Soundproofing panel

Abstract

Soundproofing panel (1) comprising a cover (2) provided with at least one opening (3) that passe through it along an opening direction (D) from its external surface (4), which faces onto an environment to be soundproofed (100), to its internal surface (5); a plurality of sound-absorbing elements (6) arranged onto the internal surface (5) of the cover (2), wherein each sound-absorbing element (6) comprises at least one cavity (8) and at least one entrance hole (7) in the cavity (8); the axis (X) of said entrance hole (7) being perpendicular to said opening direction (D); the at least one opening (3) of the cover (2) fluidly connects a space (S) defined by adjacent sound-absorbing elements (6) and by the cover (2) with the environment to be soundproofed (100), so that the sound waves do not enter the sound-absorbing elements (6) directly, but indirectly through said space (S).

Description

TECHNOLOGY SECTOR

[0001] The present invention relates to the field of soundproofing panels suitable for attenuating, dampening or mitigating noise.BACKGROUND ART

[0002] The state of the art includes various known solutions for effectively absorbing sound. For example, the use of Helmholtz resonators to capture and dampen sound waves is known.

[0003] In particular, it is known to use sound-absorbing panels comprising a perforated panel behind which is a honeycomb structure and behind which is a reflective panel, so as to create a plurality of Helmholtz resonators. The sound waves enter through the holes, are reflected by the reflective wall and, returning, enter into phase with the incoming wave, dampening it. In this way, the sound waves lose energy by converting into heat. The sound waves also remain trapped inside the cavities defined by the cells of the honeycomb structure and by the perforated and reflective panels. In this way, the sound is absorbed by the sound-absorbing panel. An example of this is described in patent document CN101962980A.

[0004] One of the problems with this type of soundproofing panels is the difficulty in effectively absorbing a plurality of sound waves at different frequencies.

[0005] For this reason, there are soundproofing panels that, to absorb sound waves at a plurality of different frequencies, vary the volume of the resonator cavity. In the solution of document CN217079210U the resonator cavities have different heights, while in the solution of document CN109397795A the height of the cavities is the same and the volume of some cavities is reduced by filling them with soundproofing material. These solutions do not allow for the creation of soundproofing panels with reduced thicknesses, as the height of some or all of the cells must remain high in order to absorb a broad spectrum of sound frequencies. The soundproofing panels must have limited thicknesses because they are normally used on the walls or ceilings of habitable environments, therefore high thicknesses would reduce the usable height of the environment. Similar problems also arise when the soundproofing panels are used as a coat for a device in order to soundproof it. The greater the thickness, the greater the overall size of the device.

[0006] For this reason, in the state of the art there are some solutions that, with the same thickness of the soundproofing panel, are able to absorb a greater range of sound frequencies by altering the shape of the cavities, as occurs in the solutions described in the documents US20220355566A1 and EP3534360B1. However, these solutions are complex and expensive to implement.

[0007] In the state of the art there is also a solution, described in the document US20230211890A1, relating to a soundproofing panel in which various resonators are placed in series and, the last of this series, is arranged transversely to optimize the overall dimensions of the panel.

[0008] In the state of the art it is also known to place adjacent resonators in fluid communication through transverse holes to increase the internal volume of the resonator and therefore the absorbable sound frequency. Solutions of this type are known from documents US20200103139A1, CN203773937U and US4135603A.

[0009] There is therefore a need to create, in a simple and economical way, soundproofing panels with reduced thicknesses and capable of absorbing a wide spectrum of sound frequencies.SUMMARY

