Electric drive system and electric power steering system

Abstract

Provided is an electric drive device of which the outer diameter size can be reduced, and the layout of a power harness and a signal harness can be changed.　The electric drive device is one in which a motor and a control unit are integrated coaxially with a motor output shaft. The control unit is arranged on the side of motor that is opposite from the output side, and is electrically connected to the outside via a wire harness. The electric drive device has a connector block having first and second connector parts each having a connector connection opening to be connected to a mating connector, and a circuit board to which connection terminals of the first and second connector parts are electrically connected. The second connector part is arranged on an exterior surface different from a connector formation surface where the first connector part is located, or on an exterior surface different from the exterior surface that covers the circuit board.

Description

Technical Field

[0001] The present invention relates to an electric drive device in which a motor and a control unit for controlling the drive of the motor are integrated, and an electric power steering device that assists the steering force of a vehicle steering device using this electric drive device. More specifically, it relates to the layout of connectors in the electric drive device.

Background Art

[0002] Conventionally, in an electric power steering device, a control unit for controlling the drive of a motor includes a plurality of connectors corresponding to a large number of sensor systems, signal systems, and power supply system harnesses (see, for example, Patent Document 1). In this Patent Document 1, each connector is arranged in the direction of the motor rotation axis, and the ignition system connector and the sensor system connector face the frontage in the direction of the motor rotation axis. Also, the angle of the frontage of the battery system connector is changed to face the outer diameter direction.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] The present invention has been made in view of the above circumstances, and its purpose is to provide an electric drive device that can be made smaller in outer diameter size and allows for changes in the layout of power harnesses and signal harnesses, and an electric power steering device using this electric drive device. [Means for solving the problem]

[0007] According to one aspect of the present invention, an electric drive device is provided in which a motor and a control unit are integrated coaxially with the motor output shaft, the control unit is positioned on the opposite side from the output side of the motor and is electrically connected to the outside via a wire harness, and the motor and the control unit are housed in a cylindrical outer cover, wherein the control unit has a connector block having a first connector portion and a second connector portion having connector connection openings formed for connection to a mating connector, and a circuit board to which the connection terminals of the first connector portion and the second connector portion are electrically connected. ,before When the direction of the rotation axis of the motor is X and the direction perpendicular to the rotation axis is Y, the first connector part is , of the aforementioned exterior covers, The second connector portion protrudes from the exterior surface in the X direction. 、 The connector protrudes from the exterior surface in the Y direction, and the first connector portion and the second connector portion each have a plurality of connection terminals, and when the second connector portion is viewed from the front, the plurality of connection terminals of the first connector portion are perpendicular to the Z direction of the X direction and the Y direction, respectively. They are arranged to line up along the same path. The multiple connection terminals of the second connector section are in the X direction Lined up along the side An electric drive device is provided, characterized by being arranged in a particular manner. Furthermore, according to another aspect of the present invention, an electric power steering system is provided, characterized in that the motor in the electric drive system is used to provide steering force to the steering system. [Effects of the Invention]

[0008] In this invention, by changing the connector forming surface to have two protruding directions for the connector opening, and by arranging a part of the connector on an outer surface different from the connector forming surface, or on an outer surface different from the outer surface covering the circuit board, the outer diameter size of the outer casing can be reduced. Furthermore, because the protruding direction of the connector opening is two-way, the layout of the power harness and signal harness can be changed according to the vehicle layout. Therefore, according to the present invention, it is possible to provide an electric drive device that can be made smaller in outer diameter size and allows for changes in the layout of power harnesses and signal harnesses, as well as an electric power steering device using this electric drive device. [Brief explanation of the drawing]

[0009] [Figure 1] This is a perspective view of the external appearance of an electric drive device according to an embodiment of the present invention. [Figure 2] Figure 1 is a plan view of the electric drive unit as seen from the first connector side. [Figure 3] Figure 2 is a plan view illustrating the circuit board inside the outer cover and the arrangement of electronic components mounted on this circuit board. [Figure 4] This is a cross-sectional view along the line A-A' in Figure 2. [Figure 5] This is a schematic diagram of an electric power steering device according to an embodiment of the present invention. [Figure 6] Figure 1 is a diagram illustrating the installation of the electric drive unit shown in Figure 1 onto the electric power steering system. [Figure 7] This figure illustrates a first modified example of an electric drive device according to an embodiment of the present invention. [Figure 8] This figure illustrates a second modified example of an electric drive device according to an embodiment of the present invention. [Figure 9] This figure illustrates a third modified example of an electric drive device according to an embodiment of the present invention. [Modes for carrying out the invention]

