JPS6397433A - Torque distributing device for four-wheel drive vehicle - Google Patents

Abstract

PURPOSE:To increase the degree of freedom in the case of setting a torque distribution ratio to front and rear wheels by using two types of planetary gear devices of a single pinion type and a double pinion type for a center differential gear. CONSTITUTION:First and second center differential gears 50, 60 both of which are formed with planetary gear devices are provided on an intermediate shaft 23. The first center differential gear 50 is formed with a single pinion type planetary gear device and has a sun gear 51, a pinion gear 52 meshed with the sun gear 51, a carrier 54, and a ring gear 55. On the other hand, the second center differential gear 60 is formed with a double pinion type planetary gear device and has a sun gear 61, a first pinion gear 62, a second pinion gear 63, a carrier 66, and a ring gear 67.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a torque distribution device for a four-wheel drive vehicle, and in particular, a torque distribution device for a four-wheel drive vehicle, in particular, a torque distribution device for a four-wheel drive vehicle, which is provided with a plurality of center differentials that divide torque from a transmission and transmit it to front wheels and rear wheels, respectively. The present invention relates to a torque distribution device for a four-wheel drive vehicle.

(Prior Art) In a four-wheel drive vehicle in which the torque output from the engine via the transmission is transmitted to the front wheels and the rear wheels respectively at a predetermined distribution ratio, in order to eliminate the so-called braking phenomenon during cornering, may be equipped with a center differential. This center differential consists of an input element into which torque from the engine or transmission is input, and output elements for front wheels and rear wheels that divide the torque input into the element and transmit it to the front wheels and rear wheels, respectively. ,
By performing differential operation between both output elements, the difference in rotational speed between the front and rear wheels during cornering is absorbed.

By the way, the center differential of a 24-wheel drive vehicle uses a ring gear consisting of an internal gear and a ring gear. 1. A planetary gear device is sometimes used, which is composed of a pinion that engages with the pinion, a gear that rotatably holds the pinion, and a gear that meshes with the pinion.

There are two types of gear devices: a single-binion type and a double-pinion type. Among these, when a single-binion type planetary gear device is used as a center differential, the carrier of the device is As input elements, a sun gear and a ring gear correspond to output elements for the front wheels and rear wheels, respectively, and when a double pinion type planetary gear device is used, the ring gear of the device corresponds to the input element, and the sun gear and carrier correspond to the output elements for the front wheels, respectively. This corresponds to the rear wheel output element.

On the other hand, as a center differential constructed using such a planetary gear device, for example, Japanese Patent Laid-Open No. 61-6264
As shown in Publication No. 1 and Japanese Patent Application Laid-Open No. 61-94822, it is equipped with a plurality of planetary gear devices having different diameters arranged concentrically, and through any one of these devices. Some vehicles are equipped with a switching gate mechanism that selectively switches the torque transmission path so that torque is transmitted from the transmission to the front and rear drive shafts. According to this, the selection operation of the switching mechanism makes it possible to change the distribution ratio of 1 herk transmitted to the front wheels and the rear wheels via the center differential, depending on the driving condition of the vehicle. Good control of differential operation of center differential 1
11 can be expected.

(Problems to be Solved by the Invention) By the way, when a plurality of planetary gear devices are used as center differentials as described above, all of them must be of the same type of planetary gear device, that is, either a single pinion type or a double pinion type. It is usually configured with a planetary gear device. Therefore, even if a configuration is provided in which a plurality of planetary gear devices are provided and these are selectively switched, the degree to which the distribution ratio of the torque transmitted to the front wheels and the rear wheels through the gear devices can be changed is within a narrow range. 1a, the problem is that the degree of freedom in setting the torque distribution ratio is reduced.

Furthermore, when configuring i12 center differentials with the same type of planetary gear device, the above-mentioned input element and front and rear wheel output elements are necessarily the same type of gear or carrier. This tends to complicate the layout or configuration of the switching mechanism. That is, to take the configuration described in the above-mentioned publication as an example, a boss portion is integrally extended and formed on each of two sun gears that are output elements of two single binion type planetary gear devices having different diameters, and Both bosses are coaxially and slidably arranged, and a switching mechanism is provided at the end of each of the bosses so that either one of the sun gears can be in a state where torque can be transmitted. . Due to the need to extend the boss portions on both sun gears and to arrange the boss portions coaxially and slidably, the configuration or layout of the switching mechanism has been changed. This makes it difficult to achieve simplification.

