FR2998603A1 - Device i.e. panel, for use at e.g. ceiling to absorb acoustic waves in e.g. conference hall, has textile coating supported by peripheral modular frame that includes groove maintaining removable central core i.e. perforated sheet - Google Patents

Abstract

The device has a textile coating (5) supported by a peripheral modular frame (1). The peripheral modular frame includes a groove maintaining a removable central core (7) i.e. perforated sheet. The central core includes two types of through-openings differing from one type to another type by diameters between 3 mm and 8 mm. A part of a space between the textile coating and the central core includes a removable material layer (9) to absorb energy of an acoustic wave. The frame maintains the layer by the interior walls of an edge of the frame.

Description

FIELD OF THE INVENTION The present invention relates to a wall-forming system having desirable absorption properties enabling it to absorb acoustic waves, and whose absorption properties are adjustable. The invention finds particular application in premises welcoming the public or equipment, to improve the sound comfort of its occupants. STATE OF THE ART Confined spaces such as buildings, conference rooms, multipurpose rooms, etc. are often the seat of a considerable noise nuisance, a function inter alia of the use made of the places and the geometry of the enclosed space in question. To remedy this noise nuisance, it is not always possible to act on the source of the noise, and therefore means must be implemented to absorb the acoustic energy present in the enclosed space.

One of the means envisaged for absorbing acoustic energy in an enclosed space is the use of absorbent panels, formed of a layer of a material capable of absorbing acoustic waves. US Patent 2008/0029336 A1 describes such absorbent panels. This document proposes to incorporate an absorbent material in a support frame and cover the whole by a veil permitting acoustic waves. Thus, it is possible to combine the aesthetics of an acoustic wave absorber with the desired functionality, namely to absorb acoustic waves. However, the use of such a panel requires a unique choice of materials for the realization of the absorber, and therefore can not adapt to environments that may have, depending on the intended use, variable sound environments requiring suitable acoustic wave absorbers. The other disadvantage of this device is that it can not be dismounted easily to be reinstalled in another place.

Similarly, an acoustic wave absorbing device in the form of a panel, with aesthetic rendering improved by the use of a textile coating, has been proposed by Sonatech. Such devices are available through Sonatech QuietLine products referenced for example on the following link: http://www.sonatech.de/. This product has an aluminum frame filled with an absorbent material, and in which the frame is covered with a textile fabric passing acoustic waves.

Obersound also offers a similar product in its Obersound range, collection 5.5 Designers, references of which are available at the following address: http://www.oberflex.com/panneaux 10 solutions-acoustic obersound- collections-55- desioners obersound-55-desi-ner 1.html # 1. This range of products includes an absorbent support having on one of its faces a wooden coating and on the other a counterbalance. Finally, the company Texaa proposes three other types of devices able to absorb acoustic waves in the form of panels, in its ranges Stereo, Vibrasto and Asto, for which information is accessible for example on this link: http: // www .texaa.fr / products / stereo / downloads /. These devices also have a support frame, an absorbent material and a fabric covering the frame. These products nevertheless all have the major disadvantage of not allowing selection and adjustment of the absorption properties of the sound wave absorption device. To obtain a different absorption spectrum, adapted to the intended use for a one-off event such as a conference, an official reception, a trade show, a recording studio, it is necessary to change the entire panel. For this reason, there is a need to develop a device for absorbing sound waves with interchangeable panels, to select according to the specific needs of the user a desired absorption spectrum, while remaining aesthetically pleasing and easy to install and / or to disassemble. SUMMARY OF THE INVENTION The object of the present invention is to provide an acoustic wave absorber device, easy to assemble, with acoustic wave absorbing elements, interchangeable and replaceable according to the needs of the user. The object of the invention also aims to have an aesthetic appearance, pleasant to look at and marrying well with the environment in which the invention is arranged. To achieve this, the present invention relates to a device adapted to absorb acoustic waves comprising a textile coating supported by a peripheral modular frame. The peripheral modular frame of this device comprises at least one groove holding a removable central core. This architecture has the advantage of allowing a simple and intuitive installation of the device, and allows in particular to easily change the removable elements such as in particular the central core of the device. This makes it possible to confer on the device different acoustic wave absorption properties depending on the elements used to constitute it.

