范围档气缸拨叉轴断裂故障分析研究

Analysis on the fracture malfunction of the fork shaft of the range stalls cylinder

针对汽车变速箱用范围档气缸拨叉轴断裂故障,应用有限元法对拨叉轴断裂处台阶过渡方式进行应力分析,定性给出了过渡半径小于0.78mm时的应力值变化情况,从工艺可控性方面提出了拨叉轴台阶过渡应选用R0.8越程槽方式。应用分析表明:该过渡方式可大幅降低拨叉轴断裂故障率,对于带台阶过渡的轴类零件结构优化具有切实可行的意义。

The author made the stress analysis about the step transient mode at the crack of the fork shaft by using the finite element method,which took the fracture malfunction of the fork shaft of the range stalls cylinder as the research object.And it shows qualitatively the stress variation when the transition radius is less than 0.78 mm.Given the process control,it suggests using R0.8 grinding undercut at the step transition of the fork shaft.Application analysis shows that the excessive way can greatly reduce the failure rate of the fracture of the fork shaft,which is instructive and meaningful to the shaft structure optimizing with step transition.