| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a composite valve which can satisfy both of improvement in control accuracy of a small flow rate area and increase in a controllable flow rate (reduction in pressure loss), and can prevent a second valve element from being opened undesirably. <P>SOLUTION: The composite valve includes a communication passage 29 which connects a first valve chamber 11 with a second valve chamber 21, a second valve port 23 which connects the second valve chamber 21 with an outlet 6, and a pilot passage 19 which connects a back pressure chamber 16 with the outlet 6, and is configured to assume a small flow rate control state in which the pilot passage 19 is closed by a pilot valve element 20 and a first valve port 13 is closed by a first valve element 15 for large flow rate control to control the flow rate according to a lift amount of a second valve element 24, if the lift amount of the second valve element 24 for small flow rate control is a predetermined amount Tc or below, and to assume a large flow rate control state in which the pilot valve element 20 is raised with the rise of a valve shaft 25 and the pilot passage 19 is opened to thus cause the first valve element 15 to open the first valve port 13, if the lift amount of the second valve element 24 exceeds the predetermined amount Tc. <P>COPYRIGHT: (C)2013,JPO&INPIT |
