JP2018207640A - 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 suppressing malfunctions of a magnetic sensor while securing a heat radiation property of an inverter circuit.SOLUTION: An electric drive device comprises: a magnet arranged at an end part of a shaft of an electric motor; a heat sink having a first through-hole; a power substrate mounted with a magnetic sensor and an inverter circuit; and a control substrate. The heat sink is fixed at an anti-load side of the electric motor in a state where the magnet is inserted into the first through-hole of the heat sink. The power substrate and the control substrate are arranged so as to be orthogonal to an axial direction of the shaft in an order of the power substrate and the control substrate from the electric motor side. In addition, the magnetic sensor is held so as to be arranged on an axial direction of the magnet. At least a part of the power substrate and the heat sink are brought into contact with each other via a heat dissipation material. The heat sink comprises a groove part for suppressing a heat dissipation material from being intruded into the first through-hole.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.

  The vehicle is equipped with an electric power steering device that assists steering by an auxiliary steering force generated by the electric motor. The electric power steering device assists the driver's steering with the auxiliary steering torque output by the electric drive device. The electric drive device generates auxiliary steering torque when an ECU (Electronic Control Unit) outputs drive power to the electric motor. Some electric drive devices have a structure in which an electric motor and an ECU are assembled together. For example, Patent Literature 1 describes an example of an electric drive device in which an electric motor and an ECU are integrally assembled. In the electric drive device described in Patent Document 1, since the switching element generates heat, the switching element is brought into contact with a heat sink via an adhesive, an insulating sheet, and the like to radiate and cool.

International Publication No. 2015/122069

  When the switching element is brought into contact with the heat sink via an adhesive or an insulating sheet, the heat dissipation is high, but it is difficult to shorten the assembly work time. In view of this, it is considered that an inverter circuit having a switching element is arranged on the first surface of the resin substrate that can be mounted on both sides, and a magnetic sensor is arranged on the second surface of the resin substrate, thereby improving the assemblability. It is done. However, since there is a resin substrate between the inverter circuit and the heat sink, a heat dissipation material is often applied between the heat sink and the resin substrate so that heat easily moves from the resin substrate to the heat sink. However, if the heat dissipating material adheres to the magnetic sensor or the magnet corresponding to the magnetic sensor, it may cause a malfunction of the magnetic sensor.

  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 can suppress malfunction of a magnetic sensor while ensuring heat dissipation of an inverter circuit. Yes.

  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. 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 a magnet fixed to an end of the shaft opposite to the load side; A heat sink having a first through hole, a first inverter circuit that supplies current to the first coil group, and a second inverter circuit that supplies current to the second coil group are mounted on a first mounting surface, and A power substrate that is a resin substrate on which a magnetic sensor for detecting rotation is mounted on a second mounting surface; the first inverter circuit; A control board on which an electronic component for controlling a current supplied by at least one of the second inverter circuits is mounted, and the heat sink has the magnet inserted into the first through hole. The power board and the control board are fixed to the non-load side, the power board and the control board are orthogonal to the axial direction of the shaft, and the power board and the control board are arranged in this order from the electric motor side, and the magnetic sensor The power board and the control board are held by the heat sink such that the power board and the control board are arranged on the axial direction of the magnet, and at least a part of the power board and the heat sink are in contact with each other via a heat dissipation material, Includes a groove portion that prevents the heat dissipation material from entering the first through hole.

  According to this, the heat of the power board can be efficiently radiated to the heat sink. Moreover, it can suppress that a thermal radiation material penetrate | invades into a 1st through-hole. As a result, the heat dissipation material is less likely to adhere to the magnetic sensor or the magnet corresponding to the magnetic sensor. For this reason, malfunction of a magnetic sensor is suppressed. And since the circumference | surroundings of a magnetic sensor are enclosed by the 1st through-hole, the influence of the magnetic field of a 1st coil wiring or a 2nd coil wiring with respect to a magnetic sensor can be suppressed. Therefore, the detection accuracy of the magnetic sensor can be improved. Also, the assembly work efficiency is improved. The power board and the control board can be arranged in the axial direction. Therefore, the electric drive device can suppress the axial thickness. As a result, the electric drive device can be reduced in size.

