车用异形件浮动凹模冷镦工艺分析及模芯结构优化

Cold upsetting process analysis and die core structure optimization on floating die for special-shaped parts of vehicle

以某车用异形件为研究对象,为解决实际生产中存在的成形力大、模具寿命短、产品填充不饱满、成形质量差等问题,根据零件的结构特征,改进原生产工艺,提出了采用浮动式凹模挤压成形的工艺方案,分析了浮动式凹模结构的工作原理及摩擦力的变化规律。采用CAE分析软件DEFORM-3D对两种工艺的成形过程进行了模拟分析,直观地了解了原生产工艺存在的问题以及改进后工艺改善的程度。基于浮动式凹模结构,以模芯磨损量最小为优化目标,对模芯结构进行优化。最后,分析研究了凸模冷镦速度、凹模圆角对凸模、凹模及模芯承受载荷的影响,对浮动式凹模结构冷镦工艺参数进行了优化。结果表明:采用浮动式凹模结构能够有效地改善原工艺缺陷;采用平底模芯结构能够有效地降低磨损;当凸模冷镦速度为10 mm·s^(-1)、凹模圆角半径为0.8 mm时,各模具所受载荷最小;利用有限元技术能够有效地解决工艺问题。

For a special-shaped part of vehicle, in order to solve the problems existing in actual production, such as large forming force, short mold life, insufficient product filling and poor forming quality, the original production process was improved according to the structural characteristics of the part, and the extrusion process with floating die was put forward, and the working principle of floating die structure and the variation law of friction force were analyzed. Then, the forming processes of the two processe were simulated and analyzed by CAE analysis software DEFORM-3 D, and the problems existing in the original production process and the improvement degree of the improved process were intuitively understood. In addition, based on the floating die structure, the die core structure was optimized with the minimum wear of the die core as the optimization goal. Finally, the influences of punch cold upsetting speed and die fillet on the loads of punch, die and die core were analyzed, and the cold upsetting process parameters of floating die structure were optimized. The results show that the defects of the original process are effectively improved by using the floating die structure, and the wear is effectively reduced by using the flat bottom die core structure. When the cold upsetting speed of punch is 10 mm·s^(-1)and the die fillet is 0.8 mm, the load on each punch and die is the minimum, and the process problems are effectively solved by the finite element technology.