JPH10331873A - Driving force transmitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a device in cost, and make the device small in size by reducing component parts in number, making its structure simple, and enhancing operating performance in assembly in a driving force transmitting device which electrically controls torque transmission between both rotating parts. SOLUTION: This device is provided with a friction clutch 10c performing torque transmission between both rotating members, a control means 10d permitting the friction clutch 10c to be frictionally engaged therewith, and with a cam means 10e which is actuated by the friction clutch 10c so as to allow the friction clutch 10c to be frictionally engaged therewith, and a current main clutch means can be eliminated by letting the cam means 10e be operated with respect to the friction clutch 10c, component parts can thereby be reduced in number, its structure can be made simple, operating performance in assembly can thereby be enhanced, the device can be lowered in cost, and furthermore, the device can thereby be made small in size.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving force transmission device disposed between a rotary shaft and a driven shaft of a vehicle, such as a driven shaft, for transmitting torque between the rotary members.

[0002]

2. Description of the Related Art As one type of a driving force transmitting device, as proposed in Japanese Patent Application Laid-Open No. 3-219123 under the name of a connecting device, a driving force transmitting device is provided between inner and outer rotating members coaxially and relatively rotatably positioned. A main clutch mechanism that is disposed and transmits torque between these two rotating members by frictional engagement;
An electromagnetic pilot clutch mechanism that operates and frictionally engages by energization, and a cam that is located between the main clutch mechanism and the pilot clutch mechanism and converts a frictional engagement force of the pilot clutch mechanism into a pressing force on the main clutch mechanism; There is a type of driving force transmission device having a mechanism.

In this type of driving force transmission device, the operation of a pilot clutch mechanism is electrically controlled to control the transmission of torque between both rotating members. The operation of the pilot clutch mechanism causes the main clutch mechanism to frictionally engage. I do. Therefore, the driving force transmission device is disposed, for example, between a drive shaft and a driven shaft that constitute a four-wheel drive vehicle, and controls the four-wheel drive vehicle to operate in a two-wheel drive state by controlling the operation of a pilot clutch mechanism. , The four-wheel drive state, and the four-wheel drive state refers to a four-wheel drive state in which the drive shaft and the driven shaft are in a directly connected state and a non-directly connected state.

[0004]

As described above, in the driving force transmission device of the type in which the torque transmission between the two rotating members is electrically controlled, the main clutch mechanism for transmitting the torque between the two rotating members, A pilot clutch mechanism that electrically controls the engagement, and a cam mechanism that transmits the friction engagement force of the pilot clutch mechanism as the friction engagement force to the main clutch mechanism are indispensable. There are many components and the structure is complicated. Therefore, the cost is inevitably high and the size is increased due to factors such as low workability of the assembly work.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to reduce the cost and reduce the size of a driving force transmission device that electrically controls torque transmission between both rotating members.

[0006]

SUMMARY OF THE INVENTION According to the present invention, a friction clutch disposed between inner and outer rotating members coaxially and relatively rotatable with each other is actuated by energization to frictionally engage the friction clutch. A driving force transmission device comprising an electromagnetic control means and a cam means operated by the friction clutch to assist frictional engagement of the friction clutch, wherein the cam means has a shaft mounted on one of the rotating members. A first cam member assembled to restrict movement in the direction and rotation in the circumferential direction; a second cam member connected to the other of the two rotating members by frictional engagement of the friction clutch; A cam follower interposed between the first cam member and the second cam member to move the second cam member in the axial direction by the relative rotation of the two cam members to assist the friction engagement of the friction clutch. Is composed It is characterized in.

In the driving force transmission device according to the present invention,
The control means includes an electromagnet located on one side of the friction clutch, and an armature located on the other side of the friction clutch, which is attracted in the axial direction by energization of the electromagnet and presses the friction clutch. A second cam member constituting the cam means is positioned opposite to the armature, and the armature is pressed against the friction clutch by axial movement to assist the friction engagement of the friction clutch. A configuration in which the second cam member is assembled while allowing the axial movement and the circumferential rotation between the two rotating members, and a spring is biased in a direction away from the armature. can do.

