Soundproof hood, soundproofing assembly including it, and corresponding joinery

Abstract

------ Soundproofing hood, soundproofing arrangement including it, and corresponding joinery The invention relates to a soundproofing hood (1) configured to be applied to an air inlet of a ventilation duct, comprising a housing (2) including an outer envelope (21) in which are formed an outlet opening (23) and an inlet opening (22) fluidly connected to each other by a conduit (24); and a soundproofing assembly (3) comprising a partitioned chamber (31) opening onto the duct (24) by a fluidic communication path (32) occupied by an acoustic filter (33), made of porous material, having sufficient resistance to airflow to prevent airflow from the duct (24) to the partitioned chamber (31) through the fluidic communication path (32), the soundproofing assembly (3) being configured to form an acoustic resonator soundproofing the duct (24) by attenuating frequencies of the audible spectrum.The invention also relates to a soundproofing arrangement (100) comprising two soundproofing covers (1) according to the invention joined in parallel to each other. Figure to be published: Figure 7.

Description

Title of the invention: Soundproofing cover, soundproofing assembly comprising it, and corresponding joinery

[0001] The present invention relates to the technical field of soundproofing hoods, and more particularly to a soundproofing hood, a soundproofing arrangement comprising it, and a corresponding joinery.

[0002] Buildings generally include ventilation air inlets to allow for the renewal of indoor air. However, sounds generated outside the buildings, for example by a road or an airport, are transmitted into the buildings through these ventilation air inlets. Solutions have been proposed in the prior art to attenuate the transmission of these sounds. One type of solution is the addition of sound-absorbing covers in front of the ventilation air inlets, possibly in addition to the interior accessories of the ventilation air inlets. French patent FR2624641 B1, for example, discloses a sound propagation attenuation device for an air inlet comprising a housing, intended to be fixed to a ventilation air inlet, in which fins are arranged configured to attenuate the sounds.However, the proposed solutions have drawbacks, notably that they only slightly improve soundproofing compared to the use of awnings without acoustic properties, and that they generate pressure losses in the airflow before the ventilation air intake.

[0003] Consequently, the prior art solutions proposed for soundproofing hoods still have drawbacks and improvements are possible.

[0004] The present invention aims in particular to solve the problems indicated above by proposing a soundproofing hood and a soundproofing arrangement comprising it.

[0005] Thus, the present invention relates to a sound-absorbing cover configured to be applied to an air inlet of a ventilation duct, comprising a housing configured to cover the air inlet, the housing comprising an outer casing in which are formed an outlet opening, configured to be fluidly connected to the air inlet, and an inlet opening, opening onto the exterior of the housing, a duct being further formed in the housing to fluidly connect the inlet opening and the outlet opening, characterized in that the sound-absorbing cover further comprises a sound-absorbing assembly comprising a partitioned chamber formed in the housing and opening onto the duct by a fluidic communication path occupied by an acoustic filter, made of a porous material, having sufficient resistance to airflow to prevent airflow from the duct to the partitioned chamber through the fluidic communication path. fluidic communication, and by the fact that the soundproofing assembly is configured to form an acoustic resonator soundproofing the duct by attenuating frequencies of the audible spectrum, by reflection, interference and dissipation of acoustic waves of the audible spectrum coming from the duct.

[0006] This configuration makes it possible to obtain a soundproofing cover configured to be applied to an air inlet of a ventilation duct and configured to, in use, reduce the transmission of sounds generated outside the buildings through the air inlet and the ventilation duct, thanks to the soundproofing assembly, without generating significant pressure losses in the airflow.

[0007] It will be understood that, preferably, the dimensions and position of the communication path, and the volume of the partitioned chamber, are chosen to maximize sound insulation over the desired audible frequency range for the soundproofing assembly of the soundproofing hood installed on an air inlet of a given ventilation duct, possibly extending into an optional interior accessory. Preferably, the soundproofing assembly is configured to maximize attenuation over the range of 100 to 3150 Hz.

[0008] In some cases, the ventilation duct extends, on a side opposite the soundproofing cover, into an optional internal accessory, such that a distal end of the ventilation duct then corresponds to a distal end of the optional internal accessory.

[0009] According to one embodiment, the fluidic communication path is formed in the duct so as to be positioned at a distance from pressure nodes of natural and longitudinal acoustic modes, at frequencies around the resonance frequency of the soundproofing assembly, from an acoustic path formed by connecting the duct and the ventilation channel in series, and preferably so as to be positioned at the antinodes of said modes.

[0010] This configuration notably improves the operating efficiency of the soundproofing assembly. Indeed, generally speaking, the acoustic path extending from the inlet opening of the soundproofing cover to the distal end of the ventilation duct, possibly through an optional internal accessory, is longer than 6 cm. This implies that at least one natural, longitudinal acoustic mode of the acoustic path (half-wave resonator mode) has a frequency within the frequency range over which noise transmission is to be reduced, specifically the range of 100 to 3150 Hz. It is therefore advantageous for the fluidic communication path of the soundproofing assembly to be located away from the pressure nodes of the natural, longitudinal acoustic modes of the acoustic path having a frequency close to the resonance frequency of the soundproofing assembly. Furthermore, it is advantageous for the path fluidic communication of the soundproofing assembly should be at least 15 mm from the inlet opening of the duct, in particular, since all the natural and longitudinal acoustic modes of the acoustic path have a pressure node at the inlet opening of the duct (more precisely, at a short distance upstream of the inlet opening of the duct because, by acoustic radiation effect, a "duct" appears longer than its physical length to acoustic waves).

