JPH0439788Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) This invention is intended for use in horizontally mounted four-wheel drive vehicles, especially those equipped with an interaxle differential device that distributes power from the engine between the front wheels and the rear wheels. The present invention relates to a torque distribution device for a four-wheel drive vehicle.

(Prior Art) In a four-wheel drive vehicle in which the torque output from the engine via the transmission is divided to drive the front wheels and the rear wheels respectively, the In addition to the inter-wheel differential, an inter-axle differential may be provided to eliminate the so-called braking phenomenon during cornering. This inter-axle differential device has an input element into which torque from the engine or transmission is input, and outputs for the front wheels and rear wheels that divide the torque input to the element and transmit it to the front wheels and rear wheels, respectively. A differential operation is performed between both output elements to absorb the difference in rotational speed between the front and rear wheels during cornering.

By the way, in this type of four-wheel drive vehicle, for example, during sharp cornering, the difference in rotational speed between the front and rear wheels is allowed to be excessive, resulting in unstable running conditions, or when one of the front wheels or rear wheels slips. In order to solve the problem that torque is not transmitted to the other when the A differential limiting mechanism may be provided between the output element and the input element to suppress relative rotation between these elements when the relative rotation exceeds a predetermined amount.

(Problems to be Solved by the Invention) By the way, when a four-wheel drive vehicle with a horizontally mounted engine in which the engine is arranged so that the output shaft extends in the width direction of the vehicle body is provided with an inter-axle differential device as described above, It is customary to integrate the differential device and an inter-wheel differential device for wheels located on the engine side to form a torque distribution device, and to connect the device to the engine via a transmission.

When this torque distribution device is equipped with a differential limiting mechanism as described above, the torque distribution device includes an inter-axle differential device, its differential limiting mechanism, and an inter-wheel differential for the wheels on the engine side. Therefore, the problem is how to arrange these many components in a compact manner. In particular, since the inter-wheel differential device is connected to the wheels via the wheels extending left and right from the device, its position in the longitudinal and vertical directions of the vehicle body is restricted.
Along with this, the arrangement of other members is also restricted, making it extremely difficult to lay out each of these constituent members in a compact manner.

The present invention deals with the above-mentioned situation, and is aimed at a transverse engine type 4 vehicle equipped with an inter-axle differential device, a differential limiting mechanism thereof, and an inter-wheel differential device for wheels located on the engine side. In a torque distribution device for a wheel drive vehicle, the purpose of the present invention is to expand the degree of freedom in its arrangement so that the inter-wheel differential device is positioned corresponding to the wheels on the engine side, and to lay out each of the above-mentioned constituent members in a compact manner. .

(Means for Solving the Problems) That is, the present invention provides a torque distribution device for a four-wheel drive vehicle with a horizontal engine, which distributes torque input from the engine through the transmission and input gear train to the front wheels. The vehicle is equipped with an inter-axle differential device that distributes torque to the rear wheels, and a front-wheel output gear train and a rear-wheel output gear train that output torque from the shaft of the inter-axle differential device to the front wheels and the rear wheels, respectively. They are placed on both sides of the input gear train. The differential limiting mechanism of the inter-axle differential device and the inter-wheel differential device of the wheels located on the engine side are provided on a separate shaft from the above-mentioned inter-axle differential device. It is characterized by being placed between the output gear train for the rear wheels.

(Operation) According to the above configuration, the inter-axle differential device allows
Torque input from the engine via the transmission and input gear train is distributed between the front wheels and the rear wheels, and these torques are distributed to the wheels located on the engine side by the wheels forming the torque distribution device. The transmission is transmitted to the other wheel via a separately provided inter-wheel differential, and the differential of the inter-axle differential is controlled by the action of the differential limiting mechanism. The operation will be controlled according to the driving condition. In particular, the inter-wheel differential device for the wheels located on the engine side is
In the torque distribution device, since it is arranged on a separate shaft from the inter-axle differential device, the degree of freedom in arrangement is increased, and therefore the inter-wheel differential device can be easily positioned to correspond to the wheels on the engine side. As a result, the layout of the torque distribution device as a whole can be simplified. Further, since the inter-wheel differential device and the differential limiting mechanism are arranged between the front wheel and rear wheel output gear trains, that is, in a position overlapping the input gear train in the axial direction, the torque distribution device The dimensions of the vehicle body in the width direction will be reduced.

