JP2015187476A - clutch device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a clutch device capable of improving transmission torque capacity without degrading operability.SOLUTION: A clutch device 1 comprises: a flywheel 20 driven to rotate by an output shaft of an engine; a clutch cover 30 fixed to the flywheel 20; a pressure plate 50 facing the flywheel 20 and supported by the clutch cover 30 to be relatively displaceable in an axial direction; a diaphragm spring 60 energizing the pressure plate 50 toward the clutch cover 30; a clutch disc 40 attached to an input shaft of a transmission and held between the flywheel 20 and the pressure plate 50; and a torque cam mechanism T including a cam 34 provided at one of the pressure plate 50 and the clutch cover 30 and a cam follower 52 provided at the other unit, and pressing the pressure plate 50 toward the clutch disc 40 in response to a torque transmitted by the pressure plate 50.

Description

  The present invention relates to a clutch device provided in a power transmission device of a vehicle, and particularly relates to an improved transmission torque capacity without deteriorating operability.

A clutch device provided between an engine of an automobile and a transmission includes a clutch disk having a friction material (facing) between a flywheel of the engine and a pressure plate provided on a clutch cover and urged by a diaphragm spring. It is comprised by pinching (crimping).
The clutch is disengaged by displacing the inner peripheral edge of the diaphragm spring in the axial direction with a release bearing to lose the pressure-bonding force.
In such a clutch device, as a technique for increasing the torque capacity that can be transmitted without causing clutch slipping, etc., corresponding to a high-power engine, the clutch disk has a large diameter, the friction material is changed, and the multi-plate clutch is used. And strengthening diaphragm springs.

However, increasing the diameter of the clutch disk is restricted by the size of the clutch housing and interference with other parts.
In addition, it is difficult to significantly increase the frictional force by changing the material of the friction material.
A multi-plate clutch such as a twin plate can increase the transmission torque capacity, but its operability such as ease of handling at the time of start-up deteriorates and is not suitable for a passenger car driven by a general driver.
When the diaphragm spring is reinforced and the spring constant is increased, it is possible to increase the transmission torque capacity by increasing the pressure applied to the clutch plate. However, in this case, the pedal force of the clutch pedal is increased and the operability is impaired. End up.

Conventionally, it has been proposed to provide a torque cam mechanism that generates thrust so as to increase the pressure-bonding force of the friction material in response to the transmission torque in a part of the torque transmission path in the clutch device.
For example, in Patent Document 1, a torsional vibration absorbing device that absorbs engine torque fluctuations using friction plate slip is provided with a torque cam mechanism that reinforces the pressure-bonding force of the friction plate as the transmission torque increases. Is described.
Patent Document 2 describes that in a vehicle having an idle stop function, a torque cam mechanism is provided in an electromagnetic start clutch provided between an engine and an automatic transmission.
Patent Document 3 describes that in a clutch device provided in a manual transmission, in order to shorten the stroke of the release bearing, the pressure plate is divided into two in the axial direction and a torque cam mechanism is provided therebetween. ing.

JP 59-151624 A JP 2004-232807 A JP 2009-264407 A

None of the above-described conventional techniques can obtain a function of amplifying the pressure-bonding force of the friction material while suppressing the operation force of the clutch device.
That is, in Patent Document 1, although the torque cam mechanism is provided in the torsional vibration absorbing device, the clutch device itself has a general configuration and does not solve the above-described problem.
Patent Document 2 relates to a special use of an electromagnetic start clutch for an automatic transmission, and describes any application of a torque cam mechanism to a general clutch device applied to a manual transmission or the like. Not suggested.
Further, in the technique described in Patent Document 3, the thrust of the torque cam mechanism acts to spread the pressure plate divided in two in the axial direction, but this thrust acts to push back the diaphragm spring. It does not lead to strengthening the crimping force
In view of the above-described problems, an object of the present invention is to provide a clutch device that has improved transmission torque capacity without deteriorating operability.

