EP0817164A1 - Noise absorbing structures and walls made therefrom - Google Patents

Noise absorbing structures and walls made therefrom Download PDF

Info

Publication number
EP0817164A1
EP0817164A1 EP97401411A EP97401411A EP0817164A1 EP 0817164 A1 EP0817164 A1 EP 0817164A1 EP 97401411 A EP97401411 A EP 97401411A EP 97401411 A EP97401411 A EP 97401411A EP 0817164 A1 EP0817164 A1 EP 0817164A1
Authority
EP
European Patent Office
Prior art keywords
membrane
structure according
dissipation
frame
plates
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP97401411A
Other languages
German (de)
French (fr)
Other versions
EP0817164B1 (en
EP0817164B2 (en
Inventor
Jean-Claude Guilloud
Dominique Collin
Jacques Julliard
Christine Fumoux
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Safran Aircraft Engines SAS
Bertin Technologies SAS
Original Assignee
Bertin et Cie SA
Societe Nationale dEtude et de Construction de Moteurs dAviation SNECMA
SNECMA SAS
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Family has litigation
First worldwide family litigation filed litigation Critical https://patents.darts-ip.com/?family=9493519&utm_source=google_patent&utm_medium=platform_link&utm_campaign=public_patent_search&patent=EP0817164(A1) "Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License.
Application filed by Bertin et Cie SA, Societe Nationale dEtude et de Construction de Moteurs dAviation SNECMA, SNECMA SAS filed Critical Bertin et Cie SA
Publication of EP0817164A1 publication Critical patent/EP0817164A1/en
Publication of EP0817164B1 publication Critical patent/EP0817164B1/en
Application granted granted Critical
Publication of EP0817164B2 publication Critical patent/EP0817164B2/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/16—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/172—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using resonance effects

Definitions

  • the invention generally relates to structures of noise absorption and walls formed by means of these structures and more particularly such light and compact structures, applicable especially in the aeronautical industry for equipment reactors, their nacelles and aircraft cabins, in the transportation industry, in the building, etc ...
  • the object of the present invention is to provide important improvements to these structures.
  • Its purpose is light structures of aforementioned type and whose acoustic impedances are modifiable, adjustable or controllable and likely to monitor changes in the noise sources to be absorbed.
  • a structure noise absorption including a support frame on which is stretched and fixed a waterproof membrane whose outside the frame receives acoustic waves, a gas such as air filling a volume delimited by the frame and the membrane, and means for energy dissipation housed in this volume, characterized in that the means of dissipation are of the type gas rolling, electrostatic type or type electromagnetic and are changeable, adjustable or controllable for modification or adaptation of the impedance acoustics of said structure with the characteristics of noise to absorb.
  • the structures according to the invention thanks to the their acoustic impedances can be changed or adjustable, can be designed or adjusted to absorb incident noise or to deflect it by reflection, by example according to the positions they occupy in a noise absorbing or protective wall the noise.
  • the energy dissipation means are of the rolling type gas and include plates arranged inside from the frame, a short distance from the membrane, and means modification of this distance.
  • the means at gas rolling dissipation include at least one gas flow passage connecting a closed chamber delimited inside the frame by the membrane at a another room located inside said structure.
  • this passage can be a conduit formed between two superimposed plates associated with means for modifying or adjusting the distance between them for modification or adjustment of the section of passage of the conduit.
  • the means dissipation to gas rolling include rods carried by the membrane and extending perpendicularly to it inside the frame in fixed tubes which are closed at their opposite end to the membrane and which delimit with the rods of the annular conduits of gas rolling.
  • the means of energy dissipation include electrode plates arranged parallel to the membrane at a distance therefrom, and to the minus another electrode formed on the membrane and connected with said plates to polarization means such as a direct current source associated with a electrical or electronic circuit comprising elements of energy dissipation by Joule effect.
  • the membrane may have one or more several metallized areas opposite the plates aforementioned electrodes, or it is made in one electrically charged plastic, in which case polarization means are not required.
  • the elements of energy dissipation by Joule effect include for example resistance electric, advantageously adjustable, the structure according to the invention then comprising means controlled from adjustment of the value of this resistance for adaptation acoustic impedance.
  • the means of energy dissipation are of the electromagnetic type and include electrical conductors moved by the membrane in relation to magnetic elements carried by the framework or constituted by it, the conductors aforementioned electrics comprising for example windings connected to the membrane or one or more circuits printed or deposited on the membrane.
  • a membrane can be used magnetic displaceable relative to a circuit electric.
  • each aforementioned structure is closed from tightly sealed and contains an expandable volume element and contractile such as a balloon or a bellows by example, filled with air and communicating with the outside by a static pressure equalization orifice, this element occupying a significant fraction of the volume of said structure.
  • an expandable volume element and contractile such as a balloon or a bellows by example
  • This feature compensates for influences of variations in pressure and external temperatures on the membrane of the structure noise absorption.
  • Each structure of the aforementioned type is intended to be juxtaposed and assembled to a plurality of structures of the same type to form a flat wall or curved, convex or concave in which the structures have similar or different acoustic impedances to absorb noise or deflect it by reflection according to cases.
  • the means of energy dissipation of at least some of the structures are associated with means for controlling, adjusting or themselves piloted by a system of data processing.
  • the noise absorption structure according to the invention includes essentially a thin, gas-tight membrane 10 which is stretched and fixed on the upper side of a frame support 12 whose upper part is formed with partitions perpendicular to the membrane and whose lower part 16 has a bottom wall 18 parallel to the membrane.
  • the membrane 10 can be produced in particular by plastic, elastomer, metal or any material to make a membrane sufficiently fine and flexible to be deformable by waves acoustic to absorb.
  • This membrane being fragile, acoustically transparent means (not shown) are designed to cover it and protect it from attack external mechanical, these means being for example constituted by a metallic fabric associated with a layer glass wool or the like.
  • the support frame 12 is made in all suitable rigid material, in particular of metal or plastic, depending on the application for which the structure according to the invention is intended.
  • the membrane 10 can be fixed on the frame 12 by its edges 20 folded over the periphery of the part upper part of the frame 12.
  • An entourage 22 can be attached to the periphery of the frame 12 as shown schematically in Figure 1 to ensure the connection of structures together, for example by means 24 attachment or assembly such as studs and dovetail grooves.
  • the structure according to the invention forms a waterproof enclosure
  • an element 26 liable to contract and expand according to pressure variations static and / or temperature outside the noise absorption structure according to the invention, this element 26 which may consist of a flexible balloon or a bellows connected to the outside by a passage or orifice 28 of static pressure equalization, crossing through example the bottom wall 18 of the frame 12.
  • This element 26 occupies a relatively significant volume delimited by frame 12 and the membrane 10, for example about a third of this volume.
  • the pressure or the gas temperature rises or falls so corresponding to the interior of element 26 and compensates at least partially the pressure variations at inside the structure, which makes it possible to membrane 10 almost insensitive to variations in external static pressure and temperature.
  • the elements 26 allow each structure to be adapted to The evolution of the static pressure in the duct.
  • the membrane 10 can be fixed by gluing on the upper peripheral part of the frame 12, as already indicated, as well as on the upper edges of the partitions internal 14 of frame 12.
  • the internal partitions 14 of the frame 12 can be replaced by studs 30 perpendicular to the membrane and on the ends which the membrane can be fixed by gluing.
  • the studs 30 can be carried by a perforated plate 32, by a grid, or by any other appropriate means.
  • the noise absorption structure according to the invention also includes means of dissipation of energy of which various embodiments are shown by way of example in FIGS. 4 to 13.
  • the means of dissipation are of the gas rolling type, (for example air).
  • the internal partitions 14 of the frame 12 delimit with the membrane 10 of the chambers 34 closed by a wall bottom 36 and which communicate with the lower volume of the frame 12 by a conduit 38 of relatively cross section small and relatively long compared to to its section, allowing energy dissipation by laminar gas flow.
  • conduit 38 is replaced by a channel 40 formed in hollow in the upper face of the bottom wall 36 to which is associated with a cover plate 42 which constitutes the upper wall of the channel 40.
  • An orifice 44 of the plate 42 connects the chamber 34 to the channel 40, while an orifice 46 of the bottom wall 36 connects the channel 40 at the lower volume of the frame 12.
  • the channel 40 can be formed in a spiral in the bottom wall 36 of the chamber 34.
  • the membrane 10 deforms and behaves like a very damped oscillator whose center frequency is a function of the voltage of the membrane, its density and thickness, among others.
  • the deformation of the membrane causes a laminar gas flow in the means of dissipation of energy constituted by the conduit 38 or the channel 40.
  • the acoustic impedance of a structure according to the invention is perfectly suited to the characteristics incident noise when it is completely absorbed, without reflection by the membrane.
  • the invention provides means for modify, adjust or control this impedance acoustic.
  • the means of energy dissipation include a channel 40 of the type shown in Figures 5 and 6, the modification or adjustment of the acoustic impedance can be obtained by variation of the cross section of channel 40.
  • the means of energy dissipation include a channel 40 of the type shown in Figures 5 and 6, the modification or adjustment of the acoustic impedance can be obtained by variation of the cross section of channel 40.
  • the means 50 being for example of the memory type of shape or piezoelectric type, controlled by a appropriate electrical circuit.
  • the membrane 10 carries rods 52 which extend to inside the support frame, perpendicular to the membrane, and which are engaged in tubes 54 carried by an intermediate wall 36 of the support frame, so that the displacement of the rods 52 in the tubes 54 caused by deformations of the membrane 10 results in a laminar gas flow in the tubes 54 and by a corresponding energy dissipation.
  • the energy dissipation means are also of the gas rolling type and comprise horizontal plates 56 arranged parallel to the membrane 10 and at a short distance from the latter inside the support frame, these plates 56 being carried by means 58 making it possible to modify the distance d between the membrane 10 and the plates 56.
  • these means 58 are carried by the intermediate wall 36 and include controlled shape memory elements by an appropriate electrical circuit 60.
  • the means of energy dissipation include electrode plates 62 arranged inside the frame of support, parallel to membrane 10 and low distance from it, and for example carried by the wall intermediate 36 of the support frame through dielectric elements 64.
  • the membrane 10 includes electrodes associated with the plates 62, such for example that metallized areas 66 of its surface, these areas 66 and the plates 62 being connected to the poles of a source 68 direct current through an element of energy dissipation such as electrical resistance 70 which is advantageously a variable resistance controlled by an appropriate means 72, the resistor 70 absorbing energy by Joule effect and the variation of its value to modify the acoustic impedance of the structure according to the invention.
  • holes 74 are drilled in the electrode plates 62 to avoid any effect of gas rolling between them and the membrane 10.
  • the electrostatic attraction exerted by plates 62 on the membrane plays the role of an anti-stiffness dynamic which opposes the stiffness of the gas contained in the structure. This reduces the total thickness (or height) of the structure and therefore its size.
  • the membrane 10 and / or the plates electrodes 62 could consist of an electret, such as a plastic like polyurethane or PVDF electrically charged in permanence, the polarization means of the electrodes then being deleted.
  • the means of energy dissipation are of the type electromagnetic.
  • the membrane 10 is connected, to inside the frame, to electrical windings 76 movable relative to magnetic elements 78 constituting for example the intermediate wall 34 of the support frame.
  • the parts 78 projecting towards the membrane may be drilled through holes 80.
  • magnetic elements 82 for example magnets permanent
  • electrical conductors 84 are carried by this last, by being constituted for example by one or more electrical circuits printed or deposited on the membrane. The displacement of these electrical conductors 84 in the magnetic field lines of the elements 80 results in energy dissipation.
  • the support frame 12 which can be made of magnetic material and constitute a magnet permanent whose field lines can be cut by the electrical conductors 84 of the membrane 10 for an energy dissipation effect.
  • a magnetic membrane that moves relative to a electrical circuit to dissipate energy.
  • the elementary noise absorption structures which have just been described can be assembled together to form flat, curved, concave or convex walls, of large dimension.
  • the elementary structures of FIGS. 4, 5, 8 and 9 may have dimensions, on the surface, of the order of 5 ⁇ 5 cm 2 and be combined to form a structure of the type of that represented in FIG. 1 having a surface of the order of 20 x 20 cm 2 , the heights of these structures generally being between 15 and 50 mm.
  • the acoustic impedances of elementary structures can be adjusted individually or in small groups of structures.
  • Adjusting the acoustic impedances makes it possible to have a well-adapted impedance for certain surface areas of a wall with maximum absorption of the incident noise, while other surface areas of the wall will have different impedances to partially absorb the noise. incident and partially reflect it in a determined direction.
  • the possibility of adjusting the acoustic impedance of each elementary structure provides a spatial evolution of acoustic characteristics of a wall.
  • the structures according to the invention such as those of Figure 2, adapt automatically at variations in static pressure external and for example to the evolution of the pressure static in a duct.

