JP2011083065A - Drive control device and motor unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a more compact drive control device efficiently dissipating heat generated from electronic components, and to provide a motor unit. <P>SOLUTION: In a control unit 3 for controlling drive of a brushless motor, a bus bar 38 for supplying power from an external power supply to the brushless motor is formed in the form of a wiring pattern, and the surface of the bus bar 38 is formed as a mounting part 50 for mounting an FET 41. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a drive control device mounted on an automobile or the like, and a motor unit using the same.

  2. Description of the Related Art Conventionally, there is an electric power steering device that assists a steering force in accordance with an operation of a steering shaft of a vehicle using a three-phase brushless motor. This type of brushless motor has a stator around which a plurality of coils are wound, and a rotor that is rotatably provided with respect to the stator, and a drive control device (control unit) that controls power feeding to the coils. ) Controls the rotational drive of the rotor.

This type of drive control device has a circuit board on which a plurality of electronic components are mounted. This circuit board is mounted with a driving board on which electronic components such as a switching element for selectively supplying power to a plurality of coils are mounted, and an electronic part such as an integrated circuit for controlling the driving of the switching elements. The control board is configured to be divided.
Here, for example, in order to mount the electric power steering device in a limited space of the vehicle, various techniques for reducing the size of the drive control device have been proposed. Also, various techniques for efficiently radiating heat from the circuit board have been proposed in order to prevent problems of the circuit board due to heat generation of electronic components.

  For example, a technology is disclosed in which a drive board and a control board are stored in a stacked state in a case, and the drive board and the control board are brought into contact with the case (see, for example, Patent Document 1). . With this configuration, the drive control device is miniaturized and heat from each substrate is efficiently radiated through the case.

JP 2009-113526 A

  By the way, in the above-described prior art, a current is supplied to the brushless motor through a pattern formed on the drive substrate. Since the thickness of the pattern formed on the substrate is small, it is necessary to set the pattern width to be large when supplying a large current to the brushless motor. For this reason, it is necessary to set the size of the drive substrate to a size capable of forming a wide pattern, and there is a problem that the drive substrate becomes large.

  Further, in the above-described conventional technology, heat generated in the electronic component is transmitted to the case via the pattern and the substrate, so that the electronic component and the pattern, the pattern and the substrate, and the substrate and the case There is a loss in heat transfer between the two. For this reason, there is a problem that it is difficult to efficiently dissipate heat generated in the electronic component.

  Accordingly, the present invention has been made in view of the above-described circumstances, and provides a drive control device and a motor unit that can be further miniaturized and can efficiently dissipate heat generated in electronic components. To do.

In order to solve the above-mentioned problem, the invention described in claim 1 is a drive control device for performing drive control of an electric motor, wherein a bus bar for supplying power from an external power source to the electric motor is provided in a wiring pattern. The surface of the bus bar is configured as a mounting portion for mounting an electronic component.
With this configuration, it is possible to reduce the number of substrates on which electronic components are mounted. In addition, the thickness of the bus bar can be easily set to be thicker than the pattern formed on the conventional substrate. For this reason, the width | variety of a bus-bar can be narrowed compared with the conventional pattern, and size reduction of a drive control apparatus can be achieved.

The invention described in claim 2 is characterized in that one end of the bus bar is configured as a connection portion for electrically connecting the electronic component and the circuit board.
By configuring in this way, for example, when a switching element or the like is mounted on a bus bar and the mounted portion is configured as a drive board, while the circuit board is configured as a control board, the drive board and the control board are Connection parts for electrical connection can be eliminated. For this reason, the number of parts of the drive control device can be reduced, and the manufacturing cost can be reduced.

The invention described in claim 3 is characterized in that the bus bar is disposed on a conductive base portion via an insulating member.
With this configuration, heat generated from the electronic component mounted on the bus bar can be transmitted to the base between the electronic component and the bus bar and between the bus bar and the base. For this reason, the loss of heat transfer is reduced as compared with the conventional case, and the heat of the electronic component can be efficiently radiated.