[0008]

In the driving force transmitting apparatus having the above-described structure, the friction clutch is frictionally engaged by energizing the control means, the friction engagement force is controlled, and the cam means is frictionally engaged by the friction clutch. Operate as described below to assist friction engagement of the friction clutch. This allows
Torque is transmitted between the inner and outer rotating members.

That is, in the cam means, the second cam member is connected to the other of the two rotating members by frictional engagement of the friction clutch, and relative rotation is generated between the second cam member and the first cam member. Thereby, the cam follower functions to move the second cam member in the axial direction to assist the friction engagement of the friction clutch.

As described above, in the driving force transmission device, the friction clutch is frictionally engaged by energizing the control means, the friction engagement force is controlled, and the cam means is operated by the friction engagement of the friction clutch. By assisting the friction engagement of the friction clutch, torque is transmitted between the inner and outer rotating members. For this reason,
The driving force transmission device does not require a main clutch mechanism that transmits torque between the two rotating members, such as a conventional driving force transmission device that electrically controls torque transmission between the two rotating members, and the pilot clutch mechanism What is necessary is just to employ the friction clutch corresponding to a friction clutch.

Therefore, according to the driving force transmission device, the number of components can be reduced, the structure can be simplified, and the workability of the assembling operation can be improved as compared with the conventional driving force transmission device. And the size of the device can be reduced.

In the driving force transmission device according to the present invention, the control means includes an electromagnet located on one side of the friction clutch and an axial magnet attracted in the axial direction by energization of the electromagnet located on the other side of the friction clutch. A configuration having an armature for pressing can be provided, whereby the frictional engagement of the friction clutch can be easily controlled by energizing the electromagnet.

Further, in the driving force transmitting device according to the present invention, the second cam member constituting the cam means is located opposite to the armature, and the armature is pressed against the friction clutch by moving in the axial direction. The friction engagement of the friction clutch can be configured to be assisted, whereby the assistance for the friction engagement of the friction clutch by the cam means can be facilitated.

Further, in the driving force transmission device according to the present invention, the second cam member is assembled between the two rotating members so as to allow axial movement and circumferential rotation, and is separated from the armature. Can be configured to bias the spring. Thereby, until the frictional engagement of the friction clutch reaches a predetermined frictional engagement force, the cam means is in a non-operating state, the assistance of the frictional engagement with the frictional clutch is regulated, and the frictional engagement of the friction clutch is reduced. When the predetermined frictional engagement force is reached, the cam means can be operated to assist the frictional engagement with the friction clutch, so that the vehicle is driven in a two-wheel drive state, and the four-wheel drive state in which the drive shaft and the driven shaft are not directly connected. , And three drive modes in which the drive shaft and the driven shaft are directly connected to each other in a four-wheel drive state can be easily configured.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 shows an example of a driving force transmission device according to the present invention. As shown in FIG. 3, the driving force transmission device 10 is disposed on a driving force transmission path to a rear wheel of a four-wheel drive vehicle.

In the four-wheel drive vehicle, the transaxle 21 has a transmission and a transfer integrally, and outputs the driving force of the engine 22 to both axle shafts 24a via the front differential 23 to drive the front wheels 24b. And output to the first propeller shaft 25. First propeller shaft 25
Is connected to the second propeller shaft 26 via the driving force transmission device 10, and when the two shafts 25 and 26 are connected to be capable of transmitting torque, the driving force is transmitted to the rear differential 27, and Differential 27
Is output to both axle shafts 28a and both rear wheels 28
b is driven.

As shown in FIG. 1, the driving force transmitting device 10 includes an outer housing 10 as an outer rotating member.
a, inner shaft 10b as inner rotating member, friction clutch 10c, control means 10d, and cam means 10e
It has.

The outer housing 10a is composed of a bottomed cylindrical outer case 11a and a cover 11b. The cover 11b is screwed into an opening at the rear end of the outer case 11a, and the opening is liquid-tight. It is covered. In the outer housing 10a, the outer case 11a is made of non-magnetic stainless steel, and the cover body 11b is made of magnetic iron. The cover body 11b has a cylindrical non-magnetic body at a radially intermediate portion. It is buried to form a nonmagnetic portion 11b1.

