JP2018207641A - Electric drive device, and electric power steering device - Google Patents

Abstract

To provide an electric drive device and an electric power steering device capable of improving efficiency in assembly work.SOLUTION: In an electric drive device, a first power substrate, a second power substrate and a control substrate are arranged around an extended line in an axial direction of a shaft. In addition, the first power substrate, the second power substrate and the control substrate, and an electric motor are arranged so as to interpose a sensor substrate thereamong in the axial direction.SELECTED DRAWING: Figure 7

Description

  The present invention relates to an electric drive device and an electric power steering device including an electronic control device that controls rotation of an electric motor.

  An electric power steering device that generates an auxiliary steering torque by an electric motor includes an electronic control device that controls the electric motor. For example, Patent Document 1 describes a motor unit that can suppress an increase in size of a motor shaft.

Japanese Patent Laid-Open No. 2006-163414

  Inside the heat sink of Patent Document 1, there is a through hole through which the shaft of the electric motor passes, and electronic components of the control board are arranged along the axial direction of the shaft. By adopting such a structure, the sensor substrate having the magnetic sensor facing the magnet attached to the opposite end portion of the shaft on the opposite side of the shaft is disposed on the side farther from the electric motor than the control substrate.

  For the electric motor, it is important that the shaft is attached in a state in which the swing is suppressed. Therefore, after the shaft of the electric motor is protected by the heat sink, the sensor board and the control board are attached around the heat sink. For this reason, there is a limit in improving the efficiency of the mounting operation.

  The present invention has been made in view of the above problems, and an object thereof is to provide an electric drive device and an electric power steering device that improve the efficiency of assembly work.

  In order to achieve the above object, an electric drive device according to one aspect includes a shaft, a motor rotor that operates in conjunction with the shaft, a motor stator that includes a stator core that rotates the motor rotor, and at least two first systems for each three phases. An electric motor including a plurality of coil groups that are divided into a coil group and a second coil group and that excites the stator core with a three-phase alternating current; and for controlling driving of the electric motor, the anti-load side of the shaft An electronic control device provided on the shaft, on the antiload side end magnet of the shaft, on the antiload side of the shaft, on an axial extension of the shaft A plurality of sensors arranged to mount a magnetic sensor for detecting the rotation of the magnet and supplying a current to the first coil group; A first power board for mounting a product on a first mounting surface on the radially outer side of the shaft, and a plurality of electronic components for supplying current to the second coil group on a second mounting surface on the radially outer side of the shaft And a control board for mounting an electronic component for controlling a current supplied by at least one of the first power board and the second power board on a third mounting surface radially outside the shaft. The first power board, the second power board, and the control board are arranged around an axial extension of the shaft, and the first power board, the second power board, and the control board The electric motor is disposed so as to sandwich the sensor substrate in the axial direction.

  Thereby, since a sensor board | substrate is arrange | positioned near an electric motor, a shaft can be shortened. For this reason, since the work procedure can be determined without considering the protection of the shaft, the work efficiency is improved.

  As a desirable mode, the first power board is arranged at a position sandwiching the extension line in the axial direction of the second power board and the shaft. As a result, when both the first power board and the second power board are operating, the bias of the heat generation distribution is reduced in the internal space.

  As a desirable mode, the mounting surface of the control board is different from the plane on which the mounting surface of the first power board and the mounting surface of the second power board are arranged. Thereby, the volume of the electronic control unit can be suppressed.

  As a desirable mode, a connector for bundling a signal transmission wiring for transmitting an input / output signal of the control board and a power wiring for transmitting power is provided, and the first power board and the second power board are in an axial direction of the shaft. In the above, the power supply terminal piece connected to the power wiring and the power supply terminal piece connected to the power wiring, and the shaft close to the sensor board in the axial direction of the shaft, the first coil group or the second coil A motor connection terminal piece connected to the coil wiring of the coil group. Thereby, a power supply terminal piece connects with electric power wiring, and a motor connection terminal piece connects with coil wiring. This improves the efficiency of the assembly work.

  As a desirable mode, the power supply terminal piece is a plate material of a good conductor, the motor connection terminal piece is a plate material of a good conductor, one surface of the plate material of the power supply terminal piece is visible from the axial direction, and the motor connection One surface of the plate material of the terminal piece is visible from the direction of the tangential line in the radial direction. This improves the efficiency of the assembly work.

  In order to achieve the above object, an electric drive device according to one aspect includes a shaft, a motor rotor that operates in conjunction with the shaft, a motor stator that includes a stator core that rotates the motor rotor, and at least two first systems for each three phases. An electric motor including a plurality of coil groups that are divided into a coil group and a second coil group and that excites the stator core with a three-phase alternating current; and for controlling driving of the electric motor, the anti-load side of the shaft An electronic control device provided on the shaft, the electronic control device comprising a magnet on the end of the shaft opposite to the load, and a substrate assembly, the substrate assembly including a heat sink, and the shaft A sensor mounted on the extension side in the axial direction of the shaft and mounting a magnetic sensor for detecting rotation of the magnet A plate, a plurality of electronic components that supply current to the first coil group, a first power board that is mounted on a first mounting surface on the radially outer side of the shaft, and a plurality that supplies current to the second coil group A second power board for mounting the electronic part on a second mounting surface radially outside the shaft, and an electronic part for controlling a current supplied by at least one of the first power board and the second power board, A control board mounted on a third mounting surface on the radially outer side of the shaft, and the first power board, the second power board, and the control board are arranged around an extension line in the axial direction of the shaft. The first power board, the second power board, and the control board are assembled to the heat sink, and the first power board, the second power board, and the control board; Serial so as to sandwich the sensor substrate in the axial direction of the electric motor, wherein the sensor substrate is assembled to the heat sink, the substrate assembly is fixed to the anti-load side of the electric motor.

  Accordingly, the first power board, the second power board, the control board, and the sensor board are attached to the electric motor by fixing the pre-assembled board assembly to the non-load side of the electric motor. For this reason, the efficiency of attachment work improves.

  As a desirable mode, the first power board is disposed at a position sandwiching the extension line in the axial direction of the second power board and the shaft, and the heat sink includes a first heat radiating arm part, a second heat radiating arm part, A connecting portion that connects the first heat dissipating arm portion and the second heat dissipating arm portion, and is U-shaped, and a back surface of the first mounting surface is attached to a radially outer side of the first heat dissipating arm portion; The back surface of the second mounting surface is attached to the radially outer side of the second heat radiating arm portion, and is between the radially inner side of the first heat radiating arm portion and the radially inner side of the second heat radiating arm portion. Has a space. Thereby, even when the operation ratios of the first power board and the second power board are different, the heat transferred to the first heat radiating arm part and the heat transferred to the second heat radiating arm part are divided into spaces, respectively. And can dissipate heat.

  As a desirable mode, the control board is attached to the heat sink so as to straddle the first heat radiating arm part and the second heat radiating arm part. Thereby, it becomes difficult to transmit the heat of a 1st thermal radiation arm part and a 2nd thermal radiation arm part to a control board.

  As a desirable aspect, in the axial direction of the shaft, a motor connection terminal piece is provided standing on a portion near the sensor substrate and connected to the coil wiring of the first coil group or the second coil group. The shaft is arranged on the outer side in the radial direction of the shaft than the heat sink. Thereby, the heat sink can suppress the influence of the magnetic field of coil wiring.

  As a desirable mode, the electronic component on the first mounting surface or the second mounting surface includes a switching element and a smoothing capacitor. Even in such an embodiment, the influence of heat generation is suppressed.

  An electric power steering device according to one aspect includes the above-described electric drive device, and the electric drive device generates an auxiliary steering torque. As a result, the efficiency of the assembly work is improved in the electric power steering apparatus.

