JP6014346B2 - 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.

  Patent Document 2 discloses a motor that detects the rotational speed of an electric motor in a drive vehicle in which wheels are driven by an electric motor via a drive shaft and the drive shaft and the electric motor are disconnected and connected by a clutch. By connecting the clutch when the rotational speed difference between the electric motor and the drive shaft detected by the rotational speed detection means and the drive shaft rotational speed detection means for detecting the rotational speed of the drive shaft is smaller than a predetermined value, Techniques for preventing connection shocks are disclosed.

  However, in the vehicle drive device described in Patent Document 1, there is no description about what to do when one of the motor rotation speed detection means and the drive shaft rotation speed detection means fails.

  On the other hand, in Patent Document 3, in a vehicle including a wheel speed sensor that detects the rotational speed of a wheel and a vehicle speed sensor that detects the rotational speed of a power transmission system, a value detected by either one of the two sensors and the other A technique is disclosed in which one of the two sensors is determined to be faulty when there is a substantial difference in the detected values.

Japanese Patent No. 3138799 JP 2002-160541 A Japanese Utility Model Publication No. 63-23650

  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, the ring gear, sun gear (electric motor), and planetary carrier (wheel) may rotate at the same time, but the control at this time is not described at all.

  In this case, the techniques of Patent Documents 2 and 3 are applied, and various controls are performed according to the rotation speed of the motor and / or the rotation speed of the wheels detected by the motor rotation speed detection means and / or the drive shaft rotation speed detection means. It is possible. At that time, it is desirable that accurate control be continued even when it is determined that one of the two means is a failure. In that regard, the technology described in Patent Document 3 does not disclose any control after determining that one of the two sensors is faulty, and there is room for improvement in controllability.

  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;
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 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. First third rotational element rotational state amount converted value (for example, first ring gear rotational speed converted value LRb in an embodiment described later) obtained based on a detected value (for example, a wheel rotational speed detected value LWa in an embodiment described later). When,
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. Second third rotational element rotational state amount converted value (for example, second ring gear rotational speed converted value RRb in an embodiment described later) obtained based on a detected value (for example, a wheel rotational speed detected value RWa in an embodiment described later). When,
When the difference is equal to or greater than a predetermined value, the control based on the first to fourth rotational state quantity detecting means is prohibited, or an abnormality of the first to fourth rotational state quantity detecting means is detected. .

In addition to the configuration of claim 1, the invention described in claim 2 can be switched to a released state or a fastened state, and a rotation restricting means for restricting the rotation of the third rotating element in the fastened state (for example, Hydraulic brakes 60A, 60B) in the 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 regulating means control device controls the rotation regulating means to the released state, and the difference is equal to or greater than the predetermined value, the engagement state is set based on the first to fourth rotation state amount detection values. It is prohibited to control, or an abnormality of the first to fourth rotation state quantity detecting means is detected.

In addition to the configuration described in claim 1 or 2, the invention according to claim 3 is configured such that the rotation state amount of the third rotation element is converted into the first third rotation element rotation state amount converted value and the first rotation element amount. Calculated based on the second third rotation element rotation state amount conversion value,
The calculation is prohibited when the difference is greater than or equal to the predetermined value.

The invention according to claim 4
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;
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;
A one-way rotation restricting means (for example, a one-way clutch 50 in an embodiment described later) that allows one-way rotation of the third rotation element and restricts rotation in the reverse direction;
With
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. First third rotational element rotational state amount converted value (for example, first ring gear rotational speed converted value LRb in an embodiment described later) obtained based on a detected value (for example, a wheel rotational speed detected value LWa in an embodiment described later). Is in the region showing the reverse rotation of the third rotation element, prohibiting control based on the second rotation state amount detection means, or detecting an abnormality of the second rotation state amount detection means,
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. Second third rotational element rotational state amount converted value (for example, second ring gear rotational speed converted value RRb in an embodiment described later) obtained based on a detected value (for example, a wheel rotational speed detected value RWa in an embodiment described later). Is in a region indicating the reverse rotation of the third rotation element, prohibiting control based on the fourth rotation state amount detection means, or detecting an abnormality in the fourth rotation state amount detection means It is characterized by.

According to the first aspect of the present invention, since the third rotating element of the first transmission and the third rotating element of the second transmission are connected to each other, the first to fourth rotation detection amount detecting means are normal. If there is, the first third rotation element rotation 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. The second third value obtained based on the 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. The rotation element rotation state amount converted value is equal.
Therefore, when the difference between the first third rotation element rotation state amount converted value and the second third rotation element rotation state amount conversion value is equal to or greater than a predetermined value, any of the first to fourth rotation detection amount detection means It is possible to prevent improper control from being executed by detecting the occurrence of a crab and prohibiting the control based on the first to fourth rotation detection amount detection means.