[0010] Embodiments of the present invention will be described below with reference to the drawings. Figure 1 is an external perspective view of an electric drive device (electric power pack) according to an embodiment of the present invention. Figure 2 is a plan view of the electric drive device shown in Figure 1, viewed from the first connector side. As shown in Figure 1, the electric power pack (EPP) 10 is cylindrical in shape, and the motor 20 and control unit 30 are integrated coaxially (in the direction of the rotation axis X) with the motor output shaft 21. The control unit 30 is positioned on the opposite side of the motor 20 from the output side. This control unit 30 is electrically connected to external devices such as a power supply, electronic equipment for in-vehicle communication (CAN: Controller Area Network), and a torque sensor via a wire harness (not shown), and controls the drive of the motor 20.

[0011] The exterior cover (exterior member) 13 of the control unit 30 is provided with a connector block having a first connector section 11 and a second connector section 12. On the control unit 30 side of the exterior cover 13, a connector connection opening (first connector section 11) is formed for connection to the mating connector. The exterior cover 13 has a cylindrical curved side surface, and on this side surface, the position where the second connector section 12 protrudes is formed as a flat surface, forming a connector connection opening for connection to the mating connector. The first connector section 11 has connection terminals 11-1 and 11-2 for power supply and in-vehicle communication, and the second connector section 12 has connection terminals 12-1 and 12-2 for a torque sensor that detects the torque applied to the steering shaft.

[0012] When the axial direction of the rotation axis of the motor 20 is defined as X and the direction perpendicular to this rotation axis is defined as Y, the first connector portion 11 protrudes from the exterior surface in the X direction, and the second connector portion 12 protrudes from the exterior surface in the Y direction. That is, the second connector portion 12 is disposed on an exterior surface different from the connector formation surface on which the first connector portion 11 is located, or an exterior surface different from the exterior surface covering the circuit board 14. Liquid curable sealants 11a and 12a are applied to the exterior surfaces around the first connector portion 11 and the second connector portion 12, and the waterproofness and airtightness of the control unit 30 and the motor 20 inside the exterior cover 13 are maintained.

[0013] The connector block serves as a connector connection interface for connecting to the mating connector of the electric power pack 10. The connection terminals 11-1 and 11-2 of the first connector portion 11 are electrically connected to the electronic circuit of the circuit board 14 shown in FIG. 3, respectively, and the connection terminals 12-1 and 12-2 of the second connector portion 12 are electrically connected to the electronic circuit of the circuit board x4 via buses formed inside the circuit board 14.

[0014] In this example, the first connector portion 11 includes a connection terminal 11-1 used for power supply and a connection terminal 11-2 for CAN communication use. On the other hand, the second connector portion 12 includes connection terminals 12-1 and 12-2 for two torque sensors provided in the steering device. When the second connector portion 12 is viewed from the front, the connection terminals 11-1 and 11-2 of the first connector portion 11 are arranged side by side in the Z direction perpendicular to the X direction and the Y direction, respectively.

[0015] FIG. 3 is a plan view for explaining the circuit board 14 inside the exterior cover 13 in FIG. 2 and the arrangement of electronic components mounted on this circuit board x4. In this example, electronic components, sensors, etc. are symmetrically arranged and mounted on a single circuit board 14 with respect to the center line indicated by the dashed-dotted line A-A', showing a layout for forming a dual-system circuit of a first system and a second system. FIG. 4 is a cross-sectional view taken along the line A-A' of FIG. 2.

[0016] The circuit board 14 is provided with a control circuit area 14a, a power supply circuit area 14b, and a power conversion circuit area 14c, as indicated by the dashed lines. The first system area of ​​the control circuit area 14a is equipped with a microcomputer 31 and a pre-driver 32. Similarly, the second system area of ​​the control circuit area 14a is equipped with a microcomputer 33 and a pre-driver 34. The first system area of ​​the power supply circuit area 14b is equipped with a MOSFET 35, a motor coil 36, and a Hall IC 37, etc. Similarly, the second system area of ​​the power supply circuit area 14b is equipped with a MOSFET 38, a motor coil 39, and a Hall IC 40, etc. The first system area of ​​the power conversion circuit area 14c is equipped with an electrolytic capacitor 41 and a coil 42, etc. Similarly, the second system area of ​​the power conversion circuit area 14c is equipped with an electrolytic capacitor 43 and a coil 44, etc. Here, although Hall ICs 37 and 40 and electrolytic capacitors 41 and 43 are shown as one unit, two Hall elements or electrolytic capacitors are actually mounted.

