Part with filling portions

Abstract

The invention relates to a method for manufacturing a part (300) comprising at least one first platform (310) and one or more branches (330), the method comprising: - arranging a fibrous blank (111) in a mould (510) comprising one or more grooves (512); - injecting a filling material (112) so as to fill the grooves (512) of the mould (510); - heat-treating the blank (111) and the injected filling material (112) so as to obtain a first platform preform (210); - assembling the first platform preform (210) to one or more branch preforms (230) in order to obtain a fibrous assembly (200); - densifying the fibrous assembly (200) with a matrix so as to obtain the part (300).

Description

Description Title of the invention: Part with filling portions Technical Field

[0001] The present invention relates to the manufacture of turbine blades, and more particularly to the manufacture of stator blades. Such blades are conventionally manufactured in a bladed wheel sector. The present invention may also relate to the manufacture of other parts comprising "T"-shaped portions or "I"-shaped or "H"-shaped portions. Prior art

[0002] Stator blades are traditionally formed by an aerodynamic profile connecting an internal platform to an external platform. Stator blades are currently made of metal, particularly titanium. It is now preferable to make stator blades from composite materials, particularly organic matrix composite (OMC) materials. Indeed, organic matrix composite (OMC) materials are lighter than most metals while retaining good mechanical properties. Thus, their use contributes to optimizing the performance of turbomachines or turbomachinery equipment, particularly by reducing the overall mass of the turbomachine. The efficiency of the turbomachine is improved, which allows for a reduction in fuel consumption and thus a reduction in harmful emissions (CO, CO2, NOx, etc.).Thus, organic matrix composite materials (OMCs) are already used for fan blades, as described in document FR 3 068 640.

[0003] However, achieving the optimal amount of material at the junction between the airfoil and the platforms is difficult. The radius between the airfoil and the platforms may lack material or have unsatisfactory material quality.

[0004] Furthermore, it is desirable that the junction portion between the aerodynamic profile and the platforms has an evolving section: in fact, it is it is preferable that the joining portion be thick in the center and thinner towards the ends of said joining portion, in order to better follow the shape of the aerodynamic profile. Statement of the invention

[0005] The aim of the invention is to propose a solution making it possible to obtain a satisfactory quantity and quality of material at the radius between at least one platform and one or more branches extending from said platform.

[0006] To this end, the invention proposes a method for manufacturing a part made of organic matrix composite material, said part comprising at least a first platform and one or more branches extending transversely from the first platform, the method comprising:

[0007] - the arrangement of a first fibrous platform blank in a mold having an imprint, the imprint comprising a main portion having the shape of the at least one first platform to be produced and one or more grooves extending in the same direction of extension, the groove(s) comprising one or more injection ports, the first fibrous platform blank being arranged in the main portion of the imprint,

[0008] - the injection of a filling material through the injection port(s) so as to fill the grooves of the mold,

[0009] - the heat treatment of the first fibrous platform blank and the injected filling material so as to obtain a first platform preform to be produced comprising projecting filling portions extending in the direction of extension,

[0010] - demolding of the first platform preform,

[0011] - assembling the first platform preform with one or more branch preforms in order to obtain a fibrous assembly having the shape of the part to be obtained, the branch preform(s) extending transversely from the first platform preform, each filling portion being covered by one or more branch preforms,

[0012] - densification by a matrix of the fibrous assembly having the shape of the part to be obtained so as to obtain said part in composite material.

[0013] Such a manufacturing process makes it easy to obtain junctions between the branch and the platform(s) that are sufficiently filled and that have good material quality. The use of overmolding allows for easy automation of the process and excellent repeatability. In addition, the production of the filling by overmolding allows great freedom in the shape of the filling to be produced, thus making it easy to obtain a variable section depending on the direction of extension.

[0014] According to a particular embodiment of the invention, the part further comprising a second platform, the branch(es) extending between the first platform and the second platform, the fibrous assembly comprising a second platform preform assembled with the branch preform(s).

