JP6984491B2 - Brush holding structure - Google Patents

Description

The present invention relates to a brush holding structure for holding a brush used in a DC motor.

For example, in a DC motor used for a starter, a technique is proposed in which a positive electrode side plate and a negative electrode side plate are arranged so as to face each other in the axial direction, and a positive electrode side brush and a negative electrode side brush are arranged in a circumferential direction between the two plates. (For example, Patent Document 1). In such a technique, a pigtail is pulled out from the brush in the circumferential direction, and the pigtail is connected to the positive electrode side plate or the negative electrode side plate.

Japanese Unexamined Patent Publication No. 2017-17924

However, in the above technique, since the pigtail is pulled out from the brush in the circumferential direction, when the distance between the brushes in the circumferential direction is reduced in order to reduce the size, the pigtail is the next brush, that is, a brush having opposite polarity. There is concern about contact with.

In addition, for starters that require a long life and are used for idling stop, it is possible to increase the number of positive electrode side brushes and negative electrode side brushes in order to suppress the amount of current flowing through each brush and suppress brush wear. It is considered. In this case, the distance between the brushes in the circumferential direction becomes small, and there is a concern that the pigtail may come into contact with the adjacent brush, that is, the brush having the opposite polarity.

The present invention has been made in view of the above problems, and a main object thereof is to provide a brush holding structure capable of suitably suppressing a short circuit between a positive electrode side and a negative electrode side.

The first means is arranged on the outer periphery of the commutator (13) provided coaxially with the rotor (12), and holds a plurality of positive electrode side and negative electrode side brushes (20) in a state of being alternately arranged in the circumferential direction. The brush holding structure (30) of the DC motor (10) includes a positive electrode side plate (40) and a negative electrode side plate (50) which are arranged to face each other with the brush sandwiched in the axial direction of the rotor. Between the positive electrode side and the negative electrode side brushes arranged in the direction, the pigtail (22) extending from the positive electrode side brush is connected to the positive electrode side plate, and the pigtail (22) extending from the negative electrode side brush is connected. Connected to the negative electrode side plate, at least one of the positive electrode side plate and the negative electrode side plate is bent toward the side between the brushes and aligned in the circumferential direction with the pigtail having the same polarity. It is provided with a contact suppressing portion (45, 51) that prevents the pigtail from coming into contact with the brush having the opposite polarity.

The brushes on the positive electrode side and the brushes on the negative electrode side are alternately arranged in the circumferential direction, and the pigtail of each brush is connected to the positive electrode side plate and the negative electrode side plate. The positive electrode side plate and the negative electrode side plate are arranged at opposite positions so as to sandwich the brush in the axial direction. Then, in at least one of the positive electrode side plate and the negative electrode side plate, a part of the contact suppressing portion is bent toward the side between the brushes and is provided so as to be lined up in the circumferential direction on the pigtails having the same polarity. It is equipped with. By providing the contact suppressing portion having the same polarity as the pigtail in this way, it is possible to prevent the pigtail having the opposite polarity from touching the brush even if the distance between the brushes in the circumferential direction becomes small.

The second means is provided for each brush between the positive electrode side plate and the negative electrode side plate, and includes a plurality of insulating accommodating portions (60) for accommodating the brushes, and the accommodating portion includes a plurality of insulating accommodating portions (60). An opening (63) that allows the pigtail to be pulled out is provided on both side surfaces in the circumferential direction, and is outside the opening of the openings on both side surfaces where the pigtail is not pulled out. The contact suppressing portion is provided so as to cover at least a part of the opening.

The brush is housed in an insulating housing to prevent contact between the pigtail and the brush. Further, so that the accommodating portion can be shared by the left-handed and right-handed motors, openings are provided on both side surfaces of the accommodating portion in the circumferential direction so that the pigtail can be pulled out. When the openings are provided on both side surfaces in this way, the pigtail having the opposite polarity may enter the opening and come into contact with the brush.

