Electromagnetic switch

Abstract

In an electromagnet switch, a stationary iron core is composed mainly of a base part and a disk part. The base part is faced to a plunger and the disk part is forcedly inserted and fixed to a boss part formed in the base part. The disk part is composed of a metal plate of ferromagnetic substance (iron plate) and another substance plate (made of resin or rubber and the like, for example,) of a smaller spring constant or a larger damping coefficient than that of the metal plate. The metal plate and another substance plate are laminated. Another substance plate absorbs or reduces the impact force when the plunger is electromagnetically attracted toward and collides with the base part. The propagation of a large impact noise or crashing sound is thereby suppressed, and as a result the impact noise can be reduced.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

A preferred, non-limiting embodiment of the present invention will be described by way of example with reference to the accompanying drawings, in which:

FIG. 1 is a sectional view showing a configuration of a stationary iron core of an electromagnetic switch according to a first embodiment of the present invention;

FIG. 2 is a sectional view showing another configuration of the stationary iron core of the electromagnetic switch according to the first embodiment;

FIG. 3 is a sectional view showing an entire configuration of the electromagnetic switch according to the first embodiment of the present invention;

FIG. 4 is a view showing an electrical circuit in the electromagnetic switch according to the first embodiment;

FIG. 5 is a sectional view showing a configuration of a stationary iron core of an electromagnetic switch according to a second embodiment of the present invention;

FIG. 6A is a plan view showing a configuration of a metal plate in which slits are formed;

FIG. 6B is a plan view showing a configuration of a metal plate in which holes are formed;

FIG. 7 is a partial view showing a configuration of an electromagnetic switch according to a third embodiment of the present invention;

FIG. 8 is a plan view showing a configuration of a disk part in the electromagnetic switch according to the third embodiment of the present invention;

FIG. 9 is a sectional view showing a configuration of a stationary iron core of an electromagnetic switch according to a fourth embodiment of the present invention;

FIG. 10 is a sectional view showing a configuration of a stationary iron core of an electromagnetic switch according to a fifth embodiment of the present invention;

FIG. 11 is a sectional view showing a configuration of a stationary iron core of an electromagnetic switch according to a sixth embodiment of the present invention; and

FIG. 12 is a sectional view showing another configuration of the stationary iron core of the electromagnetic switch according to a modification example.

Claims

1. An electromagnetic switch configured to control open/close of an electric contact, comprising: a magnet coil;a movable iron core movably contacted with the electric contact; anda stationary iron core configured to attract the movable iron core when magnetized by supplying a current to the magnet coil, the stationary iron core comprising: a base part faced in arrangement to the movable iron core; anda disk part of a cylindrical shape plate assembled to the base part, placed at one side of the magnet coil, and the disk part comprising: a metal plate of ferromagnetic substance; andanother substance plate having one of a spring constant smaller than that of the metal plate and a damping coefficient larger than that of the metal plate, and wherein the metal plate and another substance plate are laminated.

2. An electromagnetic switch configured to control open/close of an electric contact, comprising: a magnet coil;a movable iron core movably contacted with the electric contact; anda stationary iron core configured to attract the movable iron core when magnetized by supplying a current to the magnet coil, the stationary iron core comprising: a base part faced in arrangement to the movable iron core; anda disk part of a cylindrical shape plate assembled to the base part and placed at one side of the magnet coil, andthe disk part comprising a plurality of metal plates of ferromagnetic substance laminated, and at least one of the metal plates having one of a smaller spring constant, a larger damping coefficient, and a smaller coefficient of friction than those of the other metal plates.

3. The electromagnetic switch according to claim 2, wherein at least a slit or a hole is formed in at least one of a plurality of the metal plates in order to reduce a spring constant or a damping coefficient of the disk part.

4. The electromagnetic switch according to claim 3, wherein one end of the slit or of the hole does not reach the outer periphery of the disk plate and formed within an outer diameter of the metal plate.

5. The electromagnetic switch according to claim 3, wherein the slit or the hole is formed in each metal plate, and the slit or the hole formed in all of the metal plates laminated make a penetrating hole in its lamination direction, and end terminals of the magnet coil are elongated toward an opposition direction to the disk part through the penetrating hole.

6. The electromagnetic switch according to claim 5, wherein the two penetrating holes are formed in symmetry of the diameter of the disk part.

7. The electromagnetic switch according to claim 5, wherein a plurality of the metal plates in the disk part are laminated to each other regardless of a front surface and a back surface of each metal plate.

8. The electromagnetic switch according to claim 2, wherein the disk part is composed of a plurality of metal plates of ferromagnetic substance laminated, and a surface treatment or a lubrication treatment is performed on the surface of at least one metal plate in order to have a smaller coefficient of friction rather than the other metal plates.

9. An electromagnetic switch configured to control open/close of an electric contact, comprising: a magnet coil;a movable iron core movably contacted with the electric contact; anda stationary iron core configured to attract the movable iron core when magnetized by supplying a current to the magnet coil, the stationary iron core comprising: a base part faced in arrangement to the movable iron core, and comprising a plurality of metal plates of ferromagnetic substance which are laminated; anda disk part of a cylindrical shape plate assembled to the base part and placed at one side of the magnet coil.

10. The electromagnetic switch according to claim 9, wherein a slit or a hole which penetrates toward the lamination direction is formed in at least one metal plate in order to reduce its spring constant or to increase its damping coefficient rather than that of the other metal plates.

11. The electromagnetic switch according to claim 9, wherein a surface treatment or a lubrication treatment is performed on the surface of at least one metal plate in order to have a smaller coefficient of friction than the coefficient of friction of other metal plates.

12. The electromagnetic switch according to claim 9, wherein the base part is composed of the metal plate of ferromagnetic substance and another substance plate having one of a smaller spring constant and a larger damping coefficient than that of the metal plate, and the metal plate and the another substance plate are laminated.

13. The electromagnetic switch according to claim 1, wherein the base part comprises a plurality of metal plates of ferromagnetic substance which are laminated.

14. The electromagnetic switch according to claim 1, wherein the metal plates forming the disk part are fixed to each other.

15. The electromagnetic switch according to claim 13, wherein the metal plates forming the disk part are fixed to each other.

16. The electromagnetic switch according to claim 9, wherein the metal plates forming the base part are fixed to each other.

17. The electromagnetic switch according to claim 13, wherein the metal plates forming the base part are fixed to each other.