Classifications

• • D—TEXTILES; PAPER
  • D03—WEAVING
  • D03D—WOVEN FABRICS; METHODS OF WEAVING; LOOMS
  • D03D25/00—Woven fabrics not otherwise provided for
  • D03D25/005—Three-dimensional woven fabrics
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
  • B29B11/00—Making preforms
  • B29B11/14—Making preforms characterised by structure or composition
  • B29B11/16—Making preforms characterised by structure or composition comprising fillers or reinforcement
• • D—TEXTILES; PAPER
  • D03—WEAVING
  • D03D—WOVEN FABRICS; METHODS OF WEAVING; LOOMS
  • D03D11/00—Double or multi-ply fabrics not otherwise provided for
  • D03D11/02—Fabrics formed with pockets, tubes, loops, folds, tucks or flaps
• • D—TEXTILES; PAPER
  • D03—WEAVING
  • D03D—WOVEN FABRICS; METHODS OF WEAVING; LOOMS
  • D03D13/00—Woven fabrics characterised by the special disposition of the warp or weft threads, e.g. with curved weft threads, with discontinuous warp threads, with diagonal warp or weft
  • D03D13/004—Woven fabrics characterised by the special disposition of the warp or weft threads, e.g. with curved weft threads, with discontinuous warp threads, with diagonal warp or weft with weave pattern being non-standard or providing special effects
• • D—TEXTILES; PAPER
  • D03—WEAVING
  • D03D—WOVEN FABRICS; METHODS OF WEAVING; LOOMS
  • D03D41/00—Looms not otherwise provided for, e.g. for weaving chenille yarn; Details peculiar to these looms
• • D—TEXTILES; PAPER
  • D03—WEAVING
  • D03D—WOVEN FABRICS; METHODS OF WEAVING; LOOMS
  • D03D41/00—Looms not otherwise provided for, e.g. for weaving chenille yarn; Details peculiar to these looms
  • D03D41/004—Looms for three-dimensional fabrics
• • D—TEXTILES; PAPER
  • D10—INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
  • D10B—INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
  • D10B2505/00—Industrial
  • D10B2505/02—Reinforcing materials; Prepregs

