发动机油底壳冲压模具设计说明

发动机油底壳冲压模具设计

摘要汽车发动机油底壳冲压模具属于大中型模具，在实际的模具设计生产中存在一定的难点，如形状不规则，需要对压力中心进行确定；整体形状复杂，一次拉深对模具、设备的要求相对较高，但多次拉深又易引起拉裂、破损等现象。

首先利用UG对发动机油底壳进行三维实体造型，其属于具有台阶状的复杂盒形件，两侧拉深深度不一，径向拉应力沿盒形件周边分布极为不均匀，在落差的地方产生较大的附加应力，易引起材料堆积或破裂。所以设计关键在于确定拉深次数，以保证油底壳的成形；确定压力中心，以保证设备的安全工作。确定采用单工序模的工艺方案，分别为：落料模、拉深模、冲孔模。

落料模的设计着重于合理安排毛坯的排样和压力机的选择，以及凸、凹模等工作零件的设计确定。拉深模着重于工艺力的计算，并根据工艺力选择了双动拉深压力机，对凸、凹模等也做了设计。冲孔模与落料模同属冲裁模，其原理基本一致。冲孔模着重于法兰边上的25个小孔分布较为密集，因此冲孔凸模的采用过盈配合的固定方式，凹模选择最小壁厚。针对上述三副模具的凸、凹模和其他主要工作零件的服役性能要求，选择合适的材料以及合理的热处理方式，以提高其使用性能，延长使用寿命。最终通过AutoCAD绘制出每一副模具的具体结构。

关键词：油底壳落料拉深冲孔模具设计

Design of Stamping Die in Oil Sump of Engine

Abstract The stamping die of the oil sump of engine belongs to the large and medium molds, there are many difficulties in the actual design and production, such as an irregularly shaped, you need to calculate the center of the pressure; The whole shape are complex,it is a relatively high requirement of the die if drawing once ,but it is easy to be tension crack and damage after drawing many times. Frist of all, draw a stereogram of the oil sump of the engine by UG, then we can analysis technological parameter of the oil sump of the engine, the depth of drawing in both sides is different, the distribution of the radial tensile stress along the periphery of the rectangular box is extremely non-uniform, it is likely to be a great additional stress in the gap, and cause the accumulation of materials or rupture. So the key of the design is to determine the number of drawing ,in order to ensure the forming of oil sump; to determine the center of the pressure, to make sure the safety of the equipment. On this basis, we adopt the process program of single die definite which are blanking, drawing and perforating respectively.

The most important of the die of blanking is to arrange the layout of blank reasonably and select the pressing machine and design the working parts such as convex die and concave die. The most important of the die of drawing is to figure out the force of technology, and select the press machine of double action drawing rely on the force of technology. Besides, we also design the convex die and concave die. The perforating and blanking die belongs to the blanking die, the basic principle of them is consistent. The most important of the perforating die is that the distribution of the 25 small holes in the flange is very concentrated. Therefore we choose the interference fit to fix the convex die of perforating and select the minimum wall thickness of the concave die. At the same time, according the working performance requirement of the convex、concave die and other major working parts, we choose the reasonable materials and the best way to heat treatment, in order to improve its performance and extend the service life. Finally draw out each mould of concrete structures through the AutoCAD.

Key words：oil sump blanking drawing perforating mould design