JP4978350B2 - Driving force distribution device - Google Patents

Description

  The present invention relates to a driving force distribution device capable of controlling a distribution ratio of driving force input from a driving source to first and second output shafts.

  2. Description of the Related Art Conventionally, there is a road surface that is inclined along a vehicle width direction of a vehicle (a left-right direction with respect to a straight traveling direction) for draining rainwater. When traveling straight on such an inclined road surface, even if the steering wheel is held at a neutral position (a position where the steering angle of the wheel is not changed), the vehicle will be swept downward along the road surface. The steering wheel must be held in a steered state according to the degree of slope (gradient) of the road surface, which is a burden on the driver.

Therefore, the vehicle steering device described in Patent Document 1 detects the inclination angle of the road surface in the vehicle width direction, and automatically adjusts according to the inclination angle so that the vehicle goes straight with the driver holding the steering wheel neutral. The wheel steering angle is adjusted to reduce the burden on the driver.
JP 2003-267250 A

  By the way, in the vehicle steering device described in Patent Document 1, since the vehicle travels in a state where the front wheels are inclined with respect to the traveling direction of the vehicle, there is a problem that the front wheels are likely to be worn. Also, when the driver steers the steering wheel while avoiding obstacles or approaching a curved road while traveling straight on a road surface inclined along the vehicle width direction of the vehicle, the steering angle of the wheel is cut. Since the vehicle is steered from a rare state, the driver may feel uncomfortable. Further, the inclination angle of the road surface in the vehicle width direction is not always constant and varies as the vehicle travels. The turning angle and the output of the steering actuator change according to the fluctuation of the inclination angle, and accordingly. The output of the reaction force actuator also changes, and the driver may feel this change and feel uncomfortable. Such a sense of incongruity is unavoidable when an assist force is applied to the steering system, such as when changing the steering angle of the wheel, and when traveling on a road surface inclined along the vehicle width direction by other means. It has been desired to reduce the driver's discomfort.

  The present invention has been made to solve the above-described problems, and its purpose is a drive that has a good steering feeling and can reduce the burden on the driver when traveling on a road surface inclined along the vehicle width direction. It is to provide a power distribution device.

  In order to achieve the above object, the invention according to claim 1 is a driving force distribution device capable of controlling the distribution of driving force to the left wheel and the right wheel of the vehicle, wherein the vehicle extends along the vehicle width direction of the vehicle. Vehicle state determining means for determining whether or not the vehicle is traveling straight on the inclined road surface, and the vehicle state determining means determines that the vehicle is traveling straight on the inclined road surface along the vehicle width direction of the vehicle. Control means for allocating a larger driving force in accordance with an inclination angle than a wheel located at a higher inclination to a wheel located at a lower inclination of the left wheel and the right wheel. The summary is provided.

  According to the above configuration, when the vehicle is traveling straight on a road surface that is inclined along the vehicle width direction, the vehicle is located on a higher slope with respect to a wheel located on a lower slope of the left and right wheels. Since a large driving force corresponding to the inclination angle is also distributed, the vehicle tries to turn from a low inclination to a high inclination in the vehicle width direction, that is, the vehicle tends to move upward along the inclination direction. The vehicle tilts along the vehicle width direction without the driver performing a steering operation by balancing the force of the vehicle upward along the tilt direction with the force of the vehicle moving downward in the tilt direction due to its own weight. It becomes possible to go straight on the road surface and the burden on the driver is reduced. As described above, since the vehicle does not travel in a state where the front wheels are inclined with respect to the straight traveling direction of the vehicle, it is possible to avoid the front wheels from being easily worn. In addition, unlike the conventional case where the assist force is applied to the steering system based on the inclination angle of the road surface, the driving force distribution between the left and right wheels is changed, so the driver may feel uncomfortable. It is suppressed. Furthermore, in order to change the distribution ratio so as to distribute a large driving force according to the inclination angle to the wheels located at the lower inclination in the vehicle width direction, the optimal driving force is distributed based on the inclination angle of the road surface, The straight running stability when traveling on a road surface inclined along the vehicle width direction is improved.

