JP2010057298A - Electric motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric motor in which the reliability of electric connection between a ground terminal contacting a yoke and the yoke is improved. <P>SOLUTION: The electric motor has a structure in which a pair of ground terminals 81 are attached to sides of a brush holder attached to the inside of the yoke, the pair of brushes held in the brush holder are each connected to the ground terminal 81, a tip 84 of the ground terminal 81 is brought into contact with the inside of the yoke to ground the yoke. In the electric motor, the tip 84 of the ground terminal 81 is bifurcated to have a pair of branched pieces 84a, and the tip 84 of the ground terminal 81 is allowed to elastically contact the inside of the yoke at the branched pieces 84a. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electric motor with a brush provided with a brush that is in sliding contact with a commutator, and more particularly, to an electric motor having a ground terminal for grounding a brush to a yoke.

  2. Description of the Related Art Conventionally, an electric motor with a brush is often used as a drive source for vehicle electrical components such as a sunroof motor. Such an electric motor with a brush is a pair of a commutator fixed to the armature shaft and connected to the coil end of the armature coil, and a pair of sliding contacts with the outer peripheral surface of the commutator held by a brush holder mounted inside the yoke. The armature shaft is rotated by supplying a driving current commutated at a predetermined timing to the armature coil via the brush and the commutator. In addition, as an electric motor such as a sunroof motor, a reduction mechanism is attached to an electric motor body with a brush, and a control board for controlling the operation of the motor body is provided inside a gear case (end case) that houses the reduction mechanism. There is an electromechanical integrated type that can be accommodated.

  In an electro-mechanical electric motor, electrical noise generated from the sliding contact portion between the brush and commutator is radiated from the motor body to the outside, and the radiated electrical noise malfunctions in other electrical components mounted on the vehicle. There is a risk of causing.

Therefore, for example, in the electric motor shown in Patent Document 1, it is mounted on a brush holder formed in a plate shape, the base end portion of the ground terminal is connected to the brush, and the tip end portion is elastically connected to the yoke of the motor body. By making contact, the brush is grounded to the yoke to reduce electrical noise.
JP 2005-35495 A

  However, in the conventional electric motor, since the tip of the ground terminal is formed in a flat shape or an R shape, the ground terminal is grounded depending on whether the ground terminal is attached to the brush holder or the brush holder is attached to the yoke. When the terminal is deviated from the normal posture, the reliability of electrical connection with the yoke of the ground terminal may be lowered.

  An object of the present invention is to provide an electric motor having improved electrical connection reliability of a ground terminal contacting the yoke to the yoke.

  The electric motor of the present invention is formed in a bottomed cylindrical shape, and has a yoke with an end case attached to an open end, an amateur supported by an armature shaft and rotatably accommodated in the yoke, and fixed to the armature shaft. An armature core to which a plurality of amateur coils are mounted, a commutator fixed to the armature shaft and connected to the coil ends of the plurality of armature coils, and mounted inside the yoke so as to face the end case, A brush holder that holds a plurality of brushes that are in sliding contact with the commutator, a plurality of power terminals that are mounted on the brush holder and connected to the corresponding brush and connected to an external power source, and mounted on the brush holder The base end portion is electrically connected to the brush, and the tip portion is elastic to the yoke. And a ground terminal for grounding to contact with the brush to the yoke, the distal end portion of the ground terminal is characterized in that branches into a plurality.

  The electric motor of the present invention is characterized in that the tip of the ground terminal is bifurcated.

  The electric motor according to the present invention is characterized in that a plurality of the ground terminals are provided so as to be connected to the corresponding brushes, and the ground terminals are arranged symmetrically about the axis of the armature shaft.

  In the electric motor of the present invention, the tip portion of the ground terminal is in elastic contact with the inner surface of the yoke, and the side surface of the brush holder has a bottom wall parallel to the side surface extending in the axial direction of the armature shaft. And a mounting groove that is partitioned by a pair of side walls that are continuous with the bottom wall and the side surface and that is formed in a substantially trapezoidal cross section in which the width of the opening portion is narrower than the bottom wall, and the grounding terminal has a plate shape When the formed base portion is inserted into the mounting groove from the axial direction, the base portion is pressed by the side wall and is mounted on the brush holder in a state of being pressed against the bottom wall.

  In the electric motor according to the present invention, the ground terminal is formed in a plate shape and is connected to the brush by being arranged on the axial end surface of the brush holder formed perpendicular to the armature base and the base portion connected to the tip portion. A connecting portion, and an offset portion that connects the connecting portion to the base portion while being shifted in the rotational direction of the armature shaft, a chamfered portion is formed in the offset portion, and an axial end surface of the brush holder is provided on the axial end surface of the brush holder. A pair of positioning projections for positioning the ground terminal in contact with the chamfered portion are provided.

