JP2008035628A - Electric motor with reduction gear - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric motor with a reduction gear in which a brush on the negative electrode side of motor body can be grounded easily to a gear case. <P>SOLUTION: A containing case 51 being arranged on the outer side face of a gear case for containing a reduction gear is provided integrally with a brush holder of the motor body, and a pair of power supply side connection boards 53a and 53b for connecting the brush of the motor body and a power supply terminal provided in a connector are arranged in the containing case 51. A gear case side connection terminal 64 is formed in a V-shape by bending the end of the power supply side connection board 53b on the negative electrode side, and a protrusion 62 is formed on the gear case integrally therewith. The gear case side connection terminal 64 is touched to the protrusion 62 under resiliently deformed state thus grounding a brush on the negative electrode side to the gear case. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electric motor with a speed reduction mechanism that includes a motor body including a rotation shaft and a speed reduction mechanism that decelerates rotation of the rotation shaft and outputs the rotation shaft from an output shaft.

  As a drive source for a wiper device, a power window device, a sunroof device or the like provided in a vehicle, an electric motor that is operated by a power source such as a battery mounted on the vehicle is usually used. In order to adapt the electric motor to these devices, it is necessary to reduce the rotational speed of the motor to a desired rotational speed. Therefore, such an electric motor is made into one unit as an electric motor with a speed-reduction mechanism by attaching a speed-reduction mechanism, for example, as shown in Patent Document 1.

  A motor with a brush is often used as the motor body of an electric motor with a speed reduction mechanism. However, a motor with a brush generates noise from the sliding contact portion between the brush and the commutator, and this noise can interfere with other electrical components. Measures to prevent giving (radio noise, etc.) are necessary. As a means to prevent noise emission, a technology is known in which a noise prevention element such as a choke coil is provided in the power supply circuit. However, the noise can be sufficiently reduced only by providing such a noise prevention element. There are cases where it is not possible.

On the other hand, a technique is known in which a brush on the negative electrode side provided on the motor body is grounded to a gear case that houses the speed reduction mechanism, and a shield effect is generated in the gear case and the motor yoke. In this case, a connecting plate for connecting the brush and a power feeding connector is connected to the brush on the negative electrode side of the motor body, and a ground terminal provided on the connecting plate is connected to a gear case using a fastening member such as a screw. The brush is grounded to the gear case.
Japanese Utility Model Publication No. 6-24373

  However, in the conventional electric motor with a speed reduction mechanism, in order to ground the brush on the negative electrode side of the motor body, it is necessary to fix the ground terminal to the gear case using a fastening member such as a screw. As a result, the number of parts and assembly man-hours for the electric motor with the motor increase.

  An object of the present invention is to provide an electric motor with a speed reduction mechanism that can easily ground a brush on the negative electrode side of a motor body to a gear case.

  The electric motor with a speed reduction mechanism according to the present invention is an electric motor with a speed reduction mechanism including a motor body having a rotation shaft and a speed reduction mechanism that decelerates the rotation of the rotation shaft and outputs the rotation from the output shaft. An armature including a commutator fixed to a shaft and a coil connected to the commutator, a motor yoke having a magnet mounted on an inner surface thereof, and rotatably accommodating the armature, mounted inside the motor yoke, and A brush holder that holds a pair of brushes that are in sliding contact with the commutator, a gear case that is fixed to the motor yoke and accommodates the speed reduction mechanism, and a pair of power supply terminals that are each connected to a power source, are disposed on the gear case. A connector and the brush holder are provided integrally with each other and project toward the gear case side through the opening of the motor yoke. A housing case disposed on the outer surface of the gear case, and a housing case accommodated in the housing case, one end of which is connected to the brush through the opening of the motor yoke and the other end is connected to the power supply terminal. A pair of connecting plates, and a grounding terminal formed by bending a part of the connecting plate on the negative electrode side and in contact with a grounding projection provided on the gear case in an elastically deformed state. To do.

