空气弹簧液压悬置动特性及隔振特性研究

研究了具有可变刚度阻尼的发动机空气弹簧液压悬置的动特性和隔振特性。针对影响发动机空气弹簧液压悬置动特性的关键参数上液室等效体积刚度,采用理论和试验方法研究了上液室等效体积刚度的等效值,基于该等效值建立了空气弹簧液压悬置的理论模型,对空气腔开闭两种工况进行了空气弹簧液压悬置动特性的仿真和试验研究。搭建了发动机空气弹簧液压悬置系统试验台架,研究了台架各种激励频率下的空气弹簧液压悬置的隔振特性。结果表明:本研究采用的上液室等效体积刚度进行空气弹簧进行建模是正确、可行的,提高了空气弹簧建模效率和准确性;空气弹簧液压悬置在空气腔开启和关闭两种状态下,峰值动刚度增大幅值达78.5%,峰值阻尼角增大幅值达250%。台架试验表明:当台架激励频率小于25Hz时,悬置采用大刚度大阻尼;当台架激励频率大于等于25 Hz时,悬置采用小刚度小阻尼;悬置隔振率提升明显,不同频率下提升幅值达10%～67%。

Dynamic Characteristics and Isolation Characteristics of Air Spring Hydraulic Mount

In order to improve the performance of the automobile comfort, the dynamic characteristics and the vibration isolation characteristics of engine air spring hydraulic mount with variable stiffness and damping are studied. Firstly, the equivalent volume stiffness of the upper chamber, which is the key parameter affecting the dynamic characteristics of the engine air spring hydraulic mount, are studied by theoretical and experimental methods. Based on this equivalent value, the theoretical model of the air spring hydraulic mount is established, and the simulation and experimental study of the dynamic characteristics of the air spring hydraulic mount are carried out under the two conditions of air chamber opening and closing. Then, the test bench of the engine air spring hydraulic mount system is built, and the vibration isolation characteristics of the air spring hydraulic mount under various frequencies of the bench are studied. The results show that the proposed modeling method is accurate and feasible, and this method effectively improves the efficiency of modeling. By comparing the on and off working conditions of air chamber, the increase of dynamic stiffness is 78.5% and the increase of damping angle is 250%. The bench test shows that the vibration isolation rate of the mount increases obviously when the excitation frequency of the bench is less than 25 Hz, the mount adopts large stiffness and large damping, and when the excitation frequency is greater than or equal to 25 Hz, the mount adopts small stiffness and small damping. The amplitude of the increase reaches 10%~67% at different frequencies.