JP2001107990A - Coupling and differential device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the torque capacity of a coupling by making a cam have a large diameter, and facilitate assembling by reducing the number of part items to reduce cost. SOLUTION: This device is equipped with a case state torque transmitting member 17 having large-diameter parts 21 and 23, a shaftlike torque transmitting member 7 penetrating the member 17, a main clutch 9 arranged between the members 17 and 7, a pilot clutch 11 intermittently operated by an operating means 15, and a cam 5 for receiving torque applied to the members 17 and 7 to be actuated to press the clutch 9 when the clutch 11 is linked; and the cam 5 is provided on the large-diameter part 23.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coupling for transmitting power by a main clutch which is turned on and off by a cam which operates when a pilot clutch is connected, and a differential device for controlling a differential limiting force using the coupling. About.

[0002]

2. Description of the Related Art A conventional coupling and a differential device using this coupling are described in "Gaia New Model Manual 0-22 pages, edited by Toyota Motor Corporation, published by the Service Department, May 29, 1998". A coupling 201 as shown in FIG. 3 is described.

[0003] The coupling 201 is arranged in a rear wheel-side power transmission system of a four-wheel drive vehicle.
3, hub 205, multi-plate type main clutch 207 and pilot clutch 209, armature 211, electromagnet 2
13, a cam ring 215, a ball cam 217, a pressing member 219, a controller and the like.

[0004] The coupling 201 includes a differential carrier 22.
1, and the core 223 of the electromagnet 213 is supported on the inner periphery of the differential carrier 221.

[0005] The rotating case 203 has a bearing 22 at the front.
5, and a rear portion thereof is supported by a differential carrier 221 by a core 223 and a bearing 227 of the electromagnet 213.

[0006] The rotary case 203 is connected from the transfer to the transmission via a propeller shaft. A drive pinion shaft 229 is spline-connected to the hub 205, and a drive pinion gear 231 integrally formed therewith meshes with a ring gear on a rear differential (a differential device for distributing the driving force of the engine to the left and right rear wheels). ing.

The main clutch 207 includes a rotating case 203.
The pilot clutch 209 is disposed between the rotating case 203 and the cam ring 215.

The ball cam 217 is disposed between the cam ring 215 and the pressing member 219.
Are splined to hub 205.

The controller excites the electromagnet 213, controls the excitation current, and stops the excitation.

When the electromagnet 213 is excited, a magnetic loop 233 is formed in the magnetic circuit, the armature 211 is attracted, and the pilot clutch 209 is pressed and fastened. When the pilot clutch 209 is engaged, the torque between the rotating case 203 and the hub 205 is reduced by the ball cam 21.
7, the pressing member 21 is generated by the generated cam thrust force.
9, the main clutch 207 is pressed and engaged.

When the coupling 201 is connected in this manner, the driving force of the engine is sent to the rear wheels, and the vehicle is driven in a four-wheel drive state, so that the running performance on rough roads and the stability of the vehicle body are improved.

When the exciting current of the electromagnet 213 is controlled, the cam thrust force of the ball cam 217 changes due to the slip of the pilot clutch 209, and the main clutch 2
The coupling force of 07 changes, and the driving force of the rear wheel is adjusted.

On the other hand, when the excitation of the electromagnet 213 is stopped,
The pilot clutch 209 is released and the ball cam 21 is released.
7, the main thrust force is released, the main clutch 207 is released, the connection of the coupling 201 is released, and the vehicle enters a two-wheel drive state.

[0014]

However, in the coupling 201, the ball cam 217 is connected to the pilot clutch 2
09 because it is arranged on the radial inside,
The number of cam teeth is small.

Therefore, since the load per one cam tooth of the ball cam 217 becomes large, the main clutch 207 may not be pressed sufficiently strongly. In this case, the coupling 201 has a large torque capacity. I can't.

The ball cam 217 has a cam ring 2
15 and the pressing member 219, the number of parts is large, and the structure is complicated. Therefore, the assembling work is troublesome, the assembling man-hour is large, and the cost is high accordingly.

Further, the oil easily escapes from the ball cam 217 radially inside the pilot clutch 209 due to the centrifugal force, and the lubrication tends to be insufficient.

