JPS6346995Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to an electromagnetic switch that opens and closes between a movable contact and a fixed contact provided opposite to the movable contact by reciprocating motion of a movable iron core based on the energization and de-excitation of an electromagnet. Then, the peripheral surface of the annular groove is scraped by the edge portion at the end of the contact spring, which is disposed in an annular groove bored in a switch housing made of a synthetic resin material and urges the movable contact toward the fixed contact. The purpose of the present invention is to provide an electromagnetic switch which prevents contact failure between contacts due to powder.

The present invention will be explained below based on an embodiment shown in FIGS. 1 and 2.

1 is a yoke, and 2 is an electromagnet equipped with a fixed iron core 3. A coil bobbin 5 on which an electromagnetic coil 4 constituting a part of the electromagnet 2 is wound is mounted inside the yoke 1. Reference numeral 6 denotes a magnetic path plate that is press-fitted and fixed to the yoke 1. A movable core 7 is disposed facing the fixed core 3 and is slidably attached to the inner periphery of the coil bobbin 5.
have the same shape. Step portions 3a and 7a are formed on the fixed core 3 and the movable core 7, respectively.
A return spring 8 is installed between a and 7a to bias the movable core 7 away from the fixed core 3, that is, to the right in FIG. Flanges 3b and 7b are formed on the opposite end faces of the fixed core 3 and the movable core 7, and the fixed core 3 is fixed with the flange 3b sandwiched between the bottom surface of the yoke 1 and the coil bobbin 5. The iron core 3 is firmly fixed.

Reference numeral 9 denotes a movable contact holding member made of an insulating material to which the movable contact 10 is fixed, and is separated from the movable iron core 7. The movable contact holding member 9 has a head 9a.
and a shaft portion 9b continuous to the head 9a, a stepped portion is formed on the head 9a, and the movable contact 10 is press-fitted and fixed thereto. Shaft portion 9b of the movable contact holding member 9
is slidably supported on the inner periphery of a boss portion 11b formed by boring an annular groove 11a in a switch housing 11 made of synthetic resin fixed to the yoke 1, and has a movable contact in the annular groove 11a. 1
A contact spring 12 is disposed to bias the contact spring 0 toward a pair of fixed contacts 13 and 14, which will be described later. The contact spring 12 has a smaller spring force than the return spring 8, and when the electromagnet 2 is not energized, the movable iron core 7 and the head 9a of the movable contact holding member 9 are brought into a butt state as shown in FIG. .

Furthermore, a movable contact 1 is provided in the switch housing 11.
The movable iron core 7 forms a stepped surface 11c on which the
And the amount of rightward movement of the movable contact holding member 9 is regulated.

Reference numerals 13 and 14 are a pair of fixed contacts provided opposite to the movable contact 10, respectively, and fixed to the switch housing 11.

Here, since the terminal end 12a of the contact spring 12 disposed in the annular groove 11a has an edge shape, conventionally, the terminal end 12a extends into the annular groove 1.
The inner circumferential surface or outer circumferential surface of 1a is shaved, and the shavings are applied to the contact surface of the movable contact 10 and/or the fixed contact 13,
14 contact surfaces, causing poor contact between the contacts. Therefore, in the present invention, a plurality of protrusions 11d are provided on the circumferential surface of the annular groove 11a so as to protrude in the depth direction of the annular groove 11a, and the terminal end 12a of the contact spring 12 is made non-contact with respect to the circumferential surface of the annular groove 11a. The contact condition was such that the circumferential surface of the annular groove 11a was not scraped, thereby preventing poor contact between the contacts. In other words, the contact spring 12 is connected to the annular groove 1.
1a, a plurality of protrusions 11d are provided on the inner circumferential surface 11e as shown in FIG. 2 to prevent the terminal end 12a from coming into contact with the inner circumferential surface 11e. If the contact spring 12 is in contact with the outer circumferential surface 11f of the annular groove 11a, a plurality of protrusions 11d are provided on the outer circumferential surface 11f.
It is sufficient to provide the terminal end 12a so as not to contact the outer peripheral surface 11f.

In the above configuration, when the electromagnetic coil 4 is energized, the electromagnet 2 is excited and the movable core 7 is attracted toward the fixed core 3 from the state shown in FIG. 2 and moves to the left. Therefore, the movable contact holding member 9 similarly moves to the left due to the spring force of the contact spring 12, and the movable contact 10 contacts the pair of fixed contacts 13, 14 with a predetermined contact pressure, and the movable contact 10 contacts the pair of fixed contacts 13, 14 with a predetermined contact pressure. Make conductive. At this time, the flange 7b of the movable iron core 7 and the head 9a of the movable contact holding member 9 are not in contact with each other, but are configured so that a predetermined gap is created. Next, when the power to the electromagnetic coil 4 is cut off, the electromagnet 2 becomes de-energized, and the movable iron core 7 is moved to the right by the spring force of the return spring 8, and the movable contact holding member 9
The head 9a of the vehicle collides with the head 9a of the vehicle. Here, since the contact spring 12 has a smaller spring force than the return spring 8, the movable contact holding member 9 is pushed to the right, and the movable contact 10 is connected to the pair of fixed contacts 1.
3 and 14, and the conduction between the fixed contacts 13 and 14 is cut off, and then the movable iron core 7 and the movable contact holding member 9 are returned to their original positions shown in FIG. In this way, the opening/closing operation of the electromagnetic switch is obtained.

In this embodiment, the movable contact 10 is fixed to the movable contact holding member 9, but the movable contact 10 is always attached to the fixed contact 1 by the contact spring 12.
Since the movable contact 10 is biased toward the 3 and 14 sides, it is sufficient to simply fit the movable contact 10 into the stepped portion formed on the head 9a of the movable contact holding member 9.

As described above, the present invention has an annular groove in which a contact spring for biasing a movable contact toward a fixed contact is arranged in a switch housing made of a synthetic resin material, and a plurality of protrusions on the circumferential surface of the annular groove. Since the contact spring is provided protruding in the depth direction of the annular groove, it is possible to make the edge portion of the terminal end of the contact spring non-contact with the circumferential surface of the annular groove. This eliminates the need to scrape the surface, and has the effect of preventing poor contact between contacts due to the shavings adhering to the contact surfaces of the contacts as in the conventional case.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing an embodiment of an electromagnetic switch according to the present invention, and FIG. 2 is a sectional view taken along line A-A in FIG. 2...Electromagnet, 7...Movable iron core, 10...Movable contact, 11...Switch housing, 11a...
Annular groove, 11d... Projection, 12... Contact spring, 13, 14... Fixed contact.

Claims (1)

[Scope of utility model registration request] In an electromagnetic switch in which a movable contact and a fixed contact provided opposite to the movable contact are opened and closed by reciprocating motion of a movable iron core based on energization and de-energization of an electromagnet, the movable contact is attached to a switch housing made of a synthetic resin material. An electromagnetic switch characterized in that an annular groove is bored in which a contact spring biased toward the fixed contact is disposed, and a plurality of protrusions are provided on the circumferential surface of the annular groove to protrude in the depth direction of the annular groove. .