JP2008089075A - Driving force distributing device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To execute both right-and-left driving force distribution control and fore-and-aft driving force distribution control by a single power source. <P>SOLUTION: When an electric motor 32 is rotationally driven in the normal direction in a state that an electric motor 32 and a second carrier C2 are cut off by releasing a clutch CL, a differential case 26i of a differential gear device 26 for rear wheels is rotationally driven through the medium of an one-way clutch 54 to equally distribute motor torque to left and right rear wheels 30L, 30R. By so doing, driving force distribution control of front and rear wheels can be executed by torque control of the electric motor 32. When connecting the electric motor 32 and second carrier C2 through the engagement of the clutch CL, the device is brought into a first unequally distributed state for accelerating the right rear wheel 30R or a second unequally distributed state for accelerating the left rear wheel 30L in response to a rotational drive direction of the electric motor 32. By controlling the rotational drive direction and torque of the electric motor 32, the driving force distribution control of left and right rear wheels 30L, 30R can be executed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a vehicle driving force distribution device, and more particularly to an improvement of a driving force distribution device for left and right drive wheels.

2. Description of the Related Art A driving force distribution device that can distribute torque to front and rear wheels during wheel idling is known. The driving force distribution device described in Patent Document 1 is an example, and the left and right front wheels are rotationally driven by the engine, while the left and right rear wheels are rotationally driven by two independently provided electric motors. By evenly operating the left and right electric motors and evenly distributing the left and right rear wheels, the front and rear wheels can be used with a large driving force even on low μ roads where the front wheels slip. You can travel. In such a driving force distribution device, the left and right electric motors are operated non-uniformly, thereby setting the first unequal distribution state in which either one of the left and right rear wheels is accelerated, or the left and right rear wheels. It is possible to set the other of the two to be in a second unequal distribution state in which the vehicle speed is increased. By setting the unequal distribution state in VSC (Vehicle Stability Control) control, cornering control, etc., vehicle running stability, cornering performance, etc. Can be improved.
JP 63-203429 A

  However, if the left and right wheels are driven separately using two electric motors in this way, the cost increases and the weight increases, so that the left and right driving force distribution control can be performed with a single power source. It is desirable.

  The driving conditions that require torque distribution to the front and rear wheels are situations when the vehicle speed is extremely low, such as when the vehicle is stuck or starting on a low μ road, and the yaw moment is intentionally increased for the purpose of driving stability. It cannot occur under the situation where torque distribution to the left and right wheels is required. That is, it is almost unnecessary to perform the left / right driving force distribution control and the front / rear driving force distribution control at the same time, so that it can be performed by a single power source including not only the left / right driving force distribution control but also the front / rear driving force distribution control. It is desirable to make it.

  The present invention has been made in the background of the above circumstances, and its object is to enable left and right driving force distribution control and front and rear driving force distribution control to be performed with a single power source. .

  In order to achieve this object, the first invention provides an equal distribution state in which the torque of the power source is evenly distributed to the left and right drive wheels, and one first wheel of the left and right drive wheels based on the torque of the power source. A first unequal distribution state in which the speed is increased and a second unequal distribution state in which the other second wheel side of the left and right drive wheels is accelerated based on the torque of the power source. (A) a differential gear device that evenly distributes the power transmitted to the first input member to the left and right drive wheels; (b) When the second input member is rotated forward, the first wheel side is accelerated based on the torque input to the second input member, and when the second input member is driven reversely, the second input member is accelerated. Mechanically configured to increase the speed of the second wheel side based on the torque input to the input member. Drive force unequal distribution mechanism, (c) a first interrupting device for connecting and disconnecting the power source and the first input member, and (d) connecting and disconnecting the power source and the second input member. And (e) the power source is capable of rotating in both forward and reverse directions.

  A second aspect of the present invention is the vehicle driving force distribution device according to the first aspect, wherein (a) the power source is for assisting, and (b) the first intermittent device is configured such that the first input member is the power source during forward travel. The one-way clutch is characterized in that it is allowed to rotate at a rotational speed equal to or higher than the rotational speed of the power source while preventing the rotational speed from being reduced below the rotational speed of the power source.

  According to a third aspect of the present invention, there is provided the vehicle driving force distribution device according to the first or second aspect, wherein the driving force unequal distribution mechanism comprises: (a) a pair of planets each comprising three rotating elements: a sun gear, a carrier, and a ring gear; The rotating device includes a gear device, and one rotating element of the pair of planetary gear devices is connected to each other, thereby forming five rotating elements that can rotate relative to each other, and (b) each of the five rotating elements. In a collinear chart in which the rotation speed of the first planetary gear unit can be connected by a straight line for each of the pair of planetary gear devices, the first rotation element, the second rotation element, the third rotation element, the fourth rotation element, and the fifth rotation element from one end In this case, the first rotating element is connected to the second wheel, the second rotating element is fixed to be non-rotatable, and the third rotating element is connected to the pair of planetary gear devices and is rotatably held. 4th Rolling elements in the second input member, a fifth rotating element is characterized by being connected to the first input member and the first wheel.

