JPS6317119A - Four wheel drive vehicle - Google Patents

Abstract

PURPOSE:To simplify the structure of a transfer to aim at making the same compact, by providing means for changing over the drive mode among various operation modes such as two wheel drive mode, a four wheel drive mode and the like, on the downstream side of a transmission path coaxial with a planetary gear constituting a center differential gear. CONSTITUTION:A counter gear 3 and a center differential gear 4 in a four wheel drive mechanism connected to the output side of the counter gear 3 are disposed in the casing 2 of a transfer 1. Further, a pinion carrier 23, an output shaft 24 for the gear 4 and an output sprocket 25 are formed therein with splines 26 through 28, respectively. Further, a slider 29 is slidably disposed on these splines 26 through 28 which are therefore selectively engageable with each other so that a change-over means 40 for running drive modes is constituted. Thereby, the operational mode is changed over among a direct coupled four wheel drive mode due to stopping of differential motion of the gear 4, a four wheel drive mode in which the differential motion of the gear 4 is free, and a two wheel mode.

Description

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

(Prior Art) As a four-wheel drive vehicle, a full-time four-wheel drive vehicle is known in which a center differential gear is provided between a front wheel drive system and a rear wheel drive system. As a four-wheel drive vehicle, the front
Part-time four-wheel drive vehicles are known that have two-wheel drive using one of the rear wheels and perform four-wheel drive driving when necessary. Furthermore, it has both the above-mentioned full-time 4-wheel drive and part-time 4-wheel drive functions, and has a direct 4-wheel drive mode in which the center differential gear stops differentially, and a 4-wheel drive mode in which the center differential gear is differentially free. There are also known four-wheel drive vehicles that can run in either a two-wheel drive mode or a two-wheel drive mode that transmits power to only one of the front and rear wheels.
It is stated in the publication number etc.

(Problems to be Solved by the Invention) However, in the four-wheel drive vehicle described in the above-mentioned Japanese Patent Laid-Open Publication No. 59-81233, there are two modes: a direct four-wheel drive mode with differential stop of the center differential gear; a first switching means for switching a center differential gear to a differential-free four-wheel drive mode; and a four-wheel drive;
A second switching means for switching between two-wheel drive and transmitting power to only one of the front and rear wheels is provided completely separately, resulting in a complex structure and large size. Ta.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a four-wheel drive vehicle having a simple structure and a compact transfer.

(Means for Solving the Problems) The four-wheel drive vehicle of the present invention includes a center differential gear constituted by a planetary gear in a transfer case that distributes torque between front and rear wheels, and a center differential gear that is coaxial with the planetary gear. On the downstream side of the transmission path, there are a direct four-wheel drive mode in which the center differential gear stops differentially, a four-wheel drive mode in which the center differential gear is differentially free, and a mode in which power is applied to only one of the front and rear wheels. The present invention is characterized in that it is provided with a switching means for switching between two-wheel drive modes to be transmitted.

(Operations and Effects of the Invention) In the four-wheel drive vehicle of the present invention, the means for switching between two-wheel drive and four-wheel drive and the means for switching between locking and unlocking the center differential gear are the same means. The structure of the switching means can be made compact, and the size of the transfer case can be reduced.

(Embodiments) Hereinafter, a four-wheel drive vehicle according to a preferred embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a sectional view of a transfer 1 used in a four-wheel drive vehicle according to an embodiment of the present invention.

The transfer 1 has a transfer case 2. Inside the transfer case 2, there is a sub-transmission 3 connected to the output side of a main transmission (not shown), and a sub-transmission 3 connected to the output side of the sub-transmission 3. A center differential gear 4 of a connected four-wheel drive mechanism is provided.

The sub-transmission 3 includes an input shaft 5a and an output shaft 5b disposed coaxially therewith. A first gear 6 is integrally provided at the rear end of the input shaft 5a of the auxiliary transmission 3.
A second gear 7 attached to the front part of a countershaft 6 arranged parallel to the second gear 7 meshes with the second gear 7. A third gear 8 is provided at the rear of the countershaft 5C. This third gear 8 meshes with a fourth gear 9 rotatably attached to the substantially central portion of the output shaft 5b. Note that the second gear 7 and the fourth gear 9 are set to have a larger number of teeth than the first gear 6 and the third gear 8, respectively.