[0015] In particular, the invention may relate to a method for manufacturing a bladed wheel sector made of organic matrix composite material, said sector comprising an internal platform, an external platform and one or more aerodynamic profiles extending radially between the two platforms, the method comprising:

[0016] - the arrangement of a first fibrous platform blank in a mold having an imprint, the imprint comprising a main portion having the shape of one of the platforms to be produced and one or more grooves extending in the same direction of extension, the groove(s) comprising one or more injection ports, the first fibrous platform blank being arranged in the main portion of the imprint,

[0017] - the injection of a filling material through the injection port(s) so as to fill the grooves of the mold,

[0018] - the heat treatment of the first fibrous platform blank and the injected filling material so as to obtain a first preform of one of the platforms to be produced comprising projecting filling portions extending in the direction of extension,

[0019] - the demolding of the first preform of one of the platforms to be produced,

[0020] - the assembly of the first preform of one of the platforms to be produced with one or more aerodynamic profile preforms and a second preform of the other platform to be produced in order to obtain a fibrous assembly having the shape of the bladed wheel sector to be obtained, the aerodynamic profile preform(s) extending radially between the first preform and the second platform preform, the filling portion(s) extending axially so that each filling portion is covered by one or more aerodynamic profile preforms,

[0021] - densification by a matrix of the fibrous assembly having the shape of the bladed wheel sector to be obtained so as to obtain said bladed wheel sector in composite material.

[0022] According to a particular embodiment of the invention, the manufacture of the second preform of the other platform to be produced comprises:

[0023] - the arrangement of a second fibrous platform blank in a mold having an imprint, the imprint comprising a main portion having the shape of the second platform to be produced and one or more grooves extending in the same direction of extension, the groove(s) comprising one or more injection ports, the second fibrous platform blank being arranged in the main portion of the imprint,

[0024] - the injection of a filling material through the injection port(s) so as to fill the grooves of the mold,

[0025] - heat treatment of the second fibrous platform blank and the injected filling material so as to obtain the second preform comprising projecting filling portions extending in the direction of extension,

[0026] - demolding of the second platform preform;

[0027] - the assembly of the second platform preform with the first platform preform and the branch preforms being carried out so that each branch preform connects one of the filling portions of the first platform preform to one of the filling portions of the second platform preform, the filling portion(s) of the second platform preform extending axially so that each filling portion of the second platform preform is covered by one or more branch preforms.

[0028] According to another particular embodiment of the invention, the first platform blank, and where appropriate the second platform blank, is produced by superimposing pre-impregnated plies.

[0029] It is sometimes preferable to integrate the resin before assembling the fiber assembly. Indeed, the subsequent injection of a resin into the already assembled dry fiber assembly is delicate to carry out. This aspect is particularly relevant when the part to be produced is a bladed wheel sector.

[0030] According to another particular embodiment of the invention, the area of ​​the section of the grooves of the mold is variable along the direction of extension, so as to obtain filling portions having a variable section area along the direction of extension.

[0031] Indeed, the method of the invention makes it possible to produce filling portions with an adaptable geometry. Thus, the geometry of the filling portions can be adapted to follow the geometry of the branches, for example aerodynamic profiles.

[0032] According to another particular embodiment of the invention, the filling material is a thermoplastic material and in which the first fibrous platform blank, the branch preforms and, where appropriate, the second fibrous platform blank are impregnated with a thermoplastic resin.

[0033] According to another particular embodiment of the invention, the filling material is a thermosetting material and in which the first fibrous platform blank, the branch preforms and, where appropriate, the second fibrous platform blank are impregnated with a thermosetting resin.

[0034] According to another particular embodiment of the invention, the filling material is loaded with carbon particles.

[0035] This way, the viscosity of the filling material is better controlled, which facilitates the injection of an appropriate quantity of material and helps avoid excess or unwanted flow of the filling portions.

[0036] According to another particular embodiment of the invention, the branch preforms have a “C” shape, a pair of branch preforms placed back to back forming the fiber reinforcement of a single branch of the bladed wheel sector to be produced, the filling portions being arranged between two branch preforms belonging to the same pair.

[0037] According to another particular embodiment of the invention, the manufacture of the branch preforms comprises:

[0038] - the production of a fibrous branch blank by superimposing pre-impregnated plies,

[0039] - shaping the fibrous branch blank using a vacuum-sealed membrane so as to give the fibrous branch blank a “C” shape, then

[0040] - pre-consolidation of the shaped fibrous branch blank to obtain the fibrous branch preform.

[0041] According to a particular embodiment of the invention, the part obtained is a bladed wheel sector, the branch(es) being aerodynamic profiles extending radially, the filling portion(s) extending axially.

