圆形截面台阶凸模冲裁受力分析与验证

针对圆形截面台阶凸模的整体长度校核问题,将圆形截面台阶凸模冲裁时受力情况抽象成阶梯杆件受轴向力的模型,分析该模型,得到了一个关于临界载荷参数和截面直径比关系的超越方程,无法得到解析解。通过Excel软件所携带的单变量求解功能,获得了数值解,进而绘制出圆形截面台阶凸模直径比与临界载荷参数关系图。结果表明:当圆形截面台阶凸模直径比b在0~1时,随着凸模的长度比a的增加,圆形截面台阶凸模直径比与临界载荷参数关系曲线的形状差别在增大,呈“树叶形态”,此时,凸模的直径小端固定,直径大端在冲裁一端,容易被冲裁材料拉出,造成事故;当圆形截面台阶凸模直径比b在1~10时,随着凸模的长度比a的增加,圆形截面台阶凸模直径比与临界载荷参数关系曲线的形状差别在减小,此时,凸模直径的大端固定,直径小端在冲裁一端,不容易拉出。以上结果充分说明了台阶凸模设计为大端固定、小端冲裁的合理性,为台阶凸模的设计提供了参考。

Analysis and Verification of Blanking Force of Circular Step Punch

ed as the model of the step bar under the action of axial force.A transcendental equation about the relationship between critical load parameters and section diameter ratio was obtained by analyzing the model,but the analytical solution could not be obtained.The numerical solution was obtained by using the univariate solution function of Excel software,and the relationship diagram between the diameter ratio of the step punch with circular section and the critical load parameters was drawn.The results show that when the diameter ratio b of step punch with circular section is in 0~1,the shape difference of the relationship curve between the diameter ratio of the step punch with circular section and the critical load parameters increases with the increase of the step punch length ratio a,and the curve shape takes on“leaf form”;at this time,the small end of the punch diameter is fixed,and the big end of the diameter is at the blanking end,so the punch is easy to be pulled out by the blanking material and causes accidents.When the diameter ratio b of the step punch with circular section is in 1~10,the shape difference decreases with the increase of the punch length ratio a;at this time,the big end of the punch diameter is fixed and the small diameter end is at the blanking end,so the punch is not easy to be pulled out.The above results fully explain that the rationality of the design for the step punch with large end fixed and small end blanking,which provides references for the step punch design.