  ADVANTAGE OF THE INVENTION According to this invention, the electric drive device and electric power steering device which the efficiency of an assembly operation improves can be provided.

FIG. 1 is a perspective view schematically showing a vehicle equipped with the electric power steering apparatus of the present embodiment. FIG. 2 is a schematic diagram of the electric power steering apparatus of the present embodiment. FIG. 3 is a schematic diagram illustrating an example of arrangement of ECUs according to the present embodiment. FIG. 4 is a cross-sectional view schematically showing a cross section of the electric motor of the present embodiment. FIG. 5 is a schematic diagram showing wiring of the electric motor of the present embodiment. FIG. 6 is a schematic diagram showing the relationship between the electric motor and the ECU of the present embodiment. FIG. 7 is an exploded perspective view of the ECU of the present embodiment. FIG. 8A is a front view of the substrate assembly of the present embodiment. FIG. 8B is a left side view of the substrate assembly of the present embodiment. FIG. 8C is a right side view of the substrate assembly of the present embodiment. FIG. 8D is a plan view of the substrate assembly of the present embodiment. FIG. 8E is a bottom view of the substrate assembly of the present embodiment. FIG. 8F is a rear view of the substrate assembly of the present embodiment. FIG. 9 is an exploded perspective view of the substrate assembly of the present embodiment. FIG. 10A is a front view of the heat sink of the present embodiment. FIG. 10B is a left side view of the heat sink of the present embodiment. FIG. 10C is a right side view of the heat sink of the present embodiment. FIG. 10D is a plan view of the heat sink of the present embodiment. FIG. 10E is a bottom view of the heat sink of the present embodiment. FIG. 10F is a rear view of the heat sink of the present embodiment. FIG. 11 is an explanatory diagram for explaining the positional relationship among the shaft, the magnet, and the rotation angle sensor of the present embodiment. FIG. 12 is an explanatory diagram for explaining the connection between the motor connection terminal and the coil wiring of the present embodiment. FIG. 13 is an explanatory diagram for explaining the connection between the first power board and the control board according to the present embodiment. FIG. 14 is an explanatory diagram for explaining the fixing of the connector according to the present embodiment. FIG. 15 is an explanatory diagram for explaining the sealing structure of the connector of the present embodiment. FIG. 16 is an exploded perspective view of an ECU according to a modification of the present embodiment.

  Hereinafter, the present invention will be described in detail with reference to the drawings. The present invention is not limited by the following 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, those that are substantially the same, and those in a so-called equivalent range. Furthermore, the constituent elements disclosed in the following embodiments can be appropriately combined.

  DESCRIPTION OF EMBODIMENTS Embodiments (embodiments) for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited by the contents described in the following embodiments. The constituent elements described below include those that can be easily assumed by those skilled in the art and those that are substantially the same. Furthermore, the constituent elements described below can be appropriately combined.

(Electric power steering device)
FIG. 1 is a perspective view schematically showing a vehicle equipped with the electric power steering apparatus of the present embodiment. FIG. 2 is a schematic diagram of the electric power steering apparatus of the present embodiment. As shown in FIG. 1, the vehicle 101 is equipped with an electric power steering device 100. An outline of the electric power steering apparatus 100 will be described with reference to FIG.

  The electric power steering device 100 includes a steering wheel 91, a steering shaft 92, a universal joint 96, an intermediate shaft 97, a universal joint 98, and a first member in the order in which the force given by the driver (operator) is transmitted. A rack and pinion mechanism 99 and a tie rod 72 are provided. In addition, the electric power steering apparatus 100 includes a torque sensor 94 that detects the steering torque of the steering shaft 92, the electric motor 30, and an electronic control unit (hereinafter referred to as an ECU (Electronic Control Unit)) 10 that controls the electric motor 30. And a speed reduction device 75 and a second rack and pinion mechanism 70. A vehicle speed sensor 82, a power supply device 83 (for example, a vehicle-mounted battery), and an ignition switch 84 are provided in the vehicle body. The vehicle speed sensor 82 detects the traveling speed of the vehicle 101. The vehicle speed sensor 82 outputs the detected vehicle speed signal SV to the ECU 10 by CAN (Controller Area Network) communication. The ECU 10 is supplied with electric power from the power supply device 83 with the ignition switch 84 turned on.

  The electric drive device 1 includes an electric motor 30 and an ECU 10 that is fixed to the non-load side of the shaft 31 of the electric motor 30.

  As shown in FIG. 2, the steering shaft 92 includes an input shaft 92A, an output shaft 92B, and a torsion bar 92C. One end of the input shaft 92A is connected to the steering wheel 91, and the other end is connected to the torsion bar 92C. The output shaft 92 </ b> B has one end connected to the torsion bar 92 </ b> C and the other end connected to the universal joint 96. The torque sensor 94 detects steering torque applied to the steering shaft 92 by detecting torsion of the torsion bar 92C. The torque sensor 94 outputs a steering torque signal T corresponding to the detected steering torque to the ECU 10 by CAN communication. The steering shaft 92 is rotated by a steering force applied to the steering wheel 91.

  The intermediate shaft 97 has an upper shaft 97A and a lower shaft 97B, and transmits the torque of the output shaft 92B. The upper shaft 97A is connected to the output shaft 92B via the universal joint 96. On the other hand, the lower shaft 97 </ b> B is connected to the first pinion shaft 99 </ b> A of the first rack and pinion mechanism 99 via the universal joint 98. The upper shaft 97A and the lower shaft 97B are spline-coupled, for example.

  The first rack and pinion mechanism 99 includes a first pinion shaft 99A, a first pinion gear 99B, a rack shaft 99C, and a first rack 99D. The first pinion shaft 99A has one end connected to the lower shaft 97B via the universal joint 98, and the other end connected to the first pinion gear 99B. The first rack 99D formed on the rack shaft 99C meshes with the first pinion gear 99B. The rotational motion of the steering shaft 92 is transmitted to the first rack and pinion mechanism 99 via the intermediate shaft 97. This rotational motion is converted into a linear motion of the rack shaft 99C by the first rack and pinion mechanism 99. The tie rods 72 are connected to both ends of the rack shaft 99C, respectively.

  The electric motor 30 is a motor that generates auxiliary steering torque for assisting the driver's steering. The electric motor 30 may be a brushless motor or a brush motor having a brush and a commutator.

  The ECU 10 includes a rotation angle sensor 23a. The rotation angle sensor 23 a detects the rotation phase of the electric motor 30. The ECU 10 acquires the rotation phase signal of the electric motor 30 from the rotation angle sensor 23a, acquires the steering torque signal T from the torque sensor 94, and acquires the vehicle speed signal SV of the vehicle 101 from the vehicle speed sensor 82. The ECU 10 calculates an assist steering command value of the assist command based on the rotation phase signal, the steering torque signal T, and the vehicle speed signal SV. The ECU 10 supplies current to the electric motor 30 based on the calculated auxiliary steering command value.

  The reduction gear 75 includes a worm shaft 75A that rotates integrally with the shaft 31 of the electric motor 30, and a worm wheel 75B that meshes with the worm shaft 75A. Therefore, the rotational motion of the shaft 31 is transmitted to the worm wheel 75B via the worm shaft 75A. In the present embodiment, the speed reduction device 75 side of the shaft 31 is referred to as a load side end, and the opposite side of the shaft 31 from the speed reduction device 75 is referred to as an anti-load side end.

  The second rack and pinion mechanism 70 includes a second pinion shaft 71A, a second pinion gear 71B, and a second rack 71C. The second pinion shaft 71A is fixed so that one end thereof is coaxial with the worm wheel 75B and rotates integrally therewith. The other end of second pinion shaft 71A is connected to second pinion gear 71B. The second rack 71C formed on the rack shaft 99C meshes with the second pinion gear 71B. The rotational motion of the electric motor 30 is transmitted to the second rack and pinion mechanism 70 via the speed reducer 75. This rotational motion is converted into a linear motion of the rack shaft 99C by the second rack and pinion mechanism 70.

