VIBRATION DAMPING DEVICE FOR MOTOR VEHICLES

Abstract

Vibration Damping Device for a Motor Vehicle The invention relates to a vibration damping device (1) for a motor vehicle, comprising: - a torque transmission web (2); - two rotationally linked guide elements (3), coaxial about an axis of rotation (X) and arranged on either side of said torque transmission web (2); - helical compression springs (4) bearing on the torque transmission web and the guide elements via seats (10) arranged on the ends of the springs and in recesses (200, 300) of the torque transmission web (2), in which each seat (10) comprises a front face (12) defining a support plane (P1) adapted to cooperate with the end of the springs, which is inclined angularly with respect to the axis (X). Figure for the abstract: Figure 4

Description

Title of the invention: VIBRATION DAMPING DEVICE FOR MOTOR VEHICLES

[0001] The present invention relates to a vibration damping device for a motor vehicle. The motor vehicle may be an industrial vehicle, the latter being, for example, a heavy goods vehicle, a public transport vehicle, or an agricultural vehicle.

[0002] More specifically, the invention relates to an improvement to a vibration damping device for a motor vehicle, such as a friction clutch disc or a dual-mass flywheel. The vibration damping device is generally located between the internal combustion engine and the gearbox in order to filter out the irregularities originating from the driving shaft so that the driven shaft(s) are free from these irregularities or are only slightly affected by them. In a manual or automated manual transmission, a clutch mechanism fixed to the flywheel, also called a flywheel, applies a clamping force to the friction clutch disc in order to transmit the torque produced by the engine.

[0003] The friction clutch disc traditionally comprises annular friction linings fixed to a support, itself mounted on a torque transmission disc. Two guide elements arranged on either side of the disc are mounted on a central hub integral with the driven shaft of the gearbox. Helical compression springs are arranged circumferentially between the coaxial sections formed by the guide elements and the disc. Torque transmission and filtering of engine irregularities are achieved by successive compression and release of the springs during the angular movement of the coaxial sections. To improve the kinematics of the helical compression springs within the friction clutch disc, it is known to add metal seats between the springs and the coaxial sections.

[0004] In document DE102018201536A1, a friction clutch disc is described, comprising metal seats positioned between the spring ends and the coaxial parts. The springs and seats are received in housings formed in the two guide elements and the torque transmission web. In particular, the seats are centered relative to the torque transmission web so that the torque is transmitted homogeneously within the two guide elements. The friction clutch disc also includes a friction device consisting of a load-bearing spring washer and friction washers. Due to the homogeneous transmission of torque within the two elements In the guidance system, the load applied to the friction washers is constant over the entire angular travel of the vibration damping device.

[0005] However, filtration requirements within the transmission chain are evolving with the emergence of new technologies introduced by industrial vehicle manufacturers. In particular, the recent addition of the "Turbocompound" component to the transmission chain allows for the recovery of the hot gas flow containing residual energy at the turbocharger outlet and the use of this gas flow to drive a second turbocharger, which, in turn, drives a gear train connected to the output end of the internal combustion engine's crankshaft. This technology generates a greater need for filtration in the vibration damping device because the "Turbocompound" component increases cyclic irregularities at low engine speeds and reduces the maximum torque operating range.

[0006] An object of the invention is to provide a more efficient friction device in terms of filtration without increasing the production cost of the vibration damping device.

[0007] The invention aims to remedy these technical problems by proposing an improved vibration damping device using a friction device whose hysteresis level is variable and controlled over the entire angular displacement.

[0008] To this end, the present invention proposes a vibration damping device for motor vehicles, comprising:

[0009] - a torque transmission veil;

[0010] - two rotationally linked guiding elements, coaxial along an axis of rotation X and arranged on either side of said torque transmission veil;

[0011] - helical compression springs bearing on the transmission web of couple and guiding elements via seats arranged on the ends of the springs, in which each seat comprises:

[0012] - a front face defining a first support plane capable of cooperating with the ends of the springs and including a means for centering the springs along a Y-axis passing through the axis of the springs,

[0013] - a dorsal face abutting the frontal face, defining a second support plane capable of cooperating with the torque transmission shroud and the two guiding elements, and

[0014] - a convex-shaped bar section projecting outwards from the dorsal face and having in section in a geometric plane perpendicular to the X axis a substantially circular end with center C, said bar section being supported in concave recesses formed in the guide elements and in the torque transmission web so as to form a pivot joint,

[0015] wherein the first bearing plane of the spring on the seat and / or the second plane the seat support on the torque transmission web and the two guide elements is inclined at an angle α between 2° and 10° relative to the axis of rotation X.

