JP7035981B2 - Wiper motor - Google Patents

Description

The present invention relates to a wiper motor.

In a DC motor with a brush used for a wiper motor or the like, the rotor rotates when electric power is supplied to the coil of the rotor via the brush. In the brushed DC motor, as the rotor rotates, the electrical connection between the commutator provided coaxially with the rotor and the brush is intermittently switched. Such switching of electrical connections is a kind of switching operation, and along with the operation, a noise component whose potential changes at a high frequency is likely to be generated.

The generated noise component is generally flowed from the negative electrode terminal of the brush to the grounding region via the housing of the wiper motor or the like, but there is a problem that the noise component is easily diffused through the housing or the like. In order to prevent the noise component from diffusing to the outside, a separate shield for suppressing the radiation of the noise component is required in the housing or the like.

Patent Document 1 discloses an invention of a wiper motor that cuts off conduction of a noise component housing or the like by connecting a negative electrode terminal of a brush and a ground terminal of a connector with a lead wire.

In Patent Document 2, when a resin housing cover is attached to a metal housing, noise is generated by connecting the negative electrode terminal of the brush and the ground terminal of the connector with a metal plate sandwiched between the housing side and the housing cover. The invention of a wiper motor that cuts off the continuity of a component housing or the like is disclosed.

Japanese Patent Application Laid-Open No. 2003-134722 Japanese Unexamined Patent Publication No. 9-226526

However, in the wiper motor described in Patent Document 1, since a fragile lead wire is mounted on the speed reducing portion where the worm gear is rotating, there is a possibility that the lead wire may be broken. Further, there is a problem that the connection work of the lead wire is complicated.

In the wiper motor described in Patent Document 2, when attaching the housing cover, it is not easy to attach the metal plate connecting the negative electrode terminal of the brush and the ground terminal of the connector in a predetermined manner. If the metal plate is not attached in a predetermined manner, not only the negative electrode terminal of the brush and the ground terminal of the connector may not be electrically connected, but also the metal plate may come into contact with the housing of the wiper motor or the like. In case of contact, the circuit of the wiper motor may be short-circuited.

The present invention has been made in consideration of the above facts, and an object of the present invention is to provide a wiper motor that can effectively block noise components generated by rotation of the wiper motor and that can easily implement a configuration that blocks noise components.

In order to solve the above problems, the wiper motor according to claim 1 covers an opening of a yoke containing a commutator, a conductor and a brush for supplying power to the rotor, and has a negative electrode terminal of the brush and a negative electrode terminal of the brush. Arranged in the partition wall between the conductive partition wall to which the ground contact area is connected, the negative electrode terminal connection portion to which the negative electrode terminal is connected to the partition wall, and the ground contact area connection portion to which the ground contact area is connected to the partition wall. It includes a conductive portion having a higher conductivity than the adjacent portion.

According to this wiper motor, by providing a conductive portion having a higher conductivity than the adjacent portion on the partition wall, the noise component generated by the rotation of the wiper motor is suppressed from being diffused to other parts of the partition wall, so that the noise component is present. Can be effectively blocked.

The wiper motor according to claim 2 is the wiper motor according to claim 1, wherein the conductive portion is a region sandwiched between two grooves parallel to each other between the negative electrode terminal connection portion and the grounding region connection portion. By thinning the partition wall in each of the two grooves, the conductivity of the two grooves is made lower than that of other parts of the partition wall, and the conductivity of the region is adjacent to the region. It is made larger than the above two grooves.

According to this wiper motor, by providing the two parallel groove portions as the conductive portions, the noise component can flow in the region sandwiched between the two groove portions, and the noise component can be effectively cut off. Further, since the groove portion can be easily mounted, it is possible to provide a wiper motor that can be easily mounted with a configuration that blocks noise components.

The wiper motor according to claim 3 is the wiper motor according to claim 2, wherein each of the two groove portions is linear.

