JP2008064301A5 - - Google Patents

Claims (12)

A pilot-type control valve that opens and closes a pilot valve body by an electric motor and opens and closes a main valve port in response to the pilot valve body,
The main valve body is a piston type with an inverted convex cross section having a large diameter portion and a small diameter portion, and the main valve body is opened so as to follow the movement of the pilot valve body in the valve opening direction. A pilot-type control valve which is adapted to move in a valve direction. A pilot type control valve having a main valve and an electric pilot valve,
The main valve includes a valve body in which a valve chamber into which fluid is introduced and led is formed, and a large-diameter portion that is slidably inserted into the valve body and opens and closes a main valve port provided in the valve body. And a piston-type main valve body having a reverse-convex section having a small-diameter portion,
The motor-operated pilot valve is mounted so as to close an upper surface opening of the valve body and defines a back pressure chamber between the main valve body and a pilot valve provided in the main valve body A pilot valve body for opening and closing the mouth,
The main valve is provided with a pressure equalizing passage communicating the valve chamber and the back pressure chamber, the main valve body is always urged in a valve opening direction by a compression coil spring, and the pilot A pilot-type control valve, wherein the main valve body is moved in the valve opening direction so as to follow the movement of the valve body in the valve opening direction. The pilot-type control valve according to claim 2, wherein a seal member is disposed between a large diameter portion of the main valve body and a valve body inner wall into which the main valve body is inserted. The pilot type control according to any one of claims 1 to 3, wherein an outer diameter of a large diameter portion of the main valve body is 1.5 to 3 times a diameter of the main valve port. valve. 5. The pilot valve body and the main valve body are moved together in the valve opening direction with the opening degree of the electric pilot valve maintained substantially constant . The pilot type control valve according to any one of the above. The electric pilot valve includes a can, a rotor disposed on the inner periphery of the can, a stator externally mounted on the can to rotationally drive the rotor, and between the rotor and the pilot valve body. The pilot type according to any one of claims 2 to 5 , further comprising: a drive mechanism that is arranged and moves the pilot valve body in an axial direction by using rotation of the rotor. Control valve. The pilot type control valve according to claim 6 , wherein an outer diameter of the large-diameter portion of the main valve body is larger than an outer diameter of the rotor. The pilot type control valve according to any one of claims 2 to 7 , wherein a diameter of the main valve port is 3 to 9 times a diameter of the pilot valve port. The valve body includes a valve chamber cylinder into which the main valve body is slidably fitted, and a valve seat member having a stepped cylindrical portion provided at a lower portion of the valve chamber cylinder, The compression coil spring is interposed between a lower end surface portion with a downward projecting portion provided in a large diameter portion of the main valve body and a terrace surface portion of the valve seat member, and upper and lower end portions thereof are the main valve. The pilot-type control valve according to any one of claims 1 to 8 , wherein the pilot-type control valve is extrapolated to a downward projecting portion of the body and a cylindrical portion of the valve seat member. The pilot-type control valve according to claim 9 , wherein a locking portion for fixing and holding a lower end portion of the compression coil spring is provided in the cylindrical portion of the valve seat member. The pilot type control valve according to claim 10 , wherein the locking portion is constituted by a male threaded portion into which a lower end portion of the compression coil spring is screwed. The pilot-type control valve according to any one of claims 9 to 11 , wherein a conical surface portion is provided in a downward projecting portion of the main valve body.