JPS62255232A - Torque distribution device for four-wheel drive car - Google Patents

Abstract

PURPOSE:To enhance the durability and reliability as well as provide easy-to-use characteristic by connecting a plurality of differential gearing devices selectively using a plurality of switching means with possibility of transmission of torque, furnishing a two/four wheels switching mechanism, and thereby eliminating use of any clutching device. CONSTITUTION:No.1 differential gearing device 2 consisting of simple planet gears is connected with a speed changer 1. No.2 differential gearing device 9 consisting of simple planet gears is arranged on the transmission shaft 6 of said No.1 differential gearing device 2, and a drive pulley 10 is fitted loosely. Through a chain 16, said drive pulley 10 is coupled with a driven pulley 18 fitted on a front wheel propeller shaft 17. Further are furnished a No.1 switching means 19 to couple/decouple gears 5, 7 of No.1 differential gearing device 2, a No.2 switching means 20 to couple/decouple the gear 7 with/from the pulley 10, a No.3 switching means 21 to couple/decouple a gear 15 of No.2 differential gearing device 9 with/from the pulley 10, and a No.4 switching means 22 to couple/decouple gears 12, 15 of No.2 differential gearing device 9.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a torque distribution device for a four-wheel drive vehicle that drives front wheels and rear wheels.

(Prior Art) Conventionally, as a torque distribution device for this 1A four-wheel drive vehicle, as disclosed in, for example, Japanese Utility Model Application Publication No. 56-122630, a drive 1 that is transmitted from a transmission to front and rear wheels has been used.
- A clutch device consisting of a wet clutch, a fluid coupling, etc. is installed on the torque transmission system, and the clutch device is used to
Vehicles in which the distribution of drive torque to the rear wheels is made variable are known.

(Problem to be Solved by the Invention) However, the above-mentioned clutch device generally transmits torque by the frictional force acting on the friction plates, and distributes the driving torque to the front and rear wheels by adjusting the magnitude of this frictional force. Since the friction plate is configured to be variable, the friction plate is likely to wear out, and this wear becomes particularly noticeable in a so-called half-clutch state. For this reason, the conventional torque distribution device has a problem of lacking durability. Furthermore, since the frictional force acting on the friction plate is easily influenced by external factors such as temperature, humidity, and vehicle vibration, there is also the problem that the distribution of drive torque to the front and rear wheels deviates from the set value.

The present invention has been made in view of the above, and an object of the present invention is to use a plurality of differential e-gear devices in place of the above-mentioned clutch device to provide excellent durability and drive torque to the front and rear wheels. An object of the present invention is to provide a torque distribution device that can reliably distribute torque according to a set value.

Furthermore, it is an object of the present invention to provide the above-mentioned torque distribution device with a four-wheel drive system that drives only one of the front and rear wheels, in addition to a four-wheel drive system that drives both the front and rear wheels, in order to improve usability. It also allows two-wheel drive to be selected.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a torque distribution system for a four-wheel drive vehicle that selectively varies the distribution of drive torque from a transmission to front and rear wheels. The device includes a plurality of differential gear devices each having a different gear ratio and arranged on the drive torque transmission system, a switching means for selectively connecting the plurality of differential gear devices to enable torque transmission; - The configuration includes a 2-wheel to 4-wheel switching mechanism that switches between driving both rear wheels and driving only one of the rear wheels.

(Function) With the above configuration, in the present invention, when the 2-wheel to 4-wheel switching mechanism is set to J3 and is switched to 4-wheel drive, a plurality of differential gear devices are selectively connected to enable torque transmission by the switching means. The distribution of drive torque from the transmission to the front and rear wheels is selectively varied by the combination of the differential gears connected to enable torque transmission.

In this case, since the above-mentioned differential gear device transmits torque through meshing of gears, 1M! compared to the conventional clutch device! Like a scrub board 11! Wear caused by friction is not a problem. Furthermore, since the meshing of the gears is hardly affected by external factors such as temperature and vehicle body vibration, it is possible to reliably distribute the drive torque to the front and rear wheels according to the set value.

