JP2003148517A - Driving force transmission device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent abnormal sound produced in a driving force transmission device and its peripheral parts by preventing the transmission of a minor torque fluctuation produced in a pilot clutch mechanism due to minor fluctuation caused by a duty control of an input current to an electromagnetic coil and preventing the production of a large torque fluctuation in a main clutch mechanism. SOLUTION: A buffer member 18b absorbing the minor torque fluctuation produced in the pilot clutch mechanism 10e caused by the minor fluctuation in the input current to the pilot clutch mechanism 10e is disposed between the pilot clutch mechanism 10e and an outside rotating member 10a constituting the driving force transmission device.

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 which is interposed between two coaxially arranged shafts to intermittently connect a torque-transmittable connection between these two shafts.

[0002]

2. Description of the Related Art As one type of driving force transmission device, a main clutch is arranged between inner and outer rotary members which are coaxially and relatively rotatable with each other and which transmits torque between these rotary members by frictional engagement. A mechanism, an electromagnetic pilot clutch mechanism that is disposed between the rotating members and that is activated by electric conduction and frictionally engages, and disposed between the rotating clutch and the main clutch mechanism and the pilot clutch mechanism. There is a vehicle driving force transmission device provided with a cam mechanism that converts a pilot torque generated by friction of the pilot clutch mechanism into a pressing force for the main clutch mechanism.

In this type of driving force transmission device, the pilot clutch mechanism has an electromagnet, a friction clutch, and an armature. When the electromagnetic coil of the electromagnet is energized, the friction clutch and the armature are passed through the electromagnet. A circulating magnetic flux is formed, and the suction action generated thereby attracts the armature to frictionally engage the friction clutch, and the friction engagement force generated in the friction clutch is output to the cam mechanism as pilot torque.

The pilot torque generated in the pilot clutch mechanism is proportional to the input current to the electromagnetic coil, and is transmitted to the main clutch mechanism via the cam mechanism so that the outer rotating member and the inner rotating member are connected to each other. The torque can be transmitted according to the pilot torque generated in. In this case, the cam mechanism functions to amplify the pilot torque output from the pilot clutch mechanism and transmit it to the main clutch mechanism. The input current to the electromagnetic coil of the electromagnet of the pilot clutch mechanism is controlled by duty control.

[0005]

By the way, in the driving force transmission device of the type described above, when the input current to the electromagnetic coil of the electromagnet constituting the pilot clutch mechanism is controlled by duty control, a minute fluctuation of the input current is caused. Is unavoidable. The minute fluctuation caused by the duty control of the input current causes a minute fluctuation in the pilot torque generated in the pilot clutch mechanism. Further, the minute torque fluctuation generated in the pilot clutch mechanism is amplified by the cam mechanism and transmitted to the main clutch mechanism, and in the main clutch mechanism, it is manifested as a further increased large torque fluctuation. The large torque fluctuation that is manifested in the main clutch mechanism acts as a compulsory force that vibrates the driving force transmission device itself and the peripheral portion of the driving force transmission device, and causes abnormal noise in the driving force transmission device and the peripheral portion. Cause

Therefore, an object of the present invention is to eliminate such a problem that occurs when the input current to the electromagnetic coil of the electromagnet of the pilot clutch mechanism is controlled by duty control in the driving force transmission device of the type. It is in.

[0007]

SUMMARY OF THE INVENTION The present invention relates to a driving force transmission device, which is disposed between inner and outer rotary members which are coaxially and relatively rotatable with each other and which are frictionally engaged with each other. A main clutch mechanism for transmitting torque, an electromagnetic pilot clutch mechanism that is disposed between the rotating members and that is operated by energization and frictionally engages, the main clutch mechanism and the pilot between the rotating members. A drive force transmission device of a type provided with a cam mechanism arranged between clutch mechanisms and converting a pilot torque generated by friction of the pilot clutch mechanism into a pressing force for the main clutch mechanism is applied.

Therefore, the drive force transmission device according to the present invention is the drive force transmission device of the above-mentioned type, wherein the pilot is provided in the outer rotary member between the outer rotary member and the pilot clutch mechanism. The present invention is characterized in that a cushioning member is provided for alleviating minute torque fluctuations generated in the pilot clutch mechanism due to minute fluctuations in the input current to the clutch mechanism.