[0011] According to a particular embodiment, the acoustic filter is configured, dimensioned and positioned so that, in use, taking into account the entirety of a spectrum of interest in the audible spectrum, for example the range from 100 Hz to 3150 Hz, the sound power, possibly weighted, transmitted at a distal end of the ventilation duct, opposite the air inlet, is lower with the soundproofing assembly including the acoustic filter than with the partitioned chamber and the fluidic communication path alone.

[0012] In this embodiment, the acoustic filter made of porous material is configured and dimensioned such that, due to the arrangement of the acoustic filter in the fluidic communication path, the soundproofing assembly more effectively attenuates the noise transmitted to the distal end of the ventilation duct. The acoustic filter can, in particular, be selected from several filters having different pore sizes, filter heights, or filter widths. In some variations, a non-porous space within the acoustic filter can comprise an impermeable, non-porous material. Depending on the acoustic filter used, the soundproofing enclosure will have increased effectiveness over a range of frequencies and will, for example, be more effective at reducing road noise or airport noise.

[0013] According to a particular embodiment, the acoustic filter occupies the entire fluidic communication path.

[0014] This configuration makes it possible in particular to limit the pressure losses of the air flow in the duct.

[0015] According to a particular embodiment, the acoustic filter has a resistance to flow, in a thickness direction from the duct to the partitioned chamber, of between 2 x 103 and 1 x 106 N-sw5, preferably between 2 x 104 and 2 x 101, preferably again between 0.5 x 105 and 1.5 x 105 Ns.nr5, such that, in use, air circulating inside the duct does not enter the partitioned chamber, but an acoustic wave enters the partitioned chamber through the fluidic communication path, through the acoustic filter.

[0016] This resistance to flow can in particular be measured by resistivity meter, according to the American standard ASTM C522-03 or according to the European standard ISO 9053-2:2020.

[0017] It will be understood that this property of the acoustic filter makes it possible to guarantee the passage of acoustic waves and the blocking of the airflow, so that the soundproofing assembly soundproofs the duct without generating significant pressure losses.

[0018] According to a particular embodiment, the fluidic communication path further comprises peripheral walls extending from the duct into the interior of the partitioned chamber, so as to receive the acoustic filter and to make the lateral walls of the acoustic filter acoustically impermeable so that an acoustic wave from the duct is forced to pass through a whole thickness of the acoustic filter.

[0019] This configuration makes it possible in particular to guide the acoustic waves in the acoustic filter in order to improve the operation of the soundproofing assembly.

[0020] According to a particular embodiment, the partitioned chamber is empty, that is to say, it contains only air.

[0021] According to a particular embodiment, the partitioned chamber receives a porous material.

[0022] A soundproofing cover according to the invention operates with an empty partitioned chamber. It will be understood, however, that, according to variations, a porous material can be placed in the partitioned chamber, for example to adjust the soundproofing of the soundproofing assembly according to the frequency.

[0023] According to a particular embodiment, the partitioned chamber is at least partially defined by the outer casing of the housing and by the conduit.

[0024] This configuration makes it possible, in particular, to obtain a compact soundproof enclosure. Preferably, the partitioned chamber is entirely defined by the outer casing of the housing and by the duct. However, according to some variations, the partitioned chamber can be entirely defined by additional partitions formed within the housing. According to other variations, the partitioned chamber can be partially defined by the outer casing of the housing and by the duct, and partially defined by additional partitions formed within the housing. It will be understood that the use of additional partitions makes it possible, in particular, to define a volume of the partitioned chamber independently of the dimensions of the housing.

[0025] According to a particular embodiment, the fluidic communication path has an elongated slot shape extending perpendicularly to an extension direction of the conduit between the inlet opening and the outlet opening.

[0026] Preferably, the fluidic communication path is continuous. According to variants, the partitioned chamber can open onto the conduit at several points, so that the fluidic communication path is then formed of several pieces.

[0027] According to a particular embodiment, the acoustic filter made of porous material is manufactured by 3D printing from at least one of a metal, a polymer and a composite material.

[0028] The base material used for 3D printing can, for example, be in the form of filament, resin, or powder. It will also be understood that other manufacturing processes can be used instead of 3D printing to produce the acoustic filter, for example, fiber compression, a chemical reaction between elements, or the use of natural porous materials. Depending on the specific design, the acoustic filter can be made from a perforated plate or a resistive fabric.

[0029] According to a particular embodiment, at least one of the housing and the acoustic filter is made from a material configured to adsorb at least one of carbon dioxide (CO2), nitrogen oxides (NOx) and volatile organic compounds (VOCs) and to allow transformation of the adsorbed compounds into carbonates by at least one of a catalysis and a photocatalysis.

[0030] It will be understood that the soundproofing cover then has an additional function of depolluting the air entering through the air inlet and the ventilation channel.