  According to the present invention, since the tip of the ground terminal that contacts the yoke is formed in a shape that branches into a plurality of shapes, the flexible elasticity of the branch portion allows the connection terminal to follow the inner surface of the yoke. Can be increased. This ensures that the tip of the ground terminal is in contact with the yoke even if the ground terminal is displaced from the normal position with respect to the yoke due to the state of the ground terminal attached to the brush holder or the state of the brush holder attached to the yoke. The reliability of electrical connection of the ground terminal to the yoke can be improved.

  Further, according to the present invention, since the ground terminal is paired and attached to the brush holder at a point-symmetrical position around the axis of the armature shaft, each ground terminal is attached to the brush holder by contact with the yoke. By offsetting the applied load, the deviation of the brush holder in the yoke can be suppressed. As a result, it is possible to accurately position in the yoke of the brush holder and bring the ground terminal into contact with the yoke with a pressure as designed, thereby further improving the electrical connection reliability of the ground terminal to the yoke.

  Furthermore, according to the present invention, the base portion of the ground terminal is inserted into the mounting groove provided on the side surface of the brush holder, and the base portion is pressed against the bottom wall by the pair of side walls. It is possible to position the brush holder with high accuracy. As a result, the ground terminal is brought into contact with the yoke with a pressure as designed, and the reliability of electrical connection of the ground terminal to the yoke can be further enhanced.

  Furthermore, according to the present invention, the ground terminal is positioned on the brush holder by bringing the chamfered portion provided in the offset portion into contact with the pair of positioning protrusions provided on the axial end surface of the brush holder. Even when a hole or the like for positioning a power supply terminal or the like is formed on the end surface in the axial direction of the brush holder in the vicinity, the ground terminal is positioned on the brush holder and contact with a member near the ground terminal is made. Can be prevented.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is an explanatory view showing an outline of a sunroof device provided on a roof of a vehicle. The sunroof device 11 includes a roof panel 12, and an opening formed in a roof 13 a of the vehicle 13 by the roof panel 12. 14 is opened and closed. A pair of shoes 15a and 15b are fixed to both sides of the roof panel 12, while guide rails 16 extending in the vehicle front-rear direction are fixed to both sides of the opening 14 of the roof 13a. , 15b are guided by the corresponding guide rails 16, so that the roof panel 12 can be moved in the vehicle front-rear direction, that is, can be opened and closed.

  One end of geared drive cables 17a, 17b is connected to each shoe 15b on the vehicle rear side, and the other ends of these drive cables 17a, 17b are respectively routed to the vehicle front side of the opening 14. Yes. A sunroof motor 21 as an electric motor is disposed on the front side of the vehicle with respect to the opening 14 and inside the roof 13a between the windshield 13b and the drive cables 17a and 17b are connected to the sunroof motor 21. Is engaged with a drive gear 22 provided in When the sunroof motor 21 is operated, the drive cables 17a and 17b are driven in the axial direction in opposite directions by the sunroof motor 21, whereby the roof panel 12 is automatically opened and closed by being pushed and pulled by the drive cables 17a and 17b. It is like that.

  2A and 2B are perspective views showing details of the sunroof motor shown in FIG. 1, FIG. 3 is an exploded perspective view of the sunroof motor shown in FIG. 2, and FIG. 4 is a plan view showing the arrangement of the brush holder. FIG.

  As shown in FIGS. 2A and 2B, the sunroof motor 21 includes a motor body 23 that is a motor with a brush. The yoke 24 of the motor body 23 includes a pair of arc portions 24a that are curved around an axis, a pair of parallel flat plate portions 24b that connect the arc portions 24a, and a bottom portion 24c that closes one end in the axial direction. As shown in FIG. 3, an armature 25 is accommodated inside the yoke 24. The armature 25 includes an armature shaft 26, and one end of the armature shaft 26 is supported by a bearing (not shown) provided on the bottom 24 c of the yoke 24, so that the armature 25 is rotatable inside the yoke 24. ing. An amateur core 27 is fixed to the amateur shaft 26, and a plurality of amateur coils 28 are wound around the amateur core 27. Further, a commutator 29 is fixed to the armature shaft 26 adjacent to the armature core 27, and the coil ends of each armature coil 28 are connected to the commutator 29, respectively.

