| 摘要 |
PROBLEM TO BE SOLVED: To simplify a structure by dispensing with incorporation of a sealing means in a movable part, and to open/close a main valve body even at a large- capacity and high-pressure circuit at low torque by a small motor. SOLUTION: A main valve element 9 is provided in a valve chamber 5 position upstream of the main valve port 7 to open/close a main valve port by selectively seating on a valve seat part 6. The main valve element 9 is slidingly engaged with a cylinder hole 12 provided in a valve housing 3 to define a back- pressure chamber 14 in a backside, and a pilot port 16 is provided in the valve main body 10 to communicate the back-pressure chamber 14 with an outlet port 8. The pilot port 16 is opened/closed by the tip part 23 of a valve rod-like pilot valve body 20 connected to the main valve element 9 so as to be movable by a specified amount in a valve lift direction, the rotation of the rotor 30 of a stepping motor 26 is converted into the valve lift direction motion of the main valve element 9 by rotation-linear movement converting means (32, and 33), and the pilot valve main element 20 is moved in the valve lift direction of the main valve element 9.
|
