Suspension element

Abstract

Suspension element for a road vehicle for converting at least some vibrations and / or mechanical stresses into electrical energy, comprising at least one suspension element or at least one interface element configured to participate in fastening at least one suspension element of the vehicle, and at least one continuous two-dimensional pad (1), the at least one two-dimensional pad (1) is integrated into or covers a surface of the suspension element or the interface element, where the at least one two-dimensional pad (1) comprises a plurality of individual piezoelectric elements (3) arranged in the two-dimensional pad (1), and where the at least one two-dimensional pad (1) further comprises an electrical circuit (4) connecting the individual piezoelectric elements (3) together.

Description

Technical Field

[0001] The present disclosure relates to a suspension arrangement for a road vehicle for converting at least some vibrations and / or mechanical stresses into electrical energy. Background Art

[0002] The suspension elements of a vehicle, including in particular coil suspension springs and anti-roll bars, are designed to have elastic properties in order to reduce the bumps and vibrations felt in the vehicle cabin. As a result, these suspension elements are subject to significant deformation and vibrations during operation. The same is true for the interface elements used to secure these suspension elements to the chassis or underframe of the vehicle.

[0003] Naturally, these deformations and vibrations usually result in significant energy losses, mainly dissipated through friction. For thermal vehicles, it is estimated that 3% to 15% of the energy generated in the motor is dissipated in the vehicle's suspension, and if the mechanical energy effectively generated by the motor is added, ie excluding the losses related to motor emissions (33%) and cooling (29%), the losses even rise to 8% to 39%.

[0004] Therefore, it is desirable to maximize the use of at least a portion of the energy dissipated in the suspension. For this reason, several solutions have been proposed in the past, but these solutions are not completely satisfactory.

[0005] For example, some solutions aim to install a generator in the area of ​​the coil suspension spring or its shock absorber, for example by converting the hydraulic pressure of the shock absorber into torque in a hydraulic motor or by converting the linear movement of the spring or shock absorber into rotation with the help of a rack and pinion. However, these solutions require the addition of heavy and bulky elements, which ultimately offsets the expected gains in energy recovery.

[0006] Other solutions propose to recover this displacement energy via induction by installing, for example, a coil attached to one end of the spring, surrounding a magnet, attached to the other end of the spring. However, these solutions are also cumbersome and difficult to implement in practice.

[0007] Finally, there are other solutions that propose to mount one or more piezoelectric elements on the suspension element or on an element overwritten by the suspension element. However, to date, known solutions incorporating piezoelectric elements have failed to generate a truly usable current. In fact, in most known configurations, the piezoelectric elements are mounted sporadically, so that only a small potential difference is generated, and only when the piezoelectric element is applied in the correct direction. Therefore, these piezoelectric elements are usually relegated to the function of compression sensors, without having a real potential for energy recovery.

[0008] Therefore, there exists a need for a suspension arrangement for converting at least some vibrations and / or mechanical stresses into electrical energy and which is at least partially free of the disadvantages inherent in the above-mentioned configurations. Summary of the invention

[0009] The present disclosure relates to a suspension device for a road vehicle, comprising at least one suspension element, the at least one suspension element exhibiting elastic properties to act as a suspension spring during operation of the vehicle, or at least one interface element, the at least one interface element being configured to participate in securing the at least one suspension element of the vehicle exhibiting elastic properties to act as a suspension spring during operation of the vehicle; and at least one two-dimensional pad which is continuous and integrated into the suspension element or the interface element or covers at least one interface surface of the suspension element or the interface element, the interface surface being arranged to come into contact with another element of the vehicle when the vehicle is in motion, wherein the at least one two-dimensional pad comprises a plurality of individual piezoelectric elements arranged in the two-dimensional pad to convert at least some of the vibrations and / or mechanical stresses to which the suspension element is subjected during operation of the vehicle into electrical energy, and Wherein, the at least one two-dimensional pad further comprises a circuit that connects the individual piezoelectric elements together to collect electrical energy generated by the piezoelectric elements.

[0010] Based on the proposed construction, in which several piezoelectric elements are supported and distributed in a two-dimensional mat, on average, a satisfactory and recoverable voltage can be recovered. In fact, since the piezoelectric elements are distributed over the entire mat, the probability that at any time at least some of them are stressed and thus generate a potential difference rises sharply. The recoverable potential difference, as well as its stability over time, increases more the more the sheet comprises a large number of piezoelectric elements and the more the sheet covers a large section of the interface surface. In particular, by distributing the piezoelectric elements over a large surface area in this way, it is possible to recover different types of stresses that are not applied with the same amplitude, depending on the area considered.

[0011] In particular, this configuration allows adjusting the parameters of the piezoelectric elements, in particular their orientation, individually or jointly, so that they can be specifically adapted to the stresses to which they will be locally subjected.

[0012] Furthermore, the use of these individual piezoelectric elements interconnected by circuitry makes it possible to capture and amplify vibrations, which are usually difficult to use due to their low amplitude, depending on the number of piezoelectric elements.

