利用发动机瞬时转速波动诊断气门漏气故障

Diagnosing Leakage of Valves in Engines by Analyzing Instantaneous Speed Fluctuations

对瞬时转速波动进行了仿真分析计算 ;实测了发动机的瞬时转速 ;对比了实测与仿真计算的瞬时转速波形 ,两者相当一致 ;讨论了影响瞬时转速测量精度的关键因素 ;提出利用瞬时转速进行故障诊断的特征参数及判据 ,并在诊断 4 1 2 0 SG型柴油机气门漏气故障中得到证实 .

The simulated calculation and analysis of the fluctuation of the instantaneous speed of a diesel engine are presented.The important factors,influencing the measurement precision of the instantaneous speed,are discussed.The correct measurement method is presented.The instantaneous speeds of diesel engine are measured and processed in a laboratory condition.Compared the simulated instantaneous speed with the measured instantaneous speed,the simulated result is correspondence with the measured result.The characteristic parameters and the criteria of the instantaneous speed for detecting the leakage of valves in diesel engine are provided,and diagnosis accuracy is confirmed on 4120SG diesel engine.