JP5977982B2 - Vehicle drive device - Google Patents

Description

  The present invention relates to a vehicle drive device.

  In Patent Document 1, slip detection is performed in which wheel acceleration is calculated from the number of rotations of a traveling motor, and the presence or absence of wheel slip is determined from the acceleration of the wheel and the acceleration of the vehicle body based on the torque command value of the traveling motor. And when the slip detection means determines that the wheel slips, the torque command value to the travel motor is reduced, and when the slip detection means determines that the wheel slip does not occur, the torque to the travel motor Torque control means for controlling the command value to become a command value for normal travel according to the accelerator pedal depression amount is disclosed, and an electric vehicle drive control device is disclosed to smoothly travel on a road with low frictional resistance. Trying to do.

JP-A-8-182118

  By the way, the traveling motor mounted on the electric vehicle of Patent Document 1 is provided with a transaxle composed of a reduction gear and a differential gear, and the driving force of the traveling motor input to the transaxle is changed to the left and right. Is distributed to the left front wheel and the right front wheel via the front wheel shaft. Therefore, when the slip detection means determines that the left front wheel or the right front wheel has slipped on the split μ road where the road surface friction is different between the left side and the right side of the vehicle, the drive control device generates a torque command value for the driving motor. As a result, the torque distributed to the left front wheel and the right front wheel both decreases, that is, the total driving torque of the front wheels decreases, and sufficient driving torque according to the driver's request cannot be transmitted to the road surface. End up.

  The present invention has been made in view of the above problems, and can transmit sufficient driving torque and braking torque according to driver requirements to the road surface even on split μ roads with different road surface friction on the left and right sides of the vehicle. Another object of the present invention is to provide a vehicular drive device.

In order to achieve the above object, the invention described in claim 1
A first drive wheel that is one of a front wheel (for example, a front wheel Wf in a later-described embodiment) and a rear wheel (for example, a rear wheel Wr in a later-described embodiment) of a vehicle (for example, a vehicle 3 in a later-described embodiment). A first driving device (for example, a rear wheel driving device 1 in an embodiment described later) for driving (for example, a rear wheel Wr in an embodiment described later);
A second drive device (for example, a front wheel drive device 6 in an embodiment described later) that drives a second drive wheel (for example, a front wheel Wf in an embodiment described later) which is the other of the front wheel and the rear wheel. ,
The first driving device includes a left electric motor (for example, a first electric motor 2A in an embodiment described later) connected to a left wheel of the vehicle (for example, a left rear wheel LWr in an embodiment described later), and a right side of the vehicle. A right motor (for example, a second motor 2B in an embodiment described later) connected to a wheel (for example, a right rear wheel RWr in an embodiment described later), and an electric motor that controls the torque of the left motor and the torque of the right motor A vehicle drive device having a control device (for example, a control device 8 in an embodiment described later),
The vehicle drive device includes slip acquisition means (for example, a slip acquisition device 80 in an embodiment described later) for acquiring that an excess slip, which is a predetermined slip or more, has occurred on the left wheel or the right wheel.
When the slip acquisition means acquires that the excess slip has occurred on one of the left wheel or the right wheel, the motor control device calculates the torque of the motor connected to the one wheel. The first change amount (for example, first change amounts Δ1 and Δ1 ′ in an embodiment described later) is changed, and the torque of the motor connected to the other wheel is changed to a second change whose sign is opposite to that of the first change amount. Left and right torque transition control means for changing by an amount (for example, second change amounts Δ2, Δ2 ′ in an embodiment described later),
In the motor control device, when the left-right torque transition control means changes the torque of the motor connected to the other wheel by the second change amount, the slip acquisition means causes an excess slip on the other wheel. When it is acquired, only the third change amount (for example, the third change amount Δ3 in the embodiment described later) from the torque obtained by changing the torque of the motor connected to the other wheel by the second change amount is obtained. And a front-rear torque transition control means for changing the torque of the second drive device by a fourth change amount (for example, a fourth change amount Δ4 in an embodiment described later) whose sign is opposite to that of the third change amount. And
The motor controller is
The absolute values of the first change amount and the second change amount are substantially the same,
The absolute values of the third change amount and the fourth change amount are substantially the same,
The absolute value of the third change amount is substantially the same as the absolute value of the second change amount .

The invention according to claim 2
A first drive wheel that is one of a front wheel (for example, a front wheel Wf in a later-described embodiment) and a rear wheel (for example, a rear wheel Wr in a later-described embodiment) of a vehicle (for example, a vehicle 3 in a later-described embodiment). A first driving device (for example, a rear wheel driving device 1 in an embodiment described later) for driving (for example, a rear wheel Wr in an embodiment described later);
A second drive device (for example, a front wheel drive device 6 in an embodiment described later) that drives a second drive wheel (for example, a front wheel Wf in an embodiment described later) which is the other of the front wheel and the rear wheel. ,
The first driving device includes a left electric motor (for example, a first electric motor 2A in an embodiment described later) connected to a left wheel of the vehicle (for example, a left rear wheel LWr in an embodiment described later), and a right side of the vehicle. A right motor (for example, a second motor 2B in an embodiment described later) connected to a wheel (for example, a right rear wheel RWr in an embodiment described later), and an electric motor that controls the torque of the left motor and the torque of the right motor A vehicle drive device having a control device (for example, a control device 8 in an embodiment described later),
The vehicle drive device includes slip acquisition means (for example, a slip acquisition device 80 in an embodiment described later) for acquiring that an excess slip, which is a predetermined slip or more, has occurred on the left wheel or the right wheel.
The motor controller is
When the slip acquisition means acquires that the excess slip has occurred on either the left wheel or the right wheel, the torque of the motor connected to the one wheel is changed to a first change amount (for example, The first change amount Δ1, Δ1 ′ in the later-described embodiment is changed, and the torque of the motor connected to the other wheel is changed to a second change amount (for example, described later) opposite in sign to the first change amount. Left and right torque transition control to change by the second change amount Δ2, Δ2 ′) in the embodiment,
When changing the torque of the electric motor to be connected before SL other wheel by the second variation amount, when the slip acquisition means has acquired the excess slip to the other wheel occurs, the other wheel Is changed from the torque obtained by changing the torque of the motor connected to the second change amount by a third change amount (for example, a third change amount Δ3 in an embodiment described later), and the torque of the second drive device is changed. Front-rear torque transition control for changing the third change amount by a fourth change amount (for example, a fourth change amount Δ4 in an embodiment described later) opposite in sign.
Run
The motor control device preferentially executes the left-right torque transition control over the front-rear torque transition control ,
The motor control device prohibits the left-right torque transition control and executes only the front-rear torque transition control when the slip acquisition means acquires that an excess slip has occurred simultaneously on the left wheel and the right wheel. It is characterized by doing.

According to the first aspect of the present invention, when an excess slip occurs on any one of the left wheel and the right wheel, the torque of the motor connected to the wheel where the excess slip has occurred is the first change amount. By reducing the slip, while reducing the slip, the torque of the motor connected to the wheel on the opposite side to the slip wheel (the other wheel) is increased by the second change amount, and the torque of one wheel is reduced. It is possible to compensate. Accordingly, sufficient driving torque according to the driver's request can be transmitted to the road surface even on the split μ road, etc., so that traveling performance can be maintained.
Further, when the torque of the motor connected to the other wheel is increased by the second change amount and an excessive slip occurs in the other wheel, the torque of the motor connected to the other wheel is changed to the third change. By reducing the amount by the amount, while reducing the slip, the torque of the second drive device is increased by the fourth change amount to compensate for the decrease in the torque of the first drive device, so that the total torque of the vehicle, that is, the first drive The total torque of the device and the second drive device can be maintained.
Further, by executing the left-right torque transition control first (priority) over the front-rear torque transition control, it is possible to extend the time for maintaining the total torque of the first drive device. And it becomes possible to maintain the torque balance of a 2nd drive device longer.

Further , since the absolute values of the first change amount and the second change amount are substantially the same, the total torque generated in the first drive device during the left-right torque shift control can be maintained substantially the same, and the third change amount is Since the absolute value of the fourth change amount is substantially the same, the total torque of the vehicle can be maintained substantially the same during the front-rear torque transition control.

Furthermore , since the absolute value of the third change amount is substantially the same as the absolute value of the second change amount, before increasing the torque of the motor connected to the other wheel by the second change amount, Since no slip occurred, setting the absolute value of the third change amount to be substantially the same as the second change amount can eliminate the excess slip of the other wheel with the minimum required change amount. Is possible.

According to the second aspect of the present invention, when an excess slip occurs on one of the left wheel and the right wheel, the torque of the motor connected to the wheel where the excess slip has occurred is the first change amount. By reducing the slip, while reducing the slip, the torque of the motor connected to the wheel on the opposite side to the slip wheel (the other wheel) is increased by the second change amount, and the torque of one wheel is reduced. It is possible to compensate. Accordingly, sufficient driving torque according to the driver's request can be transmitted to the road surface even on the split μ road, etc., so that traveling performance can be maintained.
Further, when the torque of the motor connected to the other wheel is increased by the second change amount and an excessive slip occurs in the other wheel, the torque of the motor connected to the other wheel is changed to the third change. By reducing the amount by the amount, while reducing the slip, the torque of the second drive device is increased by the fourth change amount to compensate for the decrease in the torque of the first drive device, so that the total torque of the vehicle, that is, the first drive The total torque of the device and the second drive device can be maintained.
Further, by executing the left-right torque transition control first (priority) over the front-rear torque transition control, it is possible to extend the time for maintaining the total torque of the first drive device. And it becomes possible to maintain the torque balance of a 2nd drive device longer.

Also , if excessive slip occurs on the left and right wheels at the same time, neither the left motor nor the right motor can increase the absolute value of the torque. By shifting to, the slip of the left wheel and the right wheel can be eliminated more quickly.

1 is a block diagram showing a schematic configuration of a hybrid vehicle that is an embodiment of a vehicle on which a vehicle drive device according to the present invention can be mounted. It is a longitudinal cross-sectional view of one Embodiment of a rear-wheel drive device. FIG. 3 is a partially enlarged view of the rear wheel drive device shown in FIG. 2. It is the table | surface which described the relationship between the front-wheel drive device and rear-wheel drive device in a vehicle state with the drive state of the electric motor. It is a speed alignment chart of the rear-wheel drive device in a stop. It is a speed alignment chart of the rear-wheel drive device at the time of forward low vehicle speed. It is a speed alignment chart of the rear-wheel drive device at the time of forward vehicle speed. It is a speed alignment chart of the rear-wheel drive device at the time of deceleration regeneration. It is a speed alignment chart of the rear-wheel drive device at the time of forward high vehicle speed. It is a speed alignment chart of the rear-wheel drive device at the time of reverse drive. It is a timing chart in vehicle travel. It is a figure which shows the wheel rotation speed and motor torque in motor traction control control. It is a figure which shows the control flow of motor traction control control in case an electric motor is powering. It is a figure which shows the control flow of motor traction control control in case the electric motor is regenerating. It is a figure explaining right-and-left torque shift control when acceleration slip occurs in a left rear wheel. It is a figure which shows the command motor torque of the 1st and 2nd electric motor before and behind the left-right torque transition control when acceleration slip generate | occur | produces in a left rear wheel. It is a figure explaining the left-right torque transfer control when the deceleration slip generate | occur | produces in the left rear wheel. It is a figure which shows the command motor torque of the 1st and 2nd electric motor before and after the left-right torque transition control when the deceleration slip generate | occur | produces in the left rear wheel. It is a figure which shows the control flow of left-right torque transfer control. It is the schematic which shows the drive torque of each part of 1st Embodiment, (a) is before a left-right torque transfer control, (b) is after a left-right torque transfer control, (c) is the schematic after a front-back torque transfer control. . It is a figure which shows the command motor torque of the 1st and 2nd electric motor before and after the left-right torque transfer control of 1st Embodiment, and before and after the torque transfer control. It is a figure which shows the control flow of the back-and-forth torque transfer control of 1st Embodiment. It is the schematic which shows the drive torque of each part which concerns on the modification 1-1 of 1st Embodiment, (a) is before left-right torque transfer control, (b) is after left-right torque transfer control, (c) is front-back torque transfer. It is the schematic after control. It is the schematic which shows the drive torque of each part which concerns on modification 1-2 of 1st Embodiment, (a) is before left-right torque transfer control, (b) is after left-right torque transfer control, (c) is front-back torque transfer. It is the schematic after control. It is the schematic which shows the drive torque of each part of 2nd Embodiment, (a) is before a left-right torque transfer control, (b) is after a left-right torque transfer control, (c) is the schematic after a front-rear torque transfer control. . It is a figure which shows the command motor torque of the 1st and 2nd electric motor before and after the left-right torque transfer control of 2nd Embodiment, and before and after the torque transfer control. It is the schematic which shows the drive torque of each part which concerns on modification 2-1 of 2nd Embodiment, (a) is before left-right torque transfer control, (b) is after left-right torque transfer control, (c) is front-back torque transfer. It is the schematic after control. It is the schematic which shows the drive torque of each part which concerns on modification 2-2 of 2nd Embodiment, (a) is before left-right torque transfer control, (b) is after left-right torque transfer control, (c) is front-back torque transfer. It is the schematic after control. It is a figure which shows the command motor torque of the 1st and 2nd electric motor before and after the left-right torque transfer control of 3rd Embodiment, and before and after the torque transfer control. It is a figure which shows the control flow of the back-and-forth torque transfer control of 3rd Embodiment.