The invention described in claim 4 is characterized in that the bus bar is resin-molded to form a bus bar module.
By comprising in this way, the assembly | attachment precision of a bus-bar can be improved and the assembly | attachment workability | operativity of a bus-bar can be simplified.

According to a fifth aspect of the present invention, there is provided a motor unit, wherein the drive control device according to any of the first to fourth aspects is integrated with the electric motor via the base portion. did.
With this configuration, it is possible to provide a motor unit that can be miniaturized and can efficiently dissipate heat generated in the electronic component.

According to the present invention, it is possible to reduce the number of substrates for mounting electronic components. In addition, the thickness of the bus bar can be easily set to be thicker than the pattern formed on the conventional substrate. For this reason, the width | variety of a bus-bar can be narrowed compared with the conventional pattern, and size reduction of a drive control apparatus can be achieved.
According to the present invention, heat generated from the electronic component mounted on the bus bar can be transmitted to the base between the electronic component and the bus bar and between the bus bar and the base. For this reason, the loss of heat transfer is reduced as compared with the conventional case, and the heat of the electronic component can be efficiently radiated.

It is a perspective view of the motor unit in the embodiment of the present invention. It is a longitudinal cross-sectional view of the brushless motor in embodiment of this invention. It is sectional drawing which shows schematic structure of the control unit in embodiment of this invention. It is a perspective view of the bus-bar module in the embodiment of the present invention.

(Motor unit)
Next, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view of the motor unit 1, and FIG. 2 is a longitudinal sectional view of the brushless motor 2.
As shown in FIG. 1, the motor unit 1 is used, for example, in an electric power steering device mounted on a vehicle, and is attached to a brushless motor 2 and one end of the brushless motor 2 via a bracket 6. And a control unit 3.

The brushless motor 2 is a so-called inner rotor type three-phase motor, which has a stator 4 and a rotor 5 disposed in the stator 4, and the rotor 5 is rotatable on a bracket 6 fixed to the stator 4. It is supported.
In the stator 4, a stator core 8 is press-fitted and fixed to the inner periphery of a bottomed cylindrical stator housing 7 having one end opened.

A boss portion 14 is formed in a substantially radial center of the bottom portion 7a of the stator housing 7, and a bearing 16 that rotatably supports one end of the rotating shaft 15 of the rotor 5 is press-fitted and fixed thereto.
On the opening side of the stator housing 7, an inlay portion 17 that is used when the stamper is joined to the bracket 6 is formed. The opening of the stator housing 7 is closed by the bracket 6.

  The stator core 8 has a plurality of teeth 11 protruding from the annular outer peripheral portion 9 toward the center in the radial direction. A plurality of dovetail-shaped slots (not shown) are formed between adjacent teeth 11 on the inner peripheral side of the stator core 8. A coil 10 is wound around each tooth after the insulator 13 is mounted. The coil 10 forms a three-phase (U-phase, V-phase, W-phase) coil.

  A bus bar unit 23 is provided on the insulator 13 at the end of the stator 4 on the bracket 6 side. The bus bar unit 23 electrically connects the terminal portion of the coil 10 of the stator 4 and the control unit 3, and is formed in a substantially annular shape so as to surround the rotating shaft 15 of the rotor 5. More specifically, the bus bar unit 23 is embedded in a substantially annular resin mold body 24 in a form in which a plurality of bus bars 25 formed in a substantially annular shape corresponding to this are laminated along the axial direction. Yes.

  The bus bar 25 is provided for each phase of the coil 10, and the bus bar 25 for each phase is connected to the corresponding phase coil 10. The bus bar 25 for each phase is electrically connected to the control unit 3. That is, electric power from an external power source (not shown) is supplied to the coils 10 of each phase via the control unit 3 and the bus bar unit 23.

