JP5601272B2 - Motor equipment - Google Patents

Description

  The present invention relates to a motor device mounted on a vehicle.

  As an apparatus of this type, an inverter circuit includes a motor housing that houses a motor portion, a resin outer frame portion fixed to the outer peripheral surface of the peripheral wall of the motor housing, and a lid plate portion fixed to the outer frame portion. There is a case in which a case that accommodates a portion is configured, and a printed circuit board on which an inverter circuit portion is mounted is accommodated in the case (for example, see Patent Document 1).

Japanese Laid-Open Patent Publication No. 2003-324903

  In the device described in Patent Document 1, a case for accommodating the inverter circuit portion is formed outside the motor housing for accommodating the motor portion, and the inverter circuit portion is not sufficiently shielded electromagnetically. There is a problem in that radiation noise from the device is emitted and adversely affects peripheral devices.

  Moreover, as shown in FIG. 7, the motor apparatus mounted in a vehicle has a negative terminal of a power supply connected to the vehicle ground, and the power supply and the motor apparatus are connected via a wire harness. . In such an apparatus, when the motor M is driven, a stray capacitance C is generated between the motor M and the vehicle ground, and a common mode current flows through the vehicle ground due to the stray capacitance C.

  Also, in motor devices mounted on vehicles, PWM control for controlling the motor unit using PWM signals is widely performed. In such motor devices, the frequency of the PWM signal is used to suppress heat generation of the switching elements. Higher frequency is achieved.

  Therefore, in a motor device mounted on a vehicle, when PWM control is performed with a PWM signal having a high frequency, the common mode current flowing to the negative terminal of the power supply via the vehicle ground increases. As described above, when the common mode current increases, there is a problem in that peripheral devices and the like are adversely affected.

  The present invention has been made in view of the above problems, and an object thereof is to reduce the common mode current flowing through the vehicle ground and the radiation noise.

  In order to achieve the above object, an invention according to claim 1 is a motor device mounted on a vehicle, wherein the motor unit (30) and a circuit for PWM control of the motor unit (30) are mounted. The circuit board (26) includes a ground terminal (26b) connected to the vehicle ground together with a negative terminal of the power source (80) and a power terminal (connected to the positive terminal of the power source (80)). 26a), and heat radiation fins (50) are provided on one surface of the circuit board (26) so as to be in surface contact with the one surface of the circuit board (26), and the circuit board (26) in the heat radiation fin (50). The heat dissipating fins (50) are in contact with the inner surface of the metal housing (11, 12) that houses the motor unit (30) with the second surface opposite to the first surface in contact with the first surface. (11, 12) fixed to the inner surface of the circuit board ( 6) and the radiating fin (50) are housed in the housing (11, 12) so as to be electromagnetically shielded, and a common mode current generated by driving the motor unit (30) is generated by the housing (11, 12). 12) through the heat radiation fin (50) to the ground terminal (26b), and the common mode current flowing to the vehicle ground is reduced.

  According to such a structure, the metal housing | casing (11, 11) in which the 2nd surface which becomes the surface opposite to the 1st surface which contacts the circuit board (26) in a radiation fin (50) accommodates a motor part (30). 12) The radiating fin (50) is fixed to the inner surface of the casing (11, 12) so as to be in surface contact with the inner surface of the casing (12, 12), and the circuit board (26) and the radiating fin (50) are electromagnetically shielded. The common mode current, which is housed in the body (11, 12) and is generated by driving the motor unit (30), is transferred from the housing (11, 12) to the ground terminal (26b) through the radiation fin (50). Since the common mode current flowing and flowing to the vehicle ground is reduced, the common mode current flowing to the vehicle ground and the radiation noise can be reduced.

  In addition, you may comprise a radiation fin (50) so that it may adhere | attach on the inner surface of a housing | casing (11, 12) using a conductive adhesive (40) like invention of Claim 2. As in the third aspect of the present invention, the inner surface of the housing (11, 12) may be fixed with a plurality of screws.

  In addition, the code | symbol in the bracket | parenthesis of each means described in this column and the claim shows the correspondence with the specific means as described in embodiment mentioned later.

