JP6296911B2 - Wiper motor - Google Patents

Description

  The present invention relates to a wiper motor.

  Patent Document 1 listed below discloses a wiper motor (an electric motor with a speed reduction mechanism) that constitutes a part of a wiper device. The wiper motor described in this document drives and controls a motor body configured to include an armature, a speed reduction mechanism that decelerates the rotation of the armature at a predetermined reduction ratio, and transmits it to the output shaft. And a control circuit unit. The control circuit section has a plurality of driving elements mounted on a circuit board (control board). Since this driving element is a noise generation source, it is separated from the connector provided on the worm wheel arrangement part on one side with respect to the worm gear arrangement part, and concentrated on the other side with respect to the worm gear arrangement part. Configured.

JP 2010-288383 A

  By the way, when operating the washer, the wiper is also normally operated. Therefore, it is effective to mount on the wiper motor a wiper control circuit unit for driving and controlling the motor body that drives the wiper and a pump control circuit unit for driving and controlling the washer pump. However, not only the driving element of the motor body for driving the wiper but also the driving element for driving the washer pump provided separately from the wiper motor is provided in the wiper motor, and the wiring electrically connected to both the driving elements is connected to the antenna. Therefore, when the connector and the driving element are arranged apart from each other, it is important to suppress the noise radiated from the wiper motor because the wiring between them is long.

  In view of the above facts, an object of the present invention is to provide a wiper motor that can reduce noise emission while having a circuit unit for driving and controlling a wiper and a washer.

  According to a first aspect of the present invention, there is provided a wiper motor including a motor body configured to rotate about an axis and including a rotating shaft having a worm, a worm arrangement portion in which the worm is arranged, and a worm wheel meshing with the worm. A housing having a wheel arrangement portion and connected to the motor main body, a speed reduction portion in which rotation of the rotation shaft is decelerated from an output shaft, and a cover for closing the housing of the speed reduction portion and the opening of the housing A circuit board housed between the wiper motor and the wiper motor, wherein the circuit board drives the wiper device attached to the output shaft by driving the motor body and the washer pump. And a wiper washer control circuit for controlling the wiper drive circuit unit and the pump drive circuit unit. And an external connection terminal that is connected to an external connector to input / output at least one of a power source and an electric signal and is electrically connected to each circuit unit via a wiring. The drive circuit unit and the external connection terminal are arranged at a position corresponding to the wheel arrangement unit in the circuit board, and the wiper drive circuit unit is arranged in the worm arrangement with respect to the pump drive circuit unit in the circuit board. It is arranged on the part side.

  According to the wiper motor configured as described above, when the wiper drive circuit unit is actuated by a command from the wiper washer control circuit unit, the motor body is driven and the rotating shaft rotates together with the worm. The rotation of the rotating shaft is decelerated by the worm and the worm wheel, transmitted to the output shaft, and output. As a result, the wiper device attached to the output shaft is driven. Further, when the pump drive circuit unit is actuated by a command from the wiper washer control circuit unit, the washer pump is driven.

  Here, in this wiper motor, in addition to the pump drive circuit section and the external connection terminal being arranged corresponding to the wheel arrangement section of the housing on the circuit board, the wiper drive circuit section is provided on the circuit board. It is arrange | positioned with respect to the part at the worm arrangement | positioning part side. With this arrangement, the distance between the external connection terminal to which the external connector is connected and the pump drive circuit unit that drives the washer pump can be shortened, and the wiring that electrically connects them can be shortened. That is, on the circuit board corresponding to the wheel arrangement part, the pump drive circuit part is arranged together with the external connection terminals to which the external connector is connected, so that the motor body itself for driving the wiper device can be driven and controlled. It is possible to reduce the radiation of noise from the wiper motor by shortening the wiring between the irrelevant pump drive circuit section and the external connection terminal. On the other hand, the wiper drive circuit unit is arranged closer to the motor body than the arrangement area of the pump drive circuit unit by being arranged on the worm arrangement side with respect to the pump drive circuit unit. Therefore, the wiring between the wiper drive circuit section for switching a relatively large drive current and the motor main body can be shortened, and noise emission from the wiper motor can be reduced.

  In the wiper motor of the present invention, in addition to the above configuration, the external connection terminal is arranged on the opposite side of the worm arrangement portion with respect to the output shaft.

