JP3035487B2 - Rotating electric machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotating electric machine such as an electric motor or a generator, and more particularly, to a rotating electric machine in which a brush housed in a brush holder is moved forward and backward with respect to a commutator for sliding contact.

[0002]

2. Description of the Related Art In general, in a rotating electric machine, for example, an electric motor, a brush is held in a brush holder having an opening facing a commutator so that the brush can be housed, and the brush is moved forward and backward with respect to the commutator so that the tip of the brush is moved. The surface is brought into sliding contact with the commutator.

In this case, since the brush is connected to the electrode terminal via the pigtail, a guide for inserting the pigtail is formed in the brush holder by notch.

[0004] When a brush holder in which such a guide is notched is formed by resin molding, a brush holder having a guide is formed by matching a mold formed of a split mold. I have.

However, when the brush holder is formed by using the split mold as described above, the mold mating surface of the split mold is located on the inner wall surface of the brush holder. The resin penetrates and becomes burrs and projects on the inner wall surface of the brush holder. The projected burrs hinder the smooth advance / retreat operation of the brush, and the electric motor is not smoothly driven. There's a problem.

Therefore, as shown in Japanese Patent Publication No. Hei 7-1996, a groove forming portion is provided in the mold matching portion of the split mold, and the burr generating portion is retracted outside the inner wall surface of the brush holder in the groove. There has been known a configuration in which the burr is prevented from hindering the smooth advance / retreat operation of the brush, and the electric motor can be smoothly driven.

[0007] Further, in the above-mentioned publication, when a mold-matching edge of a split mold is formed on a brush projecting edge of a brush holder,
There is disclosed a case in which the influence of burrs is avoided by configuring a configuration in which the mold-matching edge is retracted to the outside of the inner wall surface of the brush holder at the brush projecting end edge portion of the brush holder.

[0008]

Problems to be Solved by the Invention
As disclosed in Japanese Patent Publication No. 96, when a portion where the mold matching edge is retracted outward from the inner wall surface of the brush holder is formed at the brush protruding edge of the brush holder, the influence of burrs generated at the mold matching edge is avoided. However, due to the retreating portion for the burr, the contact distance of the brush to the brush holder in the sliding direction of the brush is shortened only by the retreating portion. Is pressed in the direction of rotation of the brush, the tip of the brush moves more than the clearance between the brush and the brush holder, and the head is easily swung. As a result, there is a problem that the operating noise of the motor is increased.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a mold for forming a brush holder by molding a mold comprising a split mold. It is an object of the present invention to provide a rotating electric machine that can avoid the influence of burrs that occur and ensure smooth driving, and that can prevent the swing of the brush and prevent the operating noise from increasing.

[0010]

In order to achieve the above object, according to the first aspect of the present invention, there is provided a brush holder made of a synthetic resin having at least an opening facing a commutator, and slidable on the brush holder. And a brush that moves forward and backward with respect to the commutator, and has a front end surface slidably contacting the commutator. The brush holder is formed to face three side surfaces along the sliding direction of the brush. Three side walls, and at least one of the two side walls among the three side walls, which protrudes from one side wall end toward the other side wall end, and faces the remaining side surfaces along the sliding direction of the brush. In a rotating electric machine having a guide piece, at least a commutator-side end of an inner wall surface of a side wall having the guide piece is provided with a bus at the time of resin molding.
Li formed therein, and a first recess in which the burr is prevented from projecting inwardly from the inner wall surface formed in a direction intersecting the sliding direction of the brush, from the first recess Also, a guide surface of the brush, which is substantially flush with the inner wall surface, is formed at a position on the commutator side.

According to the present invention, at least the burr at the time of molding projects inward from the inner wall surface by the first recess formed in the direction intersecting the sliding direction of the brush on the inner wall surface of the side wall having at least the guide piece. Can be reliably prevented, and the brush can be smoothly moved forward and backward, so that the rotating electric machine can be driven smoothly. The brush is guided by the guide surface of the brush, which is almost flush with the inner wall surface formed at the bottom, preventing the brush from oscillating due to the rotation of the commutator and reducing the operating noise of the rotating electric machine. It can be reliably prevented.

According to a second aspect of the present invention, in the first aspect, the guide piece has a position where the end face on the commutator side is retracted from the position of the end face on the commutator side of the side wall having the guide piece. And the first concave portion is formed to extend over an extension of an end surface of the guide piece on the commutator side.