On the outer periphery of the rotating shaft 15 of the rotor 5, a rotor core 28 is fitted and fixed at a position facing the stator core 8. The rotor core 28 is formed by laminating metal plates (electromagnetic steel plates) in the axial direction or pressurizing soft magnetic powder. On the outer peripheral surface of the rotor core 28, a permanent magnet 29 formed in a tile shape with a magnet holder 27 interposed is provided. The permanent magnet 29 is arranged so that the magnetic poles change in order in the circumferential direction.
A resolver rotor 19 is fixed to the rotating shaft 15 of the rotor 5 via a magnet holder 27 at a position facing the bracket 6. The resolver rotor 19 constitutes one of the resolvers 18 for detecting the rotational position of the rotary shaft 15.

The bracket 6 is formed in a substantially disc shape, and is fastened and fixed to the stator housing 7 by a plurality of bolts 55. A surface of the bracket 6 on the side of the axial direction stator 4 has a cylindrical joint portion 21 that fits into the spigot portion 17 when abutting against the stator housing 7.
A bearing 22 that rotatably supports the other end of the rotary shaft 15 is press-fitted in a substantially center in the radial direction of the bracket 6. A resolver stator 20 that constitutes the other of the resolvers 18 is fixed to the stator 4 side of the bearing 22.

  A connector portion (not shown) is integrally formed on the outer peripheral portion of the bracket 6. Through this connector portion, a resolver coil (not shown) wound around the resolver stator 20 is electrically connected to an external control device. An external control device (not shown) is electrically connected to the control unit 3. A control signal is output to the control unit 3 based on the output signal from the resolver 18.

(Controller unit)
FIG. 3 is a cross-sectional view showing a schematic configuration of the control unit 3.
As shown in FIGS. 1 and 3, the control unit 3 includes a base portion 30 formed in a box shape having an opening 31 on the bracket 6 side. The base portion 30 is made of aluminum, and is formed by a bottom wall 30a and a peripheral wall 30b formed from the bottom wall 30a toward the bracket 6 side. Further, an inlay portion 32 protrudes from the bottom wall 30a toward the outer side in the axial direction, that is, the side opposite to the direction in which the peripheral wall 30b is formed (upper side in FIG. 3).
The inlay portion 32 is formed in a cylindrical shape and can be fitted to an external device. An O-ring groove 34 for attaching the O-ring 33 is formed on the outer peripheral surface of the inlay part 32.

Further, a power connector portion 39 that can be connected to an external power source (not shown) is provided on the peripheral wall 30b of the base portion 30 so as to protrude outward in the radial direction, and a sensor connector that can be connected to an external control device (not shown). The portion 40 protrudes outward in the radial direction. The power connector portion 39 is provided with a power terminal 39a, and the sensor connector portion 40 is provided with a sensor terminal 40a.
Further, a bus bar module 35 is fastened and fixed to the bottom 30 a of the base 30 by bolts 37 via an insulating sheet 36 on the inner surface side.

(Bus bar module)
FIG. 4 is a perspective view of the bus bar module 35.
As shown in FIGS. 3 and 4, the bus bar module 35 is obtained by integrating a plurality of bus bars 38 by a resin mold portion 41. The plurality of bus bars 38 are formed in a wiring pattern like a pattern formed on a circuit board or the like, for example. Each of the plurality of bus bars 38 has a thickness of about 1 mm.

  A plurality (six in this embodiment) of FETs (Field Effect Transistors) 41 are mounted on the plurality of bus bars 38 so as to straddle the predetermined bus bar 38. These FETs 41 are for selectively supplying power to the U-phase, V-phase, and W-phase coils 10 of the brushless motor 2. That is, a three-phase bridge circuit is formed by the plurality of bus bars 38 and FETs 41 formed in a wiring pattern.