[0010] These and other drawbacks of the prior art are now solved by a soundproofing panel comprising a cover provided with at least one opening that passes through it along an opening direction from its external surface, which faces towards an environment to be soundproofed external to the panel, to its internal surface; a plurality of sound-absorbing elements arranged on the internal surface of the cover in direct contact with the cover, wherein each sound-absorbing element comprises at least one cavity and at least one entrance hole into the cavity. The axis of said entrance hole is perpendicular to said opening direction. In normal soundproofing panels, the sound-absorbing elements have holes parallel or coaxial with those of the cover, to directly receive and capture the sound waves. Instead, in the panel according to the present invention, the sound-absorbing elements develop along directions orthogonal to those of the holes in the cover. Since the panels are wider than they are thick, the present inventive concept uses the width and height of the panel for the positioning and longitudinal development of the sound-absorbing elements, so as to minimize the thickness of the sound-absorbing panel. The sound-absorbing elements thus conceived act as Helmholtz resonators. Furthermore, the panel according to the present invention has few openings and is therefore more aesthetically appealing. With the same thickness, the panel according to the present invention allows for the absorption of sound waves in a wide range of frequencies. Since the sound-absorbing panel has various independent sound-absorbing elements arranged immediately behind the cover and in contact with it, the overall thickness of the sound-absorbing panel is optimized, and is therefore easily usable as a cover for a wall, ceiling or floor of a room or of a transport mean.

[0011] The opening of the cover fluidly connects a space defined by adjacent sound-absorbing elements and by the cover with the environment to be soundproofed. The sound waves do not enter the sound-absorbing elements directly, but indirectly. In practice, the sound waves enter, through an opening of the cover, into a space that is defined by the cover itself and by various sound-absorbing elements. The sound waves bounce in this space, losing energy, and then enter the entrance holes of the sound-absorbing elements, to remain trapped. In this way, the space in front of the sound-absorbing elements also helps to dampen the sound waves that enter through the opening.

[0012] In particular, each sound-absorbing element can be arranged so as not to obstruct the opening and so that its entrance hole opens into said space. The space is a volume that, through the opening, connects the cavity and the entrance hole of the sound-absorbing element with the environment to be soundproofed.

[0013] The cover can be a flat structure and, in this case, the opening direction is normal to the flat structure. When the cover is a flat structure, the sound-absorbing elements have entrance holes with axes parallel to the cover itself. In this way, the overall dimensions according to the thickness of the panel are minimized.

[0014] Some or all of the sound-absorbing elements may have cavities with different volumes from each other. By differentiating the volume of the sound-absorbing elements, it is possible to absorb sound waves with different frequencies. The resonance frequency in a Helmholtz resonator is in fact inversely proportional to the volume of the cavity.

[0015] Some or all of the sound-absorbing elements may have entrance holes with different sections and / or depths. By varying the area of the section and / or the length of the entrance hole in the various sound-absorbing elements, it is possible to absorb sound waves at different frequencies. The resonance frequency in a Helmholtz resonator is in fact directly proportional to the section of the entrance hole and inversely proportional to the length of the entrance hole.

[0016] Sound absorbing elements can be formed by modular elements joined together. Each modular element can include at least one of the entrance hole, a cavity wall and a cavity bottom. The sound absorbing element is composed of one or more modular elements, each of which includes at least a part of the sound absorbing element. In this way it is much simpler to make the sound absorbing element. By dividing the sound absorbing element into pieces, the mechanical processes to be performed on a solid piece are easier.

[0017] The sound-absorbing element may comprise a cellular structure arranged between a perforated plate and a continuous plate, and wherein the cavities are defined by the cells of the cellular structure and the entrance holes by the holes of the perforated plate. It is possible to make sound-absorbing panels of the known type, i.e. with honeycomb structures blocked between a perforated surface and a continuous one, and cut these panels into strips. These strips can then be placed orthogonally on the cover, outside its openings. By using strips all of the same width, the panel according to the present invention therefore has a constant thickness.

[0018] The sound-absorbing elements can be connected to the cover by gluing or mechanical connection means. The sound-absorbing panel thus conceived is modular and adaptable to the specific context of use. Depending on the sound frequencies to be absorbed, it is therefore possible to select the sound-absorbing element that resonates at the desired frequency and glue or connect it to the cover.

[0019] The sound-absorbing elements may have a greater extension in a direction orthogonal to the opening direction, than in a direction parallel to the opening direction of the at least one opening of the cover. In practice, given a predetermined width and height of the panel, the sound-absorbing elements extend more along the width and / or height of the panel than along the thickness of the sound-absorbing panel.