[0013] Furthermore, such a piezoelectric pad is easy to implement and can cover large surfaces without adding difficulty. In fact, the piezoelectric pad can be prepared upstream and simply installed when the suspension device is installed; it can also be directly integrated into the suspension element or the interface element during manufacturing.

[0014] In particular, such a construction adds minimal mass and takes up minimal space, without adding any difficulty: such a piezoelectric pad can therefore be placed in an existing design of a suspension device without requiring any particularly significant adjustments.

[0015] In the present disclosure, it is understood that a two-dimensional pad is a pad extending in two orthogonal directions, namely a main direction and a transverse direction, the thickness of the two-dimensional pad relative to each of these two directions being negligible. It is also understood that, since the pad may be flexible, the two directions of extension may be curvilinear. In particular, it is understood that one of the two directions may close on itself and form a loop: this is particularly the case where the pad forms a tubular sheath, the transverse direction of the pad closing on itself, or when the pad forms a loop, the main direction of the pad closing on itself.

[0016] In some embodiments, the suspension device includes a plurality of two-dimensional pads equipped with the suspension element or interface element. These two-dimensional pads can be mounted to the same interface surface or to different interface surfaces. The configuration of these pads makes it easy to install them in different locations to maximize the energy recovered by targeting the areas with the greatest stress and / or vibration.

[0017] In some embodiments, the two-dimensional pads are interconnected in series or in parallel. A hybrid configuration combining series and parallel connections is also possible.

[0018] In some embodiments, at least one and preferably each two-dimensional pad has a length in the main extension direction of at least 3 cm, preferably at least 5 cm, and more preferably at least 10 cm. The larger the pad, the larger the surface it covers, which increases, on the one hand, the number of piezoelectric elements that can be placed, and, on the other hand, increases the spatial distribution of the piezoelectric elements, thereby increasing the probability that at any time at least some of the piezoelectric elements are generating energy.

[0019] In some embodiments, at least one and preferably each two-dimensional pad has a thickness less than or equal to 5 mm, preferably less than or equal to 2 mm, and more preferably less than or equal to 1 mm. The pad is small and does not substantially alter the profile of the suspension element or the interface element.

[0020] In some embodiments, at least one two-dimensional pad includes at least 10, preferably at least 50, and more preferably at least 100 individual piezoelectric elements. The more piezoelectric elements there are, the greater the average voltage generated, and the greater the likelihood that at least some of the piezoelectric elements are properly oriented to effectively convert local stress and / or vibration.

[0021] In some embodiments, each individual piezoelectric element has a length less than or equal to 5 mm, preferably less than or equal to 2 mm, and still more preferably less than or equal to 1 mm. The smaller the piezoelectric element, the smaller the voltage generated, but the greater the density of the piezoelectric elements, which is conducive to local recovery of minimal stress including vibration. Therefore, an overall, stable, continuous and ultimately greater power generation is achieved.

[0022] In some embodiments, the density of the piezoelectric elements included in the two-dimensional pad is greater than or equal to 50 per square decimeter, preferably greater than or equal to 300 per square decimeter. In fact, the greater the density of the piezoelectric elements, the greater the local recovery of the minimum stress including vibrations. Thus, an overall, stable, continuous and ultimately greater power generation is achieved.

[0002] In some embodiments, at least one individual piezoelectric element comprises a piezoelectric material selected from the group consisting of lead zirconate titanate (PZT), polyvinyl fluoride (PVF), polyvinylidene fluoride (PVDF), polyvinyl chloride (PVC), which are synthetic and lead-free.

[0024] In some embodiments, all individual piezoelectric elements of the two-dimensional pad are oriented in the same direction. Such a configuration is the simplest to design and implement. It is understood here that the orientation direction extends in the plane of the curvature of the pad. In particular, when the pad has the geometry of a sheath or a ring, the same orientation direction can be close to itself, thereby forming, for example, a circle.

[0025] In some embodiments, the individual piezoelectric elements of the two-dimensional pad are arranged in a plurality of groups, all individual piezoelectric elements in a group being arranged in the same alignment direction. Such groups each preferably include at least ten piezoelectric elements, the orientation of the piezoelectric elements being adjusted to the stress effectively present in the relevant area, which increases the average energy recovered.

[0026] In some embodiments, the orientation direction is parallel to a main extension direction of the two-dimensional pad.

[0027] In some embodiments, the orientation direction is inclined relative to the main extension direction of the two-dimensional pad. This type of construction is particularly effective when the applied stress is mainly applied in a direction different from the main extension direction of the pad; this is especially true for helical springs.

[0028] In some embodiments, the angle formed between the orientation direction and the main extension direction of the two-dimensional pad is between 20° and 70°, preferably between 40° and 50°. This angle range is particularly suitable for helical springs.

[0029] In some embodiments, the orientation direction of individual piezoelectric elements varies depending on their position on the suspension element or interface element, which helps to adjust the orientation of the piezoelectric elements to the stress effectively existing in the relevant area, thereby increasing the average energy recovered.

[0030] In some embodiments, at least one set of individual piezoelectric elements, preferably all individual piezoelectric elements of at least one two-dimensional pad are arranged according to two dimensions, preferably an orthogonal Bravais network. This type of arrangement is easy to design and wire.

