JP2013187990A - Control device of electric motor and vehicle steering gear including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device of an electric motor which improves the reliability of smooth actuation of the electric motor with a simple structure, and to provide a vehicle steering gear including the control device of the electric motor.SOLUTION: A control device 21 provided between a motor housing 16 and a gear housing 17 includes: a base 22 fixed to the gear housing 17 and to which a circuit board 23 is fixed; and a connector module 24 for connecting the circuit board 23 with a power source B. The connector module 24 includes a bus bar 31 connecting the circuit board 23 with the power source B and a module holder 32 holding the bus bar 31. The module holder 32 is formed into a square box shape covering the circuit board 23 from the motor housing 16 side.

Description

  The present invention relates to an electric motor control device and a vehicle steering device including the same.

  2. Description of the Related Art Conventionally, some vehicle steering devices are provided with an EPS actuator (steering force assisting device) that applies an assist force for assisting a steering operation to a steering system using an electric motor as a drive source. As a control device for such an electric motor, an apparatus that is disposed between a motor housing of the electric motor and a gear housing that houses a speed reduction mechanism for transmitting motor torque and is integrated with the electric motor is known. (For example, patent document 1).

  In the control device disclosed in Patent Document 1, a control circuit for outputting a control signal is formed in a control housing including a first housing fixed to the motor housing and a second housing formed integrally with the gear housing. And a connector module (subassembly) for electrically connecting the circuit board to a power source. In addition, by making a part of the gear housing function as a control housing in this way, it is possible to reduce the number of parts. In general, a connector module has a bus bar made of a metal material and a module holder made of an insulating resin material, and the bus bar and the module holder are integrally provided by insert molding.

JP 2009-277726 A

  However, in the configuration of Patent Document 1, since a part of the gear housing is also functioning as a control housing, foreign matters such as lubricating oil and wear powder existing inside the gear housing are likely to adhere to the circuit board. At the same time, circuit components that fall off (peel) from the circuit board easily enter the gear housing. As a result, for example, the smooth operation of the electric motor may be hindered. Therefore, it is conceivable that the first housing is formed integrally with the motor housing, and the second housing formed separately is fixed to the gear housing so that a part of the motor housing functions as a control housing. However, in this case, foreign matters existing inside the motor housing are likely to adhere to the circuit board, and circuit components dropped from the circuit board can easily enter the motor housing. Similarly, the electric motor operates smoothly. May be hindered.

  Such a problem is not limited to an electric motor control device used as a drive source of an EPS actuator, but is provided between an electric motor and an output-side housing that houses an output member to which the motor torque is transmitted. If it is a control device, it can occur as well.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide an electric motor control device capable of improving the reliability of smooth operation of the electric motor with a simple configuration, and It is providing the vehicle steering device provided with this.

  In order to achieve the above object, an invention according to claim 1 is provided between a motor housing of an electric motor and an output side housing in which an output member to which a motor torque of the electric motor is transmitted is accommodated. In the electric motor control device for controlling the operation of the motor, a base fixed to one of the motor housing and the output side housing and the circuit board is fixed, and a connector for connecting the circuit board to a power source The connector module includes a bus bar for connecting the circuit board and the power source, and a module holder for holding the bus bar. The module holder includes the motor housing and the output side housing. The gist is that the circuit board is covered from either side. .

  According to the above configuration, the circuit board is covered with the base on either side of the motor housing or the output-side housing, and is covered with the module holder on the other side. Therefore, it is possible to prevent the foreign matter existing in the motor housing and the output side housing from adhering to the circuit board, and to prevent the circuit components dropped from the circuit board from entering the motor housing and the output side housing. Can be secured. Thus, in the above configuration, since the module holder has a function of covering the circuit board, the reliability can be improved with a simple configuration without increasing the number of components.

  According to a second aspect of the present invention, in the electric motor control device according to the first aspect, the module holder is formed with a through-hole through which the rotating shaft of the electric motor is inserted, and the through-hole has a The gist of the invention is that a seal member for closing a gap between the inner peripheral surface of the through hole and the outer peripheral surface of the rotating shaft is provided.

