VEHICLE WRAP PANEL

Abstract

The present invention relates to a cladding panel (10) comprising at least four fixing devices (16) and a central layer (18) covered on both sides by a lower layer and an upper layer (22), the panel (10) comprising at least four circular acoustic black holes (24) formed each near one of the fixing devices (16) of the panel (10), the acoustic black holes (24) being formed at least by a parabolic reduction of a thickness (28) of the central layer (18), such that the thickness (28) of the central layer (18) decreases from an outer circumference (EC) of the acoustic black holes (24) to an inner circumference (IC) of the acoustic black holes (24) which delimits a circular central portion (26) of the acoustic black holes (24), the central portion (26) of the acoustic black holes (24) comprising only one of the lower or upper layer (22).Figure for the abridged version: 1.

Description

Title of the invention: VEHICLE TRIM PANEL Technical field of the invention

[0001] The present invention relates to a vibration damping device for a vehicle. More particularly, the invention relates to a trim panel for a vehicle cabin. Technical background

[0002] In a vehicle, for example an airplane, the noise inside the cabin can have two origins, one airborne due to aerodynamics, and the other solid-borne resulting from the injection by fixing brackets of mechanical forces due to the engine, equipment and aerodynamics.

[0003] Such vibrations can be problematic for the comfort of users who may perceive these vibrations when they are in the cabin of the aircraft or any other type of vehicle.

[0004] To reduce structure-borne vibrations, it is known to use vibration decoupling pads mounted on the panel mounting brackets. However, such a panel arrangement can complicate its attachment to the aircraft fuselage and may also increase its weight.

[0005] Furthermore, solutions involving the use of materials or coatings with vibration damping characteristics are also known, but these materials or coatings result in a significant increase in the mass of the cladding panels.

[0006] Thus, the aim of the present invention is to propose a trim panel for a vehicle whose structure effectively reduces solid-borne vibrations while reducing the amount of material required for its design, and thus not increasing the mass of said trim panel.

[0007] Furthermore, the use of the trim panel proposed by the invention, within a vehicle, makes it possible to reduce the energy costs of said vehicle and thus to reduce its environmental impact. Summary of the invention

[0008] The invention proposes a trim panel intended to be fixed to a vehicle frame, the panel comprising at least four fixing devices, the panel comprising a central layer covered on both sides by a lower layer and an upper layer, the panel comprising at least four circular acoustic black holes, the acoustic black holes being formed each near one of the panel's fixing devices, acoustic black holes being formed at least by a parabolic reduction of the thickness of the central layer, such that the thickness of the central layer decreases from an outer circumference of the acoustic black holes to an inner circumference of the acoustic black holes which delimits a circular central portion of the acoustic black holes, the central portion of acoustic black holes comprising only one of the lower or upper layers.

[0009] According to other features of the invention: - the central layer is composed of a recyclable dense foam; - the central layer is composed of a honeycomb structure; - at least one of the lower or upper layer is coated of a damping material; - the cushioning material is a linen skin; - one of the lower or upper layers extends to the outer circumference of each of the acoustic black holes, a connecting skin extending between the inner and outer circumferences of the acoustic black holes so that it connects the lower and upper layers to each other; - the panel comprises a shape delimited by at least four corners, each fixing device being positioned near one of the corners of the panel. Brief description of the figures

[0010] Other features and advantages of the invention will become apparent upon reading the detailed description that follows, for an understanding of which reference should be made to the accompanying drawings in which:

[0011] [Fig-1] is a general perspective view of a vehicle trim panel according to the invention, the trim panel comprising four acoustic black holes;

[0012] [Fig.2] is a cross-sectional view along a plane AA visible in [Fig.1] of one of the acoustic black holes in the cladding panel of [Fig.1];

[0013] [Fig.3] is a close-up view of the section along plane AA of the acoustic black hole of [Fig.2]. Detailed description of the invention

[0014] In the description that follows, identical, similar or analogous elements will be designated by the same reference numerals.

