JPS63287632A - Power transmitting device for four-wheel drive vehicle - Google Patents

Abstract

PURPOSE:To enable a vehicle to be placed in a four-wheel drive condition, by connecting either a drive side member in a fluid coupling or its driven side member to a drive shaft or a driven shaft so is to directly connect both the drive shaft and the driven shaft. CONSTITUTION:A fluid coupling 17 has a drive side member 27 connected to the side of an output shaft 20 and a driven side member 28 which is able to relatively turn to this drive side member 27 further connected to the side of a universal joint shaft 18 serving as the driven shaft. And the fluid coupling 17 fits this drive side member 27 to the first outer spline 24, formed in the drive side member 27, to be connected to the side of the output shaft 20 while connectes this driven side member 28 to the side of the universal joint shaft 18 fitting the second inner spline 30, formed in the driven side member 28, to the second outer spline 26. When the output shaft 20 turns, the drive side member 27 and a drive disc 31 rotate, and the fluid coupling, rotating a driven disc 32 by the viscosity of silicone oil, transmits power to a rear wheel side through the driven side member 28 and the universal joint shaft 18.

Description

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

(Prior Art) When a four-wheel drive vehicle is running, the front and rear wheels are both driven by the engine. Some vehicles are equipped with a viscous multi-plate clutch, which is a fluid coupling that transmits power, and the power is transmitted from the engine to the rear wheels via this fluid coupling.

The automobile with the above configuration exhibits the following functions. That is, during normal driving, power is transmitted from the engine to the front and rear wheels mainly to the front wheels, which are directly connected to the engine. but.

For example, if the front wheel gets stuck in mud or sand and slips and spins, the power from the engine is transmitted to the rear wheel via the fluid coupling, driving the rear wheel. . Then, the rear wheels move on the road surface, allowing the vehicle to escape from the mud or sand.

On the other hand, when testing speedometers or checking exhaust gas during vehicle inspections or assembly lines,
One of the front and rear wheels is grounded on the work surface and left in a static IF, and the other wheel is idled to perform the above tests, etc. At this time, in order to idle the other wheel,
Conventionally, a pair of front and rear idling rollers is provided, and a wheel to be idled is placed between the two rollers.

(Problems to be Solved by the Invention) However, in the case of a four-wheel drive vehicle as described above, there are the following disadvantages.

Firstly, the front wheels get stuck in mud or debris and spin idly.
When the rear wheels are driven as a result of this, if the front wheels are heavily wedged, the driving side member of the fluid coupling that transmits power from the engine to the rear wheels will rotate relative to the driven side member. This results in the inconvenience that it becomes difficult for the vehicle to escape from the mud or the like.

Secondly, when testing the speedometer or checking exhaust gas, if the front wheels of the car are placed on the idle roller and the engine is driven, the front wheels will idle on the idle roller. In this case, the rear wheels are driven, so the idle rollers on which the front wheels are mounted as described above cannot be used alone.
It is not possible to test the speedometer, etc., so,
It is conceivable to provide idle rollers on which the rear wheels can be mounted, but this would increase equipment costs. It is also conceivable to provide a clutch for power connection/disconnection between the engine and the rear wheels in addition to the above-mentioned fluid coupling, thereby making it possible to disconnect the power transmission to the rear wheels. The configuration of the transmission device becomes complicated, which is not preferable.

(Purpose of the Invention) This invention was made in view of the above-mentioned circumstances, and it is designed to make it easier to escape even when a car gets stuck in mud or debris, and to improve speed. For example, when testing a 4-wheel drive vehicle, even if only one of the front and rear wheels is equipped with idle rollers that can idle the wheels.
It is an object of the present invention to enable the above-mentioned test etc. to be performed with a simple configuration using only this idle roller.

(Structure of the Invention) A feature of the present invention for achieving the above object is that a fluid coupling is engaged with a drive shaft on the engine side and a driven shaft on one of the front and rear wheels. In a power transmission system for a four-wheel drive vehicle that connects these two wheels, the fluid coupling is movable only in the axial direction with respect to the drive shaft and the driven wheel, and the sliding of the fluid coupling causes the drive side of the fluid coupling to move freely relative to the drive shaft and the driven wheel. Either one of the member and the driven member engages with both the drive shaft and the driven shaft to connect them,
In addition, the fluid coupling can be released from its attachment to either one of the two shafts by sliding the fluid coupling.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 2, l is a four-wheel drive vehicle, and this vehicle 1 has a drive device 2, and a front wheel device 3 and a rear wheel device 4 driven by the drive device 2. Further, an arrow Fr in the figure indicates the front of the automobile 1.

