JP2007202391A - Speed switching motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve torque fall and aggravation of rectification during low speed operation by shortening the short circuit time of a brush for high speed operation thereby suppressing a current generated by back-emf during low speed operation. <P>SOLUTION: Since a wide insulation part 29b and a narrow insulation part 29a are provided in the axial direction of a conductive portion 28, contact time of a brush 34 for high speed operation with the conductive portion 28 can be shortened as compared with the contact time of a brush 30 for low speed operation with the conductive portion 28. Torque fall and aggravation of rectification during low speed operation can be improved by suppressing a current generated by back-emf during low speed operation of a wiper motor 16. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a speed-switchable motor that can be switched to at least two stages of operation speeds of low-speed operation and high-speed operation.

  Conventionally, as a speed switching type motor capable of switching the operation speed of a motor, for example, a wiper motor that is applied to a wiper device that wipes raindrops, dust, and the like attached to a windshield of an automobile is known. According to the switching operation of the driver, the driving speed according to the amount of rain, that is, the low speed driving at the time of light rain such as drizzle or the high speed driving at the time of concentrated heavy rain can be appropriately selected.

As an example of the application of such a speed-switching motor to a wiper motor, a technique disclosed in Patent Document 1 is known. The wiper motor disclosed in Patent Document 1 includes three types of brushes including first to third brushes. Has a brush. These three brushes have the same circumferential width, and are arranged opposite to each other on the same plane of the commutator (commutator) at a predetermined angle, and are switched via the first and second brushes by a switching operation. Power can be supplied to the wiper motor for low speed operation, or power can be supplied to the wiper motor via the second and third brushes for high speed operation.
Japanese Patent Laid-Open No. 2005-12945

  However, in the above-described speed switching motor in the prior art, the first brush (low speed operation brush) and the third brush (high speed operation brush) having the same circumferential width are provided in the commutator. Since it is configured to be in sliding contact with the segment (conductive portion) on the same plane, the short circuit time (contact time) to the conductive portion of the low speed operation brush and the high speed operation brush is the same time. During low-speed operation of the motor, the high-speed operation brush short-circuits the conductive portions adjacent to each other in the circumferential direction, so that a current due to a relatively large counter electromotive force is generated in the short circuit, and the current generated by the counter electromotive force is There has been a problem that torque reduction and rectification deterioration during low-speed operation are caused.

  The present invention has been made in view of the above circumstances, and its purpose is to reduce the short-circuit time of the brush for high-speed operation, thereby suppressing the current generated by the counter electromotive force during low-speed operation, and low-speed operation. An object of the present invention is to provide a speed-switching motor with improved torque reduction and commutation deterioration.

  The speed switching motor of the present invention is a speed switching motor capable of switching to at least two stages of operation speeds of low speed operation and high speed operation, and the motor includes a case, a magnet disposed in the case, One end of which is rotatably supported by the end of the case and has a core around which a coil is wound, a conductive portion provided on a central axis of the armature, and connected to the coil, and the conductive portion A commutator formed of an insulating portion formed between the conductive portions along the circumferential direction of the conductive portion, abutting the conductive portion, a common brush common to the low-speed operation and high-speed operation, abutting the conductive portion, A brush for low-speed operation disposed opposite to the common brush, a brush for high-speed operation provided so as to be able to come into contact with the conductive portion, and shifted by a predetermined angle in the circumferential direction with respect to the brush for low-speed operation; A, wherein the contact time to the conductive portion of the high-speed operation brush be shorter than the contact time to the conductive portion of the low-speed operation brush.

  The speed switching type motor of the present invention is provided with a low speed driving conductive portion and a high speed driving conductive portion in the axial direction of the conductive portion, and the circumferential width of the insulating portion on the high speed driving conductive portion side is set to the low speed driving conductive portion. It is characterized in that it is wider than the circumferential width of the insulating part on the conductive part side.

  The speed switching motor of the present invention is provided with a low speed driving conductive part and a high speed driving conductive part in the axial direction of the conductive part, and a non-conductive part is provided between the conductive parts on the high speed driving conductive part side. It is characterized by that.

  The speed switching motor of the present invention is provided with a low speed driving conductive part and a high speed driving conductive part in the axial direction of the conductive part, and a non-conductive part is provided between the conductive parts on the high speed driving conductive part side. It is characterized by that.

  The speed-switching motor of the present invention is configured such that the axial length of the high-speed operation brush is increased, and the contact area of the high-speed operation brush with the commutator is set as the contact area of the low-speed operation brush with the commutator. It is characterized by being equivalent to the area.