[0031] According to a particular embodiment, the pore size of the porous material of the acoustic filter is between 0.01 and 1.5 mm. The pore size can in particular be measured optically (microscope).

[0032] The porosity of the porous material is chosen in particular according to the objectives of acoustic attenuation, while limiting airflow through the acoustic filter. Porosity can be measured using a porosimeter or a gas pycnometer (method described in the document "Air-based System for the measurement of porosity", Champoux Y., Stinson MR, Daigle GA, J. Acoust. Soc. Am. 89(2), 1991, pp. 910-916), by optical method, or by inverse characterization from acoustic measurements carried out on the porous material (method described in the document "Estimation of all 6 parameters of Johnson-Champoux-Allard-Lafarge model for acoustical porous materials from impedance tube measurements", Jaouen L., Gourdon E., Glé Ph., J. Acoust. Soc. Am.148(4), 2020, p. 1998-2005). .

[0033] The porosity range is preferably between 30% and 95% for a porous material of the "felt" or "foam" type, and between 1% and 30% for a porous material of the resistive veil or micro-perforated plate type.

[0034] According to a particular embodiment, the acoustic filter is resistant to water and to a temperature of at least 80 °C, such that the acoustic filter is suitable for being washed, the pore size of the porous material of the acoustic filter being preferably between 0.1 and 1 mm.

[0035] This configuration allows, in particular, the acoustic filter to be washed in the dishwasher, which cleans it and thus maintains the soundproofing properties of the assembly for a longer period, thereby ensuring optimal operation of the soundproof cover throughout its lifespan. It will also be understood that the outer casing of the housing is then preferably made up of several removable parts, so as to allow a user to open the housing to retrieve the acoustic filter for washing.

[0036] According to a particular embodiment, the outlet opening is configured to be fluidly connected to an air inlet having a cross-section identical to a cross-section of the outlet opening.

[0037] According to less preferred embodiments, the outlet opening can be configured to be fluidly connected to an air inlet having a cross-section different from that of the outlet opening. It will be understood that the outlet opening may, for example, include a grid to prevent the passage of foreign matter.

[0038] According to a particular embodiment, a section of the conduit is constant between the inlet opening and the outlet opening.

[0039] It will be understood that the fact that the cross-section of the duct perpendicular to the flow is substantially identical to that of the air inlet over its entire length, despite the presence of the soundproofing assembly, makes it possible to further reduce pressure losses in the air flow.

[0040] According to a particular embodiment, the soundproofing hood further comprises another soundproofing assembly, the two soundproofing assemblies having at least one of different partitioned chamber volumes and different acoustic filters.

[0041] The two soundproofing assemblies soundproof the duct more effectively over a wider frequency range in the audible spectrum than either soundproofing assembly alone.

[0042] According to a particular embodiment, the fluidic communication paths of said two soundproofing assemblies are formed on either side of the conduit.

[0043] The fluidic communication paths can be formed opposite each other or can be arranged in other ways, for example side-by-side, so as to choose the respective position of the fluidic communication paths.

[0044] It will also be understood that, according to other variants, the soundproofing cover can include three, or more, soundproofing assemblies, for example to adjust the range of frequencies of the audible spectrum to be attenuated.

[0045] According to a particular embodiment, the outlet opening is designed and dimensioned so that the soundproofing cover is configured to be functionally connected to an air inlet in the form of an elongated slot, preferably an air inlet of a ventilation duct intended for the ventilation of premises, in particular dwellings, preferably even more preferably an air inlet of a ventilation duct of a window or joinery.

[0046] The present invention also relates to a soundproofing arrangement, characterized in that it comprises a first soundproofing cover according to the invention and a second soundproofing cover according to the invention, the first soundproofing cover and the second soundproofing cover being joined in parallel to each other and being configured to be functionally connected respectively to two air inlets of two ventilation channels.

[0047] The two soundproofing covers are preferably joined end-to-end.

[0048] According to a particular embodiment, the first soundproofing cover and the second soundproofing cover are joined together by being formed in one piece.

[0049] According to variants, the two soundproofing covers can be joined together by any means, for example by gluing, elastic fitting or clipping.

[0050] According to a particular embodiment, the arrangement further includes a recess connecting a partitioned chamber of the first soundproofing cover with a partitioned chamber of the second soundproofing cover.

[0051] It will be understood that the use of a recess makes it possible to vary the volumes of the partitioned chambers put into communication, in particular to adjust the range of attenuated frequencies in the audible spectrum.

[0052] The invention also relates to a window or door frame characterized in that it comprises at least one ventilation duct having an air inlet equipped with a sound-absorbing hood as described above or a sound-absorbing arrangement as described above. The sound-absorbing hood or the sound-absorbing arrangement may be integrated into or attached to the window or door frame.

[0053] Particular embodiments of the present invention will now be described, with reference to the accompanying drawings.

[0054] On these drawings:

[0055] [Fig-1] is a perspective view of a soundproofing hood according to a first mode of realization of the present invention.

[0056] [Fig.2a] is a cross-sectional view of the soundproofing cover of [Fig. 1].

[0057] [Fig.2b] is a schematic cross-sectional view of the soundproofing cover of the [Fig. 1] applied to an air inlet of a ventilation duct of a window frame, the part shown in dotted lines representing an optional internal accessory attached to the joinery on one side opposite the soundproofing hood in relation to the joinery and in which the ventilation channel can extend.

