考虑发动机系统动力学与动力润滑耦合的活塞拍击分析

摘要

Piston slap is the major mechanical noise source of internal combustion (IC)engine.Piston slap reduction is one of the most important countermeasures to improve the noise and vibration performance of IC engine.The influences of piston skirt and cylinder liner surface roughness on the oil film dynamical behavior and piston slap were analyzed.Based on the parameters of lubricating oil film thickness and surface roughness ratio,an analytical coupled vibration model of piston skirt and cylinder liner was developed.Combined with the vibration model of piston,connecting rod,crank shaft and engine block,an analytical piston slap model which takes the coupled vibration induced by the system dynamic behaviors and hydrodynamic lubrication into account was constructed and its influences on the piston movement and piston slap induced impact force were investigated.The comparison between the presented method and the traditional method which simulates the dynamical characteristics of piston shirt and cylinder liner system by nonlinear dynamical model was discussed.Based on the experimental data,the error of the theoretical model was investigated.%为降低活塞拍击、改善发动机振动噪声性能，考虑活塞－缸套表面粗糙度对润滑状态、活塞运动及活塞拍击影响，基于膜厚比建立活塞缸套动力学分析模型。结合考虑活塞、连杆、曲轴及缸体耦合振动的发动机系统动力学分析模型，建立考虑发动机系统动力学与动力润滑的活塞拍击分析模型，探讨活塞拍击现象。与传统的活塞－缸套非线性动力学分析模型进行对比分析，并结合缸体振动响应实验数据，讨论理论模型误差原因。