汽车前壁板冲压件的拉延成形缺陷工艺优化与Autoform应用

Drawing Defect Process Optimization and Autoform Application of Automobile Front Panel Stamping Parts

某企业生产的汽车前壁板冲压件,具有复杂的凸凹台结构,采用的锌铁合金DC56D+Z(St07Z)材料,要求零件的报废目标小于0.04%,返修目标小于0.06%,实际生产中每批次生产均出现叠料、破裂缺陷,返修高达0.3965%,报废高达0.1304%。为了提高生产质量,得到合格产品,从工艺流程图与鱼骨因果图入手分析,寻找引起零件叠料、破裂缺陷产生的根本原因,除通过调整机床顶杆高度、消除未能贴合的型面等手段外,还采用Autoform多次模拟了不同压边力和拉延筋参数下的成形情况,得到了适合的工艺参数,并用于指导实际生产效果良好。实践证明,在冲压生产中,通过产品流程图和鱼骨因果图的合理运用,可以快速地找到缺陷产生的根本原因,并进行系统分析和改善;拉延筋和压边力的调整,可以改善具有较大拉深深度和复杂凸凹台结构镀锌板零件的拉延成形产品质量,消除裂纹和起皱缺陷;Autoform模拟确定的工艺参数,具有较高的可行性,可以在实际生产中得到应用;减少了试模次数,有利于缩短模具开发时间,降低生产成本。

The stamping parts of automobile front panel produced by an enterprise have complex convex and concave structure.The zinc-iron alloy DC56D+Z(St07Z)material is used.The scrap target is 0.04%and the repairing target is 0.06%.In actual production,overlapping and cracking defects occur in each batch of production.The repairing rate is as high as 0.3965%and the scrap rate is as high as 0.1304%.In order to improve the quality of production and obtain qualified products,starts with the analysis of process flow chart and fishbone causality diagram to find out the root causes of overlapping and cracking defects of parts.Besides adjusting the height of machine tool top rod and eliminating the unsuitable surface,Autoform was used to simulate different blank holder force and drawing force for many times.The forming conditions under the parameters of the extension bar were obtained,and the suitable technological parameters were obtained,which could be used to guide the actual production with good results.Practice has proved that the root causes of defects can be quickly found and systematically analyzed and improved through the rational application of product flow chart and fishbone causality diagram in stamping production.Adjustment of drawing rib and blank holder force can improve the drawing of galvanized sheet parts with large drawing depth and complex convex and concave structure and eliminate cracks and wrinkling defects.The process parameters determined by Autoform simulation are of high feasibility and can be applied in actual production.Reducing the number of die testing is beneficial to shorten the development time of the die and reduce the production cost.