单缸熄火时发动机曲轴系统扭振特性研究

利用系统矩阵法求解了发动机曲轴扭振系统的强迫振动特性,并对发动机单缸熄火时扭振系统的激励力矩进行了简谐分析.以某直列6缸发动机曲轴系统为例,分析比较了该系统在发动机正常发火和单缸熄火时额定转速下和工作转速范围内的扭振特性.结果表明,单缸熄火时,系统扭振以低谐次为主.扭转角位移显著加大,而附加扭转应力变化不明显.

Study on the Torsional Vibration Characteristics of Engine Crankshaft System When Single-Cylinder Misfires

Utilizing system matrix method,characteristics of forced vibration for the torsional vibration system of engine crankshaft are studied.Simple harmonic analysis is carried out for the excitation torque when a single-cylinder misfired.Based on these studies,with an in-line 6-cylinder crankshaft system working both under normal combustion and when facing the misfire of a single-cylinder,the system's torsional vibration characteristics under specified speed and working speed range are analyzed.The results showed that low harmonic torques mainly react on the system's torsional vibration,and torsional angle displacement increases obviously,but additional torsional stress little changes,when a single-cylinder misfires.`