JPH0558177A - Transfer device of four-wheel drive car - Google Patents

Abstract

PURPOSE:To share a housing by a full time system and a part time system with each other by storing a distribution mechanism and a rotation force parallel transmission mechanism in a housing and storing a differential limiting mechanism, used in the filter full system, in an auxiliary housing removably mounted on the housing. CONSTITUTION:A distribution mechanism and a rotation force parallel transmission mechanism 32 are stored in a single housing body 24. A differential limit mechanism 52 is stored in an auxiliary housing 58, and the auxiliary housing 58 is removably mounted on the housing body 24. When the distribution forms a center differential 16 and the differential limit mechanism 52 is used, the usage is executed in a state that the auxiliary housing 58 is mounted. When the distribution mechanism forms a 2-4 shift clutch 104 and the differential limit mechanism 52 is not used, the usage can be carried out in a state that the auxiliary housing 58 is removed. Thus, when a transfer device forms a full time system and also when it forms a part time system, the housing body 24 can be shared therebetween.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer device for a four-wheel drive vehicle, and more particularly to a transfer device in which an output shaft on the front wheel side and an output shaft on the rear wheel side are arranged in parallel with each other.

[0002]

2. Description of the Related Art Generally, a transfer device for a four-wheel drive vehicle has a full-time system and a part-time system. In the former full-time system, a differential gear called a center differential is used as a distribution mechanism for front and rear wheels. Is used, and this center differential constantly distributes the driving force to the front wheels and the rear wheels.

On the other hand, in the latter part-time system, a meshing type 2-4 switching clutch is used as a distribution mechanism.
The state in which the rotational force is transmitted to one of the front and rear wheels and the state in which the rotational force is transmitted to both the front and rear wheels are switched via the 2-4 switching clutch.

For example, as the former full-time type transfer device, for example, Japanese Patent Application Laid-Open No. 1-103540.
The engine rotation output from the transmission is first input to the center differential through an auxiliary transmission including a planetary gear set that is switched between low speed and high speed.

The center differential is configured as a simple planetary gear set consisting of a sun gear, a pinion gear, and a ring gear, and the output rotation of the auxiliary transmission is input to the pinion gear of the center differential via a pinion carrier, and the front gear is input to the sun gear. The side wheel rotational force is taken out and the rear wheel side rotational force is taken out by the ring gear. On the other hand, the rear wheel output shaft is arranged coaxially with the rotation center shaft of the center differential, and
A front wheel output shaft is arranged parallel to the center axis of rotation of the center differential, the rear wheel output shaft is coupled to the center differential ring gear, and the front wheel output shaft is provided with a rotational force parallel transmission mechanism including a sprocket and a chain. Connected to the switching device.

In the above switching device, the sun gear of the center differential, the ring gear and the sprocket of the rotational force parallel transmission mechanism can be appropriately connected and disconnected, and the sun gear and the ring gear are connected to each other, so that the center differential is connected. Locks and outputs the engine torque only to the rear wheels.

On the other hand, by connecting the sun gear, the ring gear and the sprocket, the rotational force is output to the front wheels and the rear wheels with the center differential locked, and by connecting the sun gear and the sprocket, the center differential It has a differential function and distributes the torque to the front and rear wheels for output.

[0008]

However, in such a conventional transfer device, the center differential, the switching device and the rotational force parallel transmission mechanism are housed in one housing.

Therefore, when the transfer device is constructed as a part-time system in which the center differential is not provided, the internal structure of the transfer device is largely changed, that is, when the center differential is removed, a large space is provided. Therefore, it is necessary to use another housing having a different shape in order to eliminate this space.

Therefore, in the conventional transfer apparatus of the part-time system and the transfer apparatus of the full-time system, the housings are not shared with each other, and it is inevitable to configure them as independent devices, so that the cost is inevitably increased. There was a problem that it would end up.

In view of the above conventional problems, the present invention has devised the arrangement and structure of the components to
An object of the present invention is to provide a transfer device for a four-wheel drive vehicle that enables the housing main body to be shared.