According to the present invention, the end face of the guide piece on the commutator side is formed at a position recessed from the end face position of the side wall on the commutator side, and the first recess extends over an extension of the end face position of the guide piece. With this configuration, the guide piece and the first recess can be easily formed by the mold that regulates the lower surface of the guide piece and the mold that regulates other portions.

According to a third aspect of the present invention, there is provided the first or second aspect.
Wherein the brush holder comprises: a first mold for regulating at least an inner wall surface of the guide piece and an inner wall surface at a position corresponding to the guide piece of the side wall connected to the guide piece;
Molded by a mold having a second mold covering the mold,
The first concave portion is formed by a convex portion formed at a position where the first mold and the second mold match each other.

According to the present invention, the first concave portion is formed by the convex portions of the first mold and the second mold, and the second concave portion is formed by the second mold.
The guide surface adjacent to the first concave portion can be formed so as to protrude with the mold. Therefore, it can be formed by only two molds, and simplification of the mold and cost reduction can be achieved.

According to a fourth aspect of the present invention, in the first aspect of the present invention, at least one of the corners of the guide surface is provided at least at a corner facing the direction in which the brush is inserted into the brush holder. And a non-engaging portion that does not engage with the second member is formed.

According to the present invention, the non-engaging portion is formed at the corner of the guide surface facing the direction of insertion into the brush holder, so that the tip of the brush can be inserted when the brush is inserted into the brush holder. Can be prevented from engaging with the corners and being difficult to insert.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the guide surface is formed on a side wall located on the downstream side in the rotational direction of the commutator.

According to the present invention, since the guide surface is formed on the side wall located on the downstream side in the rotational direction of the commutator, even if the brush is pressed in the rotational direction by the rotation of the commutator.
The tip of the brush can be guided by the guide surface, and swinging of the tip of the brush can be reliably prevented.

According to a sixth aspect of the present invention, in any one of the first to fifth aspects, a burr at the time of molding is prevented from protruding inward from the inner wall surface at the outer peripheral edge of the inner wall surface of the guide piece. Wherein the second concave portion is formed.

According to the present invention, by forming the second concave portion on the outer peripheral edge of the inner wall surface of the guide piece, the burr is formed by the second concave portion even when the outer peripheral edge of the guide piece coincides with the mold-matching edge portion. Can be retracted outward from the inner wall position of the guide piece, and the influence of burrs can be avoided more reliably.

According to a seventh aspect of the present invention, in any one of the first to sixth aspects, the side wall sandwiched between the opposed two side walls is located at a position corresponding to the guide piece and corresponds to an inner wall surface of the guide piece. And a third recess formed at an edge of the through hole to prevent burrs during molding from protruding inward from the inner wall surface of the side wall. I do.

According to the present invention, it is possible to insert the mold for regulating the lower surface of the guide piece from the through hole having a size corresponding to the guide piece, and furthermore, the third recess formed at the edge of the through hole. The burr generated at the edge of the mold matching between the mold penetrating the through hole and the other mold is retracted from the inner wall surface surrounded by the two side walls, so that the influence of the burr can be avoided more reliably.

[0024] The invention according to claim 8 is a brush holder made of synthetic resin having at least an opening facing the commutator,
A brush that is slidably held by the brush holder, moves forward and backward with respect to the commutator, and has a tip surface slidably in contact with the commutator. Three side surfaces along and three side walls formed opposite to each other;
And a guide piece protruding from at least one of the two side walls of the three side walls toward the other side wall end and facing the remaining side surface along the sliding direction of the brush. In at least the commutator side end of the side wall inner wall surface having the guide piece, leaving a guide surface of the brush that is substantially flush with the inner wall surface, adjacent to the guide surface, the burr at the time of molding, A first concave portion for preventing the protrusion from protruding inward from the inner wall surface is formed in a direction intersecting the sliding direction of the brush.

According to the present invention, the commutator on the inner wall surface of the side wall having at least the guide piece leaves the guide surface of the brush substantially flush with the inner wall surface at the end, and the first recess is provided adjacent to the guide surface. By forming, the same function and effect as the first aspect of the invention can be obtained.

[0026]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIGS. 1 to 9 are views showing an electric motor according to one embodiment of the present invention.

The electric motor 10 is used, for example, as a power seat motor of an automobile. As shown in FIG.
In the motor housing 16 combined with the above.

The rotor 12 has a winding portion (not shown) at a portion corresponding to the yoke, and a commutator 18 (see FIG. 4) provided at a portion corresponding to the motor housing 16.

The yoke 14 is provided with a magnet (not shown) at a position corresponding to the winding portion of the rotor 12 and a bearing (not shown) for rotatably supporting one end of the rotor 12. It is in a state.

