JP2988001B2 - Magnetic switch for starter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a starter magnet switch.

[0002]

2. Description of the Related Art For example, in a magnet switch disclosed in Japanese Patent Application Laid-Open No. Sho 61-135019, a flat portion is integrally formed with an insulating contact case having a fixed contact, and this flat portion is formed on an end face of an exciting coil. There is disclosed a technique in which a coil housing is fixed to a center case by caulking while being disposed between a plate located on the side and a fixed contact to secure a creepage distance between the two.

[0003]

However, the contact case sandwiched between the center case and the switch cover is
With the flat portion in contact with the plate, it is fastened and fixed by bolts from the switch cover to the center case. For this reason, when the bolt tightening force is weak through the sealing material provided on the switch cover bolt seat surface, the contact case is incompletely held, and when the bolt tightening force is too strong. Have problems such as damage to the flat part. Further, means for fixing the coil housing to the center case has been required.

[0004] The present invention has been made based on the above circumstances, and an object thereof is to properly hold a contact case sandwiched between a center case and a switch cover.
An object of the present invention is to provide a starter magnet switch that can simultaneously fix a coil housing.

[0005]

In order to achieve the above object, the present invention provides a plunger having a movable contact at one end, and a plunger arranged on the outer periphery of the plunger and energized to attract the plunger. An exciting coil, a coil housing that holds the exciting coil and forms a magnetic circuit of the exciting coil, a center case that houses the coil housing, and a case where the plunger is attracted by energizing the exciting coil. A fixed contact with which the movable contact comes into contact, and is disposed between the fixed contact and the coil housing, and has an opening formed in the center thereof, through which the plunger passes, and is formed in a radial direction. A contact case integrally including a flat portion; an elastic member interposed between the flat portion and the coil housing; and an opening of the contact case. A switch cover for covering the contact case between the switch cover and the center case, and fixing means for fastening and fixing the switch cover and the center case. Are assembled in a state where the end faces facing each other are in contact with the fastening direction of the fixing means,
It is a technical means that the flat portion is provided so as to press and hold the coil housing via the elastic member when the contact case is fixed.

[0006]

In the magnetic switch of the present invention having the above-described structure, the contact case and the center case are assembled in such a manner that the end faces of the contact case and the center case are in contact with each other in the fastening direction of the fixing means. For this reason, the tightening force applied to the contact case is
It is received on the end face of the center case. Therefore, the fastening force of the fixing means is prevented from being too weak or too strong due to the contact between the end faces of the contact case and the center case.

[0007] With the fixing of the contact case, the flat portion provided on the contact case presses the coil housing via the elastic member, whereby the coil housing is held in the center case.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of a magnet switch for a starter according to the present invention will be described with reference to FIGS. FIG. 1 is a cross-sectional view of the magnet switch (a cross-sectional view along line AA in FIG. 2).

The magnet switch 1 of the present embodiment includes a plunger 2 and an exciting coil 3 arranged on the outer periphery of the plunger 2. The energizing of the exciting coil 3 causes the plunger 2 to be attracted (moves to the left in the drawing). Accordingly, the pinion gear (not shown) is pushed out, and the main current of the motor circuit is turned on and off.

The plunger 2 has a movable contact 6 supported on one end side (right side in the figure) by insulating bushes 4 and 5, and a contact spring 7 for applying a contact pressure to the movable contact 6, and is pushed to the other end side. The rod 8 is connected. A return spring 9 is provided on the outer periphery of the push rod 8 to push back the plunger 2 when the power supply to the exciting coil 3 is cut off.

The exciting coil 3 is wound around a bobbin 10 made of resin and held in a coil housing 12 via a rubber cushion 11. The coil housing 12 includes a ground plate 12a and the ground plate 12a.
And a cylindrical case portion 12b forming a magnetic circuit of the exciting coil 3 together with the ground plate 12a by caulking and fixing. The ground plate 12a has a function of restricting the movement of the plunger 2 by bringing the end (the left end in the figure) of the plunger 2 into contact when the plunger 2 is attracted by the energization of the exciting coil 3.

The coil housing 12 is housed in a center case 13 formed by die-casting aluminum, and is pressed and held by a cylindrical contact case 14 attached to the open end side (right side in the drawing) of the center case 13. I have.

The contact case 14 is formed of an insulating resin, and is attached to the opening end of the center case 13 via a packing 15. The assembling portion of the contact case 14 and the center case 13 has a fitting structure in which the facing end faces have a step on the inner peripheral side and the outer peripheral side, and are assembled by so-called seal fitting. The packing 15 is mounted on the inner peripheral side of the fitting portion, as shown in FIG.

The center case 13 of the contact case 14
A switch cover 17, which will be described later, is attached to the end face on the opposite side via a packing 16. On the end face of the contact case 14, a step portion 1 on which the packing 16 is mounted on the inner peripheral side thereof is provided.
4a are formed, and the switch cover 17 is configured to be assembled in a state of being in contact with the end face of the contact case 14.

