JPH10329561A - Driving force transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To engage a main clutch mechanism by increasing the frictional engagement force of a pilot clutch mechanism in a driving force transmission which transmits the frictional engagement force, as a pressing force, of an electromagnetic pilot clutch mechanism to a main clutch mechanism through a cam mechanism. SOLUTION: A driving force transmission is formed with a first cam member 17 which is attracted by the energization of an electromagnet 15 of a pilot clutch mechanism 10e so as to engage the pilot clutch mechanism 10e frictionally and connected to an inside rotating member 10b, a second cam member 18 which is assembled so that the movement of an outside rotating member 10a is allowed only in the axial direction and presses a main clutch mechanism 10c by the axial movement for frictional engagement, and a cam follower 19a provided between both cam members 17 and 18. Also the engagement force of the pilot clutch mechanism 10f is increased by the assist action of the cam mechanism 10f so as to increase the pressing force against the main clutch mechanism 10c.

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, a main clutch mechanism is frictionally engaged by an operation of a pilot clutch mechanism to transmit torque between the two rotating members. It is disposed between the driven shaft and the driven shaft, and functions to transmit torque between these two shafts.

[0004] The pilot clutch mechanism includes a friction clutch composed of a plurality of clutch plates, an electromagnet provided on one side of the friction clutch, and an armature provided on the other side of the friction clutch. A magnetic path is formed between the electromagnet, the friction clutch, and the armature by energization, and the armature is attracted to the electromagnet side by a magnetic induction action, and the attraction force causes the armature to frictionally engage the friction clutch, and the pilot clutch mechanism operates. Configuration.

[0005]

In the driving force transmission device of this type, the magnitude of the transmission torque between the two rotating members is determined by the magnitude of the frictional engagement force of the main clutch mechanism. The magnitude of the friction engagement force depends on the magnitude of the friction engagement force in the pilot clutch mechanism. For this reason, in order to increase the transmission torque between the two rotating members, and finally to bring the main clutch mechanism into the connected state and the two rotating members into the directly connected state, the pilot clutch mechanism must have a large frictional engagement. It must be constructed so that a resultant force is obtained.

In order to make the pilot clutch mechanism capable of obtaining a large frictional engagement force, means for increasing the number of clutch plates constituting the friction clutch in the pilot clutch mechanism, and the electromagnet constituting the pilot clutch mechanism There are means for increasing the number of turns of the coil and increasing the current applied to the coil of the electromagnet to increase the attraction force of the electromagnet to the armature.However, any of these means causes an increase in the size of the device and power consumption. Cause an increase.

Accordingly, an object of the present invention is to adopt a structure in which the frictional engagement force of the pilot clutch mechanism is increased without employing these means, thereby preventing an increase in the size of the device and increasing power consumption. Is to prevent

[0008]

SUMMARY OF THE INVENTION The present invention relates to a driving force transmitting device, and more particularly to a driving force transmitting device which is disposed between inner and outer rotating members which are coaxially and relatively rotatable with each other and which is frictionally engaged between the two rotating members. A main clutch mechanism that transmits torque, an electromagnetic pilot clutch mechanism that operates by energization and frictionally engages, and a friction engagement force of the pilot clutch mechanism that is located between the main clutch mechanism and the pilot clutch mechanism, The present invention is applied to a driving force transmission device having a cam mechanism for converting a pressing force to a clutch mechanism.

According to the present invention, there is provided a driving force transmission device of the above-mentioned type, wherein the cam mechanism is moved in the axial direction by energizing the pilot clutch mechanism so that the pilot clutch mechanism is frictionally engaged so that the two rotations are performed. A first cam member connected to one of the members, and a second cam member mounted to the other of the two rotating members so as to allow only the axial movement and frictionally engaging the main clutch mechanism by the axial movement. A cam member, the first cam member is interposed between the first cam member and the second cam member, and the first cam member is moved toward the pilot clutch mechanism and the second cam member is moved by the relative rotation of the two cam members. And a cam follower that moves to the main clutch mechanism side.

