JP2017112711A - Driving force distribution device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicular drive force distribution apparatus for preventing the power of a battery from being wastefully consumed in the case of the drive efficiency of a wheel being decreased, the wheel driven with drive power supplied from the battery.SOLUTION: A vehicular drive force distribution apparatus includes: an in-wheel motor 10 for individually driving each of plural wheels 15 disposed along a longitudinal direction of a vehicle 1; a power reception unit 11 disposed with the in-wheel motor 10; a power transmission unit 12, disposed oppositely to the power reception unit 11, capable of wirelessly transmitting power to the power reception unit 11; a battery 13, connected to the power transmission unit 12-side, for supplying drive power for driving the wheel 15; and drive force distribution means 14 for adjusting a distribution ratio of the drive power to be transmitted to each power transmission unit 12 in accordance with a drive efficiency between: drive power supplied from the battery 13 to the power transmission unit 12 disposed correspondingly to each of the wheels 15; and drive force of the wheel 15 driven with the drive power.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a vehicle that drives a plurality of wheels with a wireless in-wheel motor, and controls the distribution of the drive power to each wheel in accordance with the transmission efficiency of the drive power from the battery to each in-wheel motor. The present invention relates to a driving force distribution device.

  For example, Patent Document 1 discloses a vehicle drive device that includes a power transmission antenna for wirelessly transmitting power on the vehicle side and the wheel side, and transmits driving power for driving the wheel from the battery to the in-wheel motor side by wireless power transmission. (See paragraph 0038 of this document, FIG. 3 etc.). Thus, by transmitting power wirelessly, it is not necessary to provide a power transmission cable between the vehicle and the wheel that is the movable part, and good steering performance of the wheel can be ensured (paragraph 0048 of this document). reference).

  The vehicle is provided with a first battery that is provided on the vehicle side and is charged by an external power source outside the vehicle, and a second battery that is provided inside the motor unit of each wheel and wirelessly transmits power to and from the first battery. A battery is provided (see paragraph 0022 of this document). Electric power is directly supplied from the second battery to the motor unit.

Japanese Patent No. 5775605

  In the configuration shown in Patent Document 1, power is transmitted wirelessly between the first battery and the second battery, but when the transmission efficiency of wireless power transmission of any of the four wheels decreases, In order to charge the two batteries, a larger current has to be supplied from the first battery, and there is a problem that the driving power stored in the first battery is wasted. In view of this, the present invention eliminates waste of battery power when drive efficiency between a drive power sent from a battery to a specific wheel and a drive power of the wheel driven by the drive power is reduced. The problem is to prevent consumption.

  In order to solve the above-described problems, in the present invention, an in-wheel motor that drives a plurality of wheels provided in the front-rear direction of the vehicle, a power receiving unit provided alongside the in-wheel motor, and the power receiving unit A power transmission unit capable of wireless power transmission with the power receiving unit, a battery connected to the power transmission unit for supplying driving power for driving the wheels, and Corresponding to the driving efficiency between the driving power sent from the battery to the power transmission unit provided corresponding to each and the driving force of the wheel driven by this driving power, it is sent to each power transmission unit A vehicle driving force distribution device including a driving force distribution means for adjusting a distribution ratio of the driving power is configured.

  In the above configuration, the driving force distribution means is sent to the wheel on the one side when the driving efficiency on the one side in the front and rear is reduced among the wheels provided in the front-rear direction of the vehicle. It is preferable that the driving power is decreased and the control is performed to increase the driving power sent to the wheels on the other side of the front and rear.

  Further, in this configuration, the driving force distribution means performs control to increase the driving power sent to the wheel on the other side as the amount of decrease in the driving efficiency of the wheel on the one side increases. It is preferable to do this.

  In each of the configurations, the driving efficiency may be determined by wireless transmission efficiency between the power receiving unit and the power transmission unit.

  Alternatively, the drive efficiency can be determined by the output efficiency of the in-wheel motor.

