JP5990899B2 - Terminal connection structure of electric motor, electric motor with brush and electric power steering device - Google Patents

Description

  The present invention relates to a terminal connection structure of an electric motor for electrically connecting a terminal of a motor with a brush (brush motor) and a terminal of a device, an electric motor with a brush, and an electric power steering device.

  As disclosed in Patent Document 1, a brush motor is a device in which a brush is brought into contact with a commutator to energize a coil, and the rotor is rotated by electromagnetic force. In such a brush motor, when vibration occurs when the rotor rotates, the vibration is applied to the commutator, the brush, the brush holder unit, and a member (particularly a flange) that is an outer shell of the brush motor. It is transmitted in order. Accordingly, in such a brush motor, when vibration occurs when the rotor rotates, an operation sound is generated due to the vibration. As a technique for reducing this vibration and operating noise, there is a structure in which the brush holder unit is floated. This structure is a structure in which an elastic member is interposed between a member serving as an outer shell of the brush motor and the brush holder unit. Hereinafter, this structure is referred to as a floating structure.

JP 2003-070211 A Utility Model Registration No. 3154393

  Some types of brush motors include a bus bar as in the technique disclosed in Patent Document 2, for example. The bus bar is a member for supplying electric power to the brush from the outside of the brush motor. Since the bus bar that supplies electric power is electrically connected to the brush, there is a risk that stress is applied to the brush holder unit depending on the state in which the bus bar is attached. The stress on the brush holder unit may cause minute deformation on the brush holder unit. The brush may vibrate due to minute deformation of the brush holder unit. For this reason, there is a possibility that the operation noise and vibration may occur in the brush motor.

  The present invention has been made in view of the above, and provides an electric terminal connection structure, an electric motor with a brush, and an electric power steering device that suppress deformation of the brush holder and reduce operating noise generated in the electric motor with the brush. For the purpose.

  In order to solve the above-described problems and achieve the object, the terminal connection structure of the motor is a structure that electrically connects a motor-side terminal included in the brushed motor and a device-side terminal included in the device, and the motor An elastic member interposed between a side terminal and the device side terminal; and the elastic member supported by the elastic member and extending from a surface of the elastic member near the motor side terminal to a surface of the elastic member near the device side terminal. An elastic member penetrating portion that penetrates, an elastic member surface extending portion that extends along a surface different from the extending direction of the elastic member penetrating portion and near the motor side terminal of the elastic member, and the elastic member surface extension A bus bar that extends in a direction different from the extending direction of the existing portion and that is connected to the device-side terminal, and that supplies power to the brush. To do.

  With this configuration, the elastic member surface extending portion and the device-side terminal direction extending portion can change the direction of displacement of the device-side terminal direction extending portion. For this reason, when the displacement shift of the apparatus side terminal direction extension part arises by attachment of an apparatus, the elastic member surface extension part can absorb the displacement shift of the apparatus side terminal direction extension part as bending. The bus bar can reduce the influence of the displacement deviation of the device side terminal direction extending portion on the displacement of the elastic member penetrating portion. As a result, the terminal connection structure of the electric motor can suppress the deformation of the brush holder due to the mounting accuracy of the device. And the terminal connection structure of an electric motor can reduce brush noise.

  Further, with the above configuration, in the terminal connection structure of the electric motor, the elastic member penetrating portion is inserted into the through hole of the elastic member and penetrates the elastic member. The elastic member can be supported by sandwiching and pressing the elastic member through portion by elasticity. For this reason, when the displacement shift of the apparatus side terminal direction extension part arises, the elastic member penetration part can absorb the shift of the apparatus side terminal direction extension part as bending. As a result, the terminal connection structure of the electric motor can suppress the deformation of the brush holder due to the mounting accuracy of the device. And the terminal connection structure of an electric motor can reduce brush noise.

  As a desirable aspect of the present invention, the elastic member penetrating portion and the device-side terminal direction extending portion extend in a direction approaching the device-side terminal from the motor-side terminal, and the extending plane is different. The elastic member penetrating portion is located at a position where the elastic member penetrating portion is electrically connected to the electric motor side terminal, and the elastic member penetrating portion is exposed on the surface of the elastic member near the device side terminal. A distance between the electric side electrical connection part and the bent part is a straight line from the bent part to the equipment side electrical connection part where the equipment side terminal direction extending part is electrically connected to the equipment side terminal. It is preferable that the distance is equal to or less than the distance.

  With the above configuration, in the terminal connection structure of the motor, when the mounting accuracy of the device side terminal varies, the bent portion serves as a fulcrum, and the positional displacement of the motor side electrical connection portion can be reduced.

  As a desirable aspect of the present invention, it is preferable to include a bus bar position regulating structure in the elastic member that regulates the position of the elastic member penetrating portion in the elastic elastic member.

  With the above configuration, it is possible to suppress the elastic member penetrating portion from coming out of the elastic member, and to improve the positional accuracy of the bent portion that is the displacement fulcrum. As a result, it is possible to further suppress the deformation of the brush holder due to the mounting accuracy of the device. For this reason, the terminal connection structure of the electric motor can reduce brush noise.

  As a desirable mode of the present invention, it is preferable to further include a pressing portion that protrudes from the surface of the elastic member closer to the device side terminal and presses the elastic member surface extending portion.

  With the above configuration, it is possible to reduce the risk of damage due to the vibration of the bus bar.

  As a desirable aspect of the present invention, it is preferable to include an elastic member position restricting structure for restricting a relative position of the elastic member with respect to the electric motor side terminal.

  With the above configuration, the relative position of the elastic member with respect to the electric motor side terminal is restricted. Thereby, the terminal connection structure of the electric motor can reduce the stress applied to the brush holder unit due to the displacement of the elastic member.

  As a desirable mode of the present invention, it is preferable that the bus bar is electrically connected to the electric motor side terminal via an electric conductive member having flexibility, and the electric motor side electric connecting portion is spot welded.

