差厚板汽车覆盖件的拉延成形工艺参数优化

以某汽车差厚板前门内板件作为研究对象,为解决其拉延成形过程中的破裂和起皱缺陷,首先对差厚板材料的力学性能进行测试,可知相同材质的厚板和薄板具有相似的力学性能,拼焊板的屈服强度和抗拉强度比母材高。根据零件的特点设计工艺补充面,借助有限元软件AutoForm建立差厚板拉延成形的有限元模型。通过初步分析,针对成形缺陷提出引入工艺切口。然后,采用正交试验设计、数值模拟和多目标优化相结合的方法,对拉延成形的压边力、刺破刀C1、C2的凸出高度和摩擦系数进行了优化,得到最优的工艺参数组合为:压边力为1. 1×10^6N、刺破刀C1的凸出高度为12 mm、刺破刀C2的凸出高度为8 mm、摩擦系数为0. 125。最后,采用优化的参数进行试验验证,得到拉延成形的差厚板零件和数值模拟结果基本吻合。

Optimization on drawing process parameters for differential thickness blank of automobile cover parts

For an automobile front door inner panel of differential thickness blank,in order to solve the crack and wrinkle defects in the drawing process,firstly,the mechanical properties of differential thickness blank were tested,the similar mechanical properties of thick blank and thin blank with the same material were obtained,and the yield strength and the tensile strength of tailor welded blank were higher than that of base material. Then,according to the characteristics of parts,the addendum surface was designed,and the finite element model of drawing for differential thickness blank was established by finite element software Auto Form. Through the preliminary analysis,the process incision was introduced to solve the forming defects,and the blank-holder force of drawing,the protruding height of piercing knives C1 and C2 and the friction coefficient were optimized by the method combinated the orthogonal experiment design,the numerical simulation and the multi-objective optimization. Furthermore,the optimum combination of process parameters is the blank-holder force of 1. 1 × 10^6 N,the protruding height of 12 mm for the piercing knife C1,the protruding height of 8 mm for the piercing knife C2 and the friction coefficient of 0. 125. Finally,the optimized parameters were verified in the experiments. The results show that the experimental results of differential thickness blank obtained by drawing and the numerical simulation results are basically consistent.