  In the electric motor with a speed reduction mechanism of the present invention, the grounding terminal is formed by arranging a pair of the connection plates in parallel and bending the tip of the connection plate on the negative electrode side toward the connection plate on the positive electrode side. Features.

  In the electric motor with a speed reduction mechanism according to the present invention, the protrusion is disposed on a cross line between a surface passing through the axis of the rotation shaft and orthogonal to the outer surface and the outer surface, and a pair of the connection plates are connected to the protrusion. It arrange | positions facing on both sides of a part, It is characterized by the above-mentioned.

  The electric motor with a speed reduction mechanism of the present invention is characterized in that it has a noise preventing means connected between the brush and the power supply terminal and housed in the housing case.

  The electric motor with a speed reduction mechanism according to the present invention is used as a drive source for a rear wiper device of a vehicle.

  According to the present invention, the ground terminal is formed by bending a part of the negative-side connecting plate housed in the housing case, and the ground terminal is in contact with the ground protrusion provided on the gear case in an elastically deformed state. Since the housing case is arranged on the gear case, the negative brush can be easily grounded to the gear case. Therefore, since the ground terminal can be reliably grounded to the gear case without using a fastening member such as a screw, the number of parts, the number of assembling steps, etc. of the electric motor with a speed reduction mechanism can be reduced. Even in a narrow space, a sufficient deflection length can be secured for the ground terminal, so that the power supply circuit of the electric motor with the speed reduction mechanism can be reliably grounded to the gear case.

  Further, according to the present invention, the protrusion is disposed on a line passing through the axis of the rotation shaft and orthogonal to the outer surface of the gear case and intersecting the outer surface, and the pair of connection plates are sandwiched between the protrusions. Since it is arranged so as to face each other, even if the gear case is formed in two symmetrical shapes according to the specifications of the mounting state of the electric motor with the speed reduction mechanism, the same for each gear case The motor body can be used.

  Furthermore, according to the present invention, since the noise preventing means is connected between the brush and the power supply terminal, the noise preventing means absorbs the noise flowing through the power supply circuit, and the electric motor with the speed reduction mechanism radiates. Noise can be reduced.

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

  FIG. 1 is a perspective view showing a wiper motor according to an embodiment of the present invention, and FIG. 2 is an exploded perspective view of the wiper motor shown in FIG.

  A wiper motor 11 shown in FIG. 1 is used as a drive source of a rear wiper device provided in a vehicle, and is an electric motor with a speed reduction mechanism in which a motor body 12 and a speed reducer 13 are formed as one unit.

  As shown in FIG. 2, the motor main body 12 is a motor with a brush provided with a rotating shaft 12a, and a commutator 14 (commutator) and an armature core (not shown) are fixed to the rotating shaft 12a. . A plurality of coils (armature windings) (not shown) are wound around the slots of the armature core, and the ends of these coils are respectively connected to corresponding segments of the commutator. The armature (armature) is connected by the commutator 14 and the coils. 15 is configured.

  The motor body 12 includes a motor yoke (yoke) 16 formed in a cylindrical shape with a bottom having an oval cross section, and the armature 15 has one end of a rotating shaft 12 a supported rotatably on the bottom of the motor yoke 16. Thus, the motor yoke 16 is rotatably accommodated. A pair of magnets (not shown) are mounted on the inner surface of the motor yoke 16 with different magnetic poles facing each other, and an armature core on which a coil is wound is formed by these magnets and the motor yoke 16. It is located in the magnetic field.

  3 is a power supply circuit diagram of the wiper motor shown in FIG. 1, and FIG. 4 is a perspective view showing details of a brush holder provided in the motor body.

  The wiper motor 11 is provided with a power feeding circuit 21 shown in FIG. 3 in order to supply a drive current to the motor body 12. The power supply circuit 21 has a pair of brushes 22a and 22b that are in sliding contact with the outer peripheral surface of the commutator 14. In order to hold the brushes 22a and 22b, as shown in FIG. A brush holder 23 is mounted.

