JP5805406B2 - In-wheel motor drive device - Google Patents

Description

The present invention, for example, relate to in-wheel motor drive equipment used for driving wheels of an electric vehicle.

In an electric vehicle, a failure of a motor for driving the vehicle has a serious effect. In particular, in-wheel motor drive devices are reduced in size. As a result, wheel bearings, reduction gears, and motors are accompanied by reductions in material usage and high-speed rotation of motors. It becomes.
In the in-wheel motor drive device, in order to ensure reliability, the temperature of wheel bearings, reducers, motors, etc. are measured to monitor overload, and the motor drive current is limited according to the temperature measurement value, A device that reduces the motor rotation speed has been proposed (for example, Patent Document 1).

JP 2008-168790 A

In the in-wheel motor drive device, the motor is in the vicinity of the wheel and is exposed to the road surface environment, so that the motor may be submerged.
In a battery-driven electric vehicle drive device, an IPM type synchronous motor (an embedded magnet type synchronous motor) having high efficiency performance using a neodymium magnet is used in order to improve the cruising distance under a limited battery capacity. The In this synchronous motor, when a short circuit abnormality of the motor coil occurs, a braking force is generated due to a power generation phenomenon in the motor. In particular, when the vehicle is traveling at a high speed, the motor is in a high-speed rotation state, and when a short circuit abnormality of the motor coil occurs under such circumstances, there is a problem in traveling.
Further, when a short circuit abnormality of the motor coil occurs, there is a problem that the vehicle is not easily moved by towing by an external vehicle because the motor is always braked by the rotation of the motor.
Furthermore, there is a possibility of damaging the power circuit portion 29 of the inverter device 22 that drives the motor 6.

The purpose of the present invention detects an abnormal short-circuit due to moisture motor early is to provide an in-wheel motor drive equipment capable of avoiding the problems in the vehicle traveling.

The in-wheel motor drive device 8 of the present invention is the in-wheel motor drive device having the wheel bearing 4, the motor 6, and the speed reducer 7 interposed between the motor 6 and the wheel bearing 4. inside of the terminal block 6a, characterized in that a water detection means Sk for detecting moisture in the motor 6.

The motor 6 in the in-wheel motor drive device 8 is near the wheel and is exposed to the road surface environment. According to this configuration, the moisture detecting means Sk provided in the terminal block 6a of the motor 6 always detects moisture in the motor 6, that is, in the motor housing 72. The in-wheel motor drive device 8 limits the motor current or cuts off the motor current, for example, based on the moisture detection signal. This is because when the moisture detection means Sk detects moisture, it is presumed that the wiring of the motor 6 is easily short-circuited. Thereby, it is possible to prevent the short-circuit abnormality in the motor 6 in a high-speed rotation state, for example. Therefore, it is possible to avoid that the vehicle suddenly becomes unable to travel. Moreover, although the wiring in the motor 6 has a coating, it may be exposed for connection in the vicinity of the terminal block 6a, and a short circuit is likely to occur when moisture enters the motor 6. . Therefore, short circuit abnormality can be detected effectively by providing the moisture detection means Sk in the vicinity of the terminal block 6a.

The terminal block 6a has a plurality of terminals 96, and these terminals 96 are accommodated in a housing 72 of the motor 6, and are connected to a conductive path 100 composed of wiring connected to the terminal block 6a and connection terminals of the terminal block 6a. There is an exposed part without covering. By providing the moisture detection means Sk in the vicinity of the plurality of terminals installed in such a location, moisture in the space of the exposed portion of the current passage 100 can be accurately detected, and moisture that causes a short circuit is reliably detected. In addition, it is possible to prevent erroneous detection.

Further, the in-wheel motor drive device of the present invention monitors whether or not the moisture detection signal by the moisture detection means Sk has exceeded a set threshold value, and when determining that it has exceeded the threshold value, It has a moisture detection corresponding control means 95 that limits the motor current or cuts off the motor current . When the detection signal from the moisture detecting means Sk exceeds the set threshold value, it is estimated that the motor 6 installed near the wheel is easily short-circuited. For this reason, when it is determined that the moisture detection correspondence control unit 95 has exceeded the threshold, the motor current is limited or cut off. In this way, the abnormality of the motor 6 can be detected at an early stage, and problems in vehicle travel can be avoided.

