Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B64—AIRCRAFT; AVIATION; COSMONAUTICS
  • B64C—AEROPLANES; HELICOPTERS
  • B64C1/00—Fuselages; Constructional features common to fuselages, wings, stabilising surfaces or the like
  • B64C1/14—Windows; Doors; Hatch covers or access panels; Surrounding frame structures; Canopies; Windscreens accessories therefor, e.g. pressure sensors, water deflectors, hinges, seals, handles, latches, windscreen wipers
  • B64C1/1476—Canopies; Windscreens or similar transparent elements
  • B64C1/1492—Structure and mounting of the transparent elements in the window or windscreen

Definitions

• the present invention relates to a seal for an aircraft glazed element having sound insulation properties, and more particularly a window or an aircraft windshield having such properties.
• a glazed element 2 preferably a window 14 or a windshield
• the porthole 14 may comprise a first exterior pane 3, and a second interior pane 10, which are mounted on a metal frame 19 in a seal 1.
• the sealing gasket 1 covers the edge of each of the first glazing 3 and the second glazing 10.
• the sealing gasket 1 is held by a metal section 18 mounted on a hinge 20 which is mounted fixed to the metal frame 19.
• the acoustic insulation of a glazed element of an aircraft can depend on several parameters: a variation in temperature outside the aircraft, a variation in temperature inside the aircraft, mechanical stresses at the limit of the glazed element, the geometry and the composition of the glazed element, and/or a variation of the characteristics of the materials of the glazed element with the temperature and the mechanical stresses imposed on the glazed element.
• modeling the sound insulation properties of a glazed element can be complex.
• the increase in the thickness of the first exterior glazing 3 is limited by the size of the first glazing 3 in the window 14 and by the costs entailed by the increase in this thickness during the manufacture of the porthole 14.
• An object of the invention is to provide a seal allowing a glazed element to have sound insulation properties superior to those of known glazed elements, at least in a frequency range comprised in the audible frequency spectrum.
• a seal for a glazed element of an aircraft being configured to receive an edge of a first glazing, the first glazing having a first face, the gasket comprising a first surface adapted to be mounted on the first face so as to receive the first glazing, the gasket comprising a first damping part, the first damping part comprising the first surface, a first material forming the first damping part having a first factor loss h strictly greater than 0.10.
• the first surface is adapted to be mounted on the first face and on a second face of the first glazing opposite the first face, so as to receive the first glazing
• the seal is configured to receive an edge of a second glazing, the second glazing having a third face and a fourth face opposite the third face, the seal comprising a second surface adapted to be mounted on the third face and preferably on the fourth face so as to receive the second glazing, the gasket comprising a second damping part, the second damping part comprising the second surface, a second material forming the second damping part having a second loss factor h 2 strictly greater than 0.10, - the seal comprises a first housing capable of receiving the edge of the first glazing so as to surround the first glazing, the first housing comprising the first damping part,
• the seal comprises a second housing capable of receiving an edge of a second glazing so as to surround the second glazing, the second housing having a second surface capable of being in contact with the edge of the second glazing, the second housing comprising a second damping part, the second damping part comprising the second surface, a second material forming the second damping part having a second loss factor h 2 greater than 0.10,
• the first housing forms a notch in the seal
• the second housing forms a notch in the seal
• a value of the real part E' of the Young's modulus of the first material is less than 100 MPa, in particular less than 10 MPa,
• a value of the real part E' of the Young's modulus of the second material is less than 100 MPa, in particular less than 10 MPa,
• the seal is formed from a single material in a monolithic manner
• the seal comprises a holding part different from the first damping part, the holding part being configured to be brought into contact with an element integral with a wall of the aircraft, a third material forming the holding part having a third loss factor h 3 strictly less than the first loss factor, and in particular strictly less than 0.10,
• the first loss factor h is greater than 0.20 and preferably greater than 0.50
• a value of the real part E' of the Young's modulus of the first material is less than 10 MPa, in particular strictly less than 1 MPa,
• the seal is entirely formed by one or more viscoelastic materials
• the third material is a viscoelastic material
• Another aspect of the invention is an aircraft glazed element, comprising a gasket according to one embodiment of the invention, and a first glazing, the first surface being mounted on the first face so that the gasket receives the first glazing.
• the first surface is mounted on the second face of the first glazing so that the gasket receives the first glazing.