  A brush device 31 for supplying power to the armature 25, that is, the armature coil 28 is attached to the inside of the opening end side of the yoke 24. As shown in FIG. 4, the brush device 31 has a structure in which a pair of brushes 33 a and 33 b as a plurality of brushes are held in a brush holder 32, and these brushes 33 a and 33 b are arranged on the outer peripheral surface of the commutator 29. The driving current that is in sliding contact and is commutated at a predetermined timing via the brushes 33 a and 33 b and the commutator 29 is supplied to the armature coil 28.

  The detailed structure of the brush device 31 will be described later.

  A gear case 36 as an end case is fixed to the open end of the yoke 24 by a pair of bolts 34 and nuts 35. The gear case 36 is formed in a bathtub shape from a resin material, and the armature shaft 26 of the motor body 23 protrudes from the yoke 24 to the inside of the gear case 36 and is accommodated in the gear case 36. Further, the gear case 36 closes the opening end of the yoke 24 at one end side in the longitudinal direction, and sandwiches and fixes the brush holder 32 between the yoke 24 so as to face the brush holder 32. The distal end portion and the intermediate portion of the armature shaft 26 are supported by a bearing (not shown) provided inside the gear case 36. The armature shaft 26 of the motor body 23 protrudes from the yoke 24 to the inside of the gear case 36 and is accommodated in the gear case 36. Further, a cover body 37 is attached to the gear case 36 by five claw engagements, and the open end of the gear case 36 is closed by the cover body 37.

  FIG. 5 is a cross-sectional view taken along the line AA in FIG. 2B. As shown in FIG. 5, a worm gear mechanism 41 is accommodated in the gear case 36 closed by the cover body 37. The worm gear mechanism 41 includes a worm 41a and a worm wheel 41b. The worm 41a is integrally formed on an outer peripheral surface of a portion of the armature shaft 26 protruding into the gear case 36, and the worm wheel 41b is fixed to the output shaft 42. The output shaft 42 is rotatably accommodated in a cylindrical gear accommodating portion 36a provided inside the gear case 36. The worm 41a and the worm wheel 41b are meshed with each other, whereby the rotation of the armature shaft 26 is decelerated to a predetermined rotational speed via the worm gear mechanism 41 and output from the output shaft 42.

  In the illustrated case, the worm 41a is integrally formed on the outer peripheral surface of the armature shaft 26. However, the present invention is not limited thereto, and the armature shaft 26 is connected to a shaft provided with the worm 41a. Other structures may be used as long as the worm 41a is rotationally driven by the armature shaft 26.

  A gear cover 43 is attached to the open end of the gear housing portion 36a. The gear cover 43 isolates the gear housing portion 36a in a gear case 36 from a control board housing portion 36b described later. Thereby, lubricating oil such as grease applied to the worm gear mechanism 41 is prevented from leaking to a portion other than the gear housing portion 36a of the gear case 36.

  As shown in FIG. 5, the output shaft 42 protrudes from the bottom surface of the gear case 36 to the outside of the case 36 (upward in the figure), and the drive gear 22 is fixed to the tip thereof. Also, a cable guide 36c is provided on the outside of the bottom surface of the gear case 36 (upward in the figure), and a metal guide plate 44 is mounted on the cable guide 36c. The guide plate 44 is a drive gear. A pair of guide walls 44 a facing each other across 22 is provided, and the drive cables 17 a and 17 b are arranged so as to be sandwiched between the guide walls 44 a and the drive gear 22.

  With such a configuration, when the motor main body 23 is operated, the rotation of the armature shaft 26 is transmitted to the output shaft 42 via the worm gear mechanism 41, and the drive cables 17a and 17b are predetermined by the drive gear 22 rotating together with the output shaft 42. The roof panel 12 automatically opens and closes.

  As shown in FIG. 5, a tool hole 42a that can be engaged with a tool such as a hexagon wrench is formed at the other end (downward in the figure) of the output shaft 42, and the motor main body 23 has failed. In this case, the tool is engaged with the tool hole 42a through the through hole 37a formed in the cover body 37, the output shaft 42 is rotationally driven by the tool, and the roof panel 12 is manually opened and closed. Can be done.

  The sunroof motor 21 is provided with a control board 51 for controlling the operation of the motor body 23. The control board 51 has a structure in which a control circuit 51b for controlling the drive current supplied to the amateur 25 (the amateur coil 28) is provided on the board 51a, and serves as a fixing means provided integrally with the cover body 37. It is fixed to the inner surface of the cover body 37 by three clips 52. The clip 52 is a known fixing means including a cylindrical main body 52a, a clip sphere 52b provided on the upper portion thereof, and a cross slit 52c extending from the clip sphere 52b to the main body 52a. Then, by attaching the cover body 37 to the gear case 36, the control board 51 is accommodated in a control board accommodation portion 36 b that is integrally provided inside the gear case 36.

