单气室油气弹簧阻尼特性及其影响因素分析

针对某重型特种车辆平顺性研究中单气室油气弹簧阻尼特性的研究问题,基于薄壁小孔理论和范德瓦尔实际气体状态方程,同时根据单气室油气弹簧的结构特点和阻尼的组成建立了相应的阻尼力特性模型,并推导了阻尼系数方程。利用MATLAB软件进行仿真,研究了单气室油气弹簧阻尼特性以及激振频率、幅值、自身结构参数对阻尼系数速度特性的影响。研究结果表明:单气室油气弹簧阻尼特性具有较好的非线性,在压缩阶段的阻尼力较拉伸阶段的大,能够较好地缓解冲击,达到减振效果从而改善车辆行驶平顺性;激振频率和幅值属于外因,仅影响阻尼系数的取值范围,而对其取值及曲率几乎无影响;阻尼系数随活塞杆外径、油管直径的减小而增大,随油管长度的减小而减小。研究结果能对整车振动特性研究中阻尼参数的选取及油气弹簧阻尼特性设计优化等工作提供较为系统的理论支持。

Analysis on Damping Characteristics and Effect Factors of Single Chamber Hydro-pneumatic Spring

Mathematic models of hydro-pneumatic spring damping force are established and the damping coefficient equation is derived based on the thin-walled pore theory and Van der Wals state equation for real gas and its structure, to the problem of single chamber hydro-pneumatic spring damping characteristics for heavy special vehicle ride comfort. The damping feature and influence on damping velocity characteristics by structural parameters, excitation frequency and amplitude are simulated by MATLAB software. The results show that the single chamber hydro-pneumatic spring has good nonlinear feature. The damping force in compression stage is larger than that in stretching stage, and it can alleviate shocks and improve vehicle ride comfort obviously. The damping coefficient increases as piston rod and tube diameter decreasing and decreases as tube length decreasing. It almost has no effect with excitation frequency and amplitude. The results could provide reference for damping coefficient selection in vehicle vibration study and optimum design for hydro-pneumatic spring damping feature.