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Acoustics & Sound (AREA)
  • Multimedia (AREA)
  • Soundproofing, Sound Blocking, And Sound Damping (AREA)
  • Electrostatic, Electromagnetic, Magneto- Strictive, And Variable-Resistance Transducers (AREA)

Abstract

The structure has a membrane (10) which is sealed onto a fixed supporting shell (12) so the sound is directed onto the external surface of the membrane. Plates are positioned within the shell a short, modifiable distance from the membrane. Alternatively, there may be a closed chamber with a passage or a channel between two adjustable plates linking it to an inner chamber. The membrane may carry rods which enter fixed tubes closed at the lower end where they are attached to the shell. The internal volume between the membrane and the base (18) may be adjusted by an inflatable air-filled balloon or bellows (26) connected to the exterior by a hole (28). Electrical conductors or circuit boards are printed or positioned on the membrane.

Description

L'invention concerne en général des structures d'absorption de bruit et des parois formées au moyen de ces structures et plus particulièrement de telles structures légères et de faible encombrement, applicables notamment dans l'industrie aéronautique pour l'équipement de réacteurs, de leurs nacelles et de cabines d'avions, dans l'industrie des transports, dans l'industrie du bâtiment, etc....The invention generally relates to structures of noise absorption and walls formed by means of these structures and more particularly such light and compact structures, applicable especially in the aeronautical industry for equipment reactors, their nacelles and aircraft cabins, in the transportation industry, in the building, etc ...

On a déjà proposé, dans la Demande de Brevet français n° 94 00539 (publiée sous le n° 2 715 244) des structures légères d'absorption de bruit qui comprennent chacune un cadre de support sur lequel est fixée et tendue une membrane étanche, et des plaques disposées sous la membrane pour former avec elles un amortisseur passif à laminage d'air. L'incidence d'ondes acoustiques sur la membrane, du côté opposé auxdites plaques, provoque une déformation vibratoire de la membrane qui se traduit par un écoulement laminaire d'air entre la membrane et les plaques et donc par une absorption d'énergie. Lorsque l'impédance acoustique d'une telle structure est correctement adaptée aux ondes acoustiques incidentes, une grande partie de l'énergie de ces ondes acoustiques est absorbée par la structure dans une bande de fréquences relativement large.We have already proposed, in the Patent Application French No. 94 00 539 (published under No. 2,715,244) of lightweight noise absorption structures that include each a support frame on which is fixed and stretched a waterproof membrane, and plates arranged under the membrane to form a shock absorber with them passive air rolling. The incidence of acoustic waves on the membrane, on the side opposite to said plates, causes a vibratory deformation of the membrane which results in a laminar flow of air between the membrane and plates and therefore by absorption of energy. When the acoustic impedance of such structure is correctly adapted to acoustic waves incident, a large part of the energy of these waves acoustic is absorbed by the structure in a band relatively wide frequencies.

La présente invention a pour but d'apporter des perfectionnements importants à ces structures.The object of the present invention is to provide important improvements to these structures.

Elle a pour objet des structures légères du type précité et dont les impédances acoustiques sont modifiables, réglables ou pilotables et susceptibles de suivre les évolutions des sources de bruit à absorber.Its purpose is light structures of aforementioned type and whose acoustic impedances are modifiable, adjustable or controllable and likely to monitor changes in the noise sources to be absorbed.