  According to the wiper motor having the above configuration, by setting the arrangement of the external connection terminals as described above, it is possible to suppress the noise of the wiper drive circuit unit from being input to the pump drive circuit unit or the external connection terminal side. it can.

  In the wiper motor of the present invention, in addition to the above configuration, the wiper drive circuit unit, the pump drive circuit unit, and the wiper washer control circuit unit are provided on a single circuit board.

  According to the wiper motor having the above configuration, the circuit elements constituting each circuit unit are mounted on a single circuit board, so that the wiper washer control circuit unit has both the wiper drive circuit unit and the pump drive circuit unit. In order to control, it is possible to easily form the wirings for connecting them to each other, that is, to simplify the wiring on the circuit board and to shorten the length. Thereby, the noise radiated | emitted from the wiring on a circuit board can be reduced further.

  In addition to the above-described configuration, the wiper drive circuit unit of the present invention includes a switching element that performs switching by PWM control of the motor body, and the switching element is connected to the output shaft. It arrange | positions at the said worm arrangement | positioning part side.

  According to the wiper motor having the above configuration, by setting the arrangement of the switching elements as described above, it is possible to suppress the heat of the switching elements from being transmitted to the pump drive circuit unit.

  In the wiper motor of the present invention, in addition to the above-described configuration, the pump drive circuit unit is configured independently of the wiper drive circuit unit, and the pump drive circuit unit and the wiper drive circuit unit are configured as a single unit. Is controlled based on a command from the wiper washer control circuit.

  According to the wiper motor having the above configuration, the pump drive circuit unit is controlled on the circuit board by controlling the pump drive circuit unit and the wiper drive circuit unit based on a command from a single wiper washer control circuit unit. For example, the wiring of electrical signals such as sensor signals can be simplified and the circuit board can be reduced in size compared to the case where the control circuit unit and the control circuit unit for controlling the wiper drive circuit unit are provided. .

It is the perspective view which looked at the wiper motor in this embodiment from the control device side. It is the perspective view which looked at the said wiper motor from the output-shaft side. It is a disassembled perspective view which shows the housing, control apparatus, cover, etc. of the said wiper motor. It is the top view which looked at the said control apparatus from the axial direction one side of the output shaft. It is the circuit diagram which showed the circuit of the said control apparatus typically.

  A wiper motor according to an embodiment of the present invention will be described with reference to FIGS.

  As shown in FIG. 1 and FIG. 2, the wiper motor 10 of this embodiment is used as a drive source for a wiper device 12 of a vehicle (automobile). The wiper motor 10 is configured to drive and control a motor body 14 that can be rotated forward and backward, a speed reduction unit 11 that is connected to the motor body 14 and decelerates rotation of the motor body 14, and the motor body 14 and the washer pump 18. And the control device 20. The speed reduction unit 11 includes a speed reduction mechanism 16, a housing 22 that houses the speed reduction mechanism 16, and a cover 24 attached to the housing 22.

  The motor body 14 is configured as a so-called brushed DC motor. The motor body 14 includes a substantially bottomed cylindrical motor yoke 26. Four permanent magnets (not shown) are fixed to the inner peripheral surface of the motor yoke 26, and the permanent magnets are arranged in four poles alternately arranged along the circumferential direction of the motor yoke 26. The motor is configured. As shown in FIG. 2, an armature 28 is rotatably accommodated in the motor yoke 26 inside the permanent magnet. The armature 28 includes a rotation shaft 30, and the rotation shaft 30 is formed in a substantially round bar shape and is arranged coaxially with the motor yoke 26. One end of the rotating shaft 30 in the axial direction is rotatably supported on the bottom of the motor yoke 26 via a bearing (not shown). On the other hand, the other axial end portion of the rotating shaft 30 is disposed in a housing 22 described later and is rotatably supported by the housing 22. In addition, a worm 32 constituting a part of the speed reduction mechanism 16 is formed integrally with a portion on the other axial end side of the rotary shaft 30. As shown in FIG. 1, the motor body 14 includes a brush holder device 34. The brush holder device 34 is formed in a substantially annular shape disposed on the radially outer side of a commutator 36 (see FIG. 2) provided in the armature 28. Further, the brush holder device 34 includes a plurality of brushes (not shown), and the brushes are in contact with the commutator 36 of the armature 28 so as to be slidable.