A power circuit unit 28 including an inverter 31 that converts a direct current of a battery 19 mounted on a vehicle into an alternating current used to drive the motor 6 and at least the power according to control of an ECU 21 that is an electric control unit that controls the entire vehicle. The inverter device 22 having the motor control unit 29 for controlling the circuit unit 28 may be provided with a moisture detection correspondence control means 95. By providing the moisture detection correspondence control means 95 in the inverter device 22, quick control can be performed as compared with the case where the moisture detection correspondence control means 95 is provided in the ECU 21, and problems in vehicle travel can be avoided quickly. Further, it is possible to reduce the burden on the ECU 21 that is becoming more complicated due to higher functions.
The moisture detection response control means 95 may be provided in the ECU 21 which is an electric control unit for controlling the entire vehicle.

The moisture detection means Sk may be a continuity sensor or an electrochemical sensor.
The motor 6 may be an embedded magnet type synchronous motor using a neodymium permanent magnet . Interior permanent magnet with neo indium-based permanent magnet of the synchronous motor to have a high efficiency performance, thereby improving the cruising distance of the vehicle under the battery capacity is limited. Further, when an embedded magnet type synchronous motor is used, a short circuit abnormality of the motor coil 78 can be prevented beforehand, so that it is possible to avoid the occurrence of a braking force due to a power generation phenomenon in the motor.

  The reduction gear 7 may have a cycloid type high reduction ratio. When the reduction gear 7 is a cycloid reduction gear and the reduction ratio is increased to, for example, 1/6 or more, the motor 6 can be downsized and the in-wheel motor drive device 8 can be downsized. However, if a reduction gear having a high reduction ratio is used, a reduction in size can be achieved. On the other hand, since the rotation torque of the motor 6 is enlarged and transmitted to the tire 2 by an increase in the reduction ratio, an abnormal short circuit of the motor coil 78 is caused. Therefore, it is possible to prevent the vehicle from suddenly becoming unable to travel.

The motor control method of the reference proposal example is a control method of the motor 6 of the electric vehicle in which the wheels 2 are driven by the motor 6, and a process of determining whether or not moisture has entered the housing 72 of the motor 6. When it is determined that moisture has entered the housing 72 in the above process, the motor current is limited or the motor current is cut off. When it is determined that moisture has entered the housing 72 of the motor 6 as described above, a short circuit abnormality occurs in the motor 6 in a high-speed rotation state, for example, by limiting the motor current or cutting off the motor current. It can be prevented in advance. Therefore, it is possible to avoid that the vehicle suddenly becomes unable to travel.

An in-wheel motor drive device of the present invention is an in-wheel motor drive device having a wheel bearing, a motor, and a speed reducer interposed between the motor and the wheel bearing, in the terminal block of the motor, Moisture detection means for detecting moisture in the motor is provided, the terminal block has a plurality of terminals, these terminals are accommodated in the motor housing, and wiring connected to the terminal block and connection terminals of the terminal block There is an exposed portion of the conductive path that is not covered, and monitors whether or not the moisture detection signal by the moisture detection means has entered the set state, and when it is determined that the set state has been reached, the motor current is limited. since having a water detection response control means for blocking or motor current give, that detects an abnormal short-circuit due to moisture motor early to avoid problems on the vehicle running It can be.

It is a block diagram of the conceptual composition which shows the electric vehicle which has the in-wheel motor drive concerning a 1st embodiment of this invention by a top view. It is a block diagram of the conceptual structure which provided the moisture detection corresponding | compatible control means in the inverter apparatus of the same electric vehicle. (A) is a cutaway front view of the in-wheel motor drive device, (B) is a cross-sectional view of the vicinity of the motor terminal block of the in-wheel motor drive device, and (C) is a front view showing an example of moisture detection means. is there. It is sectional drawing of the motor part used as the IV-IV line cross section of FIG. 3 (A). It is sectional drawing of the reduction gear part used as the VV line cross section of FIG. 3 (A). It is a partial expanded sectional view of FIG. It is a block diagram of the conceptual structure of the control system in the in-wheel motor drive device which concerns on other embodiment of this invention. It is the schematic which shows the circuit structural example of the motor drive device in the same in-wheel motor drive device. It is a block diagram of the conceptual structure of the control system in the in-wheel motor drive device which concerns on other embodiment of this invention.

