模具零件设计

塑料成型工艺与模具设计课程设计李平编目录模具的设计·······················错误!未定义书签。1拟定模具结构形式·························································错误!未定义书签。2确定型腔数量及排列形式················································错误!未定义书签。3分型面的确定：····························································错误!未定义书签。4注射机型号的确定·························································错误!未定义书签。4.1注射机的选择················································································14.2注射成型工艺的参数·······································································44.3注塑机的校核················································································55浇注系统设计························································································75.1浇注系统的设计原则······································································85.2浇注系统的组成············································································85.3浇注系统的作用············································································95.4浇注系统各部件设计······································································95.5浇口的设计·················································································125.6浇注系统的平衡···········································································135.7浇注系统凝料体积计算·································································135.8注塑时间的计算··········································································145.8排气系统设计················································································76成型零件的结构设计和计算······································································66.1成型零件钢材的选用·····································································166.2成型零件工作尺寸计算··································································176.3成型零件强度、刚度的校核···························································207模架的确定和标准件的选用····································································218合模导向机构的设计······················································错误!未定义书签。8.1合模导向零件机构的作用······························································228.2导向机构的设计··········································································229脱模推出机构的设计·············································································239.1推出机构的组成··········································································239.2推出机构的分类··········································································239.3推出机构的设计原则····································································239.4脱模力的计算··············································································259.5合模导向机构的设计·····································································2510侧向分型与抽芯机构的设计·································································2810.1侧向抽芯机构的分类及特点··························································2810.2本模具的侧抽芯设计···································································2810.3斜滑块侧抽芯机构······································································2911注射模温度调节系统设计·····································································3111.1冷却系统设计原则······································································3111.2冷却系统的简单计算···································································32参考文献注射机的选择完整的注射成型工艺过程，按其先后顺序应包括：成型前的准备、注射过程、塑件的后处理等。1、成型前的准备为使注射成型过程能顺利进行，并保证塑料制件的质量，在成型前应做一些必要的准备工作，包括：a.原料的检验和预处理，在成型前应对原料进行外观（如色泽、颗粒大小、均匀度）及工艺性能（如流动性、热稳定性、收缩性、水分含量等）的检验;b.料筒的清洗；c.嵌件的预热；d.脱模剂的选用。2、注射过程完整的注射过程包括加料、塑化、注射、保压、冷却和脱模几个步骤。其流动的情况又可分为充型、保压、倒流和浇口冻结后的冷却四个阶段。3、塑件的后处理塑件在成型过程中，由于塑化不均匀或由于塑料在型腔中的结晶、定向以及冷却不均匀而造成塑件各部分收缩不一致，或因其他原因使塑件内部不可避免地存在一些内应力而导致在使用过程中变形或开裂。因此常需要进行适当的后处理以消除存在的内应力，改善塑件的性能和提高尺寸稳定性。其主要方法是退火和调湿处理。注射成型工艺的参数注射成型工艺的核心问题，就是采用一切措施以得到塑化良好的塑料熔体，并把他注射到型腔中去，在控制条件下冷却定型，使塑件达到所要求的质量。在塑料成型过程中，工艺条件的选在和控制是保证成型顺利进行和塑件质量的关键因素。主要工艺条件是影响塑化流动和冷却的温度、压力、和相应的各个作用时间。温度：注射成型过程中需要控制的温度有料筒温度、喷嘴温度和模具温度等。前两种温度主要影响塑料的塑化和流动；而后一种温度主要是影响塑料的流动和冷却。压力：注射模注射过程中需要控制的压力包括塑化压力、注射压力和型腔压力三种，它们直接影响塑料的塑化和塑件质量。1、塑化压力塑化压力又称为背压，是指采用螺杆式注射成型时，螺杆头部熔体在螺杆转动后退时所受到的阻力。2、注射压力注射机的注射压力是指在注射成型时，柱塞或螺杆头部单位面积对塑料熔体所施加的压力。在注射机上常用表压指示注射压力的大小，其大小取决于塑料品种、注射机类型、模具的浇注系统状况、模具温度、塑料复杂程度和壁厚以及流程的大小等诸因素，很难具体确定，一般要经试模后才能确定。其常用的注射压力范围一般在70～150MPa之间。其作用是克服塑料熔体一定的充型速率以及对熔体进行压实等。时间：完成一次注射成型过程所需的时间称为成型(或生产)周期，它包括以下各部分：注射时间、保压时间、冷却时间、其他时间(含开模、脱模、喷涂脱模剂、放嵌件等)即：T=t注+t保压+t冷却+t其他，本设计成型周期取20s,成型周期直接影响到劳动生产率和注射机使用率，因此生产中，在保证质量的前提下，应尽量缩短成型周期中各阶段的有关时间。在整个成型周期中，以注射时间和冷却时间最重要，对塑件的质量均有决定性影响。注射时间中的保压时间就是对型腔内塑料的压实时间，在整个注射时间内所占比例较大，一般为20-25s。冷却时间主要决定于塑件的厚度、塑料的热性能和结晶性能以及模具温度等。冷却时间的长短应以脱模时塑件不引起变形为原则。冷却时间一般在30-120s之间。冷却时间过长，不仅延长生产周期，降低生产效率，对复杂塑件还将造成脱模困难。成型周期中的其他时间则与生产过程是否连续化和自动化以及两化的程度等有关。最终确定注射机型号为XS-ZY-60,参数如表住注射机主要参数注塑机的校核注射量校核注射机的表称注射量：V机=60cm3塑件体积：Vs=2×3.33=6.66cm3,而浇注系统流道凝料的体积：V凝=2.33cm3则实际需要的注射量：V实=Vs+V凝=6.66+2.33=8.99cm3所以，注射量符合理论注射容积注射压力注射时间注射速率螺杆转速60㎝3180MPa2s70g/s0～200r/min锁模力拉杆内间距开模行程最大模具厚度最小模具厚度400KN200×300mm500mm250mm150mm喷嘴孔直径定位孔直径喷嘴球半径4mm125mmSR18mm注射压力校核因为HDPE的注射压力是70－150MPa，而XS-ZY-60注塑机的压力为180Mpa，显然注塑机的注射压力满足要求。锁模力校核塑料对模板的压力为：P=0.3×P1=0.3×100=30MPaF胀=(nA塑件+A浇)×P=（2×2989+2092）×30=242KNF额=400KN242KN=F胀锁模力足够开模行程与推出机