  With the above structure, since it has flexibility, transmission of vibration can be reduced. As a result, the terminal connection structure of the electric motor can reduce the stress applied to the brush holder unit due to the displacement of the elastic member. In addition, since the electric connection on the motor side is spot welded, the effect of rotation (for example, misalignment) associated with fastening is suppressed and stress applied to the brush holder unit is reduced compared to fastening with screws. can do. Moreover, since the electric side electrical connection part is spot welded, the influence of the heat transmitted to the elastic member can be suppressed.

  As a desirable aspect of the present invention, it is preferable that the device-side electrical connection portion has a fastening structure of the device-side terminal and the device-side terminal direction extending portion, and includes a rotation prevention mechanism.

  With the above configuration, it is possible to reduce the influence of the rotational force accompanying the fastening that occurs at the device-side electrical connection portion. For this reason, a deformation | transformation of a bus-bar can be suppressed. As a result, the deformation of the brush holder can be further suppressed. For this reason, the terminal connection structure of the electric motor can reduce brush noise.

  As a desirable mode of the present invention, it is preferable that the motor with a brush is connected to the motor side terminal connected to the brush by the terminal connection structure of the motor.

  With the above configuration, the brushed electric motor can reduce deformation of the brush holder unit. For this reason, the possibility that the brush vibrates due to minute deformation of the brush holder unit can be reduced. As a result, the brushed electric motor can reduce operating noise or vibration.

  As a desirable mode of the present invention, an electric power steering device includes the brushed electric motor that applies an auxiliary steering force to a steering mechanism of a vehicle, and calculates a steering assist command calculated using at least a steering torque and a vehicle speed for the steering mechanism. The brushed electric motor is drive-controlled based on the value.

  With the above configuration, the electric power steering apparatus can reduce deformation of the brush holder unit included in the electric motor with brush. And an electric motor with a brush can reduce an operation sound and vibration. For this reason, the electric power steering apparatus can suppress resonating with other members such as a speed reducer due to the operation sound or vibration of the brushed electric motor. As a result, the steering person can steer the electric power steering apparatus without a sense of incongruity.

  The present invention can suppress the deformation of the brush holder and reduce the operating noise generated in the brushed electric motor.

FIG. 1 is a configuration diagram of an electric power steering apparatus including a brush motor. FIG. 2 is a top view illustrating an electric motor included in the electric power steering apparatus. FIG. 3 is an explanatory view for explaining a connection structure of an electric motor included in the electric power steering apparatus. FIG. 4 is an explanatory diagram schematically showing the brush motor cut on a plane orthogonal to the rotation axis. 5 is a cross-sectional view taken along the line AA in FIG. FIG. 6 is an explanatory view schematically showing a brush and a brush holder unit. FIG. 7 is an explanatory view schematically showing a brush case attached to a substrate. FIG. 8 is an explanatory diagram schematically showing the bus bar unit as viewed along the rotation axis direction. FIG. 9 is an explanatory diagram schematically showing the bus bar unit as seen along the circumferential direction. FIG. 10 is an explanatory diagram illustrating a configuration of the bus bar unit according to the first embodiment. FIG. 11 is an explanatory diagram for explaining the attachment of the bus bar unit. FIG. 12 is an explanatory view showing an exploded configuration of the bus bar unit. FIG. 13 is an explanatory diagram for explaining the connection with the device-side terminal of the bus bar unit. FIG. 14 is a schematic diagram for explaining a mounted state of the bus bar. FIG. 15 is an explanatory diagram for explaining the displacement of the bus bar of the bus bar unit. FIG. 16 is an explanatory diagram illustrating a configuration of a bus bar unit according to the second embodiment. FIG. 17 is an explanatory diagram illustrating a configuration of a bus bar unit according to the third embodiment. FIG. 18 is an explanatory diagram illustrating a configuration of a bus bar unit according to the third embodiment. FIG. 19 is an explanatory diagram for explaining the displacement of the bus bar of the bus bar unit.

  Hereinafter, the present invention will be described in detail with reference to the drawings. It should be noted that the present invention is not limited by the modes for carrying out the invention (hereinafter referred to as embodiments). In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art and those that are substantially the same.

  In the present embodiment, an example in which the brush motor according to the present invention is applied to an electric power steering device (EPS) will be described, but the application target of the present invention is not limited to the electric power steering device. Even when the present invention is applied to an electric power steering apparatus, the method is not limited.

(Embodiment 1)
FIG. 1 is a configuration diagram of an electric power steering apparatus including a brush motor. First, an outline of an electric power steering apparatus including the brush motor of the present embodiment will be described with reference to FIG. The electric power steering device 80 includes a steering wheel 81, a steering shaft 82, a steering force assist mechanism 83, a universal joint 84, a lower shaft 85, a universal joint 86, in the order in which the force applied from the steering wheel is transmitted. A pinion shaft 87, a steering gear 88, and a tie rod 89 are provided. The electric power steering device 80 includes an ECU (Electronic Control Unit) 90 and a torque sensor 91a. The vehicle speed sensor 91b is provided in the vehicle and inputs a vehicle speed signal V to the ECU 90 by CAN (Controller Area Network) communication.

  The steering shaft 82 includes an input shaft 82a and an output shaft 82b. The input shaft 82a has one end connected to the steering wheel 81 and the other end connected to the steering force assist mechanism 83 via the torque sensor 91a. The output shaft 82 b has one end connected to the steering force assist mechanism 83 and the other end connected to the universal joint 84. In the present embodiment, the input shaft 82a and the output shaft 82b are made of a magnetic material such as iron.

  The lower shaft 85 has one end connected to the universal joint 84 and the other end connected to the universal joint 86. The pinion shaft 87 has one end connected to the universal joint 86 and the other end connected to the steering gear 88. Steering gear 88 includes a pinion 88a and a rack 88b. The pinion 88a is connected to the pinion shaft 87. The rack 88b meshes with the pinion 88a. The steering gear 88 is configured as a rack and pinion type. The steering gear 88 converts the rotational motion transmitted to the pinion 88a into a linear motion by the rack 88b. The tie rod 89 is connected to the rack 88b.

