我厂生产的解放牌汽车的刹车盘(如图1),其外圆的加工,以前感到很棘手。刹车盘的外圆展开为φ487毫米,料厚为6毫米,材料是20钢,按此计算剪切力约为450吨,但厂里最大的冲床只有250吨,就是采用波浪形刃口,也不能满足要求。所以,我们不得不采用简陋的落后工艺,即先把毛坯剪成八角形,拉伸成形后再车削外圆并冲孔。这种方法费工时、质量差,适应不了生产要求。 I plant the liberation of the brand car brake discs (Figure 1), its cylindrical processing, previously felt very difficult. The outer circumference of the brake disc expands to φ487 mm, the material thickness is 6 mm, and the material is 20 steels. According to this calculation, the shearing force is about 450 tons. However, the largest punch in the factory is only 250 tons. The wavy edge is also used. Can not meet the requirements. Therefore, we have to adopt a simple backward process, that is, first cut the rough octagonal shape, then shape the outer cylindrical turning and punching. This method takes time, poor quality, can not meet the production requirements.