The present invention addresses the above-mentioned problems regarding a torque distribution device for a four-wheel drive vehicle equipped with a plurality of center differentials. It is an object of the present invention to increase the degree of freedom in setting a torque distribution ratio when changing the ratio, and to simplify the configuration or layout of a switching mechanism provided between each center differential.

(Means for Solving the Problems) A torque distribution device for a four-wheel drive vehicle according to the present invention is characterized in that it is configured as follows to achieve the above object.

That is, in a four-wheel drive vehicle equipped with an engine, a transmission into which torque from the engine is input, and a center differential that divides the torque from the transmission and transmits it to the front wheels and rear wheels at a predetermined distribution ratio. The center differential is characterized in that it includes at least a single pinion type planetary gear device and a double pinion type planetary gear device, and a switching mechanism is provided for setting either one of the two planetary gear devices in a torque transmitting state.

(Function) According to the above configuration, the center differential which divides the torque from the lance transmission and transmits it to the front wheels and the rear wheels respectively] is used as a center differential between the single pinion type planetary gear device and the double pinion type planetary gear device. By selectively switching both gear A7 devices, the degree of freedom in setting the distribution ratio of torque transmitted to the front wheels and the rear wheels, respectively, is expanded. In other words, the torque distribution ratio when transmitting torque using a single pinion type planetary gear device is significantly different from the torque distribution ratio when transmitting torque using a double pinion type planetary gear device. The difference in torque distribution ratio far exceeds the difference in torque distribution ratio that would occur if the size or diameter of each part in either gear device was changed. Therefore, when using two types of planetary gear devices, a single pinion type and a double pinion type, there is more freedom in setting the torque distribution ratio than when using multiple gear devices of the same type. becomes larger.

Furthermore, since the switching mechanism for selecting one of the center differentials is disposed across both the single pinion type and double pinion type gear devices, the structure of the mechanism can be simplified or its layout can be changed. The degree of freedom will be expanded. In other words, the torque input element and output element between the two gear V tools are different between the above-mentioned single pinion type and double pinion type, and therefore, when installing a switching mechanism across the same type of gear device. For example, due to the fact that the input element and the output element are of the same type,
1-94822), the problem of having to separately improve the structure of each switching mechanism V, which is an output element of both, is solved, and the configuration or layout of the switching mechanism is simplified accordingly. be.

(Example) Examples of the present invention will be described below.

First, the overall configuration of the four-wheel drive vehicle according to this embodiment will be explained with reference to FIG. is installed.

The engine 1 is arranged so that its output shaft 4 extends in the vehicle width direction. In addition, transmission 2 also
An input shaft 6 connected to the engine output shaft 4 via a clutch 5 and an output shaft 7 parallel thereto are arranged to extend in the vehicle width direction, and the transmission 2
Between the output shafts 6 and 7 are gear trains 81 to 8s, 8 for 1st to 5th speeds and return/reverse speeds, which are selectively brought into a torque transmitting state.
r is provided, and an output gear 9 is provided at one end of the output shaft 7 for transmitting torque from the transmission 2 to the transfer device 3.

On the other hand, the transfer device 3 divides and outputs the torque input from the transmission 2, drives left and right front wheels 12.13 via left and right front axles 10.11, and also drives a propeller shaft extending in the longitudinal direction of the vehicle body. 14, a rear wheel differential device 15 and a rear axle 1 extending left and right from the device 15;
6.17 to drive the left and right rear wheels 18.19.

Next, the internal structure of the transfer device 3 will be explained with reference to FIG. 21, 22, an intermediate shaft 23 arranged parallel to the rear of these, and a rear wheel drive shaft 24 arranged in the longitudinal direction of the vehicle body and protruding tangentially, all of which are rotatably supported.

The left and right front wheel drive shafts 21.22 are the front axle 10.11 shown in FIG. 1, and the rear wheel drive shaft 24 is the front wheel drive shaft 21.22.