[0016] This vibration damping device, according to the invention, has the advantage of using the increasing proportional load of the helical compression springs to generate a complementary force component along the X-axis without significantly impacting the torque transmission within the vibration damping device. This complementary force component along the X-axis is transmitted via the torque transmission shroud to the friction device housed within the vibration damping device. Depending on the direction of application of this complementary force, it is possible to increase the load borne by the friction washers of the friction device and thus generate more hysteresis. Therefore, the complementary force component along the X-axis generates a hysteresis torque that varies according to the angular displacement.This hysteresis torque can be added to the constant hysteresis torque applied by the load spring washer on the friction and shim washers depending on the direction of inclination of the angle a.

[0017] The possible inclination of one of the planes between the first support plane and the second support plane does not alter the general shape of the vibration damping device. The radial and / or axial dimensions of the vibration damping device remain unchanged.

[0018] According to a preferred embodiment of the invention, the back face and the front face of each seat can be inclined relative to each other at an angle a. In this way, the seat directly incorporates the inclination of the first support plane so that the rest of the components of the damping device are not impacted.

[0019] According to another embodiment of the invention, the dorsal face and the front face of each seat can be parallel to each other and the two guide elements can be angularly offset from each other with respect to the axis of rotation X along an axis [3] between 1° and 5° so that the second support plane of the seat on the torque transmission web and the two guide elements is inclined at angle a. In this way, the seat remains a standard component and the inclination of the second support plane is adjusted by the angular offset of the guide elements.

[0020] Preferably, for a single helical compression spring supported on two seats, the front faces of the two seats are parallel to each other. In this way, each helical compression spring is compressed throughout its entire angular travel while maintaining parallel bearing faces. The mechanical stresses within the spring are not increased compared to a conventional vibration damping device.

[0021] Preferably, the vibration damping device may include a friction device comprising, on the one hand, a shim washer mounted between one of the guide elements and the torque transmission web, and on the other hand, a friction washer and an elastic washer mounted between the other guide elements and the torque transmission web, the elastic washer applying a first axial force in Newtons on the friction washer and the shim washer.

[0022] Advantageously, the support of the torque transmission flange on the back face of the seat can be offset from the geometric plane passing through the midpoint of the bar section by a value K between 2 and 5 mm, and the support of the guide elements on the back face remains centered. In this way, the additional force along the X-axis transmitted via the torque transmission flange to the friction device is further increased.

[0023] According to a variant of the invention, each helical compression spring can be inclined relative to the torque transmission web at angle α and apply a second axial force oriented in the same direction as the first axial force of the spring washer, such that the first and second axial forces are added together. In this way, the friction device housed within the vibration damping device receives this additional force, which generates a hysteresis torque that varies according to the angular displacement. This hysteresis torque is added to the constant hysteresis torque applied by the load spring washer on the friction and shim washers, depending on the direction of inclination of angle α.It is therefore possible to have a friction device whose hysteresis level is variable and controlled over the entire angular displacement, with in particular a very low hysteresis level at low torque and a very high hysteresis level at high torque.

[0024] According to another embodiment of the invention, each helical compression spring can be inclined relative to the torque transmission web at angle α and apply a second axial force oriented in the opposite direction to the first axial force of the spring washer, such that the first and second axial forces cancel each other out. In this way, the friction device housed within the vibration damping device receives this additional force, which relieves the load applied by the spring washer on the friction and shim washers according to the direction of inclination of angle α. It is thus possible to have a friction device whose hysteresis level is variable and controlled over the entire angular travel.

[0025] The invention may have one or more of the features described below, either combined or taken independently of each other:

[0026] - the front and back faces of the seat can delimit a disc of material a roughly circular shape on which the spring rests, the disc of material having a thickness that varies according to the angle of inclination a;

[0027] - the median plane of the torque transmission web at the seat supports can be axially offset relative to the guide elements;

[0028] - the torque transmission shroud and the guiding elements may include housings arranged to receive the springs and the seats, each housing comprising a radially external band, two lateral bearing surfaces receiving the concave-shaped recesses and a radially internal edge, the lateral bearing surfaces being arranged to cooperate with the dorsal face of each seat;

[0029] - the lateral support surface may have a first edge and a second suitable edge to come into contact with the dorsal face of the seat during the implementation of the pivot joint, the two edges not being parallel to each other. In this way, the movement of the seat relative to the torque transmission web is facilitated while increasing the contact surface of the bar section with the recess;