  As a desirable mode, a groove of the heat sink surrounds the first through hole.

  According to this, even if the application amount of the heat radiating material is large, the magnetic sensor is less likely to malfunction, so that the heat of the power board can be efficiently radiated to the heat sink.

  As a desirable mode, when viewed in the axial direction, the first inverter circuit and the second inverter circuit are arranged at an interval on the first mounting surface of the power board, and viewed in the axial direction, The power board is held by a heat sink so that the interval and the first through hole on the second mounting surface side overlap.

  The back surface of the portion of the first mounting surface on which the first inverter circuit and the second inverter circuit are mounted can be in contact with the heat sink via a heat dissipation material. Therefore, the efficiency with which the heat generated in the first inverter circuit and the second inverter circuit can be dissipated to the heat sink is increased. Further, the heat generated in the first inverter circuit and the heat generated in the second inverter circuit can be dispersed on the power board. As a result, it is possible to suppress the warpage of the power substrate that is likely to occur in the resin substrate and is caused by thermal imbalance.

  As a desirable mode, the first insulating member inserted into the second through hole penetrating the heat sink in a direction parallel to the axial direction, and the third through hole penetrating the heat sink in a direction parallel to the axial direction. A plurality of first coil wirings connected to the first coil group, a plurality of second coil wirings connected to the second coil group, and a plurality of the first coil wirings connected to the first coil group. The coil wiring penetrates through the first insulating member and is connected to the power board, and the plurality of second coil wirings penetrate through the second insulating member and are connected to the power board.

  According to this, the direction and position where the first coil wiring or the second coil wiring protrudes can be fixed. Furthermore, it is possible to prevent the first coil wiring or the second coil wiring and the heat sink from contacting and short-circuiting.

  As a desirable mode, at least one electronic component mounted on the second mounting surface of the power board is provided, and the heat sink includes a recess capable of accommodating the electronic component.

  According to this, even when the electronic component is arranged on the mounting surface on the electric motor side of the power board, the electronic component can be accommodated in the heat sink. Furthermore, by housing the electronic component inside the heat sink, heat dissipation of the electronic component can be promoted. Therefore, the lifetime of the electronic component can be improved. As a result, the electric drive device can improve the lifetime of the electronic component while suppressing the axial thickness.

  As a desirable mode, a heat dissipation material is interposed between the electronic component mounted on the second mounting surface to be inserted into the recess and the bottom of the recess.

  According to this, the heat of the electronic component mounted on the second mounting surface inserted into the recess can be efficiently radiated to the heat sink.

  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.

  ADVANTAGE OF THE INVENTION According to this invention, the electric drive device and electric power steering device which can suppress the malfunctioning of a magnetic sensor, ensuring the heat dissipation of an inverter circuit 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. 8G is a partial cross-sectional 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. 10 is a plan view of the power board of the present embodiment. FIG. 11A is a front view of the heat sink of the present embodiment. FIG. 11B is a left side view of the heat sink of the present embodiment. FIG. 11C is a right side view of the heat sink of the present embodiment. FIG. 11D is a plan view of the heat sink of the present embodiment. FIG. 11E is a bottom view of the heat sink of the present embodiment. FIG. 11F is a rear view of the heat sink of the present embodiment. FIG. 12 is an explanatory diagram for explaining the positional relationship among the shaft, the magnet, and the rotation angle sensor of the present embodiment. FIG. 13 is an explanatory diagram for explaining the connection between the motor connection terminal piece and the coil wiring of 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.

