Valve device

Abstract

[Problem] To provide a valve device in which valve opening time and valve closing time are adjustable to be close to each other. [Solution] The valve device comprises: a valve body defining a flow path; a diaphragm 4 as a valve element for opening and closing the flow path; a stem 7 for making the diaphragm 4 separate and seat on a valve seat 3; a coil spring 15 as a spring member for constantly biasing the stem 7 in a valve-closing direction; a piston 30,36 connected to the stem 7; and an actuator body 20 for slidably accommodating the piston 30,36, wherein the inside of the actuator body 20 is partitioned by the piston 30,36 into a pressure chamber 31,37 to which a driving gas DG is supplied and an atmospheric chamber 32,38 communicating with the atmosphere via vent holes 21a, 21b formed in the actuator body 20, and the actuator body 20 includes an adjustment mechanism 50 capable of restricting the ventilation amounts of the vent holes 21a, 21b so as to adjust a valve closing time required for valve closing and a valve opening time required for valve opening to be equal to each other.

Dependencies are inferred from the claim text.