液压溢流阀的失稳分析和实验研究

Instability analysis and experimental study of a hydraulic relief valve

分析了液压回路中溢流阀的结构特点,考虑液压油压缩性、管道弹性和阀芯碰撞阀座时的能量损失,建立了溢流阀量纲一形式的数学模型,并进行了Lyapunov指数分析,目的是研究溢流阀的失稳机理和颤振行为.应用非光滑动态系统理论和MATLAB软件绘制单参数和双参数分岔图,理论解释了阀芯离开阀座时的擦边分岔.结果表明,溢流阀入口流量和预设压力直接决定着阀的振荡特性,并且存在着Hopf分岔、擦边分岔、周期和混沌等现象.搭建了测试平台,得到弹簧预压缩量x0=5 mm情况下的阀芯位移分岔图,对数学模型进行了验证.

The structure characteristic of a pressure relief valve embedded within a hydraulic circuit was analyzed. A nondimensional mathematical model was constructed by considering fluid compressibility,tube elasticity and energy loss when the valve poppet impacts its seat. Lyapunov exponent analyses were carried out. The aim is to capture the instability mechanism and chatter behavior of the relief valve. The non-smooth dynamical system theory and software MATLAB were used to draw one-parameter and two-parameter bifurcation diagrams. Grazing bifurcation which occurs at the poppet departure from the seat was explained. The results show that the flow rate into the valve and the setting pressure directly determine oscillation characters,and Hopf bifurcation,grazing bifurcation,periodic and chaotic phenomena appear. The measured bifurcation diagram at the spring pre-compression value x0= 5 mm was presented.The mathematical model of the relief valve was verified on a test platform.