On the other hand, in the 2-wheel to 4-wheel switching mechanism, when switching from the above-mentioned 4-wheel drive to 2-wheel drive, drive torque is transmitted only to either the front wheels or the rear wheels, and 2-wheel drive is realized. It turns out.

(Example) Embodiments of the present invention will be described below based on the drawings.

FIG. 1 shows a torque distribution device for a four-wheel drive vehicle according to a first embodiment of the present invention, 1 is a transmission, and the transmission 1 includes a first differential gear device 2 consisting of a simple planetary gear. are installed in succession. The first differential gear device 2 includes a planetary gear 5. connected to the output shaft 3 of the transmission 1 via a carrier 4.・・・
・And the planetary gear 5. The sun gear 7 meshes with the transmission shaft 6 and is connected to one end of the transmission shaft 6, and the planetary gear 5. It consists of ... and a ring gear it 8 that meshes with each other.

Further, a second differential gear device 9 made of a Qi pure planetary gear is disposed on the other end side of the transmission shaft 6, and a drive pulley 1o is loosely fitted on the outer periphery of the axially intermediate portion of the transmission l1illI6. is fitted in. The second differential l! !
The i width i position 9 includes a planetary gear 12° attached to the other end of the transmission shaft 6 via a carrier 11, and a number gear meshing with the planetary gear 12 and connected to one end of the rear wheel propeller shaft 13. 14, and a ring gear 15 that meshes with the planetary gear 12.

On the other hand, the drive pulley 10 is drivingly connected via a chain 16 to a driven pulley 18 attached to one end of a front wheel propeller shaft 17.
0 and 18 are set to have the same diameter.

Further, 19 is a Bratanelli V of the first differential gear device 2.
Ya5. . . . and the sun gear 7, and locks the first differential gear device 2 in the connected state. A second switching means 21 connects and disconnects the
The ring gear 4 of the differential gear device 9 and the drive pulley 1
0, and 22 is a fourth switching means that connects and disconnects the planetary gear 12 and ring gear 15 of the differential gear device 9 and locks the second differential gear II device 9 in the connected state. These four switching means 19 to 22 are all wet clutches, and the first and second difference f is
The ill gear device 2.9 is selectively connected to enable torque transmission, and serves as a two-wheel to four-wheel switching mechanism to switch between driving both front and rear wheels and driving only one of the wheels.

Next, to explain the operation of the first embodiment, the first and third switching means 19 are
．． 21 is connected and the second and fourth switching means 20.22 are disconnected, the first differential gear II device 2
are in a locked state in which they rotate integrally, and only the second differential gear device 9 operates to distribute torque. That is, the driving torque from the output shaft 3 of the transmission 1 is transmitted to the first differential gear device 2.
and is input to the planetary gear 12 side of the second differential gear device 9 via the transmission shaft 6, and is distributed in the second differential gear device 9 according to the ratio of the number of teeth between the sun gear 14 and the ring gear 15. Ru. The drive torque distributed to the sun gear 14 is transmitted to the rear wheels via the propeller shaft 13, while the drive torque distributed to the ring gear 15 is transmitted to the third switching means 21, the pulley 10.18, and the propeller shaft 17. is transmitted to the front wheels through the

Further, the second and fourth switching means 20.22 are connected as the second selection state of four-wheel drive, and the first and third switching means 1
9. When 21 is disconnected, only the first differential gear device 2 operates to distribute 1 to 1 torque, contrary to the case of the first selection state, and the second differential gear device 9 is in the locked state. Become. In other words, the drive (-) from the output shaft 3 of the transmission 1 is generated by the sun gear 7 and ring gear 8 in the first differential gear device 2.
It is distributed according to the ratio of the number of teeth. And sun gear 7
The drive torque distributed to the second switching means 20, the pulley i
o, is, and the propeller shaft 17, while the drive torque distributed to the ring gear V8 is transmitted to the rear wheels via the transmission shaft 6, the second differential gear @9, and the propeller shaft 13. communicated.