  The steering force assist mechanism 83 includes a speed reducer 92 and the brush motor 10. The reduction gear 92 is connected to the output shaft 82b. The brush motor 10 is connected to the speed reducer 92 and generates auxiliary steering torque. In the electric power steering device 80, a steering column is constituted by the steering shaft 82, the torque sensor 91a, and the speed reducer 92. The brush motor 10 gives auxiliary steering torque to the output shaft 82b of the steering column. That is, the electric power steering apparatus 80 of this embodiment is a column assist system.

  FIG. 2 is a top view illustrating an electric motor included in the electric power steering apparatus. The speed reducer 92 is, for example, a worm speed reducer. The rotational force of the brush motor 10 is transmitted to the worm wheel via the worm inside the speed reducer 92 and rotates the worm wheel. The reduction gear 92 increases the torque of the brush motor 10 by the worm and the worm wheel. Then, the reduction gear 92 rotates the output shaft 92A, and gives auxiliary steering torque to the output shaft 82b of the steering column shown in FIG.

  The torque sensor 91a shown in FIG. 1 detects the driver's steering force transmitted to the input shaft 82a via the steering wheel 81 as a steering torque. The vehicle speed sensor 91b detects the traveling speed (vehicle speed) of the vehicle on which the electric power steering device 80 is mounted. The ECU 90 is electrically connected to the brush motor 10, the torque sensor 91a, and the vehicle speed sensor 91b. The ECU 90 controls the operation of the brush motor 10.

  Moreover, ECU90 acquires a signal from each of the torque sensor 91a and the vehicle speed sensor 91b. That is, the ECU 90 acquires the steering torque T from the torque sensor 91a, and acquires the vehicle speed signal V of the vehicle from the vehicle speed sensor 91b. The ECU 90 is supplied with electric power from a power supply device (for example, a vehicle-mounted battery) 99 with the ignition switch 98 turned on. The ECU 90 calculates an assist steering command value of the assist command based on the steering torque T and the vehicle speed signal V. The ECU 90 adjusts the current value supplied to the brush motor 10 via the bus bar unit 30 based on the calculated auxiliary steering command value.

  The steering force of the driver (driver) input to the steering wheel 81 is transmitted to the speed reduction device 92 of the steering force assist mechanism 83 via the input shaft 82a. At this time, the ECU 90 acquires the steering torque T input to the input shaft 82a from the torque sensor 91a, and acquires the vehicle speed signal V from the vehicle speed sensor 91b. The ECU 90 controls the operation of the brush motor 10. The auxiliary steering torque created by the brush motor 10 is transmitted to the reduction gear 92.

  The steering torque (including auxiliary steering torque) output via the output shaft 82 b is transmitted to the lower shaft 85 via the universal joint 84 and further transmitted to the pinion shaft 87 via the universal joint 86. The steering force transmitted to the pinion shaft 87 is transmitted to the tie rod 89 via the steering gear 88 to steer the steered wheels.

  FIG. 3 is an explanatory view for explaining a connection structure of an electric motor included in the electric power steering apparatus. 3 is a side view of the brush motor 10 viewed from the direction of the rotation axis in FIG. The ECU 90 is directly attached to the speed reducer 92 so that the heat generated by the ECU 90 can be dissipated by the speed reducer 92.

  The brush motor 10 and the ECU 90 are fixed via a speed reducer 92. The bus bar unit 30 is an electric motor connection structure according to the present embodiment, and electrically connects an electric motor side terminal of the brush motor 10 that is an electric motor with a brush and an equipment side terminal of the ECU 90 that is an equipment. is there. Next, the brush motor 10 will be described.

  FIG. 4 is an explanatory diagram schematically showing the brush motor cut on a plane orthogonal to the rotation axis. 5 is a cross-sectional view taken along the line AA in FIG. As shown in FIG. 5, the brush motor 10 includes a housing 11, a magnet 13, a rotor 14, a shaft 18, a brush 19, a brush holder unit 20, and a bus bar unit 30.

  The housing 11 includes a cylindrical portion 11a, a bottom portion 11b, and a flange 12. The cylindrical portion 11a is made of a magnetic material and has a substantially cylindrical shape. The magnetic material forming the cylindrical portion 11a is, for example, a general steel material such as SPCC (Steel Plate Cold Commercial) or electromagnetic soft iron. One end of the cylindrical portion 11a is closed by the bottom portion 11b. The bottom part 11b is formed integrally with the cylindrical part 11a, for example. Further, the opening which is the other end (the side opposite to the bottom 11 b) of the cylindrical portion 11 a is closed by the flange 12.

  The magnet 13 is attached to the inner surface of the cylindrical portion 11a by a magnet holder 13a. Two magnets 13 are provided. The two magnets 13 are provided with opposite polarities. The magnet 13 is covered with a magnet scattering prevention cover 13b. Thereby, the magnet scattering prevention cover 13b prevents the two magnets 13 from being accidentally scattered. The rotor 14 is provided in the cylindrical portion 11a. The rotor 14 is centered by a shaft 18 and is fixed to the shaft 18.

  Rotor 14 includes a commutator 15, a core 16, and a coil 17. In the commutator 15, a plurality of conductive portions 15 a formed of a conductor are arranged in parallel at equal intervals on the side surface of a cylindrical insulating portion formed of an insulator. The core 16 is formed using a magnetic material. The core 16 is formed by, for example, using a silicon steel plate as a magnetic material and laminating silicon steel plates. The core 16 portion of the rotor 14 has a plurality of slots (grooves). The coil 17 is wound around the slot. One end of the coil 17 is connected to one conductive portion 15a, and the other end is connected to another conductive portion 15a.

  The shaft 18 is supported by the bearing 18a and the bearing 18b so as to be able to rotate around the rotation axis Zr. The bearing 18 a is provided inside the cylindrical portion 11 a and at a substantially central portion of the flange 12. The bearing 18b is provided inside the cylindrical portion 11a and at a substantially central portion of the bottom portion 11b.

