JP2012200146A - Wiper motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wiper motor that allows switching between rotational speeds even when the motor is configured to have multiple poles.SOLUTION: Four magnets 22 are mounted on an inner surface of a motor yoke of a wiper motor 18. Sixteen slots 27a to 27p are formed on an armature core 27. Lap windings 28 are wound on the slots 27a to 27p. A commutator 31 having sixteen commutator pieces 31a to 31p is fixed to an armature shaft. The windings 28 are connected to the commutator pieces 31a to 31p, and pairs out of the commutator pieces 31a to 31p to be at the same potential are electrically connected to each other by respective connecting wires 41a to 41h. A common brush 32 and a low-speed operation brush 33 that each contact the commutator 31 slidably are provided so as to be displaced from each other in a rotating direction. A high-speed operation brush 36 that contacts the commutator 31 slidably is provided on a side of a larger angle between the low-speed operation brush 33 and the common brush 32.

Description

  The present invention relates to a wiper motor used in a wiper device for wiping a windshield of a vehicle.

  A vehicle such as an automobile is provided with a wiper device for wiping raindrops and the like adhering to a windshield (windshield). The wiper device has a wiper arm that is swingably supported by the vehicle body, and a wiper motor that drives the wiper arm. A wiper blade is attached to the tip of the wiper arm, and when the wiper motor is activated, the wiper blade swings on the glass surface. Then the glass surface is wiped away.

  In such a wiper device, it is necessary to switch the wiper device between a low speed operation and a high speed operation in accordance with a change in the amount of raindrops adhering to the windshield. For this reason, as the wiper motor, a two-pole three-brush brush DC motor whose operation speed can be switched is often used. In a 2-pole 3-brush motor, a pair of magnets are mounted on the inner surface of the motor yoke, and the windings are mounted on the armature core by lap winding. The commutator has a common brush and a low-speed operation. In addition to the brush for high speed operation, the brush for high speed operation comes into sliding contact. When the low-speed operation is selected by the driver's switch operation, a driving current is supplied to the windings via the common brush and the low-speed operation brush, whereby the wiper motor operates at a low speed. On the other hand, when high speed operation is selected by the driver, a driving current is supplied to the windings via the common brush and the high speed operation brush, so that the wiper motor operates at high speed.

  On the other hand, a technique is known in which the motor is miniaturized by increasing the number of motor poles to four or more. For example, Patent Document 1 describes a brushed DC motor having four motor poles by mounting four magnets arranged in the rotational direction on the inner surface of a motor yoke. In this case, the commutator is in sliding contact with a pair of brushes that are offset from each other by 90 degrees in the rotational direction, and each commutator piece that constitutes the commutator is connected to the other commutator piece that should be at the same potential by a pressure equalizing line. The windings are configured by a circuit corresponding to four poles by a pair of brushes, and a four-pole motor is operated.

JP 2000-166185 A

  However, the four-pole motor disclosed in Patent Document 1 has a problem that the motor speed can be reduced by increasing the number of motor poles, but the rotation speed cannot be switched.

  An object of the present invention is to provide a wiper motor capable of switching the rotation speed even when the number of poles is increased.

  The wiper motor of the present invention is a wiper motor that drives a wiper device that wipes a windshield of a vehicle, and includes a motor yoke that rotatably supports an armature shaft, and an even number of magnetic poles that are four or more poles aligned in the rotation direction of the armature shaft. A field portion fixed to the inner surface of the motor yoke, a plurality of slots arranged in the rotation direction, an armature core fixed to the armature shaft, and a plurality of commutator pieces arranged in the rotation direction, The commutator fixed to the amateur shaft and the windings wound in a predetermined slot from each of the plurality of slots and electrically connected to the commutator pieces are respectively identical to each other. A plurality of connecting members for electrically connecting the commutator pieces to be at a potential, A wiper motor having a common brush, a first brush, and a second brush respectively along a rotation direction, wherein the first brush is shifted in the rotation direction with respect to the common brush. And is in sliding contact with the commutator piece to supply a drive current to the winding in pairs with the common brush, and the second brush and the first brush in the rotational direction. It is arranged between the common brushes and at a wider angle, and is slidably contacted with the commutator piece to supply a drive current to the windings as a pair with the common brush.

