论文部分内容阅读
冲孔时,由于材料的残余弹性变形,板料(废料)夹紧在凸模上(见图1)。为了能将板料从凸模上退下,必须进行退料力的计算。然而,影响退料力大小的因素与冲压材料种类、厚度、冲孔间隙、工件孔尺寸和形状、孔边距、凸模与切断面间的摩擦状况以及润滑程度等有关。而其中影响最大的是冲孔间隙和孔径大小,即间隙和孔径愈小,退料力就愈大,如图2所示。精确的计算退料力是不可能的,只能通过实验来确定。通常,计算退料力有下述几种方法: 1.退料力P_A按冲裁力P_S的百分数选取,即 P_A=(0.02～0.05)P_S… (1) 1) 若按模具结构类型,则对于单冲孔模:P_A=0.02P_S 对于复式冲模:P_A=0.03P_S
Punching, due to residual elastic deformation of the material, the sheet (waste) clamped in the punch (see Figure 1). In order to be able to withdraw the sheet from the punch, the calculation of the retraction force must be made. However, the factors that affect the size of the back-feeding force are related to the type of material, thickness, punching clearance, the size and shape of the workpiece hole, the margin of the hole, the friction between the punch and the cutting surface, and the degree of lubrication. The most significant impact is the size of the punch gap and aperture, that is, the smaller the gap and aperture, the greater the back-force, as shown in Figure 2. Accurate calculation of the withdrawal force is impossible, only through experiments to determine. Generally, there are several methods for calculating the material withdrawal force: 1. The material withdrawal force P_A is selected according to the percentage of the punching force P_S, that is, P_A = (0.02 ~ 0.05) P_S 1) If the structure type of the mold is For single punch die: P_A = 0.02P_S For double die: P_A = 0.03P_S