JP2008057748A - Driving force distribution device for vehicle - Google Patents

Abstract

The present invention provides a vehicle driving force distribution device having a left-right wheel torque difference control and a differential limiting function and having a compact structure.
A differential device having a mechanical differential limiting mechanism controls a rotation of a left pinion gear to control a torque of a left wheel 52 and a rotation of a right pinion gear. The right wheel torque control unit 62 that controls the torque of the right side gear 56 is provided, so that sufficient differential limitation is possible by the conventional mechanical differential limitation, and the left wheel and right wheel torque control units 60, 62 are possible. Thus, the left and right wheel torque difference control can be performed. Accordingly, the two functions of the differential limiting function and the left and right wheel torque difference control can be selectively realized according to the traveling state of the vehicle, and the maneuverability and stability of the vehicle can be greatly improved. .
[Selection] Figure 2

Description

  The present invention relates to a driving force distribution device provided in a vehicle, and more particularly, to a vehicle driving force distribution device that enables left-right torque difference control in a differential device having a mechanical differential limiting function.

  2. Description of the Related Art A vehicle driving force distribution device that distributes driving force generated by a driving source such as an engine to left and right driving wheels is known. For example, this is the vehicle driving force distribution device disclosed in Patent Document 1. In Japanese Patent Laid-Open No. 2004-228561, a differential device is assigned driving torque, input rotation is accelerated and decelerated by an increasing / decreasing gear, and the increasing / decreasing rotation by the increasing / decreasing gear is selectively hydraulically applied to one side gear of the differential device. A technique for generating a torque difference between the left and right wheels by transmitting through a multi-plate clutch is disclosed.

JP 2002-114049 A

  By the way, in the conventional vehicle driving force distribution device, a device that has both the driving force distribution function and the differential limiting function is difficult to put into practical use because the structure is enlarged. However, with these two functions, the “right and left wheel torque difference control” and “differential limiting function” are selectively applied as appropriate according to the driving situation, thereby greatly improving the maneuverability and stability of the vehicle. Can be improved. On the other hand, for example, in the vehicle driving force distribution device of Patent Document 1, the differential limiting function is performed by the left and right wheel torque difference control, but in this structure, the differential limiting torque is set by the acceleration / deceleration gear. It is limited by the speed of increase / decrease and the degree of freedom of differential limitation is limited. Furthermore, since the speed increasing / decreasing gear of the driving force distribution device is constituted by a triple gear, it is long in the axial direction, and the hydraulic multi-plate clutch is also arranged in parallel with the speed increasing / decreasing gear. It was disadvantageous for the mountability of the vehicle.

  The present invention has been made against the background of the above circumstances, and an object of the present invention is to provide a vehicle driving force distribution device having a left-right wheel torque difference control and a differential limiting function and a compact structure. It is to provide.

  In order to achieve the above object, the gist of the invention according to claim 1 is as follows: (a) a pair of right side gears configured by helical teeth and arranged adjacent to each other on a common axis; A left side gear, a right pinion gear that is composed of helical teeth and meshes with the right side gear, a left pinion gear that meshes with the left side gear, and a left and right side gear that rotates around the axis and the left and right pinion gears rotate. A differential case that supports the left and right pinion gears so that they can revolve on the shaft center in a differential carrier that is a non-rotating member, and the right pinion gear and the left pinion gear mesh with each other, and the right side gear When the left and right side gears are differential, the left and right pinion gears rotate in opposite directions. And a vehicle driving force distribution device including a differential device having a mechanical differential limiting mechanism in which the differential is limited by a thrust force generated from a meshing portion between the left and right side gears and the left and right pinion gears. (B) a first torque control unit that controls the rotation of the left pinion gear to control the torque of the left side gear; and (c) a second torque that controls the rotation of the right pinion gear to control the torque of the right side gear. And a control unit.

  According to a second aspect of the present invention, there is provided the vehicle driving force distribution device according to the first aspect, wherein (a) the first torque control unit is rotated integrally with the left pinion gear. Left wheel torque moving pinion gear, a left wheel torque moving ring gear meshing with the left wheel torque moving pinion gear, and a left wheel which is interposed between the left wheel torque moving ring gear and the differential carrier and appropriately slip-engages them. A torque amplifying clutch, and (c) the second torque control unit (d) a right wheel torque moving pinion gear rotated integrally with the right pinion gear, and a right wheel meshing with the right wheel torque moving pinion gear A torque moving ring gear, a right wheel torque moving ring gear, and the differential carrier are interposed between the ring gear and the right gear. Wherein the Tsu and a right wheel torque amplification clutch for up-engaged.

  According to a third aspect of the present invention, there is provided the vehicle driving force distribution device according to the first aspect, wherein: (a) a ring gear coupled to the differential carrier; a sun gear coupled to the differential case; and the ring gear. And a planetary gear device that outputs the rotation of the differential case decelerated from the carrier, and the carrier that supports the pinion gear meshing with the sun gear so as to rotate and revolve. (B) The first torque control unit includes (c) a left wheel torque moving pinion gear that is rotated integrally with the left pinion gear, a left wheel torque moving ring gear that meshes with the left wheel torque moving pinion gear, and a left wheel torque moving thereof. Is interposed between the ring gear for use and the carrier of the planetary gear unit, and these are appropriately slip-engaged. (D) the second torque control unit includes (e) a right wheel torque moving pinion gear that is rotated integrally with the right pinion gear, and a right wheel torque moving pinion gear. A right wheel torque moving ring gear that meshes with the right wheel torque moving ring gear and a right wheel torque amplifying clutch that is interposed between the right wheel torque moving ring gear and the carrier of the planetary gear device and appropriately slip-engages them. It is characterized by being.

  According to a fourth aspect of the present invention, there is provided the vehicle driving force distribution device according to the first aspect, wherein: (a) a sun gear coupled to the differential carrier; a ring gear coupled to the differential case; and the sun gear. And a planetary gear device that outputs a rotation of the differential case decelerated from the carrier, and a carrier that supports the pinion gear that meshes with the ring gear so as to rotate and revolve, and is disposed on the common axis. (B) The first torque control unit includes (c) a left wheel torque moving pinion gear that is rotated integrally with the left pinion gear, a left wheel torque moving ring gear that meshes with the left wheel torque moving pinion gear, and a left wheel torque moving thereof. Is interposed between the ring gear for use and the carrier of the planetary gear unit, and these are appropriately slip-engaged. (D) the second torque control unit includes (e) a right wheel torque moving pinion gear that is rotated integrally with the right pinion gear, and a right wheel torque moving pinion gear. A right wheel torque moving ring gear that meshes with the right wheel torque moving ring gear and a right wheel torque amplifying clutch that is interposed between the right wheel torque moving ring gear and the carrier of the planetary gear device and appropriately slip-engages them. It is characterized by being.

  According to a fifth aspect of the present invention, there is provided the vehicle driving force distribution device according to any one of the second to fourth aspects, wherein: (a) a twist direction of the left pinion gear and a twist of the left wheel torque moving pinion gear The direction is formed by helical teeth opposite to each other, and (b) the twist direction of the right pinion gear and the twist direction of the right wheel torque moving pinion gear are formed by helical teeth opposite to each other. Features.