One of the ways of modulating the absorption properties of acoustic waves is to adapt the geometry of the central core inserted into the peripheral modular frame. Thus, according to a particular embodiment, the central core is a perforated sheet.

The presence of perforated orifices made by perforations in the central core modifies the absorption properties of the central core as well as those of the device itself. The opening of the central core by means of these through orifices makes it possible in particular to shift the acoustic wave absorption spectrum of the low frequencies (substantially between 100 Hz and 315 Hz) towards the midrange, also called the mid-frequency , or even to acute (that is to say up to frequencies between substantially 400 Hz and 5 kHz). According to another embodiment, the central core comprises at least two types of through holes, the through orifices differing from one type to another by their diameters, these diameters being between 3 mm and 8 mm. By structuring in this manner the perforations of the central core, it is possible to adjust the absorption spectrum of the device without adding additional elements.

This makes it possible to benefit from an acoustic wave-absorbing wall without, however, increasing the weight of the device and without overloading it. According to a particular embodiment, the rate of perforation of the central core by means of the through orifices is between 25% and 40% of the surface of said central core. These values of the rate of perforation of the central core correspond to a suitable compromise between acoustic wave absorption performance, rigidity and lightness.

According to another embodiment, the central core has a thickness of between 0.5 mm and 2 mm.

Such a thickness is in particular dependent on the dimensions of the grooves made in the peripheral modular frame intended to accommodate the central core. For uncompressed insertion of the central core into the peripheral modular frame, it is preferable that the central core has a thickness less than the width of the groove made in the peripheral modular frame. The thickness of the central core also makes it possible to adjust the acoustic wave absorption spectrum of the latter. Another means of adjusting the absorption properties of the device is to introduce additional elements absorbing the acoustic waves, by inserting these elements into the peripheral modular frame. These absorbent materials can in particular be inserted at various locations in the peripheral modular frame, on either side of the central core. Thus, according to one embodiment, at least a portion of the space between the textile coating and the central core comprises a layer of a material capable of absorbing the energy of an acoustic wave, the peripheral modular frame maintaining this layer by the inner walls of the rim of the frame. According to another embodiment, the peripheral modular frame maintains a first and / or a second layer of a first and / or second material capable of absorbing the energy of an acoustic wave, by the inner walls of the rim frame, this layer being disposed opposite the face of the central core opposite the textile coating. The addition of the layer made of a material having specific acoustic wave absorption properties makes it possible to modulate the absorption spectrum of the device. The location of this layer is also a choice that influences the performance of the device, because the absorption spectrum is not the same as the layer is placed between the textile coating and the central core or facing the face of the central core not exposed to the textile coating. The specific use of a layer having a certain mechanical strength, which may for example be in the form of a rigid or semi-rigid panel, has the advantage that it is easy to replace it with another element having different absorption properties if the needs of the user so require.

According to another embodiment, the central core is disposed between a first layer of a first material and a second layer of a second material, these layers being able to absorb the energy of an acoustic wave.

By having two layers instead of only one in the device, the absorption properties of the acoustic waves that result can be different, especially in that the absorption coefficient can be higher. It is not always necessary to have a strong absorption. For this reason, the possibility offered by the invention to remove the layers and replace them with other elements represents an advantageous advantage of the invention. It is specified that the materials constituting the different layers may just as well be the same for all the layers or different from one layer to another.

