毕业设计（论文）-手机外壳塑料模具设计说明书.doc

目录前言1塑件成型工艺性分析·····························································································11.1软件简介···································································································41.2塑件（某手机外壳）分析···············································································51.3零件结构特征、塑料的性能、技术要求及结构工艺性的分析·····································51.3.1尺寸及精度·························································································61.3.2壁厚·································································································61.3.4脱模斜度···························································································61.3.5圆角·································································································71.3.6粗糙度······························································································71.3.7塑料性能的分析···················································································72模具的设计········································································································82.1拟定模具结构形式························································································82.2确定型腔数量及排列形式···············································································82.3分型面的确定：··························································································92.4注射机型号的确定························································································92.4.1注射机的选择······················································································92.4.2注射成型工艺的参数············································································102.4.3注塑机的校核····················································································112.5浇注系统设计····························································································112.5.1浇注系统的设计原则···········································································112.5.2浇注系统的组成·················································································122.5.3浇注系统的作用·················································································122.5.4浇注系统各部件设计···········································································122.5.5浇口的设计·······················································································152.5.6浇注系统的平衡·················································································152.5.7浇注系统凝料体积计算········································································162.5.8注塑时间的计算·················································································162.5.8排气系统设计····················································································172.6成型零件的结构设计和计算···········································································172.6.1成型零件钢材的选用············································································172.6.2成型零件工作尺寸计算·········································································182.6.3成型零件强度、刚度的校核···································································212.7模架的确定和标准件的选用···········································································212.8合模导向机构的设计···················································································222.8.1合模导向零件机构的作用······································································222.8.2导向机构的设计·················································································232.9脱模推出机构的设计····················································································