汽车发动机磁流变悬置隔振效果试验评估

Experimental Evaluation of Vibration Isolating Effect for Engine Magneto-rheological Mount

在采用四端参数法对加速度振级落差模型进行理论推导及分析的基础上,提出了以可测量、易操作的加速度振级落差对悬置系统的隔振效果进行试验评估。汽车发动机分别采用橡胶悬置及磁流变悬置,对采集得到的动态激振力数据进行了自功率谱函数估计,对振动加速度数据进行了频谱分析,并根据加速度频谱中二阶主频处的数据对悬置系统进行了评估。结果显示,磁流变悬置不仅被动隔振效果的评估结果优于橡胶悬置,而且发动机低速段采用较大电流、高速段采用小电流的控制策略使得隔振效果更好。

The acceleration-vibration level difference model was theoretically deduced and analyzed with four pole parameters method and then the vibration isolating effect of magneto-rheological （MR） mount with acceleration-vibration lever difference, which was measurable and easy to operate, was evaluated by the test. Using rubber mount and MR mount respectively, the collected dynamic exciting force data were analyzed with power spectral density function, the vibration acceleration data were analyzed with frequency spectrum, and the mounting system was evaluated according to the acceleration of second order dominant frequency. The results show that MR mount is better than rubber mount in the aspect of passive vibration isolating. The control strategy that the larger current is used in low speed while the smaller current is used in high speed strengthens the isolation effect.