JPH02290724A - Driving power transmission device for four-wheel drive vehicle - Google Patents

Abstract

PURPOSE:To improve the lack in driving power transmission for rear wheels so as to improve running performance by forming a front differential mechanism out of a viscous coupling and also a rear differential mechanism out of a differential gear train. CONSTITUTION:A four-wheel drive vehicle 2 converts the driving power of an internal engine 4 into a desired torque-speed by a transmission 6, and transmits it from a front end decelerating mechanism 8 to front axles 12 (12L, 12R) through a front differential mechanism 10. The driving power of the internal combustion engine 4 distributed by a driving power distribution mechanism 16 is transmitted to rear axles 24 (24L, 24R) from a rear end decelerating mechanism 20 through a rear differential mechanism 22 by a propeller shaft 18, whereas the front differential mechanism 10 is formed out of a viscous coupling 56, and the rear differential mechanism 22 is formed out of a differential gear train 58. It is thus possible to transmit driving power to front wheels side by the viscous coupling 56 only when hard starting is carried out or the difference in rotational speed occurs between front and rear wheels.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a drive power transmission device for a four-wheel drive vehicle, and particularly to a rear drive power transmission device for a four-wheel drive vehicle based on a front-mounted internal combustion engine front wheel drive vehicle. Improved the lack of drive power transmission to the wheels 4
The present invention relates to a driving force transmission device for a wheel drive vehicle.

[Conventional technology]

Recently, in order to improve driving performance and safety in all driving conditions, including driving on rough roads and uneven terrain, as well as driving on normal roads, the driving force of the internal combustion engine is transmitted to all axles to all wheels. Many types of four-wheel drive vehicles have appeared. Such a driving force transmission device for a four-wheel drive vehicle is disclosed in Japanese Patent Laid-Open No. 60-1030 and Japanese Patent Laid-Open No. 60-236839.

What is disclosed in JP-A-60-1030 is that a wet clutch device is provided radially inside and coaxially with the front final reduction large gear that meshes with the output gear of the transmission. This prevents left-right deviation of the front differential mechanism, reduces the difference in front left and right axle lengths, suppresses the occurrence of so-called torque steer, and also reduces the difference in rotational speed between the front wheels and rear wheels. In addition to being able to absorb the torque, the torque distribution of the driving force transmitted to the front wheels and rear wheels can be changed.

Furthermore, in the device disclosed in Japanese Patent Application Laid-open No. 60-236839, a differential limiting mechanism is disposed coaxially with the front differential mechanism in a mount casing that supports the gears of the driving force distribution mechanism. By interposing the limiting mechanism on the input side of the front differential mechanism and the other output side, a differential limiting torque is generated during relative rotation between the input side of the front differential mechanism and the other output side, allowing running. In addition to improving performance, the differential limiting mechanism can be assembled compactly by utilizing the space inside the mount casing.

[Problem that the invention seeks to solve]

By the way, four-wheel drive vehicles are based on so-called front-mounted internal combustion engine front wheel powered vehicles, in which the front wheels are driven by the driving force of an internal combustion engine mounted in the front, and are equipped with a driving force distribution mechanism. There are four-wheel drive vehicles that drive rear wheels by distributing the driving force of an internal combustion engine.

For example, as shown in FIG.
06 converts it into the desired torque and rotational speed and extracts it, and this driving force is transferred from the front Hiiragi speed reduction mechanism 20 to the front differential mechanism 21.
0 through the front right axle 212R, which is the front axle 212.
and the front left axle 212L, respectively, and the front wheel 21
4, the front right wheel 214R and the front left wheel 214
At the same time, the driving force distributed by the driving force distribution mechanism 216 is transferred from the rear final reduction mechanism 220 to the rear axle 224 via the rear differential mechanism 222 by the propulsion shaft 218.
The rear right axle 224R and the rear left axle 224L are
and the rear right wheel 22 which is the rear wheel 226.
There is one that drives the rear left wheel 6R and the rear left wheel 226L, respectively.

In order to allow the differential movement between the front wheels 214 and the rear wheels 226 of the four-wheel drive vehicle 202 and limit the differential movement beyond a certain level, a viscous coupling 2 is used.
There is one with 28.