232.9.1推出机构的组成·················································································232.9.2推出机构的分类·················································································232.9.3推出机构的设计原则···········································································242.9.4脱模力的计算····················································································242.9.5合模导向机构的设计············································································252.10侧向分型与抽芯机构的设计·········································································262.10.1侧向抽芯机构的分类及特点·································································262.10.2本模具的侧抽芯设计··········································································262.10.3斜滑块侧抽芯机构·············································································272.11注射模温度调节系统设计·············································································282.11.1冷却系统设计原则·············································································292.11.2冷却系统的简单计算··········································································293模具的试模与修模·····························································································313.1制品的粘着·······························································································313.2成型缺陷··································································································323.3注射填充不足····························································································323.4注射工艺不足····························································································324次品分析·········································································································335模流分析·········································································································34参考文献···········································································································45前言我国塑料模具工业现状我国塑料模具工业从起步到现在，历经了半个多世纪，有了很大的发展。模具水平有了较大提高。在大型模具方面，已经生产大屏幕彩电塑壳注塑模具等。精密塑料模具方面，已经生产照相机塑料件模具、多型腔小模数齿轮模具及塑封模具。用这些模具生产的一些塑料制品制件达到了国外同类产品的水平，但总体和国外相比仍有较大差距。在成型工艺方面，多材质塑料成型模、高效多色注塑模、抽芯脱模机构的创新方面也取得较大进展。气辅注射成型技术的使用更加成熟。热流道模具开始推广，有些企业的采用率达20%以上，一般采用内热式或外热式热流道装置，少数单位还采用了具有世界先进水平的高难度针阀式热流道模具。但总体上热流道的采用率达不道10%，与国外的50%-60%相比，差距较大。在模具方面，我国模具总量虽已位居世界第三，但设计制造水平总体上比德、美、日、法、意等发达国家落后许多，模具商品化和标准化程度比国际水平低许多。在模具价格方面，我国比发达国家低许多，约为发达国家的1/31/5，工业发达国家将模具向我国转移的趋势进一步明朗化。我国塑料模的发展迅速。塑料模的设计、制造技术、CAD技术、CAPP技术，已有相当规模的确开发和应用。在设计技术和制造技术上与发达国家和地区差距较大，在模具材料方面，专用塑料模具钢品种少、规格不全质量尚不稳定。模具标准化程度不高，系列化商品化尚待规模化；CAD、CAE、FlowCool软件等应用比例不高；独立的模具工厂少；专业与柔性化相结合尚无规划；企业大而全居多，多属劳动密集型企业。因此努力提高模具设计与制造水平，提高国际竞争能力，是刻不容缓的。塑料模发展趋势(1)出于塑料模成型的制品日渐大型化、复杂化和高精度的要求，而适应高生产率而发展的一模多腔的原因，今后应该重点提高大型、精密、复杂、长寿命模具的设计水平及比例。(2)在模具设计制造中全面推广应用CAD/CAM/CAE技术。(3)推广应用热流道技术，气辅注射成型技术和高压注射成型技术。(4)开发新的成型工艺和快捷经济模具，以适应多品种、少批量的生产方式。(5)提高塑料模标准化水平和标准件的使用率。(6)应用优质材料和先进的表面处理技术来提高模具寿命和质量此次的毕业设计（手机外壳模具设计）采用在Pro/ENGINEERWildfire环境下完成设计，其中涉及到零件模块、装配模块、工程图模块、Pro/Moldesign模块。在本次设计过程中，曾遇到了不少的困难，但在指导老师的细心指导下和同学的大力帮助下，都加以解决了。但本人知识水平有限，设计中肯定会有不完善的地方，恳请老师指正。手机外壳注塑模设计机械设计制造及自动化指导老师：摘要:本次设计的制品为ABS手机外壳注射模设计，利用Pro/E来完成制品模三唯模型，利用CAD来完成其装配图和零件图。模具采用了侧抽芯，使侧向的筋和肋能更好的脱模。模具结构紧凑、工作可靠、操作方便、运转平稳、冷却效果好、劳动强度低、生产效率高、生产的塑件精度高、生产成本低。本文从型腔数量和布局的确定、注射机选择、流道的设计、模板及其标准件的选用、冷却系统、成型部件的设计等给出了详细的设计过程。