  According to the vehicle driving force distribution device of the first aspect, the differential device having the mechanical differential limiting mechanism controls the rotation of the left pinion gear to control the torque of the left side gear. And a second torque control unit that controls the rotation of the right pinion gear to control the torque of the right side gear, so that a sufficient differential limitation can be achieved by a conventional mechanical differential limitation. The left and right wheel torque difference control can be performed by the first and second torque control units. Accordingly, the two functions of the differential limiting function and the left and right wheel torque difference control can be selectively realized according to the traveling state of the vehicle, and the maneuverability and stability of the vehicle can be greatly improved. .

  According to the vehicle driving force distribution device of the invention of claim 2, the first and second torque control units include a left wheel and right wheel torque moving pinion gear, a left wheel and right wheel torque moving ring gear, and Since the left wheel and right wheel torque amplifying clutches are respectively constituted by conventional mechanical elements, in addition to the above-described effects, the device can be made compact and a low-cost device can be realized.

  According to the vehicle driving force distribution device of the invention of claim 3, the first and second torque control units include the left wheel and right wheel torque moving pinion gear, the left wheel and right wheel torque moving ring gear, and the left wheel. And the right wheel torque amplifying clutch, each of which is constituted by a conventional mechanical element, and the planetary gear device is also constituted by a conventional mechanical element, so that the apparatus can be made compact. Further, by providing the planetary gear device, it is possible to reduce the relative rotational difference between the left and right wheel torque moving pinion gears and the carrier of the planetary gear device. Torque loss due to the wheel torque amplification clutch can be reduced.

  According to the vehicle driving force distribution device of the invention of claim 4, the first and second torque control units include a left wheel and right wheel torque moving pinion gear, a left wheel and right wheel torque moving ring gear, and a left wheel. And the right wheel torque amplifying clutch, each of which is constituted by a conventional mechanical element, and the planetary gear device is also constituted by a conventional mechanical element, so that the apparatus can be made compact. Further, by providing the planetary gear device, it is possible to reduce the relative rotational difference between the left and right wheel torque moving pinion gears and the carrier of the planetary gear device. Torque loss due to the wheel torque amplification clutch can be reduced.

  According to the vehicle driving force distribution device of the invention of claim 5, the torsion direction of the left pinion gear and the torsion direction of the left wheel torque moving pinion gear are formed by helical teeth opposite to each other, and Since the torsion direction of the pinion gear and the torsion direction of the right wheel torque moving pinion gear are formed by helical teeth opposite to each other, the left wheel torque amplification clutch of the first torque control unit and the right wheel of the second torque control unit When the torque amplification clutch slips, the thrust force generated in the left and right pinion gears by the differential limiting mechanism is generated in the direction of canceling the thrust force in the left wheel and right wheel torque moving pinion gears. Therefore, the left and right wheel torque difference control can be performed while suppressing the influence of the differential limiting mechanism.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a skeleton diagram illustrating the configuration of a front and rear wheel drive vehicle based on a front engine front wheel drive (FF) having a driving force transmission device 10 to which the present invention is preferably applied. In FIG. 1, the driving force (torque) generated by the engine 12 as a driving force source is transmitted through an automatic transmission 14, a front wheel differential gear device 16, and a pair of left and right front wheel axles 18l and 18r. While being transmitted to a pair of left and right front wheels 20l and 20r, a central differential gear device (center differential) 22, a propeller shaft 24 which is a driving force transmission shaft, and a differential gear unit for rear wheels which is an embodiment of the present invention 26 and a pair of left and right rear wheel axles 28l and 28r (hereinafter simply referred to as rear wheel axle 28 unless otherwise specified), and a pair of left and right rear wheels 30l and 30r (hereinafter, unless otherwise specified). Simply referred to as rear wheel 30). Here, as shown in FIG. 1, in the driving force transmission device 10 of this embodiment, the rotating shaft of the rear wheel 30 as the driving wheel related to the distribution of the driving force by the differential gear unit 26 for the rear wheel and the propeller. It arrange | positions so that the rotating shaft of the shaft 24 may mutually orthogonally cross. The driving force transmission device 10 is connected to a hydraulic circuit 34 for controlling the hydraulic pressure supplied into the rear wheel differential gear unit 26 and an electromagnetic control valve (not shown) provided in the hydraulic circuit 34. A control device 36 for controlling the hydraulic pressure supplied from the hydraulic circuit 34 to the rear wheel differential gear unit 26 is provided. In FIG. 1, the hydraulic pressure output from the hydraulic circuit 34 is indicated by a thin line arrow, and the control command output from the control device 36 is indicated by a thin broken line arrow.

  The engine 12 is, for example, an internal combustion engine such as a gasoline engine or a diesel engine that generates driving force by combustion of fuel injected in a cylinder. The automatic transmission 14 is, for example, a stepped automatic transmission (automatic transmission) that outputs the rotation input from the engine 12 by decelerating or increasing the speed at a predetermined gear ratio γ. Any one of the first gear, the reverse gear, and the neutral is selectively established, and the speed conversion corresponding to each gear ratio γ is performed. The input shaft of the automatic transmission 14 is connected to the output shaft of the engine 12 via a torque converter (not shown).

  The control device 36 is a so-called microcomputer that includes a CPU, a ROM, a RAM, an input / output interface, and the like, and executes signal processing according to a program stored in advance in the ROM while using a temporary storage function of the RAM. For example, by controlling the command value of the current supplied to the electromagnetic control valve provided in the hydraulic circuit 34, it is supplied to the later-described clutch and brake device provided in the rear wheel differential gear unit 26. By controlling the hydraulic pressure, left and right wheel torque difference control described later is executed. The power transmission device 10 includes a wheel speed sensor that detects an actual rotational speed of the rear wheel 30 corresponding to a vehicle speed, a shift stage sensor that detects a shift stage of the automatic transmission 14, and a supply of the engine 12. A throttle sensor for detecting the actual opening of a throttle valve (not shown) provided in the exhaust pipe, an engine rotational speed sensor for detecting the actual rotational speed of the engine 12, a steering angle sensor, a lateral acceleration sensor, a longitudinal acceleration sensor, and the like The signal indicating the vehicle speed, the signal indicating the shift stage, the signal indicating the throttle opening, the signal indicating the engine rotation speed, the signal indicating the steering angle, the signal indicating the lateral acceleration, A signal indicating acceleration in the front-rear direction and the like are supplied to the electronic control unit 36.

  FIG. 2 is a skeleton diagram illustrating the configuration of the rear wheel differential gear unit 26. The rear wheel differential gear unit 26 is mainly configured by a differential device 42 having a helical differential limiting mechanism and a left and right wheel torque moving mechanism 44 housed in a differential carrier 40 which is a non-rotating member. The differential device 42 and the left and right wheel torque moving mechanism 44 are each constituted by a conventional mechanical element, and the rear wheel differential gear unit 26 has a compact configuration. The rear wheel differential gear unit 26 of this embodiment corresponds to the vehicle driving force distribution device of the present invention.

  The differential device 42 is driven to rotate about a common shaft center J with the rear wheel axle 28 via a bevel gear 46 provided at an end of the propeller shaft 24 and a bevel gear 48 meshing with the bevel gear 46. A differential case 50, a left side gear 52 connected to the rear wheel axle 28l, a left pinion gear 54 engaged with the left side gear 52, a right side gear 56 connected to the rear wheel axle 28r, and a right pinion gear 58 engaged with the right side gear 56 are provided. ing. The differential case 50 supports the left and right side gears 52 and 56 and the left and right pinion gears 54 and 58 in a rotatable manner, and supports the left and right pinion gears 54 and 58 in a revolving manner on the axis J. The outer peripheral teeth of the left and right side gears 52 and 56 and the left and right pinion gears 54 and 58 are each composed of helical teeth having a torsion angle.