[0015] Fig. 1 illustrates a trim panel 10 intended to be fixed in a vehicle.

[0016] More specifically and according to a non-limiting example of the invention, the panel 10 of the [Fig.1] can be fixed on an aircraft fuselage.

[0017] In the following description the trim panel 10 will be described as fixed on the fuselage of an aircraft but it should be considered that the trim panel 10 proposed by the invention can be installed indifferently and in a non-limiting manner in different types of vehicles whether they are land, air or even sea.

[0018] According to the illustrated and non-limiting example of the invention, the trim panel 10 can be arranged in an aircraft cabin and then comprises an internal face 13, visible in [Fig.2], turned towards an internal volume of the cabin and an external face 12 turned away from the internal volume of the cabin and therefore invisible to a user in the aircraft cabin.

[0019] According to the example of the invention illustrated in [Fig.1], the cladding panel 10 has a shape defined by four corners 14. The corners 14 are each formed at the intersection of two sides of the cladding panel 10.

[0020] In the illustrated example of the invention, the cladding panel 10 has a rectangular shape.

[0021] It should be considered that the cladding panel 10 could have any other shape delimited by four or more corners.

[0022] Furthermore, the cladding panel 10 can be flat or curved.

[0023] According to a non-limiting example of the invention, the cladding panel 10 comprises a vertical dimension DV between 750mm and 950mm, preferably equal to 840mm and a longitudinal dimension DL between 850mm and 1050mm, preferably equal to 940mm.

[0024] The trim panel 10 is then configured so that it is fixed to the fuselage, here of the aircraft, by fastening devices 16.

[0025] According to the illustrated example of the invention, the fastening devices 16 are positioned at each of the four corners 14 of the cladding panel 10 and are schematically represented in [Fig.1].

[0026] According to another non-limiting example not shown, fastening devices may be positioned outside the corners of the trim panel. For example, when the trim panel is configured to frame an aircraft window, fastening devices may also be positioned around said window.

[0027] Thus, and without limitation, the cladding panel may include more than four fastening devices.

[0028] The fastening devices 16 may be, for example and without limitation, fastening brackets. According to other non-limiting examples of the invention, the Fastening devices can be screws cooperating with bores formed in the aircraft fuselage or even glued clips, screws or embedded inserts.

[0029] The fixing points of the cladding panel 10, formed at the fixing devices 16, then constitute points of high vibration of solid origin.

[0030] Solid-origin stresses are defined as those injected into the cladding panel by the fixing tabs and more generally by the fixing devices.

[0031] The cladding panel 10 according to the invention comprises a structure made of several layers superimposed on one another, commonly called a "sandwich" structure.

[0032] More precisely and visibly on [Fig.2], the cladding panel 10 comprises a central layer 18 covered on both sides, along a transverse direction T of the panel 10, by a lower layer 20 and an upper layer 22.

[0033] In other words, the central layer 18 forms the core of the cladding panel 10 and the lower 20 and upper 22 layers form respectively the upper and lower skins of the cladding panel 10.

[0034] It is understood that the layers 20, 18, 22 are superimposed on each other along the transverse direction T of the cladding panel 10 as seen in [Fig.2].

[0035] According to the example of the invention, the upper layer 22 corresponds to the layer which extends at the level of the external face 12 of the cladding panel 10 and the lower layer 20 corresponds to the layer which extends at the level of the internal face 13 of the cladding panel 10.

[0036] According to the example of the invention, the cladding panel 10 comprises four circular acoustic black holes 24, each extending around a distinct axis of revolution R.

[0037] According to the example of the invention, the axis of revolution R of each of the acoustic black holes 24 is parallel to the transverse direction T of the cladding panel 10.

[0038] Each of the acoustic black holes 24 is then positioned near one of the fixing devices 16 of the cladding panel 10.

[0039] In other words, and in accordance with the illustrated example, each of the acoustic black holes 24 is here arranged near one of the corners 14 of the cladding panel 10.