  As shown in FIG. 2, the speed reduction mechanism 16 is accommodated in the housing 22, and the speed reduction mechanism 16 includes the worm 32 and the worm wheel 38 described above. The worm wheel 38 is formed in a substantially disk shape, and the worm wheel 38 is fixed to an end portion on one axial side of the output shaft 40. Further, the worm 32 is meshed with the outer peripheral portion of the worm wheel 38, whereby the rotation of the rotary shaft 30 is decelerated at a predetermined reduction ratio and transmitted to the output shaft 40 to be decelerated and output. It has become. The rotation (absolute angle position) of the output shaft 40 is detected by a magnetoresistive element 63 (see FIG. 4) attached to the circuit board 54 so as to face the shaft end of the output shaft 40.

  As shown in FIG. 3, the housing 22 is formed in a substantially box shape, and on the other side in the axial direction of the rotary shaft 30 (on the opening side of the motor yoke 26) with respect to the motor yoke 26 (see FIG. 2). It arrange | positions and is connected with the motor main body 14 with the screw | thread etc. Specifically, the housing 22 is manufactured by die casting using aluminum (or an aluminum alloy) or the like, and is formed in a substantially box shape in which the opposite side of the direction in which the output shaft 40 protrudes is opened. The housing 22 is integrally formed with a holder accommodating portion 42 for accommodating and supporting the brush holder device 34 of the motor main body 14 described above. Further, the housing 22 is formed with a worm housing portion 44 as a “worm placement portion” for housing the worm 32, and the housing 22 is further provided with a “wheel placement portion” for housing the worm wheel 38. The worm wheel accommodating part 46 is formed. In addition, a support hole 48 for supporting the output shaft 40 is formed at the center of the worm wheel housing portion 46 while the output shaft 40 is inserted therethrough.

  The cover 24 is manufactured by injection molding or the like using an insulating resin material, and is formed in a substantially box shape with the housing 22 side opened. The cover 24 has an external connection terminal 50 formed by insert molding. The external connection terminal 50 includes a wiper drive circuit unit 56, a pump drive circuit unit 57, and a wiper washer control circuit unit 58 (on the circuit board described later). (See FIG. 4). More specifically, an external connector for supplying input / output of electric signals and a power source such as a vehicle speed sensor and a raindrop sensor is connected to a portion corresponding to the worm wheel housing portion 46 when the cover 24 is attached to the housing 22. The external connection terminal 50 is insert-molded. The cover 24 is insert-molded with a motor power supply terminal 52 that connects the wiper drive circuit unit 56 and a brush (not shown) of the brush holder device 34. That is, the external connection terminal 50 and the motor power supply terminal 52 are integrated with the cover 24. An external connection terminal 50 and a motor power supply terminal 52 that are insert-molded in the cover 24 are joined to a circuit board 54, which will be described in detail later, by soldering, and a screw (not shown) that is inserted into the insertion hole 54A of the circuit board 54. The circuit board 54 is fixed to the inner surface side of the cover 24 by being screwed into the cover 24. Then, the cover 24 to which the circuit board 54 is fixed is attached to the housing 22, so that the worm housing portion 44 and the worm wheel housing portion 46 are sealed in the sealed space M formed between the cover 24 and the housing 22. The circuit board 54 is arranged over the entire area. In the sealed space M, the aforementioned speed reduction mechanism 16 (worm 32 and worm wheel 38) is also disposed. The cover 24 is formed with a connector portion 24A to which an external connector (not shown) is connected.

  As shown in FIG. 4, the control device 20 drives the wiper device 12 (see FIG. 2) attached to the output shaft 40 by driving the motor body 14, and the washer pump 18 ( A circuit is composed of a plurality of circuit elements 60, 61, and 62 constituting a pump drive circuit unit 57 that drives (see FIG. 2), a wiper drive circuit unit 56 and a wiper washer control circuit unit 58 that controls the pump drive circuit unit 57. It is configured by being attached to the substrate 54.

  As described above, the circuit board 54 covers the worm housing portion 44 and the worm wheel housing portion 46 of the housing 22 by closing the opening of the housing 22 by the cover 24 having the circuit board 54 fixed to the inner surface side. Arranged. At this time, the circuit board 54 is disposed away from the shaft end on one side in the axial direction of the output shaft 40 and is formed in a rectangular plate shape extending in the thickness direction of the output shaft 40. .

