摘要 |
PURPOSE:To improve stability and responsiveness, by a method wherein a dielectric plate, made of a material, in which a strain is produced by applying an electric field in the direction of thickness, is secured to a vibrating plate whose periphery is fixed, and a pneumatic pressure is applied to the vibrating plate through a nozzle. CONSTITUTION:An electric signal E1, detected by a detector 2 such as thermocouples, is inputted to an amplifier 27. A voltage E1, amplified to a given level by the amplifier 27, is inputted to an electrostriction device 28, a dielectric body 38 is strained in a direction of a radius corresponding to the signal E1 applied between electrodes 39 and 40 attached to the dielectric body 38, and this enables the vibrating plate 37 to be bent and displaced. A displacing distance of the vibrating plate 37 is devided by balancing a strain, proportioning a square of a voltage being applied to the dielectric body 38, with the spring constant of the vibrating plate. If the vibrating plate 37 is displaced, a change in a gap between the vibrating plate 37 and a nozzle 42 is produced, which results in causing a nozzle back pressure P1 to vary with aforesaid change. |