[0040] It should also be considered that the acoustic black holes could be arranged elsewhere on the cladding panel, as long as they are arranged close to the cladding panel fixing devices.

[0041] For example, and without limitation, the acoustic black holes 24 each comprise an external circumference CE with an external diameter DE of between 280mm and 320mm, preferably 304mm, and such that their respective axis of revolution R is disposed at a first distance DI of between 150mm and 190mm, preferably at 170mm, from one side of the cladding panel 10 delimiting the corner associated with the acoustic black hole, according to the vertical direction V or the longitudinal direction L.

[0042] As seen in [Fig.2], the acoustic black holes 24 are formed at least by a parabolic reduction of a thickness 28 of the central layer 18, such that the thickness 28 of the central layer 18 decreases from the outer circumference CE mentioned previously to an inner circumference CI of the acoustic black holes 24 which delimits a circular central portion 26 of the latter.

[0043] It is understood that the central circular portion 26 of each of the acoustic black holes 24 is coaxial with the axis of revolution R of said acoustic black holes 24.

[0044] For example, and not in a limiting manner, the internal circumference CI delimiting the central portion 26 of each acoustic black hole 24 has an internal diameter DI, visible in [Fig.1], between 80mm and 120mm, preferably 100mm.

[0045] Thus, it is understood that the central layer 18 of the cladding panel 10 has its thickness 28, taken along the transverse direction T, which decreases from the external circumference CE of each acoustic black hole 24 to the internal circumference CI of each acoustic black hole 24 in such a way that their central portion 26 is devoid of a central layer 18.

[0046] It is understood from the above that the central layer 18 comprises, in radial section with respect to the axis of revolution R of each acoustic black hole 24 visible in [Fig.2], a parabolic shape generated by its thickness 28 which decreases from the outer circumference CE to the inner circumference CI of each acoustic black hole 24.

[0047] As seen in [Fig.2], the upper layer 22 extends over the central layer 18 up to the outer circumference CE of each of the acoustic black holes 24.

[0048] It is then understood that each of the acoustic black holes 24 of the cladding panel 1 is devoid of a top layer 22.

[0049] Thus it is understood that the central portion 18 of each acoustic black hole 24 comprises only the lower layer 20 among the upper layer 22 and the lower layer 20 of the cladding panel 10.

[0050] According to the invention, the cladding panel 10 comprises a connecting skin 30 which extends between the inner circumference CI and the outer circumference CE of each acoustic black hole 24 such that it connects the upper layer 22 and the lower layer 20.

[0051] It is then understood that the connecting skin 30 of each of the acoustic black holes 24 has the shape of a ring which extends circularly around each central portion 26 of each acoustic black hole 24.

[0052] More precisely, a first connecting end 32 and a second connecting end 34 of the connecting skin 30 are defined

[0053] Visible in [Fig.3], the first connecting end 32 extends between the central layer 18 and the lower layer 20 at the level of the inner circumference CI of each acoustic black hole 24.

[0054] More specifically, the first connecting end 32 extends radially towards the axis of revolution R such that it extends beyond the central layer 18 so as to partially cover the lower layer 20 in the central portion 26.

[0055] For example and without limitation, the first connecting end 32 extends radially over 4mm overlapping the lower layer 20 towards the axis of revolution R.

[0056] The second connecting end 34 extends between the central layer 18 and the upper layer 22 at the level of the outer circumference CE of each acoustic black hole 24.

[0057] More specifically, the second connecting end 34 extends radially opposite the axis of revolution R, beyond the outer circumference CE of each acoustic black hole 24 in such a way that it partially covers the upper layer 22.

[0058] For example and without limitation, the second connecting end 34 extends radially over 4mm overlapping the upper layer 22 opposite the axis of revolution R.

[0059] As illustrated in [Fig. 3], in radial section along the axes of revolution R of each acoustic black hole 24, the first connecting end 32 and the second connecting end 34 of the connecting skins 30 each form a shoulder.