It is also possible to modulate the acoustic wave absorption properties of the device by the choice of materials constituting the various elements that can be inserted into the frame and / or removed from the frame. Thus, according to one embodiment, the first and the second layer of material, able to absorb the energy of an acoustic wave are made of different materials, these materials may differ in their density. In particular, the layer or layers capable of absorbing the energy of an acoustic wave are made of a material chosen from the group comprising: polyester fibers and mineral wool, taken alone or as a mixture. The textile coating is also an important element of the device. It confers in particular a pleasant visual aspect to the device allowing it to better integrate with the surrounding environment. The choice of the textile and its general properties are therefore significant parameters of the invention. Thus, according to one embodiment, the textile coating is a microporous textile based on polyester, and has a frame retaining peripheral ring.

The microporous textile coating is advantageously provided with a decorative pattern to increase the aesthetics of the device. A microporous textile is ideal for this type of application. The addition of a peripheral retaining ring to the modular frame facilitates the installation of the textile coating on the support frame.

Finally, the arrangement of the different elements constituting the peripheral modular frame is an important feature of the invention. For this reason, an advantageous embodiment consists in producing a peripheral modular frame formed of an assembly of elements made from an aluminum-based profile having at least one groove, this groove being able to receive a metal bracket. in the junction areas of two adjacent sides. This geometry of the frame makes it easy to assemble it from profiles, and also to remove certain profiles to possibly change certain elements of the device, for example by replacing the central core or a layer of acoustic wave absorbing material. SUMMARY DESCRIPTION OF THE FIGURES The invention will be better understood on reading the description which follows, given solely by way of example, and made with reference to the appended drawings, in which the same references designate identical or similar elements and in which FIG. 1 is a schematic perspective view of a peripheral modular frame edge disassembled; and FIG. 2 is a cross-sectional view of the peripheral modular frame of FIG. 1, and FIG. 3 is a schematic perspective view of a portion of the peripheral modular frame of FIGS. 1 and 2; and - Figure 4 is a schematic perspective view of the unexposed face of a textile coating; and FIG. 5 is a schematic perspective view of a portion of the same peripheral modular frame as that represented in FIGS. 1 to 3, equipped with a textile coating; and - Figure 6 is a schematic perspective view of an acoustic wave absorbing device according to a first embodiment; and FIG. 7 is a schematic view of a perforated central core according to a first embodiment; and - Figure 8 is a schematic view of a perforated central core according to a second embodiment; and FIG. 9 is a schematic perspective view of an acoustic wave absorbing device according to a second embodiment.

Some elements of these figures have been enlarged to facilitate understanding and may not be scaled.

DETAILED DESCRIPTION OF THE INVENTION There will now be described a device in the form of a wall capable of absorbing acoustic waves, and whose absorption properties are adjustable thanks to interchangeable layers of acoustic wave absorbing materials. , inserted in a peripheral support frame. As illustrated in FIGS. 6 and 9, the proposed device comprises a frame 1, a removable central core 7, 17, a textile covering 5, and, advantageously and according to the needs of the user, removable layers 9, 19 of materials having desirable absorbent properties. The description which follows will firstly show the configuration of the frame 1, then that of the different absorbent elements 7, 17, 9, 19 intended to cooperate with this frame 1, as well as the absorption properties associated with each of the envisaged embodiments. .