  The wiper motor of the present invention is characterized in that the field magnet section includes four magnetic poles, and the first brush is disposed at a position shifted by 90 degrees in the rotation direction with respect to the common brush.

  According to the present invention, four or more magnetic poles are provided in the magnetic field portion that is attached to the inner surface of the motor yoke, and the commutator pieces that should be at the same potential are electrically connected to each other and paired with the common brush. In addition to the first brush that supplies the drive current to the winding, the second brush is provided between the first brush and the common brush in the rotation direction and at a wider angle. Even if the wiper motor is multipolarized to four poles, it can be operated with a pair of brushes and the rotational speed of the amateur shaft can be switched. Moreover, since the unbalance of the electromotive force generated in the winding by adding the second brush is balanced in the rotation direction by the connection line, the circulating current flowing in the first brush is reduced, and the first brush Wear can be suppressed.

  In addition, according to the present invention, the wiper motor can be operated by the two brushes of the common brush and the first brush even if the field part is multipolarized to four or more poles. Can be improved.

It is explanatory drawing which shows the outline of the wiper apparatus provided with the wiper motor which is one embodiment of this invention. It is sectional drawing which shows the detail of the wiper motor shown in FIG. It is sectional drawing which follows the AA line in FIG. FIG. 3 is a circuit diagram of the wiper motor shown in FIG. 2. It is explanatory drawing which shows the mounting procedure of the coil | winding to a slot. It is explanatory drawing which shows the attachment procedure of the other coil | winding to a slot. (A)-(c) is explanatory drawing which shows the modification of the arrangement position of the brush for high-speed driving | operation shown in FIG. 3, respectively. It is a circuit diagram which shows the case where this invention is applied to a 6-pole wiper motor.

  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 wiper device having a wiper motor according to an embodiment of the present invention. The vehicle 11 shown in FIG. 1 has rainwater, dust, etc. adhering to a windshield (windshield) 12. A wiper device 13 is provided to secure the driver's field of view by wiping the vehicle. The wiper device 13 is a so-called tandem type, and wiper arms 16a and 16b are fixed to two wiper shafts 15a and 15b rotatably supported by the vehicle body 14, respectively. Wiper blades 17a and 17b are respectively attached. Further, springs (not shown) are attached to the base end portions of the wiper arms 16a and 16b, and the wiper blades 17a and 17b are pressed against the windshield 12 by the spring force of the springs.

  The wiper device 13 is provided with a wiper motor 18 as its drive source. The wiper motor 18 has an output shaft 18a. The output shaft 18a is connected to the wiper shafts 15a and 15b via a link mechanism 19. When the wiper motor 18 is operated, the wiper arms 16a and 16b are swung within a predetermined angle range. The wiper blades 17a and 17b move in a swinging motion in the wiping ranges 12a and 12b between the upper and lower inversion positions so that rainwater, dust, and the like attached to the windshield 12 are wiped off. Yes.

  2 is a sectional view showing details of the wiper motor shown in FIG. 1, FIG. 3 is a sectional view taken along line AA in FIG. 2, and FIG. 4 is a circuit diagram of the wiper motor shown in FIG.

  As shown in FIGS. 2 and 3, the wiper motor 18 has a motor yoke (yoke) 21 formed of a steel material in a bottomed cylindrical shape, and four magnets 22 are formed on the inner surface of the motor yoke 21. They are mounted side by side in the rotational direction (circumferential direction). These magnets 22 are permanent magnets having a circular arc cross section, and are arranged inside the motor yoke 21 so that N poles and S poles are alternately arranged in the rotation direction. Is configured to have a field portion having four magnetic poles.