Further, the contact suppressing portion is provided by bending a part of the positive electrode side plate or the negative electrode side plate, and has either polarity. A contact suppressing portion is provided so as to cover at least a part of the opening on the outside of the opening of the accommodating portion for accommodating the brush, on which the pigtail is not pulled out. Since the contact suppressing portion arranged in the circumferential direction has the same polarity as the pigtail, there is no possibility of a short circuit due to contact between the contact suppressing portion and the pigtail.

For example, a negative electrode brush is adjacent to the accommodating portion for accommodating the positive brush. Then, in order to prevent the pigtail drawn from the negative electrode brush from coming into contact with the positive brush, the contact suppressing portion in which the negative electrode side plate is bent is the opening of the accommodating portion for accommodating the positive brush. The pigtail is provided on the outside of the opening on which the pigtail is not pulled out, and the contact suppressing portion covers at least a part of the opening. In this way, by covering at least a part of the opening with the contact suppressing portion, it is possible to prevent the pigtail having the opposite polarity from entering the opening and touching the brush.

The third means is provided for each brush between the positive electrode side plate and the negative electrode side plate, and includes an insulating accommodating portion (60) for accommodating the brush, and the accommodating portion is provided in the circumferential direction. Openings (63) are provided on both side surfaces so that the pigtail can be pulled out, and at least one of the positive electrode side plate and the negative electrode side plate stands upright on both sides in the circumferential direction of the accommodating portion. A pair of standing portions (151, 153) sandwiching the portions are provided, and one of the standing portions (151) of the pair of standing portions serves as the contact suppressing portion.

By sandwiching it between a pair of upright portions, it is possible to restrict the movement of the accommodating portion in the circumferential direction. Further, since one of the standing portions is a contact suppressing portion, it is possible to prevent the pigtail from coming into contact with the brush having the opposite polarity through the opening.

The fourth means is that the pair of upright portions has the opposite polarity to the brush housed in the sandwiched accommodating portion, and one of the upright portions of the pair of upright portions, which is the contact suppressing portion, is used. , The other upright portion (153) has a size that does not close the opening, and has a size that does not close the opening.

The pair of upright portions has the opposite polarity to the brush housed in the sandwiched accommodating portion, and one upright portion, which is the contact suppressing portion, has the same polarity as the pigtail pulled out from the adjacent brush. ing. Then, by blocking at least a part of the opening by the contact suppressing portion, it is possible to prevent the pigtail having the opposite polarity from entering the opening and touching the brush, but there is a risk of short circuit even if the pigtail and the contact suppressing portion come into contact with each other. No. Further, since the other upright portion does not block the opening, there is no possibility of contact with the pigtail pulled out from the sandwiched accommodating portion.

The fifth means is that the contact suppressing portion is such that the opening dimension in the axial direction and the opening dimension in the direction orthogonal to the axial direction are narrower than the thickness of the pigtail in the front view of the opening. It is provided so as to overlap the opening.

By overlapping the contact suppression part with the opening so that the opening size of the opening is narrower than the thickness of the pigtail, it is more reliable that the pigtail of the opposite attribute penetrates the opening and touches the brush. Can be suppressed.

Cross-sectional view of the brush assembly side of the DC motor in the first embodiment Perspective view of brush assembly Top view of the brush Circumferential development of the brush assembly Sectional drawing at VV position in FIG. Sectional drawing at the VI-VI position in FIG. Schematic development of the brush assembly in the circumferential direction in the second embodiment. Plan view of the negative electrode side plate

<First Embodiment>
Hereinafter, a configuration embodied as a DC motor used for a starter for starting an engine will be described with reference to the drawings. In each of the following embodiments, the parts that are the same or equal to each other are designated by the same reference numerals, and the description thereof will be used for the parts having the same reference numerals.

In the starter, the pinion driven by the DC motor 10 meshes with the ring gear of the engine to drive the engine. Since the structure of the starter is well known, the description thereof will be omitted.