In the driving force transmission device according to the present invention,
The outer rotating member includes a cylindrical front housing having a side wall portion on one end side and an opening on the other end side, and a rear housing that is a lid body that liquid-tightly closes the opening portion on the other end side of the front housing. The cushioning member,
It may be arranged such that it is arranged between the thrust bearing interposed between the cam mechanism and the rear housing and the rear housing. Further, as the cushioning member, one made of rubber, resin or metal having heat resistance and oil resistance, and having vibration damping and torque transmitting functions can be appropriately selected.

[0010]

In the driving force transmission apparatus according to the present invention, the input current to the electromagnetic coil of the electromagnet forming the pilot clutch mechanism is controlled by the duty control, so that minute fluctuations of the input current are unavoidable. Occurring in a sudden way. The minute fluctuations in the input current resulting from the duty control of the input currents cause minute fluctuations in the pilot torque generated in the pilot clutch mechanism. However, the minute torque fluctuation generated in the pilot clutch mechanism is absorbed by the buffer member before being transmitted to the cam mechanism, and the cam mechanism receives the torque due to the set input current controlled by the duty control. Will be transmitted.

Therefore, in the driving force transmitting apparatus according to the present invention, like the conventional driving force transmitting apparatus of this type,
A minute torque fluctuation generated in the pilot clutch mechanism is not amplified by the cam mechanism and transmitted to the main clutch mechanism, and a large torque fluctuation is not manifested in the main clutch mechanism.
Therefore, the driving force transmission device itself and the peripheral portion of the driving force transmission device, which are caused by large torque fluctuations manifested in the main clutch mechanism, do not generate a forcing force, and the driving force transmission device and the peripheral portion thereof are not generated. The cause of abnormal noise will be eliminated.

In the driving force transmitting apparatus according to the present invention, the outer rotating member has a cylindrical front housing having a side wall portion at one end side and an opening at the other end side, and an opening portion at the other end side of the front housing. In the case of a rear housing that is a lid that is liquid-tightly closed, the cushioning member is arranged between the thrust bearing and the rear housing interposed between the cam mechanism and the rear housing. Is preferred. With this configuration, minute torque fluctuations generated in the pilot clutch mechanism are efficiently absorbed by the cushioning member immediately before being transmitted to the cam mechanism, which effectively causes the abnormal noise to be generated in the driving force transmission device and its surrounding parts. Can be resolved.

Further, the cushioning member used in the driving force transmitting apparatus according to the present invention is not limited as long as it has heat resistance and oil resistance, and has a vibration isolating function and a torque transmitting function against microvibration. Instead, a cushioning member made of rubber, resin, or metal having these characteristics can be appropriately selected and used. In this case, in order not to impair the torque responsiveness of the driving force transmission device, it is preferable to select a buffer member having an appropriate hardness.

[0014]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described below with reference to the drawings. FIG. 1 is a driving force transmission device 1 according to an example of the present invention.
0 is shown. As shown in FIG. 2, the driving force transmission device 10 is arranged in a driving force transmission path to a rear wheel side in a front wheel drive-based four-wheel drive vehicle and transmits the driving force to the rear wheel side. To control.

In the four-wheel drive vehicle, the transaxle 21 integrally includes a transmission, a transfer, and a front differential, and the driving force of the engine 22 is transmitted through the front differential of the transaxle 21 to both axle shafts 23a,
23a to drive the left and right front wheels 23b and 23b, and also to the propeller shaft 24 side. The propeller shaft 24 is coupled to the drive pinion shaft 25 via the driving force transmission device 10. When the propeller shaft 24 and the drive pinion shaft 25 are coupled so that torque can be transmitted, the driving force is transmitted to the rear differential 26. It is transmitted and output from the rear differential 26 to both axle shafts 27a, 27a to drive the left and right rear wheels 27b, 27b.

The driving force transmission device 10 is a known driving force transmission device in which the present invention is implemented, and is a known device except for the arrangement of a cushioning member and the arranging means constituting the main part of the present invention. is there. The driving force transmission device 10 includes a propeller shaft 2
4 and the drive pinion shaft 25, as shown in FIG. 1, an outer case 10a which is an outer rotating member, an inner shaft 10 which is an inner rotating member.
b, a main clutch mechanism 10c, a cam mechanism 10d, and a pilot clutch mechanism 10e.