[0030] - the first edge and the second edge can be planar edges;

[0031] - the centering means may be a step extending projecting from the front face along the Y axis which is perpendicular to the first support plane;

[0032] - the vibration damping device may comprise a first mass of inertia, the first mass of inertia being brought or fixed on one of the guiding elements;

[0033] - the vibration damping device may include a second mass of inertia, the second mass of inertia being fixed on the torque transmission web;

[0034] - the vibration damping device may include a second mass of inertia, the second mass of inertia being referred, directly or indirectly, to the torque transmission veil;

[0035] Advantageously, but optionally, the seat may have at least one of the following characteristics:

[0036] - the bar section may have a rounded surface forming a vertex of the section of bar;

[0037] - the bar section may include a fillet connecting with the part back of the seat;

[0038] - the spring seat can be obtained by molding a metal or a synthetic material therapeutic according to compressed powder technology;

[0039] - the spring seat can be obtained by shaping a metal or a material synthetic according to the manufacturing technology by addition of material;

[0040] - the axis of the bar section passing through the center C of the bar section can extend to a predetermined distance d, not substantially equal to zero, from the second support plane. In this way, the contact area of ​​the bar section with the recess is increased;

[0041] - the bar section can be symmetrical with respect to the geometric plane.

[0042] - the geometric plane passes through the middle of the bar section;

[0043] - the bar section may have a shape in cross-section in the geometric plane prismatic having at least two sides moving away from each other towards the dorsal face, the two sides of the bar section being arranged to cooperate with corresponding surfaces formed in the concave-shaped recess;

[0044] - both sides of the bar section can be flat and inclined at an angle between 1 and 20 degrees;

[0045] - both sides of the bar section can be rounded;

[0046] - each seat may include retaining bars extending projecting from the dorsal face which divides the dorsal face into several support surfaces associated with the two guiding elements and the torque transmission web;

[0047] - the retaining bars can be perpendicular to the bar section and emerge from the section of bar by at least locally conforming to its shape;

[0048] - the retaining bars may be recessed relative to the top of the section of the bar;

[0049] - the retaining bars can be arranged axially between an element of The guidance and the torque transmission web are supported. In this way, the retaining bars axially secure the seat relative to the torque transmission web. The retaining bars also absorb the additional force component along the X-axis.

[0050] The invention also relates, according to another of its aspects, to a friction clutch disc comprising a friction disc equipped with friction linings and a vibration damping device incorporating all or part of the characteristics mentioned above, in which the friction disc is attached to one of the guide elements or to the torque transmission web.

[0051] The invention also relates, according to another aspect, to a double damper flywheel comprising a first inertia mass and a second inertia mass coaxial about an X-axis, a vibration damping device incorporating all or part of the characteristics mentioned above, in which the first inertia mass is carried by the guide elements and the second inertia mass is carried by the torque transmission web

[0052] The invention will be better understood upon reading the following description, given solely by way of example and made with reference to the accompanying drawings in which:

[0053] - Figure [Fig. 1] is an isometric view of a friction clutch disc incorporating a vibration damping device according to a first embodiment of the invention;

[0054] - Figure [Fig.2] is a cross-sectional view of the friction clutch disc according to the first method of implementing the invention of [Fig.1];

[0055] - Figure [Fig.3] is an isometric view of a friction seat along the first method of implementing the invention of [Fig.1];

[0056] - Figure [Fig.4] is a partial cross-sectional view of the damping device vi bratoire in a resting position according to the first embodiment of the invention of the invention of the [Fig.1];

[0057] - Figure [Fig. 5] is a partial cross-sectional view of the damping device vi bratoire in a resting position according to a second embodiment of the invention of the invention;

[0058] - Figure [Fig. 6] is a partial cross-sectional view of the damping device vi bratoire in a resting position according to a third embodiment of the invention of the invention;

[0059] - Figure [Fig.7] is an isometric view of a friction seat along a fourth method of implementing the invention;

[0060] - Figure [Fig.8] is a graph showing the effects of the invention on the torque hysteresis generated within the vibration damping device as a function of angular displacement.

[0061] In the following description and claims, the terms "front" or "rear" will be used, without limitation and to facilitate understanding, according to the direction with respect to an axial orientation determined by the main X axis of rotation of the transmission of the motor vehicle and the terms "inside / internal" or "outside / external" with respect to the X axis and along a radial orientation, orthogonal to said axial orientation.