FIG. 1 is a cross-sectional view of the brush assembly 30 side of the DC motor 10 and is a cross-sectional view of the side opposite to the side connected to the pinion or the like of the DC motor 10 in the axial direction. The DC motor 10 has a field coil 11, a rotor 12 having a space on the inner circumference of the field coil 11 and rotatably arranged, a commutator 13 provided coaxially with the rotor 12, and an outer periphery of the commutator 13. It is provided with a brush 20 to be arranged. The brush 20 is held in the brush assembly 30. The brush assembly 30 corresponds to the "brush holding structure".

The structure of the brush assembly 30 will be described with reference to FIGS. 2 to 6. FIG. 2 is a perspective view of the brush assembly 30, which is a perspective view seen from the rotor 12 side. FIG. 3 is a plan view of the brush 20. FIG. 4 is a development view of the brush assembly 30 in the circumferential direction, and is a view of the brush assembly 30 as viewed from the outer peripheral side. 5 is a cross-sectional view taken at the VV position in FIG. 4, and FIG. 6 is a cross-sectional view taken at the VI-VI position in FIG.

As shown in FIG. 2, the brush assembly 30 holds three brushes 20 on the positive electrode side and three brushes 20 on the negative electrode side alternately arranged in the circumferential direction. In the following, when distinguishing between the positive electrode side and the negative electrode side of the brush 20, the positive electrode side brush 20A and the negative electrode side brush 20B will be described. The brush assembly 30 is provided between the positive electrode side plate 40 and the negative electrode side plate 50 and the positive electrode side plate 40 and the negative electrode side plate 50 which are arranged to face each other with the brush 20 sandwiched in the axial direction of the rotor 12, and each brush is provided. It is provided with an insulating accommodating portion 60 for accommodating 20. The number of brushes 20 may be a plurality of each on the positive electrode side and the negative electrode side, and may be, for example, two on the positive electrode side and two on the negative electrode side, for a total of four brushes.

As shown in FIG. 3, the brush 20 has a brush main body 21 that comes into contact with the peripheral surface of the commutator 13 and a pigtail 22 that extends from the brush main body 21. The brush main body 21 has a prismatic shape and has a contact surface 21A with the rotor 12 and a side surface 21B orthogonal to the contact surface 21A and serving as a circumferential surface of the brush assembly 30. A pigtail 22 extends from the side surface 21B of the brush body 21. The pigtail 22 is a conductive connecting member, has flexibility, and has a connecting portion 23 connected to the positive electrode side plate 40 or the negative electrode side plate 50 at the tip end portion thereof.

As shown in FIGS. 2 and 5, the accommodating portion 60 has a box shape opened inward in the radial direction, which is a direction orthogonal to the axial direction of the rotor 12, and accommodates the brush 20 in the radial direction. The brush spring 61 is accommodated on the outside in the radial direction. The brush spring 61 presses the brush 20 against the rotor 12. Further, a fitting convex portion 62 that fits into the positive electrode side plate 40 is provided on the surface of the accommodating portion 60 on the side that comes into contact with the positive electrode side plate 40.

The accommodating portion 60 is provided with openings 63 on both side surfaces in the circumferential direction thereof so that the pigtail 22 can be pulled out. By providing openings 63 on both side surfaces, the accommodating portion 60 can be shared by the left-handed and right-handed motors. Further, the opening 63 is provided in the accommodating portion 60 so as to extend radially inward from the position of the inner end (diameterally outer side) in which the brush 20 is accommodating, and the pigtail 22 remains pulled out. Therefore, the brush 20 can be moved in the radial direction. Further, the axial dimension L1 of the rotor 12 of the opening 63 is about 1.5 to 2 times the thickness R of the pigtail 22 (see FIG. 3), and the pigtail 22 is pulled out. Until then, the brush 20 does not interfere with the movement in the radial direction. The thickness R of the pigtail 22 is the maximum external dimension of the pigtail 22 when the pigtail 22 is straightened.