  The steering force of the driver input to the steering wheel 91 is transmitted to the first rack and pinion mechanism 99 via the steering shaft 92 and the intermediate shaft 97. The first rack and pinion mechanism 99 transmits the transmitted steering force to the rack shaft 99C as a force applied in the axial direction of the rack shaft 99C. At this time, the ECU 10 acquires the steering torque signal T input to the steering shaft 92 from the torque sensor 94. The ECU 10 acquires the vehicle speed signal SV from the vehicle speed sensor 82. ECU10 acquires the rotation phase signal of electric motor 30 from rotation angle sensor 23a. Then, the ECU 10 outputs a control signal to control the operation of the electric motor 30. The auxiliary steering torque created by the electric motor 30 is transmitted to the second rack and pinion mechanism 70 via the speed reducer 75. Second rack and pinion mechanism 70 transmits auxiliary steering torque to rack shaft 99C as a force applied in the axial direction of rack shaft 99C. In this manner, the steering of the driver's steering wheel 91 is assisted by the electric power steering device 100.

  FIG. 3 is a schematic diagram illustrating an example of arrangement of ECUs according to the present embodiment. As shown in FIG. 3, the electric drive device 1 including the ECU 10 and the electric motor 30 is disposed in the vicinity of the first rack and pinion mechanism 99 and the second rack and pinion mechanism 70. As described above, the electric power steering apparatus 100 is a rack assist system in which an assist force is applied to the second rack and pinion mechanism 70, but is not limited thereto. The electric power steering apparatus 100 may be, for example, a column assist method in which an assist force is applied to the steering shaft 92 and a pinion assist method in which an assist force is applied to the first pinion gear 99B.

  FIG. 4 is a cross-sectional view schematically showing a cross section of the electric motor of the present embodiment. FIG. 5 is a schematic diagram showing wiring of the electric motor of the present embodiment. As shown in FIG. 4, the electric motor 30 includes a housing 930, a stator having a stator core 931, and a rotor 932. The stator includes a cylindrical stator core 931, a plurality of first coils 37, and a plurality of second coils 38. The stator core 931 includes an annular back yoke 931a and a plurality of teeth 931b protruding from the inner peripheral surface of the back yoke 931a. Twelve teeth 931b are arranged in the circumferential direction. Rotor 932 includes a rotor yoke 932a and a magnet 932b. The magnet 932b is provided on the outer peripheral surface of the rotor yoke 932a. The number of magnets 932b is eight, for example.

  As shown in FIG. 4, the first coil 37 is concentratedly wound around each of the plurality of teeth 931b. The first coil 37 is concentratedly wound around the outer periphery of the teeth 931b via an insulator. All the first coils 37 are included in the first coil system. The first coil system of this embodiment is excited by being supplied with current by an inverter circuit 251 (see FIG. 6) of the first power board 25A. The first coil system includes, for example, six first coils 37. The six first coils 37 are arranged such that the two first coils 37 are adjacent to each other in the circumferential direction. Three first coil groups Gr1 having adjacent first coils 37 as one group are arranged at equal intervals in the circumferential direction. That is, the first coil system includes three first coil groups Gr1 arranged at equal intervals in the circumferential direction. Note that the number of the first coil groups Gr1 is not necessarily three, and it is sufficient if 3n are arranged at equal intervals in the circumferential direction when n is a natural number. Further, n is desirably an odd number.

  As shown in FIG. 4, the second coil 38 is concentratedly wound around each of the plurality of teeth 931b. The second coil 38 is concentratedly wound around the outer periphery of the teeth 931b via an insulator. The teeth 931b around which the second coil 38 is concentrated are different teeth 931b from the teeth 931b around which the first coil 37 is concentrated. All the second coils 38 are included in the second coil system. The second coil system is excited by being supplied with current by the inverter circuit 251 (see FIG. 6) of the second power board 25B. The second coil system includes, for example, six second coils 38. The six second coils 38 are arranged such that the two second coils 38 are adjacent to each other in the circumferential direction. Three second coil groups Gr2 having the adjacent second coils 38 as one group are arranged at equal intervals in the circumferential direction. That is, the second coil system includes three second coil groups Gr2 arranged at equal intervals in the circumferential direction. Note that the number of the second coil groups Gr2 is not necessarily three, and it is sufficient if 3n are arranged at equal intervals in the circumferential direction when n is a natural number. Further, n is desirably an odd number.

  As shown in FIG. 5, the six first coils 37 include two first U-phase coils 37Ua and a first U-phase coil 37Ub excited by the first U-phase current I1u, and two excited by the first V-phase current I1v. A first V-phase coil 37Va and a first V-phase coil 37Vb, and two first W-phase coils 37Wa and a first W-phase coil 37Wb excited by a first W-phase current I1w are included. First U-phase coil 37Ub is connected in series to first U-phase coil 37Ua. First V-phase coil 37Vb is connected in series to first V-phase coil 37Va. First W-phase coil 37Wb is connected in series to first W-phase coil 37Wa. The winding direction of the first coil 37 around the teeth 931b is the same. The first U-phase coil 37Ub, the first V-phase coil 37Vb, and the first W-phase coil 37Wb are joined by a star connection (Y connection).

  As shown in FIG. 5, the six second coils 38 include two second U-phase coils 38Ua and second U-phase coils 38Ub excited by the second U-phase current I2u, and two excited by the second V-phase current I2v. It includes a second V-phase coil 38Va and a second V-phase coil 38Vb, and two second W-phase coils 38Wa and a second W-phase coil 38Wb excited by a second W-phase current I2w. Second U-phase coil 38Ub is connected in series to second U-phase coil 38Ua. Second V-phase coil 38Vb is connected in series to second V-phase coil 38Va. Second W-phase coil 38Wb is connected in series to second W-phase coil 38Wa. The winding direction of the second coil 38 around the teeth 931 b is the same direction, and is the same as the winding direction of the first coil 37. The second U-phase coil 38Ub, the second V-phase coil 38Vb, and the second W-phase coil 38Wb are joined by star connection (Y connection).

  As shown in FIG. 4, the three first coil groups Gr1 include a first UV coil group Gr1UV, a first VW coil group Gr1VW, and a first UW coil group Gr1UW. The first UV coil group Gr1UV includes a first U-phase coil 37Ub and a first V-phase coil 37Va that are adjacent to each other in the circumferential direction. The first VW coil group Gr1VW includes a first V-phase coil 37Vb and a first W-phase coil 37Wa that are adjacent to each other in the circumferential direction. The first UW coil group Gr1UW includes a first U-phase coil 37Ua and a first W-phase coil 37Wb that are adjacent to each other in the circumferential direction.

  As shown in FIG. 4, the three second coil groups Gr2 include a second UV coil group Gr2UV, a second VW coil group Gr2VW, and a second UW coil group Gr2UW. The second UV coil group Gr2UV includes a second U-phase coil 38Ub and a second V-phase coil 38Va that are adjacent to each other in the circumferential direction. The second VW coil group Gr2VW includes a second V-phase coil 38Vb and a second W-phase coil 38Wa that are adjacent to each other in the circumferential direction. The second UW coil group Gr2UW includes a second U-phase coil 38Ua and a second W-phase coil 38Wb that are adjacent to each other in the circumferential direction.

  The first coil 37 excited by the first U-phase current I1u faces the second coil 38 excited by the second U-phase current I2u in the radial direction of the stator core 931. In the following description, the radial direction of the stator core 931 is simply referred to as the radial direction. For example, as shown in FIG. 4, in the radial direction, the first U-phase coil 37Ua faces the second U-phase coil 38Ua, and the first U-phase coil 37Ub faces the second U-phase coil 38Ub.