[0031] In some embodiments, at least one set of individual piezoelectric elements, and preferably all of the individual piezoelectric elements, of at least one two-dimensional pad are connected in parallel within a given row and in series from one row to another.

[0032] In some embodiments, at least one two-dimensional pad comprises a support layer comprising a circuit on which the piezoelectric element is mounted. The support layer may in particular be a flexible printed circuit.

[0033] In some embodiments, at least one of the two-dimensional pads includes an insulating protective layer covering the individual piezoelectric elements and circuits of the two-dimensional pad. The protective layer isolates the piezoelectric elements from the circuits, reduces the risk of short circuits, and protects these elements from possible mechanical attacks such as wear or impact.

[0034] In some embodiments, the protective layer includes a material selected from the group consisting of silicone, polyethylene terephthalate (PET), polyester (PES), polyetheretherketone (PEEK), or epoxy.

[0035] In some embodiments, the protective layer comprises reinforcing fibers. These fibers can be short or long, and can in particular be glass fibers or carbon fibers.

[0036] In some embodiments, the two-dimensional pad includes several stacked stages, each stage including multiple individual piezoelectric elements and circuits. Circuits of different stages can be connected together, such as in series or in parallel. Each stage can be constructed in the same way or in a different way.

[0037] In some embodiments, the main extension direction of the two-dimensional pad is closed on itself, forming a toroidal geometry.

[0038] In some embodiments, the lateral extension of the two-dimensional pad is closed upon itself, forming a tubular geometry.

[0039] In some embodiments, the two-dimensional pad is attached to the suspension element or the interface element, preferably via bonding.

[0040] In some embodiments, the suspension element or the interface element is overmolded onto the two-dimensional pad.

[0041] In some embodiments, the two-dimensional pad is twisted around the suspension element or the interface element.

[0042] In some embodiments, a two-dimensional pad is inserted between two components of an interface element, such as a fitting and an elastomeric layer in contact with a suspension element.

[0043] In some embodiments, the suspension element is a stabilizer bar and the at least one two-dimensional pad covers at least a section of a surface of the stabilizer bar arranged to be retained by a bearing of the vehicle.

[0044] In some embodiments, the interface element is a bearing configured to be mounted about a stabilizer bar of the vehicle.

[0045] In some embodiments, the at least one two-dimensional pad covers at least a section of an interior surface of the bearing configured to maintain a stabilizing rod.

[0046] In some embodiments, said at least one two-dimensional pad is interposed between two parts of the bearing, preferably between the fitting and the elastomeric layer in contact with the stabilizer bar.

[0047] In some embodiments, the bearing comprises at least one flange, the flange comprising a bracket section and two fastening brackets, and the at least one two-dimensional pad covers at least the bracket section and preferably also the inner surfaces of the fastening brackets.

[0048] In some embodiments, the bearing includes at least one mating plate separate from the flange and configured to be attached to the housing, and the at least one second two-dimensional pad covers at least a section of an interior surface of the mating plate.

[0049] In some embodiments, the suspension element comprises at least one fastening eyelet, the at least one two-dimensional pad covering at least a section of an inner surface of the fastening eyelet. In this case, the suspension element may be, for example, a stabilizer bar or a leaf spring.

[0050] In some embodiments, the interface element is a bearing configured to be mounted in an eyelet of a suspension element of the vehicle, such as a leaf spring or a stabilizer bar.

[0051] In some embodiments, the at least one two-dimensional pad covers at least a section of an interior surface or an exterior surface of the bearing.

[0052] In some embodiments, the at least one two-dimensional pad is inserted between two parts of the bearing, preferably between the fitting and the elastomeric layer.

[0053] In some embodiments, the suspension element is a coil spring, and the at least one two-dimensional pad covers at least a section of an outer surface of the coil spring.

[0054] In some embodiments, the at least one two-dimensional pad covers at least one end section of the helical spring, preferably over at least 5 cm, more preferably over at least 10 cm. The end section of the helical spring is in fact the section subject to the greatest stress, in particular because it is supported against rigid elements of the vehicle.

[0055] In some embodiments, the at least one two-dimensional pad encloses the at least one section of the outer surface of the coil spring in the form of a sheath. Such a sheath can also play a role in protecting the coil spring.

[0056] In some embodiments, the at least one two-dimensional pad covers all exterior surfaces of the coil spring.

[0057] In some embodiments, the interface element is a support element of the coil spring, the support element being configured to be mounted on one end of the coil spring and blocked on the cup portion.

[0058] In some embodiments, the at least one two-dimensional pad covers at least a section of an outer surface of the support element arranged for contact with the cup portion.

[0059] In some embodiments, the at least one two-dimensional pad is inserted between two parts of the support element, preferably between a support section in contact with the helical spring and a base section in contact with the cup.

[0060] The above features and advantages and other features and advantages will be apparent from the following detailed description of an exemplary suspension component.This detailed description refers to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] The attached drawings are schematic diagrams, the purpose of which is firstly to illustrate the principles of the present disclosure.

