JP3056290U - DC motor with brush - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a brush capable of fixing a brush holding plate to a cover portion and a body earth on a negative brush side without requiring a fixing bolt and accompanying screw tightening work. To obtain a DC motor. SOLUTION: A holding plate fixing means 5 for fixing a brush holding plate 4 to a cover part 1 is provided with a projection 28 protruding from the cover part 1.
And a hole 29 provided in the portion of the insert-molded negative electrode conductor 13 exposed from the brush holding plate 4 by the hole 20 as a constituent element, the protrusion 28 is fitted into the hole 29, and the tip of the protrusion 28 protruding from the hole 29. A portion is prevented from being pulled out by a crushed enlarged portion formed by pressurizing and deforming the portion.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to a DC motor with a brush in which a portion connected to a negative electrode brush is body-grounded to a cover by metal holding plate fixing means for fixing the brush holding plate to the cover.

[0002]

[Prior art]

 FIGS. 6 to 9 show the relationship between a cover portion and a brush holding plate fixed to the cover portion in a conventional brushed DC motor of this type. FIG. 6 shows a state before the brush holding plate is incorporated into the cover portion. FIG. 7 is an enlarged view of the brush holding plate fixing means of the insert molded negative electrode conductor incorporated in the thick portion of the brush holding plate in FIG. 6, and FIG. FIG. 9 is a cross-sectional view taken along the line BOB of FIG.

[0003] In this DC motor with a brush, a stator and a rotor are assembled in a metal housing as opposed to each other, not shown, as is well known. A metal cover 1 at the end of the housing supports a bearing 2 for rotatably supporting a rotating shaft (not shown) supporting the rotor. The bearing 2 is fitted and supported in a cylindrical bearing holding cylinder 1 a formed around the shaft through hole 3 in the center of the cover 1. A resin brush holding plate 4 is fixed to the cover 1 by a metal brush holding plate fixing means 5.

[0004] The brush holding plate 4 has a pair of positive brush holders 6 whose inward ends are opposed to each other at 180 ° positions, and a pair of the positive brush holders 6. And a pair of negative brush holders 7 which are provided at 90 ° intervals and whose inwardly facing ends face each other. A positive brush 8 is slidably inserted into the brush insertion hole 6a of the positive brush holding section 6, and a negative brush 9 is slidably inserted into the brush insertion hole 7a of the negative brush holding section 7. One ends of conductive wires 10 and 11 called pigtails are connected to the positive brush 8 and the negative brush 9.

In addition, one insert-molded positive electrode conductor 12 and two insert-molded negative electrode conductors 13 that are insert-molded at the time of molding are embedded in the thick portion of the resin-made brush holding plate 4. The insert-molded positive electrode conductor 12 made of a thin-walled conductor has a “U” shape, and bypasses the side of the shaft through hole 14 at the center of the brush holding plate 4, and has both ends at 180 ° different positions. Positioned to be present. Both ends of the insert-molded positive electrode conductor 12 are formed by two regions 180 ° different from each other among four regions of the brush holding plate 4 divided into four by the positive brush holding portion 6 and the negative brush holding portion 7. Are located in The two insert-molded negative electrode conductors 13 made of a thin conductor are arranged in the remaining two regions of the brush holding plate 4 which are different from each other by 180 °. Positive electrode terminals 15 are integrally formed at both ends of the insert molded positive electrode conductor 12 and are exposed on the surface of the resin brush holding plate 4. Further, a negative electrode terminal 16 is integrally formed on each insert molded negative electrode conductor 13 so as to be exposed on the surface of the resin brush holding plate 4. The other end of the corresponding conductor 10 is connected to each positive electrode terminal 15 by spot welding. The other end of the corresponding conducting wire 11 is connected to each negative electrode terminal 16 by spot welding. One positive electrode terminal 15 is electrically connected to a positive electrode connector 18 in a cylindrical connector housing 17 provided integrally with a part of the brush holding plate 4. The connector housing 17 extends through the hole 19 of the cover 1 and is led out to the opposite side of the cover 1. Part of each insert molded negative electrode conductor 13 is exposed by a hole 20 provided in the brush holding plate 4.

