非对称异形管零件的液压成形轴向补料方式

Axial feeding modes of asymmetrical irregular tube part in hydroforming

为获得非对称异形管液压成形轴向补料量的最佳工艺参数组合,采用响应面法结合有限元模拟对管材液压成形过程中的轴向补料方式开展研究。以目标零件的最大减薄率和胀形高度为响应量,以左、右两侧推头的轴向进给量为设计变量。采用Design Expert 10软件根据中心复合设计法进行实验设计,建立了关于零件减薄率的二阶响应模型和胀形高度的一阶响应模型。结果表明,相比于传统对称补料方式,非对称补料方式能够显著降低目标零件的减薄率,提高胀形高度。响应面法优化结果显示,左推头进给29.37 mm、右推头进给10.00 mm的组合补料量可使零件胀形高度达到15 mm,最大减薄率控制在20%以内。开展验证实验,所获得零件的实际胀形高度为14.84 mm,最大减薄率为16.22%。进一步证实了所建立的响应面模型优化效果显著,且实验值与预测值具有较好的一致性,所得零件无过度减薄和开裂等成形缺陷。

To obtain the optimal process parameter combination of the asymmetric irregular tube part in hydroforming,the response surface method combined with finite element simulation was used to explore the axial feeding mode in hydroforming of tube.The maximum thinning rate and bulging height of the target part were taken as the response quantities.And the axial feeding amount of the left and right punch was taken as the optimization variables.According to the central composite design method,the experimental design was carried out by Design Expert 10 software.The second-order response model of the thinning rate and the first-order response model of the bulging height were established.The results show that compared with the traditional symmetrical feeding method,the asymmetrical feeding mode can significantly reduce the thinning rate of the target part and increase the bulging height.The optimization results of response surface method show that the bulging height of the part can reach 15 mm and the maximum thinning rate can be controlled within 20% with the feeding amount combination of left punch feeding 29.37 mm and right punch feeding 10.00 mm.The actual bulging height and the maximum thinning rate of parts obtained by the validation experiments are 14.84 mm and 16.22%,respectively.It is further verified that the effect of the current response surface model on the optimization is remarkable.The experimental values are in good agreement with the predicted values,and the obtained parts have no forming defects such as excessive thinning and cracking.