弯曲角度对弯曲轴线件内高压成形的影响分析

Effect of bending angle on hydroforming of curved hollow components

针对弯曲轴线矩形截面件内高压成形时容易发生开裂的问题,以轿车底盘前梁为例,采用数值模拟和试验的方法分别研究了0.98α、1.0α和1.02α(α为内高压件的轴线中心角)3种弯曲角度对弯曲轴线矩形截面件内高压成形开裂缺陷的影响.结果表明,采用0.98α和1.02α弯曲角度时,内高压成形时在弯角外侧和矩形截面过渡区叠加区域出现开裂缺陷,而采用1.0α的弯曲角度时,能够顺利成形出合格的内高压件.由此可知,对于弯曲轴线矩形截面件,弯曲工序引起的壁厚减薄及轴线偏移是导致内高压开裂的主要原因,通过合理的弯曲角度可以有效控制内高压成形截面环向变形的均匀性,避免开裂的产生.

In order to solve the crack problem of curved hollow components during hydroforming, a front chassis frame was taken as an example and the effect of three bending angles of 0.98α, 1.0α and 1.02α（α is the axis angle of hydroformed part） on the crack defect of rectangular section part was investigated by numerical simulation and experiment. The results show that if the angles of 0. 98α and 1.02α are used, the crack defect easily occurs in the superimposed area of bending lateral wall and transition zone of rectangular section. If the angle of 1.0α is used, the process can be successfully conducted. It can be seen that the non-uniform thickness of the initial tubular blank due to the thinning and thickening in the bending process and the inhomogeneous deformation due to the axis deviation are the two main reasons for the occurrence of crack defect. By controlling the bending angle, the uniform circumferential deformation of section part can be successfully achieved.