基于0.5谐次扭振的内燃机故障诊断研究

依据内燃机轴系测点扭振与各缸激振力矩的关系式，利用0．5谐次扭振的幅值与相位特性，进行内燃机各缸作功状态监测和拉缸故障诊断。以6135柴油机为对象的应用研究验证利用0．5谐次扭振确定故障阈值方法的实用性和诊断准确性。对6240柴油机的实例分析表明，不仅可以利用0．5谐次扭振相位角准确判断出内燃机拉缸缸号，还可利用其幅值反映拉缸故障程度。因此，利用0．5谐次扭振对内燃机进行一级诊断和三级诊断具有较强的工程应用价值。

STUDY ON FAULT DIAGNOSIS OF INTERNAL COMBUSTION ENGINE BASED ON 0.5 ORDER TORSIONAL VIBRATION

According to the relational expression of torsional vibration of the measuring point on crankshaft and the excited moment of each cylinder of internal combustion engine(ICE),the working condition of each cylinder was monitored and the fault of cylinder-scoring was diagnosed using the amplitude and phase characteristic of 0.5 order torsional vibration.Through the application researches on 6135 type diesel engine,the feasibility and diagnosis accuracy of the method that using 0.5 order torsional vibration to determine the fault threshold value was verified.And the case analysis on 6240 type diesel engine suggested that not only the phase angle of 0.5 order torsional vibration can be used to diagnose the cylinder-scoring number,but also the amplitude can reflect the fault degree.Consequently using 0.5 order torsional vibration to first and third stage diagnosis has much engineering utility values.