[0017] As shown in Figure 4, the circuit board 14 has circuit patterns formed on both sides, and by mounting electronic components and sensors, the outer diameter size of the product (outer cover) is further reduced. In addition, the connection terminals 11-1 and 11-2 of the first connector section 11 are connected to the first and second circuits of the control circuit area 14a, power supply circuit area 14b, and power conversion circuit area 14c on the surface side of the circuit board 14. On the other hand, the connection terminals 12-1 and 12-2 of the second connector section 12 are connected to the first and second circuits of the control circuit area 14a, power supply circuit area 14b, and power conversion circuit area 14c via buses formed inside the circuit board 14.

[0018] As described above, by changing the connector protrusion surface (connector placement surface), making the connector opening protrude in two directions, and placing a part of the connector on an exterior surface different from the connector placement surface, or on an exterior surface different from the exterior surface covering the circuit board, the outer diameter size of the exterior cover can be reduced. Furthermore, since the connector opening protrudes in two directions, the layout of the power harness and signal harness can also be changed by changing the connection destinations of the connection terminals 11-1, 11-2 of the first connector section 11 and the connection terminals 12-1, 12-2 of the second connector section 12, depending on the vehicle layout. Therefore, according to the present invention, it is possible to provide an electric drive device that can be made smaller in outer diameter size and allows for changes in the layout of power harnesses and signal harnesses.

[0019] Figure 5 is a schematic diagram of an electric power steering device according to an embodiment of the present invention. This electric power steering device 111 includes a steering mechanism 112 for steering based on driver operation and a steering assist mechanism 113 for assisting the driver's steering operation. The motor 20 in the electric power pack (electric drive device) 10 described above is used to assist the steering force, and the control unit 30 controls this motor 20 to assist the steering operation.

[0020] Figure 6 shows the configuration when the electric power pack 10 is attached to the electric power steering system. The electric power pack 10 is mounted on the gear rack 50, and the first connector section 11 is electrically connected to the battery power supply and electronic equipment for in-vehicle communication (CAN communication) via the power harness 51 and signal harness 52. The second connector section 12 is electrically connected to the torque sensor and steering angle sensor via a sensor harness (not shown).

[0021] The steering mechanism 112 includes a steering shaft 115 linked to the steering wheel 114 and a rack bar 118 linked to the tires 116 and 117. The steering shaft 115 and the rack bar 118 are linked via a rack and pinion mechanism 119.

[0022] The steering shaft 115 is constructed by connecting an input shaft 120, which is a first axial member that rotates integrally with the steering wheel 114, and an output shaft 121, which is a second axial member that is linked to the rack bar 118, with a torsion bar (not shown). One end of the input shaft 120 is connected to the steering wheel 114 in the axial direction, and the other end is connected to the torsion bar. One end of the output shaft 121 is connected to the torsion bar in the axial direction, and the other end is linked to the rack bar 118.

[0023] Then, the pinion teeth 121a formed on the outer circumference of the other end of the output shaft 121 mesh with the rack teeth 118a formed on one end of the rack bar 118 in the axial direction (longitudinal direction), thereby converting the rotational motion of the output shaft 121 into the axial motion of the rack bar 118 and transmitting it.

[0024] Furthermore, on the radially outer side (outer circumference) of the steering shaft 115, a steering angle sensor 123 for detecting the steering angle, which is the rotation angle of the steering shaft 115, and a torque sensor 124 for detecting the steering torque applied to the steering shaft 115 by the driver's steering operation are integrally provided as a single unit. The steering angle sensor 123 detects the steering angle based on the difference in rotation angles of a pair of gears that rotate in conjunction with the rotation of the steering shaft 115. The torque sensor 124 detects the steering torque based on the relative rotational displacement of the input shaft 120 and the output shaft 121.