[0058] [Fig.3] is a cross-sectional view of a soundproofing hood according to a second embodiment of the present invention.

[0059] [Fig.4] is a cross-sectional view of a soundproofing hood according to a third embodiment of the present invention.

[0060] [Fig. 5] is a cross-sectional view of a soundproofing hood according to a fourth embodiment of the present invention.

[0061] [Fig.6] is a cross-sectional view of a soundproofing hood according to a fifth embodiment of the present invention.

[0062] [Fig.7] is a perspective cross-sectional view of an arrangement soundproofing according to the present invention, comprising two soundproofing hoods according to the second embodiment shown in [Fig.3].

[0063] [Fig.8] is a schematic representation of the soundproofing arrangement of the [Fig.7], in use, applied to two air inlets of two ventilation channels of a joinery, here a window.

[0064] A sound-absorbing cover 1 according to the invention is configured, in use, to be applied to an air inlet E of a ventilation duct C, for example of a window or door frame or building, so as to attenuate the transmission, through the air inlet E and the ventilation duct C, of ​​noise generated outside. The sound-absorbing cover 1 is further configured to limit pressure losses in the airflow.

[0065] As can be seen in [Fig. 2b], in some cases, an optional internal accessory A may be present. The ventilation channel C then extends into the optional internal accessory A, such that a distal end of the ventilation channel C corresponds to a distal end of the optional internal accessory A.

[0066] Referring to Figures 1, 2a and 2b, one can see that a soundproofing cover 1 is shown according to a first embodiment of the present invention, comprising a housing 2 and a soundproofing assembly 3.

[0067] According to the invention, the housing 2 is configured to cover the air inlet E. The housing 2 comprises an outer casing 21 in which an outlet opening 23 and an inlet opening 22 are formed. The outlet opening 23 is configured to be fluidly connected to the air inlet E and the inlet opening 22 opens onto an exterior of the housing 2. A conduit 24 is further formed in the housing 2 to fluidly connect the inlet opening 22 and the outlet opening 23.

[0068] In the first embodiment shown in Figures 1, 2a and 2b, the housing 2 has the shape of a rectangular prism, one of whose edges is replaced by a radius of curvature. will understand that other shapes are possible for case 2, for example a rectangular prism, a cylinder or a prism with a polygonal base.

[0069] As can be seen in Figures 1, 2a, and 2b, in the first embodiment, the inlet opening 22 is formed in a lower part of the outer casing 21 of the housing 2, and the conduit 24 is bent between the inlet opening 22 and the outlet opening 23. According to variations, other configurations are possible, in particular the use of a straight conduit 24, or a non-bent conduit 24. The fifth embodiment, shown in [Fig. 6] and described in more detail below, presents, for example, another possibility.

[0070] In the first embodiment shown in Figures 1, 2a and 2b, the outlet opening 23 is configured to be fluidly connected to an air inlet E having a cross-section identical to a cross-section of the outlet opening 23. According to less preferred variants, the outlet opening 23 can be configured to be fluidly connected to an air inlet E having a cross-section different from the cross-section of the outlet opening 23. It will be understood that the outlet opening 23 can, for example, include a grid to prevent the passage of foreign matter.

[0071] More particularly, in the first embodiment shown in Figures 1, 2a and 2b, the outlet opening 23 is designed and dimensioned so that the soundproofing cover 1 is configured to be functionally connected to an air inlet E in the form of an elongated slot, preferably an air inlet E of a ventilation duct C intended for the ventilation of premises, in particular dwellings, preferably even more preferably an air inlet E of a ventilation duct C of a window or more generally of a joinery M. It will be understood that according to variants, the outlet opening 23 can be designed and dimensioned to be connected to ventilation air inlets E having other shapes.

[0072] As can be seen more clearly in [Fig.2a], in the first embodiment, a section of the conduit 24 is constant between the inlet opening 22 and the outlet opening 23. According to less preferred variants, the section of the conduit 24 could vary between the inlet opening 22 and the outlet opening 23; the conduit could, for example, be conical between the inlet opening 22 and the outlet opening 23.

[0073] According to the invention, the soundproofing assembly 3 comprises a partitioned chamber 31 formed in the housing 2 and opening onto the duct 24 via a fluidic communication path 32 occupied by an acoustic filter 33, made of a porous material, having sufficient resistance to airflow to prevent airflow from the duct 24 to the partitioned chamber 31 through the fluidic communication path 32. Furthermore, the soundproofing assembly 3 is configured to form an acoustic resonator that soundproofs the duct 24 by attenuating frequencies of the audible spectrum, by reflection, interference and dissipation of acoustic waves of the audible spectrum coming from duct 24.

[0074] In the first embodiment shown in Figures 1, 2a and 2b, the partitioned chamber 31 is completely defined by the outer casing 21 of the housing 2 and by the conduit 24. However, according to some variations, the partitioned chamber 31 could be completely defined by additional partitions formed in the housing 2. According to other variations, the partitioned chamber 31 could be partially defined by the outer casing 21 of the housing 2 and by the conduit 24, and partially defined by additional partitions formed in the housing 2. It will be understood that the use of additional partitions makes it possible, in particular, to define a volume of the partitioned chamber 31 independently of the dimensions of the housing 2.

