The effect of various factors on the block vibration is investigated in this paper.The peak value,vari-ance,standard deviation,root mean square and spectrum energy obtained from wavelet packet decomposition are compared at different engine speeds,torques,oil temperatures and piston-liner clearances.The results show that the peak value of combustion fluctuates with the increase of the engine speed,and the four time domain characteristic parameters and energy of frequency bands higher than 5 increase.With the augment of engine torque,the peak value of combustion pressure,time domain characteristic parameters and energy of each fre-quency band arise.Under the dual action of oil damping and combustion pressure,the four time domain charac-teristic parameters decrease and the energy of frequency bands higher than 12 increase versus the oil tempera-ture.With the augment of piston-liner clearance,the peak value of combustion pressure decreases due to the ex-cessive leakage.The four time domain characteristic parameters and frequency bands higher than 5 increase,which can be attributed to the vigorous piston secondary motion.
关键词
活塞缸套摩擦副/机体振动信号/时域分析/小波包分解/燃烧状态
Key words
piston-liner friction pair/block vibration signal/time domain analysis/wavelet packet decomposi-tion/combustion status
维普
万方数据