  In such a vehicle driving force distribution device, when the power source and the first input member are connected by the first interrupting device with the second interrupting device shut off, the power source torque is applied to the differential gear device. Therefore, the driving force distribution control of the front and rear wheels can be performed by the torque control of the power source. Further, when the power source and the second input member are connected by the second interrupting device in a state where the first interrupting device is disconnected, the first wheel side according to the rotational driving direction of the power source by the driving force unequal distribution mechanism. The first unequal distribution state for accelerating the vehicle or the second unequal distribution state for accelerating the second wheel side, so that the driving force of the left and right wheels is controlled by controlling the rotational drive direction and torque of the power source. Distribution control can be performed.

  Thus, according to the driving force distribution device of the present invention, the front / rear driving force distribution control and the left / right driving force distribution control can be performed with a single power source, and therefore, an electric motor is provided for each of the left and right wheels. Compared to the case, it is possible to reduce the weight and cost of the vehicle.

  In the second invention, a one-way clutch is used as the first interrupting device, and the first input member is allowed to rotate at a speed equal to or higher than the rotational speed of the power source during forward traveling, and is lower than the rotational speed of the power source. For example, if the power source is actuated when starting in the forward direction or accelerating, the power source torque is evenly distributed to the left and right drive wheels via the one-way clutch and differential gear unit. If the operation of the power source is stopped when it reaches a predetermined traveling state, the power source and the differential gear device are automatically operated by the action of the one-way clutch. Therefore, the assist torque can be generated as needed only by the torque control of the power source, and the assist control can be easily performed.

  In the third aspect of the invention, since the driving force unequal distribution mechanism is configured using a pair of planetary gear devices, it can be configured simply and compactly.

  The present invention is suitably applied to a front and rear wheel drive vehicle such as a four wheel drive vehicle in which one of the front and rear wheels is rotationally driven by a main power source such as an engine and the other front and rear wheels are driven by the driving force distribution device of the present invention. Is done. In this case, the torque of the main power source can be transmitted to the other wheel driven by the driving force distribution device of the present invention at all times or via a clutch or the like as necessary. That is, the first input member and the main power source are connected via a propeller shaft or the like. The auxiliary power source provided separately from the main power source may be connected to the first input member, and the front and rear wheels may be completely separated and driven separately. .

  As a power source capable of rotationally driving in both forward and reverse directions used in the driving force distribution device of the present invention, an electric motor is preferably used. However, a hydraulic motor or the like can be used, and both the electric motor and the generator can be used. A motor generator having a function can also be employed. It is also possible to configure a power source including a reverse rotation mechanism using a planetary gear device, a counter shaft, or the like.

  As the differential gear device, a bevel gear type differential gear device or a double pinion type planetary gear device is used. As the first interrupting device, a one-way clutch is preferably used as in the second invention, but it is also possible to use a friction engagement device such as an electromagnetic clutch or a hydraulic clutch capable of arbitrarily adjusting the engagement torque. It is. A pair of one-way clutches can be combined in the opposite direction so that front-rear driving force distribution control and left-right driving force distribution control can be performed both forward and backward. If a two-way clutch in which the sprags are reversed and the lock direction is switched in accordance with the direction of input rotation is adopted, a simple and compact configuration can be achieved. As the second interrupting device, an electromagnetic clutch or a hydraulic clutch is preferably used.

  As the drive force unequal distribution mechanism, a combination of a pair of planetary gear units as in the third aspect of the invention is preferably used. However, a bevel gear type differential gear unit or a countershaft is used. It is also possible to configure. The driving force unequal distribution mechanism of the third invention will be specifically described. For example, (a) a single pinion type first planetary gear device having a first sun gear, a first carrier, and a first ring gear, a second sun gear, A first pinion type second planetary gear device having a second carrier and a second ring gear, and the first ring gear and the second ring gear are integrally connected to each other, (b) the first sun gear Is connected to the second wheel by the first rotating element, the first carrier is fixed to the case by the second rotating element, and the first ring gear and the second ring gear coupled to each other are rotatable by the third rotating element. And the second carrier is connected to the power source via the second interrupting device at the fourth rotating element, that is, the second input member, and the second sun gear is connected to the first sun gear. Configured to be connected to the first input member or the first wheel in rotating element. In this case, if the first planetary gear device and the second planetary gear device having the same gear ratio ρ (the number of teeth of the sun gear / the number of teeth of the ring gear) are employed, the first ring gear and the second planetary gear device are used. A common ring gear can be used as the ring gear.