As shown in FIG. 2, the positive electrode side plate 40 and the negative electrode side plate 50 are conductive metal plates having a predetermined plate thickness, and a round hole through which the rotor 12 can be inserted is provided in the central portion in the radial direction. It is a circular ring. The positive electrode side plate 40 and the negative electrode side plate 50 are arranged parallel to each other in a direction orthogonal to the axial direction of the rotor 12. The pigtail 22 of the brush 20 of each pole is electrically connected to each of the plates 40 and 50 by welding or the like, and is mechanically fixed. The positive electrode side plate 40 is electrically connected to the electromagnetic switch of the starter via the drawer member 41. On the other hand, as shown in FIG. 1, the negative electrode side plate 50 is fixed to the end frame 14 with a screw or the like, is electrically connected to the end frame 14, and is grounded.

As shown in FIG. 2, the positive electrode side plate 40 is provided with six fitting grooves 42 for assembling the fitting convex portion 62 of the accommodating portion 60 at equal intervals in the circumferential direction. The fitting groove 42 is formed so as to open inward in the radial direction of the positive electrode side plate 40 and extend in a slit shape in the outer peripheral direction. Between the plate portions 43 provided with the fitting grooves 42 of the positive electrode side plate 40, there is a connecting portion 44 that is narrower in the radial direction than the plate portion 43. The plate portion 43 reaches a position on the outer side in the radial direction of the accommodating portion 60 on the outer side in the radial direction. The plate portion 43 is located on the inside in the radial direction, outside the accommodating portion 60 by the size of the contact suppressing portion 45 described later, and is at the same position as the inside position of the connecting portion 44. The fitting groove 42 of the plate portion 43 is assembled to the fitting convex portion 62 of the accommodating portion 60 to prevent the accommodating portion 60 from moving in the circumferential direction. Further, the negative electrode side plate 50 has an annular shape having substantially the same diameter as the radial dimension of the accommodating portion 60 and having the same width, and the accommodating portion 60 is axially aligned with the positive electrode side plate 40 and the negative electrode side plate 50. It is sandwiched.

As shown in FIGS. 2 and 4 to 6, the positive electrode side plate 40 and the negative electrode side plate 50 are provided with contact suppression portions 45 and 51. The contact suppressing portions 45 and 51 are provided in a state of being bent from each of the positive electrode side plate 40 and the negative electrode side plate 50 to the side between the brushes 20 (accommodation portion 60). The contact suppressing portions 45 and 51 are provided outside the opening 63 of the openings 63 on both side surfaces where the pigtail 22 is not pulled out, and cover at least a part of the opening 63. The contact suppressing portions 45 and 51 provided on the outside of the opening 63 have the opposite polarity to the brush 20 housed in the accommodating portion 60 provided with the opening 63. That is, the pigtail 22 pulled out from the adjacent brush 20 and the contact suppressing portions 45 and 51 arranged in the circumferential direction have the same polarity. By providing the contact suppressing portions 45 and 51, the brush 20 is prevented from coming into contact with the pigtail 22 having the opposite polarity through the opening 63 of the accommodating portion 60.

It should be noted that covering the opening 63 with the contact suppressing portions 45, 51 means that the opening is reduced so as to reduce the opening area of the opening 63 in the front view of the opening 63 (the state in which the accommodating portion 60 is viewed from the side surface in the circumferential direction). It means that the contact suppressing portions 45 and 51 are provided so as to overlap the portions 63. That is, the state in which the contact suppressing portions 45 and 51 cover the opening 63 is not only the state in which the contact suppressing portions 45 and 51 close the opening 63, but also the contact suppressing portion 45 covering the opening 63 and the opening 63. Includes a state in which they are separated from each other.