1 is an external view of a motor device according to an embodiment of the present invention. It is a figure which shows the cross-sectional structure along the AA line in Fig.1 (a). It is the C section enlarged view in FIG. It is a figure which shows the cross-sectional structure along the BB line in Fig.1 (a). It is a figure which shows the circuit structure of a motor apparatus. It is a figure for demonstrating the path | route of a stray capacitance and a common mode current. It is a figure for demonstrating a subject.

  FIG. 1 shows an external view of a motor device according to an embodiment of the present invention. (A) is the figure which looked at this motor apparatus from one direction, (b) is the figure seen from S1 direction in (a), (c) is the figure seen from S2 direction in (a). is there. This motor device is configured as a DC motor that rotationally drives a blower fan used in a radiator mounted on a vehicle.

  The motor device includes a casing including a cylindrical first case 11 having an opening and a second case 12 that closes the opening of the first case 11. The first case 11 and the second case 12 are configured using metal members. By assembling the first case 11 and the second case 12, radiation noise generated inside the housing is electromagnetically shielded.

  The first case 11 is formed with three protrusions 11a in which screw holes for attachment are formed. The motor device is screwed to the radiator shroud using the screw holes formed in these protrusions 11a.

  A resin-made connector housing 28 is arranged on the side surface of the first case 11. Via this connector housing 28, a power supply 80 and an ECU 70 to be described later are connected.

  FIG. 2 shows a cross-sectional configuration along the line AA in FIG. Inside the casing made up of the first case 11 and the second case 12, there is a motor unit comprising an armature coil 33, a magnet 34, a rotor 32, a brush 35, a commutator 36, and a rotating shaft 37, and this motor unit. A controller 20 for PWM control is provided. The armature coil 33 is configured as a winding, and the cross-sectional configuration of the armature coil 33 shown in FIG. 2 is different from the actual one. A plurality of terminals 27 housed in a connector housing 28 are connected to the controller 20.

  FIG. 3 shows an enlarged view of a portion C in FIG. The controller 20 includes a circuit board 26 on which a circuit for PWM control of the motor unit is mounted. Each circuit for PWM control of the motor unit is mounted on the surface of the circuit board 26, and these circuits are sealed with mold resin.

  Further, a metal radiation fin 50 is provided on the back surface of the circuit board 26 so as to be in surface contact with this surface.

  In addition, the second surface, which is the opposite surface of the first surface that contacts the circuit board 26 in the radiating fin 50, is in surface contact with the inner surface of the second case 12 that houses the motor unit via the conductive adhesive 40. It is fixed.

  FIG. 4 shows a cross-sectional configuration along the line BB in FIG. As shown in the figure, a brush 35, a spring member 35 a, a conductive connection member 35 b, and a controller 20 are provided inside the first case 11.

  Each brush 35 is connected to an internal terminal of the controller 20 via a conductive connecting member 35.

  The rotating shaft 36 is rotatably supported by bearings formed on the first case 11 and the second case 12 respectively. The commutator 36 is fixed to the rotating shaft 36 and rotates together with the rotating shaft 36.

  Each brush 35 is urged toward the commutator 36 by a spring 35a, and each brush 35 applies an output voltage of a power source 80, which will be described later, to the commutator 56 while being in contact with the commutator 36. .

  FIG. 5 shows a circuit configuration of the motor device. The motor device includes a controller 20 and a motor unit 30. The inductance 31a and winding resistance 31b of the motor unit 30 are shown as an equivalent circuit of the armature coil 33 shown in FIG. Moreover, the radiation fin 50 shown in FIG. 5 can be regarded as a conductor having a slight resistance value.

  The controller 20 includes capacitors, 21a and 21b, a coil 22, a control IC 23, a diode 24, and a MOS transistor 25. These circuit components are mounted on the circuit board 26 shown in FIG.

  The circuit board 26 has a power terminal 26a connected to the positive terminal of the power source 80, a ground terminal 26b connected to the vehicle ground together with the negative terminal of the power source 80, and a control signal input terminal 26c to which a control signal is input from the ECU 70. Is installed.

  The power supply filter unit including the capacitors 21a and 21b and the coil 22 is provided to remove switching noise generated when the PWM control MOS transistor 25 is driven to be switched.

  A control signal for PWM control of the motor unit 30 is input from the ECU 70 to the control IC 23 via the control signal input terminal 26c. The control IC 23 generates a pulse width modulated PWM signal according to the control signal and outputs the generated PWM signal.