[0020] The soundproofing panel may comprise a closure arranged parallel to the cover so that the plurality of sound-absorbing elements lie between the closure and the cover. Preferably the closure may comprise further openings. The closure is optional because the structure on which the panel is fixed, for example a wall or a ceiling, may act as a closure. In any case, the closure serves to provide a buffer wall on which the sound waves entering through the opening can bounce and to define, together with the cover and the sound-absorbing elements, the spaces within which the sound waves pass before entering the sound-absorbing elements themselves.

[0021] Preferably, the sound-absorbing elements extend in length, i.e. longitudinally, and, given a certain distance between the internal surfaces of the cover and the closure, called internal thickness, the longitudinal extension of each sound-absorbing element is greater than said internal thickness. The sound-absorbing elements are arranged inside the space, having said internal thickness, defined between the cover and the closure. The sound-absorbing elements are therefore extremely flat and the volume of their cavities extends more in length than in thickness, making the panel thin and allowing several sound-absorbing elements to be placed next to each other to absorb more frequencies.

[0022] Each sound-absorbing element can be in fluid communication only with said space and, through said space, with the external environment. This double passage allows the sound waves to enter first in the space in front of the sound-absorbing elements and then in the same, maximizing sound absorption.

[0023] In particular, each sound-absorbing element includes only one entrance hole in the cavity, therefore the cavity of each sound-absorbing element is not in fluid communication with the cavity of other sound-absorbing elements. Each sound-absorbing element therefore allows a certain sound frequency to be absorbed independently of the other sound-absorbing elements.

[0024] Overall, the number of entrance holes in the cavities of the sound-absorbing elements can be less than the number of openings in the cover. This allows for a panel with improved aesthetic impact and makes the cover easier and therefore more economical to build.

[0025] Sound absorbing elements can be discrete elements with respect to the cover. In practice, sound absorbing elements do not require the cover to have sound absorbing properties.

[0026] These and other advantages will be explained in more detail in the description below of an example of implementation given for indicative and non-limiting purposes with reference to the attached drawings.DESCRIPTION OF THE DRAWINGS

[0027] In the drawings: Fig. 1 illustrates a schematic side sectional view of a soundproofing panel according to the present invention; Fig. 2 illustrates a schematic front view of a soundproofing panel according to the present invention; Fig. 3 illustrates a schematic axonometric view of a first example of a sound-absorbing element according to the present invention; Fig. 4 illustrates a schematic axonometric view of a second example of a sound-absorbing element according to the present invention; Fig. 5 illustrates a schematic axonometric view of a third example of a sound-absorbing element according to the present invention; Fig. 6 illustrates a schematic axonometric view of a first embodiment of a soundproofing panel according to the present invention; Fig. 7 illustrates a schematic axonometric view of a second embodiment of a soundproofing panel according to the present invention; Fig. 8 illustrates a schematic lateral sectional view of the soundproofing panel according to the second embodiment; Fig. 9 illustrates a schematic rear view of the soundproofing panel according to the second embodiment; Fig. 10 illustrates a schematic lateral sectional view of a particular version of the soundproofing panel according to the second embodiment; Fig. 11 illustrates a schematic axonometric view of a special version of the soundproofing panel according to the present invention. DETAILED DESCRIPTION

[0028] The following description of one or more embodiments of the invention refers to the attached drawings. The same numerical references in the drawings identify equal or similar elements. The object of the invention is defined by the attached claims. The technical details, structures or characteristics of the solutions described below can be combined with each other in any manner.

[0029] In the figures, the numerical reference 1 shows a soundproofing panel.

[0030] The soundproofing panel 1 comprises a cover 2 equipped with one or more openings 3. Behind the cover 2 are arranged a plurality of sound-absorbing elements 6. The sound-absorbing elements 6 are arranged in contact with the cover 2.