The motor housing 16 is formed of a synthetic resin. As shown in FIGS.
A bearing portion 20 rotatably supporting the other end of the second 2, a fitting wall portion 22 to the yoke 14, a connector mounting portion 24, and a brush holder 26 are integrally formed.

The brush holder 26 is formed as a pair of brush holders facing each other with the commutator 18 being mounted therebetween.

Then, a pair of connector terminals 28a and 28b are mounted in the connector mounting portion 24, and a pair of brushes 30 are disposed on a pair of brush holders 26. Each of the pair of brushes 30 is provided with a pigtail 32 for conductivity, and the pigtail 32 is connected to one connector terminal 28a via a thermistor 34 and a plate terminal 36 on the one hand, and is connected via the plate terminal 36 on the other hand. The other connector terminal 28b
Connected.

Each brush 30 is slidably held by a brush holder 26, and a spring 38
To move forward and backward with respect to the commutator 18,
The tip end surface 30a is in sliding contact with the commutator 18, and each brush holder 26 has a brush 3 as shown in FIGS.
The first, which is formed to face three sides along the sliding direction of 0,
Second and third three side walls 40, 42 and 44;
The end of the side wall 40 protruding from the end opposite to the third side wall 44 toward the end of the second side wall 42 opposed thereto, and the pigtail 3
And a guide piece 46 that covers a part of the remaining side surface along the sliding direction of the brush 30 while leaving the insertion portion of the commutator 18.
And the surface on the opposite side are opened, and the commutator 18
The tip surface 30a of the brush 30 can be protruded from the surface facing the above.

An engaging portion 48 for engaging one end of the spring 38 is formed in a notch at a position opposite to the commutator 18 side of the first side wall 40. A cutout portion 50 through which the other end of the spring 38 is inserted is formed at a position opposite to the child 18 side.

When the brush holder 26 having such a guide piece 46 or the cutout portion 50 is formed by resin molding, the brush holder 26 has an inner wall surface 4 of the guide piece 46 as shown in FIG.
6a and inner guide piece 4 on inner wall surface 40a of first side wall 40
6 The first die 5 having the guide piece forming portion 52 for regulating the corresponding portion and the notch forming portion 54 for forming the notch 50
6 and a second mold 58 that covers the first mold 56 and regulates the other surface of the other part of the brush holder 26. .

In this case, the resin material protrudes into the sliding area of the brush 30 on the mating surface between the guide piece forming portion 52 of the first mold 56 and the second mold 58, and burrs are generated. In particular, when burrs occur on the side of the guide piece forming portion 52 on the side of the commutator 18 and the mold mating surface of the second mold 58,
Since the smooth operation of the brush 30 will be hindered,
By forming a recess at that position for retracting the burrs outward from the inner wall surface 40a of the first side wall 40, it is possible to eliminate the influence of the burrs.

In this case, when the end face of the guide piece 46 on the side of the commutator 18 coincides with the end face of the first side wall 40 on the side of the commutator 18, the commutator on the inner wall surface 40 a of the first side wall 40. A concave portion is formed at the end on the side of the commutator 18 when the rotor is rotated downstream from the concave side.
As a result, the brush 30 is pressed against the concave side, causing a swinging state, and the operating noise increases.

Therefore, the end face 46b of the guide piece 46 on the commutator 18 side is connected to the end face 40b of the first side wall 40 on the commutator 18 side.
Formed at a position retracted with respect to the commutator 18 from the position,
The mating surface of the guide piece forming portion 52 of the first mold 56 and the second mold 58 on the commutator 18 side is set to a position retracted from the position of the end face 40b of the first side wall 40 on the commutator 18 side. And
The first concave portion 60 is formed in a direction intersecting the sliding direction of the brush 30 over the extension of the end surface 46 b of the guide piece 46 on the commutator 18 side.

As shown in FIG. 7, the first concave portion 60 is formed between the guide piece forming portion 52 of the first mold 56 and the second mold 5.
8 are formed by the convex portions 52a and 58a formed at the position where the mold is matched with the mold 8, and the burrs generated at the position of the mold matching surface are:
First concave portion 60 formed by convex portions 52a and 58a
It fits inside.

Then, the commutator 18 is made smaller than the first recess 60.
A guide surface 62 of the brush 30, which is substantially flush with the inner wall surface 40a of the first side wall 40, is formed at a position on the side.

That is, the guide surface 62 of the brush 30 which is substantially flush with the inner wall surface 40a is left at the end of the inner wall surface 40a of the first side wall 40 on the commutator 18 side, and is adjacent to the guide surface 62. It is in a state where the first concave portion 60 is formed.