[0006] The brush holding plate fixing means 5 for fixing the brush holding plate 4 to the cover portion 1 includes a metal fixing bolt 21 which penetrates a hole 22 provided in the insert-molded negative electrode conductor 13 at the position of the hole 20. It is configured by being screwed into a screw hole 23 provided in the cover 1 and fastened. With such a configuration, each negative electrode brush 9 is connected to the conductive wire 11, the insert molded negative electrode conductor 13 connected to the conductive wire 11 and incorporated in the thick portion of the brush holding plate 4, and the holding plate fixing means 5. The body is grounded to the cover part 1.

The brush holding plate 4 holds springs 24 and 25 for individually biasing the positive brush 8 and the negative brush 9 by spring holding portions 26 and 27.

[0008]

[Problems to be solved by the invention]

 However, in such a conventional brushed DC motor, the fixing of the brush holding plate 4 to the cover 1 and the body ground on the side of the negative electrode brush 9 are performed by fixing the metal brush holding plate using the fixing bolt 21. 5, the fixing bolt 21 is required as a special part, which increases the cost. Further, there is a problem that the screw tightening operation by the fixing bolt 21 is difficult to automate.

An object of the present invention is to fix a brush holding plate to a cover portion and to perform body grounding on a negative electrode brush side without the need for a fixing bolt and accompanying screw tightening work. An object of the present invention is to provide a brushed DC motor.

[0010]

[Means for Solving the Problems]

 In the present invention, a stator and a rotor are incorporated in a metal housing so as to face each other, and a rotation shaft supporting the rotor is rotatably supported on a metal cover at an end of the housing. A bearing is supported, a brush holding plate made of resin is fixed to the cover by metal holding plate fixing means, and a positive brush and a negative brush are supported on the brush holding plate. The brush is connected to the conductor, the brush connected to the conductor, and body-grounded to the cover via the insert-molded negative conductor incorporated into the thickness of the brush holding plate and the holding plate fixing means. It is intended to improve the DC motors with the motor.

In the DC motor with brush according to the present invention, the holding plate fixing means includes, as constituent elements, a protrusion provided on one of the insert-shaped negative electrode conductor and the cover, and a hole provided on the other. The projection is fitted into the hole, and is prevented from coming off by the crushed and enlarged portion at the tip of the projection protruding from the hole.

According to such a holding plate fixing means, since the fixing is performed by using each of the insert molded negative electrode conductor and a part of the cover portion, a fixing bolt which is a separate component is not required, and An increase in cost can be prevented. In addition, in this holding plate fixing means, the tip end of the projection protruding from the hole is pressed to form a crushed enlarged portion to prevent removal, so that screw tightening work becomes unnecessary, and automation of the fixing work is facilitated. It can be aimed at. Further, in the holding plate fixing means, since the insert-molded negative electrode conductor and the metal cover are fixed by mechanical connection, body earth can be performed without any trouble.

In this case, the protrusion may be provided on the cover portion or may be provided on the insert molded negative electrode conductor. When the projection is provided on the cover, there is an advantage that the projection can be molded together when the cover is molded. If the projection is provided on the insert-molded negative conductor, the insert-molded negative conductor is made of a thin conductor, and the projection is also formed by molding from the thin conductor. The advantage is that it can be easily performed with a small force.

[0014]

[Embodiment of the invention]

 FIGS. 1 to 4 show the relationship between a cover part and a brush holding plate fixed to the cover part in the first example of the embodiment of the brushed DC motor according to the present invention. FIG. FIG. 2 is a longitudinal sectional view showing a state before the plate is incorporated in the cover portion. FIG. 2 is an enlarged view of a portion of the brush holding plate fixing means of the insert molded negative electrode conductor incorporated in the thick portion of the brush holding plate in FIG. FIG. 4 is a front view showing a state in which the brush holding plate is incorporated in the cover, and FIG. 4 is a sectional view taken along the line AOA of FIG. Parts corresponding to those in FIGS. 6 to 9 are denoted by the same reference numerals.