This viscous joint 228 may be provided, for example, between the output shaft 230 of the driving force distribution mechanism 216 and the propulsion shaft 218 as shown in FIG. 8, or in the middle of the propulsion shaft 218 as shown in FIG. , as shown in FIG. 10, is provided between the propulsion shaft 218 and the input shaft 232 of the rear final reduction mechanism 220.

However, in a four-wheel drive vehicle based on a vehicle with a front-mounted internal combustion engine and a front wheel drive system as described above, the load distribution between the front wheels and rear wheels is biased toward the front wheels, so that the load is not transmitted to the rear wheels. There is a problem of insufficient driving force. This insufficient transmission of driving force to the rear wheels becomes particularly noticeable during deceleration. For this reason, 4-wheel drive vehicles based on vehicles with a front-mounted internal combustion engine and front wheel drive system use a so-called front-mounted internal combustion engine and rear wheel drive system, in which the rear wheels are driven by the driving force of the internal combustion engine mounted in the front. It had the disadvantage of being disadvantageous in terms of running performance, etc., compared to four-wheel drive vehicles based on the same vehicle.

[Purpose of the invention]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to improve the insufficient transmission of driving force to the rear wheels in a four-wheel drive vehicle based on a vehicle with a front internal combustion engine and rear wheel drive system. The object of the present invention is to realize a driving force transmission device for a four-wheel drive vehicle that can exhibit running performance equivalent to that of a four-wheel drive vehicle based on the above, and that can improve running performance and safety.

[Means for solving problems]

In order to achieve this objective, the present invention transmits the driving force of an internal combustion engine mounted at the front to the front axle via a front differential mechanism to drive the front wheels, and distributes it by a driving force distribution mechanism. In a four-wheel drive vehicle in which the driving force of the internal combustion engine is transmitted to the rear axle via a rear differential mechanism to drive the rear wheels, the front differential mechanism is formed by a viscous coupling and the rear differential mechanism is configured. It is characterized by being constructed by a differential gear train.

[Effect]

According to the configuration of the present invention, the front differential mechanism is configured with a viscous joint, so that when there is no rotational speed difference between the front wheels and the rear wheels, the viscous joint transfers the driving force of the internal combustion engine to the front. Since the transmission is not transmitted to the rear axle, the front wheels are not driven, and only when there is a difference in rotational speed between the front wheels and rear wheels due to a sudden start or a difference in the μ of the road surface relative to the front and rear wheels. The viscous joint transmits the driving force of the internal combustion engine to drive the front wheels. On the other hand, by configuring the rear differential mechanism with a differential gear train, the driving force of the internal combustion engine is transmitted to the rear axle via the differential gear train of the rear differential mechanism, and the rear wheels are directly It will be driven.

〔Example〕

Next, embodiments of the present invention will be described in detail based on the drawings.

1 to 6 show embodiments of this invention. In FIG. 6, 2 is a four-wheel drive vehicle.

This four-wheel drive vehicle 2 converts the driving force of an internal combustion engine 4 mounted at the front into desired torque and rotational speed using a transmission 6 and extracts the driving force, and transfers this driving force from a front part P: a reduction mechanism 8 to a front part. The front right axle 12R, which is the front axle 12, via the differential mechanism 10
and the front left axle 12L, and drive the front right wheel 14R and the front left wheel 14L, which are the front wheels 14, respectively.

The four-wheel drive vehicle 2 also transmits the driving force of the internal combustion engine 4 distributed by the driving force distribution mechanism 16 from the rear final reduction mechanism 20 to the rear axle shaft 2 through the rear differential mechanism 22 via the propulsion shaft 18.
4, respectively, to the rear right axle 24R and rear left axle 24L, respectively, and drive the rear right wheel 26R and rear left wheel 26L, which are the rear wheels 26, respectively.

More specifically, as shown in FIG. 1, the driving force of the internal combustion engine 4 mounted at the front of the four-wheel drive vehicle 2 is input to the input shaft 30 of the transmission 60 via the clutch mechanism 28,
The torque and rotational speed are converted to the desired torque and rotational speed and taken out from the output shaft 34. A front final reduction gear 36 of the front final reduction mechanism 8 is fixed to the output end of the output shaft 34 . The driving force taken out from the output shaft 34 is decelerated by the front final reduction gear 36 of the front final reduction mechanism 8 and the front final reduction large gear 38 that meshes with the front final reduction gear 36. The signal is transmitted to the front differential mechanism 10, and is transmitted by the front differential mechanism 10 to the front right axle 12R and the front left axle 12L, respectively, to drive the front right wheel 14R and the front left wheel 14L, respectively.