The contact suppressing portion 45 on the positive electrode side provided on the positive electrode side plate 40 covers the radial inside of the opening 63 of the accommodating portion 60 accommodating the negative electrode side brush 20B. Specifically, the contact suppressing portion 45 is provided on the circumferential side of the accommodating portion 60 accommodating the negative electrode side brush 20B and on the side opposite to the direction in which the pigtail 22 is pulled out. The contact suppressing portion 45 is formed by bending a extending portion 46 in which a part of the plate portion 43 in contact with the accommodating portion 60 extends inward in the radial direction. A gap of about one plate thickness is provided between the contact suppressing portion 45 and the accommodating portion 60, and it is desirable that this gap is smaller than the thickness R of the pigtail 22. In this way, the contact suppressing portion 45 on the positive electrode side covers a part of the opening 63 of the accommodating portion 60 accommodating the negative electrode side brush 20B, so that the pigtail 22 extending from the adjacent positive electrode side brush 20A becomes the contact suppressing portion 45. Even if they come into contact, they will have the same polarity.

Further, the contact suppressing portion 45 covers the opening 63 so that the opening dimensions L2 and L3 are narrower than the thickness R of the pigtail 22. Here, the opening dimension L2 indicates the axial dimension between the hole edge of the opening 63 and the contact suppressing portion 45 in a state where the opening 63 is covered by the contact suppressing portion 45, and the opening dimension L2 indicates the dimension of the opening 63. It is smaller than the axial dimension L1. Further, the opening dimension L3 is a radial dimension (dimension in a direction orthogonal to the axial direction) between the hole edge of the opening 63 and the contact suppressing portion 45 in a state where the opening 63 is covered with the contact suppressing portion 45. Is shown. By covering the contact suppressing portion 45 so that the opening dimensions L2 and L3 of the opening 63 are narrower than the thickness R of the pigtail 22, the pigtail 22 can be prevented from entering the opening 63. It is preferable that the contact suppressing portion 45 is provided at a position inside in the radial direction because it is easier to prevent contact with the brush 20 protruding from the accommodating portion 60. It may be provided in.

The contact suppressing portion 51 on the negative electrode side provided on the negative electrode side plate 50 covers the opening 63 of the accommodating portion 60 accommodating the positive electrode side brush 20A. Specifically, the contact suppressing portion 51 is provided on the circumferential side of the accommodating portion 60 accommodating the positive electrode side brush 20A and on the side opposite to the direction in which the pigtail 22 is pulled out. The contact suppressing portion 51 is formed by cutting up a portion of the cut-up hole 52 of the negative electrode side plate 50 that supports the accommodating portion 60. A gap of about one plate thickness is provided between the contact suppressing portion 51 and the accommodating portion 60, and it is desirable that this gap is smaller than the thickness R of the pigtail 22. In this way, the contact suppressing portion 51 on the negative electrode side covers a part of the opening 63 of the accommodating portion 60 accommodating the positive electrode side brush 20A, so that the pigtail 22 extending from the adjacent negative electrode side brush 20B becomes the contact suppressing portion 51. Even if they come into contact, they will have the same polarity.

Further, the contact suppressing portion 51 covers the opening portion 63 so that the opening dimension L2 is narrower than the thickness R of the pigtail 22. Further, the contact suppressing portion 51 covers the entire length of the radial dimension of the opening 63. The contact suppressing portion 45 covers the entire length of the radial dimension so that the opening dimension L2 of the opening 63 is narrower than the thickness R of the pigtail 22, thereby suppressing the pigtail 22 from entering the opening 63. can.

According to the present embodiment described in detail above, the following actions and effects can be obtained.

The positive electrode side brushes 20A and the negative electrode side brushes 20B are alternately arranged in the circumferential direction, and the pigtails 22 of the brushes 20A and 20B are connected to the positive electrode side plate 40 and the negative electrode side plate 50. The positive electrode side plate 40 and the negative electrode side plate 50 are arranged at opposite positions so as to sandwich the brush 20 in the axial direction. Then, in at least one of the positive electrode side plate 40 and the negative electrode side plate 50, a part thereof is bent to the side between the brushes 20 and provided so as to be aligned in the circumferential direction on the pigtail 22 having the same polarity. The contact suppressing portions 45 and 51 are provided. By providing the contact suppressing portions 45 and 51 in this way, it is possible to prevent the pigtail 22 having the opposite polarity from touching the brush 20 even if the distance between the brushes 20 in the circumferential direction becomes small.