In the driving force transmission device according to the present invention,
A pressing force generated at a portion of the main clutch mechanism opposite to the cam mechanism by a relative rotation of the two rotating members to generate a pressing force according to a relative rotation of the two rotating members with respect to the main clutch mechanism. A mechanism may be provided, and the second cam member constituting the cam mechanism may be assembled via a spring member that restricts the movement toward the main clutch mechanism with a predetermined force.

Further, in the driving force transmission device according to the present invention, the first cam member constituting the cam mechanism can be constituted by the same member as the armature constituting the pilot clutch mechanism.

[0012]

In the driving force transmitting apparatus having the above-mentioned structure, when a current is applied to operate the pilot clutch mechanism, the first cam member constituting the cam mechanism moves in the axial direction to cause friction of the pilot clutch mechanism. While engaging, it is itself connected to one of the rotating members. For this reason, relative rotation occurs between the first cam member and the second cam member,
A cam follower moves the first cam member toward the pilot clutch mechanism and moves the second cam member toward the main clutch mechanism. As a result, the axial movement of the second cam member causes the main clutch mechanism to frictionally engage and transmit torque between the two rotating members.

During this time, the first cam member moving to the pilot clutch mechanism side is pressed by the pilot clutch mechanism by the action of the cam follower, and is finally connected to the same clutch mechanism to be interposed between the first cam member and the second cam member. To further increase the relative rotation. Therefore, the cam follower strongly presses the second cam member against the main clutch mechanism. As a result, the make clutch mechanism is connected, and both rotating members are directly connected.

As described above, according to the driving force transmission device of the present invention, the frictional engagement force generated by the pilot clutch mechanism is boosted by the cam mechanism and transmitted to the pilot clutch mechanism and the main clutch mechanism. In order to generate a large frictional engagement force in the mechanism, the number of clutch plates constituting the friction clutch of the pilot clutch mechanism is increased, the number of windings of the coil of the electromagnet is increased,
There is no need for any means such as increasing the current applied to the electromagnet. Therefore, the driving force transmission device does not increase in size, but can be reduced in size, and power consumption can be reduced.

Therefore, the driving force transmitting device is most suitable as a driving force transmitting device for a four-wheel drive vehicle and as a differential limiting device between left and right wheels.

In the driving force transmission device according to the present invention,
A pressing force generating mechanism that operates by the relative rotation of the two rotating members and generates a pressing force according to the relative rotation of the two rotating members with respect to the main clutch mechanism is disposed at a portion of the main clutch mechanism opposite to the cam mechanism. The second cam member constituting the cam mechanism may be assembled via a spring member for restricting the movement toward the main clutch mechanism with a predetermined force.

Thus, when the pilot clutch mechanism is not operated, the main clutch mechanism can generate a frictional engagement force in accordance with the relative rotation between the two rotating members to transmit torque between the two rotating members, By operating the clutch mechanism, the transmission torque between the two rotating members can be increased, and finally, the main clutch mechanism can be connected to bring the two rotating members into a directly connected state.

Further, in the driving force transmission device according to the present invention, the first cam member constituting the cam mechanism can be constituted by the same member as the armature constituting the pilot clutch mechanism. And the cam mechanism can be configured as an integral structure, and the size of the apparatus can be further reduced.

[0019]

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 transmitting device according to the present invention. As shown in FIG. 4, the driving force transmission device 10 is provided on a driving force transmission path to a rear wheel side in a four-wheel drive vehicle.

In the four-wheel drive vehicle, the transaxle 21 is provided with a transmission and a transfer integrally, and the driving force of the engine 22 is transmitted through the front differential 23 to both axle shafts 24a.
To drive the front wheels 24b and output to the first propeller shaft 25. 1st propeller shaft 2
5 is connected to the second propeller shaft 26 via the driving force transmission device 10, and when the two shafts 25, 26 are connected to be able to transmit torque, the driving force is transmitted to the rear differential 27, Same differential 2
7 to both axle shafts 28a and both rear wheels 2
8b is driven.

As shown in FIG. 1, the driving force transmitting device 10 includes an outer housing 10 which is an outer rotating member.
a, an inner shaft 10b serving as an inner rotating member, a main clutch mechanism 10c, a pressing force generating mechanism 10d, a pilot clutch mechanism 10e, and a cam mechanism 10f.