First, an embodiment of a vehicle drive device according to the present invention will be described with reference to FIGS.
The vehicle drive device according to the present invention is used, for example, in a vehicle having a drive system as shown in FIG.
A vehicle 3 shown in FIG. 1 is a hybrid vehicle having a driving device 6 (hereinafter referred to as a front wheel driving device) as a second driving device in which an internal combustion engine 4 and an electric motor 5 are connected in series at the front portion of the vehicle. While the power of the front wheel drive device 6 is transmitted to the front wheels Wf via the transmission 7, the drive device 1 (hereinafter referred to as rear wheel) as a first drive device provided at the rear of the vehicle separately from the front wheel drive device 6 is provided. The power of the driving device is transmitted to the rear wheels Wr (RWr, LWr). The electric motor 5 of the front wheel drive device 6 and the first and second electric motors 2A and 2B of the rear wheel drive device 1 on the rear wheel Wr side are connected to the battery 9, and supply power from the battery 9 and energy to the battery 9 Regeneration is possible. Reference numeral 8 denotes a control device for performing various controls of the entire vehicle.

  FIG. 2 is a longitudinal sectional view of the entire rear wheel drive device 1. In FIG. 2, 10A and 10B are left and right axles on the rear wheel Wr side of the vehicle 3, and are coaxial in the vehicle width direction. Is arranged. The reduction gear case 11 of the rear wheel drive device 1 is formed in a substantially cylindrical shape, and includes therein first and second electric motors 2A and 2B for driving an axle, and the first and second electric motors 2A and 2B. The first and second planetary gear type speed reducers 12A and 12B that decelerate the drive rotation of these are arranged coaxially with the axles 10A and 10B. The first motor 2A functions as a left motor that drives the left rear wheel LWr, the second motor 2B functions as a right motor that drives the right rear wheel RWr, and the first motor 2A and the first planetary gear speed reducer 12A The second electric motor 2 </ b> B and the second planetary gear type speed reducer 12 </ b> B are arranged symmetrically in the vehicle width direction in the speed reducer case 11. The rear wheel Wr is provided with wheel speed sensors 13A and 13B for detecting the number of rotations of the left rear wheel LWr and the right rear wheel RWr, and the left rear wheel LWr and the right rear wheel RWr are more than a predetermined acceleration slip or A slip acquisition device 80 capable of acquiring the occurrence of a deceleration slip (hereinafter, sometimes simply referred to as “slip”) is provided.

  The stators 14A and 14B of the first and second electric motors 2A and 2B are respectively fixed inside the left and right ends of the speed reducer case 11, and the annular rotors 15A and 15B are rotatable on the inner peripheral sides of the stators 14A and 14B. Is arranged. Cylindrical shafts 16A and 16B surrounding the outer periphery of the axles 10A and 10B are coupled to the inner peripheral portions of the rotors 15A and 15B, and the cylindrical shafts 16A and 16B are decelerated so as to be coaxially rotatable with the axles 10A and 10B. The machine case 11 is supported by end walls 17A and 17B and intermediate walls 18A and 18B via bearings 19A and 19B. Further, on the outer periphery of one end side of the cylindrical shafts 16A and 16B and on the end walls 17A and 17B of the speed reducer case 11, the rotational speeds of the rotors 15A and 15B are controlled by the controller of the first and second electric motors 2A and 2B ( Resolvers 20A and 20B for feeding back to (not shown) are provided.

  The first and second planetary gear speed reducers 12A and 12B include sun gears 21A and 21B, a plurality of planetary gears 22A and 22B meshed with the sun gear 21, and planetary carriers 23A that support these planetary gears 22A and 22B. , 23B and ring gears 24A, 24B meshed with the outer peripheral sides of the planetary gears 22A, 22B. The driving forces of the first and second electric motors 2A, 2B are input from the sun gears 21A, 21B, and the planetary carriers 23A, 23B Is output to the axles 10A and 10B.

  The sun gears 21A and 21B are formed integrally with the cylindrical shafts 16A and 16B. Further, for example, as shown in FIG. 3, the planetary gears 22A and 22B include large-diameter first pinions 26A and 26B that are directly meshed with the sun gears 21A and 21B, and a second pinion having a smaller diameter than the first pinions 26A and 26B. The first and second pinions 26A and 26B and the second pinions 27A and 27B are integrally formed in a state of being coaxially and offset in the axial direction. The planetary gears 22A and 22B are supported by the planetary carriers 23A and 23B, and the planetary carriers 23A and 23B are supported so as to be integrally rotatable with the axially inner ends extending inward in the radial direction and being spline-fitted to the axles 10A and 10B. Along with the bearings 33A and 33B, the intermediate walls 18A and 18B are supported.

  The intermediate walls 18A and 18B separate the motor housing space for housing the first and second motors 2A and 2B from the speed reducer space for housing the first and second planetary gear speed reducers 12A and 12B. Are bent so that the axial distance between them increases toward the inner diameter side. Bearings 33A and 33B for supporting the planetary carriers 23A and 23B are disposed on the inner diameter side of the intermediate walls 18A and 18B and on the first and second planetary gear speed reducers 12A and 12B, and the intermediate walls 18A and 18B are disposed. Bus rings 41A and 41B for the stators 14A and 14B are arranged on the outer diameter side of 18B and the first and second electric motors 2A and 2B (see FIG. 2).

  The ring gears 24A and 24B are disposed opposite to each other at gears 28A and 28B whose inner peripheral surfaces are meshed with the second pinions 27A and 27B having a small diameter, and smaller in diameter than the gear parts 28A and 28B, at an intermediate position of the speed reducer case 11. Small-diameter portions 29A and 29B, and connecting portions 30A and 30B that connect the axially inner ends of the gear portions 28A and 28B and the axially outer ends of the small-diameter portions 29A and 29B in the radial direction. Yes. In the case of this embodiment, the maximum radii of the ring gears 24A and 24B are set to be smaller than the maximum distance from the center of the axles 10A and 10B of the first pinions 26A and 26B. The small diameter portions 29A and 29B are spline-fitted to an inner race 51 of a one-way clutch 50, which will be described later, and the ring gears 24A and 24B are configured to rotate integrally with the inner race 51 of the one-way clutch 50.

  More specifically, the pistons 37A and 37B have first piston walls 63A and 63B and second piston walls 64A and 64B in the axial direction, and the piston walls 63A, 63B, 64A and 64B are cylindrical. Are connected by inner peripheral walls 65A and 65B. Therefore, an annular space that opens radially outward is formed between the first piston walls 63A and 63B and the second piston walls 64A and 64B. This annular space is formed on the inner periphery of the outer wall of the cylinder chambers 38A and 38B. It is partitioned in the axial direction left and right by partition members 66A and 66B fixed to the surface. A space between the left and right dividing walls 39 of the reduction gear case 11 and the second piston walls 64A and 64B is a first working chamber S1 into which high-pressure oil is directly introduced, and between the partition members 66A and 66B and the first piston walls 63A and 63B. Is a second working chamber S2 that is electrically connected to the first working chamber S1 through through holes formed in the inner peripheral walls 65A and 65B. The second piston walls 64A and 64B and the partition members 66A and 66B are electrically connected to the atmospheric pressure.

  In the hydraulic brakes 60A and 60B, oil is introduced into the first working chamber S1 and the second working chamber S2 from a hydraulic circuit (not shown) and acts on the first piston walls 63A and 63B and the second piston walls 64A and 64B. The fixed plates 35A and 35B and the rotating plates 36A and 36B can be pressed against each other by the pressure of. Therefore, since the large pressure receiving area can be gained by the first and second piston walls 63A, 63B, 64A, 64B on the left and right in the axial direction, the fixing plates 35A, 35B A large pressing force against the rotating plates 36A and 36B can be obtained.

  In the case of the hydraulic brakes 60A and 60B, the fixed plates 35A and 35B are supported by the outer diameter side support portion 34 extending from the reduction gear case 11, while the rotation plates 36A and 36B are supported by the ring gears 24A and 24B. When the plates 35A, 35B, 36A, and 36B are pressed by the pistons 37A and 37B, the frictional engagement between the plates 35A, 35B, 36A, and 36B causes a braking force to act on the ring gears 24A and 24B, and is fixed (locked). When the fastening by the pistons 37A and 37B is released from this state, the ring gears 24A and 24B are allowed to freely rotate.

  That is, the hydraulic brakes 60A and 60B lock the ring gears 24A and 24B at the time of engagement, make the power transmission path between the first and second electric motors 2A and 2B and the rear wheel Wr connectable to the power transmission, and the ring gear at the time of release. The rotation of 24A and 24B is permitted, and the power transmission path is set to a cut-off state where power cannot be transmitted.

  Also, a space is secured between the coupling portions 30A and 30B of the ring gears 24A and 24B facing each other in the axial direction, and only power in one direction is transmitted to the ring gears 24A and 24B in the space to transmit power in the other direction. A one-way clutch 50 is arranged to be shut off. The one-way clutch 50 has a large number of sprags 53 interposed between an inner race 51 and an outer race 52. The inner race 51 is connected to the small diameter portions 29A, 29B of the ring gears 24A, 24B by spline fitting. It is configured to rotate integrally. The outer race 52 is positioned by the inner diameter side support portion 40 and is prevented from rotating. The one-way clutch 50 is configured to engage and lock the rotation of the ring gears 24A and 24B when the vehicle 3 moves forward with the power of the first and second electric motors 2A and 2B. More specifically, the one-way clutch 50 is used when torque in the forward direction (rotation direction when the vehicle 3 is advanced) on the first and second electric motors 2A, 2B side is input to the rear wheel Wr side. When engaged and capable of transmitting power, and when reverse torques on the first and second electric motors 2A and 2B sides are input to the rear wheel Wr, they are disengaged and cannot transmit power. When the forward torque on the Wr side is input to the first and second electric motors 2A, 2B, the power is not engaged and power transmission is impossible, and the reverse torque on the rear wheel Wr side is the first and second torques. 2 When engaged with the electric motors 2A and 2B, they are engaged to transmit power. In other words, the one-way clutch 50 allows one-way rotation of the ring gears 24A and 24B by the reverse torque of the first and second motors 2A and 2B when not engaged, and the first and second motors when engaged. The reverse rotation of the ring gears 24A and 24B by the forward torque of 2A and 2B is restricted. The reverse torque refers to torque in a direction that increases reverse rotation or torque in a direction that decreases forward rotation.

