JPS60236839A - Power transmission device for vehicle - Google Patents

Abstract

PURPOSE:To improve the traveling performance of a vehicle by interposing a differential restricting device between the input side of a first differential gear and the other output side and incresing the torque on the lower speed side while reducing the torque on the higher speed side. CONSTITUTION:An intermediate differential gear 20 as a first differential gear and a front-wheel differential gear 30 as a second differential gear, are provided in the casing 13 of a transmission 10. A mount case 43 is rotatably supported by an additional housing 16, and a cylindrical hollow shaft 44 which is rotatably interposed between a front axle 42 and a hollow shaft part 21a, is inserted in the case 43. A differential restricting device 50 is provided in the larger diameter bore 43a of the case 43, and causes a differential restricting torque to be generated between plates 53, 54 due to the viscosity resistance of silicone oil contained in both of a case 51 and a hub 52 when a relative rotation occurred between these case 51 and hub 52.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a power transmission device for a vehicle, and particularly to a power transmission device for a four-wheel drive vehicle.

[Prior art]

2. Description of the Related Art Conventionally, a technique has been proposed, for example, in Japanese Patent Application Laid-Open No. 58-63523, in which a power transmission device for a front-wheel drive vehicle with a front engine placed horizontally is slightly modified to be used as a power transmission device for a four-wheel drive vehicle. However, in such a conventional device, as shown in FIG. 4, in the power transmission device of a front-wheel-drive transverse engine type vehicle, the front wheel A bevel gear type intermediate differential device 1 that divides and transmits power to the rear wheels is disposed, and a front wheel differential device 4 and a rear wheel drive gear train are installed in an additional housing 3 assembled to the transmission casing 2. Constituent gears 5, 6, 7, 8, etc. are assembled. By the way, in such a power transmission device, since the differential device 4 and the direction changing gear 5 are provided in the additional housing 3, the power transmission path from the transmission becomes long, and the power transmission efficiency is not necessarily high. In addition, as the number of power transmission shafts increases, it becomes thicker, resulting in an increase in weight.

In addition, when the casing 2 and the additional housing 3 of such a power transmission device are commonly used in a power transmission device for a four-wheel drive vehicle that is not equipped with an intermediate differential and is switchable to two-wheel drive, space is wasted. This increases the amount of lubricating oil required and increases the weight.

In order to deal with such problems, the applicant has developed a special
No. 4876 is filed for the following vehicle power transmission device. The power transmission device includes a first differential device that divides the power input from the transmission and outputs it to the front wheels and rear wheels, and an example of the first differential device that divides the power input from the transmission and outputs it to the front wheels and the rear wheels. a second differential device which is arranged to output power input from one output side of the differential device to one side of the front and rear wheels; This gear includes a direction changing gear which is arranged coaxially with the differential gear and outputs the power input from the other output side of the differential gear to the other side of the front and rear wheels.

[Object of the Invention] Accordingly, the present invention compactly assembles a differential limiting device that limits the differential mechanism of a first differential device, which is an intermediate differential device, into the power transmission device, and The purpose is to enable appropriate driving force to be transmitted to either one of them even if one of them idles.

[Structure of the invention]

In order to achieve such an object, the present invention includes the first
The feature of the structure is that a differential limiting device is disposed coaxially with the first differential device, and the differential limiting device is interposed on the input side of the first differential device and the output side of the other differential device. be.

[Action/effect of the invention]

As a result, in the present invention, the action of the differential limiting device generates a differential limiting torque during relative rotation between the input side of the first differential device and the other output side, and increases the torque on the low speed side. At the same time, it is possible to reduce the torque on the high-speed side. Therefore, the driving performance of the vehicle can be improved.

Further, in the present invention, since the differential limiting device is disposed coaxially with the first differential device within the mount case that supports the direction conversion gear, the differential limiting device is disposed coaxially with the first differential device, so that the differential limiting device is disposed coaxially with the first differential device within the mount case that supports the direction conversion gear. This space is effectively used as a location for the differential limiting device. Therefore, there is no need to provide a new location for the differential limiting device in the power transmission device, and the differential limiting device can be assembled compactly.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a first embodiment of a power transmission device according to the present invention. This power transmission device is a transverse front engine type power transmission device, and in this power transmission device, a transmission 10 is attached to the side of an engine (not shown) via a clutch device. The transmission IO is a known power transmission device for front-wheel drive vehicles using a transverse front engine integrated with a final reduction gear, and includes an input shaft 11 coaxial with the crankshaft and an output shaft 12 parallel thereto. There is.

Note that the crankshaft and the input shaft 11 extend in the vehicle width direction (lateral direction).

