JPH0235240A - Four-wheel drive device of vehicle - Google Patents

Abstract

PURPOSE:To ease the assembly and enhance the layout by installing an automatic differentiation limiting means through utilization of a mechanism by which the power is transmitted from the central differential of a power distribution device to No.1 output shaft via an idling gear. CONSTITUTION:Through an idling gear on an intermediate shaft 21, No.1 output shaft 7 to No.1 drive wheel 11 on the engine side is driven from the central differential 5 of a power distribution device, and No.2 output shaft 8 to No.2 drive wheel 13 on the opposite side is driven. An automatic differentiation limiting means 25 such as a viscous cup ring is installed on the intermediate shaft 21 interposed between No.1 output shaft 7 and No.2 output shaft 8, and its inner rotary member 25a is in connection with No.1 output shaft 7 via intermediate shaft while the outer member 25b in connection with adjoining No.2 output shaft 8.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a four-wheel drive device for a vehicle.

(Prior art) Conventionally, as a four-wheel drive system, a transmission and a power distribution device equipped with a center differential are connected to an engine in order, and the output from the center differential of this power distribution device is used to control the power of the engine. A first output shaft that outputs to the first drive wheel and a second output shaft that outputs to the second drive wheel on the opposite side are driven. For example, a technique in which an automatic differential limiting means such as a viscous coupling for limiting the rotational difference between the first output shaft and the second output shaft is provided is disclosed in Japanese Patent Application Laid-Open No. 61-119. It is publicly known as seen in Japanese Patent No.-20551.7.

Further, a four-wheel drive device in which the power distribution device transmits power from the center differential to the first output shaft via an idle gear interposed between the first output shaft and the second output shaft. is also known.

(Problem to be Solved by the Invention) However, in the above four-wheel drive device, the automatic differential limiting means such as a viscous coupling is
Since it is disposed on the outer periphery of the output shaft, the structure of the power transmission system becomes complicated, and there are problems in terms of ease of assembly and layout.

That is, the automatic differential limiting means using the above-mentioned viscous coupling or the like is effective because the rotational difference between the first output shaft on the front wheel side and the second output shaft on the rear wheel side is caused by some wheels slipping due to mud, etc. In order to increase the transmission of driving force to the wheels outside this idle wheel device, when the rotation member becomes large, the differential lock state is automatically obtained, and one of the rotating members of this automatic differential limiting means is It is necessary to link the first output shaft to the second output shaft.

Therefore, the second output shaft is arranged coaxially with the transmission and center differential which are connected in turn to the drive shaft from the engine, and the first output shaft is arranged parallel to the second output shaft. It is configured so that the power is output to the engine side.

Therefore, since a center differential is disposed on the second output shaft, when one rotating part of the automatic differential limiting means is linked to the second output shaft, the other rotating part is connected to the second output shaft. In order to link it to one output shaft, it is necessary to install a connecting part bypassing the center differential, which makes the arrangement structure complicated.

Therefore, in view of the above circumstances, the present invention installs an automatic differential limiting means using a mechanism in which power is transmitted from the center differential of the power distribution device to the first output shaft via an idle gear. The object of the present invention is to provide a four-wheel drive device for a vehicle that has improved ease of assembly and layout.

(Means for Solving the Problems) In order to achieve the above object, the four-wheel drive system for a vehicle of the present invention connects an engine to a transmission and a power distribution device in order, and outputs an output from a center differential of the power distribution device. In order to drive the first output shaft that outputs to the first drive wheel on the engine side and the second output shaft that outputs to the second drive wheel on the opposite side, there is an intermediate shaft between the first output shaft and the second output shaft. An idle gear supported by the shaft is interposed to transmit power between the first output shaft and the center differential, and the rotation difference between the first output shaft and the second output shaft is transmitted to the intermediate shaft. The automatic differential limiting means is arranged such that the inner rotation member of the automatic differential limiting means is linked to the intermediate shaft, and the outer member is linked to the second output shaft.

(Function) In the above four-wheel drive device, an automatic differential limiting means such as a viscous coupling is disposed on an intermediate shaft interposed between the first output shaft and the second output shaft, and the inner rotation The member is linked to the first output shaft via the intermediate shaft, and the outer part is linked to the adjacent second output shaft, so that the center differential is not obstructed by using the intermediate shaft with fewer installed parts. The automatic differential limiting means is installed in a simple structure in a position where it cannot be used, to improve ease of assembly and freedom of layout.