Definitions

• the invention relates to a method for manufacturing a monoblock preform for a composite structure, and to a loom for implementing such a manufacturing method.
• the invention also relates to a composite beam whose preform is derived from the manufacturing method according to the invention.
• the production of a composite structure comprises the assembly of a reinforcement, generally in the form of fibers ensuring the mechanical strength of the structure, and a matrix ensuring the cohesion of the structure.
• the reinforcement may be formed by a two-dimensional fabric (2D) constituted by weft yarns woven with warp threads, this thread being for example made of carbon, Kevlar or glass.
• 2D two-dimensional fabric
• the matrix is also known as an organic or inorganic resin.
• the method of manufacturing the composite part will consist of a resin reinforcement molding (RTM) for resin transfer molding, by infusion of liquid resin (LRI for "Liquid Resin Infusion”), by resin film infusion (RFI) or by any other method of impregnation or resin infiltration, in dry fibrous elements.
• RTM resin reinforcement molding
• LRI liquid resin
• RFI resin film infusion
• any other method of impregnation or resin infiltration in dry fibrous elements.
• a recurring problem is related to the mechanical strength of this type of structure, frequently being delaminated between the layers.
• a known solution consists in producing a composite structure based on three-dimensional reinforcement (2.5D or 3D) having a better mechanical strength between the layers of fabric, compared to a 2D fabric assembly.
• such a structure may have different types of weave (mode of interlacing son together) depending on the selected weaving process.
• weave mode of interlacing son together
• 3D weaving whereby several layers of warp yarns are woven with several layers of weft threads, the assembly possibly being bonded by at least one so-called reinforcement warp thread. That is added in the thickness of the fabric in order to bind the different layers together.
• Mechanical resistance particularly delamination is increased compared to a 2D fabric assembly.
• the operation is carried out to give it the desired cohesion. It is necessary, before introducing the reinforcement into the mold for injection of resin, to give the reinforcement a shape that is as close as possible to that to which it is desired to achieve after completion of the cohesion operation.
• This preparation operation of the preform is accomplished for example through cutting, folding, etc. some parts of the preform. To achieve this phase of preparation of the preform, it is therefore essential that the preform is easily scalable.
• the fabric layers are bound together in the direction of the thickness.
• the present invention aims to solve all of the problems of the prior art, and aims at producing a monobloc preform, whose shape approximates to the most part of the composite piece to be manufactured, that is easily adjustable before operation. cohesion.
• the present invention relates to a method of manufacturing a monoblock preform for a composite structure comprising said preform forming the reinforcement of the structure and a matrix, said preform being made by a three-dimensional weaving process by means of a loom. weaving comprising at least one comb and at least two pairs of harnesses, each harness comprising a plurality of l isses, each of the rails being equipped with a plurality of eyelets each of which is intended for the passage of a warp, the at least two pairs of harnesses being distributed at different altitudes of the loom so as to form a plurality of stages, said method of manufacture characterized in that it comprises the following steps according to which:
• the completed preform can be modulated manually before proceeding to the step of giving cohesion to the preform.
• the manufacturing method according to the invention comprises an additional step for positioning on the loom means for separating adjacent layers of the preform.
• the means for separating the layers comprise at least one rod which is positioned at will during weaving, on the one hand between the comb and the pairs of harnesses, and on the other hand between the adjacent layers.
• At least a portion of a warp beam bundle is positioned on at least one stage of pairs of harnesses, so as to carry out during the introduction of weft son a current section of the preform, and at least one son warp beam is positioned at a different altitude of the same harness so as to realize, when the introduction of weft son, at least one extra thickness of the layer.
• the thickness of the piece is varied punctually so as to create a boss in the direction of the warp.
• the manufacturing method comprises a step for leaving at least one weft yarn free so as to define a non-impact machining area.
• the manufacturing method according to the invention also comprises an additional step for cutting and / or folding the preform so as to give it a shape close to that which it is desired to give to the composite structure.
• the warp yarns and the weft yarns are woven according to an interlock type weaving process.
• the invention also relates to a loom for implementing the manufacturing method according to the invention, remarkable in that it comprises a plurality of pairs of harnesses arranged side by side in the weft direction, to allow independent servoing of each of said harnesses.
• each of the harnesses corresponds to a width of extra thickness to give to the preform.
• the invention also relates to a composite beam intended to support the sliding of at least one thrust reverser cover of a turbojet engine nacelle, said beam comprising at least one three-dimensional preform and a cohesion matrix, and being remarkable in that said preform is derived from the manufacturing method according to the invention.
• FIG. 2 represents the flat-faced preform that is to be obtained by three-dimensional weaving
• FIG. 3 schematically represents the weave of the weave, that is to say the mode of interweaving of the warp threads and weft threads;
• FIG. 4 represents a second mode of interlacing of the warp and weft yarns
• FIG. 5 illustrates the preform shown in Figure 2, one of the tongues being folded
• FIG. 7 is similar to FIG. 6, according to another method of bonding the layers of the preform
• FIG. 8 represents the shape obtained by the mode of bonding of the layers represented in FIG. 7;