• the glazed element comprises a second glazing, the second glazing having a third face and a fourth face opposite the third face, the second surface of the seal being mounted on the third face and preferably on the fourth face of the second glazing so that the seal receives the second glazing.
• Another aspect of the invention is an aircraft window, comprising a glazed element according to one embodiment of the invention, the glazed element further comprising a second glazing, the second glazing having a third face and a fourth face , the seal comprising a second surface adapted to be mounted on the third face and preferably on the fourth face so as to receive the second glazing.
• the first glazing and/or the second glazing of the window is a monolith, preferably formed from polymethyl methacrylate.
• Another aspect of the invention is an aircraft windshield, comprising a glazed element according to one embodiment of the invention, in which the first glazing is a laminated glazing.
• FIG. 1 schematically illustrates the section of a known aircraft window
• Figure 2 schematically illustrates the detail of a section of a glazed element according to one embodiment of the invention
• Figure 3 schematically illustrates the detail of a section of a glazed element according to one embodiment of the invention
• FIG. 4 Figure 4 schematically illustrates the detail of a section of a glazed element according to one embodiment of the invention
• FIG. 5 Figure 5 schematically illustrates the detail of a section of a glazed element according to one embodiment of the invention
• FIG. 6 Figure 6 schematically illustrates the detail of a section of a glazed element according to one embodiment of the invention
• FIG. 7 illustrates acoustic insulation as a function of the frequency of a sound wave through known portholes and through a porthole according to one embodiment of the invention
• FIG. 8 illustrates acoustic insulation as a function of the frequency of a sound wave through a known windshield and through a windshield according to one embodiment of the invention.
• the term “loss factor h” of a material means the material having a complex Young's modulus, the ratio between the imaginary part f” of the Young's modulus of the material and the real part f' of the Young's modulus of the material.
• the loss factor h of a material is defined by the international standard ISO 18437-2:2005 (Mechanical vibration and shock — Characterization of the dynamic mechanical properties of visco-elastic mate riais — Part 2: Resonance method, part 3.2).
• the loss factor h can be defined for a predetermined frequency.
• a material has a first loss factor h greater than a value
• the material has a first loss factor 77 greater than the value for each of the frequencies in the audible frequency range, c' that is to say in a range of frequencies extending between 20 Hz inclusive and 20,000 Hz inclusive, and preferably between 20 Hz inclusive and 10 kHz inclusive.
• a value of the real part E' of the Young's modulus of a material is greater than a value means that a value of the real part E' of the Young's modulus of the material is greater than the value of the real part E' of the Young's modulus of the material for each of the frequencies in the range of audible frequencies, that is to say in a range of frequencies extending between 20 Hz inclusive and 20,000 Hz inclusive, and preferably between 20 Hz inclusive and 10 kHz inclusive.
• the real part E’ and the imaginary part E” of Young’s modulus can be defined for a predetermined temperature.
• the temperature range considered in the present invention is between -90° C. and 60° C.
• a material has a first loss factor h greater than a value” that the material has a first loss factor 77 greater than the value for each of the temperatures between -90° C and 60° C.
• a dynamic characterization of a material is carried out on a viscoanalyzer of the Metravib viscoanalyzer type, under the following measurement conditions.
• a sinusoidal stress is applied to the material.
• a measurement sample formed by the material to be measured consists of two rectangular parallelepipeds, each parallelepiped having a thickness of 3.31 mm, a width of 10.38 mm and a height of 6.44 mm.
• Each parallelepiped formed by the material is also designated by the term “shear specimen”.
• the excitation is implemented with a dynamic amplitude of 5 ⁇ m around the rest position, by traversing the range of frequencies between 5 Hz and 700 Hz, and by traversing a range of temperatures between -90° C and + 60°C.
• the viscoanalyzer makes it possible to subject each specimen (each sample) to deformations under precise conditions of temperature and frequency, and to measure the displacements of the specimen, the forces applied to the specimen and their phase shift, which makes it possible to measure rheological quantities characterizing the material of the specimen.
• the exploitation of the measurements makes it possible in particular to calculate the Young's modulus E of the material, and particularly the real part E' of the Young's modulus and the imaginary part E” of the Young's modulus of the material, and thus to calculate the tangent the loss angle (or loss factor) h (also denoted by tan d).
• a value of the real part E' of the Young's modulus and/or a loss factor h of a material are measured without the material being prestressed.
• “Glazing” means a structure comprising at least one sheet of organic or mineral glass, preferably adapted to be mounted in an aircraft.
