JP2019022382A - Electric drive device and electric power steering device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new electric drive device and electric power steering device having good heat dissipation characteristics while reducing the appearance shape, the weight and the number of parts. SOLUTION: A motor housing side annular engaging portion having a diameter reduced inward in the radial direction formed on an outer peripheral surface of an end surface portion 15 of an aluminum metal motor housing 11 opposite to an output portion of a rotating shaft of an electric motor. The 35 and the metal cover-side annular engaging portion 37 formed at the open end of the metal cover 12 that covers the electronic control portion that controls the electric motor and engage with the reduced diameter portion of the motor housing-side annular engaging portion. In the state where the metal cover side annular engaging portion 37 is engaged with the motor housing side annular engaging portion 35, the engaging portion of the outer peripheral surface of the motor housing side annular engaging portion 35 and the metal cover side annular engaging portion 37 It is fixed with the adhesive tape 39 so as to cover the above. [Selection diagram] FIG. 11

Description

  The present invention relates to an electric drive device and an electric power steering device, and more particularly to an electric drive device and an electric power steering device incorporating an electronic control device.

  In the general industrial machinery field, a mechanical control element is driven by an electric motor. Recently, an electronic control unit including a semiconductor element or the like for controlling the rotational speed or rotational torque of the electric motor is electrically driven. A so-called electromechanical integrated electric drive device that is integrated into a motor is beginning to be adopted.

  As an example of an electromechanical integrated electric drive device, for example, in an electric power steering device of an automobile, a rotation direction and a rotation torque of a steering shaft that is rotated by a driver operating a steering wheel are detected. The electric motor is driven to rotate in the same direction as the rotation direction of the steering shaft based on the detected value, and the steering assist torque is generated. In order to control this electric motor, an electronic control unit (ECU: Electronic Control Unit) is provided in the power steering apparatus.

  As a conventional electric power steering device, for example, a device described in JP-A-2015-134598 (Patent Document 1) is known. Patent Literature 1 describes an electric power steering device that includes an electric motor unit and an electronic control unit. The electric motor of the electric motor unit is housed in a motor housing having a cylindrical part made of aluminum alloy or the like, and the board on which the electronic components of the electronic control unit are mounted is the output shaft in the axial direction of the motor housing. It is attached to a heat sink that functions as an ECU housing arranged on the opposite side.

  The substrate attached to the heat sink includes a power supply circuit unit, a power conversion circuit unit having a power switching element such as a MOSFET or IGBT for driving and controlling the electric motor, and a control circuit unit for controlling the power switching element, and power switching. The output terminal of the element and the input terminal of the electric motor are electrically connected via a bus bar.

  The electronic control unit attached to the heat sink is supplied with electric power from a power source via a connector case made of synthetic resin, and detection signals such as an operation state are supplied from detection sensors. The connector case functions as a lid, is fixed so as to seal and close the heat sink, and is fixed to the outer peripheral surface of the heat sink by a fixing screw.

  In addition, as an electric drive device integrated with an electronic control device, an electric brake, an electric hydraulic controller for various hydraulic controls, and the like are known. However, in the following explanation, an electric power steering device is representative. explain.

JP2015-134598A

  By the way, in the electric power steering apparatus having the configuration as disclosed in Patent Document 1, the metal motor housing, the metal heat sink, and the synthetic resin connector case are fixed by inserting a fixing portion that protrudes to the outer peripheral side. It is a structure that is fastened together with screws.

  However, when the fixing portion and the fixing screw are provided on the outer periphery of the motor housing, the heat sink, and the connector case, there arises a problem that the external shape becomes large and the weight increases. Furthermore, the motor housing and heat sink are in close contact with each other, but the close contact portion has a large thermal resistance and cannot perform good heat transfer, resulting in poor heat dissipation. Therefore, the problem that the connector case does not contribute to heat radiation and the heat radiation characteristics are not good also arises. Therefore, there is a demand for an electric drive device and an electric power steering device that solve these problems.

  Furthermore, in the electric power steering apparatus having a configuration as described in Patent Document 1, which is a subsidiary, a heat sink member for radiating heat of the power supply circuit unit and the power conversion circuit unit to the outside is particularly provided with the motor housing. Arranged between the ECU housings. For this reason, the length in the axial direction tends to be longer by the amount of the heat sink member. In addition, the electrical components that constitute the power supply circuit unit and the power conversion circuit unit generate a large amount of heat, and it is necessary to efficiently dissipate this heat to the outside when downsizing. Therefore, it is also required to reduce the axial length as much as possible and to efficiently dissipate the heat of the power supply circuit unit and the power conversion circuit unit to the outside.

  SUMMARY OF THE INVENTION The main object of the present invention is to provide a novel electric drive device and electric power steering device having a reduced external shape to reduce weight and having good heat dissipation characteristics.

  A feature of the present invention is that the motor housing-side annular engagement portion that is formed on the outer peripheral surface of the end surface portion of the aluminum-based metal motor housing opposite to the output portion of the rotating shaft of the electric motor is reduced inward in the radial direction. And a metal cover-side annular engagement portion that is formed at an opening end of a metal cover that covers an electronic control unit that controls the electric motor, and that engages with a reduced diameter portion of the motor housing-side annular engagement portion. With the metal cover side annular engagement portion engaged with the housing side annular engagement portion, the adhesive tape covers the engagement portions of the motor housing side annular engagement portion and the outer peripheral surface of the metal cover side annular engagement portion. The annular facing surface in which the motor housing side annular engagement portion and the metal cover side annular engagement portion are opposed to each other with the metal cover side annular engagement portion engaged with the motor housing side annular engagement portion With double-sided adhesive tape A constant, is in place.

  According to the present invention, the engagement portions of the motor housing side annular engagement portion and the outer peripheral surface of the metal cover side annular engagement portion in a state where the metal cover side annular engagement portion is engaged with the motor housing side annular engagement portion. In the state where the metal cover side annular engagement portion is engaged with the motor housing side annular engagement portion, the motor housing side annular engagement portion and the metal cover side annular engagement portion are Since the opposing annular facing surfaces are fixed with the double-sided adhesive tape, the external shape can be reduced and the weight can be reduced.

