JP2017063559A - Brush motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a brush motor capable of changing a rotational speed independently of switching of a brush from low speed use to high speed use, and of achieving multipolarization and reduction in size and weight.SOLUTION: A multipolar brush motor that generates a rotational power in one direction and that has four or more magnetic poles, comprises: a rotary armature having an equalizer line; a commutator provided on the rotary armature; a first brush and a second brush contacted with the commutator; a duty controller that determines a duty of a voltage pulse applied between the first and second brushes by a voltage signal supplied from the exterior; a PWM signal generator that outputs a PWM signal that is a pulse train of a pulse having the duty so as to correspond to information on the duty supplied from the duty controller; and a drive transistor that is connected between any one of the first and second brushes and any one of a power supply and the ground, is on/off-controlled by the PWM signal, and that applies a voltage of the power supply to between the first and second brushes as the voltage pulse.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a brush motor used in a wiper device that wipes a windshield of a vehicle.

  The operation speed of the wiper device of the vehicle can be switched between high speed and low speed (see the descriptions in Patent Document 1 and Patent Document 2). Such switching of the operating speed of the wiper device is realized by switching the rotational speed of a brush motor used in the wiper device. Usually, the rotation speed of the brush motor is switched by controlling the energization angle of the armature. Therefore, this type of brush motor includes two types of brushes, a high-speed brush and a low-speed brush, which are arranged at a position where a conduction angle corresponding to the operating speed of the wiper device can be obtained.

JP 2007-143278 A JP 2009-262726 A

  However, the arrangement position of the brush of the brush motor used in the wiper device of the vehicle is set based on the operating speed at low speed that is frequently used, and the arrangement position of the high speed brush is the original arrangement of the brush. It is out of position. For this reason, when the wiper device is operating at a low speed, a high-speed brush operating noise is generated, which contributes to an increase in the noise of the brush motor. Moreover, if both a low-speed brush and a high-speed brush are provided, the number of brushes that come into contact with the commutator provided in the armature (rotor) increases, which may cause a reduction in the life of the commutator. obtain.

  The present invention has been made in view of such circumstances, and can change the rotation speed without switching the brush from low speed to high speed, and can be multipolarized and reduced in size and weight. An object of the present invention is to provide a brush motor that can be used.

  The brush motor of the present invention is a multipolar brush motor having four or more magnetic poles that generate a rotational force in one direction, and includes a rotary armature having a pressure equalizing line, and a commutator provided in the rotary armature. Each of the first brush and the second brush in contact with the commutator, and a voltage pulse applied between the first brush and the second brush by a voltage signal supplied from the outside. A duty control unit that selects a duty; a PWM signal generation unit that outputs a PWM signal that is a pulse train of the duty according to the selected duty supplied from the duty control unit; the first brush; 2 is connected between one of the two brushes and one of the power supply and the ground, and is turned on / off by the PWM signal, and the power supply of the power supply is provided between the first brush and the second brush. The characterized in that it comprises a driving transistor for applying a said voltage pulse.

  The brush motor of the present invention is characterized in that the duty control unit changes the rotation speed of the rotary armature by changing the duty of a PWM signal for PWM control of the drive transistor.

  The brush motor of the present invention is a brush motor used in a wiper device of a vehicle, and the duty control unit operates at a low speed operation and a high speed operation of the wiper in wiping the windshield according to desired characteristic requirements. The set value of the duty of the PWM signal at each time is changed.

  In the brush motor of the present invention, in the intermittent operation of the wiper, the duty control unit causes the PWM signal generation unit to generate the PWM signal of the duty at the time of low speed operation or high speed operation at the time of operation, The duty of the PWM signal is set to 0 when stopped.

  In the brush motor of the present invention, each of the duty control unit and the PWM signal generation unit is provided on a control board, and the housing in which the rotary armature, the first brush, and the second brush are stored. And the control board is disposed in a region where the brush that is omitted by providing the pressure equalizing line in the rotary armature can be disposed inside the housing portion. To do.

  The brush motor according to the present invention further includes a speed reduction mechanism that decelerates the rotation of the rotating armature, and the control board is provided on the inner wall surface of the bottom cover of the housing portion that covers the speed reduction mechanism. It is mounted at a position that does not interfere with operation.

  As described above, according to the present invention, it is possible to provide a brush motor that can change the rotation speed without switching the brush from low speed to high speed, and that is multipolar and small and lightweight. Can do.

1 is an external view of a brush motor according to a first embodiment of the present invention. It is a figure which shows an example of a part structure, and is a detailed figure of a brush periphery. It is a block diagram which shows the structural example of the brush motor by the 1st Embodiment of this invention. It is a flowchart for demonstrating the operation example of the brush motor by the 1st Embodiment of this invention. It is a figure which shows an example which comprised each of the duty control part 1201 and the PWM signal generation part 1202 in the control board 120 using the microcomputer. It is a figure which shows another example which each comprised the duty control part 1201 and the PWM signal generation part 1202 in the control board 120 using the discrete element. It is a figure which shows another example which comprised each of the duty control part 1201 and the PWM signal generation part 1202 in the control board 120 using the microcomputer. It is a figure which shows another example which each comprised the duty control part 1201 and the PWM signal generation part 1202 in the control board 120 using the discrete element. It is a figure which shows another example which comprised each of the duty control part 1201 and the PWM signal generation part 1202 in the control board 120 using the microcomputer. It is a figure which shows the example of arrangement | positioning of the control board with which the brush motor by the 1st Embodiment of this invention was equipped, (A) shows a 1st example of arrangement, (B) shows a 2nd example of arrangement, (C) shows a third arrangement example, and (D) shows a fourth arrangement example. It is a side view showing arrangement of control board 120 or control board 120A with which brush motor 100B by a modification of a 1st embodiment of the present invention was equipped. It is a detailed view of the arrangement of the control board 120 or the control board 120A provided in the brush motor 100B according to a modification of the first embodiment of the present invention. It is a flowchart for demonstrating the operation example of the brush motor 100 by 2nd Embodiment of this invention.