  The outer peripheral teeth of the left pinion gear 54 are formed at two positions spaced apart in the axial direction, and the outer peripheral teeth 54 a formed on the rear wheel 30 l side mesh with the outer peripheral teeth of the left side gear 52. Further, the outer peripheral teeth of the right pinion gear 58 are formed at two positions spaced apart in the axial direction, and the outer peripheral teeth 58a formed on the rear wheel 30r side are meshed with the outer peripheral teeth of the right side gear 56.

  FIG. 3 is a cross-sectional view of the rear wheel differential gear unit 26 taken along the alternate long and short dash lines A to F shown in FIG. The cross sections A to F correspond to the cross sections at the positions of the alternate long and short dash lines A to F. As shown in cross sections A and D, four left and right pinion gears 54 and 58 are provided at equal angular intervals, and the left and right pinion gears 54 and 58 are meshed with each other. Specifically, the outer peripheral teeth 54a of the left pinion gear 54 and the outer peripheral teeth 58b formed on the wheel 30l side of the right pinion gear 58 are meshed, and the outer peripheral teeth 58a of the right pinion gear 58 and the wheel 30r side of the left pinion gear 54 are engaged. The outer peripheral teeth 54b formed on the outer periphery are meshed with each other. Thereby, the left pinion gear 54 and the right pinion gear 58 are rotated in opposite directions.

  3, the outer peripheral teeth 54a of the left pinion gear 54 and the outer peripheral teeth of the left side gear 52 are engaged with each other, while the right pinion gear 58 has outer peripheral teeth that can be engaged with the left side gear 52. I do not have. Similarly, as shown in section C of FIG. 3, the outer peripheral teeth 58 a of the right pinion gear 58 and the outer peripheral teeth of the right side gear 56 are meshed, while the left pinion gear 54 is an outer peripheral tooth that can mesh with the right side gear 56. Not equipped.

  Returning to FIG. 2, the differential case 50 supports a pair of left and right side gears 52, 56 disposed so as to be adjacent to each other on the same axis so as to be rotatable around the axis of the rear wheel axle 28 via a bearing (not shown). At the same time, the left and right pinion gears 54 and 58 are supported so as to be able to revolve and rotate around the axis of the rear wheel axle 28. The wall surface of the differential case 50 is formed so as to be adjacent to the side walls of the left and right side gears 52 and 56, the side walls of the left and right pinion gears 54 and 58, and the tooth tips of the outer peripheral teeth.

  The left and right wheel torque moving mechanism 44 is provided on the right rear wheel 30r side of the differential device 42, controls the rotation of the left pinion gear 54 and controls the torque of the left side gear 52, and the right pinion gear. And a right wheel torque control unit 62 that controls the rotation of 58 and controls the torque of the right side gear 56. Note that the left wheel torque control unit 60 of this embodiment corresponds to the first torque control unit of the present invention, and the right wheel torque control unit 62 corresponds to the second torque control unit of the present invention.

  The left wheel torque control unit 60 includes a left wheel torque moving pinion gear 66 and a left wheel torque moving pinion gear 66 that are rotated coaxially and integrally through a connecting shaft 64 extending integrally from the left pinion gear 54. A meshing left wheel torque moving ring gear 68; and a left wheel torque amplifying clutch 70 interposed between the left wheel torque moving ring gear 68 and the differential carrier 40, which is a non-rotating member, and appropriately slip-engaging them. Yes. In this embodiment, the pitch diameter of the left pinion gear 54 and the pitch diameter of the left wheel torque moving pinion gear 66 are formed to be the same diameter, and as shown in the cross section E of FIG. Are provided at equiangular intervals around the axis J.

  The right wheel torque control unit 62 meshes with the right wheel torque moving pinion gear 74 and the right wheel torque moving pinion gear 74 that are rotated coaxially and integrally through a connecting shaft 72 connected to the right pinion gear 58. A right wheel torque moving ring gear 76, and a right wheel torque amplifying clutch 78 interposed between the right wheel torque moving ring gear 76 and the differential carrier 40, which is a non-rotating member, and appropriately slip-engaging them. I have. In this embodiment, the pitch diameter of the right pinion gear 56 and the pitch diameter of the pinion gear 74 for right wheel torque movement are formed to be the same diameter, and as shown in the section F of FIG. Four pinion gears 74 are provided at equiangular intervals.

  Both the left wheel and right wheel torque amplifying clutches 70 and 78 are slip-engaged multi-plate friction engagement devices that are frictionally engaged by a hydraulic actuator. When the hydraulic circuit 34 is switched by the control device 36, the clutches are respectively engaged. The transmission torque at the time of slip engagement is controlled by performing hydraulic pressure control as necessary, as well as being released or combined.

  Next, the operation of the rear wheel differential gear unit 26 configured as described above will be described. In the rear-wheel differential gear unit 26 of the present embodiment, in the case of straight traveling where traction performance and straight-line stability are required, the left wheel torque amplification clutch 70 of the left wheel torque control unit 60 and the right wheel torque control unit 62 By releasing the right wheel torque amplifying clutch 78, the differential function and the differential limiting function are operated, that is, the left and right wheel torque moving mechanism 44 is disengaged from both the torque amplifying clutches 70, 78, and the torque movement inoperative state. And The upper side of FIG. 3 shows the rotation state of each gear when the torque movement of the left and right wheel torque moving mechanism 44 is not performed when the vehicle is traveling straight.

  The driving force of the propeller shaft 24 is transmitted to the differential case 50 via the bevel gears 46 and 48. The differential case 50 is driven to rotate about the axis J of the rear wheel axle 28. As a result, the differential case 50 causes the left and right pinion gears 54 and 58 supported by the differential case 50 to revolve around the axis J of the rear wheel axle 28. Further, as shown in the cross sections B and C of FIG. 3, the left and right side gears 52 and 54 meshing with the left and right pinion gears 54 and 58 are rotated together by the revolution of the left and right pinion gears 54 and 58. In such a state, the left and right pinion gears 54 and 58 do not rotate and are in a non-differential state. At this time, in the left wheel torque control unit 60, as shown in the cross section E, the left wheel torque moving pinion gear 66 is rotated integrally with the left pinion gear 54 and meshed with the left wheel torque moving pinion gear 66. Since 68 is in a no-load state, it is rotated integrally with the left wheel torque moving pinion gear 66. Further, in the right wheel torque control unit 62, as shown in the cross section F, the right wheel torque moving pinion gear 74 is rotated integrally with the right pinion gear 58 and meshed with the right wheel torque moving pinion gear 74. Since the moving ring gear 76 is in an unloaded state, the moving ring gear 76 is rotated integrally with the right wheel torque moving pinion gear 74.

