Study On The Motion Characteristics Of The Spool In Hydraulic Operated Valve

The motion of hydraulic operated spool determined open area'changement of the dominant valve, finally determined the motion characteristics of hydraulic cylinder. A test rig was designed and established to measure the motion of the spool in the hydraulic operated multi-way valve and flow amplifier valve. The signals of the spool displacement, the pilot operated pressures on the ends of the spool, the pressures in the valve ports and the cylinder displacement were obtained, The characteristic values such as the opening and closing time of the valve orifices, maximum velocity and acceleration of the spool were drawn. Established simulation platform for valve control cylinder in software of AMESim, and contrast main characteristic values with measurements, inosculated well. This study has universal significance for deeply understanding hydraulic operated spool'control characteristics, open area'design and system matching.The main content of this thesis:In chapter 1, the background and significance of this thesis is presented,the current and future research progress on the hydraulic operated multi-way valve are expatiated.In chapter 2, the inner flow field and orifice of the hydraulic operated multi-way valve is analyzed. Obtained orifice pressure loss characteristics, pressure and velocity distribution, the place of the orifice, provide foundation for open area calculation. And calculated the hydraulic operated multi-way valve'open area, obtained open area'curve.In chapter 3, A test rig was designed and established to measure the motion of the spool in the hydraulic operated multi-way valve. The signals of the spool displacement, the pilot operated pressures on the ends of the spool, the pressures in the valve ports and the cylinder displacement were obtained. Established valve control cylinder simulation model in software of AMESim, and contrast main spool'motion process in simulation with measurements, inosculated well. Obtained main spool'motion under different main spool'characteristic values in the same AMESim simulation model. Simultaneously established pilot valve control main spool'simulation model in software of AMESim, Obtained main spool'motion under different pilot valve'characteristic values.In chapter 4, A test rig was designed and established to measure the motion of the spool in the flow amplifier valve. The signals of the spool displacement, the pilot operated pressures on the ends of the spool, the pressures in the valve ports and the cylinder displacement were obtained. In chapter 5,simulation research was implemented with the AMESim model built in chapter 3 to obtain the effection that the factors of velocity of the spool, asynchronous opening, gradient of the open area of neutral return oil port, gradient of the open area of return oil port on dynamic characteristics of the hydraulic system.At the end, some conclusions in this thesis are summarized and the future research proposals are suggested.