The present invention solves the above-described problems by the following means.
According to a first aspect of the present invention, there is provided a flywheel that is rotationally driven by an output shaft of an engine, a clutch cover that is fixed to the opposite side of the engine in the flywheel, and that faces the flywheel and is opposed to the clutch cover. A pressure plate that is supported so as to be relatively displaceable in the axial direction, a diaphragm spring that urges the pressure plate toward the clutch cover, and a flywheel that is attached to the input shaft of the transmission and the pressure plate. A clutch disk sandwiched between the clutch disk; a cam provided on one of the pressure plate and the clutch cover; and a cam follower provided on the other; the pressure plate is moved in response to torque transmitted by the pressure plate; To the side A clutch device, characterized in that it comprises a pressure torque cam mechanism.
According to this, since the boosting effect of the crimping force by the thrust of the torque cam mechanism can be obtained according to the transmission torque between the pressure plate and the clutch disk, the clutch disk can be crimped without increasing the spring constant of the diaphragm spring. The force can be increased and the transmission torque capacity can be increased.
For this reason, even in a vehicle with a high engine torque, the operability can be improved by reducing the depression force of the clutch pedal.
In addition, since the clutch pressing force changes according to the engine torque, it is not necessary to subdivide the specifications of the clutch device between vehicles equipped with engines having different maximum torques, and the parts can be shared.
If the required transmission torque capacity is the same, the present invention can be applied to reduce the size and weight of the clutch device and save space.

The invention according to claim 2 is the clutch device according to claim 1, further comprising a return spring that biases the pressure plate toward the clutch cover.
According to this, for example, in a region where the engine torque is low, such as when racing (running) or starting, it is possible to cancel the boosting effect by the torque cam mechanism and prevent unintended clutch engagement.

  As described above, according to the present invention, it is possible to provide a clutch device with improved transmission torque capacity without deteriorating operability.

It is sectional drawing which cut and looked at the Example of the clutch apparatus to which this invention was applied by the plane orthogonal to an axial direction. FIG. 2 is a cross-sectional view taken along the line II-II in FIG. 1 (enlarged view of a torque cam mechanism). It is a graph which shows the correlation with the engine torque and clutch press-fit force in the clutch apparatus which is a comparative example of this invention. It is a graph which shows the correlation with the engine torque and clutch press-fit force in the clutch apparatus of an Example.

  It is an object of the present invention to provide a clutch device having an improved transmission torque capacity without deteriorating operability, in response to the transmission torque of the pressure plate between the clutch cover and the pressure plate. The problem has been solved by providing a torque cam mechanism that presses the pressure plate toward the clutch disk, and a return spring that biases the pressure plate toward the clutch cover and cancels the boosting effect of the torque cam in the low engine torque region.

Embodiments of a clutch device to which the present invention is applied will be described below.
The clutch device according to the embodiment is provided in an automobile such as a passenger car having a manual transmission with an internal combustion engine such as a gasoline engine or a diesel engine as a driving power source.
FIG. 1 is a cross-sectional view of the clutch device of the embodiment as seen along a plane orthogonal to the axial direction.
The clutch device 1 is provided between an engine (not shown) and a transmission 10 that is a manual transmission, and transmits and disconnects driving force between an output shaft of the engine and an input shaft 11 of the transmission 10.

The clutch device 1 includes a flywheel 20, a clutch cover 30, a clutch disk 40, a pressure plate 50, a diaphragm spring 60, a release bearing 70 and the like that are substantially housed in the clutch housing 12.
The clutch housing 12 is provided at an end portion on the engine side of a transmission case that is a housing that houses a transmission mechanism portion and the like of the transmission 10, and has a space portion that opens to the engine side.
The tip of the clutch housing 12 is fastened and fixed to a crankcase of an engine (not shown).

An input shaft 11 that inputs driving force to the transmission 10 is disposed concentrically with a crankshaft that is an output shaft of the engine.
The end of the input shaft 11 on the engine side protrudes from the inside of the transmission case to the inside of the clutch housing 12.
A spline 11 a that engages with the clutch disk 40 is formed on the outer peripheral surface portion at the distal end portion of the input shaft 11.

