The Basic Characteristics Of The Piezoelectric Vibrator Flow Digital Control Components

The traditional pneumatic proportional valve adopts proportional solenoid as itsactuator. It has many disadvantages, such as slow response, narrow work bandwidth, nothigh enough control precision and so on. Therefore the control characteristic of the valvecan not satisfy with the automatic production which requires of precision, rapid andstable. Because of its advantages of fast response, wide working frequency, easy tocontrol etc, the piezoelectric actuator is used for pneumatic proportional valve more andmore. But if using the piezoelectric material directly driving the valve core of pneumaticproportional valve, the open area of the valve is very small, and it is difficult to directlycontrol the flow of a valve port. So it is very necessary to develop a new digital flowcontrol device, which can amplify the micro-displacement of piezoelectric actuator tonormal opening for digital flow control and apply to pneumatic proportional valve.The principe of using the piezoelectric actuator driving the pall move upcast is usedin this thesis, which used to explore a new type piezoelectric oscillator digital flowcontrol component for pneumatic proportional valve. The research contents includefollowing aspects:(1) To solve the problem of small deformation displacement of thepiezoelectric ceramic and can not export large flow of the valve, a new type piezoelectricoscillator digital flow control component is designed, which base on the principe of thepiezoelectric ceramics driving the ball move upcast. The component includes someadvantages such as large displacement, small size, fast response and so on.(2) For anin-depth analysis and control of the upcast process, a model between the piezoelectricceramics and the pall is established, and the system parameters on the impact of testresults is analyzed by simulation, which lay a foundation for determining the mainparameters of the test.(3) In order to study the upcast motion performance of the smallball in the air, the upcast motion of ball is tested from three different factors including theball's diameter, the frequency and amplitude of the voltage, and the stimulation signal.The test results show that the ball's diameter and the voltage frequency are main factorsthat affecting the upcast displacement of the small ball in the air.(4)In the interest of studythe upcast motion performance of the ball under pressure gas, the ball is tested from threedifferent factors as the ball's diameter, the pressure difference, and the voltage frequency.It is observed from theory and test that pressure difference is the key factor of causinghall's smaller displacement. It shows that the new type piezoelectric oscillator digital flow control componentsreach a basic goal of the digital control. Take the 9mm in diameter of the ball as anexample, when pressure difference is 0.1Mpa, the ball's upcast displacement can reach80μm. When pressure difference is 0.2Mpa,the ball's upcast displacement can reach40μm. So this component can meet the displacement requirements of valve core. And itlays the foundation for further study on a new piezoelectric proportional valve. Thisshows that the new component have very good prospects for development and applicablevalue in engineering.