Patent ID: 8657257
Filing Date: 2014-02-25
Classification: F16K

Abstract:
1. A gate valve comprising: a valve box having a communicating hole communicating with a processing chamber; a valve plate mounted on a valve plate mounting portion at a tip end of a valve rod and accommodated in the valve box, the valve plate being configured to open and close the communicating hole by bringing a seal member into and out of contact with a periphery of the communicating hole; a valve rod configured to displace the valve plate to a position to open and close the communicating hole; a coupling plate coupling the valve plate and the valve rod; an opening formed on the valve box for taking out the valve plate; and a detachable lid member configured to cover the opening, wherein the valve plate includes a mounting hole which allows insertion of the valve plate mounting portion of the valve rod, and joint flat surfaces of the valve plate and the valve rod which are brought into press-contact with each other when coupling the valve plate and the valve rod with the coupling plate, are formed on a hole surface of the mounting hole and an outer surface of the valve plate mounting portion respectively, the valve rod includes a depressed-shaped joint shoulder portion which allows fitting of a base-side end portion of the valve plate at a position on a base side of the valve plate mounting portion, the joint shoulder portion is formed with an inclined surface which allows abutment of a base-end-side end portion of the valve plate, the inclined surface displaces the valve plate in the direction in which the joint flat surfaces of the valve plate and the valve rod are brought into press-contact with each other by a wedge effect, and the coupling plate couples the valve plate and the valve rod with each other in a state in which the valve plate is pressed toward a base end side of the valve plate mounting portion.