  An in-wheel motor drive device according to a first embodiment of the present invention will be described with reference to FIGS. The following description also includes a description of the motor control method. This in-wheel motor drive device is mounted on an electric vehicle. This electric vehicle is a four-wheeled vehicle in which the wheels 2 that are the left and right rear wheels of the vehicle body 1 are driving wheels, and the wheels 3 that are the left and right front wheels are steering wheels of driven wheels. Each of the wheels 2 and 3 serving as the driving wheel and the driven wheel has a tire and is supported by the vehicle body 1 via wheel bearings 4 and 5, respectively. The wheel bearings 4 and 5 are given the abbreviation “H / B” of the hub bearing in FIG. The left and right wheels 2, 2 serving as driving wheels are driven by independent traveling motors 6, 6, respectively. The rotation of the motor 6 is transmitted to the wheel 2 via the speed reducer 7 and the wheel bearing 4. The motor 6, the speed reducer 7, and the wheel bearing 4 constitute an in-wheel motor driving device 8 that is one assembly part, and the in-wheel motor driving device 8 is partially or entirely inside the wheel 2. Placed in. This in-wheel motor drive device 8 has a moisture detection means, which will be described later, and a moisture detection response control means. The in-wheel motor drive device 8 is also referred to as an in-wheel motor unit. Each wheel 2, 3 is provided with an electric brake 9, 10.

    The wheels 3 and 3 that are the steering wheels that are the left and right front wheels can be steered via the steering mechanism 11 and are steered by the steering mechanism 12. The steering mechanism 11 is a mechanism that changes the angle of the left and right knuckle arms 11b that hold the wheel bearings 5 by moving the tie rod 11a to the left and right. An EPS (electric power steering) motor 13 is driven by a command from the steering mechanism 12. It is driven and moved left and right via a rotation / linear motion conversion mechanism (not shown). The steering angle is detected by the steering angle sensor 15, and the sensor output is output to the ECU 21, and the information is used for acceleration / deceleration commands for the left and right wheels.

  As shown in FIG. 3A, the in-wheel motor drive device 8 is a wheel 2 that is a drive wheel supported by the wheel bearing 4 with a reduction gear 7 interposed between the wheel bearing 4 and the motor 6. The hub of FIG. 2 and the rotation output shaft 74 of the motor 6 (FIG. 3A) are connected on the same axis. The reduction gear 7 should have a reduction ratio of 1/6 or more. The speed reducer 7 is a cycloid speed reducer, in which eccentric portions 82a and 82b are formed on a rotational input shaft 82 that is coaxially connected to a rotational output shaft 74 of the motor 6, and bearings 85 are provided on the eccentric portions 82a and 82b, respectively. The curvilinear plates 84a and 84b are attached to the discs, and the eccentric motion of the curvilinear plates 84a and 84b is transmitted to the wheel bearing 4 as rotational motion. In this specification, the side closer to the outer side in the vehicle width direction of the vehicle when attached to the vehicle is referred to as the outboard side, and the side closer to the center of the vehicle is referred to as the inboard side.

  The wheel bearing 4 includes an outer member 51 in which a double row rolling surface 53 is formed on the inner periphery, an inner member 52 in which a rolling surface 54 facing each of the rolling surfaces 53 is formed on the outer periphery, and these The outer member 51 and the inner member 52 are composed of double-row rolling elements 55 interposed between the rolling surfaces 53 and 54 of the inner member 52. The inner member 52 also serves as a hub for attaching the drive wheels. The wheel bearing 4 is a double-row angular ball bearing, and the rolling elements 55 are made of balls and are held by a cage 56 for each row. The rolling surfaces 53 and 54 have a circular arc cross section, and the rolling surfaces 53 and 54 are formed so that the contact angles are aligned with the back surface. An end on the outboard side of the bearing space between the outer member 51 and the inner member 52 is sealed with a seal member 57.