[0012]

In order to achieve the above object, the present invention provides an input shaft to which a rotational force from a power source is transmitted, one of which is arranged coaxially with the input shaft, and the other of which is A front wheel output shaft and a rear wheel output shaft, one of which is arranged in parallel and outputs driving force to the front wheel side and the rear wheel side; and a distribution mechanism that appropriately distributes the rotational force input from the power source to the front wheel side and the rear wheel side. A front-wheel output shaft or a rear-wheel output shaft arranged in parallel with the input shaft is provided with a rotational force parallel transmission mechanism for transmitting the rotational force distributed by the distribution mechanism, and a center differential is used as the distribution mechanism. A full-time system and a part-time system using a 2-4 switching clutch are selected, and in the case of the full-time system, a transfer device for a four-wheel drive vehicle in which a differential limiting mechanism for front and rear wheels is provided, Distribution mechanism and above rotation Housing the parallel transmission mechanism in one housing, and the differential limiting mechanism is constructed by accommodating in a sub-housing is detachably attached to the housing.

[0013]

In the transfer device for a four-wheel drive vehicle of the present invention having the above-described structure, the distribution mechanism and the rotational force parallel transmission mechanism are housed in one housing body, and the differential limiting mechanism is the sub-housing. Since the auxiliary housing is detachably attached to the housing body, when the distribution mechanism is used as the center differential and the differential limiting mechanism is used, the auxiliary housing is attached and used.
4 If the differential limiting mechanism is not used as the switching clutch,
The sub-housing can be removed and used.
Therefore, the housing body can be shared when the transfer device is the full-time system using the center differential and the part-time system using the 2-4 switching clutch.

[0014]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 shows a transfer device 10 for a four-wheel drive vehicle according to an embodiment of the present invention, and the transfer device 10 will be described by way of an example configured as a full-time system.

That is, in the transfer device 10, the engine rotation as a power source output from a transmission (not shown) provided on the left side of the drawing is input to the input shaft 12 of the transfer device 10, and this input rotation is Planetary gear set 14 as an auxiliary transmission for switching between low speed and high speed
It is input to the center differential 16 as a distribution mechanism via.

The center differential 16 has a function of distributing the rotational force input thereto to the front wheel output shaft 18 and the rear wheel output shaft 20.

The rear wheel output shaft 20 penetrates through the center axis of rotation of the center differential 16 and is arranged in the vehicle front-rear direction. One end portion (the left end portion in the drawing) of the rear wheel output shaft 20 is rotatable relative to the center portion of the input shaft 12. It is fitted and supported by the main body 24a of the housing 24 of the transfer device 10 via the needle bearing 20a and the bearing 22 fitted on the outer periphery of the input shaft 12.

The planetary gear set 14 includes a sun gear 14a integral with the input shaft 12, a pinion gear 14b meshed with the sun gear 14a, and a sun gear 14a meshed with the pinion gear 14b so as to surround the sun gear 14a. It is configured as a simple planetary gear mechanism having a ring gear 14c arranged in a circle.

The pinion gear 14b is supported by the pinion carrier 14d, and the ring gear 1
4c is attached to the housing body while being locked in the rotational direction.

As is generally known as a differential device, the center differential 16 has a differential case 16a, a pinion mate shaft 16b mounted in a direction perpendicular to the rotation axis of the differential case 16a, and a pinion pivotally attached to the pinion mate shaft 16b. It is composed of a mate gear 16c and a pair of side gears 16d and 16e which mesh with the pinion mate gear 16c at right angles.

The boss portions of the side gears 16d and 16e are respectively extended in a tubular shape, and one side gear 16d is fitted to the rear wheel output shaft 20 so as to be relatively rotatable, and
The other side gear 16e is spline-fitted to the rear wheel output shaft 20, and the rotation of the side gear 16e causes the rear wheel output shaft 2 to rotate.
It is transmitted to 0.

Further, the differential case 16a is fitted and supported on the outer circumferences of the boss portions of the side gears 16d and 16e so as to be rotatable relative to each other.

Further, a bearing 26 as a bearing is fitted on the outer periphery of the extended boss portion of the side gear 16d, and the intermediate portion of the rear wheel output shaft 20 is attached to the cover 24b of the housing 24 via the bearing 26. It is supported.