The propeller shafts 14 are connected to each other.

Further, a bevel gear type front wheel differential vJ device 30 is disposed around the opposing ends of the left and right front wheel drive shafts 21 and 22.

This front wheel differential device 30 has boss portions 31 extending on both left and right sides.
a and 31b are rotatably fitted and supported on the left and right front wheel drive shafts 21.22; a differential case 31; shift 32 and the shaft 32
A pair of pinion gears 33 and 34 rotatably supported by
and a pair of left and right output gears 35.36 meshed with both pinion gears 33.34.
6, the ends of left and right front wheel drive shafts 21, 22 are largely coupled.

Then, this front wheel differential device 30 (Zuru differential case 3
A large-diameter idle gear 41 is rotatably fitted and supported on the outside of the transmission 2 and meshed with the output gear 9 of the transmission 2, and the idle gear 41 is rotatably supported on the intermediate shaft 23. First and second center differentials 50.degree. 60, both of which are planetary gear devices, are disposed on the intermediate shaft 23 and are meshed with the small-diameter input gear 42. Behind both center differentials 50 and 60, the first center differential 50 is composed of a single binion type planetary gear device, and as shown in FIG. Pinion gears 52...52 and pinion shafts 53...
53, and a ring gear 55 that is disposed on the outside of each pinion gear 52 and meshes therewith. On the other hand, the second center differential 60
is comprised of a double pinion type propeller gear T''LC, as shown in FIG. These pinion gears 62...
A plurality of second vinyl A gears 63...6 meshing with each other
3, and each of the first and second pinion gears 62...62.6
3...63 respectively to the pinion shafts 64...64.
A carrier 66 supported via 65...65, and a second
It has a ring gear 67 disposed outside of the pinion gears 11'763...63 and meshing therewith.

So, 1-1? The ring gear 55 of the center differential 50 and the carrier 66 of the second center differential 60 are coupled to a bevel gear-shaped rear wheel output gear 71 rotatably supported on the intermediate shaft 23. A bevel gear-shaped gear 72 provided at the end of the rear wheel drive shaft 2/l is meshed with the rear wheel drive shaft 2/l. Furthermore, the lean gears 51.61 of the first and second rental differentials 50.60 are integrated and spline-fitted to the intermediate @23, and the second t.
? A drum 68 is connected to a ring gear 67 of the center differential 60 so as to cover the first center differential 50.

Further, a switching mechanism 80 is provided between the first and second t-shift differentials 50, 60 and the manual gear 42. This switching mechanism 80 includes a first spline section 68' formed at one end of the drum 68 and a second spline section 54 formed at one end of the carrier 54 in the first pinta differential 50.
', a third spline part 42' formed at one end of the input gear 42, and these spline parts 68' and 54'.
, 42', and has spline portions formed at three locations, respectively, and is held so as to be slidable left and right.
It is composed of. When the sleeve 81 is slid to the right as shown, the input gear 42 and the ring gear r67 of the second center differential 60 are connected via the first and third spline portions 68' and /12'. Furthermore, by sliding the sleeve 81 to the left from the illustrated position, the input gear 42 and the carrier 54 of the first center differential 50 are connected via the second and third spline portions 54' and 42'. It has become.

A front wheel output gear 73 is integrally formed on the intermediate shaft 23, and a front wheel output gear 73 is rotatably mounted on the output gear 73 and the left front wheel drive shaft 2 via the boss portion 31a of the differential case 31. It is meshed with a reduction mechanism drive gear 74 supported by. Also, the boss portion 31a of the differential case 31
On the top, there are a sun gear 91, a plurality of pinion gears t792...92 that mesh with the sun gear 91, and these pinion gears 92 and 92.
...92 via pinion shafts 93...93, and each pinion gear 92...
A planetary gear type speed reduction mechanism 90 consisting of a ring gear 95 meshing with the gear 92 is disposed. And the mechanism 90
The sun gear 91 and the reduction mechanism driving gear 74 are integrated, the ring gear 95 is fixed to the case 20 of the transfer device 3, and the carrier 94 is connected to the boss portion 31a of the differential case 31 in the front wheel differential device 30. is combined with