(Example) Hereinafter, an example of the present invention will be described. still,
The following embodiments include a plurality of inter-axle differentials with different torque distribution ratios to the front wheels and the rear wheels,
The present invention relates to a torque distribution device that can be used selectively.

First, the overall configuration of the four-wheel drive vehicle according to this embodiment will be explained with reference to FIG. It is equipped with a power plant. The engine 1 is arranged so that its output shaft 4 extends in the axial direction of the vehicle body. Further, the transmission 2 is also arranged such that an input shaft 6 connected to the engine output shaft 4 via a clutch 5 and an output shaft 7 parallel thereto extend in the width direction of the vehicle body. Gear trains 8 1 to 8 5 , _{8 r} for _1st to 5th speeds and reverse speed, which are selectively put into a power transmission state, are provided between the input and output shafts 6 and 7 of the transmission 2, and At one end of the output shaft 7 is an output gear 9 that transmits torque from the transmission 2 to the torque distribution device 3.
is provided.

On the other hand, the torque distribution device 3 divides and outputs the torque input from the transmission 2, and drives the left and right front wheels 10, 11, as well as a propeller shaft 12 extending in the longitudinal direction of the vehicle body, and a rear wheel differential device. (hereinafter referred to as a rear differential) 13 and rear wheel drive shafts 14, 15 extending left and right from the rear differential 13 to drive left and right rear wheels 16, 17.

Next, the structure of the torque distribution device 3 will be explained with reference to FIG. 2. The device 3 includes an intermediate shaft 21 arranged in the width direction of the vehicle body, and an intermediate shaft 21 arranged parallel to the shaft 21 and extending in both left and right sides. Left and right front wheel drive shafts 22, 2
3, a first output shaft 24 for rear wheels parallel to these,
A second output shaft 27 for rear wheels is connected to the shaft 24 via a pair of bevel gears 25 and 26, and is arranged in the longitudinal direction of the vehicle body and extends rearward. 23 is connected to the front wheels 10 and 11 shown in FIG. 1, and a second output shaft 27 for rear wheels is connected to the propeller shaft 12, respectively.

An input gear 31 is rotatably supported on the intermediate shaft 21, forming an input gear train 30 extending from the transmission output gear 9 to the input gear 31 via the idle gear 32. , a differential device between the first and second axles (hereinafter referred to as the first and second center differential) 4 is disposed on the intermediate shaft 21.
0, 50, and these switching mechanisms 60 are arranged.

The first center differential 40 is composed of a single pinion type planetary gear mechanism, and as shown in FIG. 3, it includes a sun gear 41 and a plurality of pinion gears 42 arranged around the gear 41 and meshing therewith.
42, a carrier 44 that supports these pinion gears 42...42 via pinion shafts 43...43, and a ring gear 45 that is disposed outside each pinion gear 42...42 and meshes with them.

Further, the second center differential 50 is composed of a double pinion type planetary gear mechanism, and as shown in FIG. 4, it includes a sun gear 51 and a plurality of first pinion gears 52 arranged around the gear 51 and meshing therewith.
52, a plurality of second pinion gears 53...53 meshing with these pinion gears 52...52, and each of the first and second pinion gears 52...52, 53...5.
3 to the pinion shaft 54...54, 55...5, respectively.
5, and a ring gear 57 that is disposed outside of and meshes with the second pinion gears 53...53.

Then, as shown in Figure 2, the first center differential 4
The carrier 44 of the second center differential 50 and the ring gear 57 of the second center differential 50 are connected and connected to the input gear 31, and the intermediate gears 41, 51 of both center differentials 40, 50 are connected to the intermediate shaft 21, and the first center differential The ring gear 45 of 40 and the carrier 56 of the second center differential 50 are connected to the switching mechanism 60.
guided by. Further, a first output gear 71 for front wheels is fixed to one end of the intermediate shaft 21.
1 is meshed with a second output gear 72 for front wheels rotatably supported on the right front wheel drive shaft 23 to form an output gear train 70 for front wheels.