Therefore, the contact distance between the first side wall 40 and the brush 30 is reduced by the first recess 60 even though the first recess 60 allows the burr to be retracted into the first recess 60. Can be surely secured by
The rotation of the commutator 18 causes the brush 30 to move to the first side wall 4.
Even if it is pressed against the 0 inner wall surface 40a, it is possible to prevent the head from swinging.

On the other hand, a mold matching surface is also located between the surface that regulates the lower surface of the guide piece 46 of the first mold 56 and the second mold 58. As a result, when the guide piece 46 is formed, burrs protrude inward from the inner wall surface 46a at the outer peripheral edge of the inner wall surface 46a of the guide piece 46. Therefore, by forming a second recess 64 on the outer peripheral edge of the inner wall surface 46a of the guide piece 46 for retracting the burr outward from the inner wall surface 46a, the influence of the burr on the guide piece 46 is prevented. I have.

The second recess 64 is provided in the guide piece forming portion 5.
The second guide piece 46 is formed by a convex portion 52b formed in a U-shape on the periphery of the surface that regulates the lower surface of the guide piece 46.

Further, since the guide piece forming portion 52 penetrates the third side wall 44, a through hole 66 having a size corresponding to the guide piece 44 is formed at a position corresponding to the guide piece 46 on the third side wall 44. Then, the mating surface of the guide piece forming portion 52 and the second mold 58 is located at the edge of the through hole 66, and burrs during molding are formed on the edge of the through hole 66 by the third side wall 44. Will protrude more inward than the inner wall surface 44a. For this reason, by forming the third concave portion 68 at the edge of the through hole 66, the burr generated at the edge of the through hole 66 is retracted into the third concave portion 68, and the influence of the burr is prevented. .

As shown in FIG. 6, the third concave portion 68 is formed by a convex portion 58b protruding from a portion corresponding to the through hole 66 of the second die 58.

Further, the brush 3 is
0 is inserted into the commutator 18 side from a direction away from the commutator 18 side, and forms a chamfered portion 70 at the end of the first side wall 40 opposite to the commutator 18 side. At the same time, the vicinity of the end of the second side wall 42 on the side opposite to the commutator 18 side is inclined outward to facilitate insertion of the brush 30.

Further, in this embodiment, as shown in FIG. 8A, the corners 72, 74 formed by the guide surface 62, the inner wall surface 40a of the first side wall 40, and the first concave portion 60 are formed. Each of the corners 72 and 74 is formed at a right angle, but by forming a non-engaging portion that does not engage with the brush 30 at the corner 72 opposite to the direction in which the inner brush 30 is inserted into the brush holder 26 of the corners 72 and 74 It is preferable that the brush 30 can be easily inserted into the brush holder 26 even when the tip surface 30a of the brush 30 is formed in an edge shape.

For example, as shown in FIG. 8B, a chamfered non-engaging portion 76 is formed at a corner 72 facing the insertion direction of the brush 30, or as shown in FIG. Forming a tapered non-engaging portion 76 at the corner 72, or
By forming the non-engaging portion 76 having the corner portion 72R as shown in FIG. 4D, the brush 30 can be easily inserted into the brush holder 26.

The present invention is not limited to the above-described embodiment, but can be modified into various embodiments within the scope of the present invention.

For example, in this embodiment, the electric motor used for the power seat motor has been described.
The present invention is not limited to this example, and can be applied to various electric motors. Further, the present invention can be applied to not only the electric motor but also a rotating electric machine such as a generator.

The case where the first concave portion 60 and the guide surface 62 are formed in the first side wall 40 and the first side wall 40 is located on the downstream side in the rotation direction of the rotor 12 has been described. Not only when the second side wall 42 is located on the downstream side in the rotation direction of the rotor 12 and the guide piece 46 is formed on the second side wall 42, the first concave portion 60 and the guide surface 62
Must be formed on the second side wall 42, and when the guide piece 46 is formed on the first side wall 40 and the second side wall 42, at least the It is necessary to form the first concave portion 60 and the guide surface 62 on the side wall to be formed.
The first recess 60 is formed in both the side wall 40 and the second side
And the guide surface 62 must be formed.

Further, the non-engaging portion 7 which does not engage with the brush 30
6 is formed in the corner 72 on the commutator side, but the brush 30
Is inserted into the brush holder 26 from the commutator 18 side, it must be formed at a corner 74 at a position away from the commutator 18, or a non-engaging portion is formed at both corners 72, 74. It is also possible to form 76.