The inner shaft 10b has a pipe shape, is inserted into the outer housing 10a through a central portion of the cover 11b, and has a tip end formed by an inner hole of the outer case 11a. The rear end is liquid-tightly and rotatably supported by the hole. The friction clutch 10c, the control means 10d, and the cam means 10e
It is arranged between the outer housing 10a and the inner shaft 10b. The rear end of the first propeller shaft 25 is connected to the outer housing 10a, and the second propeller shaft 26 is connected to the inner shaft 10b.

In the driving force transmission device 10, the friction clutch 10 c includes a plurality of inner clutch plates 12.
a, and an outer clutch plate 12b, the control means 10d includes an electromagnet 13a, and an armature 13b, and the cam means 10e includes a first cam member 14, a second cam member 15, and a cam follower 16a.

Of these components, the cam means 10e
The first cam member 14 constituting the outer housing 10
The innermost part of the outer case 11a is spline-fitted to the inner periphery of the outer case 11a, and is assembled so as to be integrally rotatable with the outer housing 10a. Further, the second cam member 15 is assembled in the outer case 11 to allow rotation in the circumferential direction and movement in the axial direction, and faces the first cam member 14.

The inward flange portion 15a of the second cam member 15
A cam groove 15b is formed in the first cam member 14 so as to face a cam groove 14a provided in the first cam member 14.
An inner spline portion 15d is formed in 5c, and a cam follower 16a is interposed between the cam grooves 14a, 15b of the two cam members 14, 15. In the second cam member 15, as shown schematically in an enlarged manner in FIG. 2, a nut 1 screwed to a boss portion of the outer case 11 a at an inner peripheral edge thereof.
The other end of the disc spring 16b, one end of which is hooked to 1c, is hooked. The disc spring 16b presses the second cam member 15 toward the cam follower 16a with a predetermined force.

The friction clutch 10c is connected to the inner peripheral side of the second cam member 15 constituting the cam means 10e and the inner shaft 1
The outer clutch plates 12b, which are disposed between the outer circumferences of the outer clutch 0b and the friction clutch 10c, are spline-fitted to the inner spline portion 15d of the second cam member 15 on the outer circumference side, and can move in the axial direction. It is installed in
Further, each inner clutch plate 12a is spline-fitted to the outer spline portion of the inner shaft 10b on its inner peripheral side, and is mounted so as to be movable in the axial direction.

The inner clutch plates 12a and the outer clutch plates 12b are alternately arranged in the axial direction, and are located in the axial direction between the cover body 11b and an armature 13b to be described later. A plurality of elongated holes 12a1 and 12b1 extending a predetermined length in the circumferential direction are formed in each of the inner clutch plates 12a and the outer clutch plates 12b at predetermined intervals, and each of the elongated holes 12a1 and 12b1 is formed.
Are in a positional relationship capable of opposing the non-magnetic portion 11b1 formed on the cover 11b.

Armature 13 constituting control means 10d
b is a ring shape, and the cylindrical portion 15c of the second cam member 15
Is mounted between the inner flange portion 15a and the outer clutch plate 12b of the friction clutch 10c so as to allow rotation in the circumferential direction and movement in the axial direction, and the inner flange portion 15a of the second cam member 15 A predetermined gap is secured by the urging force of the disc spring 16b.

The electromagnet 13a constituting the control means 10d has a cylindrical shape, is fitted to a cylindrical support member 17, and is exposed at the distal end thereof. The support member 17 includes a cover 11b.
Is rotatably fitted to the recess 11b2 on the rear end side and is supported by a part of the vehicle body (not shown). In the electromagnet 13a assembled in this state, when the coil is energized, a magnetic path is formed between the support member 17, the cover body 11b, and the armature 13b as shown by a dashed line in FIG. It is attracted to the electromagnet 13b side by the magnetic induction action according to the applied current.

The energization of the coil of the electromagnet 13a is controlled by an operation switch, and the switch is arranged near the driver's seat so that the driver can easily operate the switch.