Therefore, in addition to low durability, it is necessary to take measures to prevent abrasion and the like, and the implementation cost is accordingly increased.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a coupling having a large diameter cam for connecting a pilot clutch and having a large capacity, and a differential device for controlling a differential limiting force using the coupling.

[0020]

According to a first aspect of the present invention, there is provided a coupling comprising: a case-shaped torque transmitting member; an axial torque transmitting member penetrating the case-shaped torque transmitting member; A main clutch arranged between the members, a pilot clutch intermittently operated by the operation means,
When the pilot clutch is engaged, the pilot clutch is operated by receiving the transmission torque applied to the two torque transmission members, and a cam for coupling the main clutch by the generated axial thrust force is provided. It is characterized in that it is provided on the large diameter portion of the member.

When the pilot clutch is connected, the cam operates by receiving the transmission torque applied to both torque transmission members, and the main clutch (coupling) is connected by the generated axial thrust force.

For example, when this coupling is arranged in a rear-wheel-side power transmission system from a transfer to a rear differential of a four-wheel drive vehicle, when the coupling is connected, the driving force of the engine is sent to the rear wheels and the vehicle is driven. Is put into a four-wheel drive state, and the running performance on rough roads and the stability of the vehicle body are improved.

Further, when the sliding of the pilot clutch is controlled by the operating means, the thrust force of the cam changes,
Main clutch coupling force (coupling transmission torque:
The driving force transmitted to the rear wheels can be adjusted.

By controlling the driving force distribution ratio between the front and rear wheels in this manner, the controllability and stability of the vehicle during turning are improved.

When the pilot clutch is released,
The thrust force of the cam is lost, the main clutch is released, the coupling is disconnected, and the vehicle enters a two-wheel drive state.

In addition to the above, in the coupling of the first aspect, the cam is provided on the large diameter portion of the case-like torque transmitting member (for example, radially outside of the pilot clutch) as described above. Unlike this, the diameter of the cam becomes large, and it becomes possible to provide a large number of cam teeth.

Therefore, the load per cam tooth (per cam surface) is greatly reduced, and the coupling force of the main clutch can be strengthened by providing a large number of cam teeth. A sufficient torque capacity can be obtained.

Further, unlike the conventional example, since a large amount of oil is supplied to the cam provided at the large diameter portion of the case-like torque transmitting member by the centrifugal force of the coupling, the cam is sufficiently lubricated. High durability can be obtained.

Therefore, for example, even when a large load is applied to the cam, no consideration is required for preventing abrasion and the like, and the cost can be reduced accordingly.

The coupling of the present invention may have a direct operation configuration in which the pilot clutch is connected when the operating means is operated, or when the operation of the operating means is stopped, for example, the pilot clutch is operated by the urging means. A negative operation configuration that is connected may be adopted.

In the case of the negative operation configuration, while the pilot clutch is connected, the operation means (for example, an electromagnet) is stopped to reduce the load on the battery, and in the case of a vehicle-mounted device, the fuel efficiency of the engine is improved accordingly. .

Further, in the present invention, the cam may be of any type as long as it can provide an axial thrust force.

For example, a rolling element may be provided between the cam surfaces, such as a ball cam, or a cam surface may be directly contacted without using a rolling element. For example, a roller may be used.

In addition, as described above, the coupling of the present invention is not only disposed in the power transmission system on the rear wheel side of the four-wheel drive vehicle, but also distributed from the transfer to the front differential (the engine driving force is distributed to the left and right front wheels). (A differential device).

Also in this case, when the coupling is connected, the vehicle is in a four-wheel drive state, and when the coupling is released, the vehicle is in a two-wheel drive state.

When the couplings are arranged in the power transmission systems on the front wheel side and the rear wheel side, the coupling is divided on the propeller shaft on the front wheel side or on the propeller shaft on the rear wheel side. The stationary casing for housing the coupling may be fixed to the vehicle body frame via rubber, a spring, a viscous damper, or the like.

Further, the coupling of the present invention can be arranged between a front differential and one of left and right front wheels or between a rear differential and one of left and right rear wheels of a four-wheel drive vehicle.

Also in this case, when the coupling is connected, the vehicle is in a four-wheel drive state. When the connection is released, the transmission of the driving force to the wheels is stopped by the differential gears rotating freely and differentially. The vehicle enters the two-wheel drive state.

