Patent ID: 9739394
Date: 2017-08-22
CPC Classifications: F16K,H01F

Claim:
1. A solenoid valve comprising: a cylindrical sleeve with a plurality of ports formed therein, through which a working fluid can flow; an elongated spool configured to move through the sleeve in an axial direction to open and close the ports; and a solenoid portion that moves the elongated spool in the axial direction with respect to the sleeve, wherein the solenoid portion includes a tubular solenoid coil able to be supplied with a current to generate a magnetic force; a cover member made of a magnetic material surrounding the solenoid coil; a shaft supported so as to be movable in the axial direction along a central axis of the solenoid coil to apply an axial moving force to the elongated spool; a plunger that is movable in the axial direction along with the shaft, and a magnetic material core configured to attract the plunger using the magnetic force generated in the solenoid coil, wherein the cover member has an outer tubular portion that covers an outer periphery of the solenoid coil, a first bottom portion that covers an end of the solenoid coil that is on the opposite side to the sleeve, an inner tubular portion interposed between the plunger and an end of the solenoid coil adjacent the first bottom portion, and a second bottom portion formed to protrude inward in a radial direction with respect to the inner tubular portion, and facing the plunger in the axial direction, the magnetic material core is interposed between the shaft and the solenoid coil in the radial direction and faces the plunger and the inner tubular portion of the cover member in the axial direction, and the magnetic material core has a cylindrical portion with an insertion hole which is formed in a central portion of the cylindrical portion and through which the shaft is inserted, and a flange portion that couples the cylindrical portion and the outer tubular portion of the cover member together, the shaft is supported by a first bearing portion of the magnetic material core and a second bearing portion of the second bottom portion of the cover member, the first bearing portion is formed by a part of the cylindrical portion of the magnetic material core in the axial direction protruding inward in the radial direction so as to contact an outer peripheral surface of the shaft in a sliding manner, and the second bearing portion is formed by a sliding hole in the second bottom portion of the cover member, the sliding hole having a surface contacting an outer peripheral surface of the shaft protruding from the plunger such that the shaft is held so as to slide freely.