According to this wiper motor, the groove portion connects the negative electrode terminal connection portion and the grounding region connection portion at the shortest distance, thereby suppressing the diffusion of the noise component to other parts of the partition wall, so that the noise component can be effectively blocked. ..

The wiper motor according to claim 4 is the wiper motor according to claim 2, wherein each of the two groove portions has a substantially arc shape.

According to this wiper motor, by making the groove portion substantially arcuate, the conductive portion can be arranged so as to avoid the opening through which the rotation axis of the wiper motor penetrates the partition wall.

The wiper motor according to claim 5 is the wiper motor according to claim 1, wherein the conductive portion protrudes from another portion of the partition wall between the negative electrode terminal connection portion and the grounding region connection portion. It is a ridge portion, and by thickening the partition wall at the ridge portion, the conductivity of the front ridge portion is made larger than that of the portion adjacent to the ridge portion.

According to this wiper motor, by providing a ridge portion having a large conductivity between the negative electrode terminal connection portion and the grounding region connection portion, a noise component can flow through the ridge portion, and the noise component can be effectively cut off. .. Further, since the ridges can be easily mounted, it is possible to provide a wiper motor that can be easily mounted with a configuration that blocks noise components.

The wiper motor according to claim 6 includes two grooves adjacent to and parallel to the ridges in the wiper motor according to claim 5, and the partition wall is thinned at each of the two grooves. As a result, the conductivity of the two grooves is made lower than that of the ridges.

According to this wiper motor, by providing two groove portions parallel to each other in the ridge portion, the noise component can be concentratedly flowed in the ridge portion, and the noise component can be effectively cut off.

The wiper motor according to claim 7 is the wiper motor according to claim 5, wherein the ridges are linear.

According to this wiper motor, the ridges connect the negative electrode terminal connection part and the grounding area connection part at the shortest distance, thereby suppressing the diffusion of the noise component to other parts of the partition wall, so that the noise component is effectively blocked. can.

The wiper motor according to claim 8 is the wiper motor according to claim 5, wherein the ridge portion has a substantially arc shape.

According to this wiper motor, by making the ridges substantially arcuate, it is possible to dispose the conductive portion by avoiding the opening through which the rotation axis of the wiper motor penetrates the partition wall.

The wiper motor according to claim 9 is the wiper motor according to claim 5, wherein the ridge portion is another partition wall at a constant height between the negative electrode terminal connection portion and the grounding region connection portion. It protrudes with respect to the site.

According to this wiper motor, by arranging the ridges at a constant height, the noise component can be surely flowed from the negative electrode terminal connection portion to the grounding region connection portion, and the noise component can be effectively cut off.

The wiper motor according to claim 10 is the wiper motor according to claim 5, wherein the ridge portion becomes lower in height from the negative electrode terminal connection portion toward the grounding region connection portion.

According to this wiper motor, the weight of the product can be suppressed by flowing a noise component from the negative electrode terminal connection portion to the grounding region connection portion and suppressing the height of the ridge portion.

It is a block diagram which showed an example of the electric structure of the wiper motor which concerns on 1st Embodiment of this invention. It is an example of the schematic diagram of the deceleration part in the state where the housing cover of the wiper motor which concerns on 1st Embodiment of this invention is removed. It is an example of the schematic view when the deceleration part of the wiper motor which concerns on 1st Embodiment of this invention is seen from the direction of arrow A of FIG. (A) is a schematic view showing an example of a housing in which the structure of a brush, a worm wheel and the like is removed from the wiper motor shown in FIG. 3, and (B) is a perspective view of (A). (A) is a schematic view of a modified example of the housing shown in FIG. 4 (A), and (B) is a perspective view of (A). 4 is a cross-sectional view taken along the line AA of FIGS. 4 (B) and 5 (B). It is the schematic which showed an example of the housing which concerns on 1st example of 2nd Embodiment of this invention. (A) is a schematic view showing the housing of the first modification of the first example of the second embodiment of the present invention, and (B) is the schematic of the second embodiment of the present invention. It is the schematic which showed the housing of the 2nd modification of 1st example. (A) is a cross-sectional view when cut along the line BB of FIG. 8 (A), and (B) is a cross-sectional view when cut along the line CC of FIG. 8 (B). It is a figure. It is the schematic which showed the housing of the 2nd example of the 2nd Embodiment of this invention. (A) is a schematic view showing the housing of the first modification of the second example of the second embodiment of the present invention, and (B) is the schematic of the second embodiment of the present invention. It is the schematic which showed the housing of the 2nd modification of the 2nd example. It is the schematic which showed an example of the housing which concerns on 3rd Embodiment of this invention. (A) is a cross-sectional view when cut along the DD line of FIG. 12 (A), and (B) is a cross-sectional view when cut along the FF line of FIG. 12 (B). It is a figure.