The resin mold portion 41 is formed in a substantially square shape in plan view, and a recess 43 is formed on one side so as to avoid the rotating shaft 15. Further, the resin mold portion 41 is formed with an opening 44 at a portion where the FET 41 is disposed, and a plurality of bus bars 38 are exposed from the opening 44.
Thereby, each FET 41 can be mounted on the bus bar 38. That is, in the plurality of bus bars 38, a portion exposed from the opening 44 of the resin mold portion 41 is configured as a mounting portion 50 for mounting the FET 41. Further, by forming the opening 44, the bus bar 38 exposed from the opening 44 can be brought into contact with the bottom wall 30 a of the base 30 via the insulating sheet 36.

Here, each of the plurality of bus bars 38 includes a power line 61 that is wide enough to supply a relatively large current and a signal line 62 that is narrow enough to supply a relatively small current. . The terminal portion 61a of the power line 61 is bent toward the axial bracket 6 side.
The terminal portions 61 a of these power lines 61 are electrically connected to a power board 70 disposed on the bracket 6 side with respect to the bus bar module 35. The terminal portion 62a of the signal line 62 is bent toward the axial bracket 6 side. Terminal portions 62 a of these signal lines 62 are connected to the control board 45 disposed on the bracket 6 side of the bus bar module 35 of the base portion 30.

The bus bar module 35, the power board 70, and the control board 45 are housed in the base portion 30 in the form of being laminated in the axial direction. The control board 45 is fastened and fixed to the bottom wall 30 a of the base portion 30 by bolts 48 via the bus bar module 35 and the intermediate support plate 47.
In the control board 45, a through hole 46 is formed in a portion corresponding to the terminal portion 62 a of the signal line 62 in the bus bar 38 protruding from the bus bar module 35.

The terminal portion 62a of the signal line 62 is inserted into the through hole 46, and the terminal portion 62a is fixed by soldering or welding. Thereby, the bus bar 38 and the control board 45 are electrically connected.
That is, among the plurality of bus bars 38, the terminal portion 62 a of the signal line 62 is configured as a connection portion 51 for connecting the bus bar module 35 to the control board 45.

  The control board 45 includes a plurality of components such as a CPU (Central Processing Unit) which is a control component for controlling the drive of the FET 53, a Zener diode for preventing overvoltage, and a regulator IC for stably supplying power to each component. An electronic component 49 is mounted. The electronic component 49 and the bus bar 38 are electrically connected via a pattern (not shown) formed on the control board 45.

  Further, the sensor board 40 a of the sensor connector part 40 provided on the base part 30 is connected to the control board 45. As a result, signal input / output can be performed between the electronic component 49 mounted on the control board 45 and an external control device (not shown) via the sensor connector unit 40.

  The power board 70 is disposed between the bus bar module 35 and the control board 45. The power board 70 is electrically connected to the power line 61 among the plurality of bus bars 38. On the power board 70, electronic components such as a current sensor and a relay element (not shown) are assembled. The power board 70 is electrically connected to the power terminals 39 a of the power connector portion 39 provided on the base portion 30 and the bus bar unit 23 of the brushless motor 2. Thereby, the energization control to the brushless motor 2 is performed by driving and controlling the FET 41 of the bus bar module 35 by the control board 45.

(Function)
Next, the operation of the motor unit 1 will be described.
First, when electric power is supplied from an external power source (not shown), the CPU mounted on the control board 45 performs on / off switching control of the FET 53. Then, a current is supplied to the coils 10 of each phase via the bus bar unit 23 (see FIG. 2) of the brushless motor 2.
When a current is supplied to the coil 10, a desired magnetic field is generated in each of the plurality of teeth 11 of the stator core 8. A magnetic attractive force or repulsive force is generated between the magnetic field and the permanent magnet 29 of the rotor 5, and the rotor 5 continues to rotate.

  Here, the rotational position of the rotor 5 is detected by the resolver 18. The rotational position signal detected by the resolver 18 is output to an external control device via a connector portion (not shown) provided on the bracket 6. The external control device outputs a control signal based on the output signal from the resolver 18. The control signal is input to a CPU or the like mounted on the control board 45 via the sensor connector unit 40 provided in the base unit 30. Based on this input signal, the CPU performs on / off switching control of the FET 53.