  Thus, in the rear wheel drive device 1 of the present embodiment, the one-way clutch 50 and the hydraulic brakes 60A and 60B are provided in parallel on the power transmission path between the first and second electric motors 2A and 2B and the rear wheel Wr. ing. It is not necessary to provide two hydraulic brakes 60A and 60B, and only one hydraulic brake may be provided and the other space may be used as a breather chamber.

  Here, the control device 8 (see FIG. 1) is a control device for performing various controls of the entire vehicle. The control device 8 rotates the left and right rear wheels LWr and RWr acquired from the wheel speed sensors 13A and 13B. The number, the rotation speed of the first and second electric motors 2A and 2B acquired from the resolvers 20A and 20B, the steering angle, the accelerator pedal opening AP, the shift position, the state of charge SOC in the battery 9, the oil temperature, and the like are input. The control device 8 outputs a signal for controlling the internal combustion engine 4, a signal for controlling the first and second electric motors 2A, 2B, and the like.

  FIG. 4 shows the relationship between the front wheel drive device 6 and the rear wheel drive device 1 in each vehicle state together with the operating states of the first and second electric motors 2A and 2B. In the figure, the front unit represents the front wheel drive device 6, the rear unit represents the rear wheel drive device 1, the rear motor represents the first and second electric motors 2A and 2B, OWC represents the one-way clutch 50, and BRK represents the hydraulic brakes 60A and 60B. 5 to 10 show speed nomographs in each state of the rear-wheel drive device 1. The LMOT is the first motor 2A, the RMOT is the second motor 2B, and the left S and C are the first motor 2A. The sun gear 21A of the first planetary gear speed reducer 12A connected, the planetary carrier 23A connected to the axle 10A, the planetary gear 22A, and the right S and C are the second planetary gear speed reducer connected to the second electric motor 2B. The 12B sun gear 21B, the planetary carrier 23B connected to the axle 10B, the planetary gears 22B, R are ring gears 24A, 24B, BRK is the hydraulic brakes 60A, 60B, and OWC is the one-way clutch 50. In the following description, the rotation direction of the sun gears 21A and 21B when the vehicle is advanced by the first and second electric motors 2A and 2B is assumed to be the forward direction. Also, in the figure, from the stationary state, the upper direction is forward rotation and the lower side is reverse direction rotation, and the arrows indicate forward torque and downward direction indicates reverse torque.

  While the vehicle is stopped, neither the front wheel drive device 6 nor the rear wheel drive device 1 is driven. Therefore, as shown in FIG. 5, the first and second electric motors 2A, 2B of the rear wheel drive device 1 are stopped, and the axles 10A, 10B are also stopped. Therefore, torque acts on any of the elements. Not. At this time, the hydraulic brakes 60A and 60B are released (OFF). The one-way clutch 50 is not engaged because the first and second electric motors 2A and 2B are not driven (OFF).

  Then, after the key position is turned ON, the rear wheel drive device 1 performs the rear wheel drive at the forward low vehicle speed with good motor efficiency such as EV start and EV cruise. As shown in FIG. 6, when the first and second electric motors 2A and 2B are power-driven so as to rotate in the forward direction, forward torque is applied to the sun gears 21A and 21B. At this time, as described above, the one-way clutch 50 is engaged and the ring gears 24A and 24B are locked. As a result, the planetary carriers 23A and 23B rotate in the forward direction and travel forward. In addition, traveling resistance from the axles 10A and 10B acts on the planetary carriers 23A and 23B in the reverse direction. As described above, when the vehicle 3 is started, the key position is turned ON to increase the torque of the first and second electric motors 2A and 2B, whereby the one-way clutch 50 is mechanically engaged and the ring gears 24A and 24B are locked. The

  At this time, the hydraulic brakes 60A and 60B are controlled in a weakly engaged state. The weak engagement means a state in which power can be transmitted but is fastened with a weak fastening force with respect to the fastening force of the hydraulic brakes 60A and 60B. When the forward torque of the first and second electric motors 2A and 2B is input to the rear wheel Wr, the one-way clutch 50 is engaged and power can be transmitted only by the one-way clutch 50. The hydraulic brakes 60A and 60B provided in parallel with the motor 50 are also weakly engaged and the first and second motors 2A and 2B and the rear wheel Wr are connected to each other, so that the first and second motors 2A and 2B are connected. Even when the forward torque input from the side temporarily decreases and the one-way clutch 50 enters the disengaged state, the first and second electric motors 2A, 2B and the rear wheel Wr are powered. It is possible to suppress the transmission failure. Further, it is not necessary to control the number of revolutions for connecting the first and second electric motors 2A, 2B and the rear wheel Wr when shifting to deceleration regeneration, which will be described later. By making the fastening force of the hydraulic brakes 60A, 60B when the one-way clutch 50 is engaged smaller than the fastening force of the hydraulic brakes 60A, 60B when the one-way clutch 50 is not engaged, the hydraulic brake 60A , Energy consumption for fastening 60B is reduced.

  When the vehicle speed increases from the forward low vehicle speed travel to the forward vehicle speed travel with good engine efficiency, the rear wheel drive by the rear wheel drive device 1 changes to the front wheel drive by the front wheel drive device 6. As shown in FIG. 7, when the power running drive of the first and second electric motors 2A, 2B is stopped, forward torque to travel forward from the axles 10A, 10B acts on the planetary carriers 23A, 23B. As described above, the one-way clutch 50 is disengaged. Also at this time, the hydraulic brakes 60A and 60B are controlled in a weakly engaged state.

  When the first and second electric motors 2A, 2B are to be regeneratively driven from the state of FIG. 6 or FIG. 7, as shown in FIG. 8, the planetary carriers 23A, 23B are in the order of continuing forward travel from the axles 10A, 10B. Since the direction torque acts, the one-way clutch 50 is disengaged as described above. At this time, the hydraulic brakes 60A and 60B are controlled to the engaged state (ON). Accordingly, the ring gears 24A and 24B are fixed, and the regenerative braking torque in the reverse direction is applied to the first and second electric motors 2A and 2B, and the first and second electric motors 2A and 2B are decelerated and regenerated. Thus, when the forward torque on the rear wheel Wr side is input to the first and second electric motors 2A, 2B, the one-way clutch 50 is disengaged, and power cannot be transmitted only by the one-way clutch 50. There is a state in which power can be transmitted by fastening hydraulic brakes 60A, 60B provided in parallel with the one-way clutch 50 and connecting the first and second motors 2A, 2B and the rear wheel Wr side. In this state, the energy of the vehicle 3 can be regenerated by controlling the first and second electric motors 2A and 2B to the regenerative drive state.

  Subsequently, at the time of acceleration, the four-wheel drive of the front wheel drive device 6 and the rear wheel drive device 1 is performed, and the rear wheel drive device 1 is in the same state as at the forward low vehicle speed shown in FIG.

  At the forward high vehicle speed, the front wheel drive device 6 performs front wheel drive, but typically the first and second electric motors 2A and 2B are stopped.

  As shown in FIG. 9, when the first and second electric motors 2A, 2B stop the power running drive, the forward torque to travel forward from the axles 10A, 10B acts on the planetary carriers 23A, 23B. As described above, the one-way clutch 50 is disengaged. At this time, the rotation loss of the sun gears 21A, 21B and the first and second electric motors 2A, 2B is input as resistance to the sun gears 21A, 21B, and the rotation loss of the ring gears 24A, 24B occurs in the ring gears 24A, 24B.

  At this time, the hydraulic brakes 60A and 60B are controlled to the released state (OFF). Accordingly, the accompanying rotation of the first and second electric motors 2A and 2B is prevented, and the first and second electric motors 2A and 2B are prevented from over-rotating at a high vehicle speed by the front wheel drive device 6.

  During reverse travel, as shown in FIG. 10, when the first and second electric motors 2A, 2B are driven in reverse power running, reverse torque is applied to the sun gears 21A, 21B. At this time, as described above, the one-way clutch 50 is disengaged.

  At this time, the hydraulic brakes 60A and 60B are controlled to be engaged. Accordingly, the ring gears 24A and 24B are fixed, and the planetary carriers 23A and 23B rotate in the reverse direction to travel backward. Note that traveling resistance from the axles 10A and 10B acts in the forward direction on the planetary carriers 23A and 23B. Thus, when the reverse torque on the first and second electric motors 2A, 2B side is input to the rear wheel Wr, the one-way clutch 50 is disengaged, and power transmission is impossible only by the one-way clutch 50. However, the hydraulic brakes 60A and 60B provided in parallel with the one-way clutch 50 are fastened, and the first and second electric motors 2A and 2B and the rear wheel Wr are kept in a connected state so that power can be transmitted. The vehicle 3 can be moved backward by the torque of the first and second electric motors 2A and 2B.

  Thus, the rear wheel drive device 1 is configured so that the traveling state of the vehicle, in other words, whether the rotation direction of the first and second motors 2A, 2B is the forward direction or the reverse direction, and the first and second motors 2A, 2B side. Engagement / release of the hydraulic brakes 60A and 60B is controlled according to which power is input from the wheel Wr side, and the engagement force is adjusted even when the hydraulic brakes 60A and 60B are engaged.

  FIG. 11 shows an electric oil pump when EV starts, EV acceleration, ENG acceleration, deceleration regeneration, medium-speed ENG cruise, ENG + EV acceleration, high-speed ENG cruise, deceleration regeneration, stop, reverse, and stop when the vehicle is stopped. 70 (EOP), one-way clutch 50 (OWC), hydraulic brakes 60A, 60B (BRK).

  First, the one-way clutch 50 is disengaged (OFF) and the hydraulic brakes 60A and 60B are released (OFF) until the key position is turned ON and the shift is changed from the P range to the D range and the accelerator pedal is depressed. To maintain. From there, when the accelerator pedal is stepped on, EV start and EV acceleration are performed by the rear wheel drive device 1 by rear wheel drive (RWD). At this time, the one-way clutch 50 is engaged (ON), and the hydraulic brakes 60A and 60B are in a weakly engaged state. When the vehicle speed changes from the low vehicle speed range to the medium vehicle speed range and changes from the rear wheel drive to the front wheel drive, ENG traveling (FWD) is performed by the internal combustion engine 4. At this time, the one-way clutch 50 is disengaged (OFF), and the hydraulic brakes 60A and 60B are maintained as they are (weakly engaged state). During deceleration regeneration such as when the brake is stepped on, the hydraulic brakes 60A and 60B are engaged (ON) while the one-way clutch 50 remains disengaged (OFF). During a medium speed cruise by the internal combustion engine 4, the state is the same as the above-described ENG traveling. Subsequently, when the accelerator pedal is further depressed to change from front wheel drive to four wheel drive (AWD), the one-way clutch 50 is engaged (ON) again. When the vehicle speed reaches from the middle vehicle speed range to the high vehicle speed range, the ENG traveling (FWD) by the internal combustion engine 4 is performed again. At this time, the one-way clutch 50 is disengaged (OFF), the hydraulic brakes 60A, 60B are released (OFF), and the first and second electric motors 2A, 2B are stopped. And at the time of deceleration regeneration, it will be in the state similar to the time of the deceleration regeneration mentioned above. When the vehicle stops, the one-way clutch 50 is disengaged (OFF) and the hydraulic brakes 60A and 60B are released (OFF).

  Subsequently, during reverse travel, the hydraulic brakes 60A and 60B are engaged (ON) while the one-way clutch 50 remains disengaged (OFF). When the vehicle stops, the one-way clutch 50 is disengaged (OFF) and the hydraulic brakes 60A and 60B are released (OFF).