According to a second aspect of the present invention, a case-like torque transmitting member which is rotated by a driving force of an engine, and a rotation of the case-like torque transmitting member is transmitted to a wheel side through a pair of shaft-like torque transmitting members. , A main clutch disposed between the case-shaped torque transmitting member and one of the shaft-shaped torque transmitting members for limiting the differential of the differential mechanism, and intermittently operated by operating means. When the pilot clutch is connected, the pilot clutch is operated by receiving a differential torque applied to the torque transmitting member, and a cam for connecting the main clutch by a generated axial thrust force is provided. It is characterized in that it is provided on the large diameter portion of the torque transmission member.

When the pilot clutch is connected, for example, the cam is actuated by receiving a differential torque between the case-shaped torque transmitting member and the shaft-shaped torque transmitting member, the main clutch is connected, and the differential friction is caused by the frictional resistance. The differential of the mechanism is limited.

When the slip of the pilot clutch is controlled by the operating means, the frictional resistance of the main clutch changes, and the differential limiting force is adjusted.

When the main clutch is released, the differential is allowed.

In addition, in the differential device according to the second aspect, the cam is provided at the large diameter portion of the case-like torque transmitting member as described above, so that the same effect as the coupling according to the first aspect is obtained. Can be obtained.

Further, by using the coupling of the first aspect having a large torque capacity, a sufficient differential limiting force can be obtained, so that the maneuverability and stability of the vehicle can be greatly improved. .

According to a third aspect of the present invention, there is provided a coupling or a differential device according to the first or second aspect, wherein the case-like torque transmitting member is relatively rotated inside the outer case and the inner case. A pilot clutch is disposed between the inner case and the shaft-like torque transmitting member, and a cam is provided between the outer case and the inner case. And the same effects as those of the first and second aspects can be obtained.

Since the cams are formed on the outer case and the inner case as described above, the number of parts is different from that of the conventional ball cam 217 using the cam ring 215 and the pressing member 219. In addition, the structure is simplified, and the cams are formed directly on the outer case and the inner case, so that the assembling becomes extremely easy and the cost can be reduced accordingly.

In particular, if the cam is provided on the side wall of the outer case and the end of the inner case, the inside of the rotating case (outer case) will not be divided by the cam. The degree of freedom when laying out and pilot clutches is greatly improved.

Further, if the cam is provided on the wall side of the outer case as described above, the arrangement space of the main clutch and the pilot clutch can be made sufficiently wide.

Therefore, for example, when the main clutch and the pilot clutch are multi-plate clutches, it is possible to use a sufficient number of clutch plates (plates) for them, and in particular, to use a large number of plates for the main clutch. If the coupling is used, the torque capacity of the coupling can be further increased.

According to a fourth aspect of the present invention, there is provided the coupling or the differential device according to the third aspect, wherein the inner case is moved by receiving the thrust force of the cam, and the main clutch is pressed and connected. And an effect equivalent to that of the third aspect can be obtained.

In addition, since the inner case is used as the pressing member of the main clutch, a dedicated pressing member is not required, the number of parts is further reduced, and the structure is simplified.
Easy assembly and low cost.

According to a fifth aspect of the present invention, there is provided the coupling or the differential device according to any one of the first to fourth aspects, wherein the operating means moves the armature to push the pilot clutch to connect the armature. This is an electromagnet that allows the same effect as in claims 1 to 4 to be obtained.

In addition, since an electromagnet is used for the operating means, it can be made compact as compared with, for example, a configuration using a pressure-type actuator, so that it can be used in a power transmission system of a vehicle or a differential device. In the case of, the vehicle mountability is improved.

Further, if the electromagnet is used, the slip of the pilot clutch can be controlled and the transmission torque of the main clutch (coupling) can be precisely controlled as described above. As described above, the driving force distribution ratio between the front and rear wheels is precisely controlled, so that the controllability and stability of the vehicle during turning can be significantly improved.

[0055]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A coupling 1 (one embodiment of the present invention) will be described with reference to FIGS.

This coupling 1 is described in claims 1, 3, 4,
It has five features. FIG. 1 shows a coupling 1,
FIG. 2 shows a power system of a four-wheel drive vehicle using the coupling 1. The left and right directions are the left and right directions of the vehicle, and the right side in FIG. 1 corresponds to the front. In addition, members and the like without reference numerals are not shown.

