| 摘要 |
PROBLEM TO BE SOLVED: To provide a suck-back valve having a suck valve function in an opening/closing valve. SOLUTION: In this suck-back valve SV, a piston 31 and a valve element 11 are connected via a shaft 50, and the opening/closing valve 10 performing the opening/closing operation of the valve element 11 by fluid pressure has the suck back function. A part between a suck-back chamber 17 formed in a valve inside flow passage of the opening/closing valve 10 and an actuator 30 for operating the piston 31 is separated by a diaphragm 60 integrally operating by being connected to the shaft 50. The shaft 50 is divided into a valve element side shaft and a piston side shaft. Independent operation in the axial direction is permitted by loosely fitting the piston side shaft to the valve element side shaft. When closing the operation of the valve element 11, the two-stage operation of a valve closing operation stage of moving the shaft 50 to a full closure position of the valve element 11 together with the piston 31 and the diaphragm 60 and a suck-back operation stage of increasing a space volume of the suck-back chamber 17 by moving the piston side shaft together with the piston 31 and the diaphragm 60 is performed. COPYRIGHT: (C)2009,JPO&INPIT
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