FR3041727A1 - CLUTCH MECHANISM AND USE THEREOF IN A TRANSMISSION SYSTEM FOR A MOTOR VEHICLE - Google Patents

Abstract

The invention relates to a clutch mechanism (M) for a motor vehicle comprising a pressure plate (1) designed to rotate between an axis (X) and a friction disc with a flywheel, characterized in that it comprises a weighting element (12) movable axially along the axis (X) with respect to the pressure plate (1) and secured to said pressure plate by at least one elastically deformable connecting element (11) capable of oscillating in phase opposition with said pressure plate.

Description

FIELD OF THE INVENTION [0001] The invention relates to a clutch mechanism for a motor vehicle.

More specifically, the invention relates to an improvement in clutches of the type comprising, firstly, a disc friction device mounted on the input shaft of the gearbox and, secondly, a mechanism of rotary clutch with rotationally symmetrical components around an axis of rotation of the mechanism.

The clutch mechanism is attached to the flywheel of the internal combustion engine. The components of the clutch mechanism consist, in particular, of a pressure plate ensuring the frictional contact of the friction disk on the flywheel in the engaged position, a lid assembled to the plate and an effective diaphragm spring loaded interposed between the plate and the lid and actuated at its center by a stop connected, via a hydraulic circuit or a cable, to the clutch pedal. The diaphragm is pivotally mounted on the cover and supported relative to the pressure plate via a support to axially move said pressure plate relative to the cover between an engaged position in which the friction pads of the friction disc are pinched between the plate of pressure and the reaction plate and a disengaged position. The use of the clutches causes wear on the friction disc linings and, to a lesser extent, associated pressure and reaction platens.

STATEMENT OF THE INVENTION

When the clutch pedal is actuated, the abutment is pressed on the diaphragm which moves the pressure plate thus releasing the friction disk which leads to disengage the flywheel from the input shaft of the box of speed.

In particular, during the clutch phase, the power transmission between the motor shaft and the wheels is progressively established and, due to the sliding at the junction between the discs and the flywheel, the mechanism is subjected to a transitional phase so-called sliding slip corresponding, for the driver, substantially at the half-way of the clutch pedal.

However, it happens that this phase is sometimes accompanied by an unpleasant noise [type "grillage"] generated by a vibratory phenomenon from the clutch mechanism.

More precisely, this phenomenon originates in an irregular, unstable or disturbed mechanical behavior of the pressure plate (the heavier component) which is likely to be maintained or even amplified at each revolution of the engine.

However, the persistence in time of this vibratory phenomenon can produce a resonance effect likely to propagate beyond the clutch mechanism and into the gearbox while becoming detrimental from a point of view of acoustic comfort.

[0003] WO 02 10611 A2 discloses flapping means attached to the flywheel for damping the bending vibrations of the crankshaft.

However, these means operate continuously to limit the stresses in the crankshaft or the steering wheel but are effective only when an engine order crosses the bending frequency of the crankshaft.

In addition, these means do not make it possible to limit the torque fluctuations generated on the pressure plate by the vibrations during the re-clutching phases.

The invention aims to remedy these technical problems and thus to suppress the vibration of the pressure plate which is generating the noise during the sliding phases, or at least to mitigate, by providing a clutch mechanism with an advanced pressure plate to be cushioned.

This object is achieved by means of a clutch mechanism for a motor vehicle comprising a pressure plate for securing in rotation about an axis a friction disk with a flywheel, an axially displaceable weighting element. along the axis of rotation relative to the pressure plate being secured to said pressure plate by at least one elastically deformable connecting element and capable of oscillating in phase opposition with said pressure plate.

This clutch mechanism according to the invention has the advantage of eliminating the vibratory phenomenon by the addition of an additional mass provided in suspension on the pressure plate and included in the internal volume of the mechanism of the invention. clutch.

According to an advantageous characteristic, the ballast element has a mass corresponding to at least 8% of the mass of the pressure plate.

According to a first variant of the invention, the ballast element comprises a solid ring suspended from the pressure plate coaxially.

Preferably, the massive ballast ring is radially suspended in the center of the pressure plate.

According to another variant, the elastically deformable connecting element comprises a set of flexible tongues.

