提高凸模冲孔最小尺寸的实践天津铁路信号工厂王渤我厂生产的某工件，需在８ｍｍ厚的材料上冲一个８．７×９．７ｍｍ的长圆孔，此孔小于冲模设计手册规定的冲孔最小尺寸与料厚的比值，即小于所规定的自由凸模最小尺寸。在最初设计中用自由凸模冲孔，同时采用固定卸料，凸... Improve the minimum punch punch size practice Tianjin Railway Signal Factory Wang Bo I plant a workpiece, the need to 8mm thick material punched a 8.7 × 9.7mm oblong hole, the hole is smaller than the die design manual provides Punching the minimum size and material thickness ratio, that is, less than the minimum size of the free punch required. In the original design punched with a free punch, while using a fixed discharge, convex ...