  In the speed switching motor according to the present invention, a magnet having four or more poles is fixed to the inner peripheral surface of the case, and a connection line connected to the same potential of the conductive portion and a predetermined interval between the cores. And a coil wound in an overlapping manner.

  The speed-switching motor according to the present invention is characterized in that the coil is wound around the core and wound around the core.

  The speed-switching motor according to the present invention is characterized in that the coil is wound around the core and wound in a short turn.

  The speed-switching motor according to the present invention is characterized in that the motor has a two-pole magnet fixed to the inner peripheral surface of the case, and has a coil wound around the core at a predetermined interval. .

  The speed switching motor of the present invention is characterized in that the motor has a magnet having four or more poles fixed to the inner peripheral surface of the case, and has a coil that is wound around the core at a predetermined interval. To do.

  The speed switching motor according to the present invention is characterized in that the motor has a coil concentratedly wound around the core.

  The speed switching motor according to the present invention is characterized in that the speed switching motor is applied to a wiper motor used in a wiper device for wiping a windshield of a vehicle.

  According to the speed switching motor of the present invention, the contact time of the brush for high speed operation with the conductive portion is made shorter than the contact time of the brush for low speed operation with the conductive portion. It is possible to suppress a current generated by electric power and improve torque reduction and rectification deterioration during low-speed operation.

  According to the speed switching motor of the present invention, the conductive portion for low speed operation and the conductive portion for high speed operation are provided in the axial direction of the conductive portion, and the circumferential width of the insulating portion on the side of the high speed operation conductive portion is set for low speed operation. Since it is wider than the circumferential width of the insulating part on the conductive part side, the contact time to the conductive part of the brush for high speed operation can be shortened by changing the shape of the commutator, and back electromotive force during low speed operation It is possible to improve the torque drop and rectification deterioration during low-speed operation by suppressing the current generated by.

  According to the speed switching type motor of the present invention, the conductive portion for low speed operation and the conductive portion for high speed operation are provided in the axial direction of the conductive portion, and the nonconductive portion is provided between the conductive portions on the conductive portion side for high speed operation. Therefore, it is possible to shorten the contact time of the brush for high speed operation to the conductive part by changing the shape of the conductive part, suppress the current generated by the counter electromotive force during low speed operation, and reduce the torque during low speed operation. Rectification deterioration can be improved.

  According to the speed switching type motor of the present invention, the circumferential width of the high-speed operation brush is made narrower than the circumferential width of the low-speed operation brush. The contact time of the brush with the conductive portion can be shortened, the current generated by the counter electromotive force during low-speed operation can be suppressed, and torque reduction and commutation deterioration during low-speed operation can be improved. In this case, by increasing the axial length of the brush for high-speed operation, the contact area of the brush for high-speed operation with the conductive portion is made equal to the contact area of the brush for low-speed operation with the conductive portion. The contact area with respect to the conductive part can be ensured.

  According to the speed switching motor of the present invention, it is possible to correspond to speed switching motors having different numbers of magnetic poles and different winding methods.

  The speed switching motor of the present invention can be applied to a wiper motor used in a wiper device that wipes a windshield of a vehicle.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to FIGS. 1 is a view showing a wiper device to which the speed switching motor according to the present invention is applied, FIG. 2 is a longitudinal sectional view of the wiper motor, and FIG. 3 is a transverse sectional view taken along line AA of the wiper motor of FIG. 4 is a cross-sectional view taken along line BB of the wiper motor of FIG. 2, and FIG. 5 is a perspective view schematically showing a commutator and a brush of the wiper motor of FIG.

  As shown in FIG. 1, under the windshield (wind shield) 11 of an automobile (vehicle) 10 (on the lower side in FIG. 1), rainwater, dust, etc. adhering to the windshield 11 are wiped off and the view of the driver A wiper device 12 is provided for ensuring the above. The wiper device 12 is a so-called tandem type wiper device, and includes two wiper shafts 13a and 13b that are rotatably supported on the vehicle body side of the automobile 10, and the wiper shaft 13a is provided on the driver side. The wiper arm 14a is fixed, and the wiper arm 14b on the passenger seat side is fixed to the wiper shaft 13b. Wiper blades 15a and 15b are attached to the distal ends of the wiper arms 14a and 14b, and springs (not shown) are attached to the base ends of the wiper arms 14a and 14b. The wiper blades 15a and 15b are pressed against the windshield 11 with a predetermined spring force by the spring force of the spring.

