JPH03186432A - Rotational speed control mechanism for wheel - Google Patents

Abstract

PURPOSE:To make an output rotational speed of each differential gear controllable so as to improve running and control properties of wheels by providing a continuously variable transmission combined with each differential gear, in the case of an engine whose power is transmitted to the front and rear wheels through the front and rear differential gears. CONSTITUTION:Front and rear propeller shafts 20, 22, serving as an output shaft, are provided in a center differential gear 14 to which output rotation of an engine 12 is input, and rotation of each propeller shaft 20, 22 is input to front and rear differential gears 24, 26. Wheels 16r, 16l are driven by front wheel drive shafts 28r, 28l which are output shaft of the front differential gear 24, and wheels 18r, 18l are driven by rear wheel drive shafts 30r, 30l which are output shafts of the rear differential gear 26. Belt type continuously variable transmissions 40, 50, 60 are respectively combined with respective differential gears 14, 24, 26, and diameters of pulleys 43, 44; 53, 54; 63, 64 in respective continuously variable transmissions 40 to 60 are continuously varied so as to continuously change speed ratio between pulleys 43 and 44, between pulleys 53 and 54 and between pulleys 63 and 64.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a wheel rotational speed control mechanism for independently controlling the rotational speed of the wheels of a four-wheeled motor vehicle.

[Conventional technology]

In order to improve the running performance and maneuverability of a vehicle, it is conceivable to control the torque transmitted from each wheel to the road surface for each wheel. For this reason, in four-wheeled vehicles,
As shown in Figure 4, the drive shaft 1.2 and the axle 31 for the front and rear wheels
．． 3r, 4],, Continuously variable transmission 51.5 between 4r
r, 61.6r, the continuously variable transmission 51.5r,
By changing the speed ratio of 61.6r, wheels 71.7r,
Some control the transmitted torque by changing the rotational speed of 81.8r for each wheel 71.7r and 81°8r. Note that the output rotation of the engine 9 is the propulsion shaft I.
The signal is transmitted to the front wheel opening shaft 1 and the rear wheel opening shaft 2 via O.

[Means to solve the problem]

However, in the conventional rotational speed control mechanism described above,
Each axle 31.3r, 4.1. , 4r and drive shaft 1
．． Since the structure has continuously variable transmissions 5], 5r, and 61.6r interposed between the vehicle and the vehicle, these continuously variable transmissions 51.5r, 6], and 6r constantly transmit torque while driving. This means that For this reason, these continuously variable transmissions 51.5r
, 61, and 6r are required to be highly durable and reliable, which increases costs. In addition, continuously variable transmission 51.5r,
If either axle 61.6r fails, either axle 31°3r or 41.4r will not be driven, making it impossible to drive.

Furthermore, since one continuously variable transmission is required for each wheel 71.7r, 81.8r, at least four continuously variable transmissions 51.5r, 61.6r are required, which increases the vehicle weight. At the same time, installation space must be secured, and costs also increase.

Therefore, the present invention provides a wheel rotational speed control mechanism that minimizes the number of continuously variable transmissions installed and prevents torque from being directly transmitted to the wheels, thereby reducing the load on the continuously variable transmissions as much as possible. is intended to provide.

[Means for Solving the Problems] In order to achieve the above object, the rotation speed control mechanism according to the present invention applies the output rotation of the engine to the front wheels through the center differential and the front differential or rear differential, respectively. In a four-wheel drive vehicle in which transmission is transmitted to the rear wheels, a continuously variable transmission is provided in combination with each of the above-mentioned differentials, and an intermediate portion of the output shaft of each differential is connected to each of the above-mentioned continuously variable transmissions. It is characterized by a combination of a differential and a continuously variable transmission.

[For production]

For example, by changing the speed ratio of a continuously variable transmission installed in combination with a rear differential, it is possible to change the rotational speed of the left and right rear wheels. The transmitted torque is redistributed by the continuously variable transmission. Therefore, the torque transmitted to the road surface can be made larger by the right rear wheel than by the left rear wheel, for example.
Vehicle performance and maneuverability can be improved.

