| 摘要 |
PURPOSE:To reduce the production steps of a flow control valve, and to make it possible to assemble it in one direction, by integrally moulding a valve seat with a casing by casting, and by welding the bearing part for a valve rod and the bottom plate of a valve chamber which are made of resin, to the casing. CONSTITUTION:A flow control valve is composed of a cylindrical casing 1 having a valve seat 1a, a lid plate 9 attached to the casing 1 and serving as a bearing part for a valve rod 5a, two upper and lower chamber 6, 7 defined by a bottom plate 19, a valve element 5 opened and closed by a diaphragm 12 to selectively communicate between both valve chambers 6, 7, and a cover 2 defining a vacuum chamber 11 in copperation of the diaphragm 12. In this arrangement, the valve seat 1a is fabricated by casting, integrally with the casing 1. Further, the lid plate 9 and the bottom plate 19 are made of resin and are welded to the casing 1. With this arrangement the production steps of the flow control valve may be reduced, and it is possible to assemble the flow control valve in one direction, thereby it may be manufactured at a low cost. |
