Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B64—AIRCRAFT; AVIATION; COSMONAUTICS
  • B64D—EQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLIGHT SUITS; PARACHUTES; ARRANGEMENT OR MOUNTING OF POWER PLANTS OR PROPULSION TRANSMISSIONS IN AIRCRAFT
  • B64D37/00—Arrangements in connection with fuel supply for power plant
  • B64D37/02—Tanks
  • B64D37/06—Constructional adaptations thereof
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C70/00—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
  • B29C70/04—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts comprising reinforcements only, e.g. self-reinforcing plastics
  • B29C70/06—Fibrous reinforcements only
  • B29C70/08—Fibrous reinforcements only comprising combinations of different forms of fibrous reinforcements incorporated in matrix material, forming one or more layers, and with or without non-reinforced layers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C70/00—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
  • B29C70/04—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts comprising reinforcements only, e.g. self-reinforcing plastics
  • B29C70/06—Fibrous reinforcements only
  • B29C70/08—Fibrous reinforcements only comprising combinations of different forms of fibrous reinforcements incorporated in matrix material, forming one or more layers, and with or without non-reinforced layers
  • B29C70/086—Fibrous reinforcements only comprising combinations of different forms of fibrous reinforcements incorporated in matrix material, forming one or more layers, and with or without non-reinforced layers and with one or more layers of pure plastics material, e.g. foam layers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C70/00—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
  • B29C70/88—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts characterised primarily by possessing specific properties, e.g. electrically conductive or locally reinforced
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60K—ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES
  • B60K15/00—Arrangement in connection with fuel supply of combustion engines or other fuel consuming energy converters, e.g. fuel cells; Mounting or construction of fuel tanks
  • B60K15/03—Fuel tanks
  • B60K15/03177—Fuel tanks made of non-metallic material, e.g. plastics, or of a combination of non-metallic and metallic material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B64—AIRCRAFT; AVIATION; COSMONAUTICS
  • B64C—AEROPLANES; HELICOPTERS
  • B64C3/00—Wings
  • B64C3/34—Tanks constructed integrally with wings, e.g. for fuel or water
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C65/00—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor
  • B29C65/48—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor using adhesives, i.e. using supplementary joining material; solvent bonding
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C65/00—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor
  • B29C65/56—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor using mechanical means or mechanical connections, e.g. form-fits
  • B29C65/562—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor using mechanical means or mechanical connections, e.g. form-fits using extra joining elements, i.e. which are not integral with the parts to be joined
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C66/00—General aspects of processes or apparatus for joining preformed parts
  • B29C66/70—General aspects of processes or apparatus for joining preformed parts characterised by the composition, physical properties or the structure of the material of the parts to be joined; Joining with non-plastics material
  • B29C66/72—General aspects of processes or apparatus for joining preformed parts characterised by the composition, physical properties or the structure of the material of the parts to be joined; Joining with non-plastics material characterised by the structure of the material of the parts to be joined
  • B29C66/721—Fibre-reinforced materials
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2063/00—Use of EP, i.e. epoxy resins or derivatives thereof, as moulding material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2071/00—Use of polyethers, e.g. PEEK, i.e. polyether-etherketone or PEK, i.e. polyetherketone or derivatives thereof, as moulding material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
  • B29L2031/00—Other particular articles
  • B29L2031/712—Containers; Packaging elements or accessories, Packages
  • B29L2031/7172—Fuel tanks, jerry cans
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
  • Y02T50/00—Aeronautics or air transport
  • Y02T50/40—Weight reduction
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T156/00—Adhesive bonding and miscellaneous chemical manufacture
  • Y10T156/10—Methods of surface bonding and/or assembly therefor
  • Y10T156/1052—Methods of surface bonding and/or assembly therefor with cutting, punching, tearing or severing
  • Y10T156/1062—Prior to assembly