  An armature 23 is provided inside the motor yoke 21, and this armature has an armature shaft 24. The armature shaft 24 is rotatably supported by the motor yoke 21 via a bearing 25, thereby The amateur 23 is rotatable inside the motor yoke 21. Reference numeral 26 denotes a support sphere that supports the armature shaft 24 in the axial direction, and the movement of the armature shaft 24 in the axial direction is restricted by the support sphere 26.

  An amateur core 27 is fixed to the amateur shaft 24. The armature core 27 is located inside the motor yoke 21 and faces the magnet 22 through a minute gap (air gap). The amateur core 27 is formed with 16 slots 27a to 27p arranged in the rotation direction. In these slots 27a to 27p, as shown in FIG. Winding 28 is attached.

  A commutator 31 is fixed to the armature shaft 24 adjacent to the armature core 27. The commutator 31 includes 16 commutator pieces 31 a to 31 p that are arranged in the rotational direction while being insulated from each other. The commutator pieces 31 a to 31 p are wound around the amateur core 27, respectively. The wound windings 28 are electrically connected.

  In order to supply a driving current to the winding 28, the wiper motor 18 is provided with a common brush 32 and a low speed operation brush (first brush) 33. These brushes 32 and 33 are supported by a brush holder 34 and are urged toward a commutator 31, that is, commutator pieces 31 a to 31 p by a spring 35, so as to be in sliding contact with the commutator pieces 31 a to 31 p, respectively. It has become. As shown in FIG. 3, the low-speed operation brush 33 is disposed at a position shifted by 90 degrees in the rotation direction with respect to the common brush 32, the common brush 32 is positive (positive electrode), and the low-speed operation brush 33 is negative (negative). The wiper motor 18 can be operated at a low speed by supplying a drive current to the winding 28 with the common brush 32 and the low-speed operation brush 33 as a pair.

  Further, the wiper motor 18 has a high-speed operation brush (second brush) that is shifted in the rotational direction with respect to the low-speed operation brush 33 as shown in FIG. 3 so that the operation speed of the wiper motor 18 can be switched. ) 36 is provided. In the illustrated case, the high-speed operation brush 36 is supported by the brush holder 34 and is urged by the spring 35 to slidably contact the commutator pieces 31 a to 31 p, and the axis of the amateur shaft 24 with respect to the common brush 32. Centering on the center, it shifts to an acute angle in the rotation direction and is arranged at a position shifted from the obtuse angle in the rotation direction with respect to the low speed operation brush 33, and its polarity is a negative electrode (minus pole). The wiper motor 18 can be operated at high speed by supplying a drive current to the winding 28 with the common brush 32 and the high-speed operation brush 36 as a pair. The high speed operation is an operation state in which the rotational speed of the amateur shaft 24 is higher than the rotational speed of the amateur shaft 24 during low speed operation.

  In this wiper motor 18, the field portion mounted on the inner surface of the motor yoke 21 has four poles, but the winding 28 is driven from a pair of brushes of a common brush 32 and a low speed operation brush 33 or a high speed operation brush 36. Current is supplied. Therefore, in this wiper motor 18, as shown in FIG. 4, in order to make the winding 28 have a circuit configuration corresponding to the magnetic poles of four poles, commutator pieces that should be at the same potential, that is, 180 degrees in the rotation direction. The commutator pieces that are displaced from each other are electrically connected by a plurality of connection lines (connection members) 41a to 41h. For example, the commutator piece 31a and the commutator piece 31i are electrically connected by the connection line 41a, and the commutator piece 31b is electrically connected by the connection line 41b to the two brushes 32, Even if a drive current is supplied from 33 through commutator pieces 31a to 31p, commutation corresponding to four poles is performed on the winding 28, and the wiper motor 18 can be operated. Further, by energizing either the low speed operation brush 33 or the high speed operation brush 36 which is paired with the common brush 32, the operation speed of the wiper motor 18 can be switched in two stages. Thus, the low speed operation brush 33 and the high speed operation brush 36 which are paired with the common brush 32 are arranged, and the common brush 32, the low speed operation brush 33 and the high speed operation brush 36 are arranged one by one. Has been.