[0060] It is then understood that the acoustic black holes 24 according to the invention are structured in such a way that they comprise both a variation in thickness between their inner circumference CI and their outer circumference CE and also a substantially uniform thickness on their central portion 26.

[0061] According to an example of the invention, the central layer 18 of the cladding panel 10 is composed of a honeycomb structure.

[0062] According to another example of the invention, the central layer 18 of the cladding panel 10 is composed of a recyclable dense foam.

[0063] For example, and without limitation, the recyclable dense foam can be polyurethane foam or polyethylene foam.

[0064] The thickness 28 of the central layer 18 of the cladding panel 10, excluding the acoustic black holes, can be between 6.5 mm and 8.5 mm. Preferably, the thickness 28 of the central layer 18 taken along the transverse direction T excluding the acoustic black holes, is equal to 7.5 mm.

[0065] According to an example of the invention, the lower layer 20 is coated in the central portion 26 of each acoustic black hole 24 with a viscoelastic absorbing material.

[0066] According to another example, the lower layer can be a linen skin, an intrinsically cushioning material, which avoids the application of the viscoelastic absorbent coating.

[0067] The advantage of the cladding panel according to the invention is thus taken by reducing the vibration level resulting from solid-borne sources starting at 1 kHz. The positioning of the four acoustic black holes near the cladding panel's fixing points allows these fixing points to be isolated from the rest of the cladding panel, thereby increasing the cladding panel's vibration-damping effect.

[0068] The invention also improves the acoustic transparency of the cladding panel.

[0069] Furthermore, another advantage of the cladding panel according to the invention is that it allows optimal anti-vibration effects to be obtained without increasing the mass of the cladding panel, the structure of the acoustic black holes not requiring the addition of additional material.

[0070] Also, the cladding panel according to the invention is advantageous in that the structure of the acoustic black holes does not require modification of the fixing conditions of the cladding panel.

[0071] Finally, the structure of the acoustic black holes allows them to be invisible and imperceptible from the internal volume of the aircraft cabin, as they are visible at the level of the external face of the trim panel.

Claims

Demands

1. A trim panel (10) intended to be fixed to a vehicle frame, the panel (10) comprising at least four fastening devices (16), the panel (10) comprising a central layer (18) covered on both sides by a lower layer (20) and an upper layer (22), the panel (10) comprising at least four circular acoustic black holes (24), the acoustic black holes (24) each being formed near one of the fastening devices (16) of the panel (10), the acoustic black holes (24) being formed at least by a parabolic reduction of a thickness (28) of the central layer (18), such that the thickness (28) of the central layer (18) decreases from an outer circumference (EC) of the acoustic black holes (24) to an inner circumference (IC) of the acoustic black holes (24) which delimits a circular central portion (26) of the acoustic black holes (24),the central portion (26) of the acoustic black holes (24) comprising only one of the lower layer (20) or the upper layer (22).

2. Panel (10) according to the preceding claim, wherein the central layer (18) is composed of a recyclable dense foam.

3. Panel (10) according to claim 1, wherein the central layer (18) is composed of a honeycomb structure.

4. Panel (10) according to any one of the preceding claims, wherein at least one of the lower layer (20) or the upper layer (22) is coated with a damping material.

5. Panel (10) according to the preceding claim, wherein the damping material is a linen skin.

6. Panel (10) according to any one of the preceding claims, wherein one of the lower layer (20) or the upper layer (22) extends to the outer circumference (OC) of each of the acoustic black holes (24), a connecting skin (30) extending between the inner circumference (IC) and the outer circumference (OC) of the acoustic black holes (24) so ​​that it connects the lower layer (20) and the upper layer (22) to each other.

7. 9 Panel (10) according to any one of the preceding claims, comprising a shape delimited by at least four corners (14), each fastening device (16) being positioned near one of the corners (14) of the panel (10).

Images