On the other hand, the switching mechanism 60 includes first and second splines 6 connected to the ring gear 45 and carrier 56 of the first and second center differentials 40 and 50, respectively.
1 and 62, and a first output gear 81 for rear wheels arranged in parallel with these and rotatably supported on the intermediate shaft 21.
The third spline 63 is coupled to the third spline 63, and the sleeve 64 is slidably fitted over the splines 61, 62, 63.
When the sleeve 64 is slid to the right as shown in the figure, the first and third splines 6
1 and 63, the ring gear 45 of the first center differential 40 and the first output gear 81 for rear wheels are connected,
Furthermore, by sliding the sleeve 64 to the left from the illustrated position, the carrier 56 of the second center differential 50 and the first output gear 81 for the rear wheels are connected via the second and third splines 62 and 63. It's summery. This rear wheel first output gear 81 is a rear wheel second output gear rotatably supported on the left front wheel drive shaft 22.
The third output gear 83 for rear wheels, which is fixed to the first output shaft 24 for rear wheels, is meshed with the output gear 82.
A rear wheel output gear train 80 is configured.

The rear wheel output gear train 80 and the front wheel output gear train 70 are arranged on both sides of the input gear train 30, respectively, and the left and right front wheel drive shafts of both output gear trains 70, 80 are disposed on both sides of the input gear train 30. 22,
23 respectively supported by second output gears 72 and 82
In between, there is a front wheel differential device (hereinafter referred to as front differential) 90 and the first and second center differentials 40, 5.
A viscous coupling spring 100 serving as a zero differential limiting mechanism is arranged.

The front differential 90 is connected to the left and right front wheel drive shafts 2.
A differential case 91 is rotatably fitted and supported on 2 and 23, and a front wheel drive shaft 2 is mounted inside the case 91.
a pinion shaft 92 installed in a direction perpendicular to the axes of the gears 2 and 23; a pair of pinion gears 93 and 94 rotatably supported by the shaft 92;
It is comprised of a pair of left and right output gears 95 and 96 meshed with both pinion gears 93 and 94. Then, the differential case 91 is connected to the second output gear 7 for the front wheels.
2, and both output gears 95, 96 are connected to the ends of the left and right front wheel drive shafts 22, 23, respectively.

The viscous cut spring 100 also includes an inner case 101 coupled to the second output gear 72 for front wheels, an outer case 102 coupled to the second output gear 82 for rear wheels, and both cases 10
It has a large number of plates 103...103 arranged between 1 and 102 and engaged with these plates alternately, and the periphery of the plates 103...103 is filled with viscous fluid. When the difference in rotational speed between the inner case 101 and the outer case 102, that is, between the second output gear 72 for front wheels and the second output gear 82 for rear wheels, is small, relative rotation between them is allowed. When the rotation speed difference exceeds a predetermined amount, the resistance of the viscous fluid acts to limit the relative rotation.

Next, to explain the operation of this embodiment, the rotation output from the engine 1 via the transmission 2 is transmitted to the output gear 9 of the transmission 2.
The torque is input from the input gear train 30 consisting of the idle gear 32 and the input gear 31 to the carrier 44 of the first center differential 40 and the ring gear 57 of the second center differential 50 on the intermediate shaft 21 in the torque distribution device 3 .

When the sleeve 64 in the switching mechanism 60 is slid to the right as shown, the torque is divided by the first center differential 40 and the sun gear 41 and ring gear 45 of the center differential 40 are divided.
At the same time, the torque output to the sun gear 41 side is transmitted to the front wheel first output gear 71 via the intermediate shaft 21, and the torque output to the ring gear 45 side is transmitted to the rear wheel first output gear 71 via the switching mechanism 60. 1 output gear 8
1, respectively. Further, when the sleeve 64 in the switching mechanism 60 is slid to the left, the torque is divided by the second center differential 50 and output to the sun gear 51 and the carrier 56 of the center differential 50, and the torque is output to the sun gear 51 and the carrier 56 of the center differential 50. Similarly, the torque output to the sun gear 51 side is transmitted to the front wheel first output gear 71, and the torque output to the carrier 56 side is transmitted to the rear wheel first output gear 81. In either case, the torque transmitted to the first output gear 71 for the front wheels is transmitted to the first output gear 71 for the front wheels and the second output gear 72 for the front wheels that meshes with the gear 71.
It is transmitted to the differential case 91 of the front differential 90 via the front wheel output gear train 70 consisting of
The front differential 90 drives the left and right front wheel drive shafts 2.
It is divided into 2 and 23 and drives the left and right front wheels 10 and 11. Further, the torque transmitted to the first output gear 81 for rear wheels is transmitted to the first output gear 81 and the second and third output gears for rear wheels.
Rear wheel output gear train 8 consisting of output gears 82 and 83
0, first output shaft 24 for rear wheels and a pair of bevel gears 2
5, 26 to the second rear wheel output shaft 27, and further transmitted to the left and right rear wheels 16, 17 via the propeller shaft 12, rear differential 13, and rear wheel drive shafts 14, 15.
to drive.