Further, when the circuit board 54 with the cover 24 assembled to the housing 22 is viewed from the axial direction of the output shaft 40 (in other words, the opening side of the housing 22), the circuit board 54 corresponds to the worm wheel housing portion 46 in the circuit board 54. One end of a plurality of external connection terminals 50 that are insert-molded in the cover 24 (an external connector is connected to the other end) is electrically connected to the portion to be performed.

  Further, when the circuit board 54 with the cover 24 assembled to the housing 22 is viewed from the axial direction of the output shaft 40, a portion corresponding to the worm wheel housing portion 46 in the circuit board 54 is connected to the plurality of external connections. A plurality of circuit elements 61 are mounted in the vicinity of (close to) the vicinity of the terminal 50 (connector portion 24A). The circuit of the pump drive circuit unit 57 is configured by the circuit element 61 and a conductive pattern unit (not shown) formed on the circuit board 54. The circuit element 61 is a field effect transistor (hereinafter referred to as FET) 61A, a relay box 61B, an electrolytic capacitor 61C, a choke coil 61D, and the like. In the present embodiment, by providing two relays in the relay box, the motor 70 of the washer pump 18 can be rotated forward and backward (see FIG. 5).

  Further, when the circuit board 54 in a state where the cover 24 is assembled to the housing 22 is viewed from the axial direction of the output shaft 40, the portion of the circuit board 54 on the worm housing portion 44 side with respect to the pump drive circuit portion 57 is more Specifically, a plurality of circuit elements 60 are mounted on the worm accommodating portion 44 side with respect to the pump drive circuit portion 57 of the circuit board 54 and on both sides of the worm 32. The circuit element 60 and a conductive pattern portion (not shown) formed on the circuit board 54 constitute a circuit of the wiper drive circuit portion 56. The circuit element 60 includes a plurality of FETs 60 </ b> A and pre-drivers 60 </ b> B as “switching elements” that are H-bridge connected.

  Further, when the circuit board 54 is viewed from the axial direction of the output shaft 40, a boundary portion between the wiper drive circuit unit 56 and the pump drive circuit unit 57 is provided on the surface opposite to the surface on which the circuit elements 60 and 61 are attached. The circuit element 62 constituting the wiper washer control circuit 58 is attached to the microcomputer 62 (positioned between the worm 32 and the output shaft 40 in FIG. 4). (Hereinafter simply referred to as “microcomputer 62”).

  The plurality of external connection terminals 50 are electrically connected to the wiper drive circuit unit 56, the pump drive circuit unit 57, and the wiper washer control circuit unit 58, and the worm wheel housing unit is viewed in the axial direction of the output shaft 40. 46 is a part corresponding to 46, and is joined to the circuit board 54 in a state of being arranged on the motor main body 14 side in the axial direction of the rotary shaft 30 on the side opposite to the worm housing portion 44 with respect to the output shaft 40. .

  Further, the plurality of FETs 60 </ b> A that constitute a part of the wiper drive circuit unit 56 and perform switching of the motor main body 14 by PWM control are on the worm housing unit 44 side with respect to the output shaft 40 when viewed in the axial direction of the output shaft 40. Therefore, it is arranged in the vicinity of the motor power supply terminal 52.

  FIG. 5 is a circuit diagram schematically showing the circuit of the control device 20. As shown in this figure, the pump drive circuit unit 57 is configured independently of the wiper drive circuit unit 56. The pump drive circuit unit 57 and the wiper drive circuit unit 56 are controlled based on a command from a single wiper washer control circuit unit 58, that is, controlled based on a command from a single microcomputer 62. It is like that. The microcomputer 62 receives a rotation position (absolute angle position) signal of the output shaft 40 detected by the magnetoresistive element 63, a vehicle speed signal input from the external connection terminal 50, a raindrop sensor detection signal, and the like.

(Operation and effect of this embodiment)
Next, the operation and effect of this embodiment will be described.