The frame 1, shown in Figures 1, 2 and 5, serves as a support for the elements 7, 17, 9, 19 able to absorb the acoustic waves. This frame 1 may for example be of substantially rectangular, circular, or triangular shape. The frame 1 may consist of 2 sections, for example in the case of a substantially circular frame 1 consisting of two sections each forming a semicircle, or four sections 11 forming the sides of the frame 1. These profiles 11 may be in aluminum 6060 and can have a substantially parallelepipedal geometry. They are held together by their smaller sides by means of brackets 2, as shown in FIG. 1. These brackets 2 are advantageously metallic, and fit into the profiles 11 in slides 4 advantageously provided in each section 11 to accommodate said brackets 2. The brackets 2 can be attached to the two sections 11 which they connect using, for example, screws, which can be introduced into a tapping made in the profiles 11. FIGS. and 2 represent a profile 11 having two rails 4 for accommodating two brackets 2. FIG. 2 shows a profile 11 in cross-section according to an embodiment in which the profile 11 comprises two slides 4. In order to allow an optimized assembly of sections 11 forming the sides of the frame 1, each section 11 has on its ends a cut substantially at an angle of 45 °. The cut allows two profiles 11 to meet at an angle of 90 ° once assembled. Alternatively, for example in an embodiment in which the frame 1 is circular, this cut can be straight. According to other embodiments not shown, it is possible to provide grooves instead of slides to accommodate the brackets 2 in each profile 11 forming a side of the frame 1. The brackets 2 are then secured to the profiles 11 to the using screws or any other means of attachment. On the other hand, the shape of the frame 1 can vary and decline for example with a polygonal geometry, or curved, without these variants do not involve particular difficulties of implementation. As shown in Figures 1 and 2, the frame 1 has a groove 3 for receiving a central core 7, 17. This groove 3 for receiving a central core 7 is preferably disposed in the central portion of each section 11; on the face turned towards the inside of the frame 1. The cross-sectional view of FIG. 2 illustrates an embodiment in which each profile 11 has hollow cavities 12 for inserting plastic brackets 22 serving as a guide for the assembly of the profiles 11. These plastic guide brackets 22 are also shown in Figure 1. These recesses are made without, however, harming the stability and rigidity of the frame 1. The grooves 3 and optionally the slides 4 which have the profiles 11 of this frame 1, allow the latter to accommodate various elements having acoustic wave absorption properties. Frame 1 thus constitutes, in the context of this invention, a peripheral modular frame 1. Each profile 11 may have for characteristic dimensions, and according to a preferred embodiment, a width of 70 mm and a thickness of 13.5 mm. The groove 3 intended to accommodate a central core 7, 17 may, in this embodiment, have a width of 2 mm. The depth of the groove 3 and the grooves or grooves 4 can in this embodiment be 5.5 mm. Once the four sections 11 constituting the modular peripheral frame 1 assembled, the dimensions of the frame 1 may, for example, be those of a table, hung on a wall, a billboard or a poster, attached to a wall in a large space as a reception room.

The device object of the present invention can be attached directly to a wall, a wall, a ceiling, or be located near any of these surfaces without being in contact therewith. The peripheral modular frame which has just been described receives a textile coating 5, represented for example in FIGS. 3, 4, 6 and 9. This textile coating 5 is advantageously substantially of the same dimensions and of the same shape as the peripheral modular frame 1 This textile 5 has particular acoustic wave absorption properties, which is a function inter alia of the porosity of the textile 5. It is thus possible to modify the spectrum of an acoustic wave transmitted by the textile by the choice of the porosity of the textile. textile 5 intended to cover the frame 1. The textile 5 also performs an aesthetic function, to give the impression that the device forming the invention is a table or a decorative element suitably integrated into the environment in which it is placed and advantageously nice to watch. The textile coating 5 may, for example, according to a particular embodiment, be a polyester-based finishing fabric TREVIRA M1, having a density of 230 g / m3 and a thickness of 0.5 mm. The textile coating 5 is microporous so as to pass the acoustic waves.

To ensure the attachment of the textile coating 5 to the peripheral modular frame 1, it is advantageous to provide a retaining ring 6 attached to the face of the unexposed textile coating 5 after installation on the frame 1. An embodiment of retaining ring 6 is shown in Figure 4. The retaining ring 6 may, in this configuration, be a semi-rigid plastic strip sewn to the textile coating 5. The retaining ring 6 is attached to the peripheral modular frame 1 through a groove 16 provided advantageously on the side faces of the sides of the frame 1, as shown in Figure 2. According to a particular embodiment of the invention, a groove of 4 mm in width is possible to form the groove 16. As shown on the 2, it is possible to provide a groove 16 on the two opposite side faces of the sides of the frame 1. In this way, the peripheral modular frame 1 pe It is advantageous to have a plane of symmetry and the installation of the textile coating 5 on one or the other of the grooves 16, or the installation of two textile coatings 5 on the two grooves 16 is possible.