[0031] The cover 2 comprises an external surface 4 that faces the environment to be soundproofed 100, as illustrated in Fig. 1, 6, 7, 8, 10. The environment to be soundproofed 100 can be a room or the interior of a vehicle, such as a train or a bus. In any case, the environment to be soundproofed is an environment external to the soundproofing panel 1.

[0032] The cover 2 also includes an internal surface 5 opposite the external surface 4. The openings 3 extend between the internal surface 5 and the external surface 4. The openings 3 are therefore through holes.

[0033] The openings 3 are preferably long and narrow slits, as illustrated in Fig. 2, 6, 7 and 9, but they can also be smaller holes. In this case, the holes will be greater in number.

[0034] The openings 3 connect the environment to be soundproofed 100 with a space S inside the soundproofing panel 1.

[0035] The openings 3 develop along a direction D which, if the cover 2 is flat, is orthogonal to the cover 2.

[0036] The cover 2 may have an external surface 4 having an irregular shape, for example for aesthetic reasons, as illustrated in Fig. 7. In this case, the opening 3 is perpendicular to the internal surface 5 of the cover 2.

[0037] On the internal surface 5, a plurality of sound-absorbing elements 6 are arranged, as illustrated in Fig. 1-2, 6-10. The sound-absorbing elements 6 are therefore separated from the environment to be soundproofed 100 by the cover 2 and fluidly communicate with it through the openings 3.

[0038] The sound-absorbing elements 6 are separate and discrete elements with respect to the cover 2.

[0039] At each opening 3 there is a space S where the sound waves W enter before entering the sound-absorbing elements 6.

[0040] Opposite the cover 2 with respect to the sound-absorbing elements 6 there may be a closure 9. The sound-absorbing elements 6 may be positioned and locked between the cover 2 and the closure 9, as illustrated in Fig. 1, 6, 7, 10. However, the closure 9 is not necessary when a wall or ceiling 110 of the environment to be soundproofed 100 acts as a closure, as illustrated in Fig. 8. In this case, the panel 1 comprises the cover 2 and the sound-absorbing elements 6 and the latter rest directly on the wall / ceiling 110. The floor of the environment to be soundproofed 100 may also act as a closure.

[0041] In known solutions, the sound-absorbing elements 6 are arranged so that the access hole to the resonator cavity is coincident or parallel to the holes in the cover. In this way, the panel must be particularly thick in order to absorb a wide range of frequencies, because the frequency of the resonator is inversely proportional to the volume of its cavity. Therefore, to absorb low frequencies, the volume of the cavity must be large and consequently the thickness of the panel increases.

[0042] Conversely, in the present invention, to increase the range of frequencies absorbed by the soundproofing panel 1, the sound-absorbing elements 6 are arranged lying on the internal surface 5 of the cover 2, thus arranged so that their longitudinal extension L is parallel to the internal surface 5 of the cover 2. In this way, given an internal thickness T of the soundproofing panel 1, the sound-absorbing elements can extend longitudinally, without thereby affecting the internal thickness T of the panel 1.

[0043] The sound-absorbing elements 6 have a longitudinal extension L greater than their thickness T. By varying the longitudinal extension L of the sound-absorbing elements 6 it is possible to vary the volume of the cavity 8 and the depth of the entrance hole 7 and therefore the sound-absorbing properties of the sound-absorbing elements 6.

[0044] The space S is defined by adjacent sound-absorbing elements 6 placed opposite each other and by the cover 2. The opening 3 connects the space S with the environment to be soundproofed 100.

[0045] The sound waves W enter through the opening 3 of the cover 2 into the space S and bounce off the closure 9, or alternatively off the wall / ceiling 110. Coming back, the sound waves W enter into phase with the W waves entering the opening 3 and, at the same time, enter the sound-absorbing elements 6, as illustrated in Fig. 1.

[0046] The sound-absorbing elements 6 may be composed of modular elements 11, as illustrated in Fig. 1-2, 6 and 10. Alternatively, the sound-absorbing elements 6 may be sound-absorbing panels comprising a cellular or honeycomb structure 12 which are arranged edgewise on the cover 2, as illustrated in Fig. 7-9. These are two embodiments of the present invention. It is understood that sound-absorbing elements 6 of one type may be combined with sound-absorbing elements 6 of the other type within the same sound-absorbing panel 1.