[0025] Tires 116 and 117 are attached to the axial ends of the rack bar 118 via tie rods 125 and 126 and knuckle arms (not shown). When the rack bar 118 moves axially, the knuckle arms are pushed and pulled via the tie rods 125, changing the orientation of tire 116. Conversely, when the rack bar 118 moves axially, the knuckle arms are pulled and pushed via the tie rods 126, changing the orientation of tire 117 to the same direction as tire 116.

[0026] The steering assist mechanism 113 includes a motor (electric actuator) 20 that generates steering assist force, a control unit 30 that drives and controls the motor 20, and a transmission mechanism 133 that transmits the rotation of the motor 20 to the rack bar 118, and assists the axial movement of the rack bar 118 with the rotational force of the motor 20. The control unit 30 is connected to other ECUs, such as an ESC (Electronic Stability Control) control device, via the CAN bus 134, and exchanges information via CAN communication.

[0027] The motor 20 is driven and controlled based on the detection results of various sensors, such as the output signal S1 of the steering angle sensor 123 and the output signal S2 of the torque sensor 124, which are input to the control unit 30 via the sensor harness 135, the output signal S3 of the vehicle speed sensor (not shown) which is input via the CAN bus 134, and the output signals of the Hall ICs 37 and 40 which detect the rotation angle of the motor 20.

[0028] The transmission mechanism 133 includes a reduction gear that reduces the rotation of the motor 20, and a conversion mechanism that converts the rotation of the reduction gear into axial motion of the rack bar 118. The reduction gear consists of, for example, an input pulley fixed to rotate integrally with the drive shaft of the motor 20, an output pulley fixed to rotate integrally with a nut that acts as a conversion mechanism, and a transmission member such as a belt or chain wound around these pulleys.

[0029] The conversion mechanism can use, for example, a ball screw mechanism with a cylindrical nut that surrounds the rack bar 118. A helical ball screw groove is formed on the inner circumference of the nut, and a helical ball screw groove is formed on the outer circumference of the rack bar 118. With the nut inserted into the rack bar 118, a ball circulation groove is formed by the nut-side ball screw groove and the steering shaft-side ball screw groove.

[0030] The ball circulation groove is filled with multiple metal balls, and as the nut rotates, the balls move within the groove, causing the rack bar 118 to move axially relative to the nut. The ball screw mechanism converts the rotational motion of the motor 20 into linear motion, and the axial movement of the rack bar 118 pushes and pulls the knuckle arm via the tie rods 125 and 126, thereby applying steering force to the tires 116 and 117.

[0031] The reduction gear described above can be a worm gear having a worm shaft that is rotatably connected integrally with the output shaft of the motor 20, and a worm wheel that rotates in mesh with the worm shaft. Furthermore, the conversion mechanism can also utilize a so-called rack and pinion mechanism, which consists of pinion teeth formed on the outer circumference of the other axial end of the output shaft that rotates integrally with the worm wheel, and rack teeth formed on the other axial end of the rack bar 118 that mesh with these pinion teeth.

[0032] As described above, the routing of the wire harness increases the degree of freedom in the direction of protrusion of the connector opening, resulting in an efficient layout of the wire harness and thus reducing the weight of the harness. Furthermore, by shortening the distance from the fixing point, it is possible to provide an electric power steering system with improved vibration resistance.

[0033] <Example 1> Figure 7 is a diagram illustrating a first modified example of an electric drive device according to an embodiment of the present invention. In this first modified example, the connector block having a first connector portion 11 and a second connector portion 12 is an integrated structure. That is, the connector block of the first connector portion 11 and the second connector portion 12 is connected by a hinge 15. Alternatively, the connector block of the first connector portion 11 and the second connector portion 12 may be formed by integral molding. Note that in this case, the outer cover 13 is a separate component. Even with this configuration, substantially the same effects and advantages as those of the embodiments described above can be obtained.

[0034] <Modification 2> Figure 8 is a diagram illustrating a second modified example of the electric drive device according to an embodiment of the present invention. In this second modified example, each connector block has a separate structure, as indicated by the dashed lines 16-1 and 16-2. In this case, the outer cover 13 is a separate component. Even with this configuration, it is naturally possible to obtain substantially the same effects and advantages as those of the above-described embodiment and the first modified example.