<First Embodiment>
FIG. 1 is an external view of a brush motor 100 according to the first embodiment of the present invention.
The brush motor 100 is a multipolar motor having four or more magnetic poles that generate a rotational force in one direction (rotate in one direction). In the first embodiment, it is assumed that the brush motor 100 is, for example, a DC motor having multiple poles, for example, four poles, for generating a rotational force that serves as power for a vehicle front wiper device. However, the brush motor 100 is arbitrary as long as it is a multi-pole DC motor, and its use is not limited to the front wiper device of the vehicle, and can be used to generate power of any device.

  In FIG. 1, the brush motor 100 includes a motor part M and a speed reduction mechanism part G. The motor unit M has a built-in motor main body 110 that generates a rotational force in one direction. The housing part MH of the motor part M includes, as the motor body part 110, a field part (not shown) fixed to the housing part MH, a rotating armature (not shown) provided with a commutator, and the commutator. The brush (not shown) arrange | positioned so that it may contact is accommodated. In the first embodiment, the rotating armature of the motor main body 110 has a so-called equalizing line, whereby the number of brushes that come into contact with the commutator of the rotating armature is reduced. The rotary armature is provided with a pressure equalizing line, so that the number of brushes is reduced, and the rotation of the rotary armature of the motor main body 110 is controlled in an empty area where the reduced brush is arranged (the brush can be arranged). A control board 120 (see FIG. 2) is disposed. Details thereof will be described later.

  The speed reduction mechanism G is for reducing the rotational speed of the rotating armature of the motor body 110 to a desired rotational speed. The housing portion GH of the speed reduction mechanism portion G accommodates a worm gear coupled to the rotating shaft (rotary armature shaft) of the motor main body 110, a worm wheel gear coupled to the worm gear, and the like. The rotation decelerated by the speed reduction mechanism G is taken out from the output shaft Q extending from the speed reduction mechanism G. Although not shown in FIG. 1, the output shaft Q is rotated in one direction generated by the motor main body 110, and the wiper (which may be referred to as a wiper blade) reciprocates to wipe the windshield. A link mechanism or the like for converting the rotation into two directions, that is, a forward direction (for example, clockwise direction) corresponding to the movement and a reverse direction (for example, counterclockwise direction) is attached.

  In the internal structure of the brush motor 100 according to the first embodiment of the present invention (FIG. 9 to be described later), the annular brush holder 110H incorporated in the housing part MH of the motor part M has a hole inward. Two brushes 111A and 111B are arranged as brushes that come into contact with the commutator of the rotating armature of the motor main body 110 located in the position. In the case of four poles, these two brushes 111A and 111B are arranged at positions different from each other by 180 in electrical angle (90 degrees in mechanical angle). This mechanical angle is arbitrarily set according to the number of poles of the brush motor 100.

FIG. 2 is a block diagram showing a configuration example of the brush motor 100 according to the first embodiment of the present invention, and shows elements involved in the rotation control of the rotating armature of the motor main body 110.
The brush motor 100 includes a control board 120, a thermal protection element 130, a diode 141, a diode 143, and a relay plate 150 as elements for controlling the rotation of the rotating armature of the motor main body 110.

The control board 120 is an element for generating a voltage applied between a brush 111A and a brush 111B shown in FIG. 9 to be described later, and is a main element for controlling the rotation of the rotating armature of the motor main body 110. Is an element. The control board 120 is provided inside the housing part MH of the motor part M with a high-speed brush that is omitted by performing PWM control, which will be described later, and a brush that is omitted because the pressure equalizing line is provided in the rotary armature. It is arranged so that it is located in the area where it was. Details thereof will be described later.
The thermal protection element 130 is an element for urgently shutting off the power supply to the motor main body 110 when the internal temperature of the motor M is abnormally increased, such as a circuit breaker (C / B) or PTC.

  The diode 141 is an element for protecting the motor main body 110 by consuming energy generated when the rotation of the motor main body 110 is stopped. The diode 143 is an element for synthesizing the high-speed operation voltage signal VH and the low-speed operation voltage signal VL that are supplied in conjunction with the operation switch of the front or rear wiper device and supplying power to the motor main body 110. Here, the high-speed operating voltage signal VH is a voltage signal indicating that the wiper of the front wiper device is operated at high speed. The low speed operation voltage signal VL is a voltage signal indicating that the wiper of the front wiper device is operated at a low speed. Each of the high-speed operating voltage signal VH and the low-speed operating voltage signal VL is supplied from an external circuit of the operation switch in the front wiper device to a duty control unit 1201 of the control board 102 described later corresponding to the state of the operation switch. Is done.