  FIG. 4 is a rotational speed diagram showing the relative relationship between the rotational speeds of the differential case 50 and the gears in a state corresponding to the upper side of FIG. Here, the intersection of the central vertical line and the horizontal line is the rotational speed of the differential case 50, R1 on the left side of the central vertical line is the rotational speed of the ring gear 68 for left wheel torque movement, and C1 is the pinion gear 66 for left wheel torque movement. , Ie, the rotational speed of the differential case 50, and S1 indicates the rotational speed of the left side gear 52. Further, R2 on the right side from the center vertical line is the rotational speed of the right wheel torque moving ring gear 76, C2 is the revolution speed of the right wheel torque moving pinion gear 74, that is, the rotational speed of the differential case 50, and S2 is the rotational speed of the right side gear 56. Is shown. As shown in FIG. 4, the revolution rotational speeds C <b> 1 and C <b> 2 of the left and right wheel torque moving pinion gears 66 and 74 are equal to the rotational speed of the differential case 50, and therefore always equal to the rotational speed of the differential case 50. The rotation speeds S1 and S2 of the left and right side gears 52 and 56 are such that the left and right pinion gears 54 and 58 do not rotate because the left wheel and right wheel torque moving pinion gears 66 and 74 do not rotate, and the rotation speed of the differential case 50 Is equal to Further, since the rotation speeds R1 and R2 of the left wheel and right wheel torque moving ring gears 68 and 76 are in an unloaded state, respectively, they are rotated integrally with the left wheel and right wheel torque moving pinion gears 66 and 74, and the differential case 50 It becomes equal to the rotation speed of.

  Further, for example, in a gentle turning state, the differential device 42 functions to enter a differential state. In such a state, the left and right pinion gears 54 and 58 rotate in opposite directions as they rotate, and the left and right pinion gears 54 and 58 rotate in opposite directions to cause the left and right side gears 52 and 56 to rotate in opposite directions. Rotate to As a result, a rotational difference occurs between the left side gear 52 and the right side gear 56, and a differential state is established.

  Here, since the outer peripheral teeth of the left and right side gears 52 and 56 and the left and right pinion gears 54 and 58 are respectively constituted by helical teeth, differential rotation occurs, that is, when the left and right pinion gears 54 and 58 rotate. A thrust force acting in the axial direction is generated from the meshing portion of each outer peripheral tooth. By this thrust force, between the adjacent left side gear 52 and the right side gear 56, between the wall surface of the differential case 50 and the side walls of the left and right side gears 52, 56, and / or the wall surface of the differential case 50 and the left and right pinion gears 54, A frictional force is generated between 58 side walls. Further, the left and right pinion gears 54 and 58 and the left and right side gears 52 and 56 are engaged with each other and rotated to generate a frictional force. Further, the left and right pinion gears 54, 58 and the left and right side gears 52, 56 mesh with each other, and the tips of the outer peripheral teeth of the left and right pinion gears 54, 58 are pressed against the differential case 50 to generate a frictional force. During straight running, when one of the rear wheels 30 slips on a slippery road surface or the like, the frictional force functions as a differential limiting force, thereby limiting a large differential.

  On the other hand, when the vehicle is turning, for example, when it is desired to suppress understeer of the vehicle, the left and right wheel torque moving mechanism 44 is operated. The left and right wheel torque moving mechanism 44 can distribute the driving force of the left and right wheels by appropriately slipping the left wheel torque amplifying clutch 70 of the left wheel torque control unit 60 or the right wheel torque amplifying clutch 78 of the right wheel torque control unit 62. Become.

  As an example of the left and right wheel torque moving mechanism 44, a case where the right wheel torque (right rear wheel 30r side) of the vehicle is increased will be described. When increasing the right wheel torque (right rear wheel 30r side), the right wheel torque amplification clutch 78 of the right wheel torque control unit 72 is slip-engaged. The lower side of FIG. 3 shows the state of each gear of the rear wheel differential gear unit 26 when the right wheel torque is increased by slip engagement of the right wheel torque amplifying clutch 78. As the right wheel torque amplifying clutch 78 is slip-engaged, as shown in the cross section F, the rotation of the right wheel torque moving ring gear 76 is decelerated. By this deceleration, the right wheel torque moving pinion gear 74 is revolved at the same rotational speed as the differential case 50 while being rotated in the direction of the arrow. The rotation of the right wheel torque moving pinion gear 74 is transmitted to the right pinion gear 58, and the rotation and revolution of the right pinion gear 58 cause the right side gear 56 to rotate at an increased speed as shown in the cross section C.

  Further, as shown in the cross sections A and D, as the right pinion gear 58 rotates, the left pinion gear 54 that meshes with the right pinion gear 58 is rotated in the opposite direction to the right pinion gear 58. Since the rotation of the left pinion gear 54 acts in a direction to decelerate the rotation of the left side gear 52 as shown in the cross section B, the left side gear 52 is rotated at a reduced speed. In the right wheel torque control unit 62, as shown in the cross section E, the left wheel torque moving pinion gear 66 is rotated in the same manner as the left pinion gear 54, and the left wheel torque moving ring gear 68 in an unloaded state is the left wheel. The speed is increased by rotation and revolution of the pinion gear 66 for torque movement.

  FIG. 5 is a rotational speed diagram showing the rotational speed of the differential case 50 and each gear when the right wheel torque is increased, corresponding to the lower side of FIG. Each rotating element is the same rotating element as in FIG. Since the right wheel torque amplifying clutch 78 is slip-engaged, the rotational speed R2 of the right wheel torque moving ring gear 76 is decelerated. Since the right wheel torque moving pinion gear 74 is rotated integrally with the differential case 50, the revolution speed C2 of the right wheel torque moving pinion gear 74 is the same as the rotational speed of the differential case 50. The rotational speed S2 of the right side gear 56 represents the rotational speed S2 of the right side gear 56 and a straight line connecting the rotational speed R2 of the right wheel torque moving ring gear 76 and the revolution rotational speed C2 of the right wheel torque moving pinion gear 74. Indicated by the intersection with the vertical line. Thereby, the right side gear 56 is rotated at an increased speed. On the other hand, when the right side gear 56 is rotated at an increased speed, the differential action of the differential device 42 causes the left side gear 52 to rotate at a reduced speed to the rotational speed S1. The revolution speed C1 of the left wheel torque moving pinion gear 66 is the same as the rotational speed of the differential case 50, and the rotational speed R1 of the left wheel torque moving ring gear 68 is opposite to the rotational speed R2 of the right wheel torque moving pinion gear 74. Increased speed rotation. As described above, the right wheel torque amplifying clutch 78 is slip-engaged to cause the differential device 42 to be differentially driven in the right wheel acceleration direction, thereby increasing the right wheel torque. Further, the increase in the left wheel torque increases the left wheel torque by slip-engaging the left wheel torque amplification clutch 70. Note that the effect of increasing the left wheel torque is the same as that for increasing the right wheel torque described above, and a description thereof will be omitted. Thus, for example, during a left turn, the right wheel torque amplification clutch 78 of the left and right wheel torque moving mechanism 44 is slip-engaged to decrease the torque of the left rear wheel 30l and increase the torque of the right rear wheel 30r. Thus, it is possible to give a yaw moment that assists the turning movement around the center of gravity of the vehicle, and to suppress understeer during left turning. For example, during a right turn, the left wheel torque amplification clutch 70 of the left and right wheel torque moving mechanism 44 is slip-engaged to reduce the torque of the right rear wheel 30r and increase the torque of the left rear wheel 30l. A yaw moment that assists the turning motion around the center of gravity of the vehicle can be applied to suppress understeer during a right turn.

