of feed section, so the cooling water jacket is arranged in the cooling it. Our factory is through the cooling circulating water cooling of the feed inlet.(4) Nozzle(I) function of spray nozzleThe nozzle is an important part of connecting plasticizing device and mold flow; nozzle has a variety of functions:The perform, establishment of backpressure, degassed, prevent melt salivation, improve plasticizing capability and measurement precision;The injection mold, forming the contact pressure and the main cast, keep good contact with pouring nozzle sleeve, forming a closed channel, to prevent the plastic melt under high pressure overflow;injection, establish the melt pressure, shear stress, and the pressure head into the velocity head, the increase of shear rate and temperature, enhance mixing and homogenizing;Changing the nozzle structure to match the mold and plasticizing device, a new type of flow channel or injection system;The nozzle also bears the thermostat, thermal insulation and cutting function;The reducing melts in the import and export of the viscoelastic effect and the eddy loss, in order to stabilize its flow;The holding pressure, easy to mold products of feeding, and the cooling shaping increased reflow resistance, reduce or prevent the melt in the cavity to return.(II) The basic form, nozzleNozzle can be divided into straight-through nozzle, locking type nozzle, hot runner nozzle and the flow nozzle, the present stage our factory are straight-through nozzle.Straight-through nozzle is the nozzle is widely applied, its characteristic is the direct and main casting mold nozzle spherical contact, the nozzle radius and the channel than the mold to be small, injection pressure, melt directly through the mold runner system is filled into the cavity, fast speed, low pressure loss, manufacturing and installation are all relatively convenient.Locking type nozzle is mainly to solve the problem through the nozzle salivation, suitable for low viscosity polymer (such as PA) processing. In the closing the nozzle plastic, prevent melt salivation phenomenon, and when the injection and injection pressure to open, so that melt into the mold cavity.2 injection cylinderIts working principle is: the injection cylinder into the oil, the piston drives the piston rod and the bearing is arranged on the thrust seat, drive screwPush the screw forward or backward. Through the nut piston rod head, can adjust the timing of two parallel to the axial position of the piston rod and the injection screw axial position.3 thrust bearingInjection, thrust bearing thrust shaft driven by screw injection; while the plastic, the oil motor drive screw rotation to achieve thrust shaft drives the perform.4 cylindersWhen a moving oil cylinder into the oil, forward seat injection or the back action, and to ensure the injection nozzle and mould the main cast set of circular arc closely contact, the injection pressure can seal the melt.The 5 part accuracy requirements for injectionAfter the assembly, the components are arranged on the machine frame, must ensure that the nozzle and mold water sleeve is tightly bonding, in order to prevent overflow, the center line of injection parts requirements and the clamping parts of the center line of concentric; in order to ensure the accuracy of injection screw and barrel inner hole, must ensure that the two injection cylinder bore and the center cylinder hole is parallel with the center line of symmetry; in the horizontal plane, parallelism and symmetry for the center of a moving oil cylinder two guide holes also must ensure that the vertical machine, it must ensure that the two seat moving oil cylinder hole and a cylinder positioning the center hole is parallel with the center line of symmetry. Factors affecting the location accuracy of hole and shaft are associated parts size precision, geometric accuracy, precision and assembly precision.Each kind of plastic, has an ideal plastic processing temperature range, should control the processing temperature of barrel, which is close to the temperature range. Granular plastic from the hopper into