  The rotation axis Zr corresponds to the central axis of the shaft 18 and coincides with the rotation axis of the rotor 14. The shaft 18 is attached with a joint 18c. The joint 18c is splined to the worm of the speed reducer 92 shown in FIG. The shaft 18 and the worm may be coupled by an elastic coupling.

  The brush 19 is supported by a brush holder unit 20 described later. A plurality of brushes 19 are provided at positions facing the commutator 15 in the radial direction of the commutator 15 in the cylindrical portion 11a. The brush 19 is a polyhedron having a substantially prismatic shape, preferably a quadrangular prism shape. More preferably, the brush 19 has a shape in which one of the two apexes on the core 16 side protrudes out of the four apexes included on the surface facing the commutator 15 instead of the flange 12 side. The brush 19 is in contact with the commutator 15 at the protruding vertex. With such a structure, the brush motor 10 has a clear position where the brush 19 and the commutator 15 come into contact. As a result, the supply of electric power from the brush 19 to the commutator 15 is stabilized in the brush motor 10. Further, the user of the brush motor 10 can easily predict the wear state of the brush 19.

  The brush 19 is made of a material that has a small contact resistance and can withstand a mechanical shock. For example, the brush 19 is made of graphite. The brush 19 is supplied with power by the bus bar unit 30. The bus bar unit 30 will be described later. The electric power is electric power having a current value controlled by the ECU 90. The current supplied to the brush 19 is guided to the coil 17 through the conductive portion 15 a of the commutator 15 that is in contact with the brush 19.

  The current guided to the coil 17 passes through the coil 17, reaches another conductive portion 15 a of the commutator 15, and flows into another brush 19. The brush motor 10 generates a magnetic field when a current flows through the coil 17. In the brush motor 10, the rotor 14 is rotated by the interaction between this magnetic field and the magnetic field of the magnet 13.

  FIG. 6 is an explanatory view schematically showing a brush and a brush holder unit. As shown in FIG. 5, the brush holder unit 20 includes a brush case 21, a spring 22, a substrate 23, and a bottom elastic member 24. The brush case 21 includes five plate-like portions, and is formed into a box shape having an opening 21f by the five plate-like portions. In FIG. 6, three of the five plate-like portions are shown. The remaining two plate-like portions are portions orthogonal to the three plate-like portions shown in FIG. 6, and are portions parallel to the paper surface in FIG.

  The brush case 21 is provided so that the opening 21 f faces the commutator 15 in the radial direction of the commutator 15. The brush case 21 is formed larger than the brush 19. This is because the brush 19 thermally expands in the brush case 21 when the temperature of the brush 19 rises. That is, the brush case 21 holds the brush 19 with a gap between itself (the brush case 21) and the brush 19.

  The spring 22 is a compression stress spring. The spring 22 is provided inside the brush case 21 and between the brush 19 and the brush case 21. The spring 22 is provided between the bottom surface portion of the five plate-like portions of the brush case 21 and the brush 19. The bottom surface portion is a plate-shaped portion on the side opposite to the opening 21 f among the five plate-shaped portions of the brush case 21.

  One end of the spring 22 is in contact with the bottom surface portion of the brush case 21, and the other end is in contact with the brush 19. As a result, the spring 22 applies a force in the direction toward the commutator 15 to the brush 19. Therefore, at least a part of the brush 19 protrudes from the opening 21 f and is pressed against the commutator 15 by the spring 22.

  FIG. 7 is an explanatory view schematically showing a brush case attached to a substrate. The substrate 23 is a member for attaching the brush case 21 to the flange 12. As shown in FIG. 5, the substrate 23 is provided between the brush case 21 and the flange 12. For example, two substrates 23 are provided as indicated by the hatched lines in FIG.

  The substrate 23 has, for example, a shape obtained by dividing an annular plate-shaped member into two. In this embodiment, one board | substrate 23 has the two brush cases 21 shown in FIG. Each substrate 23 includes a bolt through hole 23a. The bolt through hole 23 a is formed at a position facing the bolt hole 12 a formed in the flange 12. The bolt hole 12 a is a female screw hole for fastening the brush holder unit 20 to the flange 12. A bolt B as a fastening means shown in FIG. 5 is screwed into the bolt hole 12a. For example, two bolt holes 12a are provided. The board 23 is fastened to the flange 12 by the bolt B being inserted into the bolt through hole 23a and screwed into the bolt hole 12a.

  As shown in FIG. 7, the flange 12 includes a bus bar unit mounting recess 12b. The housing 33 of the bus bar unit 30 shown in FIG. 5 is fitted into the bus bar unit mounting recess 12b. Thereby, the housing 33 is interposed between the flange 12 and the cylindrical portion 11a. The housing 33 is an elastic member having elasticity. Next, the bus bar unit 30 will be described.

  FIG. 8 is an explanatory diagram schematically showing the bus bar unit as viewed along the rotation axis direction. FIG. 9 is an explanatory diagram schematically showing the bus bar unit as seen along the circumferential direction. 9 shows, for example, the CC cross section of FIG. As shown in FIGS. 8 and 9, the substrate 23 of the brush motor 10 includes a plurality of electric motor side terminals 23 </ b> A and 23 </ b> B. The plurality of electric motor side terminals 23 </ b> A and 23 </ b> B are electrode terminals for supplying electric power to the brush 19.

  The bus bar unit 30 includes a first bus bar 31, a second bus bar 32, a housing 33 as a bus bar holding means, and a pigtail 35. The first bus bar 31 and the second bus bar 32 are metal plate-like members. The first bus bar 31 and the second bus bar 32 are electrically conductive members.

  As shown in FIG. 8, the first bus bar 31 and the second bus bar 32 are provided at intervals so as not to contact each other. A part of the first bus bar 31 and the second bus bar 32 is exposed to the outside of the housing 11. The space surrounded by the cylindrical portion 11a, the bottom portion 11b, and the flange 12 described above is the inside of the housing 11, and the space other than the inside is the outside of the housing 11.