Preferably, the set of tabs is distributed circumferentially around the axis of rotation on the inner periphery of the pressure plate.

Where appropriate, the tabs comprise a stack of several metal strips.

According to another variant, the elastically deformable connecting element comprises at least one washer connected to the pressure plate and supporting the ballast element.

According to yet another variant, the elastically deformable connecting element comprises a set of two metal washers between which is mounted the ballast element.

According to an advantageous characteristic, it is intended to interpose axially in the elastically deformable connecting element a pad of elastomeric material working in shear during oscillations of the ballast element.

According to an alternative embodiment, the ballast element consists of a series of flyweights.

According to another variant, the ballast element is integrated between two flanges facing each other, forming the pressure plate via the elastically deformable connecting elements.

In the latter case, the connecting elements are preferably in the form of corrugated washers.

Alternatively, the ballast element is attached to the connecting element by riveting, gluing or welding.

According to an advantageous characteristic, the thickness of the ballast element, measured along the axis of rotation, is at least two times greater than the thickness of the connecting element.

According to another advantageous characteristic, the ballast element is disposed axially between the pressure plate and the diaphragm.

According to yet another characteristic, the weighting element and the friction face of the pressure plate overlap radially at least partially.

Advantageously, the ballast element is arranged radially on the same diameter as the friction face of the pressure plate.

According to one variant, the weighting element and the connecting element are made in one piece.

Another object of the invention is a use of a clutch mechanism as previously described in a transmission system.

The additional mass provided in suspension on the pressure plate of the clutch mechanism can dampen its axial vibrations and break or at least mitigate the excitation that is responsible for each revolution of the engine, the maintenance of the vibratory phenomenon generating harmful noise.

Thanks to the invention, the comfort of the passenger compartment of the vehicle is thus significantly improved.

BRIEF DESCRIPTION OF THE FIGURES

Other features and advantages of the invention will become apparent from reading the description which follows, with reference to the accompanying figures and detailed below.

Figure 1 shows an exploded overview of a first embodiment of the clutch mechanism of the invention.

FIGS. 2A, 2B, 2C and 2D are schematic views, respectively, in exploded perspective, in front and in partial section along planes CC and DD (FIG 2B) of a second embodiment of the damped pressure plate according to FIGS. the invention.

Figures 3.1A and 3.1B show views, respectively, exploded perspective and partial section of a first variant of a third embodiment of the cushioned plate according to the invention.

Figures 3.2A and 3.2B show views, respectively, partial front and partial section of a second variant of the third embodiment of the cushioned plate according to the invention.

Figures 4A, 4B, 4C show views, respectively, in exploded perspective, in perspective and in partial section of a fourth embodiment of the cushioned plate according to the invention.

FIGS. 5A and 5B show, respectively, partial exploded profile and sectional views of a fifth embodiment of the cushioned deck according to the invention.

Figures 6A and 6B show, respectively, front views and partial section a sixth embodiment of the cushioned plate according to the invention.

FIGS. 6C and 6D are front views and in section along DD, of a variant of the weighting element according to the sixth embodiment of the invention.

For the sake of clarity, identical or similar elements are marked with identical reference signs throughout the figures.

DETAILED DESCRIPTION OF EMBODIMENTS

Of course, the embodiments illustrated by the figures presented above are given by way of non-limiting examples. It is explicitly provided that these different modes and variants can be combined with one another to propose others.

FIG. 1 illustrates a clutch mechanism M according to a first embodiment of the invention, comprising, in particular, three components with X-axis revolution symmetry, respectively, a pressure plate 1, an intermediate diaphragm 2 and a cover 3 whose mode of cooperation has already been briefly described in the introduction.

The cover 3, of hollow form, is arranged to be fixed on a reaction plate P (Figure 2C), formed by a flywheel or a secondary flywheel of double flywheel, fixed to the crankshaft of a combustion engine. The lid has a bottom 31 having a substantially radial orientation. The bottom 31 is connected by an annular skirt to a radially oriented flange provided with fastener orifices, not shown, for fixing the cover 3 to the reaction plate P and to imprison the friction disc. F between the pressure plate 1 and the reaction plate P (Figure 2C). The bottom 31 and the annular skirt of the cover 3 define the internal volume of the clutch mechanism.

