Performance Optimization And Testing Of Engine Mount System

The matching design of engine mount system has very important impact on vehicle NVH performance.This paper based on the matching design of a project engine mounting system,apply forward development process mainly start from below key points:(1)Set the development target of the engine mount,including stiffness characteristics,powertrain rigid mode & displacement control,and mounting bracket design requirements,etc.,(2)Describe the method for measuring the parameters of powertrain,complete the measurement of the mass,centroid and moment of inertia of the powertrain(3)Based on the development theory of the engine mount system,derived the theoretical formula of the engine mounting system,set the frequency of engine mount system,calculated the initial stiffness of rubber cushion,modeling the simulation model by ADAMS software,preliminary analysis the decoupling effect of main vibration direction of the suspension system.(4)The target is to maximum decouple of vertical and rotational direction of the crankshaft,meanwhile,the upper and lower bounds of the natural frequency of the system was take into account,the single objective and multi variable is used to optimize the system,realized the reasonable frequency distribution and the energy decoupling target of the engine mount system.(5)Via the simulation model by ADAMS software worked out several results in general condition of engine mount system such as centroid displacement,angle rotation,and the mounting bracket stress load extraction result,these outputs are the source for FE strength and bench fatigue test loading force.This paper discuss the principle of engine vibration and the theory of engine mount position arrangement,also describe mechanism of vibration isolation of engine mount system in three aspects;isolation rate,decoupling degree of powertrain rigid mode,and rotation frequency of free rotating shaft.This paper did the validation for engine mount prototype dynamic performance,mainly including the dynamic& static stiffness and the fatigue of the rubber cushion.Conducted the testing under idle speed and full throttle acceleration in the real vehicle condition,collected the data of vibration acceleration on both ends of the engine mount &the steering wheel and the seat etc.The test result showed that the engine mount performance can meet the target of the vehicle NVH requirement.