Further, this transfer device 3 is equipped with a viscous coupling ring 100 as differential limiting means for the first and second differential differentials 50 and 600. this coupling 100
are arranged between an outer member 101 connected to the inner periphery of the idle gear 41, an inner member 102 connected to the outer periphery of the differential case 31, and alternately arranged between these two members 101 and 102. A large number of plates 103...
・103, and these plates 103...
103 is filled with viscous fluid, and when the rotational speed difference between the outer member 101 and the inner member 102, that is, between the idle gear r41 and the differential case 31, is small, relative rotation between these is allowed. When the rotational speed difference exceeds a predetermined amount, the resistance of the viscous fluid acts to limit the relative rotation.

Furthermore, in this embodiment, a spline portion 41 is provided at one end of the drum 41a extending rightward from the idle gear 41.
' is formed, and the cylindrical member 111 fitted into the boss part 31b of the differential case 31 is also formed with a spline part 111', and both spline parts 41', 11
1' and a differential lock sleeve 112 which is slidably fitted and held astride these to lock the differential lock mechanism 110.
is configured. Then, the differential lock sleeve 112 of J3 of the mechanism 110 slides to the right from the illustrated state and engages with the spline portion 111' of the cylindrical member 111, thereby locking the first or second center differential 50.6.
Differential operation due to 0 is prevented.

Next, to explain the operation of this embodiment, the torque output from the engine 1 via the transmission 2 is transmitted from the output gear 9 of the transmission 2 to the intermediate shaft via the idle gear 41 of the transfer device 3. The signal is transmitted to the input gear 42 on the top 23, and further input to the switching mechanism 80.

When the sleeve 81 in the switching mechanism 80 is slid to the left, the torque is applied to the first center differential 50.
4 in the carrier 54.

When the torque is divided into the sun gear 51 side and the ring gear 55 side, the torque divided to the sun gear 51 side is transmitted to the intermediate shaft 23 or the front wheel output gear 73, and the torque divided to the ring gear 55 side is transmitted to the 21st gear 51 side. The signals are transmitted to the rear wheel output gears 71 via the gear rear 66 of the differential gear 60, respectively. Further, when the sleeve 81 in the switching mechanism 80 is slid to the right as shown in the figure, the torque is transmitted through the drum 68 to the second
It is input to the ring gear 67 of the center differential 60 and is divided into the sun gear r61 and the carrier 66, and the first
Similar to the center differential 50, the torque divided to the sun gear 61 side is sent to the intermediate shaft 23 or the front wheel output gear 73, and the torque divided to the carrier 66 side is sent to the rear wheel output':I! 71 respectively. In either case, the torque transmitted to the intermediate shaft 23 or the front wheel output gear 73 is input to the sun gear 91 of the reduction gear mechanism 90 via the reduction mechanism drive gear 74, and is also reduced by the [190]. The signal is then transmitted from the carrier 94 to the differential case 31 of the front wheel differential device 30 to drive the device 30. As a result, the left and right collar drive shafts 21
．． 22 is driven, and furthermore, left and right front wheels 12.13 are driven via the front axle 10.11. Further, the torque transmitted to the rear wheel output gear 71 is transmitted to the rear wheel drive shaft 24 via the gear r72, and further to the propeller shaft 14 and the rear wheel differential device 1.
5 and the left and right rear wheels 18.19 via the dominant axle 16.17
to drive.

However, when the torque is divided by the first center differential 50 which is a single-binion type planetary gear device, the torque input to the carrier 54 of the center differential 50 is transmitted to the sun gear 51 and the ring gear 55, and to both gears 51.5.
For example, it is divided into 3-nea according to the ratio of the number of teeth of 5, so
The torque transmitted from the ring gear 55 to the rear wheels 18.19 is significantly larger than the torque transmitted from the sun gear 51 to the front wheels 12.13, making it suitable for sporty driving where the torque distribution is biased toward the rear wheels. The distribution will be as follows.

On the other hand, the second gear consisting of a double pinion type planetary gear device
When the torque is divided by the center differential 60, if the ratio of the number of teeth between the sun gear 61 and the ring gear 67 is set to 1:2, for example, the torque input to the ring gear 67 is divided into two equally between the sun gear 61 and the carrier 62. As a result,
Therefore, the torque is distributed evenly between the front and rear wheels, which is suitable for normal driving.

