Study On Automobile Engine Mount System And Software Development

The engine-transmission assembly, which includes the engine, the clutch and the transmission, is one of the most important assemblies in an automobile. The unbalance forces and torque generated by engine are the important excitation source that make the automobile vibrate, such unbalance forces and torque are transferred to the frame or bodywork through the mounts, which makes the automobile's vibration and decreases the riding performance. By selecting the mounting system's parameters correctly, the mounting system's vibrate-isolation performance can be improved and then improves the automobile's riding performance.The thesis took the engine-transmission assembly as a six-degree-freedom rigid body, established its physical and mathematical models based on analyzing the dynamic performance of rubber mount. The system's parameters are measured by experiments, including the center of gravity, the inertia and the mounts' stiffness, and then programmed the VEHMA software, which is abbreviated from Vehicle Mounting System Analysis. It has three functions, such as vibrate-isolation performance analysis, bearing parameters sensibility analysis, principal inertia axis analysis. Especially, this software has the convenient user's manual. In order to verifying the software's reliability, a modal experiment had been carried out against GW2.4S engine-transmission assembly.Through analyzing the original mounting system, we found the important cause of vehicle vibration is vibrate-modal's coupling. With analyzing and considering the engineering's practical situations, a new scheme is put forward that can improve the isolation efficiency by changing the mounting angular and principal stiffness of the rubber mount. We have the sensibility analysis curve and the optimum angular by using bearing parameters sensibility analysis module and principal inertia axis analysis module which in the VEHMA software. The isolation performance has been improved by adjusting the above parameters.The VEHMA software can makes the work, which will be done in analyzing the mounting system's vibrate-isolation performance and bearing parameters optimization easy. It has some practicability in engineering for cutting down the development period effectively.