  According to a second aspect of the present invention, in the driving force distribution device according to the first aspect, a tilt angle detecting means for detecting a tilt angle of the vehicle in the vehicle width direction, and a steering angle detection for detecting a steering angle of the steering wheel. Means for determining whether or not the vehicle is inclined in the vehicle width direction based on the inclination angle, and whether or not the vehicle is traveling straight on the basis of the steering angle. The gist is to determine whether or not.

  According to the above configuration, by detecting the inclination angle of the vehicle in the vehicle width direction and the steering angle of the steering wheel, it is accurately determined whether or not the vehicle is traveling straight on a road surface inclined along the vehicle width direction. .

  According to a third aspect of the present invention, in the driving force distribution device according to the first or second aspect, the first output shaft connected to the left wheel and the right wheel of the vehicle, respectively, A differential mechanism that transmits to the two output shafts and allows mutual differential between the first output shaft and the second output shaft; and the first output shaft and the second output shaft; A motor that relatively rotates the motor, and the control means controls a driving force distribution between the first output shaft and the second output shaft by controlling a rotation direction and a motor torque of the motor. Is the gist.

  According to the above configuration, the driving force distribution to the left wheel and the right wheel is changed by controlling the rotation direction of the motor and the motor torque, and the driving force distribution device is manufactured with a simple configuration.

  ADVANTAGE OF THE INVENTION According to this invention, a steering feeling is good and can provide the driving force distribution apparatus which can reduce a driver | operator's burden at the time of drive | working the road surface inclined along the vehicle width direction.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to the drawings.
As shown in FIG. 1, the vehicle 1 is a four-wheel drive vehicle based on a front-wheel drive vehicle, and a pair of front axles 4 </ b> L and 4 </ b> R are connected to a transaxle 3 assembled beside the engine 2. The driving force of the engine 2 is transmitted to the front wheels 5L and 5R via the front axles 4L and 4R. A propeller shaft 6 is connected to the transaxle 3 together with the front axles 4L and 4R. The propeller shaft 6 is connected to a pair of rear axles 9L and 9R via a torque coupling 7 and a rear differential 8. Has been. The driving force is also transmitted to the rear wheels 10L and 10R via the propeller shaft 6, the torque coupling 7, the rear differential 8, and the rear axles 9L and 9R. In addition, by controlling the operation of the torque coupling 7, the driving force distribution between the front wheels 5L, 5R and the rear wheels 10L, 10R is controlled. Further, the steering angle of the front wheels 5L, 5R is changed by steering the steering wheel 11, and the traveling direction of the vehicle 1 is changed.

  As shown in FIG. 2, the rear differential 8 includes a planetary gear type differential mechanism 21. The differential mechanism 21 includes a ring gear 23 formed integrally with the external gear 22, and the inner side of the ring gear 23. The sun gear 24 is coaxially arranged. Between the ring gear 23 and the sun gear 24, a plurality of planetary gear pairs 25 including a first planetary gear 25a and a second planetary gear 25b are interposed. Each first planetary gear 25 a is meshed with the ring gear 23, and each second planetary gear 25 b is meshed with the sun gear 24. The first planetary gear 25a and the second planetary gear 25b constituting each planetary gear pair 25 are supported by the planetary carrier 26 so as to be capable of rotating and revolving, respectively, in a state of being engaged with each other.

  A drive pinion 28 is provided at the tip of the input shaft 27 connected to the propeller shaft 6 via the torque coupling 7. Then, when the drive pinion 28 is engaged with the external gear 22 of the differential mechanism 21, the ring gear 23 formed on the inner periphery of the external gear 22 is drivingly connected to the drive pinion 28. The sun gear 24 is fixed to the shaft end of the left rear axle 9L, and the planetary carrier 26 is fixed to the shaft end of the right rear axle 9R, so that it can rotate together with the corresponding rear axles 9L, 9R. ing.

