FR3069604A1 - ASSUPLIED PENDULUM DAMPING DEVICE - Google Patents

Abstract

Pendulum damping device, in particular intended to be integrated in a transmission chain of a motor vehicle, in particular in a clutch, the device comprising: - a support (12); a plurality of clocks arranged around an axis X of rotation of the support; a pendulum (13) comprising an oscillating weight (14) and at least one rolling member (16) interposed between said oscillating mass and the support so as to roll on bearing tracks of support and oscillating weight during the oscillation of the oscillating mass.

Description

SOFTENED PENDULAR DAMPING DEVICE

Technical area

The invention relates to a pendular damping device, in particular for a clutch of a motor vehicle, as well as to a torsional damping device incorporating such a pendular damping device.

State of the art

A pendulum damping device is conventionally used to filter vibrations due to acyclisms in the engine of a motor vehicle.

Conventionally, it comprises an annular support intended to be driven in rotation, and several pendulum oscillating masses, mounted oscillating on the support around an axis parallel to the axis of rotation of the support. The displacement of an oscillating mass relative to the support is generally guided by two rolling members each cooperating with a rolling track of the support and a rolling track of the oscillating mass.

An oscillating mass is conventionally constituted by a pair of weights, sandwiching the support and rigidly joined together, generally by means of a spacer which defines the running track of the oscillating mass.

The pendulum damping device is conventionally rigidly fixed, by means of rivets, to a phasing washer of a torsion damping device, in particular a clutch, a hydrodynamic torque converter or a double wet or dry clutch.

The use of rivets allows fast, efficient and inexpensive assembly.

However, the impact of the rivets can break. The rupture of the rivets makes the pendulum damping device unusable.

There is therefore a need to increase the life of pendulum damping devices.

An object of the invention is to meet this need.

Summary of the invention

To this end, the invention proposes a pendular damping device, in particular intended to be integrated in a transmission chain of a motor vehicle, in particular in a clutch, the device comprising:

a support ;

a plurality of pendulums arranged around an axis X of rotation of the support, each pendulum comprising an oscillating mass and at least one rolling member, interposed between said oscillating mass and the support so as to roll on support rolling tracks and of oscillating mass during the oscillation of the oscillating mass with respect to the support.

Remarkably, in a pendulum damping device according to the invention, the support comprises one, preferably a plurality of notches configured to give the support a flexibility in torsion around the axis X.

The flexibility is determined so that the notches close resiliently, at least partially, under the effect of the shocks undergone by the device in use. The presence of such notches thus considerably increases the service life of the pendulum damping device. Without being limited by this theory, the inventors explain the results obtained by the ability of the support to partially absorb the shocks transmitted to the rivets, thanks to its torsional elasticity.

Preferably the flexibility, or angular stiffness, of the support is equal to:

ZLNCC,

Ksp: the flexibility of the support,

Nmot: the order of the engine, for example Nmot = 2 for a four-cylinder engine

Nmax: maximum engine speed in revolutions per minute, for example 5000-7000 rpm

Jsp: Support inertia,

The flexibility of the support can be between 270 Nm / ° and 4300 Nm / °.

A pendulum damping device according to the invention can also include one or more of the following optional and preferred characteristics:

- the notch opens onto a radially inner edge or onto a radially outer edge of the support. In one embodiment, at least one, preferably each notch, is substantially radial;

the support comprises a fixing lug, preferably substantially radial and, preferably, oriented towards the X axis, intended for fixing the pendular damping device to a phasing washer of a torsional damping device, the notch preferably extending, at least in part, into the fixing lug or delimiting, at least in part, an edge of said fixing lug;

- Said notch has a length greater than the largest radial dimension of the support in the regions of the support adjacent to the notch and which, when the device is observed along the X axis, are covered by an oscillating mass;

- said notch extends radially with respect to the X axis;

- The support comprises several said notches, each notch being arranged, when the pendular damping device is observed along the axis X, between regions of the support supporting adjacent oscillating masses;

- The support comprises a group of several notches, identical or different, arranged, when the pendulum damping device is observed along the axis X, between regions of the support supporting adjacent oscillating masses;

- the support is substantially flat and extends transversely;

- At least one, preferably each notch has a maximum width greater than 5 mm and / or less than 30 mm, for example between 10 mm and 20 mm.