  As shown in FIG. 4, the brush holder 23 is formed of a resin material, and is formed in a cylindrical shape along the inner surface of the motor yoke 16 and a main body wall portion 23a perpendicular to the axial direction of the rotating shaft 12a. And an outer peripheral wall portion 23 b covering the outer periphery of the motor yoke 16. The outer peripheral wall portion 23 b is mounted inside the motor yoke 16 so as to be in sliding contact with the inner surface of the motor yoke 16. Further, a through hole 23c is formed in the axis of the main body wall portion 23a. When the brush holder 23 is attached to the motor yoke 16, the commutator 14 of the armature 15 is inserted into the through hole 23c and the main body wall portion 23a. It is arranged inside.

  As shown in FIG. 4, the pair of brushes 22a and 22b held by the brush holder 23 are fixed to one ends of leaf springs 24a and 24b that are bent in a U-shape, respectively, and these leaf springs 24a and 24b. Are fixed to the brush holder 23 by fastening members (bolts) 25, so that the brushes 22a and 22b are brought into sliding contact with the outer peripheral surface of the commutator 14 while being urged by the leaf springs 24a and 24b. Yes. The plate springs 24a and 24b are formed of a metal plate such as a copper plate. When a direct current is supplied to the plate springs 24a and 24b, the current is supplied to the brushes 22a and 22b via the plate springs 24a and 24b. It has become so. When a current is supplied to the brushes 22a and 22b, the current is commutated by the commutator 14 and supplied to the coils. As a result, the coils in the magnetic field are energized to rotate the rotating shaft 12a together with the armature 15. Will do.

  The other elements constituting the power feeding circuit 21 will be sequentially described later.

  FIG. 5 is a partially cutaway sectional view showing the internal structure of the speed reducer shown in FIG.

  On the other hand, the speed reducer 13 has a gear case 26 fixed to the motor yoke 16. The gear case 26 is made of a conductor such as an aluminum alloy, and is electrically connected to the motor yoke 16 when fixed to the motor yoke 16.

  As shown in FIG. 5, a reduction mechanism 28 is accommodated in the gear case 26. The speed reduction mechanism 28 is a worm gear mechanism that includes a worm 31 and a worm wheel 32 that meshes with the worm 31. The worm 31 is integrally formed on the outer peripheral surface of the rotating shaft 12 a that protrudes into the gear case 26, and the worm wheel 32. Is supported by a support shaft 33 provided in the gear case 26 and is rotatable inside the gear case 26. Therefore, when the motor body 12 is operated and the rotary shaft 12a rotates, the rotation is reduced to a predetermined number of rotations by the speed reduction mechanism 28 and transmitted to the worm wheel 32.

  Further, the speed reducer 13 is provided with a power conversion mechanism 34 for converting the rotation of the worm wheel 32 into a swinging motion and transmitting it to the output shaft 27. The power conversion mechanism 34 includes a power conversion member 35 and an output gear 36. The power conversion member 35 includes an arm portion 35 a and a sector gear portion 35 b, and the distal end portion of the arm portion 35 a is warmed by a connecting shaft 37. The wheel 32 is rotatably connected to a position away from the rotation center axis. On the other hand, the output gear 36 is fixed to the base end portion of the output shaft 27 protruding into the gear case 26 and meshed with the sector gear portion 35 b of the power conversion member 35. A gear shaft 38 is provided at the axis of the sector gear portion 35b, and the gear shaft 38 and the output shaft 27 are slidably connected by a plate member 39, whereby the sector gear portion 35b is connected to the output gear 36. Are held in a state of being engaged with each other.

  With such a structure, when the motor main body 12 is operated and the worm wheel 32 is rotated, the arm portion 35a is reciprocated by the rotation, and the sector gear portion 35b is oscillated with respect to the output gear 36. Is converted into a swinging motion and output from the output shaft 27. That is, in the wiper motor 11, the rotational motion of the rotary shaft 12 a that is the power of the motor body 12 is decelerated by the speed reduction mechanism 28 and converted into a swing motion by the power conversion mechanism 34 and output from the output shaft 27. Yes.

