活塞裙部双凸点设计对摩擦磨损性能影响研究

Research on the Friction and Wear Performance of Piston Skirt with Double-Bump Design

活塞作为发动机的关键部件,长期在严苛的环境下工作,其摩擦性能以及运行可靠性成为大家一直以来的关注重点。以某款四缸柴油机为研究对象,在Ricardo-Pisdyn软件中建立了耦合惯性参数、表面粗糙度、热变形和弹性变形等多因素的动力学模型,研究活塞主推力侧裙部设置双凸点型线(探究上凸点高度、凹腔深度等参数)对活塞摩擦磨损性能影响。计算结果表明:在活塞主推力侧裙部中上部设置上凸点及凹腔特征,适当增加凹腔深度,可改善活塞主、次推力侧磨损,但增加过大会加重活塞主推力面的磨损。结合优化配缸间隙和采用双凸点型线方法,可进一步改善活塞摩擦磨损性能,优化设计后裙部累积磨损量从31.65MW/m2降低为14.64MW/m2,降约53.7%。

As the key part of the combustion engine,piston needs to work in harsh environment for a long time,so its friction performance and reliability are always been the research focus.In this research,based on a four-cylinder diesel engine,the dynamic model considering multi-factors such as inertial parameters,surface roughness,thermal deformation and elastic deformation is established in Ricardo-Pisdyn software.The effects of the piston main thrust side double-bump design(exploring the parameters of the upper bump height,cavity depth etc.)on the friction and wear performance were investigated.The simulating results show that appropriately increasing the depth of the cavity can improve the wear within a certain range.However,if the cavity depth is too large,the abrasion of the main thrust surface will be aggravated.After optimizing the clearance and adopting the double-bump profile of the main thrust side,the accumulated wear load of the piston can be significantly reduced and its friction and wear performance can be improved.The optimized accumulated wear load decreases from 31.65MW/m2 to 14.64 MW/m2,drops by 53.7%.