Elle a également pour objet des structures légères du type précité, comprenant des moyens de modification, de réglage ou de pilotage de leurs impédances acoustiques, qui sont eux-mêmes pilotables par un système de traitement de l'information.It also relates to structures light of the aforementioned type, comprising means for modification, adjustment or control of their acoustic impedances, which are themselves controllable by an information processing system.

Elle a encore pour objet des parois légères et de faible épaisseur, réalisées par juxtaposition et assemblage de ces structures.It also relates to light walls and thin, made by juxtaposition and assembly of these structures.

Elle propose, à cet effet, une structure d'absorption de bruit comprenant un cadre de support sur lequel est tendue et fixée une membrane étanche dont la face extérieure au cadre reçoit des ondes acoustiques, un gaz tel par exemple que de l'air remplissant un volume délimité par le cadre et la membrane, et des moyens de dissipation d'énergie logés dans ce volume, caractérisée en ce que les moyens de dissipation sont du type à laminage de gaz, du type électrostatique ou du type électromagnétique et sont modifiables, réglables ou pilotables pour modification ou adaptation de l'impédance acoustique de ladite structure aux caractéristiques du bruit à absorber.To this end, it offers a structure noise absorption including a support frame on which is stretched and fixed a waterproof membrane whose outside the frame receives acoustic waves, a gas such as air filling a volume delimited by the frame and the membrane, and means for energy dissipation housed in this volume, characterized in that the means of dissipation are of the type gas rolling, electrostatic type or type electromagnetic and are changeable, adjustable or controllable for modification or adaptation of the impedance acoustics of said structure with the characteristics of noise to absorb.

Les structures selon l'invention, grâce au fait que leurs impédances acoustiques sont modifiables ou réglables, peuvent être conçues ou réglées pour absorber le bruit incident ou pour le dévier par réflexion, par exemple en fonction des positions qu'elles occupent dans une paroi d'absorption de bruit ou de protection contre le bruit.The structures according to the invention, thanks to the their acoustic impedances can be changed or adjustable, can be designed or adjusted to absorb incident noise or to deflect it by reflection, by example according to the positions they occupy in a noise absorbing or protective wall the noise.

Dans un premier mode de réalisation, les moyens de dissipation d'énergie sont du type à laminage de gaz et comprennent des plaques disposées à l'intérieur du cadre, à faible distance de la membrane, et des moyens de modification de cette distance.In a first embodiment, the energy dissipation means are of the rolling type gas and include plates arranged inside from the frame, a short distance from the membrane, and means modification of this distance.

Dans un autre mode de réalisation, les moyens de dissipation à laminage de gaz comprennent au moins un passage d'écoulement de gaz reliant une chambre fermée délimitée à l'intérieur du cadre par la membrane à une autre chambre située à l'intérieur de ladite structure. In another embodiment, the means at gas rolling dissipation include at least one gas flow passage connecting a closed chamber delimited inside the frame by the membrane at a another room located inside said structure.

Par exemple, ce passage peut être un conduit formé entre deux plaques superposées associées à des moyens de modification ou de réglage de la distance entre elles pour modification ou réglage de la section de passage du conduit.For example, this passage can be a conduit formed between two superimposed plates associated with means for modifying or adjusting the distance between them for modification or adjustment of the section of passage of the conduit.

Selon un autre mode de réalisation, les moyens de dissipation à laminage de gaz comprennent des tiges portées par la membrane et s'étendant perpendiculairement à celle-ci à l'intérieur du cadre dans des tubes fixes qui sont fermés à leur extrémité opposée à la membrane et qui délimitent avec les tiges des conduits annulaires de laminage de gaz.According to another embodiment, the means dissipation to gas rolling include rods carried by the membrane and extending perpendicularly to it inside the frame in fixed tubes which are closed at their opposite end to the membrane and which delimit with the rods of the annular conduits of gas rolling.

Selon encore un autre mode de réalisation de l'invention, les moyens de dissipation d'énergie comprennent des plaques électrodes disposées parallèlement à la membrane à distance de celle-ci, et au moins une autre électrode formée sur la membrane et reliée avec lesdites plaques à des moyens de polarisation tels qu'une source de courant continu associée à un circuit électrique ou électronique comprenant des éléments de dissipation d'énergie par effet Joule.According to yet another embodiment of the invention, the means of energy dissipation include electrode plates arranged parallel to the membrane at a distance therefrom, and to the minus another electrode formed on the membrane and connected with said plates to polarization means such as a direct current source associated with a electrical or electronic circuit comprising elements of energy dissipation by Joule effect.

Par exemple, la membrane peut comporter une ou plusieurs zones métallisées en regard des plaques électrodes précitées, ou bien elle est réalisée en une matière plastique chargée électriquement, auquel cas les moyens de polarisation ne sont pas nécessaires.For example, the membrane may have one or more several metallized areas opposite the plates aforementioned electrodes, or it is made in one electrically charged plastic, in which case polarization means are not required.

Les éléments de dissipation d'énergie par effet Joule comprennent par exemple une résistance électrique, avantageusement réglable, la structure selon l'invention comprenant alors des moyens commandés de réglage de la valeur de cette résistance pour adaptation de l'impédance acoustique.The elements of energy dissipation by Joule effect include for example resistance electric, advantageously adjustable, the structure according to the invention then comprising means controlled from adjustment of the value of this resistance for adaptation acoustic impedance.

Selon un autre mode de réalisation, les moyens de dissipation d'énergie sont du type électromagnétique et comprennent des conducteurs électriques déplacés par la membrane par rapport à des éléments magnétiques portés par le cadre ou constitués par celui-ci, les conducteurs électriques précités comprenant par exemple des bobinages reliés à la membrane ou un ou plusieurs circuits électriques imprimés ou déposés sur la membrane.According to another embodiment, the means of energy dissipation are of the electromagnetic type and include electrical conductors moved by the membrane in relation to magnetic elements carried by the framework or constituted by it, the conductors aforementioned electrics comprising for example windings connected to the membrane or one or more circuits printed or deposited on the membrane.

En variante, on peut utiliser une membrane magnétique déplaçable par rapport à un circuit électrique.Alternatively, a membrane can be used magnetic displaceable relative to a circuit electric.

Selon encore une autre caractéristique de l'invention, chaque structure précitée est fermée de façon étanche et contient un élément volumique expansible et contractile tel qu'un ballon ou un soufflet par exemple, rempli d'air et communiquant avec l'extérieur par un orifice d'égalisation de pression statique, cet élément occupant une fraction notable du volume de ladite structure.According to yet another characteristic of the invention, each aforementioned structure is closed from tightly sealed and contains an expandable volume element and contractile such as a balloon or a bellows by example, filled with air and communicating with the outside by a static pressure equalization orifice, this element occupying a significant fraction of the volume of said structure.

Cette caractéristique permet de compenser les influences des variations de la pression et de la température extérieures sur la membrane de la structure d'absorption de bruit.This feature compensates for influences of variations in pressure and external temperatures on the membrane of the structure noise absorption.

Chaque structure du type précité est destinée à être juxtaposée et assemblée à une pluralité de structures du même type pour former une paroi plane ou incurvée, convexe ou concave dans laquelle les structures ont des impédances acoustiques semblables ou différentes pour absorber le bruit ou le dévier par réflexion selon les cas.Each structure of the aforementioned type is intended to be juxtaposed and assembled to a plurality of structures of the same type to form a flat wall or curved, convex or concave in which the structures have similar or different acoustic impedances to absorb noise or deflect it by reflection according to cases.

Dans une telle paroi, les moyens de dissipation d'énergie d'au moins certaines des structures sont associés à des moyens de commande, de réglage ou de pilotage eux-mêmes pilotables par un système de traitement de l'information.In such a wall, the means of energy dissipation of at least some of the structures are associated with means for controlling, adjusting or themselves piloted by a system of data processing.

On peut ainsi, notamment, adapter les impédances acoustiques de certaines parties ou de toutes les parties d'une paroi pour tenir compte d'une modification ou d'une évolution dans le temps des caractéristiques du bruit à absorber. In particular, we can adapt the acoustic impedances of some or all parts parts of a wall to account for a modification or evolution over time of characteristics of the noise to be absorbed.