  The outer member 51 is a stationary raceway, has a flange 51a attached to the housing 83b on the outboard side of the speed reducer 7, and is formed as an integral part. The flange 51a is provided with bolt insertion holes 64 at a plurality of locations in the circumferential direction. Further, the housing 83b is provided with a bolt screw hole 94 whose inner periphery is threaded at a position corresponding to the bolt insertion hole 64. The outer member 51 is attached to the housing 83b by screwing the mounting bolt 65 inserted into the bolt insertion hole 94 into the bolt screwing hole 94.

  The inner member 52 is a rotating raceway, and the outboard side member 59 having a hub flange 59a for wheel mounting and the outboard side member 59 are fitted to the inner periphery of the outboard side member 59. The inboard side material 60 is integrated with the outboard side material 59 by fastening. In each of the outboard side material 59 and the inboard side material 60, the rolling surface 54 of each row is formed. A through hole 61 is provided in the center of the inboard side member 60. The hub flange 59a is provided with press-fit holes 67 for hub bolts 66 at a plurality of locations in the circumferential direction. In the vicinity of the base portion of the hub flange 59a of the outboard side member 59, a cylindrical pilot portion 63 that guides driving wheels and braking components (not shown) protrudes toward the outboard side. A cap 68 that closes the outboard side end of the through hole 61 is attached to the inner periphery of the pilot portion 63.

  The motor 6 is a radial gap type IPM motor (that is, an embedded magnet type synchronous motor) in which a radial gap is provided between a motor stator 73 fixed to a cylindrical housing 72 and a motor rotor 75 attached to a rotation output shaft 74. It is. The rotation output shaft 74 is cantilevered by two bearings 76 on the cylindrical portion of the housing 83 a on the inboard side of the speed reducer 7.

As shown in FIG. 3A, moisture detection means Sk for detecting moisture in the motor 6 is provided in the terminal block 6a of the motor 6. The inside of the motor 6 is a space in the housing 72 of the motor 6 as shown in FIG. Moreover, although the wiring in the motor 6 has a coating, the conductive path 100 including the wiring and connection terminals is exposed in the vicinity of the terminal block 6a. Accordingly, in the vicinity of the terminal block 6 a where the conductive path 100 is exposed, a short circuit is likely to occur when moisture enters the motor 6. Therefore, by providing the moisture detection means Sk in the vicinity of the terminal block 6a in the housing 72, a short circuit abnormality can be detected effectively.
For example, a continuity sensor or an electrochemical sensor is applied as the moisture detecting means Sk. As shown in FIG. 3C, the continuity sensor has two terminals Sk1 and Sk2, and is a sensor having a structure in which the terminals Sk1 and Sk2 are both in a state of being immersed in water. As the electrochemical sensor, for example, a sensor having a plurality of electrodes and detecting moisture from measurement data based on electrochemical current noise generated between the electrodes is applied. The moisture detection means Sk is electrically connected to a moisture detection response control means 95 described later. As shown in FIG. 3B, the terminal block 6 a has a plurality (three in this example) of terminals 96, and these terminals 96 are accommodated in a housing 72 of the motor 6. The plurality of terminals 96 are terminals that connect the wiring of each phase in the motor 6 and the wiring outside the motor 6, and are connected to the wiring inside the motor 6, and are connected to the end of the wiring outside the motor 6. The provided wiring-side terminal 101 may be screwed or plugged in. The plurality of terminals 96 are installed at locations in the housing 72 where no oil is applied. By providing the moisture detection means Sk in the vicinity of the plurality of terminals 6a installed at such locations in the housing 72, the moisture in the space of the exposed portion of the energization path 100 can be accurately detected.

  FIG. 4 is a sectional view of the motor (IV-IV section in FIG. 3A). The rotor 75 of the motor 6 includes a core portion 79 made of a soft magnetic material and a permanent magnet 80 built in the core portion 79. The permanent magnets 80 are arranged so that two adjacent permanent magnets face each other in a cross-sectional shape on the same circumference in the rotor core portion 79. The permanent magnet 80 is a neodymium magnet. The stator 73 includes a core part 77 and a coil 78 made of a soft magnetic material. The core portion 77 has a ring shape with an outer peripheral surface having a circular cross section, and a plurality of teeth 77a protruding inward on the inner peripheral surface are formed side by side in the circumferential direction. The coil 78 is wound around the teeth 77 a of the stator core portion 77.

