Damping device for suspension element

Abstract

A damping device (20) intended for a suspension element having at least one layer of paint, the damping device (20) being configured to at least partially cover said suspension element (2), and being characterized in that the internal surface of the device (20) comprises a zone (Z1) which is in direct contact with at least a portion of said suspension element and which has a rough texture (31). Figure for the abstract: Fig. 3A

Description

Title of the invention: Damping device for suspension element. Technical field

[0001] The present exposition relates to a damping device, a suspension assembly, and a stabilizer assembly.

[0002] Such a stabilizer assembly can be suitable for any type of stabilizer bar and any type of vehicle, in order to limit vehicle roll. In particular, such a stabilizer assembly can be used for any axle of the vehicle. Prior art

[0003] The automotive suspension (or stabilizer assembly) is a complex system that plays a crucial role in managing the interactions between the vehicle and the road surface. Its primary function is to maintain optimal contact between the wheels and the road, thereby ensuring stable handling, increased comfort, and enhanced safety. To achieve these objectives, the suspension must absorb and dissipate shocks and vibrations caused by road irregularities, while allowing the vehicle to remain maneuverable and maintain good traction.

[0004] To this end, suspension elements are integrated into the stabilizer assembly to play a key role in supporting the vehicle's weight and absorbing shocks. Thus, such a suspension element, such as a spring (the term "suspension element" may be substituted for "suspension element" and vice versa in the remainder of this patent application), makes it possible to compensate for road variations and maintain a constant ride height despite load changes. The suspension elements act as elastic elements that compress and expand to manage dynamic forces.

[0005] Among the various configurations of suspension elements, and more specifically springs, available on the market, tubular springs possess unique technical characteristics that can improve overall suspension performance. Such a tubular spring is distinguished by its tubular cross-section. This configuration gives the spring a hollow structure with a longitudinal channel extending along the entire length of the suspension element. The main body of the spring is made from an elastic material chosen for its deformation and energy return properties, which are essential for suspension functions.

[0006] In addition, among these different configurations of springs as suspension elements, there are so-called "solid" or "solid" springs which are made of a The material is generally homogeneous (steel or high-strength metal alloy) and has no internal cavity, unlike tubular springs. Their design is based on a compact and robust structure, which gives them a high capacity to withstand high loads and significant stresses.

[0007] By way of example, such springs 2 and 3, as suspension elements, are shown in [Fig. 1], which illustrates a stabilizer assembly 1 for a vehicle, according to the prior art. Here, the springs 2 and 3 work in conjunction with connecting rods 4 and 5. Each connecting rod 4 and 5 is attached to a mounting point on a wheel 6 and 7 respectively, generally at a suspension support. This connection allows the connecting rods 4 and 5 to transfer the forces and movements of the springs 2 and 3 directly to the wheels 6 and 7.

[0008] The two wheels 6 and 7 are generally connected by a stabilizer bar, not visible in [Fig. 1], also called an anti-roll bar, which joins the two wheels of the same axle. It reduces body roll during cornering and dampens the deformations experienced by the suspension, in order to maintain optimal contact between the tires of said wheels 6 and 7 and ensure maximum grip. In other words, each end of the stabilizer bar is thus attached to the suspension triangle of each wheel 6 and 7, via the tie rods 4 and 5, while its central part is attached to the vehicle chassis by means of at least two bearings.

[0009] However, although suspension elements offer several advantages in a stabilizing assembly, the latter remains subject to specific problems which can alter its functions and its effectiveness.

[0010] One of the main challenges is stress concentration. Indeed, the suspension element may contain localized stress zones. In other words, stress concentration refers to the tendency of the stresses, intended to act on the suspension element, to cluster in specific areas of the spring, thus creating points of weakness. Consequently, these areas may be subject to uneven wear, increasing the risk of breakage. Thus, a uniform distribution of stresses is important to avoid weak points that could lead to premature failure.

[0011] More specifically, the suspension element is subjected to various types of stress, each of which can contribute to stress concentration. Bending stresses develop when the suspension element absorbs loads, particularly during compression or relaxation.

[0012] Furthermore, under extreme conditions, particularly in the case of very high or low temperatures, the mechanical properties of the suspension element may be affected. For example, at high temperatures, suspension elements may They can soften, lose their rigidity, and exhibit a decrease in their damping capacity. For example, in environments exceeding 80 to 100°C (such as near an engine or brake subjected to high stress), suspension components can become less resistant to dynamic loads, leading to permanent deformation or a reduction in their effectiveness at dissipating vibrational energy. Furthermore, prolonged exposure to high temperatures can cause chemical degradation, such as oxidation, which weakens the material.