The flywheel 20 is a disk-shaped member (rotating mass body) fixed to the end of the crankshaft of the engine.
A friction surface with the clutch disk 40 is formed on the surface of the flywheel 20 on the transmission 10 side.
A driven gear that engages with a drive gear of a starter motor (not shown) is formed on the outer peripheral edge of the flywheel 20.

The clutch cover 30 is an annular member that is provided on the transmission 10 side of the flywheel 20 and forms a space portion that accommodates the clutch disk 40 and the like in cooperation with the flywheel 20.
The outer peripheral edge 31 of the clutch cover 30 is fastened to the flywheel 20 by bolts 31a.

The clutch cover 30 includes a cylindrical portion 32 that protrudes from the outer peripheral edge portion 31 toward the transmission 10 side, and a diaphragm spring holding portion 33 that extends from the end portion of the cylindrical portion 32 on the transmission 10 side toward the inner diameter side.
The diaphragm spring holding portion 33 is disposed at an axial distance from the friction surface of the flywheel 20, and the regions on the outer diameter side of the clutch disk 40, the pressure plate 50, and the diaphragm spring 60 are accommodated therebetween. .
An opening is formed in the center portion of the diaphragm spring holding portion 33.
The outer peripheral edge portion 31, the cylindrical portion 32, and the diaphragm spring holding portion 33 are integrally formed.

The clutch disk 40 is a disk-shaped member that is attached to the input shaft 11 of the transmission 10 and transmits torque from the engine side to the transmission 10 side.
The clutch disc 40 is formed so as to protrude in a radial shape with respect to the input shaft 11.
The clutch disk 40 is configured by fixing friction materials (facing) 42 on both surfaces of a metal plate 41.
The region on the outer diameter side of the clutch disc 40 provided with these friction materials 42 is sandwiched between the flywheel 20 and the pressure plate 50 that rotate together with the crankshaft of the engine.

A spline engaging portion 43, a damper 44, and the like are provided in the inner diameter side region of the clutch disk 40.
The spline engaging portion 43 is a base portion to which the clutch disc 40 is attached to the input shaft 11.
The spline engaging portion 43 has a spline hole in which the input shaft 11 of the transmission 10 is inserted and engages with the spline 11a to transmit torque.
The spline engaging portion 43 is supported so as to be relatively displaceable in the axial direction with respect to the input shaft 11.
The damper 44 is a vibration damping device that absorbs torsional vibration between the plate 41 and the friction material 42 and the spline engaging portion 43.

The pressure plate 50 is a disk-like member supported so as to be capable of relative displacement in the axial direction with respect to the clutch cover 30, and holds the clutch disk 40 in cooperation with the flywheel 20 to transmit torque. It is.
An opening for accommodating the damper 44 of the clutch disk 40 and the like is formed at the center of the pressure plate 50.
A friction surface with the clutch disk 40 is formed on the surface of the pressure plate 50 on the engine side.
A protrusion 51 that is pressed by the diaphragm spring 60 is formed on the surface of the pressure plate 50 opposite to the friction surface.

The diaphragm spring 60 is a spring member that urges the pressure plate 50 toward the clutch disk 40 with respect to the clutch cover 30 to generate a pressure-bonding force of the clutch disk 40.
The diaphragm spring 60 is formed in a disk shape from an elastic material such as spring steel.
An opening into which the input shaft 11 or the like is inserted is formed at the center of the diaphragm spring 60.
A region on the outer diameter side of the diaphragm spring 60 is disposed between the diaphragm spring holding portion 33 of the clutch cover 30 and the pressure plate 50.
The inner peripheral edge portion of the diaphragm spring 60 is engaged with the release bearing 70 on the transmission 10 main body side with respect to the spline engaging portion 43 of the clutch disk 40.

  The release bearing 70 engages with the inner peripheral edge of the diaphragm spring 60 and pulls the inner peripheral edge of the diaphragm spring 60 away from the engine in conjunction with the depression of a clutch pedal (not shown). The urging force (clutch pressing force) for pressing 40 is lost, and the clutch device 1 is disconnected.