L'invention sera mieux comprise et d'autres caractéristiques, détails et avantages de celle-ci apparaítront plus clairement à la lecture de la description qui suit, faite à titre d'exemple en référence aux dessins annexés dans lesquels :

  • la figure 1 est une vue schématique en perspective avec arrachement partiel d'une structure d'absorption de bruit selon l'invention ;
  • la figure 2 est une vue schématique en coupe selon la ligne II-II de la figure 1 ;
  • la figure 3 est une vue schématique partielle en perspective d'une variante de réalisation ;
  • les figures 4 à 13 représentent schématiquement divers modes de réalisation des moyens de dissipation d'énergie.
The invention will be better understood and other characteristics, details and advantages thereof will appear more clearly on reading the description which follows, given by way of example with reference to the appended drawings in which:
  • Figure 1 is a schematic perspective view with partial cutaway of a noise absorption structure according to the invention;
  • Figure 2 is a schematic sectional view along line II-II of Figure 1;
  • Figure 3 is a partial schematic perspective view of an alternative embodiment;
  • Figures 4 to 13 schematically represent various embodiments of the energy dissipation means.

La structure d'absorption de bruit selon l'invention, dont un premier mode de réalisation est représenté à titre d'exemple aux figures 1 et 2, comprend essentiellement une membrane 10 fine et étanche au gaz qui est tendue et fixée sur la face supérieure d'un cadre de support 12 dont la partie supérieure est formée avec des cloisons perpendiculaires à la membrane et dont la partie inférieure 16 comporte une paroi de fond 18 parallèle à la membrane.The noise absorption structure according to the invention, a first embodiment of which is shown as an example in Figures 1 and 2, includes essentially a thin, gas-tight membrane 10 which is stretched and fixed on the upper side of a frame support 12 whose upper part is formed with partitions perpendicular to the membrane and whose lower part 16 has a bottom wall 18 parallel to the membrane.

La membrane 10 peut être réalisée notamment en matière plastique, en élastomère, en métal ou en toute matière permettant de réaliser une membrane suffisamment fine et souple pour être déformable par des ondes acoustiques à absorber. Cette membrane étant fragile, des moyens acoustiquement transparents (non représentés) sont prévus pour la recouvrir et la protéger des agressions mécaniques extérieures, ces moyens étant par exemple constitués par une toile métallique associée à une couche de laine de verre ou analogue.The membrane 10 can be produced in particular by plastic, elastomer, metal or any material to make a membrane sufficiently fine and flexible to be deformable by waves acoustic to absorb. This membrane being fragile, acoustically transparent means (not shown) are designed to cover it and protect it from attack external mechanical, these means being for example constituted by a metallic fabric associated with a layer glass wool or the like.

Le cadre de support 12 est réalisé en toute matière rigide appropriée, notamment en métal ou en matière plastique, en fonction des applications auxquelles la structure selon l'invention est destinée.The support frame 12 is made in all suitable rigid material, in particular of metal or plastic, depending on the application for which the structure according to the invention is intended.

La membrane 10 peut être fixée sur le cadre 12 par ses bords 20 rabattus sur la périphérie de la partie supérieure du cadre 12. Un entourage 22 peut être rapporté sur la périphérie du cadre 12 comme représenté schématiquement en figure 1 pour assurer la liaison des structures entre elles, par exemple grâce à des moyens 24 d'accrochage ou d'assemblage tels que des tenons et des rainures en queue d'aronde.The membrane 10 can be fixed on the frame 12 by its edges 20 folded over the periphery of the part upper part of the frame 12. An entourage 22 can be attached to the periphery of the frame 12 as shown schematically in Figure 1 to ensure the connection of structures together, for example by means 24 attachment or assembly such as studs and dovetail grooves.

Quand la structure selon l'invention forme une enceinte étanche, on peut prévoir en partie inférieure du cadre 12, comme représenté schématiquement en figure 2, un élément 26 susceptible de se contracter et de s'expanser en fonction des variations de la pression statique et/ou de la température extérieures à la structure d'absorption du bruit selon l'invention, cet élément 26 pouvant être constitué par un ballon souple ou un soufflet relié à l'extérieur par un passage ou orifice 28 d'égalisation de pression statique, traversant par exemple la paroi de fond 18 du cadre 12.When the structure according to the invention forms a waterproof enclosure, one can provide in the lower part of the frame 12, as shown diagrammatically in FIG. 2, an element 26 liable to contract and expand according to pressure variations static and / or temperature outside the noise absorption structure according to the invention, this element 26 which may consist of a flexible balloon or a bellows connected to the outside by a passage or orifice 28 of static pressure equalization, crossing through example the bottom wall 18 of the frame 12.

Cet élément 26 occupe une partie relativement importante du volume délimité par le cadre 12 et la membrane 10, par exemple d'environ un tiers de ce volume. Quand la pression ou la température augmente ou diminue à l'extérieur de la structure, la pression ou la température du gaz augmente ou diminue de façon correspondante à l'intérieur de l'élément 26 et compense au moins partiellement les variations de pression à l'intérieur de la structure, ce qui permet de rendre la membrane 10 à peu près insensible aux variations de pression statique et de température extérieures.This element 26 occupies a relatively significant volume delimited by frame 12 and the membrane 10, for example about a third of this volume. When the pressure or temperature increases or decreases at outside the structure, the pressure or the gas temperature rises or falls so corresponding to the interior of element 26 and compensates at least partially the pressure variations at inside the structure, which makes it possible to membrane 10 almost insensitive to variations in external static pressure and temperature.

De plus, lorsque la surface interne d'un conduit de passage de fluide comprend des structures selon l'invention ou est formée de telles structures, les éléments 26 permettent d'adapter chaque structure à 1'évolution de la pression statique dans le conduit.In addition, when the internal surface of a fluid passage conduit includes structures according to the invention or is formed of such structures, the elements 26 allow each structure to be adapted to The evolution of the static pressure in the duct.

La membrane 10 peut être fixée par collage sur la partie périphérique supérieure du cadre 12, comme déjà indiqué, ainsi que sur les bords supérieurs des cloisons internes 14 du cadre 12.The membrane 10 can be fixed by gluing on the upper peripheral part of the frame 12, as already indicated, as well as on the upper edges of the partitions internal 14 of frame 12.

En variante, et comme représenté schématiquement en figure 3, les cloisons internes 14 du cadre 12 peuvent être remplacées par des plots 30 perpendiculaires à la membrane et sur les extrémités desquels la membrane peut être fixée par collage.Alternatively, and as shown schematically in Figure 3, the internal partitions 14 of the frame 12 can be replaced by studs 30 perpendicular to the membrane and on the ends which the membrane can be fixed by gluing.

Les plots 30 peuvent être portés par une plaque ajourée 32, par une grille, ou par tout autre moyen approprié.The studs 30 can be carried by a perforated plate 32, by a grid, or by any other appropriate means.

La structure d'absorption de bruit selon l'invention comprend également des moyens de dissipation d'énergie dont divers modes de réalisation sont représentés à titre d'exemple aux figures 4 à 13.The noise absorption structure according to the invention also includes means of dissipation of energy of which various embodiments are shown by way of example in FIGS. 4 to 13.

En figure 4, les moyens de dissipation d'énergie sont du type à laminage de gaz, (par exemple d'air). Les cloisons internes 14 du cadre 12 délimitent avec la membrane 10 des chambres 34 fermées par une paroi de fond 36 et qui communiquent avec le volume inférieur du cadre 12 par un conduit 38 de section relativement faible et de longueur relativement importante par rapport à sa section, permettant une dissipation d'énergie par écoulement laminaire de gaz.In figure 4, the means of dissipation are of the gas rolling type, (for example air). The internal partitions 14 of the frame 12 delimit with the membrane 10 of the chambers 34 closed by a wall bottom 36 and which communicate with the lower volume of the frame 12 by a conduit 38 of relatively cross section small and relatively long compared to to its section, allowing energy dissipation by laminar gas flow.