Furthermore, when all four switching means 19 to 22 are connected as the third selection state of four-wheel drive, both the first and second differential gear devices 2 and 9 are locked, and the rear wheel propeller Since the shaft 13 and the pulley 10.18 or the front wheel propeller shaft 17 rotate at the same speed, the driving torque from the output shaft 3 of the transmission 1 is normally distributed and transmitted equally to the front wheels and the rear wheels. Ru. Further, when either the front wheel or the rear wheel is no longer generating driving resistance due to derailment or the like, the driving torque is transmitted only to the other wheel.

Here, if the ratio of the number of teeth of the sun gears 7, 14 and the ring gears 8, 15 in the first and second differential gear units 2°9 is set to, for example, a ratio of 40:6, The drive torque distribution is 60:4o in the first selection state and 40:6o in the second selection state.
Needless to say, it becomes 50 in the case of the third selection state.
vs. 5o.

On the other hand, in the first selection state of two-wheel drive, the first and fourth switching means 19.22 are connected, and the second and third switching means 2
When 0.21 is cut, both the first and second differential gears @2.9 are locked, and the transmission of drive torque to the drive pulley 1o or the front wheel propeller shaft 17 is cut off. Therefore, the output shaft 3 of the transmission 1
The drive torque is transmitted only to the rear wheels, creating two-wheel drive in which only the rear wheels are driven.

In addition, as the second selection state of two-wheel drive, the first and second
When the switching means 19, 20 are connected and the third and fourth switching means 2, 22 are disconnected, the first differential gear device 2 is in the locked state and the second differential gear device 9 is in the free state. (
Since the transmission of drive torque to the rear wheel propeller shaft 13 is interrupted (mid rotation state), the gear shift 11!1 is performed.
The driving torque from the output shaft 3 of the vehicle is transmitted only to the front wheels, and two-wheel drive is realized in which only the front wheels are driven.

Note that wet clutches are used as the four switching means 19 to 22 described above, but these switching means 19 to 22
In this case, the connection and disconnection of torque transmission is simply switched, and there is no so-called half-clutch state, so wear on the f'@to plate does not pose a particular problem.

FIG. 2 shows a torque distribution device for a four-wheel drive vehicle according to a second embodiment of the present invention. In this torque distribution device, the first differential gear device 2' connected to the transmission 1 is Instead of a simple planetary gear in the case of one embodiment, a double
Ti star gear is used. That is, the first differential gear device 2' includes a pair of inner and outer bracket gears r5a', 5 connected to one end of the transmission shaft 6 via a carrier 4'.
b', a sun gear 7' that meshes with the inner planetary gear 5a', and the outer planetary gear 5b/
and a ring gear 8' which meshes with the gearbox 1 and is connected to the output shaft 3 of the transmission 1.

Further, a second differential gear device 9 made of a simple planetary gear disposed on the other end side of the transmission shaft 6 has a ring gear 15 connected to one end of a rear propeller shaft 13, and a sun gear 14. 3. Drive pulley 1 via switching means 21
Connected to 0.

The rest of the configuration of the torque distribution device is the same as in the first embodiment, and the same members are given the same reference numerals and their explanations will be omitted.

In the case of the second embodiment, the four switching means 19 to
The relationship between the connection and disconnection of 22 and the operations of the first and second differential gear devices 2' and 9 is the same as in the first embodiment. That is, the first and third switching means 19.21 are connected, and the second
When the fourth switching means 20, 22 is disconnected (four-wheel drive first selection state), the first differential gear 2' is in the locked state, and only the second differential gear 9 operates for torque distribution. and connect the 263rd and fourth switching means 20.22,
When the first and third switching means 19.21 are disconnected (4
(second selection state of wheel drive), only the first differential gear device 2' operates for torque distribution, the second differential gear device 9 is in the locked state, and all four switching means 19 to 22 are connected. (4-wheel drive third selection state), the first and second
Differential gear system! 2' and 9 are both locked. still,
When the first differential gear device 2 performs a torque distribution operation, the torque distribution corresponds to the ratio of the rotation angle of the carrier 4' and the rotation angle of the sun gear 7' for one rotation of the ring gear 8'.