  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 opposite 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 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 the present embodiment is excited by being supplied with current by the inverter circuit 251 (see FIG. 6) of the first circuit portion 256A of the power board 25. 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 circuit portion 256B of the power board 25. 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 number calculation unit 22, a rotation angle sensor 23a, a gate drive circuit 242, a cutoff drive circuit 243, a first circuit unit 256A, 2 circuit portion 256B.

The control calculation unit 241 calculates a motor current command value. The motor rotation number calculation unit 22 calculates the motor electrical angle θ _m and outputs it to the control calculation unit 241. The motor current command value output from the control calculation unit 241 is input to the gate drive circuit 242 and the gate drive circuit 242. The gate drive circuit 242 controls the first circuit unit 256A and the second circuit unit 256B based on the motor current command value.

As shown in FIG. 6, the ECU 10 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 θ _m based on the detection value of the rotation angle sensor 23 a and outputs the motor electric angle θ _m 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 signal SV, which is detected by the vehicle speed sensor 82, a motor electric angle theta _m output from the motor rotational speed calculating section 22, but Entered. Control calculation unit 241, steering torque signal T, calculates a current command value based on the vehicle speed signal SV and the motor electric angle theta _m, and outputs 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 the first pulse width modulation signal to the inverter circuit 251 of the first circuit unit 256A. 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 the second pulse width modulation signal based on the current command value, and outputs it to the inverter circuit 251 of the second circuit unit 256B. 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.

  The inverter circuit 251 is a power conversion circuit that converts DC power into AC power. As shown in FIG. 6, the inverter circuit 251 has a plurality of switching elements 252. The switching element 252 is, for example, a field effect transistor. A smoothing capacitor 253 is connected to the inverter circuit 251 in parallel. The smoothing capacitor 253 is, for example, an electrolytic capacitor.

  As shown in FIG. 6, the inverter circuit 251 includes a current detection circuit 254 for detecting a current value. The current detection circuit 254 includes, for example, 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. A power wiring PW that transmits power from the power supply device 83 is connected to the power board 25 via a 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. 8G is a partial cross-sectional view of the substrate assembly of the present embodiment. FIG. 9 is an exploded perspective view of the substrate assembly of the present embodiment. 8G is a cross-sectional arrow view of VIIIG-VIIIG in FIG. FIG. 10 is a plan view of the power board of the present embodiment. In the present embodiment, a rear bracket 33 is disposed on the non-load side of the electric motor 30. The ECU 10 is fixed to the electric motor 30 via the rear bracket 33.

  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, the board assembly 200 includes a control board 24, a power board 25, an inter-board connector 257, a heat sink 40, and a connector CNT.

  The power board 25 and the control board 24 are printed boards formed of resin or the like. The power substrate 25 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 power substrate 25 is a metal substrate, the heat conductivity to the heat sink 40 is improved.

  As shown in FIG. 9, the control board 24 includes electronic components 245 that constitute the control calculation unit 241, the gate drive circuit 242, and the cutoff drive circuit 243 shown in FIG. 6. The control board 24 includes a heat sink fixing hole 246, a connector fixing hole 247, and an inter-board connector fixing hole 248.

  As shown in FIG. 10, the power board 25 includes a first circuit unit 256A and a second circuit unit 256B. The first circuit portion 256A and the second circuit portion 256B are configured by an inverter circuit 251, a current detection circuit 254, and a current cutoff circuit 255 shown in FIG. The power board 25 includes power supply terminal pieces 271 and 272 and motor connection terminal pieces 261A, 262A, 263A, 261B, 262B, and 263B. The power board 25 includes a coil wiring through hole 260, an inter-board connector fixing hole 258, a smoothing capacitor 253, heat sink fixing holes 259 and 259A, and a rotation angle sensor 23a. The power substrate 25 is a resin substrate that can be mounted on both sides.

  As shown in FIGS. 9 and 10, the power supply terminal pieces 271 and 272 are erected with respect to the first mounting surface 25 a of the power board 25. 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 261A, 262A, 263A, 261B, 262B, 263B are erected with respect to the first mounting surface 25a of the power board 25. The motor connection terminal pieces 261A, 262A, 263A, 261B, 262B, 263B are plate members made of a good conductor such as copper or aluminum.