Definitions

• the invention relates to a method for sealing a fuel tank.
• the invention is more particularly adapted to aircraft fuel tanks, formed by an assembly of elements made of a composite material with fiber reinforcement.
• the fuel tank of an aircraft is generally placed in an empty volume of a box structure, particularly in the structure of the wings.
• said volume must be sealed, and secondly, the materials constituting said box structure must be protected from any damage that could cause their contact with the fuel. This latter characteristic is particularly relevant in the case where the materials constituting the box structure are organic matrix composite materials, to which the fuel hydrocarbons act as solvents.
• this protection can be obtained by inserting a bladder into the empty volume of the caisson structure used as a reservoir.
• This solution is unfavorable for aeronautical applications because the bladder constitutes an additional mass.
• the internal shape of the empty volume dictated essentially by structural considerations, can be complex and, both the adaptation of the shape of the bladder to this volume, as the introduction of said bladder in this volume are delicate.
• Another solution of the prior art is to paint the structural parts defining the empty volume of the box structure with a specific primer, resistant to hydrocarbons. This technical solution imposes a painting operation in the manufacturing range and its quality of realization is dependent on the know-how of the operator.
• the protection is achieved by applying inside the empty volume of the assembled box structure, a liquid sealant based on polythioether. This operation, usually carried out with a brush, is commonly referred to as churning, and turns out to be particularly painful.
• WO 2007 045466 discloses a fuel tank of material organic matrix composite, as well as methods for making such a reservoir.
• the fuel tank described in this prior art document is intended for a motorcycle or automobile and constitutes a small volume reservoir.
• This document discloses two embodiments of such a reservoir, the first constant to mold an envelope made of a thermoplastic material on which reinforced plies are then draped.
• the second method consists in first producing an envelope made of a laminated composite material and then covering, after firing, the inside of this envelope with a thermoplastic film by blowing or rotomolding this film inside the volume of the reservoir thus constituted.
• the invention aims at solving the drawbacks of the prior art and for this purpose concerns a method for producing a structural element comprising a panel made of composite material with fibrous reinforcement in an organic matrix obtained by draping and baking, which panel comprises a face liable to be exposed in contact with hydrocarbons, said process comprising the steps of:
• the protection of the exposed surface is obtained during the manufacture of the elements constituting the box structure at the stage of the elementary part and the application of this protection does not change the assembly time of the structure.
• the parts are perfectly accessible and the protection is provided uniformly over the entire surface covered by the film.
• the co-firing of the film and the part ensures the cohesion of the film on the protected surface.
• the film being thin, the added mass is small.
• the matrix consists of an epoxy thermosetting resin and the protective film consists of a polyetheretherketone polymer (PEEK) with a thickness of between 0.015 mm and 0.035 mm.
• PEEK polyetheretherketone polymer
• the properties of the PEEK film are not affected by the baking of the epoxy resin, said film being otherwise perfectly resistant to the hydrocarbons used as aircraft fuel, it adds only a mass of a few tens of grams per m 2 of surface on which it is applied.
• the protective film deposited in step b) of the method which is the subject of the invention does not cover the entire face exposed to hydrocarbons.
• the method that is the subject of the invention makes it possible to preserve areas that are not covered by the protective film, in particular for gluing or assembling with other parts.
• step b) of the method which is the subject of the invention comprises the operations of:
• the protective film comprises a layer of a pressure-sensitive adhesive, called PSA, on one of its faces.
• PSA is the acronym for the English expression "Pressure Sensitive Adhesive”.