  Accordingly, the driving force transmitted to the propeller shaft 6 is transmitted from the torque coupling 7 and the input shaft 27 to the ring gear 23 via the drive pinion 28, and the sun gear 24 and the planetary carrier 26 rotate together with the ring gear 23. As a result, the driving force is transmitted from the rear axles 9L, 9R to the left and right rear wheels 10L, 10R. Then, the rotation difference generated between the left and right rear wheels 10L, 10R, such as when the vehicle is turning, is allowed when each of the first planetary gears 25a and each of the second planetary gears 25b revolves around the sun gear 24 while rotating. It is like that.

Further, the rear differential 8 has a function as a driving force distribution device 30 capable of controlling the distribution ratio of the driving force generated by the engine 2 to the left and right rear wheels 10L, 10R.
More specifically, a planetary gear mechanism 31 is interposed between the rear axles 9L and 9R constituting the first and second output shafts of the driving force distribution device 30, and a motor 32 is provided in the planetary gear mechanism 31. Are drive-coupled. Then, the operation of the motor 32 is controlled by the ECU 33 as a control means, and a relative rotation is generated between the rear axles 9L and 9R based on the motor torque, so that an input is made from the propeller shaft 6 via the drive pinion 28. The distribution ratio of the driving force to both rear axles 9L, 9R is configured to be controllable.

  The planetary gear mechanism 31 includes first and second sun gears 34 and 35 arranged coaxially with the left rear axle 9L, and a plurality of double pinions 36 that mesh with the first and second sun gears 34 and 35, A planetary carrier 37 that supports each of these double pinions 36 so as to be capable of rotating and revolving is constituted. The first and second sun gears 34 and 35 have different numbers of teeth, and the first and second pinions 36 a and 36 b of the double pinion 36 that mesh with the first and second sun gears 34 and 35. Also, different numbers of teeth are set. When the first and second sun gears 34 and 35 are rotated with the planetary carrier 37 fixed, the second sun gear 35 rotates faster than the first sun gear 34, that is, the planetary carrier 37. Is fixed, the first sun gear 34 is a reduction side gear, and the second sun gear 35 is a speed increase side gear.

  The first sun gear 34 is connected to the planetary carrier 26 of the differential mechanism 21 so as to be rotatable together, that is, connected to the right rear axle 9R via the differential mechanism 21. The second sun gear 35 is connected to the left rear axle 9L via the speed change mechanism 41. The motor 32 is drivingly connected to a planetary carrier 37 that supports each double pinion 36.

  Therefore, the planetary gear mechanism 31 inputs the motor torque generated by the motor 32 to the planetary carrier 37 as a control torque, so that the first sun gear 34 side moves to the second sun gear 35 side or the second sun gear 35 side. Torque is transmitted to the first sun gear 34 side. The ECU 33 controls the rotational direction of the motor 32 and the motor torque input as the control torque, thereby distributing the driving force between the rear axles 9L and 9R to which the first and second sun gears 34 and 35 are connected, respectively. To control.

  The transmission mechanism 41 is provided to correct the transmission gear ratio of the planetary gear mechanism 31 so as to suppress the rotation of the planetary carrier 37 based on the transmission gear ratio set in the planetary gear mechanism 31. Then, the speed change mechanism 41 reverses the arrangement of the first sun gear 44 on the speed reduction side and the second sun gear 45 on the speed increase side of the planetary gear having the same configuration as that of the planetary gear mechanism 31. It is coaxially arranged beside this and is interposed between the planetary gear mechanism 31 and the left rear axle 9L. That is, the second sun gear 45 on the speed increasing side in the speed change mechanism 41 is connected to the second sun gear 35 on the speed increasing side in the planetary gear mechanism 31 and the first sun gear 44 on the speed reducing side is connected to the left side on the left side. It is connected to the rear axle 9L. Then, the planetary carrier 47 that supports the planetary gear 46 is fixed to a casing (not shown) that is a non-rotating part, thereby canceling the speed ratio set in the planetary gear mechanism 31 and drivingly connected to the motor 32. The rotation of the carrier 37 during non-motor driving can be suppressed.