• the glazing may comprise a single sheet of glass or else a multilayer glazed assembly, at least one layer of which is a sheet of glass.
• a glazing can comprise an organic glass sheet.
• the organic glass is formed by a compound comprising acrylates, preferably by polymethyl methacrylate (acronym PMMA). It can also be formed from polycarbonate.
• a glazing may comprise a glazed assembly.
• the glazed assembly includes at least one sheet of glass.
• the glass can be organic or mineral glass.
• the glass can be tempered.
• the glazed assembly is preferably laminated glazing.
• laminated glazing means a glazed assembly comprising at least two sheets of glass and an intermediate film formed of plastic material, preferably viscoelastic, separating the two sheets of glass.
• the interlayer plastic film may comprise one or more layers of a viscoelastic polymer such as poly(vinyl butyral) (PVB) or an ethylene-vinyl acetate copolymer (EVA).
• the interlayer film is preferably standard PVB or acoustic PVB (such as single-layer or three-layer acoustic PVB).
• the acoustic PVB can comprise three layers: two external layers in standard PVB and an internal layer in PVB added with plasticizer so as to make it less rigid than the external layers.
• a seal 1 is configured to receive an edge of a first glazing 3.
• the first glazing 3 comprises a first face 4 and a second face 5 opposite the first face 6.
• the seal 1 can be entirely formed by one or more viscoelastic materials.
• the seal 1 comprises a first surface 6 adapted to be mounted on the first face 4 of the first glazing 3 so as to receive the first glazing 3.
• first glazing 3 is mounted at the seal 1, the first glazing 3 is in contact with the joint 1 on the first surface 6.
• the joint 1 comprises a first damping part 7.
• the first damping part 7 comprises the first surface 6.
• a first material forming the first damping part 7 has a first loss factor h strictly greater than 0.10, in particular greater than 0.15, and preferably greater than 0.20.
• the inventors have discovered that when the glazing is maintained, preferably only, by a first material having a loss factor greater than 0.10, in particular greater than 0.15, and preferably greater than 0.20, the insulation acoustic through the glazed element 2 increases significantly at least in frequency ranges included in the audible frequency range.
• the viscous dissipation properties of the seal 1 due to the viscous dissipation properties of the seal 1, the acoustic insulation of a glazed element 2 of an aircraft can be increased.
• Another aspect of the invention is an aircraft glazed element 2 comprising a seal 1 and a first glazing 3, the first surface 6 being mounted on the first face 4 so that the seal 1 receives the first glazing 3.
• the first surface 6 can be adapted to be mounted on the first face 4 and on a second face 5 of the first glazing 3 opposite the first face 4, so as to receive the first glazing 3.
• the first damping part 7 can maintain two opposite faces of the first glazing 3 so as to avoid the sticking of the first glazing 3 on the seal 1 while allowing an increase in acoustic insulation through a glazed element formed at least by the first glazing 3 and by the seal 1.
• the seal 1 can be configured to receive a border of a second glazing 10.
• the second glazing 10 has a third face 15 and a fourth face 16 opposite the third face 15.
• the seal 1 then comprises a second surface 11 adapted to be mounted on the third face 15, and preferably on the fourth face 16, so as to receive the second glazing 10.
• the seal 1 can comprise a second damping part 12.
• the second damping part 12 comprises the second surface 11.
• a second material forms the second damping part 12.
• the second material has a second loss factor h 2 strictly greater than 0.10, in particular greater than 0.15, and preferably greater than 0.20.
• the seal 1 may include a first housing 8 capable of receiving the edge of the first glazing 3 and preferably a second housing 9 capable of receiving the edge of the second glazing 10, so as to surround the first glazing and/or the second glazing 10.
• a first housing 8 capable of receiving the edge of the first glazing 3
• a second housing 9 capable of receiving the edge of the second glazing 10, so as to surround the first glazing and/or the second glazing 10.
• the first housing 8 and/the second housing 9 can each form a notch in the seal 1.
• the housing 8 makes it possible to install the first glazing 3 by surrounding the edge of the first glazing 3 on the first face 4, on the second face 5, and on the periphery of the first glazing 3.
• the first housing 8 and/or the second housing 9 can each form a recess in the seal 1, making it possible to control the position at which the first glazing 3 and/or the second glazing 10 is installed in the glazed element 2.
• the figure 3 illustrates a second glazing 10 held in the glazed element 2 by the seal 1, the second glazing 10 being arranged in the second housing 9 formed by a recess.
