Classifications

• • 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
• • 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
  • B29C70/28—Shaping operations therefor
  • B29C70/54—Component parts, details or accessories; Auxiliary operations, e.g. feeding or storage of prepregs or SMC after impregnation or during ageing
  • B29C70/543—Fixing the position or configuration of fibrous reinforcements before or during moulding
• • 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
  • B29C70/28—Shaping operations therefor
  • B29C70/30—Shaping by lay-up, i.e. applying fibres, tape or broadsheet on a mould, former or core; Shaping by spray-up, i.e. spraying of fibres on a mould, former or core
  • B29C70/38—Automated lay-up, e.g. using robots, laying filaments according to predetermined patterns
  • B29C70/382—Automated fiber placement [AFP]
• • 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
  • B29C70/28—Shaping operations therefor
  • B29C70/54—Component parts, details or accessories; Auxiliary operations, e.g. feeding or storage of prepregs or SMC after impregnation or during ageing
  • B29C70/545—Perforating, cutting or machining during or after moulding
• • 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
  • B29K2105/00—Condition, form or state of moulded material or of the material to be shaped
  • B29K2105/06—Condition, form or state of moulded material or of the material to be shaped containing reinforcements, fillers or inserts
  • B29K2105/08—Condition, form or state of moulded material or of the material to be shaped containing reinforcements, fillers or inserts of continuous length, e.g. cords, rovings, mats, fabrics, strands or yarns
  • B29K2105/0872—Prepregs
  • B29K2105/089—Prepregs fabric

Definitions

• the present invention relates to the field of manufacturing parts made of composite material, in particular but not exclusively in the aeronautical, naval, wind power and automotive sectors, such parts comprising a matrix, in particular polymer or ceramic, and a fibrous reinforcement.
• the invention relates to a method of manufacturing a three-dimensional preform, as well as a preform obtained by such a method, a method of manufacturing a part made of three-dimensional composite material made from such a preform and a installation for implementing the method according to the invention.
• WO 2015/170016 discloses a method of manufacturing three-dimensional preforms by draping fibers on a tool.
• the adhesion of the fibers to the tool can be achieved by the presence of a binder in the fibers, this binder can in particular be activated by heating.
• a binder in the fibers
• This binder can in particular be activated by heating.
• Such a process has the advantage of being able to produce parts in composite material with good mechanical strength due to the orientation of the fibers.
• the need for heat makes the process expensive and can slow down production rates.
• AFP automated fiber placement machines
• ATL automatic tape laying machines
• WO 2007/010050 discloses a device for the manufacture, using a TFP process, of a fiber preform having almost any surface geometry, in which a strand of fibers can be placed on a backing layer, with the using guide means, along a curved path, said strand of fibers being able to be fixed to said support layer by means of a fixing thread by means of the sewing head.
• DE 101 23 064 describes the stitching of a reinforcing fiber on a foam core using a padding process.
• DE 102009041177 presents a method of producing a three-dimensional composite part comprising the application of a fiber on a base textile rotated on a support.
• DE 102014201278 describes a device for fixing a reinforcing strip on a support layer.
• the device includes means for continuously distributing a reinforcing tape, pressing means for pressing the reinforcing tape onto the backing layer, and sewing means for stitching the backing tape to the backing layer.
• EP 1 584462 discloses the manufacture of a dry preform comprising successive layers of continuous reinforcing fibers.
• the present invention provides, according to one of its aspects, a method of manufacturing a three-dimensional preform comprising the following steps: a) depositing at least one strip of fibers on a substrate of three-dimensional shape, b) fixing by sewing said at least one strip of fibers on the substrate, with at least one sewing thread.
• Step a) is advantageously carried out so that the strip (s) of fibers match the shape of the substrate and are fixed in step b) in this position.
• a strip of fibers is deposited and it is fixed by sewing as it is deposited.
• a method is provided which enables a three-dimensional preform to be produced without requiring the use of an AFP or ATL machine.
• strip of fibers is understood to mean an assembly of fibers, optionally impregnated with a material, for example in the form of a prepreg tape, called “tape” in English, of a coil of dry fibers, called roving in English, of a mixture of reinforcing fibers and thermoplastic matrix yarn, also known as "comêlé".
• the strips of fibers have, for example, a width of between 1 mm and 600 mm, preferably less than 100 mm.
• fixing by stitching is meant “assembling by means of a thread passed through a needle”. The result is a seam with at least one thread.
• the installation according to the invention, described below, can make it possible to carry out such an operation.
