三销轴叉温锻工艺优化及数值模拟

Optimization of Warm-forming Process and Numerical Simulation for Three Pin Shaft Joints

针对三销轴叉精锻件温、冷精锻复合成形后存在头部跳动超差的问题,分析其产生的原因主要是多工位温锻反挤压温锻件头部跳动超差,而反挤压温锻件头部跳动的大小与墩粗工位温锻件形状有关。数值模拟结果表明,对于改进后的墩粗温锻件,在反挤工序中,挤压温度要小,温锻件受力较小,变形较均匀。工艺试验结果表明,墩粗工位的温锻件头部内腔表面形状与第4工位的反挤温锻件头部内腔形状相同,且墩粗工位的冲头和凹模的导向间隙为0.4~0.5mm。经反挤成形后,可有效防止锻件头部产生跳动超差,实现在自动压机上连续生产锻件。采用该方案,生产的锻件金属流线和显微组织符合产品使用要求。

There were problems of out of tolerance of run-out of head for three pin shaft joint forging parts after warmcold and complex forming,therefore,analyzed the cause lead to that was produced by the out of tolerance of run-out of head for back extrusion forging during the multistage forming,and the value of run-out of back extrusion forging part had relationship with the shape of upset forging part.The results of simulation showed that there were lower extrusion temperature,lower stress and more uniformity of deformation during back extrusion process after upset forging process improved.The result of process trial showed that the interior shape of head for upset part was similar with the interior shape of head for back extrusion part,and the gap was 0.4-0.5 mm between punch and die for upset process,the run-out was in tolerance after finishing warm-forming process,and can achieve continual mass production on automatic press,verification of this improved upset forging process showed that flow line of metal and microstructure of material can meet products using requirement.