  Here, in the rear wheel differential gear unit 26 of this embodiment, the torsion direction of the outer peripheral teeth of the left pinion gear 54 and the torsion direction of the outer peripheral teeth of the left wheel torque moving pinion gear 66 are formed in opposite directions. . Similarly, the torsion direction of the outer peripheral teeth of the right pinion gear 58 and the torsion direction of the outer peripheral teeth of the right wheel torque moving pinion gear 74 are formed in opposite directions. With this configuration, for example, when the right wheel torque amplification clutch 78 is slip-engaged, the right wheel torque moving pinion gear 74 is rotated. By this rotation, the right wheel torque moving pinion gear 74 and the right wheel are rotated. A thrust force in the axial direction is generated from the meshing portion with the torque moving ring gear 76. On the other hand, due to the rotation, a thrust force in the axial direction is also generated from the meshing portion of the right side gear 56 and the right pinion gear 58. Here, as described above, since the torsional directions of the outer peripheral teeth of the pinion gears 58 and 74 are formed in opposite directions, each thrust force acts in a direction to cancel each other's thrust force. Thereby, the thrust force generated by the right pinion gear 58 is reduced by the thrust force generated by the pinion gear 74 for right wheel torque movement, and the differential limiting force of the differential device 42 is suppressed. Similarly, when the left wheel torque amplifying clutch 70 is slip-engaged, the thrust force generated by the left pinion gear 54 is reduced by the thrust force generated by the left wheel torque moving pinion gear 66, and the differential device 42 Differential limiting force is suppressed. In this way, when the left and right wheel torque moving mechanism 44 is operated, the torsion angle of each gear is formed in a direction to suppress the differential limiting force of the differential device 42 that hinders the differential wheel 42 from moving. The torque difference between the left and right wheels can be controlled without being affected by the above.

  As described above, according to the left and right wheel torque moving mechanism 44 of this embodiment, the differential device 42 having the mechanical differential limiting mechanism controls the rotation of the left pinion gear 54 to control the torque of the left side gear 52. Since the left wheel torque control unit 60 and the right wheel torque control unit 62 for controlling the rotation of the right pinion gear 58 to control the torque of the right side gear 56 are provided, sufficient differential limitation is achieved by the conventional mechanical differential limitation. In addition, the left and right wheel torque control units 60 and 62 can control the left and right wheel torque difference. Accordingly, the two functions of the differential limiting function and the left and right wheel torque difference control can be selectively realized according to the traveling state of the vehicle, and the maneuverability and stability of the vehicle can be greatly improved. .

  Further, according to the left and right wheel torque moving mechanism 44 of the present embodiment, the left and right wheel torque control units 60 and 62 include the left and right wheel torque moving pinion gears 66 and 74, the left wheel and right wheel torque moving ring gear 68, 76, and left and right wheel torque amplifying clutches 70 and 78, and conventional mechanical elements, respectively, the device can be made compact in addition to the above-described effects, and a low-cost device can be realized. be able to.

  Further, according to the left and right wheel torque moving mechanism 44 of the present embodiment, the twist direction of the left pinion gear 54 and the twist direction of the left wheel torque moving pinion gear 66 are formed by helical teeth opposite to each other, and the twist of the right pinion gear 58 is The direction of the right wheel torque and the twist direction of the pinion gear 74 for moving the right wheel torque are formed by helical teeth that are opposite to each other. Therefore, the left wheel torque amplifying clutch 70 of the left wheel torque control unit 60 and the right wheel torque of the right wheel torque control unit 62 When the amplification clutch 78 is slip-engaged, the left and right wheel torque moving pinion gears 66 and 74 cancel the thrust force generated by the thrust force generated by the left and right pinion gears 54 and 58 by the differential limiting mechanism. In order to generate a thrust force in the direction, the torque difference control between the left and right wheels is suppressed while suppressing the influence of the differential limiting mechanism It is possible.

  Next, another embodiment of the present invention will be described. In the following description, parts common to those in the above-described embodiment are denoted by the same reference numerals and description thereof is omitted.

  FIG. 6 is a skeleton diagram illustrating a rear wheel differential gear unit 90 according to another embodiment of the present invention. The rear wheel differential gear unit 90 is mainly configured by a differential device 42 and a left and right wheel torque moving mechanism 92 having the same configuration and functions as those of the above-described embodiments. The differential device 42 and the left and right wheel torque moving mechanism 92 are each configured by conventional mechanical elements, and the rear wheel differential gear unit 90 has a compact configuration. The rear wheel differential gear unit 90 of this embodiment corresponds to the vehicle driving force distribution device of the present invention. Further, the configuration and function of the differential device 42 are the same as those in the above-described embodiment, and thus the description thereof is omitted.

  The left and right wheel torque moving mechanism 92 is provided on the right rear wheel 30r side of the differential device 42, controls the rotation of the left pinion gear 54 and controls the torque of the left side gear 52, and the right pinion gear. A right wheel torque control unit 96 that controls the rotation of 58 and controls the torque of the right side gear 56; and a differential relaxation planetary gear unit 98 provided between the right wheel torque control unit 96 and the right rear wheel 30r; Is provided. The left wheel torque control unit 94 of the present embodiment corresponds to the first torque control unit of the present invention, and the right wheel torque control unit 96 corresponds to the second torque control unit of the present invention. The dynamic relaxation planetary gear device 98 corresponds to the planetary gear device of the present invention.

  The differential relaxation planetary gear device 98 is disposed around a common shaft center with the differential case 50, the ring gear 100 is connected to the differential carrier 40 that is a non-rotating member, and the sun gear 102 is connected to the differential case 40. A pinion gear 104 is meshed between the ring gear 100 and the sun gear 102, and is supported by a carrier 106 so as to be able to revolve and rotate about an axis. As a result, the rotation of the differential case 50 is decelerated and output from the carrier 106.

  The left wheel torque control unit 94 is connected to the left wheel torque moving pinion gear 108 and the left wheel torque moving pinion gear 108, which are rotated coaxially and integrally via a connecting shaft 64 extending integrally from the left pinion gear 54. A meshing left wheel torque moving ring gear 110, and a left wheel torque amplifying clutch 112 interposed between the left wheel torque moving ring gear 110 and the carrier 106 of the differential relaxation planetary gear unit 98 to appropriately slip-engage these members. And has.

  The right wheel torque control unit 96 includes a right wheel torque moving pinion gear 114 that is rotated coaxially and integrally via a connecting shaft 72 that is integrally extended from the right pinion gear 58, and the right wheel torque moving pinion gear. 114, the right wheel torque moving ring gear 116 meshing with each other, and the right wheel torque moving ring gear 116 and the carrier 106 of the differential relaxation planetary gear unit 98 to slip-engage these members appropriately. And a right wheel torque amplifying clutch 118.

  Both the left wheel and right wheel torque amplifying clutches 112 and 118 are slip-engageable multi-plate frictional engagement devices that are frictionally engaged by a hydraulic actuator. When the hydraulic circuit 34 is switched by the control device 36, the clutches are respectively engaged. The transmission torque at the time of slip engagement is controlled by performing hydraulic pressure control as necessary, as well as being released or combined.

  Next, the operation of the rear wheel differential gear unit 90 configured as described above will be described. In the rear wheel differential gear unit 90 of the present embodiment, in the case of straight traveling where traction performance and straight traveling stability are required, the left wheel torque amplification clutch 112 of the left wheel torque control unit 94 and the right wheel torque control unit 96 By releasing the right wheel torque amplifying clutch 118, the differential function and the differential limiting function are operated, that is, by releasing both the torque amplifying clutches 112, 118 of the left and right wheel torque moving mechanism 92, the left and right wheel torque moving mechanism. 92 is a torque movement non-operation state. In such a state, since the operation is the same as that of the differential gear unit for rear wheel 26 described above, description thereof is omitted.

