异形件冲压模具设计

1异形件冲压模具设计学生姓名张江福所在系部机械电力工程系年级08级模具三班专业模具设计与制造指导教师张安民成绩泸州职业技术学院2011年6月12摘要在目前激烈的市场竞争中，产品投入市场的迟早往往是成败的关键。模具是高质量、高效率的产品生产工具，模具开发周期占整个产品开发周期的主要部分。因此客户对模具开发周期要求越来越短，不少客户把模具的交货期放在第一位置，然后才是质量和价格。因此，如何在保证质量、控制成本的前提下加工模具是值得认真考虑的问题。模具加工工艺是一项先进的制造工艺，已成为重要发展方向，在航空航天、汽车、机械等各行3目录1.绪论··············································································································41.1冲压的概念、特点及应用··············································································42零件工艺性分析··································································································52.1材料分析···································································································52.2结构分析···································································································52.3精度分析···································································································52.4冲裁工艺方案的确定····················································································53工艺计算···········································································································63.1排样设计···································································································63.2冲压力计算·······························································································73.3压力中心计算·····························································································83.4刃口尺寸计算·····························································································84冲压设备的选用··································································································95模具零部件结构的确定························································································105.1凸凹模·····································································································105.2凸模········································································································105.3凹模·······································································································105.4标准模架的选用·························································································105.5卸料橡胶的设计························································································106其它零部件设计·································································································11参考文献·············································································································1341.