Next, the electrical configuration of the driving force distribution device 30 will be described.
As shown in FIGS. 1 and 2, the ECU 33 detects the steering angle θs of the steering wheel 11 detected by the steering sensor 50 as the steering angle detection means and the vehicle detected by the inclination angle sensor 51 as the inclination angle detection means. 1 is input as an inclination angle α in the vehicle width direction (left-right direction with respect to the straight direction, see FIG. 1). In the present embodiment, the steering sensor 50 uses a rotary encoder that outputs a three-phase (A phase, B phase, Z phase) pulse signal whose output level changes according to the rotation of the steering wheel 11, and is tilted. The angle sensor 51 uses a liquid-filled capacitance type tilt angle sensor that detects the tilt angle based on a change in electrostatic capacitance accompanying the tilt of the sealed liquid. The inclination angle α is 0 when the vehicle 1 is not inclined along the vehicle width direction, and is a positive value when the vehicle 1 is inclined upward to the right. The vehicle 1 is inclined upward to the left. It will be a negative value.

  Based on the steering angle θs detected by the steering sensor 50 and the inclination angle α of the vehicle 1 detected by the inclination angle sensor 51, the ECU 33 determines whether or not the vehicle 1 is traveling straight on a road surface inclined along the vehicle width direction. Determine whether. Then, when the vehicle 1 is traveling straight on a road surface inclined along the vehicle width direction, the ECU 33 sets the wheel located on the lower one of the left rear wheel 10L and the right rear wheel 10R. On the other hand, the straight-ahead assist control is performed in which a larger driving force is distributed according to the inclination angle α than the wheel located at the higher inclination. Specifically, the ECU 33 determines that the steering angle θs is equal to or smaller than a predetermined steering angle θth (for example, an angle at which the steering angle of the steered wheels does not change), the inclination angle α is equal to the predetermined inclination angle αth (the steering angle θs is equal to or smaller than the predetermined steering angle θth). In a case where the state in which the vehicle 1 is at an angle equal to or greater than the angle at which the vehicle 1 flows downward in the inclination direction continues for a predetermined time or more, it is determined that the vehicle 1 is traveling straight on a road surface inclined along the vehicle width direction. Then, the ECU 33 determines that the left rear wheel 10L is positioned at a lower inclination in the vehicle width direction when the vehicle 1 moves to the right, that is, when the inclination angle α is a positive value, and the left rear wheel 10L. The operation of the motor 32 is controlled so that a larger driving force is distributed to the right rear wheel 10R than the right rear wheel 10R. On the other hand, the ECU 33 determines that the right rear wheel 10R is positioned at a lower inclination in the vehicle width direction when the vehicle 1 moves leftward, that is, if the inclination angle α is a negative value, and the right rear wheel 10R. The operation of the motor 32 is controlled so that a larger driving force is distributed to the left rear wheel 10L. Further, the ECU 33 distributes a larger driving force to the wheels located at the lower inclination in the vehicle width direction as the absolute value of the inclination angle α increases. That is, the ECU 33, the steering sensor 50, and the tilt angle sensor 51 constitute vehicle state determination means.

Hereinafter, the processing procedure of the rectilinear assist control in the ECU 33 will be described.
As shown in the flowchart of FIG. 3, the ECU 33 acquires the state quantities detected by the sensors (step 101), and the road surface on which the vehicle 1 is inclined in the vehicle width direction based on the state quantities (θs, α). It is determined whether the vehicle is traveling straight (steps 102 to 104).

  That is, it is determined whether or not the steering angle θs detected by the steering sensor 50 is equal to or smaller than a predetermined steering angle θth set in advance (step 102). If the steering angle θs is equal to or smaller than the predetermined steering angle θth (step 102). : YES), it is determined whether or not the absolute value of the inclination angle α of the vehicle 1 is greater than or equal to a predetermined inclination angle αth (step 103). Next, when the absolute value of the inclination angle α is equal to or larger than the predetermined inclination angle αth (step 103: YES), the ECU 33 determines whether the counter n is larger than the predetermined counter nth (step 104). When the counter n is larger than the predetermined counter nth (step 104: YES), the ECU 33 determines that the vehicle 1 is traveling straight on the road surface inclined along the vehicle width direction, and is positioned on the lower inclination side. The process proceeds to the straight-ahead assist control in which a large driving force corresponding to the inclination angle α is distributed to the wheels (step 105).