[0062] Fig. 1 illustrates a friction clutch disc 100 incorporating the vibration damping device 1 according to a first embodiment of the invention.

[0063] The friction clutch disc 100 with axis of rotation X includes a vibration damping device 1 comprising a torque transmission disc 2, guide elements 3, and helical compression springs 4. The friction clutch disc in this case illustrates a so-called "symmetrical" architecture and comprises a friction disc 6 mounted on the torque transmission disc 2. The friction disc 6 is equipped with friction linings 7 distributed around the periphery of the torque transmission disc 3 along the axis X and adapted to rub against a pressure plate of a clutch mechanism. The two guide elements 3, also called guide washers 3, are arranged on either side of the torque transmission disc 2, trapping the helical compression springs 4 in intermediate housings.

[0064] A clutch mechanism fixed to the flywheel (not shown) applies a clamping force to the friction clutch disc 1 so as to transmit the torque produced by the engine towards the gearbox.

[0065] The engine torque enters the friction clutch disc via the friction disc 6 and exits via a central means 5 disposed between the two guide washers 3. The central hub 5 is connected to the guide washers 3 by rivets 8. In this embodiment, the two guide elements 3 are not angularly offset from each other with respect to the axis of rotation X, so that the angle [3] shown in [Fig. 1] is equal to 0°. The central hub 5 engages with a pre-damper, notably via a hub body 9. The hub body 9 is mounted on the driven shaft of the gearbox (not shown) and transmits the engine torque through splines formed on its inner bore.

[0066] The coaxial parts 2 and 3 are mounted to rotate relative to each other against damping means comprising, here, helical compression springs 4 as well as interface means 10 with the two coaxial parts 2 and 3. More specifically, the interface means comprise spring seats 10 located at the ends of the springs 4, on the one hand, and, on the other hand, recesses 200, 300 formed in the guide elements 3 and in the torque transmission web 2. The spring seats 10 are adapted to cooperate with the recesses 200, 300 formed in the guide elements 3 and / or the torque transmission web 2 according to a pivot joint.

[0067] In order to absorb and dampen the vibrations and rotational acyclics from the internal combustion engine, the vibration damping device 1 includes a friction device 80, 81, 82 arranged between each of the guide elements 3 and the torque transmission web 2.

[0068] As can be seen in [Fig.2], the friction device consists, on the one hand, of a shim washer 80 mounted between one of the guide elements 3 and the torque transmission web 2, and on the other hand, of a friction washer 82 and an elastic washer 81 mounted between the other of the guide elements 3 and the torque transmission web 2.

[0069] The shim washer 80 is an annular washer equipped with an internal groove 84. The internal groove 84 meshes with an external groove 43 formed on the flange 41 of the torque output hub 4. The shim washer 80 is rotationally fixed relative to the guide element 3. The shim washer 80 is, for example, made of sheet steel. The shim washer 80 also includes, on one of its lateral faces, a friction face with the torque transmission disc 2.

[0070] The spring washer 81 applies a first axial force Fl in Newtons on the friction washer 82 and the shim washer 80. The spring washer can be a conical washer but can also take other embodiments such as than a corrugated disc.

[0071] We will now describe in more detail the arrangement of the aforementioned interfacing means, including the spring seat 10, according to a preferred embodiment of the invention, with reference to figures 3 to 4.

[0072] Seat 10 comprises:

[0073] - a front face 11 defining a first support plane PI capable of cooperating with the end of the springs 4 and comprising a means for centering the springs 14 along an axis Y passing through the axis of the springs,

[0074] - a dorsal face 12 abutting the frontal face 11, defining a second plane support P2 capable of cooperating with the torque transmission veil 2 and the two guide elements 3 and,

[0075] - a convex-shaped section of bar 13 extending projecting from the face dorsal and having in section in a geometric plane P3 perpendicular to the X axis a substantially circular end with center C, said bar section 13 being supported in concave recesses 200, 300 formed in the guide elements 3 and in the torque transmission web 2 so as to form a pivot joint. The geometric plane P3 passes through the midpoint of the bar section 13.

[0076] To ensure proper relative positioning of the end of the helical compression springs 4 on the seat 10, the front face 11 has steps 104, 106 extending outward from the front face along the Y axis which is perpendicular to the first support plane PL. The steps 104, 106 are here circular around the Y axis passing through the axis of the springs and ensure centering of the outer and inner springs.