The pressure plate 1 is integral in rotation with the lid 3 by means of tongues 6 tangential and axially elastic. These tongues are fixed, on the one hand, to the pressure plate 1, and on the other hand, to the lid 3 at its flange. The tangential tabs are means for returning the pressure plate 1 towards the bottom 31 of the lid 3. The pressure plate 1, while being integral in rotation of the lid 3, is axially movable relative thereto.

The pressure plate 1 comprises, inter alia, a solid base 16 (made of steel or cast iron) of substantially annular shape, provided with lugs 15 whose orifices are intended for fixing with the lid 3 via the tangential tongues 6. The annular base 16 supports various functional elements such as a friction face facing the flywheel intended to come into contact with one of the friction disc lining F. The base 16 of the pressure plate 1 also comprises a support portion 14, oriented towards the diaphragm 2 and arranged to cooperate with the diaphragm 2 for the purpose of transmitting the axial force generated by the diaphragm towards the flywheel. This bearing portion 14 is circular and can be broken up into support segments. Splitting creates spacings distributed circumferentially around the axis of rotation X of the mechanism. These spacings allow better air circulation inside the clutch mechanism and thus promote its cooling.

Alternatively, the clutch mechanism M may comprise a wear compensating device. These wear-compensating devices, which are well known to those skilled in the art, comprise means with ramps and against ramps making it possible to modify the distance between the working face of the pressure plate and the support through which the diaphragm 2 acts on the pressure plate 1 in order to compensate for the wear of the friction linings. Other components, such as the hinge washer 4 and the bosses 4 carried by the plate 1 and which form contact struts with the lid 3, although shown in certain figures, are traditional and will not be described in detail. .

The arrangements that may be made to the tray according to the invention, taken separately or in combination will, for their part, be described in detail below.

The invention aims to improve the traditional clutch mechanisms by eliminating, or at least greatly reducing, noise and vibration nuisance occurring in the phase of slipping to the clutch or declutching on certain vehicles.

For this purpose, the invention consists in creating an oscillation of the weighting element 12 in phase opposition with that of the pressure plate 1 in order to ensure damping of the vibrations and without the need to modify its structure .

According to the invention and as illustrated by the various figures referenced 1 to 6, the pressure plate 1 is intended to receive a ballast element 12 for the purpose of damping vibrations. The weighting element 12 is secured to and suspended from the pressure plate 1 by at least one elastically deformable connecting element 11 so that this weighting element 12 is able to oscillate [to vibrate] in phase opposition with the plate pressure 1.

The mechanical behavior of the ballast element and, in particular, the amplitude of its vibratory oscillations is such that no interaction appears and, in particular, no dynamic physical contact between this element and the pressure plate. 1 and the other components of the clutch.

Still according to the invention, this weighting element has a mass corresponding to at least 8% of the mass of the plate and which is preferably equal to 10% of the mass of the plate 1. The elastic connecting element 11 is dimensioned according to the mass of the ballast element 12 suspended. For example, for a plateau of 2 kg subjected to an acceleration of 2000 m / s 2 pp and a vibration frequency of 200 Hz, the amplitude of the displacement of the ballast element is of the order of 1.5 mm [peak to peak oscillation].

In this case, the connecting element 11 will be made so as to have an axial stiffness of 3150N / mm. In the embodiment illustrated in FIG. 1, the weighting element 12 is formed of a massive ring. 12a while the elastically deformable connecting element 11 comprises a series of flexible tongues 11a, here three in number, angularly distributed at 120 ° around the axis of rotation X.

The tongues 11a are fixed, for example, by means of rivets R, at their inner end, to the weighting element 12 via suitable through-holes 120 and, at their outer end, to projecting lugs 10 provided on the inner edge. pressure plate 1.

If necessary, the tongues 11a may comprise a stack of lamellae, preferably metal lamellae. The ballast element 12 is thus suspended from the plate 1 coaxially by being mounted radially in the center of the plate.

Figures 2A to 2D illustrate a second embodiment of the modified tray according to the invention.