[First Embodiment]
FIG. 1 is a block diagram showing an example of an electrical configuration of the wiper motor 10 according to the present embodiment.

As shown in FIG. 1, the wiper motor 10 decelerates the rotation speed of the rotating shaft by a motor unit 20 containing a stator and a rotor and a worm gear mechanism provided at the end of the rotating shaft of the rotor. It is composed of a part 30 and.

The stator and rotor of the motor unit 20 are provided in a yoke 22 made of aluminum die casting or the like. The yoke 22 has a substantially cylindrical shape with a hollow inside, and a stator and a rotor are housed in the internal space.

The worm gear mechanism described above is housed in the aluminum die-cast housing 32 of the speed reducing unit 30, and the housing 32 and the worm gear mechanism are covered with a resin housing cover 34.

The connector 36 is supplied with a high terminal 36H to which electric power for rotating the wiper motor 10 at a high speed is supplied, and an electric power having a lower voltage than the high terminal 36H for rotating the wiper motor 10 at a lower speed than the above-mentioned high-speed rotation. It includes a Low terminal 36L to be formed and a ground terminal 36N electrically connected to the negative electrode terminal 40N of the brush 40 of the wiper motor 10.

The electric power supplied from the high terminal 36H is supplied to the commutator 42 via the choke coil 38H for removing high frequency components that cause noise via the high voltage line 56 and the positive electrode terminal 40H of the brush 40. The electric power supplied from the Low terminal 36L is supplied to the commutator 42 via the choke coil 38L that removes high frequency components that cause noise via the low voltage line 58 and the positive electrode terminal 40L of the brush 40. Each of the high voltage line 56 and the low voltage line 58 is connected to the positive electrode terminals 40H and 40L via an opening 80 provided in the partition wall 50 that separates the motor unit 20 and the deceleration unit 30. The motor unit 20 is provided with a rotor and a stator, but is not shown in FIG. The partition wall 50 is integrally formed with the housing 32, and is a portion that covers the opening of the housing 32 in a state where the yoke 22 and the housing 32 are connected to each other. The connector 36 may have one positive charge terminal, one brush positive terminal, and one choke coil.

The ground terminal 36N is a terminal connected to the ground region on the vehicle side, and in the wiper motor 10, the ground line 54, the conductive partition wall 50 made of aluminum die-cast, the second connection terminal 52C, and the breaker 52B are used. , Is electrically connected to the negative electrode terminal 40N of the brush 40 via the first connection terminal 52A. The grounding line 54 is connected to the partition wall 50 at the end 54A, and connects the grounding terminal 36N, the partition wall 50 of the portion indicated by the broken line 60, the first connection terminal 52C, the breaker 52B, the first connection terminal 52A, and the negative electrode terminal 40N of the brush 40. Connect electrically. The breaker 52B is a device that opens the electric circuit when the coil current (motor current) of the wiper motor 10 becomes excessive to prevent damage to the circuit related to the wiper motor 10 and the wiper motor 10.