Therefore, the rear wheel output shaft 20 is supported by the housing 24 via the bearings 22 and 26, and the rear wheel output shaft 20 is also used as a support shaft for the center differential 16.

On the other hand, the front wheel output shaft 18 is arranged parallel to the rear wheel output shaft 20, and bearings 28, 30 are provided.
The housing 24 is rotatably supported by the main body 24a and the cover 24b of the housing 24.

Between the side gear 16d and the front wheel output shaft 18, the first and second sprockets 34 and 36 and the chain 3 which constitute the rotational force parallel transmission mechanism 32 are provided.
It is interlocked via 8.

The first sprocket 34 is provided between the center differential 16 and the bearing 26, and the side gear 16d.
Is spline-fitted to the outer periphery of the boss of the
The sprocket 36 is formed integrally with the front wheel output shaft 18, and a chain 38 is circulated between the first and second sprockets 34, 36.

Therefore, the rotational force distributed to the side gear 16d of the center differential 16 is transmitted to the front wheel output shaft 18 via the rotational force parallel transmission mechanism 32.

The first sprocket 34 has a thin wall between the boss 34a and the tooth 34b, and the tooth 34b is displaced from the boss 34a toward the center differential 16 as a whole. The end of the tooth portion 34b on the side of the center differential 16 is the differential case 1 of the center differential 16.
6a is arranged with an offset (offset amount δ) on the outer circumference.

Here, between the planetary gear set 14 and the differential case 16a of the center differential 16, a low speed / high speed switching device 40 by the planetary gear set 14 is provided.

That is, the switching device 40 has the first clutch teeth 42 integrally formed from the sun gear 14a of the planetary gear set 14, the second clutch teeth 44 integrally formed from the pinion carrier 14d, and the center differential. 16, a spline 46 formed on the outer periphery of the differential case 16a, and meshed with the spline 46 and locked in the rotational direction, and
It is constituted by an axially movable sleeve 48 and a third clutch tooth 50 integrally formed from the sleeve 48.

The first clutch teeth 42 are formed to have the same diameter as the splines 46 so that the inner circumference of the sleeve 48 can be meshed, and the second clutch teeth 44 are the third clutch teeth.
It is formed to be able to mesh with the clutch teeth 50.

Therefore, in the switching device 40, the sleeve 4 is
8 is in the position shown in the drawing, and the sleeve 48 is not engaged with either the first clutch teeth 42 or the second clutch teeth 44, it is in the neutral state and the center differential 1
No power is transmitted to 6.

On the other hand, when the sleeve 48 is moved from the illustrated neutral position to the left in the drawing to engage the inner circumference of the sleeve 48 with the first clutch teeth 42, the input shaft 12
Is directly input to the differential case 16a, and the high speed stage is set.

Next, the sleeve 48 is moved from the illustrated neutral position to the right in the drawing, and the third clutch tooth 5 is moved.
When 0 is engaged with the second clutch teeth 44, the input shaft 1
The rotation of 2 is input to the differential case 16a via the pinion carrier 14d, and the low speed stage is set.

By the way, the boss portions of the rear wheel output shaft 20 and the side gear 16d are projected from the housing 24 rearward of the vehicle (rightward in the drawing), and the outer periphery of the projected rear wheel output shaft 20 and the boss portion of the side gear 16d are projected. Between the end,
A differential control device 52 is arranged.

That is, the differential control device 52 is composed of the viscous coupling 54 and the clutch device 56, and the inner race 54a of the viscous coupling 54.
Is spline-fitted to the outer periphery of the boss of the side gear 16d, and the outer race 54b is attached to the rear wheel output shaft 20.
It is spline-fitted to the outer circumference.

The clutch device 56 is spline-fitted to the outer periphery of the boss portion of the side gear 16d, and a hub 56a having spline teeth formed on the outer periphery thereof, and the hub 5a.
6a, a sleeve 56b which is spline-fitted to the outer periphery so as to be axially movable, a clutch tooth 56c formed on the outer periphery of the sleeve 56b, and a clutch tooth 56d formed on the outer race 54b and meshable with the clutch tooth 56c.
Composed of and.