  The wiper device 12 is provided with a wiper motor (speed switching motor) 16 as a drive source, and a crank arm 18 is connected to an output shaft 17 of the wiper motor 16. The crank arm 18 is connected to a link mechanism 19 having the wiper shafts 13a and 13b as fulcrums. By rotating the crank arm 18, the wiper arms 14a and 14b are swung within a predetermined angular range. By such swinging movement of the wiper arms 14a and 14b, the wiper blades 15a and 15b are operated in the wiping ranges 20a and 20b between the upper inverted position and the lower inverted position, and rainwater and dust adhered to the windshield 11 are removed. Can be wiped off.

  As shown in FIG. 2, the wiper motor 16 has a case 21 that forms an outline thereof. A magnet 22 is fixed inside the case 21 with an adhesive or the like, and on the bottom side (left side in FIG. 2), A bearing 24 that rotatably supports the proximal end side of the shaft 23 is provided.

  The magnet 22 is a permanent magnet having an arc-shaped cross section generally used for a DC motor, and is constituted by a pair of magnets of an inner N pole / outer S pole and an inner S pole / outer N pole. The pair of magnets 22 are provided in the case 21 so as to face each other.

  The bearing 24 has a spherical outer periphery and is configured to automatically align the shaft 23. Reference numeral 25 denotes a support sphere that supports the base end portion of the shaft 23 in the axial direction. The support sphere 25 enables the shaft 23 to rotate with respect to the case 21 with almost no resistance. Reference numeral 24a denotes a fixing plate for preventing the bearing 24 from coming off to the right side in FIG.

  Inside the pair of magnets 22 fixed to the case 21, an armature 26 having a core around which a coil is wound so as to be surrounded by the magnet 22 is provided. It faces the magnet 22 via an air gap). The amateur 26 includes, for example, twelve cores, and a coil (not shown) is wound around the cores by lap winding. The armature 26 is integrally provided on the shaft 23 so that the center axis of the armature 26 and the center axis of the shaft 23 coincide with each other.

  A commutator 27 is integrally provided on the shaft 23 so as to coincide with the central axis of the shaft 23, and the commutator 27 is electrically conductive to which a coil wound around the core of the armature 26 is connected. Part (segment) 28 is provided. A plurality of (for example, twelve) conductive portions 28 are provided at predetermined intervals along the circumferential direction of the commutator 27, and a resin such as plastic is molded between the adjacent conductive portions 28 by molding. An insulating part 29 is formed. The insulating portion 29 has a narrow insulating portion 29a on the right side and a wide insulating portion 29b on the left side in FIG. 2 from the axial central portion, and a wide wide conductive portion 28a corresponding to the narrow insulating portion 29a. In addition, narrow conductive portions 28b having a narrow width are provided along the circumferential direction corresponding to the wide insulating portions 29b.

  The wide conductive portion 28a constitutes a low speed operation conductive portion in the present invention, and a low speed operation brush (first brush) 30 is slidably contacted with a predetermined spring force on the outer peripheral surface of the wide conductive portion 28a. Furthermore, the outer peripheral surface of the wide conductive portion 28a is opposed to the low-speed operation brush 30 at a position shifted by 180 ° so that the common brush (the first brush common to the low-speed operation and the high-speed operation) 2 brush) 31 is slidably contacted with a predetermined spring force (see FIG. 3).

  Here, the low-speed operation brush 30 is a negative electrode (minus pole) brush, and the common brush 31 is a positive electrode (plus electrode) brush. The low-speed operation brush 30 and the common brush 31 are as shown in FIG. The brush substrate 32 is fixed in close proximity. The brush substrate 32 is further provided with a power supply unit 33 fixed, and a drive current of a predetermined magnitude is supplied from the power supply unit 33 to the common brush 31. The drive current is supplied to the common brush 31 and the wide conductive unit. It flows to the low-speed operation brush 30 through the coil 28a and the wide conductive portion 28a, whereby the armature 26 rotates with respect to the magnet 22 and the shaft 23 rotates.

  On the other hand, the narrow conductive portion 28b constitutes a high speed operation conductive portion in the present invention, and a high speed operation brush (third brush) 34 has a predetermined spring force on the outer peripheral surface of the narrow conductive portion 28b. It comes to be slid in contact with. The high-speed operation brush 34 is provided at a position shifted from the low-speed operation brush 30 by a predetermined angle θ (for example, 100 °) along the circumferential direction (see FIG. 4). Further, as shown in FIG. 2, the high-speed operation brush 34 is fixed to the brush substrate 32 by being offset by a predetermined distance from the brush substrate 32 in the axial direction so as to face the narrow conductive portion 28b.