Dans la variante de réalisation de la figure 5, le conduit 38 est remplacé par un canal 40 formé en creux dans la face supérieure de la paroi de fond 36 à laquelle est associée une plaque de recouvrement 42 qui constitue la paroi supérieure du canal 40. Un orifice 44 de la plaque 42 relie la chambre 34 au canal 40, tandis qu'un orifice 46 de la paroi de fond 36 relie le canal 40 au volume inférieur du cadre 12. In the alternative embodiment of the figure 5, the conduit 38 is replaced by a channel 40 formed in hollow in the upper face of the bottom wall 36 to which is associated with a cover plate 42 which constitutes the upper wall of the channel 40. An orifice 44 of the plate 42 connects the chamber 34 to the channel 40, while an orifice 46 of the bottom wall 36 connects the channel 40 at the lower volume of the frame 12.

Comme on le voit mieux en figure 6, qui est une vue de dessus des moyens de dissipation d'énergie de la figure 5, le canal 40 peut être formé en spirale dans la paroi de fond 36 de la chambre 34.As best seen in Figure 6, which is a top view of the energy dissipation means of FIG. 5, the channel 40 can be formed in a spiral in the bottom wall 36 of the chamber 34.

Sous l'effet de la pression des ondes acoustiques incidentes, la membrane 10 se déforme et se comporte comme un oscillateur très amorti dont la fréquence centrale est une fonction de la tension de la membrane, de sa masse volumique et de son épaisseur, entre autres. La déformation de la membrane provoque un écoulement laminaire de gaz dans les moyens de dissipation d'énergie constitués par le conduit 38 ou le canal 40.Under the effect of wave pressure incident acoustics, the membrane 10 deforms and behaves like a very damped oscillator whose center frequency is a function of the voltage of the membrane, its density and thickness, among others. The deformation of the membrane causes a laminar gas flow in the means of dissipation of energy constituted by the conduit 38 or the channel 40.

L'impédance acoustique d'une structure selon l'invention est parfaitement adaptée aux caractéristiques du bruit incident lorsque celui-ci est totalement absorbé, sans réflexion par la membrane.The acoustic impedance of a structure according to the invention is perfectly suited to the characteristics incident noise when it is completely absorbed, without reflection by the membrane.

L'invention prévoit des moyens permettant de modifier, de régler ou de piloter cette impédance acoustique.The invention provides means for modify, adjust or control this impedance acoustic.

Par exemple, dans le cas où les moyens de dissipation d'énergie comprennent un canal 40 du type représenté aux figures 5 et 6, la modification ou le réglage de l'impédance acoustique peut être obtenu par variation de la section transversale du canal 40. Pour cela, comme représenté schématiquement en figure 7, on peut former, sur la face de la plaque 42 qui est tournée du côté de la paroi de fond 36, des nervures en saillie 48 engagées avec un jeu faible dans le canal 40 de la plaque 36, et on prévoit des moyens 50 de modification de la distance entre la plaque 42 et la paroi de fond 36, ces moyens 50 étant par exemple du type à mémoire de forme ou du type piezoélectrique, commandés par un circuit électrique approprié.For example, if the means of energy dissipation include a channel 40 of the type shown in Figures 5 and 6, the modification or adjustment of the acoustic impedance can be obtained by variation of the cross section of channel 40. For this, as shown schematically in Figure 7, we can form, on the face of the plate 42 which is turned on the side of the bottom wall 36, projecting ribs 48 engaged with a weak clearance in channel 40 of the plate 36, and means 50 are provided for modifying the distance between the plate 42 and the bottom wall 36, these means 50 being for example of the memory type of shape or piezoelectric type, controlled by a appropriate electrical circuit.

La modification de la distance entre la plaque 42 et la paroi 36 modifie la section transversale du canal 40 et donc les conditions d'écoulement laminaire du gaz dans ce canal, ce qui modifie en conséquence l'impédance acoustique de la structure selon l'invention.Changing the distance between the plate 42 and the wall 36 modifies the cross section of the channel 40 and therefore the laminar flow conditions of the gas in this channel, which changes accordingly the acoustic impedance of the structure according to the invention.

Lorsque les moyens de dissipation d'énergie sont du type représenté en figure 4, on peut modifier l'impédance acoustique de la structure en agissant sur le volume de la partie inférieure du cadre 12 (volume sous la paroi 36) par exemple en utilisant un élément gonflable analogue à l'élément 26 de la figure 2, que l'on relie à des moyens de réglage de pression.When the means of energy dissipation are of the type represented in figure 4, one can modify the acoustic impedance of the structure by acting on the volume of the lower part of the frame 12 (volume under wall 36) for example using an element inflatable similar to element 26 of Figure 2, that it is connected to pressure adjustment means.

Dans la variante de réalisation de la figure 8, la membrane 10 porte des tiges 52 qui s'étendent à l'intérieur du cadre de support, perpendiculairement à la membrane, et qui sont engagées dans des tubes 54 portés par une paroi intermédiaire 36 du cadre de support, de telle sorte que le déplacement des tiges 52 dans les tubes 54 provoqué par les déformations de la membrane 10 se traduise par un écoulement laminaire de gaz dans les tubes 54 et par une dissipation d'énergie correspondante.In the alternative embodiment of the figure 8, the membrane 10 carries rods 52 which extend to inside the support frame, perpendicular to the membrane, and which are engaged in tubes 54 carried by an intermediate wall 36 of the support frame, so that the displacement of the rods 52 in the tubes 54 caused by deformations of the membrane 10 results in a laminar gas flow in the tubes 54 and by a corresponding energy dissipation.

Dans la variante de réalisation de la figure 9, les moyens de dissipation d'énergie sont également du type à laminage de gaz et comprennent des plaques horizontales 56 disposées parallèlement à la membrane 10 et à faible distance de celle-ci à l'intérieur du cadre de support, ces plaques 56 étant portées par des moyens 58 permettant de modifier la distance d entre la membrane 10 et les plaques 56. Par exemple, ces moyens 58 sont portés par la paroi intermédiaire 36 et comprennent des éléments à mémoire de forme commandés par un circuit électrique approprié 60.In the alternative embodiment of FIG. 9, the energy dissipation means are also of the gas rolling type and comprise horizontal plates 56 arranged parallel to the membrane 10 and at a short distance from the latter inside the support frame, these plates 56 being carried by means 58 making it possible to modify the distance d between the membrane 10 and the plates 56. For example, these means 58 are carried by the intermediate wall 36 and include controlled shape memory elements by an appropriate electrical circuit 60.

La modification de la distance d entre une plaque 56 et la membrane 10 entraíne une modification de l'impédance acoustique de la structure selon l'invention.Changing the distance d between a plate 56 and the membrane 10 causes a modification of the acoustic impedance of the structure according to the invention.

Dans le mode de réalisation de la figure 10, les moyens de dissipation d'énergie comprennent des plaques électrodes 62 disposées à l'intérieur du cadre de support, parallèlement à la membrane 10 et à faible distance de celle-ci, et par exemple portées par la paroi intermédiaire 36 du cadre support par l'intermédiaire d'éléments diélectriques 64. La membrane 10 comporte des électrodes associées aux plaques 62, telles par exemple que des zones métallisées 66 de sa surface, ces zones 66 et les plaques 62 étant reliées aux pôles d'une source 68 de courant continu par l'intermédiaire d'un élément de dissipation d'énergie tel qu'une résistance électrique 70 qui est avantageusement une résistance variable commandée par un moyen approprié 72, la résistance 70 absorbant l'énergie par effet Joule et la variation de sa valeur permettant de modifier l'impédance acoustique de la structure selon l'invention.In the embodiment of Figure 10, the means of energy dissipation include electrode plates 62 arranged inside the frame of support, parallel to membrane 10 and low distance from it, and for example carried by the wall intermediate 36 of the support frame through dielectric elements 64. The membrane 10 includes electrodes associated with the plates 62, such for example that metallized areas 66 of its surface, these areas 66 and the plates 62 being connected to the poles of a source 68 direct current through an element of energy dissipation such as electrical resistance 70 which is advantageously a variable resistance controlled by an appropriate means 72, the resistor 70 absorbing energy by Joule effect and the variation of its value to modify the acoustic impedance of the structure according to the invention.

