JP5914115B2 - Vehicle drive device - Google Patents

Description

  The present invention relates to a vehicle drive device including a left wheel drive device that drives a left wheel and a right wheel drive device that drives a right wheel.

  Patent Document 1 discloses a left wheel drive device having a first electric motor that drives a left wheel of a vehicle, and a first planetary gear type transmission that is provided on a power transmission path between the first electric motor and the left wheel. A right wheel drive device comprising: a second motor for driving the right wheel of the vehicle; and a second planetary gear type transmission provided on a power transmission path between the second motor and the right wheel. A drive device is described. In the first and second planetary gear type transmissions, the first and second electric motors are connected to the sun gear, the left wheel and the right wheel are connected to the planetary carrier, respectively, and the ring gears are connected to each other. The vehicle drive device is also provided with brake means for braking the rotation of the ring gear by releasing or fastening the connected ring gear.

  In the vehicle drive device configured as described above, it is described that start assist control is performed at the start by fastening the brake means, and after starting, the first and By controlling the torque so that the torque generated by the second motor is in the opposite direction, even when a yaw moment is applied to the vehicle due to a disturbance, etc., a moment that opposes this yaw moment is generated, and straight running stability and turning stability It is described that the property is improved.

Japanese Patent No. 3138799

  In recent years, demands for energy saving, fuel efficiency improvement, comfort improvement, and the like have become strong, and the vehicle drive device described in Patent Document 1 also has room for improvement in controllability. In particular, when the brake means opens the ring gear, there is no description about a method for acquiring the rotation speed of the ring gear, and control based on the rotation speed of the ring gear cannot be performed.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a vehicle drive device with good controllability.

In order to achieve the above object, the invention described in claim 1
A first electric motor (for example, a first electric motor 2A in an embodiment to be described later) that drives a left wheel (for example, a left wheel LWr in an embodiment to be described later) of the vehicle (for example, a vehicle 3 in an embodiment to be described later); A left wheel drive device having a first transmission (for example, a first planetary gear speed reducer 12A in an embodiment described later) provided on a power transmission path between one electric motor and the left wheel;
Power transmission between a second electric motor (for example, a second electric motor 2B in an embodiment described later) that drives a right wheel of the vehicle (for example, a right wheel RWr in an embodiment described later), and the second motor and the right wheel. A right wheel drive device having a second transmission (for example, a second planetary gear speed reducer 12B in an embodiment described later) provided on the path;
An electric motor control device (for example, a control device 8 in an embodiment described later) for controlling the first electric motor and the second electric motor;
A vehicle drive device (for example, a rear wheel drive device 1 in an embodiment described later),
Each of the first and second transmissions has first to third rotating elements (for example, sun gears 21A and 21B, planetary carriers 23A and 23B, and ring gears 24A and 24B in embodiments described later),
The first electric motor is connected to the first rotating element of the first transmission;
The second electric motor is connected to the first rotating element of the second transmission;
The left wheel is connected to the second rotating element of the first transmission;
The right wheel is connected to the second rotating element of the second transmission;
The third rotating element of the first transmission and the third rotating element of the second transmission are connected to each other;
The vehicle drive device comprises:
First rotation state amount detection means (for example, described later) installed so as to be able to detect a rotation state amount of the first motor or a rotation state amount of the first rotation element of the first transmission. Resolver 20A) in the embodiment;
Second rotational state quantity detection means (for example, described later) installed so as to be able to detect the rotational state quantity of the left wheel or the rotational state quantity of the second rotational element of the first transmission. A wheel speed sensor 13A) in the form;
A third rotation state amount detecting means (for example, described later) installed so as to be able to detect a rotation state amount of the second motor or a rotation state amount of the first rotation element of the second transmission. Resolver 20B) in the embodiment;
A fourth rotational state amount detecting means (for example, implementation described later) installed so as to be able to detect the rotational state amount of the right wheel or the rotational state amount of the second rotational element of the second transmission. Wheel speed sensor 13B) in the form;
With
A fifth rotational state quantity that is a rotational state quantity of the third rotational elements coupled to each other ;
A first rotation state amount detection value (for example, a motor rotation number detection value LMa in an embodiment described later) detected by the first rotation state amount detection means and a second rotation state amount detected by the second rotation state amount detection means. A first fifth rotation state amount conversion value (a conversion value of a rotation state amount of the third rotation elements connected to each other, which is obtained based on a detection value (for example, a wheel rotation number detection value LWa in an embodiment described later) For example, a first ring gear rotation speed conversion value LRb) in an embodiment described later,
A third rotation state amount detection value (for example, a motor rotation number detection value RMa in an embodiment described later) detected by the third rotation state amount detection means and a fourth rotation state amount detected by the fourth rotation state amount detection means. A second fifth rotation state quantity conversion value (a conversion value of the rotation state quantity of the third rotation elements connected to each other obtained based on a detection value (for example, a wheel rotation speed detection value RWa in an embodiment described later) ( For example, a second ring gear rotation speed conversion value RRb) in an embodiment described later,
It calculates | requires based on.

Moreover, in addition to the structure of Claim 1, invention of Claim 2 WHEREIN: Said 5th rotation state amount is converted into said 1st 5th rotation state amount conversion value and said 2nd 2nd 5th rotation state amount. It calculates | requires based on the average value with a conversion value, It is characterized by the above-mentioned.