  According to another aspect of the drive force unequal distribution mechanism of the third aspect of the invention, (a) a double pinion type first planetary gear device having a first sun gear, a first carrier, and a first ring gear, a second sun gear, A double pinion type second planetary gear device having a carrier and a second ring gear, and the first carrier and the second carrier are integrally connected to each other, and (b) the first sun gear is The first rotating element is connected to the second wheel, the first ring gear is fixed to the case by the second rotating element, and the first carrier and the second carrier coupled to each other are rotatable by the third rotating element. A second ring gear is connected to the power source via the second interrupting device at the fourth rotating element, that is, a second input member, and a second sun gear is connected to the first input member at the fifth rotating element. Other configured to be connected to the first wheel. In this case, if the first planetary gear device and the second planetary gear device having the same size and the same gear ratio ρ are employed, a common pinion gear is used as the pinion gear of the first planetary gear device and the second planetary gear device. Can be used.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a configuration diagram illustrating a vehicle drive device 10 to which the present invention is applied, and is for a four-wheel drive vehicle based on a front engine front wheel drive (FF). In FIG. 1, the output generated by the engine 12 which is the main power source is the torque converter 13, the transmission 14, the front wheel differential gear device 16, and the left and right front wheel axles 18L and 18R. While being transmitted to the front wheel 20R, it is branched by the front wheel differential gear device 16, and the propeller shaft 22, the front and rear driving force distribution device 24, the shaft 25, the rear wheel differential gear device 26, and the right and left It is transmitted to the left rear wheel 30L and the right rear wheel 30R via the rear wheel axles 28L, 28R. Both the front wheel differential gear device 16 and the rear wheel differential gear device 26 are bevel gear differential gear devices. The front / rear driving force distribution device 24 is an electromagnetic multi-plate friction clutch or the like that can continuously change the transmission torque capacity including interruption of power transmission, and is arranged in series with the propeller shaft 22. By controlling the transmission torque capacity by the driving force distribution electronic control device 50, the driving force distribution ratio on the rear wheels 30L, 30R side with respect to the total driving force is adjusted to a predetermined value.

  An assisting electric motor 32 and a driving force unequal distribution mechanism 34 are arranged around the left rear axle 28L. The electric motor 32, the driving force unequal distribution mechanism 34, and the rear A driving force distribution device 36 according to an embodiment of the present invention is configured including the wheel differential gear device 26. The electric motor 32 can be driven to rotate in both forward and reverse directions, and its rotor is connected to a hollow shaft 52 integrally fixed to the differential case 26 i of the differential gear device 26 for the rear wheel via a one-way clutch 54. Connected. The one-way clutch 54 allows the differential case 26 i of the differential gear device 26 for the rear wheel to rotate at a speed higher than the rotational speed of the electric motor 32 during forward travel, and prevents the speed from dropping below the rotational speed of the electric motor 32. Is configured to do. The electric motor 32 corresponds to a power source, the rear wheel differential gear device 26 corresponds to a differential gear device, and the differential case 26i which is an input member of the differential gear device corresponds to a first input member. The direction clutch 54 corresponds to a first interrupting device.

  The electric motor 32 is rotationally driven in the forward direction when the vehicle is started in the forward direction by the driving force distribution electronic control device 50, and includes the one-way clutch 54 and the rear wheel differential gear device 26. Thus, assist torque is applied to the left and right rear wheels 30L, 30R. FIGS. 2 and 3 both linearly connect the rotational speeds of the three rotating elements of the rear wheel differential gear device 26, that is, the differential case 26i as the first input member, and the left and right side gears as the output members. In the collinear chart, “L” at the left end represents the left side gear and further the left rear wheel 30L, “R” at the right end represents the right side gear and further the right rear wheel 30R, and the center “I” "Represents the differential case 26i, that is, the first input member. The distance between L and I is the same as the distance between R and I, and the torque input to the first input member I, that is, the differential case 26i, is evenly distributed to the left rear wheel 30L and the right rear wheel 30R.

  FIG. 2A shows a case where assist torque is applied to the left and right rear wheels 30L and 30R by the electric motor 32 when the vehicle starts moving in the forward direction, and is input to the differential case 26i via the one-way clutch 54. The motor torque Tm of the electric motor 32 is evenly distributed to the left and right rear wheels 30L and 30R, and an assist torque having a magnitude of Tm / 2 is applied. This state is an even distribution state in which the torque Tm of the electric motor 32 is evenly distributed to the left and right rear wheels 30L and 30R. The rear wheel differential gear device 26 receives the rear wheel side distribution torque Tin from the engine 12 through the front and rear driving force distribution device 24 at a predetermined front and rear driving force distribution ratio. The side distribution torque Tin is also distributed equally to the left and right rear wheels L and R. Accordingly, the torques TL and TR of the left rear wheel 30L and the right rear wheel 30R in this case are both (Tin + Tm) / 2.

  If the operation of the electric motor 32 is stopped when the predetermined traveling state is reached, the electric motor 32 is automatically disconnected from the rear wheel differential gear device 26 by the idle rotation of the one-way clutch 54. The left and right rear wheels 30L and 30R are rotationally driven only by the rear wheel side distribution torque Tin. FIG. 2B shows the state in which the torque assist by the electric motor 32 is thus completed, and the torques TL and TR of the left rear wheel 30L and the right rear wheel 30R at this time are both Tin / 2.

  Returning to FIG. 1, the drive force unequal distribution mechanism 34 includes a first pinion type first planetary gear unit 38 having a first sun gear S1, a first carrier C1, and a first ring gear R1, a second sun gear S2, And a single pinion type second planetary gear device 40 having a second carrier C2 and a second ring gear R2. The first planetary gear device 38 and the second planetary gear device 40 have the same gear ratio ρ (the number of teeth of the sun gear / the number of teeth of the ring gear), and the ring gears R1 and R2 are the common ring gear R. It is composed of. Since the ring gears R1 and R2 are configured by the common ring gear R in this way, the first planetary gear device 38 and the second planetary gear device 40 have five rotational elements that can rotate relative to each other, that is, the first sun gear S1. The first carrier C1, the ring gear R, the second carrier C2, and the second sun gear S2. The first sun gear S1 is integrally connected to the left rear axle 28L, the first carrier C1 is integrally fixed to the case 42 and cannot be rotated, the ring gear R is rotatable, and the second carrier C2 is rotatable. Is selectively connected to the rotor of the electric motor 32 via the clutch CL, and the second sun gear S2 is integrally connected to the hollow shaft 52. The second carrier C2 is an input member of the drive force unequal distribution mechanism 34 and corresponds to a second input member.