  The first coil 37 excited by the first V-phase current I1v is opposed to the second coil 38 excited by the second V-phase current I2v in the radial direction. For example, as shown in FIG. 4, in the radial direction, the first V-phase coil 37Va faces the second V-phase coil 38Va, and the first V-phase coil 37Vb faces the second V-phase coil 38Vb.

  The first coil 37 excited by the first W-phase current I1w is opposed to the second coil 38 excited by the second W-phase current I2w in the radial direction. For example, as shown in FIG. 4, in the radial direction, the first W-phase coil 37Wa faces the second W-phase coil 38Wa, and the first W-phase coil 37Wb faces the second W-phase coil 38Wb.

  FIG. 6 is a schematic diagram showing the relationship between the electric motor and the ECU of the present embodiment. As shown in FIG. 6, the ECU 10 includes a control calculation unit 241, a motor rotation angle detection circuit 23, a motor rotation number calculation unit 22, a gate drive circuit 242, a cutoff drive circuit 243, and an inverter circuit 251. I have.

  The control calculation unit 241 calculates a motor current command value. The motor rotation number calculation unit 22 calculates the motor electrical angle θm and outputs it to the control calculation unit 241. A motor current command value output from the control calculation unit 241 is input to the gate drive circuit 242.

  As shown in FIG. 6, the electric motor 30 includes a rotation angle sensor 23a. The rotation angle sensor 23a is, for example, a magnetic sensor. The detection value of the rotation angle sensor 23 a is supplied to the motor rotation number calculation unit 22. The motor rotation number calculation unit 22 calculates the motor electrical angle θm based on the detection value of the rotation angle sensor 23 a and outputs it to the control calculation unit 241.

The control operation unit 241 includes a steering torque signal T detected by the torque sensor 94, a vehicle speed SV detected by the vehicle speed sensor 82, a motor electric angle theta _m output from the motor rotational speed calculating section 22, an input Is done. The control calculation unit 241 calculates a current command value based on the steering torque signal T, the vehicle speed SV, and the motor electrical angle θm, and outputs it to the gate drive circuit 242.

  The gate drive circuit 242 calculates a first pulse width modulation signal based on the current command value and outputs it to the inverter circuit 251 of the first power substrate 25A. The inverter circuit 251 switches the switching element 252 so as to obtain a three-phase current value according to the duty ratio of the first pulse width modulation signal, and thereby the first U-phase current I1u, the first V-phase current I1v, and the first W-phase. A three-phase alternating current including the current I1w is generated. The first U-phase current I1u excites the first U-phase coil 37Ua and the first U-phase coil 37Ub, the first V-phase current I1v excites the first V-phase coil 37Va and the first V-phase coil 37Vb, and the first W-phase current I1w becomes the first W The phase coil 37Wa and the first W-phase coil 37Wb are excited.

  The gate drive circuit 242 calculates a second pulse width modulation signal based on the current command value, and outputs it to the inverter circuit 251 of the second power substrate 25B. The inverter circuit 251 switches the switching element 252 so as to obtain a three-phase current value according to the duty ratio of the second pulse width modulation signal, thereby causing the second U-phase current I2u, the second V-phase current I2v, and the second W-phase. A three-phase alternating current including the current I2w is generated. The second U-phase current I2u excites the second U-phase coil 38Ua and the second U-phase coil 38Ub, the second V-phase current I2v excites the second V-phase coil 38Va and the second V-phase coil 38Vb, and the second W-phase current I2w becomes the second W-phase. The phase coil 38Wa and the second W-phase coil 38Wb are excited.

  For example, the inverter circuit 251 includes a switching element 252 and a smoothing capacitor 253. An example of the switching element 252 is a field effect transistor. As the smoothing capacitor 253, for example, an electrolytic capacitor is used.

  As shown in FIG. 6, the electric power steering apparatus 100 includes a current detection circuit 254 for detecting the current value of each phase of the electric motor 30. For example, the current detection circuit 254 includes a shunt resistor. The current value detected by the current detection circuit 254 is sent to the control calculation unit 241. The current detection circuit 254 may be connected so as to detect the current value of each phase of the electric motor 30.

  The current interruption circuit 255 is disposed between the inverter circuit 251 and the first coil 37 or the second coil 38. When it is determined that the current value detected by the current detection circuit 254 is abnormal, the control calculation unit 241 drives the current cutoff circuit 255 via the cutoff drive circuit 243 and the current flowing from the inverter circuit 251 to the first coil 37. Can be cut off. In addition, the control calculation unit 241 can drive the current cutoff circuit 255 via the cutoff drive circuit 243 and cut off the current flowing from the inverter circuit 251 to the second coil 38. As described above, the current flowing through the first coil 37 and the current flowing through the second coil 38 are controlled independently by the control calculation unit 241.

  Signal transmission lines for transmitting input / output signals to / from the control board 24 such as a steering torque signal T and a vehicle speed signal SV are input to the control calculation unit 241 via the connector CNT. At least one of the first power board 25A and the second power board 25B is connected with a power wiring PW that transmits power from the power supply device 83 via the connector CNT. In the present embodiment, the power wiring PW from the power supply device 83 is connected to the first power board 25A and the second power board 25B via the connector CNT.

  FIG. 7 is an exploded perspective view of the ECU of the present embodiment. FIG. 8A is a front view of the substrate assembly of the present embodiment. FIG. 8B is a left side view of the substrate assembly of the present embodiment. FIG. 8C is a right side view of the substrate assembly of the present embodiment. FIG. 8D is a plan view of the substrate assembly of the present embodiment. FIG. 8E is a bottom view of the substrate assembly of the present embodiment. FIG. 8F is a rear view of the substrate assembly of the present embodiment. FIG. 9 is an exploded perspective view of the substrate assembly of the present embodiment.

  As shown in FIG. 7, the ECU 10 includes a substrate assembly 200 and a cover 210. The cover 210 is made of metal or resin. As shown in FIG. 9, in the board assembly 200, the first power board 25A, the second power board 25B, the control board 24, the sensor board 21, and the connector CNT are attached to the five surfaces of the heat sink 40. It has been.

  The first power board 25A, the second power board 25B, the control board 24, and the sensor board 21 are printed boards formed of resin or the like. The first power substrate 25A and the second power substrate 25B may be a metal substrate in which a resin layer is laminated on a metal plate such as aluminum or copper having high heat dissipation and a circuit is formed in the resin layer. When the first power substrate 25A and the second power substrate 25B are metal substrates, the thermal conductivity to the heat sink 40 is improved.

  As shown in FIG. 8A, the control board 24 includes an electronic component 245 and a lead insertion hole 248 that constitute the control calculation unit 241, the gate drive circuit 242, and the cutoff drive circuit 243 shown in FIG.

  As shown in FIG. 8B, the first power board 25A includes an electronic component 256, power supply terminal pieces 271, 272, and motor connection terminals that constitute the inverter circuit 251, the current detection circuit 254, and the current cutoff circuit 255 shown in FIG. It includes pieces 261, 262, 263 and lead terminals 257. The power terminal pieces 271 and 272 are erected with respect to the mounting surface of the first power board 25A. The motor connection terminal pieces 261, 262, 263 are erected with respect to the mounting surface of the first power board 25A.

  As shown in FIG. 8C, the second power board 25B includes an electronic component 256, power supply terminal pieces 271 and 272, and motor connection terminals that constitute the inverter circuit 251, current detection circuit 254, and current cutoff circuit 255 shown in FIG. It includes pieces 261, 262, 263 and lead terminals 257. The power terminal pieces 271 and 272 are erected with respect to the mounting surface of the second power board 25B. The motor connection terminal pieces 261, 262, and 263 are erected with respect to the mounting surface of the second power board 25B.