- At least one, preferably each notch has a minimum width greater than the axial thickness of the support, for example 4 mm, for example 10 mm.

- At least one, preferably each notch has a length greater than 50 mm and / or less than 300 mm.

- At least one, preferably each notch is cut in a sheet forming the support;

- the notches are equiangularly distributed around the X axis.

The invention also relates to a torsional damping device incorporating a pendular damping device according to the invention.

Preferably, the pendulum damping device is fixed by means of at least one, preferably several rivets on a phasing washer of the torsion damping device, each rivet preferably passing through a fixing tab of the respective support.

Preferably, the width of a notch, preferably each notch, is determined so as to allow, without breaking the rivets, contact between the two parts of the support separated by said notch. In other words, at least one, preferably each notch has a bottom and first and second lateral edges connected to said bottom, said notch having a width such that the first and second lateral edges can be brought into contact with each other. , without breaking a said rivet, by twisting the support around Tax X.

The torsion damping device according to the invention is preferably chosen from a double damping flywheel, a hydrodynamic torque converter and a friction disc.

The invention also relates to a motor vehicle equipped with a torsion damping device according to the invention.

Brief description of the figures

Other characteristics and advantages of the invention will become apparent on reading the detailed description and on examining the appended drawing in which

- Figures la, 3 and 4 show, in perspective, a torsion damping device according to different embodiments of the invention;

- Figure lb shows, in front view, the pendulum damping device of the torsion damping device of Figure la;

- Figure 2 shows, in front view, a pendulum damping device according to a variant of the invention.

In the various figures, identical references are used to designate identical or analogous members.

Definitions

Unless otherwise stated,

- Axially means parallel to the axis X of rotation of the support;

- radially means along a transverse axis intersecting the axis of rotation of the support;

- transverse means in a plane perpendicular to the axis of rotation of the support;

- angularly or circumferentially mean around the axis of rotation of the support;

- orthoradialement means perpendicular to a radial direction and in a transverse plane.

By transverse plane is meant a plane perpendicular to the axis of rotation of the support.

By radial plane is meant a plane containing a radial axis and the X axis.

By axial plane is meant a plane containing the axis X.

The thickness of a part refers to a dimension measured along the X axis.

We call "torsion of the support around the X axis" a deformation of the support by bringing together the parts of the support separated by notches by displacement of said parts in a transverse plane. Such a twist therefore results from a closure, at least partially, of the notches.

By motor vehicle is meant not only passenger vehicles, but also industrial vehicles, which notably includes heavy goods vehicles, public transport vehicles or agricultural vehicles.

Unless otherwise indicated, the verbs to include, present or understand must be interpreted broadly, that is to say without limitation.

detailed description

As shown in FIG. 1, a torsion damping device 8 according to the invention comprises a pendular damping device 10 and a phasing washer 11.

The pendulum damping device comprises a support 12 able to move in rotation around an axis X and a plurality of pendulums 13, movable relative to the support

12.

Each pendulum 13 comprises an oscillating mass 14 and one or more, for example two rolling members, not visible. Conventionally, each oscillating mass is mounted oscillating on the support by means of two rolling members, preferably rollers, which pass through a rolling window formed in the thickness of the support.

Each oscillating weight 14 conventionally comprises first and second weights 14i and 14 ₂ , of generally planar shape, extending respectively opposite the first and second large faces 12, and 12 ₂ of the support 12.

The first and second weights 14i and 14 ₂ are rigidly fixed to one another, preferably by means of a spacer, not visible. The spacer is sandwiched between the two weights and extends into the bearing window of the support. It defines the rolling track of the oscillating weight.

Each rolling member is thus supported on the one hand on a support rolling track, preferably defined by the inner contour of the rolling window of the support which the rolling member passes through and, on the other hand, on the oscillating mass rolling track defined by the oscillating mass spacer.

The oscillating masses are preferably distributed equi-angularly around the axis X. Preferably, their number is greater than 2 and / or less than 8. The device can in particular comprise three, five or seven oscillating masses. In the example shown in Figure 1, the device comprises three oscillating masses uniformly distributed around the X axis.