[0062] In these drawings, the same elements (or parts of elements) are marked with the same reference numerals from one drawing to another. In addition, elements (or parts of elements) belonging to different embodiments, although having similar functions, are marked in the drawings by increasing the reference numerals by 100, 200, etc.

[0063] [ Figure 1 ] Figure 1 is a schematic front view of a first example of a piezoelectric two-dimensional pad.

[0064] [ Figure 2 ] Figure 2 yes Figure 1 Cross-sectional view of a piezoelectric pad.

[0065] [ Figure 3 ] Figure 3 is a schematic front view of a second example of a piezoelectric two-dimensional pad.

[0066] [ Figure 4 ] Figure 4 is a perspective view of a first example of a suspension arrangement, including a stabilizer bar and a bearing.

[0067] [ Figure 5 ] Figure 5 yes Figure 4 Exploded view of the bearing.

[0068] [ Figure 6 ] Figure 6 is a perspective view of a second example of a suspension device, including a leaf spring and a bearing.

[0069] [ Figure 7 ] Figure 7 yes Figure 6 Exploded view of the bearing.

[0070] [ Figure 8 ] Figure 8 is a perspective view of a third example of a suspension device, including a coil spring and a support element.

[0071] [ Fig. 9 ] Fig. 9 yes Figure 8 A cross-sectional view of a supporting element.

[0072] [ Fig.10 ] Fig.10 is a perspective view of a fourth example of a suspension device including a coil spring. DETAILED DESCRIPTION

[0073] In order to demonstrate the present disclosure, examples of suspension devices are described in detail below with reference to the accompanying drawings. It should be noted that the present invention is not limited to these examples.

[0074] Figure 1 A first example of a piezoelectric pad 1 according to the present disclosure is schematically shown. Such a piezoelectric pad 1 is two-dimensional, i.e. it extends in two orthogonal directions, the main direction P of the pad 1 corresponding to the direction of its longer length and the transverse direction T of the pad 1 corresponding to the direction of its shorter length, the thickness relative to these two extension directions being negligible. The piezoelectric pad 1 comprises a support layer 2 on which a plurality of individual piezoelectric elements 3 connected together by a circuit 4 are mounted.

[0075] Here, the circuit 4 takes the form of conductive tracks traced onto the surface of the support layer 2, the piezoelectric elements 3 being soldered to connectors of the circuit 4. The support layer 2 may in particular take the form of a flexible printed circuit, for example made of polyimide or polyetheretherketone (PEEK).

[0076] The piezoelectric elements 3 may take different forms, all having the ability to generate a voltage difference between their poles when they are subjected to deformation. For example, the piezoelectric elements may comprise lead zirconate titanate (PZT).

[0077] The piezoelectric element 3 is also small enough to make the piezoelectric pad 1 as a whole at least partially flexible on the one hand and to allow a considerable piezoelectric element density on the other hand. In this way, in the present example, the piezoelectric element 3 measures 5 mm long, 1 mm wide and 1 mm high; the density of the piezoelectric element 3 is 500 units per square decimeter.

[0078] There may be different arrangements of the piezoelectric elements 3. In this first example, the piezoelectric elements 3 are arranged according to an orthogonal network, ie according to regular and orthogonal rows and columns.

[0079] The piezoelectric elements 3 may have different orientations. In this first example, all piezoelectric elements 3 are oriented in the same direction, which direction constitutes the orientation direction O of the piezoelectric mat 1 , which direction is parallel to the main extension direction P of the piezoelectric mat 1 .

[0080] However, in the second example, Figure 3 As shown, all piezoelectric elements 103 may be oriented in the same direction, but this orientation direction O may form a non-zero angle θ with the main direction P of the pad 1. In this way, in the second example, this angle θ measures 20°.

[0081] In the first example, as in the second example, the piezoelectric elements 3 of the same column are connected in parallel, while the different columns of the pad 1 are connected in series. At each end of the pad 1, the circuit 4 leads to the terminals 5-, 5+, one of which constitutes the negative terminal 5- and the other constitutes the positive terminal 5+. Each terminal 5 can then be connected to a cable 6 to collect the electrical energy generated by the piezoelectric pad 1.

[0082] In addition, if Figure 2 As shown, the piezoelectric pad 1 further comprises an insulating protective layer 7 covering the circuit 4 and each piezoelectric element 3. For example, the protective layer 7 may be made of silicone and include glass fibers.

[0083] In this way, the mechanical stresses to which the piezoelectric pad 1 is subjected can be converted into electrical energy, as can the vibrations passing through the piezoelectric pad, thanks to the use of a large number of individual piezoelectric elements 3 of small size and distributed throughout the pad 1. Since this voltage fluctuates greatly over time, depending on the amplitude of the stresses and vibrations experienced, an electrical rectifier is preferably connected downstream of the piezoelectric pad 1 in order to smooth the fluctuations in the voltage generated by the piezoelectric pad 1.