The drive device 2 includes an engine 6 placed horizontally at the front of the vehicle body.
The same engine 6 is installed in parallel with this engine 6.
and a transmission 7 which is interlocked and connected to.

Further, the front wheel mounting M3 has a pair of left and right front wheels 8.8 and a front axle 9 connected to each of the front wheels 8. A front differential gear (hereinafter referred to as "front differential gear") transmits power to the front wheels 8 via each front axle 9.

This is simply referred to as a front differential (the same applies to the rear differential described later).

On the other hand, the rear wheel device 4 has a pair of left and right rear wheels 12.12, and a rear axle 13 connected to each of the rear wheels 12,
A rear differential 14 is interposed between the rear axles 13 and 13, which inputs the power from the transmission 7 through the ring gear 10a of the front differential 10 and transmits the power to the rear wheels 12 through each rear axle 13. It is.

Furthermore, in the above case, the ring gear 10 of the front differential 10
a and the input shaft 14a of the rear differential 14, a transfer 16, a fluid coupling 17, and a universal joint shaft 18 are interposed in this order from the driving side.

In FIG. 1, the output M20 of the Hokki transfer 16 extends in the front-rear direction and is rotatably supported by the transfer case 21. The rear end of this output shaft 20 is a free end, and a collar 22 is removably fitted onto this rear end by means of a spline, and is screwed 1F by a nut 23. Then, on the outer peripheral surface of this collar 22, a first
An outer spline 24 is formed. On the other hand, universal joint shaft 1
The front end of the universal joint shaft 18 is also rotatably supported by the transfer case 21, and the front end of the universal joint shaft 18 is also a free end, with a second external spline 26 formed on its outer peripheral surface.

The fluid coupling 17 is a viscous multi-plate clutch in the illustrated example,
The fluid coupling 17 is rotatable relative to the drive side member 27 connected to the output shaft 20 side that is a drive shaft, and is rotatable relative to the drive side member 27, and is connected to the universal joint shaft 18 side that is a driven shaft. 0 having a connected driven side member 28;
In this case, the first inner spline 29 formed on the drive side member 27 fits into the first outer spline 24, and the drive side member 27 is connected to the output shaft 20 side.

Further, the second internal spline 3 formed on the driven side member 28
0 fits into the second outer spline 26, and this driven side member 28 is connected to the universal joint shaft 18 side.

Further, a driving disk 31 is externally fitted onto the driving side member 27 so as to be slidable only in the axial direction, and a driven disk 32 is externally fitted onto the driven side member 28 so as to be slidable only in the axial direction. Silicone oil is sealed in the spaces covering both of these disks 31 and 32, which are arranged alternately.

Therefore, when the output shaft 20 rotates, the drive side member 27 and the drive disk 31 rotate accordingly, and at this time,
The viscosity of the silicone oil causes the driven disk 32 to rotate, thereby causing the driven side member 28 and the universal joint shaft 1 to rotate.
Power is transmitted to the rear wheel 12 side via 8.

In the above configuration, the fluid coupling 17 is slidable only in the axial direction at each spline fitting portion with respect to the output shaft 20 and the universal joint shaft 18. Further, a fork 36 is engaged with this fluid coupling 17.

This fork 36 is connected to an operating lever (not shown).

A third outer spline 35 is formed at the front end of the collar 22, and a third inner spline 3 can be freely engaged with and detached from the third outer spline 35 by sliding the fluid coupling 17 forward.
7 is formed at the front end of the driven member 28. On the other hand, at the front end of the universal joint shaft 18, a fourth outer spline 38 having the same shape and size as the second outer spline 26 is formed at a predetermined distance from the second outer spline 26.