  On the other hand, when the vehicle is turning, for example, when it is desired to suppress understeer of the vehicle, the left and right wheel torque moving mechanism 92 is operated. The left and right wheel torque moving mechanism 92 can distribute the driving force of the left and right wheels by appropriately slipping the left wheel torque amplifying clutch 112 of the left wheel torque control unit 94 or the right wheel torque amplifying clutch 118 of the right wheel torque control unit 96. Become.

  As an example of the left and right wheel torque moving mechanism 92, a case where the right wheel torque (right rear wheel 30r side) of the vehicle is increased will be described. When increasing the right wheel torque (right rear wheel 30r side), the right wheel torque amplifying clutch 118 of the right wheel torque control unit 96 is slip-engaged. Here, in the differential relaxation planetary gear device 98, the ring gear 100 is fixed to be non-rotatable, and the sun gear 102 is connected to the differential case 50 to be rotated integrally with the differential case 50. It is output at reduced speed in the same rotational direction as the rotational direction of the sun gear 102 (difference case 50). Thus, when the right wheel torque amplifying clutch 118 is slip-engaged, the right wheel torque moving pinion gear 114 is caused by the rotational speed difference between the revolution speed of the right wheel torque moving pinion gear 114 and the right wheel torque moving ring gear 116. Is rotated in the counterclockwise direction with respect to the clockwise revolution of the right torque moving pinion gear 114, for example, in the same manner as the right wheel torque moving pinion gear 74 shown in the lower section F of FIG. The rotation of the right wheel torque moving pinion gear 114 is transmitted to the right pinion gear 58, and the right side gear 56 is rotated at an increased speed by the rotation and revolution of the right pinion gear 58 in the same manner as the section C on the lower side of FIG. .

  3, as the right pinion gear 58 rotates, the left pinion gear 54 that meshes with the right pinion gear 58 is rotated in the opposite direction to the right pinion gear 58. Since the rotation of the left pinion gear 54 acts in the direction of decelerating the rotation of the left side gear 52 as in the section B, the left side gear 52 is rotated at a reduced speed. This rotational state corresponds to the rotational speed diagram of FIG. 5 described above. By slip-engaging the right wheel torque amplification clutch 118, the differential device 42 is differentially moved in the direction of increasing the speed of the right rear wheel 30r. To increase the right wheel torque. Further, the increase in the left wheel torque increases the left wheel torque by slipping the left wheel torque amplification clutch 112. The operation of increasing the left wheel torque is the same as that of increasing the right wheel torque described above, and thus the description thereof is omitted. Thus, for example, during a left turn, the right wheel torque amplification clutch 118 of the left and right wheel torque moving mechanism 92 is slip-engaged to reduce the torque of the left rear wheel 30l and increase the torque of the right rear wheel 30r. Thus, it is possible to give a yaw moment that assists the turning movement around the center of gravity of the vehicle, and to suppress understeer during left turning. For example, during a right turn, the left wheel torque amplification clutch 112 of the left and right wheel torque moving mechanism 92 is slip-engaged to reduce the torque of the right rear wheel 30r and increase the torque of the left rear wheel 30l. A yaw moment that assists the turning motion around the center of gravity of the vehicle can be applied to suppress understeer during a right turn.

  Further, in this embodiment, the differential relaxation planetary gear device 98 is provided, so that the relative rotational difference between the differential case 50 and the carrier 106 that is the output element of the differential relaxation planetary gear device 98 is reduced. Torque loss during slip engagement of the wheel torque amplifying clutches 112 and 118 is reduced. Also in this embodiment, the torsion direction of the outer peripheral teeth of the left pinion gear 54 and the torsion direction of the outer peripheral teeth of the left wheel torque moving pinion gear 108 are formed in opposite directions, and the operation of the left and right wheel torque moving mechanism 92 is performed. In this case, the differential limiting force of the differential device 42 is suppressed. Further, the torsion direction of the outer peripheral teeth of the right pinion gear 58 and the torsion direction of the outer peripheral teeth of the right wheel torque moving pinion gear 114 are formed opposite to each other, and the differential during the operation of the left and right wheel torque moving mechanism 92 is formed. The differential limiting force of the device 42 is suppressed.

  As described above, according to the left and right wheel torque moving mechanism 92 of the present embodiment, the differential device 42 having the mechanical differential limiting mechanism controls the rotation of the left pinion gear 54 to control the torque of the left side gear 52. Since the left wheel torque control unit 94 and the right wheel torque control unit 96 that controls the rotation of the right pinion gear 58 to control the torque of the right side gear 56 are provided, sufficient differential limitation is achieved by the conventional mechanical differential limitation. The left and right wheel torque control units 94 and 96 can control the left and right wheel torque difference. Accordingly, the two functions of the differential limiting function and the left and right wheel torque difference control can be selectively realized according to the traveling state of the vehicle, and the maneuverability and stability of the vehicle can be greatly improved. .

  Further, according to the left and right wheel torque moving mechanism 92 of the present embodiment, the left wheel and right wheel torque control units 94 and 96 include the left wheel and right wheel torque moving pinion gears 108 and 114, the left wheel and right wheel torque moving ring gear 110, 116 and the left and right wheel torque amplifying clutches 112 and 118, respectively, are configured by conventional mechanical elements, and the differential relaxation planetary gear unit 98 is also configured by conventional mechanical elements, so that the apparatus can be made compact. it can. Further, by providing the differential relaxation planetary gear device 98, it is possible to reduce the relative rotational difference between the left and right wheel torque moving pinion gears 108 and 114 and the carrier 106 of the differential relaxation planetary gear device 98. Torque loss due to the left wheel and right wheel torque amplifying clutches 112 and 118 that slip-engage these members can be reduced.

  FIG. 7 is a skeleton diagram illustrating a rear wheel differential gear unit 130 according to another embodiment of the present invention. The rear wheel differential gear unit 130 is mainly configured by a differential device 42 and a left and right wheel torque moving mechanism 132 having the same configuration and operation as those of the above-described embodiments. The differential device 42 and the left and right wheel torque moving mechanism 132 are each configured by conventional mechanical elements, and the rear wheel differential gear unit 130 has a compact configuration. The rear wheel differential gear unit 130 of this embodiment corresponds to the vehicle driving force distribution device of the present invention. Further, the configuration and function of the differential device 42 are the same as those in the above-described embodiment, and thus the description thereof is omitted.

  The left and right wheel torque moving mechanism 132 is provided on the right rear wheel 30r side of the differential device 42, controls the rotation of the left pinion gear 54 to control the left side gear 52 and torque, and the right pinion gear. A right wheel torque control unit 136 that controls the rotation of 58 and controls the torque of the right side gear 56; a differential relaxation planetary gear device 138 provided between the right wheel torque control unit 136 and the right rear wheel 30r; Is provided. Note that the left wheel torque control unit 134 of this embodiment corresponds to the first torque control unit of the present invention, and the right wheel torque control unit 136 corresponds to the second torque control unit of the present invention. The dynamic relaxation planetary gear device 138 corresponds to the planetary gear device of the present invention.