关键字:塑料注射模Pro/ECADMechanicaldesignandmanufacturingautomation:WangJunChaoInstructor:ChenLiFengXiaoSiWen,Topick:ThecurrentdesignofproductsformobilephonecasingsABSinjectionmoulddesign,theuseofproductsPro/Etocompletethree-statemodel,theuseofCADtocompleteitsassembly,andpartsmaps.Adjacentpumpingcorecomponentsusedtoscanthetendonsandgettingbetterdrawingofpatterns.Advancedcohesive,working,reliable,easytooperate,smoothoperation,goodcoolingeffect,lowlabourintensity,productionefficiency,theintegratedproductionofhighaccuracy,lowcostofproduction.ThenumberandlayoutfromXingqiangidentification,injectionmachineselection,flowRoaddesign,thechoiceofstandardsandtemplates,coolingsystems,shapedcomponentsofthedesigngivesdetaileddesignprocess.Internet:plasticinjectionmouldPro/ECAD1塑件成型工艺性分析1.1软件简介本设计中主要为模具的设计与计算，为后面完成装配图作好资料准备。装配图用AutoCAD来完成其三个视图的显示。零件为某手机可换机壳的后盖，整体由不规则曲面构成，壳内有多处定位和固定结构，发现小型复杂零件，不能用一般的拉伸剪切就能达到要求。而零件图的绘制在AutoCAD中也较难画出。计算机辅助设计（ComputerAidedDesign，简写为CAD），是指利用计算机的计算功能和高效的图形处理能力，对产品进行辅助设计分析、修改和优化。它终合计算机知识和工程设计知识的成果，并随计算机软硬件的不断提高而逐渐完善。AutoCAD的最大特点是让设计者更为轻松，设计者或绘图者几乎可不必离开屏幕就能连续地完成工作。AutoCAD适合于工程制造、建筑设计、装潢设计等各行业技术人员作为设计依据，完成图纸上的工作。AutoCAD是美国Autodesk公司开发的一种通用CAD软件。1982年首次推出了AutoCADR1.0版本，经过十余次的版本更新，AutoCAD已从一个简单的绘图软件发展成为包括三维建模在内的功能十分强大的CAD系统，是世界上最流行的CAD软件，现已广泛应用于机械、电子、建筑、化工、汽车、造船、轻工及航空航天等领域Pre/Engineer是美国PTC参数技术公司推出，是国际上最先进也是最成熟使用参数化特征造型技术的大型CAD/CAM/CAEA集成软件。这是我们零件模型设计与加工过程中的主要工具。下面是一些简单的介绍：Pre/Engineer包括三维实体造型，装配模拟，加工仿真NC自动编程，板金设计，电路布线，装配管路设计等专有模块，ID反求工程，CE并行工程等先进的设计方法和模式。其主要特点是参数化的牲造型；统一的能使各模块集成起来的数据库；设计修改的关联性，即一处修改，别的模块中的相应图形和数据也会自动更新。它的性能优良，功能强大，是一套可以应用于工业设计，机械设计，功能仿真，制造和管理等众多领域的工程自动化软件包。Pre/Engineer自动化自1988年问世以来，10多年来已成为全世界最普及的3DCAD/CAM系统的标准软件，Pre/Engineer在今日俨然已成为3DCAD/CAM系统的标准软件，广泛应用于电子，机械，模具，工业设计，汽车，自行车，航天，家电，玩具等各行各业。Pre/Engineer是一套由设计至生产的机械自动化软件，是新一代产品造型系统，是一个参数化，基于特征的实体造型系统，并且具有单一的数据库功能。1.2塑件（某手机外壳）分析塑件的相关技术参数见零件图纸塑件所采用的塑料名称ABS塑件的生产批量中等批量塑件的体积和重量见表1-1表1-1塑件主要参数材料密度（density）体积（volume）质量（mass）05.11.05g/cm331033.3mm350.3g1.3零件结构特征、塑料的性能、技术要求及结构工艺性的分析塑料制品形状如图1-1图1-11.3.1尺寸及精度塑件尺寸的大小取决于塑料的流动性。在注射成型过程中，流动性差的塑料及薄壁塑件等的尺寸不能设计的过大。大而薄的塑件在塑料尚未充满型腔时已经固化，或勉强能充满但料的前锋已不能很好的熔合而形成冷接缝影响塑件的外观和结构强度。塑件的尺寸精度是指所获得的塑件尺寸与产品图中尺寸的符合程度，即所获塑件尺寸的准确度。影响塑件的精度的因素很多，首先是模具的制造精度和模具的磨损程度，其次是塑料收缩率的波动以及成型是工艺条件的变化、塑件成型后的时效变化和模具的结构等。因此，塑件的尺寸精度一般不高，应在保证使用要求的前提下尽可能选用低级精度。根据我国目前塑件的成型水平，塑件的尺寸公差可依据SJ1372-78塑料制件公差数值标准确定。该标准将塑件分成8个等级，每种塑料可选其中三个等级，即高精度、一般精度、低级精度。1、2级精度要求较高，一般不采用。此外，对塑件图上无公差要求的自由尺寸，建议采用标准中的8级精度。对孔类尺寸数值冠以（+）；对于轴类尺寸数值冠以（-）；对于中心距尺寸几其他位置尺寸可取表中数值之半冠以（）号。在本设计中根据中国模具设计大典可查得：手机后盖选用的精度等级为一般精度选用4级。1.3.2壁厚塑料制件规定它的最小壁厚值，它随塑件大小不同而异。塑件过厚不但造成原料浪费，而且对热塑性塑料增加了冷却时间，降低了生产率，另外也影响了产品的质量，如产生气泡、缩孔、凹陷等缺陷。热塑性塑料易于成型薄壁塑件，最小壁厚达到0.25mm，但一般不宜小于0.60.9mm，常取24mm。在本设计中，壁厚取1mm左右。同时同一塑件的壁厚应尽可能一致，否则因冷却或固化的速度不同产生附加内应力，使塑件产生翘曲、缩孔、裂纹甚至开裂等的缺陷。1.3.4脱模斜度为了便于脱模，防止脱模是拉伤塑件在设计时必须使塑件塑料封头内外表面沿脱模方向留有足够的脱模斜度。脱模斜度取决于塑件的形状、壁厚及塑料收缩率。一般取301º30,取斜度的方向一般内孔以小端为准，符合图样要求斜度由扩大方向取得；外形以大端为准，符合图样要求，斜度由缩小方向取得，而且脱模斜度不包括在塑料制品公差范围内，脱模斜度见表：表1-2常用塑料的脱模斜度塑料名称脱模斜度型腔型芯聚乙烯、聚丙烯、软聚氯乙烯、氯化聚醚25´45´20´45´硬聚氯乙烯、聚碳酸酯、聚砜35´40´30´40´聚苯乙烯、有机玻璃、ABS、聚甲醛35´1º30´30´40´热固性塑料25´40´20´40´1.3.5圆角在塑料制品设计中，制品的转角处应尽可能采用圆弧过渡。因为带有尖角的塑件，往往会在尖角处产生应力集中，在受力或受冲击振动时会发生破裂，甚至在脱模过程由于成型内应力而开裂，特别是塑件的内角处，理想的内圆角半径应为壁厚的1/3以上。这样避免应力集中，提高塑料制品的强度，改善制品成型时的塑料流动情况及脱模。此外，有了圆角，模具在淬火或使用时不致因应力集中而开裂。但是，采用圆角会使凹模型腔加工复杂化，使钳工劳动量增大。通常内壁圆角半径应是壁厚的一半，而外壁圆角半径可为壁厚的1.5倍，一般圆角半径不应小于0.5mm。1.3.6粗糙度塑件的外观要求越高，表面粗糙度应越低。这除了在成型时从工艺上尽可能避免冷疤云纹等疵点来保证外，主要取决于模具型腔表面粗糙度。一般模具粗糙度要比塑件的要求低12级。塑料制件表面粗糙度一般为0.80.2m之间。模具在使用过程中由于型腔磨损而使表面粗糙度不断加大，所以应随时给以抛光复原。透明塑件要求型腔和型芯的表面粗糙度相同，而不透明塑件则根据使用情况决定他们的表面粗糙度。1.3.7塑料性能的分析塑料的选用及相应特征的说明：选择的塑料的要求价格合适，具有较好的加工性能、机械性能。，该塑料制品选用的是ABS塑料，ABS是丙烯晴、丁二烯和苯乙烯三种单体的三元共聚物，ABS具有较高的强度、硬度、耐热性及耐化学腐蚀性；具有弹性和较高的冲击强度；它具有优良的介电性能及成型加工性能等综合的优良性能，且价格便宜，原料易得。ABS的主要技术指针见表2-3表1-3ABS各项性能参数表密度（g/3cm）105抗拉屈服强度（mpa）50比容（3/g）092拉伸弹性模量（mpa）3101.8吸水率24h（%）032无缺口261收缩率（%）130-160缺口11熔点（C）130160弯曲强度（mpa）80C0.45mpa90108强度（hb）9.71.80mpa83103体积电阻率（2m）3109.6