  On the other hand, when the counter n is equal to or smaller than the predetermined counter nth (step 104: NO), the ECU 33 increments the counter n (n = n + 1, step 106), and the left and right rear wheels 10L, The normal control for controlling the driving force distribution between 10R is executed (step 107). Specifically, since the rotational speed of the outer wheel is faster than the inner wheel in the turning radius direction when the vehicle is turning, the ECU 33 is the one of the left and right rear wheels 10L, 10R that is the outer driving wheel. The operation of the motor 32 is controlled so as to increase the driving force distribution. Further, when the steering angle θs is larger than the predetermined steering angle θth (step 102: NO) and when the inclination angle α is smaller than the predetermined inclination angle αth (step 103: NO), the ECU 33 moves in the vehicle width direction. It is determined that the road surface inclined along the road is not going straight, the counter n is cleared (n = 0, step 108), and normal control is executed.

Next, the operation of the driving force distribution device 30 will be described.
When the vehicle 1 is traveling straight on a road surface inclined along the vehicle width direction, the vehicle 1 is affected by its own weight even if the steering wheel 11 is in the neutral position, that is, the steering angle θs is kept below the predetermined steering angle θth. It flows downward along the inclination direction. When the steering angle of the front wheels 5L and 5R is changed based on the road surface inclination angle α as in the conventional case, the steering angle of the front wheels is changed in a state where the steering angle θs is equal to or less than the predetermined steering angle θth. Therefore, when the driver tries to perform a steering operation by avoiding an obstacle or approaching a curved road, the driver steers from a state in which the steering angles of the front wheels 5L and 5R are cut, and the driver feels uncomfortable. May feel.

  In this respect, according to the present embodiment, a larger driving force corresponding to the inclination angle α is distributed to the wheel located at the lower inclination in the vehicle width direction than the wheel located at the higher inclination, so that the vehicle 1 is going to turn from a low inclination to a high inclination in the vehicle width direction, that is, the vehicle 1 is going upward along the inclination direction. The vehicle 1 moves along the vehicle width direction without the driver performing a steering operation by balancing the force of the vehicle 1 moving upward along the inclination direction with the force of the vehicle 1 moving downward in the inclination direction due to its own weight. It is possible to go straight on the inclined road surface. Thus, in this embodiment, since it does not drive | run in the state in which the rudder angle of the front wheels 5L and 5R was cut | disconnected with respect to the rectilinear direction of the vehicle 1, it is avoided that the front wheels 5L and 5R become easy to wear. Further, since the driving force distribution between the rear wheels 10L, 10R is changed, no assist force is applied to the steering system. Accordingly, when the driver performs a steering operation by avoiding an obstacle or reaching a curved road during the straight-ahead assist control, or when the inclination angle α in the vehicle width direction of the road surface changes as the vehicle 1 travels. A feeling of discomfort is suppressed.

  Further, the distribution of driving force between the rear wheels 10L and 10R enables the vehicle 1 to go straight on the road surface inclined along the vehicle width direction, so that the road surface is compared with the case where assist force is applied to the steering system. Even when the vehicle is greatly inclined in the vehicle width direction, the vehicle 1 can be moved straight without the driver performing a steering operation. Further, since the ECU 33 distributes a larger driving force to the wheel having a lower inclination in the vehicle width direction as the absolute value of the inclination angle α increases, the optimal driving force is distributed based on the degree of inclination of the road surface. The straight running stability when traveling on a road surface inclined along the width direction can be improved.