  The power terminal pieces 271 and 272 are plate members made of a good conductor such as copper or aluminum. The motor connection terminal pieces 261, 262, and 263 are plate members made of a good conductor such as copper or aluminum. As shown in FIGS. 8B and 8C, the plate material surfaces of the power supply terminal pieces 271, 272 face different directions from the plate material surfaces of the motor connection terminal pieces 261, 262, 263. The direction perpendicular to the surface of the plate material of the power supply terminal pieces 271 and 272 is preferably directed in the direction of the axial direction Ax, and the direction perpendicular to the surface of the plate material of the motor connection terminal pieces 261, 262 and 263 is oriented in the axial direction Ax. It is desirable to face one radial tangent direction on a virtual plane perpendicular to the direction.

  As shown in FIG. 8E, the sensor substrate 21 includes a rotation angle sensor 23a. The sensor substrate 21 includes lead terminals 257 on the back surface of the mounting surface of the rotation angle sensor 23a.

  As shown in FIG. 7, the connector CNT has power supply terminals Tdc and Tgnd. The power supply terminal Tdc is a metal terminal that supplies the power supply voltage Vdc of the power supply device 83. The power supply terminal Tgnd is a metal terminal that supplies a negative power supply voltage (for example, a reference voltage such as a ground) of the power supply device 83.

  The power supply terminal Tdc is pressed against the power supply terminal piece 272 (see FIG. 8B) of the first power board 25A and is resistance welded or laser welded. Thereby, one surface of the power supply terminal Tdc and one surface of the power supply terminal piece 272 of the first power board 25A are in surface contact.

  The power terminal Tgnd is pressed against the power terminal piece 271 (see FIG. 8B) of the first power board 25A, and is resistance-welded or laser-welded. Thereby, one surface of the power supply terminal Tgnd and one surface of the power supply terminal piece 271 of the first power board 25A are in surface contact.

  The power terminals Tdc and Tgnd are also on the second power board 25B side of the connector CNT. The power terminal Tdc on the second power board 25B side is pressed against the power terminal piece 272 (see FIG. 8C) of the second power board 25B and is resistance welded or laser welded. The power terminal Tgnd on the second power board 25B side is pressed against the power terminal piece 271 (see FIG. 8C) of the second power board 25B, and is resistance welded or laser welded.

  FIG. 10A is a front view of the heat sink of the present embodiment. FIG. 10B is a left side view of the heat sink of the present embodiment. FIG. 10C is a right side view of the heat sink of the present embodiment. FIG. 10D is a plan view of the heat sink of the present embodiment. FIG. 10E is a bottom view of the heat sink of the present embodiment. FIG. 10F is a rear view of the heat sink of the present embodiment.

  9 and 10A to 10F, the heat sink 40 connects the first heat radiating arm portion 41, the second heat radiating arm portion 42, the first heat radiating arm portion 41, and the second heat radiating arm portion 42. The connection part 43 is provided and it is U-shaped. As shown in FIG. 10A, the first heat radiating arm portion 41 and the second heat radiating arm portion 42 are arranged with a distance therebetween by a connecting portion 43. Therefore, an opening 44 is formed between the first heat radiating arm portion 41 and the second heat radiating arm portion 42.

  As shown in FIG. 8F, the connector CNT includes a choke coil 49. The choke coil 49 removes the high frequency component of the power wiring PW from the power supply device 83 described above. The choke coil 49 is disposed in the space of the opening 44. A connecting portion 43 is provided between the choke coil 49 and the rotation angle sensor 23a (see FIG. 8E). The connecting portion 43 can shield the noise of the choke coil 49 so that the connecting portion 43 does not transmit the noise of the choke coil 49 to the rotation angle sensor 23a.

  As shown in FIGS. 10A and 10B, the first heat dissipating arm portion 41 includes a first surface 41a disposed on the radially outer side in the axial direction Ax shown in FIG. 7 and a radially inner side in the axial direction Ax shown in FIG. The second surface 41b facing the opening 44, the third surface 41c, the fourth surface 41d and the fifth surface 41f, which are side surfaces connecting the first surface 41a and the second surface 41b, A sixth surface 41e opposite to the fifth surface 41f is provided.

  As shown in FIG. 9, the back surface of the mounting surface of the first power board 25A is fixed to the first heat radiating arm portion 41 of the heat sink 40 with screws or the like. Thereby, the back surface of the mounting surface of the first power board 25A is in contact with the first surface 41a of the first heat dissipating arm portion 41 shown in FIG. 10B directly or via a heat dissipating material. The heat dissipating material is a material in which a heat conductive filler is mixed with a silicone polymer, and is called TIM (Thermal Interface Material).

  As shown in FIGS. 10A and 10C, the second heat radiating arm portion 42 includes a first surface 42a disposed on the radially outer side in the axial direction Ax shown in FIG. 7 and a radially inner side in the axial direction Ax shown in FIG. The second surface 42b facing the opening 44, the third surface 42c, the fourth surface 42d and the fifth surface 42f, which are side surfaces connecting the first surface 42a and the second surface 42b, A sixth surface 42e opposite to the fifth surface 42f is provided.

  As shown in FIG. 9, the back surface of the mounting surface of the second power substrate 25 </ b> B is fixed to the second heat radiating arm portion 42 of the heat sink 40 with screws or the like. Thereby, the back surface of the mounting surface of the second power substrate 25B is in contact with the first surface 42a of the second heat dissipating arm portion 42 shown in FIG. 10C directly or via the heat dissipating material described above.

  As shown in FIG. 9, the control board 24 is fixed to the front surface of the heat sink 40 with screws or the like so as to straddle the first heat radiating arm portion 41 and the second heat radiating arm portion 42. Thereby, the control board 24 is fixed to a surface intersecting with a surface to which the first power board 25A and the second power board 25B are fixed. Thus, the mounting surface of the control board 24 is different from the plane on which the mounting surface of the first power board 25A and the mounting surface of the second power board 25B are arranged. Thereby, the volume of ECU10 can be made small.

  As shown in FIGS. 9 and 10A, a step is provided on the third surface 41 c of the first heat radiating arm portion 41 and the third surface 42 c of the second heat radiating arm portion 42, and there is a recess. Accordingly, in FIG. 10A, the control board 24 has a space of the opening 44 between a part of the third surface 41 c of the first heat dissipating arm part 41 and a part of the third surface 42 c of the second heat dissipating arm part 42. It is fixed to intervene. Further, since the heat sink 40 is U-shaped, the back surface of the control board 24 is exposed to the opening 44 of the heat sink 40. This makes it difficult for the heat of the first heat radiating arm portion 41 and the second heat radiating arm portion 42 to be transmitted to the control board 24.

  The connector CNT is fixed to the heat sink 40 so as to straddle the first heat radiating arm portion 41 and the second heat radiating arm portion 42. The connector CNT is fixed to the fifth surface 41 f of the first heat radiating arm portion 41 and the fifth surface 42 f of the second heat radiating arm portion 42. Since the heat sink 40 is U-shaped, the connector CNT faces the connecting portion 43.

  As shown in FIG. 10E, the heat sink 40 includes a support portion 46 and a support portion 47. The support portion 46 includes a fastening hole 43H1 penetrating in the axial direction Ax. The support portion 47 includes a fastening hole 43H2 penetrating in the axial direction Ax. Referring to FIGS. 7 and 10E, the fastening hole 43H1 and the fastening hole 314 on the non-load side of the electric motor 30 overlap with each other, and the heat sink 40 and the electric motor 30 are fastened by inserting a bolt. The The fastening hole 43H2 and the fastening hole 315 on the non-load side of the electric motor 30 overlap each other, and the heat sink 40 and the electric motor 30 are fastened by inserting a bolt.