The outer housing 10a is composed of a bottomed cylindrical front case 11a, a cylindrical rear case 11b, and a cover 11c. The front case 11a is made of iron and the rear case 11b. Is made of stainless steel and is fixed by fitting the joining ends together.
The cover 11c is screwed into the opening of the rear case 11b to cover the opening in a liquid-tight manner. The cover 11c is formed of iron, A cylindrical non-magnetic member made of stainless steel is buried in an intermediate portion, and a non-magnetic portion 11c1 is formed. The rear end of the first propeller shaft 25 is connected to the front end of the front case portion 11a so as to transmit torque.

The inner shaft 10b has a cover 11c.
Extends in the outer housing 10a in a liquid-tight manner through a central portion of the front case 11a, and is rotatably supported by the front case portion 11a and the cover body 11c in a state where movement in the axial direction is restricted. The distal end of the second propeller shaft 26 is inserted into the inner shaft 10b, and is connected to transmit torque.

The main clutch mechanism 10c is a wet-type multi-plate type friction clutch, and has a large number of inner clutch plates 12a and outer clutch plates 12b. Each of the inner clutch plates 12a is spline-fitted to the outer periphery of the inner shaft 10b and is mounted so as to be movable in the axial direction.
Are spline-fitted to the inner periphery of the outer housing 10a and are movably mounted in the axial direction. The respective inner clutch plates 12a and the respective outer clutch plates 12b are alternately positioned, abut against each other and frictionally engage with each other, and are separated from each other to be in a free state.

The pressing force generating mechanism 10d operates the main clutch mechanism 10c, and includes a working piston 13, a rotor 14, and a viscous fluid sealed in the fluid chamber R as shown in FIG. Working piston 13
Is the outer housing 1 in the outer housing 10a.
0a and the inner shaft 10b, and are mounted liquid-tightly with respect to the outer housing 10a so as to be integrally rotatable and movable in the axial direction. It is mounted tightly and rotatably and axially movable.

In this state, the working piston 13 faces the outer clutch plate 12b of the main clutch mechanism 10c, and forms a recess on the inner wall side provided in the outer housing 10a in the fluid chamber R. Fluid chamber R
The rotor 14 is disposed therein. The rotor 14 is shown in FIG.
As shown in the figure, two vanes 14a extending in the radial direction,
14b, and is housed in the fluid chamber R while being fixed to the outer periphery of the inner shaft 10b. Each of the vanes 14a and 14b divides the fluid chamber R into two retaining chambers r1 and r2, and each of the retaining chambers r1 and r2 is filled with a highly viscous fluid.

The pilot clutch mechanism 10e and the cam mechanism 10f are of an integral construction, and include an electromagnet 15, a clutch plate 16, a first cam member 17, a second cam member 18, a cam follower 19a, and a leaf spring 19b. I have.

The electromagnet 15 has an annular shape and the cover 11c
Iron support member 15 rotatably supported in the outer recess
a non-magnetic portion 1 of the cover 11c
1c1. The clutch plate 16 has a plurality of long holes 16a formed at predetermined intervals in the circumferential direction.
16b are provided in two rows, are spline-fitted to the outer periphery of the inner shaft 10b, and are assembled so as to be movable in the axial direction. In the clutch plate 16, in this assembled state, each of the outer long holes 16 a is covered with the cover body 11.
Each of the inner long holes 16b faces the non-magnetic portion 11c1 in FIG. c, and is located away from the contact surface of the cover body 11c.

First and second cam members 17 and 18
As shown in FIG. 3, the cam surfaces 17a, 18a facing each other are provided on the facing surface.
A plurality of reference numerals 18a are formed at predetermined intervals in the circumferential direction, and a cam follower 19a is provided between the two cam grooves 17a, 18a.
Is interposed.

The first cam member 17 is connected to the outer housing 1.
0a and the inner shaft 10b in a free state and located on the clutch plate 16 side. The second cam member 18 is spline-fitted to the inner periphery of the rear case portion 11c in the outer housing 10a and is located on the side of the main clutch mechanism 10c, and can rotate integrally with the outer housing 10a and in the axial direction. It is movably assembled.

