基于应变路径的复杂汽车结构件多工位级进模精确刃口线优化

Optimization on accurate cutting line of multi-station progressive die for complicated automotive structure parts based on strain path

复杂汽车结构件多工位级进模具有工位多、结构复杂、工位关联性强的特点,其冲裁工位刃口线受成形工位的影响,刃口线的预测精度低。基于此,提出一种基于应变路径的精确刃口线优化方法。采用有限元逆算法对零件分步展开,获得板料的初始轮廓线;基于真实压力机参数、精细化模面和真实工艺参数,对条料进行全工序精细化数值模拟。将板料初始网格的边界节点基于B样曲线拟合,提取成形前后边界节点的应变及其路径。以设计零件的产品边界为目标,建立精确刃口线优化的目标函数,通过调整B样条曲线,对轮廓线进行迭代优化。实例表明,该优化方法可有效提高复杂多工位级进模刃口线优化的精度和效率。

The complex multi-station progressive die of complicated automotive parts has many characteristics of many stations,complicated structure and strong correlation between stations. However,the cutting line is affected by the forming stations,and the predict accuracy of the cutting line is very low. Therefore,a new optimization method of cutting line was proposed based on the strain path of material,and the part was unfolded step by step by inverse algorithm of finite element method to obtain the initial blank outline. Then,the refined numerical simulation of whole process was carried out based on the real parameters of press,refined die surface and real process parameters. The boundary nodes of the initial mesh of blank were fitted according to the B-spline curve,and then the strain value and the path of boundary nodes were extracted based on the simulation before and after forming. Furthermore,the optimization objective function of the cutting line was established by taking the boundary of the design part as the target,and the iterative optimization of the cutting line was made by adjusting the B-spline curve. The results show that the proposed method can effectively improve the accuracy and efficiency of the optimization of the cutting line for the complex multi-station progressive die.