  Here, the low-speed operation brush 30, the common brush 31, and the high-speed operation brush 34 are made of the same material and the same size, and thus the contact area of each brush with the commutator 27 is the same. (See FIG. 5). In addition, the dimension in the circumferential direction width of each brush is set to a predetermined dimension that straddles two conductive portions 28 but does not straddle three.

  The wiper motor 16 includes a gear case 36 that houses therein a speed reduction mechanism 35 that reduces the rotation of the shaft 23. The gear case 36 is formed of a die-cast product or the like. The gear case 36 is fixedly provided with a ball bearing 37 that rotatably supports the shaft 23.

  The base end side of the gear case 36 is airtightly fixed to the case 21 via a sealing material (not shown) with a screw (not shown), and the distal end side of the gear case 36 is airtightly closed by the adjusting member 38. . The adjusting member 38 includes a ball 39 in a recess provided in the adjusting member 38, and the tip end side of the shaft 23 is in contact with the ball 39. The contact force of the ball 39 with respect to the shaft 23 is adjusted by adjusting the screwing amount of the adjusting member 38 with respect to the gear case 36 to prevent the shaft 23 from rattling in the axial direction.

  A worm 40 having a spiral tooth portion formed on the outer periphery thereof is integrally provided on the distal end side of the shaft 23, and the worm 40 can rotate together with the shaft 23. The worm 40 meshes with teeth (not shown) of a worm wheel 41, and the worm 40 and the worm wheel 41 constitute a speed reduction mechanism 35.

  The worm wheel 41 is integrally provided with an output shaft 17 connected to the crank arm 18 constituting the wiper device 12 on the central axis thereof, and the crank arm 18 is attached to a tapered portion 17 a formed on the output shaft 17. The crank arm 18 is fixed to the output shaft 17 by fitting and fitting a nut (not shown) to the male screw portion 17b.

  In the vicinity of the left side of the worm 40 provided on the shaft 23 in FIG. 2, a rotational position detecting magnet 42 for detecting the rotational position of the shaft 23 is integrally provided on the shaft 23, and this rotational position detecting magnet 42 is provided. Has a plurality of magnetized portions (for example, four poles of N pole, S pole, N pole, and S pole) along the circumferential direction.

  A control board 43 for controlling the rotation of the shaft 23 is provided above the speed reduction mechanism 35 accommodated in the gear case 36 in FIG. 2. The control board 43 receives a switching operation of the driver, and receives the driver's switching operation. A current is supplied via the wiring 44 to drive and control the wiper motor 16. A Hall sensor 45 that detects the rotational position of the rotational position detecting magnet 42 is provided in the vicinity of the rotational position detecting magnet 42 on the control board 43.

  A cover 46 that partitions the speed reduction mechanism 35 and the control board 43 is disposed between the speed reduction mechanism 35 and the control board 43. The cover 46 is formed of a resin molded product such as plastic, and holds the control board 43 and plays a role of preventing the grease applied to the speed reduction mechanism 35 from scattering and adhering to the control board 43. .

  In the upper part of the control board 43 in FIG. 2, an outside having a heat sink 47 for preventing rainwater and dust from entering the inside of the gear case 36 and for radiating the temperature rise of the control board 43 to the outside. A cover 48 is airtightly fixed to the gear case 36. The heat sink 47 provided integrally with the outer cover 48 is formed of a resin excellent in heat dissipation, and the heat sink 47 is embedded in the outer cover 48 also formed of resin.

  Next, the operation of the present embodiment configured as described above will be described in detail below. When the driver switches the wiper switch to the low speed driving side, the low speed driving power source of the wiper device 12 is turned on. Then, a current for low-speed operation flows from the control board 43 to the power supply unit 33 via the wiring 44, and the common brush 31 that is the positive electrode, the wide conductive portion 28a, the coil, and the negative electrode for low-speed operation from the power supply unit 33. A current flows through the brush 30 and the shaft 23 of the wiper motor 16 rotates at a low speed. As the shaft 23 rotates, the output shaft 17 is decelerated and rotated by the decelerating mechanism 35. As a result, the wiper arms 14a and 14b swing at a low speed. At this time, the commutator 27 rotates integrally with the rotation of the shaft 23, and the high-speed operation brush 34 is short-circuited across two of the narrow conductive portions 28b. By providing the wide insulating portion 29b in the direction, the time (contact time) for the high speed operation brush 34 to short-circuit the conductive portion can be shortened, and the current due to the counter electromotive force generated by the short circuit of the high speed operation brush 34 is reduced. be able to.