The outer case 10a constituting the driving force transmission device 10 has a front housing 11a having a side wall portion at one end and an opening at the other end, and a front housing 11a.
The rear housing 11b is a lid that liquid-tightly closes the opening on the other end side of a. Rear housing 1
1b is screwed to the opening on the other end side of the front housing 11a to cover the opening. The front housing 11a is made of stainless steel which is a non-magnetic material, and the propeller shaft 2 is provided on the front surface of the side wall portion which is the front surface thereof.
4 is connected so that power can be transmitted. In addition, the rear housing 11b is made of a magnetic material such as iron inner and outer cylindrical portions 11b1 and 1b.
1b2 and an intermediate cylindrical portion 11b3 made of stainless steel which is a non-magnetic material and is fixed between the cylindrical portions 11b1 and 11b2 by welding or the like.

The inner shaft 10b is coaxially inserted into the front housing 11a with the central portion of the rear housing 11b penetrating liquid-tightly, and is axially restricted to the front housing 11a. It is rotatably supported by the rear housing 11b. A main clutch mechanism 10c, a cam mechanism 10d, and a pilot clutch mechanism 10e are assembled between the outer circumference of the inner shaft 10b and the inner circumference of the outer case 10a.
The front end portion of the drive pinion shaft 25 is inserted into the rear end portion of the inner shaft 10b, and is connected so that torque can be transmitted.

The main clutch mechanism 10c is a wet multi-plate type friction clutch, which is provided with a large number of clutch plates (inner clutch plate 12a and outer clutch plate 12b), and which is located on the side wall of the front housing 1a. It is arranged between the inner circumference and the outer circumference of the inner shaft 10b. Each inner clutch plate 12a that constitutes the friction clutch is assembled so as to be axially movable by spline fitting to an outer spline on the outer circumference of the inner shaft 10b, and each outer clutch plate 12b is attached to the inner circumference of the front housing 11a. The inner spline is spline-fitted to be movable in the axial direction. The inner clutch plates 12a and the outer clutch plates 12b are alternately located, and are in contact with each other and frictionally engaged with each other, and are separated from each other to be in a free state.

The cam mechanism 10d comprises a front housing 1
It is disposed between the inner periphery of 1a and the outer periphery of the inner shaft 10b, adjacent to the other side of the main clutch mechanism 10c. The cam mechanism 10d includes a first cam member 13, a second cam member 14, and a plurality of cam followers 15. The first cam member 13 is spline-fitted to an outer spline on the outer periphery of the inner shaft 10b and is movably assembled in the axial direction so as to be close to the inner clutch plate 12b on the other end side constituting the main clutch mechanism 10c. Are facing each other. The second cam member 14 has a smaller diameter than the first cam member 13, has an outer spline on the outer circumference, and is rotatably assembled to the outer circumference of the inner shaft 10b. Each cam follower 15 has a ball shape, and is fitted in each ball groove formed on the facing surfaces of the cam members 13 and 14 facing each other.

The pilot clutch mechanism 10e is an electromagnetic clutch and comprises an electromagnet 16a, a yoke 16b, an armature 16c, and a friction clutch 17. The electromagnet 16a has an annular shape, and is fitted into the yoke 16b and fitted into the annular recess 11c of the rear housing 11b. The yoke 16b is the rear housing 11b.
And are rotatably assembled with a slight gap maintained. Pilot clutch mechanism 10e having such a configuration
In the above, the rear housing 11b functions as a support member that supports the yoke 16b to which the electromagnet 16a is assembled and also functions as a magnetic path forming member, and is also a constituent member that constitutes the pilot clutch mechanism 10e.

The friction clutch 17 is a wet multi-plate friction clutch composed of a plurality of inner clutch plates 17a and outer clutch plates 17b. The inner clutch plates 17a are provided on the outer periphery of the second cam member 14 constituting the cam mechanism 10d. The outer clutch plates 17b are spline-fitted so as to be movable in the axial direction, and the outer clutch plates 17b are spline-fitted to the inner splines on the inner circumference of the front housing 11a so as to be movable in the axial direction. ing. The armature 16c has an annular shape, is spline-fitted to the inner spline of the inner circumference of the front housing 11a, and is assembled so as to be movable in the axial direction. ing.

