WO2011060752A1

WO2011060752A1 - Friction clutch having a clutch disk for transmitting torques

Info

Publication number: WO2011060752A1
Application number: PCT/DE2010/001255
Authority: WO
Inventors: Markus Hausner; Steffen Lehmann; Martin HÄSSLER
Original assignee: Schaeffler Technologies Gmbh & Co. Kg
Priority date: 2009-11-17
Filing date: 2010-10-28
Publication date: 2011-05-26
Also published as: CN102612613A; DE112010004468B4; DE102010049929A1; DE112010004468A5; CN102612613B

Abstract

The invention relates to a friction clutch having a clutch disk (1, 1a) for transmitting torques by means of a friction apparatus (11, 11a). The friction apparatus is provided with a friction torque that depends on the relative angle of twist between a damping mass (10, 10a) and a mass to be damped so that damping of the rotational vibrations superposed on the torque to be transmitted can be designed at least substantially independently of the vibration amplitude of said rotational vibrations.

Description

Friction clutch with a clutch disc for the transmission of torques

The invention relates to a friction clutch with a clutch disc for transmitting torque with a friction device.

Friction clutches with such clutch plates have long been known and are used for example as separation or starting clutches in motor vehicles between the internal combustion engine and the transmission. Here, the power transmission between the internal combustion engine such as diesel or gasoline engine and transmission as manual transmission, automated manual transmission, dual-clutch transmission is provided with frictional friction clutches, which is controlled by a complete separation over a slipping to complete operation continuously controlled by an actuating system. In this case, in particular in the slip phase, the mean friction torque can be superimposed on an alternating torque, which can lead to disturbing vibrations in the drive train or to disturbing vibrations on the motor vehicle. One way to reduce these vibrations is in addition to the use of torsional vibration dampers with integrated into the power flow energy storage such as coil springs, the use of torsional vibration dampers, which are designed for the problematic frequency range of the torsional vibrations. A known technique for this purpose is a parallel to the drive train, for example on the clutch disc, coupled via an energy storage device and a friction absorber mass, the possible occurring vibrations compensated by a counter-torque in the correct phase. This is known, for example, from DE 10 2008 028 570 A1, the disclosure content of which with regard to the construction is hereby expressly integrated.

In the design of such a mass-spring friction system, the height of the possible occurring alternating moments for the design must be estimated or fixed. The friction is then optimized for the selected alternating torque and executed constructively as a constant friction torque. This vibration damping system achieves its optimum effect during operation when the actual alternating torque occurring during operation corresponds to the assumption in the design. If, on the other hand, the alternating moment occurring during operation is smaller than the assumption, the spring-mass system tends to adhere to the mass to be occupied, thereby possibly losing its effect. On the other hand, in a comparison with the assumption higher occurring in operation change moment while the Although the critical frequency is better attenuated, the amplitudes increase before and after the original critical frequency, which may also increase the risk of disturbing vibrations.

The object of the invention is therefore an advantageous development of a friction clutch with a clutch disc, which allows at least largely independently of the amplitudes of the torque to be transmitted superimposed torsional vibrations an efficient elimination of torsional vibrations.

The object is achieved by a friction clutch with a clutch disc for transmitting torques, wherein, forming a torsional vibration damper, a friction device integrated in the clutch disc is provided with a frictional torque dependent on the relative angle of rotation between the absorber mass and the mass to be engaged.

The proposed friction clutch, for example, in the drive train of motor vehicles regardless of the vehicle type such as passenger cars, commercial vehicles, motorized two-wheelers and the like and transmissions regardless of the type of transmission such as manual, automated manual, double clutch and the like may be provided as a frictional friction clutch, preferably as a dry clutch.

The proposed friction clutch avoids or at least reduces torsional vibrations, in particular in the drive train of a motor vehicle, preferably also for reducing possible torsional vibrations due to periodic torque fluctuations in friction clutch systems such as a motor vehicle clutch, which have a substantially constant excitation frequency but different amplitudes. These torque fluctuations can arise both from external excitation and from self-excitation (instability). According to the invention, the proposed solution can also be used for all other torsional vibration problems with a critical frequency range.