The peripheral modular frame 1, provided with a textile coating 5, is intended to accommodate elements having desirable acoustic wave absorption properties. In its smallest configuration, the device according to the invention comprises in addition to the frame 1 and the textile coating 5 a central core 7, 17, intended to be inserted into the groove 3 advantageously disposed substantially in the middle of the inner faces of each frame side 1. This central core 7, 17 may be made of a metallic material or any other material with the desired acoustic wave absorption properties. The thickness of the central core 7, 17 is substantially the same as that of the groove 3 in which the central core 7, 17 is intended to be inserted.

Advantageously, the thickness of the central core 7, 17 is between 0.5 mm and 2 mm so as to ensure satisfactory absorption properties. In the event that the central core 7, 17 has a thickness less than that of the groove 3 in which it is intended to be inserted, this central core 7, 17 is then able to move slightly inside the peripheral modular frame 1. The absorption properties of the present invention are a function of the various embodiments provided within the scope of the present invention. It is easy to switch from one embodiment to another by replacing the elements that differ from one embodiment to another. This interchangeability of the elements conferring acoustic wave absorption properties on the device of the invention constitutes an ingenious advantage of the present invention. Acoustic waves in the "high", "medium" or "low" frequencies will be referred to, taking as reference the following frequency ranges, covering 6 octaves between 100 Hz and 5 kHz: the low frequencies, defining so-called "serious" sounds, between 100 Hz and 315 Hz; medium frequencies, defining so-called "midrange" sounds, between 400 Hz and 1250 Hz; the high frequencies, defining so-called "acute" sounds, between 1600 Hz and 5000 Hz.

The various embodiments of the invention can be divided into two groups. A first group contains the devices having a central core 7 full, and a second group contains the devices having a perforated central core 17. A device comprising a central core 7 only full offers good absorption at low frequencies, with peaks of absorption which are inter alia function of the material constituting the central core 7 and the thickness of the latter. This type of device can for example be suitable for music rooms, multipurpose rooms or any institution with a specific mode marked at low frequencies and may be a nuisance noise.

On the other hand, it is possible to modify the absorption properties of this minimalist device by making perforations 8 in the central core 17 so as to obtain the device shown in FIG. 6. The presence of these perforations or through orifices 8 , allows to obtain a dome-shaped absorption spectrum, centered at low frequencies and medium frequencies, but without significantly absorbing in the treble. Such a device can, for example, be adapted to conference rooms.

The nature of the perforations, that is to say the shape of the through holes 8 pierced in the central core 17, their distribution, their number, their size are factors that allow to adjust substantially the absorption spectrum of Such a central core 17. According to a preferred embodiment, it is advantageous to provide a configuration in which the through orifices 8 are all identical, of substantially round shape, all having the same diameter and distributed uniformly over the surface of the core. central 17, like the perforated central core 17 of Figures 6 and 7. In another embodiment, the through holes 8 are not all the same diameter, as in the case of the perforated central core 17 shown in Figure 8, while being homogeneously distributed over the entire surface of the central perforated core 17, so that there is no local concentration of through holes of the same diameter. In both embodiments, these through orifices 8 advantageously occupy an area of between 25% and 40% of the total area of the surface of the central core 17. It should be noted that the surface of the central core 17 taken Here account includes the portion which is intended to fit into the groove 3. The diameter of the through holes is advantageously between 3 mm and 8 mm. From these two particular embodiments, one having a solid central core 7 and the other a perforated central core 17, it will be described below eight possible embodiments. Among the group of devices comprising a perforated central core 17, it is possible to add layers of materials having desired acoustic absorption properties according to several embodiments, in particular three different embodiments described below. It is thus possible to leave an empty space, forming an air gap, between the textile coating 5 and the perforated central core 17, and to add a layer of material having absorption properties 19, held by the walls inside the rim of the frame 1, the layer 19 being disposed facing the face of the central core 17 opposite the textile coating 5. The layer 19 may alternatively be covered with an adhesive for fixing the layer 19 in contact with a wall on which is placed the frame 1. This configuration makes it possible to achieve absorption centered around a frequency range mainly between 250 Hz and 500 Hz. This type of device can particularly find application in multipurpose rooms or rooms of music for example.