  The inter-board connector 257 is a connector that electrically connects the control board 24 and the power board 25. The board-to-board connector 257 is fixed to the control board 24 and the power board 25 by fixing pins, for example. Specifically, the inter-board connector 257 is fixed by inserting the fixing hook of the inter-board connector 257 into the inter-board connector fixing hole 248 of the control board 24. The inter-board connector 257 is fixed by inserting the fixing hook of the inter-board connector 257 into the inter-board connector fixing hole 258 of the power board 25. The gate drive circuit 242 and the cutoff drive circuit 243 on the control board 24 control the switching element 252 via the board-to-board connector 257.

  The coil wiring through hole 260 is a hole that penetrates the power board 25 in the axial direction Ax. As shown in FIG. 8E, the rotation angle sensor 23a is mounted on the second mounting surface 25b of the power board 25 on the electric motor 30 side. As shown in FIGS. 8G and 9, the smoothing capacitor 253 is mounted on the second mounting surface 25b of the power board 25 on the electric motor 30 side. The heat sink fixing holes 259 and 259A are holes that penetrate the power board 25 in the axial direction Ax. As shown in FIG. 10, the heat sink fixing hole 259 is a circular hole in plan view. The heat sink fixing hole 259A is an elliptical hole in plan view.

  As shown in FIG. 9, the connector CNT includes power supply terminals Tdc and Tgnd, a boss 50, and a fixing hook 52. 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. 8A) of the power board 25 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 power board 25 are in surface contact.

  The power supply terminal Tgnd is pressed against the power supply terminal piece 271 (see FIG. 8A) of the power board 25 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 power board 25 are in surface contact.

  As shown in FIGS. 9 and 8D, the bosses 50 are protrusions formed at the four corners of the connector CNT. The boss 50 has a substantially cylindrical shape and penetrates in the axial direction Ax.

  As shown in FIG. 9, the fixing hooks 52 are protrusions formed at the four corners of the connector CNT. The fixed hook 52 protrudes toward the control board 24. An engaging portion 52 </ b> H having a diameter larger than that of the connector fixing hole 247 of the control board 24 is formed at the tip of the fixing hook 52. As shown in FIGS. 8A, 8B, 8C, and 8F, the connector CNT is fixed by inserting the fixing hook 52 into the connector fixing hole 247 and engaging the engaging portion 52H with the connector fixing hole 247. The

  FIG. 11A is a front view of the heat sink of the present embodiment. FIG. 11B is a left side view of the heat sink of the present embodiment. FIG. 11C is a right side view of the heat sink of the present embodiment. FIG. 11D is a plan view of the heat sink of the present embodiment. FIG. 11E is a bottom view of the heat sink of the present embodiment. FIG. 11F is a rear view of the heat sink of the present embodiment.

  As shown in FIGS. 9 and 11A to 11F, the heat sink 40 includes a first through hole 41, a second through hole 42A, a third through hole 42B, a recess 43, a fastening hole 43H, and a boss 44. , A groove portion 45, an electronic component housing portion 46, and a power board fixing hole 47. The heat sink 40 is integrally formed by die casting, for example. The heat sink 40 is made of aluminum, for example.

  As shown in FIGS. 9, 11D, and 11E, the first through hole 41, the second through hole 42A, and the third through hole 43A are openings that penetrate the heat sink 40 in the axial direction Ax. As shown in FIGS. 11D and 11E, the first through hole 41 is a circular opening as viewed from the axial direction Ax. The diameter of the first through hole 41 is larger than the diameter of the magnet 32. The second through hole 42A and the third through hole 42B are rectangular openings when viewed from the axial direction Ax.