  2 and 3 are nomographic charts in which the rotational speed of each of the five rotating elements can be connected by a straight line for each pair of planetary gear units 38 and 40. These are shown together in the diagram, and are located in the order of the first sun gear S1, the first carrier C1, the ring gear R, the second carrier C2, and the second sun gear S2 from the left end, and are connected to the left rear wheel axle 28L. The first sun gear S1 is rotated integrally with “L” representing the left rear wheel 30L, and the second sun gear S2 connected to the hollow shaft 52 is matched with “I” representing the differential case 26i. It can be rotated integrally. These intervals are determined in accordance with the gear ratio ρ of the planetary gear units 38 and 40. In this embodiment, the gear ratio ρ of the planetary gear units 38 and 40 is equal, so that the ring gear R and the carriers C1 and C2 are separated from each other. The distance between the sun gear S1 and the carrier C1, and the distance between the sun gear S2 and the carrier C2 are also equal, while the distance between the ring gear R and the carriers C1 and C2, the sun gears S1 and S2, and the carriers C1 and C2. The ratio of the distance to is ρ: 1. In the present embodiment, the first rotation element to the fifth rotation element are arranged in the order of the first sun gear S1, the first carrier C1, the ring gear R, the second carrier C2, and the second sun gear S2, which are sequentially positioned from the left side in the alignment chart. The left rear wheel 30L corresponds to the second wheel, and the right rear wheel 30R corresponds to the first wheel.

  The clutch CL corresponds to a second interrupting device, and is constituted by, for example, an electromagnetic clutch. The clutch CL is engaged and released by the driving force distribution electronic control device 50, whereby the electric motor 32 and the second carrier C2 Connect and disconnect. Then, as shown in FIG. 2B, when the clutch CL is engaged during forward travel when the assist control is finished, and the electric motor 32 is driven to rotate in the forward direction, it is shown in FIG. Thus, the motor torque Tm in the positive direction (upward in the drawing) acts on the second carrier C2, and the torque of the right rear wheel 30R becomes TR = Tin / 2 + ρTm / (2 (1 + ρ)), and the torque TL of the left rear wheel 30L = Tin / 2−ρTm / (2 (1 + ρ)). That is, the forward torque increases by ρTm / (2 (1 + ρ)) at the right rear wheel 30R, while the forward torque decreases by ρTm / (2 (1 + ρ)) at the left rear wheel 30L. The right rear wheel 30R side is accelerated in accordance with a torque difference (TR−TL) = ρTm / (1 + ρ). This state is a first unequal distribution state in which the right rear wheel 30R side, which is the first wheel, is accelerated based on the torque Tm of the electric motor 32.

  When the clutch CL is engaged and the electric motor 32 is rotationally driven in the reverse direction, the motor torque Tm in the reverse direction (downward in the figure) is applied to the second carrier C2 as shown in FIG. Acts, the torque of the left rear wheel 30L becomes TL = Tin / 2 + ρTm / (2 (1 + ρ)), and the torque of the right rear wheel 30R becomes TR = Tin / 2−ρTm / (2 (1 + ρ)). That is, while the forward torque is increased by ρTm / (2 (1 + ρ)) at the left rear wheel 30L, the forward torque is decreased by ρTm / (2 (1 + ρ)) at the right rear wheel 30R. The left rear wheel 30L side is accelerated according to the torque difference (TL-TR) = ρTm / (1 + ρ). This state is a second unequal distribution state in which the speed of the left rear wheel 30L, which is the second wheel, is increased based on the torque Tm of the electric motor 32.

  In other words, the driving force of the left and right rear wheels 30L and 30R can be unequally distributed by connecting the clutch CL during forward travel and rotating the electric motor 32 in the forward or reverse direction with a predetermined motor torque Tm. In the VSC control, cornering control, etc., the vehicle can be changed to a first unequal distribution state in which the right rear wheel 30R is accelerated or a second unequal distribution state in which the left rear wheel 30L is accelerated. The running stability and cornering performance can be improved.

  When there is a difference in rotational speed between the left and right rear wheels 30L and 30R as shown in FIGS. 3A and 3B, the clutch CL is connected to the electric motor 32 in the reverse rotation direction, that is, ( In the case of (a), it is possible to apply a torque in the reverse direction (downward), and in the case of (b) in FIG. If possible, the electric motor 32 is regeneratively controlled to apply a braking torque, whereby the second carrier C2 can be driven in the reverse rotation direction to be in an unequal distribution state.

