Fuel Injection System Fault Diagnosis Based on Cylinder Head Vibration Signal

This work aims at monitoring diesel engine fuel injection system by analyzing the cylinder head variations. It focuses on dual-peak phenomenon in combustion stage signal of cylinder head vibration under certain work condition. The first peak of dual-peak is the vibratory response signal of fuel injector needle valve crash which is proved by the time domain analysis between cylinder head vibration and in-cylinder combustion pressure, analysis for cylinder head vibration of misfire and analysis of fuel feeding law change following engine rotational speed. The start time of the fuel injector needle valve crash vibratory response signal can describe the fuel injector needle valve closing timing. The acceleration peak of fuel injector needle valve crash vibratory response signal can describe crash strength. From the results under different work conditions and faulty conditions it is revealed that these characteristics can accurately describe injection information and can be used for fuel injection system fault diagnosis.