1 is an overall perspective view of a steering apparatus as an example to which the present invention is applied. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an overall perspective view showing an overall shape of an electric power steering apparatus according to an embodiment of the present invention before fixing with an adhesive tape. FIG. 3 is an exploded perspective view of the electric power steering device shown in FIG. 2. It is a perspective view of the motor housing shown in FIG. FIG. 5 is a cross-sectional view of the motor housing shown in FIG. 4 taken along the axial direction. It is a perspective view which shows the state which mounted and fixed the power conversion circuit part in the motor housing shown in FIG. It is a perspective view which shows the state which mounted and fixed the power supply circuit part to the motor housing shown in FIG. It is a perspective view which shows the state which mounted and fixed the control circuit part in the motor housing shown in FIG. It is a perspective view which shows the state which mounted and fixed the connector terminal assembly to the motor housing shown in FIG. It is a front view of the electric power steering device after fixing with an adhesive tape. FIG. 11 is a cross-sectional view of the electric power steering apparatus shown in FIG. 10 and after fixing with an adhesive tape. It is a partial expanded sectional view which shows the axial direction cross section after fixing with an adhesive tape near the engaging part of a motor housing and a metal cover. It is a top view of the electric power steering device after fixing with an adhesive tape. It is an enlarged view of the A section of FIG. The modification of this invention is shown, The cross section of an electric power steering apparatus is shown, and it is an expanded sectional view after fixing with an adhesive tape. It is a top view which shows the shape of the adhesive tape shown in FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following embodiments, and various modifications and application examples are included in the technical concept of the present invention. Is also included in the range.

  Before describing an embodiment of the present invention, a configuration of an exemplary steering apparatus to which the present invention is applied will be briefly described with reference to FIG.

  First, a steering device for steering the front wheels of an automobile will be described. The steering device 1 is configured as shown in FIG. A pinion (not shown) is provided at the lower end of the steering shaft 2 connected to a steering wheel (not shown), and this pinion meshes with a rack (not shown) that is long in the left-right direction of the vehicle body. Tie rods 3 for steering the front wheels in the left-right direction are connected to both ends of the rack, and the rack is covered with a rack housing 4. A rubber boot 5 is provided between the rack housing 4 and the tie rod 3.

  An electric power steering device 6 is provided to assist torque when the steering wheel is turned. In other words, a torque sensor 7 that detects the turning direction and turning torque of the steering shaft 2 is provided, and an electric motor unit 8 that applies a steering assist force to the rack via the gear 10 based on the detection value of the torque sensor 7. And an electronic control unit (ECU) unit 9 that controls the electric motor disposed in the electric motor unit 8 is provided. The electric motor steering unit 6 of the electric power steering device 6 is connected to the gear 10 through a screw (not shown) at the outer periphery of the output shaft side, and the electronic control unit 9 on the opposite side of the output shaft of the electric motor 8 unit. Is provided.

  In the electric power steering device 6, when the steering shaft 2 is rotated in either direction by operating the steering wheel, the torque sensor 7 determines the rotational direction and the rotational torque of the steering shaft 2. Based on the detected value, the control circuit unit calculates the drive operation amount of the electric motor. The electric motor is driven by the power switching element of the power conversion circuit unit based on the calculated drive operation amount, and the output shaft of the electric motor is rotated so as to drive the steering shaft 1 in the same direction as the operation direction. The rotation of the output shaft is transmitted from a pinion (not shown) to a rack (not shown) via the gear 10 to steer the automobile. Since these structures and operations are already well known, further explanation is omitted.

  As described above, in the electric power steering apparatus having the configuration as disclosed in Patent Document 1, the metal motor housing, the metal heat sink, and the synthetic resin connector case are provided with a fixing portion that protrudes toward the outer peripheral side. It is the structure fastened together by the fixing screw inserted. For this reason, when a fixing part and a fixing screw are provided on the outer periphery of the motor housing, the heat sink, and the connector case, there arises a problem that the external shape becomes large and the weight increases.

  Against this background, the present embodiment proposes an electric power steering apparatus having the following configuration. In other words, in the present embodiment, the motor housing-side annular engagement that is formed on the outer peripheral surface of the end surface portion of the aluminum-based motor housing opposite to the output portion of the rotating shaft of the electric motor is reduced radially inward. And a metal cover side annular engagement portion that is formed at the opening end of the metal cover that covers the electronic control unit that controls the electric motor and engages with the reduced diameter portion of the motor housing side annular engagement portion. In a state where the metal cover side annular engagement portion is engaged with the motor housing side annular engagement portion, the adhesive is provided so as to cover the engagement portions of the outer peripheral surface of the motor housing side annular engagement portion and the metal cover side annular engagement portion. In which the motor housing side annular engagement portion and the metal cover side annular engagement portion face each other in a state where the metal cover side annular engagement portion is engaged with the motor housing side annular engagement portion. Both sides are facing It fixed in-adhesive tape, is intended.

  According to this, in a state where the metal cover side annular engagement portion is engaged with the motor housing side annular engagement portion, the engagement portions of the outer peripheral surfaces of the motor housing side annular engagement portion and the metal cover side annular engagement portion are set. The motor housing side annular engagement portion and the metal cover side annular engagement portion are opposed to each other in a state in which the metal cover side annular engagement portion is engaged with the motor housing side annular engagement portion. Since the annular facing surface is fixed with the double-sided adhesive tape, the external shape can be reduced and the weight can be reduced.

  Hereinafter, a specific configuration of an electric power steering apparatus according to an embodiment of the present invention will be described in detail with reference to FIGS. 2 to 13. 2 is a diagram showing the overall configuration of the electric power steering apparatus according to the present embodiment, and FIG. 3 is a diagram showing the components of the electric power steering apparatus shown in FIG. 4 to 9 are views showing a state in which the respective component parts are assembled in accordance with the assembly order of the respective component parts.