• said at least one strip of fibers is deposited on the substrate so as to form a fold of said three-dimensional preform, in particular with a predetermined orientation of the fibers.
• the term “ply” is understood to mean a layer of the three-dimensional preform comprising at least one strip of fibers, in particular several strips of fibers deposited side by side.
• the method may include repeating steps a) and b), at least once, so as to form at least one additional fold on the previously formed fold.
• the additional ply may have a different fiber orientation than the fiber orientation of the underlying ply.
• the fibers may or may not have the same orientation.
• Circular draping can be implemented.
• the tape is then laid in a circular fashion.
• said at least one strip of fibers is pressed against the substrate, in particular with the aid of a roller, and preferably as it is being deposited. of the band, before fixing by sewing in step b). In this way, sewing is facilitated and the smoothness of the fiber strip is improved. In addition, by pressing, it is possible to control the direction of depositing said at least one strip of fibers.
• the method may include the step of cutting the or each strip of fibers, in particular after fixing by stitching, in at least one predefined location, for example after making a complete straight line using the strip, in particular before each change in the direction of depositing said at least one strip of fibers.
• This cut can make it possible to limit the losses of material as well as the formation of loops on the strip of fibers during changes of direction, for example. You can use a specific knife to cut the strip precisely and without damaging it.
• the fixing by sewing is preferably carried out by moving a sewing head, in particular using a robot or robot arm, relative to said at least one strip of fibers.
• the sewing head is moved, preferably with the aid of a robot or robot arm, relative to said at least one strip of fibers, both in the direction of laying of the strip and also transversely to it. the latter on one side and then on the other side of the strip so as to form stitches on either side of the latter.
• the seam is then in the form of a zig zag stitch around the or each strip of fibers.
• Different stitching points may be suitable, in particular for fixing the strip of fibers after its removal, the preferred stitching point being the zig zag stitch, as indicated above.
• the width of the zig zag stitch can be adapted to the width of the strip of fibers deposited on the substrate. It should be noted that it is also possible to make a straight stitch or chain stitch directly through the band of fibers, without departing from the scope of the invention.
• the stitching points are advantageously made so as not to cross the strip.
• said at least one sewing thread is made of a thermoplastic polymer material.
• said at least one sewing thread is made of another material, in particular a ceramic material or another polymer material.
• the material constituting the sewing thread can be chosen from the group consisting of thermosetting polymers.
• the width of said at least one strip of fibers can vary within the same preform. Such a variable width of the strip of fibers can make it possible to adapt the rigidity of the strip of fibers as a function of the local curvature of the substrate and to optimize the deposit rate. In areas with a complex geometry (strong curvature), it is preferable or even necessary to reduce the width of the strip so as to facilitate its removal and guarantee its flatness. In areas where the geometry is simpler (flat areas), the bandwidth can be increased so as to increase the amount of material deposited per unit of time.
• Said at least one strip of fibers is preferably unwound from at least one reel before being deposited in step a).
• the substrate can be flexible.
• the method may include the step of stretching the substrate, locally or in its entirety, and performing step b) on the substrate thus stretched.
• the substrate When it is flexible, the substrate can be fixed, to be tensioned locally or in its entirety, on a rigid tool, in at least one zone, so as to achieve its three-dimensional shape.
• a rigid tool Preferably, such a rigid tool is perforated and / or movable so as to free up sufficient space to sew the strip of fibers.
• the substrate can be rigid.
• the substrate can be made from a thermoplastic polymer material, for example but not exclusively polypropylene, polyester, polyamide, polyetheretherketone (PEEK), polyetherketoneketone (PEKK), polyether sulfone (PES) ) and / or polyetherimide (PEI).
• the substrate may merge with the matrix of the final composite material part, made from the preform, during its shaping. The number of foreign bodies in said part made of composite material is then reduced, which can improve its quality.
• the substrate can be made of a material other than a polymer material, for example a woven fabric, for example a carbon fabric or glass fabric, among others.
• Said at least one strip of fibers may comprise at least one additional element, in particular at least one sensor and / or at least one electronic circuit and / or at least one metallic element and / or any type of long body and / or any continuous element. and narrow.
• long body is meant a tube, for example. It is thus possible to position cooling channels for example.
• the width of the long body is advantageously less than the width of the stitching point so as not to be pierced.
• three-dimensional composite material parts comprising an electronic system.
• a composite material part capable of communicating on its temperature, on its internal stresses and / or on its accelerations to an external or internal system, for example an electronic chip with diodes and / or a display. .
