VEHICLE WHEEL RIM WITH STRUCTURAL RESONATOR VIBRATION TRAP

Abstract

A rim (R) is part of a vehicle wheel, exhibits at least one natural mode of vibration having at least one principal frequency that generates vibrations, and comprises a multitude of structural resonators (SRs), distributed spatially and frequency-wise around a circumference of an inner (IR) or outer (OO) face, within a frequency range including this principal frequency, and defining a vibration trap capable of attenuating the intensities of the generated vibrations. Figure 2

Description

Title of the invention: VEHICLE WHEEL RIM WITH VIBRATION TRAP WITH STRUCTURAL RESONATORS Technical field of the invention

[0001] The invention relates to vehicles comprising at least two wheels, and more precisely to the rims equipping the wheels of such vehicles. State of the art

[0002] Certain vehicles, generally of the automobile type, comprise at least two wheels, each comprising a rim on which a tire is usually fixed. As is known to those skilled in the art, due to the road surface / tire interaction, this rim has at least one natural mode of vibration having at least one main frequency which generates vibrations. This results from the fact that at least one resonance is created at the rim, very generally metallic, due to a natural mode.

[0003] Generally, the main (resonant) frequencies are between 50 Hertz and a few hundred Hertz. This frequency range is critical for controlling the rolling noise of a vehicle because the spectral density of the excitatory power of the wheel (tire-road interaction) is high. As a result, the noise generated by the aforementioned vibrations is audible to the vehicle's passengers and can be a nuisance, particularly when the vehicle is relatively quiet (such as when it is moving thanks to the engine torque produced by an electric motor of its powertrain (or GMP)).

[0004] Among the various causes of resonances that a metal rim may experience, we can notably cite the role of the "tilting mode" which is characterized by a torsional movement around the plane of the wheel, and which is linked, among other things, to the flexibility of the wheel-bearing connection. This tilting mode is particularly annoying and, in addition, the rotation of the wheel causes a frequency splitting resulting in two twin resonance frequencies generally separated by 0 Hz to 30 Hz. It should be noted that there are also other influential natural modes for noise arising at the level of the wheel system, such as for example the ovalization mode, which can also pose problems (especially if they couple with the cavity mode of the wheel tire).

[0005] It has been proposed to equip the wheels with a noise-reducing device. Generally, the latter is installed inside the tire cavity, on the latter or on the internal face of the metal rim. This type of noise-reducing device generally comprises acoustic resonators (frequently of the Helmholtz type). Due to the location of the noise-reducing device, it may interfere with and / or risk being damaged when mounting / dismounting the tire. In addition, if attached to the removable tire, when the latter is replaced the wheel is left without an anti-noise device (unless it is also equipped with an anti-noise device (which significantly increases the cost). In addition, when acoustic foams are used inside the tire cavity, they can also pose recycling problems. Finally, the known anti-noise devices fitted to the wheels prove incapable of simultaneously handling a wide range of resonance frequencies.

[0006] The invention therefore aims in particular to improve the situation. Presentation of the invention

[0007] For this purpose, it proposes in particular a rim suitable for forming part of a wheel of a vehicle and having at least one natural mode of vibration corresponding to at least one main frequency generating (harmful) vibration resonances.

[0008] This rim is characterized by the fact that it comprises a multiplicity of structural resonators, distributed over a circumference of an internal or external face, spatially, and, frequently, in a frequency interval including the (each) main frequency, this set of structural resonators defining a vibration trap capable of smoothing and / or attenuating the intensities of the vibration resonances generated.

[0009] This double distribution, spatial and frequency, of the structural resonators makes it possible to obtain an overall damping of the rim and of the harmful resonance(s), and therefore a very effective reduction in the level of noise that they generate in the vehicle.

[0010] The rim according to the invention may include other characteristics which may be taken separately or in combination, and in particular:

[0011] - each structural resonator can functionally constitute a system of type damped spring mass;

[0012] - in the presence of the first option, each structural resonator may comprise a flexible support having a first end suitable for being fixedly secured to the internal or external face and a second end opposite the first end and to which is secured a weight acting as a mass, of a value which is a function of the frequency of the frequency interval on which it acts;

[0013] - in the presence of the last sub-option, the weights can have a cy shape circular lindic and either the same orientation by being placed one behind the other on the same circle or on two circles parallel to each other, or for a first part of them a first orientation by being placed on a first circle and for a second part of them a second orientation, different from the first orientation, being placed on a second circle parallel to the first circle;

[0014] - the vibration trap may be of the multiple tuned mass damper type (or MTMD (“Multiple Tuned Mass Damper”;

[0015] - its structural resonators can be spatially distributed on the circumference from the external face;

[0016] - the multiplicity can be between 10 and 300;

[0017] - the frequency interval, where the structural resonators have a first natural mode of vibration, may have a lower limit between 50 Hz and 90 Hz and an upper limit between 120 Hz and 150 Hz;

[0018] - it may comprise at least one circular groove in which are installed and spatially distributed structural resonators.