  The PWM signal from the control IC 23 is input to the gate terminal of the MOS transistor 25. The MOS transistor 25 is turned on or off according to the PWM signal.

  In the above-described configuration, when a PWM signal is input to the gate of the MOS transistor 25, a current flows through the armature coil 33 of the motor unit 30 connected in series with the MOS transistor 25. A rotating torque based on the magnetic field generated from the armature coil 33 and the magnetic field generated from the magnet 34 is generated by the current, and the rotating shaft 37 rotates. Further, when the MOS transistor 25 is turned off for a certain period or longer, the rotational torque is lost and the rotary shaft 37 does not rotate. The magnitude of the rotational torque generated in the armature coil 33 changes according to the duty ratio of the PWM signal.

  According to the configuration described above, the radiation fins are such that the second surface of the radiation fin 50 opposite to the first surface that contacts the circuit board 26 is in surface contact with the inner surface of the metal housing that houses the motor unit 30. 50 is fixed to the inner surface of the second case 12, and the circuit board 26 and the heat radiating fins 50 are housed in the casings 11 and 12 so as to be electromagnetically shielded, so that radiation noise can be reduced. .

  As shown in FIG. 6, a stray capacitance C1 is generated between the motor unit 30 and the casings 11 and 12, and the stray capacitance C2 generated between the motor unit 30 and the vehicle ground is generated by the stray capacitance C1. The size of becomes smaller. Then, a common mode current flows through a path indicated by an arrow in FIG. That is, the common mode current generated by driving the motor unit 30 flows from the casings 1 and 12 to the ground terminal 26b through the heat radiation fin 50, and the common mode current flowing to the vehicle ground is reduced. Thus, it is possible to reduce the common mode current flowing through the vehicle ground and the radiation noise.

  In addition, this invention is not limited to the said embodiment, Based on the meaning of this invention, it can implement with a various form.

  For example, in the above-described embodiment, the configuration including the resin connector housing 28 is shown, but a metal connector may be used to further suppress emission of radiation noise.

  Moreover, in the said embodiment, although the radiation fin 50 was adhere | attached on the inner surface of the housing | casing 11 and 12 using the conductive adhesive 40, for example, the radiation fin 50 is fixed to the housing | casing 11 and 12 by the screw fastening fixation with a some screw. You may make it fix to the inner surface of. Further, the radiating fins 50 may be fixed to the inner surfaces of the casings 11 and 12 by both adhesion by the conductive adhesive 40 and screw fastening by a plurality of screws.

  Moreover, although the example which comprised this motor apparatus as what drives the ventilation fan used for the radiator mounted in a vehicle was shown in the said embodiment, it is not limited to such a use, It is not limited to a vehicle. It can be applied to various motor devices to be mounted.

DESCRIPTION OF SYMBOLS 11 1st case 12 2nd case 20 Controller 30 Motor part 40 Conductive adhesive agent 50 Radiation fin 70 ECU
80 power supply

Claims (3)

A motor device mounted on a vehicle,
A motor section (30);
A circuit board (26) on which a circuit for PWM control of the motor part (30) is mounted,
The circuit board (26) has a ground terminal (26b) connected to the vehicle ground together with a negative terminal of the power supply (80) and a power supply terminal (26a) connected to the positive terminal of the power supply (80).
One surface of the circuit board (26) is provided with heat radiation fins (50) so as to be in surface contact with one surface of the circuit board (26).
A second surface opposite to the first surface in contact with the circuit board (26) in the heat radiating fin (50) is an inner surface of a metal housing (11, 12) that houses the motor unit (30). The radiating fins (50) are fixed to the inner surfaces of the casings (11, 12) so as to come into surface contact, and the casing (26) and the radiating fins (50) are electromagnetically shielded. Stored in the body (11, 12),
A common mode current generated by driving the motor unit (30) flows from the housing (11, 12) to the ground terminal (26b) through the heat dissipating fin (50) and flows to the vehicle ground. A motor device characterized in that current is reduced.   The motor device according to claim 1, wherein the radiating fin (50) is bonded to an inner surface of the casing (11, 12) using a conductive adhesive (40).   3. The motor device according to claim 1, wherein the heat dissipating fin is fixed to the inner surface of the housing with a plurality of screws.

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