[0077] Generally, the bar section 13 is prismatic in shape, with its base resting on the dorsal face 12, and its apex rounded. The apex comprises a surface 16 with a substantially circular cross-section, center C, and radius R. The center C is located at a distance d from the plane P. In the illustrated example, the distance d has a value substantially not equal to zero. Furthermore, the two sides 15 of the prismatic shape each comprise a nearly flat surface. The two sides 15 of the prismatic shape are not parallel to each other; they diverge from each other in the direction of the base of the prismatic shape to form an angle p between 1 and 20 degrees. Finally, the connection between each of the sides 15 and the dorsal face 12 is made by a fillet 18 having a radius. Alternatively, the two sides 15 of the prismatic shape may be rounded.

[0078] The spring seat 10 also includes on its dorsal face 12 two retaining bars 17 arranged in projection and distributed on either side of the geometric plane P3. The retaining bars 17 are, in particular, arranged axially between a guide element and the torque transmission web. For example, the retaining bars 17 are axially spaced by a distance slightly greater than that of the torque transmission web 2 and extend parallel to this geometric plane P3 over the height of the seat. The web 2 is positioned between the retaining bars 17. In this way, the spring seat 10 is positioned axially with respect to the web 2. The retaining bars 17 are perpendicular to the bar section 13 and emerge from the bar section 13, at least locally conforming to its shape.

[0079] As illustrated in [Fig. 2], the dorsal face 12 and the bar section 13 are suitable for being received in a housing 20, 30 provided for this purpose in the torque transmission web 2 and the guide elements 3. The housing 20 of the torque transmission web 2 has a closed contour, as do the housings 30 of the guide elements 3. Each of the housings 30 comprises a radially external band 31, two lateral bearing surfaces 32 receiving the concave recesses 300, and a radially internal edge 34. The radially internal edge 34 is formed by the central part of the guide element 3.

[0080] In general, the housing 30 is substantially complementary to the portion of the seat described above, with which it is required to cooperate. To this end, the lateral bearing surface 32 comprises a recess 300, the bottom of which has a concave base with a substantially circular cross-section and two nearly flat, non-parallel lateral walls. Thus, the recess 300 has a prismatic shape substantially complementary to the prismatic shape of the bar section 13 described previously and is suitable for receiving into said recess 300. Therefore, the housing 30 and the seat 10 can form a pivot joint, the operation of which will be described later.

[0081] On either side of the recess 300, the lateral bearing surface 32 has a first inner edge 321 and a second outer edge 322, both of which are substantially flat. The first inner edge 321 acts as a stop against the seat 10 during the operation of the pivot joint. Indeed, the dorsal face 12 is able, during this operation, to bear against the first inner edge 321. The two edges 321 and 322 are not parallel to each other.

[0082] Figure 4 illustrates a set of helical compression springs 4 supported on two seats 10. According to the first embodiment of the invention, the vibration damping device is characterized in that the first support plane PI of the spring 4 on the seat 10 is inclined at an angle α with respect to the axis of rotation X. In this example, the angle α is 5°. The second support plane P2 is parallel to the axis of rotation X. In this first embodiment, the dorsal face 12 and the frontal face 11 of each seat 10 are inclined relative to each other at the angle α. However, the frontal faces 11 of the two seats 10 remain parallel to each other.

[0083] As illustrated in [Fig.3], the front face 11 and the back face 12 of the seat 10 define a disc of material of substantially circular shape on which the spring rests, the disc of material having a thickness that varies according to the angle of inclination a.

[0084] Each helical compression spring 4 is inclined relative to the torque transmission web 2 at angle α and applies a second axial force F2 oriented in the same direction as the first axial force Fl of the elastic washer, such that the first and second axial forces Fl, F2 are additive. In this way, the increasing proportional load of the helical compression springs is used to generate a complementary force component along the X-axis without affecting the torque transmission within the vibration damping device.

[0085] We will now describe the operation of the preferred embodiment of the invention with reference to Figures 4 and 8.

[0086] Figure 8 illustrates the evolution of the hysteresis torque generated by the friction device 80, 81, 82 during the angular displacement in the forward direction of the vibration damping device 1 under four different configurations. In the rest state of the vibration damping device 1, the angular displacement is zero, corresponding to a value of 0°. Figure 4 illustrates the rest state of the vibration damping device 1 according to the invention, i.e., without angular displacement between the guide elements 3 and the torque transmission web 2, and without any centrifugal force acting on the springs.