A leaf spring 19b is interposed between the cam members 17 and 18. The leaf spring 19b urges the second cam member 18 toward the cam follower 19a with a predetermined spring force, and separates from the outer clutch plate 12b of the main clutch mechanism 10c whose movement is restricted by the snap ring 12c. , Outer clutch plate 12
b is in a non-contact state.

In a structure in which the pilot clutch mechanism 10e and the cam mechanism 10f are integrally formed, by energizing the coil of the electromagnet 15, the support member 15a, the cover 11c, the first A magnetic path circulating through the cam member 17 and the support member 15a is formed. Further, the first cam member 17 is connected to the pilot clutch mechanism 10e.
, And is attracted to the electromagnet 15 side by a magnetic induction action to press the clutch plate 16 to press against the cover body 11c.

The switch for interrupting the energization of the coil of the electromagnet 15 is disposed near the driver's seat in the vehicle compartment, so that the driver can easily turn on and off as desired.

In the driving force transmission device 10 having such a configuration, when the coil of the electromagnet 15 is in a non-energized state,
The first cam member 17 is in a free state with respect to the clutch plate 16 and the second cam member 18 with a cam follower 19a.
Are in an integrated state through Therefore, the pilot clutch mechanism 10e and the cam mechanism 10f are in a non-operating state. Accordingly, the main clutch mechanism 10c is operated by the pressing force generated in the pressing force generating mechanism 10d due to the differential rotation between the two propeller shafts 25 and 26, and frictionally engages to reduce the torque of the outer housing 10a. 10b.

That is, both propeller shafts 25, 26
When differential rotation occurs between them, relative rotation occurs between the outer housing 10a and the inner shaft 10b, and the pressing force generating mechanism 10d generates a pressing force corresponding to the differential rotation speed between the two propeller shafts 25 and 26. This pressing force is transmitted to the main clutch mechanism 10c via the operating piston 13 and the main clutch mechanism 10c is frictionally engaged, so that torque is transmitted between the outer housing 10a and the inner shaft 10b.

As a result, the torque of the first propeller shaft 25 is transmitted to the second propeller shaft 26, and the vehicle runs in a four-wheel drive state. The torque transmission during this time is shown in FIG.
The state shown in the graph (I) of FIG.

In the driving force transmitting device 10, when a coil of the electromagnet 15 constituting the pilot clutch mechanism 10e is energized, a magnetic path indicated by a chain line in FIG. 1 is formed between the pilot clutch mechanism 10e and the cam mechanism 10f. The first cam member 17 is attracted to the electromagnet 15 side by the magnetic induction action, presses the clutch plate 16 and presses the cover plate 1.
1c. As a result, the first cam member 17 is connected to the inner shaft 10b via the clutch plate 16, and a relative rotation occurs between the first cam member 17 and the second cam member 18.

As a result, the cam follower 19a climbs over the two cam grooves 17a and 18a, presses the first cam member 17 toward the clutch plate 16, and releases the second cam member 1a.
8 against the main clutch mechanism 10c against the leaf spring 19b, and the clutch plate 16 of the first cam member 17 is pressed.
And the relative rotation between the second cam member 18 and the second cam member 18 is further increased. As a result, the pressing force against the second cam member 18 overcomes the urging force of the leaf spring 19b and presses the main clutch mechanism 10c, so that the main clutch mechanism 10c is strongly frictionally engaged to be in the connected state, and the two propeller shafts 25, 26 is directly connected.

As a result, the vehicle is driven by the first propeller shaft 2
The vehicle travels in a four-wheel drive state in which the fifth and second propeller shafts 26 are directly connected. The torque transmission during this time is represented by the graph (I
The state shown in I) is obtained.

As described above, according to the driving force transmission device 10, the frictional engagement force generated by the pilot clutch mechanism 10e is boosted by the cam mechanism 10f and transmitted to the pilot clutch mechanism 10e and the main clutch mechanism 10c. In order to generate a large frictional engagement force in the pilot clutch mechanism 10e, the number of clutch plates of the friction clutch constituting the pilot clutch mechanism is increased, the number of coil turns of the electromagnet 15 is increased, and the current applied to the coil of the electromagnet 15 is increased. You don't have to.