• FIG. 9 shows two layers of the preform, between which are installed means for separating the layers
• FIG. 10 illustrates the production of a boss in the C-chain direction of the preform
• Figure 1 1 shows the preform that one seeks to manufacture, whose view is centered on the rails;
• FIGS. 1 3 to 1 5 show the folding and cutting steps of the preform resulting from the weaving process
• FIG. 1 6 illustrates a step of the manufacturing method according to which one carries out a non-perpendicular loosening of the warp son
• An aircraft is driven by several turbojets each housed in a nacelle also housing a set of ancillary actuators related to its operation and providing various functions when the turbojet engine is in operation or stopped.
• These ancillary actuating devices include a mechanical thrust reverser actuation system, whose role is to help braking the aircraft during landing.
• a thrust reverser comprises one or more movable covers between, on the one hand, an extended position in which they open in the nacel a passage for deflected flow and, on the other hand, a retracted position in which they close this passage.
• the movable hood slide along one or more beams comprising rails so that, when moving back during the opening phase, they discover deflection vane grids arranged in the thickness of the nacelle, the cold air flow through the nacelle thus being expelled upstream of the nacelle.
• Figure 1 illustrates the beam of composite materials that it is desired to achieve.
• a composite structure comprises a piece of "stiffening", which gives the mechanical strength to the final structure, and a matrix, generally based on resin, which ensures the cohesion of the structure.
• the reinforcing structure is made according to the method according to the invention, according to which a 3D monoblock preform woven by the loom according to the invention is manufactured.
• Figure 2 illustrates the preform, flat, that is desired after the weaving 3D.
• the preform 1 comprises a tongue 3 at its lower part, surmounted by an intermediate wall 5, then a current section 7.
• the current section 7 comprises in its upper face 9 two tabs 1 1, of parallelepipedal shape, forming an extra thickness of the current section 7.
• the tongue 3, the intermediate wall 5, the current section 7 and the tongues 1 1 form sub-assemblies of the preform, which should be realized in a unitary manner, that is to say without having to report a subset with respect to another subset.
• the production of such a monobloc preform makes it possible, as we have stated previously, to give the final composite structure greater mechanical strength than that obtained by a reinforcement composed of multiple preforms.
• the preform 1 is made by three-dimensional weaving, and comprises in the direction of its length of the warp son (in the direction C), and in the direction of its width of the weft son (in the direction T).
• the weave of the weave that is to say the mode of interweaving warp son and weft son, is illustrated in Figure 3.
• Figure 3 shows in longitudinal section (in the direction of the chain) a zone of the preform that has been made by 3D weaving.
• the warp threads 13 take the form of saw teeth along the entire length of the illustrated area of the preform.
• Weft yarns 15 are installed perpendicular to the warp yarns, so as to bind the warp yarns together.
• interlock reinforcement is used as an example in the description, but it goes without saying that the preform can be made by any other type of reinforcement, for example of the "canvas", “twill", “satin”, etc. type.
• the warp and weft threads 15 do not intersect themselves, but the so-called "reinforcement” warp threads 16 are introduced through the preform into its thickness to maintain between them the weft son and the warp son.
• the density of the reinforcement warp yarn 16 is variable depending on the type of reinforcement retained.
• the subassemblies of the preform 1 can indifferently be made by any type of 3D fabric reinforcement, each subassembly possibly being made from a different reinforcement if the skilled person finds it of particular interest.
• the tongue 3 and the wall 5 will have to be linked together only in part, in order to be able to manipulate each of these subassemblies independently of one another. the other on the unbound part.
• Figure 6 illustrates in longitudinal section the manner in which the adjacent lower layers 17, forming the tongue 3, and upper 19, forming the wall 5, have been woven by means of the method according to the invention.
• the layers 17 and 19 comprise a plurality of warp 13 and weft 15 son.
• the layers 17 and 19 are independent on the portions 21a and 21b and are bonded to each other on the portion 23.
• the loom for performing this type of partial connection comprises a plurality of pairs of harnesses, arranged at different altitudes of the loom, forming a plurality of stages.
• a harness typically comprises two frames connected and separated by healds.
• Each leash comprises a plurality of eyelets into which the warp yarns are introduced.
• the loom comprises two stages of harnesses, i.e., a pair of lower harnesses and a pair of upper harnesses.
• the warp threads 13 are inserted at the beginning of the weaving process into the eyelets of the lower and upper harness pairs.
• the lower and upper harnesses are moved so as to create, when we introduce weft thread 15, the adjacent lower 17 and upper 19 layers, independently of one another, obtained for a limited amplitude of movement. harnesses.
• the adjacent layers 17 and 19 are made independent on the portions 21a and 21b and bonded to each other on the portion 23, which makes it possible to fold, for example manually or with the aid of a specific external machine of the tongue 3 with respect to the wall 5.
• the amplitude of the movements of the harness can be variable during weaving, so as to allow the realization of hollow shapes of different thicknesses.
• the movement amplitude of the harnesses is reduced on a portion 25, on which the weft threads are no longer installed, so as to form a hollow zone 27. of the complete craft by symmetry so as to obtain the piece shown in FIG. 8.
• the adjacent layers are of identical and constant thickness as shown in FIG. 8. However, it is entirely possible to produce adjacent layers of distinct and evolutive thickness through the manufacturing method according to the invention.