De préférence, des trous 74 sont percés dans les plaques électrodes 62 pour éviter tout effet de laminage de gaz entre elles et la membrane 10.Preferably, holes 74 are drilled in the electrode plates 62 to avoid any effect of gas rolling between them and the membrane 10.

L'attraction électrostatique exercée par les plaques 62 sur la membrane joue le rôle d'une anti-raideur dynamique qui s'oppose à la raideur du gaz contenu dans la structure. Cela permet de réduire l'épaisseur (ou hauteur) totale de la structure et donc son encombrement.The electrostatic attraction exerted by plates 62 on the membrane plays the role of an anti-stiffness dynamic which opposes the stiffness of the gas contained in the structure. This reduces the total thickness (or height) of the structure and therefore its size.

En variante, la membrane 10 et/ou les plaques électrodes 62 pourraient être constituées d'un electret, tel par exemple qu'une matière plastique du type polyuréthanne ou PVDF chargée électriquement en permanence, les moyens de polarisation des électrodes étant alors supprimés.As a variant, the membrane 10 and / or the plates electrodes 62 could consist of an electret, such as a plastic like polyurethane or PVDF electrically charged in permanence, the polarization means of the electrodes then being deleted.

Dans le mode de réalisation de la figure 11, les moyens de dissipation d'énergie sont du type électromagnétique. La membrane 10 est reliée, à l'intérieur du cadre, à des bobinages électriques 76 mobiles par rapport à des éléments magnétiques 78 constituant par exemple la paroi intermédiaire 34 du cadre de support. Pour éviter tout effet de laminage de gaz, les parties 78 en saillie vers la membrane peuvent être percées de trous traversants 80.In the embodiment of Figure 11, the means of energy dissipation are of the type electromagnetic. The membrane 10 is connected, to inside the frame, to electrical windings 76 movable relative to magnetic elements 78 constituting for example the intermediate wall 34 of the support frame. To avoid any rolling effect from gas, the parts 78 projecting towards the membrane may be drilled through holes 80.

Dans la variante de réalisation de la figure 12, des éléments magnétiques 82 (par exemple des aimants permanents) sont disposés sous la membrane 10 et des conducteurs électriques 84 sont portés par cette dernière, en étant constitués par exemple par un ou des circuits électriques imprimés ou déposés sur la membrane. Le déplacement de ces conducteurs électriques 84 dans les lignes de champ magnétique des éléments 80 se traduit par une dissipation d'énergie.In the alternative embodiment of the figure 12, magnetic elements 82 (for example magnets permanent) are arranged under the membrane 10 and electrical conductors 84 are carried by this last, by being constituted for example by one or more electrical circuits printed or deposited on the membrane. The displacement of these electrical conductors 84 in the magnetic field lines of the elements 80 results in energy dissipation.

Dans la variante de réalisation de la figure 13, c'est une partie du cadre support 12 qui peut être réalisée en matière magnétique et constituer un aimant permanent dont les lignes de champ peuvent être coupées par les conducteurs électriques 84 de la membrane 10 pour un effet de dissipation d'énergie.In the alternative embodiment of the figure 13, it is a part of the support frame 12 which can be made of magnetic material and constitute a magnet permanent whose field lines can be cut by the electrical conductors 84 of the membrane 10 for an energy dissipation effect.

Dans une autre variante, on utilise une membrane magnétique qui se déplace par rapport à un circuit électrique pour dissiper de l'énergie.In another variant, a magnetic membrane that moves relative to a electrical circuit to dissipate energy.

Les structures élémentaires d'absorption de bruit qui viennent d'être décrites peuvent être assemblées les unes aux autres pour former des parois planes, incurvées, concaves ou convexes, de grande dimension. Par exemple, les structures élémentaires des figures 4, 5, 8 et 9 peuvent avoir des dimensions, en surface, de l'ordre de 5 x 5 cm2 et être associées pour former une structure du type de celle représentée en figure 1 ayant une surface de l'ordre de 20 x 20 cm2, les hauteurs de ces structures étant en général comprises entre 15 et 50 mm. Les impédances acoustiques des structures élémentaires peuvent être réglées individuellement ou par petits groupes de structures. Le réglage des impédances acoustiques permet d'avoir une impédance bien adaptée pour certaines zones de surface d'une paroi avec une absorption maximale du bruit incident, tandis que d'autres zones de surface de la paroi auront des impédances différentes pour absorber partiellement le bruit incident et le réfléchir partiellement dans une direction déterminée.The elementary noise absorption structures which have just been described can be assembled together to form flat, curved, concave or convex walls, of large dimension. For example, the elementary structures of FIGS. 4, 5, 8 and 9 may have dimensions, on the surface, of the order of 5 × 5 cm 2 and be combined to form a structure of the type of that represented in FIG. 1 having a surface of the order of 20 x 20 cm 2 , the heights of these structures generally being between 15 and 50 mm. The acoustic impedances of elementary structures can be adjusted individually or in small groups of structures. Adjusting the acoustic impedances makes it possible to have a well-adapted impedance for certain surface areas of a wall with maximum absorption of the incident noise, while other surface areas of the wall will have different impedances to partially absorb the noise. incident and partially reflect it in a determined direction.

Par ailleurs, la possibilité de réglage de l'impédance acoustique de chaque structure élémentaire permet d'obtenir une évolution spatiale des caractéristiques acoustiques d'une paroi. On peut également obtenir une paroi à impédance acoustique non localisée lorsque les parties inférieures des structures élémentaires sont reliées entre elles, l'impédance acoustique des moyens de liaison étant un paramètre de réglage des bandes de fréquences acoustiques à traiter. De plus, comme déjà indiqué, les structures selon l'invention telles que celles de la figure 2, s'adaptent automatiquement aux variations de la pression statique extérieure et par exemple à l'évolution de la pression statique dans un conduit.In addition, the possibility of adjusting the acoustic impedance of each elementary structure provides a spatial evolution of acoustic characteristics of a wall. We can also get a non-acoustic impedance wall localized when the lower parts of the structures are connected together, the impedance acoustics of the connecting means being a parameter of adjustment of the acoustic frequency bands to be processed. In addition, as already indicated, the structures according to the invention such as those of Figure 2, adapt automatically at variations in static pressure external and for example to the evolution of the pressure static in a duct.

Claims (15)

