JP4886546B2 - Electric motor with reduction mechanism - Google Patents

Description

  The present invention relates to an electric motor with a speed reduction mechanism that reduces the influence of noise on a control board accommodated in a housing.

This type of electric motor is used in a wiper device, a power window device, a sunroof device, a sliding door opening and closing device, etc., as an actuator for a vehicle-mounted device. The rotation of the motor body is output via a speed reduction mechanism composed of a worm and a worm wheel. The housing that houses the speed reduction mechanism houses a control board that controls the rotational speed and direction of the motor body. This control board may be affected by noise and cause malfunction of the motor body. Therefore, the housing is grounded to electrostatically shield the control board. As a method for grounding the housing, a method in which a U-shaped terminal is attached to a substrate and brought into contact with the housing is known (see Patent Document 1).
Japanese translation of PCT publication No. 2002-534046

  However, this method requires a dedicated ground terminal for grounding the housing, which increases the number of parts and the number of work steps, and increases costs.

  An object of the present invention is to eliminate a dedicated ground terminal for grounding the housing.

  An electric motor with a speed reduction mechanism according to the present invention includes a rotor having a rotation shaft, a speed reduction mechanism meshing with the rotation shaft, a speed reduction mechanism housing portion that rotatably supports the rotation shaft and houses the speed reduction mechanism. A housing having a bottomed shape and a connector portion for covering the opening of the housing and supplying electric power from the outside, and a plurality of terminals having at least ground terminals embedded therein from the connector portion A motor with a speed reduction mechanism having a cover and a control circuit for controlling the rotation of the rotor, wherein the speed reduction mechanism is fixed to one of the housing or the housing cover; Is characterized in that it penetrates the control board and abuts on a connecting portion formed on the bottom surface of the housing.

  The motor with a speed reduction mechanism according to the present invention is characterized in that the connection portion has a connection means for engaging with and electrically connecting to an end portion of the ground terminal.

  The motor with a speed reduction mechanism according to the present invention is characterized in that the connecting means is disposed at a position close to a connector of the gear housing.

  The motor with a speed reduction mechanism according to the present invention is characterized in that the connection means is a clip attached to the conductive material molding portion so as to be engaged with the distal end of the extension portion of the ground terminal.

  The motor with a speed reduction mechanism according to the present invention is characterized in that the connection means is a snap that is elastically deformed by being provided at an end of the ground terminal so as to be fitted into a recess provided in the gear housing.

  A motor with a speed reduction mechanism according to the present invention includes a bottomed yoke, a rotary shaft having one end rotatably supported on the bottom of the yoke, a core having a plurality of slots fixed to the rotary shaft, A plurality of windings wound around each slot of the core; an armature including a commutator connected to an end of the plurality of windings and adjacent to the core; and a plurality of brushes slidably contacting the commutator; A gear housing with a bottom connected to the opening of the yoke and rotatably supported at the other end of the armature, and a worm formed at the other end of the armature, and housed in the gear housing And a plurality of ends having at least a ground terminal from the connector portion, the connector portion for covering the opening of the gear housing and supplying power from outside is integrally formed. An electric motor with a speed reduction mechanism having a housing cover embedded therein and a control board fixed to the housing cover so as to face the speed reduction mechanism and having a control circuit for controlling the rotation of the armature, The ground terminal penetrates the control board and abuts on a connection portion formed on a bottom surface of the gear housing.

  The motor with a speed reduction mechanism according to the present invention is characterized in that the connection portion has a connection means for engaging with and electrically connecting to an end portion of the ground terminal.

  The motor with a speed reduction mechanism according to the present invention is characterized in that the connecting means is disposed at a position close to a connector of the gear housing.

  The motor with a speed reduction mechanism according to the present invention is characterized in that the connection means is a clip attached to the conductive material molding portion so as to be engaged with the distal end of the extension portion of the ground terminal.

  The motor with a speed reduction mechanism according to the present invention is characterized in that the connection means is a snap that is elastically deformed by being provided at an end of the ground terminal so as to be fitted into a recess provided in the gear housing.

  According to the present invention, since the conductive material molding portion of the speed reduction mechanism housing portion is grounded using the ground terminal that connects the control board and the connector, it is not necessary to separately provide a dedicated ground terminal. In addition, when the assembly of both molding parts of the speed reduction mechanism housing part is completed, the extension part of the ground terminal engages with the connecting means and is electrically connected to the conductive material molding part, so that the ground terminal is electrically connected to the speed reduction mechanism housing part. Eliminates the need to connect to the material molding part. That is, the number of parts and the number of work steps are reduced, which is advantageous in terms of cost.

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

  FIG. 1 is an explanatory diagram showing an outline of a vehicle in which a wiper device using a wiper motor according to an embodiment of the present invention is installed.

  The vehicle 10 is provided with a wiper device 12 for securing the driver's field of view by wiping rain attached to the front window glass 11 and splashes of the front vehicle. The wiper device 12 includes two wiper arms 13 on the driver's seat side and the passenger's seat side. These wiper arms 13 are respectively attached to wiper shafts 14 provided on the vehicle 10 and swing around the wiper shaft 14. It is free to move.