Therefore, in the driving force transmission device 10 according to an example of the present invention, the thrust bearing 18a is provided on the outer periphery of the inner shaft 10b between the second cam member 14 constituting the cam mechanism 10d and the rear housing 11b. A cushioning member 18b is provided. Thrust bearing 1
8a functions to receive the second cam member 14 in the rear housing 11b when the cam mechanism 10d operates. Further, the cushioning member 18b is the pilot clutch mechanism 10e.
The second cam member 1 from the rear housing 11b during the operation of the
4 functions as a buffer for the torque transmitted to the motor 4 and to absorb a minute torque fluctuation contained in the torque.

The buffer member 18b is a ring-shaped member having a predetermined width, is heat resistant and oil resistant, and has a vibration damping function for microvibration and a torque transmitting function. Buffer member 1
8b is not limited as long as it has these characteristics, and a rubber, resin or metal cushioning member having these characteristics can be appropriately selected and used. In this case, in order not to impair the torque responsiveness of the driving force transmission device, it is important to select a buffer member having an appropriate hardness. In the driving force transmission device 10, the shock absorbing member 18b is made of synthetic rubber such as chloroprene.

In the driving force transmission device 10 having such a structure, the electromagnet 1 which constitutes the pilot clutch mechanism 10e.
When the electromagnetic coil 6a is in the non-energized state, the magnetic path is not formed and the friction clutch 17 is in the non-engaged state. Therefore, the pilot clutch mechanism 10e is in the non-operating state, and the cam mechanism 10d has the second cam member 14
Is in a state of being rotatable integrally with the first cam member 13 via the cam follower 15, and the main clutch mechanism 10c is in a non-operating state. Therefore, the vehicle constitutes the first drive mode which is the two-wheel drive.

On the other hand, when the electromagnetic coil of the electromagnet 16a is energized, the pilot clutch mechanism 10e has the yoke 16b and the rear cover 11 with the electromagnet 16a as a starting point.
b, a magnetic path circulating through the friction clutch 17 and the armature 16c is formed, and the electromagnet 16a is connected to the armature 16c.
Aspirate. Therefore, the armature 16c presses the friction clutch 17 into frictional engagement. As a result, pilot torque is generated in the pilot clutch mechanism 10e, and in the cam mechanism 10d, relative rotation is generated between the first cam member 13 and the second cam member 14, and the cam follower 15 and the ball groove act to cause the first rotation. The cam member 13 is pressed toward the main clutch mechanism 10c, and the first cam member 13 presses the main clutch mechanism 10.

As a result, the main clutch mechanism 10c
Frictionally engages in accordance with the frictional engagement force of the friction clutch 17, and torque transmission occurs between the outer case 10a and the inner shaft 10b. Therefore, the vehicle configures the second drive mode in which the propeller shaft 24 and the drive pinion shaft 25 are four-wheel drive between the non-direct connection state and the direct connection state. In this drive mode, the drive force distribution ratio between the front and rear wheels is set from 100: 0 (two-wheel drive state) to the drive state according to the running state of the vehicle.
It can be controlled within a range of 50:50 (direct connection state).

When the current supplied to the electromagnetic coil of the electromagnet 16a is increased to a predetermined value, the armature 1 of the electromagnet 16a is changed.
The attraction force for 6c increases, the armature 16c is strongly attracted, and the friction engagement force of the friction clutch 17 increases,
The relative movement between the first cam member 13 and the second cam member 14 is increased. As a result, the pressing force of the first cam member 13 on the main clutch mechanism 10c increases, and the main clutch mechanism 10c is brought into the engaged state. For this reason, the vehicle constitutes the third drive mode in which the propeller shaft 24 and the drive pinion shaft 25 are directly connected to each other and are four-wheel drive.

As described above, in the driving force transmission device 10, the driving force transmission device 10 operates in the same manner as this type of driving force transmission device to distribute the driving force to the rear wheel side by changing the input current to the electromagnetic coil of the electromagnet 16a. The control of the input current is performed by duty control. For this reason,
A minute fluctuation of the input current is inevitably caused by the duty control. In addition, the minute fluctuation caused by the duty control of the input current is caused by the pilot clutch mechanism 10e.
It causes a slight variation in the pilot torque generated in.