  The relay plate 150 is an element for obtaining the timing of the start point and the end point of the reciprocating motion of the wiper blade of the front wiper device. The relay plate 150 is provided inside the housing part GH of the speed reduction mechanism part G, and rotates in conjunction with the operation of the motor main body part 110. Here, the brake contact B is a contact for generating a timing for braking the front wiper device (with a snow clutch function). The start contact S is a contact that generates a timing for operating the front wiper device. The brake contact B and the start contact S are electrically connected to the ground E according to the rotation angle of the motor main body 110. Therefore, it is possible to grasp the braking timing and the operation timing of the front wiper device from the timing when each contact point becomes the ground potential. The relay plate 150 is an element that can be realized using a known technique.

  The control board 120 will be described in detail. The control board 120 includes a duty control unit 1201, a PWM (Pulse Width Modulation) signal generation unit 1202, a drive unit 1203, and a drive transistor (FET) 1204. Among these, the duty control unit 1201, the PWM signal generation unit 1202, and the drive unit 1203 constitute a PWM control unit (no symbol) that performs PWM control of the drive transistor 1204. The PWM control unit changes the rotation speed of the rotating armature of the motor main body 110 by changing the duty of the PWM signal for performing PWM control of the drive transistor 1204 (duty ratio, ratio of H level in the pulse period). This changes the operating speed of the front wiper device.

In this embodiment, the case where the operation speed of the wiper of the front wiper device is a two-stage operation of high speed operation and low speed operation will be described.
When the high-speed operating voltage signal VH is input, the duty control unit 1201 constituting the PWM control unit outputs a control signal that sets the duty of the PWM signal supplied to the gate of the drive transistor 1204 as the duty of the high-speed operation. Output to the generation unit 1202. On the other hand, when the low speed operating voltage signal VL is input, the duty control unit 1201 sends a control signal for setting the duty of the PWM signal supplied to the gate of the driving transistor 1204 to the PWM signal generating unit 1202. Output.

The PWM signal generation unit 1202 constituting the PWM control unit generates a PWM signal that is a pulse train of pulses having a high-speed operation duty set in advance when a control signal having a high-speed operation duty is supplied. Output to the unit 1203. In addition, when a control signal for supplying a low speed operation duty is supplied, the PWM signal generation unit 1202 generates a PWM signal having a preset low speed operation duty and outputs the PWM signal to the drive unit 1203.
The drive unit 1203 constituting the PWM control unit performs power amplification of pulses in the PWM signal supplied from the PWM signal generation unit 1202 and outputs the amplified power to the drive transistor 1204. In the first embodiment, the drive transistor 1204 is driven to an on state during the pulse high level interval in the PWM signal, and the drive transistor 1204 is driven to an off state during the pulse low level interval in the PWM signal. The

  The duty of the PWM signal is set according to the characteristic requirements of the motor main body 110. In the first embodiment, for convenience of explanation, when the motor body 110 is operated at high speed, the duty of the PWM signal is set to 100%, and when the motor body 110 is operated at low speed, the duty of the PWM signal is set. Is set to 70%, but the present invention is not limited to this example, and the duty of the PWM signal can be arbitrarily set. That is, in the present embodiment, the duty is applied to the motor main body 110 so as to apply the current for either the high speed operation or the low speed operation to the motor main body 110, and the duty corresponds to the characteristics of each motor main body 110. And set in advance.

  The driving transistor 1204 is an element for generating a voltage applied via a brush to the commutator of the rotating armature of the motor main body 110 and energizing the winding of the rotating armature. In the first embodiment, the drive transistor 1204 is an n-channel power FET (Field Effective Transistor). Further, as the drive transistor 1204, a bipolar transistor may be used instead of the n-channel power FET. The drive transistor 1204 is connected between the brush 111 </ b> A provided in the motor main body 110 and the ground E. Specifically, the source of the driving transistor 1204 is connected to a ground E such as a vehicle body, and the drain thereof is connected to the brush 111 </ b> A of the motor main body 110 through the thermal protection element 130. The drive transistor 1204 receives a PWM signal from the PWM signal generation unit 1202 through the drive unit 1203 to the gate. The driving transistor 1204 includes a so-called body diode 1204a.

  The drive transistor 1204 may be connected in series between another brush 111B of the motor main body 110 and a connection point between the wiring of the low-speed operating voltage signal VL and the cathode of the diode 143. The drain of the driving transistor 1204 is connected to the anode of the diode 141. The cathode of the diode 141 is connected to the brush 111 </ b> B of the motor main body 110. In the motor main body 110, the brush 111 </ b> B is connected to the wiring of the low-speed operating voltage signal VL and the cathode (connection point) of the diode 143. The low speed operating voltage signal VL is supplied to the wiring of the low speed operating voltage signal VL. The diode 143 is supplied with the high-speed operating voltage signal VH to the anode via the wiring of the high-speed operating voltage signal VH. In this embodiment, since the reciprocating operation of the wiper is performed by a link mechanism, the brush motor 100 has a specification that generates a rotational force in only one direction (rotates only in one direction). One drive transistor 1204 may be provided, and the number of drive transistors for driving the brush motor 100 to rotate is minimized.

FIG. 3 is a flowchart for explaining an example of the operation of the brush motor 100 according to the first embodiment of the present invention, which is formed by discrete elements constituting the duty control unit 1201, the PWM signal generation unit 1202, and the drive unit 1203. FIG. 6 is a diagram for explaining an example of duty control processing by a discrete circuit.
When the vehicle user sets the operation switch of the front wiper device from the stopped state to either the high speed operation or the low speed operation mode, the voltage signal corresponding to the operation mode (the high speed operation voltage signal or the low speed operation voltage signal) is generated. Input to the duty controller 1201 from an external circuit connected to the operation switch.