• the strip of fibers preferably comprises fibers chosen for example from the group consisting of carbon fibers, glass fibers, ceramic fibers, fibers of polymeric material, for example thermoplastic, in particular aramid fibers or fibers. polyester, fibers of plant origin, in particular flax fibers, optical fibers, metal fibers, preferably carbon and glass fibers, long bodies and a mixture thereof.
• the fiber web may have a shape selected from the group consisting of rovings, woven, knitted, braided, and a mixture thereof.
• long continuous fiber is used which will only be cut during removal.
• the fibers of said at least one fiber strip are dry.
• the fibers of said at least one strip of fibers are pre-impregnated.
• said at least one strip of fibers may comprise a mixture of reinforcing fibers previously impregnated with a polymer material, such as a polypropylene, a polyester, a polyamide, a polyetheretherketone (PEEK), a polyetherketoneketone (PEKK). , a polyether sulfone (PES) and / or a polyetherimide (PEI) .z
• the fibers of said at least one strip of fibers comprise reinforcing fibers chosen from carbon fibers, glass fibers, ceramic fibers, aramid fibers and / or fibers. of plant origin, in particular flax fibers and fibers of polymer material chosen from among polypropylenes, polyamides, polyetheretherketones (PEEK) and / or polyetherketonketones (PEKK). The fibers are then said to be “co-mingled”.
• Another subject of the invention is a three-dimensional preform produced using a process as defined above.
• the preform may comprise between 1 and 500 folds superimposed on one another, preferably between 10 and 500 folds, more preferably between 50 and 100 folds, for example approximately 100 folds.
• Two adjacent plies may have different fiber orientations, for example differing by an angle between 0 ° and 90 °.
• the invention relates, according to another of its aspects, in combination with the above, to a method of manufacturing a three-dimensional part made of composite material, comprising the following steps: producing a three-dimensional preform using the method as defined above, format the part by consolidating or adding a die.
• the method may include the step of moving the three-dimensional preform in a tool such as a mold, a press, an autoclave or an oven after making the preform and in order to shape it.
• a tool such as a mold, a press, an autoclave or an oven
• the step of shaping the preform by consolidation consists, for example, in heating and / or compressing the preform in a press, an autoclave or an oven.
• the step of shaping the preform by adding a matrix consists, for example, of impregnating, infusing, injecting a polymer material in fluid form into the preform placed in a mold. It includes the polymerization of the polymer material.
• the step of shaping the preform by adding a matrix can also consist, for example, in depositing, by gas cracking or by pyrolysis of an organic material (polymer, coal pitch, etc.), d 'a ceramic matrix on the preform.
• the composite material part comprises a fibrous reinforcement and a polymer or ceramic matrix.
• the fibers of the three-dimensional preform are dry, they constitute the fibrous reinforcement of the part made of composite material when it is shaped by adding a matrix, in particular by infusion or injection.
• the fibers of the three-dimensional preform When the fibers of the three-dimensional preform are pre-impregnated, the fibers form the fibrous reinforcement and the polymer material impregnating the fibers forms all or part of the polymer matrix of the part made of composite material during its shaping, in particular by consolidation.
• the fibers of the three-dimensional preform comprise a mixture of reinforcing fibers and fibers of polymer material, also called “coiled fibers”, the reinforcing fibers form the fibrous reinforcement and the fibers of polymer material form all or part of the polymer matrix. of the composite material part during its shaping, in particular by consolidation.
• said at least one sewing thread used for the manufacture of the three-dimensional preform is made of the same thermoplastic polymer material as the matrix
• the sewing thread may merge into the matrix during the shaping of the part. in final composite material. This limits foreign bodies in the final composite material part.
• said at least one sewing thread used for the manufacture of the three-dimensional preform is made of a polymer material other than the matrix, in particular a material with a melting point higher than the melting temperature of the material of the matrix, there is no fusion of the die and the wire, which can make it possible to improve the hot handling of the preform by a robot, for example.
• Another subject of the invention is a three-dimensional part made of composite material, comprising a fibrous reinforcement and a polymer matrix, obtained using the process for manufacturing a composite material. part made of three-dimensional composite material as defined above.
• Such a composite material part made from a three-dimensional preform comprising at least one strip of fibers comprising at least one optical fiber can make it possible to transfer information through the composite material part.
• the invention also relates, according to another of its aspects, in particular in combination with the foregoing, an installation for implementing the method of manufacturing a three-dimensional preform as defined above, the installation comprising: a three-dimensional substrate, at least one depositing head comprising at least one spool carrying said at least one wound strip of fibers, at least one sewing head configured to sew with at least one sewing thread said at least one strip of fibers on the substrate.
