JP3317517B2 - Power transmission device for four-wheel drive vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power transmission device for a four-wheel drive vehicle, and more particularly, to a power transmission device near one of the front and rear axles.
The present invention relates to an engine and a transmission arranged side by side with their shafts oriented in the vehicle width direction and arranged in series.

[0002]

2. Description of the Related Art Conventionally, as a power transmission device for a four-wheel drive vehicle, for example, as disclosed in Japanese Patent Application Laid-Open No. 62-286835, an engine and a transmission are mounted near an axle of a front wheel. Along with being arranged horizontally in the width direction and in series, the output from the transmission is transmitted to the axle of the front wheel, and a transfer shaft arranged in parallel with the axle and a propeller shaft extending in the front-rear direction of the vehicle body. It is known that the transmission is transmitted to an axle of a rear wheel via an axle. In this case, the propeller shaft is usually 3
A friction clutch (so-called 2-4 switching clutch for switching between two-wheel drive and four-wheel drive) for interrupting transmission of output from the transmission is provided on the propeller shaft. The transmission of power from the transmission to the transfer shaft is performed integrally with an output gear provided on an output shaft of the transmission and a differential case of a front-wheel differential device on an axle of a front wheel. And a transfer gear provided on the transfer shaft and meshing with the ring gear. The power transmitted to the ring gear (that is, the output from the transmission) is also transmitted from the front wheel differential to the left and right front axles.

[0003]

Incidentally, in the above-mentioned conventional power transmission device, when a friction clutch is provided on a propeller shaft, there is a demand that the size and arrangement of the friction clutch be set to some extent freely. but, there is a drawback that it is not possible to obtain sufficiently respond to this request. That is, in order to obtain response to the above request, it is necessary to increase the degree of freedom of the gear ratio of the power transmission to the transfer shaft from the transmission, in the conventional power transmission device
Is that the gear ratio of the power transmission from the transmission to the transfer shaft is closely related to the gear ratio of the power transmission from the transmission to the front-wheel differential (ie, the final reduction ratio to the front wheels), and the ring gear and the transfer gear If the gear ratio between the gear and the gear is greatly changed, the distance between the axle of the front wheels and the transfer axle becomes longer, and there are problems such as the case for storing them becoming larger. the high <br/> Melco enough it can not. In addition, if the distance between the axle of the front wheel and the transfer shaft is increased, the total length of the propeller shaft becomes shorter by that amount, so that the bending angle at the joint portion of the propeller shaft becomes larger,
Power transmission loss is increased, and there are also problems such as inducing body vibration.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is to provide a friction clutch on a propeller shaft without affecting the final reduction ratio of the axle on the engine arrangement side. Further, while reducing the distance between the axle and the transfer shaft, the degree of freedom in the gear ratio of power transmission from the transmission to the transfer shaft can be increased, and thus the degree of freedom in the layout and the like of the friction clutch can be increased. It is intended to provide a power transmission device for a four-wheel drive vehicle.

[0005]

In order to achieve the above object, according to the present invention, an engine and a transmission are provided near one of the front and rear axles as a power transmission device for a four-wheel drive vehicle. Are arranged horizontally in a horizontal direction with the shaft of the vehicle directed in the vehicle width direction, and the output from the transmission is transmitted to the one axle, and the transfer shaft and the vehicle body are arranged in parallel with the axle. It is assumed that the transmission is transmitted to the other axle via a propeller shaft extending in the front-rear direction. A friction clutch for interrupting transmission of output from the transmission is arranged on the propeller shaft, and an output from the transmission is received on the axis of the axle on the side where the engine and the transmission are arranged.
Ring gear around the differential case of the differential gear
It is provided on the second ring gear for transmitting power to the transfer shaft from the first ring gear
The differential casing is located at a position closer to the transmission than the first ring gear.
And is provided integrally with the differential case so as to be adjacent to the side of the disk. Further, the second ring gear has a smaller diameter than the first ring gear.

The inventions of claims 2 to 4 are all dependent on the invention of claim 1 and specifically show the location of the friction clutch. In other words, the invention according to claim 2 has a configuration in which the friction clutch is arranged at an end of the propeller shaft on the engine arrangement side, and the invention according to claim 3 arranges the friction clutch at an intermediate portion of the propeller shaft. Configuration. Further, the invention according to claim 4 is configured such that the friction clutch is arranged at an end of the propeller shaft on the side opposite to the engine arrangement side.