  As shown in FIGS. 10B, 10C, and 10F, the positions of the fourth surface 41d of the first heat dissipating arm portion 41 and the fourth surface 42d of the second heat dissipating arm portion 42 extend in the axial direction Ax and are counterbored. Accordingly, a concave portion 421 (see FIG. 10D) is provided. As shown in FIG. 10D, when viewed through the recess 421, the fastening hole 43H1 is exposed. As a result, the driver can be inserted into the recess 421. As a result, the bolt inserted into the fastening hole 43H1 is disposed in the recess 421. Even if the heat dissipation efficiency is improved by making the maximum use of the volume of the cover 210, the cover 210 can be fixed to the electric motor 30.

  As illustrated in FIG. 10E, the connecting portion 43 includes a recess 43 </ b> H on the mounting surface of the sensor substrate 21. The connecting portion 43 includes a sensor substrate support portion 45 around the recess 43H. As shown in FIG. 8E, the sensor substrate 21 is fixed to the sensor substrate support 45 (see FIG. 10E) with screws or the like. The sensor substrate 21 is stored in the recess 43 </ b> H of the heat sink 40 and is surrounded by the connecting portion 43. The sensor substrate 21 is fixed by the recess 43H so that a space is interposed between the sensor substrate 21 and the connecting portion 43. Thereby, the heat of the first heat dissipating arm portion 41 and the second heat dissipating arm portion 42 is hardly transmitted to the sensor substrate 21.

  FIG. 11 is an explanatory diagram for explaining the positional relationship among the shaft, the magnet, and the rotation angle sensor of the present embodiment. As shown in FIGS. 11 and 7, the magnet 32 is fixed to the opposite end portion of the shaft 31. The magnet 32 has S poles and N poles arranged alternately in the circumferential direction on the outer peripheral surface.

  The sensor substrate 21 is disposed on the opposite side of the shaft 31 and on an extension line in the axial direction Ax. The sensor substrate 21 has a plane orthogonal to the axial direction Ax as a mounting surface of the rotation angle sensor 23a. The rotation angle sensor 23a is mounted on the sensor substrate 21 so that a change in the magnetic field of the magnet 32 can be detected. It is desirable that the magnet 32 and the rotation angle sensor 23a face each other in the axial direction Ax.

  The rotation angle sensor 23a is, for example, a spin valve sensor. A spin valve sensor is a device that sandwiches a nonmagnetic layer between a ferromagnetic pinned layer whose magnetization direction is fixed by an antiferromagnetic layer, etc., and a ferromagnetic free layer, and detects changes in the direction of magnetic flux. It is a sensor that can. Spin valve sensors include GMR (Giant Magneto Resistance) sensors and TMR (Tunnel Magneto Resistance) sensors. The rotation angle sensor 23 a may be any sensor that can detect the rotation of the magnet 32. The rotation angle sensor 23a may be, for example, an AMR (Anisotropic Magneto Resistance) sensor or a Hall sensor.

  FIG. 12 is an explanatory diagram for explaining the connection between the motor connection terminal and the coil wiring of the present embodiment. As shown in FIG. 7, the electric motor 30 has coil wirings 321, 322, and 323 that protrude to the anti-load side. The coil wirings 321, 322, and 323 are copper wires or aluminum wires, and are so-called flat rectangular wires. The planes of the motor connection terminal pieces 261, 262, and 263 face the planes of the coil wirings 321, 322, and 323, and are pressed so that the planes are in contact with each other, and resistance welding or laser welding is performed.

  FIG. 13 is an explanatory diagram for explaining the connection between the first power board and the control board according to the present embodiment. As shown in FIG. 13, in the electrical connection portion Q between the control board 24 and the first power board 25A, lead terminals 257 are inserted into the lead insertion holes 248 and joined with a metal paste such as solder. Even if the connection part Q is a solderless electrical connection called a so-called press fit, the lead terminal 257 is bent so that the outer periphery of the lead terminal 257 can be elastically deformed and can be connected to the conductor on the inner wall surface of the lead insertion hole 248. Good. The electrical connection part between the control board 24 and the second power board 25B also has the same structure as the connection part Q described above (hereinafter referred to as the connection part Q). Further, the electrical connection portion between the control board 24 and the sensor substrate 21 has the same structure as the connection portion Q described above (hereinafter referred to as the connection portion Q).

  As shown in FIG. 7, the power supply voltage of the power supply device 83 is supplied to the first power board 25A and the second power board 25B via the power supply terminals Tdc and Tgnd. As shown in FIG. 6, the power supply voltage of the power supply device 83 supplied to at least one of the first power board 25A and the second power board 25B is supplied to the control board 24 via the connection portion Q described above. Yes. Similarly, the power supply voltage of the power supply device 83 supplied to the control board 24 is supplied to the sensor board 21 via the connection portion Q.

  As described above, the electric drive device 1 shown in FIG. 3 is disposed in the vicinity of the first rack and pinion mechanism 99 and the second rack and pinion mechanism 70. For this reason, the junction part of ECU10 and the electric motor 30 is sealed via a sealing member so that a water | moisture content and dust may not enter into the inside of ECU10 and the electric motor 30 as much as possible. Further, the connector CNT and the cover main body 211 also have a sealed structure in order to improve waterproofness and dustproofness.

  FIG. 14 is an explanatory diagram for explaining the fixing of the connector according to the present embodiment. FIG. 15 is an explanatory diagram for explaining the sealing structure of the connector of the present embodiment. As shown in FIGS. 7 and 14, the cover 210 has a through hole 212 that exposes the connector CNT on the front surface of the cylindrical cover body 211. As shown in FIG. 15, the inner wall 219 of the through hole 212 includes a protrusion 221 that protrudes to the inside of the cover 210 (on the electric motor 30 side in the axial direction Ax). On the outer diameter side of the connector CNT, there are provided a protruding bottom portion 233 and a weir portion 232 in which the radially outer side of the protruding bottom portion 233 is bent to the outside of the cover 210 (opposite to the electric motor 30 in the axial direction Ax). A concave storage portion 231 is formed between the overhanging bottom portion 233, the weir portion 232, and the connector CNT main body, and the end portion of the projection portion 221 is inserted into the storage portion 231.

  When the storage portion 231 is filled with the sealing material, the space between the storage portion 231 and the protruding portion 221 is sealed, and a sealed structure is created between the cover main body 211 and the connector CNT. The sealing material may be an O-ring of an elastic member such as a gasket, an adhesive, or rubber.

  As shown in FIG. 7, the cover 210 has a fastening hole 213 provided in the attachment portion of the cover main body 211. The electric motor 30 includes a fastening hole 313 for fixing the cover 210. The cover 210 and the electric motor 30 are fixed with bolts inserted through the fastening holes 213 and the fastening holes 313. The outer diameter of the cover body 211 is substantially the same as the outer diameter of the electric motor 30. Thereby, the electric drive device 1 can be attached in a state where interference with other parts outside is suppressed (see FIG. 3). Since the fastening holes 213 and the fastening holes 313 are equally arranged at three locations in the circumferential direction, they are difficult to loosen even if vibrations are applied when they are fixed with bolts.

  FIG. 16 is an exploded perspective view of an ECU according to a modification of the present embodiment. In the electric drive device 1 shown in FIG. 16, the same components as those of the electric drive device 1 shown in FIG. In addition to the configuration of the electric drive device 1 shown in FIG. 7, the electric drive device 1 shown in FIG. 16 includes an internal pressure adjusting unit 218 that enhances waterproofness and dustproofness while maintaining ventilation with a porous material. By the way, the internal pressure of the internal space surrounded by the cover body 211 may change due to an external environment such as a temperature rise. Even in this case, since the internal space is ventilated to the outside via the internal pressure adjusting unit 218, the change in the internal pressure of the internal space surrounded by the cover main body 211 is suppressed over time. As a result, breakage of the cover body 211 and damage to the joint portion between the cover body 211 and the electric motor 30 are suppressed, and the durability of the electric drive device 1 is improved.

