自动化闭式反挤压工艺中成形凸模结构设计

Structural design of forming punches applied in automatic closed backward extrusion process

以锚固装置中的夹片为产品,设计了用于自动化生产的多工位闭式反挤压工艺。为了保证自动化连续生产,生产线上使用的模具必须设置上、下顶出。常规模具顶出结构都是中心顶出方式,但这种结构在应用于内孔较小的反挤压件时,不能实现稳定连续地脱模。对常规中心顶出的模具结构进行了锻打试验,总结了脱模失败的原因并优化了顶出结构,将顶出机构设计成外环顶出,并将在高温高压下使用的冲头部分设计成镶嵌式结构。模拟分析对比2种模具结构的等效应力和受力位移量,确定了外环顶出结构的优越性。最后,通过试验,验证了优化后的外环顶出模具结构在应用方面的可靠性。

In this paper, the closed backward extrusion process with multi-station was designed for the automatic production of the anchorage clip in the anchor device. To ensure the automatic continuous production, an injector system should be set on mould in the production line. Central ejection structure is the conventional ejection method, however, in the application of backward-extrusion part with small inner hole, the demoulding process becomes unstable by using this kind of ejection. Therefore, forging tests of the conventional center-ejected mould were carried out and the cause of demoulding failure of the mould was figured out. The ejector mechanism was thus optimized with the outer ejector structure and the mosaic structure was designed for punches worked in high temperature and high pressure. Equivalent stress and the stress induced offset in the two mould structures were simulated and the superiority of outer ejector was identified. Finally, the reliability of the optimized outer ring structure was validated by experiment.