JPS58209624A - Power transmission device for four-wheel vehicle - Google Patents

Abstract

PURPOSE:To reduce a noise, improve fuel consumption and prevent wear in a transmission system by a method wherein the transmission system is constructed such that during running with two-wheel driving operation, a power transmission system for driven wheels on the engine side is inhibited from rotation, rather the final deceleration gear for said driven wheels may be so inhibited. CONSTITUTION:Changing-over between two-wheel driving operation and four- wheel driving operation is performed in four-wheel driving vehicle by operating a sub-clutch 11 arranged between a pinion shaft 9 and a rear driving shaft 12. In case of running under four-wheel driving operation, the power of an engine 1 is transmitted to the right and left front wheels FR and FL through a transmission gear 2 and a final reduction gear 5 for front wheels, and to the right and left rear wheels RR and RL through a sub-clutch 11, said shaft 12, pinion 16 and a final reduction gear 19 for rear wheels. In this case, said reduction gear 19 is integrally formed with a free wheel housing 20 for storing a pair of free wheels 22 and 24 for transmitting a rotation in only one direction, and then the right and left rear wheels 23 and 21 are connected to each of the free wheels 24 and 22.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention defines, for example, the front wheels as the main drive wheels and the rear wheels as the sub-drive wheels, and selectively switches between two-wheel drive driving using only the front wheels and four-wheel drive driving using the front wheels and rear wheels. The present invention relates to a power transmission device for a four-wheel drive vehicle.

In this type of four-wheel drive vehicle, for example, switching between driving the rear wheels as subordinate drive wheels (four-wheel drive driving) and stopping the drive (two-wheel drive driving) is performed at the rear.

Utilizing the disconnection of a clutch installed in the power transmission path for the wheels 1. It would be common to do 1 or 1. Therefore, in conventional four-wheel drive vehicles, when running in two-wheel drive using only the main drive wheel and one front wheel, the rear wheel drive system after the clutch, that is, the propeller shaft, the final reduction gear , the rear wheel differential mechanism was rotated unnecessarily,
This was a major cause of increased noise, worsened fuel efficiency, and accelerated wear.

Conventionally, a gear-type differential mechanism was used for the rear wheels, but this gear-type differential mechanism generates quite a lot of noise. Moreover, it had to be a large and heavy book.

The present invention solves the above-mentioned problems, so the clutch is installed closer to the engine than the propeller shaft that transmits power to the driven wheels, and the differential mechanism for the driven wheels is mounted on the 7-lead wheel. By using the characteristic of the directionality of rotation transmission of the seven wheels, when driving in two-wheel drive, the power transmission path for the driven wheels is set closer to the engine than the final reduction gear for the driven wheels. 1- so that it is not rotated
It is characterized by:

The present invention will be described below in detail with reference to drawings showing an embodiment in which the front wheels are defined as the main drive wheels and the rear wheels are defined as the subordinate drive wheels.

In Figure 1, l is the engine, 2 is the main clutch 3
The drive gear 4 of the transmission 2 is connected to the engine IK via the front wheel final reduction gear 5.
1, so that the left and right front wheels FL and PR are driven.Of course, there are appropriate gears between the front wheel final reduction gear 5 and the left and right front wheels PL and axle 6.7 of the PR. A type of differential mechanism is provided at the front end of the pinion shaft 9 for the gear 8 integrated with the final reduction gear 5 for the front wheels, which is not shown since it is not the gist of the present invention. The pinion IO is engaged and the rear end of the pinion shaft 9 is connected to the rear end of the pinion shaft 9 via a clutch (Dog Clara f) 11 which is manually operated to switch between two-wheel drive and four-wheel drive. and is connected to the rear drive shaft 12. Rear drive shaft 12
teeth.

Through the universal joint 13 1. The propeller shaft 14 is connected to a rear pinion shaft 16 via a universal joint 15, and a pinion 17 provided at the rear end of the pinion shaft 16.
is located inside the rear axle housing 18.

It meshes with the final reduction gear 19 for rear wheels. The final reduction gear 19 for the rear wheels is integrated with a seven-wheel wheel nozzle 20VC rotatably held within the axle nozzle 18. Part 1. Therefore, this freewheel housing 20 is connected to the left axle 21 via the first freewheel 22. 1. is connected to the right rear wheel R general axle 23. iiJ, which is connected via the second free point 24. As shown in FIG. 2, the second freewheel 22.24 includes an inner ring 25, an outer ring 26 having a plurality of recesses 26a that provide a wedge effect on the inner circumferential surface, and a member that is displaceable within the recesses 26a. j-
A plurality of rollers 27 are arranged between the two wheels 25 and 26, and the rollers 27 are held 1. An inner ring 25 having a cage 28 etc.
The outer ring 26 is integrated with the axle 21 or 23 by spline fitting, for example, and the outer ring 26 is attached to the freewheel housing 20 so as to rotate together with the freewheel housing 20. Outer ring 25
However, when the roller 27 rotates clockwise (in the direction of the arrow) in FIG. 2, for example, the roller 27 moves toward one end in the circumferential direction of the recess 26a due to sliding resistance and gets wedged between the two wheels 25 and 26.
The rotation of the outer ring 26 is transmitted to the inner ring 25 by the wedge action. The outer ring 26 rotates counterclockwise in FIG. 2.1. When this occurs, the roller 27 moves toward the other end in the circumferential direction of the recess 26a.