As shown in FIG. 3, the motor 6 is provided with an angle sensor 36 that detects a relative rotation angle between the motor stator 73 and the motor rotor 75. The angle sensor 36 detects and outputs a signal representing a relative rotation angle between the motor stator 73 and the motor rotor 75, and an angle calculation circuit 71 that calculates an angle from the signal output from the angle sensor body 70. And have. The angle sensor main body 70 includes a detected portion 70a provided on the outer peripheral surface of the rotation output shaft 74, and a detecting portion 70b provided in the motor housing 72 and disposed in close proximity to the detected portion 70a, for example, in the radial direction. Become. The detected portion 70a and the detecting portion 70b may be arranged close to each other in the axial direction. The angle sensor 36 may be a resolver. In this motor 6, in order to maximize the efficiency, each phase of each wave of alternating current flowing through the coil 78 of the motor stator 73 based on the relative rotation angle between the motor stator 73 and the motor rotor 75 detected by the angle sensor 36. the application timing of, and is adapted to control the motor drive control unit 33 of Motakon trolls unit 29.

  As described above, the speed reducer 7 is a cycloid speed reducer, and two curved plates 84a and 84b formed with a wavy trochoidal curve having a gentle outer shape as shown in FIG. The shaft 82 is attached to each eccentric part 82a, 82b. A plurality of outer pins 86 for guiding the eccentric movements of the curved plates 84a and 84b on the outer peripheral side are provided across the housing 83b, and a plurality of inner pins 88 attached to the inboard side member 60 of the inner member 2 are provided. The curved plates 84a and 84b are engaged with a plurality of circular through holes 89 provided in the inserted state. The rotation input shaft 82 is spline-coupled with the rotation output shaft 74 of the motor 6 and rotates integrally. The rotary input shaft 82 is supported at both ends by two bearings 90 on the inboard side housing 83a and the inner diameter surface of the inboard side member 60 of the inner member 52.

  When the rotation output shaft 74 of the motor 6 rotates, the curved plates 84a and 84b attached to the rotation input shaft 82 that rotates integrally therewith perform an eccentric motion. The eccentric motions of the curved plates 84 a and 84 b are transmitted to the inner member 52 as rotational motion by the engagement of the inner pins 88 and the through holes 89. The rotation of the inner member 52 is decelerated with respect to the rotation of the rotation output shaft 74. For example, a reduction ratio of 1/10 or more can be obtained with a single-stage cycloid reducer.

  The two curved plates 84a and 84b are attached to the eccentric portions 82a and 82b of the rotary input shaft 82 so as to cancel out the eccentric motion with each other, and are mounted on both sides of the eccentric portions 82a and 82b. A counterweight 91 that is eccentric in the direction opposite to the eccentric direction of the eccentric portions 82a and 82b is mounted so as to cancel the vibration caused by the eccentric movement of the curved plates 84a and 84b.

  As shown in an enlarged view in FIG. 6, bearings 92 and 93 are mounted on the outer pins 86 and the inner pins 88, and outer rings 92a and 93a of these bearings 92 and 93 are respectively connected to the curved plates 84a and 84b. It comes into rolling contact with the outer periphery and the inner periphery of each through hole 89. Therefore, the contact resistance between the outer pin 86 and the outer periphery of each curved plate 84a, 84b and the contact resistance between the inner pin 88 and the inner periphery of each through hole 89 are reduced, and the eccentric motion of each curved plate 84a, 84b is smooth. Can be transmitted to the inner member 52 as a rotational motion.

  In FIG. 3, the wheel bearing 4 of the in-wheel motor drive device 8 is attached to the vehicle body via a suspension device (not shown) such as a knuckle on the outer periphery of the housing 83 b of the speed reducer 7 or the housing 72 of the motor 6. Fixed.

  The control system will be described with reference to FIG. The vehicle body 1 includes an ECU 21 that is an electric control unit that performs overall control of the automobile, an inverter device 22 that controls the motor 6 for traveling in accordance with a command from the ECU 21, and a brake controller 23. The ECU 21 includes a computer, a program executed by the computer, various electronic circuits, and the like.