[0075] In the first embodiment shown in Figures 1, 2a, and 2b, the acoustic filter 33 is configured, dimensioned, and positioned such that, in use, taking into account the entirety of a spectrum of interest within the audible spectrum, for example, the range from 100 Hz to 3150 Hz, the sound power transmitted to a distal end of the ventilation duct C, opposite the air inlet E, is lower with the soundproofing assembly 3 comprising the acoustic filter 33 than with the partitioned chamber (31) and the fluid communication path (32) alone. Thus, the acoustic filter 33 made of porous material is configured and dimensioned such that, due to the arrangement of the acoustic filter 33 in the fluid communication path 32, the soundproofing assembly 3 more effectively attenuates the noise transmitted to the distal end of the ventilation duct C.

[0076] Moreover, in the first embodiment, the acoustic filter 33 occupies the entire fluidic communication path 32. According to less preferred variants, the acoustic filter 33 could occupy only a portion of the fluidic communication path 32.

[0077] Furthermore, in the first embodiment, the acoustic filter 1 has a resistance to flow, in a thickness direction from the duct 24 to the partitioned chamber 31, of between 0 5 X 103 and 1 5 x 105 such that, in use, air circulating inside the duct 24 does not enter the partitioned chamber 31, but an acoustic wave enters the partitioned chamber 31 through the fluidic communication path 32, through the acoustic filter 33.

[0078] According to less preferred variants, the acoustic filter 1 may have a flow resistance, in the thickness direction from the duct 24 to the partitioned chamber 31, of between 2 x 10⁴ and 2 x 10⁵. Generally, the acoustic filter 1 preferably has a flow resistance, in the thickness direction from duct 24 to partitioned chamber 31, between 2 x 103 and 1 x 106

[0079] Preferably, the pore size of the porous material of the acoustic filter 33 is between 0.01 and 1.5 mm, in particular to promote the passage of acoustic waves of the audible spectrum and to limit airflow.

[0080] Advantageously, the acoustic filter 33 is resistant to water and to a temperature of at least 80 °C, so that the acoustic filter 33 is suitable for washing, the size of the pores of the porous material of the acoustic filter 33 then being, preferably, between 0.1 and 1 mm.

[0081] This configuration allows, in particular, the acoustic filter 33 to be washed in the dishwasher, which cleans it and thus maintains the properties of the soundproofing assembly 3 for a longer period, thereby ensuring optimal operation of the soundproofing cover 1 throughout its lifespan. It will also be understood that the outer casing 21 of the housing 2 is then preferably made up of several removable parts, so as to allow a user to open the housing 2 to retrieve the acoustic filter 33 for washing.

[0082] According to the invention, the acoustic filter 33 made of porous material can be manufactured by 3D printing from a metal, a polymer, a composite material, or a combination thereof. The base material used for 3D printing can, for example, be in the form of filament, resin, or powder. In the first embodiment, the acoustic filter 33 is manufactured by 3D printing from polymer filaments.

[0083] Preferably, the acoustic filter 33 is made from a material configured to adsorb carbon dioxide (CO2), nitrogen oxides (NOx), and volatile organic compounds (VOCs), and to allow the transformation of the adsorbed compounds into carbonates by catalysis, for example, photocatalysis. This material may, for example, be a "PLA Purifier" type filament marketed by RECREUS. It will be understood that the sound-absorbing cover 1 then has an additional function of purifying the air entering through the air inlet E and the ventilation duct C. In alternative embodiments, the housing 2 may also be made from such a material.

[0084] It will be understood, however, that other manufacturing processes can be used instead of 3D printing to manufacture the acoustic filter 33, for example fiber compression, a chemical reaction between elements or the use of natural porous materials.

[0085] According to variants, the acoustic filter 33 can be made from a perforated plate or a resistive veil.

[0086] As can be seen more clearly in [Fig.2a], in the first embodiment, the fluidic communication path 32 further includes peripheral walls 32a extending from the conduit 24 into the interior of the partitioned chamber 31, so as to receive the acoustic filter 33 and to make acoustically impermeable the lateral walls 33a of the acoustic filter 33 so that an acoustic wave from the conduit 24 is forced to pass through the entire thickness of the acoustic filter 33.

[0087] Furthermore, in the first embodiment shown in Figures 1, 2a and 2b, the partitioned chamber 31 is empty, that is to say, it contains only air. It will be understood that, according to variations, the partitioned chamber 31 could receive a porous material, preferably a porous material different from the porous material of the acoustic filter 33, for example, to adjust the frequency range of the audible spectrum to be attenuated.

[0088] In the first embodiment, the fluidic communication path 32 has an elongated slot shape extending perpendicularly to a direction of extension of the conduit 24 between the inlet opening 22 and the outlet opening 23. This configuration of the fluidic communication path 32 is also visible in [Fig. 7], which represents a sound-absorbing arrangement according to the invention, which will be described in more detail below. According to variants, the partitioned chamber 31 could open onto the conduit 24 at several points, such that the fluidic communication path 32 would then be formed of several sections.