Similarly, the rotation of the outer ring 26 is transmitted to the inner ring 25 by the wedge action. However, even if the inner ring 25 rotates clockwise or counterclockwise in FIG.

Since the rollers 27 are located at the intermediate portion in the circumferential direction of the recessed portion 26a, no wedge action is exerted, and the rotation of the inner ring 25 is not transmitted to the outer ring 2G. Furthermore, the structure and operation of the freewheel itself have been known to be good (as it is known,
Further detailed explanation will be omitted.

Next, the operation of the above configuration will be explained separately for two-wheel drive driving and four-wheel drive driving.

・In the case of two-wheel drive driving, the sub-clutch 11 is disengaged, and only the front wheels PL and F are driven, while the rear wheels PL and F are rotated freely following the running speed of the vehicle and the driving force is Not given. At this time, i ring ■1. Method 1. The i'fl rotation is the first.
Since the transmission is only to the second freewheel 22.24 (-t detail 1.< is the inner ring 25 of the first and second freewheel 21), Each component forming the power transmission line 1
6,14.12 is not rotated in any way and remains stationary/
'1. .

・When driving in four-wheel drive, sub-clutch 11 is connected! Tadashi, front wheel FL,
FR(r) and others, (f;-@1(lL, R1 thighs are shaking).

At this time, when driving straight, the left and right rear wheels RL.

Rn are rotated at the same rotational speed, but when turning, the first. Due to the differential operation of the 27th Lee wheel 22.24,
An appropriate rotational speed difference is given between the rear wheels kLL and Rn. Namely.

Turn right in Figure 1. In this case, the left rear wheel must rotate at a higher rotation speed than the right rear wheel.
The inner ring 25 of the inner ring 25 can rotate freely and faster than the outer ring 26. Of course, in the case of a left turn, the second freewheel 24 will provide the same differential action as in the case of a right turn.
Only one of R gets stuck in mud etc. and slips 1. However, the driving force is necessarily transmitted to the other rear wheel,
The differential operation by the freewheels 22 and 24 of both cars, which have a so-called non-slip differential function, has been explained in detail, for example, in Japanese Patent Publication No. 15245/1982, so a more detailed explanation will be omitted. Explanation about the implementation row 1-1 Unexploded IJIj is not limited to this.1 For example, it can be applied in the same way even if the rear wheels are the main drive wheels and 1-1 the front wheels are the sub-drive wheels. Maybe again. In the one shown in Figure 1, the difference IJ for the front wheels
It is also possible to use a freewheel 22, 24 as the jh mechanism. In addition, the length book clutch l
By adding a synchro mechanism that is normally used, it is possible to shift from two-wheel drive to four-wheel drive without any shock even while driving.

As is clear from the above description, the present invention prevents the power transmission system for the driven wheels from being rotated unnecessarily when two wheels are running, thereby reducing noise, improving fuel efficiency, and reducing wear and tear. Preferable 1. In addition, since a pair of freewheels can be used for the differential mechanism for the driven wheels, the structure is simpler and smaller than when using a gear-type differential mechanism. , weight reduction can be achieved, and less noise is generated. Furthermore, the differential mechanism that uses a pair of freewheels also has a non-slip differential function, which is extremely advantageous for this type of vehicle, which often runs on slippery surfaces such as snowy roads and muddy roads. .

[Brief explanation of drawings]

Figure 1 is a simplified overall system diagram showing the practical application of the present invention, and Figure 2 is a diagram showing an example of a freewheel. , 几1 also ... rear wheel (following front wheel j11...
Clutch 19... (for slave drive wheels) Final reduction gear 21, 23...
・(For slave drive wheel) Axle 22.24...Freewheel

Claims (1)

[Scope of Claims] (II. One of the front wheels and the rear wheels is defined as the main drive wheel, and the other is defined as the slave drive wheel to which power is transmitted via the propeller shaft, and only the main drive wheel is operated by clutch operation. 1. In a four-wheel drive vehicle capable of selectively switching between two-wheel drive driving and four-wheel drive driving using the main drive wheels and secondary JIE!wJ wheels.The clutch is installed closer to the engine than the propeller shaft, and the clutch is installed closer to the engine than the propeller shaft, The final reduction gear for the slave drive wheel and the axle for the right slave drive wheel, and the final reduction gear and the axle for the left slave drive wheel are connected through 7 Lee wheels, respectively. 1-1 The two freewheels connect the A four-wheel drive vehicle characterized by transmitting rotation from the final reduction gear to left and right driven wheels, but not transmitting rotation from the left and right driven wheels to the final reduction gear. Power transmission device