[0042] The invention further relates to a bladed wheel sector obtained according to the manufacturing method as described above.

[0043] The invention also relates to a bladed wheel comprising a plurality of sectors produced according to the manufacturing method described above.

[0044] According to another particular embodiment of the invention, the part obtained is a stiffener. Brief description of the drawings

[0045] [Fig. 1] Figure 1 is a schematic sectional view of a bladed wheel sector.

[0046] [Fig. 2] Figure 2 is a schematic sectional view of a mold and counter-mold for manufacturing a fiber platform preform.

[0047] [Fig. 3] Figure 3 is a schematic perspective view of the mold of Figure 2.

[0048] [Fig. 4] Figure 4 is a schematic sectional view of the mold of Figures 2 and 3 in which a fibrous platform blank is positioned.

[0049] [Fig. 5] Figure 5 is a schematic sectional view of the mold of Figures 2 to 4 into which a filling material is injected.

[0050] [Fig. 6] Figure 6 is a schematic perspective view of a platform fiber preform.

[0051] [Fig. 7] Figure 7 is a schematic sectional view of an aerofoil fiber blank being shaped on a mandrel.

[0052] [Fig. 8] Figure 8 is a schematic sectional view of the assembly of the platform fiber preforms and the aerodynamic profile fiber preforms to obtain the bladed wheel sector of Figure 1. Description of the embodiments

[0053] The present invention relates to the manufacture of a wide variety of parts made of organic matrix composite material, in particular parts comprising "T"-shaped portions or "I"- or "H"-shaped portions. The present invention relates in particular to the manufacture of blades or stiffeners, in particular stiffeners attached to a flat or curved skin, for example for static booster stages or for outlet guide vane stages known as "OGVs" for "outlet guide vanes". The present invention preferably relates to the manufacture of bladed wheel sectors.

[0054] In the examples below, the part described comprises two platforms. It is of course not outside the scope of the invention if the part to be obtained comprises a single platform.

[0055] Figure 1 illustrates an example of a bladed wheel sector 300 achievable by the method of the invention. The bladed wheel sector 300 conventionally comprises an internal platform 310, or first platform, and an external platform 320, or second platform, extending in a circumferential direction De around an axial direction DA. The bladed wheel sector 300 comprises one or more aerodynamic profiles 330 each extending between the two platforms 310 and 320 following a radial direction DR perpendicular to the axial direction DA. The aerodynamic profiles 330 correspond to blades.

[0056] In the context of any part 300, the first platform and / or the second platform may extend in a circumferential direction or in a rectilinear direction. The radial direction then corresponds to a transverse direction.

[0057] The bladed wheel sector 300 produced by the method of the invention may comprise a single aerodynamic profile: the bladed wheel sector 300 will then be comparable to a blade provided with an internal platform and an external platform.

[0058] In the example illustrated in Figure 1, the bladed wheel sector 300 comprises three aerodynamic profiles. However, it does not depart from the scope of the invention if the bladed wheel sector comprises a different number of aerodynamic profiles. In particular, the invention is particularly advantageous for producing bladed wheel sectors comprising between 10 and 15 sectors. The invention is also particularly advantageous for producing bladed wheel sectors corresponding to one sixth of the total bladed wheel to be produced, i.e. for bladed wheel sectors extending circumferentially over 60°.

[0059] More generally, the part 300 may comprise a single branch, or a plurality of branches.

[0060] Figures 2 and 3 illustrate an example of a mold 510 for implementing the method of the invention. The mold 510 can be associated with a counter-mold 520.

[0061] The mold 510 comprises an imprint having the shape of one of the platforms to be produced. The imprint of the mold 510 comprises a main portion 511. The main portion 511 of the imprint comprises a bottom 511a. The main portion 511 of the imprint extends in depth along a depth direction Dp. The main portion 511 of the imprint extends in depth to the bottom 511a along the depth direction DP. The main portion 511 of the imprint extends along a length direction DL between a first edge lateral and a second lateral edge. The main portion 511 of the imprint extends in an extension direction DE between a first longitudinal edge and a second longitudinal edge. The extension direction DE is perpendicular to the length direction DL. The extension direction DE is perpendicular to the depth direction Dp. The length direction DL is preferably circumferential. Thus, the main portion 511 of the imprint preferably has a slightly curved shape in the length direction DL.