[0089] Advantageously, the fluidic communication path 32 is formed in the conduit 24 so as to be positioned at a distance from pressure nodes of natural and longitudinal acoustic modes, at frequencies around the resonance frequency of the soundproofing assembly 3, from an acoustic path formed by connecting the conduit 24 and the ventilation channel C in series, and preferably so as to be positioned at the antinodes of said modes.

[0090] As can be seen more clearly in [Fig. 2a], in the first embodiment, the fluidic communication path 32 is formed in the duct 24 in the immediate vicinity of the outlet opening 23. In this embodiment, the fluidic communication path 32 is therefore as far as possible from the inlet opening 22, which corresponds to the position most favorable for attenuating frequencies close to the frequency of the first natural and longitudinal acoustic mode of the acoustic path. Indeed, this acoustic mode has two nodes, one at the inlet opening 22 of the duct 24 and the other at the distal end of the ventilation channel C.

[0091] According to variants, the fluidic communication path 32 could be offset within the conduit 24. For example, if it is desired that the soundproofing assembly 3 provides maximum attenuation around the frequency of a natural acoustic mode and In the longitudinal acoustic path having a pressure node near the outlet opening 23 of the duct 24, it is advantageous to bring the fluidic communication path 32 closer to the inlet opening 22 of the duct 24, while maintaining it at more than 15 mm from the inlet opening 22 of the duct 24. According to a particular embodiment, the fluidic communication path 32 can be formed in the half of the duct 24 closest to the outlet opening 23 and advantageously formed in the quarter of the duct 24 closest to the outlet opening 23.

[0092] If we now refer to Figures 3 and 4, we can see that a soundproofing hood 1 according to a second embodiment of the present invention and a soundproofing hood 1 according to a third embodiment of the invention are shown there.

[0093] The soundproofing hoods 1 according to the second and third embodiments are identical to the soundproofing hood 1 according to the first embodiment described above, except that they also include another soundproofing assembly 3'.

[0094] The other soundproofing assembly 3' has a structure analogous to that of the soundproofing assembly 3 of the first embodiment described above. Thus, the other soundproofing assembly 3' comprises a partitioned chamber 31' formed in the housing 2 and opening onto the duct 24 via a fluidic communication path 32' occupied by an acoustic filter 33', made of a porous material, having sufficient resistance to airflow to prevent air from flowing from the duct 24 to the partitioned chamber 31' through the fluidic communication path 32'. The other soundproofing assembly 3' is also configured to form an acoustic resonator that soundproofs the duct 24 by attenuating frequencies of the audible spectrum through reflection, interference, and dissipation of acoustic waves of the audible spectrum originating from the duct 24.

[0095] The two soundproofing assemblies 3, 3' have different partitioned chamber volumes 31 and different acoustic filters 33, 33', such that the two soundproofing assemblies 3, 3' soundproof the duct 24 by attenuating a wider range of frequencies in the audible spectrum than either of the soundproofing assemblies 3, 3' alone. According to less preferred embodiments, the two soundproofing assemblies 3, 3' may have only different partitioned chamber volumes 31 or only different acoustic filters 33, 33'.

[0096] Preferably, and as can be seen in Figures 3 and 4, in the second and third embodiments, the fluidic communication path 32' of the other soundproofing assembly 3' further comprises peripheral walls 32a' extending from the duct 24 into the interior of the partitioned chamber 31', so as to receive the acoustic filter 33' and to make the walls acoustically impermeable lateral 33a' of the acoustic filter 33' so that an acoustic wave coming from the duct 24 is forced to pass through the entire thickness of the acoustic filter 33'.

[0097] In the second embodiment represented in [Fig.3], the two soundproofing assemblies 3, 3' are formed on either side of the conduit 24, and the fluidic communication paths 32, 32' of said two soundproofing assemblies 3, 3' are formed on either side of the conduit 24, opposite each other.

[0098] In the third embodiment represented in [Fig.4], the two soundproofing assemblies 3, 3' are formed on the same side of the conduit 24, and the fluidic communication paths 32, 32' of said two soundproofing assemblies 3, 3' are formed on the same side of the conduit 24, next to each other.

[0099] The preferred configuration between the second and third embodiments depends in particular on the resonance frequency of each of the two sound-absorbing assemblies 3, 3' and on the position of the nodes of the natural and longitudinal acoustic modes of the acoustic path. For example, the configuration of the third embodiment is preferred if the sound-absorbing assembly 3 has a resonance frequency close to the frequency of the first natural and longitudinal acoustic mode of the acoustic path, and the other sound-absorbing assembly 3' has a resonance frequency close to the frequency of another natural and longitudinal acoustic mode of the acoustic path having a pressure node at the outlet opening 23 of the duct 24.

[0100] By referring to [Fig.5], it can be seen that a soundproofing hood 1 is shown therein according to a fourth embodiment of the present invention.

[0101] In this, the soundproofing hood 1 comprises three soundproofing assemblies 3, 3', 3" whose structures and arrangements are analogous to those of the soundproofing assemblies 3, 3' of the second and third embodiments described above, two soundproofing assemblies 3, 3' being arranged on the same side of the conduit 24 and the third soundproofing assembly 3" being arranged on the other side of the conduit 24.

