JPH0318063B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a four-wheel drive vehicle that can be switched to two-wheel drive using a transfer device, and particularly relates to a four-wheel drive vehicle that is equipped with a drive shaft disconnection mechanism in such a four-wheel drive vehicle. Regarding four-wheel drive vehicles.

[Conventional technology]

As a type of four-wheel drive vehicle, a pair of drive shafts are installed on both side gears of a differential, which is the non-drive side during two-wheel drive, with an inner shaft on the inner end and an outer shaft on the outer end. The inner shaft and the outer shaft are separated and connected at their end portions so as to be relatively rotatable, and each coupling member is assembled to the connecting portion between the inner shaft and the outer shaft so as to be movable in the axial direction. There is a four-wheel drive vehicle in which the connection between both inner shafts and an outer shaft is selectively disconnected.

In this type of 4-wheel drive vehicle, by cutting off the power transmission between the non-drive wheel and the drive shaft during two-wheel drive, the noise generated from the non-drive system is reduced, and the rotational resistance of the non-drive system is reduced. This aims to improve fuel efficiency and reduce wear.

In addition, in such four-wheel drive vehicles, the drive shaft disconnection mechanism is connected to the differential gear in the differential carrier, as shown in the specifications and drawings of U.S. Pat. It is placed on one side of the dial.

[Problem that the invention seeks to solve]

By the way, in conventional four-wheel drive vehicles of this type, the differential does not have a function to limit the differential, so the running performance during four-wheel drive running tends to be slightly inferior. For this reason, it is desirable that the differential has a function of limiting the differential only when the vehicle is in four-wheel drive.

Further, since the disconnection mechanism of the four-wheel drive vehicle is large, the differential carrier itself becomes large, and when a differential limiting mechanism is disposed within the differential carrier, the differential carrier must be made even larger.

[Means for solving problems]

In order to deal with this, the present invention provides a four-wheel drive vehicle of this type, in which the coupling members are connected to each other by a connecting rod that concentrically and movably passes through both the inner shafts, and the differential A differential limiting mechanism is provided between the input and output sides of the case.

[Action/effect of the invention]

As a result, in the present invention, the differential during four-wheel drive of the differential that is on the non-drive side during two-wheel drive is restricted without impairing the operation of the drive shaft disconnection mechanism and the effects brought about by the mechanism. can do. Therefore, according to the present invention, the noise generated from the non-drive system during two-wheel drive can be reduced, and the rotational resistance of the non-drive system can be reduced to improve fuel efficiency and reduce wear. It is possible to improve running performance during four-wheel drive.

Further, according to the present invention, since both coupling members are connected to each other by a connecting rod that passes through both inner shafts, a connecting member that connects both coupling members is newly disposed on the outer circumferential side of both drive shafts. In this respect, there is no need to increase the size of the differential carrier, and even if a differential limiting mechanism is newly installed, there is no need to increase the size of the differential carrier.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 schematically shows a four-wheel drive vehicle according to a first embodiment of the present invention. This 4-wheel drive vehicle is a 4-wheel drive vehicle based on a front engine/front drive system (FF vehicle), and in this vehicle, both front and rear The axle shaft 13 can be driven at all times, and power transmission to the propeller shaft 14 can be switched on and off using a transfer switching mechanism. Therefore, in this vehicle, both rear axle shafts 15 are on the non-drive side during two-wheel drive, and both rear axle shafts 15 are connected to the propeller shaft 14 via a differential 20 integrated with a final gear. .

