PURPOSE: To provide a smooth change in the water flow rate even when a valve is opened/closed at a relatively high speed.
CONSTITUTION: A fixed side valve element 4 of a disk type valve and a movable side valve element 5 are arranged in a flow passage between a fluid inlet port 2 and a fluid discharge port 3 in a valve body 1, and the movable side valve element 5 is overlapped the fixed valve element 4 in a slidable manner. An opening part 14 is provided, which is mutually overlapped the fixed side valve element 4 and the movable side valve element 5 when the opening part is opened, while which is not overlapped these valves when the opening part is closed. A driving shaft 6 connected to the movable side valve element 5 is interlocked with a motor 7. A semi-recessed part is continuously provided on at least either of the fixed side valve element 4 and the movable side valve element 5 in the circumferential direction from the end part of the opening part 14 on the overlapped surface side. This constitution allows the gradual increase of the flow rate through communication with the semi-recessed part when the movable side valve element 5 is rotated and opened.
NAGAI MASATO
HIBINO MINORU