[0062] The mold cavity 510 further comprises grooves 512. The grooves 512 extend in the direction of extension DE. The grooves 512 are made in the bottom 511a of the main portion 511 of the mold cavity 510. Preferably, the grooves 512 extend from the first longitudinal edge to the second longitudinal edge of the main portion 511. The grooves 512 comprise, in the direction of extension DE, a first end 512a, then a central portion 512b, then a second end 512a. The grooves 512 are hollowed out in the bottom 511a of the main portion 511. The grooves 512 extend in depth in the direction of depth Dp. The grooves 512 comprise a groove bottom. Thus, the grooves 512 extend in depth to the groove bottom. The grooves 512 extend in width along the length direction D L .

[0063] The grooves 512 may have a constant section along the direction of extension DE. However, preferably, the grooves 512 have a variable section along the direction of extension DE. Preferably, the area of ​​the section of the grooves 512 is smaller at the ends 512a than in the central portion 512b.

[0064] The maximum depth of the grooves 512 along the depth direction DP can remain constant along the extension direction DE, even if the section of the grooves 512 varies along the extension direction DE.

[0065] The grooves 512 may have a constant width along the length direction DL at the junction between the main portion 511 and the grooves 512 along the extension direction DE. The bottoms of the grooves 512 may have a variable width along the length direction DL along the direction of extension DE. In particular, it is preferable that the grooves 512 are wider at the ends 512a of said grooves 512 than in the central portion 512b of said grooves 512 along the direction of extension DE.

[0066] The mold 510 further comprises injection ports 513 opening into the grooves 512. Each groove 512 is associated with at least one injection port 513. In order to facilitate injection via the injection ports 513, the injection ports 513 preferably extend along the depth direction DP.

[0067] The main portion 511 of the mold cavity 510 is intended to receive a fiber blank of one of the platforms to be produced. The grooves 512 are intended to allow the formation of the filling portions.

[0068] The mold 510 conventionally comprises as many grooves 512 as aerodynamic profiles, in other words blades, are desired on the bladed wheel sector 300 to be produced. Thus, the number of grooves conventionally corresponds to the number of aerodynamic profiles, in other words the number of blades, desired. More generally, the number of grooves corresponds to the number of branches.

[0069] Thus, the method according to the invention comprises arranging a platform fiber blank 111 in the mold 510, as illustrated in FIG. 4. The platform fiber blank 111 is arranged in the main portion 511 of the imprint. The platform fiber blank 111 rests against the bottom 511a of the main portion 511. The platform fiber blank 111 is in contact with the bottom 511a of the main portion 511 of the imprint.

[0070] The mold 510 is closed by the counter-mold 520. Preferably, the mold 510 is closed by the counter-mold 520 so that the counter-mold 520 exerts pressure on the platform fiber blank 111.

[0071] The platform fiber blank 111 is preferably obtained by superimposing pre-impregnated plies. It is of course not beyond the scope of the invention if the platform fiber blank 111 is obtained by superimposing dry plies. It is also not beyond the scope of the invention if the platform fiber blank 111 is produced by another means.

[0072] The fibers of the platform fiber blank 111 are preferably made of carbon. It is of course not outside the scope of the invention if the fibers of the platform fiber blank 111 are made of glass. It is also not outside the scope of the invention if the fibers of the fiber blank are made with a mixture of material comprising at least two materials from among: carbon, glass, a ceramic.

[0073] In the case where the fibrous platform blank 111 is pre-impregnated, it may be pre-impregnated with a thermosetting or thermoplastic resin. The fibrous platform blank 111 may, for example, be pre-impregnated with an epoxy resin, a polyimide (PI) or a bismaleimide resin (BMI). If the fibrous platform blank 111 is pre-impregnated with a thermoplastic material, it may, for example, be pre-impregnated so as to obtain a matrix made of polyaryletherketone (PAEK), polyetherketoneketone (PEKK), polyetheretherketone (PEEK), polyetherimide (PEI), polyphenylene sulfide (PPS), polyethersulfone (PESU) or polycarbonate (PC).

[0074] A filling material 112 is then injected into the grooves 512 of the mold 510, as illustrated in FIG. 5. The filling material 112 fills the grooves 512 of the mold 510. Preferably, the counter-mold 520 maintains pressure on the fiber platform blank 111 during the injection of the filling material 112.