<Motor traction control>
As described above, the control device 8 controls the front wheel drive device 6 and the rear wheel drive device 1 in accordance with the state of each vehicle, but particularly with respect to the rear wheel drive device 1, the wheel rotation speed of the rear wheel Wr. Alternatively, it functions as an electric motor control device having a motor traction control system (M-TCS) that performs motor traction control control based on the motor rotational speeds of the first and second electric motors 2A, 2B. The torque generated by the electric motors 2A and 2B is controlled, and the rotation state of the rear wheels LWr and RWr is controlled.

(Motor traction control control during power running)
For example, as shown in FIG. 12, in motor traction control control when the rear wheels LWr and RWr are driven by the first and second electric motors 2A and 2B that are driven by power running, the slip acquisition device 80 includes a wheel speed sensor. The left and right wheel rotation speeds LR and RR acquired by 13A and 13B are compared with the upper limit slip determination threshold rotation speeds LVmax and RVmax of the left and right wheels LWr and RWr obtained based on the wheel target rotation speed (not shown). As shown in a), when both the left and right wheel rotation speeds LR and RR are equal to or lower than the upper limit slip determination threshold rotation speeds LVmax and RVmax (LR ≦ LVmax and RR ≦ RVmax), acceleration slip occurs in the rear wheels LWr and RWr. The control device 8 determines that it has not occurred and the first and second control devices 8 satisfy the driver request torques L_REQ and R_REQ. Motivation 2A, 2B to a command motor torque (power running driving torque) L_CMD, to output R_CMD (L_CMD = L_REQ, R_CMD = R_REQ). Here, the driver request torques L_REQ and R_REQ are substantially the same positive value (L_REQ = R_REQ> 0).

  When the slip acquisition device 80 acquires that the wheel rotational speeds LR and RR are larger than the upper limit slip determination threshold rotational speeds LVmax and RVmax as shown in (b) (LR> LVmax or RR> RVmax), it is determined that an acceleration slip (excess slip) exceeding a predetermined value has occurred in the rear wheels Wr (LWr, RWr). At this time, the control device 8 sets the command motor torques L_CMD and R_CMD of the first electric motor 2A and / or the second electric motor 2B connected to the left wheel LWr and / or the right rear wheel RWr where the acceleration slip has occurred to the upper limit slip. It is changed by the first change amount Δ1 determined based on the acceleration slip amounts LR−LVmax and RR−RVmax which are the differences between the determination threshold rotation speeds LVmax and RVmax and the wheel rotation speeds LR and RR (L_CMD = L_REQ + Δ1, R_CMD = R_REQ + Δ1). Here, the first change amount Δ1 is set to a negative number (Δ1 <0), and the command motor torques L_CMD and R_CMD decrease by the absolute value of the first change amount Δ1. That is, the absolute values of the command motor torques L_CMD and R_CMD are reduced by the absolute value of the first change amount Δ1.

  When the slip acquisition device 80 acquires again that the wheel rotational speeds LR and RR are equal to or lower than the upper limit slip determination threshold rotational speeds LVmax and RVmax as shown in (c) (LR ≦ LVmax and RR ≦ RVmax), it is determined that the acceleration slip of the rear wheels LWr and RWr has been settled, and the control device 8 outputs the command motor torques L_CMD and R_CMD to the first and second motors 2A and 2B so as to satisfy the driver request torques L_REQ and R_REQ. (L_CMD = L_REQ, R_CMD = R_REQ).

  Here, the flow of the motor traction control control will be described with reference to FIG. 13 as an example in which the left rear wheel LWr is driven by the first electric motor 2A driven by powering. First, the left rear wheel rotational speed LR is acquired by the wheel speed sensor 13A (S1), and then the upper limit slip determination threshold rotational speed LVmax is calculated based on the wheel target rotational speed (not shown) (S2). Then, the slip acquisition device 80 compares the left rear wheel rotation speed LR and the upper limit slip determination threshold rotation speed LVmax to determine whether acceleration slip has occurred in the left rear wheel LWr (S3). As a result, if the left rear wheel rotation speed LR is equal to or lower than the upper limit slip determination threshold rotation speed LVmax (LR ≦ LVmax), it is determined that acceleration slip has not occurred or is within an allowable range of acceleration slip, and processing is performed. finish. On the other hand, if the left rear wheel rotational speed LR is larger than the upper limit slip determination threshold rotational speed LVmax (LR> LVmax), it is determined that an unacceptable predetermined acceleration slip has occurred, and the first rear wheel LWr connected to the first rear wheel LWr is determined. A command motor torque amount (first change amount Δ1) to be reduced by the electric motor 2A is calculated based on the acceleration slip amount LR-LVmax (S4). Then, the command motor torque L_CMD of the first motor 2A is changed by the first change amount Δ1 (<0), that is, the absolute value of the command motor torque L_CMD of the first motor 2A is changed to the absolute value of the first change amount Δ1. Decrease by the amount (S5). As a result, the acceleration slip state of the left rear wheel LWr can be quickly resolved, energy consumption can be suppressed, and the unstable state of the vehicle 3 can be resolved.

(Motor traction control during regeneration)
So far, the motor traction control control in the case where the rear wheels LWr and RWr are driven by the first and second electric motors 2A and 2B that are driven by power is described, but the first and second electric motors 2A and 2A that are driven by regeneration are described. Even when the rear wheels LWr and RWr are braked by 2B, it is possible to perform motor traction control control. The motor traction control control when the first and second electric motors 2A and 2B are regeneratively driven is the motor traction control control when the first and second electric motors 2A and 2B are power-driven (see FIG. 12), and is not shown here.

  In the motor traction control control when the first and second electric motors 2A and 2B are both regeneratively driven, the slip acquisition device 80 is obtained based on the left and right wheel rotation speeds LR and RR and the wheel target rotation speed. The lower limit slip determination threshold rotational speeds LVmin and RVmin of the left and right wheels LWr and RWr are compared, and when both the left and right wheel rotational speeds LR and RR are equal to or higher than the lower limit slip determination threshold rotational speeds LVmin and RVmin (LR ≧ LVmin, And RR ≧ RVmin), it is determined that no deceleration slip has occurred in the rear wheels LWr, RWr, and the control device 8 instructs the first and second motors 2A, 2B to satisfy the command motor torque so as to satisfy the driver request torques L_REQ, R_REQ. (Regenerative drive torque) L_CMD and R_CMD are output (L_CMD = L_REQ, R_C D = R_REQ). Here, the driver request torques L_REQ and R_REQ are substantially the same negative value (L_REQ = R_REQ <0).

  On the other hand, when it is acquired that the rear wheel rotational speeds LR and RR are smaller than the lower limit slip determination threshold rotational speeds LVmin and RVmin (LR <LVmin or RR <RVmin), the rear wheel Wr (LWr, RWr) It is determined that a deceleration slip exceeding a predetermined value has occurred. At this time, the control device 8 sets the command motor torques L_CMD and R_CMD of the first electric motor 2A and / or the second electric motor 2B connected to the left rear wheel LWr and / or the right rear wheel RWr where deceleration slip has occurred to the lower limit. The slip determination threshold rotational speed LVmin, RVmin is changed by a first change amount Δ1 ′ determined based on the deceleration slip amount that is the difference between the wheel rotational speeds LR, RR (L_CMD = L_REQ + Δ1 ′, R_CMD = R_REQ + Δ1 ′). Here, the first change amount Δ1 ′ is set to a positive number (Δ1 ′> 0), and the command motor torques L_CMD and R_CMD increase by the absolute value of the first change amount Δ1 ′. That is, the absolute values of the command motor torques L_CMD and R_CMD decrease by the absolute value of the first change amount Δ1 ′.

  Here, the flow of the motor traction control control will be described with reference to FIG. 14, taking as an example a case where the left rear wheel LWr is braked by the first electric motor 2A that is regeneratively driven. First, the left rear wheel rotational speed LR is acquired by the wheel speed sensor 13A (S1 ′), and then the lower limit slip determination threshold rotational speed LVmin is calculated based on the wheel target rotational speed (not shown) (S2 ′). Then, the slip acquisition device 80 compares the left rear wheel rotation speed LR and the lower limit slip determination threshold rotation speed LVmin to determine whether deceleration slip has occurred in the left rear wheel LWr (S3 ′). As a result, if the left rear wheel rotation speed LR is equal to or greater than the lower limit slip determination threshold rotation speed LVmin (LR ≧ LVmin), it is determined that deceleration slip has not occurred or is within an allowable range of deceleration slip. finish. On the other hand, if the left rear wheel rotation speed LR is smaller than the lower limit slip determination threshold rotation speed LVmin (LR <LVmin), it is determined that an unacceptable predetermined deceleration slip (excess slip) has occurred and is connected to the left rear wheel LWr. The command motor torque amount (first change amount Δ1 ′) to be decreased of the first electric motor 2A is calculated based on the deceleration slip amount LVmin−LR (S4 ′). Then, the command motor torque L_CMD of the first motor 2A is changed by the first change amount Δ1 ′ (> 0), that is, the absolute value of the command motor torque L_CMD of the first motor 2A is changed to the first change amount Δ1 ′. Decrease by the absolute value (S5 '). As a result, the deceleration slip state of the left rear wheel LWr can be quickly resolved, energy consumption can be suppressed, and the unstable state of the vehicle 3 can be resolved.

<Right and left torque transition control>
In this way, the command of the first motor 2A and / or the second motor 2B connected to the left rear wheel LWr and / or the right rear wheel RWr in which acceleration slip (deceleration slip) of a predetermined level or more has occurred by the motor traction control control. Since the absolute values of the motor torques L_CMD and R_CMD are reduced from the driver request torques L_REQ and R_REQ by the absolute value of the first change amount Δ1 (Δ1 ′), a sufficient rear wheel driving force (rear wheel braking force is maintained as it is. ) May be difficult to transmit to the road surface.

  Therefore, in the rear wheel drive device 1 of the present invention, when an excess slip that is a predetermined slip or more has occurred on one of the left rear wheel LWr and the right rear wheel RWr, the control device 8 The command motor torques L_CMD and R_CMD of the first or second electric motors 2A and 2B connected to one of the wheels in which the occurrence of the engine is changed by the first change amount Δ1 (Δ1 ′) and the other in which no excess slip has occurred The second change in which the command motor torques L_CMD and R_CMD of the first or second electric motor 2A or 2B connected to the wheel are opposite in sign to the first change amount Δ1 (Δ1 ′) and the absolute value is substantially the same. Left and right torque shift control is performed to control the amount to change by an amount Δ2 (Δ2 ′).

(Left and right torque shift control during power running)
More specifically, as shown in FIG. 15, the first and second power-driven driving is performed on the split μ road where the road friction on the left side of the vehicle 3 is low μ and the road friction on the right side of the vehicle is high μ. A description will be given of left-right torque shift control in a case where a predetermined or higher acceleration slip occurs in the left rear wheel LWr when the rear wheels LWr, RWr are driven by the electric motors 2A, 2B. In addition, before the acceleration slip more than predetermined occurs in the left rear wheel LWr, the first and second electric motors 2A and 2B have the command motor torque (power running drive torque) L_CMD to satisfy the driver request torques L_REQ and R_REQ, Assume that R_CMD is output (L_CMD = L_REQ, R_CMD = R_REQ, L_REQ = R_REQ> 0).

  First, as shown by (1) in FIG. 15 and FIG. 16, the control device 8 determines the command motor torque L_CMD of the first electric motor 2A connected to the left rear wheel LWr in which the acceleration slip has occurred, by motor traction control control. The driver request torque L_REQ is changed by the first change amount Δ1 (L_CMD = L_REQ + Δ1, Δ1 <0). That is, the absolute value of the command motor torque L_CMD is decreased by the absolute value of the first change amount Δ1.

  Then, as indicated by (2), the control device 8 changes the command motor torque R_CMD of the second electric motor 2B connected to the right rear wheel RWr where no acceleration slip is generated, by the left / right torque transition control, to the first change amount. Control is performed so as to change by a second change amount Δ2 having a sign opposite to that of Δ1 and having substantially the same absolute value (R_CMD = R_REQ + Δ2 = R_REQ−Δ1, Δ1 <0 <Δ2, Δ1 = −Δ2). That is, the absolute value of the command motor torque R_CMD is increased by the absolute value of the second change amount Δ2.

