裙部刚度对内燃机活塞二阶运动的影响研究

Study on the Influences of Skirt Stiffness on the Second-Order Motion of Pistons in Internal Combustion Engines

针对裙部刚度对活塞运动的影响,设计了活塞刚度测试试验工装,测量裙部子午线刚度,并与有限元计算相结合得到了准确的活塞刚度矩阵。在考虑活塞、缸套热变形的基础上,建立活塞动力学仿真模型,进行了不同活塞裙部结构的二阶运动分析。分析结果表明:裙部刚度增大后,活塞运动过程中的径向位移、摆动角度及敲击能都有所减小,在一定范围内减轻了二阶运动的幅度;适度减小裙部次推力侧(antithrust side,ATS)刚度可以有效降低活塞与缸套之间的摩擦损失,实现活塞的轻量化和低摩擦设计。

Aiming at the influence of skirt stiffness on piston motion,the piston stiffness test tool was designed to measure the skirt meridian stiffness,and the accurate piston stiffness matrix was obtained by combining with the finite element calculation.On the basis of considering the thermal deformation of piston and cylinder liner,the dynamic simulation model of piston was established,and the second-order motion of pistons with different skirt structures was analyzed.The analysis results show that with the increase of skirt stiffness,the radial displacement,swing angle and kinetic energy during the piston movement are reduced,and the amplitude of the second-order motion is reduced within a certain range.The friction loss between piston and cylinder liner can be effectively reduced by moderately reducing the stiffness of skirt secondary antithrust side(ATS),and the lightweight and low friction design of piston can be realized.