比例方向阀静态特性仿真与实验

Static Simulation and Experimentation of Proportional Directional Valves

比例方向阀是电液控制技术中最基础的元件之一,其作用是对液压执行机构的速度、方向、位置和输出力进行连续控制。在比例方向阀使用过程中,发现电压指令相同时,当比例方向阀阀口的压差较大时,随着压差的增加,流量出现了不增反减的现象。为了解释该现象,建立两种比例方向阀的静态仿真模型:第一种静态仿真模型基于液动力和阀口流量的经验公式;第二种静态仿真模型基于通过ANSYS Fluent流场数值计算得到的液动力和阀口流量插值公式。静态仿真结果表明:阀口流量不增反减的原因在于当压差增大时,液动力增加导致阀芯位移减小,进而使流量减小。实验结果证明:相比传统的经验公式,使用基于流场仿真数据得出的稳态液动力和阀口流量插值公式时,静态仿真结果更接近实验结果。

The proportional directional valve is a fundamental component in electro-hydraulic control technology.Its function is to provide continuous control to the speed,direction,position,and output force of hydraulic actuators.During the operation of the proportional directional valve,it is observed that when the voltage command remains constant,an interesting phenomenon occurs:as the differential pressure at the valve port increases,the flow rate does not increase but rather decreases.In order to explain this phenomenon,two static simulation models for the proportional directional valve was developed.The first static simulation model was based on an empirical equation of the flow force and the flow rate at the valve port.The second static simulation model was based on the interpolated equations for the flow force and the orifice flow obtained through numerical calculations of the ANSYS Fluent flow field.The static simulation results show that the orifice flow rate decreases rather than increases because when the differential pressure increases,the increase in flow force leads to a decrease in spool displacement,which in turn leads to a decrease in flow rate.Experimental findings demonstrate that utilizing the derived interpolation formulas based on flow field simulation data for steady-state flow force and orifice flow yields static simulation results is closer to experimental data when compared to traditional empirical formulas.