  Here, the sum of the command motor torques L_CMD and R_CMD of the first and second electric motors 2A and 2B after the motor traction control control and the left and right torque shift control is (L_REQ + Δ1) + (R_REQ−Δ1) = L_REQ + R_REQ, There is no change from the total value of the command motor torques L_CMD and R_CMD before traction control control and left / right torque shift control (before acceleration slip). That is, a decrease in the driving torque of the left rear wheel LWr can be compensated by an increase in the driving torque of the right rear wheel RWr, and sufficient driving torque according to the driver's request can be transmitted to the road surface even on the split μ road. It becomes possible.

  Note that the difference between the left and right of the command motor torques L_CMD and R_CMD is L_REQ−R_REQ = 0 before motor traction control control and left / right torque transition control (before slip), but after motor traction control control and left / right torque transition control. Since (L_REQ + Δ1) − (R_REQ−Δ1) = 2Δ1, the vehicle 3 generates a counterclockwise yaw moment F. However, the yaw moment F is not particularly a problem because it can be sufficiently tolerated by the driver's steering operation.

(Right and left torque transition control during regeneration)
Next, as shown in FIG. 17, the first and second electric motors 2A are driven to be regenerated on a split μ road where the road friction on the left side of the vehicle 3 is low μ and the road friction on the right side of the vehicle is high μ. The left-right torque shift control when a predetermined or greater deceleration slip occurs in the left rear wheel LWr when the rear wheels LWr and RWr are braked by 2B will be described. Note that before the deceleration slip exceeding a predetermined value occurs in the left rear wheel LWr, the first and second electric motors 2A and 2B have command motor torque (regenerative drive torque) L_CMD to satisfy the driver request torques L_REQ and R_REQ. Assume that R_CMD is output (L_CMD = L_REQ, R_CMD = R_REQ, L_REQ = R_REQ <0).

  First, as indicated by (1) in FIG. 17 and FIG. 18, the control device 8 determines the command motor torque L_CMD of the first electric motor 2A connected to the left rear wheel LWr in which deceleration slip has occurred, by motor traction control control. The driver request torque L_REQ is changed by the first change amount Δ1 ′ (L_CMD = L_REQ + Δ1 ′, Δ1 ′> 0). That is, the absolute value of the command motor torque L_CMD is decreased by the absolute value of the first change amount Δ1.

  Then, as indicated by (2), the control device 8 changes the command motor torque R_CMD of the second electric motor 2B connected to the right rear wheel RWr where no deceleration slip is generated, by the left / right torque transition control, to the first change amount. Control is performed so as to change by a second change amount Δ2 ′ whose sign is opposite to that of Δ1 ′ and whose absolute value is substantially the same (R_CMD = R_REQ + Δ2 ′ = R_REQ−Δ1 ′, Δ2 ′ <0 <Δ1 ′, Δ1 ′ = −Δ2 ′). That is, the absolute value of the command motor torque R_CMD is increased by the absolute value of the second change amount Δ1 ′.

  Here, the sum of the command motor torques L_CMD and R_CMD of the first and second electric motors 2A and 2B after the motor traction control control and the left and right torque shift control is (L_REQ + Δ1 ′) + (R_REQ−Δ1 ′) = L_REQ + R_REQ. There is no change in the total value of the command motor torques L_CMD and R_CMD before the motor traction control control and the left / right torque shift control (before the deceleration slip). That is, a decrease in the braking torque of the left rear wheel LWr can be compensated by an increase in the braking torque of the right rear wheel RWr, and a sufficient braking torque according to the driver's request can be transmitted to the road surface even on the split μ road. It becomes possible.

  Note that the difference between the left and right of the command motor torques L_CMD and R_CMD indicates that the motor traction control control and the left / right torque transition control are L_REQ−R_REQ = 0 before the motor traction control control and the left / right torque transition control (before the deceleration slip). Later, since (L_REQ + Δ1 ′) − (R_REQ−Δ1 ′) = 2Δ1 ′, the vehicle 3 generates a clockwise yaw moment F ′. However, the yaw moment F ′ is not particularly problematic because it can be sufficiently tolerated by the driver's steering operation.

  Here, the flow of the left-right torque transition control will be described with reference to FIG. First, it is determined whether motor traction control control is intervening (S11). If not intervening, left-right torque transition control is not executed (S12), and the number N of left-right torque transition control is set to 0 (S13). Return to the top of the flow.

  On the other hand, when the motor traction control control intervenes in S11, it is determined whether the left / right torque transition control is the first time, that is, whether N = 1 (S14). If N = 1, it is determined whether motor traction control control is intervening simultaneously in the first and second electric motors 2A, 2B connected to the left and right rear wheels LWr, RWr (S15). If it is, the left-right torque transition control is not executed (S12), the number N of left-right torque transition control is set to 0 (S13), and the process returns to the top of the flow.

  On the other hand, if the motor traction control control is not simultaneously intervening in the first and second motors 2A, 2B connected to the left and right rear wheels LWr, RWr in S15, the first motor 2A connected to the left rear wheel LWr. Whether the motor traction control control is intervening is determined (S16), and if it is intervening, the process proceeds to S17. In step S17, the command motor torque R_CMD of the second electric motor 2B is set to the second change amount Δ2 (Δ2 ′ when the rear wheels LWr and RWr are braked by the first and second electric motors 2A and 2B that are regeneratively driven). (R_CMD ← R_CMD + Δ2 or R_CMD ← R_CMD + Δ2 ′). At this time, the command motor torque L_CMD of the first electric motor 2A connected to the left rear wheel LWr has already changed by the first change amount Δ1 (Δ1 ′) by the motor traction control control. Do not issue (L_CMD ← L_CMD). Next, in S18, the number N of left and right torque shift control is set to n + 1, and the process returns to the top of the flow.

  In S16, when the motor traction control control does not intervene in the first electric motor 2A connected to the left rear wheel LWr, that is, the motor traction control control intervenes in the second electric motor 2B connected to the right rear wheel RWr. If yes, the process proceeds to S21. Then, the command motor torque L_CMD of the first electric motor 2A connected to the left rear wheel LWr is controlled to change by the second change amount Δ2 (Δ2 ′) (L_CMD ← L_CMD + Δ2, or L_CMD ← L_CMD + Δ2 ′). At this time, the command motor torque R_CMD of the second electric motor 2B connected to the right rear wheel RWr has already changed by the first change amount Δ1 (Δ1 ′) by the motor traction control control. Do not issue (R_CMD ← R_CMD). Next, in S22, the number N of left and right torque shift control is set to n + 1, and the process returns to the top of the flow.

  If the left and right torque transition control is not the first time in S14 (N ≠ 1), the process proceeds to S19, and motor traction control control is performed for the first motor 2A connected to the left rear wheel LWr for the first time (N = 1). Determine if you have intervened. If motor traction control control is not intervening in the first electric motor 2A, it is determined in S20 whether motor traction control control is intervening in the second electric motor 2B connected to the right rear wheel RWr. If so, the above-described control is performed in S21 and S22. On the other hand, when the motor traction control control is not intervening in the second electric motor 2B connected to the right rear wheel RWr in S20, the left / right torque transition control is not executed (S23), and the number N of the left / right torque transition control is set to 0. (S24), the process returns to the top of the flow.

  Further, when motor traction control control intervenes in the first motor 2A connected to the left rear wheel LWr for the first time (N = 1) in S19, the first motor 2A connected to the left rear wheel LWr in S25. It is determined whether or not the motor traction control control is in the middle of intervention. On the other hand, if motor traction control control is intervening in the first electric motor 2A connected to the left rear wheel LWr in S25, the command motor torque R_CMD of the second electric motor 2B connected to the right rear wheel RWr in S26. Is changed by the second change amount Δ2 (Δ2 ′) (R_CMD ← R_CMD + Δ2 or R_CMD ← R_CMD + Δ2 ′). At this time, the command motor torque L_CMD of the first electric motor 2A connected to the left rear wheel LWr has already changed by the first change amount Δ1 (Δ1 ′) by the motor traction control control. Do not issue (L_CMD ← L_CMD). Next, in S27, the number N of left and right torque shift control is set to n + 1, and the process returns to the top of the flow.

<Front-rear torque transition control>
(First embodiment)
As described above, in the left-right torque transition control, the command motor torques L_CMD and R_CMD of the first or second electric motor 2A, 2B connected to the other wheel in which excess slip has not occurred are changed to the second change amount Δ2 ( Since the control is performed so as to increase by the absolute value of Δ2 ′), excessive slip may occur on the other wheel, and sufficient rear wheel driving force (rear wheel braking force) cannot be transmitted to the road surface. There is a fear.

  Therefore, the control device 8 according to the first embodiment of the present invention uses the command motor torque L_CMD of the first or second electric motor 2A or 2B connected to the other wheel in which excess slip has not occurred in the left-right torque transition control. , When the R_CMD is changed by the second change amount Δ2 (Δ2 ′), when the slip acquisition means 80 acquires that the excess slip has occurred in the other wheel, the first or first connected to the other wheel 2 The command motor torques L_CMD and R_CMD of the electric motors 2A and 2B are changed by the third change amount Δ3 from the torque changed by the second change amount Δ2 (Δ2 ′), and the torque of the front wheel drive device 6 is changed by the third change amount Δ3. And forward / backward torque transition control for changing by a fourth change amount Δ4 having the opposite sign.

  More specifically, with reference to FIG. 20, when the rear wheels LWr and RWr are driven by the first and second electric motors 2A and 2B that are driven by power running, an acceleration slip more than a predetermined amount occurs in the left rear wheel LWr. The left-right torque transition control and the front-rear torque transition control will be described. In FIG. 20, ENG is the internal combustion engine 4, MOT is the electric motor 5, BATT is the battery 9, L-MOT and R-MOT are the first and second electric motors 2A, 2B, LWf and RWf are the left and right front wheels, LWr and RWr, respectively. Represents the left and right rear wheels, respectively. In FIG. 20, the torque generated by each drive source, the torque distributed to the left and right front wheels LWf, RWf and the left and right rear wheels LWr, RWr, and the like are shown in a simplified and numerical form for the sake of explanation. The same applies to FIGS. 23 to 25, 27, and 28 described later.

  First, as shown in FIGS. 20 (a) and 21 (I), the first and second electric motors 2A are before the acceleration slip more than a predetermined value occurs in the left rear wheel LWr (before the left-right torque shift control). 2B output command motor torques (power running torque) L_CMD and R_CMD so as to satisfy driver request torques L_REQ = 3 and R_REQ = 3 (L_CMD = L_REQ = 3, R_CMD = R_REQ = 3). At this time, the battery 9 connected to the first and second electric motors 2A and 2B is supplied with electric power by a torque “7”, and the first and second electric motors 2A and 2B each have a torque of “0.5”. There is a loss of. That is, the torque efficiency in the first and second electric motors 2A and 2B is “−0.5”. Here, the sum of the command motor torques L_CMD and R_CMD of the first and second electric motors 2A and 2B (hereinafter, also referred to as “rear left and right sum”) is 6, and the difference between the command motor torques L_CMD and R_CMD is “Rear wheel left / right difference”) is “0”, and the total driving force of the rear wheel driving device 1 and the front wheel driving device 6 (hereinafter also referred to as “vehicle total torque”) is “6”.

  When acceleration slip occurs in the left rear wheel LWr, as shown in FIG. 20 (b) and FIG. 21 (II), the left and right torque shift control is executed by the control device 8, thereby The command motor torque L_CMD of the first electric motor 2A connected to the LWr is changed by the first change amount Δ1 = −1 from the driver request torque L_REQ = 3 (L_CMD = L_REQ + Δ1 = 2), and no acceleration slip occurs. The command motor torque R_CMD of the second electric motor 2B connected to the right rear wheel RWr is changed by a second change amount Δ2 = −Δ1 = 1 that is opposite in sign to the first change amount Δ1 and has substantially the same absolute value. (R_CMD = R_REQ + Δ2 = 4). At this time, the left and right sum of the rear wheels and the total vehicle torque are not changed from those before the left and right torque transition control, but the difference between the left and right rear wheels is “−2”, so a yaw moment is generated in the vehicle 3.