  FIG. 10 is a drawing showing the entire electric power steering apparatus after fixing with an adhesive tape, and FIG. 11 shows a cross section of the electric power steering apparatus, and also shows a cross section after fixing with an adhesive tape. FIG. 12 is a drawing showing an axial cross section near the joint between the motor housing and the metal cover, FIG. 13 is a drawing of the electric power steering device viewed from the axial direction, and FIG. 14 is a single-sided adhesive property. It is drawing which expanded the overlapping part of a tape. Therefore, in the following description, description will be made with reference to each drawing as appropriate.

  As shown in FIG. 2, the electric motor unit 8 constituting the electric power steering apparatus includes a motor housing 11 having a cylindrical part made of aluminum or an aluminum metal such as an aluminum alloy and an electric motor (not shown) housed in the motor housing 11. The electronic control unit 9 is made of an aluminum-based metal such as aluminum or aluminum alloy, or an iron-based metal disposed on the opposite side of the output shaft in the axial direction of the motor housing 11. The metal cover 12 and an electronic control assembly (not shown) housed in the metal cover 12 are included.

  The motor housing 11 and the metal cover 12 are integrally fixed by an adhesive tape, which will be described later, in a fixed area AD in the outer peripheral direction formed on the opposite end face. The electronic control assembly housed in the metal cover 12 has a power conversion unit having a power switching element made up of a power source circuit unit for generating a necessary power source, a MOSFET or IGBT for driving and controlling the electric motor of the electric motor unit 8. The circuit includes a control circuit unit that controls the power switching element, and the output terminal of the power switching element and the coil input terminal of the electric motor are electrically connected via a bus bar.

  On the end surface of the metal cover 12 opposite to the motor housing 11, the connector terminal assembly 13 is exposed from the hole formed in the metal cover 12. The connector terminal assembly 13 is fixed to a fixing portion formed on the motor housing 11 with a fixing screw. The connector terminal assembly 13 includes a connector terminal forming portion 13A for supplying power, a connector terminal forming portion 13B for detection sensor, and a connector terminal forming portion 13C for sending a control state to send the control state to an external device.

  The electronic control assembly housed in the metal cover 12 is supplied with electric power from the power supply via a connector terminal forming portion 13A for supplying electric power made of synthetic resin, and detects an operating state from detection sensors. The signal is supplied via the connector forming terminal portion 13B for the detection sensor, and the current control state signal of the electric power steering apparatus is sent via the connector terminal forming portion 13C for sending the control state.

  FIG. 3 shows an exploded perspective view of the electric power steering device 6. An annular iron side yoke (not shown) is fitted inside the motor housing 11, and an electric motor (not shown) is accommodated in the side yoke. The output portion 14 of the electric motor applies a steering assist force to the rack via a gear. Since the specific structure of the electric motor is well known, the description thereof is omitted here.

  The motor housing 11 is made of an aluminum alloy, and functions as a heat sink member that releases heat generated by the electric motor and heat generated by a power supply circuit unit and a power conversion circuit unit described later to the outside atmosphere. The electric motor and the motor housing 11 constitute an electric motor unit 8.

  An electronic control unit EC is attached to the end surface portion 15 of the motor housing 11 opposite to the output portion 14 of the electric motor portion 8. The electronic control unit EC includes a power conversion circuit unit 16, a power supply circuit unit 17, a control circuit unit 18, and a connector terminal assembly 13. The end surface portion 15 of the motor housing 11 is formed integrally with the motor housing 11. However, only the end surface portion 15 may be formed separately and integrated with the motor housing 11 by screws or welding. It is.

  Here, the power conversion circuit unit 16, the power conversion circuit unit 17, and the control circuit unit 18 constitute a redundant system, and constitute a dual system of a main electronic control unit and a sub electronic control unit. Normally, the electric motor is controlled and driven by the main electronic control unit, but if an abnormality or failure occurs in the main electronic control unit, the electric motor is controlled and driven by switching to the sub electronic control unit. It will be.

  Therefore, as will be described later, normally, heat from the main electronic control unit is transmitted to the motor housing 11, and if an abnormality or failure occurs in the main electronic control unit, the main electronic control unit stops and the sub electronic control unit operates. The heat from the sub-electronic control unit is transmitted to the motor housing 11.

  However, although not adopted in this embodiment, the main electronic control unit and the sub electronic control unit are combined to function as a regular electronic control unit, and if one electronic control unit malfunctions or fails, the other electronic control unit It is also possible to control and drive the electric motor with half the capacity. In this case, the capacity of the electric motor is halved, but a so-called “limp home function” is ensured. Therefore, in the normal case, heat from the main electronic control unit and the sub electronic control unit is transmitted to the motor housing 11.

  The electronic control unit EC includes a control circuit unit 18, a power supply circuit unit 17, a power conversion circuit unit 16, and a connector terminal assembly 13, and the power conversion circuit unit 16 and the power supply are arranged in a direction away from the end face unit 15 side. The circuit portion 17, the control circuit portion 18, and the connector terminal assembly 13 are arranged in this order. The control circuit unit 18 generates a control signal for driving the switching element of the power conversion circuit unit 16, and includes a microcomputer, peripheral circuits, and the like. The power supply circuit unit 17 generates a power source for driving the control circuit unit 18 and a power source for the power conversion circuit unit 16, and includes a capacitor, a coil, a switching element, and the like. The power conversion circuit unit 16 adjusts the electric power flowing through the coil of the electric motor, and is composed of a switching element or the like that constitutes a three-phase upper and lower arm.

  The electronic control unit EC generates a large amount of heat mainly from the power conversion circuit unit 16 and the power supply circuit unit 17, and the heat of the power conversion circuit unit 16 and the power supply circuit unit 17 is radiated from the motor housing 11 made of an aluminum alloy. It is what is done. This configuration will be described later.