The ground line 54 and the high voltage line 56 are connected by a noise prevention capacitor 46. Further, the ground line 54 and the low voltage line 58 are connected by a noise prevention capacitor 48. One end of the capacitor 46 is connected between the choke coil 38H of the high voltage line 56 and the high terminal 36H of the connector 36, and the other end is between the end 54A of the ground line 54 and the ground terminal 36N of the connector 36. Be connected. Further, one end of the capacitor 48 is connected between the choke coil 38L of the low voltage line 58 and the Low terminal 36L of the connector 36, and the other end is the end portion 54A of the grounding line 54 and the grounding terminal 36N of the connector 36. Connected in between.

A high-frequency noise component is generated by the rotation of the wiper motor 10. The noise component passes from the negative electrode terminal 40N of the brush 40 through the first connection terminal 52A, the breaker 52B, and the second connection terminal 52C, and the broken line 60 in FIG. As shown by, it passes through the partition wall 50, and passes through the grounding line 54 from the end portion 54A.

Since the noise prevention capacitors 46 and 48 do not pass direct current but pass alternating current, the noise component whose potential changes at high frequency is guided to the choke coil 38H via the capacitor 46. Further, the noise component can also be guided to the choke coil 38L via the capacitor 48.

Since the choke coils 38H and 38L are elements with high inductance and exhibit high impedance with respect to a noise component having a high frequency, the noise component is cut off by the choke coils 38H and 38L. Even if the noise component is insufficiently cut off by the choke coils 38H and 38L, the noise component is supplied to the wiper motor 10 via the positive electrode terminals 40H and 40L and is exhausted together with the electric power for rotating the wiper motor 10. ..

As shown in FIG. 1, in the present embodiment, the noise component is conducted to the ground line 54 via the first connection terminal 52A, the breaker 52B, and the second connection terminal 52C. As shown by the broken line 60 in FIG. 1, the noise component conducts the partition wall 50 which is a part of the housing 32 of the wiper motor 10 and flows to the ground line 54. In the present embodiment, the noise component is prevented from being diffused to the outside world by preventing the noise component from diffusing other than the portion indicated by the broken line 60.

FIG. 2 is an example of a schematic view of the deceleration unit 30 in a state where the housing cover 34 of the wiper motor 10 according to the present embodiment is removed. Usually, the housing cover 34 is connected to the housing 32 by a fixing member such as a fixing bolt 68 and covers the inside of the housing 32.

A worm wheel 74 for decelerating the rotational speed of the wiper motor 10 is housed inside the housing 32 of the deceleration unit 30 from which the housing cover 34 is removed. A circuit including a High terminal 36H and a high voltage line 56, a Low terminal 36L and a low voltage line 58, a ground terminal 36N and a ground line 54, and capacitors 46 and 48 is configured so as to straddle the worm wheel 74. Each of the high voltage line 56, the low voltage line 58, and the grounding line 54 shown in FIG. 2 is composed of a rigid metal wire or a metal plate.

The high voltage line 56 and the low voltage line 58 are connected to the positive electrode terminals 40H and 40L of the brush 40, respectively, via an opening provided in the partition wall 50. Since the partition wall 50 is conductive, the high voltage line 56 and the low voltage line 58 pass through the opening of the partition wall 50 in a state of being covered with the insulating member 76.

As shown in FIG. 2, the ground line 54 is electrically connected to the partition wall 50 by the end 54A. The grounding line 54 has conductivity and elasticity at the end 54A and may be electrically connected by the end 54A coming into contact with the partition wall 50, but in order to ensure the connection, a bolt or the like may be used. The end portion 54A may be fixed to the partition wall 50 by using a fixing member.

FIG. 3 is an example of a schematic view when the deceleration unit 30 of the wiper motor 10 according to the present embodiment is viewed from the direction of arrow A in FIG. FIG. 3 shows a state in which the yoke 22, the rotor and the stator are removed, and the configuration of the brush 40 is shown. Further, an output shaft 78 provided coaxially with the worm wheel 74 of the deceleration unit 30 is shown. A link mechanism of the wiper device or the like is connected to the end of the output shaft 78.