As shown in FIG. 2, the power system includes a horizontally disposed engine 101, a transmission 103, a transfer 105, a front differential 107, and front axles 109 and 11.
1, left and right front wheels 113 and 115, a rear wheel side propeller shaft 117, a coupling 1, a rear differential 119, rear axles 121 and 123, left and right rear wheels 125 and 127, and the like.

As described above, the coupling 1 is arranged in the power transmission system on the rear wheel side.
5, 127, and controls the driving force transmitted to the rear wheels.

The driving force of the engine 101 is transmitted from the output gear 129 of the transmission 103 to the differential casing 133 of the front differential 107 via the ring gear 131, and from the front differential 107 via the front axles 109 and 111 to the left and right front wheels 113. , 115, and the propeller shaft 117 is rotated from the differential casing 133 via the transfer 105 to be transmitted to the coupling 1.

When the coupling 1 is connected, the driving force of the engine 101 is transmitted from the rear differential 119 to the rear axle 121,
Distributed to the left and right rear wheels 125, 127 via 123,
The vehicle enters the four-wheel drive state.

On the other hand, when the coupling 1 is disconnected, the rear wheels below the rear differential 119 are disconnected, and the vehicle enters a two-wheel drive state.

As shown in FIG. 2, the rear differential 119 is accommodated in a differential carrier 135. This differential carrier 135
Is formed by connecting a front cover-139 to a front end of a carrier body 137 with a bolt 141. Oils having different compositions are sealed in the carrier body 137 and the front cover-139, respectively.

As shown in FIG. 1, the coupling 1 is composed of a rotating case 3 (case-like torque transmitting member), a cam 5, and an inner case.
Shaft 7 (axial torque transmitting member), multi-plate type main clutch 9 and pilot clutch 11, armature 1
3. It is composed of an electromagnet 15 (operation means), a controller and the like.

The rotating case 3 is composed of an outer case 17 and an inner case 19, and these are the cams 5.
Are linked by

The outer case 17 has large-diameter portions 21 and 23
The cam 5 is formed on the side wall 25 of the large diameter portion 23 and the front end of the inner case 19, and is constituted by cam teeth 27 and 29 meshing with each other.

Like the shape of the cam teeth 27 and 29 shown in FIG. 1, the cam 5 is bidirectional between the outer case 17 (the rotating case 3) and the inner case 19 (the inner shaft 7). (In both forward running and reverse running of the vehicle).

The cam 5 is disposed radially outward of the pilot clutch 11 and has an outer casing 17.
(The side wall 25).

The inner case 19 is supported on the inner periphery of the large diameter portion 23 so as to be relatively rotatable and axially movable.

The inner shaft 7 penetrates from the rear into the outer case 17 and is rotatably supported by the boss portions 31 and 33 of the outer case 17. Thrust washers 34 are disposed between the inner shaft 7 and the outer case 17, respectively. The thrust washers 34 are arranged in the axial direction while receiving the thrust force of each other. Positioning.

The main clutch 9 is connected to the outer case 17.
The outer plate 35 is disposed between the large-diameter portion 21 and the inner shaft 7, and the outer plate 35 is spline-connected to a spline portion 37 formed on the inner periphery of the large-diameter portion 21. The shaft 39 is spline-connected to a spline portion 41 formed on the outer periphery of the inner shaft 7.

The pilot clutch 11 is
And between the inner shaft 19 and the inner shaft 7,
The outer plate 43 is spline-connected to a spline portion 45 formed on the inner periphery of the inner case 19,
The inner plate 47 is spline-connected to the spline portion 41 of the inner shaft 7.

The armature 13 has a ring shape and is disposed between the pressing wall 49 provided on the inner case 19 and the pilot clutch 11.

The core 51 of the electromagnet 15 is
35 is fixed to the front cover-139 side, and forms an air gap 53 with the side wall 25 of the outer case 17.

The rear end of the inner shaft 7 is connected to a drive pinion shaft 143 on the rear differential 119 side.

The outer case 17 has a connecting shaft 5
5 are integrally formed, and the connecting shaft portion 55 projects forward from the front cover-139.