In this embodiment, as shown in FIGS. 1 and 2, an intermediate differential device 20 serving as a first differential device and an intermediate differential device 20, which is a first differential device, and an intermediate differential device Front wheel differential device 30 which is the second differential device
and are arranged.

The intermediate differential bag W20 is a bevel gear type differential device that divides input power and outputs it to the front and rear wheels, and includes a ring gear 15 that is constantly meshed with an output gear 14 provided on the output shaft 12 of the transmission 10. is integrally supported. This intermediate i-drive device 20 is rotatably supported by the casing 13 of the transmission 10 through its case 21, and a front wheel differential device 30 is disposed within this case 21. In this intermediate differential device 20, a left side gear 22 is integrally formed with a case 31 of a front wheel differential device 30, and a hollow shaft portion 22 is provided in the case 21.
1a is formed. This hollow shaft portion 21a is
Transmission 10 behind the engine (not shown)
It protrudes into an additional housing 16 assembled to the casing 13 of. The front wheel differential 30 is arranged coaxially with the intermediate differential 20 on one side, and its left side gear 32 is rotatably inserted into the case 21 of the intermediate differential 2o. A left front axle 41 connected to the side gear 32 in a power transmittable manner protrudes from the casing 13 in a fluid-tight and rotatable manner. Further, the right side gear 33 rotatably passes through the case 31 of the front wheel differential 30, and the right front axle 42 connected to the side gear 33 so as to transmit power is connected to the right side gear 23 of the intermediate differential 2°. The right end portion of the additional housing 16 protrudes liquid-tightly and rotatably through the hollow shaft portion 21a.

Inside this additional housing 16, a stepped cylindrical mount case 43 having a large diameter inner hole 43a is rotatably supported. The right end is rotatable. In addition, the mount case 43 includes a front axle 42.
A cylindrical hollow shaft 44 rotatably interposed between the hollow shaft portion 21a and the hollow shaft portion 21a is inserted. The hollow shaft 44 is spline-fitted to the side gear 23 and the mount case 43 of the intermediate differential 2o, and these 23.4
3 are connected so that torque can be transmitted.

A rear wheel drive ring gear 45 is assembled to the large-diameter outer peripheral portion of the mount case 43. The ring gear 45 functions to change the direction of the power input from the intermediate differential device 20 and output it to the rear wheel side.
The pinion shaft 46 is always engaged with a pinion shaft 46 rotatably supported. The pinion shaft 46 is located approximately at the center of the vehicle in the longitudinal direction thereof, and is connected to the rear axle via a known propeller shaft and a final reduction gear for rear wheels (not shown) so as to be capable of transmitting power.

Therefore, in this embodiment, the differential limiting device 50 is disposed within the large diameter inner hole 43a of the mount case 43. The differential limiting device 50 uses the viscous resistance of silicone oil to limit the differential, and includes a stepped cylindrical case 51,
A cylindrical hub 52 that covers the inner opening of the large-diameter inner hole 51a of the case 5, a number of plates 53 arranged at predetermined intervals in the large-diameter inner hole 51a of the case 51, and a plate 54 facing these plates. It is composed of. In this differential limiting device 50, the case 51 is spline-fitted to the hollow shaft portion 21a, and the mount case 4
3 and the hub 52.

Further, the hub 52 is spline-fitted to the intermediate shaft 44, and the mount case 43 is spline-fitted to the hollow shaft 44. As a result, in the differential limiting device 5°, when relative rotation occurs between the case 51 and the hub 52, the viscous resistance of the silicone oil accommodated in both the plates 51 and 52 causes the differential to shift between the plates 53 and 54. Generates limited torque.

In this embodiment configured in this way, when the driving force of the engine is input from the crankshaft to the input shaft 11 of the transmission 10 via the clutch device, the speed is changed by one of the gear sets. It is transmitted to the output shaft 12. This driving force is transmitted from the output gear 14 to the link gear 15.
is transmitted to the intermediate differential device 20 via both site gears 2
It is divided into 2.23 parts. The driving force transmitted to the left side gear 22 is transmitted to the front wheel differential 30, and the driving force transmitted to the left side gear 22 is transmitted to the front wheel differential device 30,
'732.33 to the front axle 41°42. Further, the driving force transmitted to the right side gear 23 is transmitted to the rear wheel drive ring gear 45 via the mount case 43, and is transmitted from the ring gear 45 to both rear axles via a pinion shaft 46, a propeller shaft (not shown), and a final reduction gear. During this transmission, the left and right side gears 22 of the intermediate differential bag W20
If the rotation speeds of ゜23 are different, side gear 2
A differential limiting torque is generated between each play of the differential limiting device 50 interposed between the front and rear wheels and the case 21, increasing the drive torque on the low speed side of the front and rear wheels and increasing the drive torque on the high speed side. Reduce.

