PILOT VALVE USING PIEZOELECTRIC ACTUATOR

摘要

A pilot valve using a piezoelectric actuator is provided to control flow in proportional by switching a channel between chambers by using a characteristic of a piezoelectric actuator of which displacement is changed in linearly proportional to an amount of applied voltage. A pilot valve using a piezoelectric actuator(200) includes a valve body(110) and a poppet(120). The valve body includes a fluid inlet(111), a fluid outlet(112), a first chamber(130) connected to the fluid inlet, a second chamber(140) connected to the fluid inlet, the first chamber, and the fluid outlet, and a third chamber(150) connected to the first chamber and the fluid outlet. The piezoelectric actuator includes at least two piezoelectric materials arranged in parallel and a sealing pad between the first and second chambers to switch the channel. The piezoelectric actuator is operated to open a channel between the first and third chambers according to the deformation of at least two piezoelectric materials when voltage is applied. The poppet is arranged between the first and second chambers. The poppet seals between the second chamber and the fluid inlet by the pressure of fluid inside of the first chamber when the voltage is not applied to the piezoelectric actuator and opens between the fluid inlet and the second chamber when the voltage is applied to the piezoelectric actuator. A control unit(160) controls an opening degree of the piezoelectric actuator by controlling the voltage applied to the piezoelectric actuator.