Furthermore, connecting the first and fourth switching means 19.22,
When the second and third switching means 20.21 are disconnected (2
In the first selection state of wheel drive), both the first and second differential gear devices 2'9 are in a locked state, transmission of drive torque to the front wheel propeller shaft 17 is cut off, and only the rear wheels are driven.

Further, when the first and second switching means 19, 20 are connected and the third and fourth switching means 2, 22 are disconnected (second selection state 1g of two-wheel drive), the first differential gear device 2' is in a locked state, the second differential gear device 9 is in a free state, transmission of drive torque to the rear wheel propeller shaft 13 is cut off, and only the front wheels are driven.

It should be noted that the present invention is not limited to the first and second embodiments described above, but includes various other modifications. For example, in each of the above embodiments, two differential gear devices 2 (or 2') and 9 are arranged on the drive torque transmission system, and
Although the present invention is configured so that the distribution of drive torque to the front and rear wheels during wheel drive can be selected in three stages,
Three or more differential gear devices may be disposed on the drive torque transmission line so that the drive torque distribution to the front and rear wheels can be selected in a plurality of stages.

The point is that the distribution of driving torque can be made variable by the combination of differential gears.

It goes without saying that the differential gear device may be constructed using a bevel gear or the like in addition to the simple planetary gear or double planetary gear as in the embodiment.

Furthermore, in each of the above embodiments, four switching means 19 to 22 are provided.
By connecting and disconnecting the differential gear device, the differential gear device is connected to enable selective torque transmission, and the differential gear device is configured to switch between driving both the front and rear wheels and driving only one of them. It may be configured to switch between driving both the front and rear wheels and driving only one of them by another mechanism that is independent of the switching means that is connected to selectively transmit torque. Further, the switching means 19 to 22 are as follows:
In addition to using a wet type clutch as in the embodiment, various other devices such as a dog clutch may be used for switching between connection and disconnection.

(Effects of the Invention) As described above, according to the torque distribution device for a four-wheel drive vehicle of the present invention, a plurality of differential gear devices are selectively connected to enable torque transmission by the switching means, and this torque transmission is possible. Difference connected! Even with the combination of lJ gears,
The structure is such that the distribution of drive torque from the transmission to the front and rear wheels is selectively varied, so wear due to frictional force does not become a problem, improving durability and improving external performance. This means that the torque distribution can be performed reliably according to the set value without being affected by many factors.

In addition, the two-wheel-to-four-wheel switching mechanism enables two-wheel drive in which only one of the front and rear wheels is driven, in addition to four-wheel drive, to improve usability.

[Brief explanation of drawings]

The drawings relate to embodiments of the present invention; FIG. 1 is a schematic diagram showing the overall configuration of a torque distribution device for a four-wheel drive vehicle according to the first embodiment, and FIG. This is a diagram equivalent to Figure 1. 1... Transmission, 2.2'... First differential gear device, 9
...Second differential tooth width device, 19-22...Switching means.

Claims (1)

[Claims] (1) A torque distribution device for a four-wheel drive vehicle that selectively varies the distribution of drive torque from a transmission to front and rear wheels, the device being a torque distribution device for a four-wheel drive vehicle that selectively varies the distribution of drive torque from a transmission to front and rear wheels, which A plurality of different differential gear devices, a switching means for selectively connecting the plurality of differential gear devices to enable torque transmission, and two wheels for switching between driving both front and rear wheels and driving only one of them. -4 wheel switching mechanism;
Torque distribution device for wheel drive vehicles.