[0055]

[Brief description of the drawings]

FIG. 1 is a perspective view showing an attached state of a brush in a motor housing of an electric motor according to an embodiment of the present invention.

FIG. 2 is a plan view showing a mounting state of the brush of FIG. 1;

FIG. 3 is a plan view showing a state of a brush holder with a brush removed from the state of FIG. 2;

FIG. 4 is a partially enlarged plan view showing a state of a brush holder accommodating a brush.

FIG. 5 is a partial perspective view of a brush holder.

FIG. 6 is a longitudinal sectional view showing a state when the brush holder is formed.

FIG. 7 is a sectional view taken along the line VII-VII of FIG. 6;

FIGS. 8A to 8D are partial cross-sectional views each showing a state of a corner of a guide surface.

FIG. 9 is an external view showing an electric motor according to one embodiment of the present invention.

DESCRIPTION OF SYMBOLS 10 Electric motor 18 Commutator 26 Brush holder 30 Brush 40 First side wall 40a Inner wall surface 42 Second side wall 44 Third side wall 44a Inner wall surface 46 Guide piece 46a Inner wall surface 52a Convex portion 56 First Mold 58 Second mold 58a Convex part 60 First concave part 62 Guide surface 64 Second concave part 66 Through hole 68 Third concave part 72 Corner part 76 Non-engagement part

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) H02K 13/00 H01R 39/38

Claims (8)

(57) [Claims] A brush holder made of a synthetic resin having at least an opening facing the commutator; a brush holder slidably held by the brush holder; A brush slidably in contact with a commutator, wherein the brush holder includes three side walls formed to face three side surfaces along the brush sliding direction, and two side walls of the three side walls facing each other. A rotating electrical machine comprising: a guide piece protruding from at least one side wall end toward the other side wall end and facing a remaining side surface along the sliding direction of the brush; In the vicinity of the commutator side end, burrs at the time of resin molding are formed inside,
And formed in a direction intersecting the first recess in which the burr is prevented from projecting inwardly from the inner wall surface and the sliding direction of the brush, the position of the commutator side of the first recess And a guide surface of the brush, which is substantially flush with the inner wall surface, is formed so as to protrude. 2. The commutator according to claim 1, wherein the guide piece is formed at a position where an end face on a commutator side is retracted with respect to the commutator from an end face position on a commutator side of a side wall having the guide piece. The rotating electrical machine according to claim 1, wherein the first recess is formed over an extension of an end face of the guide piece on the commutator side. 3. The first mold according to claim 1 or 2, wherein the brush holder regulates at least an inner wall surface of the guide piece and an inner wall surface at a position corresponding to the guide piece of the side wall connected to the guide piece. A first mold and a second mold covering the first mold, wherein the first concave portion is formed by a convex portion formed at a matching position of the first mold and the second mold. A rotating electric machine characterized by being performed. 4. The non-engaging member that does not engage with the brush at least at a corner of the guide surface facing a direction in which the brush is inserted into the brush holder, among corners of the guide surface. A rotating electric machine, wherein a joining portion is formed. 5. The rotating electric machine according to claim 1, wherein the guide surface is formed on a side wall located on a downstream side in a rotational direction of the commutator. 6. A second concave portion for preventing burrs during molding from protruding inward from the inner wall surface at an outer peripheral edge of an inner wall surface of the guide piece according to any one of claims 1 to 5. A rotating electric machine characterized by being formed. 7. The through-hole having a size corresponding to an inner wall surface of the guide piece, at a position corresponding to the guide piece, wherein the side wall sandwiched between the two opposing side walls is provided. And a third recess formed at an edge of the through hole to prevent burrs during molding from protruding inward from an inner wall surface of the side wall. 8. A brush holder made of a synthetic resin having at least an opening facing the commutator, slidably held by the brush holder, moving forward and backward with respect to the commutator, and having a front end face having the tip surface. A brush slidably in contact with a commutator, wherein the brush holder includes three side walls formed to face three side surfaces along the brush sliding direction, and two side walls of the three side walls facing each other. A rotating electrical machine comprising: a guide piece protruding from at least one side wall end toward the other side wall end and facing a remaining side surface along the sliding direction of the brush; A guide surface of the brush, which is substantially flush with the inner wall surface, is left at the end of the commutator, and is adjacent to the guide surface to prevent burrs during molding from protruding inward from the inner wall surface. First recess for Rotating electric machine, characterized in that formed in the direction intersecting the sliding direction of the brush.