[0075] The filler material 112 may be a thermoplastic or thermosetting material. If the fibrous platform blank 111 is pre-impregnated with a thermosetting material, the filler material 112 will also preferably be a thermosetting material. Similarly, if the fibrous platform blank 111 is pre-impregnated with a thermoplastic material, the filler material 112 will also preferably be a thermoplastic material. Generally, it is preferable that the filler material 112 be the same or similar to the material pre-impregnating the fibrous platform blank 111.

[0076] The filler material 112 may be filled. For example, the filler material 112 may be filled with fibers or particles. Indeed, it is It is desirable that the viscosity of the filling material 112 be controlled in order to obtain satisfactory filling portions. In particular, the filling material 112 may be loaded with carbon fibers or particles, or with nanomaterial particles.

[0077] The injection of the filling material 112 is preferably carried out by controlling the temperature and pressure of the mold 510.

[0078] The mold 510 can be heated and pressurized so as to perform a heat treatment of the injected filling material 112 and the fibrous platform blank 111.

[0079] A fibrous platform preform 210 is thus obtained as illustrated in FIG. 6. The fibrous platform preform 210 is removed from the mold 510.

[0080] The fibrous platform preform 210 comprises a main body 211 and filling portions 212 projecting from the main body 211. The main body 211 corresponds to the fibrous platform blank 111. Thus, the main body 211 has been formed in the main portion 511 of the mold 510. The filling portions 212 correspond to the filling material 112 injected into the grooves 512. Thus, the filling portions 212 have been formed in the grooves 512 of the mold 510.

[0081] The main body 211 of the platform fiber preform 210 extends in length and width along the extension directions DE and length DL. The main body 211 of the platform fiber preform 210 extends in thickness along the depth direction DP. Preferably, the main body 211 is curved along the length direction DL.

[0082] The filling portions 212 extend along the extension direction DE. The filling portions 212 may extend over the entire width of the platform fiber preform 210 along the extension direction DE. The filling portions 212 comprise, along the extension direction DE, a first end 212a, then a central portion 212b, then a second end 212a. The filling portions 212 extend projecting from the main body 211 along the depth direction Dp. The filling portions 212 comprise a vertex. The vertices of the filling portions 212 correspond to the parts of the filling portions 212 formed at the bottoms of the grooves 512. Thus, the filling portions 212 extend in height to the vertex. The filling portions 212 extend in width along the length direction DL.

[0083] The filling portions 212 may have a constant section along the direction of extension DE. However, preferably, the filling portions 212 have a variable section along the direction of extension DE, as illustrated in FIG. 6. Preferably, the area of ​​the section of the filling portions 212 is smaller at the ends 212a than in the central portion 212b.

[0084] The maximum height of the filling portions 212 along the depth direction DP can remain constant along the extension direction DE, even if the section of the filling portions 212 varies along the extension direction DE.

[0085] The filling portions 212 may have a constant width along the length direction DL at the junction between the main body 211 and the filling portions 212 along the extension direction DE. The tops of the filling portions 212 may have a variable width along the length direction DL along the extension direction DE. In particular, it is preferable for the filling portions 212 to be less wide at the ends 212a of said filling portions 212 than in the central portion 212b of said filling portions 212 along the extension direction DE.

[0086] The fiber platform preform 210 conventionally comprises as many filling portions 212 as aerodynamic profiles, in other words blades, are desired on the bladed wheel sector 300 to be produced. Thus, the number of filling portions 212 conventionally corresponds to the number of aerodynamic profiles, in other words the number of blades, desired. More generally, the number of filling portions corresponds to the number of branches.

[0087] The platform fiber preform 210 can be used to produce the first platform or the second platform, for example the internal platform or the external platform of the bladed wheel sector to be produced. It thus constitutes the first platform fiber preform 210, obtained from a first platform fiber blank 111. The platform fiber preform 220 of the other platform can be produced in a similar manner to that described previously, from a second platform fiber blank. It constitutes the second platform fiber preform 220. Thus, the two platform fiber preforms 210 and 220 can be produced according to the method described previously.For the remainder of the description, it will be considered that the first fiber platform preform 210 is intended to form the first platform, for example the internal platform of the bladed wheel sector to be obtained, and that the second fiber platform preform 220 is intended to form the second platform, for example the external platform of the bladed wheel sector to be obtained.

