JPS62255233A - Torque distribution device for four-wheel drive car - Google Patents

Abstract

PURPOSE:To enhance the durability and reliability as well as to compact the construction by connecting a plurality of differential gearing devices selectively using a plurality of switching means with possibility of transmission of torque, arranging differential gearing devices parallelly on the torque transmission path, and eliminating use of any clutching device. CONSTITUTION:No.1 differential gearing device 4 consisting of double planet gear and No.2 differential gearing device 5 consisting of simple planet gear are placed parallelly at one end of a rear wheel propeller shaft 2 arranged concentrically with the output shaft 3 of a speed changer 1. A drive pulley 14 is loosely fitted on the periphery of said rear wheel propeller shaft 2 and coupled with a sun gear 12 of No.2 differential gearing device 5 through No.1 switching means 15 and also with a sun gear 8 of No.1 differential gearing device 4 through No.2 switching means 16. Through a chain 17, the said pulley 14 is coupled with a driven pulley 19 fitted on the front wheel propeller shaft 18. Thereby a plurality of differential gearing devices, 4 5 are connected selectively by a plurality of switching means 15, 16 with possibility of torque transmission.

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.

(Conventional technology) Conventionally, this [! As a torque distribution device for a four-wheel drive ETI, for example, as disclosed in Japanese Utility Model Application No. 56-122630, a wet clutch or fluid is installed on the transmission system for drive torque transmitted from the transmission to the front and rear wheels. A clutch device consisting of a coupling, etc. is provided, and the front and rear
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 plate, and distributes the drive torque to the front and rear wheels by adjusting the magnitude of the frictional force of the bracket. Since it is configured to be variable, the above 1! ! The friction plate is prone to wear, and this wear is particularly severe in the so-called half-clutch state. For this reason, the conventional torque distribution device has a problem of lacking durability. In addition, since the frictional force acting on the II friction plate is easily affected by external factors such as temperature, humidity, and vehicle vibration, there is also the problem that the distribution of 1-lux of drive to the front and rear wheels deviates from the set value. be.

The present invention has been made in view of these points, and its purpose is to use a plurality of differential gear devices in place of the above-mentioned clutch device, thereby achieving compactness, durability, and It is an object of the present invention to provide a torque distribution device that can reliably distribute drive torque to rear wheels according to a set value.

(Means for Solving the Problems) In order to quickly achieve the above object, the solving means of the present invention provides a drive system from a transmission to front and rear wheels (a four-wheel drive system in which the distribution of torque is selectively variable). As a torque distribution device for a vehicle, a plurality of differential gear devices each having a different gear ratio are arranged in parallel on the drive torque transmission system, and the plurality of differential gear devices are connected so as to selectively transmit torque. The configuration includes a switching means for switching.

(Function) With the above configuration, in the present invention, a plurality of differential gear devices are selectively connected to each other so that torque can be transmitted by the switching means,
With this combination of differential gears connected to enable torque transmission, the distribution of drive torque from the transmission to the front and rear wheels can be selectively varied.

In this case, since the differential tooth i device transmits torque through meshing of gears, there is no problem of wear due to frictional force, unlike the friction plates in conventional clutch devices. 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.

Furthermore, the plurality of differential gear devices are arranged in parallel and integrated on the drive torque transmission path, which contributes to making the torque distribution device more compact.

(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 VJ vehicle according to a first embodiment of the present invention, in which 1 is a transmission, and 2 is a torque distribution device for rear wheels located on the same axis as an output shaft 3 of the transmission 1. A first differential gear device 4 consisting of a double planetary gear and a second differential gear device 5 consisting of a simple planetary gear are arranged in parallel on one end side of the propeller shaft 2 of the propeller shaft. . The first differential gear device 4 includes a pair of inner and outer planetary gears 7a and 7b connected to one end of the propeller shaft 2 via a main rear 6, a sun gear 8 that meshes with the inner planetary gear 7a, and a sun gear 8 that meshes with the inner planetary gear 7a. 7b and a ring gear 9 connected to the output shaft 3 of the speed change ii. On the other hand, the second differential gear device 5 is connected to the transmission 1
A planetary gear 11° connected to the output shaft 1 of the planetary gear 11 through a carrier 10, and a planetary gear 11. ...
a sun gear 12 that meshes with the planetary gear 11.
... and a ring gear 13 connected to one end of the propeller shaft 2.