  According to the said structure, the clearance gap between the internal peripheral surface of a through-hole, and the outer peripheral surface of a rotating shaft is block | closed with a sealing member. For this reason, foreign matters existing inside the motor housing and the output side housing enter the module holder through the gap and adhere to the circuit board, and circuit components dropped from the circuit board are removed from the motor housing and the output side housing. It is possible to further suppress entering the inside.

  According to a third aspect of the present invention, in the electric motor control device according to the first aspect, the module holder is formed with a through-hole through which the rotating shaft of the electric motor is inserted, and the inner periphery of the through-hole The gist of the present invention is that a labyrinth-like gap is formed including a gap between the surface and the outer peripheral surface of the rotating shaft.

  According to the said structure, the labyrinth-like clearance gap including the clearance gap between the internal peripheral surface of a through-hole, and the outer peripheral surface of a rotating shaft is formed. For this reason, foreign matters existing inside the motor housing and the output side housing enter the module holder through the gap and adhere to the circuit board, and circuit components dropped from the circuit board are removed from the motor housing and the output side housing. It is possible to further suppress entering the inside.

  According to a fourth aspect of the present invention, in the electric motor control device according to any one of the first to third aspects, a drive current is supplied to the electric motor on the circuit board placed on the base. A driving circuit to be supplied is formed, and the base is fixed to the output side housing.

  Here, since a large drive current supplied to the electric motor flows through the drive circuit, the amount of heat generation tends to increase. In addition, since the output member housed in the output side housing is generally less likely to generate heat than the electric motor, the output side housing is unlikely to become hot. Therefore, by fixing the base to the output side housing as in the above configuration, the heat generated in the circuit board can be efficiently radiated.

  The gist of the fifth aspect of the invention is a vehicle steering apparatus including the electric motor control device according to any one of the first to fourth aspects. According to the above configuration, it is possible to provide a vehicle steering apparatus that has a simple configuration and excellent reliability.

  ADVANTAGE OF THE INVENTION According to this invention, the control apparatus of the electric motor which can improve the reliability about smooth operation | movement of an electric motor with simple structure, and a vehicle steering device provided with the same can be provided.

The schematic block diagram of the steering apparatus for vehicles. The partial cross section figure which shows schematic structure of the EPS actuator of 1st Embodiment. (A), (b) is explanatory drawing at the time of connecting a circuit component to a module holder. (A), (b) is explanatory drawing at the time of connecting a connector module to a base. The expanded sectional view which shows the through-hole vicinity of the module holder in the EPS actuator of 2nd Embodiment. The expanded sectional view which shows the through-hole vicinity in the module holder of another example. The partial cross section figure which shows schematic structure of the EPS actuator of another example.

(First embodiment)
A first embodiment of the present invention will be described below with reference to the drawings.
As shown in FIG. 1, in the vehicle steering apparatus 1, a steering shaft 3 to which a steering wheel 2 is fixed is connected to a rack shaft 5 via a rack and pinion mechanism 4. Thereby, the rotation of the steering shaft 3 accompanying the steering operation is converted into a reciprocating linear motion of the rack shaft 5 by the rack and pinion mechanism 4. The steering shaft 3 is formed by connecting a column shaft 8, an intermediate shaft 9, and a pinion shaft 10. Then, the reciprocating linear motion of the rack shaft 5 accompanying the rotation of the steering shaft 3 is transmitted to the knuckle (not shown) via the tie rods 11 connected to both ends of the rack shaft 5, thereby the steering angle of the steered wheels 12, That is, the traveling direction of the vehicle is changed.

  In addition, the vehicle steering apparatus 1 includes an EPS actuator (steering force assisting device) 13 that applies an assist force for assisting a steering operation to the steering system. The vehicle steering apparatus 1 according to the present embodiment is configured as a so-called column-type electric power steering apparatus that rotationally drives the column shaft 8, and the electric motor 14 that is a drive source of the EPS actuator 13 is an output of a worm & wheel or the like. It is drivingly connected to the column shaft 8 via a speed reduction mechanism 15 as a member. The rotation of the electric motor 14 is decelerated by the speed reduction mechanism 15 and transmitted to the column shaft 8 so that the motor torque is applied as an assist force to the steering system.

