Research On Matching With Vibration Isolation Performance Of Power-train Mount System Of Cars

With the developing of science and technology, people's requirement on ride comfort of automobiles is increasing, and excellent ride comfort and low noise are important symbols of present-day automobiles. Automobile power-train is one main vibration source which has great influence on ride comfort. The well designed power-train mount system not only can improve ride comfort and decrease the level of noise but also can extend service life of engine and other components.In this dissertation, the engine (481Q3) mounting system of some economic car has been deeply studied. Based on Multi-Body Dynamic theory and vibration theory, The model of UG provided by manufacturer is transformed into solid model by further processing.The solid model is imported into ADAMS by using the interface of parasolid between the software ADAMS and UG and then built dynamic model of power-train mount system.In order to reflect real situation of power-train, some parameters including mass of power-train, centroid position, inertia parameters are measured by methods of platform scale, torque equilibrium and compound pendulum. The measurements results are imported into the solid model of ADAMS.ADAMS/view applied performs time domain simulation of power-train mount system. The conclusion that idle condition is the worst condition in vibration isolation performance is obtained through the simulation results. The module of ADAMS/vibration applied performs frequency domain simulation of power-train mount system and gets first six order natural frequency. The results show that the sixth order natural frequency is too high to meet with vibration isolation performance requirement. The amplitude-frequency characteristic of responsive force proves this opinion .In order to obtain the optimal vibration isolation performance, parametric model of power-train mount system is built in this paper. The stiffness of mount elements is chosen as design variable and the least amplitude of responsive force is chosen as objective function.,meanwhile angular acceleration that centroid interwines axis of roll is chosen as reference performance to optimize the power-train mount system. The result obtained by contrastive analysis shows that the vibration isolation performance of Optimization Model of power-train mount system is improved. The displacement amplitude of all mount elements is considered and the optimum results show that the displacement amplitude is in the range of allowable range, so the service life of all mount elements can be ensured. The improvement is successful.