[0019] The invention also provides a wheel suitable for equipping a vehicle and comprising a rim of the type presented above.

[0020] The invention also proposes a vehicle, possibly of the automobile type, and comprising at least two wheels of the type presented above. Brief description of the figures

[0021] Other characteristics and advantages of the invention will appear on examining the detailed description below, and the attached drawings (some of which were obtained in CAD / CAM (“Computer Aided Design / Computer Aided Drawing”)), in which:

[0022] [Fig.l] schematically illustrates, in a perspective view from the inside, an example of embodiment of a rim according to the invention,

[0023] [Fig.2] schematically illustrates, in a sectional view in a transverse and vertical plane, a part of the rim of [Fig.l],

[0024] [Fig.3] schematically illustrates, in a perspective view, an exemplary embodiment of a structural resonator of a rim according to the invention,

[0025] [Fig.4] schematically illustrates, in a top view from the outer face side, a groove of a rim according to the invention comprising a first arrangement of structural resonators,

[0026] [Fig.5] schematically illustrates, in a top view from the outer face side, a groove of a rim according to the invention comprising a second arrangement of structural resonators, and

[0027] [Fig.6] schematically illustrates, in a top view from the external face side, a groove of a rim according to the invention comprising a third arrangement of structural resonators. Detailed description of the invention

[0028] The invention aims in particular to propose a JM rim intended to be part of a wheel of a vehicle and comprising a vibration trap acting on a frequency band.

[0029] In the following, it is considered, by way of non-limiting example, that the vehicle is of the automobile type. It is for example a car. But the invention is not limited to this type of vehicle. It relates in fact to any land vehicle comprising at least two wheels with rims (possibly metal).

[0030] Furthermore, it is considered in the following, by way of non-limiting example, that the JM rim is metallic. But this is not an obligation.

[0031] In Figures 1 to 6, the direction X is parallel to the longitudinal direction of the vehicle V, which is substantially parallel to the lateral (or longitudinal) sides comprising the side doors, the direction Y is parallel to the transverse direction of the vehicle V, which is perpendicular to the longitudinal direction X, and the direction Z is parallel to the vertical direction of the vehicle V, which is perpendicular to the longitudinal directions X and transverse directions Y.

[0032] [Fig. 1] schematically illustrates an exemplary embodiment of a JM rim according to the invention, intended to be part of a wheel of a vehicle (here a motor vehicle). As partially illustrated in [Fig. 1], this rim (here a metal one) JM comprises an internal face FI intended to be oriented towards the cavity of the tire of the wheel and an external face FE opposite the internal face FI and defining a cavity intended to house in particular the wheel hub and a part of the braking device. In addition, this JM rim has, when it is attached to the mechanical train which carries it, at least one natural mode of vibration having at least one main frequency fp which generates vibrations and the nuisance of which is sought to be limited. For example, this natural mode of vibration can be the so-called tilting mode described in the introductory part.

[0033] Furthermore, this rim JM comprises a multiplicity of structural resonators RS which are distributed on the circumference of its internal face FI or its external face FE not only spatially, but also frequency-wise, in a frequency interval which includes the (each) main frequency fp. These structural resonators RS define a vibration trap which is capable of smoothing and / or attenuating the intensities of the vibration resonances generated (by the main modes which could propagate in the mechanical system to which the wheel is attached).

[0034] It is important to note that RS structural resonators are structural and not acoustic.

[0035] Thanks to the double distribution, spatial and frequency, of the RS structural resonators, an overall damping of the JM rim and of the harmful resonance(s) of the vibration mode(s) is obtained, which makes it possible to very effectively reduce the level of noise that they generate in the vehicle, and therefore the acoustic nuisance. of the vehicle passengers. It should be noted that a reduction in the resonance level of the order of 10 dB to 20 dB can thus be obtained. The aforementioned interval depends in fact at least on the arrangement of each RS structural resonator, the number (or multiplicity) of RS structural resonators, as well as the overall optimization of the masses and functional stiffnesses of the RS structural resonators.