In the embodiment shown, the weighting element 12 is always constituted by a solid ring 12a suspended from the pressure plate 1 coaxially by being mounted radially in the center of the plate.

However, this solid ring is here provided with radial outer lugs 121 through which are formed the orifices 120 for receiving the fastening rivets R to the elastically deformable connecting element 11.

As illustrated in FIG. 2C, the clutch mechanism [M] is intended to be used in a motor vehicle transmission system comprising at least one friction disk F and a reaction plate P.

According to this second embodiment, the elastically deformable connecting member 11 is constituted by at least one washer 11c connected to the pressure plate 1. The washer 11c is made of thin sheet, type "foil". The washer 11c is fixed on radial lugs 10 made especially for this purpose inside the pressure plate 1. In a variant, the washer 11c can be fastened to pre-existing members of the pressure plate 1. washer 11c can be attached to the outside of the pressure plate 1.

In a first variant of a third embodiment illustrated in Figures 3.1A and 3.1B, the elastically deformable connecting member 11 comprises a pair of washers 11c, 11d mounted via rivets R, on the tabs 10 , on either side of the plate 1 and which extend substantially tangentially to the outer periphery of the solid ring 12a thus trapping this ballast element.

According to a variant, it is provided to interpose axially, between the washers 11c, 11d and the weighting element 12, at least one stud 13 intermediate ("silent block" type) made of elastomeric material (rubber, ...) and working in shear during oscillations of the ballast element 12.

In a second variant of this third embodiment illustrated by FIGS. 3.2A and 3.2B, the elastically deformable connecting element 11 consists of at least two flexible tongues 11a, 11b superimposed and mounted via rivets R on the legs 10, on either side of the pressure plate 1 and which extend substantially tangentially to the outer periphery of the solid ring 12a of the ballast element.

In order to limit the amplitude of the oscillations of the ballast element 12, it may be advantageous to make the tongues 11a, 11b by means of a stack of several spring metal lamellae whose respective surfaces facing each other are in contact with each other. friction. During the oscillation of the ballast element with respect to the pressure plate, the friction of the lamellae between them attenuates the vibratory phenomenon with the consequence of reducing the noise in the passenger compartment.

According to a variant, it is provided to interpose axially, between the tongues 11a, 11b and the weighting element 12, at least one stud 13 intermediate ("silent block" type) made of elastomeric material (rubber, ...) and working in shear during oscillations of the ballast element 12.

In the fourth embodiment illustrated by FIGS. 4A to 4C, the weighting element 12 comprises a solid ring 12b pressed against the elastically deformable connecting element 11 made here in the form of a washer (or a crown) 11c of support. The washer 11c is made of thin sheet metal preferably or composite material.

The washer 11c comes to cap the face of the pressure plate 1 located opposite the lid 3 by trapping the solid ring 12b interposed. The washer 11c has orifices 110 through which are housed the bosses 14 carried by the pressure plate 1 as well as orifices 111 for mounting rivets R.

The orifices 110 are arranged facing corresponding orifices 120 formed on the solid ring 12b, between the orifices 111 for fixing the rivets.

In a fifth embodiment shown in Figures 5A and 5B, the pressure plate 1 is itself formed by the assembly of two flanges 1a, lb opposite. The two flanges 1a, 1b are arranged axially facing each other. For example, the two flanges 1a, 1b are assembled using rivets. The weighting element 12 is made here in the form of at least one feeder 12c which is integrated in an intermediate way inside the pressure plate 1, in contact with the elastically deformable connecting elements 11 made here in the form of waved washers lld allowing the oscillating deflection of the ballast element 12 and the damping of the vibrations by elastic deformation.

In the variant illustrated in Figures 5A and 5B, the weight 12c is in one piece and takes the form of a solid ring. Alternatively, the feeder 12c could also be formed of several solid sections [variant not shown] housed in the intermediate cylindrical cavity 100 formed between the flanges 1a, 1b.

The sixth embodiment is divided into two variants illustrated respectively by Figures 6A, 6B and 6C. 11 is to be compared with the embodiment of FIGS. 2A to 2D in which the connecting element 11 is in the form of an elastically deformable washer 11c fixed on the lugs 10 of the pressure plate 1.