Then, the duty control unit 1201 determines whether or not the supplied voltage signal is the high-speed operating voltage signal VH (step S1).
At this time, when the supplied voltage signal is the high-speed operating voltage signal VH, the duty control unit 1201 advances the process to step S2. On the other hand, when the supplied voltage signal is not the high speed operating voltage signal VH, that is, when the supplied voltage signal is the low speed operating voltage signal VL, the duty control unit 1201 advances the process to step S3.

When the supplied voltage signal is the high-speed operating voltage signal VH, the duty control unit 1201 outputs a control signal with the duty of the pulse of the PWM signal as the duty of the high-speed operation to the PWM signal generation unit 1202.
As a result, the PWM signal generation unit 1202 generates a PWM signal corresponding to a high-speed operation that is set in advance, for example, with a pulse duty of 100%. Then, the PWM signal generation unit 1202 outputs the generated PWM signal with 100% duty to the drive unit 1203 (step S2).

On the other hand, when the supplied voltage signal is the low-speed operation voltage signal VL, the duty control unit 1201 outputs a control signal that sets the pulse duty of the PWM signal to the low-speed operation duty to the PWM signal generation unit 1202. .
As a result, the PWM signal generation unit 1202 generates a PWM signal corresponding to a low-speed operation that is set in advance, for example, with a pulse duty of 70%. Then, the PWM signal generation unit 1202 outputs the generated PWM signal with a duty of 70% to the drive unit 1203 (step S3).

The drive transistor 1204 is on / off controlled by a pulse of a PWM signal input via the drive unit 1203. As a result, the drive transistor 1204 supplies and applies a current corresponding to the duty of the pulse in the PWM signal to the motor main body 110 (step S4).
As a result, under the control of the duty control unit 1201, the motor main body 110, which is a brush motor, rotates in one direction at a rotational speed corresponding to high-speed operation or low-speed operation corresponding to the duty of the pulse of the PWM signal. The front windshield is wiped by the wiper of the front wiper device through the link mechanism.

  As described above, according to the first embodiment, since the control of the operating speed of the brush motor by PWM control (control of the rotational speed of the brush motor) is performed, the brushes for high speed and low speed as in the past are used. It is not necessary to switch between the high speed brush and the low speed brush depending on the operating speed. For this reason, it is not necessary to provide a plurality of brushes according to the operating speed. For this reason, according to the first embodiment, for example, it is possible to omit a high-speed brush, and the inconveniences such as an increase in noise, a decrease in the life of the commutator, and a decrease in efficiency due to the provision of the high-speed brush are eliminated. can do.

  Further, according to the first embodiment described above, it is necessary to provide a high-speed brush by controlling the operating speed of the brush motor by PWM control even if the magnetic poles of the brush motor are multipolarized to four or more. Absent. For this reason, according to 1st Embodiment, the restrictions regarding the assembly | attachment precision of a brush can be avoided, and multipolarization and size reduction and weight reduction can be accelerated | stimulated. In particular, in the case of a brush motor used in a wiper device, the regulation defines the switching function between low speed operation / high speed operation and the speed difference between low speed and high speed. The case where it becomes impossible to satisfy is assumed. However, according to the first embodiment described above, since the rotational speed of the brush motor is adjusted by PWM control, the operating speed of the wiper can be flexibly set according to the regulations by adjusting the duty.

  Further, according to the first embodiment, even if the power supply voltage of the brush motor is increased (for example, from 12V to 42V, 48V, etc.), the duty of the PWM signal in the PWM control is adjusted. Thereby, the substantial power supply voltage applied to the brush motor can be maintained at a conventional voltage (for example, 12 V). For this reason, according to the first embodiment, it is possible to flexibly cope with an arbitrary power supply voltage, and even if the power supply voltage is increased, it is continuously used as a brush motor of a conventional front or rear wiper device. It becomes possible to do. Therefore, measures for increasing the voltage of the motor become unnecessary.

Further, according to the first embodiment, it is possible to realize a brush motor having desired characteristic requirements required for a front or rear wiper device without requiring a design change on the vehicle side.
Further, according to the first embodiment, when the motor is stopped (the drive motor 1204 is in an off state), the diode 141 and the motor main body 110 form a closed circuit, so that the auto-stop function based on the electromagnetic brake action is provided. Can be realized.

  Further, according to the first embodiment, in a situation where the wiper is forcibly moved by an external force, for example, when the external force is an external force corresponding to the rotation direction of the motor, the diode 141 connected to the motor body 110 is used. When the closed circuit effect (electromagnetic brake effect) is obtained and the external force corresponds to the reverse rotation direction of the motor, the closed circuit effect is obtained by the body diode 1204a of the drive transistor 1204.

Further, according to the first embodiment, the brush motor that generates the rotational force in one direction may be provided with one drive transistor 1204, and the number of drive transistors can be minimized. Thereby, reduction of apparatus cost can be aimed at.
Further, according to the first embodiment, it is not necessary to mount a rotation sensor (a sensor magnet, a Hall IC, etc.) or a relay on the brush motor within a range where general specifications are assumed. Therefore, further cost reduction can be achieved.