[0036] It will be noted that in the example illustrated non-limitingly in [Fig.l], the structural resonators RS are distributed spatially on the circumference of the external face FE. Such a location for installing the vibration trap is advantageous because it does not interfere with and does not risk being damaged during mounting / dismounting of the tire, and remains attached to the rim JM, thus avoiding having to replace it at the same time as the tire.

[0037] For example, and as illustrated non-limitingly in Figures 2 to 6, each structural resonator RS can functionally constitute what is called a damped mass-spring type system.

[0038] When this type of system is chosen, each structural resonator RS may comprise, as illustrated non-limitingly in Figures 2 and 3, a flexible support SF and a weight MR, respectively, approximately, functionally, playing the roles of stiffness and mass. This support SF has first E1 and second E2 opposite ends. As illustrated non-limitingly in Figures 2 and 4 to 6, the first end E1 is suitable for being fixedly secured to the internal face FI or external face FE. The weight MR is secured to the second end E2 and acts as a mass, with a value which is a function of the frequency on which it acts within the frequency interval. It will be understood that since the structural resonators RS must act on different frequencies of the frequency interval, their weights MR have different masses.

[0039] For example, the first end El of each support SF can be fixedly secured by gluing (for example via an adhesive) to the internal face FI or external face FE.

[0040] Also for example, the SF support can be made of elastomer or rubber (possibly synthetic).

[0041] It will be noted that the SF support is certainly flexible, but its stiffness must be sufficiently high in the direction of the centrifugal forces so as not to buckle and not to crush too much, and it must be relatively flexible in another direction in order to resonate with the MR weight that it supports at a determined frequency, located in the correct frequency range for trapping.

[0042] It will also be noted that the RS structural resonators have mechanical characteristics (dimensions and / or shape and / or material(s)) which vary slightly so that their natural frequencies are distributed in frequency (and possibly according to a constant pitch) throughout the frequency range to be processed and including the (each) main (resonant) frequency fp considered.

[0043] It will also be noted that the distribution of the masses of the structural resonators RS is carried out in such a way as not to generate unbalance (or at least to minimize the unbalance) when the wheel is rotating around its axis (need to have a “balanced” wheel). For example, and as illustrated non-limitingly and partially in [Fig.l], the structural resonators RS can be distributed spatially over the entire circumference (here of the external face FE). But they could only be distributed spatially over a part of the circumference of the external face FE or internal face FI.

[0044] It will also be noted that the overall mass of the vibration trap (defined by the structural resonators RS) is chosen as a function of the level of efficiency which is generally desired and the additional mass which can be tolerated to be added to the wheel to minimize the reduction in the overall dynamics of the ground connection. For example, this overall mass is preferably of the order of 1% to 10% of the mass of the JM rim.

[0045] Also for example, and as illustrated non-limitingly in Figures 2 and 3, the MR weights may have a circular cylindrical shape. In this case, at least three arrangements of the set of MR weights may be envisaged.

[0046] In a first arrangement illustrated non-limitingly in [Fig.4], the MR weights can have the same orientation (here following the longitudinal direction X) by being placed one behind the other on the same circle.

[0047] In a second arrangement illustrated non-limitingly in [Fig. 5], the MR weights can have the same orientation (here following the longitudinal direction X) by being placed one behind the other on two circles which are parallel to each other.

[0048] In a third arrangement illustrated non-limitingly in [Fig. 6], a first part of the MR weights can have a first orientation by being placed on a first circle and a second part of the MR weights can have a second orientation, different from the first orientation, by being placed on a second circle parallel to the first circle. This third arrangement makes it possible to better handle any type of natural vibration mode (and in particular spatial vibration shapes), and to avoid, in the event of impacts or rebounds of a wheel on the road, contact between the MR weights and the JM rim.

[0049] Also for example, the MR weights can be made of metal. Thus, they can be made of steel or lead, for example.

[0050] Also for example, and as illustrated non-limitingly and at least partially in Figures 2 and 3, the support SF may comprise four legs, for example slightly curved, secured at its first end E1. But it could have other arrangements, and in particular comprise only two legs, for example. Generally speaking, any shape allowing the support SF to be suf sufficiently rigid to take up centrifugal forces and to have a stiffness adapted to the mass of the MR weight that it supports to resonate at a chosen frequency can be considered.