  As shown in FIGS. 3 and 4, the brush device 31 is provided with a pair of power terminals 53 and 54 as a plurality of power terminals connected to the corresponding brush, and the control board 51 has a pair of connection pieces 55. , 56 are provided, and by connecting these connection pieces 55, 56 to the corresponding power supply terminals 53, 54, the control board 51 (control circuit 51b) and the brushes 33a, 33b are electrically connected. It has become so.

  The gear case 36 is provided with a ground terminal 57 whose one end is electrically connected to the yoke 24 via the bolt 34 and the nut 35, and the control board 51 is provided with a ground connection piece 58. By connecting the connecting piece 58 to the ground terminal 57, the control circuit 51b can be grounded (grounded) to the yoke 24.

  FIG. 6 is a perspective view showing a connection structure between the power supply terminal and the connection piece. The power supply terminals 53 and 54 provided in the brush device 31 are each formed in a plate shape, and the longitudinal direction thereof is the axial direction of the amateur shaft 26. And the thickness direction is orthogonal to the opening direction of the gear case 36 and is arranged inside the gear case 36 in a direction orthogonal to the axial direction of the armature shaft 26, that is, in the width direction of the sunroof motor 21. ing. The ground terminal 57 is also formed by bending a plate material. The terminal portion disposed in the gear case 36 and connected to the connection piece 58 has a longitudinal direction parallel to the axial direction of the armature shaft 26 and has a thickness. The direction is orthogonal to the opening direction of the gear case 36, and the power terminals 53 and 54 are arranged in the direction perpendicular to the axial direction of the armature shaft 26, that is, in the width direction of the sunroof motor 21. Has been.

  On the other hand, as shown for the connection piece 55 in FIG. 6, the connection pieces 55, 56, and 58 provided on the control board 51 are each provided with a clamping portion 55a that is formed in a fork shape and a support portion 55b that supports the clamping portion 55a. And a connecting piece restricting portion 55c that receives stress applied to the sandwiching portion 55a, and a connecting portion 55d that is electrically connected to the control circuit 51b by solder or the like. On the other hand, the control board 51 is provided with a dummy hole 51c, and the connection piece restricting portion 55c can be displaced slightly in the dummy hole 51c. Thus, the connection terminals 55, 56, and 58 are connected to each other. The structure can be bent in four directions with respect to the control board 51.

  When the cover body 37 to which the control board 51 is fixed is attached to the gear case 36, as shown in FIG. 6, the corresponding power supply terminal on the gear case 36 side between the clamping portions 55a of the connection pieces 55 provided on the control board 51. 53 is sandwiched, whereby the connection piece 55 and the power supply terminal 53 are electrically connected. Although not shown in detail, the connection pieces 56 and 58 are also connected to the power supply terminal 54 and the ground terminal 57 by the same structure as the connection piece 55.

  A connector 59 for external connection is provided at one end of the control board 51. As shown in FIG. 2, the connector 59 protrudes from the gear case 36, and the control circuit 51b is connected to an external power source (not shown) such as a battery mounted on the vehicle 13 via the connector 59 or a sunroof switch provided in the vehicle interior. (Not shown). That is, the power supply terminals 53 and 54 of the brush device 31 are connected to an external power supply via the connector 59, the control circuit 51b, and the connection pieces 55 and 56. When the sunroof switch is operated, a drive current is supplied from the external power source to the control circuit 51b via the connector 59, and this drive current is controlled to a predetermined current by the control circuit 51b. , 58 and power terminals 53 and 54, brushes 33 a and 33 b, and a commutator 29, are supplied to the amateur 25 (the amateur coil 28).

  Reference numeral 61 denotes a positioning portion provided in the cover body 37. The positioning portion 61 is inserted into a positioning hole 62 formed in the control board 51 and engages with a positioning protrusion 63 provided in the gear case 36. Thus, the control board 51 can be positioned at a predetermined position of the gear case 36.

  In order to detect the rotation of the amateur shaft 26, the sunroof motor 21 is provided with a rotation sensor. The rotation sensor includes a sensor magnet 72 fixed to the armature shaft 26. The sensor magnet 72 is a multipolar magnetized magnet in which a plurality of magnetic poles are magnetized in the circumferential direction. It is designed to rotate with it.