Furthermore, a driven gear 42 fixed to one end of the input shaft 40 of the driving force distribution mechanism 16 is meshed with the front final reduction large gear 38 of the front final reduction mechanism 8 .

The driving force distributed and input to the input shaft 42 is output to the output shaft 48 by an output gear 46 that meshes with an input gear 44 fixed to the other end of the input shaft 42.

The driving force distributed by the driving force distribution mechanism 16 and output from the output shaft 48 is transmitted to the rear final reduction mechanism 20 by the propulsion shaft 18.
is transmitted to the input shaft 50 of. A rear terminal speed small gear 52 is fixedly attached to the input shaft 50 . The driving force transmitted to the human power shaft 50 is decelerated by a rear final reduction small gear 52 and a rear final reduction large gear 54 that meshes with this rear final reduction small gear 52, and is transmitted to the rear differential mechanism 22. The differential mechanism 22 allows the rear right axle 24R and the rear left axle 24L to
and drive the rear right wheel 26R and the rear left wheel 26L, respectively.

In this way, the driving force of the internal combustion engine 4 mounted at the front is transmitted to the front axle 12 via the front differential mechanism 10, and the driving force is transmitted to the front axle 12.
In the four-wheel drive vehicle 2, the driving force of the internal combustion engine 4 distributed by the driving force distribution mechanism 16 is transmitted to the rear axle 24 via the rear differential mechanism 22 to drive the rear wheels 26.・As shown in Figure 2, the front differential mechanism 1
0 is constituted by a viscous coupling 56, and the rear differential mechanism 22 is constituted by a differential gear train 58.

That is, the front differential mechanism 10 includes a front differential right housing 60R, which is a front differential housing 60, as shown in FIG.
and a front differential left housing 60L. The front differential left housing 60L is fixed to the front final reduction large gear 3 of the front final reduction mechanism 8, and is pivotally supported on the transmission first casing 64a by a front differential left bearing 62L. It is set up. The front differential right housing 60R is
It is fixed to the front final reduction large gear 38 via the front differential left housing 60L, and the front differential right bearing 6
2R to be pivotally supported on the transmission second casing 64b. Further, as shown in FIG. 3, fan-shaped openings 66 are formed in the front right housing 60R at equal angular positions on the side and outer circumference.

A viscous joint 56 is provided in the front differential right housing 60R and the front differential left housing 60L. The viscous joint 56 includes a right viscous joint 56R and a left viscous joint 56L. That is, the viscous joint 56 is
Outer case 6 composed of right outer case 68R, center outer case 68C, and left outer case 68L.
It has 8.

A right outer case 68R and a left outer case 68L of the outer case 68 are rotatably supported on one end side of the front right axle 12R and the front left axle 12L, respectively.

On the other end sides of the front right axle 12R and the front left axle 12L, a front right wheel 14R and a front left wheel 14 are provided, respectively.
L is attached. Furthermore, an outer case side spline 70 is formed on the outer periphery of the right outer case 68R of the outer case 68.

The outer periphery of a plurality of right outer plates 72R is fixed to the inner periphery of the central outer case 68C of the outer case 68 on the right outer case 68R side. Moreover, the outer peripheries of a plurality of left outer plays 1-72L are fixedly provided on the left outer case 68L side of the inner periphery of the central outer case 68C. On the other hand, the inner peripheries of right inner plates 74R, which are arranged alternately with the right outer plates 72R, are fixed to the outer periphery of one end of the front right axle 12R.

Furthermore, the inner peripheries of left inner plates 74L, which are arranged alternately with the left outer plates 72L, are fixed to the outer periphery of one end of the front left axle 12L.

A viscous fluid 76 is filled in the outer case 68 so that the right outer plate 72R, the left outer plate 72L, the right inner plate 74R, and the left inner plate 74L are immersed.

As a result, the right side viscous joint 56R is constituted by the right side outer case 68R side of the central outer case 68C of the outer case 68, the right side outer case 68R, the right side outer plate 72R, the right side inner plate 74R, and the viscous fluid 76. are doing. Further, the outer case 6
8, left outer case 68L of center outer case 68C
side, the left outer case 68L, the left outer plate 72L, the left inner plate 74L, and the viscous fluid 76.
These constitute a left viscous joint 56L.