A torque cam mechanism T described below is provided between the clutch cover 30 and the pressure plate 50.
The torque cam mechanism T generates a thrust for pressing the pressure plate 50 to the clutch disk 40 in response to torque transmitted from the clutch cover 30 to the clutch disk 40 via the pressure plate 50.

FIG. 2 is a cross-sectional view taken along the line II in FIG. 1 and shows the torque cam mechanism T as viewed from the radial direction with respect to the rotation shaft of the clutch device 1.
The torque cam mechanism T includes a cam 34 formed at an end on the engine side on the inner peripheral surface of the cylindrical portion 32 of the clutch cover 30 and a cam follower 52 formed at an end on the transmission 10 side at the outer peripheral edge of the pressure plate 50. And is configured.

As shown in FIG. 2, the cam 34 is formed as a protrusion that protrudes from the clutch cover 30 to the pressure plate 50 side substantially along the rotation axis direction.
The shape of the cam 34 as viewed from the radial direction of the clutch cover 30 is a trapezoidal shape with the front end side (pressure plate 50 side) narrowed.
The cam follower 52 is formed as a recess in which the pressure plate 50 is recessed in a trapezoidal shape when viewed from the radial direction of the pressure plate 50 so as to match the shape of the cam 34.
The inner surface of the cam follower 52 and the surface of the cam 34 are formed so as to face each other with a gap inevitably provided.
The pressure plate 50 can rotate relative to the clutch cover 30 around the central axis within a range allowed by a clearance in the circumferential direction between the cam 34 and the cam follower 52.
When driving torque is transmitted from the engine to the transmission 10, the angle formed by the inclined surface that transmits torque from the cam 34 to the cam follower 52 with respect to the circumferential direction (vertical direction in FIG. 2) is a thrust that must be obtained by the torque cam ( It is set in consideration of the compression force of the clutch disk.
For example, a plurality of such torque cam mechanisms T are provided dispersed in the circumferential direction of the clutch device 1.

A return spring S is provided between the clutch cover 30 and the pressure plate 50 to urge the pressure plate 50 toward the clutch cover 30 (to the side away from the clutch disk 40).
As the return spring S, for example, a tension coil spring disposed along the rotation axis direction of the clutch device 1 and having both ends connected to the clutch cover 30 and the pressure plate 50 can be used.
In the embodiment, the intermediate portion of the return spring S is inserted into an opening formed in the diaphragm spring 60.
The return spring S cancels the thrust generated by the torque cam mechanism T in a low torque region where the engine torque is T0 or less, for example, so that the boosting effect is not substantially generated.

Hereinafter, the effects of the above-described embodiment will be described in comparison with a clutch device of a comparative example of the present invention described below.
In the comparative example, portions that are substantially the same as those in the above-described embodiment are denoted by the same reference numerals, description thereof is omitted, and differences are mainly described.
The clutch device of the comparative example has substantially the same configuration as the clutch device of the embodiment except that the torque cam mechanism (cam 34 and cam follower 52) is not provided.

FIG. 3 is a graph showing the correlation between the engine torque and the clutch pressing force in the clutch device of the comparative example.
In FIG. 3, the horizontal axis indicates the engine torque, and the vertical axis indicates the pressing force of the clutch plate. In the drawing, the crimping force required for torque transmission is indicated by a broken line, and the actual clutch crimping force is indicated by a solid line (the same applies in FIG. 4).
In the comparative example, the clutch pressing force is obtained only by the spring force of the diaphragm spring 60.
For this reason, the clutch pressing force is a constant value regardless of the engine torque.

For example, in the specification with the clutch pressing force F1 shown in FIG. 3, the upper limit of the transmittable engine torque is T1, and in the case of the high output specification where the maximum engine torque is T2, the spring constant of the diaphragm spring 60 is increased. Thus, the clutch pressing force needs to be F2.
However, if the diaphragm spring 60 is strengthened in this way, the depressing force of the clutch pedal is increased and the operability is impaired.
Further, it is necessary to prepare a diaphragm spring 60 and the like having different specifications for each engine specification.