Further, the invention according to claim 3 is the configuration according to claim 1 or 2, wherein the motor control device is a target value of the second rotational state quantity or a target value of the fourth rotational state quantity. A target wheel rotation state quantity (for example, target wheel rotation speed LWc, RWc in an embodiment described later) is acquired,
Based on the target wheel rotation state amount and the fifth rotation state amount, a target motor rotation state amount that is a target value of the first rotation state amount or a target value of the third rotation state amount (for example, an embodiment described later) Target motor rotation speed LMc, RMc) at
When the difference between the target motor rotation state quantity and the motor rotation state quantity that is the first rotation state quantity or the third rotation state quantity is greater than or equal to a predetermined value, the motor rotation state quantity is the target motor rotation state quantity. The first electric motor or the second electric motor is controlled so as to approach

According to a fourth aspect of the present invention, in addition to the configuration according to any one of the first to third aspects, the third rotation can be switched to a released state or a fastening state, and connected to each other in the fastening state. Rotation restricting means for restricting the rotation of the elements (for example, hydraulic brakes 60A and 60B in embodiments described later);
A rotation restricting means control device (for example, a control device 8 in an embodiment described later) for controlling the rotation restricting means to a released state or a fastening state;
With
When the rotation restricting means control device controls the rotation restricting means to the released state, the fifth rotation state amount is converted into the first fifth rotation state amount converted value and the second fifth rotation state amount converted value. And obtaining based on the above.

According to a fifth aspect of the present invention, in addition to the configuration of the fourth aspect, the rotation restriction means control device obtains the fifth rotation state amount when the rotation restriction means control device controls the rotation restriction means. Is prohibited.

According to the first aspect of the present invention, since the third rotating elements of the first and second transmissions are connected to each other, each third rotating element is always in the same rotation, and the first rotation state amount detecting means is used. This is a converted value of the rotational state amount of the mutually connected third rotational elements obtained based on the detected first rotational state amount detection value and the second rotational state amount detection value detected by the second rotational state amount detection means. The first rotation state quantity converted value, the third rotation state quantity detection value detected by the third rotation state quantity detection means, and the fourth rotation state quantity detection value detected by the fourth rotation state quantity detection means were obtained. The second fifth rotational state quantity converted value, which is the converted value of the rotational state quantity of the third rotating elements connected to each other , is always the same value. Therefore, by obtaining the fifth rotational state quantity that is the rotational state quantity of the third rotational elements coupled to each other based on the first fifth rotational state quantity converted value and the second fifth rotational state quantity converted value. Thus, the fifth rotational state quantity can be obtained more accurately, and the accuracy and robustness of various controls using the fifth rotational state quantity can be improved.

  According to the invention of claim 2, the first and second fifth rotational state quantity converted values may be different from each other due to the twist difference between the left and right power transmission paths, the backlash difference, and the like. By obtaining the fifth rotational state quantity based on the value, it is possible to obtain the fifth rotational state quantity more accurately.

  According to the invention of claim 3, the target motor rotation state quantity is obtained based on the accurately obtained fifth rotation state quantity and the target wheel rotation state quantity, and the target motor rotation state quantity and the motor rotation state quantity are obtained. When the difference between the first motor and the second motor is controlled so that the motor rotation state amount approaches the target motor rotation state amount, the wheel slip is suppressed, and the stability and running performance of the vehicle are controlled. Can be improved.

  According to the invention of claim 4, when the rotation regulating means control device controls the rotation regulating means to the released state, the fifth rotation state quantity is converted into the first fifth rotation state quantity converted value and the second fifth rotation. Since it calculates | requires based on a state quantity conversion value, it is possible to acquire the 5th rotation state quantity in a releasing state more accurately.

  According to the invention of claim 5, when the rotation restricting means control device controls the rotation restricting means to the fastening state, it is prohibited to obtain the fifth rotation state amount, so that the third rotating element does not rotate, The time and energy consumed for calculating the fifth rotational state quantity can be reduced.

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. (A) is a speed alignment chart of the rear-wheel drive device in the case where the motor is controlled to the target torque in the ring-free state, and (b) is a rear view in the case where the motor is controlled to the target rotational speed in the ring-free state. It is a speed alignment chart of a wheel drive device. It is a speed alignment chart of the rear-wheel drive device in a ring free state. It is a speed alignment chart of the rear-wheel drive device when a slip occurs in the left wheel in the ring-free state.

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 uses an electric motor as a drive source for driving an axle, and is used, for example, in a vehicle having a drive system as shown in FIG. In the following description, the case where the vehicle drive device is used for rear wheel drive will be described as an example, but it may be used for front wheel drive.
A vehicle 3 shown in FIG. 1 is a hybrid vehicle having a drive device 6 (hereinafter referred to as a front wheel drive device) in which an internal combustion engine 4 and an electric motor 5 are connected in series at the front portion of the vehicle. Is transmitted to the front wheels Wf via the transmission 7, while the power of the driving device 1 (hereinafter referred to as a rear wheel driving device) provided at the rear of the vehicle separately from the front wheel driving device 6 is the rear wheel 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 are disposed coaxially with the axles 10A and 10B. The first motor 2A and the first planetary gear type speed reducer 12A function as a left wheel driving device that drives the left rear wheel LWr, and the second motor 2B and the second planetary gear type speed reducer 12B drive the right rear wheel RWr. The first electric motor 2A and the first planetary gear type speed reducer 12A, the second electric motor 2B and the second planetary gear type speed reducer 12B function in the vehicle width direction in the speed reducer case 11. They are arranged symmetrically. The rear wheel Wr is provided with wheel speed sensors 13A and 13B that detect the rotational speeds of the left rear wheel LWr and the right rear wheel RWr. The wheel speed sensors 13A and 13B function as second and fourth rotational state quantity detection means of the present invention.

  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, the rotational position information of the rotors 15A and 15B is transferred to the control walls of the first and second electric motors 2A and 2B on the end walls 17A and 17B of the reduction gear case 11 on the outer periphery on one end side of the cylindrical shafts 16A and 16B. Resolvers 20A and 20B are provided for feedback to (not shown). The resolvers 20A and 20B function as first and third rotational state amount detecting means of the present invention.