  During reverse travel, the assist control and the left / right driving force distribution control are not performed, the clutch CL is held in a disconnected state, the electric motor 32 is in a non-energized state, and the rotation of the differential case 26i is performed by the action of the one-way clutch 54. With this, it is rotated backward. If a two-way clutch is used in which the sprags are reversed and the locking direction is switched according to the direction of the input rotation, torque assist and left / right driving by front / rear driving force distribution control can be performed during backward travel as well as during forward travel. Force distribution control can be performed.

  As described above, according to the driving force distribution device 36 of the present embodiment, when the vehicle starts in the forward direction, the electric motor 32 is released in a state where the clutch CL is released and the electric motor 32 and the second carrier C2 are disconnected. When the differential case 26i of the differential gear device 26 for the rear wheels is rotationally driven in the forward direction with a predetermined motor torque Tm and the differential gear device 26 for the rear wheels is rotationally driven via the one-way clutch 54, the motor torque Tm is evenly applied to the left and right rear wheels 30L and 30R Therefore, the torque assist of the front and rear wheels can be performed by the torque control of the electric motor 32 to perform the torque assist. Further, if the operation of the electric motor 32 is stopped when the predetermined traveling state is reached, the one-way clutch 54 is idled so that the electric motor 32 is disconnected from the rear wheel differential gear device 26. In this state, when the clutch CL is engaged and the electric motor 32 and the second carrier C2 are connected, the first unequal distribution state in which the right rear wheel 30R is accelerated according to the rotational drive direction of the electric motor 32. Or the second non-uniform distribution state in which the speed of the left rear wheel 30L is increased, so that the driving force distribution control of the left and right rear wheels 30L and 30R is controlled by controlling the rotational drive direction and torque Tm of the electric motor 32. It can be carried out. That is, the front / rear driving force distribution control and the left / right driving force distribution control can be performed by a single electric motor 32, compared to a case where an electric motor is provided for each of the left and right rear wheels 30L and 30R. Can be reduced in weight and cost.

  Further, in this embodiment, a one-way clutch 54 is used as the first interrupting device, and the differential case 26i of the rear wheel differential gear device 26 is allowed to rotate at a speed higher than the rotational speed of the electric motor 32 during forward traveling. Since the electric motor 32 is prevented from falling below the rotational speed of the electric motor 32, if the electric motor 32 is operated at the time of starting in the forward direction, the one-way clutch 54 and the rear wheel differential gear device 26 are used. The motor torque Tm is evenly transmitted to the left and right rear wheels 30L and 30R, and assist torque can be generated. On the other hand, if the operation of the electric motor 32 is stopped at a stage where a predetermined traveling state is reached, the one-way clutch Since the electric motor 32 is automatically disconnected from the rear wheel differential gear device 26 by the action of 54, the torque is controlled only by the torque control of the electric motor 32 as needed. Can generate a torque, it is possible to perform the assist control easily.

  Further, the driving force distribution device 36 of the present embodiment is simple and compact because the driving force unequal distribution mechanism 34 is configured using a pair of planetary gear devices 38 and 40.

  Next, another embodiment of the present invention will be described. In the following embodiments, portions that are substantially common to the above embodiments are denoted by the same reference numerals, and detailed description thereof is omitted.

  The driving force distribution device 60 of FIG. 4 employs a first clutch CL1 such as an electromagnetic clutch or a hydraulic clutch that can arbitrarily adjust the engagement torque in place of the one-way clutch 54, and the driving force distribution electronic The electric motor 32 and the hollow shaft 52 are connected and disconnected by controlling the engagement and release by the control device 50. In this case, the first clutch CL1 is engaged with a predetermined engagement torque when an assist torque is required at the time of starting or the like, and the electric motor 32 and the hollow shaft 52, that is, the differential case 26i are integrally connected, while a predetermined If the assist torque is no longer necessary in the running state, the first clutch CL1 may be released to disconnect the electric motor 32 and the hollow shaft 52 from each other. The second clutch CL2 is the same as the clutch CL in the above embodiment, and the first clutch CL1 and the second clutch CL2 correspond to a first interrupting device and a second interrupting device, respectively.

  The driving force distribution device 70 of FIG. 5 is a case where the rear wheel differential gear device 72 is configured by a double pinion type planetary gear device with a gear ratio ρ = 0.5, and the ring gear R0 is an input member ( The first input member) receives the rear wheel side distribution torque Tin from the shaft 25 via a bevel gear, and is connected to the electric motor 32 via the one-way clutch 54. Further, the left rear wheel axle 28L is connected to the sun gear S0, and the right rear wheel axle 28R is connected to the carrier C0. The torque transmitted to the ring gear R0 is transmitted to the sun gear S0, the carrier, and the like. It is distributed to the left and right rear axles 28L, 28R via C0. The second sun gear S2 of the drive force unequal distribution mechanism 34 is integrally connected to the carrier C0 and further to the right rear wheel axle 28R via the hollow shaft 74.

