组合式凸轮轴热胀锻成形工艺

Hot gas hydro-forging process of combined camshaft

针对组合式凸轮轴成形困难的技术现状,提出了以热胀锻工艺成形组合式凸轮轴的工艺方案。通过有限元软件ABAQUS,对组合式凸轮轴热胀锻成形过程进行数值模拟分析,研究了凸轮端面斜度、镶块斜面长度、成形温度、内压和单侧效果轴向补料量对成形质量的影响规律。研究结果表明:当凸轮端面斜度减小、镶块斜面长度增大时,有利于轴管外壁和凸轮的填充;成形温度为850℃时,填充效果最好;随着内压和轴向补料量的增大,有利于轴管外壁和凸轮的填充,但是轴管内壁也会出现折叠现象。设计工装对此工艺进行验证,实验结果证明了热胀锻工艺的可行性,以及数值分析的正确性,使用热胀锻工艺成形的组合式凸轮轴,其静扭强度完全符合凸轮轴的使用要求。

For the technical status of difficulty in forming the combined camshaft,a process scheme of forming the combined camshaft by hot gas hydro-forging was put forward.The hot gas hydro-forging process of combined camshaft was numerically simulated by finite element software ABAQUS,and the influence laws of inclination of cam end face,inclined length of insert,forming temperature,internal pressure and unilateral axial feeding amount on the forming quality were studied.The results show that when the inclination of cam end face decreases and the inclined length of insert increases,it is beneficial to the filling of outer wall for shaft tube and cam,and the filling effect is the best when the forming temperature is 850 ℃.With the increasing of internal pressure and axial feeding amount,it is beneficial to fill the outer wall of shaft tube and cam,and the inner wall of shaft tube is also fold.The experimental results prove the feasibility of hot gas hydro-forging process and the correctness of numerical analysis by design tooling,and the static torsion strength of combined camshaft formed by the hot gas hydro-forging process completely conforms to the requirements of camshaft.