  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 gears 21A and 21B, and planetary gears 22A and 22B that support these planetary gears 22A and 22B. Carriers 23A, 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 decelerated. A driving force is output through the planetary carriers 23A and 23B.

  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. . 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.

  By the way, a cylindrical space is secured between the speed reducer case 11 and the ring gears 24A and 24B, and in the space, a released state or a fastened state is established, and rotation that restricts the rotation of the ring gears 24A and 24B in the fastened state. Hydraulic brakes 60A and 60B as restricting means are arranged so as to overlap the first pinions 26A and 26B in the radial direction and overlap the second pinions 27A and 27B in the axial direction. The hydraulic brakes 60A and 60B include a plurality of fixed plates 35A and 35B that are spline-fitted to the inner peripheral surface of a cylindrical outer diameter side support portion 34 that extends in the axial direction on the inner diameter side of the speed reducer case 11, a ring gear 24A, A plurality of rotating plates 36A, 36B that are spline-fitted on the outer peripheral surface of 24B are alternately arranged in the axial direction, and these plates 35A, 35B, 36A, 36B are fastened and released by the annular pistons 37A, 37B. It is like that. The pistons 37 </ b> A and 37 </ b> B are formed between the left and right dividing walls 39 extending from the intermediate position of the reduction gear case 11 to the inner diameter side, and the outer diameter side support portion 34 and the inner diameter side support portion 40 connected by the left and right division walls 39. The pistons 37A and 37B are moved forward by introducing high pressure oil into the cylinder chambers 38A and 38B, and the oil is discharged from the cylinder chambers 38A and 38B. The pistons 37A and 37B are moved backward. The hydraulic brakes 60A and 60B are connected to the electric oil pump 70 (see FIG. 1).

  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, 24B is allowed, and the power transmission path between the first and second electric motors 2A, 2B and the rear wheel Wr 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. That is, the ring gear 24A and the ring gear 24B are connected to each other by the inner race 51 so as to be integrally rotatable. 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. The engaged state is established, and when the reverse torque on the first and second motors 2A, 2B side is input to the rear wheel Wr, the disengaged state is established, and the forward torque on the rear wheel Wr side is the first. And when engaged with the second motor 2A, 2B, the engaged state when the reverse torque on the rear wheel Wr side is input to the first and second motors 2A, 2B. It becomes. 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 includes wheel speed sensor values, motor speeds of the first and second electric motors 2A and 2B. While the sensor value, steering angle, accelerator pedal opening AP, shift position, state of charge SOC in the battery 9, oil temperature, and the like are input, the control device 8 receives signals for controlling the internal combustion engine 4, first and second A signal for controlling the electric motors 2A and 2B, a signal for controlling the hydraulic brakes 60A and 60B, a control signal for controlling the electric oil pump 70, and the like are output.

  That is, the control device 8 has a function as an electric motor control device that controls the first and second electric motors 2A and 2B, and a function as a rotation regulating means control device that controls the hydraulic brakes 60A and 60B to a released state or an engaged state. At least.

  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. FIGS. 5 to 10 and FIGS. 12 to 17 represent speed collinear charts in each state of the rear-wheel drive device 1, where LMOT is the first motor 2A, RMOT is the second motor 2B, and the left S, C, PG is a sun gear 21A of the first planetary gear speed reducer 12A connected to the first electric motor 2A, a planetary carrier 23A of the first planetary gear speed reducer 12A, a planetary gear 22B of the second planetary gear speed reducer 12B, S, C, and PG are the sun gear 21B of the second planetary gear speed reducer 12B, the planetary carrier 23B of the second planetary gear speed reducer 12B, and the planetary gears 22A and R of the first planetary gear speed reducer 12A are first and second, respectively. The ring gears 24A, 24B, BRK of the planetary gear speed reducers 12A, 12B represent hydraulic brakes 60A, 60B, OWC, and 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 to be 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 to 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 locked 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. At this time, the first and second electric motors 2A and 2B are stopped and the hydraulic brakes 60A and 60B are controlled to be in a released state. The one-way clutch 50 is disengaged because the forward torque on the rear wheel Wr side is input to the first and second electric motors 2A, 2B, and the hydraulic brakes 60A, 60B are controlled to be released. The ring gears 24A and 24B start to rotate.

  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.

  By controlling the hydraulic brakes 60A and 60B to the released state, the ring gears 24A and 24B are allowed to freely rotate (hereinafter referred to as ring-free state), and the first and second electric motors 2A and 2B and the rear wheels Wr. The side is cut off and power transmission is impossible. 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. In the above, the first and second electric motors 2A and 2B are stopped in the ring-free state. However, the first and second electric motors 2A and 2B may be driven in the ring-free state (hereinafter simply referred to as ring-free control). Call it.) The ring free control will be described later.

  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 the engaged state (ON). Accordingly, the ring gears 24A and 24B are locked, 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 rear 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 disengaged (OFF), and the first and second motors 2A, 2B are not requested to drive, the first and first 2 The motors 2A and 2B are stopped, and when there is a drive request, ring-free control described later is performed. 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 one-way clutch 50 remains disengaged (OFF) and the hydraulic brakes 60A and 60B are engaged (ON). When the vehicle stops, the one-way clutch 50 is disengaged (OFF) and the hydraulic brakes 60A and 60B are released (OFF).