First, second, and third splines 10, 11, and 12 arranged on the same cylindrical surface are formed on the human power shaft 5as output shaft 5b and the fourth gear 9. The first of these
, a slider 13 is movable on the second and third splines 10.1112 for selectively coupling the first and second splines to, 11 or the second and third splines 11.12. It is provided.

With the above structure, in the sub-transmission 3, the first and second
When the splines 10S and 11 are connected, the input shaft 4 and the output shaft 5 are directly connected, and when the first spline 2 and the third spline 11.12 are connected, rotation is transmitted through the gear train, thus Perform deceleration.

The center differential gear 4 is connected to the output shaft 5b.
It is equipped with a ring gear 20 fixed to the rear end. This ring gear 20 acts as an input gear for the center differential gear 4.

The center differential gear 4 further includes a sun gear 21 concentric with the ring gear 20, a plurality of pairs of pinions 22 that mesh with each other, the ring gear 20, and the sun gear 21, and a pinion carrier 23 that supports these pinions 22. There is.

The sun gear 21 includes the human power shaft 5a and the output shaft 5b.
It is formed integrally with the output shaft 24 on the rear wheel side, which is arranged coaxially with the rear wheel side. On this output shaft 24, the pinion carrier 23 is supported by its cylindrical portion. An output block 25 for transmitting power to the front wheels is rotatably supported on the outer peripheral surface of the cylindrical portion of the pinion carrier 23.

The output shaft 24, pinion carrier 23, and output sprocket 25 are formed with fourth, fifth, and sixth splines 26, 27, and 28 arranged on the same cylindrical surface. These fourth, fifth and sixth splines 26
．． 27. On 28 are the fourth and fifth splines 26 and 2.
7, a second slider 29 that selectively connects the fifth and sixth splines 27 and 28 or all the splines, i.e. the fourth, fifth and sixth splines 26, 27, 28;
is movable. This second slider 29 and the fourth, fifth and sixth splines 26, 27, 28
This constitutes a traveling drive mode switching means 40.

A chain 32 is connected between the output sprocket 25 and the manpower shaft 31 fixed to the manpower shaft 30 of the front wheel 0.
The stake has been passed.

FIG. 2 shows the skeleton of the transfer structure described above.

(Function) Next, the function of the transfer explained above will be explained.

First, to explain the sub-transmission 3, when the first and second splines 10.11 are connected by the slider 13 as described above, the input shaft 4 and the output shaft 5 are directly connected, and the output is output in a high speed rotation state. , one measure 2 and the third spline 11
．． When 12 is connected, rotation is transmitted through the gear train, decelerated, and output in a low speed rotation state.

Next, we will explain the operation mode of the center differential gear 4 and the switching between two-wheel drive and four-wheel drive.
These switching operations are performed by the switching means 40 described above.

First, the differential free 4 of center differential gear 4
For wheel drive mode, 5th and 6th splines 2
7.28 may be joined by the second slider 29.

Next, in order to create a four-wheel drive mode in which the center differential gear 4 is in a differential stop state, that is, a four-wheel drive mode in which the four wheels are directly connected, all the splines, that is, the fourth and fifth and sixth spline 26.27.
28 may be joined.

Finally, to set the rear wheel drive to four-wheel drive mode, the fourth
and the fifth splines 26 and 27 may be joined by the second slider 29.

Switching between the state of the sub-transmission 3 and the two-wheel drive and four-wheel drive states is performed by operating a motor (not shown) provided for each using a manual button located in the driver's seat of the automobile. However, in view of structural strength, it is desirable to set the system so that the two-wheel drive mode and the low-speed rotation mode of the sub-transmission 3 cannot be combined.