  As shown in FIG. 1, the gear case 26 is formed with a boss portion 26a that protrudes parallel to the support shaft 33, and the output shaft 27 is parallel to the support shaft 33 and is rotatably supported by the boss portion 26a. Yes. Further, the distal end of the output shaft 27 protrudes to the outside from the boss portion 26a, and a rear wiper arm constituting the rear wiper device is attached to the distal end. Thereby, when the motor main body 12 is operated, the rear wiper arm swings together with the output shaft 27, and the wiping operation by the rear wiper device is performed.

  The wiper motor 11 is provided with a connector 43 for connecting the power feeding circuit 21 to a power source 41 such as a battery mounted on the vehicle and a wiper switch 42. As shown in FIG. 1, the connector 43 is formed as an independent unit, arranged on the outer surface of the gear case 26, and fixed to the gear case 26 by fastening members (bolts) 44. 3 and 5, the connector 43 is provided with a pair of power supply terminals 45a and 45b. The power supply terminal 45a is connected to the power source 41 and the wiper switch 42 via wiring, It is connected to an external connector (not shown) on the vehicle body side and grounded to the vehicle body. When the wiper switch 42 is turned on, power is supplied from the power supply 41 to the power supply terminal 45a.

  The connector 43 is provided with a switch terminal 46 for an auto stop circuit. The switch terminal 46 is inserted into the gear case 26 through an insertion hole (not shown) provided in the gear case 26 and rotates together with the worm wheel 32. In contact with a relay plate (not shown). When the rear wiper arm is in the lower inverted position, a position detection signal is output from the position detection terminal 47 of the connector 43 to a control device (not shown) via the switch terminal 46 and the relay plate. And even if the wiper switch 42 is randomly stopped, the control device stops the motor main body 12 when the rear wiper arm is in the lower reverse position.

  As shown in FIG. 1, a housing case 51 is disposed on the outer surface of the gear case 26.

  FIG. 6 is a perspective view showing details of the storage case shown in FIG. 1, and this storage case 51 is formed in a vertically long bathtub shape with a resin material, and as shown in FIG. Is fixed to the brush holder 23 so as to be along. That is, the storage case 51 is fixed to the brush holder 23 and is provided integrally with the brush holder 23. When the brush holder 23 is attached to the motor yoke 16, the storage case 51 is opened from the inside of the motor yoke 16. It protrudes to the gear case 26 side via When the gear case 26 is fixed to the motor yoke 16, the housing case 51 is arranged on the outer surface of the gear case 26.

  As shown in FIG. 6, a pair of brush side connection plates 52 a and 52 b are fixed to the end of the housing case 51 on the brush holder 23 side. Each of the brush side connection plates 52a and 52b is formed by bending a metal plate such as a copper plate, and one end thereof is a leaf spring 24a of the corresponding brush 22a and 22b via a wiring board provided in the brush holder 23. 24b, and the other end protrudes in parallel with the interior of the housing case 51 through the opening of the motor yoke 16.

  In addition, a pair of power supply side connection plates 53 a and 53 b are fixed to the end of the housing case 51 on the connector 43 side. Each of these power supply side connection plates 53a and 53b is formed by bending a metal plate such as a copper plate and arranged in parallel with each other, and one end thereof is connected to the corresponding power supply terminals 45a and 45b of the connector 43, The other end protrudes in parallel with the inside of the housing case 51.

  FIG. 6 shows a state in which the lid of the storage case 51 is removed.

  In order to connect the brushes 22a and 22b to the power supply terminals 45a and 45b and to absorb noise generated from the sliding contact portions of the brushes 22a and 22b and the commutator 14, a noise prevention means 54 is housed in the housing case 51. Yes.