As shown in FIG. 2, a companion flange 145 is connected to the connecting shaft portion 55, and the companion flange 145 is connected to a flange 149 on the joint 147 side. -S3)
Is connected to the propeller shaft 117 side.

Oil is injected into the rotating case 3, and an oil different from each oil of the differential carrier 135 is used for this oil.

The outer case 17 is made of a magnetic material because the side wall 25 forms a magnetic circuit of the electromagnet 15, and the inner case 19 is made of a non-magnetic material to prevent a magnetic short circuit. Made of material.

Further, the side wall 25 of the outer case 17
Is divided into a radially outer side and an inner side by a ring 57 made of stainless steel (nonmagnetic material). This ring 57
Prevents the magnetic force of the electromagnet 15 from being short-circuited and concentrates the magnetic force on the armature 13.

The lead wire of the electromagnet 15 is
5 is drawn out through a grommet attached to the connector 5, and is connected to a connector on the vehicle-mounted battery side via a connector.

Outer case 17 and inner shaft 7
A space 59 is formed between them, and a space 61 is formed between the inner case 19 and the inner shaft 7. In these spaces 59 and 61, a rotating case 3 is provided.
Oil and a moderate amount of air are stored.

When the coupling 1 rotates, the oil in the space 59 lubricates and cools the sliding surface between the outer plate 35 and the inner plate 39 of the main clutch 9. Similarly, the oil in the space 61 lubricates and cools the sliding surface between the outer plate 43 and the inner plate 47 of the pilot clutch 11 and the cam 5.

The centrifugal force of the coupling 1 promotes oil flow and diffusion, and improves lubricity and cooling.

In addition to this, the large diameter portion 23 of the rotating case 3
Since a large amount of oil is supplied to the cam 5 provided by the centrifugal force, the cam 5 is sufficiently lubricated and cooled, and high durability can be obtained.

The controller detects the start, the degree of acceleration, the turning, the road surface condition, and the like from the vehicle speed, the steering angle, the lateral G, etc., and according to these, the excitation of the electromagnet 15, the control of the excitation current, and the excitation. Stop and so on.

When the electromagnet 15 is excited, the air gap 53, the side wall 25 of the outer case 17, the outer plate 43 and the inner plate 4 of the pilot clutch 11,
7. A magnetic loop is formed in the magnetic circuit including the armature 13, the armature 13 is attracted, and the pilot clutch 11 is engaged.

When the pilot clutch 11 is engaged,
The transmission torque between the rotating case 3 (outer case 17) and the inner shaft 7 is applied to the cam 5, and the inner case 19 moves rearward due to the generated axial cam thrust force. The main clutch 9 is pressed by the pressing wall 49 to be engaged, and the coupling 1 is connected.

When the coupling 1 is connected, the driving force of the engine 101 is transmitted from the rear differential 119 to the rear wheels 125 and 12.
The vehicle is sent to the vehicle 7 to be in a four-wheel drive state, so that the running performance on rough roads, the maneuverability and stability of the vehicle body, and the like are improved.

When the attraction force of the armature 13 is adjusted by controlling the exciting current of the electromagnet 15, the cam thrust force of the cam 5 changes due to the slip of the pilot clutch 11, and the transmission torque of the main clutch 9 (coupling 1) is changed. (Torque capacity) changes, and the driving force sent to the rear wheels 125 and 127 can be adjusted.

Controlling the driving force distribution ratio between the front and rear wheels in this way improves, for example, the steering and stability of the vehicle during turning.

On the other hand, when the excitation of the electromagnet 15 is stopped, the pilot clutch 11 is released, the cam thrust force of the cam 5 disappears, the main clutch 9 is released, the connection of the coupling 1 is released, and the vehicle is driven by two wheels. State.

The coupling 1 corresponds to the arrow 15 in FIG.
As shown in FIG. 1, it may be arranged between the transfer 105 and the propeller shaft 117.

In this case, the coupling 1 is provided between the propeller shaft 117 and the rear differential 119 as shown in FIG.
As in the case of, the connection and disconnection of the rear wheels 125 and 127 and the control of the transmission torque are performed.

The coupling 1 has arrows 153 and 15
5, the front differential 107 may be disposed between the left and right front wheels 113 and 115.
7, 159, it may be disposed between the rear differential 119 and either of the left and right rear wheels 125, 127.