  FIGS. 6 and 7 are collinear diagrams of the present embodiment. Since the gear ratio ρ of the rear wheel differential gear device 72 is 0.5, “L” represents the left rear wheel 30L to which the sun gear S0 is connected. ”And the ring gear R0 as the input member and the distance between“ R ”representing the right rear wheel 30R to which the carrier C0 is connected and the ring gear R0 are the same. b) Torque distribution at the end of assist is the same as in FIG. That is, in a state where the clutch CL is released and the electric motor 32 and the second carrier C2 are disconnected, the electric motor 32 is rotationally driven in the forward direction with a predetermined motor torque Tm, and the rear wheel is connected via the one-way clutch 54. When the ring gear R0 of the differential gear device 72 is rotationally driven, the motor torque Tm is evenly distributed to the left and right rear wheels 30L and 30R. Therefore, the torque control of the electric motor 32 controls the front and rear wheels. Driving force distribution control can be performed, and the same operational effects as in the above-described embodiment can be obtained, such that predetermined torque assist can be performed on the rear wheels 30L and 30R when starting.

  On the other hand, since the second sun gear S2 of the drive force unequal distribution mechanism 34 is connected to the right rear wheel 30R, the second sun gear S2 and "R" representing the right rear wheel 30R coincide and rotate integrally. In addition, the ring gear R of the drive force unequal distribution mechanism 34 is in the same position as the ring gear R0 that is the input member of the rear wheel differential gear device 72. Therefore, as shown in FIG. 6 (b), the clutch CL is engaged during forward travel when the assist control is completed, and the electric motor 32 is driven to rotate in the forward direction, as shown in FIG. 7 (a). When the motor torque Tm in the positive direction (upward in the drawing) acts on the second carrier C2, the torque TR of the right rear wheel 30R becomes TR = Tin / 2 + ρTm / (1 + ρ), and the torque TL of the left rear wheel 30L = Tin / 2− ρTm / (1 + ρ). That is, while the forward torque is increased by ρTm / (1 + ρ) at the right rear wheel 30R, the forward torque is decreased by ρTm / (1 + ρ) at the left rear wheel 30L, and the torque difference (TR -TL) = 2ρTm / (1 + ρ), the right rear wheel 30R side is accelerated. This state is a first unequal distribution state in which the right rear wheel 30R, which is the first wheel, is accelerated based on the torque Tm of the electric motor 32.

  When the clutch CL is engaged and the electric motor 32 is rotationally driven in the reverse direction, the motor torque Tm in the reverse direction (downward in the figure) is applied to the second carrier C2 as shown in FIG. Acts, the torque of the left rear wheel 30L becomes TL = Tin / 2 + ρTm / (1 + ρ), and the torque of the right rear wheel 30R becomes TR = Tin / 2−ρTm / (1 + ρ). That is, while the forward torque is increased by ρTm / (1 + ρ) at the left rear wheel 30L, the forward torque is decreased by ρTm / (1 + ρ) at the right rear wheel 30R. -TR) = 2ρTm / (1 + ρ), the left rear wheel 30L side is accelerated. This state is a second unequal distribution state in which the speed of the left rear wheel 30L, which is the second wheel, is increased based on the torque Tm of the electric motor 32.

  Thus, if the electric motor 32 is rotationally driven in the forward direction at a predetermined motor torque Tm with the clutch CL disengaged and the electric motor 32 and the second carrier C2 disconnected, the one-way clutch 54 is used. When the ring gear R0 of the rear wheel differential gear device 72 is rotationally driven, the motor torque Tm is evenly distributed to the left and right rear wheels 30L and 30R, and the torque control of the electric motor 32 is performed. It is possible to perform the driving force distribution control for the front and rear wheels, and to perform a predetermined torque assist for the rear wheels 30L and 30R at the start. Further, when the clutch CL is engaged during forward traveling and the electric motor 32 and the second carrier C2 are connected, a first unequal distribution state in which the right rear wheel 30R is accelerated according to the rotational drive direction of the electric motor 32, Alternatively, since the second unequal distribution state in which the left rear wheel 30L is accelerated is achieved, the driving force distribution control of the left and right rear wheels 30L and 30R is performed by controlling the rotational drive direction and torque Tm of the electric motor 32. be able to. In that case, since the front and rear driving force distribution control and the left and right driving force distribution control can be performed with a single electric motor 32, compared to the case where an electric motor is provided for each of the left and right rear wheels 30L and 30R, The same effects as those of the above embodiment can be obtained, such as reduction in weight and cost of the vehicle.

  The driving force distribution device 80 in FIG. 8 differs from the embodiment in FIG. 1 in the configuration of the driving force unequal distribution mechanism 82. That is, the drive force unequal distribution mechanism 82 includes a first sun gear S1, a first carrier C1, and a double pinion type first planetary gear unit 84 having a first ring gear R1, a second sun gear S2, and a second carrier C2. And a second pinion type second planetary gear device 86 having a second ring gear R2. The first planetary gear unit 84 and the second planetary gear unit 86 have the same size and the same gear ratio ρ, and the carriers C1 and C2 are integrally connected to be a common carrier C. Yes. Since the carriers C1 and C2 are thus constituted by the common carrier C, the first planetary gear device 84 and the second planetary gear device 86 have five rotational elements that can rotate relative to each other, that is, the first sun gear S1. The first ring gear R1, the carrier C, the second ring gear R2, and the second sun gear S2 are configured. The first sun gear S1 is integrally connected to the left rear wheel axle 28L, the first ring gear R1 is integrally fixed to the case 42 and cannot rotate, the carrier C is rotatable, and the second ring gear R2 Is selectively connected to the rotor of the electric motor 32 via the clutch CL, and the second sun gear S2 is integrally connected to the hollow shaft 52. The second ring gear R2 is an input member of the drive force unequal distribution mechanism 82 and corresponds to a second input member.

