【摘要】 基于发动机动力学理论,建立发动机停止过程中活塞的动力学模型,推导出停油熄火后缸内气体力矩以及曲轴输出力矩的计算公式.以三菱公司的4G15GDI发动机为例进行了仿真计算和台架实验,详细分析了发动机停止过程的缸内气体力矩和曲轴输出力矩特性、曲轴速度特性及活塞停止位置概率分布.仿真和实验结果显示:停机过程的缸内气体力矩和曲轴输出力矩变化过程是周期衰减过程,经过1.28 s转速由2000 r/s降至0 r/s.活塞自由停止位置约90%分布在上止点前60°~80°CA.更多还原

【Abstract】 The dynamic model of the engine shutdown process is estabished. The both calculation formula of the cylinder gas and crankshaft output torque are derived. The 4G15 GDI engine is taken as an example to do simulation calculation and bench experiment. Torque and speed characteristics of the shutdown process is analyzed in detail. Results show that the torque changes are approximate cycle attenuation process. The distribution of the piston stop before the check point within 60°-80°CA is about 90%.This study provide the key information for the next piston position control strategy.更多还原