JPS6114285Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an improvement of a brush device for an engine starting motor.

First, a well-known conventional device of this type will be explained with reference to FIGS. 1 and 2.

In each figure, an end bracket 1 constitutes a part of the starter motor, is made of a conductor, and is grounded to the outer shell of the starter motor main body. 2 is an annular brush holding board made of a conductive material, which is fixed to the end bracket by a screw 3 made of a conductive material;
It has two screw holes 2a on the circumference for screw fixing. Reference numeral 4 denotes insulating plates fixed to two locations on the brush holding substrate, each having through holes (not shown) for fixing. Reference numeral 5 denotes a positive brush holder, which is a first brush holder, which is caulked to the brush holder substrate 2 through these insulating plates, and is made of a conductive material and is constituted by the insulating plate 4. It has a brush holding part 5a, a spring mounting part 5b formed integrally with the brush holding part 5a on one side thereof, and a protruding part 5c for caulking. Reference numeral 6 denotes a positive side brush, which is a first brush, and is slidably inserted into the brush holding portion 5a. 7 is the spring mounting part 5 mentioned above.
A brush spring attached to b presses the plus side brush 6 in one direction. Reference numeral 8 denotes a commutator which is a power supply section mounted on the armature of the electric motor, and the positive side brush 6 is always in pressure contact with the outer peripheral surface of the commutator. 9 is the positive lead wire, one end of which is
The other end is electrically connected to the positive side brush 6, and the other end is electrically connected to the field coil 10 of the motor. 1
Reference numeral 1 denotes a negative side brush holder which is a second brush holder, which is made of a conductive material and is caulked directly to the brush holding substrate 2.
The brush holding part 11a is formed by a spring mounting part 11b to which the spring 7 is attached, and a protruding part 11c for caulking.
Reference numeral 12 denotes a minus side brush which is a second brush slidably inserted into the brush holding portion 11a of the minus side brush holder 11 and is always pressed against the outer circumferential surface of the commutator 8 by the brush spring 7. ing. Reference numeral 13 denotes a negative lead wire, one end of which is connected to the negative brush 12, and the other end connected to the brush holding board 2.

In the conventional device configured as described above, when starting the engine, the field coil 10 is connected to a power source (not shown).
via, positive side lead wire 9 → positive side brush 6
→ Commutator 8 → Negative side brush 12 → Negative side lead wire 13 → Brush holding board 2 → End bracket 1 - Forms a closed circuit of ground, and supplies power to the field coil 10 and armature coil of the starting motor to connect the starting motor. rotates and starts the engine.

By the way, in this conventional device, since the brush holding substrate 2 and the brush holders 5 and 11 are made of a conductive material, the brush holding substrate 2 is used to insulate the positive side brush 6 from them.
An insulating plate 4 was fixed on top, and a positive side brush holder 5 was mounted on this insulating plate 4. Therefore, in this case, since the insulating plate 4 is used, manufacturing the insulating plate 4 and assembling it to the brush holding board 2 requires a lot of effort, resulting in extremely poor productivity.

This invention aims to eliminate the above-mentioned drawbacks and provides an excellent brush device for an engine starting motor as described below.

An embodiment of this invention shown in FIGS. 3 and 4 will be described below.

That is, in FIGS. 3 and 4, reference numeral 14 denotes a brush holding board made of an insulator fixed to the end bracket 1 by the screws 3, and has through holes 14a at two locations on the circumference through which the screws 3 pass. . Each of the brush holders 5 and 11 is caulked onto this brush holder substrate 14.

Further, one of the protrusions 11c of the negative side brush retainers 11 facing each other is provided with the screws 3, respectively.
The negative side brush holder 11 is grounded to the rear bracket 1 via the screw 3. Furthermore, since the minus side brush 12 is electrically connected to the brush holder 11 by contacting the holding portion 11a of the minus side brush holder 11 and the spring 7, the minus side lead wire 13 is not provided.

In the embodiment configured in this way, when starting the engine, the power source is connected via the field coil 10 to the positive lead wire 9 → the positive brush 6 → the commutator 8.
→ Minus side brush 12 → Minus side brush retainer 11 → Screw 3 → End bracket 1 → Forms a closed circuit of ground, and field coil 10 of the starting motor,
Power is supplied to the armature coil to rotate the starter motor and start the engine.

That is, in this embodiment, the brush holding substrate 1
4 is made of an insulator to maintain the insulation of the positive side brush 6. Therefore, the positive side brush holder 5 can be used to hold brushes in the same way as the negative side brush holder 11 without using the conventional insulating plate 4. Since it can be directly fixed to the substrate 14, the manufacturing and assembly man-hours are reduced compared to conventional ones. Further, each of the brush holders 5 and 11 is caulked to one side of the brush holder base plate 14, but the brush holder 1 on the negative side
By providing a threaded part on the caulking protrusion 11c of 1, and screwing the screw 3 into this threaded part, each brush holder 5, 11 and brush holding board 14 are fixed to the rear bracket 1, and the screw 3 Since the brush holder 11 and the brush holding board 14 are electrically connected through the
There is no need to use any special fixing means or electrical connection means when installing the brush holder 11 and electrically connecting the brush holder 11 and the rear bracket 1.

In the above description, the negative side of the power supply is grounded, but the same effect can be achieved with a power supply grounded on the positive side.

As described above, this invention consists of a board made of an insulator, on which the first and second brush holders are respectively provided, and a conductive fixing member attached to the conductive casing of the starting motor. and one end of the second brush held by the second brush holder is in sliding contact with the power supply part of the armature of the starting motor,
Since the other end of the brush is connected to the fixing member, in the insulating means of the first brush,
Since there is no need to attach the first brush holder to the board via an insulating plate as in the conventional case, the insulating plate can be eliminated. The second brush holder can be attached to a common board, which reduces the number of parts and makes manufacturing extremely easy.Furthermore, the fixing member that fixes the board to the casing allows the second brush to be attached to the casing of the starter motor. Since the electrical connections are made, there is no need to provide any special electrical connection means.

[Brief explanation of the drawing]

Figure 1 is a front view showing a conventional device partially in section;
FIG. 2 is a plan view showing the main parts of the conventional device shown in FIG. 1, FIG. 3 is a partially sectional front view showing an embodiment of the invention, and FIG. FIG. 3 is a plan view showing main parts of an example. In the figure, 1 is a housing of the starting motor, 2 and 14 are substrates, 3 is a fixing member, 4 is an insulating plate, 5 is a first brush holder, 6 is a first brush, 8 is a power supply unit, 9,
13 is a lead wire, 10 is a field coil, 11 is a second
12 is a second brush. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] A substrate made of an insulator and fixed to the conductive casing of the starting motor by a conductive fixing member, first and second brush holders each provided on one side of the substrate, and the first brush holder. a first end held at the starting motor armature, one end connected to the field coil of the starting motor, and the other end slidably connected to the power supply part of the starting motor armature.
A brush device for an engine starting motor, comprising: a second brush held by the second brush holder, one end of which is in sliding contact with the power feeding section, and the other end of which is connected to the fixing member.