As shown in FIG. 2, the differential 20 houses a differential gear unit including a ring gear 22 constituting a final gear unit in a differential carrier 21 that is integrated with the extension tube 16. The ring gear 22 is integrally supported by a differential case 23, and the differential case 23 is rotatably supported by the differential carrier 21. This ring gear 22 is constantly meshed with a drive pinion 24 connected to the propeller shaft 14. The differential gear unit also includes two sets of pinion gears 26 assembled to the differential case 23 via a pinion shaft 25, and a pair of side gears 27 that are rotatably supported by the differential case 23 and always mesh with the pinion gears 26. Each of these side gears 2
Drive shafts 28 and 29 forming part of each rear axle shaft 15 are spline-fitted into the drive shafts 7 . These drive shafts 28,2
9, the illustrated right drive shaft 28 is a long one, which penetrates the differential carrier 21 in a liquid-tight and rotatable manner, protrudes from the extension tube 16, and has a rear axle shaft 15 at its outer end.
A main shaft 15a constituting the main shaft 15a is connected to the main shaft 15a. The illustrated left drive shaft 29 is shorter than the right drive shaft 28, projects through the differential carrier 21 in a fluid-tight and rotatable manner, and has a rear axle shaft 15 at its outer end.
A main shaft 15b constituting the main shaft 15b is connected to the main shaft 15b.

The right drive shaft 28 is divided into an inner shaft 28a at the inner end and an outer shaft 28b at the outer end.
The shafts 28a, 28b are connected at their ends so that they can rotate relative to each other, and the disconnection mechanism 30 connects both shafts 28a, 28.
The bond of b is interrupted. The left drive shaft 29 is divided into an inner shaft 29a on the inner end side and an outer shaft 29b on the outer end side, and the disconnection mechanism 30 connects both shafts 29a,
The connection of 29b is interrupted.

The disconnection mechanism 30 includes a coupling sleeve 31 that is a first coupling member, a coupling rod 32 that also serves as an inner shaft 29a that is a second coupling member, an operating rod 33, and an operating lever 3.
4. The main components are both compression springs 35, 36, which are first and second spring members, and a connecting rod 37.

The coupling sleeve 31 is attached to both shafts 28.
External spline 28 provided on the outer periphery of the ends of a and 28b
The outer spline 28 of the inner shaft 28a is provided with an inner spline 31a that meshes with a1 and 28b1.
It is assembled so that it can mesh with a1 and move in the axial direction. This coupling sleeve 31 connects and disconnects the outer shaft 28b to the inner shaft 28a by moving in the axial direction, and is operated by an operating lever 34 assembled on an operating rod 33.

The coupling rod 32 also serves as the inner shaft 29a of the left drive shaft 29, and is attached to the side gear 27 so as to be slidable only in the axial direction, and rotatably fitted to the outer shaft 29b. . The outer end of the coupling rod 32 is provided with an outer spline 32a that engages with and disengages from an inner spline 29b1 provided on the outer shaft 29b, and when the coupling rod 32 slides in the axial direction, both shafts 29a,
29b, that is, the connection between the outer shaft 29b and the side gear 27 is disconnected. The coupling rod 32 is connected to the coupling sleeve 31 via a connecting rod 37, which will be described later.

The actuating rod 33 is attached to one side of the output end of the differential carrier 21 so as to be movable in the axial direction in parallel with the drive shaft 28, and the inner wire 41 of the push-pull cable is connected to one end of the actuating rod 33. There is. This actuating rod 33 is reciprocated by the operation of a push-pull cable, and is intermittently reciprocated by a predetermined amount by the action of the detent mechanism 42. The operating lever 34 is attached to the outer periphery of the operating rod 33 at a cylindrical base 34a so as to be movable by a predetermined amount in the axial direction.
is constantly engaged. A compression spring 35 is interposed between the outer periphery of the actuating rod 33 and the cylindrical base 34a of the operating lever 34. This compression spring 35 is always compressed in the moving direction when the actuating rod 33 moves, and its reaction force urges the operating lever 34 in the moving direction of the actuating rod 33.