  As described above, the electric drive device 1 includes the electric motor 30 and the ECU 10 provided on the non-load side of the shaft 31 in order to drive and control the electric motor 30. The ECU 10 includes a magnet 32 on the opposite end of the shaft 31, a sensor board 21 on which the rotation angle sensor 23 a is mounted, a first power board 25 </ b> A, a second power board 25 </ b> B, and a control board 24. Here, the rotation angle sensor 23 a is a magnetic sensor that detects the rotation of the magnet 32.

  25 A of 1st power boards mount the some electronic component 256 which supplies an electric current to 1st coil group Gr1 on the mounting surface of the radial direction outer side of the shaft 31. As shown in FIG. The second power board 25B mounts a plurality of electronic components 256 that supply current to the second coil group Gr2 on the mounting surface on the radially outer side of the shaft 31. The control board 24 mounts an electronic component 245 that controls a current supplied by at least one of the first power board 25 </ b> A and the second power board 25 </ b> B on the mounting surface on the radially outer side of the shaft 31.

  The first power board 25 </ b> A, the second power board 25 </ b> B, and the control board 24 are arranged around an extension line in the axial direction of the shaft 31. The first power board 25A, the second power board 25B, the control board 24, and the electric motor 30 are arranged so as to sandwich the sensor board 21 therebetween.

  According to this structure, since the sensor substrate 21 is disposed closer to the electric motor 30, the shaft 31 can be shortened. Thereby, the whirling of the shaft 31 is suppressed and the vibration of the electric motor 30 is suppressed. In addition, since the swing of the shaft 31 is suppressed, the detection accuracy of the rotation angle of the rotation angle sensor 23a is improved. Since the work procedure can be determined without considering the protection of the shaft 31, work efficiency is improved.

  In the electric drive device 1 of the present embodiment, the ECU 10 includes a magnet 32 at the end of the shaft 31 on the side opposite to the load and a board assembly 200. The board assembly 200 includes a heat sink 40, a sensor board 21, a first power board 25A, a second power board 25B, and a control board 24.

  The board assembly 200 includes a first power board 25A, a second power board 25A, a second power board 25B, and a control board 24 arranged around an extension line of the shaft 31 in the axial direction Ax. 25B and the control board 24 are assembled to the heat sink 40. The sensor board 21 is assembled to the heat sink 40 so that the first power board 25A, the second power board 25B, and the control board 24 are sandwiched between the electric motor 30 and the sensor board 21 in the axial direction Ax. Then, the board assembly 200 is fixed to the non-load side of the electric motor 30.

  According to this structure, the first power board 25A, the second power board 25B, the control board 24, and the sensor board 21 are fixed to the electric motor 30 by fixing the pre-assembled board assembly 200 to the opposite load side of the electric motor 30. 30. For this reason, the efficiency of attachment work improves.

  On the first power board 25A and the second power board 25B, in the axial direction Ax of the shaft 31, respectively, power terminal pieces 271 and 272 standing on the part near the connector CNT and standing on the part near the sensor board 21 are provided. Motor connection terminal pieces 261, 262, and 263. By attaching the connector CNT to the board assembly 200, the power supply terminal pieces 271 and 272 are connected to the power wiring PW. By fixing the board assembly 200 to the non-load side of the electric motor 30, the motor connection terminal pieces 261, 262, and 263 are easily connected to the coil wirings 321, 322, and 323.

  The power supply terminal pieces 271 and 272 and the motor connection terminal pieces 261, 262 and 263 are good conductor plate materials, and one surface of the plate material of the power supply terminal pieces 271 and 272 can be seen from the axial direction Ax. One surface of the plate materials 261, 262, and 263 is visible from the direction of the tangential line in the radial direction. With this structure, the power supply terminal pieces 271 and 272 can be easily connected to the power wiring PW by attaching the connector CNT in the axial direction. Further, by contacting the board assembly 200 on the opposite side of the electric motor 30 in the axial direction Ax and slightly rotating the board assembly 200 around the axial direction Ax, the motor connection terminal pieces 261, 262, 263 are The coil wirings 321, 322, and 323 can be easily contacted with each other. This improves the efficiency of the assembly work.

  As shown in FIG. 7, a positioning boss 330 serving as a positioning projection is provided on the non-load side of the electric motor 30. The positioning boss 330 regulates the position of the substrate assembly 200.

  As shown in FIGS. 8E and 10E, the connecting portion 43 of the heat sink 40 is provided with a recess 43H3 at a position corresponding to the positioning boss 330. The positioning boss 330 and the recess 43H3 are fitted together, and the position of the board assembly 200 with respect to the electric motor 30 is regulated.

  As shown in FIG. 7 or FIG. 16, after fixing the board assembly 200 to the anti-load side of the electric motor 30, the cover 210 covering the entire board assembly 200 is fixed to the anti-load side of the electric motor 30. Thereby, a part of the connector CNT passes through the through hole 212, and as described above, a sealed structure can be easily formed between the cover body 211 and the connector CNT.

  As shown in FIGS. 7 and 16, the coil wirings 321, 322, and 323 are arranged on the radially outer side than the heat sink 40. As a result, the coil wirings 321, 322, and 323 are arranged on the outer side in the radial direction than the sensor substrate 21, so that the influence of the magnetic field of the coil wirings 321, 322, and 323 is suppressed by the heat sink 40.

  The first power board 25A and the second power board 25B generate heat when the inverter circuit 251 operates. As shown in FIG. 7, the first power board 25 </ b> A is disposed at a position between the second power board 25 </ b> B and an extension line in the axial direction Ax of the shaft 31. Thereby, when both the first power board 25 </ b> A and the second power board 25 </ b> B are operating, the bias of the heat generation distribution is reduced in the internal space of the cover 210. In the present embodiment, the first power board 25A and the second power board 25B are parallel. Note that the first power board 25A and the second power board 25B may be arranged on a non-parallel plane across the extension line of the shaft 31 in the axial direction Ax.

  The heat sink 40 includes a first heat radiating arm portion 41, a second heat radiating arm portion 42, and a connecting portion 43, and has a U shape. The back surface of the first mounting surface of the first power substrate 25A is attached to the first surface 41a on the radially outer side of the first heat dissipation arm portion 41, and the back surface of the mounting surface of the second power substrate 25B is the second heat dissipation arm portion. 42 is attached to the first surface 42a on the radially outer side of 42. There is a space of the opening 44 between the second surface 41 b on the radially inner side of the first heat radiating arm portion 41 and the second surface 42 b on the radially inner side of the second heat radiating arm portion 42. According to this structure, even when the operation ratios of the first power board 25 </ b> A and the second power board 25 </ b> B are different, the heat transmitted to the first heat radiating arm part 41 and the second heat radiating arm part 42 are transmitted. Heat is divided by the openings 44 and can be dissipated. Further, since the second inner surface 41b in the radial direction of the first heat radiating arm portion 41 and the second inner surface 42b in the radial direction of the second heat radiating arm portion 42 are provided, the heat radiating area of the heat sink 40 is increased. Increases efficiency.

  For example, in the second power board 25B, when it is determined that the current value detected by the current detection circuit 254 is abnormal, the control calculation unit 241 drives the current cutoff circuit 255 via the cutoff drive circuit 243, and the inverter circuit 251. From the current to the second coil 38 is cut off. The control calculation unit 241 allows current to flow to the first coil 37 only from the inverter circuit 251 of the first power board 25A. Thereby, the heat generation of the first power board 25A increases, and the heat generation of the second power board 25B decreases. Even in this case, the heat transmitted from the first power board 25A to the first heat radiating arm portion 41 is efficiently radiated. Similarly, even when the heat generation of the second power board 25B increases and the heat generation of the first power board 25A decreases, the heat transmitted to the first heat dissipation arm portion 41 and the second heat dissipation arm portion 42 are similarly transmitted. Heat is divided by the openings 44 and can be dissipated.