Next, ring free control will be described.
In the ring-free control, the one-way clutch 50 is disengaged and the hydraulic brakes 60A and 60B are disengaged, in other words, the free rotation of the coupled ring gears 24A and 24B is allowed (ring-free state). Drive control of the first and second electric motors 2A, 2B, in order to generate a target torque in the first and second electric motors 2A, 2B in order to generate a target yaw moment (target left-right difference torque) (target torque control), The first and / or second electric motors 2A and 2B are controlled to a target rotational speed (target rotational speed control), and the rotational speeds of the ring gears 24A and 24B are acquired (ring gear rotational speed acquisition control). In the following description, the rotational speed (r / min) is used as the rotational state quantity. However, the rotational speed is not limited to the rotational speed (r / min), and other rotational state quantities such as angular velocity (rad / s) may be used. . Similarly, although the motor torque (N · m) is used as the torque state quantity, other torque state quantities such as a motor current (A) correlated with the motor torque may be used.

<Target torque control>
In the ring-free state, as described above, the first and second electric motors 2A, 2B and the rear wheel Wr are cut off and cannot transmit power. And the second motor 2B is controlled so that the absolute value of the second motor 2B is equal to that of the first motor 2A in the opposite direction (reverse direction or forward direction). It is possible to generate the desired yaw moment by generating a left-right differential torque between the left rear wheel LWr and the right rear wheel RWr without causing a rotational speed fluctuation in 2B.

  For example, a case where a clockwise yaw moment M is generated in the vehicle 3 will be specifically described with reference to FIG. By performing torque control so that the first motor base torque TM1 in the forward direction is generated in the first motor 2A, the first motor base torque TM1 in the forward direction acts on the sun gear 21A. At this time, as in FIG. 9, forward torque (not shown) acting to travel forward from the axle 10 </ b> A is acting on the planetary carrier 23 </ b> A. Accordingly, in the first planetary gear type speed reducer 12A, the planetary carrier 23A serves as a fulcrum, and the forward first motor base torque TM1 acts on the sun gear 21A, which is the power point, so that it acts on the ring gears 24A, 24B, which are the action points. The first motor base torque distribution force TM1 'in the reverse direction acts. Note that in FIG. 12 and the subsequent figures, the vector due to the loss or the like that is constantly applied to each rotating element is also omitted.

  On the other hand, by performing torque control so that the second motor base torque TM2 in the reverse direction is generated in the second electric motor 2B, the second motor base torque TM2 in the reverse direction acts on the sun gear 21B. At this time, as in FIG. 9, forward torque (not shown) acting to travel forward from the axle 10 </ b> B acts on the planetary carrier 23 </ b> B. Therefore, in the second planetary gear type speed reducer 12B, the planetary carrier 23B serves as a fulcrum, and the second motor base torque TM2 in the reverse direction acts on the sun gear 21B, which is the power point, so that it acts on the ring gears 24A, 24B, which are the action points. The forward second motor base torque distributing force TM2 'acts.

  Here, since the first motor base torque TM1 and the second motor base torque TM2 are torques in the opposite directions having the same absolute value, the first motor base torque distributing force TM1 ′ acting in the reverse direction acting on the ring gears 24A and 24B and the forward direction. The second motor base torque distribution force TM2 'cancels each other (offset). Accordingly, the first motor base torque TM1 and the second motor base torque TM2 do not contribute to the rotation fluctuation, and the sun gears 21A and 21B and the ring gears 24A and 24B are maintained in their respective rotation states. At this time, the forward left rear wheel torque TT1 obtained by multiplying the first motor base torque TM1 by the reduction ratio of the first planetary gear type speed reducer 12A acts on the planetary carrier 23A, and the planetary carrier 23B has The right rear wheel torque TT2 in the reverse direction acts by multiplying the second motor base torque TM2 by the reduction ratio of the second planetary gear type reduction gear 12B.

  Since the reduction ratios of the first and second planetary gear type speed reducers 12A and 12B are equal, the left and right rear wheel torques TT1 and TT2 become torques in opposite directions having the same absolute value, and thereby the difference between the left and right rear wheel torques TT1 and TT2 ( A clockwise yaw moment M corresponding to TT1-TT2) is stably generated.

  The target motor base torque when the target torque control is performed on the first and second electric motors 2 </ b> A and 2 </ b> B is obtained based on the target yaw moment of the vehicle 3. A method of obtaining the target motor base torque will be described using the following formula.

  The left rear wheel target torque of the left rear wheel LWr is WTT1, the right rear wheel target torque of the right rear wheel RWr is WTT2, and the total target torque of the left and right rear wheels LWr and RWr (the sum of the left rear wheel torque and the right rear wheel torque) Where TTT is the target torque difference between the left and right rear wheels LWr and RWr (the difference between the left rear wheel torque and the right rear wheel torque) is ΔTT, the following equations (1) and (2) are established.

WTT1 + WTT2 = TRT (1)
WTT1-WTT2 = ΔTT (2)

ΔTT is expressed by the following equation (3), where YMT is the target yaw moment (clockwise is positive), r is the wheel radius, and Tr is the tread width (distance between the left and right rear wheels LWr and RWr).
ΔTT = 2 · r · YMT / Tr (3)

Here, in the ring-free state, torque in the same direction by the first and second electric motors 2A and 2B is not transmitted to the rear wheel Wr, so the total target torque TRT of the left and right rear wheels LWr and RWr is zero. Accordingly, the target torques WTT1 and WTT2 for the left and right rear wheels LWr and RWr are uniquely determined from the above equations (1) and (2).
That is, WWT1 = −WTT2 = ΔTT / 2 (4)

  When the target motor base torque of the first electric motor 2A connected to the left rear wheel LWr is TTM1, and the target motor base torque of the second electric motor 2B connected to the right rear wheel RWr is TTM2, The target motor base torques TTM1, TTM2 of the second electric motors 2A, 2B are derived from the following equations (5), (6).

TTM1 = (1 / Ratio) · WTT1 (5)
TTM2 = (1 / Ratio) · WTT2 (6)
Ratio is the reduction ratio of the first and second planetary gear type speed reducers 12A and 12B.

