针对某发动机在进行耐久性试验时出现的缸盖、罩盖、正时盖三结合面附近渗油现象，通过建立发动机的有限元分析模型，模拟汽车发动机的冷机工况，运用数值分析的方法，对发动机冷机工况下正时盖与缸盖、罩盖之间接触面的压力以及渗油点附近各部件的变形量进行分析，确定正时盖渗油原因与渗油点附近螺栓座刚度不足有关。加强螺栓座及其附近结构的刚度之后，正时盖不再渗油。

For the oil leakage problems near the joint of engine cylinder cover, engine cover and timing cover during the durability test, the finite element model of engine was built to simulate the engine cold condition. Using the numerical analysis method, the stress of joint surface and the deformation of each component near the oil leakage point were analyzed. In the end, it was determined that the reason of oil leakage was the insufficient stiffness of bolt seat. The oil leakage problems were solved after improving the stiffness of bolt seat.