  A connector terminal assembly 13 made of synthetic resin is provided between the control circuit unit 18 and the metal cover 12, and is connected to a vehicle battery (power source) and other control devices (not shown). Needless to say, the connector terminal assembly 13 is connected to the power conversion circuit unit 16, the power supply circuit unit 17, and the control circuit unit 18.

  The metal cover 12 has a function of housing the power conversion circuit unit 16, the power supply circuit unit 17, and the control circuit unit 18 and sealing them in a liquid-tight manner. It is fixed to the housing 11. That is, the motor housing side annular engagement portion that is radially reduced in diameter and the metal cover side annular engagement that is formed at the opening end of the metal cover and engages the reduced diameter portion of the motor housing side annular engagement portion. And the engagement portion of the outer peripheral surface of the motor housing side annular engagement portion and the metal cover side annular engagement portion in a state where the metal cover side annular engagement portion is engaged with the motor housing side annular engagement portion. It is fixed with an adhesive tape so as to cover. Details thereof will be described later. Therefore, the external shape can be reduced and the weight can be reduced.

  Next, the configuration of each component and the assembly method will be described with reference to FIGS. First, FIG. 4 shows the appearance of the motor housing 11, and FIG. 5 shows an axial cross section thereof. 4 and 5, the motor housing 11 is formed in a cylindrical shape and closes the side peripheral surface portion 11A, the end surface portion 15 that closes one end of the side peripheral surface portion 11A, and the other end of the side peripheral surface portion 11A. And an end face portion 19. In the present embodiment, the motor housing 11 has a bottomed cylindrical shape, and the side peripheral surface portion 11A and the end surface portion 15 are integrally formed. The end surface portion 19 has a lid function and closes the other end of the side peripheral surface portion 11A after the electric motor is stored in the side peripheral surface portion 11A.

  Further, an annular step portion (= motor housing side annular engagement portion) 35 having a diameter reduced radially inward is formed on the end surface peripheral surface of the end surface portion 15, and the opening end of the metal cover 12 is formed on the step portion 35. (= Metal cover side annular engagement portion) 37 is engaged. The form of engagement between the stepped portion 35 and the opening end 37 of the metal cover 12 is a so-called “stamp engagement” or “stamp fitting”. This engagement state will be described later.

  As shown in FIG. 5, a stator 21 in which a coil 20 is wound around an iron core is fitted inside the side peripheral surface portion 11 </ b> A of the motor housing 11, and a permanent magnet is embedded in the stator 21. The rotor 22 is housed rotatably. A rotation shaft 23 is fixed to the rotor 22, one end is an output unit 14, and the other end is a rotation detection unit 24 for detecting the rotation phase and the number of rotations of the rotation shaft 23. The rotation detection unit 24 is provided with a permanent magnet, and protrudes to the outside through a through hole 25 provided in the end surface portion 15. Then, the rotational phase and the rotational speed of the rotary shaft 23 are detected by a magnetic sensing unit comprising a GMR element or the like (not shown).

  Returning to FIG. 4, the heat conversion portion of the power conversion circuit portion 16 (see FIG. 3) and the power supply circuit portion 17 (see FIG. 3) are disposed on the surface of the end surface portion 15 located on the opposite side of the output portion 14 of the rotating shaft 23. 15A and 15B are formed. The board / connector fixing convex portions 26 are integrally planted at the four corners of the end surface portion 15, and screw holes are formed therein. The board / connector fixing projection 26 is provided to fix the board of the control circuit section 18 and the connector terminal assembly 13 which will be described later. Further, a substrate receiving portion 27 having the same height in the axial direction as a power supply heat radiation region 15B, which will be described later, is formed on the substrate fixing convex portion 26 planted from the power conversion heat radiation region 15A described later. The substrate receiving portion 27 is for mounting and fixing a glass epoxy substrate 31 of the power supply circuit portion 17 to be described later.

  A radial plane region perpendicular to the rotation shaft 23 that forms the end face portion 15 is divided into two. One forms a power conversion heat dissipation region 15A to which a power conversion circuit unit 16 made of a switching element such as a MOSFET is attached, and the other forms a power supply heat dissipation region 15B to which a power supply circuit unit 17 is attached. In the present embodiment, the power conversion heat dissipation region 15A is formed to have a larger area than the power supply heat dissipation region 15B. This is because the installation area of the power conversion circuit unit 16 is secured because the dual system is adopted as described above.

  The power conversion heat dissipation region 15A and the power supply heat dissipation region 15B have steps with different heights in the axial direction (the direction in which the rotating shaft 23 extends). That is, the heat-dissipating region for power supply 15B is formed with a step in a direction away from the heat-dissipating region for power conversion 15A when viewed in the direction of the rotating shaft 23 of the electric motor. This step is set to a length that does not cause interference between the power conversion circuit unit 16 and the power supply circuit unit 17 when the power supply circuit unit 17 is installed after the power conversion circuit unit 16 is installed.

  In the power conversion heat radiation area 15A, three elongated rectangular heat radiation portions 28 are formed. The projecting heat radiating portion 28 is provided with a double power conversion circuit portion 16 to be described later. Further, the protruding heat radiating portion 28 extends so as to protrude in a direction away from the electric motor when viewed in the direction of the rotating shaft 23 of the electric motor.

  Further, the heat radiation area 15B for power supply has a planar shape and is provided with a power supply circuit portion 17 to be described later. Therefore, the projecting heat radiating portion 28 functions as a heat radiating portion that transfers the heat generated in the power conversion circuit portion 16 to the end face portion 15, and the power radiating area 15 B transfers the heat generated in the power circuit portion 17 to the end face portion 15. It functions as a heat radiating part that conducts heat.

  Note that the projecting heat radiating portion 28 can be omitted, and in this case, the power conversion heat radiating region 15 </ b> A functions as a heat radiating portion that transfers heat generated in the power conversion circuit portion 16 to the end face portion 15. However, in the present embodiment, the metal substrate of the power conversion circuit unit 16 is welded to the projecting heat radiating unit 28 by friction stir welding to ensure secure fixing.