[0047] The sound-absorbing elements 6 of both embodiments comprise a cavity 8 and an entrance hole 7 that connects the space S with the interior of the cavity 8.

[0048] The X-axis of the entrance hole 7 of each sound-absorbing element 6 is orthogonal to the opening direction D of the opening 3 of the cover 2. In practice, the entrance holes 7 are parallel to the internal surface 5 of the cover 2, as better illustrated in Fig. 1, 6, 7, 8 and 10.

[0049] In the first embodiment, the sound-absorbing element 6 is made by joining together modular elements 11. Each modular element 11 can comprise at least part of the entrance hole 7 or at least part of the cavity 8, as illustrated in Fig. 1, 4, 5, 6 and 10.

[0050] In particular, Fig. 3-5 illustrates the sound-absorbing element 6 and its modular elements 11.

[0051] Each sound-absorbing element 6 can have sound-absorbing properties that are independent of the presence of the cover 2.

[0052] More modular elements 11 joined together form a sound-absorbing element 6 to facilitate its assembly. In a particular version not illustrated, the cover 2 can help to delimit the cavity 8 of one or more sound-absorbing elements 6.

[0053] Fig. 3 shows a first modular element 11 consisting of a solid block drilled on one side and on the other side, with different coaxial holes, to create the entrance holes 7 and the cavities 8. A second modular element 11 is a solid block without holes which, when connected to the first modular element 11, forms the bottom of the cavities 8. By connecting the two modular elements 11 together, the sound-absorbing element 6 is realized. The solid block, dug with said holes to create the modular element 11, can be a soft and economical material such as MDF (Medium Density Fibreboard). A sound-absorbing element 6 like the one in Fig. 3 is also used in panel 1 of Fig. 1 (see sound-absorbing element 6 on the right), in panel 1 of Fig. 2 (see sound-absorbing elements 6 above) and in panel 1 of Fig. 6. In this sound-absorbing element 6 the entrance holes 7 are parallel to each other and face the same side.

[0054] Fig. 4 illustrates another example of a sound-absorbing element 6, in which there are three modular elements 11 with the same width and height, but different depths. A first modular element 11 is a solid block comprising a single hole which constitutes the entrance hole 7. A second modular element 11 is a solid block comprising a single hole with a larger diameter than the previous one which constitutes the sides of the cavity 8. A third modular element 11 is a solid block without holes which constitutes the bottom of the cavity 8. By joining the three modular elements 11 together, the sound-absorbing element 6 is created and in particular a Helmholtz resonator.

[0055] Fig. 5 shows a sound-absorbing element 6 of the same type as that of Fig. 4, but with a smaller cavity 8 and an entrance hole 7 with a smaller section and greater length. Fig. 4 shows the sound-absorbing element 6 in exploded view, where the modular elements 11 are clearly visible. A sound-absorbing element 6 of the type shown in Fig. 5 and 6 is also used in panel 1 of Fig. 1 (see sound-absorbing element 6 on the left) and in panel 1 of Fig. 2 (see the two sound-absorbing elements 6 at the bottom right).

[0056] As already mentioned, by varying the depth of the modular element 11 with which the side of the cavity 8 is created, the volume of the cavity 8 changes. Similarly, by varying the depth of the modular element 11 comprising the entrance hole 7, the length of the entrance hole 7 changes.

[0057] The modular elements 11 can therefore be composed to create sound-absorbing elements 6 capable of absorbing sound waves at different frequencies.

[0058] The modular elements 11, once assembled, form discrete sound-absorbing elements 6 which, like modules, can be connected to the cover 2.

[0059] The modular elements 11 thus designed can be connected to the cover 2, for example by gluing or by means of connection, such as screws.

[0060] In Fig. 1 it is visible how the sound-absorbing elements 6 are arranged opposite each other in direct contact with the cover 2. This aspect can also be seen in Fig. 6.