  Further, when the driver switches the wiper switch to the high speed driving side, the high speed driving power source of the wiper device 12 is turned on. Then, a high-speed operation current flows from the control board 43 to the power feeding unit 33 via the wiring 44, and the common brush 31 that is the positive pole, the narrow conductive portion 28b, the coil, and the high-speed operation that is the negative pole from the power feeding unit 33. A current flows through the brush 34 for rotation, and the shaft 23 of the wiper motor 16 rotates at a high speed. And while the shaft 23 rotates, the output shaft 17 is decelerated and rotated by the reduction mechanism 35, and as a result, the wiper arms 14a and 14b swing at high speed.

  As described above, according to the present embodiment, since the wide insulating portion 29b and the narrow insulating portion 29a are provided in the axial direction of the conductive portion 28, the contact time of the high-speed operation brush 34 with the conductive portion 28 is increased. Can be made shorter than the contact time of the brush 30 for low-speed operation with the conductive portion 28, and the current generated by the counter electromotive force during the low-speed operation of the wiper motor 16 can be suppressed to reduce torque and deteriorate commutation during low-speed operation. Can be improved. In addition, according to the present embodiment, it is only necessary to change the shape of the commutator 27, so that the manufacturing cost can be suppressed.

  Next, another embodiment of the present invention will be described with reference to FIGS. 6 and 7 are perspective views schematically showing commutators and brushes according to other embodiments showing the essential parts of the present invention, respectively, and have the same functions as the above-described embodiments. The parts having the same reference numerals are designated by the same reference numerals, and the description thereof is omitted.

  The commutator 27 according to another embodiment shown in FIG. 6 includes a low-speed operation conductive portion 28c in which the low-speed operation brush 30 and the common brush 31 are in sliding contact, and the commutator 27 in the axially lower direction in FIG. A high-speed driving conductive portion 28d that is positioned and in sliding contact with the high-speed driving brush 34 is provided, and the low-speed driving conductive portion 28c and the high-speed driving conductive portion 28d are intermediate in the axial direction of the commutator 27. The intermediate insulating portion 29c formed in the portion is divided into boundaries.

  A plurality of (for example, twelve) low-speed driving conductive portions 28c are provided at predetermined intervals along the circumferential direction of the commutator 27, and a resin such as plastic is placed between adjacent low-speed driving conductive portions 28c. The low speed operation insulating portion 29d is formed by molding. A plurality of (for example, six) high-speed driving conductive portions 28d are provided at predetermined intervals along the circumferential direction of the commutator 27, and a resin such as plastic is provided between the adjacent high-speed driving conductive portions 28d. A high-speed operation insulating portion 29e formed by molding and a non-conductive portion 49 having the same circumferential width as the high-speed operation conductive portion 28d are provided. The non-conductive portion 49 may be formed by molding a resin such as plastic, or may be formed by embedding another non-conductive material.

  As shown in FIG. 6, the high-speed operation brush 34 has a flat shape in which the circumferential width is extended and the axial width is reduced as compared with the above-described embodiment. Short circuit is possible. Further, the contact area of the high-speed operation brush 34 with the commutator 27 is set to be equivalent to the contact area of the low-speed operation brush 30 with the commutator 27. Thus, a predetermined current density can be obtained by setting the contact areas of the low-speed operation brush 30 and the high-speed operation brush 34 to the commutator 27 to be equal. In this case, the contact time of the high-speed operation brush 34 to the high-speed operation conductive portion 28d is shorter than the contact time of the low-speed operation brush 30 to the conductive portion 28c because the non-conductive portion 49 is included. Yes.

  In the embodiment shown in FIG. 6 configured as described above, the same effects as those in the embodiment shown in FIGS. 1 to 5 described above can be obtained. Since the non-conductive portions 49 are alternately provided in the circumferential direction of the commutator 27, the number of effective conductors can be reduced (for example, reduced from 24 to 12), so that the high-speed operation brush 34 is operated at a low speed. It can be placed close to a position close to the driving brush 30 and is less susceptible to electromotive force generated by the magnet 22, and torque reduction and rectification deterioration during lower speed operation can be suppressed.

  The commutator 27 according to another embodiment shown in FIG. 7 includes a conductive portion 28 in which the low-speed operation brush 30 and the common brush 31 are in sliding contact, and the conductive portion 28 extends along the axial direction of the commutator 27. In FIG. 7, it extends in the vertical direction, and is a common conductive portion in which the low-speed operation brush 30 and the high-speed operation brush 34 are in sliding contact. A plurality of (for example, twelve) conductive portions 28 are provided at predetermined intervals along the circumferential direction of the commutator 27, and insulation between the adjacent conductive portions 28 is performed by molding a resin such as plastic. A portion 29 is formed.