In that case, if the torque is divided by the first center differential 40, the first center differential 40
The torque input to the carrier 44 is transmitted to the sun gear 4.
1 and ring gear 45 in a ratio of, for example, 3:7 depending on the ratio of the number of teeth of both gears 41 and 45.
The torque transmitted from the ring gear 45 to the rear wheels 16, 17 is larger than the torque transmitted from the sun gear 41 to the front wheels 10, 11, so that the so-called torque distribution is biased toward the rear wheels, making it suitable for sporty driving. becomes. On the other hand, the second center differential 50
If you want to distribute the torque by setting the ratio of the number of teeth between the sun gear 51 and the ring gear 57 to, for example, 1:2, the torque input to the ring gear 57 will be divided equally between the sun gear 51 and the carrier 56. Therefore, the torque is distributed evenly to the front and rear wheels, which is suitable for normal driving or driving on rough roads.

In any case, during relatively gentle cornering, the viscous cut spring 10
0 allows relative rotation between the second output gear 72 for the front wheels and the second output gear 82 for the rear wheels. A differential operation is performed between the sun gear 51 and the carrier 56, which are also two output elements in the 2-center differential 50, so that the difference in rotational speed between the front and rear wheels due to cornering is absorbed and braking is performed. The phenomenon will be resolved. On the other hand, when the rotational speed difference between the front and rear wheels exceeds a predetermined amount, such as during sharp cornering or when either the front or rear wheels slip, the viscous coupling spring 100 1 center differential 40 or 2nd
Since the differential operation between the two output elements in the center differential 50 is limited, the center differential 40 or 50 approaches the locked state, and the rotational speed difference between the front and rear wheels as described above is eliminated or suppressed. Become. Therefore, during sharp cornering, it is possible to prevent the driving condition from becoming unstable due to excessive rotational speed difference between the front and rear wheels, and when either the front or rear wheels slip, the other Power is transmitted to, for example, making it possible to escape from a slip state or obtaining the required starting acceleration. In this manner, the differential operation of the center differentials 40, 50 is controlled according to the driving condition by the action of the viscous coupling spring 100.

However, in this torque distribution device 3, the left and right front wheel drive shafts 2 on which the front differential 90 is disposed
2 and 23, an intermediate shaft 21 is provided, and the first and second center differentials 40 and 50 are mounted on the intermediate shaft 21.
and its switching mechanism 60 are arranged. In other words, the front differential 90 is arranged on a separate axis from the first and second center differentials 40, 50, etc. Therefore, when laying out each component of the torque distribution device 3, the front differential 90 can be relatively freely arranged without being restricted by the first and second center differentials 40, 50, etc. The torque distribution device 3 can be easily positioned to correspond to the front wheels 10 and 11.
The overall layout of each component is also simplified. The front differential 90 and the viscous cut spring 100 are arranged between the second output gears 72 and 82 in the front and rear output gear trains 70 and 80, respectively. Since they are arranged on both sides of the input gear train 30, the front differential 90 and the viscous coupling spring 100 overlap the input gear train 30 in the axial direction. This allows the torque distribution device 3 to be configured compactly, especially in the vehicle width direction.

5 to 9 show torque distribution devices 3a to 3e, respectively, according to other embodiments of the present invention, and these torque distribution devices will be described next.

First, the torque distribution device 3a shown in FIG.
The rotation from 40a divides the torque, and the output to the sun gear 41a is transferred to the switching mechanism 60.
a, output gear train 80a for rear wheels, first output shaft 24a for rear wheels, and a pair of bevel gears 25a, 26a to a second output shaft 27a for rear wheels; output to ring gear 45a; Output gear train 70a for
and is transmitted to the left and right front wheel drive shafts 22a, 23a, respectively, via the front differential 90a. Also, when the sleeve 64a is slid to the left, the second
The center differential 50a divides the torque and sends it to the sun gear 51a in the same way as in the case of the first center differential 40a.
The output to the rear wheel first and second output shafts 24a, 27
In a, the output to the carrier 56a is from the front differential 9.
0a to the left and right front wheel drive shafts 22a and 23a, respectively. In other words, this torque distribution device 3
In a, the ring gear 45a of the first center differential 40a and the carrier 56 of the second center differential 50a
a and output element for the front wheels, both center differentials 40a, 5
Sun gears 41a and 51a of 0a serve as output elements for the rear wheels.

