Design Analysis and Optimization to Dynamic Characteristic of Engine Mounting System

摘要

The engine is the important source of excitation of the vehicle, which seriously influences the level of automotive vibration. The ideal engine mounting system should isolate engine vibration caused by engine disturbance force in engine speed range and prevent vehicle body bounce from road excitation. In recent years, the requirements of vibration and noise level isolation for vehicle became more and more, and the modern vehicle designs have a trend for lighter bodies and more power-intensive engines. As a result, it makes body rigidity reduce, engine excitation amplify and vehicle interior noise and vibration characteristic worsen. This paper the summarized optimum design method of the engine mounting system and gave the optimum calculations against the problem of vibration for a vehicle. In the optimum process, with the mounts rigidity as the design variable, with the systematic natural frequency as the constraint condition and with the decoupling of the vibration mode in z and θ_x direction as the objective function, the optimum design of the dynamic characteristic of the engine mounting system is made by using a complex method. The date shows the vibration level of test vehicle is effectively reduced. The dynamic characteristics of the mounting system are improved effectively through optimization design for the mounting parameters and the vibration state of vehicle gets better improvement.