[0087] Curve 90 in [Fig. 8] illustrates the case of a conventional vibration damping device for which the hysteresis torque remains constant over the entire angular displacement. In this conventional vibration damping device, the first and second support planes PI, P2 are parallel to the axis of rotation X.

[0088] Curve 91 of [Fig. 8] illustrates the case of the vibration damping device according to the first embodiment of the invention, in which the first bearing surface PI of the spring 4 on the seat 10 is inclined at an angle α with respect to the axis of rotation X. During the angular displacement, the helical compression spring 4 is compressed more and more until it reaches a state of maximum compression in which the winding coils are joined. In this state, and regardless of the rotational speed of the vibration damping device, the front faces 11 of the two seats 10 are parallel to each other. Thus, during the angular displacement, the additional force component F2 along the axis X is transmitted via the torque transmission web 2 to the friction device 80, 81, 82 housed within the vibration damping device. As illustrated in curve 91 of the graph in [Fig. 8], the first bearing surface PI of the spring 4 on the seat 10 is inclined at an angle α with respect to the axis of rotation X.8], the direction of application of the additional force F2 allows to increase the load supported by the shim washer 80 of the friction device. and thus generate more hysteresis. Therefore, the additional force component along the X-axis generates a hysteresis torque that varies according to the angular displacement. This additional hysteresis torque is added to the constant hysteresis torque applied by the load-bearing spring washer 81 on the friction washers 82 and the shim washers 80. At the end of the angular displacement, the hysteresis torque value of curve 91 is greater than the hysteresis torque value of curve 90.

[0089] We will now describe, with reference to [Fig. 5], a vibration damping device 1 according to a second embodiment of the invention substantially similar to the previous one. This second embodiment of the invention is distinguished by the fact that the support of the torque transmission web 2 on the dorsal face 12 of the seat 10 is offset with respect to the geometric plane P3 passing through the middle of the bar section, and the support of the guide elements on the dorsal face remains centered.

[0090] As illustrated in [Fig. 5], the median plane of the torque transmission web 2 at the seat supports is axially offset relative to the guide elements 3. Thus, the support of the torque transmission web 2 is offset relative to the geometric plane P3 by a value K of 2 mm. According to the invention, the value of the offset K can be between 2 and 5 mm. In this way, the additional force F2 along the X axis transmitted via the torque transmission web to the friction device is further increased.

[0091] Curve 92 in [Fig. 8] illustrates the case of the vibration damping device according to the second embodiment of the invention, in which the first bearing surface PI of the spring 4 on the seat 10 is inclined at an angle α of 5° with respect to the axis of rotation X, and the bearing surface of the torque transmission plate 2 is offset from the geometric plane P3 by a value K of 2 mm. During the angular displacement, the helical compression spring 4 is increasingly compressed until it reaches a state of maximum compression in which the windings are joined. The direction of application of the additional force F2 increases the load borne by the shim 80 of the friction device and thus generates more hysteresis. Therefore, the component of the additional force along the X axis generates a hysteresis torque that varies according to the angular displacement.This additional hysteresis torque is added to the constant hysteresis torque applied by the load spring washer 81 on the friction washers 82 and shim washers 80. At the end of the angular displacement, the hysteresis torque value of curve 92 is greater than the hysteresis torque values ​​of curves 90 and 91. In this second embodiment of the invention, the friction device comprises two friction faces, one face associated with the shim washer 80 and one face associated with the friction washer 82.

[0092] It is possible to increase the number of friction faces in order to increase the effect of the invention. For example, curve 93 in [Fig. 8] illustrates the case of the vibration damping device according to the second embodiment of the invention, in which the friction device comprises four friction faces. The additional friction faces are then arranged between the guide element 3 and the torque transmission plate 2, but on the side opposite the spring washer 81 in order to benefit from the additional load F2. At the end of the angular travel, the hysteresis torque value of curve 93 is greater than the hysteresis torque values ​​of curves 90, 91, and 92.

[0093] We will now describe, with reference to [Fig. 6], a vibration damping device 1 according to a third embodiment of the invention. This third embodiment of the invention is distinguished by the fact that the first support plane PI of the spring on the seat and the second support plane P2 of the seat on the torque transmission web and the two guide elements are inclined at an angle α between 2° and 10° with respect to the axis of rotation X. More precisely, the dorsal face 12 and the frontal face 11 of each seat 10 are parallel to each other.

