大高径比凸台冷镦成形极限研究

Research on Cold Upsetting Forming Limit of Large Height-diameter Ratio Boss

针对长轴大高径比凸台在冷镦过程中的失稳问题,研究了凸台冷镦成形的极限和锥模聚料后冷镦成形的极限。采用实验和数值模拟相结合的方法,得到了凸台成形工艺参数及凸台成形质量预测公式。理论推导出锥模聚料后冷镦凸台的成形极限。并以C100发动机主轴为对象,借助DEFORM-3D进行数值模拟。结果表明,采用锥模聚料+冷镦成形方案可避免镦粗失稳缺陷的产生。工艺试验表明,试验结果与数值模拟结果一致。数值模拟结果对工艺试验有一定的指导意义。

Aiming at the instability problem of large height-diameter ratio boss for long axis in the process of cold upsetting, the forming limit of cold upsetting and the forming limit of cold upsetting after gathering material were researched. The boss forming process parameters and forecasting formula of its forming quality were obtained by adopting numerical simulation combined with experiment. The forming limit of cold upsetting after gathering material was derived by theory. Taking C100 motorcycle engine principal axis as the research object, numerical simulation was conducted by DEFORM-3D software. The results show that using cold upsetting after gathering material can avoid upsetting instability. Technology tests show that testing results are in accordance with the simulation. The numerical simulation results have certain guiding significance to the process test.