  Thus, in the end surface portion 15 of the motor housing 11 according to the present embodiment, the heat sink member is omitted, and the axial length can be shortened. Further, since the motor housing 11 has a sufficient heat capacity, the heat of the power supply circuit unit 17 and the power conversion circuit unit 16 can be efficiently radiated to the outside.

  Next, FIG. 6 shows a state in which the power conversion circuit unit 16 is installed on the protrusion heat radiating unit 28 (see FIG. 4). As shown in FIG. 6, the power conversion circuit unit 16 composed of a double system is installed on the upper part of the protruding heat radiation unit 28 (see FIG. 4) formed in the power conversion heat radiation region 15 </ b> A. The switching elements constituting the power conversion circuit unit 16 are placed on a metal substrate (here, aluminum-based metal is used) and are configured to be easily radiated. The metal substrate is welded to the projecting heat radiation portion 28 by friction stir welding.

  Therefore, the metal substrate is firmly fixed to the projecting heat radiating portion 28 (see FIG. 4), and heat generated by the switching element can be efficiently transferred to the projecting heat radiating portion 28 (see FIG. 4). The heat transmitted to the projecting heat radiating portion 28 (see FIG. 4) is diffused to the power conversion heat radiating region 15A, further transferred to the side peripheral surface portion 11A of the motor housing 11, and radiated to the outside. Here, as described above, since the height of the power conversion circuit unit 16 in the axial direction is lower than the height of the heat dissipation region 15B for power supply, it does not interfere with the power supply circuit unit 17 described later.

  In this way, the power conversion circuit unit 16 is installed on the upper portion of the protruding heat dissipation unit 28 formed in the heat conversion heat dissipation region 15A. Therefore, the heat generated by the switching element of the power conversion circuit unit 16 can be efficiently transferred to the projecting heat radiating unit 28. Further, the heat transferred to the projecting heat radiating portion 28 is diffused to the power conversion heat radiating region 15A, and is transferred to the side peripheral surface portion 11A of the motor housing 11 to be radiated to the outside.

  Next, FIG. 7 shows a state in which the power supply circuit unit 17 is installed from above the power conversion circuit unit 16. As shown in FIG. 7, a power supply circuit unit 17 is installed above the heat dissipation region 15B for power supply. A capacitor 29, a coil 30 and the like constituting the power supply circuit unit 17 are placed on a glass epoxy substrate 31. The power supply circuit unit 17 also adopts a double system, and as can be seen from the figure, a power supply circuit composed of a capacitor 29, a coil 30, and the like is formed symmetrically. An electrical element such as a capacitor other than the switching element of the power conversion circuit 16 is placed on the glass epoxy substrate 31.

  The surface of the glass epoxy substrate 31 on the side of the power radiation area 15B (see FIG. 6) is fixed to the end face portion 15 so as to be in contact with the power radiation area 15B. As shown in FIG. 7, the fixing method is to fix the screw hole provided in the substrate receiving portion 27 of the substrate fixing convex portion 26 with a fixing screw (not shown). Further, it is also fixed to a screw hole provided in the power radiation region 15B (see FIG. 6) by a fixing screw (not shown).

  In addition, since the power supply circuit part 17 is formed with the glass epoxy board | substrate 31, double-sided mounting is possible. The surface of the glass epoxy substrate 31 on the side of the heat radiation area 15B for power supply (see FIG. 6) is mounted with a rotational phase / rotational speed detection unit including a GMR element (not shown) and its detection circuit. In cooperation with the rotation detection unit 24 (see FIG. 5) provided in FIG. 5, the rotation phase and the number of rotations are detected.

  As described above, the glass epoxy substrate 31 is fixed so as to be in contact with the power supply heat dissipation region 15B (see FIG. 6). Therefore, the heat generated in the power supply circuit unit 17 is efficiently transferred to the power supply heat dissipation region 15B (FIG. 6). Heat transfer). The heat transferred to the heat dissipation region 15B for power supply (see FIG. 6) is diffused and transferred to the side peripheral surface portion 11A of the motor housing 11 to be radiated to the outside. Here, between the glass epoxy substrate 31 and the heat radiation area 15B for power supply (see FIG. 6), any one of an adhesive, a heat radiation grease, and a heat radiation sheet having a good heat transfer property is interposed to further increase the heat transfer performance. Can be improved.

  As described above, the power supply circuit unit 17 is installed on the upper portion of the heat dissipation region 15B for power supply. The surface of the glass epoxy substrate 31 on which the circuit elements of the power supply circuit section 17 are placed is fixed to the end face section 15 so as to be in contact with the power supply heat dissipation area 15B. Therefore, the heat generated in the power supply circuit unit 17 can be efficiently transferred to the heat dissipation region 15B for power supply. The heat transmitted to the power radiation region 15B is diffused and transferred to the side peripheral surface portion 11A of the motor housing 11 to be radiated to the outside.

  Next, FIG. 8 shows a state in which the control circuit unit 18 is installed from above the power supply circuit unit 17. As shown in FIG. 8, the control circuit unit 18 is installed above the power supply circuit unit 17. The microcomputer 32 and the peripheral circuit 33 constituting the control circuit unit 18 are placed on a glass epoxy substrate 34. The control circuit unit 18 also adopts a double system, and as can be seen from the figure, a control circuit including a microcomputer 32 and a peripheral circuit 33 is formed for each target. The microcomputer 32 and the peripheral circuit 33 may be provided on the surface of the glass epoxy substrate 34 on the power supply circuit 17 side.

  As shown in FIG. 8, the glass epoxy board 34 is fixed by a fixing screw (not shown) in a form of being sandwiched by the connector terminal assembly 13 in a screw hole provided at the top of the board fixing convex portion 26 (see FIG. 7). 7 is disposed between the glass epoxy substrate 31 of the power supply circuit unit 17 (see FIG. 7) and the glass epoxy substrate 34 of the control circuit unit 18. It is a space.