[0051] Also for example, the vibration trap (defined by the structural resonators RS) can be of the multiple tuned mass damper (or MTMD) type.

[0052] Also for example, the multiplicity (or the number) of structural resonators RS can be between 10 and 300. Preferably, this multiplicity (or this number) can be between 20 and 200. The higher the number of structural resonators RS, the more the noise level is potentially reduced, and the more it can make it possible to process a high number of main frequencies of the frequency interval considered.

[0053] Also for example, the frequency interval where the structural resonators RS have a first natural mode of vibration, or where appropriate the natural mode of vibration which makes them active as a trap, may have a lower limit which is between 50 Hz and 90 Hz and an upper limit between 120 Hz and 150 Hz. As an illustrative example, the frequency interval may be between 70 Hz and 130 Hz. But the frequency interval may have other lower and upper limits than those mentioned above, because this depends on the (each) main frequency fp of the natural mode of vibration to be treated and its spatial typology. Furthermore, it will be noted that the frequency interval is not necessarily centered on the main frequency fp to be treated.

[0054] Also for example, the individual structural damping of the RS structural resonators, essentially associated with the properties of the material forming their stiffness part, can be of the order of magnitude of one percent. For example, this individual structural damping can be between 2% and 10%.

[0055] Also for example, and as illustrated non-limitingly in Figures 2 and 4 to 6, the rim JM may comprise, on the internal face FI or external FE receiving the structural resonators RS, at least one circular groove RC in which the structural resonators RS are installed and spatially distributed (possibly along at least two parallel circles). This makes it possible to reduce the space requirement in the housing delimited by the internal face FI or external FE.

[0056] The invention offers several advantages, including:

[0057] - it allows not to have the two parasitic resonances (one upstream and one in downstream of a main frequency fp to be processed), as a classic resonator (of the TMD (or “Tuned Mass Damper”) type) would produce them,

[0058] - it constitutes a purely passive vibration trap using low-carbon materials. expensive and inert,

[0059] - it proves to be robust in construction to changes in the life situation of the vehicle, and in particular to variations in wheel rotation speed (which influences the main frequencies fp to be processed), to the temperature which can influence the behavior of the materials, and to manufacturing hazards because RS structural resonators can be made efficient and robust in a relatively wide frequency range,

[0060] - it allows the easy adaptation of a vibration trap of the same design in wheels of different dimensions,

[0061] - it offers greater robustness to strong variations in the central force fields the stresses that a wheel experiences during its operation.

Claims

Claims

1. Rim (JM) suitable for forming part of a wheel of a vehicle and having at least one natural mode of vibration corresponding to at least one main frequency generating vibration resonances, characterized in that it comprises a multiplicity of structural resonators (RS), distributed on a circumference of an internal (FI) or external (FE) face spatially, and frequently, in a frequency interval including said main frequency, and defining a vibration trap suitable for attenuating the intensities of said generated vibration resonances.

2. Rim according to claim 1, characterized in that each structural resonator (RS) functionally constitutes a damped mass-spring type system.

3. Rim according to claim 2, characterized in that each structural resonator (RS) comprises a flexible support (SF) having a first end (El) suitable for being fixedly secured to said internal (FI) or external (FE) face and a second end (E2) opposite said first end (El) and to which is secured a weight (MR) acting as a mass, of a value depending on the frequency of said frequency interval on which it acts.

4. Rim according to claim 3, characterized in that said mass-selottes (MR) have a circular cylindrical shape and either the same orientation by being placed one behind the other on the same circle or on two circles parallel to each other, or for a first part of them a first orientation by being placed on a first circle and for a second part of them a second orientation, different from the first orientation, by being placed on a second circle parallel to said first circle.

5. Rim according to one of claims 1 to 4, characterized in that said vibration trap is of the multiple tuned mass damper type.

6. Rim according to one of claims 1 to 5, characterized in that said structural resonators (RS) are distributed spatially on said circumference of the external face (FE).

7. Rim according to one of claims 1 to 6, characterized in that said multiplicity is between 10 and 300.

8. Rim according to one of claims 1 to 7, characterized in that it comprises at least one circular groove (RC) in which are

9. installed and spatially distributed said structural resonators (RS). Wheel suitable for equipping a vehicle, characterized in that it comprises a rim (JM) according to one of the preceding claims.

10. Vehicle, characterized in that it comprises at least two wheels according to claim 9.