The contact case 14 has, on its inner peripheral surface,
Two fixed contacts 18 and 19 to which the movable contact 6 comes in contact with the movement of the plunger 2 (see FIG. 2: FIG. 2 (a plan view of the contact case 14 from the end face side with the switch cover 17 removed)) are attached. The fixed contacts 18, 19
Has an L-shaped cross section, is supported by terminals 20 and 21 at radially opposed positions, and is fixed by tightening nuts 22 and 23.

The contact case 14 includes a fixed contact 1.
Between the end faces of the cylindrical case portion 12b and the end portions 8 and 19, there is provided a flat portion 24 integrally formed in a radial direction with an opening portion 24a through which the plunger 2 passes in a central portion.
The coil housing 12 and the fixed contacts 18, 1 are located between the end face of the cylindrical case portion 12b and the fixed contacts 18, 19.
9 is provided to ensure a creepage distance. An elastic member 25 such as rubber is interposed between the flat portion 24 and the end face of the cylindrical case portion 12b.
4 and the center case 13, the flat portion 24
Are provided so as to press and hold the coil housing 12 via the elastic member 25.

The switch cover 17 is made of, for example, iron. The switch cover 17 covers the open end of the contact case 14. When the power supply to the exciting coil 3 is cut off and the plunger 2 is pushed back, the outer peripheral surface of the insulating bush 5 is formed. The contact has the function of restricting the movement of the plunger 2.

The above-mentioned center case 13 and contact case 1
4 and the switch cover 17 form an outer shell of the magnet switch 1. The contact case 14 is sandwiched between the center case 13 and the switch cover 17, and FIG. 3 (the magnet switch 1 viewed from the switch cover 17 side). The contact case 14 and the switch cover 17 are fastened and fixed to the center case 13 by three through bolts 26 (fixing means of the present invention).

In the magnet switch 1 of the present embodiment, the center case 13 and the contact case 14 are assembled by a fitting structure (ink cage fitting), and the packing 15 is attached to the magnet switch 1 at the outer peripheral side of the fitting portion. The end face is in contact with the direction in which the through bolt 26 is tightened. Also, in assembling the switch cover 17 and the contact case 14,
The switch cover 17 is attached to the end face of the contact case 14 in a state where the packing 16 is attached between the two.

Therefore, the tightening force applied to the contact case 14 when tightened and fixed by the through bolts 26 can be received by the outer peripheral end surface of the center case 13 in the seal fitting portion. As a result, the contact case 14 and the switch cover 17 can be always fixed to the center case 13 with a constant tightening force, so that the force for pressing and holding the coil housing 12 via the elastic member 25 by the flat portion 24 is also constant. For this reason, it is possible to prevent the contact case 14 from being incompletely held due to too small a tightening force and to prevent the flat portion 24 from being damaged due to too much tightening, as in the related art. Means for fixing to the case 13 (such as caulking) becomes unnecessary.

[0021]

According to the present invention, the tightening force applied to the contact case is received by the assembled end face of the center case, and the contact case sandwiched between the center case and the switch cover is properly tightened and fixed. In addition to this, it is possible to prevent the flat portion from being damaged due to excessive tightening of the fixing means. Further, since means for fixing the coil housing to the center case is not required, the present invention is also effective in reducing the number of steps required for fixing means such as caulking.

[Brief description of the drawings]

FIG. 1 is a sectional view of a magnet switch.

FIG. 2 is a plan view showing a state where a switch cover is removed.

FIG. 3 is a plan view showing a state where a switch cover is assembled.

[Explanation of symbols]

 Reference Signs List 1 magnet switch 2 plunger 3 exciting coil 6 movable contact 12 coil housing 13 center case 14 contact case 17 switch cover 18 fixed contact 19 fixed contact 24 plane portion 24a opening 25 elastic member 26 through bolt (fixing means)

Claims (1)

(57) [Claims] A) a plunger having a movable contact on one end side; b) an exciting coil disposed on an outer periphery of the plunger to attract the plunger when energized; c).
A coil housing for holding the exciting coil and forming a magnetic circuit of the exciting coil; d) a center case for housing the coil housing; and e) when the plunger is attracted by energizing the exciting coil. A fixed contact with which the movable contact comes into contact, and is disposed between the fixed contact and the coil housing, and has an opening formed in the center thereof, through which the plunger passes, and having an insulating property formed in a radial direction. A contact case integrally provided with a flat part,
f) an elastic member interposed between the flat portion and the coil housing; g) a switch cover covering an opening of the contact case; h) a contact case between the switch cover and the center case. And a fixing means for tightening and fixing the switch cover and the center case.The contact case and the center case are in a state in which mutually facing end faces abut in the tightening direction of the fixing means. A magnet switch for a starter which is assembled and provided so that the flat portion presses and holds the coil housing via the elastic member when the contact case is fixed.