The Research Of Thin-walled Parts Of Engine’s Vibration And Noise

The research of engine’s vibration and noise is an important part of the modernengine structural design. The cylinder head cover is one of the thin-walled components,the radiation noise caused by its vibration is the main source of the whole engine noise.Therefore, the study of the vibration and noise of the cylinder head cover has a greatsignificance in reducing the engine’s overall noise.In this paper, a6cylinder diesel engine cylinder head cover has been used as theresearch object, and its dynamic characteristics was gained by applying the methods ofthe experiments and computational simulations on its modal analysis. Throughstructure optimization and replacement of cylinder head cover engineering plastics andthe rubber vibration isolation cushion, the vibration and radiation noise of the enginehas finally been reduced. The research mainly includes the following aspects:To study the influence and contribution of the noise of cylinder head cover, thewhole engine’s noise and the cylinder head cover’s vibration has been tested on thebench in semi-anechoic chamber.Modal analysis of the cylinder head cover. Using Hypermesh to built the finiteelement model of the cylinder head cover, its modal analysis under free state was alsoconducted in Abaqus. After calibration, the engine cylinder head cover’s structure andmaterial optimization has been accomplished.The experimental verification of cylinder head cover optimization. In the end, thewhole engine’s noise and the optimized cylinder head cover’s vibration was tested.Compared to the earlier test, the results show that after being optimized in structureand material, the vibration of the cylinder head cover and the noise of the cylinderhead cover are both effectively reduced.