  Then, as a result of the command motor torque R_CMD of the second electric motor 2B being increased by the second change amount Δ2, as shown in FIG. 20 (c) and FIG. 21 (III) when acceleration slip occurs also in the right rear wheel RWr. In addition, the control device 8 executes front / rear torque transition control, and the command motor torque R_CMD of the second electric motor 2B connected to the right rear wheel RWr is opposite in sign to the second change amount Δ2 and has an absolute value of second. The third change amount Δ3 = −2 × Δ2 = −2, which is twice the absolute value of the change amount Δ2, is changed to converge the slip of the right rear wheel RWr (R_CMD = R_REQ + Δ2 + Δ3 = 2). At this time, electric power is supplied from the battery 9 by the torque “5”. Further, the control device 8 changes the torque of the internal combustion engine 4 of the front wheel drive device 6 by a fourth change amount Δ4 = −Δ3 = 2, which is opposite in sign to the third change amount Δ3 and has substantially the same absolute value. Thus, the torque is distributed by “1” to the left and right front wheels LWf and RWf.

  As a result of the front / rear torque transition control, the rear wheel left / right sum is “4”, and the total torque of the rear wheel drive device 1 is reduced by the absolute value of the third variation Δ3 = −2, but the total of the front wheel drive device 6 is reduced. By increasing the torque (the sum of the torques distributed to the left and right front wheels LWf and RWf; hereinafter also referred to as “front wheel left and right sum”) by a fourth change amount Δ4 = 2, the reduction in the torque of the rear wheel drive device 1 is compensated. The total vehicle torque can be maintained at “6”. Further, since the difference between the left and right rear wheels is “0”, the yaw moment caused by the rear wheel drive device 1 is not generated, and the difference in torque distributed to the left and right front wheels LWf and RWf (hereinafter referred to as “front wheel left / right difference”) ) Is also “0”, so the yaw moment caused by the front wheel drive device 6 does not occur. That is, the yaw moment is not generated in the entire vehicle 3, and it is possible to return to the yaw moment before the left and right torque shift control.

  Here, the flow of the front-rear torque transition control will be described with reference to FIG. First, it is determined whether left-right torque transition control is being executed (S31). If not, the front-rear torque transition control is not performed and the flow ends. On the other hand, when the left / right torque transition control is being executed, the command motor torques L_CMD and R_CMD of the first or second electric motors 2A and 2B connected to the other wheel where no excess slip has occurred are changed to the second change amount Δ2. When only (Δ2 ′) is changed, it is determined whether an excess slip has occurred on the other wheel (S32).

  As a result, when the excess slip has not occurred on the other wheel, the front-rear torque transition control is terminated. On the other hand, when excessive slip has occurred in the other wheel, the command motor torques L_CMD and R_CMD of the first or second electric motor 2A or 2B connected to the other wheel are changed by the third change amount Δ3. As a result, the total torque (rear left and right sum) of the rear wheel drive device 1 is reduced, and the slip of the other wheel is eliminated (S33).

  Then, the total torque of the front wheel drive device 6 (front wheel left-right sum) is increased by changing the third change amount Δ3 by a fourth change amount Δ4 opposite in sign to compensate for the lowering of the torque of the rear wheel drive device 1. The vehicle total torque is maintained (S34).

  Next, as a result of increasing the total torque (front wheel left-right sum) of the front wheel drive device 6, it is determined whether an excess slip has occurred in the left front wheel LWf or the right front wheel RWf (S35), and the excess slip has occurred. If not, the front / rear torque transition control is terminated. On the other hand, when an excess slip has occurred in the left front wheel LWf or the right front wheel RWf, by reducing the total torque (front wheel left-right sum) of the front wheel drive device 6, that is, by reducing the vehicle total torque (S36). ), The slip of the front wheels LWf, RWf is eliminated, and the front-rear torque transition control is terminated.

As described above, according to the vehicle drive device of the present embodiment, when an excess slip occurs on either the left rear wheel LWr or the right rear wheel RWr, the vehicle is connected to the wheel where the excess slip has occurred. The command motor torques L_CMD, R_CMD of the first or second electric motor 2A, 2B to be decreased by the absolute value of the first change amount Δ1 (Δ1 ′), thereby reducing the slip and left and right opposite to the slip wheel. Decreasing the torque of one wheel by increasing the command motor torque L_CMD, R_CMD of the first or second electric motor 2A, 2B connected to the wheel on the side (the other wheel) by the absolute value of the second change amount Δ2. Can be supplemented. Accordingly, sufficient torque according to the driver's request can be transmitted to the road surface even on the split μ road, etc., so that traveling performance can be maintained.
When the command motor torques L_CMD, R_CMD of the first or second electric motor 2A, 2B connected to the other wheel are increased by the absolute value of the second change amount Δ2 (Δ2 ′), the other wheel When the excess slip occurs, the command motor torques L_CMD, R_CMD of the first or second electric motor 2A, 2B connected to the other wheel are reduced by the absolute value of the third change amount Δ3, thereby reducing the slip. While reducing, the torque of the front wheel drive device 6 (front wheel left-right sum) is increased by the absolute value of the fourth change amount Δ4 to compensate for the decrease in the torque of the rear wheel drive device 1 (rear wheel left-right sum). Torque can be maintained.
Further, by executing the left-right torque transition control first (priority) over the front-rear torque transition control, the time for maintaining the total torque of the rear wheel drive device 1 can be made longer, and the rear wheel drive is performed. The torque balance between the device 1 and the front wheel drive device 6 can be maintained longer.

  Further, the control device 8 makes the absolute values of the first change amount Δ1 and the second change amount Δ2 (Δ2 ′) substantially the same, and makes the absolute values of the first change amount Δ3 and the fourth change amount Δ4 substantially the same. Therefore, the total torque generated by the rear wheel drive device 1 at the time of the left / right torque transition control (the rear wheel left / right sum) can be maintained substantially the same, and the vehicle total torque can be maintained at the same time during the front / rear torque transition control. It becomes.

Further, the control device 8 sets the absolute value of the third change amount Δ3 to twice the absolute value of the second change amount Δ2 (Δ2 ′), so that the yaw moment generated during the left-right torque transfer control is controlled by the front-rear torque transfer control. Sometimes, it can be eliminated and returned to the yaw moment before the left and right torque shift control.
In order to reduce the yaw moment generated during the left-right torque transition control during the front-rear torque transition control, it is sufficient that the third change amount Δ3 is at least opposite in sign to the second change amount Δ2 (Δ2 ′) ( Δ3 × Δ2 <0 or Δ3 × Δ2 ′ <0), more preferably the absolute value is larger than the absolute value of the second change amount Δ2 (Δ2 ′) (Δ3 <−Δ2 or Δ3> −Δ2 ′). More preferably, the absolute value is preferably twice the second change amount Δ2 (Δ2 ′) as in the above-described embodiment (Δ3 = −2 × Δ2 or Δ3 = −2 × Δ2 ′).

(Modification 1-1)
In the above-described embodiment, the front wheel drive device 6 is configured by connecting the internal combustion engine 4 and the electric motor 5 in series. However, as shown in FIG. It is good also as a structure which has two electric motors (it represents with L-MOT and R-MOT in FIG. 23). When configured in this way, the two electric motors of the front wheel drive device 6 are connected to the battery 9 in the same manner as the first and second electric motors 2A and 2B of the rear wheel drive device 1, and the power supply from the battery 9; Energy regeneration to the battery 9 is enabled.

  Also in this modified example, when the rear wheel LWr, RWr is driven by the first and second electric motors 2A, 2B driven by power running, if an acceleration slip exceeding a predetermined value occurs in the left rear wheel LWr (see FIG. 23 (a)), the left-right torque shift control is executed in the same manner as in the above-described embodiment (see FIG. 23 (b)).

  Then, as a result of the command motor torque R_CMD of the second electric motor 2B being increased by the second change amount Δ2 = 1, when the acceleration slip occurs also in the right rear wheel RWr, as shown in FIG. Executes the front-rear torque transition control, and the command motor torque R_CMD of the second electric motor 2B connected to the right rear wheel RWr is 2 with the second change amount Δ2 having the opposite sign and the absolute value of the second change amount Δ2. The third change amount Δ3 = −2 × Δ2 = −2, which is double, is changed to converge the slip of the right rear wheel RWr (R_CMD = R_REQ + Δ2 + Δ3 = 2). Further, the control device 8 sets the total value of the command motor torques of the two electric motors of the front wheel drive device 6 as a fourth change amount Δ4 = −Δ3 whose sign is opposite to that of the third change amount Δ3 and whose absolute value is substantially the same. = 2 is changed, and the command motor torque is output by “1” to the two electric motors. At this time, since there is a torque loss of “0.5” for each of the two motors of the front wheel drive device 6 and the first and second motors 2A and 2B of the rear wheel drive device 1, the torque from the battery 9 Electric power is supplied for “8”.

  As a result of the front / rear torque transition control, the rear wheel left / right sum is “4”, and the total torque of the rear wheel drive device 1 is reduced by the absolute value of the third variation Δ3 = −2, but the front wheel drive device 6 is reduced. Is increased by the fourth change amount Δ4 = 2 to compensate for a decrease in the torque of the rear wheel drive device 1, and the total vehicle torque can be maintained at “6”. Further, since the rear wheel left / right difference is “0”, no yaw moment due to the rear wheel drive device 1 is generated, and since the front wheel left / right difference is also “0”, no yaw moment due to the front wheel drive device 6 is generated. . That is, the yaw moment is not generated in the entire vehicle 3, and it is possible to return to the yaw moment before the left and right torque shift control. As described above, this modification can also achieve the same effects as those of the above-described embodiment.

  In this modification as well, control is performed in accordance with the above-described front-rear torque transition control flow (see FIG. 22). However, in S35, an excess slip has occurred in either the left front wheel LWf or the right front wheel RWr. In this case, in S36, the total torque (front wheel left / right sum) of the front wheel drive device 6 is not reduced, and the same method as the above-described left / right torque transition control is applied, and the command motor torque of the motor connected to one of the front wheels is set. The command motor torque of the electric motor connected to the other front wheel in which excess slip has not occurred may be increased. By controlling in this way, it is possible to maintain the total torque (front wheel left-right sum) of the front wheel drive device 6 and maintain the vehicle total torque.

(Modification 1-2)
Further, as shown in FIG. 24, the front wheel drive device 6 does not have the internal combustion engine 4 and may be configured by an electric motor 5. Also in this modified example, when the rear wheel LWr, RWr is driven by the first and second electric motors 2A, 2B driven by power running, if an acceleration slip exceeding a predetermined value occurs in the left rear wheel LWr (see FIG. 24 (a)), right / left torque transition control is executed in the same manner as in the above-described embodiment (see FIG. 24 (b)).

  Then, as a result of the command motor torque R_CMD of the second electric motor 2B being increased by the second change amount Δ2 = 1, when acceleration slip occurs also in the right rear wheel RWr, as shown in FIG. Executes the front-rear torque transition control, and the command motor torque R_CMD of the second electric motor 2B connected to the right rear wheel RWr is 2 with the second change amount Δ2 having the opposite sign and the absolute value of the second change amount Δ2. The third change amount Δ3 = −2 × Δ2 = −2, which is double, is changed to converge the slip of the right rear wheel RWr (R_CMD = R_REQ + Δ2 + Δ3 = 2). Further, the control device 8 changes the command motor torque of the electric motor 5 of the front wheel drive device 6 by a fourth change amount Δ4 = −Δ3 = 2, which is opposite in sign to the third change amount Δ3 and has substantially the same absolute value. Thus, the torque is distributed by “1” to the left and right front wheels LWf and RWf. At this time, electric power is supplied to the electric motor 5 of the front wheel drive device 6 from the battery 9 by the torque “3”, and the electric motor 5 loses the torque by “1”. Further, since there is a torque loss of “0.5” in each of the first and second electric motors 2A, 2B, the battery 9 has a torque of “8” relative to the electric motor 5, the first and second electric motors 2A, 2B. Only power is supplied.