FIG. 4 is a graph showing the correlation between the engine torque and the clutch pressing force in the clutch device of the example.
In the embodiment, in the middle to high torque region where the engine torque is equal to or higher than T0, the clutch pressing force increases as the engine torque increases due to the boosting action obtained by the thrust of the torque cam mechanism T. Even when the maximum torque is increased from T1 to T2, it is not necessary to increase the spring constant of the diaphragm spring 60.
Further, in a low torque region where the engine torque is T0 or less and sufficient clutch pressing force can be obtained with only the diaphragm spring 60, the return spring S cancels the boosting effect of the torque cam mechanism T, and the clutch pressing force is a constant value. (F1 in the case of FIG. 4).

According to the embodiment described above, the clutch operating force can be reduced even in a vehicle with a high engine torque specification, and the operability and ease of handling of the vehicle can be improved.
Further, since a boosting effect according to the engine torque can be obtained, it is not necessary to make the specifications of the clutch device different depending on the specification of the maximum torque, and the parts can be shared.
In addition, by boosting the clutch pressing force, it is possible to increase the transmission torque capacity without increasing the diameter or increasing the number of plates, resulting in higher output without affecting the arrangement of other parts. Can respond.
Further, when the required transmission torque capacity is equal, the clutch device can be reduced in size.
Further, in the low torque region where the engine torque is equal to or lower than T0 by the return spring S, the boosting effect by the torque cam mechanism T is canceled, so that the clutch device 1 is unintentionally engaged by the thrust of the torque cam mechanism T when starting or idling. Can be prevented, and the operability can be further improved.

(Modification)
The present invention is not limited to the embodiments described above, and various modifications and changes are possible, and these are also within the technical scope of the present invention.
The configuration of the clutch device is not limited to the configuration of the embodiment described above, and can be changed as appropriate.
For example, the shape and cam profile of the torque cam mechanism are not limited to the configuration of the embodiment, and can be changed as appropriate.
In the embodiment, the boosting effect is obtained according to both the driving torque from the engine to the transmission and the back torque from the transmission to the engine side. However, the boosting effect is at least only on the driving torque side. May be set to obtain
The release bearing is not limited to the pull type as in the embodiment, and may be a push type, and the number of clutch plates is not particularly limited.
Further, the present invention is not limited to a clutch device of a manual transmission in which a driver performs clutch operation with leg force, but a manual transmission-based automatic transmission (AMT) or a double clutch transmission (DCT) in which a clutch operation is performed by an actuator. The present invention can also be applied to other clutch devices. In this case, the capacity of the actuator can be reduced.

DESCRIPTION OF SYMBOLS 1 Clutch apparatus 10 Transmission 11 Input shaft 11a Spline 12 Clutch housing 20 Flywheel 30 Clutch cover 31 Outer peripheral edge part 31a Bolt 32 Cylindrical part 33 Diaphragm spring holding part 34 Cam 40 Clutch disk 41 Plate 42 Friction material 43 Spline engaging part 44 Damper 50 Pressure Plate 51 Protrusion 52 Cam Follower 60 Diaphragm Spring 70 Release Bearing T Torque Cam Mechanism S Return Spring

Claims (2)

A flywheel that is rotationally driven by the output shaft of the engine;
A clutch cover fixed to the opposite side of the engine in the flywheel;
A pressure plate opposed to the flywheel and supported so as to be relatively displaceable in the axial direction with respect to the clutch cover;
A diaphragm spring for urging the pressure plate toward the clutch cover;
A clutch disk attached to the input shaft of the transmission and sandwiched between the flywheel and the pressure plate;
A torque cam mechanism having a cam provided on one of the pressure plate and the clutch cover and a cam follower provided on the other, and pressing the pressure plate toward the clutch disk in response to torque transmitted by the pressure plate; A clutch device comprising: The clutch device according to claim 1, further comprising a return spring that biases the pressure plate toward the clutch cover.

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