According to the invention of claim 2, in the state where the rotation restricting means control device controls the rotation restricting means to the released state, the first third rotating element rotating state amount converted value and the second third rotating element rotating state amount converted. When the difference between the value and the value is equal to or greater than a predetermined value, it is prohibited to control the rotation restricting means to the engaged state based on the first to fourth rotation state amount detection values.
Accordingly, it is possible to prevent erroneous control of the rotation restricting means due to any one of the first to fourth rotation state amount detection values being abnormal. In particular, when the second rotation state amount or the fourth rotation state amount is large, the rotation restricting means is erroneously controlled to the engaged state, and the first rotation state amount or the third rotation state amount increases rapidly, and the first electric motor Alternatively, it is possible to prevent the second electric motor from over-rotating.

According to the invention of claim 3, the rotation state amount of the third rotation element is calculated based on the first third rotation element rotation state amount conversion value and the second third rotation element rotation state amount conversion value. Therefore, the rotational state quantity of the third rotating element can be obtained more accurately, and the accuracy and robustness of various controls using the rotational state quantity of the third rotating element can be improved.
Further, when the difference between the first third rotational element rotational state amount converted value and the second third rotational element rotational state amount converted value is a predetermined value or more, the calculation of the rotational state amount of the third rotational element is prohibited. Therefore, it is possible to prevent erroneous control of various controls using the rotation state quantity of the third rotating element.

According to the invention of claim 4, since the reverse rotation of the third rotating element is restricted by the one-way rotation restricting means, the first rotational state quantity detection value detected by the first rotational state quantity detecting means and the first When the first third rotation element rotation state amount converted value obtained based on the second rotation state amount detection value detected by the two rotation state amount detection means is in the region indicating the reverse rotation of the third rotation element, By detecting an abnormality in the second rotation state quantity detection means and prohibiting the control based on the second rotation state quantity detection means, it is possible to prevent improper control execution.
Further, the second third rotation element rotation state 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. When the amount converted value is in the region indicating the reverse rotation of the third rotation element, by detecting an abnormality of the fourth rotation state amount detection means and prohibiting the control based on the fourth rotation state amount detection means, Inappropriate control can be prevented from being executed.

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 operation 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 the wheel speed sensor 13B is broken. It is a speed alignment chart of the rear-wheel drive device when the resolver 20B breaks down. It is a speed alignment chart of the rear-wheel drive device when the wheel speed sensor 13A breaks down. It is a speed alignment chart of the rear-wheel drive device when the resolver 20A breaks down.

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, 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, 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 any 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.

  Next, the abnormality detection control that is a feature of the present invention will be described. 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. .

<Abnormality detection control>
In the ring-free state described above, the abnormality detection control includes the motor rotation speed detection value LMa (first rotation state amount detection value) detected by the resolver 20A and the wheel rotation speed detection value LWa (second rotation) detected by the wheel speed sensor 13A. The first ring gear rotation speed conversion value LRb obtained based on the state quantity detection value), the motor rotation speed detection value RMa (third rotation state quantity detection value) detected by the resolver 20B, and the wheel rotation detected by the wheel speed sensor 13B. When the difference from the second ring gear rotation number conversion value RRb obtained based on the number detection value LWa (fourth rotation state amount detection value) is a predetermined value or more, the resolvers 20A and 20B and the wheel speed sensors 13A and 13B This control is based on prohibiting the control based on the detection or detecting an abnormality in the resolvers 20A and 20B and the wheel speed sensors 13A and 13B.

  As shown in FIG. 13, when the resolvers 20A and 20B and the wheel speed sensors 13A and 13B are functioning normally, in the ring-free state, the motor rotation speed detection value LMa and the wheel speed sensor 13A detected by the resolver 20A are detected. The first ring gear rotation speed converted value LRb, which is the rotation speed of the ring gear 24A obtained based on the detected wheel rotation speed detection value LWa, the motor rotation speed detection value RMa detected by the resolver 20B, and the wheel rotation detected by the wheel speed sensor 13B. The second ring gear rotation speed conversion value RRb, which is the rotation speed of the ring gear 24B obtained based on the number detection value RWa, matches because the ring gears 24A and 24B are connected to each other (LRb = RRb). Here, the first ring gear rotation speed conversion value LRb is calculated based on the motor rotation speed detection value LMa and the wheel rotation speed detection value LWa and the reduction ratio of the first planetary gear type speed reducer 12A. The rotation speed conversion value RRb is calculated based on the motor rotation speed detection value RMa and the wheel rotation speed detection value RWa and the reduction ratio of the second planetary gear speed reducer 12B. 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 FIGS. 14 to 17 described later.