  As a result of the front / rear torque transition control, the rear wheel left / right sum is “4”, and the total torque of the rear wheel drive device 1 is reduced by the absolute value of the third variation Δ3 = −2, but the front wheel drive device 6 is reduced. Is increased by the fourth change amount Δ4 = 2 to compensate for a decrease in the torque of the rear wheel drive device 1, and the total vehicle torque can be maintained at “6”. Further, since the rear wheel left / right difference is “0”, no yaw moment due to the rear wheel drive device 1 is generated, and since the front wheel left / right difference is also “0”, no yaw moment due to the front wheel drive device 6 is generated. . That is, the yaw moment is not generated in the entire vehicle 3, and it is possible to return to the yaw moment before the left and right torque shift control. As described above, this modification can also achieve the same effects as those of the above-described embodiment.

(Second Embodiment)
Next, a vehicle drive device according to a second embodiment of the present invention will be described with reference to FIGS. 25 and 26. The vehicle drive device of the present embodiment has the same basic configuration as that of the vehicle drive device (see FIG. 23) according to the modified example 1-1 of the first embodiment. The difference is that the absolute value of the three variation Δ3 is substantially the same as the absolute value of the second variation Δ2 (Δ2 ′) (Δ3 = −Δ2 or Δ3 = −Δ2 ′).

  More specifically, when the rear wheel LWr, RWr is driven by the first and second electric motors 2A, 2B that are driven by power running, an acceleration slip exceeding a predetermined value occurs in the left rear wheel LWr (FIG. 25). (Refer to (A) and (I) of FIG. 26), the left-right torque shift control is executed as in the first embodiment (see (II) of FIG. 25 (b) and FIG. 26).

  Then, as a result of the command motor torque R_CMD of the second electric motor 2B being increased by the second change amount Δ2 = 1, when an acceleration slip also occurs in the right rear wheel RWr, FIG. 25 (c) and FIG. 26 (III) As shown, the control device 8 executes front / rear torque transition control, and the command motor torque R_CMD of the second electric motor 2B connected to the right rear wheel RWr has the opposite sign and the absolute value of the second variation Δ2. The third change amount Δ3 = −Δ2 = −1, which is substantially the same as the absolute value of the second change amount Δ2, is changed to converge the slip of the right rear wheel RWr (R_CMD = R_REQ + Δ2 + Δ3 = R_REQ = 3). Here, the reason why the absolute value of the third variation Δ3 is substantially the same as the absolute value of the second variation Δ2 is that the command motor torque R_CMD of the second electric motor 2B connected to the right rear wheel RWr by the left-right torque shift control. This is because no slip occurs on the right rear wheel RWr before increasing the second change amount Δ2 and it is possible to eliminate the slip of the right rear wheel RWr with the minimum necessary change amount.

  Next, the control device 8 calculates the total value of the command motor torques of the two electric motors of the front wheel drive device 6 as the fourth change amount Δ4 = − whose sign is opposite to that of the third change amount Δ3 and whose absolute value is substantially the same. By changing Δ3 = 1, the command motor torque is output by “0.5” to the two motors. At this time, since there is a torque loss of “0.5” in each of the two motors of the front wheel drive device 6 and the first and second motors 2A and 2B of the rear wheel drive device 1, the torque from the battery 9 is equal to “8”. Only power is supplied.

  As a result of the front-rear torque transition control, the rear wheel left-right sum is “5”, and the total torque of the rear wheel drive device 1 is reduced by the absolute value of the third change amount Δ3 = −1. Is increased by the fourth change amount Δ4 = 1 to compensate for a decrease in the torque of the rear wheel drive device 1, and the total vehicle torque can be maintained at “6”.

  Here, in the present embodiment, the front wheel left / right difference is “0”, so the yaw moment caused by the front wheel drive device 6 does not occur, but the rear wheel left / right difference becomes “−1”, so the rear wheel drive device 1. A yaw moment is generated due to. Therefore, although the yaw moment is generated as a whole of the vehicle 3, it is reduced as compared with the yaw moment generated in the entire vehicle 3 before the front-rear torque transition control, so that the running performance can be maintained.

  The front wheel drive device 6 of this embodiment may be configured by connecting the internal combustion engine 4 and the electric motor 5 in series as in the first embodiment (see FIG. 20). It goes without saying that the internal combustion engine 4 may not be provided as in the modified example 1-2 (see FIG. 24) and may be configured by the electric motor 5.

(Modification 2-1)
Further, when the front wheel drive device 6 is composed of two electric motors as in the vehicle drive device according to the second embodiment, the right side of the front wheel drive device 6 is used in the front-rear torque transition control as shown in FIG. The command motor torque may be output by only “1” to drive only the right front wheel RWr. At this time, the electric motor on the right side of the front wheel drive device 6 is supplied with electric power from the battery 9 by a torque “1.5”, and a loss occurs by an amount corresponding to the torque “0.5” in the electric motor. Further, since there is a torque loss of “0.5” in each of the first and second electric motors 2A and 2B, the battery 9 is in comparison with the right motor of the front wheel drive device 6 and the first and second electric motors 2A and 2B. Then, power is supplied for a torque of “7.5”.

  As a result of the front-rear torque transition control, the rear wheel left-right sum is “5”, and the total torque of the rear wheel drive device 1 is reduced by the absolute value of the third change amount Δ3 = −1. Is increased by the fourth change amount Δ4 = 1 to compensate for a decrease in the torque of the rear wheel drive device 1, and the total vehicle torque can be maintained at “6”.

  Furthermore, since it is the left rear wheel LWr that caused the excess slip before the left / right torque shift control, there is a possibility that the vehicle 3 is traveling on a split μ road where the left side is low μ and the right side is high μ. Since it is high, it is possible to transmit more driving torque to the road surface by configuring to drive only the right front wheel RWr as in this modification.

  In the present embodiment, the difference between the left and right front wheels is “−1”, so the yaw moment caused by the front wheel drive device 6 is generated, and the difference between the left and right rear wheels is “−1”. The resulting yaw moment is also generated. Therefore, although the yaw moment is generated in the entire vehicle 3, it is not particularly a problem because it can be sufficiently tolerated by the driver's steering operation.

(Modification 2-2)
Further, as shown in FIG. 28, in the front-rear torque transition control, only the left motor of the front wheel drive device 6 may output the command motor torque “1” to drive only the left front wheel LWr. At this time, the electric motor on the left side of the front wheel drive device 6 is supplied with electric power from the battery 9 by the torque “1.5”, and the electric motor generates a loss by the torque “0.5”. Further, since there is a torque loss of “0.5” in each of the first and second electric motors 2A and 2B, the battery 9 is in comparison with the right motor of the front wheel drive device 6 and the first and second electric motors 2A and 2B. Then, power is supplied for a torque of “7.5”.

  As a result of the front-rear torque transition control, the rear wheel left-right sum is “5”, and the total torque of the rear wheel drive device 1 is reduced by the absolute value of the third change amount Δ3 = −1, but the total of the front wheel drive device 6 is reduced. By increasing the torque (front wheel left / right sum) by the fourth change amount Δ4 = 1, it is possible to compensate for the decrease in the torque of the rear wheel drive device 1 and to maintain the total vehicle torque at “6”. Further, since the rear wheel left / right difference is “−1” and the front wheel left / right difference is “1”, the vehicle 3 as a whole does not generate a yaw moment, and can return to the yaw moment before the left / right torque shift control. .

(Third embodiment)
Next, a vehicle drive device according to a second embodiment of the present invention will be described with reference to FIG. The vehicle drive device of the present embodiment has the same basic configuration as the vehicle drive devices of the first and second embodiments, and is connected to the other wheel in which excess slip does not occur during left-right torque transition control. When the command motor torques L_CMD, R_CMD of the first or second motor 2A, 2B are changed by the second change amount Δ2, the command motor torques L_CMD, R_CMD of the first or second motor 2A, 2B connected to the other wheel Of the first or second electric motor 2A, 2B so as not to exceed the upper limit when the upper limit (the upper limit of the physique of the first or second electric motor 2A, 2B) is exceeded or when the upper limit is expected to be exceeded. The difference is that the command motor torques L_CMD and R_CMD are changed by the third change amount Δ3 from the torque changed by the second change amount Δ2 (Δ2 ′).

  More specifically, with reference to FIG. 29, when the rear wheels LWr and RWr are driven by the first and second electric motors 2A and 2B that are driven by powering, the left rear wheel LWr generates an acceleration slip greater than a predetermined value. The left-right torque transition control and the front-rear torque transition control will be described.

  First, as shown in (I) of FIG. 29, the first and second electric motors 2 </ b> A and 2 </ b> B make a driver request before an acceleration slip exceeding a predetermined value occurs before the left rear wheel LWr (before the left and right torque shift control). Command motor torque (powering drive torque) L_CMD and R_CMD are output so as to satisfy torque L_REQ = 3.5 and R_REQ = 3.5 (L_CMD = L_REQ = 3.5, R_CMD = R_REQ = 3.5).

  When acceleration slip occurs in the left rear wheel LWr, as shown in (II) of FIG. 29, the control device 8 executes the above-described left-right torque transition control, and thereby the first slip connected to the left rear wheel LWr. 1 The command motor torque L_CMD of the electric motor 2A is changed by the first change amount Δ1 = −1 from the driver request torque L_REQ = 3.5 (L_CMD = L_REQ + Δ1 = 2.5), and the right rear where no acceleration slip occurs The command motor torque R_CMD of the second electric motor 2B connected to the wheel RWr is changed by a second change amount Δ2 = −Δ1 = 1 that is opposite in sign to the first change amount Δ1 and has substantially the same absolute value. Control.

  At this time, if the upper limit value of the command motor torques L_CMD, R_CMD of the first or second electric motor 2A, 2B (physical upper limit of the first or second electric motor 2A, 2B) is “4”, the command of the second electric motor 2B When the motor torque R_CMD is controlled to change by the second change amount Δ2, R_CMD = R_REQ + Δ2 = 4.5, which is a value exceeding the upper limit value. Therefore, as shown in (III) of FIG. 29, the control device 8 sets the value exceeding the upper limit value of the command motor torque R_CMD of the second electric motor 2B to be equal to the upper limit value, that is, “4”. Thus, the third change amount Δ3 is changed by −0.5 (R_CMD = R_REQ + Δ2 + Δ3 = 4). By controlling in this way, it is possible to protect the second motor 2B connected to the right wheel RWr while eliminating the slip of the left rear wheel LWr.

  Then, the control device 8 changes the torque of the front wheel drive device 6 by a fourth change amount Δ4 = −Δ3 = 0.5 whose sign is opposite to that of the third change amount Δ3 and whose absolute value is substantially the same. The reduction in the torque of the rear wheel drive device 1 is compensated for and the total vehicle torque is maintained.

  In the present embodiment, the third change amount Δ3 = −0.5, and the value exceeding the upper limit value of the command motor torque R_CMD of the second electric motor 2B is changed to be equal to the upper limit value (R_CMD). = R_REQ + Δ2 + Δ3 = 4), not particularly limited to this configuration. As Δ3 <−0.5, the value exceeding the upper limit value of the command motor torque R_CMD of the second electric motor 2B is changed to be smaller than the upper limit value. (R_CMD = R_REQ + Δ2 + Δ3 <4). Further, when the command motor torque R_CMD of the second electric motor 2B is changed by the second change amount Δ2 in the left-right torque transition control, a value exceeding the upper limit value of the command motor torque R_CMD of the second electric motor 2B (R_CMD = 4.5). When it is predicted in advance, the above-described third change amount Δ3 may be changed so as not to exceed the upper limit value.

