Analysis of Misfire Faults in Multi-cylinder Diesel Engines Considering Self-excited Vibration of Components

Abstract

Aiming at the problem of difficult feature acquisition caused by coupling and aliasing of high and low frequency signals in diesel
engine misfire fault vibration signals, a simulation modeling method based on transient dynamics is proposed to simulate the vibration signals
of multi-cylinder diesel engine cylinder heads. First, expressions of inertial driving force, driving moment and valve seat impact force were
established, and the dynamic characteristics of crankshaft connecting rod and valve train were analyzed. Secondly, an in-cylinder combustion
model was built to simulate the distribution of in-cylinder combustion pressure. Then, the whole machine model was established using the finite element method, loading the combustion pressure inside the cylinder, the seat excitation of the valve train and the inertial excitation of the
crank connecting rod, and the digital characteristics of the vibration signal of the cylinder head were studied.