  The noise prevention means 54 has a pair of choke coils 55a and 55b and a bidirectional varistor 56 as a capacitive element having the functions of a capacitor and a varistor. A partition wall 57 that is divided into two spaces is provided. The choke coils 55a and 55b are arranged in parallel in the housing case 51 and are separated from each other by the partition wall 57. The bidirectional varistor 56 is connected to the choke coils 55a and 55b. Are arranged side by side on the connector 43 side and separated from the choke coils 55a and 55b by a partition wall 57. Each space defined by the partition wall 57 is set to have a shape and size corresponding to the outer shape of the choke coils 55a and 55b and the bidirectional varistor 56, whereby the choke coils 55a and 55b and the bidirectional The varistor 56 can be easily mounted.

  As the capacitive element, only a capacitor or only a varistor may be mounted.

  One end of the choke coil 55a is connected to the brush side connection plate 52a, and the other end is connected to the power supply side connection plate 53a. That is, the choke coil 55a is connected between the brush 22a on the positive electrode side and the power supply terminal 45a on the positive electrode side. Connected in series. Similarly, one end of the choke coil 55b is connected to the brush side connection plate 52b, and the other end is connected to the power supply side connection plate 53b. That is, the choke coil 55b includes the negative electrode side brush 22b and the negative electrode side power supply terminal 45b. Are connected in series. One end of the bidirectional varistor 56 is connected to the power supply side connection plate 53a, and the other end is connected to the power supply side connection plate 53b. That is, the bidirectional varistor 56 is electrically connected between the choke coils 55a and 55b. It is connected to the.

  As a result, even if noise is generated from the sliding contact portion between the brushes 22a, 22b and the commutator 14, the choke coils 55a, 55b and the bidirectional varistor 56 absorb the noise flowing in the power feeding circuit 21, and to the outside of the motor. Noise emission can be reduced. Further, since the noise preventing means 54 is provided immediately after the exit of the power feeding circuit 21 from the motor yoke 16, that is, immediately after the opening through which each of the brush side connection plates 52a and 52b passes, the opening from the inside of the motor yoke 16 is provided. The noise radiated to the outside can be removed by the noise prevention means 54 before propagating to other wirings, etc., thereby reducing the radiation of noise to the outside of the motor.

  As described above, in the wiper motor 11, the noise preventing means 54 is arranged outside the motor yoke 16, so that noise coming out from the inside of the motor yoke 16 through the opening is propagated to other wirings. Thus, the noise radiated from the wiper motor 11 can be reduced.

  Further, in the wiper motor 11, since the noise prevention means 54 is accommodated in the accommodation case 51 provided integrally with the brush holder 23, the assembly work of the noise prevention means 54 can be facilitated.

  Further, in the wiper motor 11, the storage case 51 is provided with the partition wall 57, and the choke coils 55 a and 55 b and the bidirectional varistor 56 are stored in the storage space formed by the partition wall 57. The assembling work of the constituent elements to the housing case 51 can be facilitated.

  Further, in the wiper motor 11, since the housing case 51 is disposed on the outer surface of the motor yoke 16 and the gear case 26, the noise preventing means 54 can be assembled at the final stage of the motor assembling process. It becomes easy to classify the specifications of the wiper motor 11 by the presence or absence of 54.

  FIGS. 7A and 7B are cross-sectional views showing a procedure for grounding the motor yoke side ground terminal to the motor yoke.

  In order to ground the negative brush 22b to the motor yoke 16, the brush holder 23 is provided with a motor yoke ground terminal 61. The motor yoke side ground terminal 61 is formed by bending a metal plate such as a copper plate, and is fixed to the main body wall portion 23a of the brush holder 23 in the main body portion 61a, and the terminal portion 61b is connected to the main body portion 61a. As shown in FIG. 7A, it is bent into a U-shape and protrudes from the notch formed in the outer peripheral wall portion 23b to the outside of the outer peripheral wall portion 23b. Further, the main body 61 a of the motor yoke side ground terminal 61 is connected to the negative brush 22 b and the negative brush side connection plate 52 b through a wiring board provided in the brush holder 23.