  The ECU 21 is roughly divided into a drive control unit 21a and a general control unit 21b when classified roughly by function. The drive control unit 21a gives the left and right wheel motors 6 and 6 the acceleration command output from the accelerator operation unit 16, the deceleration command output from the brake operation unit 17, and the turning command output from the steering angle sensor 15. The given acceleration / deceleration command is generated and output to the inverter device 22. In addition to the above, the drive control unit 21a outputs an acceleration / deceleration command to be output, information on the tire rotation speed obtained from the rotation sensor 24 provided on the wheel bearings 4 and 5 of the wheels 2 and 3, You may have the function to correct | amend using the information of each sensor. The accelerator operation unit 16 includes an accelerator pedal and a sensor 16a that detects the amount of depression and outputs the acceleration command. The brake operation unit 17 includes a brake pedal and a sensor 17a that detects the amount of depression and outputs the deceleration command.

The general control unit 21b of the ECU 21 processes a function of outputting a deceleration command output from the brake operation unit 17 to the brake controller 23, a function of controlling various auxiliary machine systems 25, and an input command from the console operation panel 26. A function of displaying on the display device 27. The display device 27 can display an image of a liquid crystal display device or the like. The auxiliary machine system 25 is, for example, an air conditioner, a light, a wiper, a GPS, an airbag or the like, and is shown here as a representative block.

  The brake controller 23 is means for giving a braking command to the brakes 9 and 10 of the wheels 2 and 3 in accordance with a deceleration command output from the ECU 21. In addition to the command generated by the deceleration command output from the brake operation unit 17, the braking command output from the ECU 21 includes a command generated by means for improving the safety of the ECU 21. In addition, the brake controller 23 includes an antilock brake system. The brake controller 23 is configured by an electronic circuit, a microcomputer, or the like.

The inverter device 22 is comprised of a power circuit part 28 provided for each motor 6, the Motakon trolls unit 29 for controlling the power circuit unit 28. Motakon trolls section 29, be provided in common to each power circuit unit 28, it may be provided separately, even when provided in common, the power circuit unit 28 can be controlled independently, for example, so that the motor torques are different from each other. Motakon trolls unit 29 has a function of outputting the information of the detected values and the control values for the in-wheel motor drive device 8 or the like having this Motakon trolls unit 29 (referred to as "IWM system information") to the EC U21 .

  FIG. 2 is a block diagram of a conceptual configuration in which an inverter device is provided with moisture detection support control means. The power circuit unit 28 includes an inverter 31 that converts the DC power of the battery 19 into three-phase AC power that is used to drive the motor 6, and a PWM driver 32 that controls the inverter 31. The motor 6 includes a three-phase synchronous motor or the like. The inverter 31 is composed of a plurality of semiconductor switching elements (not shown), and the PWM driver 32 performs pulse width modulation on the input current command and gives an on / off command to each of the semiconductor switching elements.

Motakon trolls unit 29 comprises a computer and a program executed thereto, and the electronic circuit, and a motor drive control unit 33 as a control unit serving as the basic. Motor drive control unit 33 in accordance with acceleration and deceleration command by the torque command and the like given EC U21 whether we are upper-level control unit, and converts the current command, a means of giving a current command to the PWM driver 32 of the power circuit unit 28 is there. The motor drive control unit 33 obtains a motor current value to be passed from the inverter 31 to the motor 6 from the current detection unit 35 and performs current feedback control. The motor drive control unit 33 obtains the rotation angle of the rotor of the motor 6 from the angle sensor 36 and performs vector control.

  In this embodiment, the water control unit 95 and the abnormality report unit 41 are provided in the motor control unit 29 having the above-described configuration in the inverter device 22. The ECU 21 is provided with an abnormality display means 42. The moisture detection correspondence control means 95 determines whether or not the moisture detection signal from the moisture detection means Sk has exceeded a set threshold value, and the motor current when it is determined that the moisture detection signal has been set. And a control unit 40 for limiting or interrupting the motor current.