• This arrangement is advantageous because the preform can be equipped in this hollow area of a tool-piece to achieve a day in the final composite structure.
• This hollow zone may also be of interest when it is desired to integrate in the final composite structure a foam core or a "honeycomb" type, for example, advantageously making it possible to improve the mechanical strength of the final piece, especially in compression.
• separation means of the layers 17 and 19 are installed.
• the separating means comprise, as represented in FIG. 9, a rod 28 which is arranged between the comb of the loom (not shown) and the harnesses (not shown), and between two independent adjacent layers 1 7 and 1 9. This ensures that the warp son of one of the layers 1 7 or 19 are not inadvertently linked with weft son of the other layer 17 or 19.
• the harnesses of warp threads 13 are initially provided which are arranged so as to define, during the insertion of weft threads 15, the layer 17 corresponding to the current section of the preform.
• the harnesses are also provided with warp threads 29, arranged at a distinct altitude from the warp threads 13.
• Such a boss in the C-chain direction is made by temporarily installing during weaving weft threads 30 to a thickness 31 distinct from the layer 17 which defines the current section.
• the loom comprises a plurality of pairs of harnesses arranged side by side in the weft direction, so as to allow independent servoing of each of said harnesses.
• the width of a pair of harnesses corresponds to the widths of the extra thicknesses that it is desired to give the preform. It is then made possible to introduce weft yarn which will be bound to the structure only over predetermined widths of the preform so as to achieve a thickness over a predetermined width.
• each of the overthicknesses 1 1 corresponds to a pair of harnesses whose width of a region of ha rna is substantially equal to a width L d 'an extra thickness.
• the loom comprises as many pairs of harnesses as desired, each pair corresponding to a layer width.
• the extra thicknesses 1 1 of the current section 7 are intended to ensure the function of rails 32 of the beam, visible in Figure 1 1, along which will slide the thrust reverser cover.
• the rails 32 undergo significant mechanical forces when the hood runs off, and the manufacturing method according to the invention, which makes it possible to produce the preform in a single part, is particularly advantageous for providing the part with the mechanical strength it need. It should be understood that such levels of mechanical requirements can not be achieved by a preform manufacturing process according to the prior art, wherein the rails are inevitably constituted by preforms attached to the main preform.
• the warp son 13 are packed by the weft son 15, which allows to create a groove.
• the shape of the preform as illustrated in FIG. 14 is achieved by a step of folding the current section 7 of the preform along a line 33.
• these reinforcements are made from the preform 1, without having to bring additional part, which makes it possible to obtain good mechanical characteristics of the final composite structure.
• the reinforcements 34 are cut to give them their final shape, as shown in FIG.
• Warp threads that are not assembled with weft threads after the weaving process are cut.
• Figure 16 illustrating a step of the manufacturing method according to which one carries out a non-perpendicular loosening of the warp son.
• the rod 28 is mounted to move in translation on the loom in a direction parallel to that of the direction of the chain, and slides during weaving. This makes it possible to avoid the bonding of the two adjacent layers 17, 19 over the entire width of the fabric where the rod is located.
• two rods are provided each positioned at one end of the bonded part of the preform.
• the rods are movably mounted in translation on the loom, and move in a direction parallel to that of the direction of the chain, in a contrary direction.
• the reinforcements 34 must not be perpendicular to the wall 5 of the beam.
• the interlock links are stopped at an angle thanks to the rod.
• the preform can also be machined in order to produce bores 36, visible in particular in FIG.
• the preform there is provided in the preform a portion provided only with weft son.
• a non-impact machining area 37 corresponding to a portion of the layer in which weft son are left free, allowing not to assigning the vertices 39 of warp threads 13 during a piercing operation.
• the links between them do not have a good mechanical strength.
• the preform described in the invention can be made indifferently by replacing the warp son by the son of frame, and replacing the weft threads by the warp threads. This substitution can allow a saving in manufacturing time of the preform or a reduction in the loss of material.
• weft son and the warp son may also be interesting to interchange the weft son and the warp son according to the nature of the loom, or depending on the technical constraint related to the geometry of the part to be manufactured.
• the manufacturing method is not limited in any way to the manufacture of a preform of a thrust reverser beam, this example having been described solely for the purpose of illustrating the implementation of the method but applies in contrast to any three-dimensional weaving process.

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• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Mechanical Engineering (AREA)
• Woven Fabrics (AREA)
• Moulding By Coating Moulds (AREA)
• Looms (AREA)

Applications Claiming Priority (2)

Publications (1)

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ID=48083531

Family Applications (1)

Country Status (7)

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Family Cites Families (23)

• 2012
  • 2012-03-22 FR FR1252563A patent/FR2988407B1/fr not_active Expired - Fee Related
• 2013
  • 2013-03-21 CN CN201380015570.1A patent/CN104204320A/zh active Pending
  • 2013-03-21 EP EP13715365.6A patent/EP2828426A1/fr not_active Withdrawn
  • 2013-03-21 WO PCT/FR2013/050609 patent/WO2013140100A1/fr active Application Filing
  • 2013-03-21 RU RU2014141870A patent/RU2014141870A/ru not_active Application Discontinuation
  • 2013-03-21 CA CA2866617A patent/CA2866617A1/fr not_active Abandoned
• 2014
  • 2014-09-22 US US14/492,277 patent/US20150007905A1/en not_active Abandoned

Non-Patent Citations (1)

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