  When the brush holder 23 is mounted inside the motor yoke 16, as shown in FIG. 7B, the terminal portion 61b of the motor yoke-side ground terminal 61 contacts the inner surface of the motor yoke 16 in an elastically deformed state. Thus, the negative brush 22b is grounded to the motor yoke 16. When the negative brush 22b is grounded to the motor yoke 16, the motor yoke 16 has a shielding effect, and noise can be prevented from being radiated to the outside of the motor via the motor yoke 16.

  FIG. 8 is a perspective view showing the gear case before the brush holder is attached, and FIG. 9 is an explanatory view showing the positional relationship between the protrusion shown in FIG. 8 and the rotating shaft. FIG. 10 is a cross-sectional view taken along the line AA in FIG. 9, and FIGS. 11A and 11B are front views showing a connection procedure of the gear case side ground terminal to the protrusion.

  As shown in FIG. 8, a grounding protrusion 62 is provided on the outer surface of the gear case 26. As shown in FIG. 10, the protrusion 62 is formed of a conductor such as an aluminum alloy integrally with the gear case 26 and is electrically connected to the gear case 26 and the motor yoke 16. Further, as shown in FIGS. 9 and 10, the projection 62 passes through the axis of the rotation shaft 12a of the motor body 12 and is orthogonal to the outer surface of the gear case 26 (shown by a one-dot chain line in FIG. 10). And on the crossing line (indicated by the alternate long and short dash line in FIG. 9). That is, the protrusion 62 is disposed on the central axis of the motor body 12, that is, the rotating shaft 12 a when viewed from the axial direction of the output shaft 27.

  On the other hand, as shown in FIG. 6, a locking plate 63 is provided at the tip of the housing case 51 on the connector 43 side, and as shown in FIG. 11, a locking groove 63a formed in the locking plate 63 is provided. The housing case 51 is positioned on the gear case 26 by engaging with the protrusion 62. In addition, each of the power supply side connection plates 53a and 53b fixed to the housing case 51 has the projection 62 arranged so that the projection 62 is positioned in the middle when the housing case 51 is positioned by the projection 62. They are placed opposite to each other.

  As shown in FIG. 6, a gear case side ground terminal 64 is provided on the negative power supply side connection plate 53 b in order to ground the power supply side connection plate 53 b to the gear case 26. The gear case side ground terminal 64 is configured so that a part of the power supply side connection plate 53 b protruding from the housing case 51 toward the connector 43, that is, the tip end portion is folded back from the positive power supply side connection plate 53 a toward the housing case 51. It is formed by bending in a V shape, and is elastically deformable in the bending direction, that is, in a direction approaching and separating from the power supply side connection plate 53b. That is, the gear case side ground terminal 64 is formed of a metal plate such as a copper plate integrally with the power supply side connection plate 53b. When the housing case 51 is positioned on the gear case 26 while being positioned by the protrusion 62, it comes into contact with the side surface of the protrusion 62 in an elastically deformed state as shown in FIG. ing. The housing case 51 is provided with an abutment portion 65 that abuts against the distal end portion of the gear case side grounding terminal 64 in contact with the side surface of the projecting portion 62. The contact portion 65 is sandwiched between the contact portion 65 and the abutment portion 65 so as to be brought into contact with the projection portion 62 more firmly.

  The gear case side ground terminal 64 is grounded to the gear case 26 on the power supply terminals 45a and 45b side of the noise preventing means 54, the gear case 26 is electrically connected to the motor yoke 16, and the motor yoke 16 is further connected to the motor yoke side ground terminal 61. , The noise that could not be absorbed by the noise prevention means 54 is returned to the inside of the motor main body 12 through the gear case 26 and the motor yoke 16, and is radiated to the outside of the motor. Noise can be reduced.