From the above formulas (4) to (6), the target motor base torques TTM1, TTM2 of the left and right first and second electric motors 2A, 2B are expressed by the following formulas (7), (8).
TTM1 = (1 / Ratio) · ΔTT / 2 (7)
TTM2 = − (1 / Ratio) · ΔTT / 2 (8)
Therefore, the target torque difference ΔTT between the left and right rear wheels LWr, RWr is obtained based on the target yaw moment YMT of the vehicle 3, and half the target torque difference ΔTT is divided by the reduction ratio of the first planetary gear type speed reducer 12A. By setting the values to the target motor base torques TTM1 and TTM2 of the first and second electric motors 2A and 2B for target torque control, the desired yaw moment can be generated.

<Target speed control>
In the ring-free state, that is, when the one-way clutch 50 is disengaged and the hydraulic brakes 60A and 60B are disengaged, the connected ring gear even if torque is generated in the same direction from the first and second electric motors 2A and 2B Since 24A and 24B are not locked and the above-described cancellation of the motor torque distribution force does not occur, torque is not transmitted to the rear wheel Wr, and the sun gears 21A and 21B (first and second electric motors 2A and 2B) Only the rotational speed fluctuations of the ring gears 24A and 24B occur.

  In this case, the first and / or second electric motors 2A and 2B generate the rotation control torque in the same direction having the same absolute value so that the rotation control torque is not transmitted to the rear wheel Wr and the first and / or second electric motors 2A. 2B can be controlled to an intended rotational speed.

  For example, the case where the rotation speeds of the first and second electric motors 2A and 2B are lowered is described as an example with reference to FIG. By performing torque control so that the first rotation control torque SM1 in the reverse direction is generated in the first motor 2A, the first rotation control torque SM1 in the reverse direction acts on the sun gear 21A. At this time, as in FIG. 9, forward torque (not shown) acting to travel forward from the axle 10 </ b> A is acting on the planetary carrier 23 </ b> A. Accordingly, in the first planetary gear type speed reducer 12A, the planetary carrier 23A serves as a fulcrum, and the first rotation control torque SM1 in the reverse direction acts on the sun gear 21A that is the power point, so that it acts on the ring gears 24A and 24B that are the action points. The first rotation control torque distribution force SM1 ′ in the forward direction acts.

  Similarly, by performing torque control so that the second rotation control torque SM2 in the reverse direction is generated in the second electric motor 2B, the second rotation control torque SM2 in the reverse direction acts on the sun gear 21B. At this time, as in FIG. 9, forward torque (not shown) acting to travel forward from the axle 10 </ b> B acts on the planetary carrier 23 </ b> B. Therefore, in the second planetary gear type speed reducer 12B, the planetary carrier 23B serves as a fulcrum, and the second rotation control torque SM2 in the reverse direction acts on the sun gear 21B that is the power point, so that it acts on the ring gears 24A and 24B that are the action points. The second rotation control torque distribution force SM2 ′ in the forward direction acts.

  Here, since the first and second rotation control torques SM1 and SM2 are torques in the same direction having the same absolute value, the first and second rotation control torque distribution forces SM1 ′ and SM2 ′ acting on the ring gears 24A and 24B are also absolute. The torques in the same direction have the same value, and the first and second rotation control torque distribution forces SM1 ′ and SM2 ′ act in the direction of increasing the rotation speed of the ring gears 24A and 24B. At this time, since the first and second planetary gear type speed reducers 12A and 12B do not have a torque balanced with the first and second rotation control torques SM1 and SM2, the planetary carriers 23A and 23B include the first and first planetary gear speed reducers 12A and 12B. The left and right rear wheel torque is not generated by the two-rotation control torques SM1 and SM2. Therefore, the first and second rotation control torques SM1 and SM2 contribute only to the rotation fluctuation, reduce the rotation speeds of the first and second electric motors 2A and 2B and the rotation speeds of the sun gears 21A and 21B, and increase the first and second rotation torques SM1 and SM2. The two-rotation control torque distribution forces SM1 ′ and SM2 ′ increase the rotation speed of the ring gears 24A and 24B. Thus, by appropriately generating the first and second rotation control torques SM1 and SM2, the first and second electric motors 2A and 2B can be controlled to arbitrary target rotational speeds, and the first and second electric motors are eventually added. 2A and 2B are motor target rotational speeds.

  Since the rear wheel drive device 1 is connected to the ring gears 24A and 24B, the rear wheel drive device 1 cannot be controlled to satisfy the motor target speed of the first electric motor 2A and the motor target speed of the second electric motor 2B at the same time. In this case, the target rotational speed of one of the motors is controlled so as to satisfy the motor target rotational speed of either one of the motors.

  Although not described in detail, in the ring-free state, target torque control for generating a target torque in the first and second motors 2A and 2B to generate a target yaw moment, and the first and / or second motor 2A. By simultaneously performing target rotational speed control for controlling 2B to the target rotational speed, the first and / or second electric motors 2A and 2B are controlled to the intended rotational speed while generating the desired yaw moment. It is also possible.

<Ring gear rotation speed acquisition control>
Next, ring gear rotation speed acquisition control, which is a feature of the present invention, will be described with reference to FIG. Since the ring gears 24A and 24B of the first and second planetary gear type speed reducers 12A and 12B are connected to each other and are always in the same rotation state, the single R is used in FIGS. However, in FIG. 13, the ring gears 24 </ b> A and 24 </ b> B are represented using two different Rs for convenience of explanation. The same applies to FIG. 14 described later.