As described above, according to the present embodiment, the following effects can be obtained.
(1) When the vehicle 1 is traveling straight on a road surface inclined along the vehicle width direction, the ECU 33 is a wheel located on the lower inclination of the left rear wheel 10L and the right rear wheel 10R. On the other hand, a larger driving force corresponding to the inclination angle α is distributed than the wheel located on the higher inclination side. For this reason, the vehicle 1 tries to turn from a low inclination to a high inclination in the vehicle width direction, that is, the vehicle 1 tends to move upward along the inclination direction. The vehicle 1 moves along the vehicle width direction without the driver performing a steering operation by balancing the force of the vehicle 1 moving upward along the inclination direction with the force of the vehicle 1 moving downward in the inclination direction due to its own weight. It is possible to go straight on the inclined road surface, and the burden on the driver can be reduced. Thus, since it does not drive | run in the state which changed the rudder angle of the front wheels 5L and 5R with respect to the straight direction of the vehicle 1, it can avoid that the front wheels 5L and 5R become easy to wear. Further, unlike the conventional case where the assist force is applied to the steering system based on the inclination angle α of the road surface, the driving force distribution between the left and right rear wheels 10L, 10R is changed, so that the driver can It is possible to suppress feeling uncomfortable. Further, the distribution of driving force between the rear wheels 10L and 10R enables the vehicle 1 to travel straight on a road surface inclined along the vehicle width direction, so that the road surface can be compared with a case where assist force is applied to the steering system. Even when the vehicle is greatly inclined in the vehicle width direction, the vehicle 1 can be driven straight without the driver performing a steering operation.

  (2) As the absolute value of the inclination angle α increases, the ECU 33 distributes a larger driving force to the wheel having the lower inclination in the vehicle width direction, and therefore, the optimal driving force is distributed based on the inclination angle of the road surface. The straight running stability when traveling on a road surface inclined along the vehicle width direction can be improved.

  (3) According to the above configuration, it is determined whether or not the vehicle is traveling straight on the road surface inclined in the vehicle width direction by detecting the inclination in the vehicle width direction of the vehicle traveling straight. Therefore, for example, an image of the front of the vehicle is captured by an imaging device such as a CCD camera, and the vehicle is moved in the vehicle width direction with a simple configuration as compared with the case where it is determined whether the road surface is inclined in the vehicle width direction based on the image. It is determined whether or not the vehicle is traveling straight on an inclined road surface.

  (4) Since the driving force distribution between the left and right rear wheels 10L, 10R is changed by controlling the rotation direction and motor torque of the motor 32 that is drivingly connected to the planetary gear mechanism 31, a large speed change is achieved with a small number of gear stages. The ratio is obtained, and the driving force distribution device 30 can be downsized.

In addition, you may implement this embodiment in the following aspects.
In the present embodiment, as the tilt angle sensor 51, a liquid-filled capacitance type tilt angle sensor that detects a tilt angle based on a change in electrostatic capacitance accompanying the tilt of the sealed liquid is used. A displacement sensor for detecting the amount of displacement may be provided on the suspension connected to the left and right rear wheels 10L, 10R to detect α of the vehicle 1.

  In the present embodiment, it is determined whether or not the vehicle 1 is traveling straight based on the steering angle θs. However, the present invention is not limited to this. For example, a yaw rate sensor is provided in the vehicle 1 and the yaw rate detected by the yaw rate sensor is used. Then, it may be determined whether the vehicle 1 is traveling straight.

  In the present embodiment, whether or not the road surface is inclined in the vehicle width direction is determined based on the steering angle θs of the vehicle 1 and the α of the vehicle 1. However, the present invention is not limited to this. 1 may be taken and it may be determined whether the road surface is inclined in the vehicle width direction based on the image.

  In the present embodiment, based on the steering angle θs detected by the steering sensor 50 and the inclination angle α of the vehicle 1, it is determined whether or not the vehicle 1 is traveling straight on a road surface inclined along the vehicle width direction. Not limited to this. For example, the vehicle 1 is provided with a torque sensor that detects the steering torque of the steering wheel 11, and the vehicle has a steering angle θs that is equal to or smaller than a predetermined steering angle θth and whether or not a state in which the steering torque is detected to be equal to or greater than a predetermined value continues. It may be determined whether or not 1 is traveling straight on a road surface inclined along the vehicle width direction.

  In the present embodiment, the ECU 33 distributes a larger driving force to the wheel located at the lower inclination in the vehicle width direction as the absolute value of the inclination angle α increases. The driving force distribution may be increased step by step.