As a result, even if one of the front or rear wheels is spinning on muddy or icy roads and the drive torque decreases, the drive torque of the other wheel increases, improving the vehicle's running performance. .

Further, in this embodiment, in particular, the differential limiting device 50 is disposed coaxially with the intermediate differential bag ff20 within the mount case 43 that supports the ring gear 45. Therefore, in the power transmission device, the differential limiting device 50 is arranged in the existing space formed by the mount case 43, and there is no need to secure a new space for disposing the differential limiting device 50, and the differential is limited. The device 50 can be assembled compactly.

FIG. 3 shows a second embodiment of the power transmission device according to the present invention. This power transmission device has substantially the same structure as the power transmission device of the first embodiment except that it includes a differential lock mechanism 60.

Compling sleeve 6 constituting the differential lock mechanism 60
1 is attached to the outer periphery of the intermediate shaft 44 so as to be slidable in the axial direction, and is slid via a lever 63 by intermittent sliding of the operating rod 62 in the axial direction. Disconnect the connection. Note that the force/7 pulling sleeve 61 is always connected to the case 51 of the differential limiting device 50.

Thereby, when the driving force of the engine is input from the crankshaft to the input shaft 11 of the transmission 10 via the clutch device, the speed is changed by one of the transmission gear sets and transmitted to the output shaft 12. This driving force is input from the output gear 14 to the intermediate differential device 20 via the ring gear 15, and is outputted by the compression sleeve 61 as follows.

1) When the coupling sleeve 61 is in the lower illustrated position in FIG. 3, the case 21 of the intermediate differential device 20 and the mount case 43 are not connected. Therefore, the driving force input to the intermediate differential bag W20 is divided and outputted to both side gears 22 and 23, and the driving force is output from the left side gear 22 to the front wheel differential device 30.
(front wheel side), and is transmitted from the right side gear 23 to the ring gear 45 (rear wheel side). Therefore, the power transmission device enables four-wheel drive of the vehicle with the differential function of the intermediate differential device 20 and the limiting function of the differential limiting device 50 enabled.

(2) When the compulsory sleeve 61 is in the position shown in the upper part of FIG.
It is connected with. Therefore, the driving force input to the intermediate differential device 20 is divided into both side gears 22, 23, outputted, and transmitted to the front wheels and rear wheels, but the intermediate differential device 20
0 differential function is disabled. Therefore, the power transmission device enables four-wheel drive of the vehicle in a state where the differential function of the intermediate differential device 20 and the limiting function of the differential limiting device 50 are disabled. Thereby, it is possible to improve running performance in a circuit where escape is difficult due to the action of the differential limiting device 50.

(Modifications) In each embodiment, the present invention is applied to a power transmission device for a four-wheel drive vehicle with a horizontal front engine, and an example in which a differential limiting device that utilizes viscous resistance of fluid is used. but,
In the present invention, each embodiment can be modified as follows.

(]) Adopting a rear wheel differential device in place of the front wheel differential device 30, adopting a front wheel drive ring gear in place of the rear wheel drive ring gear 45, and arranging these in front of the engine ( Engine type after horizontal installation).

(2) Changing either or both of the differential devices 20 and 30 to a planetary gear type differential device.

(3) Instead of the differential limiting device 50, various friction type differential limiting devices may be employed.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a first embodiment of the power transmission device according to the present invention, FIG. 2 is an enlarged sectional view of the main part of the same device, and FIG. 3 is an enlarged sectional view of the main part of the second embodiment. FIG. 4 is a sectional view corresponding to FIG. 2 showing a conventional example of a power transmission device. Description of symbols 10...Transmission, 20...Intermediate differential device, 30...Front wheel differential device, 41.42...Front axle, 43...Mount case, 45...
Ring gear, 50...Differential limiting device, 60...Differential lock mechanism. Applicant Toyota Motor Corporation Representative Patent Attorney Teru Hase -

Claims (1)

[Claims] A 10th differential device that divides the power input from the transmission and outputs it to the front and rear wheels, and an example of the 1st differential device that is arranged coaxially with the same differential device. a second differential device that outputs power input from one output side of the device to one side of the front and rear wheels; and a second differential device arranged coaxially with the first differential device on the other side of the first differential device. A direction conversion gear that outputs the power input from the other output side of the differential to the other side of the front and rear wheels, and a direction conversion gear that is coaxial with the first differential in a mount case that supports this direction conversion gear. A vehicular power transmission device comprising a differential limiting device disposed in a differential device and interposed between an input side and the other output side of the differential device.