The proposed torsional vibration damper with torsion-dependent friction achieved regardless of the height of the alternating torques occurring a constant degree of reduction of these alternating torques or torsional vibrations. The theoretical degree of reduction in the case of forced excitation may advantageously be greater than or equal to 50%, preferably greater than or equal to 60%, that is, the residual vibrations when using the proposed torsional vibration damper in the clutch disc are less than 50% and 40% compared to a system without torsional vibration damper. The torsional vibration damper can therefore also be used alternatively to increase the permissible alternating torques at a constant vibration level. Self-excitation by negative overall damping of the drive train is avoided when using such a torsional vibration damper. The torsional vibration damper offers due to its positive damping properties, for example, in addition to use alternative covering materials for the friction linings of the clutch disc, such as the use of ceramic-based pads instead of organic-based pads in a dry friction clutch, for example, by their large friction coefficients and low padding suspension the excitation of the clutch disc and the subsequent drive train is particularly high, but these can be eliminated by the proposed torsional vibration damper in an improved form.

According to the inventive concept, a torsional vibration damper is proposed with absorber mass energy storage friction device system arranged in parallel, which attenuates possible vibrations in a critical frequency range of a torsional vibration excitation and whose effectiveness is independent of the amplitude of an exciting alternating torque. For this purpose, a friction device is provided with a friction torque dependent on the predetermined relative angle of rotation between the absorber mass and the mass to be used. This dependence can be carried out with angular proportionality but also according to any law. This achieves a degree of reduction independent of the excitation amplitude. The entire energy storage / friction unit is designed so that a flexible characteristic design is possible. The friction can be realized with and without basic friction, as well as with play. The first energy storage can also be realized with or without bias, as well as with game.

According to an advantageous embodiment, a friction clutch is provided for this purpose, in which the clutch disc contains a disc part and a counter to the action of a first energy storage relative to the disc part by a predetermined angle of rotation relatively rotatable absorber mass and the first energy storage, the friction device is connected in parallel with verdrehwinkelabhängigem friction torque. According to an advantageous exemplary embodiment, the friction torque which can be set via the angle of rotation can be provided by the friction device comprising a ramp device with a first ramp part provided with rotation in the circumferential direction with ramps arranged in the circumferential direction and a second ramp part provided with the drive part with counter ramps complementary to the ramps and one of the two ramp parts a friction surface against the action of an axially effective, axially firmly received second energy storage acted upon. As a result, with a rotation of the disk part relative to the absorber mass by the disk part is rotated relative to the absorber mass with a predetermined moment of inertia, for example as a result of spin through a torque peak, ramps and counter ramps relative to each other relatively rotated, one against the second energy storage, such as a plate spring or the like, biased friction surface axially displaced against the second energy storage and thereby increases the voltage of the friction pair between the friction surfaces of the friction device and thereby the friction torque is increased. Consequently, as the angle of rotation increases, which is a measure of the amplitude of the registered torsional vibrations, an increasing frictional torque is generated, which dissipates these excessive torsional vibration amplitudes to a better degree by a higher moment of inertia of the absorber mass due to friction.

The configuration of the slopes of the ramps and complementary counter ramps to these can be adapted to the requirements of the provided over the angle of rotation friction torque. For example, ramps and counter ramps in a central position of the absorber mass relative to the disc part over a twist angle smaller than a maximum angle of rotation have a slope zero. This means that at small angles of rotation over a predetermined angle of rotation range, a constant, for example, from an additional and / or the ramps having friction pair or only the physically not excludable Störreibungsmoment is applied. The pitch profile over at least a portion of the predetermined angle of rotation may be linear, progressive, degressive or formed in free form.