  In each of the above configurations, the driving power distribution unit may adjust a distribution ratio of the driving power sent to the power transmission units according to a road surface condition where the vehicle is traveling.

  According to the present invention, the drive power distribution means drives the power sent to the in-wheel motor of each wheel in accordance with the drive efficiency between the drive power sent from the battery and the drive power of the wheel driven by this drive power. Since the power distribution ratio is adjusted, a large amount of driving power can be sent to the wheel side having low driving efficiency to prevent the battery power from being wasted.

Overall configuration diagram showing a four-wheel drive vehicle equipped with a vehicle driving force distribution device according to the present invention 1 is an overall configuration diagram showing a state in which drive power is evenly distributed to all wheels in the vehicle of FIG. In the state shown in FIG. 2, an overall configuration diagram showing a state where power transmission efficiency is reduced in the right rear wheel In the state shown in FIG. 3, the whole block diagram which shows the state which changed the distribution ratio of the driving force from a battery to the front-back wheel.

  FIG. 1 shows an overall configuration diagram of a vehicle 1 equipped with a vehicle driving force distribution device according to the present invention. The vehicle driving force distribution device includes an in-wheel motor 10, a power receiving unit 11, a power transmission unit 12, a battery 13, and a driving force distribution means 14 as main components. The vehicle shown in FIG. 1 is a four-wheel drive vehicle in which driving force is applied to all the front and rear wheels.

  The in-wheel motor 10 is provided in the wheel 15 and functions as a driving source that applies driving force to the wheel 15 during power running, while as a braking device that brakes the wheel 15 while regenerating electric power during regeneration. Function. Although not shown, the in-wheel motor 10 is provided with a power conversion unit and an inverter.

  The power receiving unit 11 is provided in the in-wheel motor 10. The power transmission unit 12 is provided to face the power reception unit 11 while being separated from the power reception unit 11 by a predetermined interval. Thus, by arranging the power reception unit 11 and the power transmission unit 12, wireless power transmission by electromagnetic waves can be performed between the power reception unit 11 and the power transmission unit 12 (see arrows e1 and e2 in FIG. 1). By wireless power transmission, it is possible to supply driving power from the battery 13 to the in-wheel motor 10 and to charge the regenerative power generated by the in-wheel motor 10 to the battery 13 (see arrow f in FIG. 1).

  As the power reception unit 11 and the power transmission unit 12, for example, a wound coil can be employed. The power transmission unit 12 is provided with a power conversion unit 16, and the power conversion unit 16 performs conversion between direct current and alternating current.

  The driving force distribution means 14 responds to a decrease in driving efficiency between the driving power sent from the battery 13 to the power transmission unit 12 provided in each wheel 15 and the driving force of the wheel 15 driven by this driving power. The function of adjusting the distribution ratio of the drive power sent from the battery 13 to each power transmission unit 12 is provided. As a cause of the decrease in the drive efficiency, there is a decrease in the wireless power transmission efficiency between the power receiving unit 11 and the power transmission unit 12 between the power transmission unit 12 and the in-wheel motor 10 (between the units 11 and 12). It is conceivable that foreign matter is present or the alignment is deviated), the output efficiency of the in-wheel motor 10 is lowered (when some problem occurs in the in-wheel motor 10 itself), and the like.

  In this case, in order to drive the wheel 15 with reduced driving efficiency with a predetermined driving force, a larger current must be supplied from the battery 13, and the driving power stored in the battery 13 is wasted. . Therefore, while reducing the distribution ratio of the driving power to the wheels 15 whose driving efficiency has been reduced, increasing the distribution ratio of the driving power to the wheels 15 having a normal driving efficiency, the driving power of the vehicle 1 as a whole can be reduced. While ensuring, it can prevent that the electric power of the battery 13 is consumed wastefully.

  The operation of the vehicle driving force distribution device according to the present invention will be described with reference to FIGS.