  FIG. 9 and FIG. 10 show collinear charts in which the rotational speeds of the five rotating elements can be connected by straight lines for each of the pair of planetary gear units 84 and 86. These are shown in the diagram, and are arranged in order of the first sun gear S1, the first ring gear R1, the carrier C, the second ring gear R2, and the second sun gear S2 from the left end, and are connected to the left rear wheel axle 28L. The first sun gear S1 coincides with “L” representing the left rear wheel 30L, and the second sun gear S2 connected to the hollow shaft 52 coincides with “I” representing the differential case 26i. These intervals are determined according to the gear ratio ρ of the planetary gear devices 84 and 86. In this embodiment, the gear ratio ρ of both the planetary gear devices 84 and 84 is equal, so the carrier C and the ring gears R1 and R2 While the intervals are equal to each other and the intervals between the carrier C and the sun gears S1 and S2 are also equal to each other, the ratio of the interval between the carrier C and the ring gears R1 and R2 and the interval between the carrier C and the sun gears S1 and S2 is ρ: 1. Become. In the present embodiment, the first sun gear S1, the first ring gear R1, the carrier C, the second ring gear R2, and the second sun gear S2 are arranged in this order from the left side in the order of the first to fifth rotation elements. The left rear wheel 30L corresponds to the second wheel, and the right rear wheel 30R corresponds to the first wheel.

  When the clutch CL is disengaged and the electric motor 32 and the second ring gear R2 are disconnected, the same state as that of the first embodiment is obtained. Therefore, at (a) start assisting in FIG. The torque distribution at the end of the assist is the same as in FIG. That is, in a state where the clutch CL is released and the electric motor 32 and the second ring gear R2 are disconnected, the electric motor 32 is rotationally driven in the forward direction with a predetermined motor torque Tm, and the rear wheels are connected via the one-way clutch 54. When the differential case 26i of the differential gear device 26 is rotationally driven, the motor torque Tm is evenly distributed to the left and right rear wheels 30L and 30R. Therefore, the torque control of the electric motor 32 controls the front and rear wheels. Driving force distribution control can be performed, and a predetermined torque assist can be performed on the rear wheels 30L and 30R when starting.

  On the other hand, as shown in FIG. 9 (b), when the clutch CL is engaged during forward travel after the end of the assist control and the electric motor 32 is driven to rotate in the forward direction, it is shown in FIG. 10 (a). Thus, the motor torque Tm in the positive direction (upward in the drawing) acts on the second ring gear R2, and the torque of the right rear wheel 30R becomes TR = Tin / 2 + ρTm / 2, and the torque of the left rear wheel 30L TL = Tin / 2−ρTm / 2. That is, while the forward torque is increased by ρTm / 2 at the right rear wheel 30R, the forward torque is decreased by ρTm / 2 at the left rear wheel 30L, and the torque difference (TR−TL) = The right rear wheel 30R side is accelerated according to ρTm. This state is a first unequal distribution state in which the right rear wheel 30R side, which is the first wheel, is accelerated based on the torque Tm of the electric motor 32.

  When the clutch CL is engaged and the electric motor 32 is rotationally driven in the reverse direction, the motor torque Tm in the reverse direction (downward in the figure) is applied to the second ring gear R2 as shown in FIG. 10 (b). Acts, the torque TL of the left rear wheel 30L becomes TL = Tin / 2 + ρTm / 2, and the torque TR of the right rear wheel 30R becomes TR = Tin / 2−ρTm / 2. That is, while the forward torque is increased by ρTm / 2 at the left rear wheel 30L, the forward torque is decreased by ρTm / 2 at the right rear wheel 30R, and the torque difference (TL−TR) = The left rear wheel 30L side is accelerated according to ρTm. This state is a second unequal distribution state in which the speed of the left rear wheel 30L, which is the second wheel, is increased based on the torque Tm of the electric motor 32.

  As described above, also in the present embodiment, the front / rear driving force distribution control and the left / right driving force distribution control can be performed by the single electric motor 32. Therefore, when the electric motor is provided for each of the left and right rear wheels 30L and 30R. Compared to the above, the same effects as the above-described embodiment can be obtained, such as reduction in weight and cost of the vehicle.

  The driving force distribution device 90 in FIG. 11 is the same as the driving force distribution device 70 having the planetary gear type rear wheel differential gear device 72 in FIG. This is a case where the mechanism 82 is provided. Also in such a driving force distribution device 90, the front and rear driving force distribution control and the left and right driving force distribution control can be performed by the single electric motor 32 as in the driving force distribution device 70 of FIG. Compared with the case where an electric motor is provided for each of the wheels 30L and 30R, the same effects as those of the above-described embodiment can be obtained, such as reduction in weight and cost of the vehicle.

  The driving force distribution device 100 in FIG. 12 is the same as the driving force distribution device 70 in FIG. 5 except that the second sun gear S2 of the driving force unequal distribution mechanism 34 is used as the input member (first input member) of the rear wheel differential gear device 72. This is a case where the ring gear R0 is integrally connected. In this case, torque distribution is performed according to the same collinear chart as in FIGS. 2 and 3, and the same effect as the first embodiment can be obtained.