  On the other hand, as shown in FIG. 3, a pair of Hall ICs 73 a and 73 b are arranged on the control board 51 so as to face the sensor magnet 72 so as to form an angle of 90 degrees with respect to the axis of the armature shaft 26. The change in the magnetic field output from the sensor magnet 72 is detected with a phase difference of 45 degrees. Each Hall IC 73a, 73b detects a change in the magnetic field generated by the sensor magnet 72 and outputs it as a pulse signal having a period inversely proportional to the rotational speed of the armature shaft 26. Detection signals, that is, pulse signals of the Hall ICs 73a and 73b are input to the control circuit 51b, and the control circuit 51b receives the period of the pulse signals input from the Hall ICs 73a and 73b and the pulse signals input from the Hall ICs 73a and 73b. Control of the drive current supplied to the amateur coil 28 is executed based on the appearance timing and the like.

  Next, details of the brush device 31 will be described.

  7 is a perspective view showing the details of the brush device shown in FIG. 3, FIG. 8 is a plan view of the brush device shown in FIG. 7, and FIG. 9 is a circuit diagram of the motor body.

  In the brush device 31 used in the sunroof motor 21, the brush holder 32 is formed of a resin material in a substantially oval shape that matches the shape of the yoke 24, and a through hole 32 a in which the commutator 29 is disposed is provided in the shaft center. It has been. The brushes 33a and 33b are held in the brush holder 32 so as to be movable forward and backward in the radial direction toward the axial center of the through hole 32a. Each of the brushes 33a and 33b is urged by a torsion spring 74 and is subjected to a predetermined pressure. It comes in sliding contact with the outer peripheral surface of.

  The brush holder 32 is provided with a pair of coil holding portions 75 adjacent to the corresponding brushes 33a and 33b in a point-symmetrical manner with respect to the axis of the armature shaft 26. Each is provided with a choke coil 76. The coil holding portions 75 are each formed in a cylindrical shape having a C-shaped cross section parallel to the axial direction of the brush holder 32, that is, the axial direction of the armature shaft 26, and the choke coil 76 is inserted into the coil holding portion 75 from the axial direction. It is like that.

  Each of these coil holding portions 75 is formed of a resin material integrally with the brush holder 32, and is elastically deformable in a direction in which the C-shaped opening is expanded, that is, in a direction in which the inner diameter is increased. As a result, a plurality of types of choke coils 76 having different external dimensions can be attached to the coil holding portion 75.

  As shown in FIG. 9, one end of the choke coil 76 is connected to the corresponding brushes 33a and 33b, and the other end is connected to the corresponding power supply terminals 53 and 54, whereby the power supply terminals 53 and 54 and the brushes are connected. The electrical noise between 33a and 33b can be absorbed by the choke coil and reduced.

  A pair of ground terminals 81 as ground terminals are mounted on both side surfaces 32b of the brush holder 32 facing the flat plate portion 24b of the yoke 24, and the brushes 33a and 33b are connected to the yoke 24 by these ground terminals 81. The electrical noise generated from the sliding contact portion between the brushes 33 a and 33 b and the commutator 29 is prevented from being radiated to the outside of the yoke 24.

  In addition, since the same thing is used as a pair of these ground terminals 81, and the attachment structure to the brush holder 32 is also the same, it demonstrates based on one ground terminal 81 below.

  FIG. 10 is a perspective view showing details of the ground terminal, and FIG. 11 is a cross-sectional view showing an engagement state between the ground terminal and the mounting groove. 12 is a partially cutaway perspective view showing a mounting portion of the brush holder ground terminal, and FIG. 13 is a cross-sectional view showing a contact state between the ground terminal and the yoke.

  The ground terminal 81 is formed by bending a predetermined-shaped plate material having conductivity and elasticity, such as a steel plate or a copper plate, and as shown in FIG. 10, a base portion 81a formed in a flat plate shape and a base portion 81a. A contact portion 81b that is connected to one end side of the base portion 81b and bent at an acute angle with respect to the base portion 81a, and a base end portion that is connected to the other end side of the base portion 81a and is bent perpendicularly to the base portion 81a and orthogonal to the axial direction of the armature shaft 26. As a connecting portion 81c.

  On the other hand, on both side surfaces 32b of the brush holder 32, as shown in FIG. 8, a pair of mounting grooves 82 extending along the axial direction of the brush holder 32, that is, the armature shaft 26, is provided. As shown in FIG. 11, these mounting grooves 82 are respectively formed in a planar shape extending in the axial direction of the armature shaft 26 and parallel to the side surface 32 b of the brush holder 32, and the bottom wall 82 a and the side surface, respectively. It is partitioned and formed by a pair of side walls 82b that are connected to 32b, and the shape seen from the axial direction is a substantially trapezoidal shape whose opening width is narrower than the bottom wall 82a.