[0013] At low temperatures, suspension elements become more rigid and brittle when exposed to temperatures near or below 0°C. This reduces their shock absorption capacity and increases the risk of cracking under sudden loads.

[0014] Furthermore, suspension components are subject to progressive wear under repeated loads (e.g., driving on rough roads), necessitating periodic replacement. Under these high-stress conditions, suspension components can undergo permanent deformation (creep). The material can then lose its ability to return to its original shape after compression, thus reducing its long-term effectiveness.

[0015] Suspension components can also be exposed to chemical or physical agents that alter their structure. For example, oils, fuels, or de-icing products used on roads can interact with the elastomer, causing a loss of elasticity. Prolonged exposure to water or humid conditions can also promote material degradation. Furthermore, dust, sand, and other abrasive particles present in the environment can accelerate mechanical wear through constant friction. This abrasion phenomenon can be exacerbated by a mechanism known as sliding / fretting, where repetitive micro-slips between contact surfaces cause localized wear, notably creating noise and discomfort for vehicle passengers.

[0016] Finally, their behavior can be non-linear, making the precise adjustment of certain stabilizer configurations complex.

[0017] To overcome these problems, damping devices (known as "pads" in the technical jargon known to those skilled in the art) are often integrated into the stabilizers.

[0018] These damping devices, generally made from elastomeric materials such as rubber or polyurethane, act as intermediaries between the suspension element and the other components. Their main function is to complement the action of the suspension elements by providing additional damping. By acting as a barrier against the conditions by minimizing environmental factors and mechanical friction, damping devices are designed to protect suspension components.

[0019] In other words, the damping devices protect the suspension elements against these aggressions, just as they serve as a shock-absorbing cushion, reducing friction and distributing forces, thus preventing premature wear of the contact surfaces.

[0020] For the damping device to perform these functions, the connection between the suspension element and the damping device plays a crucial role in the performance and durability of both components. Indeed, an effective and durable connection ensures that the damping device correctly fulfills its protective and damping functions. A solid connection between the suspension element and the damping device allows for a homogeneous distribution of loads over the entire interface surface. This is important for minimizing stress concentration points and ensuring optimal mechanical performance: a suspension element protected by a well-fixed damping device retains its elastic properties over a prolonged period because it is less susceptible to permanent deformations due to unevenly distributed loads.

[0021] If the connection is weak or deteriorates, the damping device could detach or slip, leaving the suspension element exposed to severe conditions, leading to its rapid degradation. Furthermore, a weak connection can also cause unwanted movement of the damping device, exposing its edges to accelerated mechanical wear or permanent deformation, and can cause internal shearing in the material of the damping device if it momentarily slips relative to the suspension element under dynamic loads, which could lead to breakage.

[0022] In the prior art, several solutions have been proposed to improve adhesion and thus contact between the suspension element and the damping device in vehicle stabilization systems. For example, some solutions combine chemical bonding with mechanical fasteners (e.g., clips, inserts, or pins with or without shims) to reinforce and enhance the connection between the suspension element and the damping device. However, the addition of mechanical fasteners increases the number of components and the complexity of the system, and can introduce unwanted movement between the damping device and the suspension element, especially in environments with high vibration or significant temperature variations.

[0023] Other solutions propose a method of applying spot adhesive to predetermined areas. More specifically, the adhesive is deposited in the form of small dots or segments strategically distributed over the surface of the device damping. However, the localized adhesive application points concentrate the bond between the suspension element and the damping device on a limited area, leaving unbonded zones between these points. These zones can become weak points where the damping device is susceptible to slippage or detachment under vibration or dynamic loads. Because the bonding areas are limited, mechanical stresses are not distributed evenly, which can lead to premature bond failure.

[0024] There is therefore a real need for a more efficient and more durable linking solution between the damping device and the suspension element, which is free, at least in part, from the disadvantages inherent in the aforementioned known configurations. Description of the invention

[0025] The present description relates to a damping device for a suspension element having at least one layer of paint, the damping device being configured to cover at least partially said suspension element, and being characterized in that the internal surface of the device includes an area which is in direct contact with at least a portion of said suspension element and which has a rough texture.

[0026] The suspension element can be a spring or a vehicle stabilizer bar. In the latter case, the damping device is a bearing suitable for at least partially covering the stabilizer bar.