[0035] <Variation 3> Figure 9 is a diagram illustrating a third modified example of the electric drive device according to an embodiment of the present invention. In this third modified example, the outer cover and connectors 11 and 12 are integrated into a single structure (integrated outer cover 17). Even with this configuration, substantially the same effects and advantages as those of the above-described embodiment and the first and second modifications can be obtained.

[0036] The configurations and methods described in the embodiments described above are merely schematic representations to the extent that the present invention can be understood and implemented. Therefore, the present invention is not limited to the embodiments described, and can be modified in various forms as long as it does not deviate from the scope of the technical idea set forth in the claims.

[0037] For example, while we have described its application to an electric power steering system that assists the driver's steering operations, it can be similarly applied to electric steering systems that perform steering operations in autonomous vehicles. [Explanation of symbols]

[0038] 10…Electric drive unit (electric power pack), 11…First connector section, 11-1, 11-2…Connection terminals, 12…Second connector section, 12-1, 12-2…Connection terminals, 13…Exterior cover (exterior component), 14…Circuit board, 14a…Control circuit area, 14b…Power supply circuit area, 14c…Power conversion circuit area, 20…Motor, 21…Motor output shaft, 30…Control unit, 37, 40…Hall IC, 41, 43…Electrolytic capacitors, 51…Power harness (wire harness), 52…Signal harness (wire harness)

Claims

1. An electric drive device in which a motor and a control unit are integrated coaxially with the motor output shaft, the control unit is positioned on the opposite side from the motor's output side and is electrically connected to the outside via a wire harness, and the motor and the control unit are housed in a cylindrical outer cover, The control unit is A connector block having a first connector portion and a second connector portion, each having a connector connection opening formed for connection with a mating connector, The circuit board comprises the connection terminals of the first connector portion and the second connector portion, which are electrically connected to each other. When the direction of the rotation axis of the motor is X, and the direction perpendicular to the rotation axis is Y, The first connector portion protrudes from the outer surface of the outer cover in the X direction, and the second connector portion protrudes from the outer surface in the Y direction. The first connector section and the second connector section each have a plurality of connection terminals, When the second connector portion is viewed from the front, the multiple connection terminals of the first connector portion are arranged along the Z direction which is perpendicular to the X direction and the Y direction, respectively, and the multiple connection terminals of the second connector portion are arranged along the X direction. An electric drive device characterized by the following features.

2. The electric drive device according to claim 1, characterized in that the position on which the second connector portion protrudes is a plane formed by cutting out a part of the side surface of the outer cover.

3. The first connector portion is for power supply and communication, The electric drive device according to claim 1, characterized in that the second connector portion is for a sensor.

4. The circuit board has a control circuit area, a power supply circuit area, and a power conversion circuit area. The electric drive device according to claim 1, characterized in that the control circuit area, the power supply circuit area, and the power conversion circuit area are each composed of a dual system consisting of a first circuit and a second circuit.

5. The electric drive device according to claim 4, further comprising: first and second systems of sensor elements mounted on the circuit board at a position corresponding to the motor output shaft for detecting the rotation of the motor; and first and second systems of electronic components mounted on the circuit board.

6. The electric drive device comprises a motor that provides steering force to the vehicle's steering system, and a control unit that is integrated with the motor on the opposite side of the motor's output shaft and coaxially with the motor's output shaft, electrically connected to the outside via a wire harness, and controls the motor, with the motor and the control unit housed in a cylindrical outer cover. The control unit is A connector block having a connector connection opening formed for connection with a mating connector, a first connector section used for at least one of power supply and in-vehicle communication, and a second connector section for a sensor that detects torque applied to the steering shaft, The circuit board comprises the connection terminals of the first connector portion and the second connector portion, which are electrically connected to each other. When the direction of the rotation axis of the motor is X, and the direction perpendicular to the rotation axis is Y, The first connector portion protrudes from the outer surface of the outer cover in the X direction, and the second connector portion protrudes from the outer surface in the Y direction. The first connector section and the second connector section each have a plurality of connection terminals, When the second connector portion is viewed from the front, the multiple connection terminals of the first connector portion are arranged along the Z direction which is perpendicular to the X direction and the Y direction, respectively, and the multiple connection terminals of the second connector portion are arranged along the X direction. An electric power steering system characterized by the following features.

7. The electric power steering device according to claim 6, characterized in that the position where the second connector portion protrudes is a plane formed by cutting out a part of the side surface of the outer cover.

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