  FIG. 5 is an explanatory diagram showing a procedure for mounting a winding in the slot, and FIG. 6 is an explanatory diagram showing a procedure for mounting another winding in the slot. In the wiper motor 18, the windings 28 and the connection lines 41 a to 41 h are formed by winding the conductors in the slots 27 a to 27 p and connecting the conductors to the commutator pieces 31 a to 31 p according to the procedure shown in FIG. 5 or 6. Are formed by the same conducting wire.

  That is, the method shown in FIG. 5 is based on a double flyer system in which two conductors are simultaneously wound on each of the slots 27a to 27p from a position 180 degrees out of phase with each other, and each conductor is connected to a predetermined commutator piece. Then, after winding a conducting wire in a predetermined slot, connect the conducting wire to a commutator piece adjacent to the commutator piece, and then connect the conducting wire to a commutator piece that is 180 degrees away from the commutator piece. Connect the lead wire to the original commutator piece again. Thereafter, by repeating the same procedure, the winding 28 is mounted in the slot and the connection lines 41a to 41h are formed. For example, the conductor is connected to the commutator piece 31c, the conductor is wound around the slot 27b and the slot 27f, the conductor is connected to the commutator piece 31d, and then the commutator pieces to be at the same potential. That is, after connecting the conducting wire to the commutator piece 31l arranged 180 degrees away from each other in the rotational direction, the conducting wire is connected again to the original commutator piece 31d, and thereafter the winding of the conducting wire in the slot and the connecting wire Are sequentially formed.

  On the other hand, in the method shown in FIG. 6, as in the case shown in FIG. 5, the lap winding by the double flyer method is basically used, and each conducting wire is connected to a predetermined commutator piece, and then the conducting wire is wound around a predetermined slot. Then, a conducting wire is connected to the commutator piece adjacent to the commutator piece, and then the conducting wire is connected to the commutator piece that is shifted from the commutator piece by 180 degrees in the rotation direction. And after winding the conducting wire around each slot with the commutator piece shifted by 180 degrees as a reference and connecting the conducting wire to the commutator piece adjacent to the commutator piece, the original commutator piece, that is, the commutator piece The conducting wire is connected to the commutator piece shifted by 180 degrees in the rotation direction, and thereafter the same procedure is repeated to mount the winding 28 in the slot and form the connection wires 41a to 41h. For example, the conductor is connected to the commutator piece 31c, the conductor is wound around the slot 27b and the slot 27f, the conductor is connected to the commutator piece 31d, and then the commutator pieces to be at the same potential. That is, after conducting wires are connected to the commutator pieces 31l arranged 180 degrees apart from each other in the rotational direction, the conducting wires are wound around the slots 27k and 27o, and the original commutator pieces, that is, the commutator pieces are rotated in the rotational direction. After connecting the conducting wire again to the commutator piece 31l which is shifted by 180 degrees, the conducting wire is connected to the commutator piece 31d, and thereafter the winding around the slot and the formation of the connecting wire are sequentially performed. Here, the number of slots and commutator pieces is 16, but the number varies depending on the characteristics of the motor. Further, the interval between the slots in which the conductive wires are wound can be changed according to the characteristics of the motor.

  As described above, in the wiper motor 18, the conductors are overlapped with the slots 27 a to 27 p and connected to the windings 28 by connecting the conductors to the commutator pieces 31 a to 31 p in the procedure shown in FIG. Since the wires 41a to 41h are formed by the same conducting wire, the connection wires 41a to 41h can be easily formed. Moreover, since it is not necessary to use another member other than the conducting wire as a connecting member for connecting the commutator pieces 31a to 31p to each other, an increase in the number of parts is prevented and the cost of the wiper motor 18 is reduced. Can be made.

