Abstract: A nozzle flapper mechanism includes an electrostrictive device, a plate member coupled to the electrostrictive device, a nozzle having an orifice facing the electrostrictive device or the plate member, and a controller for applying a voltage to the electrostrictive device to keep a nozzle back pressure constant or vary the nozzle back pressure. The electrostrictive device comprises a shim, piezoelectric ceramics members disposed on the shim, and thin-film electrodes disposed on the piezoelectric ceramics members, the electrodes having an area smaller than that of the piezoelectric ceramics members, the piezoelectric ceramics members having one end directly fixed in position on a stationary member.

Abstract: A nozzle flapper mechanism includes an electrostrictive device, a plate member coupled to the electrostrictive device, a nozzle having an orifice facing the electrostrictive device or the plate member, and a controller for applying a voltage to the electrostrictive device to keep a nozzle back pressure constant or vary the nozzle back pressure. The electrostrictive device comprises a shim, piezoelectric ceramics members disposed on the shim, and thin-film electrodes disposed on the piezoelectric ceramics members, the electrodes having an area smaller than that of the piezoelectric ceramics members, the piezoelectric ceramics members having one end directly fixed in position on a stationary member.

Abstract: A nozzle flapper mechanism includes an electrostrictive device, a plate member coupled to the electrostrictive device, a nozzle having an orifice facing the electrostrictive device or the plate member, and a controller for applying a voltage to the electrostrictive device to keep a nozzle back pressure constant or vary the nozzle back pressure. The electrostrictive device comprises a shim, piezoelectric ceramics members disposed on the shim, and thin-film electrodes disposed on the piezoelectric ceramics members, the electrodes having an area smaller than that of the piezoelectric ceramics members, the piezoelectric ceramics members having one end directly fixed in position on a stationary member.

Abstract: An electropneumatic transducer for converting an electric signal to a pneumatic pressure has a nozzle flapper mechanism and a pilot valve engaging a diaphragm assembly. The nozzle flapper mechanism has a nozzle flapper composed of an electrostrictive element. The diaphragm assembly comprises two diaphragms having different effective areas. A nozzle back pressure is applied to one of the diaphragms, and an atmospheric pressure is applied to the other diaphragm. A supplied pressure or output pressure is applied between the two diaphragms. The nozzle back pressure is varied dependent on the voltage applied to the electrostrictive element for moving the diaphragms to enable the pilot valve to control a valve disposed in a passage connecting supply and output ports.

Abstract: A fluid regulator including, in a housing, a nozzle flapper mechanism, a diaphragm displaceable by the nozzle back pressure of the nozzle flapper mechanism, a valve body for controlling fluid communication through a fluid passage in accordance with displacement of the diaphragm, and a sensor for picking up a change in output fluid pressure from the fluid passage as a change in an electric signal. The nozzle flapper mechanism includes an electrostrictive element positioned closely to the nozzle of the nozzle flapper mechanism. Displacement of the electrostrictive element with respect to the nozzle is controlled by a differential signal resulting from comparison between an electric input signal and an electric signal from the sensor. The nozzle back pressure is varied dependent on the displacement of the electrostrictive element for thereby displacing a valve body in the fluid passage until the valve body is brought into equilibrium.