(Example) Hereinafter, the present invention will be explained in detail with reference to the drawings.

FIG. 1 shows a schematic configuration of a four-wheel drive vehicle equipped with a four-wheel drive device according to the present invention.

A four-wheel drive vehicle 1 is equipped with an engine 2 at the front of the vehicle body, and the driving force of this engine 2 is transmitted from a transmission 3 connected in order to a power distribution device 4 (transfer) equipped with a center differential 5. The distribution device 4 distributes the water to the front and rear wheels. In the power distribution device 4, the driving force distributed by the center differential 5 is transmitted from the first output shaft 7 installed parallel to the input shaft 6 from the transmission 3 to the engine side (frontward) via the front differential. ) is transmitted to the first drive wheel 11 (front wheel) located at
The signal is transmitted from a second output shaft 8 installed coaxially with the input shaft 6 via a rear differential 12 to second drive wheels 13 (rear wheels) located on the opposite side (rearward).

In addition, in FIG. 1 schematically showing the mechanism of the power distribution device 4 and FIG. A second output shaft 8 on the rear wheel side is arranged on the axis so as to be rotatable relative to the human power shaft 6. A center differential gear 5 is disposed around the outer periphery of the fitting portion between the input shaft 6 and the second output shaft 8.

The center differential gear 5 is composed of a planetary gear device, and includes a sun gear 5 formed on the outer periphery of the end of the second output shaft 8, and a sun gear 5 formed on the outer periphery of the sun gear 5 relative to the second output shaft 8. It has a ring gear 16 that is rotatably supported, and a plurality of pinion gears 17 that are located between the sun gear 15 and the ring gear 16 and rotate and revolve around the sun.

The pinion gear [7] is rotatably supported by a carrier [8], and the carrier [18] is supported at the end of the human power shaft 6 so as to be rotatable together.

The outer layer of the pivot portion of the link gear 16 includes a first drive wheel 11.
An output gear 19 is formed to the side, and this output gear 1
A linkage gear 20 is supported on the second output shaft 8 adjacent to the second output shaft 8 so as to be rotatable together.

On the other hand, a first output shaft 7 and two intermediate shafts are supported by the casing 14 in parallel with the human power shaft 6 and the second output shaft 8,
A transfer gear 22 is formed on the outer periphery of the inner shaft 7, and an idle gear 23 is formed on the intermediate shaft 2. The meshed idle gears 23 are meshed and power is transmitted.

Furthermore, automatic differential limiting means 25 using a viscous coupling is disposed on the intermediate shaft 21. The inner rotary portion 25a of the automatic differential limiting means 25 is linked to the intermediate shaft 21 by spline connection or the like so as to rotate together, while the outer circumference of the outer portion +-4' 25b is An outer peripheral gear 26 that meshes with the linkage gear 20 of the two output shafts 8 is formed. This viscous coupling 25
This constitutes a multi-disc clutch in which fluid is sealed between the inner rotating part) rA25a and the outer part $4'25b, and the inner rotating part +4 rotates in conjunction with the first output shaft 7.
25a and the outer member 25b, which rotates in conjunction with the second output member 8, increases to a predetermined value, an automatic control system that connects the two and limits the differential function of the center differential 5. This constitutes differential limiting means.

With the configuration of the center differential 5 as described above,
The power input to the input shaft 6 is input to the carrier 18 and then distributed to the ring gear] 6 and the sun gear 15 via the pinion gear 17.

The power distributed to the ring gear 6 by the differential operation accompanying the rotation and revolution of the pinion gear 17 is transmitted to the output gear 19.
, the power is transmitted from the first output shaft 7 to the first drive wheels 11 (front wheels) via the idle gear 23 and transfer gear 22, while the power distributed to the sun gear 15 is directly transmitted from the second output shaft 8 to the second drive wheels 11 (front wheels). The signal is transmitted to the wheels 13 (rear wheels), and four-wheel drive is obtained by the front wheels and the rear wheels.

In the four-wheel drive state as described above, under normal running conditions, the power is distributed approximately equally between the first output shaft 7 and the second output shaft 8, and the difference in rotation between the two output shafts 7 and 8 is small. Also in the viscous coupling 25, the difference in rotation between the inner rotary part 25a and the outer member 25b is small, and each rotates freely without being restricted.