  The differential relaxation planetary gear device 138 is disposed around a common shaft center with the differential case 50, the sun gear 140 is connected to the differential carrier 40 that is a non-rotating member, and the ringer 142 is connected to the differential case 40. A pinion gear 144 is meshed between the ring gear 142 and the sun gear 140, and is supported by the carrier 146 so as to be able to revolve and rotate around the axis. As a result, the rotation of the differential case 50 is decelerated and output from the carrier 146.

  The left wheel torque control unit 134 includes a left wheel torque moving pinion gear 148 that is integrally rotated coaxially via a connecting shaft 64 that is integrally extended from the left pinion gear 54, and the left wheel torque moving pinion gear 148. A meshing left wheel torque moving ring gear 150, and a left wheel torque amplifying clutch 152 interposed between the left wheel torque moving ring gear 150 and the carrier 146 of the differential relaxation planetary gear device 138 for appropriately slip-engaging them. Have.

  The right wheel torque control unit 136 includes a right wheel torque moving pinion gear 154 that is rotated coaxially and integrally through a connecting shaft 72 that is integrally extended from the right pinion gear 58, and the right wheel torque moving pinion gear. 154, a right wheel torque moving ring gear 156 that meshes with each other, and a right wheel that is interposed between the right wheel torque moving ring gear 156 and the carrier 146 of the differential relaxation planetary gear unit 138 to appropriately slip-engage them. A torque amplifying clutch 158.

  Both the left wheel and right wheel torque amplifying clutches 152 and 158 are slip-engaged multi-plate frictional engagement devices that are frictionally engaged by a hydraulic actuator. The transmission torque at the time of slip engagement is controlled by performing hydraulic pressure control as necessary, as well as being released or combined.

  Next, the operation of the rear wheel differential gear unit 130 configured as described above will be described. In the rear-wheel differential gear unit 130 of the present embodiment, in a situation such as straight running where traction performance and straight running stability are required, the left wheel torque amplification clutch 152 and the right wheel torque control unit 136 of the left wheel torque control unit 134 By releasing the right wheel torque amplifying clutch 158, the differential function and the differential limiting function are operated, that is, by releasing both the torque amplifying clutches 152, 158 of the left and right wheel torque moving mechanism 132, the left and right wheel torque moving mechanism 132 is a torque movement non-operation state. In such a state, since the operation is the same as that of the differential gear unit for rear wheel 26 described above, description thereof is omitted.

  On the other hand, when the vehicle is turning, for example, when it is desired to suppress understeer of the vehicle, the left and right wheel torque moving mechanism 132 is operated. The left and right wheel torque moving mechanism 132 can distribute the driving force of the left and right wheels by appropriately slip-engaging the left wheel torque amplification clutch 152 of the left wheel torque control unit 134 or the right wheel torque amplification clutch 158 of the right wheel torque control unit 136. Become.

  As an example of the left and right wheel torque moving mechanism 132, a case where the right wheel torque (right rear wheel 30r side) of the vehicle is increased will be described. When the right wheel torque (right rear wheel 30r side) is increased, the right wheel torque amplification clutch 158 of the right wheel torque control unit 136 is slip-engaged. Here, in the differential relaxation planetary gear device 138, the sun gear 140 is fixed to be non-rotatable, and the ring gear 142 is connected to the differential case 50 to be rotated integrally with the differential case 50. It is output at reduced speed in the same rotational direction as the rotational direction of the ring gear 142 (difference case 50). Thus, when the right wheel torque amplifying clutch 158 is slip-engaged, the right wheel torque moving pinion gear 154 is caused by the difference in rotational speed between the revolution speed of the right wheel torque moving pinion gear 154 and the right wheel torque moving ring gear 156. Is rotated counterclockwise with respect to, for example, clockwise revolution of the right torque moving pinion gear 154 in the same manner as the right wheel torque moving pinion gear 74 shown in the lower section F of FIG. The rotation of the right wheel torque moving pinion gear 154 is transmitted to the right pinion gear 58, and the right side gear 56 is rotated at an increased speed by the rotation and revolution of the right pinion gear 58 in the same manner as the lower section C of FIG. .

  3, as the right pinion gear 58 rotates, the left pinion gear 54 that meshes with the right pinion gear 58 is rotated in the opposite direction to the right pinion gear 58. Since the rotation of the left pinion gear 54 acts in the direction of decelerating the rotation of the left side gear 52 as in the section B, the left side gear 52 is rotated at a reduced speed. This rotational state corresponds to the rotational speed diagram of FIG. 5 described above, and the differential device 42 is differentially moved in the direction of increasing the speed of the right rear wheel 30r by slip-engaging the right wheel torque amplification clutch 158. To increase the right wheel torque. Further, the increase in the left wheel torque increases the left wheel torque by causing the left wheel torque amplification clutch 152 to slip-engage. The operation of increasing the left wheel torque is the same as that of increasing the right wheel torque described above, and thus the description thereof is omitted. Thus, for example, during a left turn, the right wheel torque amplification clutch 158 of the left and right wheel torque moving mechanism 132 is slip-engaged to reduce the torque of the left rear wheel 30l and increase the torque of the right rear wheel 30r. Thus, it is possible to give a yaw moment that assists the turning movement around the center of gravity of the vehicle, and to suppress understeer during left turning. For example, during a right turn, the left wheel torque amplification clutch 152 of the left and right wheel torque moving mechanism 132 is slip-engaged to reduce the torque of the right rear wheel 30r and increase the torque of the left rear wheel 30l. A yaw moment that assists the turning motion around the center of gravity of the vehicle can be applied to suppress understeer during a right turn.

  Further, in this embodiment, the differential relaxation planetary gear device 138 is provided, so that the relative rotational difference between the differential case 50 and the carrier 146 that is the output element of the differential relaxation planetary gear device 138 is reduced. Torque loss during slip engagement of the wheel torque amplifying clutches 152 and 158 is reduced. Also in this embodiment, the torsion direction of the outer peripheral teeth of the left pinion gear 54 and the torsion direction of the outer peripheral teeth of the left wheel torque moving pinion gear 148 are formed opposite to each other. The differential limiting force of the differential device 42 at the time of the combination is suppressed. Further, the torsion direction of the outer peripheral teeth of the right pinion gear 58 and the torsion direction of the outer peripheral teeth of the right wheel torque moving pinion gear 154 are formed opposite to each other, and at the time of slip engagement of the right wheel torque amplifying clutch 158. The differential limiting force of the differential device 42 is suppressed.

  As described above, according to the left and right wheel torque moving mechanism 132 of this embodiment, the differential device 42 having the mechanical differential limiting mechanism controls the rotation of the left pinion gear 54 to control the torque of the left side gear 52. Since the left wheel torque control unit 134 and the right wheel torque control unit 136 that controls the rotation of the right pinion gear 58 to control the torque of the right side gear 56 are provided, sufficient differential limitation is achieved by the conventional mechanical differential limitation. In addition, the right and left wheel torque control units 134 and 136 can control the left and right wheel torque difference. Accordingly, the two functions of the differential limiting function and the left and right wheel torque difference control can be selectively realized according to the traveling state of the vehicle, and the maneuverability and stability of the vehicle can be greatly improved. .