[0007]

According to the above-mentioned structure, according to the first aspect of the present invention,
On the engine and the transmission axis of the arrangement side of the axle, a first ring gear which receives the output from the transmission, and a second ring gear for transmitting power to the transfer shaft from the ring gear is provided separately are therefore, without affecting the final reduction ratio of one axle set by the gear ratio between the first ring gear and the transmission side of the gear meshing therewith, meshed with therewith said second ring gear By changing the gear ratio with the gear on the transfer shaft side, the gear ratio of power transmission from the transmission to the transfer shaft can be changed. In addition, the gear ratio between the second ring gear and the gear on the side of the transfer shaft can be freely changed and set independently of the first ring gear. particularly necessary to increase the distance between the axis rather than, not only that,
Upper Symbol second ring gear are positioned adjacent to the side of the differential case position a and the differential apparatus for a transmission side of the first ring gear, the diameter of the second ring gear is first re
Transfer gear is smaller than the
Close to the axle as long as it does not interfere with the first ring gear
As the distance is shortened, the transfer
It is also possible to make the key mechanism compact.

Further, the second ring gear is connected to the first ring gear.
At the transmission side of the gearing and the differential gear
Since the first ring gear is disposed adjacent to the side of the base, the inter-wheel differential device in which the first ring gear is provided on the outer periphery is relatively disposed closer to the vehicle body center line on the engine side, The lengths of the left and right axles can be made uniform.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a power transmission system for a four-wheel drive vehicle according to a first embodiment of the present invention. Reference numeral 1 denotes an output shaft 2 disposed horizontally in a vehicle width direction in an engine room at a front portion of a vehicle body. The engine 3 is a transmission which is arranged in series and laterally in the axial direction of the output shaft 2 of the engine 1. Between the engine 1 and the transmission 3, there is a transmission from the engine 1 to the transmission 3. A clutch 4 for interrupting transmission of engine output is provided.

The transmission 3 is provided on the same axis as the output shaft 2 of the engine 1, and receives an engine output via a clutch 4, and an output shaft 6 arranged in parallel with the input shaft 5. And a plurality of sets of gear trains 7, 7,... Provided between the input / output shafts 5, 6.
The engine output is changed by selectively transmitting power through one gear train from among 7,. The engine output shifted by the transmission 3 is output from an output gear 8 provided at the clutch-side end of the output shaft 6.
Left and right front wheel axles 12L through front wheel differential 11
12R or to the left and right front wheels (not shown), a transfer mechanism 13, a propeller shaft 14
And left and right rear wheel axles 16 via a rear wheel differential 15
L, 16R or left and right rear wheels (not shown).

A first ring gear 21 meshing with an output gear 8 of the transmission 3 and receiving an output from the transmission 3 is provided on the axis of the front wheel axles 12L and 12R.
To transmit power to the transfer mechanism 13 from the
And the ring gear 22 are provided in parallel. The first
The ring gear 21 is provided on the outer periphery of the central portion of the differential case 11a of the front wheel differential device 11 so as to rotate integrally therewith. The second ring gear 22 is located at a position closer to the transmission 3 than the first ring gear 21 is.
and is provided adjacent to and aside from the differential case 11a so as to rotate integrally therewith. The second ring gear 22 has a smaller diameter than the first ring gear 21. Therefore, when the first ring gear 21 is rotated by the output from the transmission 1, the differential case 11 a of the front wheel differential 11 and the second ring gear 22 are rotated integrally with the first ring gear 21.
Is transmitted to the front wheel differential 11 via the first ring gear 21 and to the transfer mechanism 13 via the first and second ring gears 21 and 22.

The transfer mechanism 13 is fixed to one end of the transfer shaft 26, which is arranged in the vehicle width direction in parallel with the front wheel axles 12L, 12R, and meshes with the second ring gear 22. Gear 27
And a pair of bevel gears 2 that extend in the front-rear direction at a substantially central portion in the vehicle width direction of the vehicle body and rotate the transfer shaft 26.
And a rotating shaft 29 that receives and rotates through the shafts 8a and 28b.

Further, the propeller shaft 14 is connected to a first shaft 14a connected to a rotation shaft 29 of the transfer mechanism 13 via a universal joint 31 or a rubber coupling, and to the rear wheel differential device 15 side. And a second shaft 14b. A friction clutch 32 is disposed between the first shaft 14a and the second shaft 14b (i.e., an intermediate portion of the propeller shaft 14) to block transmission of power from the transmission 3 to the rear wheels. The friction clutch 32 is of a hydraulically operated type whose connection and disconnection are switched by hydraulic pressure, and is mounted on the vehicle body floor portion 41 substantially horizontally as shown in FIG.