[0084] Figure 4A first example 10 of a suspension device for a vehicle is shown, comprising such a piezoelectric pad 1. This is a stabilizer assembly 10, comprising a stabilizer bar 11, solid or hollow, painted or unpainted, whose central portion 12 is equipped with two bearings 13. The bearings 13 are intended to be fixed to the chassis of the vehicle, while the ends 14 of the stabilizer bar 11 each comprise an eyelet 15 intended to be attached to a vehicle component, in particular to the suspension triangle of each wheel connected to the same axle.

[0085] Figure 5 A bearing 13 of this type is shown. The bearing 13 comprises a flange 20, a counter plate 30 and an elastomer layer 19.

[0086] The flange 20 firstly comprises a fitting 20a having a substantially U-shape and comprising two retaining brackets 21 connected by a hoop 25 to form a groove 26. This fitting 20 is symmetrical with respect to its main axis A which more generally constitutes the main axis of the bearing 13.

[0087] Each retaining bracket 21 extends laterally from the bottom of the hoop 25, perpendicularly to the main axis A. Each retaining bracket 21 has a bearing surface 22, which forms the bearing surface of the flange 20, and a through hole 23, the axis C of which is perpendicular to the bearing surface 22 and therefore parallel to the main axis A. Each hole 23 is provided with a metal bushing 24 which passes through the retaining bracket 21 and projects onto the bearing surface 22 of the flange 20 over a length substantially equal to the thickness of the counterplate 30.

[0088] The groove 26 is substantially U-shaped, also symmetrical with respect to the main axis A. It has a semi-cylindrical base section, forming a bracket section 27, flanked by two flat side walls 28 which terminate in the bearing surface 22 of the flange 20. When the bearing 13 is mounted, the semi-cylindrical bracket section 27 is guided according to an axis B which is orthogonal to the axis A and corresponds to the direction of extension of the stabilizer bar 11.

[0089] The fitting 20a of the flange 20 is made by molding and injection in polyamide 66 reinforced with glass fibers. These glass fibers are short fibers, with a length between 3 mm and 3.2 mm and a diameter between 0.2 and 0.25 mm. The metal bushing 24, for its part, is inserted into the mold of the fitting 20a before the injection of the thermoplastic material. In some examples, the bushing 24 may include annular protrusions for blocking their position inside the fitting 20a once the material has hardened.

[0090] The flange 20 also comprises a first piezoelectric pad 80, similar to the piezoelectric pad 1 shown above, molded to the geometry of the lower surface of the accessory 20a: the first piezoelectric pad 80 comprises two lateral supports 81, lining the bearing surface 22 of each retaining support 21 of the accessory 20a, connected by a central hoop 85, molded to the form of the groove 26 of the accessory 20a. A notch 82 is formed in each lateral support 81 to allow the bushing 24 of the flange 20 to pass through.

[0091] The first piezoelectric pad 80 may be attached to the lower surface of the accessory 20a after obtaining the lower surface of the accessory 20a, such as by bonding, or may be pre-installed in a mold of the accessory 20a, and the accessory 20a may be subsequently overmolded onto the piezoelectric pad 80.

[0092] The counterplate 30 for its part has a general plate shape. It comprises a fitting 30a having a flat upper face 31 and a flat lower face 32 connected by a lateral peripheral wall 33. The fitting 30a is also symmetrical with respect to the main axis A of the bearing 13. More precisely, the dimensions of the fitting 30a correspond to the external dimensions of the flange 20, so that by precisely extending the contour of the flange 20, the counterplate 30 can be attached against the bearing surface 22 of the flange 20, or more precisely, against the piezoelectric pad 80 lined thereon.

[0093] In this example, the mating plate 30 is substantially flat; however, in other examples, it may take other forms, such as a bracket that conforms to the form of the vehicle's flange and / or chassis.

[0094] More specifically, the fitting 30a of the counterplate 30 has a sealing section 36 assembled from two assembly sections 37: each assembly section 37 is arranged to coincide with the retaining bracket 21 of the flange 20, while the sealing section 36 is arranged to span the groove 26 of the flange 20 and accordingly close it.

[0095] Each assembly section 37 includes a hole 34 that coincides with the fastening hole 23 of the corresponding retaining bracket 21 of the flange 20: its diameter basically corresponds to the outer diameter of the bushing 24, that is, the gap with the outer diameter of the bushing 24 is very small, so that the part of the bushing 24 protruding on the supporting surface 22 of the flange 20 can engage in the hole 34.

[0096] The fitting 30a of the counterplate 30 is made by injection molding in a polyamide 66 reinforced with glass fibers. The glass fibers used to reinforce the polyamide of the counterplate 30 are similar to the glass fibers used for the flange 20.

[0097] The mating plate 30 also includes a rectangular second piezoelectric pad 90 , which is also similar to the piezoelectric pad 1 shown above, lining the upper surface of the sealing section 36 of the fitting 30 a .

[0098] The second piezoelectric pad 90 may be attached to the upper surface of the fitting 30 a of the mating plate 30 after obtaining the upper surface of the fitting 30 a of the mating plate 30 , or may be pre-installed in a mold of the fitting 30 a , which may then be overmolded onto the piezoelectric pad 90 .