For this reason, in the driving force transmitting device 10, a single clutch plate 16 may be used as the clutch plate of the pilot clutch mechanism 10e, and the pilot clutch mechanism 10e is significantly smaller than the conventional pilot clutch mechanism. As well as
Power consumption can also be reduced. Therefore, the driving force transmission device 10 is optimal as a driving force transmission device for a four-wheel drive vehicle.

In the driving force transmitting device 10, the main clutch mechanism 10c is provided at a position opposite to the cam mechanism 10f in the main clutch mechanism 10c in accordance with the relative rotation between the outer housing 10a and the inner shaft 10b.
Is provided via a leaf spring 19b for regulating the movement of the second cam member 18 constituting the cam mechanism 10f toward the main clutch mechanism 10c with a predetermined force. Assembled.

For this reason, the pilot clutch mechanism 10e
Is inoperative, the main clutch mechanism 10c is frictionally engaged in accordance with the differential rotation speed between the two propeller shafts 25 and 26 to transmit torque from the first propeller shaft 25 to the second propeller shaft 26, A real-time four-wheel drive state can be established, and by operating the pilot clutch mechanism 10e, the main clutch mechanism 10c is connected and the two propeller shafts 25,
26 can be in a four-wheel drive state with a direct connection state.

In the driving force transmitting device 10, the armature forming the pilot clutch mechanism 10e is formed of the same member as the first cam member 17 forming the cam mechanism 10f. Can be further reduced in size, and the device can be significantly reduced in size.

[Brief description of the drawings]

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

FIG. 2 is a cross-sectional view of the same driving force transmission device taken along a line 2-2 in FIG. 1;

FIG. 3 is a sectional view of a cam groove of a cam mechanism constituting the driving force transmission device.

FIG. 4 is a schematic configuration diagram of a four-wheel drive vehicle equipped with the drive transmission device.

FIG. 5 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: front case portion, 11b: rear case portion, 11c ...
Cover body, 11c1 non-magnetic part, 10b inner shaft, 10c main clutch mechanism, 12a inner clutch plate, 12b outer clutch plate, 1
2c: snap ring, 10d: pressing force generating mechanism, 13
... working piston, 14 ... rotor, 14a, 14b ... vane part, 10e ... pilot clutch mechanism, 10f ... cam mechanism, 15 ... electromagnet, 15a ... support member, 16 ... clutch plate, 16a, 16b ... long hole, 17 ... 1 cam member, 18 ... second cam member, 17a, 18a ... cam groove, 1
9a: cam follower, 19b: leaf spring, 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, R: fluid chamber, r1, r2: retention chamber.

Claims (3)

[Claims] A main clutch mechanism disposed between inner and outer rotating members coaxially and relatively rotatable to each other to transmit torque between these 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; A driving force transmission device having a mechanism, wherein the cam mechanism is moved in the axial direction by energizing the pilot clutch mechanism to frictionally engage the pilot clutch mechanism and connect the cam mechanism to one of the rotating members. A cam member, a second cam member assembled to the other of the two rotating members so as to allow only the movement in the axial direction, and frictionally engaging the main clutch mechanism by the movement in the axial direction, and the first cam The first cam member is interposed between the member and the second cam member, and the first cam member is rotated by the relative rotation of the two cam members. Driving force transmission device, characterized in that the mechanism side to and the second cam member is constituted by a cam follower to move to the main clutch mechanism side. 2. The driving force transmission device according to claim 1, wherein a portion of the main clutch mechanism opposite to the cam mechanism is actuated by the relative rotation of the two rotating members to cause the main clutch mechanism to rotate relative to the main clutch mechanism. A pressing force generating mechanism for generating a pressing force according to the relative rotation of the two rotating members is provided, and the movement of the second cam member constituting the cam mechanism toward the main clutch mechanism is regulated by a predetermined force. A driving force transmitting device, wherein the driving force transmitting device is assembled via a spring member. 3. The driving force transmission device according to claim 1, wherein the first cam member forming the cam mechanism is the same as an armature forming the pilot clutch mechanism. Driving force transmission device.