模具型面工艺孔对面畸变的影响

Effects of punch process hole on surface deflection

为了研究成形凸模工艺孔对面畸变形态及大小的影响,以矩形双曲面扁壳为模型,采用拉深成形工艺方法获得了不同成形条件下的拉深件,利用油砂轮研磨双曲面扁壳拉深件表面,局部的畸变呈圆形暗坑,取暗坑直径(D)与工艺孔径(d)之比作为面畸变的评价指标,研究成形条件对面畸变的影响规律.研究结果表明:凸模型面工艺孔可以诱发双曲面扁壳拉深件面畸变;屈服强度越大、板料厚度越大、凸模型面弦高越小、压边力越小,面畸变越小.

In order to study the effects of punch process holes on the configuration and magnitude of the surface deflection, a model of rectangle double-curved shallow shell is founded, and the parts of various forming conditions are obtained by drawing process. The circular dull pits are exhibited by using a whetstone with oil to rub off the surface of double-curved shallow shell. The ratio (D/d) of dull pit diameter (D) to process pole diameter (d) is regarded as the evaluation criterion of surface deflection. And the influence laws of forming conditions on surface deflection are studied. The results show that the surface deflections can be induced by process holes. The surface deflection is decreased with increasing yield strength, increasing sheet thickness, decreasing arc height of punch, and decreasing binder force.