  Next, FIG. 9 shows a state in which the connector terminal assembly 13 is installed from above the control circuit unit 18. As shown in FIG. 9, the connector terminal assembly 13 is installed above the control source circuit section 18. The connector terminal assembly 13 is fixed by a fixing screw 36 so as to sandwich the control circuit portion 18 in a screw hole provided at the top of the board fixing convex portion 26. In this state, the connector terminal assembly 13 is connected to the power conversion circuit unit 16, the power supply circuit unit 17, and the control circuit unit 18, as shown in FIG.

  Further, after this, the opening end 37 of the metal cover 12 is engaged with the step portion 35 of the motor housing 11 by stamping or the like, and is fixed with an adhesive tape in a fixing region AD provided in the outer peripheral direction. As described above, the annular step portion 35 as the motor housing side annular engagement portion formed on the end peripheral surface of the end surface portion 15 and the opening end 37 of the metal cover 12 as the metal cover side annular engagement portion are: It is engaged in a form called “stamp engagement” or “seal fitting”.

Here, the fixing area AD using the adhesive tape will be described with reference to FIG. The opening end 37 of the metal cover 12 is engaged with the stepped portion 35 formed at the outer peripheral end of the side peripheral surface portion 11A of the motor housing 11 so as to face each other. In this case, the outer peripheral shape of the side peripheral surface portion 11A of the motor housing 11 forming the step portion 35 and the outer peripheral shape of the opening end 37 of the metal cover 12 are in a shape that matches each other. For this reason, in the state which engaged both, the outer peripheral surface of 11 A of side peripheral surface parts and the outer peripheral surface of the opening end 37 of the metal cover 12 are the continuous surfaces called "level." (See FIGS. 11 and 12)
And it combines so that the inner peripheral surface of the opening end 37 of the metal cover 12 may contact the outer peripheral surface of the step part 35, and both opposing contact surface 38 will be formed. A single-sided adhesive tape 39 is attached to the outer periphery of the side peripheral surface portion 11A of the motor housing 11 and the outer periphery of the opening end 37 of the metal cover 12 from the outer peripheral side with the facing surface 38 as a boundary.

  The single-sided adhesive tape 39 is a so-called industrial adhesive tape, which is a pressure-sensitive adhesive tape having functions such as water tightness, heat resistance, high weather resistance, and high adhesiveness. For example, an adhesive using an acrylic adhesive Tape can be used. In addition to this, an adhesive tape using an epoxy-based or silicon-based adhesive can also be used. In short, any adhesive tape that has water tightness, heat resistance, and weather resistance and does not easily peel off may be used, and is not limited to the above-described materials. If sufficient watertightness is ensured, the arrangement of the watertight O-ring and the application process of the waterproof adhesive can be abolished at the engaging portion of the motor housing 11 and the metal cover 12, and the manufacturing process can be reduced. It is possible to omit the manufacturing cost. Of course, an O-ring or a waterproof adhesive can be used as needed.

  11 and 12 show an axial cross section of the engagement portion between the metal cover 12 and the motor housing 11 of the electric power steering apparatus shown in FIG. 10, and particularly in FIG. 12, the engagement portion between the metal cover 12 and the motor housing 11. The enlarged cross section of is shown.

  As can be seen from FIGS. 11 and 12, the opening end 37 of the metal cover 12 is fitted into a stepped portion 35 formed on the outer peripheral surface of the side peripheral surface portion 11 </ b> A of the motor housing 11 and having a diameter reduced toward the inside. The inner peripheral surface of the opening end 37 of the metal cover 12 is in contact with the outer peripheral wall 35F of the step portion 35. Then, a single-sided adhesive tape 39 having a length W1 toward the metal cover 12 and a width W2 toward the motor housing 11 with the step 35 and the opposed contact surface 38 of the opening end 37 of the metal cover 12 as the center. It is pasted. Here, each length is set to W1 = W2.

  The single-sided adhesive tape 39 has heat shrinkability. After the single-sided adhesive tape 39 is attached to the metal cover 12 and the motor housing 11, the single-sided adhesive tape 39 can be obtained by pressing and heating with a heating roller. By contracting, the contact state between the outer peripheral wall 35F of the step portion 35 and the inner peripheral surface of the opening end 37 of the metal cover 12 can be strengthened, and water or the like can be prevented from entering. In particular, the application start end and the application end end of the single-sided adhesive tape 39 are overlapped with each other, but a gap is generated at the overlap portion, and there is a risk of moisture intrusion. Therefore, if this part is pressure-bonded and heated with a heating roller, the gap can be eliminated and the intrusion of moisture can be suppressed.

  Further, the sticking start end 39 </ b> S and the sticking end end 39 </ b> E of the single-sided adhesive tape 39 are disposed in the planar area of the motor housing 11 and the metal cover 12. As shown in FIGS. 13 and 14, the cross-sectional shape orthogonal to the axial direction of the end surface portion 15 of the motor housing 11 is roughly formed of a circular portion 11R and a rectangular portion 11S. Similarly, the open end 37 of the metal cover 12 is also formed according to this shape. The three rectangular regions 40C and 40S are formed in the rectangular portion 11, but in this embodiment, the single-sided adhesive property is present on the planar region 40C located on the opposite side of the circular portion 11R and sandwiched between the planar regions 40S. A sticking start end 39S and a sticking end end 39E of the tape 39 are arranged.

  As described above, when the sticking start end 39S and the sticking end end 39E of the single-sided adhesive tape 39 are arranged in the flat area 40C (or 40S), the adhesiveness of the single-sided adhesive tape 30 can be improved, and further, it is difficult to peel off. Can be obtained. That is, when pasting on the circular portion 11, a thin streak is formed on the surface, so that a phenomenon such as a decrease in adhesion and a tendency to peel off easily occurs. Therefore, it is advantageous to stick the sticking start end 39S and the sticking end end 39E of the single-sided adhesive tape 39 to the planar region 40C (or 40S) as in this embodiment.