  The housing 33 is an elastic member, and is formed of, for example, a rubber material and has elasticity. The rubber material is preferably ethylene propylene rubber or a thermoplastic elastomer. The housing 33 is more preferably insulating.

  As shown in FIG. 9, the first bus bar 31 and the second bus bar 32 penetrate the housing 33. The housing 33 can cover the first bus bar 31 and the second bus bar 32. Thereby, the housing 33 insulates the first bus bar 31 and the second bus bar 32. The housing 33 insulates the first bus bar 31 and the second bus bar 32 from the cylindrical portion 11a and the flange 12 when the bus bar unit 30 is attached to the brush motor 10.

  The pigtail 35 is an electrically conductive member. The pigtail 35 electrically connects the first bus bar 31 and the second bus bar 32 to the motor-side terminals 23A and 23B on the substrate 23. The substrate 23 is provided with an electric circuit including motor side terminals 23 </ b> A and 23 </ b> B for supplying electric power to the brush 19. The electric circuit is electrically connected to the brush 19 by a wiring member 35a of an electric conductive member shown in FIG. Thereby, the brush 19 is supplied with electric power from the first bus bar 31 and the second bus bar 32 via the pigtail 35 and the substrate 23. The first bus bar 31 and the second bus bar 32 may be directly electrically connected to the brush 19 by the pigtail 35 without passing through an electric circuit formed on the substrate 23.

  The pigtail 35 is electrically connected to both the first bus bar 31 and the second bus bar 32 by, for example, welding, more specifically, spot welding or projection welding, and the electric side electrical connection portion 35B is formed. Further, the pigtail 35 is electrically connected to an electric circuit formed on the substrate 23 by, for example, welding, more specifically, spot welding or projection welding, so that the motor side electric connecting portion 35A is formed.

  In the electric motor side electric connection part 35B, the 1st bus bar 31, the 2nd bus bar 32, and the pigtail 35 are electrically connected by spot welding. This structure can suppress the influence (for example, position shift) of the rotation accompanying fastening, and can reduce the stress added to the brush holder unit 20 compared with the case of fastening like screwing. Moreover, since the electric side electrical connection part 35 </ b> B is spot-welded, heat generation during welding transmitted to the housing 33 can be suppressed. Thereby, the influence of the heat to the housing 33 can be reduced. Spot welding is a type of resistance welding in which metal plates are stacked, the stacked metal plates are sandwiched from above and below by electrodes, and energized and welded in a pressurized state. Spot welding is a technique capable of manufacturing the bus bar unit 30 at low cost because it can be welded in a short time.

  The pigtail 35 has flexibility. Since it has flexibility, the pigtail 35 is difficult to transmit vibration. Therefore, the brush motor 10 is unlikely to transmit the vibration of the brush 19 to the bus bar unit 30 via the substrate 23. Moreover, since the pigtail 35 bends, the brush motor 10 is likely to allow an attachment error between the bus bar unit 30 and the flange 12. Further, since the pigtail 35 bends in the brush motor 10, the bus bar unit 30 can be easily attached by the flange 12.

  Thus, since the pigtail 35 bends, the freedom degree of arrangement of the brush holder unit 20 and the bus bar unit 30 is improved in the brush motor 10. Further, the pigtail 35 can reduce the stress applied to the brush holder unit 20 by the displacement of the electric side electrical connection portion 35 </ b> A of the bus bar unit 30. The pigtail 35 may be a flexible substrate or a spring-like conductor. Next, a more preferable arrangement of the brush holder unit 20 and the bus bar unit 30 will be described.

  FIG. 10 is an explanatory diagram illustrating a configuration of the bus bar unit according to the first embodiment. FIG. 11 is an explanatory diagram for explaining the attachment of the bus bar unit. FIG. 12 is an explanatory view showing an exploded configuration of the bus bar unit. The housing 33 protrudes into a side surface 33S between the surface 33O near the device side terminal, the surface 33I near the motor side terminal, the surface 33O near the device side terminal, and the surface 33I near the motor side terminal by molding with a mold. And the formed positioning projection 33T. As shown in FIG. 11, the flange 12 is formed along the shape of the side surface of the housing 33, and the flange 12 includes a bus bar unit mounting recess 12 b.

  By fitting the positioning convex portion 33T and the bus bar unit mounting concave portion 12b, the relative position of the housing 33 of the bus bar unit 30 with respect to the substrate 23 of the brush holder unit 20 is regulated. The structure in which the positioning convex portion 33T and the bus bar unit mounting concave portion 12b are fitted is an elastic member position restricting structure that restricts the relative position of the housing 33 with respect to the electric motor side terminals 23A and 23B. The concave-convex relationship between the positioning convex portion 33T and the bus bar unit mounting concave portion 12b may be reversed. Since the relative position of the housing 33 with respect to the motor-side terminals 23A and 23B is restricted, the stress applied to the brush holder unit 20 due to the displacement of the housing 33 can be reduced.

  The housing 33 includes a through hole 33H penetrating between the surface 33O near the device side terminal and the surface 33I near the motor side terminal. As shown in FIGS. 10 and 12, the first bus bar 31 and the second bus bar 32 have the same shape, and the elastic member penetrating portion 36, the elastic member surface extending portion 37, and the device side terminal direction extending. And the existing portion 38.

  The first bus bar 31 and the second bus bar 32 are formed by bending a linear and plate-like conductive member twice at the bent portions 39A and 39B, and elastic member penetrating portions 36, elastic member surface extending portions 37, and device side terminals. A direction extending portion 38 is formed. The device side terminal direction extending portion 38 includes claw portions 31P and 32P, which are rotation prevention mechanisms, and a device side electrical connection portion 31H described later.

  The elastic member penetration portion 36 is inserted into the through hole 33 </ b> H in the direction of the arrow Q and penetrates the housing 33. The housing 33 presses the elastic member penetration part 36 by elasticity. Therefore, the housing 33 can support the first bus bar 31 and the second bus bar 32 easily and inexpensively.