• the depositing head may comprise: at least one knife for cutting the strip of fibers, and / or at least one support member, in particular a roller, for pressing said at least one strip of fibers against the substrate.
• the installation preferably includes a fiber placement machine
• the sewing head preferably comprises a bobbin and a needle, in a manner known per se.
• the installation may include rigid tooling to tension the substrate locally or in its entirety, when the latter is flexible.
• the installation may include an arm, preferably robotic, in particular in the form of a swan neck, carrying at least the sewing head.
• an arm preferably robotic, in particular in the form of a swan neck, carrying at least the sewing head.
• Such an arm is advantageously configured to hold the bobbin fixedly relative to the needle while surrounding the substrate.
• the sewing head can be configured to be moved, in particular by the arm, relative to said at least one band of fibers, so as to produce stitches on either side of the latter while at the same time. advancing.
• the installation may include a plurality of coils each carrying at least one wound band of fibers.
• the installation can include a plurality of sewing heads, each of them being coupled to at least one spool. It is thus possible to deposit and sew, for example simultaneously, several bands of fibers on the substrate at different locations on the substrate. This can make it possible to increase the production rate of the preform, each sewing head being responsible for depositing the strip of fibers on only one predefined zone.
• the coil (s) and the sewing head can be moved relative to the substrate.
• the substrate is fixed and the spool (s) and the sewing head are movable.
• the substrate is movable and the spool (s) and the sewing head are stationary.
• the substrate, the spool (s) and said sewing head are movable in a complementary manner in order to achieve the desired stitches.
• Figure 1 shows, schematically, partial and in cross section, an example of a preform made using the manufacturing process according to the invention
• Figure 2 shows, schematically, partial and in top view, part of the preform of Figure 1,
• Figure 3 shows, schematically and in perspective, a fold of an example of a preform being produced with the method of the invention
• Figure 4 shows, schematically and in perspective, the preform of Figure 3 with a second fold
• Figure 5 shows in isolation, schematically and in perspective, the rigid substrate for the manufacture of the preform of Figures 3 and 4,
• Figure 6 shows, schematically and in perspective, another example of a preform according to the invention
• Figure 7 shows, schematically and in cross section, an example of an installation according to the invention
• FIG. 8 shows in isolation, schematically and in perspective, a flexible substrate and its rigid support for the manufacture of a preform according to the invention
• FIG. 9 shows in isolation, partially and schematically an example of a strip of fibers that can be used to make a preform according to the invention
• Figure 10 shows in isolation, partially and schematically, another example of a strip of fibers
• Figure 11 shows in isolation, partially and schematically another example of a strip of fibers
• FIG. 12 is a block diagram view illustrating the steps of an example of a method of manufacturing a part made of composite material according to the invention
• FIG. 13 is a schematic perspective view of another example of an installation according to the invention.
• FIG. 1 illustrates an example of a three-dimensional preform 1 produced by implementing the method according to the invention.
• a strip 2 of fibers 5 is conveyed and deposited on a three-dimensional substrate 3.
• the strip 2 of fibers 5 is composed of glass fibers 5 pre-impregnated with 50% by mass of polymeric material, which are oriented in the strip 2 of fibers 5 in the direction of deposition thereof.
• the substrate 3 is made, in this example, in a rigid thermoplastic polymer material, for example in polyamide or in PEEK.
• the strip 2 of fibers 5 is then sewn onto the substrate 3. This attachment by stitching is carried out so that the strip 2 of fibers 5 matches the shape of the substrate 3. A seam 6 is made with a thread 4.
• the seam 6 is made on either side of the strip 2 of fibers 5, while advancing in the direction thereof, so as to form zig zag stitches 7.
• the width between two zig zag points 7, located opposite to each other from the strip 2 of fibers 5, is greater than the width of the strip 2 of fibers 5 so as not to cross it.
• This width can of course be different without departing from the scope of the invention. Likewise, it is possible to use other stitches. Likewise, it is possible to reduce the width so as to sew through the web of fibers.
• the bands 2 of fibers 5 are deposited parallel to each other and cover at least part of the surface 40 of the underlying substrate 3 delimited by an outline 8.
• the bands 2 of fibers 5 do not overlap, in this example, the outline 8. .
• the method may include the step of depositing the strips 2 of fibers 5 so as to form a first ply 9.