  In the ground terminal 81, the base portion 81a is inserted into the mounting groove 82 in the axial direction from one end side where the contact portion 81b is provided, so that the connecting portion 81c contacts the axial end surface 32c of the brush holder 32 as shown in FIG. It comes into contact and is attached to the attachment groove 82. Further, the width dimension of the base portion 81a is slightly smaller than the width dimension of the mounting groove 82, and as shown in FIG. 10, the other end portion on the other end side where the connection portion 81c of the base portion 81a is provided is on the other end side. A wide portion 81d whose width dimension gradually increases toward the surface is integrally formed, and the wide portion 81d is press-fitted into the mounting groove 82, whereby the ground terminal 81 is fixed to the mounting groove 82, that is, the brush holder 32. It is like that.

  When the base portion 81a is mounted in the mounting groove 82, each side wall 82b defining the mounting groove 82 is pushed by the base portion 81a and elastically deforms toward the outside of the side surface 32b, and the base portion 81a inserted into the mounting groove 82 is It is pressed toward the bottom wall 82a by the elastic force of the side wall 82b. As a result, the base portion 81a is pressed against the bottom wall 82a by being pushed by the side wall 82b, and the ground terminal 81 is positioned with high accuracy on the brush holder 32.

  Thus, in the sunroof motor 21, the base portion 81a of the ground terminal 81 is inserted into the mounting groove 82 provided on the side surface 32b of the brush holder 32, and the base portion 81a is pressed against the bottom wall 82a by the pair of side walls 82b. Therefore, the ground terminal 81 can be accurately positioned on the brush holder 32 with the bottom wall 82a as a reference.

  As shown in FIGS. 7 and 8, a pair of capacitors 83 is mounted on the brush holder 32, and the connection portions 81 c of the ground terminals 81 are respectively connected to the corresponding choke coils 76 via the corresponding capacitors 83. It is connected to terminals 53 and 54.

  On the other hand, the contact portion 81b of the ground terminal 81 attached to the brush holder 32 protrudes radially outward from the side surface 32b of the brush holder 32, and the brush holder 32 is attached to the inside of the yoke 24 as shown in FIG. Then, it is pushed and elastically deformed by the inner surface 24d of the yoke 24, and its tip end portion 84 is elastically brought into contact with the inner surface 24d of the yoke 24 while being urged by the elastic deformation. As a result, each brush 33a, 33b is grounded to the yoke 24 by the corresponding ground terminal 81, and a shielding effect is produced in the yoke 24, and the electric noise yoke 24 generated from the sliding contact portion between each brush 33a, 33b and the commutator 29. Can be reduced.

  Here, in the sunroof motor 21, in order to improve the connection reliability between the ground terminal 81 and the inner surface 24d of the yoke 24, as shown in FIG. 10, the tip end portion 84 of the contact portion 81b is bifurcated. I am doing so. That is, the front end portion 84 of the contact portion 81b of the ground terminal 81 is formed into a shape including a pair of branch pieces 84a that bifurcates, and the front end portion 84 is brought into contact with the inner surface 24d of the yoke 24 at both branch pieces 84a. I am doing so. Thereby, even when the ground terminal 81 is deviated from the normal posture with respect to the yoke 24 due to the attachment state of the ground terminal 81 to the brush holder 32 or the attachment state of the brush holder 32 to the yoke 24, the tip portion Each branch piece 84a provided in 84 is individually elastically deformed flexibly, so that the tip end portion 84 can be reliably brought into contact with the inner surface 24d of the yoke 24.

  As described above, in the sunroof motor 21, the tip end portion 84 of the ground terminal 81 is formed into a shape including a pair of branch pieces 84 a that bifurcate, and these branch pieces 84 a are brought into contact with the inner surface 24 d of the yoke 24. Therefore, the followability of the ground terminal 81 to the inner surface 24d of the yoke 24 can be enhanced by the flexible elastic deformation of the branch piece 84a. Thereby, even if the ground terminal 81 is deviated from the normal posture with respect to the yoke 24 due to the attachment state of the ground terminal 81 to the brush holder 32 or the attachment state of the brush holder 32 to the yoke 24, the distal end portion 84 of the ground terminal 81. Can be reliably brought into contact with the inner surface 24d of the yoke 24, and the electrical connection reliability of the ground terminal 81 to the yoke 24 can be improved.

  Further, as described above, in the sunroof motor 21, the base portion 81a inserted into the mounting groove 82 is pressed against the bottom wall 82a by the side walls 82b, so that the base portion 81a is brought into close contact with the bottom wall 82a. The ground terminal 81 can be accurately positioned on the brush holder 32 with reference to the bottom wall 82a. Thereby, the front end portion 84 of the ground terminal 81 is brought into contact with the inner surface 24d of the yoke 24 with a pressure as designed, and the electrical connection reliability of the ground terminal 81 to the yoke 24 can be further enhanced.