[0061] In Fig. 2 it is visible how the sound-absorbing elements 6 are arranged next to each other, so that the X axes of the entrance holes 7 are parallel to each other.

[0062] In Fig. 6, the sound-absorbing elements 6 are of the type illustrated in Fig. 3 and have entrance holes 7 with identical cross-section, but different hole lengths. The cavities 8 also have different volumes. In this sound-absorbing panel 1, the sound-absorbing elements 6 are arranged between a cover 2 with two openings 3 and a closure 9. The space S is therefore defined by the opposing sound-absorbing elements, the cover 2 and the closure 9.

[0063] Fig. 10 shows a panel 1 with sound-absorbing elements 6 comprising modular elements 11 sectioned longitudinally. In practice, a sound-absorbing element 6 is made from two half-halves joined together and these half-halves are the modular elements 11. In this version of the modular elements 11, each modular element 11 comprises half an entrance hole 7 and half a cavity 8.

[0064] The panel 1 of Fig. 10 also comprises a closure 9 equipped with further openings 10. These openings 10 can be used to allow air conditioning from an air conditioning system 120 to enter the panel. The flow of cold or hot air coming from the air conditioning system 120 enters the space S through the openings 10 and from there, through the openings 3 of the cover 2, flows into the room to be soundproofed 100. In this way, the panel 1 has the dual function of soundproofing and air conditioning.

[0065] In an alternative version of panel 1 not shown, the holes 11 of the closure 9 can be used to make a Helmholtz resonator also behind the closure 9.

[0066] In an alternative version of the panel 1 not illustrated, the air-conditioned air flow from the air conditioning system 120 can enter the panel not through the openings 11 of the closure 9, but rather enter the space S via a flow parallel to the cover 2.

[0067] Fig. 11 shows a special version of the soundproofing panel 1, used as the base of a lamp or streetlamp. The base of the lamp is made from a solid body whose external lateral surface represents the cover 2 and includes a circular slit 3. Through the circular opening 3 the sound waves coming from the environment to be soundproofed 100 enter the space S. From the space S, the sound waves then enter the sound-absorbing elements 6 which, in this case, are holes made in the solid body. In particular, the entrance holes 7 are all parallel to each other and oriented vertically, so as to be orthogonal to the radial opening 3. The cavities 8 are also holes coaxial to the respective entrance holes 7. A stem branches off vertically from the base, at the top of which a light 130 is installed.

[0068] The second embodiment of the sound-absorbing element 6 according to the present invention is made from a perforated plate 13 and a continuous plate 14, between which a cellular structure 12 is arranged. The perforated plate 13 has a plurality of holes 16, as better illustrated in Fig. 7. These holes 16 constitute the entrance holes 7 to the cavity 8.

[0069] The cavity 8 is defined by the cells 15 of the cellular structure 12. The walls of the cells 15 define the sides of the cavities 8. The continuous plate 14 and the perforated plate 13 close the opposite openings of the cells 15, thus creating a plurality of resonators. The thickness of the cellular structure 12 determines the volume of the cavities 8, as well as the width of the cell 15, as illustrated in Fig. 8 and 9.

[0070] Also in this version of panel 1, sound waves at different frequencies enter through each opening 3 of the cover 2 into the space S. From the space S, the sound waves then enter the cells 15, through the holes 16 of the perforated plate 13.

[0071] The sound-absorbing elements 6 consisting of the perforated plate 13, the cellular structure 12 and the continuous plate 14 can be cut into strips all of the same width and arranged edgewise on the internal surface 5 of the cover 2, as illustrated in Fig. 7 and 8.