[0027] The distinctive feature of the damping device lies in a zone on the device's internal surface, representing the face of the device oriented towards the suspension element and in direct contact with it. This zone is characterized by a rough texture specifically configured to make direct contact with at least a portion of the suspension element. "Direct contact" means an immediate physical interaction between the rough surface of the damping device and the surface of the suspension element concerned, without the interposition of any additional mechanical elements (an adhesive may then serve as an intermediate layer between the two).

[0028] The rough texture of this direct contact area is a key feature. Indeed, a surface with a rough structure improves the bond between the damping device and the suspension element by strengthening their mechanical adhesion and increasing the effective contact area. This roughness generates physical micro-anchors between the two components, which act as fixing points preventing any relative movement.

[0029] These micro-anchors are particularly effective in limiting deformations and delaminations induced by thermal and / or mechanical cycles, thanks to a better tolerance to differential expansion or contraction of materials, maintaining a functional bond even in demanding environmental conditions, such as the presence of condensation, humidity, or exposure to corrosive chemicals.

[0030] Unlike purely chemical bonds, which are sensitive to these factors, mechanical micro-anchors ensure lasting stability. Furthermore, this configuration minimizes relative movement between surfaces, guaranteeing a strong hold even in the presence of intense vibrations or significant dynamic loads.

[0031] In addition, roughness plays a crucial role in the distribution of mechanical forces. It allows the applied loads to be distributed over a wider contact area, reducing stress concentrations that could otherwise cause localized failures in the connection. This mechanism thus contributes to the durability and reliability of the system by preventing breaks or other structural damage related to excessive pressure on specific points.

[0032] According to one embodiment of the invention, the suspension element being made of elastic material and having a plurality of turns, such as a spring, the device is configured to cover at least partially at least one of said turns, the area being in direct contact with at least a portion of said at least one of the turns.

[0033] In other words, this embodiment consists of a damping device suitable for use in conjunction with a suspension element made of an elastic material. In this embodiment, the suspension element is understood to be a component such as a spring, generally used in mechanical or vehicle stabilization systems to absorb shocks and vibrations. This suspension element comprises a plurality of coils, that is, successive loops that make up its structure.

[0034] In the remainder of this patent application, and unless otherwise indicated or the context is inconsistent, the expression "at least a portion of said at least one of the turns," in the context of the use of said damping device, shall be understood as including the following concepts: "a turn," "a plurality of turns," or "one or more portions of several turns," or "one or more portions of a single turn." Thus, each of the above terms may be substituted by any of the other above terms.

[0035] As indicated above, the damping device is configured to at least partially cover one or more turns of this suspension element. This feature means that the damping device envelops or covers a section of the external surface of one or more loops of the suspension element. without necessarily covering the entire area. This partial coverage allows for targeted protection and improved performance of the suspension element under specific conditions, such as reducing friction noise or absorbing vibrations.

[0036] According to certain embodiments, said zone is configured to at least partially cover said at least one of the turns which is intended to be subjected: - to friction where the coefficient of friction exceeds a predetermined threshold value; and / or - to greater friction than that exerted on the other turns of the suspension element; and / or - to contact pressures or bending stresses greater than those supported by the other turns of the suspension element; and / or - to fatigue phenomena induced by repeated axial displacements; and / or - to a circular or radial slide.

[0037] Thus, said rough area is intended to target critical areas of the suspension element which are subjected to particularly intense mechanical stresses.

[0038] Initially, the roughened area is designed to cover the coils or portion(s) of coil(s) exposed to significant frictional forces, where the coefficient of friction between the suspension element and its environment exceeds a predetermined value. This can occur in situations where the coils rub against other mechanical components, or when the environment contains abrasive particles or contaminants that increase friction.

[0039] Secondly, it should be noted that certain portions of the coils, or individual coils, depending on their position in the suspension element, experience disproportionate friction compared to other coils. This friction can result from variations in the load distribution that increase local pressure.

[0040] Some turns (or parts of turns) also bear higher contact pressures or bending stresses than others due to their role in distributing dynamic loads. The roughened area provides better distribution of these localized loads.

[0041] Certain turns or parts of turns are often subjected to repetitive axial movements, i.e., continuous cycles of compression or relaxation along their longitudinal axis. These cycles cause mechanical fatigue that can lead to microscopic cracks in the material and / or progressive failure of the turn in question. By covering the stressed areas, the roughened zone helps to limit, or even eliminate, the effects of this fatigue.

[0042] Finally, in some cases, certain turns (or parts of turns) may be subjected to circular (around the axis of the turns) or radial (perpendicular to this axis) sliding movements, caused by lateral forces that generate a displacement in the position of the turns or result from interactions with adjacent surfaces in relative motion. The roughness of the direct contact area then increases mechanical friction in these directions, which limits undesirable movements.

