Solenoid valve

Abstract

A solenoid valve includes: a moving core; a coil for generating magnetic force that attracts the moving core; a stator that forms a magnetic circuit in cooperation with the moving core and attracts the moving core; and a cup-shaped member disposed at the inner periphery of the stator and on the outer periphery of the moving core. The cup-shaped member reciprocatably supports the moving core, and restricts hydraulic fluid leakage from the moving core side to the outer periphery side. A collar made of a soft magnetic material, disposed so as to face a face on the stator side in the axial direction of the moving core, and forming a magnetic circuit in cooperation with the moving core and the stator.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects, feature and advantages of the present invention will become more apparent from the following detailed description made with reference to the accompanying drawings, in which like parts are designated by like reference numbers and in which:

FIG. 1 is a diagram showing a first embodiment in which a solenoid valve of the present invention is applied to a hydraulic control valve in a valve timing controller in an internal combustion engine;

FIG. 2A is an enlarged cross section of a collar and FIG. 2B is an enlarged diagram of the collar viewed from a moving core;

FIG. 3 is a diagram illustrating magnetic circuits in the first embodiment;

FIG. 4 is a diagram showing the relation between a movement amount of the moving core and the attracting force in the first embodiment in comparison with the case where the collar is not provided and the case where a solid collar is used;

FIG. 5 is a perspective view showing a collar in a second embodiment;

FIG. 6 is a cross section of a portion of the collar of a hydraulic control valve in the second embodiment;

FIGS. 7A and 7B are cross section and side view, respectively, sowing a modification of a collar;

FIGS. 8A and 8B are cross section and side view, respectively, showing another modification of a collar; and

FIG. 9 is a cross section of a solenoid valve using a wave washer.

Claims

1. A solenoid valve comprising: a moving core moving in an axial direction;a coil for generating magnetic force that attracts the moving core to one side in the axial direction;a stator having an attracting part, forming a magnetic circuit in cooperation with the moving core, and attracting the moving core when magnetic force is generated by the coil;a cup-shaped member disposed at an inner periphery of the stator and on an outer periphery of the moving core, the cup-shaped member reciprocatably supporting the moving core and restricting a fluid leakage in a direction from the moving core to the stator side, anda facing member made of a soft magnetic material, disposed in such a manner as to face an end face of the moving core confronting to the attracting part, and forming a magnetic circuit in cooperation with the moving core and the attracting part of the stator.

2. The solenoid valve according to claim 1, wherein the facing member has a facing surface that faces the moving core, and a part of which area of a section perpendicular to magnetic flux on a passage of the magnetic flux entering from the facing surface is smaller than an area of the facing surface.

3. The solenoid valve according to claim 2, wherein the facing member has a cylindrical part of which one end face serves as a part of the facing surface, and a facing plate part that projects from an end on the facing surface side of the cylindrical part to the inside in the radial direction,one end face of the facing plate combines with the end face of the cylindrical part to form the facing surface, andthe area of the connection part with the cylindrical part of the facing surface is smaller than the area of the end face on the side on which the end face forms a part of the facing surface of the cylindrical part.

4. The solenoid valve according to claim 2, wherein the facing member has a cylindrical part of which one end face serves as a part of the facing surface, and a facing plate part that projects from an end on the facing surface side of the cylindrical part to the inside in the radial direction,one end face of the facing plate combines with the end face of the cylindrical part to form the facing surface, andthe area of a section in the radial direction of the cylindrical part is smaller than the area of the facing surface.

5. The solenoid valve according to claim 1, wherein the facing member has a cylindrical part of which one end face serves as a part of the facing surface, and a facing plate part that projects from an end on the facing surface side of the cylindrical part to the inside in the radial direction,one end face of the facing plate combines with the end face of the cylindrical part to form the facing surface, anda through hole penetrating in the thickness direction is formed in the facing plate part.

6. The solenoid valve according to claim 1, wherein the facing member has a cylindrical part of which one end face serves as a part of the facing surface, and a facing plate part that projects from an end on the facing surface side of the cylindrical part to the inside in the radial direction,one end face of the facing plate combines with the end face of the cylindrical part to form the facing surface, anda through hole is formed in the cylindrical part.

7. The solenoid valve according to claim 1, wherein the facing member has a flange which comes into contact with a position fixing member of which position is unchanged with respect to the stator, anda biasing member for biasing the flange toward the position fixing member.

8. The solenoid valve according to claim 7, wherein the biasing member is integrated with the facing member.

9. The solenoid valve according to claim 8, wherein the biasing member is made of the same soft magnetic material as that of the facing member.

10. The solenoid valve according to claim 9, wherein the biasing member is elastic plastic deformed to thereby the facing member is biased toward the position fixing member.