When the couplings are connected at the positions indicated by arrows 153 and 155, the vehicle enters a four-wheel drive state when the coupling 1 is connected. When the connection is released, the differential rotation of the front differential 107 becomes free. The transmission of the driving force to 115 is stopped, and the vehicle enters the two-wheel drive state.

When the coupling 1 is connected, the vehicle is driven in a four-wheel drive state when the coupling 1 is connected, and when the coupling is released, the differential rotation of the rear differential 119 becomes free, and the rear wheel is released. The transmission of the driving force to 125 and 127 is stopped, and the vehicle enters the two-wheel drive state.

In this case, the transfer 105
If the clutch for interrupting the driving force is provided, the propeller shaft 117 can be kept completely stationary, so that noise, vibration, wear and the like can be greatly reduced, and the fuel efficiency of the engine 101 can be improved.

Further, as shown by an arrow 161, the coupling 1 may be arranged in combination with a gear mechanism in the transfer 105. In this case, the propeller shaft 1
The function equivalent to that of FIG. 2 disposed between the rear differential 17 and the rear differential 119 can be obtained.

Further, the coupling 1 is indicated by arrows 151, 16
1, the hub clutches 163 and 165 are arranged between the rear axles 121 and 123 and the rear wheels 125 and 127, and the connection between them is released in conjunction with the coupling 1. 1 to the rear wheels 125, 127, the rotation of the engine 101 and the rear wheels 125, 1
27, the rotation is stopped, noise, vibration, wear, etc. are greatly reduced, and the fuel efficiency of the engine 101 is improved.

Thus, the coupling 1 is configured.

As described above, the coupling 1 is
To the large diameter portion 23 of the rotating case 3 (outer case 17).
By providing the cam 5 on the outside (in the radial direction of the pilot clutch 11), the cam 5 has a large diameter and a large number of cam teeth 27 and 29 can be provided unlike the conventional example.

Therefore, the load on each of the cam teeth 27 and 29 is greatly reduced, the main clutch 9 can be strongly engaged, and the coupling 1 can obtain a sufficient torque capacity.

Further, since the cam 5 is provided on the side wall 25 of the outer case 17 and the end of the inner case 19, the inside of the rotating case 3 is divided by the cam 5. Therefore, the degree of freedom in layout of the main clutch 9 and the pilot clutch 11 is greatly improved.

In addition, the provision of the cam 5 at the end of the rotating case 3 makes it possible to make the arrangement space of the main clutch 9 and the pilot clutch 11 sufficiently wide.

Therefore, the number of plates of the main clutch 9 and the pilot clutch 11 can be increased,
In particular, by using a large number of plates 35 and 39 for the main clutch 9, the torque capacity of the coupling 1 is further increased.

In this way, a large driving force is transmitted to the rear wheels 125 and 127, so that the starting performance, acceleration performance, running performance, and the like of the vehicle can be greatly improved.

Further, unlike the conventional example, the rotating case 3
Since a large amount of oil is supplied to the cam 5 provided in the large-diameter portion 23 by centrifugal force, sufficient lubrication and high durability can be obtained.

Therefore, no consideration is required for preventing abrasion and the like, and the cost can be reduced accordingly.

Further, the outer case 17 and the inner case
Since the cam 5 is formed directly on the cam ring 21,
5 and the ball cam 21 in the conventional example using the pressing member 219.
Unlike the seventh embodiment, the number of parts is small, the structure is simple, the assembling becomes extremely easy, and the cost can be reduced.

Further, since the pressing wall 49 is formed on the inner case 19 and used as the pressing member of the main clutch 9, a dedicated pressing member is not required, and the number of parts is reduced, and the structure is simplified. This makes assembly easier and lowers costs.

Further, since the electromagnet 15 is used as the operating means, the coupling 1 is made compact and the in-vehicle mountability is improved as compared with, for example, a configuration using a pressure type actuator.

In addition, according to the electromagnet 15, when the transmission torque of the main clutch 9 (coupling 1) is controlled as described above, it is possible to precisely control the slip of the pilot clutch 11, By controlling the driving force distribution ratio between the front and rear wheels, the maneuverability and stability of the vehicle during turning can be greatly improved.

In the coupling of the present invention, the cam may be of any type as long as it can provide an axial thrust force.