  FIG. 4 is a diagram illustrating an example in which each of the duty control unit 1201 and the PWM signal generation unit 1202 in the control board 120 is configured using a microcomputer. In FIG. 2, each of the duty control unit 1201 and the PWM signal generation unit 1202 in the control board 120 is configured by a discrete circuit together with the drive unit 1203. However, as shown in FIG. 4, in the control board 120A, each of the duty control unit 1201 and the PWM signal generation unit 1202 is used as an element for generating a PWM signal for driving the brush motor 100A by a program using the microcomputer 1208. It may be configured. Here, each of the duty control unit 1201A and the PWM signal generation unit 1202A realized by the microcomputer 1208 using a program performs the same operations as the duty control unit 1201 and the PWM signal generation unit 1202 in FIG. Moreover, although it has a snow clutch function similarly to FIG. 2, the sensing of the output shaft of the motor main body 110 is not performed by the microcomputer. In the relay plate 150A, the start contact S is a contact for generating timing for operating the front or rear wiper device.

FIG. 5 is a diagram illustrating another example in which each of the duty control unit 1201 and the PWM signal generation unit 1202 in the control board 120 is configured using discrete elements.
The configuration in FIG. 5 has the same function as the circuit shown in FIG. In the structure of FIG. 5, it does not have a snow clutch. Further, sensing of the output shaft of the motor main body 110 is performed by a microcomputer. In the relay plate 150A, the start contact S is a contact for generating timing for operating the front or rear wiper device.

FIG. 6 is a diagram illustrating another example in which each of the duty control unit 1201 and the PWM signal generation unit 1202 in the control board 120 is configured using a microcomputer.
6 has the same function as the circuit shown in FIG. 4, and the same reference numerals are given to the same configurations. The configuration of FIG. 6 does not have a snow clutch as in the configuration of FIG. Further, sensing of the output shaft of the motor main body 110 is performed by a microcomputer. In the relay plate 150A, the start contact S is a contact for generating timing for operating the front or rear wiper device.

  FIG. 7 is a diagram illustrating another example in which each of the duty control unit 1201 and the PWM signal generation unit 1202 in the control board 120 is configured using discrete elements. The configuration of FIG. 5 has the same function as the circuit shown in FIG. 2, and the same reference numerals are given to the same configuration. In the structure of FIG. 7, it has a snow clutch. Further, sensing of the output shaft of the motor main body 110 is performed by a microcomputer. In the relay plate 150B, the start contact S is a contact that generates timing for operating the front or rear wiper device.

FIG. 8 is a diagram illustrating another example in which each of the duty control unit 1201 and the PWM signal generation unit 1202 in the control board 120 is configured using a microcomputer.
8 has the same function as the circuit shown in FIG. 4, and the same reference numerals are given to the same configurations. The configuration of FIG. 8 has a snow clutch as in the configuration of FIG. Further, sensing of the output shaft of the motor main body 110 is performed by a microcomputer. In the relay plate 150B, the start contact S is a contact that generates timing for operating the front or rear wiper device.

  The brush motor 100 in FIG. 2, the brush motor 100A in FIG. 4, the brush motor 100B in FIG. 5, the brush motor 100C in FIG. 6, the brush motor 100D in FIG. 7, and the brush motor 100E in FIG. Although there are differences such as whether or not the motor rotation axis is sensed by a microcomputer and the presence or absence of a snow clutch, the configuration of the present embodiment is compared to any conventional configuration without changing these conventional configurations. Can also be used.

Next, the arrangement of the control board 120 will be described in detail with reference to FIG.
FIG. 9 is a diagram illustrating an arrangement example of the control board 120 provided in the brush motor 100 according to the first embodiment of the present invention. Detailed wiring and the like are omitted.

  Here, FIG. 9A shows a first arrangement example (mechanical angle 90 °) of the brushes 111A and 111B when the number of magnetic poles of the brush motor 100A is four. The brush 111A and the brush 111B are disposed on the annular brush holder 110H incorporated in the housing part MH of the motor part M at positions different from each other by 90 ° in mechanical angle.

In the first arrangement example of FIG. 9A, there is an area on the brush holder 110H where no brush is arranged at a position facing the brush 111A and the brush 111B with a rotating armature (not shown) interposed therebetween. . That is, in the example of FIG. 9A, as already described, since a high-speed brush for high-speed operation is no longer necessary by PWM control, approximately 0 ° to 270 in the clockwise direction with reference to the brush 111B. There are no brushes in the ° area. The control board 120 (duty control unit 1201, PWM signal generation unit 1202, drive unit 1203) and the thermal protection element 130 are arranged in a region on the brush holder 110H where no brush exists. Further, when each of the duty control unit 1201 and the PWM signal generation unit 1202 is configured by a microcomputer instead of a discrete circuit, a microcomputer chip and a drive unit 1203 are arranged on the control board.
Here, since the brush does not exist in the region where the control board 120 and the thermal protection element 130 are arranged as described above, the control board 120 and the thermal protection element 130 do not interfere with the brush. Housed in the housing part MH of the part M.

  FIG. 9B shows a second arrangement example (mechanical angle 180 °) of the brushes 111A and 111C when the number of magnetic poles of the brush motor 100 is six. The brush 111A and the brush 111C are disposed on the annular brush holder 110H forming a part of the housing part MH of the motor part M at positions different from each other by 180 ° in mechanical angle.

Here, in the example of FIG. 9B, there is an area on the brush holder 110H where the brush is not disposed at a position that differs by 60 ° and 120 ° in mechanical angle with respect to each of the brush 111A and the brush 111C. To do. That is, in the example of FIG. 9B, as already described, since a high-speed brush for high-speed operation is no longer necessary by PWM control, approximately 0 ° to 180 ° in the clockwise direction with reference to the brush 111A. There is no brush in the first region of ° and the second region of approximately 0 ° to 180 ° in the counterclockwise direction with reference to the brush 111A. The thermal protection element 130 is disposed in the first region, and the control board 120 is disposed in the second region. Further, when each of the duty control unit 1201 and the PWM signal generation unit 1202 is configured by a microcomputer instead of a discrete circuit, a microcomputer chip and a drive unit 1203 are arranged on the control board.
Here, as in FIG. 9A, since there is no brush in the region where the control board 120 and the thermal protection element 130 are arranged, the control board 120 and the thermal protection element 130 interfere with the brush. It is housed inside the housing part MH of the motor part M.