[0043] According to some embodiments, said zone is configured to at least partially cover said at least one of the turns which forms one of the ends of the suspension element or to at least partially cover the body of the suspension element.

[0044] The ends of the suspension element are often particularly critical areas because they are generally in direct contact with supports or anchor points of the suspension element, which increases localized mechanical stresses, primarily of the bending or hydrostatic pressure type. Furthermore, during use, the ends can rub against fixed or moving surfaces, generating increased wear. Thus, by covering these coils with a roughened area, the damping device acts as a protective barrier that improves the distribution of mechanical stresses and preserves the structural integrity of the anchor points.

[0045] The body of the suspension element refers to the intermediate coils located between the two ends. These coils also play a central role in the bending and shock absorption function of the suspension element. They are also subjected to specific stresses, including repeated bending and torsional stresses, variable dynamic loads, and relative motion vibrations.By covering at least a portion of the main body with a rough area (this configuration being called a "buffer"), i.e. the areas likely to be subjected to these stresses, the damping device increases the mechanical adhesion between the suspension element and itself, reducing slippage or relative displacement, further protects these surfaces against wear due to external friction or abrasion or inter-coil contact (i.e. one coil against another coil in the body of the suspension element), and minimizes fatigue phenomena induced by cyclic stresses.

[0046] According to certain embodiments, said zone comprises a plurality of relief patterns, preferably undulating, such as undulations, and / or comprises a plurality of cavities, preferably in the form of shafts and / or longitudinal bands, and / or comprises longitudinal relief bands, preferably parallel or undulating.

[0047] The rough area of ​​the internal surface of the damping device can be provided with specific characteristics designed to optimize its interaction with the suspension element.

[0048] The patterns, for example, are designed to increase the effective contact area and provide better mechanical adhesion. The patterns can be undulating, that is, forming, for example, undulations or regular or irregular waves. As for the cavities, these are depressions integrated into the rough area. Different cavity configurations are envisaged: pits, for example, represent point cavities, circular or otherwise shaped, while longitudinal bands are cavities extending lengthwise.

[0049] Such longitudinal bands may be raised and arranged in parallel, i.e. bands aligned next to each other, without crossing or significant deviation, or may be raised and wavy, i.e. alternating regular or irregular variations of curvature along the longitudinal direction.

[0050] According to certain embodiments, the longitudinal bands are raised and wavy and have at least one of the following configurations:

[0051] - undulations whose amplitude gradually increases from the center of said area; and / or

[0052] - undulations whose amplitude gradually decreases from the center of said area; and / or

[0053] - undulations exhibiting a constant amplitude over the whole of said zone.

[0054] The design of these raised undulations is therefore based on the defined amplitude like the distance between the highest and lowest points of each wave. The amplitude can vary depending on several configurations.

[0055] According to a first configuration, the undulations are weak at the center of the zone and become progressively more pronounced towards the extremities. Conversely, the undulations may have a maximum amplitude at the center of the zone, gradually decreasing towards the extremities. Finally, the undulations may be uniform, with an identical amplitude over the entire surface of the rough zone.

[0056] The amplitude parameter allows a person skilled in the art to optimize the management of mechanical stresses applied to the suspension element, particularly on its critical portions, as this reduces the risk of excessive stress concentrations. Indeed, the undulation creates a controlled discontinuity in the contact so that the pressures are distributed more evenly, thus reducing areas of potential deformation or failure.

[0057] According to certain embodiments, said area of ​​the internal surface is intended to be at least partially chemically adhered to said at least a portion of said suspension element.

[0058] Adhesion here refers to the establishment of a bond between the internal, rough surface of the damping device and at least a portion of the suspension element. This bond is primarily mechanical adhesion via the rough structure of said area, but can also optionally be supplemented by chemical adhesion, through the application of an adhesive agent or a compatible coating (for example, an adhesive tape which may be pre-glued and therefore ready for use).

[0059] Among the possible adhesive tapes known to those skilled in the art, one can mention the so-called "double-sided" tape, that is to say, a tape which has adhesive surfaces on both sides. Such an adhesive tape may also have, but is not limited to, a thickness of between 1 and 2 millimeters, and be applied to the ends of the suspension element.

[0060] Furthermore, it should be noted that a chemical adhesive agent is a term that designates any material used to promote adhesion by chemical reaction between two surfaces. It can therefore include adhesives with a thickness of less than 30 microns, for example, such as epoxy, or adhesives that are activated or not by heat or cold.