• the protective film is deposited in several layers with overlaps of the edges of said strips.
• the method which is the subject of the invention is suitable for covering large elementary parts while ensuring the seal between the deposited protective film strips.
• the method which is the subject of the invention comprises, between steps b) and c), a step consisting of:
• the invention also relates to a method for manufacturing a box structure having a volume adapted to contain fuel which method comprises the steps of:
• step ii) of the method is carried out by riveting.
• step ii) of the process is carried out by gluing.
• the invention also relates to an aircraft comprising a box structure of which an empty volume is used as a fuel tank, said box structure comprising a structural element comprising a composite panel with fiber reinforcement obtained according to the method which is the subject of the invention.
• the use of composite materials for the constitution of this box structure associated with the method of protection of these materials makes it possible to achieve a gain in mass compared to the known solutions of the prior art and to facilitate the manufacture of such a structure.
• the aircraft object of the invention is advantageous both in terms of manufacturing cost and operating cost.
• FIG. 1 is a partial sectional view and exploded of an embodiment of a box structure according to the invention
• FIG. 3 shows in perspective and exploded one of the elementary parts of the box structure of Figures 1 and 2 during the production of said part elementary;
• FIG. 4 is a flowchart showing the steps of the method according to an exemplary embodiment of the invention.
• the box structure (100) object of the invention consists of a plurality of elementary parts (1 10, 121, 122) made of a composite material with fibrous reinforcement.
• said composite material comprises carbon fibers in an epoxy resin matrix.
• the elementary parts are assembled along assembly interfaces (1 12, 1 13). This assembly can be achieved by gluing or co-cooking. Alternatively or jointly, the assembly can be made by riveting. These assembly techniques are known from the prior art and are not discussed further.
• the interior volume (150) of this box structure is likely to contain fuel.
• this protective film consists of polyetheretherketone or PEEK.
• Such films are, for example, marketed under the trademark APTIV® by VICTREX®.
• mastic 2 ⁇ 2 ⁇ mastic (212, 213) ⁇ 2 ⁇ 2 ⁇ 2 ⁇ 2 ⁇ 2 ⁇ 2 ⁇ 2 ⁇ 2 ⁇ 2 ⁇ 2 ⁇ 2 ⁇ 2 ⁇ 2 ⁇ 2 ⁇ 2 ⁇ 2 ⁇ 2 ⁇ 2 ⁇ 2 ⁇ 2 ⁇ 2 ⁇ 2 ⁇ 2 ⁇ 2 ⁇ 2 ⁇ 2 ⁇ 2 ⁇ 2 ⁇ 2 ⁇ 2 ⁇ 2 ⁇ 2 ⁇ 2 ⁇ 2 ⁇ 2 ⁇ 2 ⁇ 2 ⁇ 2 ⁇ 2 ⁇ 2 ⁇ 2 ⁇ 2 ⁇ 2 ⁇ 2 ⁇ 2 ⁇ 2 ⁇ 2 ⁇ 2 ⁇ , mastic based on polythioether distributed under the name PR by the company Le Joint faci®.
• FIG 3 according to an exemplary embodiment of an elementary part (1 10) of the box structure object of the invention, said piece is made by draping folds of prepreg fibers.
• the draping may be partially performed around a core (310) for example around a honeycomb plate.
• This draping can be automatic or manual.
• the protective film is placed on the fuel-exposed area of the preform of the workpiece (1 10), for example in the form of a plurality (331, 332) of PEEK film webs.
• Each strip (331, 332) comprises a zone of overlap with the side which is juxtaposed to it, so that the junction between two strips is sealed.
• the protective film is here represented in a rectilinear cut.
• the contour of the film may be more complex so as to save savings (331, 332) of a more complex form.
• the strips (331, 332) of the protective film are, before being laid, cut to the desired contour.
• the operation of laying protective films is performed manually. It is greatly facilitated by the fact that the elementary piece is flat, accessible from all sides during this operation.
• the protective film can also be cut into several strips so as to facilitate handling thereof.
• the outline of the lé to be deposited on the preform can be projected by laser on said preform according to a known method of the prior art for manual draping.
• the protective film strips are stabilized on the structure during installation, thanks to the tackiness of the folds previously draped.
• the protective film strips may be applied to the preform by compacting under a vacuum bag just before said preform is fired.