  As described above, in the wiper motor 11, the brush 22 b is grounded to the motor yoke 16 by the motor yoke side ground terminal 61, and the power feeding circuit 21 is disposed on the power feeding terminals 45 a and 45 b side from the noise prevention means 54 by the gear case side ground terminal 64. Since the gear case 26 is grounded, the noise that cannot be removed by the noise prevention means 54 is returned to the inside of the motor body 12 via the gear case side ground terminal 64 and the motor yoke side ground terminal 61 to be connected to the outside of the motor. Noise emission can be reduced.

  In the wiper motor 11, the front end portion of the power supply side connection plate 53 b is bent into a V shape to form a gear case side ground terminal 64, and the gear case side ground terminal 64 is formed on a grounding projection 62 provided on the gear case 26. Since the contact is made in an elastically deformed state, the gear case side ground terminal 64 can be brought into contact with the protrusion 62 in a state where a spring force is always applied. In particular, by bending a part of the power supply side connection plate 53b into a V shape to form the gear case side ground terminal 64, a sufficient deflection length can be secured for the gear case side ground terminal 64 even in a narrow space. As a result, the gear case side ground terminal 64 can be reliably brought into contact with the protrusion 62 and the power feeding circuit 21 can be reliably grounded to the gear case 26. Further, by attaching the housing case 51 to the gear case 26, the gear case-side ground terminal 64 can be easily grounded to the protrusion 62. That is, since the gear case side ground terminal 64 can be reliably grounded to the gear case 26 without using a fastening member such as a screw, the number of parts of the wiper motor 11 and the number of assembling steps can be reduced.

  Further, in the wiper motor 11, the protrusion 62 is disposed on a line passing through the axis of the rotating shaft 12a and orthogonal to the outer surface of the gear case 26 and intersecting the outer surface, and the pair of power supply side connection plates 53a and 53b. Are arranged so as to face each other with the projection 62 interposed therebetween, so that the gear case 26 may be formed in two types of symmetrical shapes according to specifications such as the mounting state of the vehicle body of the wiper motor 11. The same motor body 12 can be used for each gear case 26. That is, the versatility of the motor main body 12 against the wrongness of the gear case 26 can be improved, and the cost of the wiper motor 11 can be reduced.

  It goes without saying that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. For example, in the present embodiment, the case where the present invention is applied to the wiper motor 11 that drives the rear wiper arm of the vehicle is shown. However, the present invention is not limited to this. For example, driving of a power window device or a sunroof device for a vehicle is performed. The present invention may be applied to a motor or the like used as a source.

  In the present embodiment, the speed reducer 13 is provided with the power conversion mechanism 34. However, the present invention is not limited to this, and the presence of the power conversion mechanism 34 is not limited as long as the speed reduction mechanism 28 is provided.

  Further, in the present embodiment, the brush side connection plates 52a and 52b and the power supply side connection plates 53a and 53b are formed separately, and the connection plates 52a to 53b are connected by the noise preventing means 54. However, the present invention is not limited to this, and the noise prevention means 54 may not be provided, and the brush side connection plates 52a and 52b and the power supply side connection plates 53a and 53b may be integrally formed.

  Furthermore, in the present embodiment, the gear case side ground terminal 64 is formed by bending the front end portion of the power supply side connection plate 53b into a V shape. Any other shape may be used as long as it can be brought into contact with the protruding portion 62 in a state where a part of the power supply side connection plate 53b is elastically deformed, such as a part of which is bent into a U-shape.

It is a perspective view which shows the wiper motor which is one embodiment of this invention. It is a disassembled perspective view of the wiper motor shown in FIG. FIG. 2 is a power supply circuit diagram of the wiper motor shown in FIG. 1. It is a perspective view which shows the detail of the brush holder provided in a motor main body. FIG. 2 is a partially cutaway cross-sectional view showing an internal structure of the reduction gear shown in FIG. 1. It is a perspective view which shows the detail of the storage case shown in FIG. (A), (b) is sectional drawing which shows the grounding procedure to the motor yoke of a motor yoke side ground terminal, respectively. It is a perspective view which shows the gear case before a brush holder is attached. It is explanatory drawing which shows the positional relationship of the projection part shown in FIG. 8, and a rotating shaft. It is sectional drawing which follows the AA line in FIG. (A), (b) is a front view which shows the connection procedure of the gear case side ground terminal to a projection part, respectively.