It is understood that the second energy storage can generate a basic friction by corresponding bias against the friction surface of the friction disc provided for this purpose. Alternatively or additionally, the friction device may include a further friction disc for providing a basic friction. The friction surfaces of the variable friction friction device may be provided, for example, between a friction plate and the absorber mass be, wherein the friction disc and the absorber mass have the corresponding ramps and counter ramps. Alternatively, for example, the second energy storage have counter-ramps, which are applied to ramps of the absorber mass or connected to this friction disc. Furthermore, for example, the second energy store can be arranged on the absorber mass and apply a friction disk fixedly connected to the disk part. It is understood that the enumeration of the execution options of ramps, counter ramps in connection with the application of these by the second energy storage are not restrictive compared to the spirit of the invention to understand.

In an advantageous embodiment of the clutch disc of the first energy storage can be formed in a spring cage, effective in the circumferential direction helical compression springs, wherein the absorber mass is rotatably mounted on the spring cage and the coil springs in the direction of action in each case on one side on the spring cage and radially in the spring cage extended cam support. In this case, the spring cage may have radially expanded, in recesses of the absorber mass at least in the amount of the angle of rotation play engaging cam. By extending the recesses in the circumferential direction, for example, the angle of rotation of the absorber mass relative to the disc part can be defined when the spring cage is rotatably connected to the disc part. In this case, the cams of the spring cage abut on the peripheral boundaries of the recesses. To such, relatively hard attacks the twist angle can be made soft, for example by interposing buffers such as spring elements or rubber buffers. Alternatively or additionally, the angle of rotation can be determined by a block position of the coil springs, hard attacks can be avoided by partial Überlaglagem the spring coils of the coil springs.

It has proved to be particularly advantageous if, alternatively or in addition to other Verdrehwinkelbegrenzungen between the clutch disc and the torsional vibration damper, a slip clutch is provided. The slip clutch is preferably arranged between the disc part and the absorber mass effectively. For example, the spring cage with the helical springs relative to the disc part against the action of a third energy storage, for example, a plate spring can be rotated biased. In this case, a frictional torque between the disc part and the spring cage is formed, which is overcome upon reaching a predetermined torque between absorber mass and disc part, so that the absorber mass relative to the disc part over the predetermined angle of rotation can be twisted out and therefore avoid hard attacks. The interpretation of this friction torque depending on the torsional stiffness of the first energy storage controls whether the absorber mass slips against the disc part before or upon reaching a hard stop, for example when reaching the block position or striking the absorber masses on a component of the disc part.

In the embodiment of the clutch disc with torsional vibration damper with spring cage can advantageously provide the spring cage axially between an axially supported on the disk part, third energy storage and a relative to the disk part axially spaced and firmly recorded cover sheet to be braced. In addition, between the third energy storage and the cover plate additionally a friction disc and the second energy storage be braced.

The friction clutch can according to the inventive idea continue to include a torsional vibration damper in addition to the proposed torsional vibration damper. For this purpose, the disk part is divided into an input and output part, between which a fourth energy store, which is effective in the circumferential direction, is connected, for example helical springs distributed over the circumference. In addition, a friction device can be connected in parallel with this fourth energy store.

The invention will be explained in more detail with reference to the embodiments shown in Figures 1 to 6.

Showing:

1 shows a partial section through a clutch disc of a friction clutch,

Figure 2 is a partial section through one of the clutch disc of Figure 1 similar

Clutch disc,

3a shows a partial view of a friction device with variable over the angle of rotation friction torque in the middle position in a schematic representation, FIG. 3b shows the friction device of FIG. 3a in a twisted state,

4a shows a plurality of individual representations of the torque behavior of a torsional vibration damper according to the prior art over the frequency,

4b shows several individual representations of the torque behavior of the proposed

Torsional vibration damper over the frequency,

Figure 5 is a torque / angle of rotation characteristic of the proposed torsional vibration damper and

FIG. 6 shows a detailed view of the torsional vibration damper of FIGS. 1 and 2.

Figure 1 shows the housed in a friction clutch, not shown, clutch disc 1, which is arranged about the rotation axis 2 and is rotationally connected by means of the hub 3 with a transmission input shaft. With the hub 3, the friction linings, not shown, to form the friction engagement with the friction clutch receiving disc part 4 is firmly connected, for example - as shown here - caulked.