  FIG. 13 shows a case where the present invention is applied to a vehicle drive device 110 for a four-wheel drive vehicle that is driven separately from the front wheels 20L, 20R and the rear wheels 30L, 30R. The front wheels 20L, 20R The rear wheels 30L and 30R are driven by a front wheel drive device 112 having a main power source such as an electric motor or a hybrid having both of them, a transmission, etc., while a rear wheel motor generator MGR as a sub power source. It is to be driven by. A driving force distribution device 36 similar to that of the first embodiment is provided on the rear wheels 30L and 30R side, and the same effects as those of the first embodiment can be obtained.

  In the vehicle drive device 110, the drive force distribution device 60, 70, 80, 90, or 100 may be employed instead of the drive force distribution device 36. It is also possible to omit the rear wheel motor generator MGR and perform the torque assist by the front / rear driving force distribution control only by the electric motor 32 and the left / right driving force distribution control. Also in the vehicle drive device 10, the front / rear driving force distribution device 24 can be cut off, and the torque assist or the left / right driving force distribution control by the front / rear driving force distribution control can be performed only by the electric motor 32.

  As mentioned above, although the Example of this invention was described in detail based on drawing, these are one Embodiment to the last, This invention is implemented in the aspect which added the various change and improvement based on the knowledge of those skilled in the art. be able to.

It is a schematic block diagram explaining the vehicle drive device to which this invention was applied. FIGS. 2A and 2B are collinear diagrams of the driving force distribution device provided in the vehicle drive device of FIG. 1, in which FIG. 1A shows a state at the start assist time, and FIG. In the same collinear chart as FIG. 2, (a) shows a state where the torque of the right axle is increased, and (b) shows a state where the torque of the left axle is increased. It is a skeleton figure of other examples of the present invention. It is a skeleton figure of another Example of this invention. FIG. 6 is a collinear diagram of the embodiment of FIG. 5, corresponding to FIG. 2. FIG. 6 is a collinear diagram of the embodiment of FIG. 5, corresponding to FIG. 3. It is a skeleton figure of another Example of this invention. FIG. 9 is a collinear diagram of the embodiment of FIG. 8, corresponding to FIG. 2. FIG. 9 is a collinear diagram of the embodiment of FIG. 8 and corresponding to FIG. 3. It is a skeleton figure of another Example of this invention. It is a skeleton figure of another Example of this invention. It is a schematic block diagram explaining an example at the time of this invention being applied to the drive device of a Pellerless four-wheel drive vehicle.

Explanation of symbols

  26, 72: differential gear device for rear wheel (differential gear device) 26i: differential case (first input member) 30R: right rear wheel (first wheel) 30L: left rear wheel (second wheel) 32: electric motor (Power source) 34, 82: Unequal driving force distribution mechanism 36, 60, 70, 80, 90, 100: Driving force distribution device 38, 84: First planetary gear device 40, 86: Second planetary gear device 54: One-way clutch (first intermittent device) CL: Clutch (second intermittent device) CL1: First clutch (first intermittent device) CL2: Second clutch (second intermittent device) C2: Second carrier (second input member) R0: Ring gear (first input member) R2: Second ring gear (second input member)

Claims (3)

An equal distribution state in which the torque of the power source is evenly distributed to the left and right drive wheels, and a first unequal distribution state in which the first wheel side of the left and right drive wheels is accelerated based on the torque of the power source; A vehicle that can mechanically establish a second unequal distribution state in which the other second wheel side of the left and right drive wheels is accelerated based on the torque of the power source using a single power source. A driving force distribution device,
A differential gear device that evenly distributes the power transmitted to the first input member to the left and right drive wheels;
When the second input member is rotated forward, the first wheel side is accelerated based on the torque input to the second input member, and when the second input member is driven reversely, the second input member is A driving force unequal distribution mechanism mechanically configured to increase the speed of the second wheel side based on the input torque;
A first interrupting device for connecting and disconnecting the power source and the first input member;
And a second intermittent device that connects and disconnects the power source and the second input member, and the power source is capable of rotational driving in both forward and reverse directions. Power distribution device. The power source is for assist,
The first interrupting device is a one-way clutch that prevents the first input member from rotating below the rotational speed of the power source while allowing the first input member to rotate at a speed higher than the rotational speed of the power source during forward traveling. The vehicle driving force distribution device according to claim 1. The drive force unequal distribution mechanism is
5 rotations each having a pair of planetary gear units each composed of three rotation elements of a sun gear, a carrier, and a ring gear, and one rotation element of the pair of planetary gear units being connected to each other so that they can rotate relative to each other. Elements are composed,
In the collinear diagram in which the rotational speed of each of the five rotating elements can be connected by a straight line for each of the pair of planetary gear units, the first rotating element, the second rotating element, the third rotating element, the fourth rotating from one end When the element is the fifth rotating element, the first rotating element is connected to the second wheel, the second rotating element is fixed so as not to rotate, and the third rotating element connects the pair of planetary gear units to each other. The fourth rotating element is connected to the first input member or the first wheel, and the fourth rotating element is connected to the first input member or the first wheel. 3. A driving force distribution device for a vehicle according to 2.

Images