哈克抽芯铆钉铆套冷精锻成形工艺

针对哈克抽芯铆钉铆套成形过程中头部出现的填充不饱满、折叠、飞边等缺陷,在金属流动行为方面分析了缺陷形成的原因。在此基础上初步设计了两种冷精锻成形工艺并优化了模具结构,在工位3模具结构中铆套顶部外圆角处、杆部与头部连接处分别预留一个直径为Ф0. 2 mm的排气孔,目的是解决制件填充不满问题,并分别建立有限元模型,利用DEFORM-3D进行数值模拟。对比两种工艺成形过程的等效应力、等效应变、成形载荷和金属流向,仿真结果表明:工艺2成形终段的等效应力、应变值比工艺1分别高出15%和34. 6%,且金属流动混乱,从而得出工艺1更加合理的结论。并通过JBF-19B-4S螺栓冷镦机进行试模,得到了无缺陷、填充饱满的制件,实验结果与数值模拟结果保持一致。

Cold precision forging process of rivet sleeve with Huck core-pulling rivet

For the defects of incomplete filling,folding and flash in the head of rivet sleeve with Huck core-pulling rivet during the forming process,the causes of defects were analyzed in terms of metal flow behavior. On this basis,two kinds of cold precision forging process were preliminarily designed,and the die structures were optimized. Then,in the die structure of step 3,an exhaust hole with Ф0. 2 mm was reserved respectively at the outer corner of the top of rivet sleeve and the joint between rod and head in order to solve the incomplete filling problem of parts. Furthermore,the finite element models were established respectively,and the numerical simulation was carried out by DEFORM-3 D. Comparing the effective stress,effective strain,forming load and metal flow direction of the two kinds of forming process,the simulation results show that the effective stress and strain values at the end of the second process are 15% and 34. 6% higher than those of the first process respectively,and the metal flow is chaotic. Thus,the first process is more reasonable. Through the JBF-19 B-4 S bolt cold heading machine,the flawless and full-filled parts are obtained,and the experimental results are consistent with the numerical simulation results.