In this embodiment, the planetary gear type differential mechanism 21 is used, but a bevel gear type differential mechanism may be used.
In the present embodiment, a pair of first and second sun gears 34 and 35, a plurality of double pinions 36 meshing with the first and second sun gears 34 and 35, and each double pinion 36 can rotate. A planetary gear mechanism 31 including a planetary carrier 37 that is supported so as to be able to revolve is adopted, and the planetary carrier 37 is used as an input element that is drivingly connected to the motor 32. However, the configuration of the planetary gear mechanism is not limited to this, and the input element thereof is not limited to the planetary carrier.

  In this embodiment, the planetary gear having the same configuration as that of the planetary gear mechanism 31 is symmetrically connected via the differential mechanism 21 to form the transmission mechanism 41. However, the configuration of the transmission mechanism is not limited to this. It is not a thing.

-In this embodiment, although the motor 32 was arrange | positioned coaxially with the rear axle 9L, it is not restricted to this, For example, the structure which drive-connects with the planetary gear mechanism 31 via a connection mechanism may be sufficient.
In the present embodiment, the driving force distribution between the left and right rear wheels 10L and 10R is controlled based on the steering angle θs during normal control. However, the present invention is not limited to this, and the driving force distribution to the left and right rear wheels 10R and 10L is controlled. And the distribution ratio may not be changed.

  In the present embodiment, the driving force distribution between the left and right rear wheels 10L, 10R is changed by controlling the rotation direction and motor torque of the motor 32 that is drivingly connected to the planetary gear mechanism 31, but this is not restrictive. For example, the driving force distribution may be changed by a hydraulic motor that applies a motor torque that relatively rotates the left and right rear axles 9L and 9R depending on the hydraulic pressure supply direction.

  In the present embodiment, the motor torque of the motor 32 causes relative rotation between the rear axles 9L and 9R, and the driving force distribution to the left and right rear wheels 10L and 10R is changed. However, the present invention is not limited to this, and a torque coupling is provided between the rear differential 8 and both rear axles 9L and 9R, and the driving force to the left and right rear wheels 10L and 10R is controlled by controlling the operation of the torque coupling. The distribution may be changed.

  In the present embodiment, the present invention is embodied in the driving force distribution device 30 that distributes the driving force transmitted to the rear wheels 10L, 10R to the left and right wheels, but is not limited thereto, and the front wheels 5L, 5R side A driving force distribution device that distributes the driving force transmitted to the left and right wheels may be embodied.

The schematic block diagram of a vehicle. The schematic block diagram of a rear differential. The flowchart which shows the process sequence of rectilinear advance auxiliary control of ECU.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Vehicle, 2 ... Engine, 5L, 5R ... Front wheel, 10L, 10R ... Rear wheel, 11 ... Steering wheel, 21 ... Differential mechanism, 30 ... Driving force distribution apparatus, 32 ... Motor, 50 ... Steering sensor, 51 inclination Angle sensor, θs: steering angle, α: tilt angle.

Claims (3)

A driving force distribution device capable of controlling the distribution of driving force to the left wheel and the right wheel of a vehicle,
Vehicle state determination means for determining whether the vehicle is traveling straight on a road surface inclined along the vehicle width direction of the vehicle;
When it is determined by the vehicle state determination means that the vehicle is traveling straight on a road surface inclined along the vehicle width direction of the vehicle, the vehicle is positioned on the lower one of the left wheel and the right wheel. A driving force distribution device comprising: a control unit that distributes a larger driving force corresponding to an inclination angle than a wheel located at a higher inclination to the wheel. An inclination angle detecting means for detecting an inclination angle of the vehicle in the vehicle width direction;
Steering angle detection means for detecting the steering angle of the steering wheel,
The vehicle state determination means determines whether or not the vehicle is inclined in the vehicle width direction based on the inclination angle, and determines whether or not the vehicle is traveling straight based on the steering angle. 2. The driving force distribution device according to claim 1, wherein The input driving force is transmitted to a first output shaft and a second output shaft respectively connected to the left wheel and the right wheel of the vehicle, and the first output shaft and the second output shaft A differential mechanism that allows mutual differentials of
A motor that relatively rotates the first output shaft and the second output shaft,
3. The control unit according to claim 1, wherein the control unit controls a driving force distribution between the first output shaft and the second output shaft by controlling a rotation direction and a motor torque of the motor. The driving force distribution device described.

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