Structure d'absorption de bruit, comprenant un cadre de support (12) sur lequel est tendue et fixée une membrane étanche (10) dont la face extérieure reçoit des ondes acoustiques, un gaz tel par exemple que de l'air remplissant un volume interne délimité par le cadre (12) et la membrane (10), et des moyens de dissipation d'énergie logés dans ledit volume, caractérisée en ce que les moyens de dissipation d'énergie sont du type à laminage de gaz, du type électrostatique ou du type électromagnétique et sont modifiables, réglables ou pilotables pour modification de l'impédance acoustique de ladite structure en fonction des caractéristiques du bruit à absorber.Noise absorption structure, comprising a support frame (12) on which is stretched and fixed a waterproof membrane (10) whose outer face receives acoustic waves, a gas such as for example air filling an internal volume delimited by the frame (12) and the membrane (10), and means of dissipation of energy housed in said volume, characterized in that the means of energy dissipation are of the type gas rolling, electrostatic type or type electromagnetic and are changeable, adjustable or controllable for modification of the acoustic impedance of said structure according to the characteristics of the noise to absorb. Structure selon la revendication 1, caractérisée en ce que les moyens de dissipation du type à laminage de gaz comprennent des plaques (56) disposées à l'intérieur du cadre (12), à faible distance de la membrane (10), et des moyens (58,60) de modification de cette distance.Structure according to claim 1, characterized in that the dissipation means of the type with gas rolling comprises plates (56) arranged inside the frame (12), a short distance from the membrane (10), and means (58,60) for modifying this distance. Structure selon la revendication 1, caractérisée en ce que les moyens de dissipation à laminage de gaz comprennent au moins un passage ou conduit (38) d'écoulement de gaz reliant une chambre fermée (34) délimitée à l'intérieur du cadre (12) par la membrane (10) à une autre chambre à l'intérieur de ladite structure.Structure according to claim 1, characterized in that the means of dissipation to gas rolling include at least one pass or gas flow conduit (38) connecting a chamber closed (34) delimited inside the frame (12) by the membrane (10) to another chamber inside said structure. Structure selon la revendication 3, caractérisée en ce que ledit passage est un canal (40) formé entre deux plaques superposées (36,42).Structure according to claim 3, characterized in that said passage is a channel (40) formed between two superimposed plates (36,42). Structure selon la revendication 4, caractérisée en ce qu'elle comprend des moyens (48,50) de modification de la section du canal (40) par modification de la distance entre les deux plaques superposées (36,42). Structure according to claim 4, characterized in that it comprises means (48.50) for modification of the section of the channel (40) by modification the distance between the two overlapping plates (36.42). Structure selon la revendication 1, càractérisée en ce que les moyens de dissipation à laminage de gaz comprennent des tiges (52) portées par la membrane (10) et s'étendant perpendiculairement à celle-ci à l'intérieur du cadre dans des tubes fixes (54) qui sont fermés à leur extrémité opposée à la membrane (10) et qui délimitent avec les tiges (52) des conduits annulaires de laminage de gaz.Structure according to claim 1, characterized in that the means of dissipation gas rolling comprises rods (52) carried by the membrane (10) and extending perpendicular thereto inside the frame in fixed tubes (54) which are closed at their end opposite the membrane (10) and which delimit with the rods (52) of the conduits gas rolling annulars. Structure selon l'une des revendications précédentes, caractérisée en ce que son volume interne délimité par la membrane (10), le cadre de support (12) et une paroi de fond (18) portée par le cadre (12) est réglable, par exemple au moyen d'un élément gonflable logé à l'intérieur du cadre.Structure according to one of the claims previous, characterized in that its internal volume delimited by the membrane (10), the support frame (12) and a bottom wall (18) carried by the frame (12) is adjustable, for example by means of an inflatable element housed inside the frame. Structure selon la revendication 1, caractérisée en ce que les moyens de dissipation du type électrostatique comprennent des plaques électrodes (62) disposées parallèlement à la membrane (10) à distance de celle-ci et au moins une autre électrode formée sur la membrane et reliée avec lesdites plaques (62) à des moyens de polarisation (68) comprenant des éléments de dissipation d'énergie tels qu'une résistance électrique (70) par exemple.Structure according to claim 1, characterized in that the dissipation means of the type electrostatic include electrode plates (62) arranged parallel to the membrane (10) at a distance from this and at least one other electrode formed on the membrane and connected with said plates (62) to polarization means (68) comprising elements of energy dissipation such as electrical resistance (70) for example. Structure selon la revendication 8, caractérisée en ce qu'elle comprend des moyens (72) de réglage de la valeur de la résistance électrique (70).Structure according to claim 8, characterized in that it comprises means (72) for adjustment of the value of the electrical resistance (70). Structure selon la revendication 8 ou 9, caractérisée en ce que la membrane (10) comporte une ou plusieurs zones métallisées (66) en regard desdites plaques électrodes (62).Structure according to claim 8 or 9, characterized in that the membrane (10) has one or more several metallized zones (66) opposite said electrode plates (62). Structure selon la revendication 1, caractérisée en ce que les moyens de dissipation du type électrostatique comprennent des plaques électrodes disposées parallèlement à la membrane à distance de celle-ci et au moins une autre électrode formée par la membrane (10), celle-ci et/ou les plaques (62) étant chargées électriquement en permanence.Structure according to claim 1, characterized in that the dissipation means of the type electrostatic include electrode plates arranged parallel to the membrane at a distance from this and at least one other electrode formed by the membrane (10), the latter and / or the plates (62) being permanently electrically charged. Structure selon la revendication 1, caractérisée en ce que les moyens de dissipation du type électromagnétique comprennent une membrane magnétique déplacée par rapport à un conduit électrique ou bien des conducteurs électriques déplacés par la membrane (10) par rapport à des éléments magnétiques (78,82) portés par le cadre (12) ou constitués par celui-ci, les conducteurs électriques comprenant par exemple des bobinages (76) reliés à la membrane (10) ou des circuits électriques (84) imprimés ou déposés sur la membrane.Structure according to claim 1, characterized in that the dissipation means of the type electromagnetic include a magnetic membrane moved relative to an electrical conduit or electrical conductors displaced by the membrane (10) by compared to magnetic elements (78.82) carried by the frame (12) or constituted by it, the conductors electrics comprising for example windings (76) connected to the membrane (10) or electrical circuits (84) printed or deposited on the membrane. Structure selon l'une des revendications précédentes, caractérisée en ce qu'elle est fermée de façon étanche et contient un élément volumique (26) expansible et contractile tel qu'un ballon ou un soufflet par exemple, rempli d'air et communiquant avec l'extérieur par un orifice (28) d'égalisation de pression statique, cet élément (26) occupant une fraction notable du volume interne de ladite structure.Structure according to one of the claims previous, characterized in that it is closed from tightly sealed and contains a volume element (26) expandable and contractile such as a balloon or a bellows for example, filled with air and communicating with the exterior by a pressure equalization orifice (28) static, this element (26) occupying a significant fraction of the internal volume of said structure. Structure selon l'une des revendications 1 à 13, caractérisée en ce qu'elle est juxtaposée et assemblée à une pluralité de structures du même type pour former une paroi plane ou incurvée, convexe ou concave dans laquelle les structures ont des impédances acoustiques semblables ou différentes pour absorber le bruit incident ou le dévier par réflexion selon les cas.Structure according to one of claims 1 to 13, characterized in that it is juxtaposed and assembled to a plurality of structures of the same type for form a flat or curved wall, convex or concave in which the structures have impedances similar or different acoustics to absorb the incident noise or deflect it by reflection as appropriate. Paroi selon la revendication 14, caractérisée en ce que les moyens de dissipation d'énergie de certaines au moins desdites structures sont associés à des moyens de commande, de réglage ou de pilotage eux-mêmes pilotables par un système de traitement de l'information, et sont par exemple adaptables au bruit à absorber et à son évolution.Wall according to claim 14, characterized in that the means of dissipation energy of at least some of said structures are associated with means for controlling, adjusting or themselves piloted by a system of information processing, and are for example adaptable to the noise to be absorbed and its evolution.
EP97401411A 1996-06-28 1997-06-19 Noise absorbing structures and walls made therefrom Expired - Lifetime EP0817164B2 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR9608064A FR2750527B1 (en) 1996-06-28 1996-06-28 NOISE ABSORPTION STRUCTURES AND WALLS MADE OF SUCH STRUCTURES
FR9608064 1996-06-28

Publications (3)

Publication Number Publication Date
EP0817164A1 true EP0817164A1 (en) 1998-01-07
EP0817164B1 EP0817164B1 (en) 2001-11-28
EP0817164B2 EP0817164B2 (en) 2004-08-25

Family

ID=9493519

Family Applications (1)

Application Number Title Priority Date Filing Date
EP97401411A Expired - Lifetime EP0817164B2 (en) 1996-06-28 1997-06-19 Noise absorbing structures and walls made therefrom

Country Status (5)

Country Link
US (1) US6332027B1 (en)
EP (1) EP0817164B2 (en)
CA (1) CA2209302C (en)
DE (1) DE69708523T3 (en)
FR (1) FR2750527B1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1998022934A1 (en) * 1996-11-15 1998-05-28 Northrop Grumman Corporation Noise absorption system having active acoustic liner
EP0897176A1 (en) * 1997-08-14 1999-02-17 Thomson Marconi Sonar Sas Underwater acoustic absorber

Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6382603B1 (en) * 2001-02-08 2002-05-07 Lockheed Martin Corporation Ridged elastomer mount
PL1779375T3 (en) * 2004-08-06 2013-05-31 Niels Werner Larsen Method, device and system for altering the reverberation time of a room
US7992678B2 (en) * 2005-05-12 2011-08-09 Pilaar James G Inflatable sound attenuation system
JP4782193B2 (en) * 2005-05-13 2011-09-28 ラルセン、ニールス、ヴェルナー Method, apparatus, and system for changing reverberation time in space
US7819221B1 (en) * 2005-09-27 2010-10-26 The United States Of America As Represented By The Secretary Of The Air Force Lightweight acoustic damping treatment
US8295505B2 (en) * 2006-01-30 2012-10-23 Sony Ericsson Mobile Communications Ab Earphone with controllable leakage of surrounding sound and device therefor
JP2008213547A (en) * 2007-02-28 2008-09-18 Nissan Motor Co Ltd Noise control unit
RU2357109C1 (en) * 2007-11-07 2009-05-27 Международный Научно-Исследовательский Институт Проблем Управления (Мниипу) Device and method for influence at vortical structures in turbulent air jet
US20170040014A1 (en) * 2015-08-07 2017-02-09 Alcatel-Lucent Usa Inc. Acoustic Noise Attenuation Device, Assembly And Metamaterial Structure
CN110106999A (en) * 2019-03-29 2019-08-09 深圳中天精装股份有限公司 A kind of assembled architecture sound-absorbing timber partition and its design method

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2482663A1 (en) * 1980-05-17 1981-11-20 Rolls Royce MULTI-LAYER ACOUSTIC INSULATION COATING
FR2715244A1 (en) * 1994-01-19 1995-07-21 Bertin & Cie Method of absorbing acoustic waves for noise suppression

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4068736A (en) † 1975-04-14 1978-01-17 Tempmaster Corporation Method and device for reducing noise
DE2834823C2 (en) † 1978-08-09 1980-07-17 Messerschmitt-Boelkow-Blohm Gmbh, 8000 Muenchen Volume-changing resonators based on the disc spring principle
DE3615360A1 (en) † 1986-05-06 1987-11-12 Stankiewicz Alois Dr Gmbh COMPONENT WITH ACOUSTIC PROPERTIES
DE4228356C2 (en) † 1992-08-26 1995-10-19 Daimler Benz Aerospace Ag Cavity resonator for noise reduction
DE9414943U1 (en) † 1994-09-14 1996-01-18 Faist M Gmbh & Co Kg Foil resonance absorber
DE9418063U1 (en) † 1994-11-11 1995-01-19 Wilhelmi Werke Gmbh & Co Kg Component for sound absorption
US5778081A (en) * 1996-03-04 1998-07-07 United Technologies Corp Active noise control using phased-array active resonators
JP3510427B2 (en) * 1996-08-15 2004-03-29 三菱重工業株式会社 Active sound absorbing wall

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2482663A1 (en) * 1980-05-17 1981-11-20 Rolls Royce MULTI-LAYER ACOUSTIC INSULATION COATING
FR2715244A1 (en) * 1994-01-19 1995-07-21 Bertin & Cie Method of absorbing acoustic waves for noise suppression

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1998022934A1 (en) * 1996-11-15 1998-05-28 Northrop Grumman Corporation Noise absorption system having active acoustic liner
EP0897176A1 (en) * 1997-08-14 1999-02-17 Thomson Marconi Sonar Sas Underwater acoustic absorber

Also Published As

Publication number Publication date
FR2750527A1 (en) 1998-01-02
EP0817164B1 (en) 2001-11-28
US6332027B1 (en) 2001-12-18
CA2209302C (en) 2010-12-14
FR2750527B1 (en) 1998-08-21
EP0817164B2 (en) 2004-08-25
CA2209302A1 (en) 1997-12-28
DE69708523T2 (en) 2002-06-13
DE69708523T3 (en) 2005-06-09
DE69708523D1 (en) 2002-01-10

Similar Documents

Publication Publication Date Title
EP0817164B1 (en) Noise absorbing structures and walls made therefrom
FR2473242A1 (en) ACTIVE DOME ELECTROACOUSTIC TRANSDUCER
FR2571076A1 (en) REFLECTOR SOUNDING DEVICE FOR PREMISES.
FR2790731A1 (en) METHOD OF SIMULATING EXTERNAL THERMAL FLOWS ABSORBED IN FLIGHT BY THE EXTERNAL RADIATIVE ELEMENTS OF A SPACE ENGINE AND SPACE ENGINE FOR THE IMPLEMENTATION OF THIS PROCESS
WO2017077236A1 (en) Multi-glazed window incorporating a noise reduction device
EP3411874A1 (en) Low thickness perforated mille-feuille acoustic resonator for absorbing or radiating very low acoustic frequencies
WO1980001128A1 (en) Electro acoustic transducer
EP0118329A2 (en) Velocity hydrophone
EP0663136B1 (en) Diffusing volume electroacoustic transducer
FR3043179A1 (en) INSTALLATION FOR THE NATURAL VENTILATION OF A LOCAL HAVING A VENTILATION PASSAGE ASSOCIATED WITH A NOISE DAMPER
EP3718759B1 (en) Assembly forming an acoustically absorbent material
FR2955731A1 (en) Acoustic enclosure for emitting acoustic waves, has viscoelastic membrane displaced under action of wavy excitation to attenuate stationary acoustic wave created by cavity, at or around resonance frequency
FR2881765A1 (en) Sound absorbent assembly for use in apartment, has poly vinyl chloride canvas with two series of micro-perforations having respective small and large surfaces and distributed in regular manner on square shaped meshing on canvas
FR2693070A1 (en) Electro-acoustic electrodynamic transducers with moving coil.
EP3371519A1 (en) Unit for the natural ventilation of a room, provided with a sound absorber
FR2471114A1 (en) LOUD SPEAKER
EP3278330B1 (en) Acoustic impedance matching device and loudspeaker provided with such a device
WO2005020623A2 (en) Sound-reproducing transducer
FR2943880A1 (en) ACOUSTIC PANEL FOR RECEIVING, TRANSMITTING OR ABSORBING SOUNDS.
EP0491034A1 (en) Device for absorbing sound energy originating inside the hull of a vessel, and modular acoustic baffle forming a part thereof
FR2526985A1 (en) ANTISONIC ELEMENT WITH RESONATORS
WO2010133782A1 (en) Acoustic wave generation device and equipment including a plurality of such devices
FR2671899A1 (en) Coating for wide band passive acoustic absorption in a liquid
EP3639526A1 (en) Loudspeaker
EP4315315A1 (en) Acoustic absorbing structures

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): DE GB

17P Request for examination filed

Effective date: 19980619

AKX Designation fees paid

Free format text: DE GB

RBV Designated contracting states (corrected)

Designated state(s): DE GB

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

17Q First examination report despatched

Effective date: 20001219

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE GB

REG Reference to a national code

Ref country code: GB

Ref legal event code: IF02

REF Corresponds to:

Ref document number: 69708523

Country of ref document: DE

Date of ref document: 20020110

GBT Gb: translation of ep patent filed (gb section 77(6)(a)/1977)

Effective date: 20020128

RAP2 Party data changed (patent owner data changed or rights of a patent transferred)

Owner name: SNECMA MOTEURS

Owner name: BERTIN & CIE

PLBI Opposition filed

Free format text: ORIGINAL CODE: 0009260

PLBF Reply of patent proprietor to notice(s) of opposition

Free format text: ORIGINAL CODE: EPIDOS OBSO

26 Opposition filed

Opponent name: EADS DEUTSCHLAND GMBH

Effective date: 20020816

PLBF Reply of patent proprietor to notice(s) of opposition

Free format text: ORIGINAL CODE: EPIDOS OBSO

PUAH Patent maintained in amended form

Free format text: ORIGINAL CODE: 0009272

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: PATENT MAINTAINED AS AMENDED

27A Patent maintained in amended form

Effective date: 20040825

AK Designated contracting states

Kind code of ref document: B2

Designated state(s): DE GB

GBTA Gb: translation of amended ep patent filed (gb section 77(6)(b)/1977)
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20150521

Year of fee payment: 19

Ref country code: GB

Payment date: 20150527

Year of fee payment: 19

REG Reference to a national code

Ref country code: DE

Ref legal event code: R119

Ref document number: 69708523

Country of ref document: DE

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20160619

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20170103

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20160619