[0061] When a glue or other adhesive is applied, the roughness of this area allows the chemical agent to penetrate the grooves in the roughness, forming solid anchor points once cured. Thus, the roughness of this area considerably increases the surface area available for a chemical agent, compared to a smooth surface. The adhesive can then spread over a larger area, increasing the overall bond strength.

[0062] According to certain embodiments, said area of ​​the internal surface is at least partially cold-bonded or hot-bonded to said at least a portion of said suspension element.

[0063] According to some embodiments, the device has an ovoid, circular, rectangular, square, or conical shape.

[0064] The shape of the damping device refers to the shape of its surface which will be in contact with the suspension element so as to protect it. Different geometries can be chosen, depending, for example, on that of the suspension element.

[0065] The present description further relates to a suspension assembly, comprising a suspension element having at least one layer of paint, and comprising a damping device as defined above, the area of ​​whose internal surface is in direct contact with at least a portion of the suspension element so as to to conform to the shape of said portion, the area of ​​the internal surface having a rough texture.

[0066] According to some embodiments, the suspension element has a plurality of turns, the shape of at least a portion of at least one of said turns of the suspension element being either ground, or ovoid, or circular, or rectangular, or square, or conical.

[0067] It should be noted that the ground shape means that the portion of the coil (or the coil(s), or a portion of several coils) has been mechanically treated to obtain a smooth surface. This process helps to eliminate imperfections and improve wear resistance in these areas of the suspension element. Furthermore, grinding reduces the overall weight of the component by removing excess material, thus contributing to a lighter assembly, which is particularly advantageous in certain applications, including valve springs. Moreover, in specific applications, notably for vehicle suspension springs, grinding can be used to reduce the overall spring height, which is advantageous when the vehicle body geometry cannot be modified.

[0068] The present description further relates to a vehicle stabilizer assembly, comprising at least two suspension assemblies as defined above, and comprising a stabilizer bar, connecting said at least two suspension assemblies.

[0069] The present description also relates to a vehicle comprising a stabilizer assembly as defined above.

[0070] The aforementioned features and advantages, as well as others, will become apparent from the following detailed description, examples of embodiments of the vehicle stabilizer bar bearing, and the proposed support and stabilizer assembly. This detailed description refers to the accompanying drawings. Brief description of the drawings

[0071] The accompanying drawings are schematic and are intended primarily to illustrate the principles of the exposition. On these drawings, from one figure to another, identical elements (or parts of elements) are identified by the same reference symbols.

[0072] [Fig-1] Fig. 1 is a perspective view of a stabilizing assembly comprising two suspension elements according to the state of the art;

[0073] [Fig. 2A], [Fig. 2C] Figures 2A and 2C are each a perspective view of a suspension element covered at least partially by a damping device according to the state of the art;

[0074] [Fig.2B] The [Fig.2B] is a cross-sectional view, along a longitudinal plane, of one end of the suspension element according to the state of the art;

[0075] [Fig.3A], [Fig.3B], [Fig.3C], [Fig.3D] Figures 3A, 3B, 3C and 3D illustrate each a perspective view of an area of ​​the internal surface of the damping device, the area being intended to be in direct contact with at least a portion of the suspension element, according to embodiments of the invention;

[0076] [Fig. 4A], [Fig. 4B] Figures 4A and 4B illustrate different configurations of said area according to embodiments of the invention; and

[0077] [Fig. 5] Figure 5 illustrates a perspective view of a landing according to a mode of realization of the invention. Description of the implementation methods

[0078] It is recalled that a suspension element, such as a spring 2 illustrated in [Fig. 1], comprises a plurality of turns forming a main body 10 disposed between two ends 10a and 10b, visible in [Fig. 2A].

[0079] The suspension element 2 is here provided with at least one layer of paint and is made of an elastic material which may be, for example, a composite material, or steel, or a steel-based alloy. More generally, the elastic material has a hardness greater than 200 HV (Vickers), preferably greater than 450 HV.

[0080] It should be noted that the external cross-section of the main body 10 and / or its ends 10a and 10b can be, without limitation, circular, ovoid, rectangular, square, or conical in shape. Of course, the term "external" here refers to the shape of the outer contour of the suspension element 2.

[0081] Alternatively, the external cross-section of the main body 10 and / or its ends 10a and 10b may have a so-called "ground" shape, meaning that the suspension element 2 has undergone a grinding process intended to refine the surface, at least partially, of one or more turns of the suspension element 2. In other words, the surface is smoothed or shaped to achieve desired dimensions and texture.

