大截面差空心件内高压成形研究

Internal high pressure forming of hollow part with a big section difference

截面周长差较大的空心零件的内高压成形需要解决膨胀区的轴向补料问题和预成形问题,才能获得壁厚分布较为均匀的合格零件.以某轿车转向节臂零件的成形过程为例,对上述问题进行了试验研究.首先设计、试制了瓶形预制件,在预成形中利用'有益起皱'实现了大量的补料,获得了壁厚分布符合要求的预制件;然后在终成形前使零件截面具有合理的形状,再进行终成形,既保证了圆角部位的外形尺寸,又提高了壁厚均匀性.采用本文介绍的方法实现了截面周长差达70%的瓶形预制件的制备,从而获得了壁厚、外形尺寸均满足设计要求的转向节臂零件.

For internal high pressure forming of a hollow part with big difference on section perimeter, the problems of axial feeding and preforming are necessary to be solved to produce qualified parts with more uniform thickness distribution. As a typical example, forming process of a car steering arm is researched to solve the problems mentioned above. At first, a bottle-shaped preform is designed and manufactured. During the preforming, a big feeding is realized by using 'beneficial wrinkles' and a bottle-shaped preform with an expansion ratio of 70% and qualified thickness distribution is manufactured. Then, the section part with reasonable shape is got before the final forming, which ensures the shape dimensions and improves the uniformity. At last, through the final internal high pressure forming, parts with qualified shape dimensions and good thickness uniformity are produced.