  The ring gear rotation speed acquisition control is control for acquiring the rotation speeds of the ring gears 24A and 24B by the method described below in the above-described ring-free state. In the ring gear rotation speed acquisition control of the present invention, first, the resolver 20A detects a motor rotation speed detection value LMa (first rotation state amount detection value) that is the motor rotation speed of the first electric motor 2A, and the resolver 20B 2 The motor rotation speed detection value RMa (third rotation state amount detection value) that is the motor rotation speed of the electric motor 2B is detected, and the wheel speed sensor 13A detects the wheel rotation speed detection value LWa (the wheel rotation speed of the left wheel LWr). (Second rotation state amount detection value) is detected, and the wheel speed sensor 13B detects a wheel rotation number detection value RWa (fourth rotation state amount detection value) that is the wheel rotation number of the right wheel RWr.

  Next, the first ring gear rotational speed converted value LRb based on the motor rotational speed detection value LMa of the first electric motor 2A and the wheel rotational speed detection value LWa of the left wheel LWr and the reduction ratio of the first planetary gear type speed reducer 12A. (First 5th rotation state quantity conversion value) is calculated, the motor rotation speed detection value RMa of the second electric motor 2B and the wheel rotation speed detection value RWa of the right wheel RWr, and the reduction ratio of the second planetary gear type speed reducer 12B , The second ring gear rotation speed conversion value RRb (second fifth rotation state amount conversion value) is obtained.

  Here, theoretically, the first and second ring gear rotational speed converted values LRb and RRb are equal, but in practice, the first and second ring gear rotational speed converted values LRb and RRb are different depending on the torsional difference between the left and right power transmission paths, the backlash difference, and the like. Since the ring gear rotation speed conversion values LRb and RRb may be different, the ring gear rotation speed conversion value Rb is obtained based on the average value of the first ring gear rotation speed conversion value LRb and the second ring gear rotation speed conversion value RRb {Rb = (LRb + RRb) / 2}, the ring gear rotation speed conversion value Rb is acquired as the rotation speed (fifth rotation state quantity) of the connected ring gears 24A and 24B.

  The rotation speeds of the ring gears 24A and 24B acquired by the ring gear rotation speed acquisition control can be used for various controls based on the rotation speeds of the ring gears 24A and 24B. Therefore, the rotation speeds of the ring gears 24A and 24B are used. The accuracy and robustness of various controls to be controlled can be improved.

  When the one-way clutch 50 is engaged or when the hydraulic brakes 60A and 60B are controlled to be engaged by the control device 8, the rotation of the ring gears 24A and 24B is restricted, so that the ring gear rotation speed acquisition control is performed. It may be prohibited to obtain the ring gear rotation speed conversion value Rb based on the average value of the first and second ring gear rotation speed conversion values LRb and RRb without performing the above. Thereby, the time and energy consumed for calculating the first and second ring gear rotation speed conversion values LRb and RRb can be reduced.

<Motor traction control>
The rotation speeds of the ring gears 24A and 24B acquired by the ring gear rotation speed acquisition control can be applied to, for example, motor traction control control described below.

  In the motor traction control control, first, the control device 8 has a target wheel rotation speed LWc that is a target value of the wheel rotation speed of the left wheel LWr and a target wheel rotation speed RWc that is a target value of the wheel rotation speed of the right wheel RWr. , Get.

  Next, based on the target wheel rotational speeds LWc and RWc and the rotational speeds of the ring gears 24A and 24B (ring gear rotational speed converted values Rb) and the reduction ratios of the first and second planetary gear speed reducers 12A and 12B, Target motor rotational speeds LMc and RMc, which are target values of the motor rotational speeds of the first and second electric motors 2A and 2B, are obtained.

  When the difference between the target motor speeds LMc and RMa of the first and second electric motors 2A and 2B and the motor speed detection values LMa and RMa of the first and second electric motors 2A and 2B are equal to or greater than a predetermined value The left and right wheels LWr and RWr are judged to have slipped unacceptably, and the motor rotation speeds (motor rotation speed detection values LMa and RMa) of the first and second electric motors 2A and 2B approach the target motor rotation speeds LMc and RMC. Thus, torque down control is performed on the first and second electric motors 2A and 2B. As a result, the idling state of the left and right wheels LWr, RWr can be quickly resolved, energy consumption can be suppressed, and the unstable state of the vehicle 3 can be resolved.

  On the other hand, when the difference between the target motor rotational speeds LMC, RMC of the first and second electric motors 2A, 2B and the motor rotational speed detection values LMa, RMa of the first, second electric motors 2A, 2B is smaller than a predetermined value, It is determined that no slip has occurred or that an allowable range of slip has occurred, and the processing is terminated.

  More specifically, the motor traction control control when the left wheel LWr slips will be described with reference to FIG.

  First, the target wheel rotation speeds LWc and RWc of the left and right wheels LWr and RWr and the target motor rotation speeds LMc and RMc of the first and second electric motors 2A and 2B are obtained by the same method as described above. Then, the difference between the target motor rotational speeds LMc, RMc of the first and second electric motors 2A, 2B and the motor rotational speed detection values LMa, RMa of the first, second electric motors 2A, 2B are compared.

  As a result, the target motor rotational speed RMc of the second electric motor 2B and the motor rotational speed detection value RMa of the second electric motor 2B are substantially equal, so that the right wheel RWr does not slip or is in an allowable range. It is determined that slip has occurred, and the process is terminated. On the other hand, since the difference between the target motor rotation speed LMC of the first electric motor 2A and the motor rotation speed detection value LMa of the first electric motor 2A is greater than or equal to a predetermined value, it is determined that an unacceptable slip has occurred in the left wheel LWr. Then, torque reduction control is performed on the first electric motor 2A so that the motor rotation speed (motor rotation speed detection value LMa) of the first electric motor 2A approaches the target motor rotation speed LMC. Thereby, it becomes possible to suppress the slip of the left wheel LWr.