Explanation of symbols

11 Wiper motor (electric motor with reduction mechanism)
DESCRIPTION OF SYMBOLS 12 Motor main body 12a Rotating shaft 13 Reduction gear 14 Commutator 15 Armature 16 Motor yoke 21 Feed circuit 22a, 22b Brush 23 Brush holder 23a Main body wall part 23b Outer peripheral wall part 23c Through-hole 24a, 24b Plate spring 25 Fastening member 26 Gear case 26a Boss part 27 Output shaft 28 Deceleration mechanism 31 Worm 32 Worm wheel 33 Support shaft 34 Power conversion mechanism 35 Power conversion member 35a Arm portion 35b Sector gear portion 36 Output gear 37 Connection shaft 38 Gear shaft 39 Plate member 41 Power source 42 Wiper switch 43 Connector 44 Fastening member 45a, 45b Power supply terminal 46 Switch terminal 47 Position detection terminal 51 Housing case 52a, 52b Brush side connection plate (connection plate)
53a, 53b Power supply side connection plate (connection plate)
54 Noise prevention means 55a, 55b Choke coil 56 Bidirectional varistor 57 Bulkhead 61 Motor yoke side ground terminal 61a Main body part 61b Terminal part 62 Projection part 63 Locking plate 63a Locking groove 64 Gear case side grounding terminal (grounding terminal)
65 Contact part

Claims (5)

An electric motor with a speed reduction mechanism, comprising: a motor body including a rotation shaft; and a speed reduction mechanism that decelerates rotation of the rotation shaft and outputs the rotation shaft.
An armature comprising a commutator fixed to the rotating shaft and a coil connected to the commutator;
A motor yoke that has a magnet mounted on its inner surface and accommodates the armature rotatably;
A brush holder that is mounted inside the motor yoke and holds a pair of brushes in sliding contact with the commutator;
A gear case fixed to the motor yoke and housing the speed reduction mechanism;
A pair of power supply terminals each connected to a power source, and a connector disposed on the gear case;
A housing case that is provided integrally with the brush holder, protrudes toward the gear case through the opening of the motor yoke, and is disposed on the outer surface of the gear case;
A pair of connection plates housed in the housing case, each having one end connected to the brush through the opening of the motor yoke and the other end connected to the power supply terminal;
An electric motor with a speed reduction mechanism, comprising: a ground terminal that is formed by bending a part of the connection plate on the negative electrode side and that is in contact with a ground projection provided on the gear case in an elastically deformed state.   2. The electric motor with a speed reduction mechanism according to claim 1, wherein the pair of connection plates are arranged in parallel, and a tip end portion of the connection plate on the negative electrode side is bent toward the connection plate side on the positive electrode side to form the ground terminal. An electric motor with a speed reduction mechanism.   3. The electric motor with a speed reduction mechanism according to claim 2, wherein the protrusion is disposed on an intersection line between a surface passing through the axis of the rotation shaft and orthogonal to the outer surface and the outer surface, and the pair of connection plates An electric motor with a speed reduction mechanism, wherein the electric motor is disposed so as to face each other with the protrusion interposed therebetween.   The electric motor with a speed reduction mechanism according to any one of claims 1 to 3, further comprising noise preventing means connected between the brush and the power supply terminal and housed in the housing case. Electric motor with reduction mechanism.   The electric motor with a speed reduction mechanism according to any one of claims 1 to 4, wherein the electric motor with a speed reduction mechanism is used as a drive source for a rear wiper device of a vehicle.

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