However, the ballast element and the connecting element are here made in one piece in the form of a single ring 112 directly suspended via the rivets R and the lugs 10, in the center of the pressure plate 1.

The outer periphery 112a of the ring 112 is made with a thickness which enables it to provide the elastically deformable connection function whereas its inner edge 112b provided with crenellations 112c, ensures, for its part, by an appropriate structure, the function of the internship.

In the variant illustrated in FIGS. 6C and 6D, the inner edge 112b of the ring 112 has, at the level of the slots 112c, extra thicknesses 112d relative to the outer periphery 112a which weigh this area significantly in order to optimize the central ballast.

These oversizes 112d can be reported and fixed on the ring 112, or made in one piece with the ring by casting or machining.

According to another variant not shown, it is possible to provide that only some of the slots 112c are provided with extra thicknesses.

In general, the various configurations of the invention described above and illustrated in FIGS. 1 to 6, all confer on the assembly consisting of the connecting element 11 and the weighting element 12, both appropriate capacities of elastic deformation and damping of the pressure plate 1.

Specifically, the thickness of the ballast element 12, measured along the axis of rotation X, is at least two times greater than the thickness of the elastically deformable connecting element 11.

In addition, it is provided that the weighting element is disposed axially between the pressure plate 1 and the diaphragm 2 and, preferably, on the same diameter as the friction face of the pressure plate 1.

The improvement of the pressure plate according to the invention is compatible with most clutch mechanisms and, in particular, those of the type "pulled" or "pushed", those equipped with a device to compensate for wear and tear. trims, as well as dual clutch mechanisms.

Claims (15)

1. clutch mechanism (M) for a motor vehicle comprising a pressure plate [1] for securing in rotation about an axis (X) a friction disk with a flywheel, characterized in that it comprises a weighting element [12] displaceable axially along the axis [X] with respect to the pressure plate [1] being secured to said pressure plate by at least one elastically deformable connecting element [11] capable of oscillating in opposition in phase with said pressure plate. 2. clutch mechanism [M] according to claim 1, characterized in that said weighting element [12] has a mass corresponding to at least 8% of the mass of the plate (1). 3. clutch mechanism [M] according to one of the preceding claims, characterized in that said weighting element [12] comprises a solid ring [12a] suspended from said pressure plate [1] coaxially. 4. clutch mechanism [M] according to the preceding claim, characterized in that said ring [12a] is radially suspended in the center of the pressure plate [1]. 5. clutch mechanism [M] according to claim 3 or 4, characterized in that said elastically deformable connecting element [11] comprises a set of flexible tongues [11a, 11b]. 6. Clutch mechanism [M] according to the preceding claim, characterized in that said tongues [11a, 11b] comprise a stack of several metal strips. 7. clutch mechanism [M] according to one of claims 1 to 4, characterized in that said elastically deformable connecting member [11] comprises at least one washer [11c] connected to the plate [1] and supporting said element ballast [12]. 8. Clutch mechanism [M] according to the preceding claim, characterized in that said elastically deformable connecting element (11) comprises a set of two washers (11c, 11d) between which is mounted the ballast element (12) . 9. clutch mechanism (M) according to one of the preceding claims, characterized in that it comprises a pad (13) of elastomeric material, working in shear during oscillations of the ballast element (12), which is axially interposed in the connecting element (11). 10. clutch mechanism (M) according to the preceding claim, characterized in that said weighting element (12) consists of a series of weights (12c). 11. clutch mechanism (M) according to one of claims 1 to 3, characterized in that said weighting element (12) is integrated between two flanges (la, lb) facing assembled, forming the plate (1 ), via said elastically deformable connecting elements (11). 12. clutch mechanism (M) according to the preceding claim, characterized in that said connecting elements (11) are in the form of corrugated washers (lld). 13. clutch mechanism (M) according to one of the preceding claims, characterized in that said ballast element (12) is disposed axially between the pressure plate (1) and the diaphragm. 14. Clutch mechanism (M) according to one of the preceding claims, characterized in that the weighting element (12) and the friction face of the pressure plate (1) overlap radially at least partially. 15. Use of a clutch mechanism (M) according to one of the preceding claims in a transmission system for a motor vehicle.