The brush 20 is housed by an insulating accommodating portion 60 in order to prevent contact between the pigtail 22 and the brush 20. An opening 63 is provided on both side surfaces of the accommodating portion 60 in the circumferential direction so that the pigtail 22 can be pulled out so that the accommodating portion 60 can be shared by the left-handed and right-handed motors. When the openings 63 are provided on both side surfaces in this way, the pigtail 22 having the opposite polarity may enter the opening 63 and come into contact with the brush 20.

Further, the contact suppressing portions 45 and 51 are provided by bending a part of the positive electrode side plate 40 or the negative electrode side plate 50, and have either polarity. Then, the contact suppressing portions 45 and 51 cover at least a part of the opening 63 on the outside of the opening 63 of the accommodating portion 60 accommodating the brush 20 on which the pigtail 22 is not pulled out. It is provided. Since the contact suppression portions 45 and 51 arranged in the circumferential direction with the pigtail 22 have the same polarity, there is no possibility of a short circuit due to contact between the contact suppression portions 45 and 51 and the pigtail 22.

For example, the negative electrode side brush 20B is adjacent to the accommodating portion 60 accommodating the positive electrode side brush 20A. Then, in order to prevent the pigtail 22 drawn from the negative electrode side brush 20B from coming into contact with the positive electrode side brush 20A, the contact suppressing portion 51 in which the negative electrode side plate 50 is bent is the accommodating portion 60 for accommodating the positive electrode side brush 20A. The pigtail 22 is provided on the outside of the opening 63 on which the pigtail 22 is not pulled out, and the contact suppressing portion 51 covers at least a part of the opening 63. In this way, by covering at least a part of the opening 63 with the contact suppressing portions 45, 51, it is possible to prevent the pigtail 22 having the opposite polarity from invading the opening 63 and touching the brush 20, and also to make contact. Since the suppression portions 45 and 51 and the pigtail 22 have the same polarity, a short circuit can be suppressed.

The contact suppression portions 45 and 51 are provided so as to overlap the opening 63 so that the opening dimensions L2 and L3 of the opening 63 are narrower than the thickness R of the pigtail 22, so that the pigtail 22 having the opposite attribute can be obtained. It is possible to more reliably prevent the brush 20 from entering the opening 63 and touching the brush 20.

<Second Embodiment>
In the second embodiment, a pair of upright portions standing on both sides in the circumferential direction of the accommodating portion and sandwiching the accommodating portion are provided, and one of the upright portions of the pair of upright portions serves as a contact suppressing portion. Hereinafter, a detailed description will be given with reference to FIGS. 7 and 8. FIG. 7 is a development view of the brush assembly 30 of the second embodiment in the circumferential direction, and is a view of the brush assembly 30 as viewed from the outer peripheral side. FIG. 8 is a plan view of the negative electrode side plate 50, and the contact suppressing portion 151 and the regulating portion 153 in the state before being cut up are shown by a two-dot chain line.

The contact suppressing portion 145 on the positive electrode side provided on the positive electrode side plate 40 accommodates the negative electrode side brush 20B so that the opening dimensions L2 and L3 of the opening 63 are narrower than the thickness R of the pigtail 22. Covers the radial inside of the opening 63 of. The contact suppressing portion 145 is formed by bending the extending portion 46, and is a circumferential side surface of the accommodating portion 60 accommodating the negative electrode side brush 20B, which is opposite to the direction in which the pigtail 22 is pulled out. It is in contact with the side surface. Compared to the first embodiment, the extending portion 46 and the contact suppressing portion 145 are in contact with each other so as to cover the corners of the accommodating portion 60, and the distance in which the fitting convex portion 62 is in contact with the positive electrode side plate 40 is increased. Therefore, the movement of the accommodating portion 60 in the circumferential direction can be further restricted. Further, since the contact suppressing portion 145 covers the opening 63 so that the opening dimensions L2 and L3 are narrowed in the state of being in contact with the accommodating portion 60, the pigtail 22 is further suppressed from entering the opening 63. can.