In this way, the first. 2nd t? By configuring the rotation gear 50.60 with planetary gear devices of different types, a single pinion type and a double pinion type, the first. Compared to the case where the second center differential is configured with the same type of planetary gear device, the degree of freedom in setting torque distribution to the front and rear wheels is expanded.

Also, the above 1. A switching mechanism 80 that selectively switches the second center differential 50, 60 has a carrier 54 that is an input element of the first center differential 50, a ring gear 67 that is an input element of the second center differential 60, and a 1-lux from the transmission 2. The spline portions 54', 68', and 42' are formed by adding simple structural changes to the input gear 42 that is input through the idle gear 41, and sleeves are formed in correspondence with these spline portions. 81 is arranged. Therefore, for example, the first. 21st. ?
Each input element (or output element) of the same type is
This eliminates the problem of having to provide a switching mechanism while avoiding interference between the two, and the degree of freedom in the layout of the mechanism is expanded or its configuration is simplified.

In this embodiment, a viscous coupling 100 is provided between the idle gear 41 and the differential case 31 in addition to the differential lock I (Tom 110), so a good running condition can be obtained as follows.

That is, when the vehicle is cornering relatively gently, the viscous coupling 100 is in idle gear.
41 and the differential case 31, a differential operation is performed by the first center differential 50 or the second center differential 60. Therefore, the difference in rotational speed between the front and rear wheels due to cornering is absorbed. The braking phenomenon will be eliminated.

On the other hand, if the difference in rotational speed between the front and rear wheels exceeds a predetermined distance, such as when the vehicle is sharply cornering or when either the front or rear wheels slip, the viscous coupling 100 limits the relative rotation between the idle gear 41 and the differential case 31, that is, the differential operation of the first center differential 50 or the second hint differential 60, so that when the center differential 50 (60) approaches the locked state,
The difference in rotational speed between the front and rear wheels as described above is eliminated or suppressed. Therefore, during sharp cornering, it is possible to prevent the driving condition from becoming unstable due to excessive rotational speed difference between the front and rear wheels, and when either the front or rear wheels slip, the other Torque is transmitted to, for example, making it possible to escape from a slip state or obtaining the required starting acceleration.

Further, in this embodiment, since torque is input from the output key ψ9 of the transmission 2 to the small-diameter input gear 42 via the large-diameter idle gear 41, the input gear 42
The first or second center differential 50 (
60), the output rotation of the transmission 2 is 111
After being decelerated, the speed will be increased again and input.

Therefore, compared to the case where the output rotation of the transmission is directly inputted to the center differential in a decelerated state, it is possible to reduce these torque capacities, and the above-mentioned item 1. The size of the second t-diaphragm 50.60 will be reduced.

Next, referring to a second embodiment of the present invention shown in FIG. 5, a transfer device 3' according to this embodiment also has left and right front wheel drive shafts 21' extending in the vehicle width direction on the same axis.
, 22', an intermediate shaft 23' arranged parallel to the rear of these, and a rear wheel drive shaft 24' extending in the longitudinal direction of the vehicle body. The left and right front wheel drive shafts 21', 2
2', as in the previous embodiment, a differential case 31', a pinion shaft 32', pinion gears V33', 34', and output gears 35', 36'.
J3 is equipped with a front wheel differential device 30, and a large-diameter idle gear 41'' is rotatably supported on the outside of a differential case 31' in the device 30, and meshed with an output key A79' of the transmission. and intermediate shaft 23'
It is engaged with a small diameter input key t742' rotatably supported above. Furthermore, the first transmission gear 75', which is integrally provided with the input gear 42', is connected to the right front wheel drive shaft 2.
A second transmission gear 76' rotatably supported on the differential case 31' is meshed with the second transmission gear 76', and a first transmission gear 76' is disposed adjacent to the gear 76'. 2nd center differential drive gear 77
', 78' are each rotatably supported.

Further, a front wheel output gear 7 is provided at one end of the intermediate shaft 23'.
3' is integrally formed, and this output gear 73'
is meshed with a reduction mechanism drive gear 74' integrated with a gear 91' of a reduction gear m90, which is a planetary gear device.