In the driving force transmission device 10 having such a configuration, when the coil of the electromagnet 13a constituting the control means 10d is in a non-energized state, the electromagnet 13a does not attract the armature 13b and the friction clutch 10c Is in a disengaged state, and the cam means 10e is in a non-operated state. Therefore, there is no torque transmission between the outer housing 10a and the inner shaft 10b, and the connection between the first propeller shaft 25 and the second propeller shaft 26 is interrupted, and the vehicle constitutes a two-wheel drive mode. In this state, the transmission torque between the two propeller shafts 25 and 26 is zero irrespective of the differential rotation speed between the two propeller shafts 25 and 26, as shown in the graph (2) of FIG.

In the driving force transmission device 10, when the coil of the electromagnet 13a is energized, a magnetic path indicated by a dashed line in FIG. 1 is formed, and the armature 13b is attracted to the electromagnet 13a by a magnetic induction action. As a result, the armature 13b presses the friction clutch 10c to frictionally engage,
The second member forming the inner shaft 10b and the cam means 10e
A connection state is formed between the cam members 15 by a force corresponding to the frictional engagement force of the friction clutch 10c.

As a result, the inner shaft 10b is connected to the outer housing 10a via the friction clutch 10c and the cam means 10e with a force corresponding to the frictional engagement force of the friction clutch 10c, and the inner shaft 10b is connected between the outer housing 10a and the inner shaft 10b. In this case, torque is transmitted in accordance with the frictional engagement force of the friction clutch 10c, and the vehicle constitutes a four-wheel drive mode.

The frictional engagement force of the friction clutch 10c increases and decreases according to the current applied to the coil of the electromagnet 13a. By controlling the current applied to the coil of the electromagnet 13a, the frictional engagement force of the friction clutch 10c is changed. The transmission torque between the propeller shafts 25 and 26 can be changed. For example, the electromagnet 13a
By controlling the applied current to the coil according to various running conditions, the transmission torque with respect to the differential rotation speed between the two propeller shafts 25 and 26 can be changed within the range shown in the graph (1) of FIG. . Further, if desired, it is possible to control the transmission torque simply according to only the differential rotation speed between the two propeller shafts 25, 26.

In the driving force transmission device 10, when the current applied to the coil of the electromagnet 13a is increased to a predetermined value to increase the friction engagement force in the friction clutch 10c to a predetermined value, the second cam member 15 Shaft 1
0b, relative rotation occurs with the first cam member 14. As a result, in the cam means 10e, the cam followers 16a are
a, 15b and the second cam member 15 is
The armature 13b is moved toward the armature 13b against the armature 13b, and the armature 13b is strongly pressed against the friction clutch 10c.

FIG. 2 schematically shows the operation of the cam means 10e. When the relative rotation between the first cam member 14 and the second cam member 15 reaches a predetermined value, the cam follower 16a
The pressing force FC against the second cam member 15 is the disc spring 16b.
The second cam member 15 moves in the axial direction to strongly press the armature 13b against the friction clutch 10c.

As a result, the friction clutch 10c is brought into a connected state, and the inner shaft 10
b is coupled to the outer housing 10a, and the vehicle constitutes a four-wheel drive drive mode in which both propeller shafts 25 and 26 are directly connected. Both propeller shafts 2 in this state
The transmission torque between the propeller shafts 5 and 26 reaches a maximum value irrespective of the differential rotational speed between the propeller shafts 25 and 26, as shown in a graph (3) in FIG.

As described above, in the driving force transmission device 10, the friction clutch 1
0c is frictionally engaged, the frictional engagement force is controlled, and the cam means 1 is frictionally engaged by the friction clutch 10c.
0e to assist the frictional engagement of the friction clutch 10c, the outer housing 10
and the inner shaft 10b is configured to transmit torque.

For this reason, the driving force transmitting device 10 includes a main clutch mechanism for transmitting torque between both rotating members, such as a conventional driving force transmitting device for electrically controlling torque transmission between both rotating members. Clutch 10 corresponding to the pilot clutch mechanism friction clutch without requiring
c may be adopted.

Therefore, according to the driving force transmission device 10, compared with the conventional driving force transmission device, the number of components can be reduced, the structure can be simplified, and the workability of the assembling operation can be improved. The cost can be reduced and the device can be downsized.

