基于型面台阶法和工艺凹包法的车门内板局部起皱控制研究

Research on local wrinkles of inner door panel based on die surface steps method and process convex hull method

以某车型后背门内板为研究对象,基于数值模拟,结合生产现场实验,验证仅通过成形极限图评判准则来判定板件起皱状态的不完备性;针对此类产品平缓面塑性成形起皱问题,基于板料成形进料原理,提出型面台阶法和工艺凹包法来优化设计前期的拉延局部工艺造型,达到阻碍材料过早进入产品型腔的目的,解决局部起皱缺陷;针对试模现场局部微小起皱缺陷,提出更为简便、可操作性强的加强起皱区域周边的拉延筋,打磨变薄风险点圆角(后序整形整回)的方法改善缺陷,并进行实际试冲压试制,通过对比板件拉延结束状态以及最终产品结果,进一步验证了该方案的有效性。

The forming process of inner panel of back door was focused,based on the simulation and experimental manufacture,the incompleteness of judging the forming wrinkles of the sheet metal only through FLD（ Forming Limit Diagram） was verified. For the wrinkle problem of flat surface of the similar product,and based on the feeding principle of sheet forming,the method combined surface steps with craft convex hull was introduced to optimize the early process of drawing to prevent the blanking from entering the die too early,then the local wrinkle defect was solved. For the slightly local wrinkle defect in the test on site,the more convenient and efficient methods that enhancing the drawbeads around the local wrinkle area and polishing the radius in the crack-tendency zone were put forward to improve the defects. Then the actual stamping process was conducted,and the feasibility of the method was verified by comparing the end state of drawing and the final products.