汽车囊式空气弹簧变刚度特性拟合分析

Fitting Analysis on Stiffness Variation Property for Bellows Type Air Spring of Vehicles

空气弹簧的变刚度特性对悬架系统动力学研究有着重要影响,而制造商所提供的空气弹簧实验特性曲线图并不能完全反映这一特性。结合理想气体状态方程确立了空气弹簧刚度与形变量的多项式方程。通过有限元仿真得到空气弹簧动态特性曲线并进行弹簧刚度的多项式拟合,在确定悬架动力学仿真模型的基础上,研究了定压条件下,不同初始高度(初始负载)对空气弹簧变刚度特性曲线的影响,并将理论刚度变化曲线与仿真刚度变化曲线进行比对,得出实际空气弹簧承载刚度值比理论工况下大,实际刚度变化曲线不等于理论公式中依照形变量偏移后的刚度曲线这一结论。

The stiffness variation of air spring has a great impact on the analysis and dynamic modeling of vehicle suspension system, while the experimental characteristics curve of the air spring provided by the manufacturer can not reflect its property. The state equation of ideal gas was used to establish the polynomial equation for the spring stiffness and deformations. The dynamic characteristics curve of air spring was obtained by finite element simulation and the stiffness property was fitted with polynomial. Based on the simulation models of suspension dynamics, the effect of different initial spring height on the stiffness variation property curve of air spring was studied in the condi tion of constant pressure. The theoretical stiffness curve was compared with the simulated one. The results show that the stiffness values of loaded air spring in actual conditions are larger than the theoretical values and the actual stiff ness variation curve is not to the same as the curve shifted by the deformation in the theoretical formulation.