In order to deal with this, in the driving force transmission device 10, the second cam member 14 and the rear housing 1 which constitute the cam mechanism 10d are provided on the outer periphery of the inner shaft 10b.
A cushioning member 18b is arranged between the thrust bearing 18a and the rear housing 11b between the 1b. The buffer member 18b buffers the pilot torque transmitted from the rear housing 11b to the second cam member 14 during operation of the pilot clutch mechanism 10e, and functions to absorb a minute torque fluctuation contained in the torque. Therefore, the minute torque fluctuation generated in the pilot clutch mechanism 10e is absorbed by the buffer member 18b before being transmitted to the cam mechanism 10d, and the set input that is controlled by the duty control is set in the cam mechanism 10d. The pilot torque due to the current will be transmitted.

Therefore, in the driving force transmission device 10, as in the conventional driving force transmission device of this type, the minute torque fluctuation generated in the pilot clutch mechanism 10e is amplified by the cam mechanism 10d and the main clutch mechanism 10c. Is not transmitted to the main clutch mechanism 10c, and a large torque fluctuation does not become apparent in the main clutch mechanism 10c. Therefore, the main clutch mechanism 10
The driving force transmission device itself and the peripheral portion of the driving force transmission device due to the large torque fluctuation manifested in c do not generate a forcing force, and an abnormal noise is generated in the driving force transmission device and the peripheral portion thereof. The cause that causes it will be eliminated.

[Brief description of drawings]

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

FIG. 2 is a skeleton diagram showing a vehicle equipped with the same driving force transmission device.

[Explanation of symbols]

10 ... Driving force transmission device, 10a ... Outer case, 10b
… Inner shaft, 10c… Main clutch mechanism, 10
d ... Cam mechanism, 10e ... Pilot clutch mechanism, 11
a ... front housing, 11b ... rear housing, 1
1b1 ... Inner tubular portion, 11b2 ... Outer tubular portion, 11b3 ... Intermediate tubular portion, 11c ... Annular recess, 12a ... Inner clutch plate, 12b ... Outer clutch plate, 13 ... First cam member, 14 ... Second cam member, 15 ... Cam follower, 1
6a ... electromagnet, 16b ... yoke, 16c ... armature,
17 ... Friction clutch, 17a ... Inner clutch plate, 17b ... Outer clutch plate, 18a ... Thrust bearing, 18b ... Buffer member, 21 ... Transaxle, 22 ... Engine, 23a, 23a ... Axle shaft, 23b, 23b ... Front wheel, 24 ... propeller shaft, 25 ... drive pinion shaft, 26 ... rear differential, 27a, 27a ... axle shaft,
27b, 27b ... rear wheels.

Claims (3)

[Claims] 1. A main clutch mechanism which is disposed between both inner and outer rotating members which are coaxially and relatively rotatable with each other and which transmits torque between these rotating members by frictional engagement.
An electromagnetic pilot clutch mechanism which is disposed between the both rotary members and which is activated by energization and frictionally engages, and a pilot clutch mechanism which is disposed between the both rotary members and between the main clutch mechanism and the pilot clutch mechanism. In a vehicle drive force transmission device including a cam mechanism for converting a pilot torque generated by friction of a clutch mechanism into a pressing force for the main clutch mechanism, the outer rotating member and the pilot clutch mechanism are provided in the outer rotating member. A driving force transmission device, characterized in that a cushioning member for relaxing a slight torque fluctuation generated in the pilot clutch mechanism due to a fluctuation of the input current to the pilot clutch mechanism is disposed between 2. The driving force transmission device according to claim 1, wherein the outer rotary member has a cylindrical front housing having a side wall portion on one end side and an opening on the other end side, and the other end of the front housing. The rear housing is a lid that liquid-tightly closes the side opening, and the cushioning member is disposed between the thrust bearing and the rear housing interposed between the cam mechanism and the rear housing. A driving force transmission device characterized by being. 3. The drive force transmission device according to claim 1 or 2, wherein the buffer member is made of rubber, resin or metal having heat resistance and oil resistance, and having vibration and torque transmission functions. A drive force transmission device characterized by the above.