When the sleeve 56b is at the position shown and the clutch teeth 56c and the clutch teeth 56d are disengaged, the differential function of the center differential 16 is utilized between the rear wheel output shaft 20 and the side gear 16d. Meanwhile, the slip limiting function of the viscous coupling 54 is exerted.

On the other hand, when the sleeve 56b moves to the right in the figure and the clutch teeth 56c and 56d are meshed with each other, the viscous coupling 54 is locked and the rear wheel output shaft 20 and the side gear 16d rotate integrally. And always before,
The same rotational force is transmitted to the rear wheels. By the way, the differential control device 52 is attached to the cover 24b of the housing 24 in a detachable manner via a bolt or the like (not shown).
It is stored in 8. Then, the rear wheel output shaft 20
Is projected from the sub housing 58 toward the rear of the vehicle,
The protruding portion of the rear wheel output shaft 20 is supported by the sub housing 58 via a bearing 60.

Further, flanges 62, 64 for connecting a rear wheel side propeller shaft and a front wheel side propeller shaft (not shown) to the vehicle rear end portion of the rear wheel output shaft 20 and the vehicle front end portion of the front wheel output shaft 18, respectively. Is installed.

Reference numeral 70 denotes an oil pump, and the lubricating oil pumped up by the oil pump 70 is used as the housing main body 24.
It is supplied to the central hole 74 of the rear wheel output shaft 20 through a passage 72 formed within the thickness of a, and is supplied from the central hole 74 to the lubricated portions of the respective parts.

In the transfer device 10 of this embodiment having the above-mentioned structure, the input shaft 12 to the planetary gear set 14 are connected.
The engine rotation input to the differential case 16a of the center differential 16 via the switching device 40 is distributed by the center differential 16, and one is output from the side gear 16d to the front wheel output shaft 18 via the rotational force parallel transmission mechanism 32. And the other is output to the rear wheel output shaft 20 via the side gear 16e.

At this time, it is possible to select a low speed stage or a high speed stage state by switching the switching device 40, and
Clutch 56 of differential control device 52 in sub-housing 58
It is possible to select the locked state or the unlocked state of the viscous coupling 54 by switching.

The rotational force distributed to the front wheel output shaft 18 is transmitted to a front differential (not shown) via a front wheel side propeller shaft (not shown) and drives the left and right front wheels via the front differential. ..

Further, the rotational force distributed to the rear wheel output shaft 20 is transmitted to a rear differential (not shown) via a rear wheel side propeller shaft (not shown) and drives the left and right rear wheels via the rear differential. To do.

By the way, the transfer device 10 of the present embodiment is configured as a full-time system by providing the center differential 16, and the planetary gear set 14 as the auxiliary transmission, the switching device 40, the center differential 16 and the rotational force parallel transmission. The mechanism 32 is housed in one housing 24, and the differential control device 52 is housed in a sub-housing 58 detachably attached to the housing 24.

Therefore, when the transfer device 10 configured as the full-time system is configured as the part-time system, the center differential 16 will be described later in 2-4.
It is roughly configured by replacing the switching clutch 104 and eliminating the differential control device 52.

That is, FIG. 2 shows a transfer device 10a configured as a part-time system, and the same components as those of the transfer device 10 of the full-time system are designated by the same reference numerals and a duplicate description will be omitted.

That is, in the transfer device 10a of such a part-time system, the sleeve 48 of the switching device 40 for switching between the low speed and high speed of the planetary gear set 14 is splined on the outer periphery of the hub 100 which is spline-fitted to the rear wheel output shaft 20. The rotation fitted and switched by the switching device 40 is directly input to the rear wheel output shaft 20.

The first sprocket 34, which constitutes the rotational force parallel transmission mechanism 32, is rotatably fitted to the rear wheel output shaft 20 via a bearing 102, and the first sprocket 34 and the switching device 40 are connected to each other. The 2-4 switching clutch 104 is arranged between the two.