  As shown in FIG. 7, the high-speed operation brush 34 is formed in a shape that extends in the axial direction and narrows in the circumferential direction compared to the above-described embodiment, and the circumferential width of the low-speed operation brush 30. It is narrower than. Further, the contact area of the high-speed operation brush 34 with the commutator 27 is set to be equivalent to the contact area of the low-speed operation brush 30 with the commutator 27. Thus, a predetermined current density can be obtained by setting the contact areas of the low-speed operation brush 30 and the high-speed operation brush 34 to the commutator 27 to be equal.

  In the embodiment shown in FIG. 7 configured as described above, the same operational effects as those in the embodiment shown in FIGS. 1 to 5 can be obtained, and in addition to this, the shape of the conductive portion 28 is generally changed. Since the shape of the brush 34 for high-speed operation only has to be changed while keeping the original shape, the manufacturing cost can be reduced.

  Next, motor types that can be applied to the wiper motor 16 according to each of the above-described embodiments will be described with reference to FIGS. Note that portions having the same functions as those of the above-described embodiments will be described with the same reference numerals.

  As a method of winding the coil wound around the core, for example, there are methods shown in FIGS. 8 to 14. FIG. 8 shows a winding diagram of a 4-pole-full-node-lap winding-equalizing linear motor. 9 is a winding diagram of a 6-pole-all-node-lap winding-equal-pressure linear motor, FIG. 10 is a winding diagram of a 4-pole-short-node balance-lap winding motor, and FIG. FIG. 12 is a winding diagram of a two-pole-short-spin balance-lap winding motor, FIG. 13 is a winding diagram of a four-pole-wave winding motor, and FIG. The winding diagram of the pole-concentrated winding motor is shown respectively.

  The wiper motor 16 shown in FIG. 8 is a four-pole motor in which four-pole magnets 22 are alternately arranged along the circumferential direction on the inner peripheral surface of the case 21 (see FIG. 1). Sixteen teeth (cores) T are provided so as to face each other. Between each tooth T, a winding groove (core) G on which the coil is wound is provided, and the width dimension (winding groove pitch) L1 of the winding groove G is a clearance dimension (magnetic pole pitch) between the magnets 22. ) The dimension is set approximately equal to L2. As described above, the wiper motor 16 shown in FIG. 8 employs a full-pitch winding in which the winding groove pitch L1 and the magnetic pole pitch L2 are substantially equal. Of the 16 conductive portions 28 provided so as to correspond to the respective teeth T, a pair of conductive portions (for example, number 8 and 16 in the figure) that are opposed to each other (for example, spaced by 180 °) are connected. They are connected by a pressure equalizing line E as a line. As described above, since the circuit configuration can be substantially the same as that of the two-pole motor, brushes for the number of poles are not necessary, and the low-speed operation brush 30, the common brush 31, and the high-speed operation brush 34 are provided. A four-pole speed switching motor can be formed.

  The wiper motor 16 shown in FIG. 9 is a 6-pole motor in which 6-pole magnets 22 are alternately arranged along the circumferential direction on the inner peripheral surface of the case 21 (see FIG. 1), compared to the wiper motor 16 shown in FIG. Among the 24 conductive portions 28 provided so as to correspond to each point T and each tooth T, three conductive portions (for example, No. 8 and No. 16 in the figure) are arranged at an equal angle (120 ° interval). , No. 24) is connected by a pressure equalizing line E as a connecting line. As described above, since the circuit configuration can be substantially the same as that of the two-pole motor, brushes for the number of poles are not necessary, and the low-speed operation brush 30, the common brush 31, and the high-speed operation brush 34 are provided. A 6-pole speed-switching motor can be formed.

  The wiper motor 16 shown in FIG. 10 is larger in width dimension (magnetic pole pitch) L3 between the magnets 22 than the width dimension (winding groove pitch) L1 of the winding groove G as compared with the wiper motor 16 shown in FIG. (L3> L1) is set, and short-pitch winding is adopted, and a so-called short-balanced type in which a coil is wound around the core so as to straddle between adjacent magnets 22 is different. ing. As a result, the counter electromotive force can be reduced as compared with the full-pitch winding, and the motor weight can be reduced and stable rotation characteristics can be obtained.

