关键词: 电液阀, 功率键合图, 一阶灵敏度, 自激振荡, 结构优化

Abstract: In order to study the influences of load port independent electro-hydraulic valve system parameters on the main valve fretting characteristics, a state space equation of electro-hydraulic valve systems was established based on the power bond graph theory, and the first-order sensitivity method was used to analyze the influences of system parameters on the main valve fretting characteristics. The pilot structure parameters of the feedback control systems were very important to the movement characteristics of the main valve, the dead zone width of the pilot stage, the form of the valve port and the matching coefficient of the inlet and return oil valve port were studied under the constraint conditions of no self-excited oscillation and the best damping ratio, the best match between the lead stage and the main stage was achieved. The results show that the main valve fretting characteristics are greatly affected by the friction force of the main valve core, the liquid capacity of the non-spring control chamber, the liquid capacity of the pipeline from the pilot valve inlet to the main valve control chamber(non-spring side) and the preload force of the main valve spring. While optimizing the above influencing parameters, the dead zone width of the pilot valve δ≤0.25 mm, the U-shaped valve port, and the matching coefficient of the inlet and return oil valve ports η=0.53, the overall performance of the system is effectively improved.

Key words: electro-hydraulic valve, power bond graph, first-order sensitivity, self-excited oscillation, structure optimization