On the hub 3, the torsional vibration damper 5 is also arranged, which contains the spring cage 6 formed from the cage parts 7, the first energy accumulator 8 received therein in the form of the coil springs 9, the absorber mass 10 and the friction device 11. The torsional vibration damper 5 is rotatably received on the hub 3 and under formation of the slip clutch 12 between the disc part 4 and connected to the hub 3, for example - as shown here - caulked cover plate 13 axially braced. To produce the bias, a cage part 7 is applied to the cover plate 13 and the other cage part 7 of the split to accommodate the coil springs 9 spring cage 6 with the second energy storage 14 of the friction device 11. The designed as a plate spring 15 second energy storage 14 serves as a contact for the friction disc 16 of the slip clutch 12, which is acted upon axially by the third energy storage 17 in the form of the disk part 4 axially supporting plate spring 18 and the friction torque of the slip clutch 12 determines. Exceeds a rotational acceleration between the disc part 4 and the absorber mass the predetermined amount of the frictional engagement between the plate spring 18 and the friction disc sixteenth fixed friction torque, the spring cage 6 slips against disk part 4 and cover plate 13 and hard stops between absorber mass 10 and spring cage 6 are avoided.

The absorber mass 10 is limited to the spring cage 6 against the action of the coil springs 9 rotatable. For this purpose, on the spring cage 6 radially outwardly widened cam 19 and the absorber mass 10 radially inwardly extended, provided in the spring cage 6 radially engaging cam 20, which act on the circumference and inserted into the spring cage 6 coil springs 9 each act on the front side. In block position of the coil springs 9 or striking the cams 19 and 20 cams on the absorber mass 10 and the spring cage 6 more or less hard stops the absorber mass 10 can be adjusted relative to the spring cage 6 and thereby the angle of rotation between them are specified. Before or upon reaching a stop, the slip clutch 12 can be effective.

The effect of the first energy store 8 can be connected in parallel at least over a predetermined angle of rotation range, the friction device 11. For this purpose, the friction device 11 has the ramp device 21, which is formed from the two mutually relatively rotated ramp parts 22, 23 with the circumferentially formed ramps 24 and counter-ramps 25 complementary thereto. In this case, the ramp part 22 is preferably integrated in the absorber mass 10, for which purpose the ramps 24 can be stamped into the absorber mass or inserted as a ramp ring. The ramp portion 23 is preferably formed of plastic and firmly connected to the plate spring 15, for example, hung or - as shown - melted by means of the warts 26.

The frictionally engaged by the frictional contact with the slip clutch 12 with the disk part 4 plate spring 15 sets the frictional engagement of ramps 24 and counter ramp 25. Upon entry of torque fluctuations such as torque peaks in the frequency range of the tuned torsional vibration damper 5 in the rotating at a predetermined speed disc part 4 attempts the absorber mass 10 due to the action of the first energy storage 8, the set on the friction device 11 friction torque and the moment of inertia of the absorber mass 10 in a stable To remain rotational position, whereby a twist angle between disc part 4 and absorber mass 10 sets. The setting of this angle of rotation causes the eradication effect and is dependent inter alia on the set on the friction device 11 friction torque. Since the friction torque with increasing angle of rotation due the formation of an increasing bias voltage of the second energy storage 14 by the ramp means 21 increases, torque peaks of larger amplitude, causing the larger angle of rotation are sufficiently eradicated by the arranged on the resonant frequency torsional vibration damper 5.

Figure 2 shows a relation to the clutch disc 1 of Figure 1 slightly modified clutch disc 1a with the disc part 4a with friction linings 27, the torsional vibration absorber 5a and the slip clutch 12a.