  Moreover, in order to insert in the through-hole 33H, it is preferable that the extending direction of the elastic member penetration part 36 is linear. Thereby, when inserting the elastic member penetration part 36 in the through-hole 33H, since resistance between both can be reduced, the work load at this time can be reduced. In addition, since the extending direction of the elastic member penetration portion 36 is linear, the elastic member penetration portion 36 is easily affected by welding heat in the electric motor side electrical connection portion 35B. For this reason, in the electric side electrical connection part 35B, the first bus bar 31, the second bus bar 32 and the pigtail 35 are electrically connected by spot welding, thereby suppressing the heat generation during welding transmitted to the housing 33. preferable. The distance BA in the extending direction of the elastic member penetrating portion 36 may be longer than the distance between the surface 33O near the device side terminal and the surface 33I near the motor side terminal.

  The extending direction of the elastic member surface extending portion 37 is a direction along the surface 33O close to the device side terminal. The device-side terminal direction extending portion 38 extends from the surface 33 </ b> O close to the device-side terminal to the terminal of the ECU 90. FIG. 13 is an explanatory diagram for explaining the connection with the device-side terminal of the bus bar unit. FIG. 13 schematically shows the bus bar unit as seen in the circumferential direction, as in FIG. 9.

  As shown in FIG. 13, the device-side terminal 90A of the ECU 90 is overlapped with the device-side terminal direction extending portion 38, attached by fastening means E such as a screw, and electrically connected to the device-side electric connection portion 31H. It has become. The fastening means E generates a rotational force centered on the attachment center EX, and the rotational force is transmitted also to the device side terminal direction extending portion 38. For this reason, the stress transmitted from the apparatus side terminal direction extension part 38 to the apparatus side terminal direction extension part 38 changes with fastening states.

  Here, since the device side terminal direction extending portion 38 extends along the housing 33, even if a large stress is applied to the device side terminal direction extending portion 38, the elastic member penetrating portion 36 is caused by the buffering action of the housing 33. It becomes difficult to be transmitted. In order to increase the buffering action, it is preferable that the distance BB in the extending direction of the elastic member surface extending portion 37 shown in FIG. 12 is long.

  Moreover, the one where the distance BC of the extension direction of the apparatus side terminal direction extension part 38 is short reduces stress transmitted from the apparatus side terminal direction extension part 38 to the apparatus side terminal direction extension part 38 by a fastening state. be able to. That is, the distance BB in the extending direction of the elastic member surface extending portion 37 is more preferably longer than the distance BC in the extending direction of the device-side terminal direction extending portion 38.

  Further, the claw portions 31P and 32P serve as a rotation prevention mechanism that holds the side surface of the device-side terminal 90A of the ECU 90 and fixes the device-side terminal 90A and the device-side terminal direction extending portion 38 of the ECU 90 to be overlapped. It is possible to prevent positional deviation with respect to the rotational force. The housing 33 is an elastic member, and the rotational force by the fastening means E may cause the first bus bar 31 and the second bus bar 32 to twist and cause the first bus bar 31 and the second bus bar 32 to be deformed. For this reason, the claw portions 31P and 32P can reduce deformation of the first bus bar 31 and the second bus bar 32 by suppressing twisting of the first bus bar 31 and the second bus bar 32. As a result, the deformation of the brush holder unit 20 can be further suppressed. For this reason, the bus bar unit 30 can reduce brush noise.

  FIG. 14 is a schematic diagram for explaining a mounted state of the bus bar. FIG. 15 is an explanatory diagram for explaining the displacement of the bus bar of the bus bar unit. As shown in FIG. 14, when the mounting accuracy of the equipment side terminals of the ECU 90 varies, the bent portion 39A may serve as a fulcrum, and the position of the electric motor side electrical connection portion 35B may be displaced.

  Further, in the bus bar unit 30, the elastic member penetrating portion 36 and the device-side terminal direction extending portion 38 extend in a direction approaching the device-side terminal 90A from the motor-side terminals 23A and 23B, and an extending plane is provided. Different. Therefore, as shown in FIG. 13, the elastic member penetration portion 36 includes a motor-side electrical connection portion 35 </ b> B in which the elastic member penetration portion 36 is electrically connected to the motor-side terminals 23 </ b> A and 23 </ b> B, and an elastic member penetration portion 36 is a device of the housing 33. And a bent portion 39A of the first bus bar 31 or the second bus bar 32 at a position exposed at the surface 33O near the side terminal. The distance l between the motor-side electrical connection portion 35B and the bent portion 39A is from the 39A bent portion to the device-side electric connection portion 31H (32H) where the device-side terminal direction extending portion 38 is electrically connected to the device-side terminal 90A. The straight line distance L or less.

  As shown in FIG. 15, when the mounting accuracy of the equipment-side terminal 90A of the ECU 90 varies, it is assumed that the mounting center EX is displaced by Δm. In this case, the electric side electrical connection portion 35B is displaced by Δn with the bent portion 39A as a displacement fulcrum. The displacement angle θ at which the attachment center EX is displaced with respect to the displacement fulcrum is the same as the displacement angle at which the electric motor side electrical connection portion 35B is displaced with respect to the displacement fulcrum. For this reason, when the distance l is set to be equal to or less than the distance L, the influence of the displacement Δn can be suppressed. Further, when the distance l is made smaller than the distance L, the influence of the displacement Δn can be further suppressed.

  As described above, it is preferable that the distance l from the electric motor side electrical connection portion 35B to the bent portion 39A is not more than the distance L from the bent portion 39A to the device side electric connection portion 31H. With this configuration, the bus bar unit 30 can reduce the positional displacement of the electric side electrical connection portion 35B by using the bent portion 39A as a fulcrum when the mounting accuracy of the equipment side terminals of the ECU 90 varies.