• the bands 2 of fibers 5 have the same width, are mutually parallel and cover more than 90% of the surface 40 of the substrate 3.
• the first ply 9 then has a surface 41 delimited by an outline 10.
• the fibers 5 of the bands 2 of the first ply 9 are substantially parallel to each other, which gives a predominant orientation to the first ply 9, in this example substantially orthogonal to the curved longitudinal axis X.
• the outline 8 of the substrate 3 has two edges 12 opposite the longitudinal ends in this example.
• a second ply 13 can be deposited on the first ply 9, as illustrated in FIG. 4.
• This second ply 13 is also fixed on the substrate 3 by a seam.
• the direction of deposition of the bands 2 of fibers 5 makes an angle of 45 ° with respect to the direction of deposition of the bands 2 of fibers 5 of the ply 9 and therefore an angle of 45 ° with respect to the ply.
• curved longitudinal axis X Therefore, the fibers 5 of the second ply 13 and the fibers 5 of the first ply 9 form an angle of 45 ° between them.
• the bands 2 of fibers 5 of the second ply 13 have the same width between them and cover more than 90% of the surface 41 delimited by the contour 10 of the first ply 9.
• the second ply 13 then itself defines a surface 42 delimited by an outline 14. So that the bands 2 of fibers 5 of the second ply 13 do not overlap the outline 10 of the first ply 9, they have an end 15 of suitable shape.
• the strips 2 of fibers 5 can for example be cut during installation, line by line, once the strip has been deposited and, preferably, sewn. P is also possible to deposit and sew other plies of bands of fibers with a variation of orientation of the fibers, or not, without departing from the scope of the invention.
• the substrate 3 has a double curvature shape.
• the substrate 3 is in the form of a three-dimensional rigid mold 32, as in FIG. 5. It has the desired shape for the preform 1.
• the substrate 3 in the form of the rigid mold 32 retains its rigidity afterwards. production of the seam (s) of the strip (s) 2 of fibers 5.
• the substrate 3 is curved along the longitudinal axis X only, and has a zone of strong curvature 22 surrounded by zones of weak curvature 21.
• the ply 9 comprises strips of different widths deposited. on the substrate 3, in this case wide bands 19 and narrow bands 20.
• the bands 19 are, in this example, deposited on the areas of low curvature 21 and the bands 19 in the area of high curvature 22.
• the bands 19 and 20 are, apart from their width, identical in material and assembly in this example. It is nevertheless possible to use bands 19 and 20 made of different materials and / or with fibers assembled in different ways.
• G installation 23 is used, an example of which is illustrated in FIG. 7.
• the installation 23 comprises a depositing head 24 and a sewing head 25.
• the depositing head 24 comprises a reel 28 of wound strip 2 of fibers 5 and a support member 29, in this example in the form of a roll.
• the depositing head 24 allows the strip 2 of fibers 5 to be conveyed to the substrate 3 from the reel 28 from which it is unwound and is moved in the direction of depositing the strip 2.
• the strip 2 is pressed on the substrate 3 by the support member 29.
• the support member 29 makes it easier to sew the strip 2 of fibers 5 on the substrate 3 and ensure good smoothing of the strip 2 of fibers 5.
• the member d The support 29 also makes it possible to control the direction of depositing the strip 2 of fibers 5.
• the depositing head 24 also comprises, in this example, a knife 30 which makes it possible to cut the strip 2 of fibers 5 in a predetermined and precise manner, without damaging the strip 2, once the strip 2 has been placed on a complete line or segment.
• the cutting the strip 2 of fibers 5 makes it possible in particular to prevent the formation of loops during changes in direction of the depositing head 24, in particular at the ends 31 of the substrate 3.
• the sewing head 25 comprises a needle 26 and a bobbin 27 fixedly connected to one another by an arm 50, in this case a robotic arm, in the form of a gooseneck, which carries the sewing head 25.
• an arm 50 in this case a robotic arm, in the form of a gooseneck, which carries the sewing head 25.
• the latter makes it possible to produce the seam 6 of the strip 2 of fibers 5 on the substrate 3 with two threads 4, one being moved using the needle 26 and the other being unwound from the bobbin 27 so as to achieve the zig stitches zag 7.
• the zig zag points 7 pass through the substrate 3 on either side of the strip 2 of fibers 5, preferably while avoiding crossing the latter.
• the arm 50 moves the sewing head 25 relative to the strip 2 of fibers 5 so as to make the seam 6 in zig zag stitches 7 while advancing along the strip 2 of fibers 5 during its deposition by the head of removal 24.
