VALVE GEAR

To provide an improved constant-pressure valve which can achieve low costs.SOLUTION: A constant-pressure valve 1 includes: a case 8 including a pressure detection chamber PD, through which a refrigerant passes, and a pressure operation chamber PO, in which a gas is enclosed, therein; a flexible diaphragm 7 which partitions the pressure detection chamber PD from the pressure operation chamber PO in the case 8; a cylindrical shaft 62 which includes a valve body 62c and moves in response to displacement of the diaphragm 7; a valve body 2 including an orifice part 20e through which the refrigerant passes and joined to the case 8; and a coil spring 3 which biases the valve body 62c to the orifice part 20e. The valve body 62c moves close to the orifice part 20e to restrict the orifice part 20e from opening. The cylindrical shaft 62 is inserted into the orifice part 20e and its one end is plastically deformed.SELECTED DRAWING: Figure 1 【課題】低コストを実現できる、改良された定圧弁を提供する。【解決手段】定圧弁１は、冷媒が通過する圧力検出室ＰＤと、ガスが封入された圧力作動室ＰＯとを内部に備えたケース８と、ケース８内において、圧力検出室ＰＤと圧力作動室ＰＯとを仕切る可撓性のダイアフラム７と、弁体６２ｃを備え、ダイアフラム７の変位に応じて移動する円筒軸６２と、冷媒が通過するオリフィス部２０ｅを備え、ケース８に接合された弁本体２と、弁体６２ｃをオリフィス部２０ｅに向かって付勢するコイルばね３と、を有し、オリフィス部２０ｅに弁体６２ｃが接近することにより、オリフィス部２０ｅの開口制限がなされ、円筒軸６２は、オリフィス部２０ｅ内に挿通され、一端が塑性変形されている。【選択図】図１