  As described above, the pair of ground terminals 81 are attached to the brush holder 32 of the sunroof motor 21. These ground terminals 81 protrude from the side surface 32b of the brush holder 32, and are elastically deformed. It contacts the inner surface 24d. Therefore, a load is applied to the brush holder 32 by the elastic force of the ground terminal 81, and the brush holder 32 may be displaced with respect to the yoke 24 due to the load.

  Therefore, in the sunroof motor 21, as shown in FIG. 8, the pair of ground terminals 81 attached to the brush holder 32 are arranged symmetrically about the through hole 32 a, that is, the axis of the armature shaft 26. . Thereby, the load which each ground terminal 81 applies to the brush holder 32 by the contact with the yoke 24 can be canceled, and the positional deviation in the inside of the yoke 24 of the brush holder 32 by the said load can be suppressed.

  As described above, in the sunroof motor 21, the pair of ground terminals 81 attached to the brush holder 32 are arranged symmetrically with respect to the axis of the amateur shaft 26. It is possible to cancel the load applied to 32 and suppress the displacement of the brush holder 32 inside the yoke 24. Thereby, each ground terminal 81 is brought into contact with the inner surface 24d of the yoke 24 in a normal posture, that is, with a pressure as designed, so that the connection reliability between the ground terminal 81 and the yoke 24 can be further improved.

  Further, since the same shape of the pair of ground terminals 81 to be mounted on the brush holder 32 is used, the cost can be reduced.

  As shown in FIG. 12, the axial end face 32c of the brush holder 32 is provided with an attachment hole 85 penetrating the brush holder 32 in the axial direction adjacent to the connection portion 81c of the ground terminal 81. The power supply terminals 53 and 54 attached to the brush holder 32 are inserted into the attachment hole 85, and the power supply terminals 53 and 54 are guided to the back side of the brush holder 32 through the attachment hole 85 and are connected to the capacitor 83 and the choke coil 76. To be connected to. Further, the connecting portion 81c of the ground terminal 81 is formed so as to be shifted in the rotation direction of the armature shaft 26 with respect to the base portion 81a, and the offset portion 81e between the base portion 81a and the connecting portion 81c is offset with respect to the base portion 81a. A chamfered portion 81f that is inclined in the direction is formed, and the chamfered portion 81f faces a portion inserted through the mounting hole 85 of the power supply terminals 53 and 54. A pair of positioning projections 86 are provided on the axial end surface 32 c of the brush holder 32 in order to prevent contact between the power terminals 53 and 54 and the ground terminal 81.

  These positioning projections 86 are formed in a cylindrical shape protruding in the axial direction from the axial end surface 32 c of the brush holder 32, and are arranged around a chamfered portion formed at the edge of the mounting hole 85. As a result, the chamfered portion 81 f of the ground terminal 81 abuts against these positioning protrusions 86 and is positioned on the brush holder 32, and the positioning protrusion 86 is disposed between the ground terminal 81 and the power supply terminals 53 and 54. Contact between the power terminals 53 and 54 and the ground terminal 81 is prevented.

  As described above, in the sunroof motor 21, the chamfered portion 81 f provided on the ground terminal 81 is brought into contact with the pair of positioning protrusions 86 provided on the axial end surface 32 c of the brush holder 32 so that the ground terminal 81 is placed on the brush holder 32. Since the positioning is performed, a mounting hole 85 for attaching the power supply terminals 53 and 54 to the brush holder 32 is formed in the vicinity of the ground terminal 81, and a partition wall or the like is provided between the ground terminal 81 and the mounting hole 85. Even if there is no contact, the ground terminal 81 can be positioned on the brush holder 32 by the pair of positioning projections 86 to prevent contact with the power supply terminals 53 and 54.

  It goes without saying that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. For example, in the above-described embodiment, the present invention is applied to the sunroof motor 21 used in the sunroof device 11 of the vehicle 13. However, the present invention is not limited to this, for example, a slide door device or a power window device provided in the vehicle. You may make it apply to the electric motor used for.

  In the above-described embodiment, the tip of the ground terminal is bifurcated. However, the present invention is not limited to this, and the ground terminal may be bifurcated, for example, three.