• the seam 6 is thus produced by an alternation of points 7 on either side of the strip 2 of fibers 5 deposited.
• the average speed of movement, in the direction of deposition of the strip 2, of the sewing head 25 carried by the arm 50 is close to the speed of movement, in the direction of deposition of the strip 2 of fibers 5, of the dispensing head 24.
• the substrate 3 is made of a rigid material.
• the substrate 3 can also be in a flexible form, as in FIG. 8. Such a substrate 3 is, in this example, stretched by a rigid tool 34 perforated which makes it possible to form a mold.
• the sewing head 25 can be configured so as to be able to locally tension the substrate 3 in the sewing zone at an instant t, that is to say substantially in line with the bobbin 27 and the needle. 26, as the stitching is carried out, for example to improve the quality of the stitching of strip 2 of fibers 5.
• the method for manufacturing the preform 1 may include the step of removing the surface of the substrate 3 delimited between the outline 8 and the outline 35.
• the substrate 3 can comprise a thermoplastic polymer material, a thermosetting polymer material and / or a woven fabric. It can also include other materials without departing from the scope of the invention.
• the strips 2 of fibers 5 may be in the form of dry fibers, coalesced fibers or pre-impregnated fibers.
• the bands 2 of fibers 5 may also comprise, as in the embodiment illustrated in FIG. 9, one or more optical fibers 36 and / or an additional element 37, for example a sensor, an electronic circuit and / or a metallic element. .
• the fibers 5 in the strip 2 can be parallel to each other and preferably oriented in the direction of deposition of the strip 2, as in the embodiment illustrated in FIG. 10. Such an arrangement can correspond to a strip 2 of rovings. fibers.
• the fibers 5 in the strip 2 can still intersect with each other in different directions, as in the embodiment illustrated in FIG. 11. Such an arrangement can correspond to fibers 5 woven, knitted and / or in the form of wicks.
• the invention also relates to a method of manufacturing a part made of composite material comprising two steps.
• the first step 38 of this method consists in producing a three-dimensional preform 1 according to the method described above and then in shaping the preform 1 in a second step 39.
• the three-dimensional preform 1 is placed in a tool, for example a mold, an oven, an autoclave, a press, in order to shape it.
• the three-dimensional preform 1 can be heated and / or compressed, in particular if the latter comprises strips of pre-impregnated fibers or strips of co-mingled fibers.
• a polymer material it is possible to infuse, impregnate or inject in order to shape the part made of composite material, in particular when the three-dimensional preform comprises strips of dry fibers.
• a ceramic matrix by gas cracking or by pyrolysis of an organic material (polymer, coal tar pitch).
• FIG. 13 Another example of installation 23 according to the invention is shown in FIG. 13.
• the installation 23 comprises a robot 51 in the form of an arm articulated along six axes, carrying a frame 52, which supports the arm 50 in the form of a gooseneck.
• the frame 52 comprises, above and below, rails 53 provided with bearings 55 and hydraulic jacks 54.
• the arm 50 as visible, is supported by the frame 52 by a parallel axis. to the rails 53, provided with the hydraulic cylinders 54, and is mounted on the rails 53 so as to be able to move according to the double arrow.
• the arm 50 supports the sewing head 25 and the dispensing head 24.
• the mounting on the rails 53 of the arm 50 in the form of a gooseneck allows the movement of the sewing head 25 integrally with the dispensing head 24 and relative to the substrate 3.
• the depositing head 24 consists in this example of a motorized unwinder, fixed on the sewing head 25, which makes it possible to unwind the strip of fibers while the robot advances.
• Two adjacent plies may have a fiber orientation that is 45 °, 90 °, or another angle, or not.
• the bands of fibers 2 can also be made of different materials and / or assembled in a different way. For example, it is possible to have a mixture of carbon and glass fibers, both dry or prepreg.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Composite Materials (AREA)
• Robotics (AREA)
• Textile Engineering (AREA)
• Moulding By Coating Moulds (AREA)
• Reinforced Plastic Materials (AREA)
• Processing And Handling Of Plastics And Other Materials For Molding In General (AREA)

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• 2020
  • 2020-04-28 FR FR2004228A patent/FR3109551B1/fr active Active
• 2021
  • 2021-04-27 EP EP21723953.2A patent/EP4142997A1/de active Pending
  • 2021-04-27 US US17/997,115 patent/US20230166462A1/en active Pending
  • 2021-04-27 WO PCT/EP2021/060917 patent/WO2021219593A1/fr unknown

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