Further, the transfer device 3b shown in FIG.
Rotation from the transmission output gear 9b is transmitted to the first and second center differentials 4 via the input gear train 30b.
0b, 50b carrier 44b, ring gear 57
b. When the sleeve 64b of the switching mechanism 60b is in the illustrated position, the first center differential 40b divides the torque, and the output to the sun gear 41b is transferred to the switching mechanism 60b and the rear wheel output gear train 80.
The first and second output shafts 24b and 27 for rear wheels are connected via b.
b, the output to the ring gear 45b is the intermediate shaft 21
b, front wheel output gear train 70b and front differential 9
0b to the left and right front wheel drive shafts 22b and 23b, respectively. Further, when the sleeve 64b is slid to the left, the second center differential 50b divides the torque, and the output is transmitted to the sun gear 51b via the intermediate shaft 21b, the front wheel output gear train 70b, and the front differential 90b to the front wheel drive shaft 22b. ,23b
, the output to the carrier 56b is changed to a switching mechanism 60b,
The power is transmitted to the first and second rear wheel output shafts 24b and 27b via the rear wheel output gear train 80b, respectively. That is, in this torque distribution device 3b, the ring gear 45b of the first center differential 40b and the sun gear 51b of the second center differential 50b are output elements for the front wheels, and the sun gear 41b of the first center differential 40b and the carrier 56b of the second center differential 50b are the output elements for the front wheels. It is an output element for wheels.

Furthermore, in the torque distribution device 3c shown in FIG. 7, the rotation from the transmission output gear 9c is input to the carrier 44c and ring gear 57c of the first and second center differentials 40c and 50c via the input gear train 30c. At the same time, when the sleeve 64c of the switching mechanism 60c is in the illustrated position, the first center differential 40c divides the torque and the sun gear 41c
The output to the intermediate shaft 21c and the front wheel output gear train 70
The output to the ring gear 45c is sent to the front differential 90c or the front wheel drive shafts 22c, 23c via the switching mechanism 60c and the rear wheel output gear train 80c to the first and second rear wheel output shafts 24c, 27c. are transmitted respectively. Furthermore, when the sleeve 64c is slid to the left, the second center differential 50c divides the torque, and the output to the sun gear 51c is transmitted to the first and second rear wheel output gears via the switching mechanism 60c and the rear wheel output gear train 80c. The output to the carrier 56c is transmitted to the two output shafts 24c, 27c via the intermediate shaft 21c and the front wheel output gear train 70c to the front differential 90c or the front wheel drive shafts 22c, 23c, respectively.
That is, in this torque distribution device 3c, the sun gear 41c of the first center differential 40c and the carrier 56c of the second center differential 50c are output elements for the front wheels, and the ring gear 45c of the first center differential 40c and the sun gear 51c of the second center differential 50c are the rear wheel output elements. It is an output element for wheels.

In addition, in each of the above torque distribution devices 3, 3a to 3c, the first center differential 40, 40a to
40c is a single pinion type planetary gear mechanism, and the second center differential 50, 50a to 50c are constituted by a double pinion type planetary gear mechanism, but the torque distribution device 3d in FIG. 8, which will be explained next,
In the case, the first and second center differentials 40d, 50
d is also constructed with a single pinion type planetary gear mechanism.

In this torque distribution device 3d, the rotation from the transmission output gear 9d is transmitted to the first and second center differentials 40d, 5 through the input gear train 30d.
It is designed to be input to carriers 44d and 54d of 0d. When the sleeve 64d of the switching mechanism 60d is in the illustrated position, the first center differential 40d divides the torque, and the output to the sun gear 41d is transmitted to the switching mechanism 60d, the intermediate shaft 21d, the front wheel output gear train 70d, and the front differential 90d. The output to the ring gear 45d is transmitted to the front wheel drive shafts 22d, 23d via the rear wheel output gear train 80d to the first and second rear wheel output shafts 24d, 27d, respectively. Also, when the sleeve 64d is slid to the left, the second center differential 50d divides the torque, and as in the case of the first center differential 40d, the output to the sun gear 51d is sent to the front differential 90d or the front wheel drive shafts 22d, 23d. , ring gear 55d
The output to the rear wheel first and second output shafts 24d, 27
d, respectively. That is, in this torque distribution device 3d, the first and second center differentials 40
For both d and 50d, the carriers 44d and 54d are input elements, the sun gears 41d and 51d are output elements for the front wheels, and the ring gears 45d and 55d are output elements for the rear wheels, and the diameters of the gears of both center differentials 40d and 50d are made different. The torque distribution ratio between the front and rear wheels can be switched. In this torque distribution device 3d, unlike each of the torque distribution devices 3, 3a to 3c, the center differential is switched in the middle of the output path to the front wheels.

