JP3435697B2 - magnetic switch - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnet switch mounted on a starter of an automobile engine or the like.

[0002]

2. Description of the Related Art A magnet switch used in a starter has a structure in which an exciting coil is provided in a cylindrical case, a movable iron core is arranged in the hollow portion, and a pair of fixed contacts are attached to both sides of the movable iron core. . An annular movable contact is insulated and slidably fitted over the movable iron core, and an elastic member for urging the movable contact toward the fixed contact is provided. When the starter switch is turned on to energize the exciting coil to start the engine, the movable iron core is attracted by the magnetic force, and the movable contact comes into contact with the pair of fixed contacts to turn on the switch. At this time, the elastic member has a function of absorbing a shock caused by collision between the contacts and obtaining a contact pressure of the contacts.

[0003]

However, since the conventional elastic member uses the coil spring, the biasing force of the spring to the movable contact is unbalanced in the circumferential direction depending on the position of the winding end of the spring. Was becoming.
Therefore, when the movable contact and the fixed contact collide with each other, the dynamic load applied to the movable contact by the spring is large at the contact position of the winding end, and the movable contact is inclined. As a result, the bounce generated upon collision increases the number of times of contact dissociation and collision (the number of times of flapping), which promotes wear due to electric dislocation and shortens the contact life. An object of the present invention is to provide a magnet switch that can reduce fluttering at the time of collision between a movable contact and a fixed contact, reduce wear of contacts and spark consumption due to chattering, and improve durability.

[0004]

According to the present invention, there is provided a movable iron core having a movable contact and axially slidably disposed in the housing, and a movable iron core in the housing corresponding to the movable contact of the movable iron core. A pair of fixed contacts arranged opposite to each other around the axis, and an exciting coil that attracts the movable iron core by being fed with power and abuts the movable iron core on the fixed contact. In the starter magnet switch, the movable contact is slidably held by the movable iron core and is urged toward the fixed contact by an elastic member, and the elastic member has the movable contact as the fixed contact. for each contact surface in contact with, around said axis
Radially arranged and independent two or more urging points
And the two or more urging points are centered on the axis
And are arranged so as to face each other. Claim 2
In the invention described in (1), the movable contact has an annular plate shape.
Both are arranged concentrically with the pair of fixed contacts,
The elastic member is radially formed from the annular base and the outer periphery of the base.
A disc spring consisting of a number of protruding arm portions,
A plurality of parts that the movable contact contacts the fixed contact
Characteristic that it always urges two or more points against each contact surface
And

[0005]

In the present invention, the elastic member is
The movable contact makes contact with each contact surface that contacts the fixed contact.
However, two or more independent points are arranged radially around the axis.
Has an upper bias point, and two or more bias points are centered on the axis
Are arranged opposite to each other. Therefore, when the movable contact collides with the fixed contact, the biasing force applied to the movable contact by the elastic member becomes uniform. As a result, the imbalance of the dynamic load at the time of collision is reduced, and the number of times the movable contact and the fixed contact are dissociated and collided (flapping) due to the impact bound can be reduced. As a result, wear of the contacts and spark consumption due to electric dislocation are prevented, and the life of the contacts can be extended. Also, in claim 2.
In the above invention, the elastic member is changed in the rotation direction for some reason.
Position of the elastic member against the contact surface of the movable contact
There is an advantage that it can be activated by two or more points of each.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a magnet switch 100 according to the present invention, which is mounted on a reduction type engine starter 200 shown in FIG. The starter 200 includes a magnet switch 100, a starter motor M, a pinion P, and a reduction gear train G. The magnet switch 100 has a cylindrical housing 1 having a lid 11 fixed to the rear end (the right end in the figure) and an exciting coil 2 incorporated therein.
A fixed iron core 21 with a shaft hole is fitted into the tip of the. A front end of a movable iron core (plunger) 3 with a shaft hole is fitted in the rear end of the coil 2 so as to be slidable in the axial direction. On the rear side of the exciting coil 2, a pair of fixed contacts (main contacts) 4 and 4 electrically insulated from the housing 1 are oppositely fastened so as to be located on both sides of the movable iron core 3.

A washer 31 is fixed to the rear end of the movable iron core 3, and a rod 32 is biased and fitted into the shaft hole by an elastic member provided on the back. Rod 32
Is disposed so as to pass through the shaft hole of the fixed iron core 21, and its tip 33 is provided on the front side of the housing 1 as shown in FIG. 2, and contacts the rear end of the pinion shaft PS on which the pinion P is mounted. There is. The rear end portion of the movable iron core 3 has a small diameter, and the annular plate-shaped movable contact 5 externally fitted to the annular insulating member 51 is slidably fitted on the small diameter portion 34. An insulator 35, which forms a stop ring of the movable iron core 3, is fitted to the rear end side of the washer 31 so as to be externally fitted thereto. Between the insulating member 51 and the insulator 35, a disc-shaped spring 6 which is an elastic member for urging the movable contact 5 in the fixed contacts 4 and 4 directions.
Is intervening.