  As shown in FIG. 2, in the EPS actuator 13, a motor housing 16 of the electric motor 14 and a gear housing 17 in which a speed reduction mechanism 15 (not shown in FIG. 2) to which the motor torque of the electric motor 14 is transmitted are accommodated. A control device 21 for controlling the operation of the electric motor 14 is provided between them. That is, the EPS actuator 13 of the present embodiment has a so-called electromechanical integrated structure in which the electric motor 14 and the control device 21 are integrated.

  The motor housing 16 is formed in a bottomed cylindrical shape, and a cylindrical extending portion 16 a extending toward the gear housing 17 is integrally formed in the opening of the motor housing 16. The gear housing 17 is made of a metal material having a high thermal conductivity such as an aluminum alloy, and has a relatively large heat capacity.

  The control device 21 includes a base 22 fixed to the gear housing 17, a circuit board 23 fixed to the base 22, and a connector module 24 for connecting the circuit board 23 and a power source (battery) B. . The base 22 is formed in a flat plate shape, and an accommodation recess 22a to which the circuit board 23 is fixed is formed on the side surface of the base 22 on the motor housing 16 side. Further, the extending portion 16a of the motor housing 16 is in contact with the outer peripheral edge of the base 22 in such a manner that the connector module 24 is accommodated therein. The motor housing 16 is connected to the gear housing 17 by bolts 25 so that the base 22 is sandwiched between the motor housing 16 and the gear housing 17. That is, in this embodiment, the control housing of the control apparatus 21 is comprised by the base 22 and the extension part 16a. Various circuit components (not shown) are mounted on the circuit board 23, and a control circuit that outputs a control signal and a drive circuit that supplies a drive current to the electric motor 14 based on the control signal are formed. ing.

  The connector module 24 includes a plurality of bus bars 31 that connect the circuit board 23 and the power source B, and a module holder 32 that holds the bus bars 31. The bus bar 31 is made of a metal material, the module holder 32 is made of an insulating resin material, and the bus bar 31 and the module holder 32 are integrally provided by insert molding. The bus bar 31 is connected to the circuit board 23 and is electrically connected to the power source B at a connector portion (not shown).

  The module holder 32 is shaped to cover the circuit board 23 from the motor housing 16 side. Specifically, the module holder 32 is formed in a square box shape opened to the base 22 side (upper side in FIG. 2). The opening shape of the module holder 32 is formed substantially the same as the outer shape of the circuit board 23 and is formed so as to cover the entire side surface of the circuit board 23 on the motor housing 16 side. The module holder 32 is fixed to the circuit board 23 with a screw, an adhesive, or the like (not shown). In the module holder 32, circuit components 33 such as capacitors and coils connected to the circuit board 23 via the bus bar 31 are held.

  As shown in an enlarged view in FIG. 2, a through hole 35 through which the rotation shaft 34 of the electric motor 14 is inserted is formed in the bottom 32 a of the module holder 32. The through hole 35 is provided with a seal member 36 that closes the gap S <b> 1 between the inner peripheral surface of the through hole 35 and the outer peripheral surface of the rotation shaft 34. The seal member 36 of the present embodiment is made of an oil seal (lip seal) or the like, and is elastically slidably in contact with the outer peripheral surface of the rotating shaft 34. Further, through holes 37 and 38 are formed in the base 22 and the circuit board 23 coaxially with the through hole 35 of the module holder 32, respectively. The rotating shaft 34 is rotatably supported by a bearing 39 provided in the through hole 37 and a bearing (not shown) provided in the motor housing 16.

  In the EPS actuator 13 configured as described above, power is supplied from the power supply B to the circuit board via the connector module 24, and power is supplied from the drive circuit to the electric motor 14 via a connection line (not shown). The electric motor 14 is driven.

Next, the manufacture of the control device (EPS actuator) will be described.
As shown in FIGS. 3A and 3B, a circuit component 33 is inserted into the module holder 32 formed integrally with the bus bar 31 by insert molding from the opening, and the circuit component 33 is attached to the bus bar 31. On the other hand, it joins by resistance welding, TIG welding, etc. Subsequently, as shown in FIGS. 4A and 4B, the bus bar 31 is joined to the circuit board 23 fixed to the base 22 and the module holder 32 is fixed. Then, a seal member 36 is provided in the through hole 35 and a bearing 39 is provided in the through hole 37 so that the rotary shaft 34 is inserted into the through holes 35, 37, 38, and the control device 21 is connected between the motor housing 16 and the gear housing 17. The EPS actuator 13 is manufactured by being fixed so as to be sandwiched therebetween (see FIG. 2).