[0072] In conclusion, it is clear that the invention thus conceived is susceptible to numerous modifications or variations, all falling within the invention; furthermore, all the details are replaceable by technically equivalent elements. In practice, the quantities may be varied according to technical needs.Numerical references legend:

[0073] 1soundproofing panel 2cover 3opening (of the cover) 4external surface (of the cover) 5internal surface (of the cover) 6sound-absorbing element 7entrance hole 8cavity 9closure 10further opening (of the closure) 11modular element 12cell structure 13perforated plate 14continuous plate 15cell (of the cellular structure) 16hole (of the perforated plate) 100environment to be soundproofed 110wall / ceiling 120air conditioning system 130light Dopening direction Llongitudinal extension of the sound-absorbing element Sspace Tinternal thickness of the soundproofing panel Wsound wave Xinput hole axis

Claims

1. Soundproofing panel (1) comprising: - a cover (2) provided with at least one opening (3) that passe through it along an opening direction (D) from its external surface (4), which faces towards an environment to be soundproofed (100), to its internal surface (5); - a plurality of sound-absorbing elements (6) arranged onto the internal surface (5) of the cover (2), wherein each sound-absorbing element (6) comprises at least one cavity (8) and at least one entrance hole (7) in the cavity (8); the axis (X) of said entrance hole (7) being perpendicular to said opening direction (D); the at least one opening (3) of the cover (2) fluidly connects a space (S) defined by adjacent sound-absorbing elements (6) and by the cover (2) with the environment to be soundproofed (100), so that the sound waves do not enter the sound-absorbing elements (6) directly, but indirectly through said space (S).

2. Soundproofing panel (1) according to claim 1, wherein each sound-absorbing element (6) is arranged so as not to obstruct the opening (3) and so that its entrance hole (7) opens into said space (S).

3. Soundproofing panel (1) according to claim 1 or 2, wherein said cover (2) is a flat structure and the opening direction (D) is orthogonal to the flat structure.

4. Soundproofing panel (1) according to any of the preceding claims, wherein some or all of the sound-absorbing elements (6) have cavities (8) with different volumes from each other.

5. Soundproofing panel (1) according to any of the preceding claims, wherein some or all of the sound-absorbing elements (6) have entrance holes (7) with different sections and / or depths.

6. Soundproofing panel (1) according to any of the preceding claims, wherein the sound-absorbing elements (6) are formed by modular elements (11) joined together, each modular element (11) comprising at least one of the entrance hole (7) and a portion of the cavity (8).

7. Soundproofing panel (1) according to any of the preceding claims, wherein the sound-absorbing element (6) comprises a cellular structure (12) arranged between a perforated plate (13) and a continuous plate (14), and wherein the cavities (7) are defined by the cells (17) of the cellular structure (12) and the entrance holes (8) by the holes (16) of the perforated plate (13).

8. Soundproofing panel (1) according to any of the preceding claims, wherein the sound-absorbing elements (6) are connected to the cover (2) by gluing or mechanical connection means.

9. Soundproofing panel (1) according to any of the preceding claims, wherein the sound-absorbing elements (6) have a greater extension in a direction orthogonal to the opening direction (D) than in a direction parallel to the opening direction (D) of the at least one opening (3) of the cover (2).

10. Soundproofing panel (1) according to any of the preceding claims, comprising a closure (9), parallel to the cover (2), arranged so that the plurality of sound-absorbing elements (6) lie between the closure (9) and the cover (2), preferably the closure (9) comprises further openings (10).

11. Soundproofing panel (1) according to claim 10, wherein the distance between the cover (2) and the closure (9) defines an internal thickness (T) of the soundproofing panel (1) within which the sound-absorbing elements (6) extend longitudinally and wherein the longitudinal extension (L) of each sound-absorbing element (6) is greater than the internal thickness (S).

12. Soundproofing panel (1) according to any of the preceding claims, wherein each sound-absorbing element (6) is in fluid communication only with said space (S).

13. Soundproofing panel (1) according to any of the preceding claims, wherein each sound-absorbing element (6) comprises a single entrance hole (7) into the cavity (8).

14. Soundproofing panel (1) according to any of the preceding claims, wherein the number of entrance holes (7) in the cavities (8) of the sound-absorbing elements (6) is less than the number of openings (3) of the cover (2).

15. Soundproofing panel (1) according to any of the preceding claims, wherein the sound-absorbing elements (6) are discrete elements with respect to the cover (2).

Images