某车型麦弗逊转向悬架分析与优化设计

针对某轿车改款为SUV,抬高车身后悬架系统重新布局,出现前麦弗逊转向悬架在车轮上跳行程朝正前束变化,整车趋于过度转向,且阿克曼偏差较大,转向过程中轮胎磨损较大的不良情况,根据悬架结构特点,利用其几何约束条件,分别对有无转向拉杆时的悬架运动学进行了分析,揭示了转向拉杆对车轮前束角与外倾角的影响量。通过转向梯形断开点位置对阿克曼特性和前束角的影响分析以及整车实际空间布局限制,建立了优化设计模型,在Matlab中进行了优化计算。优化结果避免了前束恶化现象,并减小了阿克曼偏差,从而提高了整车操纵稳定性,并减少了汽车转向过程中的轮胎磨损。

Analysis and Optimization of Macpherson Steering Suspension

Aiming at a car modified as SUV, the layout of the front Macpherson steering suspension system needs to be redesigned after raising the car body. As a result, the toe-in of front wheel changes towards a positive rate in the process of the wheel jounce, which causes the vehicle tends to over steer. And Ackerman deviation is large which makes severe tire wear in progress of turning around. According to the structure characteristics of Macpherson suspension mechanism, the kinematics of suspension is analyzed based on space geometry method when it has or not has the steering linkage. And the influences on the amount of toe-in and camber of steering linkage are found. The optimization model is set up based on the influences on toe-in of steering linkage and space limitation of splitting point, which is calculated with Matlab. After optimization, the toe-in deterioration is eliminated, and Ackerman deviation is effectively reduced. As a result, the handling and stability of the vehicle and tire wear are improved in progress of turning around.