〔Example〕

Hereinafter, the rotational speed control mechanism according to the present invention will be specifically explained based on the preferred embodiment shown in FIGS. 1 to 3. Note that FIGS. 1 and 2 show an embodiment marked with -, and FIG. 3 shows another embodiment.

FIG. 1 is a schematic diagram showing the power transmission system of a four-wheel drive vehicle, in which the output rotation of the engine 12 is controlled by the center differential 14.
is transmitted to. The center differential 14 absorbs the difference in rotational speed between the front wheels 161.16r and the rear wheels 181.18r, and the center differential 14 is provided with a front wheel propulsion shaft 20 and a rear wheel propulsion shaft 22 as output shafts. . The front wheel propulsion shaft 20 is an input shaft of a front differential 24, and the rear wheel propulsion shaft 22 is an input shaft of a rear differential 26. The front wheel drive shaft 2 is the output shaft of the front differential 24.
81.28r drives the front wheels 161.16r, and the rear wheel drive shaft 301.30r, which is the output shaft of the rear differential 26, drives the rear wheels 181.18r.

A belt-type continuously variable transmission 40 is combined with the center differential 14. A drive gear 20a is provided on the front wheel propulsion shaft 20, which is the output shaft of the center differential 14, and a drive gear 22a is provided on the rear wheel propulsion shaft 22, and these drive gears 20a and 22a rotate driven gears 41 and 42 that mesh with them. Then, the pulleys 43 and 44 of the continuously variable transmission 40 are rotated. These pulleys 4
At 3.44, a belt 45 is attached. By continuously changing the diameters of the pulleys 43, 44, the speed ratio between these pulleys 43, 44 can be continuously changed.

Furthermore, a belt-type continuously variable transmission 50 is combined with the front differential 24.

The front wheel drive shaft 281.28r has drive gears 28a, 28
b is provided, and the pulleys 53 and 54 are rotated by driven gears 51 and 52 that mesh with the drive gears 28a and 28b,
A belt 55 is passed between the pulleys 53 and 54. Then, the diameters of the pulleys 53, 54 are continuously changed to continuously change the speed ratio between the pulleys 53, 54.

Furthermore, a belt-type continuously variable transmission 60 is combined with the rear differential 26.

Drive gears 30a, 30b are attached to the rear wheel drive shaft 301.3Or.
are provided, and pulleys 63 and 64 are rotated by driven gears 61 and 62 in mesh with the driving gears 30a and 30b, and a belt 65 is passed between the pulleys 63 and 64.

Then, the diameters of the pulleys 63 and 64 are continuously changed to continuously change the speed ratio between the pulleys 63 and 64.

The operation of the rotational speed control mechanism shown in FIGS. 1 and 2 will be explained below.

Figure 2 shows the opening system of the rear @181.18r.
The rotation speed of the rear wheel 181 is N, and the rotation speed of the rear wheel 18r is N.
If the rotation speed of the pulley 63 is NIV and the rotation speed of the pulley 64 is Nr9, then N, /N, = Nl, /N- (1) Therefore, the continuously variable transmission 60 By changing the speed ratio of the left and right rear wheels 18] and +8r, the rotational speeds of the left and right rear wheels 18] and +8r can be changed. Note that the difference in rotational speed of the rear wheels 181.18r is absorbed by the rear differential 26.

Also, the torque T transmitted from the rear wheel propulsion shaft 22.

is equally distributed by the rear differential 26, so each
Herc T01, To, is T,,=T,,=T/2 ・・・・・・・・・(2
). However, since the continuously variable transmission 60 causes a difference in the rotational speed of the left and right rear wheels 181.18r, torque is transmitted between the pulleys 63.64, and the magnitude of the transmitted torque is as shown in FIG. If expressed as T, including the direction, the torques T1 and T4 transmitted to the left and right rear tla181.18r are: T,=T,/2-TV -=...=-(3)T,=
T, /2+TV ・-------・-(4), and the torque T transmitted to the left and right rear @181.18r,,
It is possible to make a difference in T.

Therefore, it is possible to vary the amount of 1-lux to be transmitted from the left and right rear wheels 18] and 18r to the road surface, thereby improving the running performance of the vehicle and stabilizing the maneuverability.