Next, the operation of the control device will be described.
In the control device 21 of the present embodiment, the side surface of the circuit board 23 on the gear housing 17 side is covered with the base 22, and the side surface of the circuit board 23 on the motor housing 16 side is covered with the module holder 32. For this reason, it is possible to suppress wear powder, lubricating oil, and the like existing inside the motor housing 16 and the gear housing 17 from adhering to the circuit board 23, and the circuit components and the like that have dropped off from the circuit board 23 can be removed. Intrusion into the motor 17 is suppressed, and the smooth operation of the electric motor 14 is ensured.

As described above, according to the present embodiment, the following effects can be obtained.
(1) Since the module holder 32 is formed in a square box shape that covers the circuit board 23 from the motor housing 16 side, and the module holder 32 has a function of covering the circuit board 23, the configuration can be simplified without increasing the number of components. Reliability can be improved. As a result, the vehicle steering apparatus 1 having a simple configuration and excellent reliability can be provided.

  (2) The seal member 36 that closes the gap S <b> 1 between the inner peripheral surface of the through hole 35 and the outer peripheral surface of the rotating shaft 34 is provided in the through hole 35 of the module holder 32. For this reason, foreign matter existing inside the motor housing 16 and the gear housing 17 enters the module holder 32 through the gap S1 and adheres to the circuit board 23, and circuit components and the like that have dropped off from the circuit board 23 are removed from the motor housing. 16 and the gear housing 17 can be further suppressed.

  (3) The base 22 on which the circuit board 23 having the drive circuit is mounted is fixed to the gear housing 17. Here, since a large drive current supplied to the electric motor flows through the drive circuit, the amount of heat generation tends to increase. Further, the speed reduction mechanism 15 housed in the gear housing 17 is less likely to generate heat than the electric motor 14, and the gear housing 17 is unlikely to become hot. Therefore, by fixing the base 22 to the gear housing 17 as described above, the heat generated in the circuit board 23 can be efficiently radiated.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to the drawings. The main difference between this embodiment and the first embodiment is only the configuration in the vicinity of the through hole of the module holder. For this reason, for convenience of explanation, the same components are denoted by the same reference numerals as those in the first embodiment, and description thereof is omitted.

As shown in FIG. 5, the control device 21 is formed with a labyrinth-like gap S <b> 2 including a gap S <b> 1 between the inner peripheral surface of the through hole 35 and the outer peripheral surface of the rotating shaft 34.
Specifically, a cylindrical inner tube portion 41 that protrudes from the periphery of the through hole 35 toward the base 22 is formed on the bottom portion 32 a of the module holder 32. On the other hand, an annular gap forming member 42 having an outer diameter larger than the outer diameter of the inner cylinder portion 41 is fixed to the rotating shaft 34 so as to be integrally rotatable. An outer cylindrical portion 43 protrudes toward the bottom 32 a side and a cylindrical outer cylindrical portion 43 having an inner diameter larger than the outer diameter of the inner cylindrical portion 41 is formed on the outer peripheral edge of the gap forming member 42. ing. As a result, a labyrinth-like gap S <b> 2 that is continuous with the gap S <b> 1 and folded back within the module holder 32 is formed in the control device 21. Therefore, in the control device 21 of this embodiment, for example, foreign matters such as wear powders are prevented from entering the module holder 32 through the gap S1 only by moving linearly.

As described above, according to this embodiment, in addition to the effects (1) and (3) of the first embodiment, the following effects can be achieved.
(4) A gap forming member 42 that forms a labyrinth-like gap S <b> 2 including the gap S <b> 1 is fixed to the rotating shaft 34. For this reason, foreign matter existing inside the motor housing 16 and the gear housing 17 enters the module holder 32 through the gap S1 and adheres to the circuit board 23, and circuit components and the like that have dropped off from the circuit board 23 are removed from the motor housing. 16 and the gear housing 17 can be further suppressed.

In addition, each said embodiment can also be implemented in the following aspects which changed this suitably.
In the first embodiment, the seal member 36 that closes the gap S <b> 1 may not be provided in the through hole 35 of the module holder 32.