[0082] However, certain portions of the coils are exposed to significant frictional forces and contact pressures that can approach 5 MPa (megapascals), noting that this value depends on the hardness and stiffness of the suspension element and the applied dynamic forces. This can occur in situations where the coils (or portions of coils) rub against other mechanical components, or when the environment contains abrasive particles or contaminants that increase friction. Similarly, certain portions of coils, or entire coils, depending on their position within the suspension element, experience disproportionate friction compared to other coils. This friction can result from variations in load distribution that increase local pressure.

[0083] Furthermore, some turns (or parts of turns) are subjected to higher contact pressures or bending and torsional stresses than others due to their role in distributing dynamic loads. In addition, some turns or parts of turns are often subjected to repetitive axial movements, i.e., continuous cycles of compression or relaxation along their longitudinal axis. These cycles cause mechanical fatigue that can lead to microscopic cracks in the material and / or progressive failure of the turn in question.

[0084] Finally, in some cases, certain turns (or part(s) of turn(s)) may be subjected to circular or radial sliding movements, caused by lateral forces which generate a shift in the position of the turns or caused by interactions with adjacent surfaces in relative motion.

[0085] To address these issues, it is known to use a damping device 20 (a "pad" in technical jargon familiar to those skilled in the art). These damping devices 20 are generally made from elastomeric materials such as rubber or polyurethane, and act as an intermediary between the suspension element 2, 3 and the other components. Their main function is to complement the action of the suspension elements 2, 3 by providing additional damping.

[0086] The damping device 20 may include an insert, not visible in the figures, which serves as reinforcement and is often made of a plastic composite material such as polyamide. The insert thus improves the structural rigidity of the damping device and allows for better distribution of mechanical loads. The insert may also be at least partially covered with a layer of rubber to improve the absorption of vibrations and shocks thanks to its damping properties.

[0087] Furthermore, such a damping device 20 is designed to conform to the shape of the surface it protects, whether it be a portion of a single turn, a single turn, several turns, several portions of a single turn, or several portions of several turns. In the example of [Fig. 2A], the damping device 20 is arranged to partially enclose the end 10a of the suspension element 2. It therefore partially protects the turn located at this end 10a.

[0088] More particularly, as shown in [Fig. 2B], which presents a cross-sectional view of the end 10a of the suspension element 2, along plane PI of [Fig. 2A], the damping device 20 includes a zone ZI in its internal surface which is in direct contact with said portion. Since the outer section of the end 10a is circular, the zone ZI is also circular.

[0089] Of course, the internal surface of the damping device, and more particularly its ZI zone, can have different shapes, for example an ovoid shape, or rectangular, or square, or conical shape for example.

[0090] As shown in [Fig. 2B], the ZI zone is here bonded to said portion of the end coil 10a, so as to create a chemical bond 30 by the application of an adhesive agent (e.g., glue) or a compatible coating. Similarly, as illustrated in [Fig. 2C], the ZI zone is bonded between two coil portions or at strategic points along the suspension element. This configuration is known by the English term "buffer".

[0091] The chemical bond 30 is not sufficient in itself to guarantee an effective and durable fixing between the suspension element 2 and the damping device 20. Indeed, under these conditions, the damping device 20 could detach or slip, leaving the suspension element 2 exposed to severe conditions, which will lead to rapid degradation of the latter.

[0092] Moreover, such a chemical bond 30 can further cause parasitic movements of the damping device 20, exposing its edges to accelerated mechanical wear or permanent deformations, and can cause internal shearing in the material of the damping device 20 if it momentarily slips relative to the suspension element 2 under dynamic loads, which could lead to breakage.

[0093] Thus, the invention proposes a more efficient and more durable connection solution between the damping device 20 and the suspension element 2, which is free, at least in part, from the disadvantages inherent in known attempts to create such a connection.

[0094] To this end, it is proposed that zone ZI have a rough texture 31 which improves the connection between the damping device 20 and the suspension element 2 (or 3) by strengthening their mechanical adhesion and increasing the effective contact area. As explained above, this roughness 31 generates physical micro-anchors between the two components, which act as fixing points preventing any relative movement.

[0095] Indeed, these micro-anchors are particularly effective at limiting deformations and delaminations induced by thermal cycles, thanks to a better tolerance to differential expansion or contraction of the materials, and maintaining a functional bond even under demanding environmental conditions, such as the presence of condensation, humidity, or exposure to corrosive chemicals, or the presence of pollutants that may include abrasive particles such as Arizona sand or basaltic gravel, which can infiltrate the interfaces. Thus, unlike In addition to purely chemical bonds 30, which are sensitive to these factors, mechanical micro-anchors 31 ensure lasting stability. Furthermore, this configuration minimizes relative movement between surfaces, guaranteeing a strong hold even in the presence of intense vibrations or significant dynamic loads.