Similarly, the torsional vibration damper 5a is formed of the spring cage 6a, the absorber mass 10a, the first energy storage 8a, and the friction device 11a. The ramp device 21a and the energy storage 8a, 14a, 17a and the cover plate 13a received on the hub 3a and the friction disk 16a for forming the friction torque of the slip clutch 12a are formed corresponding to the clutch disk 1 of FIG. In a detailed view, it can be seen that in order to reduce the axial space of the clutch disc 1a disc part 4a and absorber mass 10a radially outward axially relative to their storage radially inwardly displaced parallel to order the friction linings 27 axially within the end face 28 of the hub 3a. Furthermore, the ramp part 23a is provided with axial projections 29 which are hooked into corresponding openings of the plate spring 15a. The axial securing of the ramp part 23a with respect to the plate spring 15a takes place by means of at least slight pretensioning with respect to the ramp part 22a of the absorber mass 10a.

FIGS. 3a and 3b schematically show a section of the friction device 11 of FIG. 1 (reference numerals not referenced to FIG. 1) with the ramp device 21 formed by the ramp parts 22, 23. The ramp part 22 is received axially fixedly on the absorber mass 10. the ramp part 23 axially against the action of the second, on the disc part 4 supporting energy storage 14 is arranged axially displaced. The ramp portions 22, 23 have circumferentially aligned ramps 24, and counter ramps 25, which in the representation of the approximate center position shown in Figure 3 with not mutually rotated disc part 4 and absorber mass 10 are approximately opposite, so that the second energy storage 14 this under the set bias tensioned. If disk part 4 and absorber mass 10 are rotated against one another, as shown in FIG. 3b, the ramp parts 22, 23 are increasingly spaced with increasing compression angle with further compression of second energy accumulator 14 along ramps 24 and counter ramps 25, so that the frictional torque is dependent thereon increased by the angle of rotation. In the exemplary embodiment shown, ramps 24 and counter ramps 25 also have, in the region of the central position, a plateau 30 extending over a slight angle of rotation range without an incline, so that a constant basic friction is ensured at small angles of rotation.

FIG. 4 a shows a basic sequence of individual diagrams of a torque amplitude over the frequency in a resonance region with an amplitude increasing from left to right of a torsional vibration damper according to the prior art. As a result of the setting of a constant friction torque, two adjacent peaks of the untreated surface portion 32 are formed with increasing amplitude in addition to the erased area component 31.

FIG. 4b shows a basic sequence of individual diagrams of a torque amplitude over the frequency in a resonance range with amplitude increasing from left to right of the torsional vibration absorber 5 of FIG. 1 or 5a of FIG. 2. The setting of the friction torque depends largely on the amplitude Moment fluctuation, a substantially equal proportion of erased surface portion 31a and uncoated surface portion 32a without further training additional torque amplitudes, which usually have a disturbing effect achieved.

FIG. 5 shows a principal characteristic curve 33 of the torsional vibration absorbers 5, 5a of FIGS. 1 and 2 with the moment M over the angle of rotation a. Compared to the dashed line, which shows a non-frictional and thus hysteresis-free torsional vibration damper, the torque lines 34, 35 are loaded at positive and negative angle of rotation α with in each case the same magnitude friction moment equal pitch. The ramps or counter ramps are therefore symmetrical to the central position (a = 0) and without backlash - as shown in Figures 3a, 3b - formed.

FIG. 6 shows a detailed view of the torsional vibration damper 5 of FIG. 1 accommodated on the hub 3 and secured axially by means of the cover plate 13. The absorber mass 10 is centered on the spring cage 6 and rotatable against the action of the coil springs 9. outsourced. The coil springs 9 are received in recesses 36 of the spring cage 6 and are acted upon at the end faces of the radial boundaries 37 of the recesses 36 in the circumferential direction. On the opposite side, the coil springs 9 are acted upon by radially engaging in the recesses 36 cam 20 of the absorber mass 10. The absorber mass 10 also has recesses 38 into which the radially expanded cams 19 of the spring cage 6 engage and with the circumferentially provided stops 39 of the recesses 38 form the Verdrehwinkelbegrenzung the absorber mass 10 relative to the spring cage 6. Upon reaching one of the two-sided stops 39 of the recesses 38 through the cam 19, the slip clutch 12 (Figure 1) is activated at the latest. Alternatively, the slip clutch 12 by setting the slip torque smaller than the friction torque of the friction device 11 (Figure 1) slip at angles of rotation before reaching the stops 39 through the cam 19 and therefore a hard stop of the cam 19 can be avoided at the stops 39.