Further, the front differential mechanism 10 is provided with a switching mechanism 78. The switching mechanism 78 includes a switching sleeve 80, as shown in FIGS. 4 and 5. Inside the switching sleeve 80, there is an outer cover formed on the outer periphery of the right outer case 68R at a position corresponding to the fan-shaped opening 66 formed at equiangular positions on the side and outer periphery of the front right outer housing 60R. A sleeve-side spline 82 is formed which engages and separates from the case-side spline 70. This switching sleeve 8
A sleeve groove 84 is formed on the outer periphery of the sleeve. A switching fork 86 is slidably engaged with the sleeve cover 84.

The switching fork 86 is fixed to one end side of the switching shaft 88. The switching shaft 88 is held in a holding portion 90 provided in the second transmission casing 64b so as to be movable in the axial direction.

An engagement recess 92 is formed at the other end of the switching shaft 88 . An engaging protrusion 96 provided on the rotating tip side of the actuating layer 94 is engaged with the engaging recess 92 . The rotation base end side of the actuation lever 94 is fixed to one end side of the actuation shaft 98. The operating shaft 98 has both ends protruding in and out of the second transmission casing 64b, and is rotatably supported by a support portion 100 provided in the second transmission casing 64b. The operating lever 94 is fixed to one end of the operating shaft 98 inside the second transmission casing 64b. Further, a switching lever 102 is attached to the other end of the operating shaft 98 outside the transmission second casing 64b. This switching lever 102 is operated manually or by a drive unit (not shown).

Thereby, by operating the switching lever 102 in the direction of arrow A, the operating shaft 98 is rotated, and the operating lever 94 is rotated.
When the switching shaft 8 is moved in the axial direction by swinging, and the switching fork 86 is moved to the position shown by the solid line in FIG. The right outer case 68 is inserted into the front differential right housing 60R through fan-shaped openings 66 formed at equal angular positions on the side and outer circumference of the right outer case 68.
It is engaged with an outer case side spline 70 formed on the outer periphery of R. Therefore, the front differential housing 60 and the outer case 68 rotate together, so that the four-wheel drive state is switched.

Further, by operating the switching lever 102 in the direction of arrow B, the operating shaft 98 is rotated, and the operating lever 94 is swung to move the switching shaft 88 in the axial direction, and the switching fork 86 is moved along the broken line in FIG. When the switching sleeve 80 is moved to the position shown, the sleeve-side spline 82 of the switching sleeve 80 moves from the fan-shaped opening 66 formed at equal angular positions on the side and outer circumference of the front differential right housing 60R to the outside of the front differential right housing 60R. It is pulled out and separated from the outer case side spline 70 formed on the outer periphery of the right outer case 68R. Therefore, the front differential housing 60 and the outer case 68 are separate bodies and can rotate relative to each other.
Switched to wheel drive mode.

The rear differential mechanism 22 is a rear terminal P of the rear final reduction mechanism 20.
．． A rear part P meshing with the small reduction gear 52: A large reduction gear 54 is fixed to the rear differential housing 104 of the rear differential mechanism 22. The rear differential housing 104 is pivotally supported by the rear axle housing 106 by a rear differential right bearing 108R and a rear differential left bearing 108L. A differential gear train 5 is provided within the rear differential housing 104. The differential gear train 58 includes a first rear differential pinion 112a and a second rear differential pinion 112b that are pivotally supported by a gear shaft 110.
and a rear differential large gear 114 that meshes with the first rear differential pinion 112a and the second rear differential pinion 112b, respectively.
It is composed of a rear differential right-hand large gear 114R and a rear differential left-hand large gear 114L.

Rear differential right large gear 114R and rear differential left large gear 1
One end side of the rear right axle 24R and the rear left axle 24L are connected to the rear right axle 24R and the rear left axle 24L, respectively, and the rear right wheel 26R and the rear left wheel 26L are attached to the other end sides of the rear right axle 24R and the rear left axle 24L, respectively. It is being

Next, the action will be explained.

The driving force of the internal combustion engine 4 mounted in the front of the four-wheel drive vehicle 2 is
It is inputted to the input shaft 30 of the transmission 6 via the clutch mechanism 28, converted to desired torque and rotational speed by the speed change gear train 32, and taken out from the output shaft 34. The driving force taken out from the output shaft 34 is generated by the front final speed small gear 36 of the front final speed mechanism 8 and the front final reduction large gear 38 that meshes with the front final speed small gear 36. The speed is reduced and the front differential mechanism lO
The front differential mechanism 10 transmits the signal to the front right axle 12R and the front left axle 12L, respectively, to drive the front right wheel 14R and the front left wheel l4L, respectively.