[0099] The stabilizer assembly 10 is then assembled as follows. After the flange 20 and the counterplate 30 have been made, each equipped with its piezoelectric pads 80, 90, the flange 20 is placed around the stabilizer bar 11. The assembly is then placed in a mold so that the stabilizer bar 11 extends inside the flange 20 according to the axis B, leaving a continuous and constant gap between the stabilizer bar 11 and the bracket section 27 of the flange 20.

[0100] Rubber is then injected into the mold to fill the space of the groove 26 opening from the bracket section 27 of the flange 20 to the groove 26 around the left and right sides of the lateral stabilizer bar 11, forming the elastomer layer 19. The resulting elastomer layer 19 is then vulcanized so that it connects the stabilizer bar 11 within the flange 20.

[0101] Next, the counterplate 30 is attached to the bearing surface 22 of the flange 20 . In this case, the protruding portion of the bushing 24 helps to position and properly align the counterplate 30 by fitting the holes 34 of the counterplate around the bushing 24 of the flange 20 .

[0102] The bearing 13 is thus assembled, and the same operation can be performed on the second bearing 13. Alternatively, both bearings can be assembled simultaneously.

[0103] The stabilizer assembly 10 assembled in this way can then be mounted on the chassis of the vehicle by pressing the lower surface 32 of the bearing 13 onto the chassis and screwing the bearing 13 onto the chassis by means of two screws passing through the holes 23 and 34 of the retaining bracket 21 of the flange 20 and the assembly section 37 of the matching plate 30.

[0104] During operation, the bearing 13 is stressed in six directions: three displacement directions (axial, radial and normal) and three rotation directions (torsion, conical about the radial axis and conical about the normal axis). The location of the piezoelectric pads 80 and 90 at the interface between the stabilizer bar 11 and the fitting of the bearing 13 allows them to capture a large amount of the mechanical stresses and vibrations to which the bearing 13 is subjected and thus generate a large amount of electrical energy.

[0105] More specifically, although the main extension direction P of the first piezoelectric pad 80 extends along the retaining bracket and the groove 26, when the flange 20 of the bearing 13 is subjected to a mixed vibration mode related to stress triaxiality (i.e., in the torsional direction, the conical direction and the radial direction), the orientation direction O of the piezoelectric element forms an angle θ of 45° with the main direction P.

[0106] However, when the main extension direction P of the second piezoelectric pad 90 extends according to the main direction of the fitting 30a of the mating plate 30, the orientation direction O of the piezoelectric element makes an angle of 0° or 90° with the main direction P, because the mating plate 30 of the bearing 13 is mainly affected by the radial bending vibration mode.

[0107] Figure 6 A second example 110 of a suspension device for a vehicle including a piezoelectric pad as previously shown is shown. This is a leaf spring 110 including a metal sheet 111 bent upward at each end thereof to form an eyelet 115. For each eyelet 115, the leaf spring 110 also includes a cylindrical bearing 113 inserted into the eyelet 115.

[0108] Figure 7 Such a bearing 113 is shown. The bearing 113 comprises an inner part 141 and an outer part 142, both cylindrical and coaxial, between which an elastomer layer 143 extends. Between the inner part 141 and the elastomer layer 143, a first piezoelectric pad 180 is arranged, which is similar to the piezoelectric pad 1 shown previously, but takes the form of a cylindrical sleeve, and between the outer part 142 and the elastomer layer 143, a second piezoelectric pad 190 is arranged, which is similar to the piezoelectric pad 1 shown previously, but also takes the form of a cylindrical sleeve.

[0109] In this example, the main extension direction P of the first piezoelectric pad 180 extends parallel to the central axis of the bearing 113, while its transverse direction T corresponds to the self-closed tangential direction of the bearing 113. The orientation direction O of its piezoelectric element forms an angle of 45° with the main direction P of the piezoelectric pad 180 to capture internal vibrations in torsional and conical modes.

[0110] The main extension direction P of the second piezoelectric pad 190 also extends parallel to the central axis of the bearing 113, while its transverse direction T corresponds to the self-closed tangential direction of the bearing 113. The orientation direction O of its piezoelectric elements also forms an angle of 45° with the main direction P of the piezoelectric pad 190 to capture external vibrations in torsional and conical modes; however, this 45° angle preferably does not show the same signs as the first piezoelectric pad 180.

[0111] Figure 8A third example 210 of a suspension arrangement for a vehicle comprising a piezoelectric pad as previously shown is shown. This is an assembly 210 comprising a coil spring 211 and a support element 213 mounted on a cup 216 for a rear suspension and against which the coil spring 211 rests.

[0112] Fig. 9 The support element 213 is shown in a cross-sectional view. The upper surface of the support element 213 has a groove 251 that can occupy a section of the end coil 211A of the helical spring 211. The groove 251 is curved so that it can receive this section of the end coil 211A. More precisely, the groove 251 is curved in the form of a helical arc that substantially corresponds to the helical arc described by the cross section of the end coil 211A.

[0113] Furthermore, the support element 213 has at least one elastic retaining element which is configured to retain a section of the end coil 213A in the groove 251. More precisely, the support element 213 has a plurality of elastic retaining elements 253 and 255.