  Next, a modification of this embodiment will be described. In the example shown in FIGS. 15 and 16, a double-sided adhesive tape is disposed on the facing surface of the stepped portion 35 and the opening end 37 of the metal cover 12.

  15 and 16, the opening end 37 of the metal cover 12 is fitted into a stepped portion 35 formed on the outer peripheral surface of the side peripheral surface portion 11 </ b> A of the motor housing 11 and having a diameter reduced toward the inside. The tip end surface 37T of the opening end 37 of the metal cover 12 is opposed to the axial wall portion 35B of the portion 35. A double-sided adhesive tape 41 is disposed between the axial wall portion 35 </ b> B of the step portion 35 and the distal end surface 37 </ b> T of the opening end 37 of the metal cover 12. As shown in FIG. 16, the shape of the double-sided adhesive tape 41 matches the shape of the engagement portion between the axial wall portion 35 </ b> B of the step portion 35 and the tip end surface 37 </ b> T of the opening end 37 of the metal cover 12. It is.

  The double-sided adhesive tape 41 has the same function as the single-sided adhesive tape 39 described above, and is interposed between the tip surface 37T of the opening end 37 of the metal cover 12 and the wall portion 35B of the step portion 35 of the motor housing 11. After mounting, when a load is applied so that the metal cover 12 and the motor housing 11 are in close contact with each other by a pressurizing mechanism, they are pressure-bonded. The double-sided adhesive tape 41 strengthens the contact state between the wall portion 35B of the step portion 35 and the tip end surface 37T of the opening end 37 of the metal cover 12, and further suppresses the intrusion of water or the like. It becomes possible.

  In particular, since the double-sided adhesive tape 41 is in close contact with the three surfaces of the wall portion 35B of the step portion 35, the outer peripheral wall 35F, and the tip end surface 37T of the opening end of the metal cover 12, it effectively suppresses the ingress of moisture. It becomes possible. The double-sided pressure-sensitive adhesive tape 41 is also a so-called industrial pressure-sensitive adhesive tape, and is a pressure-sensitive adhesive tape having a high water-tightness, heat resistance and weather resistance, and a function having high adhesiveness. For this reason, if watertightness is sufficiently ensured, the arrangement of the watertight O-ring and the application process of the waterproof adhesive can be abolished at the engaging portion of the motor housing 11 and the metal cover 12, and the manufacturing process The manufacturing cost can be reduced by omitting. Of course, as in the embodiment shown in FIG. 12, etc., it is possible to use an O-ring or a waterproof adhesive as needed.

  Further, if a flexible material having resilience (repulsive force) is used for the double-sided adhesive tape 41, even if materials having different linear expansion coefficients between the metal cover 12 and the motor housing 11 are used, the temperature It becomes possible to reduce the influence due to the difference in the expansion amount due to. Furthermore, fixing with a double-sided adhesive tape and fixing with a single-sided adhesive tape can be used in combination.

  As described above, according to the present invention, the motor housing that is radially inwardly formed on the outer peripheral surface of the end surface portion of the aluminum-based metal motor housing opposite to the output portion of the rotating shaft of the electric motor. The metal cover side annular engagement portion that is formed at the opening end of the metal cover that covers the side annular engagement portion and the electronic control portion that controls the electric motor and engages the reduced diameter portion of the motor housing side annular engagement portion And covering the engagement portions of the outer peripheral surface of the motor housing side annular engagement portion and the metal cover side annular engagement portion with the metal cover side annular engagement portion engaged with the motor housing side annular engagement portion. In this state, the motor housing side annular engagement portion and the metal cover side annular engagement portion are opposed to each other with the metal cover side annular engagement portion engaged with the motor housing side annular engagement portion. The two annular facing surfaces Fixed with adhesive tape, and a configuration.

  According to this, in a state where the metal cover side annular engagement portion is engaged with the motor housing side annular engagement portion, the engagement portions of the outer peripheral surfaces of the motor housing side annular engagement portion and the metal cover side annular engagement portion are set. The motor housing side annular engagement portion and the metal cover side annular engagement portion are opposed to each other in a state in which the metal cover side annular engagement portion is engaged with the motor housing side annular engagement portion. Since the annular facing surface is fixed with the double-sided adhesive tape, the external shape can be reduced and the weight can be reduced.

  In addition, this invention is not limited to an above-described Example, Various modifications are included. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Further, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

  DESCRIPTION OF SYMBOLS 6 ... Electric power steering apparatus, 8 ... Electric motor part, 9 ... Electronic control part, 11 ... Motor housing, 12 ... Metal cover, 13 ... Connector terminal assembly, 14 ... Output part, 15 ... End surface part, 15A ... Power conversion Heat dissipation area, 15B ... heat dissipation area for power supply, 16 ... power conversion circuit section, 17 ... power supply circuit section, 18 ... control circuit section, 19 ... end face section, 20 ... coil, 21 ... stator, 22 ... rotor, 23 ... rotation Axis 24: Rotation detection part 25 ... Through hole 26 ... Substrate fixing convex part 27 ... Substrate receiving part 28 ... Projection heat dissipation part 29 ... Capacitor 30 ... Coil 31 ... Glass epoxy board 32 ... Microphone Computer 33 ... Peripheral circuit 34 ... Glass epoxy board 35 ... Step part 35B ... Wall part 35F ... Outer wall 36 ... Fixing screw 37 ... Open end 38 ... Opposite contact surface 39 ... Single-sided adhesive tape Flop, 39S ... joining start end, 39E ... sticking finish end, 40C, 40S ... planar area of 41 ... double-sided adhesive tape, AD ... fixed area.