The fixed contact 4 is inserted through an insulating pipe 41 penetrating through a hole 12 formed in the housing 1 and the nut 4
It is composed of a base portion 43 fastened at 2, and a strip-shaped portion 45 having a contact surface 44, and the contact surface 44 is set in a radial direction in a plane orthogonal to the axis of the housing 1. When the fixed contact 4 and the movable contact 5 are in contact with each other, conduction is established between the fixed contacts 4 and 4, and the starter motor M is energized.

As shown in FIGS. 3 and 4, the disc-shaped spring 6 is provided with a ring-shaped base portion 61 and a radial projection from the outer periphery of the base portion 61. The tip of the disc-shaped spring 6 contacts the insulating member 51 holding the movable contact 5. 16 of the arms 62 are formed. The arm 62 is
A plurality of tips (6a, 6b, 6 in this embodiment) are provided with respect to the contact surface S (shown in FIG. 4) between the fixed contact 4 and the movable contact 5.
3 pieces of c and 3 pieces of 6d, 6e, 6f ) abut,
The movable contact 5 is set so as to urge the movable contact 5 in the direction of the fixed contact 4 from behind on each contact surface S at a plurality of urging points F. As a result, the surface pressure when the movable contact 5 collides with the fixed contacts 4 and 4 is equalized over the entire contact surface S,
Flapping of contacts due to collision bounce is minimized.
In this embodiment, the reason why the number of biasing points F is three with respect to the contact surface S is that the plurality of biasing points F are located within the contact surface S even if the disc-shaped spring 6 rotates. . It is desirable that the arrangement of the biasing points F has at least two points sandwiching the center of the contact surface S.

Further, in order to reduce the fluttering of the contact point, the positions of the urging point F and the contact surface S in the radial direction do not necessarily match, but the contact surface S and the urging position of the disc-shaped spring 6 are If the deviation in the radial direction is large, the number of times of flapping increases. As a result of the test, the diameter D1 of the tip of the arm portion 62 (diameter of the biasing point F) is preferably 50% or more of the minimum contact diameter D2 between the fixed contact 4 and the movable contact 5, and smaller than 50%. It was found that the number of flaps increased.

In this magnet switch 100, when electric power is supplied to the exciting coil 2, the movable iron core 3 is attracted and displaced toward the tip side. As a result, the movable contact 5 becomes the fixed contact 4,
It collides with 4 and contacts. At the time of this collision, the contact surface S of the movable contact 5 with the fixed contact 4 is urged by the plurality of arm portions 62 from the rear side, so that the contact surface S is applied with a substantially uniform urging force. As a result, due to the imbalance of the urging force from the back of the movable contact 5, it is possible to suppress the fluttering of the contact that occurs during a collision. As a result, the number of times of contact fluttering (collision, repulsion), which was about 7 times on average when the coil spring was used, could be reduced to about 2 times on average.

FIG. 5 shows another embodiment. In this embodiment, two disc-shaped springs 6 are arranged back to back so that the elastic member has a large stroke. If a larger stroke is required, a larger number of disc springs 6 can be stacked. FIG. 6 shows still another embodiment. In this embodiment, extended portions 52, 52 are provided on the outer edge of the movable contact 5 to increase the contact area with the fixed contacts 4, 4, and
Rotation preventing means 53 for the movable contact 5 is provided. This increase in the contact area can reduce the wear of the contacts and further improve the durability of the magnet switch. In this invention,
The elastic member that causes the movable contact to have two or more urging points for each contact surface that contacts the fixed contact may be a plate spring having a strip shape, a rectangular shape, or the like and provided with rotation preventing means.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a magnet switch according to the present invention.

FIG. 2 is a cross-sectional view of main parts of a starter including the magnet switch of FIG.

FIG. 3 is a perspective view of a main part of the magnet switch of FIG.

FIG. 4 is an enlarged view of a main part of the magnet switch shown in FIG.

FIG. 5 is a cross-sectional view of essential parts of a magnet switch according to another embodiment.

FIG. 6 is a perspective view of a main part of a magnet switch according to still another embodiment.

[Explanation of symbols]

100 magnet switch 1 housing 2 excitation coil 3 movable iron core 4 fixed contacts 5 movable contacts 6 Disc-shaped spring 51 Insulation member F Force point S contact surface

Claims (2)

(57) [Claims] 1. A movable contact is provided in the housing.
Medium and the movable core slidably disposed in the axial direction, the shaft in the housing in response to the movable contact of the movable iron core
A starter provided with a pair of fixed contacts arranged opposite to each other as a core, and an exciting coil that attracts the movable iron core by being supplied with power and brings the movable iron core into contact with the fixed contact.
In the magnet switch for use , the movable contact is slidably held by the movable iron core and is urged toward the fixed contact by an elastic member, and the elastic member is configured such that the movable contact is the fixed contact. Radially arranged around the axis for each contact surface
And has two or more independent bias points, and
The two or more urging points are arranged so as to face each other around the axis.
A magnet switch characterized by being placed . 2. The magnet switch according to claim 1.
In addition, the movable contact has an annular plate shape, and
The elastic member is concentrically arranged with respect to a pair of fixed contacts.
Is a ring-shaped base and is radially projected from the outer periphery of the base.
A disc spring composed of a number of arms, wherein a plurality of the arms are
Each contact in which the movable contact contacts the fixed contact
A mug characterized by always urging two or more points on the surface
Net switch.