[0114] The first elastic retaining element 253 is a protrusion protruding from the lateral radial inner wall 252 of the groove 251. The second elastic retaining element 255 is attached to the lateral radial outer wall 254 of the groove 251.

[0115] In the example shown, the support element 213 comprises a support section 250 and a base section 260. The base section 260 is attached to the support section 250.

[0116] The support section 250 has the groove 251 and the elastic retaining elements 253 , 255 described above.

[0117] The base plate segment 260 itself can be mounted on the cup 216. In this way, the base plate segment 260 presents a peripheral segment 265P and a central segment 265C. The central segment 265C presents a substantially cylindrical form for receiving the centering means 216C of the cup 216. The support element 213 is in contact with the centering means 216C.

[0118] The peripheral section 265P has a substantially flat lower portion, intended to come into contact with the section 216P of the cup 214. The upper portion of the peripheral section 265P is itself intended to come into contact with the lower portion of the support section 250. The upper portion of the peripheral section 265P has a substantially annular shape, the lower portion of the support section 250 having a substantially annular sector form. On the other hand, the central section 265C is occupied by the central section 259 of the substantially cylindrical form presented by the support section 250.

[0119] A piezoelectric pad 280 similar to the aforementioned piezoelectric pad 1 is installed between the support section 250 and the substrate section 260. Thus, it includes: a peripheral section 280P having a generally annular form, which extends along the peripheral section 265P of the substrate section 260; and a central section 280C having a substantially cylindrical form, which extends along the central section 265C of the base section 260.

[0120] In this example, the main extension direction P of the piezoelectric pad 280 follows the geometry of the interface between the support segment 250 and the substrate segment 260: it is therefore locally radial in the region of the peripheral segment 280P, but axial in the region of the central segment 280C. Here, the piezoelectric pad 280 comprises two sets of piezoelectric elements. The orientation direction O of the piezoelectric elements of the peripheral segment 280P forms an angle of 45° with the main direction P, so as to capture the axial and rotational vibrations of the spring 211 on the peripheral segment 216P of the cup 216.

[0121] However, the orientation direction O of the piezoelectric elements of the central section 280C forms an angle of 0° or 90° with the main direction P in order to capture the lateral vibrations of the spring 211 on the centering device 216C of the cup 216 .

[0122] In a preferred variant, the support 250 is made of a first material that is elastic and the base plate section 260 is made of a second material that is more rigid than the first material. Preferably, the first material is an elastomer, more particularly a thermoplastic elastomer, optionally expanded, which may be synthetic or non-synthetic, and / or the second material is preferably a composite material with an organic matrix.

[0123] The support section 250 is made of a first material which tends to absorb noise due to the elasticity of the first material (such as the previously mentioned known support element). On the other hand, the base section 260 ensures the mechanical connection between the support element 213 and the cup 216 and is made of a second material which is more rigid than the first material and is therefore less susceptible to the wear associated with the contact with the cup 216. As a result, the service life of the support element 213 is increased and it has the same noise attenuation function as the previously mentioned known support element and the protection of the spring coating.

[0124] It is worth noting that the support element 213 can be made by the above-mentioned dual-material injection molding of the first material and the second material. More specifically, the support element 213 can be made by injection molding of the substrate segment 260 first, and then by injection molding of the support segment 250 on the substrate segment. The two injection molding steps can be performed in the same injection mold by installing the piezoelectric pad 280 in the mold between the two molding steps. As an alternative, the injection molding of the substrate segment 260 can be performed in the first mold, and then the molded substrate segment 260 can be shifted to the second mold, and then the piezoelectric pad 280 is installed in the second mold, and finally the injection molding of the support segment 250 is completed.

[0125] In a particularly preferred example, the support section 250 is made of expanded thermoplastic polyurethane (“thermoplastic polyurethane” or TPU in English) and / or the base section 260 is made of glass-fiber-reinforced polyamide.

[0126] Fig.10 A fourth example 310 of a suspension device for a vehicle comprising a piezoelectric pad as previously described is shown. This is an assembly 310 comprising a helical spring 311 and a piezoelectric pad 380 in the form of a sheath screwed around at least a portion of the helical spring 311.

[0127] The piezoelectric pad 380 is similar to the piezoelectric pad 1 described above, except that its transverse direction T is closed on itself to form a tubular sheath; its main direction P extends for its part in the form of a spiral along the spring 311. The diameter of this sheath formed by the piezoelectric pad 380 is adjusted to correspond substantially to the diameter of the coils of the spring 311. As is the case in the present example, the piezoelectric pad 380 extends over the entire length of the spring 311. However, in other examples, the piezoelectric pad may be provided only at one and / or the other end of the spring 311: in fact, the end coils of the spring 311 are the coils that accumulate the greatest mechanical stresses, in particular compression.

[0128] In this example, the piezoelectric pad 380 comprises three different sections, each section comprising a set of piezoelectric elements of a different configuration. In the central section 380C, the orientation direction O forms an angle of 45° with the main direction P of the pad 380 and therefore with the helical direction of the spring 311, which enables the torsional deformation stored in the spring wire and the associated vibrations to be captured.