On the other hand, when some of the front wheels or rear wheels become slushy and the road resistance decreases, the differential operation of the center differential 5 causes the first output shaft 7 or the second output shaft 8 to be The rotation increases, the rotation difference with the other second output shaft 8 or the first output shaft 7 increases, and the rotation difference between the inner rotating member 25a and the outer member 25b in the viscous coupling 25 also increases, so that the predetermined state is not reached. When you cross it,
Power is transmitted between the two so that the difference in rotation between the two does not become larger than that, and in effect the center differential 5
It functions to limit the differential function of the motor to avoid slip conditions.

According to the above embodiment, the center differential 5 and the first
The power is transmitted to and from the output shaft 7 via the idle gear 23 of the intermediate shaft 2, and an automatic differential limiting means 25 using a viscous coupling is disposed on the intermediate shaft 21.
The inner rotating part trA25a is connected as it is to the intermediate shaft 2]-, while the outer member 25b is connected from the outer peripheral gear 26 to the link 1 east arm 20 of the second output shaft 8, and the viscous coupling 25 is connected to the intermediate shaft 2]. It is possible to improve the ease of assembly by attaching the device to the shaft 2], and it is possible to obtain a good layout without making the casing 4 excessively large. The buffering function of the self-viscous coupling 25 reduces rattling noise caused by power transmission caused by the use of the idle gear 23.

In addition to the above-mentioned viscous coupling, the automatic differential limiting means 25 includes an oil pump driven by the rotational difference between the first output shaft 7 and the second output shaft 8 (details are given in Japanese Patent Application Laid-open No. 24155]).

In addition, in the above embodiment, the engine 2 is installed at the front of the vehicle body, and the first driving wheel 1 on the engine side is the front wheel and the second driving wheel 13 on the opposite side is the rear wheel. In the case of arrangement, the configuration is similar.

(Effects of the Invention) According to the present invention as described in item 1, the first output shaft from the center differential of the power distribution device to the first drive wheel on the engine side is driven via the idle gear of the intermediate shaft, and the opposite A second output shaft for a second drive wheel on the side is driven, and an automatic differential limiting means such as a viscous coupling is disposed on the intermediate shaft interposed between the first output shaft and the second output shaft. However, the inner rotating member is linked to the first output shaft via the intermediate shaft, and the outer member is linked to the adjacent second output shaft, making it possible to utilize the intermediate shaft with fewer installed parts. The automatic differential limiting means can be installed with a simple structure in a position that avoids the 1st and 21st power axes, where various parts such as the center differential are installed, making it lightweight and easy to assemble. , it is possible to improve the degree of freedom in layout, and furthermore, it is possible to reduce the noise of the idle gear.

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[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of a four-wheel drive vehicle equipped with a four-wheel drive device according to an embodiment of the present invention, and FIG. 2 is a sectional view showing a specific structural example of the four-wheel drive device. 1...4-wheel drive vehicle, 2...engine, 3...
...Transmission device, 4...Power distribution device, 5...
・Center differential, 6... Input shaft, 7
...First output shaft, 8...Second output shaft, 11
...First driving wheel,]3...Second driving wheel, 19
...Output gear, 20...Linkage gear, 2
DESCRIPTION OF SYMBOLS 1... Intermediate shaft, 22... i. Lance gear, 23... Idle gear, 25... Automatic differential limiting means, 25a... Inner rotating member, 25b...
...Outer member, 26...Outer gear.

Claims (1)

[Claims] (1) It has a transmission connected to the engine in order and a power distribution device equipped with a center differential, and the output from the center differential of the power distribution device is used to output the output to the first drive wheel on the engine side. A second output shaft that outputs an output to a second drive wheel on the opposite side to the first output shaft is driven, and an idle gear supported by an intermediate shaft is interposed between the first output shaft and the second output shaft. In a four-wheel drive system for a vehicle that transmits power between a first output shaft and a center differential, the intermediate shaft is equipped with an automatic differential that limits the rotational difference between the first output shaft and the second output shaft. A four-wheel drive system for a vehicle, characterized in that a limiting means is provided, an inner rotating member of the automatic differential limiting means is linked to the intermediate shaft, and an outer member is linked to the second output shaft.