  In order to drive the wiper arm 13 in a swinging manner, the wiper device 12 is provided with a wiper motor (electric motor with a speed reduction mechanism) 15, and the wiper motor 15 has an output shaft 16 directed obliquely downward and rearward of the vehicle 10. It is fixed in an engine room (not shown), and the output shaft 16 is connected to the left and right wiper shafts 14 via a link mechanism 17. When the wiper motor 15 is operated, the rotational movement of the output shaft 16 is converted into a swinging motion by the link mechanism 17 and transmitted to the wiper shaft 14, whereby the wiper arm 13 swings. A wiper blade 18 is attached to the distal end side of the wiper arm 13, and these wiper blades 18 are in elastic contact with the front windshield 11. When the wiper arm 13 is driven to swing by the wiper motor 15, the wiper blade 18 is moved. Swings on the front window glass 11 within a predetermined wiping range (a range indicated by a two-dot chain line in the figure), and the front window glass 11 is wiped.

  2 is a plan view of the wiper motor 15 shown in FIG. 1, FIG. 3 is a cross-sectional view taken along line AA in FIG. 1, FIG. 4 is a cross-sectional view taken along line BB in FIG. FIG.

  The wiper motor 15 constitutes a motor body 21 and a speed reduction mechanism 20. The wiper motor 15 includes a yoke 22 that houses the motor body 21 and a gear housing 23 that houses the speed reduction mechanism 20. The gear housing 23 includes a gear housing body 24 made of aluminum die cast and a housing cover 25 made of resin. (See FIG. 3). The motor body 21 is a so-called brushed DC motor, and includes an armature 27 provided on the rotating shaft 26, a commutator 28 connected to the coil (not shown) of the armature 27 and attached to the rotating shaft 26, and a slide on the commutator 28. The brush 29 is in contact with the magnet 30 and is fixed to the inner peripheral surface of the yoke 22. The speed reduction mechanism 20 includes a worm 31 connected to the rotation shaft 26 of the motor body 21 and a worm wheel (not shown) that meshes with the worm 31.

The gear housing main body (conductive material molding portion) 24 and the housing cover (resin molding portion) 25 are formed in a bottomed dish shape, and the gear housing 23 is configured by combining them vertically (see FIG. 4). The gear housing 23 accommodates the control board 32 so that the upper surface faces the housing cover 25 and the lower surface faces the gear housing body 24. The control board 32 is provided with a control circuit for controlling the rotational speed and direction of the motor body 21.
A connector 33 for connecting to an external device is integrally formed at the end of the housing cover 25 on the motor body 21 side. Some of the terminals of the connector 33 are insert-molded in the housing cover 25 and connected to the control board connection terminals 34, 35, and 36. Among these, the ground terminal 35 connected to the ground portion of the control board 32 extends through the control board 32 to the gear housing body 24 side.

  When the gear housing 23 is assembled, the gear housing body 24 is provided with a clip (connecting means) 37 having a substantially Ω-shaped cross section that is engaged with the extension portion 35 a of the ground terminal 35 and electrically connected to the gear housing body 24. It is provided. The clip 37 is attached to the boss portion 38 of the gear housing body 24 in a state where the extension portion 35a of the ground terminal 35 can be engaged. Further, the clip 37 is disposed near the connector 39 to shorten the ground terminal 35.

  When assembling the gear housing 23, the terminals 34, 35, and 36 are inserted into holes (not shown) of the control board 32, and the periphery of the control board 32 is engaged with the hook 41 to control the terminals 34, 35, and 36. After soldering to the substrate 32, the gear housing main body 24 and the housing cover 25 may be fixed to each other by a fixing tool 39. In FIG. 3, a heat sink 40 is insert-molded in the housing cover 25, and an electronic component 42 such as an FET is attached to the back surface thereof. Reference numeral 43 denotes a cooling fin provided on the gear housing body 24.

  In the wiper motor 15, when the assembly of the gear housing 23 is completed, the extension 35 a of the ground terminal 35 engages with the clip 39 and is electrically connected to the gear housing body 24, and the gear housing body 24 is grounded. That is, the control board 32 is electrostatically shielded by the gear housing body 24 and is not affected by external noise. Further, it is less susceptible to noise generated by the brush 29. In particular, since the clip 37 is disposed in the vicinity of the connector 33 and the ground terminal 35 is shortened, the electrostatic shielding effect is enhanced and effective in preventing the influence of noise.

  By the way, since the gear housing main body 24 is grounded using the ground terminal 35 for connecting the control board 32 and the connector 33, it is not necessary to separately provide a dedicated ground terminal. Further, when the assembly of the gear housing 23 is completed, the extension portion 35a of the ground terminal 35 engages with the clip 37 and is electrically connected to the gear housing main body 24. Therefore, the trouble of connecting the ground terminal 35 to the gear housing main body 24 is eliminated. Can be omitted. That is, the number of parts and the number of work steps are reduced, which is advantageous in terms of cost.

  6 and 7 are views showing a modification of the connecting means shown in FIG. 5. FIG. 6 is a front view of the extension portion 35a of the ground terminal 35, and FIG. 7 is a sectional view taken along the line DD in FIG.