  As described above, according to the rear wheel drive device 1 of the present embodiment, the ring gears 24A and 24B of the first and second planetary gear speed reducers 12A and 12B are connected to each other. 24B is always the same rotation, and the first ring gear obtained based on the motor rotation speed detection value LMa of the first electric motor 2A detected by the resolver 20A and the wheel rotation speed detection value LWa of the left wheel LWr detected by the wheel speed sensor 13A. The second ring gear rotation obtained based on the rotational speed conversion value LRb, the motor rotational speed detection value RMa of the second electric motor 2B detected by the resolver 20B, and the wheel rotational speed detection value RWa of the right wheel RWr detected by the wheel speed sensor 13B. The number conversion value RRb is always the same value. Therefore, the ring gear 24A can be more accurately obtained by determining the rotation speed of the ring gears 24A and 24B (ring gear rotation speed conversion value Rb) based on the first ring gear rotation speed conversion value LRb and the second ring gear rotation speed conversion value RRb. , 24B can be obtained, and the accuracy and robustness of various controls using the rotational speeds of the ring gears 24A, 24B can be improved.

  In addition, the first and second ring gear rotational speed converted values LRb and RRb may be different from each other due to a torsional difference between the left and right power transmission paths, a backlash difference, and the like. Therefore, the ring gear 24A is based on an average value of these values. , 24B (ring gear rotation speed conversion value Rb) can be obtained to obtain the rotation speeds of the ring gears 24A and 24B more accurately.

  The target motor speeds LMc and RMc of the first and second electric motors 2A and 2B are calculated based on the accurately calculated ring gear speed conversion value Rb and the target wheel speeds LWc and RWc of the left and right wheels LWr and RWr. When the difference between the target motor rotational speed LMC, RMc and the motor rotational speed detection value LMa, RMa is equal to or greater than a predetermined value, the motor rotational speed (motor rotational speed detection value LMa, RMa) is the target motor rotational speed LMC, Since the first and second electric motors 2A and 2B are controlled so as to approach RMc, slipping of the left and right wheels LWr and RWr can be suppressed, and the stability and running performance of the vehicle 3 can be improved.

  Further, when the control device 8 controls the hydraulic brakes 60A and 60B to the released state, the rotation speed of the ring gears 24A and 24B (the ring gear rotation speed conversion value Rb), the first ring gear rotation speed conversion value LRb, and the second ring gear Since it calculates | requires based on rotation speed conversion value RRb, it is possible to acquire more accurately the rotation speed of ring gear 24A, 24B in a releasing state.

  In addition, when the control device 8 controls the hydraulic brakes 60A and 60B to the engaged state, when it is prohibited to obtain the first and second ring gear rotational speed converted values LRb and RRb, the ring gears 24A and 24B are not rotated. The time and energy consumed for calculating the first and second ring gear rotation speed conversion values LRb and RRb can be reduced.

In addition, this invention is not limited to embodiment mentioned above, A deformation | transformation, improvement, etc. are possible suitably.
For example, in the above-described embodiment, the motor rotation speed detection values LMa and RMa as the first and third rotation state quantities are detected by the resolvers 20A and 20B, and the wheel rotation speed detection as the second and fourth rotation state quantities is detected. The values LWa and RWa are detected by the wheel speed sensors 13A and 13B. However, the present invention is not limited to the above-described configuration, and the first and third rotational state quantities are the same as the first and second electric motors 2A and 2B during the ring-free control (for example, the first and second planetary gears). The speed of the sun gears 21A, 21B) of the speed reducers 12A, 12B, or the rotational speed of the portion that rotates at a constant ratio with respect to the first and second electric motors 2A, 2B at the time of ring-free control. The fourth rotational state amount is determined by the number of rotations of the part (for example, the planetary carriers 23A and 23B of the first and second planetary gear speed reducers 12A and 12B) that rotates in the same manner as the left and right wheels LWr and RWr during ring-free control, It is good also as a rotation speed of the site | part which rotates with a fixed ratio with respect to the left-right wheel LWr and RWr at the time of free control. In such a configuration, a sensor is appropriately arranged at each detection portion so that the number of rotations can be detected.

Further, the motor traction control control described above is performed using the rotation speeds of the ring gears 24A and 24B (ring gear rotation speed conversion value Rb) acquired by the ring gear rotation speed acquisition control. However, the rotation speeds of the ring gears 24A and 24B are changed. It is also possible to perform motor traction control control without using it.
In this case, when the difference between the target wheel rotation speeds LWc and RWc of the left and right wheels LWr and RWr and the wheel rotation speed detection values LWa and RWa of the left and right wheels LWr and RWr is greater than or equal to a predetermined value, the left and right wheels LWr and RWr are allowed. The first and second electric motors 2A and 2B are determined so that the slip which cannot be performed has occurred and the rotation speeds of the left and right wheels LWr and RWr (wheel rotation speed detection values LWa and RWa) approach the target wheel rotation speeds LWc and RWc. Torque down control.
Thus, in this motor traction control control, the presence or absence of occurrence of slip is determined based on the difference between the target wheel rotation speeds LWc and RWc and the wheel rotation speed detection values LWa and RWa detected by the wheel speed sensors 13A and 13B. doing. On the other hand, in the motor traction control control of the above-described embodiment, the presence / absence of occurrence of slip is determined based on the difference between the target motor speeds LMc and RMC and the motor speed detection values LMa and RMa detected by the resolvers 20A and 20B. doing. In general, the resolver 20A, 20B has a shorter detection interval and higher detection accuracy than the wheel speed sensors 13A, 13B. Therefore, the motor traction control control of the above-described embodiment is more accurately controlled. Is possible.