[0129] In each similar end section 380E, the orientation direction O forms an angle of 0° or 90° with the main direction P of the pad 380 , which makes it possible to be more sensitive to the bending forces of the end turns and the related axial vibrations.

[0130] Although the invention has been described with reference to specific embodiments, it is obvious that modifications and changes may be made to these embodiments without departing from the general scope of the invention as defined by the claims. In particular, individual features of the different embodiments illustrated / mentioned may be combined in further embodiments. The description and drawings must therefore be considered in an illustrative rather than a restrictive sense.

[0131] It is also self-evident that all features described with reference to the device can be implemented individually or in combination into the process and conversely, all features described with reference to the process can be implemented individually or in combination into the device.

Claims

1. A suspension element for a road vehicle, comprising: at least one suspension element exhibiting elastic properties to act as a suspension spring when the vehicle is in motion, or at least one interface element (13) configured to participate in securing the at least one suspension element (11) of the vehicle exhibiting elastic properties to act as a suspension spring when the vehicle is in motion; and at least one continuous two-dimensional pad (1, 80, 90), which is integrated into the suspension element or the interface element (13) or covers at least one interface surface of the suspension element or the interface element, the interface surface being arranged to contact another element of the vehicle when the vehicle is in motion, in, The at least one two-dimensional pad (1, 80, 90) comprises a plurality of individual piezoelectric elements (3) arranged in the two-dimensional pad (1, 80, 90) to convert at least some of the vibrations and / or mechanical stresses to which the suspension element (11) is subjected during operation of the vehicle into electrical energy, and Wherein, the at least one two-dimensional pad (1, 80, 90) further comprises a circuit (4) which connects the individual piezoelectric elements (3) together to collect the electrical energy generated by the piezoelectric elements.

2. The suspension element according to claim 1, characterized in that at least one, preferably each, two-dimensional pad (1) has a length in the main extension direction (P) of at least 3 cm, preferably at least 5 cm, more preferably at least 10 cm, and At least one and preferably each two-dimensional pad (1) has a thickness less than or equal to 5 mm, preferably less than or equal to 2 mm, and more preferably less than or equal to 1 mm.

3. The suspension element according to claim 1 or 2, characterized in that The length of each individual piezoelectric element (3) is less than or equal to 5 mm, preferably less than or equal to 2 mm, and more preferably less than or equal to 1 mm.

4. A suspension element according to any one of claims 1 to 3, characterized in that The density of the piezoelectric element (3) included in the two-dimensional pad (1) is greater than or equal to 50 per square decimeter, preferably greater than or equal to 300 per square decimeter.

5. The suspension element according to any one of claims 1 to 4, characterized in that All individual piezoelectric elements (3) of the two-dimensional mat (1) are oriented in the same orientation direction (O).

6. The suspension element according to claim 5, characterized in that The orientation direction (O) is inclined relative to the main extension direction (P) of the two-dimensional pad (101), and The angle (θ) formed between the orientation direction (O) and the main extension direction (P) of the two-dimensional pad (101) is between 20° and 70°, preferably between 40° and 50°.

7. A suspension element according to any one of claims 1 to 4, characterized in that The orientation direction (O) of the individual piezoelectric elements (1) varies depending on their position on the suspension element (11) or on the interface element (13).

8. A suspension element according to any one of claims 1 to 7, characterised in that At least one two-dimensional mat (1) comprises an insulating protective layer (7) which covers the individual piezoelectric elements (3) and the circuit (4) of the two-dimensional mat (2).

9. A suspension element according to any one of claims 1 to 8, characterised in that The transverse extension direction (T) of the two-dimensional pad (380) is closed on itself, forming a tubular geometry, and Wherein, the two-dimensional pad (380) is screwed around the suspension element (311) or the interface element.

10. A suspension element according to any one of claims 1 to 8, characterised in that The interface element is a bearing (13) configured to be mounted around a stabilizer bar (11) of the vehicle, and Therein, the at least one two-dimensional pad (80, 90) is inserted between two parts of the bearing (13), preferably between a fitting (20a, 30a) and an elastomer layer (19) in contact with the stabilizer bar (11).

11. A suspension element according to any one of claims 1 to 8, characterized in that The interface element is a bearing (113) configured to be mounted in an eyelet (115) of a suspension element (111) of the vehicle, and Therein, the at least one two-dimensional pad (180, 190) is inserted between two parts of the bearing (113), preferably between the accessories (141, 142) and the elastomer layer (143).

12. A suspension element according to any one of claims 1 to 9, characterised in that The suspension element is a coil spring (311), and The at least one two-dimensional pad (380) covers at least a section of the outer surface of the coil spring (311).

13. A suspension element according to any one of claims 1 to 8, characterised in that The interface element is a support element (213) for the coil spring, configured to be mounted at one end (211A) of the coil spring (211) and blocked on the cup portion (216), and The at least one two-dimensional pad (280) is inserted between two parts of the support element (213), preferably between the support section (250) in contact with the coil spring (211) and the base section (260) in contact with the cup portion (216).

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