Study On Torsional Vibration Of Vehicle Transmission System Of Starting Clutch Engagement Based On Engine Excitation

With the rapid development of automobile industry, the continuous improvement of automobile power and speed, the development of automobile structure lightweight trend, people begin to pay attention to the safety, comfort, and other perfor mance of vehicles. Torsional vibration will not only affect the automobile power performance and comfort, but also affect the fuel economy, safety and other performance, improve the torsional vibration characteristics of the vehicle transmission system is an important way to improve the comprehensive performance of the vehicle. In this paper, the torsional vibration characteristics of vehicle transmission system are analyzed based on engine excitation, which is simulated in the starting clutch engagement process. Mainly research on the following aspects:1.Elaborated the function and classification of vehicle transmission system and clutch of vehicle, and analyzed the major vibration source that cause the torsional vibration phenomenon of vehicle transmission, especially, the engine excitation was analyzed, and then the main theoretical basis of torsional vibration of vehicle transmission system was studied, and the two kinds of mathematical model of torsional vibration of vehicle transmission system were analyed, and the calculation method for free vibration and forced vibration were studied.2.In the analysis of the equivalent system of vehicle transmission system and the simplified method, the main assembly of vehicle transmission system is simplified, and according to the principle of equivalent system and modeling method of lumped mass model, the vehicle transmission free torsional vibration and the forced torsional vibration mathematical model is given, and the model matrix parameters were determined, and then the simulation analysis of vehicle transmission system free torsional vibration characteristics and forced torsional vibration characteristics were conducted, and by building a simple clutch model, the clutch response to incentives and the driveline forced vibration characteristics during acceleration were analyzed, the results of which indicates that basically the critical rotation speed is not in the common rotation speed range of the major vibration source, and when the excitation frequency coincides with the natural frequency, the torque amplitude is relatively large.3.In order to research the torsional vibration characteristics of vehicle transmission system during the starting clutch engagement process, the car from the start to the stable operation of the clutch engagement process is divided into three stages, and the three different stages of vehicle power transmission system torsional vibration modeled separately, with the simulation software Matlab / Simulink torsional vibration response of the system simulation, the simulation results show that: the responsiveness of each order torsional vibration in the slipping phase is more bigger than in the synchronized operation phase.