Further, in the driving force transmission device 10, the control means 10d is driven by energizing the electromagnet 13a located on one side of the friction clutch 10c and the coil of the electromagnet 13a located on the other side of the friction clutch 10c. 13b which is sucked in the direction and presses the friction clutch 10c
, And the second part constituting the cam means 10e.
The cam member 15 is positioned so as to face the armature 13b, and the armature 13b is pressed against the friction clutch 10c by axial movement to assist the friction engagement of the friction clutch 10c.

Thus, the frictional engagement of the friction clutch 10c can be easily controlled by energizing the coil of the electromagnet 13a, and the cam means 10e can facilitate the frictional engagement of the friction clutch 10c. it can.

Further, in the driving force transmitting device 10, the second cam member 15 is assembled between the outer housing 10a and the inner shaft 10b so as to be allowed to move in the axial direction and to rotate in the circumferential direction. The structure is such that a spring is urged in the separating direction. As a result, the cam means 10e is in a non-operating state until the frictional engagement of the friction clutch 10c reaches a predetermined frictional engagement force, and the assistance of the frictional engagement with the frictional clutch 10c is regulated, so that the frictional clutch 10c When the frictional engagement reaches a predetermined frictional engagement force, the cam means 10e is operated, and the friction clutch 10c
To facilitate frictional engagement.

Therefore, according to the driving force transmission device 10, the vehicle is driven in a two-wheel drive state, a four-wheel drive state in which the drive shaft and the driven shaft are not directly connected, and a four-wheel drive state in which the drive shaft and the driven shaft are directly connected. It is possible to easily configure three driving modes in the driving state.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of a driving force transmission device according to the present invention.

FIG. 2 is an enlarged view schematically showing a part of cam means constituting the driving force transmission device.

FIG. 3 is a schematic configuration diagram of a four-wheel drive vehicle equipped with the drive transmission device.

FIG. 4 is a graph showing a relationship between a transmission torque and a differential rotation speed between both propeller shafts in the driving force transmission device.

[Explanation of symbols]

Reference numeral 10: driving force transmission device, 10a: outer housing, 1
1a: outer case, 11b: cover body, 11b1: non-magnetic part, 11b2: recess, 11c: nut, 10b ...
Inner shaft, 10c: friction clutch, 12a: inner clutch plate, 12b: outer clutch plate, 12a1, 12b1: long hole, 10d: control means, 13
a: electromagnet, 13b: armature, 10e: cam means,
Reference numeral 14: first cam member, 14a: cam groove, 15: second cam member, 15a: inward flange portion, 15b: cam groove, 15
c: cylindrical portion, 15d: inner spline portion, 16a: cam follower, 16b: disc spring, 17: support member, 21: transaxle, 22: engine, 23: front differential, 24a: axle shaft, 24b: front wheel, 25 ... first propeller shaft, 26 ... second propeller shaft, 27 ... rear differential, 28a ... axle shaft, 28b ... rear wheel.

Claims (4)

[Claims] A friction clutch disposed between inner and outer rotating members coaxially and relatively rotatable relative to each other; an electromagnetic control means which operates by energization to frictionally engage the friction clutch; A driving force transmission device provided with a cam means operated by a friction clutch to assist frictional engagement of the friction clutch, wherein the cam means applies axial movement and circumferential rotation to one of the two rotating members. A first cam member that is assembled in a regulated manner, a second cam member that is connected to the other of the two rotating members by frictional engagement of the friction clutch, the first cam member and the second cam member. A cam follower interposed between the cam members to move the second cam member in the axial direction by the relative rotation of the two cam members and to assist the frictional engagement of the friction clutch. Driving force transmission Location. 2. The driving force transmitting device according to claim 1, wherein said control means includes an electromagnet located on one side of said friction clutch and energizing a coil of said electromagnet located on the other side of said friction clutch. A driving force transmission device comprising: an armature that is sucked in an axial direction by the actuator to press the friction clutch. 3. The driving force transmitting device according to claim 2, wherein the second cam member constituting the cam means is located opposite to the armature, and the armature is moved in the axial direction to connect the armature to the friction clutch. A driving force transmitting device for assisting frictional engagement of the friction clutch by pressing the driving force. 4. The driving force transmission device according to claim 3, wherein the second cam member is assembled between the two rotating members so as to allow axial movement and circumferential rotation. A driving force transmission device, which is biased by a spring in a direction away from the armature.