  When the continuity sensor is applied as the moisture detection means Sk, the continuity sensor becomes conductive when both of the two terminals of the continuity sensor are submerged while the motor current is flowing, and the continuity sensor sends a detection signal to the determination unit 39. The determination unit 39 monitors, for example, whether or not the detection signal is present or whether or not the detection signal is continuously detected for a predetermined time, or the number of detection signals within the predetermined time. This is because it is presumed that the wiring of the motor 6 is likely to be short-circuited when the continuity sensor conducts beyond a predetermined time or when the number of detection signals within a predetermined time exceeds a predetermined number. is there. In addition, a test for submerging the motor 6 is performed in advance, and a plurality of samples are investigated for a limit time when the short circuit abnormality of the motor coil occurs due to the influence of water immersion in the housing 72. The time shorter than these limit times, that is, a time with a margin is set as the predetermined time.

  When the electrochemical sensor is applied as the moisture detection means Sk, the electrochemical sensor obtains data, that is, a detection signal based on electrochemical current noise generated between the electrodes in a state where the motor current is flowing. The detection signal is represented by a voltage value, for example. The determination unit 39 monitors whether this detection signal is present or whether the detection signal exceeds a threshold value. In this case as well, a test for submerging the motor is performed in advance, and a plurality of samples of the voltage value of the electrochemical sensor when a short circuit abnormality of the motor coil occurs due to the flooding in the housing is investigated. A voltage value lower than these voltage values is set as the threshold value. For this electrochemical sensor, as in the case of the continuity sensor, the determination unit 39 determines whether or not the detection signal from the electrochemical sensor is detected for a predetermined time, or a predetermined time, for example. You may make it monitor the frequency | count of the detection signal in the inside.

When the determination unit 39 determines that the detection signal is in the set state, the control unit 40 limits the motor current that flows through the motor 6. That is, the output of the inverter device 22 is limited. At the same time, the abnormality report means 41 reports an abnormality to the ECU 21, and the abnormality display means 42 of the ECU 21 displays an abnormality on the display device 27 in the driver's seat according to the abnormality report. In addition to this, the ECU 21 performs control corresponding to the limitation on the output of the inverter device 22 by the control unit 40. Note that when a detection signal is sent from the continuity sensor or the electrochemical sensor to the determination unit 39, the control unit 40 may limit the motor current that flows to the motor 6.
When the determination unit 39 determines that the detection signal has been set, the control unit 40 may set the motor current flowing through the motor 6 to “0” A, that is, block the motor current.

  In this way, the moisture detection correspondence control means 95 limits the motor current or cuts off the motor current based on the detection signal from the moisture detection means Sk, so that a short circuit abnormality occurs in the motor 6 in a high-speed rotation state, for example. This can be prevented beforehand. When the motor current is interrupted, it is possible to prevent the motor coil 78 from being seized by stopping the rotation of the motor 6 at an early stage. Therefore, it is possible to avoid that the vehicle suddenly becomes unable to travel. In this way, the abnormality of the motor 6 can be detected at an early stage, and problems in vehicle travel can be avoided. By providing moisture detecting means Sk near the plurality of terminals, moisture in the space of the exposed portion of the energization path 100 can be accurately detected, moisture that causes a short circuit can be reliably detected, and erroneous detection is prevented. It becomes possible.

By providing the moisture detection correspondence control means 95 in the inverter device 22, quick control can be performed as compared with the case where the moisture detection correspondence control means 95 is provided in the ECU 21, and problems in vehicle travel can be avoided quickly. Further, it is possible to reduce the burden on the ECU 21 that is becoming more complicated due to higher functions. Since the motor 6 is an embedded magnet type synchronous motor having a high efficiency performance using a neodymium-based permanent magnet, the cruising distance of the vehicle can be improved under a limited battery capacity.
The abnormality report means 41 reports an abnormality to the ECU 21 and the abnormality display means 42 of the ECU 21 displays an abnormality on the display device 27 in the driver's seat based on the abnormality report, so that the driver recognizes the abnormality immediately. Thus, the driver can quickly take appropriate measures such as stopping or slowing the vehicle or traveling to a repair shop.

  Since the reduction gear 7 has a high reduction ratio of 1/6 or more of a cycloid type (more specifically, a high reduction ratio of 1/10 or more), the motor 6 is reduced in size and driven in-wheel motor. The apparatus 8 can be made compact. When the reduction ratio is increased, the motor 6 that rotates at high speed is used. When the motor 6 is in a high-speed rotation state, it is possible to prevent a short circuit abnormality from occurring in the motor coil 78 based on the detection signal from the moisture detecting means Sk as described above, so that the vehicle suddenly becomes unable to run. You can avoid that.