  The wiper motor 16 shown in FIG. 11 employs a general motor type, and is a two-pole motor in which a two-pole magnet 22 is disposed opposite to the inner peripheral surface of a case 21 (see FIG. 1). Twelve teeth T forming a core are provided so as to face 22 each. The gap dimension (magnetic pole pitch) L4 between the magnets 22 is set to a wide dimension (L4> L1) larger than the width dimension (winding groove pitch) L1 of the winding groove G on which the coil is overwrapped, resulting in a short-pitch winding. ing. In addition, the wiper motor 16 shown in FIG.

  The wiper motor 16 shown in FIG. 12 is different from the wiper motor 16 shown in FIG. 11 in that it is a short-pitch balanced type, so that the counter electromotive force can be reduced as compared with the full-pitch winding. At the same time, a reduction in motor weight and stable rotation characteristics can be obtained.

  The wiper motor 16 shown in FIG. 13 is a four-pole motor in which four-pole magnets 22 are alternately arranged along the circumferential direction on the inner peripheral surface of the case 21 (see FIG. 1). Sixteen teeth T forming the core are provided so as to face each other. As shown in FIG. 13, a coil is wound in the winding groove G formed between the teeth T. By adopting the wave winding in this way, a small current with a higher voltage than that of the lap winding. It can be used by connecting to the supply equipment.

  The wiper motor 16 shown in FIG. 14 is a four-pole motor in which four-pole magnets 22 are alternately arranged along the circumferential direction on the inner peripheral surface of the case 21 (see FIG. 1) so as to face each magnet 22. Thus, six teeth T forming the core are provided. In the winding groove G formed between the teeth T, as shown in FIG. The segments 28 (S1 to S12) serving as the conductive portions having the same potential are short-circuited by the connection line E so as to form a pair. That is, every fifth segment 28 (for example, segment S1 and segment S7) is short-circuited by the connection line E.

  In addition, each tooth T is assigned U, V, and W phases in this order. That is, the first and fourth teeth T correspond to the U phase, the second and fifth teeth T correspond to the V phase, and the third and sixth teeth T correspond to the W phase.

  By adopting concentrated winding in this way, compared to lap winding, it can be operated at normal operation (power is supplied by a low-speed operation brush and a common brush) and at high speed operation (power is supplied by a high-speed operation brush and a common brush). It is possible to make a difference in the number of effective conductors. Therefore, a three-phase concentrated winding motor with a brush can be used as a three-brush motor, which makes it possible to reduce the size of the three-brush motor that can switch the rotation speed.

  As described above in detail, according to the present invention, it is possible to correspond to the wiper motors 16 having different types of coil winding types.

  In addition, this invention is not limited to each embodiment mentioned above, A various change is possible in the range which does not deviate from the summary. For example, in each of the above-described embodiments, the speed-switchable motor has been shown to be capable of switching to the two-stage operation speed of the low-speed operation and the high-speed operation. The present invention can also be applied to a speed switching motor that can be switched to a speed. For example, in the case of a three-stage speed switching motor, a conductive part or brush having a circumferential width set corresponding to the operation speed of each of the three stages may be provided.

  Further, in each of the above-described embodiments, the speed switching type motor is a wiper motor used in a vehicle wiper device. However, the present invention is not limited to this, and the speed switching type motor includes a brush for each speed. Needless to say, it can be applied to all motors. Furthermore, in the present invention, a cylindrical commutator is used. However, each brush may be brought into sliding contact with a disc-shaped commutator.

It is a figure which shows the wiper apparatus to which the speed switching type motor in this invention is applied. It is a longitudinal cross-sectional view of a wiper motor. FIG. 3 is a cross-sectional view taken along line AA of the wiper motor of FIG. 2. FIG. 3 is a transverse sectional view taken along line BB of the wiper motor of FIG. 2. It is a perspective view which shows typically the commutator and brush of the wiper motor of FIG. It is a perspective view which shows typically the commutator and brush which concern on other embodiment which shows the principal part of this invention. It is a perspective view which shows typically the commutator and brush which concern on other embodiment which shows the principal part of this invention. It is a winding diagram of a 4-pole-full-node-lap winding-equal pressure linear motor. FIG. 6 is a winding diagram of a 6-pole-full-node-lap-winding-equalizing linear motor. FIG. 4 is a winding diagram of a 4-pole-short-strip balance-lap winding motor. FIG. 3 is a winding diagram of a two-pole-short-node lap winding motor. FIG. 3 is a winding diagram of a two-pole-short-balance-overlap winding motor. It is a winding diagram of a 4-pole-wave winding motor. It is a winding diagram of a 4-pole concentrated winding motor.

