JP2000050561A - Small-sized dc motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the possibility of the fault of a small-sized DC motor, by improving the fixing strength of its brush terminal. SOLUTION: Bendable claw portions 18 are formed on the outside surfaces of a leg portion 13 of a brush terminal 11. Squeezing the leg portion 13 into a terminal inserting hole 20a of a terminal holder 20 made of an insulation resin made to pass the end of the brush terminal 11 through the hole 20a, pull- out preventing claw portions 16 bite fixedly into the wall surfaces of the terminal inserting hole 20a, to protrude downward from the hole 20a the claw portions 18 of the lower side of the leg portion 13. By having claw portions 18 protruded outward, they are crimped thereafter to have the brush terminal 11 join firmly to the terminal holder 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small DC motor, and more particularly, to a small DC motor having an improved mounting strength of a brush terminal.

[0002]

2. Description of the Related Art A conventional technique will be described with reference to FIGS. In FIG. 8, 1
Is a small DC motor, 2 is a magnet as a stator, 3 is a rotor, 4 is a core of the rotor, 5 is a winding, and 6 is a commutator. A brush 7 is in contact with the outer peripheral surface of the commutator 6. The base end of the brush 7 is welded to a brush terminal 8. The brush terminal 8 is fitted to a resin terminal holder 9 and protrudes outward from a hole in the rear cover 10.

FIG. 9 shows a state in which the brush terminal 8 is fitted to the brush terminal 8. A wedge-shaped retaining claw 8b protruding outward is provided on both sides of a leg 8a of the brush terminal 8 formed in a T-shape. Is provided.

When the leg portion 8a of the brush terminal 8 is pressed into the terminal insertion hole 9a of the terminal holder 9 and penetrates the tip, the retaining claw portion 8b bites into the wall surface of the terminal insertion hole 9a and is fixed. However, when the power supply wires are soldered to the legs 8a that penetrate the terminal insertion holes 9a and protrude outward, the heat conducted to the brush terminals 8 softens the wall surfaces of the terminal insertion holes 9a of the terminal holder 9. , Retaining claw 8b of brush terminal 8
When the brush terminal 8 is shaken, the contact between the commutator 6 and the brush 7 may be poor.

Therefore, there arises a technical problem to be solved in order to prevent the brush terminal 8 from oscillating and to reduce the possibility of motor failure, and the present invention aims to solve the above-mentioned problem. I do.

[0006]

SUMMARY OF THE INVENTION The present invention proposes a small DC motor in which a brush terminal is press-fitted and fixed in a terminal insertion hole of an insulating terminal holder of a motor. A small DC motor is provided, wherein a bendable claw portion is formed on a leg portion protruding outward through a terminal insertion hole, and the claw portion is bent and fixed to a terminal holder. .

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a brush terminal 11. The brush terminal 11 is a terminal part formed by stamping and plating a steel plate, and for inserting an electric wire into a tip portion of a leg 13 extending downward from the center of a long head 12 to the left and right. Is punched out.

Downward wedge-shaped retaining claws 15 and 16 projecting outward are provided on both side surfaces of the head 12 and the leg 13, and the claw 17 is cut and raised at the center of the leg 13. I have. The leg 13 has a width that is once reduced in the middle from the lower end to the upper side, then expands, and a claw portion 18 that extends downward from both sides of the enlarged portion is formed.

[0009] As shown in FIG.
The base of a nickel-white brush 19 is spot-welded to the head 12 of the brush terminal, and the three-part cut end of the brush 19 projects horizontally from the head 12 of the brush terminal 11.

FIG. 3 shows a process of mounting the brush terminal 11, in which the leg 13 of the brush terminal 11 is pressed into the terminal insertion hole 20a of the terminal holder 20 made of resin as shown in FIG. When this is done, the retaining claws 15 and 16 bite into the wall surface of the terminal insertion hole 20a and are fixed, and the lower claw 18 is inserted into the terminal insertion hole 2a.
0a protrudes downward. Then, as shown in (b), when the nail portion 18 is bent outward and laterally crimped, the terminal holder 20 is sandwiched between the head portion 12 of the brush terminal 11 and the nail portion 18 from above and below, and the brush terminal 1
1 and the terminal holder 20 are firmly connected.

In the caulking step, as shown in FIG. 4, a dedicated die 21 having a groove 21a formed in the center of the tip of the wedge is used.
By using, the two claw portions 18 can be crimped outward in one step.

The method of bending the claw portions is not limited to the above-described lateral direction, and the two claw portions 18 may be bent forward or backward as shown in FIG. 5, or may be bent as shown in FIG. One of the claws 18 may be bent forward and the other may be bent rearward. Further, as shown in FIG. 7, a claw portion 24 may be formed at the center of the leg portion 23 of the brush terminal 22 by a cutout process, and the claw portion 24 may be bent and fixed to the terminal holder.

It should be noted that the present invention is not limited to the above-described embodiment, and various modifications are possible within the technical scope of the present invention, and it goes without saying that the present invention extends to those modifications. is there.

[0014]

As described above, in the small DC motor of the present invention, the claw portion is formed on the leg portion of the brush terminal that protrudes outward through the terminal insertion hole, and the claw portion is bent so that the terminal holder is bent. So that it can be fixed to
The brush terminal is firmly fixed to the terminal holder. Therefore, even if an external force is applied to the brush terminal or the terminal insertion hole of the terminal holder is softened by the heat generated when the power supply wire is soldered to the legs, the brush terminal does not shake, and the contact between the commutator and the brush does not occur. It is an invention that can eliminate the possibility of causing an abnormality in the motor and contributes to the improvement of the reliability of the small DC motor.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention, wherein (a) is a front view of a brush terminal, and (b) is a side view.

FIG. 2 shows a brush terminal with a brush attached,
(A) is a plan view, (b) is a front view, and (c) is a side view.

FIGS. 3 (a) and 3 (b) are explanatory diagrams showing a process of attaching a brush terminal.

FIG. 4 is an explanatory view showing a process of mounting a brush terminal using a special caulking jig.

FIG. 5 is an explanatory view showing another embodiment and showing an attached state of a brush terminal.

FIG. 6 is an explanatory view showing another embodiment and showing an attached state of a brush terminal.

FIG. 7 is a front view of a brush terminal according to another embodiment.

FIG. 8 shows a conventional example, and is a partially cutaway side view of a small DC motor.

FIG. 9 is an explanatory view showing an attached state of a conventional brush terminal.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Brush terminal 12 Head 13 Leg 18 Claw 20 Terminal holder 20a Terminal insertion hole 21 Die

 ────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Koichi Higashii 8-8-2 Kokuryo-cho, Chofu-shi, Tokyo Mitsumi Electric Co., Ltd. F-term (reference) 5H605 AA04 BB05 BB09 CC07 EA23 GG03 5H623 AA04 BB07 GG11 LL04

Claims (1)

[Claims] 1. A small DC motor in which a brush terminal is press-fitted and fixed in a terminal insertion hole of an insulating terminal holder of a motor, wherein a bendable claw is formed on a leg that penetrates the terminal insertion hole and protrudes outward. A small DC motor formed and fixed to a terminal holder by bending the claw portion.