• the glazing can be glued to the first surface 6 and/or to a second surface 11 .
• the second housing 9 may have a second surface 11 capable of being in contact with the edge of the second glazing 10.
• the second housing 9 may comprise the second damping part 12.
• the second damping part 12 comprises the second surface 11.
• the second material forming the second damping part 12 can have a second loss factor h 2 greater than 0.10, in particular greater than 0.15, and preferably greater than 0.20.
• a value of the real part f′ of the Young's modulus of the first material and/or of the second material is less than 100 MPa, in particular less than 10 MPa, and preferentially less than 1 MPa.
• the seal 1 can be formed from a single material, monolithically.
• the inventors have discovered that it is possible to choose the characteristics of the material forming the gasket 1 so that the gasket 1 can maintain the glazing(s) during tightening and fixing to an element integral with a wall of the aircraft.
• the first loss factor h is strictly greater than 0.10, in particular greater than 0.15, and preferably greater than 0.20, and the value of the real part f' of the Young's modulus of the material forming the gasket 1 is greater at 1 MPa.
• the seal 1 can be formed by one or more parts without covering the end of the edge of the first glazing 3 and / or the second glazing 10.
• the seal 1 may include a holding part 13 different from the first damping part 7.
• the holding part 13 and the first damping part 7 have no common part.
• the holding part 13 is mounted fixed on the damping part 7.
• the holding part 13 can be configured to be brought into contact with an element fixed to a wall of the aircraft.
• a third material, preferably viscoelastic, forming the holding part 13 has a third loss factor h 3 strictly lower than the first loss factor, and in particular strictly lower than 0.10, preferably lower than 0.05.
• the seal 1 can both be configured to be fixedly mounted on the wall of an aircraft in a manner similar to known seals, and at the same time have characteristics making it possible to increase the acoustic insulation with regard to known seals, by viscous dissipation.
• a seal 1 comprising a retaining part 13 can have a first loss factor h greater than 0.20 and preferably greater than 0.50.
• the joint 1 comprises a holding part 13, it is possible to adapt the first material and preferably the second material, so as to increase the acoustic insulation without complicating the implementation of the fixing of the joint 1 to an element secured to the wall of the aircraft.
• a seal 1 comprising a holding part 13 can comprise a first damping part 7 and/or a second damping part 12, having a value of the real part f' of the Young's modulus strictly less than 10 MPa, in particular strictly less than 1 MPa.
• the first material and/or the second material are preferably chosen from a silicone, a nitrile and a polyurethane.
• the viscoelastic properties of known materials can be measured by the methods described herein.
• the first material and/or the second material may have a glass transition temperature of between -80° C. and -50° C. inclusive.
• the first material and/or the second material may comprise a methyl vinyl silicone (MVQ) crosslinked with benzoyl peroxide.
• MVQ methyl vinyl silicone
• the first material and/or the second material can also be a porous material.
• the loss factor of the first material and/or of the second material can also be adjusted by a tackifying agent, for example a glycerin ester, calcium carbonate or carbon nanotubes.
• the polyurethane sealant Weberseal PU 40 (registered trademark) of the Weber brand has a loss factor h equal to 0.41 and a value of the imaginary part f' of the Young's modulus equal to 7.2 MPa .
• the polyurethane sealant Sikaflex PRO-11 FC (registered trademark) of the Sika brand has a loss factor 77 equal to 0.20 and a value of the imaginary part E 'of the Young's modulus equal to 1, 2MPa.
• the gasket 1 preferably comprises a spacer 21 able to separate the first pane 3 from the second pane 10 by a predetermined thickness.
• the spacer 21 may be part of the seal 1 arranged between the first housing 8 and the second housing 9.
• the spacer 21 may be formed by the first damping part 7 and by the second damping part 12.
• the spacer 21 may be formed by the retaining part 13 and by the first damping part 7 and/or the second damping part 12.
• the first damping part 7 and/or the second damping part 12 can be formed by a layer of polymer material deposited on the holding part 13.
• Window 14 Another aspect of the invention is an aircraft window 14, comprising a glazed element 2, the glazed element 2 comprising a second glazing 10.
• the second glazing 10 has a third face 15 and a fourth face 16.
• the second surface 11 is adapted to be mounted on the third face 15 and preferably on the fourth face 16 so as to receive the second glazing 10.