Note that the front wheel propulsion shaft 20 and the rear wheel propulsion shaft 22 are the output shafts of the center differential 14, and the front wheel drive shaft 281 is the output shaft of the front differential 24.
The same applies to 28r.

Another embodiment is shown in FIG. 3, which is a diagram showing a rear wheel opening system corresponding to FIG. 2. In this embodiment, clutches 66, 67 are interposed between the driven gear 61 and the pulley 63, and between the driven gear 62 and the pulley 64, and by engaging and connecting the clutches 66, 67, the The transmission 60 can be switched between operation and non-operation. That is, if the clutches 66, 67 are connected, the continuously variable transmission 60 functions, and the same effect as in the embodiment shown in FIG. For example, a rear wheel opening system without the continuously variable transmission 60 may be used. Note that clutches 66 and 67 are provided between the driven gear 6I and the pulley 63 and between the driven gear 62 and the pulley 64, respectively. and the pulley 64.

When the vehicle normally runs straight, the clutch 66,
If 67 is disconnected, the rear differential 26 will evenly distribute one transmission herk to the rear wheels 181.18r, allowing stable driving. Also, for example, a continuously variable transmission 6
If the clutch 66, 67 is disconnected and the clutches 66, 67 are disconnected, the vehicle will not be unable to run if the failure causes a problem in running the vehicle.

Note that the continuously variable transmission 4o combined with the center differential 14 and the continuously variable transmission 50 combined with the front differential 24 may each be provided with a clutch.

Although this embodiment uses a belt type continuously variable transmission 40, 50, 60, it is not limited to a belt type as long as it is a continuously variable transmission.

〔Effect of the invention〕

As explained above, according to the rotational speed control mechanism according to the present invention, the torque generated by each wheel can be controlled by controlling the output rotational speed from the differential, thereby improving the running performance and maneuverability of the vehicle. can be done.

Moreover, the opening torque is not directly transmitted to the wheels by the continuously variable transmission, but only the difference in torque between the left and right wheels is transmitted, so there is less burden on the continuously variable transmission, it is inexpensive, and has a long lifespan. It can provide a long rotation speed control mechanism. Furthermore, since the opening torque is not directly transmitted, even if the continuously variable transmission fails, the vehicle will not be unable to run.

Furthermore, since it is sufficient to provide a number of continuously variable transmissions corresponding to the number of differentials, it is possible to reduce the number of continuously variable transmissions and reduce costs.

[Brief explanation of drawings]

The drawings show a preferred embodiment of the rotational speed control mechanism according to the present invention. Figures 1 and 2 show an example of -, where Figure ■ is a schematic diagram showing the power transmission system of a four-wheeled traction vehicle, and Figure 2 is a diagram showing the rear wheel drive system in Figure 1. It is. FIG. 3 shows another embodiment, and is a diagram showing a rear wheel drive system corresponding to FIG. 2. FIG. 4 is a schematic diagram showing a power transmission system of a vehicle equipped with a conventional rotational speed control mechanism, and corresponds to FIG. 1. 12... Engine 14... Center differential 161.16r
-Front @ 181,18r-Rear wheel 20...Front wheel propulsion shaft 22...Rear wheel propulsion shaft 24...Front differential 26...Rear differential 2g1,28r...Front @ Egg drive shaft 301,3Or・・・
・Rear wheel opening shaft 40...Continuously variable transmission 43.44...Pulley 45...Belt 5
0...Continuously variable transmission 53.54...Pulley 55...Belt 6
0...Continuously variable transmission 63.64...Pulley 65...Belt diagram diagram diagram diagram diagram diagram

Claims (1)

[Claims] In a four-wheel drive vehicle in which engine output rotation is transmitted to front wheels and rear wheels via a center differential and a front differential or a rear differential, respectively. A continuously variable transmission is provided in combination with each of the differentials, and the intermediate portions of the output shafts of the respective differentials are connected to each of the continuously variable transmissions. A wheel rotation speed control mechanism characterized by being combined with a continuously variable transmission.