For example, a rolling element may be disposed between cam surfaces, such as a ball cam, or a cam surface may be directly contacted without using a rolling element.
Instead of a ball, for example, a roller may be used.

Further, the main clutch and the pilot clutch may be other types of friction clutches. Further, in the case of a multi-plate clutch, a wet clutch or a dry clutch may be used.

[0116]

According to the first aspect of the present invention, the cam is provided with a casing.
By providing the large-diameter portion of the torque transmission member (radially outside of the pilot clutch), the diameter of the cam becomes large unlike the conventional example, so that a sufficient number of cam teeth are provided to connect the main clutch. The force can be strengthened and the torque capacity of the coupling can be increased.

Further, a large amount of oil is supplied to the cam provided at the large diameter portion of the case-like torque transmitting member by centrifugal force, and high durability can be obtained.

According to the differential device of the second aspect, the same effect as the coupling of the first aspect can be obtained by providing the cam at the large diameter portion of the case-like torque transmitting member.

According to the third aspect of the invention, the same effects as those of the first or second aspect can be obtained, and the cams are directly formed on the outer case and the inner case. It is small, has a simple structure, is easy to assemble, and can be implemented at low cost.

Further, in the configuration in which the cam is provided on the side wall of the outer case and the end of the inner case, the degree of freedom in laying out the main clutch, the pilot clutch and the like is greatly improved.

According to the fourth aspect of the invention, the same effects as those of the third aspect can be obtained, and a pressing member dedicated to the main clutch is not required, the number of parts is reduced accordingly, the structure is simple, the assembly is easy, and Low cost.

According to the fifth aspect of the present invention, the same effects as those of the first to fourth aspects can be obtained, and the use of the electromagnet makes it possible to achieve an advantage in comparison with a configuration using a pressure type actuator.
It is compact, and in the case of a differential device, the on-board performance is improved accordingly.

Further, the electromagnet can precisely control the transmission torque of the coupling and the differential limiting force of the differential device.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a coupling according to an embodiment of the present invention.

FIG. 2 is a skeleton mechanism diagram showing a power system of a four-wheel drive vehicle using the coupling of FIG. 1;

FIG. 3 is a sectional view of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Coupling 3 Rotating case (casing torque transmitting member) 5 Cam 7 Inner shaft 7 (axial torque transmitting member) 9 Main clutch 11 Pilot clutch 13 Armature 15 Electromagnet (Operating means) 17 Outer Case 19 Inner case 21, 23 Large diameter portion of outer case 17 25 Side wall of large diameter portion 23 of outer case 17 27, 29 Cam teeth of cam 5

Claims (5)

[Claims] 1. A case-like torque transmitting member, comprising:
When the shaft-shaped torque transmitting member penetrating into the gear-shaped torque transmitting member, the main clutch disposed between these two torque transmitting members, the pilot clutch intermittently operated by the operating means, and the pilot clutch are connected, And a cam that operates by receiving the transmission torque applied to both torque transmission members and connects the main clutch by the generated axial thrust force. The cam is provided at a large diameter portion of the case-like torque transmission member. A coupling characterized in that: 2. A case which is rotated by a driving force of an engine.
A torque transmission member, a differential mechanism for distributing the rotation of the case torque transmission member to the wheel side through a pair of shaft torque transmission members, and a case torque transmission member and one shaft. A main clutch disposed between the torque transmitting member and limiting a differential of the differential mechanism; a pilot clutch intermittently operated by an operating means; and a differential torque applied to the torque transmitting member when the pilot clutch is connected. And a cam that operates in response to the axial force to connect the main clutch by the generated axial thrust force, wherein the cam is provided at a large diameter portion of the case-shaped torque transmitting member. apparatus. 3. The invention according to claim 1, wherein the case-like torque transmitting member includes an outer case,
An inner case is disposed inside the inner case so as to be relatively rotatable. A pilot clutch is disposed between the inner case and the shaft-like torque transmitting member.
A coupling or differential device wherein the cam is formed between the outer case and the inner case. 4. The coupling according to claim 3, wherein the inner case moves by receiving a thrust force of the cam and presses and connects the main clutch. Differential device. 5. The coupling according to claim 1, wherein the operating means is an electromagnet for moving the armature to press and connect the pilot clutch. Or a differential device.