The connecting rod 37 is connected to the inner shafts 28a, 29
A is fitted concentrically and slidably in the axial direction, and a cross rod 37a is implanted at its right outer end. The cross rod 37a is a pair of slit holes 2 provided in the inner shaft 28a in the radial direction.
It protrudes from 8a2 and is connected to the coupling sleeve 31. The left outer end of the connecting rod 37 is connected to the outer end of the coupling rod 32 via a compression spring 36. This compression spring 36 is always compressed in the direction of movement of the connecting rod 37, and its reaction force urges the coupling rod 32 in the direction of movement of the connecting rod 37. Incidentally, reference numeral 43 is a switch that is activated when the actuating rod 33 is moved to indicate that the two drive shafts 28 and 29 are connected.

Therefore, differential limiting mechanisms 50A and 50B are provided within the differential case 23 of the differential 20. The differential limiting mechanisms 50A, 50B are composed of a large number of friction plates 51a, 51b and friction disks 52a, 52b, and each friction plate 51a, 51b is attached to a shaft on the inner periphery of the differential case 23 at the outer periphery of the cylindrical portion of each side gear 27. It is assembled so that it can slide in this direction and rotate integrally with it. In addition, each friction disk 52
a, 52b are the respective friction plates 51a, 5
1b, and are assembled to the outer periphery of the cylindrical portion of each side gear 27 so as to be slidable in the axial direction and rotatable therewith. Further, a compression spring 53 is interposed in the inner hole of the cylindrical portion that is the common base of each pinion shaft 25. This compression spring 53 presses each side gear 27 via each retainer 54a, 54b, and presses each friction plate 51a, 51b and friction disk 52.
a and 52b are brought into contact with each other.

When the vehicle configured as described above is in two-wheel drive, the drive shafts 28 and 29 are disconnected from each other, as shown in FIG. For this reason,
Each rear wheel only rotates the outer shafts 28b, 29b of each drive shaft 28, 29, and does not drive the constituent members of the differential 20, the propeller shaft 14, etc. Therefore, the noise generated from the non-drive system is reduced, and
By reducing the rotational resistance of the non-drive system, it is possible to improve fuel efficiency and reduce wear.

On the other hand, when the vehicle is in four-wheel drive, the push-pull cables are operated in advance so that both shafts 28a and 28 of each drive shaft 28 and 29 are
28b, 29a, and 29b are combined. When the inner wire 41 of the push-pull cable is pulled to the right in the second figure, the actuating rod 33 intermittently moves to the right by a predetermined amount by the action of the detent mechanism 42, bending the compression spring 35, and releasing the operating lever 34. The coupling sleeve 31 is urged to the right through the coupling sleeve 31. In this case, if the rotations of the coupling sleeve 31 and the outer shaft 28b are synchronized, the coupling sleeve 31 will rotate against the outer shaft 28b.
The outer shaft 28b is smoothly engaged with the inner shaft 28a. Further, when the rotations of the coupling sleeve 31 and the outer shaft 28b are not synchronized, the coupling sleeve 31 resiliently contacts the outer shaft 28b side, and after a temporary standby, the outer shaft 28b
This is connected to the inner shaft 28a by meshing with the inner shaft 28a. Further, as the coupling sleeve 31 moves, the coupling rod 37 moves in the same direction, bending the compression spring 36, and causing the coupling rod 32 to move.
(Inner shaft 29a) is urged to the right. In this case, if the rotations of the coupling rod 32 and the outer shaft 29b are synchronized, the coupling rod 32 will smoothly mesh with the outer shaft 29b to couple the outer shaft 29b to the inner shaft 29a. Further, when the rotations of the coupling rod 32 and the outer shaft 29b are not synchronized, the coupling rod 32 resiliently contacts the outer shaft 29b side, waits temporarily, and then engages with the outer shaft 29b. and connect this to the inner shaft 29a. As a result,
The power input from the drive pinion 24 is output to both drive shafts 28 and 29, resulting in four-wheel drive. Note that when switching to two-wheel drive, pushing the inner wire 41 causes the disconnection mechanism 3 to
0 performs the opposite operation to the above to interlock and disconnect the respective drive shafts 28 and 29.