Further, it is not necessary to provide the hydraulic brakes 60A and 60B on the ring gears 24A and 24B, respectively, and it is sufficient that at least one hydraulic brake and one one-way clutch are provided on the connected ring gears 24A and 24B. Further, the one-way clutch may be omitted.
Moreover, although the hydraulic brake is illustrated as the rotation restricting means, the present invention is not limited to this, and a mechanical type, an electromagnetic type, or the like can be arbitrarily selected.
Further, the first and second electric motors 2A and 2B are connected to the sun gears 21A and 21B, and the ring gears are connected to each other. However, the present invention is not limited to this, the sun gears are connected to each other, and the first and second electric motors are connected to the ring gear. May be.
Further, the front wheel drive device may use an electric motor as a sole drive source without using an internal combustion engine.

1 Rear wheel drive system (vehicle drive system)
2A 1st motor 2B 2nd motor 3 Vehicle 8 Control device (motor control device, rotation restriction means control device)
12A First planetary gear type speed reducer (first transmission)
12B Second planetary gear type speed reducer (second transmission)
13A Wheel speed sensor (second rotational state quantity detection means)
13B Wheel speed sensor (fourth rotational state quantity detection means)
20A resolver (first rotation state quantity detection means)
20B resolver (third rotational state quantity detection means)
21A, 21B Sun gear (first rotating element)
23A, 23B Planetary carrier (second rotating element)
24A, 24B Ring gear (third rotating element)
60A, 60B Hydraulic brake (rotation restricting means)
LWr Left wheel RWr Right wheel LMa Motor rotation speed detection value (first rotation state amount detection value)
RMa Motor rotation number detection value (third rotation state amount detection value)
LWa wheel rotation speed detection value (second rotation state quantity detection value)
RWa Wheel rotation speed detection value (4th rotation state quantity detection value)
LRb 1st ring gear rotation speed conversion value (1st 5th rotation state amount conversion value)
RRb Second ring gear rotation number conversion value (second fifth rotation state amount conversion value)
Rb Ring gear rotation speed conversion value LMc, RMc Target motor rotation speed (target motor rotation state quantity)
LWc, RWc Target wheel rotation speed (target wheel rotation state quantity)

Claims (5)

A left wheel drive device comprising: a first electric motor for driving a left wheel of a vehicle; and a first transmission provided on a power transmission path between the first electric motor and the left wheel;
A right wheel driving device comprising: a second electric motor that drives the right wheel of the vehicle; and a second transmission that is provided on a power transmission path between the second electric motor and the right wheel;
An electric motor control device for controlling the first electric motor and the second electric motor;
A vehicle drive device comprising:
The first and second transmissions each have first to third rotating elements,
The first electric motor is connected to the first rotating element of the first transmission;
The second electric motor is connected to the first rotating element of the second transmission;
The left wheel is connected to the second rotating element of the first transmission;
The right wheel is connected to the second rotating element of the second transmission;
The third rotating element of the first transmission and the third rotating element of the second transmission are connected to each other;
The vehicle drive device comprises:
A first rotation state amount detection means installed so as to be able to detect a rotation state amount of the first electric motor or a rotation state amount of the first rotation element of the first transmission;
A second rotational state amount detecting means installed so as to be able to detect a rotational state amount of the left wheel or a rotational state amount of the second rotational element of the first transmission;
A third rotation state amount detecting means installed so as to detect a rotation state amount of the second electric motor or a rotation state amount of the first rotation element of the second transmission;
A fourth rotational state amount detecting means installed so as to be capable of detecting a rotational state amount of the right wheel or a rotational state amount of the second rotational element of the second transmission;
With
A fifth rotational state quantity that is a rotational state quantity of the third rotational elements coupled to each other ;
The third rotations connected to each other obtained based on the first rotation state amount detection value detected by the first rotation state amount detection means and the second rotation state amount detection value detected by the second rotation state amount detection means. A first fifth rotational state amount converted value that is a converted value of the rotational state amount of the element;
The third rotations connected to each other obtained based on the third rotation state amount detection value detected by the third rotation state amount detection means and the fourth rotation state amount detection value detected by the fourth rotation state amount detection means. A second fifth rotational state amount converted value that is a converted value of the rotational state amount of the element;
The vehicle drive apparatus characterized by calculating | requiring based on this. 2. The vehicle according to claim 1, wherein the fifth rotational state quantity is obtained based on an average value of the first fifth rotational state quantity converted value and the second fifth rotational state quantity converted value. Drive device. The electric motor control device acquires a target wheel rotation state amount that is a target value of the second rotation state amount or a target value of the fourth rotation state amount,
Based on the target wheel rotation state amount and the fifth rotation state amount, a target motor rotation state amount that is a target value of the first rotation state amount or a target value of the third rotation state amount is obtained,
When the difference between the target motor rotation state quantity and the motor rotation state quantity that is the first rotation state quantity or the third rotation state quantity is greater than or equal to a predetermined value, the motor rotation state quantity is the target motor rotation state quantity. 3. The vehicle drive device according to claim 1, wherein the first electric motor or the second electric motor is controlled so as to approach to the vehicle. A rotation restricting means for restricting the rotation of the third rotating elements that are switchable to a released state or a fastened state and are connected to each other in the fastened state;
A rotation regulating means control device for controlling the rotation regulating means to a released state or a fastening state;
With
When the rotation restricting means control device controls the rotation restricting means to the released state, the fifth rotation state amount is converted into the first fifth rotation state amount converted value and the second fifth rotation state amount converted value. The vehicle drive device according to claim 1, wherein the vehicle drive device is calculated based on 5. The vehicle drive device according to claim 4, wherein when the rotation restriction unit control device controls the rotation restriction unit to be in a fastening state, the vehicle drive device according to claim 4 is prohibited from obtaining the fifth rotation state amount.

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