Claims (16)

A motor housing made of an aluminum metal in which an electric motor for driving a mechanical control element is housed, and an end surface portion of the motor housing opposite to an output portion of the rotating shaft of the electric motor; An electronic control unit including a control circuit unit for driving the electric motor, a power supply circuit unit, and a power conversion circuit unit, and a metal metal cover that covers the electronic control unit,
A motor housing side annular engagement portion that is formed on the outer peripheral surface of the end surface portion of the motor housing opposite to the output portion of the rotating shaft of the electric motor and that is radially inwardly reduced, and an opening end of the metal cover Forming a metal cover side annular engagement portion that engages with a reduced diameter portion of the motor housing side annular engagement portion;
With the metal cover side annular engagement portion engaged with the motor housing side annular engagement portion, the engagement portions of the motor housing side annular engagement portion and the outer peripheral surface of the metal cover side annular engagement portion are covered. A single-sided adhesive tape is attached and fixed as described above. The electric drive device according to claim 1,
The single-sided adhesive tape is affixed across the metal cover side and the motor housing side, with an annular facing surface where the motor housing side annular engagement portion and the metal cover side annular engagement portion face each other. An electric drive device characterized by being attached and fixed. The electric drive device according to claim 2,
The sticking start end and sticking end end of the single-sided adhesive tape are overlapped and attached so as to cover the engaging portions of the outer peripheral surface of the motor housing side annular engagement portion and the metal cover side annular engagement portion. An electric drive device characterized by that. In the electric drive device according to claim 3,
The part where the sticking start end and the sticking end end of the single-sided adhesive tape are overlapped and pasted is the outer peripheral surface of the engaging part of the motor housing side annular engaging part and the metal cover side annular engaging part. Is an area formed in a planar shape. In the electric drive device according to claim 3,
The electric drive device according to claim 1, wherein the single-sided adhesive tape is bonded and fixed over the same length toward the metal cover side and the motor housing side. In the electric drive device according to any one of claims 1 to 5,
The electric drive device, wherein the single-sided adhesive tape is made of a heat-shrinkable material. A motor housing made of an aluminum metal in which an electric motor for driving a mechanical control element is housed, and an end surface portion of the motor housing opposite to an output portion of the rotating shaft of the electric motor; An electronic control unit including a control circuit unit for driving the electric motor, a power supply circuit unit, and a power conversion circuit unit, and a metal metal cover that covers the electronic control unit,
A motor housing side annular engagement portion that is formed on the outer peripheral surface of the end surface portion of the motor housing opposite to the output portion of the rotating shaft of the electric motor and that is radially inwardly reduced, and an opening end of the metal cover Forming a metal cover side annular engagement portion that engages with a reduced diameter portion of the motor housing side annular engagement portion;
An annular facing surface in which the motor housing side annular engagement portion and the metal cover side annular engagement portion face each other in a state where the metal cover side annular engagement portion is engaged with the motor housing side annular engagement portion. An electric drive device characterized by being fixed with a double-sided adhesive tape. The electric drive device according to claim 7,
The motor housing side annular engagement portion includes a wall portion facing a tip surface side of the metal cover side annular engagement portion and an outer peripheral wall portion in contact with an inner peripheral surface of the metal cover side annular engagement portion. ,
In a state where the metal cover side annular engagement portion is engaged with the motor housing side annular engagement portion, the double-sided adhesive tape comprises the wall portion and the outer peripheral wall portion of the motor housing side annular engagement portion, and An electric drive device, wherein the electric drive device is in contact with and fixed to a front end surface of the metal cover side annular engagement portion. The electric drive device according to claim 8,
The double-sided adhesive tape fixes the motor housing-side annular engagement portion and the metal cover-side annular engagement portion by pressing the motor housing and the metal cover in a direction facing each other. Drive device. The electric drive device according to claim 9, wherein
The electric double-sided adhesive tape is made of a flexible material having resilience (repulsive force). An electric motor that applies a steering assist force to the steering shaft based on an output from a torque sensor that detects a turning direction and a turning torque of the steering shaft, and an aluminum metal motor housing that houses the electric motor; An electronic circuit comprising a control circuit unit, a power circuit unit, and a power conversion circuit unit for driving the electric motor, which is disposed on the side of the end surface of the motor housing opposite to the output unit of the rotating shaft of the electric motor. A control unit, and a metal metal cover that covers the electronic control unit,
A motor housing side annular engagement portion that is formed on the outer peripheral surface of the end surface portion of the motor housing opposite to the output portion of the rotating shaft of the electric motor and that is radially inwardly reduced, and an opening end of the metal cover Forming a metal cover side annular engagement portion that engages with a reduced diameter portion of the motor housing side annular engagement portion;
With the metal cover side annular engagement portion engaged with the motor housing side annular engagement portion, the engagement portions of the motor housing side annular engagement portion and the outer peripheral surface of the metal cover side annular engagement portion are covered. Thus, an electric power steering apparatus characterized by sticking and fixing a single-sided adhesive tape. The electric power steering apparatus according to claim 11,
The single-sided adhesive tape is affixed across the metal cover side and the motor housing side, with an annular facing surface where the motor housing side annular engagement portion and the metal cover side annular engagement portion face each other. An electric power steering device characterized by being attached and fixed. The electric power steering apparatus according to claim 12,
The sticking start end and sticking end end of the single-sided adhesive tape are overlapped and attached so as to cover the engaging portions of the outer peripheral surface of the motor housing side annular engagement portion and the metal cover side annular engagement portion. An electric power steering device characterized by that. The electric power steering apparatus according to claim 13,
The part where the sticking start end and the sticking end end of the single-sided adhesive tape are overlapped and pasted is the outer peripheral surface of the engaging part of the motor housing side annular engaging part and the metal cover side annular engaging part. Is an area formed in a planar shape. The electric power steering apparatus according to claim 14,
The electric power steering device according to claim 1, wherein the single-sided adhesive tape is bonded and fixed over the same length toward the metal cover side and the motor housing side. The electric power steering apparatus according to any one of claims 11 to 15,
The electric power steering apparatus, wherein the single-sided adhesive tape is made of a heat-shrinkable material.

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