  That is, two slits 50 extending in the longitudinal direction are formed in the extended portion 35a of the ground terminal 35, and a convex portion 51a and a concave portion 51b having a semicircular cross section are formed on both sides thereof. As a result, a snap 53 that fits into the recess 52 of the gear housing body 24 while being elastically deformed is formed.

  It goes without saying that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention. For example, in the embodiment shown in FIG. 7, the ground terminal 35 is formed with the semicircular arc-shaped convex portion 51a and the concave portion 51b, but the cross-sectional shape may be a triangle.

It is explanatory drawing which shows the outline of the vehicle in which the wiper apparatus using the wiper motor which is one embodiment of this invention was installed. It is a top view of the wiper motor shown in FIG. It is the sectional view on the AA line of FIG. FIG. 3 is a sectional view taken along line B-B in FIG. 2. It is an enlarged view in the dotted-line frame C of FIG. It is a figure which shows the modification of the connection means shown in FIG. 5, and is a front view of the extension part of a ground terminal. It is the DD sectional view taken on the line of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Vehicle 11 Front window glass 12 Wiper apparatus 13 Wiper arm 14 Wiper shaft 15 Wiper motor 16 Output shaft 17 Link mechanism 18 Wiper blade 20 Deceleration mechanism 21 Motor main body 22 Yoke 23 Gear housing 24 Gear housing main body 25 Housing cover 26 Rotating shaft 27 Armature 28 Commutator 28 29 Brush 30 Magnet 31 Worm 32 Control board 33 Connector 34 Terminal 35 Ground terminal 35a Extension part 36 Terminal 37 Clip 38 Boss part 39 Fixing tool 40 Heat sink 41 Gear cover 42 Electronic part 43 Cooling fin 50 Slit 51a Convex part 51b Concave part 52 Concave part 53 Snap

Claims (10)

A rotor having a rotation axis;
A speed reduction mechanism meshing with the rotating shaft;
A bottomed housing having a speed reduction mechanism accommodating portion for rotatably supporting the rotation shaft and accommodating the speed reduction mechanism;
A housing cover that covers the opening of the housing and is integrally formed with a connector part for supplying electric power from the outside, and a plurality of terminals having at least ground terminals from the connector part embedded therein,
A control circuit that controls the rotation of the rotor, and the speed reduction mechanism is fixed to one of the housing or the housing cover;
A motor with a speed reduction mechanism comprising
The electric motor with a speed reduction mechanism, wherein the ground terminal penetrates the control board and abuts on a connection portion formed on a bottom surface of the housing. In the motor with a reduction mechanism according to claim 1,
The electric motor with a speed reduction mechanism, characterized in that the connection portion has connection means for engaging with and electrically connecting to an end portion of the ground terminal.   3. The electric motor with a speed reduction mechanism according to claim 2, wherein the connecting means is disposed at a position close to a connector of the gear housing.   4. The electric motor with a speed reduction mechanism according to claim 2, wherein the connecting means is a clip attached to the conductive material molding portion so as to be engaged with an end of the extension portion of the ground terminal. motor.   4. The electric motor with a speed reduction mechanism according to claim 2, wherein the connecting means is a snap that is elastically deformed by being provided at an end of the ground terminal so as to be fitted into a recess provided in the gear housing. An electric motor with a speed reduction mechanism. A bottomed yoke,
A rotating shaft having one end rotatably supported at the bottom of the yoke, a core having a plurality of slots fixed to the rotating shaft, a plurality of windings wound around each slot of the core, and An armature comprising a commutator to which ends of a plurality of windings are connected and connected adjacent to the core;
A plurality of brushes in sliding contact with the commutator;
A bottomed gear housing connected to the opening of the yoke and rotatably supported at the other end of the armature;
A reduction mechanism that meshes with a worm formed at the other end of the armature and is accommodated in the gear housing;
A housing cover that covers the opening of the gear housing and is integrally formed with a connector for supplying electric power from the outside, and a plurality of terminals having at least ground terminals from the connector are embedded therein,
A control board fixed to the housing cover so as to face the speed reduction mechanism and having a control circuit for controlling the rotation of the armature;
An electric motor with a speed reduction mechanism having
The electric motor with a speed reduction mechanism, wherein the ground terminal penetrates the control board and abuts on a connection portion formed on a bottom surface of the gear housing. The motor with a speed reduction mechanism according to claim 6,
The electric motor with a speed reduction mechanism, characterized in that the connection portion has connection means for engaging with and electrically connecting to an end portion of the ground terminal.   8. The electric motor with a speed reduction mechanism according to claim 7, wherein the connecting means is disposed at a position close to a connector of the gear housing.   9. The electric motor with a speed reduction mechanism according to claim 7 or 8, wherein the connection means is a clip attached to the conductive material molding portion so as to be engaged with an end of the extension portion of the ground terminal. motor.   9. The electric motor with a speed reduction mechanism according to claim 7 or 8, wherein the connecting means is a snap that is elastically deformed by being provided at an end of the ground terminal so as to be fitted into a recess provided in the gear housing. An electric motor with a speed reduction mechanism.

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