  As shown in FIGS. 9, 11A to 11D, and 11F, the heat sink 40 is provided with four concave portions 43 that are formed by counterboring in the axial direction Ax. In the axial direction Ax of the recess 43, there is a fastening hole 43H. Referring to FIGS. 7 and 11E, the fastening hole 43H and the fastening hole 314 of the rear bracket 33 overlap each other, and the bolts are inserted, whereby the heat sink 40 and the electric motor 30 are fastened. In the recess 43, a bolt inserted into the fastening hole 43H is arranged. As a result, the driver can be inserted into the recess 43. Accordingly, the heat sink 40 can be fixed to the electric motor 30 even if the heat dissipation efficiency is improved by making the maximum use of the volume of the cover 210.

  As shown in FIG. 9, the bosses 44 are protrusions formed at the four corners of the heat sink 40. The boss 44 is hollow inside. The boss 44 is threaded. Referring to FIGS. 8D and 9, the boss 44 and the heat sink fixing hole 246 of the control board 24 overlap with the boss 50, and the fixing screw 50 </ b> M is fastened, whereby the control board 24 and the connector CNT are attached to the heat sink 40. Fixed.

  As shown in FIGS. 9 and 11D, the groove 45 is a groove formed on the contact surface 48 of the heat sink 40 opposite to the electric motor 30 side. A heat radiating material (TIM; Thermal Interface Material) 49 is applied to the contact surface 48. The heat radiating material 49 is also called a heat radiating grease, for example, and is a heat radiating material in which an insulating base material such as a silicone polymer is mixed with a heat conductive filler. Carbon, silver paste, or the like is used for the heat conductive filler. The contact surface 48 is in contact with the power board 25 through the heat dissipation material 49. The groove 45 is around the first through hole 41 and is formed in an annular shape, for example. As long as the groove 45 is around the first through hole 41, the groove 45 may be rectangular or hexagonal, and may surround the first through hole 41. According to this, it is possible to suppress the heat dissipation material 49 from entering the first through hole 41.

  As shown in FIGS. 9 and 11D, the electronic component housing portion 46 is a recess formed in the contact surface 48 of the heat sink 40. The electronic component housing portion 46 houses the smoothing capacitor 253 shown in FIG. The power board fixing hole 47 is a screw hole. Referring to FIG. 9, the power board fixing hole 47 and the heat sink fixing holes 259 and 259 </ b> A overlap each other, and the fixing board is fastened to fix the power board 25 to the heat sink 40.

  FIG. 12 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. 12 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 on the outer peripheral surface when viewed in the circumferential direction. The heat sink 40 holds the power board 25 so that the rotation angle sensor 23 a is disposed on an extension line of the magnet 32 in the axial direction Ax. 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. 13 is an explanatory diagram for explaining the connection between the motor connection terminal piece and the coil wiring of the present embodiment. As shown in FIG. 7, the electric motor 30 includes coil wirings 321A, 322A, 323A, 321B, 322B, and 323B that protrude to the anti-load side. The coil wirings 321A, 322A, 323A, 321B, 322B, 323B are copper wires or aluminum wires, and are so-called plate-like rectangular wires. As shown in FIG. 7, the coil wirings 321A, 322A, 323A pass through the first insulating member 330A. The coil wirings 321B, 322B, and 323B penetrate the second insulating member 330B. The first insulating member 330A and the second insulating member 330B are insulating guide members. That is, as shown in FIG. 13, the first insulating member 330 </ b> A is a member that guides the coil wirings 321 </ b> A, 322 </ b> A, and 323 </ b> A to be inserted into the coil wiring through hole 260. Similar to the first insulating member 330A, the second insulating member 330B is a member that guides the coil wirings 321B, 322B, and 323B to be inserted into the coil wiring through hole 260. Thereby, the direction and position where coil wiring 321A, 322A, 323A, 321B, 322B, and 323B protrude can be fixed. Furthermore, it is possible to prevent the coil wirings 321A, 322A, 323A, 321B, 322B, 323B and the heat sink 40 from coming into contact with each other and short-circuiting.

