JPH0130771Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an electromagnetic switch device, particularly an electromagnetic switch device mounted on a DC motor (starter motor) for starting an engine.

A cross-sectional configuration of a conventional electromagnetic switch device of this type is shown in FIG. That is, in this FIG. 1, reference numeral 1 indicates the entire electromagnetic switch device attached to a starter motor (not shown), 2 is a cylindrical yoke formed from a mild steel member by cold forging, and 3 is this yoke. The solenoid is fitted into the yoke 2 and is formed by winding a solenoid coil 5 around a bobbin 4 which is molded from a nylon resin material containing glass fiber as its main component. A non-magnetic metal bush 6 is attached to the peripheral surface.

Further, 7 is a movable iron core assembly loosely fitted to the inner circumferential surface of the metal bushing 6 so as to be able to slide back and forth in the axial direction, 8 is a rear end spigot part 2a of the yoke 2,
It is inserted together with the cap assembly 9 and fixed by caulking integrally, and a concave groove 8 is formed at the front end side of the center through hole 8a.
Rear lid body with fixed iron core function forming b, 10
is a movable contact shaft made of a resin mold, in which the front end groove 11a is caulked and crimped A to the rear end central groove 11a of the movable iron core 11 made of a mild steel member constituting the movable iron core assembly 7. , a step portion 10b is left in the axially intermediate portion, and an engagement groove 10c is formed in the rear end portion having a small diameter.

Furthermore, 12 is a movable contact plate loosely fitted to the rear end side of the movable contact shaft 10, and 13 is interposed between the concave groove 8b of the rear lid 8 and the rear end surface of the movable iron core 11, and the movable Iron core 11 and eventually movable contact shaft 10
A return plunger spring 14 that presses forward the movable iron core assembly 7 including
A contact spring 16 that presses the movable contact plate 12 is mounted in a through hole 18 of a resin molded cap 17 constituting the cap assembly 9 so as to face the movable contact plate 12.
A pair of fixed contact terminals 19 are formed at the front end of the movable iron core 11 and are hook portions for cam-engaging a shift lever of the starter motor.

However, in this conventional configuration, when the solenoid 3 is energized and energized, the magnetic closed circuit of the yoke 2 - the rear cover 8 - the gap - the movable iron core 12 - the yoke 2 is energized and energized, and the movable iron core 11 toward the rear lid body 8 side, the pinion of the starter motor is meshed with the ring gear of the internal combustion engine using a shift lever (not shown) that is cam-engaged with the hook portion 19, and then the movable contact plate 12 is brought into contact with a pair of fixed contact terminals 16 to close the main contact circuit, and the starter motor is rotationally driven to start, that is, crank, the internal combustion engine, and after starting, the solenoid 3 is de-energized. It is returned to its original state by the return biasing force of the plunger spring 13.

However, in conventional cases like this,
A movable contact shaft 10 passes through a central through hole 8a of the rear cover 8, and a space B in this through hole 8a is a sliding space C on the movable iron core 11 side, a movable contact plate 12, and a fixed contact terminal 16. The so-called contact chamber space D on the side
Because of this, when the movable core 11 is operated, especially when it returns, the air pressure in the space D decreases along with the space C, so this contact chamber space D sucks in outside air and moistens the contact area. In addition to having an adverse effect on the opening and closing of the contacts, there was a drawback in that, especially when space C was coated with lubricating oil such as grease, this grease entered space D and caused an even more significant adverse effect.

In view of these conventional drawbacks, this invention forms a contact spring receiving part having a cylindrical sleeve toward the rear on the outer periphery of the movable contact shaft. When the movable core is attracted to the rear side when the solenoid is energized and energized, the sleeve of the contact spring receiver slides into the through hole of the rear lid.

Hereinafter, embodiments of the electromagnetic switch device according to this invention will be described in detail with reference to FIGS. 2a and 2b and FIG. 3.

FIGS. 2a and 2b show one embodiment, and FIG. 3 shows another embodiment, and in each embodiment, the same reference numerals as in the conventional example shown in FIG. 1 indicate the same or corresponding parts.

First, in the embodiment of FIG. 2, as shown in FIG.
As shown, the intermediate step portion 10b of the movable contact shaft 10
is fitted so as to be elastically engaged by the contact spring 14, and its outer peripheral portion 20a is brought into sliding contact with the center through hole 8a of the rear lid body 8,
The communication space B can be slid and sealed.