  As described above, the brush motor 10 includes the flange 12, the commutator 15, the brush 19, the brush holder unit 20, and the bus bar unit 30. The brush 19 faces the commutator 15 in the radial direction, and is provided in contact with the commutator 15. The brush holder unit 20 is provided between the flange 12 via a bottom elastic member 24 and holds the brush 19. The bus bar unit 30 includes a first bus bar 31 and a second bus bar 32, and a housing 33. The brush motor 10 is electrically connected to the ECU 90 via the bus bar unit 30.

  The first bus bar 31 and the second bus bar 32 supply power to the brush 19. The first bus bar 31 and the second bus bar 32 have the same shape and include an elastic member penetrating portion 36, an elastic member surface extending portion 37, and a device side terminal direction extending portion 38.

  The housing 33 supports the first bus bar 31 and the second bus bar 32. The elastic member penetrating portions 36 of the first bus bar 31 and the second bus bar 32 penetrate the housing 33 from the surface 33I of the elastic member near the motor side terminal to the surface 33O of the elastic member near the device side terminal. The elastic member surface extending part 37 extends along a surface 33I in a direction different from the elastic member penetrating part 36 and near the motor side terminal of the elastic member. The device side terminal direction extending portion 38 extends in a direction different from the elastic member surface extending portion 37 and is connected to the device side terminal 90A.

  With the above configuration, the bus bar unit 30 that is the terminal connection structure of the brush motor 10 can suppress deformation of the brush holder unit 20 due to the mounting accuracy of the ECU 90. For this reason, the brush motor 10 can reduce brush noise.

  The elastic member surface extending portion 37 and the device side terminal direction extending portion 38 are substantially L-shaped, and when the displacement of the device side terminal direction extending portion 38 occurs due to the attachment of the ECU 90, the elastic member The surface extension part 37 can absorb the deviation of the device side terminal direction extension part 38 as a deflection. For this reason, the first bus bar 31 and the second bus bar 32 can reduce the displacement displacement of the device-side terminal direction extending portion 38 from affecting the displacement of the elastic member penetration portion 36.

  In the bus bar unit 30, the elastic member through portion 36 is inserted into the through hole 33 </ b> H and penetrates the housing 33. The housing 33 can be supported by sandwiching and pressing the elastic member through portion 36 by elasticity. For this reason, when the displacement deviation of the apparatus side terminal direction extension part 38 arises, the elastic member penetration part 36 can absorb the deviation of the apparatus side terminal direction extension part 38 as bending.

  The brush motor 10 which is an electric motor with a brush is provided in the housing 11, the rotor 14 including the commutator 15 and the core 16, and the housing 11. It includes a brush holder unit 20 provided to face in the radial direction, a brush 19 held by the brush holder unit 20 and provided in contact with the commutator 15, and the bus bar unit 30 for the brush motor 10 described above.

  With the above configuration, the brush motor 10 can reduce deformation of the brush holder unit 20. For this reason, the possibility that the brush 19 vibrates due to minute deformation of the brush holder unit 20 can be reduced. As a result, the brush motor 10 can reduce operating noise or vibration.

  The electric power steering apparatus 80 according to the present embodiment includes a brush motor 10 that applies an auxiliary steering force to a steering mechanism of a vehicle, and a brush based on a steering auxiliary command value calculated using at least a steering torque and a vehicle speed for the steering mechanism. The motor 10 is driven and controlled.

  With the above configuration, the electric power steering device 80 can reduce deformation of the brush holder unit 20 included in the brush motor 10. The brush motor 10 can reduce operating noise and vibration. For this reason, the electric power steering device 80 can suppress resonating with other members such as the speed reducer 92 due to the operation sound or vibration of the brush motor 10. As a result, the steering person can steer the electric power steering device 80 without feeling uncomfortable.

(Embodiment 2)
FIG. 16 is an explanatory diagram illustrating a configuration of a bus bar unit according to the second embodiment. The housing 33 of the second embodiment includes an elastic member bus bar position restricting structure that restricts the position of the elastic member through portion 36 in the housing 33. Note that the same components as those described in the above-described embodiment are denoted by the same reference numerals, and redundant description is omitted.

  The housing 33 includes a projecting portion 33X in the through hole 33H on the surface 33O side near the device side terminal. Further, the elastic member penetrating portion 36 is provided with a protruding portion 33X in the through hole 33H not on the surface 33O side near the device side terminal but on the surface 33I side near the motor side terminal or the central portion in the through hole 33H. May be. Or the elastic member penetration part 36 may be provided with the protrusion part 33X in the through-hole 33H in the surface 33O near the equipment side terminal and the surface 33I near the motor side terminal. Moreover, the elastic member penetration part 36 of the 1st bus bar 31 and the 2nd bus bar 32 equips the side surface with the recessed part 39X. As described above, the elastic member penetration part 36 is inserted into the through hole 33 </ b> H and penetrates the housing 33. The protrusion 33 </ b> X fits into the recess 39 </ b> X, and the housing 33 restricts the position of the elastic member through portion 36 in the housing 33. In addition, the elastic member penetration part 36 equips a side surface with a convex part, and an uneven | corrugated relationship may be reverse. The protruding portion 33 </ b> X and the recessed portion 39 </ b> X serve as an elastic member bus bar position restricting structure that restricts the position of the elastic member penetrating portion 36 in the housing 33.

  In the bus bar unit 30 according to the second embodiment, since the elastic member bus bar position restricting structure restricts the position of the elastic member penetrating part 36 in the housing 33, the displacement of the elastic member penetrating part 36 can be suppressed. For this reason, it can suppress that elastic member penetration part 36 comes off from housing 33, and can raise the position accuracy of bent part 39A which is a displacement fulcrum. As a result, the deformation of the brush holder unit 20 due to the mounting accuracy of the ECU 90 can be further suppressed. For this reason, the brush motor 10 can reduce brush noise.