  As shown in FIG. 2, in the case of a four-wheel drive vehicle having a driving force distribution ratio with respect to the front and rear wheels 15 of 50:50 (refer to the numbers enclosed in the squares in the figure), the driving force distribution means 14 includes The distribution ratio of the driving power is adjusted so that 25% of the total driving force is distributed to the left and right wheels 15 (see the numbers in circles in the figure). For example, when the output required for the vehicle 1 (the driving force of the wheel 15 determined by the amount of depression of the accelerator) is 100 kW, the required output to each wheel 15 is 25 kW. In order to set the output of each wheel 15 to 25 kW when the wireless power transmission efficiency (drive efficiency) from the power transmission unit 12 to the power reception unit 11 is 90% (a state where wireless power transmission is normally performed without loss), The drive power sent from 13 to the power transmission unit 12 of each wheel 15 is about 111 kW (= 25 kW / 0.9 × 4).

  Here, as shown in FIG. 3, when an abnormality occurs in the power transmission / reception units 11 and 12 of the right rear wheel among the four wheels, and only the wireless power transmission efficiency of the right rear wheel is reduced to 70%, the front and rear wheels 15 In order to maintain the output of each wheel 15 at 25 kW if the driving force distribution ratio with respect to is kept 50:50 (refer to the number enclosed in the square in the figure), the power transmission unit of each wheel 15 from the battery 13 is maintained. The drive power sent to 12 is about 119 kW (= 25 kW / 0.9 × 3 + 25 kW / 0.7), and the power consumption is about 8 kW compared to the case where wireless power transmission is normally performed without loss in all the wheels 15. To increase. This is because it is necessary to send more electric power from the battery 13 in order to drive the right rear wheel with reduced wireless power transmission efficiency with an output of 25 kW.

  Thus, when the wireless power transmission efficiency is reduced in the rear wheels as described above, as shown in FIG. 4, the driving force distribution ratio with respect to the front and rear wheels 15 is set to 60:40 (refer to the numbers enclosed in the squares in this figure). ), The required output to the left and right front wheels is set to 30 kW, and the required output to the left and right rear wheels is set to 20 kW, respectively (see the numbers in circles in the figure). In this case, the drive power sent from the battery 13 to the power transmission unit 12 of each wheel 15 is approximately 117.5 kW (= 30 kW / 0.9 × 2 + 20 kW / 0.9 + 20 kW / 0.7). This driving power is increased by about 6.5 kW compared with the case where the wireless power transmission efficiency of all the wheels 15 is normal (the state shown in FIG. 2), but the wireless power transmission efficiency of the right rear wheel is reduced. Compared with the case where the driving force distribution ratio with respect to the front and rear wheels 15 is kept 50:50 (the state shown in FIG. 3), it is reduced by about 1.5 kW.

  As described above, when the power transmission efficiency of the front and rear wheels 15 is reduced on the rear wheel side, the driving power transmitted from the battery 13 to the rear wheel side is reduced, while the wireless power transmission is normally performed without loss. By increasing the driving power sent to the front wheel side being performed, it is possible to prevent the power of the battery 13 from being wasted as much as possible while ensuring the driving power of the vehicle 1 as a whole.

  The driving force distribution ratio for the front and rear wheels 15 is merely an example. That is, the driving force distribution ratio to the wheel 15 where the wireless power transmission is normally performed without loss is increased in accordance with the degree of decrease in the wireless power transmission efficiency of the wheel 15 in which the wireless power transmission efficiency is reduced. Good. Further, the driving force distribution ratio is appropriately changed depending on the road surface condition, the idling rate of the wheels 15, the weather condition, and the like.