  As shown in FIG. 13, the planes of the motor connection terminal pieces 261A, 262A, and 263A are opposed to the planes of the coil wirings 321A, 322A, and 323A, pressed so that the planes are in contact, and resistance welding or laser welding is performed. Yes. The planes of the motor connection terminal pieces 261B, 262B, and 263B are opposed to the planes of the coil wirings 321B, 322B, and 323B, pressed so that the planes are in contact with each other, and resistance welding or laser welding is performed.

  As shown in FIGS. 6 and 8A, the power supply voltage Vdc of the power supply device 83 is supplied to the power board 25 via the power supply terminals Tdc and Tgnd. Further, the power supply voltage of the power supply device 83 supplied to the power board 25 is supplied to the control board 24 via the inter-board connector 257 described above.

  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 sealing material of the storage portion 231 is filled, the space between the storage portion 231 and the protrusion 221 is sealed, and a sealed structure is created between the cover 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).

  As shown in FIGS. 7 and 14, the cover 210 includes an internal pressure adjustment 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 power board 25, a control board 24, and a heat sink 40. The heat sink 40 is fixed to the non-load side of the electric motor 30. The heat sink 40 holds the power board 25 and the control board 24 so that the power board 25 and the control board 24 are orthogonal to the axial direction Ax. According to this, the power board 25 and the control board 24 can be arranged side by side in the axial direction Ax. Therefore, the electric drive device 1 can suppress the thickness of the ECU 10 in the axial direction Ax.

  In addition, the heat sink 40 includes an electronic component housing portion 46 that houses the smoothing capacitor 253 of the power board 25. The smoothing capacitor 253 is one of electronic components. According to this, even when the smoothing capacitor 253 is disposed on the second mounting surface 25 b on the electric motor 30 side of the power board 25, the smoothing capacitor 253 can be accommodated inside the heat sink 40. Further, by housing the smoothing capacitor 253 inside the heat sink 40, heat dissipation of the smoothing capacitor 253 can be promoted. Therefore, the life of the smoothing capacitor 253 can be improved. As a result, the electric drive device 1 can improve the life of the smoothing capacitor 253 while suppressing the thickness in the axial direction Ax. Note that an electronic component other than the smoothing capacitor 253 may be mounted on the second mounting surface 25 b of the power board 25 and stored in the electronic component storage portion 46.

  A heat dissipation material 49 is applied between the smoothing capacitor 253 and the bottom of the electronic component housing 46. Since the heat radiating material 49 having a higher thermal conductivity than air is in contact with the end face of the smoothing capacitor 253 and the bottom of the electronic component housing portion 46, the heat radiating efficiency is improved as compared with the case where there is no heat radiating material 49. The heat radiating material 49 does not necessarily have to be in contact with the entire bottom end surface of the electronic component housing portion 46 of the smoothing capacitor 253. The heat dissipating material 49 only needs to be in contact with at least a part of the bottom side end surface of the electronic component housing portion 46 of the smoothing capacitor 253. However, it is preferable that the heat dissipation material 49 is in contact with at least the center of the end surface on the bottom side of the electronic component housing portion 46 of the smoothing capacitor 253. Further, the heat radiating material 49 may be in contact with the outer peripheral surface of the smoothing capacitor 253 as well as the end surface on the bottom side of the electronic component housing portion 46 of the smoothing capacitor 253.

  Here, the inverter is known to cause noise. The inverter generates an alternating current by switching control. The alternating current generated by the inverter may induce an induced voltage in the control circuit. Therefore, for example, when a control circuit is arranged between the inverter and the load, there is a concern about the influence of noise on the control circuit.

  On the other hand, the electric drive device 1 holds the power board 25 and the control board 24 so that the heat sink 40 is in the order of the power board 25 and the control board 24 from the electric motor 30 side. Therefore, the alternating current converted by the first circuit unit 256 </ b> A and the second circuit unit 256 </ b> B is directly supplied to the electric motor 30 without flowing in the vicinity of the control board 24. According to this, the influence of the noise which the inverter circuit 251 gives to the control board 24 can be suppressed.

