Simulation And Experimental Research Of Digital Servo Proportional Valve

Electro-hydraulic proportional valve is a core element in the electro-hydraulic controlsystem, and used in the hydraulic control system widely. Electric-machine conversioncomponent as a key element of electro-hydraulic proportional control components, itsperformance influences the performance of electro-hydraulic proportional control componentdirectly. Electric-machine conversion component of Traditional proportional valve isproportional solenoid, which has advantage of rugged construction, low cost, anddisadvantage of bad linearity, big hysteresis. Recently, with rapid development of electronictechnology and control theory, AC servo motor has been developed well, which has highcontrol precision, fast response. This paper adopts AC servo motor to replace proportionalsolenoid as e electric-machine conversion component of electro-hydraulic proportional valve,solves the problems of proportional solenoid.This paper use PMSM drives valve core to move, control valve orifice and the outputflow of valve. Analysis the characteristic of the different program of digital proportional valve,and complete the design. Analysis the different structure of valve core, valve body andthrottling groove, and complete the design. On basis of force analysis of valve core, designball screw, and check it.Set up steady state mathematic model of digital proportional valve. And set upmathematic model of servo drive system, mechanical transmission system, equation of motionof spool, and dynamic state mathematic model of digital proportional valve for the furthertheoretical research. Analyze steady and dynamic state characteristic of digital proportionalvalve using MATLAB.Under the same condition, the paper engaged in comparative experimental researchbetween servo motor droved proportional valve and traditional proportional valve. The resultdemonstrate that digital proportional valve has better linearity, less dead band and biggerlinear region, and wider speed range compare with traditional proportional valve, undercondition of same valve core and valve body.