  FIG. 9C shows a third arrangement example (mechanical angles, 180 ° each) of the brushes 111A, 111D, 111E, and 111F when the number of magnetic poles of the brush motor 100 is six. The brush 111A and the brush 111E which are different from each other by 180 ° in mechanical angle correspond to the positive and negative electrodes, respectively, and the brush 111D and the brush 111F which are different from each other by 180 ° in mechanical angle are another pair of positive and negative electrodes. It corresponds to. The brush 111A and the brush 111D are arranged at positions different from each other by 60 ° in mechanical angle, and the brush 111E and the brush 111F are also arranged at positions different from each other by 60 ° in mechanical angle.

In the example of FIG. 9C, the third region of approximately 0 ° to 120 ° in the clockwise direction with respect to the brush 111D and the approximately 0 ° to 120 ° in the counterclockwise direction with respect to the brush 111A. There is no brush in the fourth region. The thermal protection element 130 is disposed in the third region, and the control board 120 is disposed in the fourth region. That is, in the example of FIG. 9C, as described above, the brush for high-speed operation is not required by the PWM control, and as described above, approximately 0 ° in the clockwise direction with reference to the brush 111A. There are no brushes in the third region of ~ 120 ° and the fourth region of approximately 0 ° to 120 ° in the counterclockwise direction with reference to the brush 111A. The thermal protection element 130 is disposed in the third region, and the control board 120 is disposed in the fourth region. Further, when each of the duty control unit 1201 and the PWM signal generation unit 1202 is configured by a microcomputer instead of a discrete circuit, a microcomputer chip and a drive unit 1203 are arranged on the control board.
Here, as in FIG. 9A, since there is no brush in the region where the control board 120 and the thermal protection element 130 are arranged, the control board 120 and the thermal protection element 130 interfere with the brush. It is housed inside the housing part MH of the motor part M.

FIG. 9D shows a fourth arrangement example (mechanical angle 60 °) of the brushes 111A and 111D when the number of magnetic poles of the brush motor 100 is six. The brushes 111A and 111D, which differ from each other by 60 ° in mechanical angle, correspond to the positive and negative electrodes, respectively. In the example of FIG. 9D, as already described, the brush for high-speed operation is no longer necessary due to the PWM control. Therefore, the first rotation of approximately 0 ° to 300 ° in the clockwise direction with respect to the brush 111D. There are no brushes in the five regions. The thermal protection element 130 and the control board 120 are disposed in the fifth region. Further, when each of the duty control unit 1201 and the PWM signal generation unit 1202 is configured by a microcomputer instead of a discrete circuit, a microcomputer chip and a drive unit 1203 are arranged on the control board.
Here, as in FIG. 9A, since there is no brush in the region where the control board 120 and the thermal protection element 130 are arranged, the control board 120 and the thermal protection element 130 interfere with the brush. It is housed inside the housing part MH of the motor part M.

  According to the first embodiment described above, a brush for high speed operation is not required by PWM control, the number of brushes is reduced, and a pressure equalizing line is used for the rotating armature of the motor main body 110. The number of brushes has been reduced, so the brushes are reduced. Thereby, according to the first embodiment, the area where the reduced brush can be arranged becomes an empty area on the brush holder 110H, and the thermal protection element 130 and the control board 120 are arranged in the generated empty area. The control board 120 and the like can be accommodated in the housing part MH of the motor part M without increasing the size of the motor 100. Therefore, according to the first embodiment, it is possible to reduce the size of the front or rear wiper device while increasing the number of magnetic poles of the brush motor.

Next, a modification of the first embodiment will be described with reference to FIGS. 10 and 11.
FIG. 10 is a side view showing the arrangement of the control board 120 or the control board 120A provided in the brush motor 100B according to a modification of the first embodiment of the present invention. FIG. 11 is a detailed view of the arrangement of the control board 120 or the control board 120A provided in the brush motor 100B according to the modification of the first embodiment of the present invention. Except for the arrangement position of the control board 120 or the control board 120A, the brush motor 100B of the modification of the first embodiment is configured similarly to the brush motor 100 of the first embodiment described above.

  As shown in FIG. 10, in this modification, the control board 120 is disposed inside the housing part GH of the speed reduction mechanism part G of the brush motor 100B. Specifically, as shown in FIG. 11, the control board 120 or the control board 120A is an inner surface of a bottom cover (iron or resin cover) constituting the housing part GH of the brush motor 100B, and the brush motor 100B. The speed reduction mechanism G is disposed at a site that does not interfere with the operation of the worm wheel gear or the like. That is, the control board 120 or the control board 120A is a housing part that covers the worm wheel gear and the like so as not to contact the worm wheel gear and the like in the speed reduction mechanism part G in which the rotating shaft of the rotary armature is extended and engaged. The inner wall surface and the surface of the substrate are attached to the inner wall surface of the bottom cover of the GH so as to face each other.