  For example, when the road surface condition is good, traveling is easy without the wheels 15 idling, so the driving power sent to the side of the front and rear wheels 15 on which the wireless power transmission efficiency is reduced is greatly reduced (in some cases The control by the driving force distribution means is performed so as to reduce the loss of wireless power transmission as much as possible by cutting off the supply of driving power. On the other hand, for example, in a situation where the road surface is slippery, the wheel 15 is idling and traveling is likely to be unstable, so that it is accepted that a loss of wireless power transmission occurs, and the front and rear wheels 15 are evenly driven. Maintain power distribution. This change in the driving force distribution ratio can be appropriately performed even while the vehicle 1 is traveling.

  Moreover, in the above, although the case where the wireless power transmission efficiency fell on the rear-wheel side was illustrated, the wireless power transmission efficiency may fall on both the front and rear wheels. In this case, for example, the power of the battery 13 is wasted while ensuring the driving force of the vehicle 1 as a whole by reducing the distribution of the driving power to the side of the front and rear wheels 15 where the wireless power transmission efficiency is lower. It is possible to prevent consumption as much as possible.

  Furthermore, in the above, the case where the wireless power transmission efficiency between the power receiving unit 11 and the power transmission unit 12 has been described has been described, but also when the output efficiency of a specific wheel 15 is reduced due to the in-wheel motor 10, By controlling the drive power sent from the battery 13 to each in-wheel motor 10 by the drive force distribution means 14, the power of the battery 13 is wasted while ensuring the drive power of the vehicle 1 as a whole. It is possible to prevent consumption as much as possible.

  The above embodiment is merely an example, and when the drive efficiency between the drive power sent from the battery 13 to the specific wheel 15 and the drive force of the wheel 15 driven by this drive power occurs. As long as the problem of the present invention of preventing wasteful consumption of the power of the battery 13 can be solved, the configuration, arrangement, materials, and the like of each component can be changed as appropriate.

  For example, in the above description, a four-wheeled vehicle has been described as an example. However, the configuration according to the present invention can be applied to a two-wheeled vehicle, a three-wheeled vehicle, or the like if the vehicle 1 includes a plurality of wheels 15 provided in the front-rear direction. Can also be applied.

  In the above description, the driving force distribution during power running has been described, but the same applies to the driving force distribution during regeneration.

DESCRIPTION OF SYMBOLS 1 Vehicle 10 In-wheel motor 11 Power receiving unit 12 Power transmission unit 13 Battery 14 Driving force distribution means 15 Wheel 16 Power conversion unit

Claims (6)

An in-wheel motor for driving each of a plurality of wheels provided in the longitudinal direction of the vehicle;
A power receiving unit attached to the in-wheel motor;
A power transmission unit provided to face the power reception unit and capable of wireless power transmission with the power reception unit;
A battery connected to the power transmission unit for supplying driving power for driving the wheels;
Each power transmission corresponding to the driving efficiency between the driving power sent from the battery to the power transmission unit provided corresponding to each wheel and the driving force of the wheel driven by this driving power. Driving force distribution means for adjusting a distribution ratio of driving power sent to the unit;
A vehicle driving force distribution device comprising:   The drive power distribution means reduces the drive power sent to the one wheel when the drive efficiency on one of the front and rear sides of the wheels provided in the front-rear direction of the vehicle decreases. The vehicle driving force distribution device according to claim 1, wherein control for increasing the driving power sent to the front and rear wheels is performed.   3. The vehicle according to claim 2, wherein the driving force distribution unit performs control to increase the driving power sent to the wheel on the other side as the amount of decrease in the driving efficiency of the wheel on the one side increases. Driving force distribution device.   The vehicle driving force distribution device according to any one of claims 1 to 3, wherein the driving efficiency is determined by wireless power transmission efficiency between the power receiving unit and the power transmission unit.   The vehicle driving force distribution device according to any one of claims 1 to 3, wherein the driving efficiency is determined by an output efficiency of the in-wheel motor.   6. The vehicle according to claim 2, wherein the driving force distribution unit adjusts a distribution ratio of the driving power sent to the power transmission units according to a road surface condition where the vehicle is traveling. Driving force distribution device.

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