The negative electrode side plate 50 is provided with a pair of upright portions that stand up on both sides of the accommodating portion 60 accommodating the positive electrode side brush 20A in the circumferential direction and sandwich the accommodating portion 60. The contact suppression portion 151 on the negative electrode side provided on the negative electrode side plate 50, which is one of the upright portions, accommodates the positive electrode side brush 20A so that the opening dimension L2 of the opening 63 is narrower than the thickness R of the pigtail 22. It covers the opening 63 of the accommodating portion 60. Further, the regulating portion 153, which is the other standing portion, is provided so as to sandwich the accommodating portion 60 together with the contact suppressing portion 151. The rising dimension of the restricting portion 153 is smaller than the rising dimension of the contact suppressing portion 151, and is a dimension that does not reach the hole edge of the opening 63. That is, the regulation portion 153 has a size that does not block the opening 63.

The contact suppressing portion 151 and the regulating portion 153 are formed by cutting up the negative electrode side plate 50. In a state where the contact suppressing portion 151 and the regulating portion 153 are cut and raised, the cut and raised hole 152 is formed. The total of the rising dimension (axial dimension) of the contact suppressing portion 151 and the rising dimension (axial dimension) of the regulating portion 153 is smaller than the circumferential dimension of the accommodating portion 60. Further, the cut-up hole 152 is provided on a surface in contact with the accommodating portion 60 (a position covered by the accommodating portion 60), and is provided slightly inside the radial center position of the negative electrode side plate 50. Therefore, the negative electrode side plate 50 supports the accommodating portion 60 on both the inner and outer sides of the cut-up hole 152 in the radial direction.

Further, the radial dimension of the contact suppressing portion 151 formed by the cut-up hole 152 is shorter than the radial dimension of the opening 63, and the inside of the opening 63 in the radial direction is not covered by the contact suppressing portion 151. A part is provided. Since the portion not covered by the contact suppressing portion 151 has an opening width (diametrical dimension) narrower than the thickness R of the pigtail 22, the pigtail 22 is prevented from entering the opening 63. can. Further, the contact suppressing portion 151 and the restricting portion 153 stand so as to face each other so as to be separated from each other in the circumferential direction, and by sandwiching the accommodating portion 60 between them, the accommodating portion 60 is restricted from moving in the circumferential direction. be able to.

The accommodating portion 60 accommodating the negative electrode side brush 20B is in contact with the extending portion 46 and the contact suppressing portion 145 so as to cover the corner in contact with the positive electrode side plate 40, and the fitting convex portion 62 is in contact with the positive electrode side plate 40. Since the distance of contact with the housing unit is increasing, it is possible to restrict the movement of the accommodating portion 60 in the circumferential direction. On the other hand, the accommodating portion 60 accommodating the positive electrode side brush 20A can be restricted from moving in the circumferential direction by being sandwiched between the contact suppressing portion 151 and the restricting portion 153. Further, since each of the regulating means extends in the axial direction, each pigtail 22 can be welded to each of the plates 40 and 50 in advance. Therefore, the positive electrode side plate 40, the accommodating portion 60, and the negative electrode side plate 50 can be easily assembled.

<Other embodiments>
The present invention is not limited to the above embodiment, and may be implemented as follows, for example. Incidentally, the configuration of the following alternative example may be applied individually to the configuration of the above embodiment, or may be applied in any combination.

-The contact suppressing portions 45 and 51 may be provided on only one of the positive electrode side plate 40 and the negative electrode side plate 50.

-The size and shape of the contact suppressing portions 45 and 51 may be arbitrary. In short, it suffices if it covers at least a part.