Here, the positional relationship between the components of the power transmission device as viewed from the side of the vehicle body will be described with reference to FIG. The engine 1 and the transmission 3 include front wheel axles 12L, 1
The engine output shaft 2 and the transmission 3 are disposed laterally in the engine room 42 on the vehicle body front side with respect to the shaft center P1 of the 2R.
Is the axis P2 of the output shaft 6 of the transmission 3.
It is located on the front side of the car body than 3. The axis P4 of the transfer shaft 26 is located on the rear side of the vehicle body and below the axis P1 of the front wheel axles 12L and 12R. The friction clutch 32 is attached to the vehicle body floor portion 41 at a position above the axis P4 of the transfer shaft 26,
The first shaft 14a of the propeller shaft 14 is disposed so as to be inclined rearward and upward. In FIG. 2, 4
Reference numeral 3 denotes a dash panel for partitioning the engine room 42 from the passenger compartment 44, and reference numeral 45 denotes a steering rack mounted below the dash panel 43 so as to face the engine room 42. It is located above the casing 46.

Therefore, in the first embodiment,
A first ring gear 21 and a twenty-first ring gear 22 are separately provided on the axes of the front wheel axles 12L, 12R, and the output from the transmission 3 is transmitted through the first ring gear 21 to the front wheel axles 12L, 12R. And the transmission to the transfer mechanism 13 or the rear wheel axles 16L and 16R via the first and second ring gears 21 and 22. The transmission is changed by changing the gear ratio between the second ring gear 22 and the gear 27 of the transfer mechanism 13 without affecting the final reduction ratio of the front wheels set by the gear ratio with the output gear 8 of the machine 3. The gear ratio of power transmission from the drive mechanism 3 to the transfer mechanism 13 can be freely changed. As a result, the degree of freedom in the size and arrangement layout of the friction clutch 32 provided on the propeller shaft 14 can be increased.

The gear ratio between the second ring gear 22 and the gear 27 of the transfer mechanism 13 is equal to the first gear ratio.
Can be freely changed and set regardless of the ring gear 21 of the front wheel axle 1 for setting the gear ratio.
There is no need to particularly increase the distance between the transfer shaft 26 and the transfer shaft 26.
Can be approached to the front wheel axles 12L and 12R as long as they do not interfere with the ring gear 21. Here, for comparison with the present embodiment, in the conventional case where the second ring gear 22 is not provided and the power is directly transmitted from the first ring gear 21 to the gear 27 of the transfer mechanism 13,
Gear 27 'of transfer mechanism 13, casing 46
'And the first shaft 14a' of the propeller shaft 14
Is shown by a virtual line in FIG. As can be seen from this figure, in this embodiment, the front wheel axle 12L,
The distance between the axis P1 of the 12R and the axis P4 of the transfer shaft 26 can be shortened by Δ. As the distance is shortened, the transfer mechanism 13 can be made compact, and a large gap δ between the casing 46 of the transfer mechanism 13 and the steering rack 45 can be secured. Further, since the vertical inclination angle α of the first shaft 14a of the propeller shaft 14 and the bending angle of the joint thereof can be reduced (α ′), the power transmission loss in the propeller shaft 14 can be reduced, Induction of vehicle body vibration due to rotation of the propeller shaft 14 can be suppressed.

Further, in the case of the present embodiment, the second ring gear 22 is disposed at a position closer to the transmission 3 than the first ring gear 21 and adjacent to the differential case of the front wheel differential 11. Thereby, the front-wheel differential device 11 can be disposed relatively near the center line of the vehicle body on the engine 1 side, so that the lengths of the left and right front-wheel axles 12L, 12R can be equalized as much as possible. . Further, an intermediate portion of the propeller shaft 14 (the first shaft 14a and the second shaft 1
4b), the friction clutch 32 is provided.
The friction clutch 32 can be securely and easily mounted on the vehicle body in a horizontal state.

FIG. 3 shows a power transmission device for a four-wheel drive vehicle according to a second embodiment of the present invention. In the case of the second embodiment, the friction clutch 32 for interrupting the transmission of power from the transmission 3 to the rear wheels is provided on the front end side of the propeller shaft 14, that is, on the rotating shaft 29 of the transfer mechanism 13.
The other configuration of the power transmission device is substantially the same as that of the first embodiment, and the same members are denoted by the same reference numerals and description thereof will be omitted.

In the second embodiment, the first
The same effect as in the embodiment can be obtained, and the distance between the transmission 3 and the friction clutch 32 can be shortened as much as possible by providing the friction clutch 32 on the front end side of the propeller shaft 14, so that the friction is reduced. There is also an effect that a passage for the working liquid of the clutch 32 can be relatively easily formed therebetween.

FIG. 4 shows a power transmission device for a four-wheel drive vehicle according to a third embodiment of the present invention. In the case of the third embodiment, the friction clutch 32 is provided on the rear end side of the propeller shaft 14, that is, on the side of the rear wheel differential device 15. The other configuration of the power transmission device is substantially the same as that of the first embodiment, and the same members are denoted by the same reference numerals and description thereof will be omitted.