Furthermore, the torque distribution device 3e shown in FIG. 9 is substantially the same as that shown in FIG. 8, but the torque distribution device 3e shown in FIG. The output torque is transmitted to the first and second rear wheel output shafts 24e and 27e via the rear wheel output gear train 80e, and the torque output to the ring gears 45e and 55e is transmitted to the front wheel output gear train 70e and the front differential 90e. The power is transmitted to the front wheel drive shafts 22e and 23e through the respective front wheel drive shafts 22e and 23e. In other words, this torque distribution device 3e
8, the output elements for the front wheels and the rear wheels of both center differentials 40d and 50d of the torque distribution device 3d shown in FIG. 8 are interchanged.

In the above torque distribution devices 3a to 3c as well, viscous coupling springs 100a to 100e are interposed between the second output gears 72a to 72e for front wheels and the second output gears 82a to 82e for rear wheels. As in the torque distribution device 3 of the first embodiment, the first and second center differentials 40a to 40e, 50a to 50e and their switching mechanisms 60a to 60e are arranged together on the intermediate shafts 21a to 21e. At the same time, front differentials 90a to 90e are separated from these and placed on separate shafts. Also,
Front wheel and rear wheel output gear trains 70a to 70e, 80a to 80e are provided on both sides of the input gear trains 30a to 30e.
are arranged, and front differentials 90a to 90e and viscous coupling springs 100a to 100e are arranged between these output gear trains, similar to the first embodiment.

(Effects of the invention) As described above, the present invention provides torque distribution for a four-wheel drive vehicle that is equipped with an inter-axle differential, its differential limiting mechanism, and an inter-wheel differential for wheels located on the engine side. Since the device has a configuration in which the inter-wheel differential device is arranged on a separate shaft from the above-mentioned inter-axle differential device, the inter-wheel differential device is not constrained by the inter-axle differential device, and the It can be freely arranged according to the position, and therefore, the layout of each component as a torque distribution device is facilitated. Furthermore, since the differential limiting mechanism and the inter-wheel differential overlap the input gear train in the axial direction, the torque distribution device is shortened in the width direction of the vehicle body.

[Brief explanation of the drawing]

1 to 4 show a first embodiment of the present invention, FIG. 1 is a schematic diagram showing the overall configuration of a four-wheel drive vehicle according to the embodiment, and FIG. 2 is an enlarged schematic diagram of the main parts thereof. , 3 and 4 are schematic diagrams showing the configurations of the first and second center differentials in this embodiment. Also, the fifth
Figures 9 to 9 are schematic diagrams showing the main parts of the second to sixth embodiments of the present invention, respectively. 1...Engine, 2...Transmission,
3,3a-3e...torque distribution device, 30,30
a~30e...Input gear train, 40, 40a~40
e, 50, 50a to 50e... Inter-axle differential device (first and second center differential), 70, 70a to 70e
...Output gear train for front wheels, 80, 80a to 80e...
...Output gear train for rear wheels, 90, 90a to 90e...
Wheel differential (front differential), 100,10
0a to 100e...Differential limiting mechanism (viscous cut spring).

Claims (1)

[Scope of utility model registration request] Torque distribution in a four-wheel drive vehicle that divides the torque input from the engine, whose output shaft extends in the axial direction of the vehicle body, through the transmission and input gear train, and outputs the divided torque to the front wheels and rear wheels. The device includes an inter-axle differential device that receives torque from the input gear train and distributes it to the front wheel side and the rear wheel side, and from the shaft of the differential device to the front wheel side and the rear wheel side, respectively. A front wheel output gear train and a rear wheel output gear train that output torque are arranged on both sides of the input gear train, and the rotational speed difference between each element of the inter-axle differential exceeds a predetermined amount. A differential limiting mechanism that limits the differential operation when A torque distribution device for a four-wheel drive vehicle, characterized in that the device is disposed between an output gear train.