  As shown in FIGS. 1 and 2, in the present embodiment, when the wiper drive circuit unit 56 is actuated by a command from the wiper washer control circuit unit 58, the motor body 14 is driven and the rotating shaft 30 is moved together with the worm 32. Rotate. The rotation of the rotary shaft 30 is decelerated by the worm 32 and the worm wheel 38 and transmitted to the output shaft 40 for output. Based on the rotation position signal from the magnetoresistive element 63 that detects the rotation angle (absolute angle position) of the output shaft 40, the motor body 14 is rotated forward and backward to reciprocate the output shaft 40 within a range of less than 360 degrees. . As a result, the wiper device 12 attached to the output shaft 40 is driven. That is, the wiper arm 64 attached to the output shaft 40 is reciprocally rotated, and the wiper blade 66 attached to the tip of the wiper arm 64 wipes the windshield glass of the vehicle.

  Further, when the pump drive circuit unit 57 is actuated by a command from the wiper washer control circuit unit 58, the motor 70 (see FIG. 5) of the washer pump 18 is driven. As a result, the cleaning liquid is ejected from the nozzle 68 connected to the washer pump 18 toward the windshield glass. In the vehicle having the wiper motor 10 of the present embodiment, when the driver commands the operation of the washer pump 18 by operating a not-shown washer switch, the wiper washer control circuit unit 58 is connected to the pump drive circuit unit 57 and the wiper drive circuit unit 56. The cleaning liquid is sprayed toward the windshield glass, and the wiper motor 10 is also operated in conjunction with this to wipe the windshield glass by the wiper blade 66.

  Here, as shown in FIG. 4, in the present embodiment, the pump drive circuit portion 57 and the external connection terminal 50 are arranged corresponding to the worm wheel housing portion 46 of the housing 22 in the circuit board 54. In addition, the wiper drive circuit portion 56 is disposed on the worm housing portion 44 side with respect to the pump drive circuit 57 in the circuit board 54. With this arrangement, the distance between the external connection terminal 50 to which an external connector (not shown) is connected and the pump drive circuit unit 57 that drives the washer pump 18 is shortened, and the wiring that electrically connects them is shortened. can do. That is, the motor main body for driving the wiper device 12 by arranging the pump drive circuit portion 57 together with the external connection terminal 50 to which the external connector is connected on the circuit board 54 corresponding to the worm wheel housing portion 46. The wiring between the pump drive circuit unit 57 and the unit connection terminal 50, which is not related to the drive and control of the 14 itself, can be shortened to reduce noise emission from the wiper motor 10. On the other hand, the wiper drive circuit unit 56 is arranged closer to the motor body 14 than the arrangement area of the pump drive circuit unit 57 by being arranged on the worm storage unit 44 side with respect to the pump drive circuit unit 57. Therefore, the wiring between the wiper drive circuit unit 56 that switches a relatively large drive current to the motor body 14 and the motor body 14 can be shortened, and electromagnetic noise radiated from the wiper motor 10 can be reduced.

  Further, in this embodiment, the external connection terminal 50 electrically connected to the wiper drive circuit unit 56, the pump drive circuit unit 57, and the wiper washer control circuit unit 58 via wiring is accommodated in the worm housing with respect to the output shaft 40. By setting it as the structure arrange | positioned on the opposite side to the part 44, it can suppress inputting into the pump drive circuit part 57 or the external connection terminal 50 side.

  Further, in the present embodiment, the wiper drive circuit unit 56, the pump drive circuit unit 57, and the wiper washer control circuit unit 58, that is, the circuit elements 60, 61, and 62 constituting each circuit unit are arranged on a single circuit board 54. Since the wiper washer control circuit unit 58 controls both the wiper drive circuit unit 56 and the pump drive circuit unit 57, it is possible to easily form wiring arrangements for interconnecting them. The wiring on the circuit board 54 can be simplified to shorten the length. Thereby, the noise radiated | emitted from the wiring on the circuit board 54 can be reduced further.

  In the present embodiment, the FET 60 </ b> A as a “switching element” that constitutes a part of the wiper drive circuit unit 56 and performs switching by PWM control of the motor body 14 is disposed on the worm housing unit 44 side with respect to the output shaft 40. By doing so, it is possible to suppress the heat of the FET 60 </ b> A from being transmitted to the pump drive circuit unit 57.

