| 摘要 |
PROBLEM TO BE SOLVED: To attain the miniaturization of a product and the higher accuracy of product characteristics by reducing sliding resistance generated accompanied by the reciprocation of a pressure control shaft. SOLUTION: The pressure reducing valve 1 used for water supply piping comprises the pressure control shaft 16 which reciprocates by being connected with a pressure control diaphragm 14 operating for determining an equilibrium point between outflow secondary pressure P<SB>2</SB>and the spring force of a pressure control spring 15 arranged so as to cope with the secondary pressure, thereby approaching and separating a valve element 20 to and from a valve seat 21 in which the secondary pressure P<SB>2</SB>acts on the shaft 16 as back pressure. The shaft 16 is slidably supported by a holder 22, and the holder 22 is retained by a valve case 2 in a floating state. An inside seal 32 provided between the shaft 16 and the holder 22 for preventing the inflow primary pressure P<SB>1</SB>to a back pressure chamber 26 is fitted to a mounting groove 33 formed on the inner circumferential surface of the holder 11 while closely contacting with the outer circumferential surface of the shaft 16 so as to be slidable. COPYRIGHT: (C)2007,JPO&INPIT
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