Then, when the fluid coupling 17 is moved forward through the fork 36 to the position shown by the two-dot chain line in the figure by operating the operating lever, the first inner spline 29 is fitted into the first outer spline 24. Leave the third outer spline 3
5, the third internal spline 37 is fitted, and at the same time the fourth
The second inner spline 30 is adapted to fit into the outer spline 38. That is, in this case, the driven side member 28
directly connects the output shaft 20 side and the universal joint shaft 18, so that the power of the engine 6 is also directly transmitted to the rear wheels 12, that is, a directly connected four-wheel drive state is obtained.

Further, if the fluid coupling 17 is moved to the position shown by the dashed line in the figure via the fork 36 in the same manner as above, the first inner spline 29 remains fitted to the first outer spline 24, and the The second internal spline 30 is disengaged from the second external spline 26 and the fourth external spline 38. That is, in this case, 1, output shaft 20
Power transmission from the side to the universal joint shaft 18 side is cut off, so that a two-wheel drive state in which only the front wheels 8 can be driven is obtained.

Note that one or more steps are based on the illustrated example, but when cutting off power transmission to the universal joint shaft 18 side, the fluid coupling l7 is moved rearward and the second inner spline 30 is moved relative to the second outer spline 26.
the first outer spline 24 while keeping them fitted.
The fitting of the inner spline 29 may be released.
In addition, when directly connecting the output shaft 20 side and the universal joint shaft 18, the fluid joint 17 is moved backward, and the first outer spline 2
4, the rear part of the first internal spline 29 may be fitted into an external spline formed on the universal joint shaft 18 side.
In the above embodiment, the fluid coupling 17 is interposed between the engine 6 and the rear wheels 12, but the fluid coupling 17 may be interposed between the engine 6 and the front wheels 8.

(Effects of the Invention) According to the present invention, the fluid coupling is made slidable only in the axial direction with respect to the drive shaft and the driven wheel, and the sliding of the fluid coupling causes either the drive side member or the driven side member of the fluid coupling to move freely. Since one member engages with both the drive shaft and the driven shaft to connect them, the front and rear wheels can be directly connected by sliding the fluid coupling to directly connect the drive shaft and the driven shaft. It is possible to obtain a direct four-wheel drive state in which both are directly driven by the engine. Therefore, if the wheels get stuck in mud or crushed water, if the four-wheel drive state is directly coupled as described above, the drive side member and the driven side member of the fluid coupling rotate relative to each other, as in the conventional case. There are no major inconveniences, so it is easy to escape from here.

In addition, in this invention, since the fluid coupling can be released from engagement with either one of the above-mentioned two shafts by sliding the fluid coupling, sliding of the fluid coupling can release the engagement of the fluid coupling with either the drive shaft or the driven shaft. If one of the wheels is disengaged, a two-wheel drive state can be obtained in which power transmission to one of the front and rear wheels is cut off. Therefore, in this state, power transmission can be cut off, one wheel can be kept in contact with the ground, and only the other wheel can be idled on the idle roller. Therefore, even if the vehicle is equipped with only an idling roller on which only one of the front and rear wheels can be placed and idled, speedometer tests and exhaust gas checks can be performed.

In addition, the above-mentioned directly connected four-wheel drive state and two-wheel drive state can be obtained by using an existing fluid coupling, so that configuration is simple and advantageous.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, in which Fig. 1 is a side sectional view of a portion provided with a fluid coupling, and Fig. 2 is an overall view of the automobile. 1.・Automobile, 60. Engine, 80. Front wheel, 12.
- Rear wheel, 17 - fluid coupling, 18 - Φ universal joint shaft (driven shaft), 20 - output shaft (drive shaft), 27 - drive side member, 28 - driven side member.

Claims (1)

[Claims] 1. A fluid coupling is interposed between one of the front and rear wheels driven by the engine and the engine, and this fluid coupling is connected to the drive shaft on the engine side and the driven shaft on the one wheel side. In a power transmission system for a four-wheel drive vehicle that connects both shafts by engaging with each other, the fluid coupling is slidable only in the axial direction with respect to the drive shaft and the driven shaft, and the sliding of the fluid coupling causes Either one of the driving side member and the driven side member of the fluid coupling engages with both the driving shaft and the driven shaft to connect them, and the fluid coupling slides to connect the two shafts. A power transmission device for a four-wheel drive vehicle, characterized in that the engagement of a fluid coupling with either one of the shafts can be released.