汽油机正时罩盖密封性能研究

Research on Sealing Performance of Gasoline Engine Timing Cover

在对某汽油机进行耐久性试验时,正时罩盖腰部与缸体结合面处出现渗油现象。建立了汽油机装配体三维有限元模型,采用数值仿真分析结合面压试验的方法,对发动机预紧力工况及热机工况下,密封面处的接触间隙、接触压力以及渗油点附近正时罩盖、缸体的变形量进行分析。预紧力工况仿真结果与面压试验结果对比,验证了仿真模型可靠,热机工况仿真分析结果表明,渗油现象是由于渗油点附近正时罩盖法兰局部刚度不足,以及螺栓基座位置布置不合理造成。对渗油点附近正时罩盖结构局部刚度进行加强,同时调整部分螺栓布置位置后,渗油问题得到解决。

During the durability test of a gasoline engine,oil leakage occurred between the contact surface of timing cover and cylinder. A three-dimensional finite element model of gasoline engine assembly was established, based on the numerical simulation analysis and the method of surface pressure test, the contact clearance, contact pressure and the deformation of the timing cover and cylinder near the oil leakage point are analyzed under the condition of engine preload and heat sealing condition. Compared the simulation results in the cases of preload condition and surface pressure test, the simulation model is proved to be reliable, the simulation results of heat sealing condition, show that the phenomenon of oil leakage is due to the insufficient local stiffness of the cover flange near the oil leakage point and the unreasonable arrangement of the bolt base position. Strengthen the local stiffness of the timing cover structure near the oil leakage point, while adjusting part of the bolt layout position at the same time, the oil leakage problem is solved.