  A gear case 51 is fixed to the motor yoke 21, and a reduction mechanism 52 that decelerates the rotation of the armature shaft 24 is accommodated in the gear case 51. The amateur shaft 24 protrudes into the gear case 51, and a worm 53 is integrally formed on the outer peripheral surface of the portion of the armature shaft 24 protruding into the gear case 51. The worm 53 rotates together with the amateur shaft 24. It is like that. A worm wheel 54 is rotatably accommodated in the gear case 51, the worm 53 is engaged with the worm wheel 54, and the worm 53 and the worm wheel 54 constitute a speed reduction mechanism 52. An output shaft 18a to which the above-mentioned link mechanism 19 is connected is fixed on the central axis of the worm wheel 54, whereby the rotation of the armature shaft 24 is reduced to a predetermined rotational speed by the speed reduction mechanism 52 and output. It is output from the shaft 18a.

  In addition, a control board 55 that controls the operation of the wiper motor 18 is accommodated in the gear case 51. The control board 55 is connected to a wiper switch (not shown) or a battery (power source) mounted on the vehicle by wiring, and when the wiper switch is operated by a driver or the like, each brush 32, 33, 36 is supplied from the control board 55. Is supplied with a drive current, and the wiper motor 18 is thereby operated. The control board 55 is provided with a hall sensor (not shown) facing the rotation detection magnet 56 fixed to the armature shaft 24, and the control board 55 detects the rotation speed of the armature shaft 24 detected by the hall sensor. The operation control of the wiper motor 18 is performed based on the above.

  Next, the operation of the wiper motor 18 will be described.

  When the wiper switch is operated to the low speed driving side by a driver or the like, a driving current is supplied from the control board 55 to the winding 28 via the common brush 32 that is a positive pole and the low speed driving brush 33 that is a negative pole. The At this time, the low-speed operation brush 33 is arranged 90 degrees away from the common brush 32 in the rotation direction, but the commutator pieces 31a to 31p are connected to each other by 180 degrees. Since the pair of brushes 32 and 33 are electrically connected to each other by 41a to 41h, the winding 28 is supplied with a drive current corresponding to the four-pole magnetic poles provided on the motor yoke 21 to operate the wiper motor 18. be able to. Thus, during low speed operation, the common brush 32 and the low speed operation brush 33 are paired to supply drive current to the winding 28, and the armature shaft 24 of the wiper motor 18 rotates at low speed. When the amateur shaft 24 rotates, the rotation is decelerated to a predetermined rotational speed by the speed reduction mechanism 52 and is output from the output shaft 18a, and the wiper arms 16a and 16b swing at a low speed.

  On the other hand, when the wiper switch is operated to the high speed driving side by a driver or the like, a driving current is applied to the winding 28 from the control board 55 via the common brush 32 that is the positive pole and the high speed driving brush 36 that is the negative pole. Supplied. That is, during high-speed operation, the common brush 32 and the high-speed operation brush 36 are paired to supply drive current to the winding 28. At this time, the high-speed driving brush 36 is arranged so as to be shifted in the rotational direction with respect to the low-speed driving brush 33, that is, is advanced, so that the armature shaft 24 of the wiper motor 18 has a higher speed than that during the low-speed operation. Rotate with. When the armature shaft 24 rotates, the rotation is decelerated to a predetermined number of rotations by the decelerating mechanism 52 and output from the output shaft 18a, and the wiper arms 16a and 16b swing at a high speed.