  Also according to this modification, the brush motor can be reduced in size while achieving multipolarization in which the magnetic poles of the brush motor are four or more. Moreover, since the rotational speed of the motor main body 110 is controlled by PWM control as in the first embodiment described above, the rotational speed can be changed without switching brushes. In addition, according to the present modification, the control board 120 or the control board 120A can be arranged regardless of the arrangement of the brushes, and thus is not restricted by the arrangement position of the brushes.

<Second Embodiment>
The second embodiment has the same configuration as each of the brush motor 100 of FIG. 2 or the brush motor 100A of FIG. 4 according to the first embodiment described above, and the high speed operation and low speed operation of the wiper of the front wiper device. The operation speed is controlled by adjusting the pulse duty of the PWM signal (PWM control). Also in the second embodiment, regarding the arrangement of the control board 120 or the control board 120A, the control board 120 or the control board 120A provided in the brush motor 100 of the first embodiment shown in FIGS. This is the same as the arrangement example.
Hereinafter, operations different from the brush motor 100 according to the first embodiment in the second embodiment will be described.

  FIG. 12 is a flowchart for explaining an operation example of the brush motor 100 according to the second embodiment of the present invention, and describes an example of duty control processing by a microcomputer constituting the duty control unit 1201 and the PWM signal generation unit 1202. It is a figure for doing. Here, FIG. 12A shows the flow of the initial setting process. When a vehicle user (for example, a driver) sets an operation switch (not shown) of a front or rear wiper device to an intermittent operation mode (hereinafter referred to as intermittent operation mode), for example, intermittent operation from an external circuit of the operation switch A low speed operating voltage signal VL or a high speed operating voltage signal VH is supplied to the duty controller 1201 together with a signal (not shown).

  The duty control unit 1201 determines whether or not an intermittent operation signal is supplied from an external circuit (step S11). At this time, when the intermittent operation signal is supplied from the external circuit, the duty control unit 1201 is in the intermittent operation mode, so the process proceeds to step S12. On the other hand, when the intermittent operation signal is not supplied from the external circuit, the duty control unit 1201 advances the process to step S13 because it is not the intermittent operation mode.

  The PWM signal generation unit 1202 controls the duty control unit 1201 until the wiper of the front or rear wiper device reaches the stop position (in this embodiment, the duty in the low speed operation of the wiper) until the wiper reaches the stop position. A pulse PWM signal is supplied to the drive transistor 1204 via the drive unit 1203 (step S12). The PWM signal generation unit 1202 sets the pulse duty of the PWM signal to 0 when the wiper of the front or rear wiper device reaches the stop position under the control of the duty control unit 1201. Accordingly, the wiper of the front or rear wiper device is driven to a predetermined stop position and stopped.

  The duty control unit 1201 starts a timer provided therein and sets a predetermined intermittent time (count value) in the timer. Then, the duty control unit 1201 starts measuring the elapsed time compared with the intermittent time (step S14).

  The duty control unit 1201 determines whether or not the elapsed time of the timer has exceeded the intermittent time, that is, whether or not the intermittent time has elapsed (step S15). At this time, if the elapsed time of the timer exceeds the intermittent time, the duty control unit 1201 advances the process to step S16 because the intermittent time has elapsed. On the other hand, when the elapsed time of the timer does not exceed the intermittent time, the duty control unit 1201 repeats the process of step S15 assuming that the intermittent time has not elapsed.

The duty control unit 1201 stops the timer, resets the elapsed time to “0”, and returns the process to step S11 (step S16).
As described above, the motor main body 110 rotates intermittently in one direction under the control of the duty control unit 1201, and the wiper of the front or rear wiper device operates intermittently using the rotational force of the motor main body 110 as power. To do. Thus, the front or rear windshield is wiped by the wiper of the front or rear wiper device.
Further, the wiper operation process in step S13 of the flowchart of FIG. 11 is the same process as the flowchart in the first embodiment shown in FIG. Here, when the process of the flowchart of FIG. 3 ends, the duty control unit 1201 returns the process to step S11 of the flowchart of FIG.

  FIG. 12B is a flowchart showing the flow of the wiper operation process (step S12 described above) when the wiper is intermittently operated after the initial setting process. Here, the duty of the PWM signal for driving the drive transistor 1204 is set to use, for example, 100 percent during high-speed operation.

Since the low-speed operation voltage signal VL is supplied to the duty control unit 1201, a PWM control control signal that sets the duty of the pulse of the PWM signal to a duty corresponding to the low-speed operation of the wiper (70% in this embodiment) The signal is output to the signal generation unit 1202.
As a result, the PWM signal generation unit 1202 generates a PWM signal corresponding to a high-speed operation that is set in advance, for example, with a pulse duty of 70%. Then, the PWM signal generation unit 1202 outputs the generated PWM signal to the drive transistor 1204 via the drive unit 1203 (step S21).

  The duty control unit 1201 determines whether or not the wiper of the front or rear wiper device has reached the initial stop position in the intermittent operation (step S22). At this time, when the wiper of the front or rear wiper device reaches the stop position, the duty control unit 1201 advances the process to step S23. On the other hand, when the wiper of the front or rear wiper device has not reached the stop position, the duty control unit 1201 repeats the process of step S22.

  When the wiper of the front or rear wiper device reaches the stop position, the duty control unit 1201 outputs a control signal for setting the duty of the PWM signal for driving the drive transistor 1204 to 0 percent to the PWM signal generation unit 1202. Then, the process proceeds to step S14. As a result, the PWM signal generation unit 1202 sets the duty of the pulse of the PWM signal to 0 percent (step S23). As a result, the PWM signal pulse is not output from the PWM signal generation unit 1202, the drive transistor 1204 is turned off, and the motor body 110 is not energized. For this reason, the rotating armature of the motor main body 110 stops rotating, and the wiping of the front or rear windshield by the front or rear wiper device is stopped.