Further, a drive pulley 14 is loosely fitted to the outer periphery of the rear wheel propeller shaft 2. The drive pulley 14 is connected to the sun gear 12 of the second differential gear device 5.
It is connected to the sun gear 8 of the first diaphragm gear device 4 via a second switching means 16. The first and second switching means 15 and 16 are both comprised of wet clutches,
The second and first differential gear devices 5 and 4 are connected to the drive pulley 1
4 so as to be able to selectively transmit torque. Further, the drive pulley 14 is driven via a chain 17 to a driven pulley 19 attached to one end of a propeller shaft 18 for the front wheels. +131! Both pulleys 14 and 19 are set to have the same diameter.

Next, to explain the operation of the first embodiment, the first
When the first switching means 15 is connected and the second switching means 16 is disconnected in the selected state, the two differential gear devices 4 and 5
Of these, only the second differential gear unit 5 operates to transmit drive torque and distribute torque, and the first differential gear unit 4 is in a free state (idle rotation state). That is, the driving torque from the output shaft 3 of the speed change l111 is input to the planetary gear r11 side of the second differential gear device 5, and the driving torque is inputted to the planetary gear r11 side of the second differential gear device 5.
3, and is distributed according to the ratio of the number of teeth between the sun gear 12 and the ring gear 13. The drive torque distributed to the sun gear 12 is transmitted to the front wheels via the first switching means 15, the pulley 14.19 and the propeller shaft 18, while the drive torque distributed to the ring gear 13 is transmitted to the rear wheels via the propeller shaft 2. transmitted to the side.

Also, as a second selection state, the first switching means 15 is disconnected,
When the second switching means 16 is connected, contrary to the case of the first selection state described above, only the first differential gear device 4 operates to transmit the drive torque and distribute the torque, and the second differential gear device The device becomes free. In other words, the output of the speed change n1 @3
The driving torque from is input to the ring gear 9 side of the first differential gear device 4, and in the first differential gear device 4, the drive torque is applied to the key 1 per rotation of the ring gear 9. It is distributed according to the ratio of the rotation angle of the rear 6 and the rotation angle of the sun gear 8. The drive torque distributed to the planetary gears 7a, 7b or the carrier 6 is transmitted to the rear wheels via the propeller shaft 2, while the drive torque distributed to the sun gear 8 is transmitted to the second switching means 1.
6. The power is transmitted to the front wheels via the pulleys 14 and 19 and the propeller shaft 18.

Roughly speaking, as the third selection state, the first and second switching means 1
5.16 are connected together, the first and second differential gear devices 4 and 5 are locked together, and the rear propeller shaft 2 and the pulleys 14 and 19 or the front propeller shaft 18 operate at the same speed. Since it rotates, 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. 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.

Note that a wet clutch is used as the first and second switching means 15.16, but this switching means 15.1
6, the connection and disconnection of torque transmission is simply switched, and there is no so-called half-clutch state, so ffJ! Wear on the rubbing 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 which reference numeral 31 denotes a transmission;
includes a torque converter 32 and a transmission main body 33. The output shaft 34 of the transmission main body 33 is drivingly connected to one end of a subshaft 38 arranged parallel to the output shaft 34 via a pair of transmission gears 37a, 37b. Above subshaft 3
On the other end side of 8, three first differential gear devices and a second differential gear device 40 each consisting of a simple planetary gear are arranged in parallel, and a The drive gear 41 is loosely fitted. The first and second differential gear devices 39 and 40 each have a blurring gear 42 connected to the other end of the countershaft 38. ...or 43.
..., a sun gear 44 or 45 that meshes with the planetary gear 42 or 43, and the planetary gear 42 or 4.
Each of the ring gears F46 and F47 is connected to one end of a front wheel propeller shaft 48, which is disposed concentrically with the subshaft 38.

On the other hand, the drive gear 41 is connected to the sun gear 45 of the second differential gear device 40 via four first switching means.
They are respectively connected to the sun gear 44 of the first differential gear device 39 via switching means 50 . The four first and second switching means 50 are both wet clutches,
The second and first differential gear devices 40.39 are each selectively connected to the drive gear 41 so as to be capable of transmitting torque. Further, the drive gear 41 meshes with a driven gear 51 attached to one end of the rear wheel propeller shaft 36, and both gears 41 and 51 are set to have the same teeth.