At this time, the operating shaft 98 is rotated by operating the switching lever 102 of the switching mechanism 78 in the direction of arrow A,
When the operating lever 94 is swung to slide the switching shaft 88 in the axial direction and the switching fork 86 is moved to the position shown by the solid line in FIG. It is engaged with an outer case side spline 70 formed on the outer periphery. For this reason,
Since the front differential housing 60 and the outer case 68 rotate together, the four-wheel drive state can be switched.

In this four-wheel drive state, if there is no rotational speed difference between the front right wheel 14R and front left wheel 14L and the rear left wheel 26R and rear left wheel 26L, the front differential mechanism 10 Right side outer plate 72 of joint 56R
There is no rotation speed difference between R and the right inner plate 74R, and the left outer plate 7 of the left viscous joint 56L
Since there is no rotation speed difference between the inner plate 2L and the left inner plate 74L, the driving force is not transmitted to the front right axle 12R and the front left axle 12L, and the front right wheel 14R and the front left wheel 14L are not driven. Not done.

However, due to a sudden start, a difference in road surface μ between the front right wheel 14R, the front right wheel 14L, the rear left wheel 26R, and the rear left wheel 26L, etc., the front right wheel 14R, the front left wheel 14L, and the rear right wheel 26R When a rotational speed difference occurs between the front differential mechanism 10 and the rear left wheel 26L, a rotational speed difference also occurs between the right outer plate 72R and the right inner plate 74R of the right viscous joint 56R. Furthermore, since a difference in rotational speed occurs between the left outer plate 72L and the left inner plate 74L of the left viscous joint 56L, driving force is transmitted to the front right axle 12R and the front left axle 12L, and the front right wheel 14R
And the front left wheel 14L is driven.

On the other hand, the driving force of the internal combustion engine 2 is distributed from the front final reduction mechanism 8 by the driving force distribution mechanism 16 and transmitted to the propulsion shaft 18, and from the rear final reduction mechanism 20 to the differential gear train 58 of the rear differential mechanism 22. The rear right wheel 26R and the rear left wheel 26L are directly driven by being transmitted to the rear right axle 24R and the rear left axle 24L via.

Therefore, it is possible to improve the insufficient transmission of driving force to the rear right side vehicle 26R and the rear left side vehicle 26L in the four-wheel drive vehicle 2 based on a front wheel drive vehicle with a front internal combustion engine. It can exhibit running performance equivalent to a four-wheel drive vehicle based on a rear wheel drive vehicle, and can improve running performance and safety.

In addition, since the front differential mechanism 10 is constituted by the viscous joint 56, the drive power transmission system of a so-called part-time four-wheel drive vehicle based on a conventional front-mounted internal combustion engine front wheel drive vehicle is relatively small. By changing it, you can make it a so-called full-time four-wheel drive vehicle, and unlike the conventional case where a viscous joint is installed on the propulsion shaft, there is no need for installation space for a viscous joint, and there is no installation space for a front differential mechanism. By using , it is possible to achieve downsizing and cost reduction.

Furthermore, since the viscous joint 56, which is relatively heavy, is installed in the front differential mechanism 10, which has a relatively low rotational speed, it is advantageous in terms of vibration. The joint can be cooled.

Furthermore, by operating the switching lever 102 of the switching mechanism 78 in the direction of arrow B, the operating shaft 98 is rotated,
When the operating lever 94 is swung to slide the switching shaft 88 in the axial direction and the switching fork 86 is moved to the position shown by the broken line in FIG. It is separated from the outer case side spline 70 formed on the outer periphery. Therefore, the front differential housing 60 and the outer case 68 become separate bodies and can rotate relative to each other, so that the two-wheel drive state is switched.

As described above, by switching between the two-wheel drive state and the four-wheel drive state by the switching mechanism 78, it is possible to easily switch from the four-wheel drive state to the two-wheel drive state at the time of vehicle inspection or maintenance. By providing a part of the viscous joint in the viscous joint, the number of parts can be reduced, which can contribute to cost reduction.

