汽车发动机磁流变悬置动特性研究

Dynamical Performance Research of a Magneto-rheological Engine Mount

针对某型号动力总成,基于阻尼可控、宽频隔振的思想,设计具有解耦膜、可控阻尼通道结构的磁流变悬置新型结构,使磁流变悬置在低频、大振幅时,具有高刚度大阻尼特性,高频、小振幅时,具有低刚度、小阻尼特性,同时悬置的高频动态硬化被有效抑制。采用键合图理论,根据磁流变悬置在不同激振条件下的实际工作状态,建立分段式动态特性集总参数模型,利用键合图理论推导了磁流变悬置的状态方程,并对磁流变悬置的动特性进行了仿真分析与试验验证。结果表明：在0~200 Hz频率范围内,该磁流变悬置具有良好的动态性能,能满足发动机的隔振需求,并论证了分段式磁流变悬置集总参数模型的有效性。

A novel MR （Magneto-Rheological） engine mount with decoupler and controllable damping channel is designed and used to vibration isolation for a vehicle engine. Its principle involves controllable damping and vibration isolation through a wide frequency range. This novel MR mount has high stiffness and damping at low-frequency,large amplitude vibration,as well as low stiffness and damping at high-frequency,small amplitude vibration,meanwhile dynamical hardening is suppressed at high-frequency effectively. According to the excitation conditions of engine,a piecewise lumped parameter model of this novel MR mount was established and nonlinear mathematical state equations of bond graph model for the MR mount is developed. Finally,its dynamical performance is analyzed and predicted. The results show that this novel MR mount demonstrates a good dynamical performance in a wide frequency range from 0 to 200Hz,which can meet the demand of vibration isolation on vehicle engine. The rationality of a piecewise lumped parameter model is also demonstrated.