In the third embodiment, the first
The same effect as that of the embodiment can be obtained, and the provision of the friction clutch 32 on the rear end side of the propeller shaft 14 can suppress the weight of the power transmission device from being biased toward the front wheels, and accordingly, the weight of the front and rear wheels can be reduced. This also has the effect of making the weight distribution uniform.

In each of the first to third embodiments, the engine 1 and the transmission 3 are connected to the front wheel axle 12 at the front of the vehicle body.
The case where the engine 1 and the transmission 3 are arranged horizontally and in series on the rear wheel axles 16L and 16R side of the rear part of the vehicle body has been described above in the case where the engine 1 and the transmission 3 are arranged horizontally and in series on the L and 12R sides. It is needless to say that the present invention can be similarly applied to a four-wheel drive vehicle.

[0024]

As described above, according to the power transmission system for a four-wheel drive vehicle of the present invention, when the friction clutch for 2-4 switching is provided on the propeller shaft, the axle on the side where the engine and the transmission are arranged. on the axis, a first ring gear which receives the output from the transmission, by a second ring gear that separately provided for transmitting power to the transfer shaft from the ring gear, arranged side axles such as the engine Without affecting the final reduction ratio of the transmission and while reducing the distance between the axle and the transfer shaft, the gear ratio of power transmission from the transmission to the transfer shaft can be freely changed and set. The degree of freedom in the size and arrangement layout of the friction clutch can be effectively increased.

Further, by arranging adjacent to the side of the differential case of the second ring gear first position a and the differential apparatus for a transmission side of the ring gear, the wheels between differential engine arranged side can be placed on the vehicle body center line side of the relatively engine side, the effect is obtained that it is possible to equalize as much as possible the length of the left and right axles together
In addition, the diameter of the second ring gear is made larger than that of the first ring gear.
Also make the transfer axis closer to the axle
And can be made compact.

According to the second aspect of the invention, by disposing the friction clutch at the end of the propeller shaft on the engine arrangement side, a passage for supplying working fluid or the like from the transmission to the friction clutch is relatively formed. Can be easily formed.

According to the third aspect of the present invention, the friction clutch can be easily and reliably fixed to the vehicle body floor by disposing the friction clutch at an intermediate portion of the propeller shaft.

Furthermore, an invention according to claim 4, wherein the friction clutch at the opposite end to the engine arrangement side of the propeller shaft, i.e. by arranging the position of the axle toward distant from the engine and the transmission, that amount The weight distribution of the front and rear wheels can be made uniform.

[Brief description of the drawings]

FIG. 1 is a skeleton diagram of a power transmission device for a four-wheel drive vehicle according to a first embodiment of the present invention.

FIG. 2 is a side view of the power transmission device as viewed from a side of a vehicle body.

FIG. 3 is a view corresponding to FIG. 1 showing a second embodiment of the present invention.

FIG. 4 is a view corresponding to FIG. 1 showing a third embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 engine 3 transmission 12L, 12R front wheel axle 14 propeller shaft 16L, 16R rear wheel axle 21 first ring gear 22 second ring gear 26 transfer shaft 32 friction clutch

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-2-248754 (JP, A) JP-A-61-169328 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B60K 17/28-17/36 B60K 23/00-23/08

Claims (4)

(57) [Claims] An engine and a transmission are arranged in series and horizontally in the vicinity of one of the front and rear axles, with their axes oriented in the vehicle width direction, and the output from the transmission is A power transmission device for a four-wheel drive vehicle configured to be transmitted to one axle and transmitted to the other axle via a transfer shaft disposed in parallel with the axle and a propeller shaft extending in the vehicle longitudinal direction. In the above, on the propeller shaft, a friction clutch for interrupting transmission of output from the transmission is arranged, and on the axis of the axle on the side where the engine and the transmission are arranged,
A first ring gear receiving output from the transmission is a differential gear
Is provided integrally with the outer circumference of the differential case ,
Second ring gear first ring gear for transmitting power to the transfer shaft from the first ring gear
At the transmission side and adjacent to the side of the differential case
Is provided to rotate integrally with the differential case, the second ring gear power transmission system for a four wheel drive vehicle, wherein the diameter than the first ring gear is small. Wherein said friction clutch, four-wheel drive vehicle power transmission device according to claim 1 which is disposed on the engine disposed side end portion of the propeller shaft. Wherein said friction clutch, a power transmission device for a four wheel drive vehicle according to claim 1, wherein arranged in the middle part of the propeller shaft. 4. The friction clutch is disposed at an end of the propeller shaft opposite to the engine disposed side.
The power transmission device for a four-wheel drive vehicle according to claim 1 .