Study On A New Type Of Pneumatic Valve Based On Piezoelectric Stacks

In this dissertation, a new kind of valve based on piezoelectric stacks was proposed, and a theoretical and experimental research was performed.In Chapter one, the research aim and significance of piezoelectric valve was generalized, and the advantage over the traditional electromagnetic valve was analyzed. The up-to-date research status and existing problems were introduced, and the research task in this dissertation was determined.In Chapter two, the theoretical analysis of the principle and character of the piezoelectric actuator was performed. The fatigue phenomenon and hysteresis character of the piezoelectric actuator were discussed. The static and dynamic characters of the piezoelectric actuator was tested by experimentsIn Chapter three, based on the requirement of driving power supply of the piezoelectric actuator, a piezoelectric driving power supply was designed using amplifying principle, and its property was obtained by experiments. The experimental results show the linearity of the driving power supply is less than <1.1%, and the responding frequency can reach 10kHz in case of no load.In Chapter four, ,a nozzle flapper valve based on piezoelectric stacks was designed. The flexure hinge flapper was designed and dynamic analysis was performed, and the maximum flux was evaluated. the natural frequency of the flexure hinge flapper is studied by finite element.In Chapter five, a piezoelectric pneumatic valve was designed, and its property was tested by experiments. The results show that the responding time is about 10ms, and the permissible working pressure is more than 6bar, and the maximum output flux exceeds 37L/min when the working pressure is 3 atmosphere pressure. Therefore, the designing aim of high pressure, large flux and fast response is utilized.In Chapter six, the main work of in this dissertation is generalized, and the further work is proposed.