  As described above, in the wiper motor 18, four or more magnetic poles are provided in the field portion mounted on the inner surface of the motor yoke 21, and the commutator pieces that should have the same potential are electrically connected to each other, and the common brush In addition to the low-speed operation brush 33 that supplies a drive current to the winding 28 in pairs with the high-speed operation brush 33, a high-speed operation brush 36 that is displaced in the rotational direction with respect to the low-speed operation brush 33 is provided. Therefore, the rotational speed of the four-pole wiper motor 18 can be switched. Further, since the unbalance of the electromotive force generated in the winding 28 due to the addition of the high-speed operation brush 36 is balanced in the rotation direction by the connection lines 41a to 41h, the circulating current flowing through the high-speed operation brush 36 is reduced. Thus, wear of the low-speed operation brush 33 can be suppressed. That is, in the wiper motor 18 having the high-speed operation brush 36 for switching the operation speed, the high-speed operation brush 36 shorts the adjacent commutator pieces even when the high-speed operation brush 36 is not energized. Coils are generated, the number of effective conductors changes, and a circulating current flows through each brush to promote brush wear. However, in this wiper motor 18, commutator pieces shifted by 180 degrees are connected by connecting wires 41a to 41h. Therefore, the durability of the brushes 32 and 33 can be improved by flowing a circulating current through the connection lines 41a to 41h.

  Further, in the wiper motor 18, even if the number of poles is increased to four, the wiper motor 18 can be operated by the two brushes of the common brush 32 and the low-speed operation brush 33, so that the layout of the high-speed operation brush 36 is improved. At the same time, the cost can be reduced. That is, since it is not necessary to provide four brushes in accordance with the four-pole field portion, the space for arranging the high-speed operation brush 36 is increased correspondingly, thereby improving the layout of the high-speed operation brush 36. Will be enhanced.

  FIGS. 7A to 7C are explanatory views showing modifications of the arrangement position of the brush for high speed operation shown in FIG. In the wiper motor 18 shown in FIG. 3, the high-speed operation brush 36 is shifted in an obtuse angle in the rotation direction around the axis of the amateur shaft 24 with respect to the low-speed operation brush 33, and is acute in the rotation direction with respect to the common brush 32. As shown in FIG. 7 (a), the high-speed operation brush shown in FIG. 3 is located at an acute angle in the rotational direction with respect to both the common brush 32 and the low-speed operation brush 33. You may make it arrange | position in the position symmetrical with respect to the line segment which passes along the common brush 32 and the axial center of the amateur shaft 24 with respect to 36 positions.

  Further, as shown in FIG. 7B, the high speed operation brush 36 may be arranged at a position deviated in an obtuse angle in the rotation direction with respect to both the common brush 32 and the low speed operation brush 33. That is, the high speed operation brush 36 is arranged at a position symmetrical to the line passing through the low speed operation brush 33 and the axis of the armature shaft 24 with respect to the position of the high speed operation brush 36 shown in FIG. Also good. That is, the high-speed operation brush 36 is arranged between the common brush 32 and the low-speed operation brush 33 in the rotation direction and at a wider angle.

  Further, as shown in FIG. 7C, the high-speed driving brush shown in FIG. 3 is located at an obtuse angle in the rotational direction with respect to the common brush 32 and at an acute angle in the rotational direction with respect to the low-speed driving brush 33. The high-speed operation brush 36 may be disposed at a point-symmetrical position around the axis of the amateur shaft 24 with respect to the position 36. In this case, the rotation directions of the common brush 32 and the low-speed operation brush 33 are opposite to each other.

  Thus, in the wiper motor 18, the motor can be operated by a pair of brushes even if the field portion is set to four poles. Therefore, the arrangement position of the high-speed operation brush 36 on the brush holder 34 is shown in FIG. 3. Or the layout property of each brush 32, 33, 36 can be improved, such as setting to each position shown in FIG.

  FIG. 8 is a circuit diagram showing a case where the present invention is applied to a 6-pole wiper motor.