[0094] This embodiment of the invention is obtained by angularly offsetting the two guide elements 3 relative to the axis of rotation X along an axis [3] between 1° and 5° so that the second support plane P2 of the seat on the torque transmission web and the two guide elements is inclined at angle a. In this third embodiment of the invention, the front faces 11 of the two seats 10 remain parallel to each other.

[0095] As illustrated in [Fig.6], the front face 11 and the back face 12 of the seat 10 define a disc of material of substantially circular shape on which the spring rests, the disc of material having a constant thickness unlike other embodiments of the invention.

[0096] Each helical compression spring 4 is inclined relative to the torque transmission web 2 at an angle α and applies a second axial force F2 oriented in the same direction as the first axial force Fl of the elastic washer, such that the first and second axial forces Fl, F2 are additive. In this way, the increasing proportional load of the helical compression springs is used to generate a complementary force component along the X-axis without affecting the torque transmission within the vibration damping device.

[0097] We will now describe, with reference to [Fig. 7], a vibration damping device 1 according to a fourth embodiment of the invention. This fourth embodiment of the invention is distinguished by the fact that the second support plane P2 of the seat on the torque transmission web and the two guide elements is inclined at an angle α between 2° and 10° with respect to the axis of rotation X.

[0098] As illustrated in [Fig.7], the front face 11 and the back face 12 of the seat 10 define a disc of material of substantially circular shape on which the spring rests, the disc of material having a thickness that varies according to the angle of inclination a.

[0099] The spring seat 10 also includes on its dorsal face 12 two projecting retaining bars 17 distributed on either side of the geometric plane P3. The retaining bars 17 are perpendicular to the bar section 13 and emerge from the bar section 13, at least locally conforming to its shape. The retaining bars 17 are recessed relative to the top of the bar section 13.

[0100] According to another embodiment of the invention, each helical compression spring 4 can be inclined relative to the torque transmission web 2 at an angle α and apply a second axial force F2 oriented in the opposite direction to the first axial force Fl of the spring washer, such that the first and second axial forces Fl, F2 cancel each other out. In this way, the friction device 80, 81, 82 housed within the vibration damping device 1 receives this additional force, which relieves the load applied by the spring washer 81 on the friction and shim washers 80, 82 according to the direction of inclination of the angle α. It is thus possible to have a friction device whose hysteresis level is variable and controlled over the entire angular travel, such that at the end of the angular travel, the hysteresis torque value is less than the hysteresis torque value of curve 90.

[0101] The invention is not limited to the first embodiment of the invention just described. According to another aspect of the invention, the vibration damping arrangement may be in the form of a double damper flywheel.

[0102] In this further embodiment of the invention, the double damper flywheel 1 comprises a first flywheel, also called the primary flywheel, serving as a torque input element for the vibration damping device, and a second flywheel, also called the secondary flywheel, serving as a torque output element for the vibration damping device. The two primary and secondary flywheels are mounted coaxially with respect to each other about an axis of rotation X of the double damper flywheel.

[0103] In this vibration damping device, the first inertial mass is fixed to one of the guide elements and the second inertial mass is fixed to the torque transmission web. For example, the two primary and secondary flywheels are mounted to rotate relative to each other against helical compression springs, as well as interface means such as seats 10 with the two flying. More specifically, the interfacing means comprise spring seats placed at the ends of the springs, on the one hand, and, on the other hand, guide elements framing a secondary web. In this other example of an embodiment of the invention, the seat incorporates all the characteristics presented in the first embodiment of the invention.

[0104] The vibration damping device 1 can also be integrated into a so-called "hybrid" motor vehicle transmission comprising a combustion engine and an electric motor. In this "hybrid" transmission, the torque input of the vibration damping device 1 is downstream of the combustion engine, and the torque output of the vibration damping device 1 is directly or indirectly rotationally connected to the rotor of the electric motor.

Claims

Demands

1. A vibration damping device (1) for a motor vehicle, comprising: - a torque transmission web (2); - two rotationally linked guide elements (3), coaxial about an axis of rotation (X) and arranged on either side of said torque transmission web (2); - helical compression springs (4) bearing on the torque transmission web and the guide elements by means of seats (10) arranged on the ends of the springs, in which each seat (10) comprises: - a front face (11) defining a first support plane (PI) adapted to cooperate with the end of the springs and comprising a means for centering the springs about an axis (Y) passing through the axis of the springs, - a back face (12) abutting the front face (11), defining a second support plane (P2) adapted to cooperate with the torque transmission web and the two guide elements, and- a convex bar section (13) projecting from the dorsal face and having, in section in a geometric plane (P3) perpendicular to the axis (X), a substantially circular end with center (C), said bar section (13) being supported in concave recesses (200, 300) formed in the guide elements (3) and in the torque transmission web (2) so as to form a pivot joint, characterized in that the first support plane (PI) of the spring on the seat and / or the second support plane (P2) of the seat on the torque transmission web and the two guide elements is inclined at an angle (a) between 2° and 10° with respect to the axis of rotation (X).