[0088] In particular, the two platform fiber preforms 210 and 220 are made of the same material. The two platform fiber preforms 210 and 220 are made with fibers of the same nature and the same size. The two platform fiber preforms 210 and 220 are impregnated with the same resin.

[0089] Preferably, the filling portions of the first platform fiber preform 210 have different dimensions from the filling portions of the second platform fiber preform 220. Thus, the dimensions of the filling portions can be adapted to the shape of the aerodynamic profile. Indeed, the shape of the aerodynamic profile is conventionally different between the junction with the external platform and the junction with the internal platform.

[0090] Similarly, the thickness of the main body 211 of the first platform fiber preform 210 along the depth direction DP will preferably be different from the thickness of the main body of the second platform fiber preform 220 along the depth direction Dp. For example, the main body 211 of the first platform fiber preform 210, intended to form the internal platform, may be thicker than the main body of the second platform fiber preform 220, intended to form the external platform. In the case where the first platform fiber blank 111 and the second platform fiber blank are produced by superimposing plies, the number of plies of the first platform fiber blank may be different from that of the second platform fiber blank. For example, the second platform fiber blank may comprise a number of plies of between 40% and 60% of the number of plies of the first platform fiber blank 111. For example, the second platform fiber blank may comprise 6 plies and the first platform fiber blank 111 may comprise 12 plies.

[0091] The fiber branch preforms, in particular the fiber preforms of the aerodynamic profiles of the bladed wheel sector 300 to be obtained, are produced from fiber branch blanks, in particular from fiber aerodynamic profile blanks 130, as illustrated in FIG. 7.

[0092] The aerodynamic profile fiber blank 130 is preferably obtained by superimposing pre-impregnated plies. It is of course not beyond the scope of the invention if the aerodynamic profile fiber blank 130 is obtained by superimposing dry plies. It is also not beyond the scope of the invention if the aerodynamic profile fiber blank 130 is produced by another means.

[0093] Preferably, the aerodynamic profile fiber blanks 130 are made of the same material as the two platform fiber preforms 210 and 220. The aerodynamic profile fiber blanks 130 are made with fibers of the same nature and the same size as the two platform fiber preforms 210 and 220. The aerodynamic profile fiber blanks 130 are made with the same resin as the platform fiber blanks 111.

[0094] The airfoil fiber blank 130 may be shaped on a mandrel 601. The airfoil fiber blank 130 is shaped to provide an airfoil fiber preform 230. The airfoil fiber preform 230 preferably has a "C" shape. The “C” can be rounded with a variable radius of curvature, even very small, of the order of a millimeter, or even at right angles.

[0095] As illustrated in Figure 7, the aerodynamic profile fiber blank 130 is thus shaped on the mandrel 601 so as to bend the fiber blank 130 at its ends 130a, on either side of a central portion 130b of the fiber blank 130. The ends 130a of the aerodynamic profile fiber blank 130 are bent on the same side, so as to obtain a “C” shape.

[0096] The shaping of the aerodynamic profile fiber blank 130 into an aerodynamic profile fiber preform 230 can be facilitated by the use of a tarpaulin 602. In particular, the tarpaulin 602 can be placed under vacuum to facilitate the shaping of the aerodynamic profile fiber blank 130. This fiber preform being heated prior to vacuum drawing in order to lower its viscosity and facilitate forming. The heating can be carried out using infrared radiation or any other heating means.

[0097] The shaped fiber aerofoil blank 130 is then pre-consolidated to obtain the fiber aerofoil preform 230. The pre-consolidation is conventionally carried out by heat treatment. In the case of a preform with a thermosetting matrix, the matrix remains with a very low rate of advancement after the shaping step, in order to keep all of its development at low viscosity during the assembly step.

[0098] A fiber preform of aerodynamic profile 230 is thus obtained comprising a central portion 230b from which two end portions 230a extend, as illustrated in FIG. 8. The end portions 230a extend towards the same side from the central portion 230b so as to obtain the shape of a “C”.

[0099] When all the fiber preforms 210, 220, 230 necessary for the production of the bladed wheel sector 300 have been produced, the assembly of said fiber preforms 210, 220, 230 is carried out in order to obtain a fiber assembly.

[0100] