基于变压边力的侧围外板成形研究

目的 为了提高侧围外板成形裕度，降低拉延开裂风险。方法 运用CATIA软件设计了侧围外板精细化工艺模面，并借助AutoForm软件对侧围外板拉延成形过程进行了有限元分析。结果 在恒定压边力加载的工况下，侧围外板在后三角窗及后门洞区域发生轻微开裂，无法满足成形要求。基于恒定压边力工况条件，对压边力加载方式进一步研究，提出变压边力工况条件，并模拟了9种变压边力加载方式下的成形效果，从中筛选出最优变压边力工况条件，改善了侧围外板拉延成形性，消除了开裂风险。将最优仿真数据用于侧围外板实际试模，试模结果与仿真结果基本一致，零件成形良好，最大减薄率为19.8%，最大增厚率为6.7%，符合产品质量需求，证明了变压边力工艺方案的可行性。结论 变压边力工况条件可以提高零件成形裕度。

Forming of Side Outer Panel Based on Variable Blank Holder Force

The work aims to improve the forming margin of the side outer panel and reduce the risk of drawing cracking. A refined drawing process surface was designed with CATIA software, and the finite element analysis of the drawing process was carried out with the help of AutoForm software. Under the condition of constant blank holder force loading, there were slight cracks on the rear quarter window and the rear door opening area of side outer panel, which failed to meet the forming requirements. Based on the condition of constant blank holder force, further research on the blank holder force loading method was implemented. Variable blank holder force conditions were proposed and the forming effects under 9 types of variable blank holder force loading modes were simulated. Then the optimal variable blank holder force method was selected. It improved the drawing formability of the side outer panel and eliminated the risk of cracking. The optimal simulation data was used for the actual die tryout of the side outer panel, and the tryout results were basically consistent with the simulation results. The parts were well formed, the maximum thinning rate was 19.8%, and the maximum thickening rate was 6.7%, which met the product quality requirements. Therefore, the feasibility of the process plan with variable blank holder force was certified. Research shows that the working conditions of variable blank holder force can improve the forming margin of parts.