  Further, according to the left and right wheel torque moving mechanism 132 of the present embodiment, the left wheel and right wheel torque control units 134 and 136 include the left wheel and right wheel torque moving pinion gears 148 and 154, the left wheel and right wheel torque moving ring gear 150, 156 and the left and right wheel torque amplifying clutches 152 and 158 and the conventional mechanical elements, respectively, and the differential relaxation planetary gear unit 138 is also configured by the conventional mechanical elements. Can do. In addition, since the differential relaxation planetary gear device 138 is provided, the relative rotational difference between the left and right wheel torque moving pinion gears 148 and 154 and the differential relaxation planetary gear device 138 can be reduced. Torque loss due to the left wheel and right wheel torque amplifying clutches 152 and 158 with which these members are slip-engaged can be reduced.

  As mentioned above, although the Example of this invention was described in detail based on drawing, this invention is applied also in another aspect.

  For example, the left and right wheel torque moving mechanisms 44, 92, and 132 of the above-described embodiment are provided in the rear wheel differential gear unit 26 for the rear wheel, but also in the front wheel differential gear device 16 on the front wheel side. This mechanism can be provided for implementation.

  Further, the left and right wheel torque moving mechanisms 44, 92, and 132 of the above-described embodiment are provided on the right rear wheel 30r side of the differential device 42. It can also be carried out by providing it on the left rear wheel 30l side.

  In the left and right wheel torque moving mechanisms 44, 92, and 132 of the above-described embodiments, the pitch diameter of the left pinion gear 54 and the pitch diameter of the left wheel torque moving pinion gear 66, the pitch diameter of the right pinion gear 58, and the pinion gear for moving the right wheel torque. The pitch diameter of 74 is formed to be the same diameter, but is not necessarily the same diameter, and the present invention can be applied even if the pitch diameters are different.

  The above description is only an embodiment, and the present invention can be implemented in variously modified and improved forms based on the knowledge of those skilled in the art.

[BRIEF DESCRIPTION OF THE DRAWINGS] It is a skeleton diagram explaining the structure of the front-and-rear wheel drive vehicle based on the front engine front wheel drive (FF) which has a drive force transmission device with which this invention is applied suitably. FIG. 2 is a skeleton diagram illustrating a configuration of a rear wheel differential gear unit in FIG. 1. FIG. 3 is a cross-sectional view of the rear wheel differential gear unit cut along the dashed-dotted lines A to F shown in FIG. 2. It is a rotational speed diagram which shows the rotational speed of each gear at the time of the vehicle traveling straight and non-differential. It is a rotational speed diagram which shows the rotational speed of each gear at the time of right wheel torque increase. It is a skeleton drawing explaining the structure of the differential gear unit for rear wheels which is the other Example of this invention. It is a skeleton diagram explaining the structure of the differential gear unit for rear wheels which is further another Example of this invention.

Explanation of symbols

26, 90, 130: Rear wheel differential gear unit (vehicle driving force distribution device) 42: Differential device 50: Differential case 52: Left side gear 54: Left pinion gear 56: Right side gear 58: Right pinion gear 60, 94, 134 : Left wheel torque control unit (first torque control unit) 62, 96, 136: Right wheel torque control unit (second torque control unit) 66, 108, 148: Pinion gear for left wheel torque movement 68, 110, 150: Left wheel torque movement Ring gears 70, 112, 152: Left wheel torque amplifying clutches 74, 114, 154: Right wheel torque moving pinion gears 76, 116, 156: Right wheel torque moving ring gears 78, 118, 158: Right wheel torque amplifying clutches 98, 138 : Differential relaxation planetary gear unit (planetary gear unit)

Claims (5)

A pair of right side gear and left side gear, which are formed of helical teeth and arranged adjacent to each other on a common axis, and a left pinion gear which is formed of helical teeth and meshes with the right side gear and meshes with the right side gear. And a differential case that is rotatably provided about the shaft center and rotatably supports the left and right side gears and the left and right pinion gears, and supports the left and right pinion gears so that they can revolve on the shaft center. Provided in a differential carrier which is a non-rotating member, the right pinion gear and the left pinion gear are meshed with each other, and when the right side gear and the left side gear are differentially rotated, the left and right pinion gears rotate in opposite directions, Generated from the meshing part of the left and right side gears and the left and right pinion gears A vehicular drive force distribution device comprising a differential device having a mechanical differential limiting mechanism in which the differential is restricted by the thrust force that,
A first torque control unit that controls rotation of the left pinion gear to control torque of the left side gear;
A second torque control unit that controls the rotation of the right pinion gear to control the torque of the right side gear;
A vehicle driving force distribution device comprising: The first torque control unit includes:
The left wheel torque moving pinion gear rotated integrally with the left pinion gear, the left wheel torque moving ring gear meshing with the left wheel torque moving pinion gear, and the left wheel torque moving ring gear and the differential carrier are interposed between these. A left wheel torque amplifying clutch for appropriately slip-engaging the
The second torque control unit includes:
A right wheel torque moving pinion gear that is rotated integrally with the right pinion gear, a right wheel torque moving ring gear meshing with the right wheel torque moving pinion gear, and a ring gear between the right wheel torque moving ring gear and the differential carrier. The vehicle driving force distribution device according to claim 1, further comprising a right wheel torque amplification clutch that is mounted and appropriately slip-engaged. A ring gear connected to the differential carrier; a sun gear connected to the differential case; and a carrier that supports the ring gear and the pinion gear meshing with the sun gear so as to be capable of rotating and revolving, and rotation of the differential case decelerated from the carrier. The planetary gear device to be output is disposed on the common axis,
The first torque control unit includes:
A left wheel torque moving pinion gear that is rotated integrally with the left pinion gear, a left wheel torque moving ring gear that meshes with the left wheel torque moving pinion gear, and a space between the left wheel torque moving ring gear and the planetary gear unit carrier. A left wheel torque amplifying clutch that is fitted and appropriately slip-engaged,
The second torque control unit includes:
A right wheel torque moving pinion gear rotated integrally with the right pinion gear, a right wheel torque moving ring gear meshing with the right wheel torque moving pinion gear, the right wheel torque moving ring gear, and a carrier of the planetary gear unit; A vehicle driving force distribution device according to claim 1, further comprising a right wheel torque amplifying clutch that is interposed between the two and configured to appropriately slip-engage them. A sun gear coupled to the differential carrier; a ring gear coupled to the differential case; and a carrier that supports the sun gear and the pinion gear meshing with the ring gear so as to be capable of rotating and revolving, and the rotation of the differential case decelerated from the carrier. The planetary gear device to be output is disposed on the common axis,
The first torque control unit includes:
A left wheel torque moving pinion gear that is rotated integrally with the left pinion gear, a left wheel torque moving ring gear that meshes with the left wheel torque moving pinion gear, and a space between the left wheel torque moving ring gear and the planetary gear unit carrier. A left wheel torque amplifying clutch that is fitted and appropriately slip-engaged,
The second torque control unit includes:
A right wheel torque moving pinion gear rotated integrally with the right pinion gear, a right wheel torque moving ring gear meshing with the right wheel torque moving pinion gear, the right wheel torque moving ring gear, and a carrier of the planetary gear unit; A vehicle driving force distribution device according to claim 1, further comprising a right wheel torque amplifying clutch that is interposed between the two and configured to appropriately slip-engage them. The torsion direction of the left pinion gear and the torsion direction of the left wheel torque moving pinion gear are formed of helical teeth that are opposite to each other,
5. The vehicle driving force distribution according to claim 2, wherein the twist direction of the right pinion gear and the twist direction of the right wheel torque moving pinion gear are formed by helical teeth that are opposite to each other. apparatus.

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