(Example of modification) The structure and configuration of the center differential gear section can be modified in various ways other than those described above, some of which are described below. In the following explanation, elements having the same functions as the elements and members shown in FIGS. 1 and 2 will be used.
Components shall be given the same reference numerals regardless of their arrangement or position.

First Modification Example First, the first modification example will be explained with reference to FIG.
, a center differential gear 4 is arranged. Further, in this modification, the pinion carrier 23 serves as an input means, and the ring gear 20 serves as a rear wheel side output gear. The fourth, fifth, and sixth splines 26, 27, and 28 of the switching means 40 are connected to the sun gear 21 and the output shaft 2.
4 and the pinion carrier 23 respectively.

Second Modified Example The structure and composition of this modified example are as shown in FIG. 4, and the sixth spline 28 is the same as that of the first modified example shown in FIG. It's the same.

Third Modified Example The structure and composition of this modified example are similar to those of the first modified example shown in FIG. This is the same as the modified example.

Fourth Modified Example The structure and composition of this modified example are the 6th T5! This is the same as the second modification shown in FIG. 4, except that the switching means 40 is constituted by two clutches 50, 51, as shown in FIG.

Fifth Modification Example In this fifth modification example, as shown in FIG. It is arranged between.

Sixth Modification Example In this sixth modification example, as shown in FIG. The output shafts 24, 30 of are arranged coaxially. Further, the sprocket 31 is fixed to a pinion carrier 23, so the pinion carrier 23 serves as an input means for the center differential gear 4, and the ring gear 20 serves as an output gear.

Seventh Modified Example This modified example is, as shown in FIG. 9, in the sixth modified example shown in FIG.
0.51.

8th Modified Example This modified example, as shown in FIG. 10, is a modification of the seventh modified example shown in FIG. 9, in which the center differential gear 4 is locked by fixing the ring gear 20. be.

Ninth Modified Example In this modified example, as shown in FIG. 11, the two clutches 50 and 51 of the seventh modified example shown in FIG. 9 are arranged separately.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the structure of a transfer for a four-wheel drive vehicle according to an embodiment of the present invention, FIG. 2 is a schematic diagram showing the structure of a transfer for the four-wheel drive vehicle, and FIG. FIG. 4 is a schematic diagram showing the structure of a second modified example of the transfer of the four-wheel drive vehicle; FIG. 5 is a schematic diagram showing the structure of a second modified example of the transfer of the four-wheel drive vehicle; FIG. FIG. 6 is a schematic diagram showing the structure of a fourth modified example of the transfer of the four-wheel drive vehicle; FIG. 7 is a schematic diagram showing the structure of a fourth modified example of the transfer of the four-wheel drive vehicle. A schematic diagram showing the structure of a fifth modification of the transfer; FIG. 8 is a schematic diagram showing the structure of a sixth modification of the transfer of the four-wheel drive vehicle; FIG. 9 is a schematic diagram showing the structure of a sixth modification of the transfer of the four-wheel drive vehicle. FIG. 10 is a schematic diagram showing the structure of the eighth modification of the transfer of the four-wheel drive vehicle; FIG. 11 is a schematic diagram showing the structure of the eighth modification of the transfer of the four-wheel drive vehicle; FIG. It is a schematic diagram showing the structure of a modification example. 1 Transfer, 2- Transfer case, 4 Center differential gear, 20- Ring gear, 21 Sun gear, 22 Pinion, 23 Pinion carrier, 25- Output sprocket, 26.27.28-- Spline, 29 Second slider, 40 Switching means. Figure 3 Figure 4 Figure 5 Figure 6 Figure 7vIJ Figure 8 Figure 9 Figure 0

Claims (1)

[Claims] A center differential gear composed of a planetary gear is provided in the transfer case that distributes torque to the front and rear wheels, and a four-wheel direct-coupling system is provided on the downstream side of the power transmission path on the same axis as the planetary gear by differential stop of the center differential gear. The vehicle is characterized by being provided with a switching means for switching between a drive mode, a four-wheel drive mode in which the center differential gear is differentially free, and a two-wheel drive mode in which power is transmitted only to one of the front and rear wheels. A four-wheel drive vehicle.