  Furthermore, in this embodiment, the pump drive circuit unit 57 is controlled on the circuit board 54 by controlling the pump drive circuit unit 57 and the wiper drive circuit unit 56 based on a command from a single microcomputer 62. For example, wiring of electric signals such as sensor signals can be simplified and the circuit board can be miniaturized as compared with the case where the microcomputer for controlling the wiper drive circuit unit 56 is provided. Further, the single microcomputer 62 has a surface (housing 22) opposite to a surface (surface on the cover 24 side) on the circuit board 54 on which the pump driving circuit portion 57 and the wiper driving circuit portion 56 are arranged. Side surface).

  In the present embodiment, the preferred example in which the circuit board 54 is disposed in the sealed space M formed between the housing 22 and the cover 24 has been described. However, the present invention is not limited to this, and for example, the cover A part of 24 may be opened. As described above, whether or not the circuit board 54 is arranged in the sealed space M may be appropriately set in consideration of the heat radiation amount of the circuit elements 60 and 62, the waterproof property of the wiper motor 10, and the like.

  In the present embodiment, the preferred example in which the circuit elements 60, 61, 62 are attached to the single circuit board 54 has been described, but the present invention is not limited to this. For example, it is also possible to configure a control device corresponding to the control device 20 described above by attaching the circuit elements 60, 61, 62 to a plurality of circuit boards and connecting the plurality of circuit boards to each other via wiring.

  Furthermore, although this embodiment has described a preferred example in which the pump drive circuit unit 57 and the wiper drive circuit unit 56 are controlled based on a command from a single microcomputer 62, the present invention is not limited to this. For example, a configuration may be employed in which a microcomputer for controlling the pump drive circuit unit 57 and a microcomputer for controlling the wiper drive circuit unit 56 are provided on the circuit board 54.

  Although one embodiment of the present invention has been described above, the present invention is not limited to the above, and various modifications other than the above can be implemented without departing from the spirit of the present invention. Of course.

DESCRIPTION OF SYMBOLS 10 ... Wiper motor, 12 ... Wiper device, 14 ... Motor body, 18 ... Washer pump, 22 ... Housing, 24 ... Cover, 30 ... Rotating shaft, 32 ... Worm, 38 ... Worm wheel, 40 ... Output shaft, 50 ... External connection Terminals 54... Circuit board 56. Wiper drive circuit unit 57 57 Pump drive circuit unit 58. Wiper washer control circuit unit 60. Circuit element 60 A FET 61 61 circuit element 62.

Claims (5)

A motor body configured to include a rotating shaft that rotates about an axis and has a worm;
A housing connected to the motor body, the worm having a worm arrangement portion in which the worm is arranged, and a wheel arrangement portion in which a worm wheel meshing with the worm is arranged;
A decelerating unit that decelerates and outputs rotation of the rotating shaft from an output shaft;
A circuit board housed between the housing of the speed reduction portion and a cover for closing the opening of the housing;
In a wiper motor comprising:
The circuit board drives the motor body to drive a wiper device attached to the output shaft, a pump drive circuit unit to drive a washer pump, the wiper drive circuit unit, and the pump drive A wiper washer control circuit unit for controlling the circuit unit, and an external connection terminal to which an external connector is connected to input / output at least one of a power supply and an electrical signal and to be electrically connected to each circuit unit via a wiring; , And
The pump drive circuit unit and the external connection terminal are arranged at positions corresponding to the wheel arrangement unit in the circuit board,
The wiper drive circuit unit is a wiper motor disposed on the worm arrangement unit side with respect to the pump drive circuit unit on the circuit board.   2. The wiper motor according to claim 1, wherein the external connection terminal is disposed on a side opposite to the worm arrangement portion with respect to the output shaft.   The wiper motor according to claim 1 or 2, wherein the wiper drive circuit unit, the pump drive circuit unit, and the wiper washer control circuit unit are provided on a single circuit board. The wiper drive circuit unit includes a switching element that performs switching by PWM control of the motor body.
The wiper motor according to any one of claims 1 to 3, wherein the switching element is arranged on the worm arrangement portion side with respect to the output shaft. The pump drive circuit unit is configured independently of the wiper drive circuit unit,
The wiper motor according to any one of claims 1 to 4, wherein the pump driving circuit unit and the wiper driving circuit unit are controlled based on a command from a single wiper washer control circuit unit.

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