  The electric power steering apparatus 100 includes an electronic control unit (ECU 10) and an electric motor 30 that is controlled by the electronic control unit (ECU 10) to generate an auxiliary steering torque. Thereby, the electric power steering apparatus 100 improves the efficiency of the assembly work.

1 Electric Drive Device 10 ECU (Electronic Control Device)
DESCRIPTION OF SYMBOLS 21 Sensor board | substrate 22 Motor rotation speed calculating part 23 Motor rotation angle detection circuit 23a Rotation angle sensor 24 Control board 25A 1st power board 25B 2nd power board 30 Electric motor 31 Shaft 32 Magnet 37 1st coil 38 2nd coil 40 Heat sink 41 First heat dissipating arm part 42 Second heat dissipating arm part 43H, 43H3 Recess 43H1, 43H2 Fastening hole 43 Connecting part 44 Opening part 45 Sensor substrate support part 46, 47 Support part 49 Choke coil 70 Second rack and pinion mechanism 71A Second pinion Shaft 71B Second pinion gear 71C Second rack 72 Tie rod 75A Worm shaft 75B Worm wheel 75 Deceleration device 82 Vehicle speed sensor 83 Power supply device 84 Ignition switch 91 Steering wheel 92 Steering shaft 92C G Shaft 92A output shaft 92A input shaft 94 torque sensor 96 universal joint 97A upper shaft 97 intermediate shaft 97B lower shaft 98 universal joint 99 first rack and pinion mechanism 99A first pinion shaft 99B first pinion gear 99C rack shaft 99D first rack DESCRIPTION OF SYMBOLS 100 Electric power steering apparatus 101 Vehicle 200 Board | substrate assembly 210 Cover 211 Cover main body 212 Through-hole 213 Fastening hole 218 Internal pressure adjustment part 219 Inner wall 221 Projection part 231 Storage part 232 Weir part 233 Overhang bottom part 241 Control calculation part 242 Gate drive circuit 243 Cutoff drive circuit 245 Electronic component 248 Lead insertion hole 251 Inverter circuit 252 Switching element 253 Smoothing capacitor 254 Current Detection circuit 255 Current interruption circuit 256 Electronic component 257 Lead terminal 261, 262, 263 Motor connection terminal piece 271 Power supply terminal piece 272 Power supply terminal piece 313 Fastening hole 314 Fastening hole 315 Fastening hole 321, 322, 323 Coil wiring 421 Recess 930 Housing 931 Stator core 931b Teeth 931a Back yoke 932b Magnet 932 Rotor 932a Rotor yoke Ax Axial CNT Connector Gr1 First coil group Gr2 Second coil group PW Power wiring Q Connection portion SV Vehicle speed signal T Steering torque signal Tdc Power supply terminal Tgnd Power supply terminal θm Motor electrical angle

Claims (11)

A shaft,
A motor rotor interlocked with the shaft;
A motor stator having a stator core for rotating the motor rotor, and a plurality of coil groups that are divided into at least two systems of first coil group and second coil group for every three phases, and that excites the stator core with a three-phase alternating current; Including an electric motor;
In order to drive and control the electric motor, an electronic control device provided on the anti-load side of the shaft,
The electronic control device
A magnet at the end of the shaft on the side opposite to the load, and a sensor substrate on the side opposite to the side of the shaft that is mounted on an extension line in the axial direction of the shaft and that mounts a magnetic sensor that detects the rotation of the magnet; ,
A first power board that mounts a plurality of electronic components that supply current to the first coil group on a first mounting surface on a radially outer side of the shaft;
A second power board for mounting a plurality of electronic components for supplying current to the second coil group on a second mounting surface on the radially outer side of the shaft;
A control board for mounting an electronic component for controlling a current supplied by at least one of the first power board and the second power board on a third mounting surface on a radially outer side of the shaft;
The first power board, the second power board, and the control board are disposed around an axial extension of the shaft, and the first power board, the second power board, the control board, and the electric motor Is an electric drive device arranged so as to sandwich the sensor substrate in the axial direction.   2. The electric drive device according to claim 1, wherein the first power board is disposed at a position sandwiching an extension line in the axial direction of the second power board and the shaft.   The electric drive device according to claim 2, wherein a mounting surface of the control board is different from a plane on which the mounting surface of the first power board and the mounting surface of the second power board are arranged. A connector for bundling a signal transmission wiring for transmitting an input / output signal of the control board and a power wiring for transmitting power;
The first power board and the second power board are erected on a portion near the connector in the axial direction of the shaft, and a power supply terminal piece connected to the power wiring,
In the axial direction of the shaft, a motor connection terminal piece standing on a portion near the sensor substrate and connected to the coil wiring of the first coil group or the second coil group;
The electric drive device according to claim 1, further comprising: The power supply terminal piece is a plate material of a good conductor,
The motor connection terminal piece is a plate member of a good conductor,
One surface of the plate of the power supply terminal piece is visible from the axial direction,
The electric drive device according to claim 4, wherein one surface of the plate member of the motor connection terminal piece is visible from the direction of the tangential line in the radial direction. The stator is divided into a shaft, a motor rotor interlocked with the shaft, a stator having a stator core for rotating the motor rotor, and at least two systems of first coil group and second coil group for every three phases. An electric motor including a plurality of coil groups excited by phase alternating current;
In order to drive and control the electric motor, an electronic control device provided on the anti-load side of the shaft,
The electronic control device
A magnet at the end of the shaft on the side opposite to the load, and a board assembly;
The substrate assembly includes:
A heat sink,
A sensor substrate mounted on a non-load side of the shaft and disposed on an extension line in the axial direction of the shaft and detecting a rotation of the magnet;
A first power board that mounts a plurality of electronic components that supply current to the first coil group on a first mounting surface on a radially outer side of the shaft;
A second power board for mounting a plurality of electronic components for supplying current to the second coil group on a second mounting surface on the radially outer side of the shaft;
A control board for mounting an electronic component for controlling a current supplied by at least one of the first power board and the second power board on a third mounting surface on a radially outer side of the shaft;
The first power board, the second power board, and the control board are arranged so that the first power board, the second power board, and the control board are arranged around an axial extension of the shaft. The sensor board is assembled to the heat sink so that the first power board, the second power board, the control board, and the electric motor are sandwiched between the sensor board in the axial direction.
An electric drive device in which the substrate assembly is fixed to a non-load side of the electric motor. The first power board is disposed at a position sandwiching the extension line in the axial direction of the shaft with the second power board,
The heat sink includes a first heat dissipating arm part, a second heat dissipating arm part, a connecting part that connects the first heat dissipating arm part and the second heat dissipating arm part, and is U-shaped.
The back surface of the first mounting surface is attached to the radially outer side of the first heat dissipating arm portion,
The back surface of the second mounting surface is attached to the radially outer side of the second heat dissipating arm part,
The electric drive device according to claim 6, wherein there is a space between a radially inner side of the first heat radiating arm portion and a radially inner side of the second heat radiating arm portion.   The electric drive device according to claim 7, wherein the control board is attached to the heat sink so as to straddle the first heat radiating arm portion and the second heat radiating arm portion.   In the axial direction of the shaft, there is provided a motor connection terminal piece standing on a portion near the sensor substrate and connected to the coil wiring of the first coil group or the second coil group. The electric drive device according to any one of claims 6 to 8, wherein the electric drive device is also arranged on a radially outer side of the shaft.   The electric drive device according to any one of claims 1 to 9, wherein the electronic component on the first mounting surface or the second mounting surface includes a switching element and a smoothing capacitor.   An electric power steering apparatus comprising the electric drive device according to any one of claims 1 to 10, wherein the electric drive device generates an auxiliary steering torque.

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