Therefore, during this four-wheel drive, if the rotational speeds between both side gears 27 are different, that is, if relative rotation occurs between both side gears 27 and the differential case 23, each friction plate 51
a, 51b and each friction disk 52a, 5
Frictional torque is generated between 2b. As a result, the drive torque on the low-speed side of both side gears 27 increases, and the drive torque on the high-speed side decreases, thereby preventing a drop in driving performance. That is, running performance during four-wheel drive is improved.

In this way, according to this embodiment, the noise generated from the non-drive system during two-wheel drive can be reduced, and
Not only can the rotational resistance of the non-drive system be reduced to improve fuel efficiency and reduce wear, but also the running performance during four-wheel drive can be improved.

Further, in this embodiment, the connecting rod 37 connecting the coupling sleeve 31 and the coupling rod 32 is connected to the inner shafts 28a, 29a.
Since the actuating rod 33 is fitted concentrically and slidably in the axial direction, there is no need to extend the actuating rod 33 to the vicinity of the outer shaft 29b, and there is also a unit on the actuating rod 33 for operating the coupling sleeve 31. It is sufficient to assemble the operating lever 34 of the book.
Therefore, the differential carrier 21 may be exactly the same or approximately the same size as a normal differential carrier, and the differential carrier 21 is prevented from increasing in size.

FIG. 3 shows a four-wheel drive vehicle according to a second embodiment of the invention. This 4-wheel drive vehicle is a 4-wheel drive vehicle based on a front engine/rear drive (FR vehicle), and in this vehicle, the engine 1
Transmission 12a assembled at the rear of 1,
The transfer force 12b allows both rear axles to be driven at all times, and the transfer force 12b
The power transmission to the propeller shaft 14 is switched on and off by the switching mechanism b. Therefore, in this vehicle, both front axles 13 are on the non-drive side during two-wheel drive, and the front side differential 20A is similar to the differential 20 of the first embodiment. ing. In addition, in FIG. 3, the reference numeral 20B is a rear differential.

In addition, in the present invention, a known differential limiting mechanism can be used as appropriate, and a compression spring 36 with a large amount of deflection can be used to prevent the coupling rod 37 from moving when the coupling rod 32 is on standby. It is also possible to make the stroke longer.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of a four-wheel drive vehicle according to a first embodiment of the present invention, FIG. 2 is an enlarged cross-sectional plan view of a differential in the same vehicle, and FIG. FIG. 1 is a schematic configuration diagram of a wheel drive vehicle. Explanation of symbols, 20, 20A, 20B... Differential, 21... Differential carrier, 27...
Side gear, 28, 29...drive shaft,
28a, 28b, 29a, 29b...divided shaft, 30...intermittent mechanism, 31...coupling sleeve, 32...coupling rod, 33...
Operating rod, 34... Operating lever, 35, 36...
...Compression spring, 37...Connection rod, 42...
...Detent mechanism, 50A, 50B...Differential limiting mechanism.

Claims (1)

[Claims] 1. A pair of drive shafts assembled to both side gears of the differential, which is the non-drive side when driving two wheels, is divided into two, an inner shaft on the inner end side and an outer shaft on the outer end side, and these inner shafts and outer shafts are separated. A pair of inner shafts and an outer shaft are connected to each other so as to be relatively rotatable at their end portions, and each coupling member is assembled to the connecting portion between the inner shafts and the outer shaft so as to be movable in the axial direction. In a four-wheel drive vehicle in which coupling is selectively interrupted, the two coupling members are coupled to each other by a coupling rod that concentrically and movably passes through both the inner shafts, and the differential case A four-wheel drive vehicle equipped with a drive shaft disconnection mechanism, characterized in that a differential limiting mechanism is provided between an input side and an output side of the vehicle.