Furthermore, if the switching mechanism 78 is configured to be operated by a drive section, a four-wheel drive system equipped with an anti-lock brake system may be used.
It is possible to achieve consistency with the four-wheel drive state when the anti-lock brake system is activated in a wheel drive vehicle, which is advantageous in practice.

〔Effect of the invention〕

As described above, according to the present invention, the front differential mechanism is configured with a viscous joint, so that when there is no difference in rotational speed between the front wheels and the rear wheels, the viscous joint reduces the driving force of the internal combustion engine. is not transmitted to the front axle, so the front wheels are not driven.
The viscous joint transmits the driving force of the internal combustion engine to the front wheels only when there is a difference in rotational speed between the front wheels and the rear wheels due to a sudden start or a difference in the μ of the road surface for the front and rear wheels. The wheels will be driven. On the other hand, by configuring the rear differential mechanism with a differential gear train, the driving force of the internal combustion engine is transmitted to the rear axle via the differential gear train of the rear differential mechanism, and the rear wheels are directly It will be driven.

Therefore, it is possible to improve the insufficient power transmission to the rear wheels in a four-wheel drive vehicle based on a vehicle with a front-mounted internal combustion engine and rear wheel drive system. It can demonstrate the same running performance as a wheel drive vehicle,
Driving performance and safety can be improved.

In addition, since the front differential mechanism is configured with a viscous joint,
The drive power transmission system of a so-called part-time four-wheel drive vehicle based on a conventional front-mounted internal combustion engine front-wheel drive vehicle can be made into a so-called full-time four-wheel drive vehicle with relatively few changes. , unlike the conventional case where a viscous joint is installed on the propulsion shaft, no installation space is required for the viscous joint, and by using the installation space of the front differential mechanism, it is possible to achieve compactness and cost reduction. .

Furthermore, since the viscous joint, which is relatively heavy, is installed in the front differential mechanism part where the rotation speed is relatively low, it is advantageous in terms of vibration. Can be cooled.

Furthermore, if the configuration is such that the switching mechanism can switch between the two-wheel drive state and the four-wheel drive state, the four-wheel drive state can be switched during vehicle inspection or maintenance.
It is possible to easily switch from the wheel drive state to the two-wheel drive state, and by providing part of the mechanism in the viscous joint, the number of parts can be reduced, contributing to cost reduction. Furthermore, if this switching mechanism is configured to be operated by the drive unit, consistency with the 4-wheel drive state when the anti-lock brake system is activated in a 4-wheel drive vehicle equipped with an anti-lock brake system can be achieved, making it practical. It is advantageous.

[Brief explanation of the drawing]

1 to 6 show embodiments of the present invention, FIG. 1 is a schematic diagram of the driving force transmission system, FIG. 2 is an enlarged diagram of the front differential mechanism, and FIG. 3 is the front differential mechanism. 4 is a side view of the switching sleeve, FIG. 5 is a front view of the switching mechanism, and FIG. 6 is a schematic plan view of the driving force transmission system of a four-wheel drive vehicle. Figures 7 to 10 show a conventional example, Figure 7 is a schematic explanatory diagram of a transmission, front differential mechanism, and driving force distribution mechanism, and Figures 8 to 10 are respective driving force transmission systems of a four-wheel drive vehicle. FIG. In the figure, 2 is a four-wheel drive vehicle, 4 is an internal combustion engine, 6 is a transmission, 8 is a front final reduction gear, 10 is a front differential mechanism, 12R is a front right axle, 12L is a front left axle, 14R is the front right wheel, 14L is the front left wheel, 16 is the driving force conversion mechanism, 18 is the propulsion shaft, 20 is the rear final reduction mechanism, 22 is the rear differential mechanism, 24R is the rear right axle, 24L is the rear left side Axle, 26R is rear right wheel, 26L is front right wheel, 56
58 is a differential gear train, and 78 is a switching mechanism. engraving of drawings

Claims (1)

[Claims] 1. The driving force of the internal combustion engine mounted at the front is transmitted to the front axle via the front differential mechanism to drive the front wheels, and the driving force of the internal combustion engine is distributed by the driving force distribution mechanism to the rear differential. A four-wheel drive vehicle in which transmission is transmitted to a rear axle via a dynamic mechanism to drive rear wheels, characterized in that the front differential mechanism is configured by a viscous joint, and the rear differential mechanism is configured by a differential gear train. A driving force transmission device for four-wheel drive vehicles.