• the protective film is advantageously treated on its face in contact with the resin constituting the matrix of the part, by a method to increase the wettability so as to improve the adhesion of the film to the part over its entire surface.
• Such a treatment consists in increasing the free surface energy of the film so that it is greater than that of the liquid resin and that said resin wets the surface of the film correctly during the cooking operation.
• this treatment carried out by plasma, UV or ozone, without this list being exhaustive, makes it possible to increase the free surface energy of the treated surface to a value between 55 and 60 Joules. m "1.
• treatment to improve the wettability is formed on both sides of the protective film.
• the protective film strips may be coated on all or part of their face. contact with the lamination, with a pressure-sensitive adhesive, or PSA, for example with a silicone-based adhesive, in order to facilitate their installation. So the The method of the invention is also suitable for producing parts from dry fibers, in particular by injection or infusion of resin.
• the method of the invention comprises a first series of steps corresponding to the realization of the elementary parts.
• a first step (410) of draping makes it possible to form the preform of the part.
• the protective film is cut to the target contour to cover all or part of the surface of the part exposed to hydrocarbons.
• the film strip thus cut is deposited on the preform during a step (430) of removing said strip.
• This lé is maintained on the preform by the tackiness prepreg folds previously draped, or by the presence of a PSA-type adhesive on all or part of the surface of the web in contact with the preform.
• the previous steps (420,430) are repeated for different threads to cover the entire hydrocarbon exposed surface of the workpiece.
• the preform is bagged, during a bagging step (440), and the whole is compacted, during a compaction step (450) by drawing vacuum. together and bagged.
• the preform is then directed to an autoclave for a cooking step (460).
• the firing is carried out at a temperature T1 of the order of 180 ° C.
• the protective film consisting of PEEK withstands perfectly this temperature T1 without undergoing degradation, that is to say without melting and without leakage of the film.
• the cooking may be partial so as to maintain a possibility of assembly by co-cooking.
• This assembly can be achieved by gluing, riveting or co-cooking according to methods known from the prior art.
• step (480) of completion the tightness of the interstices between the parts thus assembled is achieved by laying cords sealing mastic.
• the invention achieves the desired objectives, in particular it makes it possible to obtain a box structure made of a composite material with a fibrous reinforcement, said box structure comprising an empty volume capable of containing fuel, which structure is obtained economically and reproducibly, with a low added mass to obtain the seal of said empty volume and the protection of the structural materials vis-à-vis the contact with the hydrocarbons.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Composite Materials (AREA)
• Aviation & Aerospace Engineering (AREA)
• Sustainable Development (AREA)
• Sustainable Energy (AREA)
• Combustion & Propulsion (AREA)
• Transportation (AREA)
• Life Sciences & Earth Sciences (AREA)
• Moulding By Coating Moulds (AREA)
• Filling Or Discharging Of Gas Storage Vessels (AREA)
• Reinforced Plastic Materials (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Related Child Applications (1)

Publications (1)

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Family Applications After (1)

Country Status (7)

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Family Cites Families (21)

• 2011
  • 2011-10-28 FR FR1159817A patent/FR2981880B1/fr not_active Expired - Fee Related
• 2012
  • 2012-10-29 BR BR112014010170A patent/BR112014010170B1/pt not_active IP Right Cessation
  • 2012-10-29 CA CA2849707A patent/CA2849707A1/fr not_active Abandoned
  • 2012-10-29 US US14/352,685 patent/US9475586B2/en active Active
  • 2012-10-29 WO PCT/EP2012/071383 patent/WO2013060890A2/fr active Application Filing
  • 2012-10-29 EP EP12779065.7A patent/EP2771169A2/de not_active Withdrawn
  • 2012-10-29 EP EP18195582.4A patent/EP3446863B1/de active Active
  • 2012-10-29 ES ES18195582T patent/ES2785027T3/es active Active

Non-Patent Citations (2)

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