Therefore, in the case of the embodiment shown in FIG. 2, the contact chamber space D is closed, and the air flowing into the contact chamber is excessively restricted, preventing rusting of the contacts and moisture buildup. In addition to preventing ice formation,
This has the advantage that the contact spring 14 is not allowed to deviate from the stepped portion 10b, and operation can be made smoother.

Further, as shown in FIG. 2b, when the movable core 11 is not attracted to the rear side (to the left in the figure), that is, when the movable core 11 is in the normal rest position, the outer circumferential surface 20a of the sleeve 20 is It is in opposing sliding contact with the central through hole 8a of the lid body 8. Therefore, the solenoid 3 is energized and the movable iron core 11
When the sleeve 20 is sucked rearward (to the left in the figure), the outer circumferential surface 20a of the sleeve 20 is inserted into the central through hole 8 of the rear lid 8.
Slide with a. At this time, even if the contact spring 14 located on the inner peripheral side of the sleeve 20 is bent, this contact spring 14 does not contact the central through hole 8a of the rear lid body 8. As a result, the operation of the movable contact shaft 10 is stabilized, and the movable contact shaft 10 is connected to the rear cover body 8 via the contact spring 14.
The effect is that there is no electrical contact between the two.

In addition, the embodiment in FIG. 3 is similar to the movable contact shaft 10 in the previous example.
This is an example in which the sleeve 20 and the sleeve 20 are integrated. That is, on the movable contact shaft 21, there is a cylindrical portion 2 corresponding to the sleeve.
2, it can obtain the same functions and effects as the previous example, and has the added advantage of being able to reduce the number of parts.

In each of the above embodiments, the movable contact shaft and the sleeve are made of resin mold, but of course they can be made of metal by providing the movable contact plate with ground insulation.

As described in detail above, according to this invention, a contact spring receiving part having a cylindrical sleeve is formed on the outer periphery of the movable contact shaft facing rearward, and the sleeve of the contact spring receiving part is used for non-energized excitation of the solenoid. When the movable core is attracted to the rear side when the solenoid is energized and energized, it slides against the through hole in the rear lid, so the contact chamber space and the sliding space are separated. The through-hole, which is the communication space, has a sliding and sealed structure, which prevents moisture and grease from entering the contact chamber, allowing the contact to open and close reliably, and because the contact spring does not come into contact with the through-hole. , the operation of the movable contact shaft is stable, the movable contact shaft does not come into electrical contact with the rear cover via the contact spring, etc., and it has a simple structure and can be implemented easily and inexpensively. It has characteristics.

[Brief explanation of the drawing]

Fig. 1 is a side sectional view of a conventional electromagnetic switch device, Figs. 2a and b are half-cut sections of a sleeve used in an electromagnetic switch device according to an embodiment of the present invention, and sectional views of essential parts of the device. FIG. 2 is a sectional view of a main part of a device according to another embodiment of the same. 1... Electromagnetic switch device, 2... Yoke, 3...
Solenoid, 7... Movable core assembly, 8... Rear lid body (fixed core), 8a... Center through hole, 9...
Cap assembly, 10, 21...Movable contact shaft, 1
1...Movable iron core, 12...Movable contact plate, 13...
Plunger spring, 14...Contact spring, 16...Fixed contact terminal, 20...Sleeve,
22...Cylindrical part, B...Communication space, C...Movable contact sliding space, D...Contact chamber space.

Claims (1)

[Scope of Claim for Utility Model Registration] A solenoid, a movable core that is fitted into the solenoid from the front side and is sucked toward the rear side when the solenoid is energized, and a fixed core function provided at the rear of the solenoid. a rear lid and a cap assembly, a movable contact shaft that is integrated with the movable iron core and has a rear end protruding into the cap assembly through a through hole of the rear lid; and after the movable contact shaft protrudes. a movable contact plate held at an end; a contact spring receiver having a cylindrical sleeve formed rearward on the outer periphery of the movable contact shaft; and a contact spring receiver held by the contact spring receiver to support the movable contact. a contact spring that biases the plate rearward; a pair of fixed contact terminals disposed within the cap assembly and facing the movable contact plate; and a plunger spring that biases the movable core back; The sleeve of the spring receiving portion faces the rear cover when the solenoid is not energized, and when the movable core is attracted to the rear side when the solenoid is energized, the sleeve of the contact spring receiving portion An electromagnetic switch device that slides on the through hole of the rear lid.