先导式电液比例阀的特性研究

Study on characteristics of pilot-operated electro-hydraulic proportional valve

液压阀是控制液流的压力、流量和方向的控制元件。目前在液压领域的流量控制阀主要原理是采用阀芯运动改变节流面积进而改变流量的。基于先导式溢流阀的原理,设计一款先导阀芯与主阀芯同轴配合的液压阀,提出基于CFD仿真的液压阀流量性能控制设计方法,比较主阀芯的结构形式。建立基于先导式电液比例阀结构的数学模型,并利用MATLAB进行建模仿真分析。为验证阀的动、静态流量性能,建立MATLAB模型,确定阀芯的面积—位移特性实现比例流量控制,并在试验台进行试验,验证其静态和动态流量性能。结果显示,采用矩形空心缓冲头阀芯具有良好的小流量比例特性,电液比例阀电压与流量的曲线线性度系数为0.983,流量的动态阶跃效应超调量为7%,调整时间为0.02 s。

A hydraulic valve is a control element that controls the pressure,flow,and direction of the fluid flow.At present,the main principle of the flow control valve in the hydraulic field is to change the throttling area and then change the flow using the spool movement.Based on the principle of a pilot relief valve,a hydraulic valve with a coaxial pilot spool and main spool was designed.The design method of flow performance control for the hydraulic valve based on CFD simulation was proposed,and different structures of the main spool were compared.A mathematical model based on the structure of the pilot electro-hydraulic proportional valve was established and simulated with MATLAB.In order to verify the dynamic and static flow performance of the valve,a MATLAB model was established to determine the area-displacement characteristics of the valve core to achieve proportional flow control.Experiments were carried out on a test bench to verify the static and dynamic flow performance.The results show that the valve core with a rectangular hollow buffer head has good small flow ratio characteristics.The curve linearity coefficient between voltage and flow of the electro-hydraulic proportional valve was 0.983,the dynamic step effect overshoot of flow was 7%,and the adjustment time was 0.02 s.