  In the wiper motor shown in FIG. 2, the motor yoke 21 is provided with a four-pole field portion, and the commutator pieces 31a to 31p constituting the commutator 31 are electrically connected to each other by connecting lines 41a to 41h. The windings 28 are formed by a circuit corresponding to the four-pole field portion by this connection, and the four-pole wiper motor 18 is operated by a pair of brushes. The present invention can also be applied to a wiper motor having a field part having more than poles. For example, in the wiper motor 61 shown in FIG. 8, six magnets 22, that is, field portions having six magnetic poles are attached to the inner surface of the motor yoke 21, and windings 28 are attached to the slots 27 a to 27 x, Each commutator piece 31a-31x which comprises the commutator 31 is electrically connected by connection line 41a-41h by making three pairs of commutator pieces which shifted | deviated 120 degree | times to the rotation direction. Accordingly, the winding 28 is formed by a circuit corresponding to the six-pole field portion, and the wiper motor 61 can be operated by the pair of brushes of the common brush 32 and the low-speed operation brush 33.

  The wiper motor 61 is also provided with a high-speed operation brush 36 that is shifted in the rotational direction with respect to the low-speed operation brush 33. By energizing the high-speed operation brush 36 and the common brush 32 as a pair, the wiper motor 61 is provided. 18 can be operated at high speed.

  In FIGS. 7 and 8, members corresponding to those described above are denoted by the same reference numerals.

  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 present embodiment, the case where the number of motor poles, that is, the number of poles of the magnetic field part is 4 poles and 6 poles, is shown, but the present invention is not limited to this.

  Further, in the present embodiment, the wiper motors 18 and 61 can be switched between two operating speeds of low speed operation and high speed operation. It may be possible.

  Furthermore, in the present embodiment, the connection wires 41a to 41h, which are connection members, are configured by the conductive wire forming the winding 28, but the present invention is not limited to this, and the commutator pieces can be connected to each other. If it is a member, you may make it use another member.

11 Vehicle 12 Windshield (windshield)
DESCRIPTION OF SYMBOLS 13 Wiper apparatus 14 Vehicle body 15a, 15b Wiper axis | shaft 16a, 16b Wiper arm 17a, 17b Wiper blade 18 Wiper motor 18a Output shaft 19 Link mechanism 21 Motor yoke 22 Magnet (field part)
23 Amateur 24 Amateur shaft 25 Bearing 26 Support ball 27 Amateur core 27a to 27x Slot 28 Winding 31 Commutator 31a to 31x Commutator piece 32 Common brush 33 Brush for low speed operation (first brush)
34 Brush holder 35 Spring 36 Brush for high speed operation (second brush)
41a to 41h Connection line (connection member)
51 Gear Case 52 Deceleration Mechanism 53 Worm 54 Worm Wheel 55 Control Board 56 Rotation Detection Magnet 61 Wiper Motor

Claims (2)

In a wiper motor that drives a wiper device that wipes a windshield of a vehicle,
A motor yoke that rotatably supports the amateur shaft;
A magnetic field part having four or more poles arranged in the rotational direction of the amateur shaft and an even number of magnetic poles, and fixed to the inner surface of the motor yoke;
An amateur core comprising a plurality of slots arranged in the rotational direction, and fixed to the amateur shaft;
A plurality of commutator pieces arranged in the rotational direction, and a commutator fixed to the amateur shaft;
Windings that are overlapped with a predetermined slot from each of the plurality of slots, and are electrically connected to the respective commutator pieces;
A plurality of connecting members that electrically connect the commutator pieces to each other to have the same potential;
A wiper motor including one common brush, one first brush, and one second brush around the commutator along a rotational direction,
The first brush is disposed at a position shifted in the rotation direction with respect to the common brush, is in sliding contact with the commutator piece, and supplies a drive current to the winding as a pair with the common brush. And
The second brush is disposed between the first brush and the common brush in the rotation direction and at a wider angle, and is in sliding contact with the commutator piece to be paired with the common brush. A wiper motor characterized in that a driving current is supplied to the winding.   2. The wiper motor according to claim 1, wherein the field magnet portion includes four magnetic poles, and the first brush is disposed at a position shifted by 90 degrees in the rotation direction with respect to the common brush. Wiper motor.

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