汽车发动机气门弹簧残余应力的研究

根据气门弹簧失效机理和气门弹簧的应力分析,阐述了与钢丝轴线呈45°(或135°)方向的残余应力是直接影响气门弹簧疲劳性能的因素。采用X射线应力测试仪对去应力退火和喷丸强化处理两道关键工序中弹簧的内、外圈表面和不同喷丸强化处理参数下次表面的残余应力进行了试验,并对气门弹簧进行了模拟发动机实际工况疲劳试验验证,得到了气门弹簧在这两道关键工序中残余应力和疲劳性能的关系,为今后通过优化工艺来改善气门弹簧的疲劳寿命和性能奠定基础。

Study on Residual Stress of Valve Spring for Vehicle Engine

According to the analysis of valve spring failure and spring stress,it was thought that the residual stress that made an angle of 45°(or 135°) with the wire axes was the most important factor of valve spring fatigue.Furthermore,X-ray stress detector was used to measure the residual stress which lay in hypo-surface of various shot peening parameters and inner and outer surface of spring after the key processes of temper and shot peening process.Then the fatigue test of valve spring was carried out by simulating engine actual conditions,and the relation between residual stress and fatigue performance in the two key processes was acquired,which brought the reference for improving spring fatigue life and performance by optimizing the process in the future.