  Here, the flow of the front-rear torque transition control of this embodiment will be described with reference to FIG. First, it is determined whether left-right torque transition control is being executed (S41). If not, the flow is terminated without performing front-rear torque transition control. On the other hand, when the left / right torque transition control is being executed, the command motor torques L_CMD and R_CMD of the first or second electric motors 2A and 2B connected to the other wheel where no excess slip has occurred are changed to the second change amount Δ2. Whether or not the upper limit value of the command motor torques L_CMD and R_CMD of the first or second electric motors 2A and 2B (the upper limit of the physique of the first or second electric motors 2A and 2B) is exceeded when only (Δ2 ′) is changed, Alternatively, it is determined whether or not the upper limit value is expected (S42).

  As a result, when the command motor torques L_CMD, R_CMD of the first or second electric motors 2A, 2B are changed by the second change amount Δ2 (Δ2 ′), the upper limit value is not exceeded, or the upper limit value is not exceeded. If predicted, the front-rear torque transition control is terminated. On the other hand, when the command motor torques L_CMD and R_CMD of the first or second electric motors 2A and 2B are changed by the second change amount Δ2 (Δ2 ′), it is predicted that the upper limit value is exceeded or the upper limit value is exceeded. The total torque (rear sum of left and right wheels) of the rear wheel drive device 1 is reduced by changing the command motor torques L_CMD, R_CMD of the first or second electric motor 2A, 2B by the third change amount Δ3, The first or second electric motor 2A, 2B is protected (S43).

  Then, the total torque of the front wheel drive device 6 (front wheel left-right sum) is increased by changing the third change amount Δ3 by a fourth change amount Δ4 opposite in sign to compensate for the lowering of the torque of the rear wheel drive device 1. The vehicle total torque is maintained (S44).

  Next, as a result of increasing the total torque (front wheel left / right sum) of the front wheel drive device 6, it is determined whether an excess slip has occurred in the left front wheel LWf or the right front wheel RWf (S45), and the excess slip has occurred. If not, the front / rear torque transition control is terminated. On the other hand, if an excess slip has occurred in the left front wheel LWf or the right front wheel RWf, by reducing the total torque of the front wheel drive device 6, that is, by reducing the vehicle total torque (S46), both front wheels LWf , RWf slip is eliminated, and the front-rear torque transition control is terminated.

In addition, this invention is not limited to embodiment mentioned above, A deformation | transformation, improvement, etc. are possible suitably.
For example, the first and second embodiments described above are configured such that the front-rear torque transition control is executed only when the left-right torque transition control is performed. Torque transfer control is preferentially executed. However, before the left / right torque transition control, when the slip acquisition means 80 acquires that the excess slip has occurred at the left rear wheel LWr and the right rear wheel RWr at the same time, depending on the left / right torque transition control, the left rear wheel LWr and the right Since the slip of the rear wheel RWr cannot be eliminated, the slip of the left rear wheel LWr and the right rear wheel RWr is eliminated early by prohibiting the left / right torque transition control and executing only the front / rear torque transition control. To do. In this case, in the front-rear torque transition control, the command motor torques L_CMD and R_CMD of the first and second electric motors 2A and 2B connected to the left rear wheel LWr and the right rear wheel RWr are both reduced, and the rear wheel drive device 1 The total torque of the vehicle is maintained by increasing the torque (front-wheel left-right sum) of the front-wheel drive device 6 by the reduction of the torque (rear-wheel left-right sum).

  Further, in each of the above-described embodiments, the driving device 1 (first driving device) having the first and second electric motors 2A and 2B is used for rear wheel driving, and the driving device 6 (second driving device) is used for front wheel driving. However, conversely, the driving device 1 (first driving device) may be used for front wheel driving, and the driving device 6 (second driving device) may be used for rear wheel driving.

  In each of the above-described embodiments, the command motor torques L_CMD and R_CMD of the first or second electric motors 2A and 2B connected to the slipped wheel are changed by the first change amount Δ1 (Δ1 ′), The command motor torques L_CMD and R_CMD of the first or second electric motors 2A and 2B connected to the left and right wheels (the other wheel) are opposite in sign to the first change amount Δ1 and substantially the same in absolute value. Only the second change amount Δ2 (Δ2 ′) is changed (Δ1 = −Δ2 or Δ1 ′ = − Δ2 ′). However, the first change amount Δ1 (Δ1 ′) and the second change amount Δ2 (Δ2 ′) do not necessarily have the same absolute value, and at least the signs may be opposite (Δ1 × Δ2 <0, or Δ1 ′ × Δ2 ′ <0).

  Further, in each of the above-described embodiments, in the front-rear torque transition control, the torque of the front wheel drive device 6 has the same sign as the third change amount Δ3 and the absolute value is substantially the same but is changed by the fourth change amount Δ4 (= −Δ3). However, the third change amount Δ3 and the fourth change amount Δ4 do not necessarily have the same absolute value, and at least the signs may be opposite (Δ3 × Δ4 <0).

  In addition, the motor traction control control described above is performed by the first and second motors 2A, 2A and 2B obtained based on the motor speeds of the first and second motors 2A, 2B acquired by the resolvers 20A, 20B and the motor target speed. You may carry out by comparing with 2B upper limit slip judgment threshold rotation speed. For example, when the rear wheels LWr and RWr are driven by the first and second electric motors 2A and 2B that are driven by power running, the control device 8 determines that the motor rotational speeds of the first and second electric motors 2A and 2B are upper limit slips. When the rotational speed is equal to or lower than the threshold rotational speed, the command motor torques L_CMD and R_CMD are output to the first and second electric motors 2A and 2B so as to satisfy the driver request torques L_REQ and R_REQ, and the rotational speeds of the second electric motors 2A and 2B Exceeds the upper limit slip determination threshold rotational speed, it is determined that a predetermined or higher acceleration slip has occurred in the rear wheels LWr and RWr. Then, the control device 8 determines the command motor torques L_CMD and R_CMD of the first electric motor 2A and / or the second electric motor 2B connected to the left wheel LWr and / or the right rear wheel RWr where the acceleration slip has occurred, as an upper limit slip determination threshold value. Only the first change amount determined based on the acceleration slip amount which is the difference between the rotation speed and the motor rotation speed is changed to suppress the acceleration slip.

Further, it is not necessary to provide the hydraulic brakes 60A and 60B on the ring gears 24A and 24B, respectively, and it is only necessary that one hydraulic brake and one one-way clutch are provided on the connected ring gears 24A and 24B. In addition, any one of a hydraulic brake and a one-way clutch may be provided as the power transmission means.
Moreover, although the hydraulic brake is illustrated as the connecting / disconnecting means, the invention is not limited to this, and a mechanical type, an electromagnetic type, or the like can be arbitrarily selected.
Further, in the left wheel drive device and the right wheel drive device, a planetary gear type reduction gear is arranged between the electric motor and the wheel, but any transmission can be used instead of the planetary gear type reduction device. As long as the power transmission means capable of connecting / disconnecting the power transmission between the motor and the wheel is provided on the power transmission path between the motor and the wheel, the transmission can be omitted.
Moreover, although the electric motor is illustrated as the drive source, other drive sources such as an engine may be used.
In the above-described embodiment, the resolvers 20A and 20B serving as the first rotation state quantity detection means are provided in the first and second motors 2A and 2B, respectively. However, the first rotation state quantity detection means is the first and second motors. What is necessary is just to be arrange | positioned on the 1st and 2nd electric motor 2A, 2B side rather than a power transmission means on the power transmission path | route of 2A, 2B and the wheel Wr.
Similarly, in the above-described embodiment, the wheel speed sensors 13A and 13B serving as the second rotation state amount detecting means are provided on the left rear wheel LWr and the right rear wheel RWr, respectively. What is necessary is just to be arrange | positioned on the wheel Wr side rather than a power transmission means on the power transmission path | route of 2nd electric motor 2A, 2B and the wheel Wr.

1 Rear wheel drive system (vehicle drive system)
2A 1st motor (left motor)
2B Second motor (right motor)
3 Vehicle 8 Control device (motor control device)
80 Slip acquisition device (slip acquisition means)
LWf Left front wheel RWf Right front wheel LWr Right rear wheel (left wheel)
RWr Left rear wheel (right wheel)
LR, RR Wheel rotation speed LVmax, RVmax Upper limit slip determination threshold rotation speed LVmin, RVmin Lower limit slip determination threshold rotation speed L_CMD, R_CMD Command motor torque (torque)
L_REQ, R_REQ Driver requested torque F, F ′ Yaw moment Δ1, Δ1 ′ First variation Δ2, Δ2 ′ Second variation Δ3 Third variation Δ4 Fourth variation

Claims (2)

A first drive device that drives a first drive wheel that is one of a front wheel and a rear wheel of the vehicle;
A second drive device for driving a second drive wheel which is the other of the front wheel and the rear wheel;
With
The first drive device includes a left motor connected to a left wheel of the vehicle, a right motor connected to a right wheel of the vehicle, and a motor control device that controls the torque of the left motor and the torque of the right motor. A vehicle drive device comprising:
The vehicle drive device includes slip acquisition means for acquiring that an excess slip, which is a predetermined slip or more, has occurred on the left wheel or the right wheel,
When the slip acquisition means acquires that the excess slip has occurred on one of the left wheel or the right wheel, the motor control device calculates the torque of the motor connected to the one wheel. Left and right torque transition control means for changing only the first change amount and changing the torque of the electric motor connected to the other wheel by the second change amount opposite in sign to the first change amount;
In the motor control device, when the left-right torque transition control means changes the torque of the motor connected to the other wheel by the second change amount, the slip acquisition means causes an excess slip on the other wheel. When the acquisition is made, the torque of the motor connected to the other wheel is changed by the third change amount from the torque changed by the second change amount, and the torque of the second drive device is changed by the second change amount. 3 variation and the code will have a longitudinal torque transition controlling means for changing by a fourth variation of the opposite,
The motor controller is
The absolute values of the first change amount and the second change amount are substantially the same,
The absolute values of the third change amount and the fourth change amount are substantially the same,
The vehicle drive device characterized in that the absolute value of the third change amount is substantially the same as the absolute value of the second change amount . A first drive device that drives a first drive wheel that is one of a front wheel and a rear wheel of the vehicle;
A second drive device for driving a second drive wheel which is the other of the front wheel and the rear wheel;
With
The first drive device includes a left motor connected to a left wheel of the vehicle, a right motor connected to a right wheel of the vehicle, and a motor control device that controls the torque of the left motor and the torque of the right motor. A vehicle drive device comprising:
The vehicle drive device includes slip acquisition means for acquiring that an excess slip, which is a predetermined slip or more, has occurred on the left wheel or the right wheel,
The motor controller is
When the slip acquisition means acquires that the excess slip has occurred on either the left wheel or the right wheel, the torque of the motor connected to the one wheel is changed by a first change amount. Left and right torque transition control for changing the torque of the motor connected to the other wheel by a second change amount opposite in sign to the first change amount;
When changing the torque of the electric motor to be connected before SL other wheel by the second variation amount, when the slip acquisition means has acquired the excess slip to the other wheel occurs, the other wheel The torque of the motor connected to the second change amount is changed from the torque changed by the second change amount by the third change amount, and the torque of the second drive device is changed to the fourth change amount having the opposite sign to the third change amount. Front and rear torque transition control that only changes,
Run
The motor control device preferentially executes the left-right torque transition control over the front-rear torque transition control ,
The motor control device prohibits the left-right torque transition control and executes only the front-rear torque transition control when the slip acquisition means acquires that an excess slip has occurred simultaneously on the left wheel and the right wheel. A vehicle drive device characterized by that.

Images