[0096] In addition, the roughness 31 plays a crucial role in the distribution of mechanical forces. It allows the applied loads to be distributed over a larger contact area, reducing stress concentrations that could otherwise cause localized failures of the connection. This mechanism thus contributes to the durability and reliability of the system by preventing breaks or other structural damage related to excessive pressure on specific points.

[0097] Naturally, this bond 31, facilitated by the roughness of zone Zl, primarily creates a mechanical adhesion, but can also be optionally supplemented by a chemical adhesion 30, for example, by the application of an adhesive. More precisely, when an adhesive is applied, the asperities of said zone Zl allow the adhesive to penetrate the hollows of the roughness 31, forming solid anchor points once cured. Thus, the roughness 31 of this zone Zl considerably increases the surface area available for an adhesive, compared to a smooth surface. The adhesive can then spread over a larger area, increasing the overall bond strength.

[0098] The rough Zl zone, with or without chemical adhesive 30, can have several configurations. As an example, [Fig. 3A] illustrates a first configuration of the Zl zone, which here features a plurality of undulating relief patterns. A second configuration of the Zl zone is illustrated in [Fig. 3B], in which a plurality of pit-like cavities can be seen. Such cavities can be in the form of longitudinal bands, as illustrated in [Fig. 3C].

[0099] Other configurations of the rough zone Zl are possible. For example, the zone Zl may have raised longitudinal bands as illustrated in [Fig. 3D] and referenced as 36. These longitudinal bands are shown here as wavy but may also be alternately or additionally parallel. Similarly, as can be seen in this [Fig. 3D], the bands may also be transverse and wavy, but also parallel.

[0100] The Zl zone may have several possible forms which follow one another among the aforementioned forms. Thus, this does not exclude the possibility that the rough zone Zl may contain excavated pits followed by a series of longitudinal raised bands, for example.

[0101] Fig. 4A illustrates three particular configurations VI, V2 and V3 of the rough zone Z1, along the plane PI, when the latter has undulations in relief.

[0102] More particularly, in configuration VI, the undulations have an amplitude that increases progressively from the center 40 of said zone Zl, then that in configuration V2, the amplitude of the undulations gradually decreases from the center 40 of said zone Zl. Finally, in the last alternative configuration V3, the undulations can have a constant amplitude over the entire said zone Zl.

[0103] Of course, the undulations of the rough zone Zl can very well exhibit at least two of the configurations VI, V2 and V3. For example, the undulations can increase progressively from the center 40, then decrease progressively and finally be of constant amplitude on the edges.

[0104] As indicated above, the amplitude parameter allows a person skilled in the art to perform optimized management of the mechanical stresses applied to the suspension element, and particularly on its critical portions, as this reduces the risks of excessive stress concentrations.

[0105] Indeed, the undulation creates a controlled discontinuity in the contact so that the pressures are distributed more uniformly, thus reducing areas of potential deformation or failure. Such a controlled discontinuity aims to allow a smooth transition between peaks, which minimizes stress concentrations and promotes better load distribution.

[0106] By way of example, the peak positive amplitude in configuration V1 can be between 10 pm and 5 mm, just as the maximum negative amplitude in configuration VI can be between 5 mm and 10 pm. Finally, in configuration V3, the constant amplitude can also be, for example, between 10 pm and 5 mm.

[0107] Such undulations can be formed by various technical processes adapted to manufacturing requirements. For example, undulations can be generated by molding, where a preformed matrix directly creates the undulating texture on the surface during the molding process. Another method involves using 3D printing, which allows for the production of undulating structures with high precision. Finally, undulations can be created by laser engraving, a process that involves directly engraving a undulating structure onto the Zl area by removing material in a controlled manner.

[0108] It should be noted that once the damping device 20 is positioned around the portion to be covered, its roughness in zone Zl allows it to act like a suction cup, thus creating effective adhesion between the portion of the suspension element to be covered and the damping device 20. More specifically, this roughness makes it possible to use the principle of differential pressure to create an adhesive force without requiring mechanical fastening. Thus, when pressure is applied to zone Zl, the roughness generates compression that modifies the shape of the surface of the damping device 20, as can be seen in [Fig. 4B]. The Arrows 80 on either side of the portion of the suspension element 2 then symbolize and indicate the direction in which the damping device 20 reacts once the portion is in place in the damping device 20, in other words once the pressure is applied.