The positive electrode terminals 40H and 40L and the negative electrode terminals 40N constituting the brush 40 come into contact with the commutator 42 (not shown) of the wiper motor 10 to supply electric power to the rotor. As shown in FIG. 3, the first connection terminal 52A is connected to the negative electrode terminal 40N. The first connection terminal 52A is connected to the breaker 52B. The breaker 52B is connected to the partition wall 50 via the second connection terminal 52C.

4 (A) and 4 (B) are schematic views showing an example of a housing 32 in which the brush 40, the worm wheel 74, and the like are removed from the wiper motor 10 shown in FIG. As shown in FIGS. 4A and 4B, the partition wall 50 of the wiper motor 10 according to the present embodiment has two grooves from the second connection terminal mounting portion 52CA toward the opening 80 of the partition wall 50. 90A1 and 90B1 are engraved in a straight line.

As described above, the second connection terminal mounting portion 52CA is a portion to which the negative electrode terminal 40N of the brush 40 is connected. The end portion 54A of the grounding line 54 is connected near the end of the grooves 90A1 and 90B1 on the opening 80 side. Therefore, the noise component sent from the negative electrode terminal 40N of the brush 40 is conducted to the ground line 54 via the region 90C1 sandwiched between the grooves 90A1 and 90B1.

Since the linear groove portions 90A1 and 90B1 can connect the second connection terminal mounting portion 52CA and the portion to which the end portion 54A of the grounding line 54 is connected in the shortest distance, the noise component is diffused to other portions of the partition wall 50. However, it is necessary to dispose of the wiper motor 10 so as not to interfere with the rotating shaft opening 82 through which the rotating shaft penetrates.

5 (A) and 5 (B) are schematic views showing modified examples of FIGS. 4 (A) and 4 (B). As shown in FIGS. 5A and 5B, the groove portions 90A2 and 90B2 carved in the partition wall 50 are substantially circular unlike the groove portions 90A1 and 90B1 of FIGS. 4A and 4B which are linear. Since it exhibits an arc-shaped curve, it is possible to avoid interference with the rotation shaft opening 82.

In the modified examples shown in FIGS. 5A and 5B, the second connection terminal mounting portion 52CA is also a portion to which the negative electrode terminal 40N of the brush 40 is connected, as described above. Further, the end portion 54A of the grounding line 54 is connected near the end of the groove portions 90A2 and 90B2 on the opening 80 side. Therefore, the noise component supplied from the negative electrode terminal 40N of the brush 40 is conducted to the ground line 54 via the region 90C2 sandwiched between the groove portions 90A2 and 90B2.

FIG. 6 is a cross-sectional view taken along the line AA of FIGS. 4 (B) and 5 (B). As shown in FIG. 6, the partition wall 50 is thin in the portion of the partition wall 50 provided with the groove portions 90A1, 90A2, 90B1 and 90B2, and the electrical resistance of the portion is other than the regions 90C1, 90C2 and the partition wall 50. It becomes larger than the part of, and the conductivity decreases. As a result, the noise component supplied from the negative electrode terminal 40N of the brush 40 preferentially flows through the regions 90C1 and 90C2 having higher conductivity than the groove portions 90A1, 90A2, 90B1 and 90B2 which are adjacent portions, and the regions 90C1 and 90C2. It is possible to suppress diffusion to other parts of the housing 32 other than the above.

Therefore, according to the present embodiment, it is possible to provide a wiper motor that can effectively block the noise component generated by the rotation of the wiper motor and can easily implement a configuration that blocks the noise component.

[Second Embodiment]
Subsequently, a second embodiment of the present invention will be described. In the present embodiment, the same configurations as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

FIG. 7 is a schematic view showing an example of the housing 32 according to the first example of the present embodiment. The present embodiment is different from the first embodiment in that the partition wall 50 between the second connection terminal mounting portion 52CA and the opening 80 has a linear ridge portion 92 protruding like a ridge. ..

