PIEZOELECTRIC ELEMENT-DRIVEN CONTROL VALVE

摘要

A piezoelectric element-driven control valve in which tensile force acting on a piezoelectric element when a piezoelectric actuator (16) contracts is reduced to enable the valve to perform stable flow rate control even in a high-temperature environment. The piezoelectric element-driven control valve (1) has a body (8) with a valve seat (8d), a metal diaphragm (9) in contact with and separating from the valve seat (8d), an actuator box (13) supported on the body (8) side so as to be movable up and down, a split base (11) fixed to the body (8) side, a coned disc spring (15) for pressing and urging the actuator box (13) downward and causing the metal diaphragm (9) to be seated on the valve seat (8d), and the piezoelectric actuator (16) received in the actuator box (13) and extending upward by being subjected to a voltage, pushing up the actuator box (13) against elastic force of the coned disc spring (15). A preload mechanism (20) for constantly applying compression force to the piezoelectric element of the piezoelectric actuator (16) is placed between the split base (11) and the piezoelectric actuator (16).