Vibration And Noise Analysis Of Engine Timing Silent Chain System On Hybrid Electric Vehicle

In the paper,the vibration and noise characteristics of the timing silent chain system（TSCS）in the hybrid electric engine are studied based on the design of the structure of the TSCS.The research was carried out under the Science and Technology Development Project of Jilin Province “Key Technology Research on the Timing Chain System of Passenger Vehicle Hybrid Engine（20200401136GX）”and National Natural Science Foundation project “Variation Theory and Key Design Technology of Silent Chain（51775222）”.This paper combines the specific working conditions of the TSCS on the engine of hybrid electric vehicle,establishes the physical model base on structural design.Firstly,the dynamic characteristics and rigid-flexible coupling multi-body dynamic characteristics are analyzed,then the vibration characteristics are studied by finite element analysis,modal analysis and frequency response analysis,and finally the noise characteristics are studied by acoustic radiation analysis.The results of the paper provide a reference for the subsequent optimization of the TSCS,and the research method of this paper also has a certain reference for the TSCS of other arrangements.This paper establishes the physical model base on the structural form of each component and the arrangement of the TSCS,and the boundary conditions of the TSCS on a hybrid passenger car engine are also analyzed in the context of the specific operating conditions of a hybrid electric vehicle engine and its operating characteristics.The dynamics analysis model was obtained by adding the boundary conditions in the dynamics analysis software Recur Dyn,and further obtained its rigid-flexible coupling analysis model.The multi-body dynamics analysis and rigid-flexible coupling analysis were carried out at different rotational speeds to obtain the dynamics characteristics parameters such as chain plate trajectory,chain plate angular velocity,instantaneous transmission ratio,and the rigid-flexible coupling characteristics such as instantaneous stress state of the TSCS,and the data were extracted to prepare for the subsequent vibration analysis.The results of dynamic analysis show that there is no obvious fluctuation phenomenon when the TSCS is in motion,and the TSCS runs smoothly as well as it has good dynamic characteristics.The results of the rigid-flexible coupling analysis show that the TSCS has good stiffness and strength characteristics and no structural damage will occur due to normal operation.Based on the modal analysis method of vibration structure,the established physical model of the TSCS was meshed in the finite element analysis software Ansys Workbench to obtain its FEA model.Boundary conditions were added to the FEA model based on the system conditions,and based on the data obtained from the multi-body dynamics analysis,the static analysis,modal analysis and frequency response analysis were performed in turn.The static stress and deformation condition of the TSCS were obtained from the static analysis,and the results showed that the TSCS had good strength and stiffness,and also provided pre-stress for the modal analysis.The first 20 order natural frequency and modal vibration patterns of the TSCS were obtained by modal analysis with pre-stressing,and the results showed that the vibrations mostly occurred on the loose and tight sides of the TSCS.The dynamic-frequency response curve of the TSCS was obtained by frequency response analysis,and it was found that there were peaks at 160 Hz,280 Hz,600 Hz,880 Hz,1080 Hz,etc.The peak frequencies were all dangerous frequencies,and it was found that resonance did not occur easily when the TSCS was running smoothly by comparing them with the normal operating frequency of the TSCS.Finally,based on the vibration analysis,the acoustic boundary element model of the TSCS was built and the acoustic radiation simulation analysis was carried out using LMS Virtual.Lab.The noise characteristics such as the sound pressure distribution and the sound pressure-frequency response curve of the TSCS were analyzed and obtained,the results show that the noise mainly appears near the sprocket and the elastic side of the TSCS,and the noise value conforms to the noise standard specified in GB-1495-2002,and the peak value of the sound pressure-frequency response curve and the peak value of the dynamics-frequency response curve appear at the same position.The analysis results proved that the TSCS has good noise characteristics and also verified the accuracy of the vibration analysis.The vibration and noise characteristics of the TSCS of hybrid vehicles conducted in this paper can provide reference for the subsequent vibration and noise reduction of the TSCS.