The linear ridge 92 can connect the second connection terminal mounting portion 52CA and the portion to which the end portion 54A of the grounding line 54 is connected at the shortest distance, so that the noise component can be diffused to other portions of the partition wall 50. Although it can be suppressed more effectively, it is necessary to dispose of the wiper motor 10 so as not to interfere with the rotation shaft opening 82 through which the rotation shaft penetrates.

FIG. 8A is a first modification of the first example of the present embodiment, in which the ridge portion 92A has a constant height from the base portion of the second connection terminal mounting portion 52CA toward the opening 80 of the partition wall 50. It is stretched. FIG. 8B is a second modification of the first example of the present embodiment, in which the height of the ridge 92B is increased from the base of the second connection terminal mounting portion 52CA toward the opening 80 of the partition wall 50. The ridge 92B is stretched so as to form a gradual lower slope.

9 (A) is a cross-sectional view taken along the line BB of FIG. 8 (A), and FIG. 9 (B) is a cut along the line CC of FIG. 8 (B). It is a cross-sectional view in the case of. As shown in FIG. 9A, in the first modification of the first example of the present embodiment, the ridge portion 92A protrudes from the partition wall 50 at a constant height. Further, in the second modification of the first example of the present embodiment, the ridge portion 92B is extended in a slope shape from the base portion of the second connection terminal mounting portion 52CA toward the opening 80 of the partition wall 50. The weight of the product can be suppressed by suppressing the height by forming a slope like the ridge 92B.

FIG. 10 is a second example of the present embodiment. Unlike the linear ridges 92 in FIG. 7, the ridges 94 shown in FIG. 10 have a substantially arcuate curve, so that interference with the rotation shaft opening 82 can be avoided.

FIG. 11A is a first modification of the second example of the present embodiment, in which the ridge portion 94A has a constant height from the base portion of the second connection terminal mounting portion 52CA toward the opening 80 of the partition wall 50. It is stretched. FIG. 11B is a second modification of the second example of the present embodiment, in which the height of the ridge portion 94B is increased from the base portion of the second connection terminal mounting portion 52CA toward the opening portion 80 of the partition wall 50. The ridge 94B is stretched so as to form a gradual lower slope.

In the first example and the second example, the ridges 92A, 92B, 94A, 94B are thicker than the other parts of the partition wall 50, so that the electric resistance is lower than the other parts of the partition wall 50. The conductivity increases. As a result, the noise component supplied from the negative electrode terminal 40N of the brush 40 preferentially flows through the ridges 92A, 92B, 94A, 94B having higher conductivity than the adjacent portions, and the ridges 92A, 92B, 94A, 94B. It is possible to suppress diffusion to other parts of the housing 32 other than the above.

As a result, according to the present embodiment, it is possible to provide a wiper motor which can effectively block the noise component generated by the rotation of the wiper motor and can easily implement a configuration for blocking the noise component.

[Third Embodiment]
Subsequently, a third embodiment of the present invention will be described. In the present embodiment, the same configurations as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

FIG. 12 is a schematic view showing an example of the housing 32 according to the present embodiment. In the present embodiment, the partition wall 50 between the second connection terminal mounting portion 52CA and the opening 80 has a ridge portion 96 protruding like a ridge and grooves 98A and 98B parallel to the ridge portion 96, respectively. , Different from the modification of the first embodiment. As shown in FIG. 12, the ridges 96 and the grooves 98A and 98B are substantially arcuate, but may be linear.

13 (A) is a cross-sectional view when cut along the DD line of FIG. 12 (A), and FIG. 13 (B) is a cut along the FF line of FIG. 12 (B). It is a cross-sectional view in the case of. As shown in FIG. 13A, in the present embodiment, the ridge portion 96 protrudes from the plane of the partition wall 50 from a position one step lower than the partition wall 50 by the groove portions 98A and 98B. Further, as shown in FIG. 13B, the ridge portion 96 is extended in a slope shape from the base portion of the second connection terminal mounting portion 52CA toward the opening portion 80 of the partition wall 50. The ridge portion 96 may extend from the base portion of the second connection terminal mounting portion 52CA toward the opening portion 80 of the partition wall 50 at a constant height.