  On the other hand, when the sensors such as the resolvers 20A and 20B and the wheel speed sensors 13A and 13B are broken due to disconnection or the like, a rotation speed lower than the normal rotation speed (including zero rotation) is output from the failed sensor as a signal. Sent.

  For example, when the wheel speed sensor 13B breaks down, as shown in FIG. 14, the wheel rotation speed detection value RWa is grounded (RWa = 0). At this time, the second ring gear rotation speed conversion value RRb obtained based on the motor rotation speed detection value RMa and the wheel rotation speed detection value RWa is a negative value indicating the reverse rotation of the ring gear 23B (RRb <0). . Here, the second ring gear rotational speed converted value RRb is smaller than the first ring gear rotational speed converted value LRb which is a normal value obtained based on the motor rotational speed detected value LMa and the wheel rotational speed detected value LWa (RRb < LRb), which is an abnormal value. Further, since the one-way clutch 50 is configured to restrict the rotation of the ring gears 23A and 23B in the reverse direction, the rotation speed of the ring gears 23A and 23B cannot be a negative value. It can be seen that the second ring gear rotation speed conversion value RRb is an abnormal value.

  Further, when the resolver 20B breaks down, as shown in FIG. 15, the motor rotation speed detection value RMa has a ground fault (RMa = 0). At this time, the second ring gear rotation speed conversion value RRb obtained based on the motor rotation speed detection value RMa and the wheel rotation speed detection value RWa is obtained normally based on the motor rotation speed detection value LMa and the wheel rotation speed detection value LWa. It is larger than the first ring gear rotational speed converted value LRb which is a small value (RRb> LRb), and it is understood that the value is abnormal.

  When the wheel speed sensor 13A breaks down, as shown in FIG. 16, the wheel rotation speed detection value LWa is grounded (LWa = 0). At this time, the first ring gear rotation speed conversion value LRb obtained based on the motor rotation speed detection value LMa and the wheel rotation speed detection value LWa is a negative value indicating the reverse rotation of the ring gear 23A (LRb <0). . Here, the first ring gear rotational speed converted value LRb is smaller than the second ring gear rotational speed converted value RRb which is a normal value obtained based on the motor rotational speed detected value RMa and the wheel rotational speed detected value RWa (LRb < RRb), an abnormal value. Further, since the one-way clutch 50 is configured to restrict the reverse rotation of the ring gears 24A and 24B, the rotation speed of the ring gears 24A and 24B cannot be a negative value. It can be seen that the first ring gear rotation speed conversion value LRb is an abnormal value.

  Further, when the resolver 20A breaks down, as shown in FIG. 17, the motor rotation speed detection value LMa is grounded (LMa = 0). At this time, the first ring gear rotation speed converted value LRb obtained based on the motor rotation speed detection value LMa and the wheel rotation speed detection value LWa is obtained normally based on the motor rotation speed detection value RMa and the wheel rotation speed detection value RWa. It is larger than the second ring gear rotation speed conversion value RRb which is a small value (LRb> RRb), and it can be seen that the value is abnormal.

Thus, when any of the wheel speed sensors 13A, 13B and the resolvers 20A, 20B fails, the difference between the first ring gear rotational speed converted value LRb and the second ring gear rotational speed converted value RRb is equal to or greater than a predetermined value. .
In particular, when the wheel speed sensor 13A fails, the first ring gear rotation number conversion value LRb becomes a negative value to indicate the reverse rotation of the ring gear 23A (LRb <0), and the wheel speed sensor 13B fails. Indicates a reverse rotation of the ring gear 23B when the second ring gear rotation speed conversion value RRb is a negative value (RRb <0).

  Therefore, in the abnormality detection control of the present invention, when the difference between the first ring gear rotational speed converted value LRb and the second ring gear rotational speed converted value RRb is equal to or larger than a predetermined value set in advance, the resolvers 20A, 20B, wheels It is detected that an abnormality has occurred in either of the speed sensors 13A and 13B, and control based on the resolvers 20A and 20B and the wheel speed sensors 13A and 13B is prohibited. Thereby, execution of improper control based on the resolvers 20A and 20B and the wheel speed sensors 13A and 13B in which an abnormality has occurred can be prevented.

  Further, when the first ring gear rotational speed converted value LRb is in a region indicating the reverse rotation of the ring gear 24A (LRb <0), an abnormality of the wheel speed sensor 13A is detected, and control based on the wheel speed sensor 13A is prohibited. When the second ring gear rotational speed converted value RRb is in a region indicating the reverse rotation of the ring gear 24B (RRb <0), an abnormality of the wheel speed sensor 13B is detected and control based on the wheel speed sensor 13B is prohibited. To do. As a result, it is possible to prevent execution of inappropriate control based on the resolvers 20A and 20B and the wheel speed sensors 13A and 13B.