2. Vibration damping device (1) according to claim 1, characterized in that the back face (12) and the front face (11) of each seat are inclined relative to each other at angle (a).

3. Vibration damping device (1) according to claim 1, characterized in that the dorsal face (12) and the frontal face (11) of each seat are parallel to each other and the two guide elements (3) are angularly offset from each other with respect to the axis of rotation (X) along an axis (|3) between 1° and 5° such that the second support plane (P2) of the seat on the torque transmission web and the two guide elements are inclined according to the angle (a).

4. Vibration damping device (1) according to any one of claims 1 to 3, characterized in that for the same helical compression spring (4) supported on two seats (10), the front faces (11) of the two seats are parallel to each other.

5. Vibration damping device (1) according to any one of claims 1 to 4, characterized in that the support of the torque transmission veil (2) on the back face (11) of the seat is offset from the geometric plane (P3) passing through the middle of the bar section by a value (K) between 2 and 5 mm and the support of the guide elements (3) on the back face remains centered.

6. Vibration damping device (1) according to any one of claims 1 to 5, characterized in that it comprises a friction device (80, 81, 82) composed, on the one hand, of a shim washer (80) mounted between one of the guide elements (3) and the torque transmission web (2), and on the other hand, of a friction washer (82) and an elastic washer (81) mounted between the other of the guide elements (3) and the torque transmission web (2), the elastic washer (81) applying a first axial force (Fl) in Newtons on the friction washer and the shim washer.

7. Vibration damping device (1) according to claim 6, characterized in that each helical compression spring (4) is inclined relative to the torque transmission web (2) at angle (a) and applies a second axial force (F2) oriented in the same direction as the first axial force (Fl) of the elastic washer so that the first and second axial forces (Fl, F2) add up.

8. Vibration damping device (1) according to claim 6, characterized in that each helical compression spring (4) is inclined relative to the torque transmission web (2) at angle (a) and applies a second axial force (F2) oriented in the opposite direction to the axial force (Fl) of the elastic washer so that the first and second axial forces (Fl, F2) cancel each other out.

9. Vibration damping device (1) according to any one of the preceding claims, characterized in that the axis of the bar section (13) passing through the center (C) of the bar section extends to a predetermined distance (d) not substantially equal to zero from the second support plane (P2).

10. Vibration damping device (1) according to any one of the preceding claims, characterized in that the torque transmission web (2) and the guide elements (3) comprise housings (20, 30) arranged to receive the springs and the seats, each housing (20, 30) comprising a radially external band (21, 31), two lateral bearing surfaces (22, 32) receiving the concave recesses (200, 300) and a radially internal edge (24, 34), the lateral bearing surfaces (22, 32) being arranged to cooperate with the dorsal face of each seat.

11. Vibration damping device (1) according to the preceding claim, characterized in that the lateral bearing surface (22, 32) has a first edge (221, 321) and a second edge (222, 322) capable of coming into butt contact with the dorsal face (12) of the seat during implementation of the pivot joint, the two edges (321, 322) not being parallel to each other.

12. Vibration damping device (1) according to any one of the preceding claims, characterized in that each seat comprises retaining bars (17) extending in projection from the dorsal face (12) which divide the dorsal face into several bearing surfaces associated with the two guide elements (3) and the torque transmission web (2).

13. Vibration damping device (1) according to claim 11 or 12, characterized in that the retaining bars (17) are arranged axially between a guide element (3) and the torque transmission veil (2).

14. Friction clutch disc comprising a friction disc (6) equipped with friction linings (7) and a vibration damping device (1) according to any one of the preceding claims, characterized in that the friction disc (6) is attached to one of the guide elements (3) or to the torque transmission disc (2)

15. Double damper flywheel comprising a first inertia mass and a second inertia mass coaxial about an axis (X), a vibration damping device (1) according to any one of claims 1 to 13, characterized in that the first inertia mass is carried by the guide elements (3) and the second inertia mass is carried by the torque transmission web (2).

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