[0102] It will be understood that, preferably, the volumes of the partitioned chambers 31, 31', 31" of the three sound-absorbing assemblies 3, 3', 3" are chosen to be different, so as to attenuate frequencies over a wider range in the audible spectrum. It will also be understood that, according to other variants, the sound-absorbing hood 1 could comprise more than three sound-absorbing assemblies 3, 3', 3".

[0103] Referring now to [Fig.6], it can be seen that a soundproofing hood 1 is shown there according to a fifth embodiment of the present invention.

[0104] The fifth embodiment is almost identical to the second embodiment shown in [Fig. 3] and described above. However, in the fifth embodiment, the inlet opening 22 is formed in a lateral part of the outer casing 21 of the housing 2 and the conduit is inclined between the opening inlet 22 and outlet opening 23. According to the invention, the inlet opening 22 is preferably formed in a lower part of the outer casing 21 of the housing 2, or in a lateral part of the outer casing 21 of the housing 2, so as to limit the entry of foreign material into the soundproofing cover 1.

[0105] The invention also relates to a soundproofing arrangement 100, comprising a first soundproofing cover 1 according to the invention and a second soundproofing cover 1 according to the invention.

[0106] In the embodiment shown in [Fig. 7], the first soundproof cover 1 and the second soundproof cover 1 are soundproof covers 1 according to the second embodiment shown in [Fig. 3]. It will be understood, however, that, according to variations, the two soundproof covers 1 can adopt any of the configurations of a soundproof cover 1 according to the invention. It will also be understood that the first and second soundproof covers 1 may possibly be different from each other.

[0107] The first soundproofing cover 1 and the second soundproofing cover 1 are joined in parallel to each other and are configured so that, in use, they are respectively functionally connected to two air inlets E of two ventilation channels C.

[0108] In the embodiment shown in [Fig. 7], the first soundproof cover 1 and the second soundproof cover 1 are joined together as a single unit. In alternative embodiments, the two soundproof covers 1 can be joined by any means, for example by gluing, by elastic interlocking, or by clipping. Preferably, the two soundproof covers 1 are joined end-to-end.

[0109] According to variants, the soundproofing arrangement 100 may further include a recess connecting a partitioned chamber 31, 31', 31" of the first soundproofing hood 1 with a partitioned chamber 31, 31', 31" of the second soundproofing hood 1. It will be understood that the use of such a recess allows the volumes of the partitioned chambers 31, 31', 31" connected to vary, in particular to adjust the range of attenuated frequencies in the audible spectrum.

[0110] Figure 8 schematically represents the soundproofing arrangement 100 of Figure 7 in use, positioned in front of two air inlets E of two ventilation ducts C of a window or door frame M. It will be understood, however, that the soundproofing arrangement 100 can be configured to be functionally connected to other types of air inlets E, for example, other window or door frames M.

[0111] Finally, the invention further relates to a joinery M comprising at least one ventilation channel C having an air inlet E equipped with a soundproofing hood 1 according to the invention or a soundproofing arrangement 100 according to the invention.

[0112] It is understood that the particular embodiments which have just been described have been given by way of indication and not limitation, and that modifications may be made without departing from the scope of the present invention.

Claims

Demands

1. - A sound-absorbing cover (1) configured to be applied to an air inlet (E) of a ventilation duct (C), comprising: a housing (2), configured to cover the air inlet (E), the housing (2) comprising an outer casing (21) in which are formed an outlet opening (23), configured to be fluidly connected to the air inlet (E), and an inlet opening (22), opening onto the exterior of the housing (2), a conduit (24) further being formed in the housing (2) to fluidly connect the inlet opening (22) and the outlet opening (23), characterized in that the sound-absorbing cover (1) further comprises a sound-absorbing assembly (3) comprising a partitioned chamber (31) formed in the housing (2) and opening onto the conduit (24) by a fluid communication path (32) occupied by an acoustic filter (33), made of material porous,exhibiting sufficient resistance to airflow to prevent airflow from the duct (24) to the partitioned chamber (31) through the fluidic communication path (32), and by the fact that the soundproofing assembly (3) is configured to form an acoustic resonator soundproofing the duct (24) by attenuating frequencies of the audible spectrum, by reflection, interference and dissipation of acoustic waves of the audible spectrum originating from the duct (24).

2. - Soundproofing hood (1) according to claim 1, characterized in that the fluidic communication path (32) is formed in the conduit (24) so ​​as to be positioned at a distance from pressure nodes of natural and longitudinal acoustic modes, at frequencies around the resonance frequency of the soundproofing assembly (3), from an acoustic path formed by connecting the conduit (24) and the ventilation channel (C) in series, and preferably so as to be positioned at the antinodes of said modes.

3. - A sound-absorbing hood (1) according to claim 1 or claim 2, characterized in that the acoustic filter (33) is configured, dimensioned and positioned such that, in use, taking into account the entirety of a spectrum of interest in the audible spectrum, preferably the range from 100 Hz to 3150 Hz, the sound power transmitted at a distal end of the ventilation duct (C), opposite the air inlet (E), is lower with the assembly soundproofing (3) comprising the acoustic filter (33) only with the partitioned chamber (31) and the fluidic communication path (32) alone.