the barrel, the first will arrive at a feeding section, in the feeding section will appear dry friction, when the plastic is heated, melting is not uniform, very easy to cause the barrel wall and screw wear surface. Similarly, the compression section and the entire segment, if the molten state disorder plastic uneven will result in increased wear.Speed should be adjusted properly. The friction force of these substances on the metal material is often much larger than the molten plastic. In the plastic injection molding, if using high speed in the shear stress on the plastic at the same time, it will also strengthen correspondingly more torn fibers, the torn fibers containing sharp end, to wear a large force to increase. Inorganic minerals on the surface of metal high-speed taxiing, the scraping is not a small role. So the speed should not be too high.In addition to check in plastic debris, the original purchase fresh plastic and no debris, but after weighing, transport, drying, mixing, especially to add recycling back material, there may be mixed with debris. Small as metal filings, as big as a heating ring nut clip, or clusters of warehouse key, mixed into the barrel had occurred, the screw damage is self-evident. (barrel of course also damage), therefore must install the magnetic iron material, strict management and monitoring.Moisture in plastics has a certain effect on the wear surface of the screw. If the plastic in injection unprecedented will eliminate all residual moisture, moisture into the screw compression section, they formed before melt blend in molten plastic with high temperature and high pressure steam particles, with the injection process screw propulsion, from homogeneous section until the screw head, these steam particle, pressure drop and expansion in the injection process, the impurities such as a fine grain, rubbing on the wall damage. In addition, for some types of plastic, under high temperature and high pressure, the water may become a catalyst for cracking of plastic, harmful impurities can corrode the metal surface. Therefore, the drying work plastic injection before, not only has a direct relationship to the product quality, but also affects the service life of the screw.中文译文注塑成型机注塑成型机简称注塑机。注塑成型是利用塑料的热物理性质，把物料从料斗加入料筒中，料筒外由加热圈加热，使物料熔融，在料筒内装有在外动力马达作用下驱动旋转的螺杆，物料在螺杆的作用下，沿着螺槽向前输送并压实，物料在外加热和螺杆剪切的双重作用下逐渐地塑化，熔融和均化，当螺杆旋转时，物料在螺槽摩擦力及剪切力的作用下，把已熔融的物料推到螺杆的头部，与此同时，螺杆在物料的反作用下后退，使螺杆头部形成储料空间，完成塑化过程，然后，螺杆在注射油缸的活塞推力的作用下，以高速、高压，将储料室内的熔融料通过喷嘴注射到模具的型腔中，型腔中的熔料经过保压、冷却、固化定型后，模具在合模机构的作用下，开启模具，并通过顶出装置把定型好的制品从模具顶出落下。按合模部件与注射部件配置的型式有卧式、立式、角式三种（1）卧式注塑机：卧式注塑机是最常用的类型。其特点是注射总成的中心线与合模总成的中心线同心或一致，并平行于安装地面。它的优点是重心低、工作平稳、模具安装、操作及维修均较方便，模具开档大，占用空间高度小；但占地面积大，大、中、小型机均有广泛应用。（2）立式注塑机：其特点是合模装置与注射装置的轴线呈一线排列而且与地面垂直。具有占地面积小，模具装拆方便，嵌件安装容易，自料斗落入物料能较均匀地进行塑化，易实现自动化及多台机自动线管理等优点。缺点是顶出制品不易自动脱落，常需人工或其它方法取出，不易实现全自动化操作和大型制品注射；机身高，加料、维修不便。（3）角式注塑机：注射装置和合模装置的轴线互成垂直排列。根据注射总成中心线与安装基面的相对位置有卧立式、立卧式、平卧式之分：卧立式，注射总成线与基面平行，而合模总成中心线与基面垂直；立卧式，注射总成中心线与基面垂直，而合模总成中心线与基面平行。角式注射机的优点是兼备有卧式与立式注射机的优点，特别适用于开设侧浇口非对称几何形状制品的模具。目前，常见的注塑装置有单缸形式和双缸形式，我厂注塑机都是双缸形式的，并且都是通过液压马达直接驱动螺杆注塑。因不同的厂家、不同型号的机台其组成也不完全相同，下面就对我厂用的机台作具体分析。工作原理是：预塑时，在塑化部件中的螺杆通过液压马达驱动主轴旋转，主轴一端与螺杆键连接，另一端与液压马达键连接，螺杆旋转时，物料塑化并将塑化好的熔料推到料筒前端的储料室中，与此同时，螺杆在物料的反作用下后退，并通过推力轴承使推力座后退，通过螺母拉动活塞杆直线后退，完成计量，注射时，注射油缸的杆腔进油通过轴承推动活塞杆完成动作，活塞的杆腔进油推动活塞杆及螺杆完成注射动作。螺杆式塑化部件的工作原理：预塑时，螺杆旋转，将从料口落入螺槽中的物料连续地向前推进，加热圈通过料筒壁把热量传递给螺槽中的物料，固体物料在外加热和螺杆旋转剪切双重作用下，并经过螺杆各功能段的热历程，达到塑化和熔融，熔料推开止逆环，经过螺杆头的周围通道流入螺杆的前端，并产生背压，推动螺杆后移完成熔料的计量，在注射时，螺杆起柱塞的作用，在油缸作用下，迅速前移，将储料室中的熔体通过喷嘴注入模具。螺杆式塑化部件一般具有如下特点： 螺杆具有塑化和注射两种功能； 螺杆在塑化时，仅作预塑用 塑料在塑化过程中，所经过的热历程要比挤出长； 螺杆在塑化和注射时，均要发生轴向位移，同时螺杆又处于时转时停的间歇式工作状态，因此形成了螺杆塑化过程的非稳定性。（1） 螺杆螺杆是塑化部件中的关键部件，和塑料直接接触，塑料通过螺槽的有效长度，经过很长的热历程，要经过3态（玻璃态、黏弹态、黏流态）的转变，螺杆各功能段的长度、几何形状、几何参数将直接影响塑料的输送效率和塑化质量，将最终影响注射成型周期和制品质量。与挤出螺杆相比，注塑螺杆具有以下特点： 注射螺杆的长径比和压缩比比较小； 注射螺杆均化段的螺槽较深； 注射螺杆的加料段较长，而均化段较短； 注射螺杆的头部结构，具有特殊形式。 注射螺杆工作时，塑化能力和熔体温度将随螺杆的轴向位移而改变。（）、螺杆的分类注塑螺杆按其对塑料的适应性，可分为通用螺杆和特殊螺杆，通用螺杆又称常规螺杆，可加工大部分具有低、中黏度的热塑性塑料，结晶型和非结晶型的民用塑料和工程塑料，是螺杆最基本的形式，与其相应的还有特殊螺杆，是用来加工用普通螺杆难以加工的塑料；按螺杆结构及其几何形状特征，可分为常规螺杆和新型螺杆，常规螺杆又称为三段式螺杆，是螺杆的基本形式，新型螺杆形式则有很多种，如分离型螺杆、分流型螺杆、波
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