Also in this embodiment, a first center differential 50' made of a single pinion type planetary gear device and a second center differential 60' made of a double pinion type planetary gear device are provided on the intermediate shaft 23'. The first center differential 5O has a sun gear 51', pinion gears 52'...52', a carrier 54', and a ring gear 55'. It is meshed with the center differential drive gear 77'. Also, the above 2nd t? The differential gear 60 includes a sun gear 61' and a first gear. Second pinion gears 62', 63
', a carrier 66', and a ring gear 67', and an input gear 68' formed around the outer periphery of the ring gear 67' is meshed with the second center differential drive gear 78'. And the above 1st t? Ring gear 55' of center differential 50' and carrier 66' of second center differential 60'
are coupled to a bevel gear-shaped rear wheel output gear 71' rotatably supported on the intermediate shaft 23', and the gear V71' is connected to the rear wheel drive shaft 24'. A bevel gear type gear 72' provided at the end is engaged.

Further, between the first center differential drive gear 77' and the second center differential drive gear 78', there is provided a switching device &! for selectively switching between the first and second center differentials 50' and 60'. t8
0' is provided. This switching mechanism 80' is the same as the above-mentioned first switching mechanism 80'. The first center differential drive gear 77', 78' is integrated with the second center differential drive gear 77', 78'. It is composed of second spline members 81', 82', a third spline member 83' integrated with the second transmission gear 76', and a sleeve 84' slidably held astride these members. Depending on the sliding position of the sleeve 84', the input gear 42' on the intermediate shaft 23' and the carrier 54 of the first center differential 50'
' or the ring gear 67' of the second center differential 60'. Note that a first gear is provided between the intermediate shaft 23' and the rear wheel output gear 71'.
A viscous coupling 100' is provided as differential limiting means for the second center differentials 50' and 60'.

As mentioned above, also in this second embodiment, the first and second
Since the center differentials 50' and 60' are each comprised of two types of planetary gear devices, a single pinion type and a double pinion type, the degree of freedom in setting the torque distribution ratio for the front wheels and rear wheels is expanded. Further, the switching mechanism 80' is interlocked with a first center differential drive gear 77' which is interlocked with a carrier 54' which is an input element of the first center differential 50', and with a ring gear A767' which is an input element of the second center differential 60'. Since the second center differential drive gear 78' is a component of the switching mechanism, the structure or layout of the switching mechanism is simpler than when the same type of input element (or output element) is used as a component of the switching mechanism. will be made into

(Effects of the Invention) As described above, according to the present invention, two types of planetary gear devices, a single pinion type and a double pinion type, are used as a center differential that divides the torque from the transmission and transmits it to the front wheels and the rear wheels, respectively. By using this method, the degree of freedom in setting the torque distribution ratio to the front and rear wheels is expanded, and the configuration or layout of the switching mechanism that selectively switches between the two gear devices is simplified. Become.

[Brief explanation of the drawing]

1 to 4 show a first embodiment of the present invention, and FIG. 1 is a schematic diagram showing the overall configuration during four-wheel drive according to the embodiment;
FIG. 2 is a longitudinal cross-sectional view of the main part, and FIG. 3-4 is the first section of the embodiment. FIG. 6 is a schematic diagram showing the configuration of a second center differential. Further, FIG. 5 is a schematic diagram of main parts showing a second embodiment of the present invention. 1...Engine, 2...-+-Lance transmission, 5
0.50'...Single binion type planetary gear device (first center differential>, 60.60'...Double union type planetary gear device (second center differential>, 80.
80'...Switching mechanism.

Claims (1)

[Claims] (1) Four wheels equipped with an engine, a transmission into which torque from the engine is input, and a center differential that divides the torque from the transmission and transmits it to the front wheels and rear wheels, respectively, at a predetermined distribution ratio. A torque distribution device for a driving vehicle, wherein the center differential includes at least a single pinion type planetary gear device and a double pinion type planetary gear device, and either one of the planetary gear devices is set in a torque transmitting state. A torque distribution device for a four-wheel drive vehicle, characterized by being provided with a switching mechanism.