4. - Soundproofing cover (1) according to any one of claims 1 to 3, characterized in that the acoustic filter (33) occupies the entire fluidic communication path (32).

5. - Soundproofing hood (1) according to any one of claims 1 to 4, characterized in that the acoustic filter (33) has a resistance to flow, in a thickness direction from the duct (24) to the partitioned chamber (31), of between 2 x 103 and 1 x 106 preferably between 2 x 104 and 2 x 105 N mm5, preferably again between 0 5 x 105 and 15 x 105 such that, in use, air circulating inside the duct (24) does not enter the partitioned chamber (31), but an acoustic wave enters the partitioned chamber (31) through the fluidic communication path (32), through the acoustic filter (33).

6. - Soundproofing hood (1) according to any one of claims 1 to 5, characterized in that the fluidic communication path (32) further comprises peripheral walls (32a) extending from the conduit (24) into the interior of the partitioned chamber (31), so as to receive the acoustic filter (33) and to make acoustically impermeable the lateral walls (33a) of the acoustic filter (33) so that an acoustic wave from the conduit (24) is forced to pass through a whole thickness of the acoustic filter (33).

7. - Soundproofing hood (1) according to any one of claims 1 to 6, characterized in that the partitioned chamber (31) is empty, i.e. it contains only air.

8. - Soundproofing hood (1) according to any one of claims 1 to 6, characterized in that the partitioned chamber (31) receives a porous material.

9. - Soundproofing cover (1) according to any one of claims 1 to 8, characterized in that the partitioned chamber (31) is at least partially defined by the outer envelope (21) of the housing (2) and by the conduit (24).

10. - Soundproofing cover (1) according to any one of claims 1 to 9, characterized in that the fluidic communication path (32) has an elongated slot shape extending perpendicularly to an extension direction of the conduit (24) between the inlet opening (22) and the outlet opening (23).

11. - Soundproofing cover (1) according to any one of claims 1 to 10, characterized in that the acoustic filter (33) made of porous material is manufactured by 3D printing from at least one of a metal, a polymer and a composite material.

12. - Soundproofing cover (1) according to any one of claims 1 to 11, characterized in that at least one of the housing (2) and the acoustic filter (33) is made from a material configured to adsorb at least one of carbon dioxide, CO2, nitrogen oxides, NOX, and volatile organic compounds, VOCs, and to allow transformation of the adsorbed compounds into carbonates by at least one of a catalysis and a photocatalysis.

13. - Soundproofing cover (1) according to any one of claims 1 to 12, characterized in that the pore size of the porous material of the acoustic filter (33) is between 0.01 and 1.5 mm.

14. - Soundproofing cover (1) according to any one of claims 1 to 13, characterized in that the acoustic filter (33) is resistant to water and to a temperature of at least 80 °C, such that the acoustic filter (33) is suitable for washing, the pore size of the porous material of the acoustic filter (33) being, preferably, between 0.1 and 1 mm.

15. - Soundproofing hood (1) according to any one of claims 1 to 14, characterized in that the outlet opening (23) is configured to be fluidly connected to an air inlet (E) having a cross-section identical to a cross-section of the outlet opening (23).

16. - Soundproofing cover (1) according to any one of claims 1 to 15, characterized in that a section of the conduit (24) is constant between the inlet opening (22) and the outlet opening (23).

17. - Soundproofing hood (1) according to any one of claims 1 to 16, characterized in that the soundproofing hood (1) further comprises another soundproofing assembly (3'), the two soundproofing assemblies (3, 3') having at least one of different partitioned chamber volumes (31, 31') and different acoustic filters (33).

18. - Soundproofing cover (1) according to claim 17, characterized in that the fluidic communication paths (32, 32') of said two soundproofing assemblies (3, 3') are formed on either side of the conduit (24).

19. - Soundproofing hood (1) according to any one of claims 1 to 18, characterized in that the outlet opening (23) is designed and dimensioned so that the soundproofing hood (1) is configured to be functionally connected to an air inlet (E) in the form of an elongated slot, preferably an air inlet (E) of a ventilation duct (C) intended for the ventilation of premises, in particular dwellings, preferably again an air inlet (E) of a ventilation duct (C) of a window or joinery (M).

20. - Soundproofing arrangement (100), characterized in that it comprises a first soundproofing cover (1) according to any one of claims 1 to 19 and a second soundproofing cover (1) according to any one of claims 1 to 19, the first soundproofing cover (1) and the second soundproofing cover (1) being joined in parallel to each other and being configured to be functionally connected respectively to two air inlets (E) of two ventilation channels (C).

21. - Soundproofing arrangement (100) according to claim 20, characterized in that the first soundproofing cover (1) and the second soundproofing cover (1) are joined together by being formed in one piece.

22. - Soundproofing arrangement (100) according to claim 20 or claim 21, characterized in that the arrangement (100) further comprises a recess connecting a partitioned chamber (31, 31') of the first soundproofing cover (1) with a partitioned chamber (31, 31') of the second soundproofing cover (1).

23. - Joinery (M) characterized in that it comprises at least one ventilation channel (C) having an air inlet (E) equipped with a soundproofing hood (1) according to any one of claims 1 to 19 or a soundproofing arrangement (100) according to any one of claims 20 to 22.

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