Pressure Regulator for Pneumatic Valve with a PZT Actuator

The pressure regulator which is used for controlling the reducing pressure in the piezoelectrically driven pneumatic valve has been studied. The pneumatic valve of this study object is 2-stage type and consists of a piezoelectric actuator, a controller, a poppet valve and a pressure regulator. Nominal flow of 50 1 pm, maximum operating pressure of 0.9 MPa and frequency characteristic of 10 Hz and over are required in this pneumatic valve, but the pressure regulator is needed because piezoelectric actuator has no ability to control the pressure of 0.9 MPa directly. In this study, bimorph type PZT actuator of 25.2 mm (L)times7.2 mm (W)times0.5 mm (H) with constant of -220 times10 ^-12 CN^-1 was proposed and investigated. Maximum operating force of 0.052 N and maximum displacement of 63 mum were gotten from the fabricated PZT actuator. From the analysis results, the orifice diameter of 0.6 mm for a piezoelectric actuator was derived and then the pressure regulator which can be operated under 0.15 MPa easily was designed and manufactured. Performance and effects of design parameters were simulated by the Simulink of Matlab software, and it was confirmed that the performance characteristics of manufactured pressure regulator are superior in the common use pressure range of 0.5 MPa to 0.7 MPa. The results show that the proposed pressure regulator is suitable for the pneumatic valve with a PZT actuator