三轮汽车前轮自激摆振特性研究

Shimmy Research on the Front Wheel of Three-Wheeled Vehicles

为获得转向系统结构参数对三轮汽车摆振影响,以国产某型三轮汽车作为样车,简化建立了二自由度前轮摆振系统动力学模型。对模型进行数值计算,得到了随车速变化的前轮摆振系统振动特性及结构参数变化对其的影响。结果表明,分别增大减振器刚度、转向系扭转角刚度或转向柱与车架间的干摩擦力矩,能有效减小三轮汽车前轮自激摆振的速度区间。而当车速较高,前轮摆振系统发生自激振动时,增大减振器刚度、转向系扭转角刚度或转向柱与车架间的干摩擦力矩能有效降低前轮自激摆振极限环幅值,甚至消除自激摆振现象。

In order to study the influence of structural parameters of the steering system on the front wheel shimmy of three-wheeled vehicles, a simplified model for a domestic three-wheeled vehicle was built up and a 2DOF dynamic model of the front wheel shimmy system was established. The system vibration characteristics changing with velocity and the effects of the structural parameters were obtained by numerical calculation. The results show that the shimmy velocity range of the front wheel is reduced with the increase of the shock absorber stiffness, the steering system angular stiffness or the dry friction torque between the steering column and the frame. When the shimmy occurs with high velocity, increasing the shock absorber stiffness, the steering system angular stiflhess or the dry friction torque will reduce the amplitude of the shimmy or even eliminate the shimmy phenomenon.