  As shown in FIG. 10, in the electric drive device 1, the first circuit portion 256 </ b> A and the second circuit portion 256 </ b> B have the first through hole 41, the second through hole 42 </ b> A, the third through hole 42 </ b> B and the axial direction Ax. Do not overlap. In other words, when the heat sink 40 is viewed from the electric motor 30 side, the first circuit portion 256A and the second circuit portion 256B are all covered with the heat sink 40. That is, the back surfaces of the first circuit portion 256 </ b> A and the second circuit portion 256 </ b> B are in contact with the contact surface 48 of the heat sink 40 via the heat dissipation material 49. According to this, the heat generated in the inverter circuits 251 of the first circuit portion 256A and the second circuit portion 256B can be effectively radiated to the heat sink 40.

  As shown in FIG. 10, the first circuit portion 256 </ b> A and the second circuit portion 256 </ b> B are arranged with an interval when viewed in a plan view. The interval between the first circuit portion 256A and the second circuit portion 256B is an empty section having no electronic components on the first mounting surface 25a. Then, when viewed in the axial direction Ax, the interval (the above-described empty section) between the first circuit portion 256A including the first inverter circuit 251 and the second circuit portion 256B including the second inverter circuit, and the first penetration The power board 25 is held by the heat sink 40 described above so that the hole 41 overlaps. As described above, the first circuit portion 256A and the second circuit portion 256B are arranged at positions where the first through hole 41 is interposed between the first circuit portion 256A and the second circuit portion 256B as viewed in a plan view. According to this, the heat generated in the first circuit portion 256A and the heat generated in the second circuit portion 256B can be dispersed on the power board 25. Therefore, the electric drive device 1 can disperse the heat generated on the power board 25. Thereby, it is possible to suppress the warpage of the power substrate 25 that is likely to occur in the resin substrate and is caused by thermal imbalance.

  In the electric drive device 1, it is more preferable that the first circuit portion 256 </ b> A and the second circuit portion 256 </ b> B are arranged point-symmetrically with respect to the axial direction Ax in plan view. In the electric drive device 1, it is more preferable that the first circuit portion 256 </ b> A and the second circuit portion 256 </ b> B are arranged in line symmetry with respect to a straight line that intersects the axial direction Ax in plan view. Thereby, the heat generated in the power substrate 25 can be more uniformly dispersed.

  In the axial direction Ax, the electric drive device 1 is erected at a position where the power terminal pieces 271 and 272 are in contact with the power terminals Tdc and Tgnd of the connector CNT. Therefore, by attaching the connector CNT to the board assembly 200, the power terminal pieces 271 and 272 can be connected to the power wiring PW. Further, the electric drive device 1 is erected at positions where the motor connection terminal pieces 261A, 262A, 263A are in contact with the coil wirings 321A, 322A, 323A. Therefore, by fixing the board assembly 200 to the side opposite to the load of the electric motor 30, the motor connection terminal pieces 261A, 262A, 263A can be easily connected to the coil wirings 321A, 322A, 323A. Moreover, the electric drive device 1 is erected at a position where the motor connection terminal pieces 261B, 262B, 263B are in contact with the coil wirings 321B, 322B, 323B. Thus, by fixing the board assembly 200 to the opposite side of the electric motor 30, the motor connection terminal pieces 261B, 262B, 263B can be easily connected to the coil wirings 321B, 322B, 323B. This improves the efficiency of the assembly work.

  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.