  In the second embodiment, the shape of the labyrinth-shaped gap S2 may be a shape that cannot move between the gear housing 17 side and the motor housing 16 side of the module holder 32 only by moving the foreign matter linearly. These can be changed as appropriate. Specifically, as shown in FIG. 6, for example, an annular annular recess 51 is formed around the through hole 35 in the bottom portion 32 a, and the gap forming member 52 is formed in an annular shape disposed in the annular recess 51. May be.

  In the first embodiment, the base 22 is fixed to the gear housing 17, but not limited to this, the base 22 may be fixed to the motor housing 16 as shown in FIG. 7. In the configuration shown in the figure, the gear housing 17 is formed with an extending portion 17 a that extends toward the motor housing 16 and accommodates a part of the control device 21. Similarly, in the second embodiment, the base 22 may be fixed to the motor housing 16.

  In each of the above embodiments, the bearing 39 is provided in the through hole 37 of the base 22. However, the present invention is not limited to this. For example, the bearing 39 may be disposed in the gear housing 17 and a seal member may be provided in the through hole 37. Moreover, you may form the labyrinth-like clearance gap comprised including the clearance gap between the internal peripheral surface of the through-hole 37, and the outer peripheral surface of the rotating shaft 34. FIG.

  In each of the above embodiments, the opening shape of the module holder 32 is formed to be substantially the same as the outer shape of the circuit board 23, but is formed larger than the circuit board 23, and the circuit board 23 is completely accommodated in the module holder 32. You may make it do. The shape of the module holder 32 is not limited to a box shape, and may be formed in a flat plate shape, for example, and can be changed as appropriate.

  In each of the above embodiments, the circuit board 23 and the module holder 32 are arranged on the axis of the rotating shaft 34 and the through holes 35 and 37 are formed in the circuit board 23 and the module holder 32. There is no need to form a through-hole in these without being arranged on top.

  In each of the above embodiments, the control circuit and the drive circuit are formed on the circuit board 23, but the control circuit and the drive circuit may be formed on separate circuit boards. In this case, the circuit board on which the control circuit is formed may not be in contact with the base 22.

  In each of the above embodiments, the present invention is applied to the control device 21 of the electric motor 14 used as the drive source of the EPS actuator 13, but for example, control of the electric motor used as the drive source of other devices such as an electric pump device. You may apply to an apparatus.

  DESCRIPTION OF SYMBOLS 1 ... Vehicle steering device, 14 ... Electric motor, 16 ... Motor housing, 17 ... Gear housing, 21 ... Control device, 22 ... Base, 23 ... Circuit board, 24 ... Connector module, 31 ... Bus bar, 32 ... Module holder, 34 ... Rotating shaft, 35, 37, 38 ... Through hole, 36 ... Seal member, 42, 52 ... Gap forming member, B ... Power source, S1, S2 ... Gap.

Claims (5)

In the control apparatus for the electric motor, which is provided between the motor housing of the electric motor and the output side housing in which the output member to which the motor torque of the electric motor is transmitted is housed, and controls the operation of the electric motor.
A base fixed to either the motor housing or the output housing and a circuit board is fixed; and a connector module for connecting the circuit board to a power source, the connector module including the circuit board A bus bar connecting the power source and the module holder for holding the bus bar,
The control unit for an electric motor, wherein the module holder is configured to cover the circuit board from the other side of the motor housing and the output side housing. In the control apparatus of the electric motor according to claim 1,
The module holder is formed with a through hole through which the rotating shaft of the electric motor is inserted.
The control device for an electric motor, wherein the through hole is provided with a seal member that closes a gap between an inner peripheral surface of the through hole and an outer peripheral surface of the rotating shaft. In the control apparatus of the electric motor according to claim 1,
The module holder is formed with a through hole through which the rotating shaft of the electric motor is inserted.
A control device for an electric motor, characterized in that a labyrinth-like gap including a gap between an inner circumferential surface of the through hole and an outer circumferential surface of the rotating shaft is formed. In the control apparatus of the electric motor as described in any one of Claims 1-3,
A drive circuit that supplies a drive current to the electric motor is formed on the circuit board placed on the base,
The control apparatus for an electric motor, wherein the base is fixed to the output-side housing.   A vehicle steering system comprising the electric motor control device according to any one of claims 1 to 4.