某车液压助力转向系统动态特性的仿真

Simulation of Dynamic Characteristic of a Hydraulic Power Steering System

为了分析某车齿轮齿条式液压助力转向系统的动态特性,建立了液压系统转向控制阀、转向液压缸及其他主要元件的数学模型。采用SIMULINK对该系统进行分析,仿真模型以前轮受到交变载荷时产生的偏转角为输入,以转向液压缸输出力为输出。仿真结果表明,当转角频率不变时,液压缸输出力随前轮转角幅值增大而增大;当转角幅值不变时,液压缸输出力随前轮转角频率增大而增大。最后,为了改善液压助力转向系统的动态特性,分析了扭杆刚度、转向液压缸负载质量和液压系统的液体体积弹性模量对液压缸输出力的影响。

Aiming at researching the dynamic characteristics of a rack-and-pinion hydraulic power steering system,the mathematical models of the hydraulic system are established,which included conversion valve,steering hydraulic cylinder and other components.The dynamic characteristics of the system are simulated by using SIMULINK.The deflection angle emerged by the fluctuating load is taken as the input of the system,and the force of steering hydraulic cylinder is taken as the output.The results show that,the force of steering hydraulic cylinder increased when amplitude of deflection angle increased,and the force of steering hydraulic cylinder increased when frequency of deflection angle increased.In order to improve the dynamic characteristics of the hydraulic power steering system,torsion bar stiffness,the load mass and the effective fluid volumetric modulus of elasticity are analyzed.