In the brush-equipped DC motor of this embodiment, the holding plate fixing means 5 includes a projection 28 protruding together with the cover 1 at the time of molding and an insert-molded negative electrode exposed from the brush holding plate 4 by the hole 20. A hole 28 provided in the conductor 13 is a constituent element, and a protrusion 28 is fitted into the hole 29, and a crushing expansion formed by compressing and deforming the tip of the protrusion 28 protruding from the hole 29. It is configured to be retained by the diameter portion 30.

Other configurations of this DC motor with brush are the same as those of the conventional example shown in FIGS.

According to such a holding plate fixing means 5, since the fixing is performed by using a part of each of the cover portion 1 and the insert-molded negative electrode conductor 13, a fixing bolt, which is a separate component, becomes unnecessary. An increase in cost can be prevented. In addition, in this holding plate fixing means 5, since the distal end portion of the projection 28 protruding from the hole 29 is pressed to form the crushing enlarged diameter portion 30 to prevent the protrusion, the screw tightening work becomes unnecessary. The fixing work can be easily automated. Further, since the holding plate fixing means 5 is fixed by mechanical coupling between the insert molded negative electrode conductor 13 and the metal cover portion 1, body earth can be performed without any trouble. In particular, when the projections 28 are provided on the cover 1 as in this example, there is an advantage that the projections 28 can be molded together when the cover 1 is molded.

FIGS. 5A and 5B show the relationship between the cover part and the insert-molded negative electrode conductor of the brush holding plate fixed to the cover part in the second embodiment of the brushed DC motor according to the present invention. 5 (A) is a longitudinal sectional view showing a state before fixing the cover and the insert-molded negative electrode conductor, and FIG. 5 (B) is a state after fixing the cover and the insert-molded negative electrode conductor. FIG. Parts corresponding to those in FIGS. 1 to 4 are given the same reference numerals.

In the DC motor with brush of this embodiment, the holding plate fixing means 5 includes a projection 28 formed by projecting the insert-molded negative electrode conductor 13 by press molding, and a hole 29 provided in the metal cover 1. The protrusion 28 is fitted into the hole 29, and is prevented from being pulled out by the crushed enlarged portion 30 formed by pressing and deforming the tip of the protrusion 28 protruding from the hole 29. ing.

The other configuration of the DC motor with brush is the same as that of the first embodiment of the present invention shown in FIGS. 1 to 4.

In the holding plate fixing means 5 as well, the fixing is performed by using a part of each of the insert-molded negative electrode conductor 13 and the cover 1, so that a fixing bolt as a separate component is not required, and cost is reduced. Can be prevented from rising. Also, in the holding plate fixing means 5, the distal end portion of the projection 28 protruding from the hole 29 is pressed to form the crushed enlarged-diameter portion 30, thereby preventing the protrusion 28 from coming off. Work can be easily automated. Further, since the holding plate fixing means 5 is also fixed by mechanical coupling between the insert-molded negative electrode conductor 13 and the metal cover portion 1, body earth can be performed without any trouble. In particular, when the projection 28 is provided on the insert-molded negative electrode conductor 13 as in this example, the insert-molded negative electrode conductor 28 is formed of a thin-walled conductor, and accordingly, the projection 28 is also formed from a thin-walled conductor. Because of this configuration, there is an advantage that the work of crushing the projection 28 can be easily performed with a small force.

The holding plate fixing means 5 may be formed by spot welding the insert molded negative electrode conductor 13 and the cover 1.

