Smc Corporation

Seiichi Furutate

Tsuneo Ishigaki

Masao Kajitani

Kenji Waragai

In a gate valve having a rectangular gate, generation of flection at opposite end portions due to bending moment applied to the gate is suppressed easily. For this purpose, in the gate valve in which a central portion of a longer side of the rectangular gate is mounted to a tip end of a shaft operated by driving of a cylinder device and the gate is pressed against a valve seat provided around a rectangular valve opening by tilting the shaft after the gate is moved to a position facing the valve opening by movement of the shaft by driving of the cylinder device, the gate is formed to have an uneven wall thickness including a large thickness in a vicinity of a fulcrum portion connected to the shaft and a small thickness on each of opposite end portion sides.

Gate valve

A main valve mechanism for opening and closing a main flow path between a first port and a second port has a main valve body, a large-diameter first piston for opening the main valve body, a main pressure operating chamber for driving the first piston, and first spring means for closing the first piston. An auxiliary valve mechanism for opening and closing an auxiliary flow path has an auxiliary valve body, a small-diameter second piston for opening the auxiliary valve body, an auxiliary pressure operating chamber for driving the second piston, and second spring means for closing the second piston. The main pressure operating chamber and the auxiliary pressure operating chamber are connected to each other through a connecting hole. There are such relationships between piston diameters of both the pistons and repulsing forces of both the spring means that the second piston is actuated by lower fluid pressure than the first piston.

Growing community of inventors

Tsukuba-gun, Japan

Seiichi Furutate