• the first glazing 3 and/or the second glazing 10 of a window 14 are each a monolith, preferably formed from polymethyl methacrylate (acronym PMMA).
• the porthole 14 increases the acoustic insulation in the medium and high audible frequencies, in particular in a frequency range between 200 Hz and 1300 Hz, and preferably in a frequency range between 350 Hz and 450 Hz. These frequency ranges can include the resonance frequency of the two panes of window 14.
• Figure 7 illustrates a simulation by the finite element method of acoustic insulation (TL for transmission loss in English) through three portholes.
• Each of the three simulated portholes includes glazing with a maximum diameter of 520 mm.
• the first glazing 3 is made of PMMA and has a thickness of 12.7 mm.
• the second glazing 10 is made of PMMA and has a thickness of 6.1 mm.
• the first glazing 3 and the second glazing 10 are separated by 5 mm of air.
• the joint of each of the simulated windows has a value of the real part f' of the Young's modulus equal to 3 MPa and a Poisson's ratio equal to 0.49.
• Curve (a) illustrates the sound insulation for a known porthole that does not include a gasket.
• Curve (b) illustrates the acoustic insulation for a known porthole, comprising a seal formed by a material having a loss factor h equal to 0.001.
• Curve (b) illustrates an increase in the decoupling frequency between the first glazing 3 and the second glazing 10 when using a known window, compared to a window without a seal.
• Curve (c) illustrates the sound insulation for a window 14 according to one embodiment of the invention, which comprises a seal comprising a first damping part 7 and a second damping part 12 respectively having a first loss factor h and a second loss factor r j 2 each equal to 0.7.
• Curve (c) illustrates an increase in acoustic insulation when using a window according to one embodiment of the invention compared with known windows.
• Windshield Another aspect of the invention is an aircraft windshield, comprising a glazed element 2.
• the first glazing 3 of the glazed element 2 can be a laminated glazing.
• the windshield can comprise as only glazing the first glazing 3, or not include a second glazing 10.
• the windshield makes it possible to increase the acoustic insulation in particular in the low and medium audible frequencies , especially in a frequency range between 50 Hz and 3 kHz.
• Figure 8 illustrates a finite element simulation of sound insulation through two windshields.
• Each of the two simulated windshields comprises a first laminated pane 3 .
• Curve (d) illustrates the sound insulation for a known windshield, comprising a seal formed by a material having a loss factor h equal to 0.001.
• Curve (e) illustrates the sound insulation for a windshield according to one embodiment of the invention, which comprises a seal 1 comprising a first damping part 7 having a first loss factor h equal to 0.5.
• Curve (e) illustrates an increase in sound insulation when using a windshield according to one embodiment of the invention compared to a known windshield.
• Another aspect of the invention is a process for manufacturing the seal 1.
• the process for manufacturing the seal 1 may comprise a step of extruding the seal 1.
• the extrusion of the seal 1 may be implemented from the first material so as to form the first damping part 7 and preferably from the second material so as to form the second damping part 12.
• the process for manufacturing gasket 1 may include a step of co-extrusion of gasket 1 .
• the co-extrusion of gasket 1 can be implemented from the first material having a first loss factor h strictly greater than 0.10 so as to form the first damping part 7, and from the third material having a third loss factor h 3 strictly less than the first loss factor, and in particular strictly less than 0.10, so as to form the holding part 13.
• the co-extrusion can also be implemented from the second material having a third loss factor h 2 strictly greater than 0.10 so as to form the second damping part 7.
• seal 1 may have two ends.
• the process for manufacturing gasket 1 may include a step subsequent to the extrusion or coextrusion step, in which the two ends of gasket 1 are welded together.
• the process for manufacturing seal 1 can include a step of injecting seal 1 on the edge of a glazing.
• the manufacturing process comprises a first step of injecting the first material and a second step of injecting the second material and/or the third material.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Aviation & Aerospace Engineering (AREA)
• Securing Of Glass Panes Or The Like (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=77021445

Family Applications (1)

Country Status (4)

Family Cites Families (7)

• 2021
  • 2021-04-29 FR FR2104520A patent/FR3122403A1/fr active Pending
• 2022
  • 2022-04-29 EP EP22727956.9A patent/EP4330135A1/de active Pending
  • 2022-04-29 WO PCT/FR2022/050834 patent/WO2022229580A1/fr active Application Filing
  • 2022-04-29 CN CN202280031556.XA patent/CN117242002A/zh active Pending

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