Further, when the difference between the first ring gear rotational speed converted value LRb and the second ring gear rotational speed converted value RRb is equal to or larger than a predetermined value set in advance, the control device 8 detects the motor rotational speed detected values LMa, RMa and the wheels. It is prohibited to control the hydraulic brakes 60A and 60B to the engaged state based on the rotation speed detection values LWa and RWa. Thereby, erroneous control of the hydraulic brakes 60A and 60B caused by any of the resolvers 20A and 20B and the wheel speed sensors 13A and 13B being abnormal can be prevented.
In particular, if the hydraulic brakes 60A and 60B are erroneously controlled to the engaged state when the rotation speed of the left rear wheel LWr or the rotation speed of the right rear wheel RWr is large, the first or the left rear wheel LWr or the right rear wheel RWr Since the second electric motors 2A and 2B can transmit power, and the rotation speed of the first or second electric motors 2A and 2B may increase rapidly, the configuration of the present invention is the first or second electric motor 2A. This is particularly effective for preventing 2B over-rotation.

Further, when the difference between the first ring gear rotational speed converted value LRb and the second ring gear rotational speed converted value RRb is smaller than a predetermined value set in advance, all of the resolvers 20A and 20B and the wheel speed sensors 13A and 13B are normal. (See FIG. 13), and the rotation speeds of the ring gears 24A and 24B are calculated based on the first ring gear rotation speed conversion value LRb and the second ring gear rotation speed conversion value RRb. 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 of the connected ring gears 24A and 24B. Therefore, the rotational speeds of the ring gears 24A and 24B can be obtained more accurately, and the accuracy and robustness of various controls using the rotational speeds of the ring gears 24A and 24B can be improved.
On the other hand, when the difference between the first ring gear rotational speed converted value LRb and the second ring gear rotational speed converted value RRb is equal to or greater than a predetermined value set in advance, the first ring gear rotational speed converted value LRb and the second ring gear rotational speed converted value RRb Since either of these is an abnormal value, the calculation of the rotational speeds of the ring gears 24A and 24B described above is prohibited, and erroneous control of various controls using the rotational speeds of the ring gears 24A and 24B is prevented.

In addition, this invention is not limited to embodiment mentioned above, A deformation | transformation, improvement, etc. are possible suitably.
In the above-described embodiment, the motor rotational speed detection values LMa and RMa as the first and third rotational state quantities are detected by the resolvers 20A and 20B, and the wheel rotational speed detection as the second and fourth rotational 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, 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.
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 electric motor 2B 2nd electric motor 3 Vehicle 8 Control apparatus (rotation control means control apparatus)
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)
50 One-way clutch (one-way rotation restricting means)
60A, 60B Hydraulic brake (rotation restricting means)
LWr Left rear wheel (left wheel)
RWr Left rear wheel (right wheel)
LMa Motor rotation speed detection value (first rotation state quantity 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 3rd rotation element rotation state amount conversion value)
RRb Second ring gear rotation number conversion value (second third rotation element rotation state amount conversion value)
Rb Ring gear speed conversion value

Claims (4)

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;
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
The first third rotation element rotation state 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. Amount-converted value and
A second third rotation element rotation state 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. Amount-converted value and
When the difference is equal to or greater than a predetermined value, the control based on the first to fourth rotational state quantity detecting means is prohibited, or an abnormality of the first to fourth rotational state quantity detecting means is detected. Vehicle drive device. A rotation restricting means that is switchable to a released state or an engaged state, and restricts the rotation of the third rotating element in the engaged 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 regulating means control device controls the rotation regulating means to the released state, and the difference is equal to or greater than the predetermined value, the engagement state is set based on the first to fourth rotation state amount detection values. 2. The vehicle drive device according to claim 1, wherein control is prohibited or an abnormality of the first to fourth rotation state amount detection means is detected. A rotation state amount of the third rotation element is calculated based on the first third rotation element rotation state amount conversion value and the second third rotation element rotation state amount conversion value;
The vehicle drive device according to claim 1, wherein the calculation is prohibited when the difference is equal to or greater than the predetermined value. 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;
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;
Unidirectional rotation restricting means for allowing rotation in one direction of the third rotating element and restricting rotation in the reverse direction;
With
The first third rotation element rotation state 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. When the amount converted value is in a region indicating the reverse rotation of the third rotation element, the control based on the second rotation state amount detection unit is prohibited, or an abnormality of the second rotation state amount detection unit is detected. Detect
A second third rotation element rotation state 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. When the amount conversion value is in a region indicating the reverse rotation of the third rotation element, the control based on the fourth rotation state amount detection unit is prohibited, or the abnormality of the fourth rotation state amount detection unit is detected. A vehicle drive device that detects the vehicle.

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