[0023]

[Effect of the invention]

 In the brushed DC motor according to the present invention, the holding plate fixing means includes, as constituent elements, a projection provided on one of the insert-shaped negative electrode conductor and the cover, and a hole provided on the other. And is prevented from being pulled out by the crushed and enlarged portion of the tip of the projection protruding from the hole, so that the fixing is performed using a part of the insert molded negative electrode conductor and a part of the cover. As a result, a fixing bolt, which is a separate component, is not required, and a rise in cost can be prevented. In addition, in this holding plate fixing means, the tip end of the protrusion protruding from the hole is pressed to form a crushed enlarged diameter portion, thereby preventing the protrusion from being removed. It can be easily achieved. Further, in the holding plate fixing means, the fixing is performed by mechanical coupling between the insert molded negative conductor and the metal cover portion, so that the body grounding can be performed without any trouble.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a state before a brush holding plate is incorporated in a cover part in a first example of an embodiment of a DC motor with a brush according to the present invention.

FIG. 2 is an enlarged view of a portion of a brush holding plate fixing means of an insert molded negative electrode conductor incorporated in a thick portion of the brush holding plate in FIG. 1;

FIG. 3 is a front view showing a state in which a brush holding plate is incorporated in a cover in the first example.

FIG. 4 is a sectional view taken along line AOA of FIG. 3;

FIGS. 5A and 5B show the relationship between the cover and the insert-molded negative electrode conductor of the brush holding plate fixed to the cover in the second embodiment of the brushed DC motor according to the present invention; (A) is a longitudinal sectional view showing a state before fixing the cover portion and the insert molded negative electrode conductor,
(B) is a longitudinal cross-sectional view showing a state after the cover and the insert-molded negative electrode conductor are fixed.

FIG. 6 is a longitudinal sectional view showing a state before a brush holding plate is incorporated into a cover portion in a conventional DC motor with a brush.

7 is an enlarged view of a portion of the brush holding plate fixing means of the insert-molded negative electrode conductor incorporated in the thick portion of the brush holding plate in FIG. 6;

FIG. 8 is a front view showing a state in which a brush holding plate is incorporated in a cover portion in a conventional DC motor with a brush.

FIG. 9 is a sectional view taken along the line BOB of FIG. 8;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cover part 1a Bearing holding cylinder part 2 Bearing 3 Shaft through-hole 4 Brush holding plate 5 Brush holding plate fixing means 6 Positive brush holding part 6a Brush insertion hole 7 Negative brush holding part 7a Brush insertion hole 8 Positive brush 9 Negative brush 10, DESCRIPTION OF SYMBOLS 11 Lead wire 12 Insert molded positive conductor 13 Insert molded negative conductor 14 Shaft through-hole 15 Positive terminal 16 Negative terminal 17 Connector housing part 18 Positive connector 19, 20 hole 21 Fixing bolt 22 Hole 23 Screw hole 24, 25 Spring 26, 27 Spring holding Part 28 protrusion 29 hole 30 crushing enlarged diameter part

Claims (3)

[Utility model registration claims] A stator and a rotor are assembled in a metal housing so as to face each other, and a rotation shaft supporting the rotor is rotatable on a metal cover at an end of the housing. The cover is fixed to the cover with a resin brush holding plate fixed by metal holding plate fixing means. The brush holding plate supports a positive brush and a negative brush, and The negative-electrode brush is connected to the shaft-side commutator, and the negative-electrode brush is connected to the conductive wire through the insert-molded negative-electrode conductor incorporated in the thick portion of the brush holding plate and the holding-plate fixing means. In a brushed DC motor body-grounded to a cover part, the holding plate fixing means is provided on one of the insert molded negative electrode conductor and the cover part, and provided on the other. A hole as a component, the protrusion is fitted into the hole, brush DC motor, characterized in that it is constituted by fit retaining the crush enlarged diameter portion of the tip portion of the projection which projects from the hole. 2. The DC motor with a brush according to claim 1, wherein the protrusion is provided on the cover. 3. The brushed DC motor according to claim 1, wherein the protrusion is provided on the insert-molded negative electrode conductor.