  As described above, according to the second embodiment, since the configuration is the same as that of the first embodiment, the control of the operating speed of the brush motor by PWM control (control of the rotational speed of the brush motor) is performed. There is no need to switch brushes according to the operating speed as in the prior art, and there is no need to provide a plurality of brushes according to the operating speed. For this reason, according to the first embodiment, it is possible to eliminate inconveniences such as an increase in noise, a decrease in the life of the commutator, and a decrease in efficiency due to the provision of a high-speed brush.

  In addition, according to the second embodiment described above, even if the number of poles is increased to four or more, it is not necessary to provide a high-speed brush, so that restrictions on the assembly accuracy of the brush can be avoided, and the number of poles is reduced and the weight is reduced. Can be promoted. In particular, in the case of wiper motors, laws and regulations stipulate switching functions between low-speed operation and high-speed operation, speed differences between low-speed and high-speed, etc., so that the regulations can be satisfied when the motor rotational speed becomes large. However, according to the first embodiment described above, the rotational speed of the motor is adjusted by PWM control, so that the operating speed can be set flexibly in accordance with regulations.

  Further, according to the second embodiment, the PWM control by the duty control unit 1201 can be applied to the intermittent operation of the wiper as described above. Thus, according to the second embodiment, the same control board 120 can be used in each of the front wiper device for the front windshield and the rear wiper device for the rear windshield. For this reason, the manufacture of the control board 120 can be unified by the front wiper device and the rear wiper device, and the manufacturing cost of the control board 120 can be reduced.

  According to the second embodiment, a relay is conventionally provided in the rear wiper device to intermittently operate the wiper. However, the duty is set to 100% and 0% by PWM control to operate or stop the wiper. However, it is not necessary to provide a relay, and the cost can be reduced by reducing the number of mechanism parts.

  Further, the program for realizing the operation of the microcomputer 1208 in FIGS. 3 and 12 described above is recorded on a computer-readable recording medium, and the program recorded on the recording medium is read into a computer system. Execution processing may be performed by execution. Here, the “computer system” may include an OS and hardware such as peripheral devices.

  Further, the “computer system” includes a homepage providing environment (or display environment) if a WWW system is used. The “computer-readable recording medium” means a flexible disk, a magneto-optical disk, a ROM, a writable nonvolatile memory such as a flash memory, a portable medium such as a CD-ROM, a hard disk built in a computer system, etc. This is a storage device.

The program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium.
The program may be for realizing a part of the functions described above.
Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, and what is called a difference file (difference program) may be sufficient.

  DESCRIPTION OF SYMBOLS 100,100A, 100B ... Brush motor, 110 ... Motor main-body part, 110H ... Brush holder, 111A, 111B, 111C, 111D, 111E, 111F ... Brush, 120, 120A ... Control board, 130 ... Thermal protection element, 141, 143 ... Diode, 150 ... Relay plate, 1201, 1201A ... Duty controller, 1202, 1202A ... PWM signal generator, 1203 ... Driver, 1204 ... Drive transistor, 1204a ... Body diode, 1208 ... Microcomputer, 2205 ... Overcurrent detection Part, B ... brake contact, G ... deceleration mechanism part, GH ... housing part, M ... motor part, MH ... housing part, S ... start contact.

Claims (6)

A multi-pole brush motor having four or more magnetic poles for generating a rotational force in one direction,
A rotating armature having a pressure equalizing line;
A commutator provided in the rotating armature;
Each of a first brush and a second brush in contact with the commutator;
A duty control unit that selects a duty of a voltage pulse applied between the first brush and the second brush by a voltage signal supplied from the outside;
A PWM signal generation unit that outputs a PWM signal that is a pulse train of the duty in accordance with the selected duty supplied from the duty control unit;
Connected between one of the first brush and the second brush and either the power source or the ground, turned on and off by the PWM signal, and between the first brush and the second brush A brush motor comprising: a drive transistor that applies the voltage of the power source as the voltage pulse. The duty control unit
The brush motor according to claim 1, wherein the rotation speed of the rotary armature is changed by changing the duty of a PWM signal for PWM control of the drive transistor. The brush motor is a brush motor used in a vehicle wiper device,
The duty control unit
3. The brush motor according to claim 2, wherein the set value of the duty of the PWM signal is changed in each of a low-speed operation and a high-speed operation of the wiper in wiping the windshield according to desired characteristic requirements. . In the intermittent operation of the wiper, the duty control unit causes the PWM signal generation unit to generate the PWM signal of the duty at the time of low speed operation or high speed operation at the time of operation, while the PWM signal of the PWM signal at the time of stop The brush motor according to claim 3, wherein the duty is set to zero. Each of the duty control unit and the PWM signal generation unit is provided on a control board, and includes a housing unit in which the rotating armature, the first brush, and the second brush are stored.
The control board is disposed in an area of the housing portion in which a brush that is omitted by providing the pressure equalizing line in the rotary armature can be disposed. The brush motor according to claim 4. And further comprising a speed reduction mechanism that decelerates the rotation of the rotating armature,
The control board is
The brush motor according to claim 5, wherein the brush motor is attached to an inner wall surface of a bottom cover of a housing portion that covers the speed reduction mechanism portion so as not to interfere with the operation of the speed reduction mechanism portion.

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