The 2-4 switching clutch 104 has a hub 106 spline-fitted to the rear wheel output shaft 20, and a sleeve 1 spline-fitted to the outer periphery of the hub 106.
08, the clutch teeth 110 fixed to the first sprocket 34, the sleeve 108 and the clutch teeth 11
0 and a rotation synchronizer 112 interposed between them.

Therefore, the above 2-4 switching clutch 104
The sleeve 108 has clutch teeth 110 as shown.
In the state in which the rear wheel output shaft 20 is not meshed with the front wheel output shaft 18, the rotational force of the rear wheel output shaft 20 is not transmitted to the front wheel output shaft 18 via the first sprocket 34, that is, the rotational force parallel transmission mechanism 32. Become.

On the other hand, when the sleeve 108 is meshed with the clutch teeth 110, the rotational force of the rear wheel output shaft 20 is also transmitted to the front wheel output shaft 18 via the rotational force parallel transmission mechanism 32, and the front and rear wheels. It becomes a four-wheel drive state.

By the way, since the differential control device 52 used in the full-time system is unnecessary in such a part-time system, in this embodiment, the differential control device 52 is removed and the sub-housing used in FIG. 58 is removed from the housing 24.

Since the sub-housing 58 is removed in this way, the rear wheel output shaft 20 of the part-time system is shortened as compared with the full-time system.

As described above, when comparing the transfer device 10 of the full-time system shown in FIG. 1 with the transfer device 10a of the part-time system shown in FIG. 2, when changing from the full-time system to the part-time system,
The 2-4 switching clutch 104 can be arranged in the space where the center differential 16 is arranged, and the layout within the housing body 24 is not significantly changed.

Further, since the sub-housing 58 accommodating the differential control device 52 is only detachably attached to the housing 24, when the change between the full-time system and the part-time system is performed. Also, the housing 24 can be shared.

In other words, the housing 24 occupies a considerably large cost ratio in constructing the transfer devices 10 and 10a, and by sharing the housing 24, the cost of the transfer devices 10 and 10a is significantly reduced. You can do it.

[0061]

As described above, in the transfer device for a four-wheel drive vehicle according to the present invention, the distribution mechanism and the rotational force parallel transmission mechanism are housed in the housing and detachably attached to the housing. Since the differential limiting mechanism used in the full-time system is housed in the secondary housing,
Combined with the fact that the housing can be shared when changing the configuration between the full-time method and the part-time method, the productivity can be greatly improved.
It has an excellent effect that a significant cost reduction can be achieved.

[Brief description of drawings]

FIG. 1 is a sectional view of a transfer device for a four-wheel drive vehicle showing an embodiment of the present invention.

FIG. 2 is a sectional view of a transfer device for a four-wheel drive vehicle showing another embodiment of the present invention.

[Explanation of symbols]

10, 10a ... Transfer device, 12 ... Input shaft,
16 ... Center differential, 18 ... Front wheel output shaft, 20 ...
Rear wheel output shaft, 24 ... Housing, 32 ... Rotational force parallel transmission mechanism, 40 ... Switching device, 52 ... Differential control device, 58
... Sub-housing, 104 ... 2-4 switching clutch.

Claims (1)

[Claims] 1. An input shaft, to which a rotational force from a power source is transmitted, and one of which is coaxially arranged with respect to the input shaft, and the other of which is arranged in parallel, so that a driving force is applied to a front wheel side and a rear wheel side. A front wheel output shaft and a rear wheel output shaft, a distribution mechanism that appropriately distributes the rotational force input from the power source to the front wheel side and the rear wheel side, and a front wheel output shaft or a rear wheel arranged in parallel with the input shaft. The output shaft is provided with a rotational force parallel transmission mechanism for transmitting the rotational force distributed by the distribution mechanism, and as the distribution mechanism, a full-time system using a center differential and a part-time system using a 2-4 switching clutch. In the transfer device of a four-wheel drive vehicle in which a front and rear wheel differential limiting mechanism is provided when the system is selected and a full-time system is selected, the distribution mechanism and the rotational force parallel transmission mechanism are provided in one housing. And store The differential limiting mechanism transfer device for a four wheel drive vehicle, characterized in that accommodated in the sub housing is detachably attached to the housing.