表机防尘罩如图1所示,落料拉伸后,如按一般工艺方法冲去缺口需三个工步,即两边分别剪切出切口,再用成型冲头切掉缺口(T_1—T_o)部分。但因切口剪切时两边重叠(图2a处), 难以达到图1所要求的精度,而且要占用三个机台,效率低,每班最多可生 Dust cover machine shown in Figure 1, blanking stretch, according to the general process method to go to the gap required three steps, that is, cut the incision on both sides, and then cut off the molding punch (T_1- T_o) section. However, due to the incision shearing overlap on both sides (Figure 2a Department), it is difficult to achieve the accuracy required in Figure 1, and to take up three machines, low efficiency, each class can be up to