LIST OF REFERENCE NUMBERS

clutch disc

a clutch disc

axis of rotation

hub

a hub

disk part

a disc part

A torsional vibration damper

a torsional vibration damper

spring cage

a spring cage

cage part

first energy store

a first energy storage

coil spring

0 absorber mass

0a absorber mass

1 friction device

1a friction device

2 slip clutch

2a slip clutch

3 cover plate

3a cover sheet

4 second energy storage

4a second energy storage

5 plate spring

5a plate spring

6 friction disc

6a friction disc

7 third energy storage

7a third energy storage

8 plate spring 19 cams

20 cams

21 ramp device

21a ramp device

22 ramp part

22a ramp part

23 ramp part

23a ramp part

24 ramp

25 counter ramp

26 wart

27 friction lining

28 front side

29 advantage

30 plateau

31 erased area proportion

31a erased area proportion

32 area not eradicated

32a area not eradicated

33 characteristic

34 moment line

35 moment line

36 recess

37 limitation

38 recess

39 stop

α twist angle

M moment

Claims

claims

Friction clutch with a clutch disc (1, 1a) for transmitting torque with a friction device (11, 11a) with a dependent on the relative angle of rotation between the absorber mass (10, 10a) and to be loaded mass friction torque.

Friction clutch according to claim 1, characterized in that the clutch disc (1, 1a) a disc part (4, 4a) and against the action of a first energy storage device (8, 8a) relative to the disc part (4, 4a) rotatable by a predetermined angle of rotation relatively Tilgermasse (10, 10a) contains and the first energy storage (8, 8a), the friction device (11, 11a) is connected in parallel with verdrehwinkelabhängigem friction torque.

Friction clutch according to claim 1 or 2, characterized in that the friction device (11, 11a) a ramp device (21, 21a) with a first, on the absorber mass (10, 10a) rotatably provided ramp portion (22, 22a) in the circumferential direction arranged ramps (24) and a second, from the disc part (4, 4a) in the direction of rotation entrained ramp portion (23, 23a) with the ramps (24) complementary counter ramps (25) and one of the two ramp parts (22, 23) has a friction surface acted upon against the action of an axially effective, axially firmly received second energy storage device (14, 14a).

Friction clutch according to claim 1 or 2, characterized in that the first energy store (8, 8a) is formed in a spring cage (6, 6a) introduced, in the circumferential direction effective coil springs (9), wherein the absorber mass (10, 10a) is rotatably mounted on the spring cage (6, 6a) and the coil springs (9) in the direction of action in each case on one side on the spring cage (6, 6a) and radially in the spring cage extending cam (20) of the absorber mass (10, 10a) are supported.

Friction clutch according to one of claims 1 to 4, characterized in that the spring cage (6, 6a) radially enlarged, in recesses (38) of the absorber mass (10, 10a) at least in the amount of the angle of rotation play engaging cam (19).

6. Friction clutch according to one of claims 1 to 5, characterized in that between the disc part (4, 4a) and the absorber mass (10, 10a) a slip clutch (12, 12a) is effective.

7. friction clutch according to claim 6 in conjunction with claim 4 or 5, characterized in that the spring cage (6, 6a) axially between a on the disc part (4, 4a) axially supporting, third energy storage (17, 17a) and one opposite the disk part (4, 4a) axially spaced and firmly received cover plate (13, 13a) is braced.

8. friction clutch according to claim 7, characterized in that between the third energy storage (17, 17 a) and the cover plate (13, 13 a) in addition a friction disc (16, 16 a) and the second energy storage (14, 14 a) is braced.

9. friction clutch according to one of claims 3 to 8, characterized in that ramps (24) and counter ramps (25) in a central position of the absorber mass (10, 10 a) relative to the disc part (4, 4 a) via a twist angle smaller than a maximum angle of rotation Slope zero.

10. Friction clutch according to one of claims 3 to 9, characterized in that the slope over at least a portion of the predetermined angle of rotation is linear.