(effect)
Therefore, according to the above-described embodiment, the plurality of bus bars 38 are formed in a wiring pattern on the base portion 30 of the control unit 3 and the FETs 41 are mounted on the bus bars 38. The circuit board can be deleted. Further, by using the bus bar 38, the thickness of the passage for supplying current can be set thicker than that of the pattern formed on the conventional substrate.
That is, the thickness of the pattern formed on the circuit board is set to about 35 μm to 100 μm, for example, but the thickness of the bus bar 38 can be set to about 1 mm, for example. For this reason, the width | variety of the bus-bar 38 can be narrowed compared with the conventional pattern by this. Therefore, it is possible to reduce the size of the control unit 3.

  Furthermore, by integrating the plurality of bus bars 38 by the resin mold part 41 to form the bus bar module 35, the assembly accuracy of each bus bar 38 can be improved and the assembly workability of each bus bar 38 can be simplified. it can.

  An opening 44 for mounting the FET 41 on the bus bar 38 is formed in the resin mold portion 41, so that the bus bar 38 comes into contact with the bottom wall 30 a of the base portion 30 via the insulating sheet 36. Yes. Therefore, heat generated from the FET 41 mounted on the bus bar 38 can be transmitted to the base portion 30 between the FET 41 and the bus bar 38 and between the bus bar 38 and the base portion 30.

Here, for example, in the case where the FET 41 is mounted on a circuit board or the like as in the prior art, the heat generated from the FET 41 is between the FET 41 and the pattern formed on the circuit board, and the pattern and the circuit board. In the meantime, the signal is transmitted to the base part 30 via the circuit board and the base part 30. For this reason, the loss of heat transfer will become large.
However, in the present embodiment, since the circuit board on which the FET 41 is mounted becomes unnecessary, the heat transfer loss is reduced as compared with the conventional case. For this reason, the heat of the FET 41 can be efficiently radiated.

  Further, according to the above-described embodiment, the terminal portion 62 a of the signal line 62 among the plurality of bus bars 38 is configured as the connection portion 51 for connecting the bus bar module 35 to the control board 45, and thus the bus bar module 35. There is no need to separately prepare components for connecting the control board 45 and the control board 45. For this reason, the number of parts of the control unit 3 can be reduced, and the manufacturing cost can be reduced.

The present invention is not limited to the above-described embodiment, and includes various modifications made to the above-described embodiment without departing from the spirit of the present invention.
For example, in the above-described embodiment, the case where the motor unit 1 is used for an electric power steering device mounted on a vehicle has been described. However, the present invention is not limited to this, and the motor unit 1 can be applied to various electrical components having the brushless motor 2.

  In the above-described embodiment, the case where only the FET 41 is mounted on the bus bar 38 of the bus bar module 35 as an electronic component has been described. However, the present invention is not limited to this, and other electronic components that can withstand a relatively large current, such as a choke coil and a capacitor, can be mounted.

1 Motor unit 2 Brushless motor (electric motor)
3 Control unit (drive control device)
30 Base part 35 Bus bar module 36 Insulation sheet (insulation member)
38 Bus bar 41 FET (electronic parts)
42 Resin mold part 45 Control board (circuit board)
50 mounting part 51 connection part 61 power line 61a, 62a terminal part 62 signal line

Claims (5)

In a drive control device for performing drive control of an electric motor,
A drive control device characterized in that a bus bar for supplying electric power from an external power source to the electric motor is formed in a wiring pattern, and the surface of the bus bar is configured as a mounting portion for mounting electronic components.   The drive control device according to claim 1, wherein one end of the bus bar is configured as a connection portion for electrically connecting the electronic component and the circuit board.   The drive control device according to claim 1, wherein the bus bar is disposed on an electrically conductive base portion via an insulating member.   4. The drive control device according to claim 1, wherein the bus bar is resin-molded to form a bus bar module.   The drive control device according to any one of claims 1 to 4, wherein the drive unit is integrated with the electric motor via the base portion.

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