[0109] This then provides additional sealing protection against intrusions, preventing small debris, such as dust, sand or other contaminants, from entering the junction between the portion of the suspension element to be covered and the ZI zone of the damping device 20.

[0110] Although the present invention has been described with reference to specific embodiments, it is evident that modifications and changes can be made to these examples without departing from the general scope of the invention as defined by the claims. In particular, the damping device 20 can be in the form of a bearing, as illustrated in [Fig. 5], which at least partially covers a stabilizer bar 90 for a vehicle. It should be noted that a bearing, a device known to those skilled in the art, serves to allow the stabilizer bar to be attached to the vehicle chassis while providing a certain amount of damping.

[0111] Thus, the internal surface of the bearing also includes here a ZI zone which is in direct contact with at least a portion of the stabilizer bar, the ZI zone having a rough texture as described above with its various embodiments.

[0112] Furthermore, individual features of the various embodiments illustrated / mentioned can be combined in additional embodiments. Therefore, the description and drawings should be considered in an illustrative rather than restrictive sense.

[0113] It is also evident that all the characteristics described with reference to a process are transposable, alone or in combination, to a device, and conversely, all the characteristics described with reference to a device are transposable, alone or in combination, to a process.

Claims

Demands

1. Damping device (20) for a suspension element having at least one layer of paint, the damping device (20) being configured to at least partially cover said suspension element (2), and being characterized in that the internal surface of the device (20) includes an area (Zl) which is in direct contact with at least a portion of said suspension element and which has a rough texture (31).

2. Damping device (20) according to claim 1, the suspension element (2) being made of elastic material and having a plurality of coils, such as a spring, the device (20) is configured to cover at least partially at least one of said coils, the area (Zl) being in direct contact with at least a portion of said at least one of the coils.

3. Damping device (20) according to claim 2, wherein said zone (Zl) is configured to cover at least partially said at least one of the turns which is intended to be subjected: - to friction whose coefficient of friction is greater than a predetermined threshold value; and / or - to friction greater than that exerted on the other turns of the suspension element; and / or - to contact pressures or bending stresses greater than those supported by the other turns of the suspension element; and / or - to fatigue phenomena induced by repeated axial displacements; and / or - to circular or radial sliding.

4. Damping device (20) according to claim 2 or 3, wherein said zone (Zl) is configured to at least partially cover said at least one of the coils which forms one of the ends (10a; 10b) of the suspension element (2) or to at least partially cover the body (10) of the suspension element (2).

5. Damping device (20) according to any one of the preceding claims, wherein said zone (Zl) comprises a plurality of raised patterns, preferably undulating, such as undulations, and / or comprises a plurality of cavities, preferably in the form of shafts and / or longitudinal bands, and / or includes raised longitudinal bands, preferably parallel or wavy.

6. Damping device (20) according to claim 5, wherein the longitudinal bands are raised and wavy, and have at least one of the following configurations (VI; V2; V3): - undulations whose amplitude gradually increases from the center of said zone (Zl); and / or - undulations whose amplitude gradually decreases from the center of said zone (Zl); and / or - undulations having a constant amplitude over the whole of said zone (Zl).

7. Damping device (20) according to any one of the preceding claims, wherein said zone (Zl) of the internal surface is intended to be at least partially chemically bonded to said at least a portion of said suspension element.

8. Damping device (20) according to claim 7, wherein said zone (Zl) of the internal surface is at least partially cold-bonded or hot-bonded to said at least a portion of said suspension element.

9. Damping device (20) according to any one of the preceding claims, having an ovoid, or circular, or rectangular, or square, or conical shape.

10. Suspension assembly, comprising a suspension element (2; 3) having at least one layer of paint, and comprising a damping device (20) according to any one of the preceding claims, the area (Zl) of the internal surface of which is in direct contact with at least a portion of the suspension element (2; 3) so as to conform to the shape of said portion, the area (Zl) of the internal surface having a rough texture.

11. Suspension assembly according to claim 10, wherein the suspension element (2; 3) is provided with a plurality of turns, and wherein the shape of at least a portion of at least one of said turns of the suspension element (2; 3) is either ground, or ovoid, or circular, or rectangular, or square, or conical.

12. Stabilizer assembly (1) for a vehicle, comprising at least two suspension assemblies according to any one of the claims

13. 10 and 11, and including a stabilizer bar, connecting said at least two suspension assemblies. Vehicle comprising a stabilizer assembly (1) according to claim 12.

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