The support 12 has a generally planar shape, generally annular. It has a radially inner edge 15i and a radially outer edge 15e, conventionally of generally circular shape, and first and second large faces 12i and 12 _{2 which are} substantially transverse.

The support 12 includes fixing lugs 16 allowing fixing to the phasing washer 11 by means of rivets 18. The fixing lugs 16 extend radially towards the axis X and are pierced with one or more fixing orifices 19 , each crossed by a rivet 18.

The support is conventionally constituted by a cut metal sheet, generally made of steel, of a thickness typically less than 10 mm.

Additional elements, such as damping buffers and / or stops and / or guides for damping and / or limiting and / or guiding the oscillation movement of the oscillating masses, for example made of polymer, can be fixed to this sheet. .

According to the invention, the support 12 comprises at least one, preferably several notches 20. In the embodiment of FIG. 1, the support 12 comprises three notches.

A notch 20, preferably each notch 20, preferably radial, extends, preferably exclusively, between regions of the support traversed, during use, by two adjacent oscillating masses, 17a and 17b, when the damping device pendulum is observed along the X axis, as in Figure lb. These regions are called "pendulum regions".

Several notches 20a, 20b and 20c can be grouped between two adjacent pendulum regions 17a and 17b, as in FIGS. 3 and 4.

A notch is a notch which crosses the thickness of the support, that is to say which, substantially over its entire length, is open on each large face 12i and 12 ₂ of the support.

A notch is defined by first and second lateral edges 21a and 21b which extend from an opening 22 through which the notch opens in the general plane of the support, preferably substantially radially, to a bottom 24, which defines the end of the notch opposite its opening 22.

A notch does not necessarily open radially outward from the support. For example, in the embodiment of FIG. 3, the notches 20a and 20b open radially towards the axis X, that is to say towards the inside.

In FIG. 3, the two notches 20a and 20b extend on each side of the fixing lug 16, thus coming to extend the fixing lug beyond the radially inner edge 15i of the support.

In the embodiment of FIG. 4, each group of notches separating two adjacent pendulum regions has two lateral notches 20a and 20b, opening radially towards the axis X, and a central notch 20c, partially extending between the two lateral notches and opening radially outwards. The central notch is therefore made in the fixing lug.

There is no limit to the shape and number of cuts.

A notch allows an elastic approximation, in a transverse plane, of the two parts of the support 12a and 12b which it separates. To allow this approximation, a notch defines one or more bridges of material, which constitute hinge zones in which the material of the support will deform during approximation.

When the notch 20 extends radially towards the axis X without radially exceeding the two parts of the support 12a and 12b, it defines a single bridge of material, between its bottom and the radially inner edge 15i of the support. Similarly, when the notch 20 extends radially away from the axis X without radially exceeding the two parts of the support 12a and 12b, it defines a single bridge of material, between its bottom and the radially outer edge 15e of support.

When the notch 20 extends radially towards the axis X beyond the two parts of the support 12a and 12b, as in FIG. 1, it defines several material bridges, namely a material bridge 30i between its bottom and the radially inner edge 15i of the support, but also two lateral material bridges 30 ₂ and 30 ₃ . All of these material bridges, as well as the arrangement of the rivets, contribute to the stiffness of the flexion imparted by the notch.

The material bridge (s) are determined as a function of the desired stiffness. This stiffness is variable depending on the torsional damping device considered. Simple tests however make it possible to determine an adapted stiffness, and therefore the dimensions of the material bridge (s).

The length Z of the notch is preferably greater than 50 mm to and / or less than 300 mm, preferably the length L is greater than the largest radial dimension r of the support in the pendulum regions that it separates.

The width l of the notch can be variable depending on its length.

In the embodiment of FIG. 3, for example, each notch has a width which gradually increases as one approaches the opening of the notch.

Preferably, the width of the notch is adapted so that the two parts of the support 12a and 12b which it separates can come into contact with one another before any degradation of the rivets. Preferably, however, it is large enough so that the amplitude of the bringing together of the two parts of the support gives a high capacity for absorbing shocks. Preferably, the width at the level of the zone of said contact is greater than 0.5 mm and / or less than 4 mm. In a preferred embodiment, as in FIG. 1, this width of the notch is defined by at least one, in this case two lateral bulges 32a and 32b, projecting from the two lateral edges 21a and 21b of the notch , respectively.