  Another embodiment of the present invention will be described. In the following description, the same reference numerals are given to the portions corresponding to the matters described in the preceding forms in each embodiment, and the overlapping description is omitted. When only a part of the configuration is described, the other parts of the configuration are the same as those described in the preceding section. Not only the combination of the parts specifically described in each embodiment, but also the embodiments can be partially combined as long as the combination does not hinder.

  FIG. 7 is a block diagram of a conceptual configuration of a control system in an in-wheel motor drive device according to another embodiment, and FIG. 8 is a schematic diagram illustrating a circuit configuration example of the motor drive device in the in-wheel motor drive device. is there. In this example, as shown in FIG. 8, the inverter 31 includes, for example, an electromagnetic contactor or an electromagnetic switching device between the internal wiring of each phase connected to each driving element 97 such as a switching transistor and the output terminal 98. An open / close switch 99 is provided. As shown in FIGS. 7 and 8, the control unit 40 is electrically connected to each open / close switch 99.

  In a normal state where the motor current is flowing, the control unit 40 controls each open / close switch 99 to be in an open state. When the determination unit 39 determines that the detection signal has been set, the control unit 40 switches each open / close switch 99 to the closed state. As a result, the motor current is cut off. Therefore, it is possible to avoid that the vehicle suddenly becomes unable to travel. In this way, the abnormality of the motor 6 can be detected at an early stage, and problems in vehicle travel can be avoided.

As shown in FIG. 9, the moisture detection correspondence control means 95 may be provided in the ECU 21 that is an electric control unit for controlling the entire vehicle. In this case, as shown in FIG. 9A, the control unit 40 may be electrically connected to the motor drive control unit 33 to limit the output of the inverter device 22. Further, as shown in FIG. 9B, the control unit 40 is electrically connected to each electromagnetic contactor 99 (see FIG. 8) of the inverter 31 in the power circuit unit 28, and the open / close position of each electromagnetic contactor 99. May be controlled to be switched.
This in-wheel motor drive device can be applied not only to electric vehicles but also to fuel cell vehicles and hybrid vehicles.

4, 5 ... Wheel bearing 6 ... Motor 6a ... Terminal block 7 ... Reducer 8 ... In-wheel motor drive 19 ... Battery 21 ... ECU
28 ... power circuit portion 29 ... Motakon trolls 31 ... inverter 72 ... housing 95 ... moisture detecting the response control means Sk ... moisture detecting means

Claims (6)

In an in-wheel motor drive device having a wheel bearing, a motor, and a reduction gear interposed between the motor and the wheel bearing,
Moisture detection means for detecting moisture in the motor is provided inside the terminal block of the motor, the terminal block has a plurality of terminals, and these terminals are accommodated in the motor housing and connected to the terminal block. When the conductive path composed of the wiring and the connection terminal of the terminal block has an exposed portion without covering, it is monitored whether or not the moisture detection signal by the moisture detection means has been set, and has entered the setting state. An in-wheel motor drive device comprising: a moisture detection control unit that restricts the motor current or cuts off the motor current when determined . According to claim 1, at least the a power circuit section, the control of the ECU is an electric control unit for controlling the vehicle in general including an inverter that converts the battery DC current to be installed in a vehicle to an alternating current used to drive the motor An in-wheel motor drive device in which a moisture detection response control means is provided in an inverter device having a motor control unit for controlling a power circuit unit. The in-wheel motor drive device according to claim 1 , wherein the moisture detection response control unit is provided in an ECU that is an electric control unit that controls the entire vehicle. In any one of claims 1 to 3, wherein the water detecting means, the in-wheel motor drive device is conductive sensor or electrochemical sensor. The in-wheel motor drive device according to any one of claims 1 to 4 , wherein the motor is an embedded magnet type synchronous motor using a neodymium permanent magnet. In any one of claims 1 to 5, wherein the speed reducer, in-wheel motor drive device having a high reduction ratio of cycloidal.

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