Research On High Pressure And Large Flow Water Pressure Control Valve Driven By Servo Motor And Its Control System

Pressure control valve is an important component in hydraulic system of hydroforming process.The system pressure and maximum flow rate determined by pressure control valve directly affect the dimension,efficiency and quality of manufacturing parts.The hydroforming process replaces rigid dies with liquid as force transfer medium.Water as working medium has the advantages of low cost,environment friendly and high safety.However,at present,water hydraulic components are vulnerable to cavitation damage and pressure control is unstable.Large flow hydraulic control valves are still blank in the domestic market.This article takes a high pressure and large flow hydraulic control valve as the research object and mainly solves the above two shortcomings.In the aspect of structure design,the main body,transmission mechanism and other subsidiary structures of the valve are designed,and the prototype machine of the hydraulic control valve is manufactured.The groove structure is designed on the upper part of the poppet throttle to reduce cavitation damage.The rationality of the spool structure design is verified by CFD analysis tool.In order to solve the problems of pressure fluctuation and small pressure regulation range of general large flow hydraulic control valves due to the use of pilot valves,servo motors are used to drive the valve directly.The purpose is to obtain higher pressure control accuracy and pressure stability through closed-loop control system with the help of the characteristics of high-speed response of servo motors.Through mathematical modeling and simulation analysis of each part of the system,the simulation is divided into position control simulation and pressure control.In position control,attention should be paid to the non-overshoot characteristic and anti-disturbance ability of spool position control.In pressure control,the response characteristics of the system under different flow loads are mainly studied,and the pressure response under different flow rates is consistent through gain compensation.The experimental platform for the hydraulic control valve is built,including the hardware platform and the control software design.The response characteristics of the opening of the hydraulic control valve are analyzed experimentally.The experimental results are in good agreement with the simulation results.