  As shown in FIG. 7, after fixing the board assembly 200 to the anti-load side of the electric motor 30, a cover 210 that covers 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 FIG. 12, the rotation angle sensor 23 a is inserted into the first through hole 41 of the heat sink 40. That is, the rotation angle sensor 23 a is covered with the heat sink 40 on the radially outer side in the axial direction Ax. Thereby, the influence of the magnetic field of coil wiring 321A, 322A, 323A, 321B, 322B, 323B with respect to the rotation angle sensor 23a is suppressed. Therefore, the electric drive device 1 can suppress the influence of noise on the rotation angle sensor 23a. As a result, the angle detection accuracy of the rotation angle sensor 23a can be improved.

1 Electric drive device 10 ECU
23a Rotation angle sensor 24 Control board 25 Power board 30 Electric motor 31 Shaft 32 Magnet 37 First coil 38 Second coil 40 Heat sink 41 First through hole 42A Second through hole 42B Third through hole 46 Electronic component housing part 100 Electric power Steering device 101 Vehicle 200 Substrate assembly 210 Cover 241 Control operation unit 242 Gate drive circuit 243 Cutoff drive circuit 251 Inverter circuit 253 Smoothing capacitor 256A First circuit unit 256B Second circuit units 261A, 262A, 263A, 261B, 262B, 263B Motor connection terminal pieces 271,272 Power supply terminal pieces 321A, 322A, 323A, 321B, 322B, 323B Coil wiring 330A First insulating member 330B Second insulating member CNT Connector Ax Axial direction Gr1 First coil group r2 second coil group Tdc, Tgnd power supply terminal

Claims (7)

A shaft,
A motor rotor interlocked with the shaft;
A motor stator having a stator core that rotates the motor rotor, and a plurality of coil groups that are divided into at least two systems of first coil groups and second coil groups every three phases, and that excites the stator core with three-phase alternating current; Including an electric motor;
A magnet fixed to the end of the shaft on the opposite side of the load;
A heat sink having a first through hole;
A first inverter circuit that supplies current to the first coil group and a second inverter circuit that supplies current to the second coil group are mounted on a first mounting surface, and a magnetic sensor that detects rotation of the magnet is a second. A power board which is a resin board mounted on the mounting surface;
A control board on which electronic components that control current supplied by at least one of the first inverter circuit and the second inverter circuit are mounted;
The heat sink is fixed to the non-load side of the electric motor in a state where the magnet is inserted into the first through hole,
The power board and the control board are orthogonal to the axial direction of the shaft, and are arranged in order of the power board and the control board from the electric motor side, and the magnetic sensor is in the axial direction of the magnet. The power board and the control board are held by the heat sink so as to be disposed on the top,
At least a part of the power board and the heat sink are in contact with each other through a heat dissipation material,
The said heat sink is an electric drive device provided with the groove part which suppresses that the said heat radiating material penetrate | invades into the said 1st through-hole.   The electric drive device according to claim 1, wherein a groove portion of the heat sink surrounds the first through hole. When viewed in the axial direction, the first inverter circuit and the second inverter circuit are arranged at an interval on the first mounting surface of the power board,
3. The electric drive device according to claim 1, wherein the power board is held by a heat sink so that the distance and the first through hole on the second mounting surface side overlap each other when viewed in the axial direction. A first insulating member inserted into a second through hole penetrating the heat sink in a direction parallel to the axial direction;
A second insulating member inserted into a third through hole penetrating the heat sink in a direction parallel to the axial direction;
A plurality of first coil wires connected to the first coil group;
A plurality of second coil wirings connected to the second coil group,
The plurality of first coil wirings are connected to the power board through the first insulating member,
4. The electric drive device according to claim 1, wherein the plurality of second coil wirings are connected to the power board through the second insulating member. 5. Comprising at least one electronic component mounted on the second mounting surface of the power board;
The electric drive device according to any one of claims 1 to 4, wherein the heat sink includes a recess capable of accommodating the electronic component.   The electric drive device according to claim 5, wherein a heat dissipating material is interposed between the electronic component mounted on the second mounting surface inserted into the recess and the bottom of the recess.   An electric power steering device comprising the electric drive device according to any one of claims 1 to 6, wherein an auxiliary steering force is applied to the vehicle.

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