-In the above embodiment, the contact suppressing portions 45 and 145 on the positive electrode side are narrower than the contact suppressing portions 51 and 151 on the negative electrode side, but may have the same width, or the contact suppressing portions 45 on the positive electrode side. , 145 may be wider than the contact suppression portions 51, 151 on the negative electrode side.

-In the first embodiment, the contact suppressing portions 45 and 51 are separated from the accommodating portion 60, but the accommodating portion 60 may be in contact with the accommodating portion 60 as in the second embodiment.

-The brush 20 may not be housed in the box-shaped housing and may be exposed.

On the side of the opening 63 from which the pigtail 22 is pulled out, the tip of the pigtail 22 may be welded to the contact suppressing portions 45, 51 bent from a plate having the same polarity as the pigtail 22. In this case, it is preferable that the pigtail 22 is welded to the side surface of the contact suppressing portions 45, 51 on the side of the pigtail 22.

10 ... DC motor, 12 ... Rotor, 13 ... Commuter, 20 ... Brush, 22 ... Pigtail, 40 ... Positive electrode side plate, 45 ... Contact suppression part, 50 ... Negative electrode side plate, 51 ... Contact suppression part, 60 ... Storage part , 63 ... opening, 145 ... contact suppressing part, 151 ... contact suppressing part, 152 ... cutting hole, 153 ... regulating part.

Claims (5)

A DC motor (10) arranged on the outer periphery of a commutator (13) coaxially provided with a rotor (12) and holding a plurality of positive electrode side and negative electrode side brushes (20) in a state of being alternately arranged in the circumferential direction. It has a brush holding structure (30) and has a brush holding structure (30).
A positive electrode side plate (40) and a negative electrode side plate (50) arranged to face each other with the brush sandwiched in the axial direction of the rotor are provided.
Between the positive electrode side and the negative electrode side brushes arranged in the circumferential direction, the pigtail (22) extending from the positive electrode side brush is connected to the positive electrode side plate, and the pigtail (22) extending from the negative electrode side brush is connected. Is connected to the negative electrode side plate,
In at least one of the positive electrode side plate and the negative electrode side plate, the pigtails are bent toward the side between the brushes and provided so as to be aligned in the circumferential direction with the pigtails having the same polarity, and the pigtails have the opposite polarity. A brush holding structure including a contact suppressing portion (45, 51) that suppresses contact with the brush. An insulating accommodating portion (60) provided for each brush between the positive electrode side plate and the negative electrode side plate and accommodating the brush is provided.
The accommodating portion is provided with openings (63) on both side surfaces in the circumferential direction so that the pigtail can be pulled out.
According to claim 1, the contact suppressing portion is provided on the outside of the opening on both side surfaces where the pigtail is not pulled out so as to cover at least a part of the opening. Described brush holding structure. An insulating accommodating portion (60) provided for each brush between the positive electrode side plate and the negative electrode side plate and accommodating the brush is provided.
The accommodating portion is provided with openings (63) on both side surfaces in the circumferential direction so that the pigtail can be pulled out.
A pair of upright portions (151, 153) standing on both sides of the accommodating portion in the circumferential direction and sandwiching the accommodating portion are provided on at least one of the positive electrode side plate and the negative electrode side plate.
The brush holding structure according to claim 1, wherein one of the standing portions (151) of the pair of standing portions serves as the contact suppressing portion. The pair of upright portions has the opposite polarity to the brush accommodated in the sandwiched accommodating portion.
Of the pair of standing portions, one of the standing portions, which is the contact suppressing portion, has a size of closing a part of the opening.
The brush holding structure according to claim 3, wherein the other upright portion (153) has a size that does not block the opening. The contact suppressing portion overlaps the opening so that the opening dimension in the axial direction and the opening dimension in the direction orthogonal to the axial direction are narrower than the thickness of the pigtail in the front view of the opening. The brush holding structure according to any one of claims 2 to 4, which is provided.

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