(Embodiment 3)
FIG. 17 is an explanatory diagram illustrating a configuration of a bus bar unit according to the third embodiment. FIG. 18 is an explanatory diagram illustrating a configuration of a bus bar unit according to the third embodiment. FIG. 19 is an explanatory diagram for explaining the displacement of the bus bar of the bus bar unit. The housing 33 according to the third embodiment further includes a pressing portion 33Y that protrudes from the surface 33O near the device-side terminal and presses the elastic member surface extending portion 37. The same components as those described in the above-described embodiment are used. Are denoted by the same reference numerals and redundant description is omitted.

  As illustrated in FIG. 17, the housing 33 according to the third embodiment includes a through hole 33 </ b> H and a pressing portion 33 </ b> Y that protrudes from the surface 33 </ b> O near the device-side terminal. The pressing part 33Y should just protrude in the direction away from the surface 33O near the equipment side terminal around the through hole 33H. It is preferable that the pressing portion 33 </ b> Y is integrally formed of the same elastic body as the housing 33. Since the pressing portion 33Y is an elastic body, as shown in FIG. 18, the pressing portion 33Y can apply pressure to the elastic member surface extending portion 37 that is in contact with the pressing portion 33Y. When there is no pressing part 33Y, as shown in FIG. 19, a gap ΔY may be generated between the surface 33O close to the equipment-side terminal and the elastic member surface extending part 37 in accordance with the mounting accuracy of the ECU 90. .

  The pressing portion 33Y that presses the elastic member surface extending portion 37 can suppress the gap ΔY and also suppress the vibration of the first bus bar 31 and the second bus bar 32 by pressurization. As a result, the risk of damage to the first bus bar 31 and the second bus bar 32 due to vibration can be reduced.

DESCRIPTION OF SYMBOLS 10 Brush motor 11 Housing | casing 11a Cylindrical part 11b Bottom part 12 Flange 12a Bolt hole 12b Bus bar unit attachment recessed part 13 Magnet 13a Magnet holder 13b Magnet scattering prevention cover 14 Rotor 15 Commutator 15a Conductive part 16 Core 17 Coil 18 Shaft 18a Bearing 18b Bearing 18c Joint 19 Brush 20 Brush holder unit 21 Brush case 21f Open 22 Spring 23 Substrate 23a Bolt through hole 24 Bottom elastic member 30 Bus bar unit 31 First bus bar 32 Second bus bar 33 Housing (elastic member)
33I, 33O Surface 33S Side 33T Protruding part 33X Protruding part 33Y Pressing part 33H Through hole 35 Pigtail 35a Wiring member 35A, 35B Motor side electric connecting part 36 Elastic member penetrating part 37 Elastic member surface extending part 38 Device side terminal direction extending Part 39X Concave part 39A, 39B Bending part 80 Electric power steering device 81 Steering wheel 82 Steering shaft 82a Input shaft 82b Output shaft 83 Steering force assist mechanism 84 Universal joint 85 Lower shaft 86 Universal joint 87 Pinion shaft 88 Steering gear 88a Pinion 88b Rack 89 Tie rod 90 ECU
90A Device side terminal 91a Torque sensor 91b Vehicle speed sensor 92 Deceleration device 98 Ignition switch 99 Battery B Bolt Zr Rotating shaft

Claims (8)

It is a structure that electrically connects the motor side terminal of the motor with brush and the equipment side terminal of the device,
An elastic member interposed between the electric motor side terminal and the equipment side terminal;
An elastic member penetration portion that is supported by the elastic member and penetrates the elastic member from a surface of the elastic member near the motor side terminal to a surface of the elastic member near the device side terminal, and an extending direction of the elastic member penetration portion The elastic member surface extending portion extending along the surface near the motor side terminal of the elastic member and the extending direction of the elastic member surface extending portion, and the device side terminal of the elastic member A bus bar that extends in a direction away from the near surface and that connects to the device side terminal, and that supplies power to the brush,
Including
The bus bar is a linear and plate-like conductive member, and includes a first bent portion where the elastic member penetrating portion and the elastic member surface extending portion are bent, and the elastic member surface extending portion and the device side. A second bent portion that bends in the terminal direction extending portion, and the plane in which the elastic member penetrating portion and the device side terminal direction extending portion are different,
The first bent portion is at a position where the electric-side electric connecting portion and the elastic member penetrating portion are exposed on the surface of the elastic member near the device-side terminal, and the second bent portion is close to the device-side terminal of the elastic member. Located near the surface of
A distance between the first bending portion and the first bending portion where the elastic member penetration portion is electrically connected to the electric motor side terminal extends from the first bending portion and the device so as to approach the second bending portion. Fastening center of the fastening structure of the device side terminal direction extending portion for fastening the device side terminal overlapped with the device side electric connection portion bent in a direction away from the surface of the elastic member near the device side terminal The terminal connection structure of an electric motor which is less than or equal to the linear distance.   2. The motor terminal connection structure according to claim 1, wherein the bus bar is electrically connected to the motor-side terminal through a flexible electric conduction member, and the electric conduction member is curved.   3. The terminal connection structure for an electric motor according to claim 1, further comprising a bus bar position restricting structure in the elastic member for restricting a position of the elastic member penetrating portion in the elastic elastic member.   The terminal connection structure for an electric motor according to any one of claims 1 to 3, further comprising a pressing portion that protrudes from a surface of the elastic member closer to the device-side terminal and presses the elastic member surface extending portion.   The motor terminal connection structure according to any one of claims 1 to 4, further comprising an elastic member position restricting structure that restricts a relative position of the elastic member with respect to the electric motor side terminal. The terminal connection structure for an electric motor according to any one of claims 1 to 5 , wherein the fastening structure includes a rotation prevention mechanism. The electric motor with a brush connected to the electric motor side terminal connected with a brush by the terminal connection structure of the electric motor according to any one of claims 1 to 6 . The brushed electric motor according to claim 7 , wherein an auxiliary steering force is applied to a steering mechanism of a vehicle, wherein the brushed electric motor is based on a steering auxiliary command value calculated using at least a steering torque and a vehicle speed for the steering mechanism. An electric power steering device characterized by controlling the drive of the motor.

Images