Three-way change-over valve

摘要

An input port, an output port, and an exhaust port are opened on inside walls of a fluid chamber in a valve box. A valve body is provided which is capable of swing in the fluid chamber so as to change over the opening and closing of the input and exhaust ports. A controlling mechanism for the valve body is provided which is capable of swing toward the input port to close the input port. The valve body is capable of swing against the pressure of a fluid flowing in from the input port to close the exhaust port, allowing a pressurized fluid to flow out from the output port. For exhaust, the controlling mechanism forces the valve body to swing against the flow-in pressure of the fluid from the input port to close the input port and the pressurized fluid which has entered the output port side is discharged through the exhaust port.