It is explanatory drawing which shows the outline of the sunroof apparatus provided in the roof of the vehicle. (A), (b) is a perspective view which shows the detail of the sunroof motor shown in FIG. 1, respectively. FIG. 3 is an exploded perspective view of the sunroof motor shown in FIG. 2. It is a top view which shows arrangement | positioning of a brush holder. It is sectional drawing which follows the AA line in FIG.2 (b). It is a perspective view which shows the connection structure of a power supply terminal and a connection piece. It is a perspective view which shows the detail of the brush apparatus shown in FIG. It is a top view of the brush apparatus shown in FIG. It is a circuit diagram of a motor body. It is a perspective view which shows the detail of a ground terminal. It is sectional drawing which shows the engagement state of a ground terminal and a mounting groove. It is a partially cutaway perspective view showing a mounting portion of the brush holder ground terminal. It is sectional drawing which shows the contact state of a ground terminal and a yoke.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Sunroof apparatus 12 Roof panel 13 Vehicle 13a Roof 13b Windshield 14 Opening part 15a, 15b Shoe 16 Guide rail 17a, 17b Drive cable 21 Sunroof motor (electric motor)
22 drive gear 23 motor main body 24 yoke 24a arc portion 24b flat plate portion 24c bottom portion 24d inner surface 25 amateur 26 amateur shaft 27 amateur core 28 amateur coil 29 commutator 31 brush device 32 brush holder 32a through hole 32b side surface 32c axial end surfaces 33a, 33b brush 34 bolt 35 nut 36 gear case (end case)
36a Gear housing portion 36b Control board housing portion 36c Cable guide 37 Cover body 37a Through hole 41 Worm gear mechanism 41a Worm 41b Worm wheel 42 Output shaft 42a Tool hole 43 Gear cover 44 Guide plate 44a Guide wall 51 Control board 51a Board 51b Control circuit 51c Dummy Hole 52 Clip 52a Body 52b Clip ball 52c Slit 53, 54 Power supply terminal 55, 56 Connection piece 55a Holding portion 55b Support portion 55c Connection piece regulating portion 55d Connection portion 57 Ground terminal 58 Connection piece 59 Connector 61 Positioning portion 62 Positioning hole 63 Positioning Protrusion 72 Sensor magnet 73a First Hall IC
73b Second Hall IC
74 Torsion spring 75 Coil holder 76 Choke coil 81 Ground terminal (ground terminal)
81a Base part 81b Contact part 81c Connection part 81d Wide part 81e Offset part 81f Chamfering part 82 Mounting groove 82a Bottom wall 82b Side wall 83 Capacitor 84 Tip part 84a Branch piece 85 Mounting hole 86 Positioning projection 86

Claims (5)

A yoke that is formed in a bottomed cylindrical shape and has an end case attached to the open end;
An amateur supported by an amateur shaft and rotatably accommodated in the yoke;
An amateur core fixed to the amateur shaft and mounted with a plurality of amateur coils;
A commutator fixed to the armature shaft and connected to coil ends of the plurality of armature coils;
A brush holder mounted inside the yoke opposite the end case and holding a plurality of brushes in sliding contact with the commutator;
A plurality of power terminals each mounted on the brush holder and connected to the corresponding brush and connected to an external power source;
A ground terminal that is mounted on the brush holder and has a base end portion that is electrically connected to the brush and elastically contacts the yoke at a distal end portion to ground the brush to the yoke;
An electric motor characterized in that a tip portion of the ground terminal is branched into a plurality.   2. The electric motor according to claim 1, wherein a tip end portion of the ground terminal is bifurcated.   3. The electric motor according to claim 1, wherein a plurality of the ground terminals are provided so as to be connected to the corresponding brushes, and the ground terminals are arranged symmetrically with respect to the axis of the armature shaft. Electric motor.   4. The electric motor according to claim 1, wherein the tip portion of the ground terminal is in elastic contact with an inner surface of the yoke, and a side surface of the brush holder includes an axis of the armature shaft. 5. A mounting groove formed in a substantially trapezoidal cross section that is partitioned by a bottom wall parallel to the side surface extending in the direction and a pair of side walls that are continuous with the bottom wall and the side surface, and the width of the opening portion is narrower than the bottom wall. The grounding terminal is mounted on the brush holder in a state in which the base formed in a plate shape is inserted into the mounting groove from the axial direction so that the base is pressed by the side wall and pressed against the bottom wall. Electric motor characterized by being made.   5. The electric motor according to claim 1, wherein the grounding terminal is formed in a plate shape and is formed orthogonal to the armature shaft and a base portion that is continuous with the tip portion, and an axial direction of the brush holder. A connecting portion disposed on an end surface and connected to the brush; and an offset portion that connects the connecting portion to the base portion while being shifted in a rotation direction of the armature shaft, and the chamfered portion is formed in the offset portion. The electric motor is characterized in that a pair of positioning projections for positioning the grounding terminal in contact with the chamfered portion are provided on the end surface in the axial direction of the brush holder.

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