Explanation of symbols

10 Automobile (vehicle)
11 Windshield (windshield)
12 Wiper device 13a, 13b Wiper shaft 14a, 14b Wiper arm 15a, 15b Wiper blade 16 Wiper motor (speed switching motor)
17 Output shaft 17a Tapered portion 17b Male thread portion 18 Crank arm 19 Link mechanism 20a, 20b Wiping range 21 Case 22 Magnet 23 Shaft 24 Bearing 24a Fixing plate 25 Support ball 26 Amateur (armature)
27 Commutator
28 Conductive part (segment)
28a Wide conductive part (conductive part for low speed operation, segment)
28b Narrow conductive part (conductive part for high-speed operation, segment)
28c Conductive part for low speed operation (segment)
28d High-speed operation conductive part (segment)
DESCRIPTION OF SYMBOLS 29 Insulation part 29a Narrow insulation part 29b Wide insulation part 29c Intermediate insulation part 29d Low speed operation insulation part 29e High speed operation insulation part 30 Low speed operation brush 31 Common brush 32 Brush substrate 33 Power supply part 34 High speed operation brush 35 Deceleration mechanism 36 gear case 37 ball bearing 38 adjustment member 39 ball 40 worm (deceleration mechanism)
41 Worm wheel (deceleration mechanism)
42 Magnet for Rotation Position Detection 43 Control Board 44 Wiring 45 Hall Sensor 46 Cover 47 Heat Sink 48 Outer Cover 49 Non-conducting Portion E Equal Pressure Line (Connection Line)
G winding groove (core)
T Teeth (Core)

Claims (12)

A speed-switchable motor that can be switched to at least two speeds of low-speed operation and high-speed operation,
The motor is
Case and
A magnet disposed in the case;
One end is rotatably supported on the end of the case, and an armature having a core around which a coil is wound,
A commutator provided on a central axis of the armature and including a conductive portion to which the coil is connected and an insulating portion formed between the conductive portions along a circumferential direction of the conductive portion;
A common brush in contact with the conductive portion, common to the low speed operation and the high speed operation;
A brush for low-speed operation that is in contact with the conductive portion and is disposed to face the common brush;
A brush for high-speed operation provided so as to be in contact with the conductive portion, and disposed at a predetermined angle in the circumferential direction with respect to the brush for low-speed operation, and
A speed-switching motor, wherein a contact time of the high-speed operation brush with the conductive portion is shorter than a contact time of the low-speed operation brush with the conductive portion.   The speed switching motor according to claim 1, wherein a low speed driving conductive portion and a high speed driving conductive portion are provided in the axial direction of the conductive portion, and the circumferential width of the insulating portion on the high speed driving conductive portion side is A speed-switching motor characterized in that it is wider than the circumferential width of the insulating portion on the low-speed driving conductive portion side.   2. The speed switching motor according to claim 1, wherein a conductive portion for low speed operation and a conductive portion for high speed operation are provided in the axial direction of the conductive portion, and a nonconductive portion is provided between the conductive portions on the side of the high speed driving conductive portion. A speed-switching motor characterized by being provided.   2. The speed switching motor according to claim 1, wherein a circumferential width of the high speed driving brush is narrower than a circumferential width of the low speed driving brush.   5. The speed-switching motor according to claim 4, wherein an axial length of the high-speed operation brush is increased, and a contact area of the high-speed operation brush with the commutator is increased to the commutator of the low-speed operation brush. A speed-switching motor characterized in that it has the same contact area.   The speed switching motor according to any one of claims 1 to 5, wherein the motor has a magnet having four or more poles fixed to an inner peripheral surface of the case, and is connected to the same potential of the conductive portion. A speed-switching motor, comprising: a connecting wire; and a coil wound around the core at a predetermined interval.   7. The speed switching motor according to claim 6, wherein the coil is wound around the core and wound around the core.   The speed switching motor according to claim 6, wherein the coil is wound around the core and short-turned.   The speed-switching motor according to any one of claims 1 to 5, wherein the motor has a two-pole magnet fixed to the inner peripheral surface of the case, and is wound around the core with a predetermined interval. A speed-switching motor characterized by having a coil that has been made.   6. The speed switching motor according to claim 1, wherein a magnet having four or more poles is fixed to the inner peripheral surface of the case, and the motor is waved at a predetermined interval from the core. A speed-switching motor having a wound coil.   The speed switching motor according to any one of claims 1 to 5, wherein the motor has a coil concentratedly wound around the core.   The speed switching motor according to any one of claims 1 to 11, wherein the speed switching motor is applied to a wiper motor used in a wiper device for wiping a windshield of a vehicle. motor.

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