US 6,981,688 B2
Flow control device
Seiichiro Noritake, Nagano (Japan); and Ryuhei Wada, Nagano (Japan)
Assigned to Sankyo Seiki Mfg. Co., Ltd., Nagano (Japan)
Filed on Feb. 19, 2004, as Appl. No. 10/782,384.
Claims priority of application No. 2003-042060 (JP), filed on Feb. 20, 2003.
Prior Publication US 2004/0200986 A1, Oct. 14, 2004
Int. Cl. F16K 31/04 (2006.01)
U.S. Cl. 251—122 17 Claims
OG exemplary drawing
 
1. A flow control device comprising:
an opening part through which an upstream side of a fluid flow passage is in communication with a downstream side of the fluid flow passage;
a valve element for closing the opening part, the valve element comprising:
a large flow rate controlling valve element capable of adjusting an opening degree of the opening part;
a sealing member provided with a valve hole having an open area smaller than the opening part and formed to be capable of being brought into tight contact with a peripheral wall part of the opening part; and
a small flow rate controlling valve element capable of adjusting an opening degree of the valve hole; and
a valve drive device which rotates to drive the valve element in a closed direction for closing the opening part or in an opened direction for opening the opening part,
wherein the small flow rate controlling valve element is a rod-shaped valve element formed so as to extend in a driving direction of the valve element,
wherein a front end portion of the rod-shaped valve element in the driving direction of the valve element is fixed to the large flow rate controlling valve element with a diameter larger than that of the valve hole of the sealing member,
wherein the sealing member is mounted to the rod-shaped valve element so as to be capable of forming a small flow rate state through a space between an outer face of the rod-shaped valve element and an inner face of the valve hole of the sealing member and a subsequent space between the sealing member and the large flow rate controlling valve element, and
wherein the space between the outer face of the rod-shaped valve element and the inner face of the valve hole of the sealing member is closed according to a further movement of the rod-shaped valve element in the driving direction of the valve element.