Alternatively, it is conceivable to arrange between the textile coating 5 and the perforated central core 17 a layer 9 of material having desired acoustic wave absorption properties, and to maintain the space opposite the face of the central core 17 opposite to the textile coating 5. This variant makes it possible to achieve a broadband absorption spectrum, covering the low frequencies, the high frequencies and the medium frequencies in a substantially identical manner. This type of sensor thus makes it possible to attenuate the amplitude of all the sounds, without significantly modifying their spectrum. This type of device is therefore, for example, particularly interesting for applications in multipurpose rooms to not distort the perception of sounds. Finally, it is conceivable to have layers 9 of material possessing the desired acoustic wave absorption properties both between the textile coating 5 and the perforated central core 17, and facing the face of the central core 17 opposite to the textile coating 5. Several variants are possible in this case. In a first variant, the two layers 9, 19 are made of identical materials and have the same thickness. This type of configuration makes it possible to obtain broadband absorption, which is particularly marked in the high frequencies and the medium frequencies. It is also conceivable to have layers 9, 19 made of the same material but having different densities. This would allow in particular to adjust the absorption spectrum to adapt to the desired performance. In another variant embodiment, the two layers 9, 19 are made of different materials, in particular having different densities. This type of configuration makes it possible to obtain broadband absorption, in particular marked at low frequencies. These alternative embodiments are adjustable inter alia by two parameters: the thicknesses of the layers 9, 19 used, and the nature of the constituent material of the layers 9, 19. According to one embodiment, it is possible to use absorbent materials based on POLYPHONE® Ml polyester fibers, or even MO mineral wool. A thickness of 30 mm is advantageously preferred in most embodiments. The density of these layers 9, 19 is advantageously between 20 kg / m 3 and 70 kg / m 3.

The same variants as those described above are conceivable with a second category of embodiments, all involving the presence of a solid central core 7.

Thus, the first configuration that can be envisaged comprises a peripheral modular frame 1, a solid central core 7, a textile coating 5, and a layer 19 of material having desired acoustic wave absorption properties located opposite the face of the central core 7 opposite to the textile coating 5. This configuration makes it possible to achieve an absorption spectrum centered on the low frequencies and the medium frequencies. Another configuration involving the presence of a layer 9 of material having the desired acoustic wave absorption properties disposed between the textile coating 5 and the solid central core 7 makes it possible to obtain an absorption spectrum centered on the high frequencies and medium frequencies. Finally, a configuration involving the presence of two layers 9, 19 of materials having desired acoustic wave absorption properties, arranged between the textile coating 5 and the central core 7 on the one hand, and facing the face the central core 7 opposite the textile coating 5 on the other hand. This configuration itself may have several variants. In a first embodiment, the two layers 9, 19 are made of materials of the same density. The absorption spectrum is broadband and particularly marked at medium frequencies and high frequencies. Such a device has high acoustic wave absorption coefficients, and is suitable for example for very reverberant spaces. In another variant embodiment, the layers 9, 19 are made of materials of different densities. This makes it possible to adjust substantially the absorption spectrum of the device for the same applications.

One of the main advantages conferred by the architecture of the device that is the subject of the invention is that it allows easy installation of the various elements, and also makes it possible to modulate the absorption spectrum of the device according to the needs of the user. . Thus, it is easy to disassemble one or more sides of the modular modular frame 1 to remove a layer 9, 19 or a central core 7, 17 and replace these elements by other elements having absorption properties more suitable to those sought. The various embodiments described above disclose the various and most basic configurations of the invention. Among the additional variants that can be envisaged, it would be possible to adjust the thicknesses of the various elements, to change the nature of the materials constituting these elements, or the nature of the possible perforations of some of these elements.