绪论1.1冲压的概念、特点及应用冲压是利用安装在冲压设备（主要是压力机）上的模具对材料施加压力，使其产生分离或塑性变形，从而获得所需零件（俗称冲压或冲压件）的一种压力加工方法。冲压通常是在常温下对材料进行冷变形加工，且主要采用板料来加工成所需零件，所以也叫冷冲压或板料冲压。冲压是材料压力加工或塑性加工的主要方法之一，隶属于材料成型工程术。冲压所使用的模具称为冲压模具，简称冲模。冲模是将材料（金属或非金属）批量加工成所需冲件的专用工具。冲模在冲压中至关重要，没有符合要求的冲模，批量冲压生产就难以进行；没有先进的冲模，先进的冲压工艺就无法实现。冲压工艺与模具、冲压设备和冲压材料构成冲压加工的三要素，只有它们相互结合才能得出冲压件。与机械加工及塑性加工的其它方法相比，冲压加工无论在技术方面还是经济方面都具有许多独特的优点。主要表现如下。(1)冲压加工的生产效率高，且操作方便，易于实现机械化与自动化。这是因为冲压是依靠冲模和冲压设备来完成加工，普通压力机的行程次数为每分钟可达几十次，高速压力要每分钟可达数百次甚至千次以上，而且每次冲压行程就可能得到一个冲件。（2）冲压时由于模具保证了冲压件的尺寸与形状精度，且一般不破坏冲压件的表面质量,而模具的寿命一般较长,所以冲压的质量稳定,互换性好,具有“一模一样”的特征。（3）冲压可加工出尺寸范围较大、形状较复杂的零件，如小到钟表的秒表，大到汽车纵梁、覆盖件等，加上冲压时材料的冷变形硬化效应，冲压的强度和刚度均较高。（4）冲压一般没有切屑碎料生成，材料的消耗较少，且不需其它加热设备，因而是一种省料，节能的加工方法，冲压件的成本较低。但是，冲压加工所使用的模具一般具有专用性，有时一个复杂零件需要数套模具才能加工成形，且模具制造的精度高，技术要求高，是技术密集形产品。所以，只有在冲压件生产批量较大的情况下，冲压加工的优点才能充分体现，从而获得较好的经济效益。冲压加工在现代工业生产中，尤其是大批量生产中应用十分广泛。相当多的工业部门越来越多地采用冲压法加工产品零部件，如汽车、农机、仪器、仪表、电子、航空、航天、家电及轻工等行业。在这些工业部门中，冲压件所占的比重都相当的大，少则60%以上，多则90%以上。不少过去用锻造=铸造和切削加工方法制造的零件，现在大多数也被质量轻、刚度好的冲压件所代替。52零件工艺性分析工件为图1所示的落料冲孔件，材料为10钢，材料厚度为2mm，生产批量为大批量。工艺分析内容如下图一、工件图2.1材料分析10刚为优质碳素结构刚，含碳量低，塑性和韧性较好，强度和硬度都很低，具有良好的冲裁性能。2.2结构分析零件结构简单对称无尖角，对冲裁加工较为有利。零件最小冲裁R角为Rmin≥0.5t=1mm。另外经计算最小孔边距为7.4mm。满足冲裁件最小孔边距lmin≥1.5t=3的要求。所以该零件的结构满足冲裁的要求。2.3精度分析由零件的标注查表得。其公差要求属于IT12，所以普通冲裁可以达到零件的冲裁要求。对于未注公差尺寸按IT13等级查补。由以上分析可知，该零件可以用普通冲裁的加工方法制得。2.4冲裁工艺方案的确定零件为落料冲孔件，可提出的加工方案如下：方案一：先落料，后冲孔。采用两套单工序模生产。6方案二：落料—冲孔复合冲压，采用复合模生产。方案三：冲孔—落料连续冲压，采用级进模生产。方案一模具结构简单，但需要两道工序、两副模具，生产这效率低，零件精度较差，在生产批量较大的时候不适用。方案二只需一副模具，冲压件的形位精度和尺寸精度易保证，且生产效率高。尽管模具结构较方案一复杂，但由于零件的几何形状较简单，模具制造并不困难。方案三也只需一副模具，生产效率也很高，但与方案二比生产的零件精度稍差。欲保证冲压件的形位精度，需在模具上设置导正销导正，模具制造、装配较复合模略复杂。所以，比较三个方案令人喷欲采用方案二生产。现对复合模中凸凹模壁厚进行较核，当材料厚度为2mm时，可查得凸凹最小壁厚为4.9mm，现零件上的最小孔边距为7.4mm，所以可以采用复合模生产，即采用方案二。3工艺计算3.1排样设计分析零件形状，应采用单直排的排样方式，零件排样方式如图所图二排样图查《冲压具设计与制造》表2.5.2得a1=2.2mma=2.5mm7B=50mm+2a=55mmL=25+2X5+2a1=39.4mm因此可将调料板裁成宽54.4mm，长为1972.2mm的矩形调料板(每块可冲50件工件)。其具体排样图如图（三）所示图三:排样图3.2冲压力计算查《冲压具设计与制造》69页得：冲裁力的计算公式为F=KLtbK系数(一般取K=1.3)F冲裁力L冲裁周边长度t材料厚度b材料抗剪强度8L(3.14X5X6+2X20+2X35)mm=204.2mmT=2mm查《冲压模具设计与制造》表1.3.6得b为260-340MPa这里取300则F=1.3X204.2X2X300=159276N159kN模具采用弹性卸料装置和推件结构，所以所需卸料力XF和推件力TF为FKFXX卸料力推件力FNKFTT式中F冲裁力KX、KT、KD卸料力、推件力、顶件力系数，见《冲压模具设计与制造》表2.6.1kN95.7kN15905.0XXFKFkN5.32kN197055.03TTFNKF所以总的冲压力F总=F+FX+FT=(159+7.95+32.5)KN=199.45kN3.3压力中心计算该零件结构对称，固压力中心为零件的几何中点。3.4刃口尺寸计算零件形状特点，刃口尺寸计算采用分开制造法。（1）落料件尺寸的基本计算公式为。A0maxA)(XΔDD0minmax0minATTT)()(ZXΔDZDD尺寸R5mm，可查《冲压具设计与制造》表2.3.3及2.4.1得。凸、凹模最小间隙Zmin=0.246，最大间隙Zmax=0.360，凸模制造公差δT=0.02mm，凹模制造公差δA=0.03，将以上各值代入δT+δA≤Zmax-Zmin校验是否成立，经校验不