The partition wall 50 is thin in the portion of the partition wall 50 provided with the grooves 98A and 98B, and the electric resistance of the portion is larger than that of the partition wall 50 not provided with the grooves 98A and 98B. Further, since the ridge 96 is thicker than the other parts of the partition wall 50, the electric resistance is lower than that of the part of the partition wall 50 provided with the adjacent groove portions 98A and 98B and the other parts of the partition wall 50. , The conductivity becomes large. As a result, the noise component supplied from the negative electrode terminal 40N of the brush 40 can be prevented from flowing preferentially through the ridge 96 and diffusing to other parts of the housing 32 other than the ridge 96.

As a result, according to the present embodiment, it is possible to provide a wiper motor which can effectively block the noise component generated by the rotation of the wiper motor and can easily implement a configuration for blocking the noise component.

10 ... Wiper motor, 20 ... Motor unit, 22 ... York, 30 ... Deceleration unit, 32 ... Housing, 34 ... Housing cover, 36 ... Connector, 36H ... High terminal, 36L ... Low terminal, 36N ... Ground terminal, 38H, 38L ... Choke coil, 40 ... brush, 40H, 40L ... positive terminal, 40N ... negative terminal, 42 ... commutator, 46,48 ... condenser, 50 ... partition, 52A ... first connection terminal, 52B ... breaker, 52C ... second connection Terminal, 52CA ... Connection terminal mounting part, 54 ... Grounding line, 54A ... End, 56 ... High voltage line, 58 ... Low voltage line, 60 ... Broken line, 68 ... Fixing bolt, 74 ... Worm wheel, 76 ... Insulation member, 78 ... Output shaft, 80 ... Opening, 82 ... Rotating shaft opening, 90A1, 90B1, 90A2, 90B2 ... Groove, 90C1, 90C2 ... Region, 92, 92A, 92B, 94, 94A, 94B, 96 ... Ridge , 98A, 98B ... Groove

Claims (10)

A conductive partition wall that covers the opening of the yoke containing the commutator, the rotor, and the brush that supplies power to the rotor, and is connected to the negative electrode terminal of the brush and the grounding region.
Conductivity having higher conductivity than the adjacent portion arranged in the partition wall between the negative electrode terminal connection portion to which the negative electrode terminal is connected to the partition wall and the ground contact area connection portion to which the ground contact region is connected to the partition wall. Department and
Wiper motor including. The conductive portion is a region sandwiched between two grooves parallel to each other between the negative electrode terminal connection portion and the grounding region connection portion, and the partition wall is thinned in each of the two groove portions. The wiper motor according to claim 1, wherein the conductivity of the two grooves is lower than that of other portions of the partition wall, and the conductivity of the region is made larger than that of the two grooves adjacent to the region. The wiper motor according to claim 2, wherein each of the two grooves is linear. The wiper motor according to claim 2, wherein each of the two groove portions has a substantially arc shape. The conductive portion is a ridge portion that protrudes from the other portion of the partition wall between the negative electrode terminal connection portion and the grounding region connection portion. The wiper motor according to claim 1, wherein the conductivity of the ridge portion is made larger than that of the portion adjacent to the ridge portion. By including two grooves adjacent to and parallel to the ridges and thinning the partition wall in each of the two grooves, the conductivity of the two grooves is made lower than that of the ridges. The wiper motor according to claim 5. The wiper motor according to claim 5 or 6, wherein the ridge is linear. The wiper motor according to claim 5 or 6, wherein the ridge portion has a substantially arc shape. The wiper motor according to claim 5 or 6, wherein the ridge portion projects from the negative electrode terminal connection portion and the grounding region connection portion at a constant height with respect to another portion of the partition wall. The wiper motor according to claim 5 or 6, wherein the height of the ridge portion decreases from the negative electrode terminal connection portion toward the grounding region connection portion.

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