As shown in Figure 2, such bulges are optional.

The maximum width of the notch is defined to minimize the weight of the support. In the embodiment of Figure 1, the maximum width of the notch is also defined according to the desired stiffness. Preferably, the maximum width is greater than 10 mm and / or less than 30 mm.

The ratio LH _max of the length of a notch over its maximum width is preferably greater than 2, or even greater than 3, 4 or 5.

Operation follows directly from the above.

In service, the pendulums oscillate under the effect of motor acyclisms. At the end of the stroke, the oscillating masses come into abutment with the support, which causes shocks on the support. The support transmits these shocks to the rivets.

According to the invention, the impact energy is partly used to bring one of the other parts of the support adjacent and separated by a notch. This approximation corresponds to a closure, at least partial, of the opening 22 of the notch. Thanks to the torsional flexibility imparted by the notch, part of the impact energy is therefore not transmitted to the rivets, which ensures their protection. Advantageously, the amount of energy transferred to the phasing washer through the rivets is also reduced.

Excessive approximation of the adjacent parts of the support can, however, be detrimental to the rivets. Preferably, when the impact exceeds a threshold level, the two lateral edges 21a and 21b of the notch come into contact with one another. The support then becomes rigid again, which protects the rivets.

The rivets are therefore protected by a support which has flexural flexibility up to a certain threshold, then becomes rigid again beyond.

At the end of the impact, the notch opens again, due to the elasticity of the metal constituting the support, and returns to its initial shape.

As is now clear, the invention provides a solution to limit the risk of breakage of the rivets.

The service life of the pendulum damping device is increased.

Of course, the invention is not limited to the particular embodiments described above.

Claims (10)

1. Pendulum damping device, in particular intended to be integrated in a transmission chain of a motor vehicle, in particular in a clutch, the device comprising: a support (12); a plurality of pendulums arranged around an axis X of rotation of the support; each pendulum (13) comprising an oscillating mass (14) and at least one rolling member, interposed between said oscillating mass and the support so as to roll on the support and the oscillating mass during the oscillation of the oscillating mass with respect to to the support, the device being characterized in that the support comprises a notch configured to give the support flexibility in torsion around Tax X. 2. A pendulum damping device according to the preceding claim, wherein the notch opens onto a radially inner edge (15i) or onto a radially outer edge (15e) of the support. 3. pendulum damping device according to any one of the preceding claims, in which the support comprises a fixing lug (19) intended for fixing the pendulum damping device to a phasing washer of a damping device torsional, the notch extending, at least in part, into the fixing lug or delimiting, at least in part, an edge of said fixing lug. 4. pendulum damping device according to any one of the preceding claims, in which said notch has a length (L) greater than the greatest radial dimension (r) of the regions of the support adjacent to the notch and which, when the device is observed according to Tax X, are covered by an oscillating weight. 5. A pendulum damping device according to any one of the preceding claims, in which said notch extends radially with respect to Tax X. 6. pendulum damping device according to any one of the preceding claims, in which the support comprises several said notches, each notch separating, when the pendulum damping device is observed along the axis X, regions of the support supporting adjacent oscillating masses. 7. pendulum damping device according to the immediately preceding claim, wherein the support comprises a group of several notches, identical or different, arranged, when the pendulum damping device is observed along the axis X, between regions of the support supporting adjacent oscillating masses. 8. torsional damping device comprising a pendular damping device according to any one of the preceding claims, the pendular damping device being fixed by means of rivets (18) on a phasing washer (11) of the device torsional damping, said notch having a bottom (24) and first and second lateral edges (21a; 21b) connected to said bottom, said notch having a width such that the first and second lateral edges can be brought into contact with one another with the other, without breaking a said rivet, by twisting the support around the X axis. 9. A torsion damping device according to the immediately preceding claim, chosen from a double damping flywheel, a hydrodynamic torque converter and a friction disc. 10. Motor vehicle equipped with a torsion damping device according to the immediately preceding claim.