Next, to explain the operation of the second embodiment, in the four-wheel drive mode, the first switching means 49 is in the first selection state.
is connected and the second switching means 50 is disconnected, the second differential gear 1 device 4o of the two differential gear devices 39,40
Only the gearbox transmits the drive torque and operates according to the torque distribution, and the first differential 1I7I gear device 39 is in a free state. That is, the driving torque output from the output shaft 34 of the transmission 31 is transmitted to the second differential tooth II gear via the subshaft 38! 140
The input signal is input to the planetary gear 43 side, and distributed in the second differential gear device 40 according to the tooth number ratio between the sun gear 45 and the ring gear 47. The driving torque distributed to the sanggi I=45 of the second differential tlJ vehicle device 40 is
The driving torque is transmitted to the rear wheels via the switching means 49, the drive gear 41, the drive gear 51, and the propeller shaft 36, while the driving torque distributed to the ring gear 47 is transmitted to the front wheels via the propeller shaft 48.

Also, as a second selection state, the first switching means 49 is disconnected,
When the second switching means 50 is connected, contrary to the case of the first selection state described above, only the first differential gear device 39 operates to transmit the drive torque and distribute the torque, and the second differential gear device The device 1ff40 becomes free. That is, the driving torque from the output shaft 34 of the transmission 31 is input to the planetary gears 42 of the three first differential gears via the subshaft 38, and is input to the sun gear 44 at the first differential gear GI position 39. and ring gear 46 according to the tooth number ratio. The drive torque distributed to the gears 1-44 of the first differential gear device 39 is transferred to the second switching means 50, the drive gear 41
, is transmitted to the rear wheels via the driven gear 51 and the propeller shaft 36, while the driving torque distributed to the ring gear 46 is transmitted to the front wheels via the propeller shaft 48.

Further, as a third selection state, the first and second switching means 4
9.50 are connected together, the first and second differential gear devices 39.40 are locked together and the rear wheel propeller shaft 36 and the front wheel propeller shaft 48 rotate at the same speed, so that the speed change is not possible. The drive torque from the output shaft 34 of the machine 31 is normally distributed and transmitted equally to the front and rear wheels.

Here, the sun gear 4 in the first differential gear device 39
4 and the ring gear 46, and the second differential gear device 4
The ratio of the number of teeth between the sun gear 45 and the ring gear 47 in the state 47 is different, for example, the ratio of the number of teeth of the first differential gear device 39 is set to 30:70, and the ratio of the number of teeth of the second differential #g wheel 40 is set to 30:70. When the numerical ratio is set to 40:60, the distribution of drive torque to the front and rear wheels will be 60:40 in the first selection state and 70% in the second selection state.
It will be 30 vs.

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 4.5 or 39.40 are arranged in parallel on the drive torque transmission system, and the drive torque is distributed to the front and rear wheels during four-wheel drive. Although the configuration is configured so that switching can be selected in three stages, the present invention arranges three or more differential gear devices in parallel on the drive torque transmission system, and distributes the drive torque to the front and rear wheels in multiple stages. It may also be configured so that it can be switched and selected in stages.

Moreover, it goes without saying that the shell gear device may be constructed using a bevel gear or the like instead of using a planetary gear as in the embodiment. Further, as a switching means for selectively connecting the differential gear device to enable torque transmission, in addition to using a wet 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 according to the present invention, a plurality of differential #1iiila vehicle devices are selectively connected to enable torque transmission by the switching means, and this torque transmission is possible. The combination of connected differential gears allows the distribution of drive torque from the transmission to the front and rear wheels to be selectively varied, so wear due to frictional force does not become a problem. , durability can be improved, and torque distribution can be reliably performed according to set values without being affected by external factors.

Moreover, since the plurality of differential gear devices are arranged in parallel and integrated on the drive torque transmission path, the 1-luke distribution device can be made more compact.

[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. 1.31...Transmission, 4,39...First differential gear device, 5.40...Second differential gear device, 15.49...
- First switching means, 16.50... second switching means. Figure 1

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, wherein each gear is arranged in parallel on the drive torque transmission path. A torque distribution device for a four-wheel drive vehicle, comprising a plurality of differential gear devices having different ratios, and a switching means for selectively connecting the plurality of differential gear devices to enable torque transmission.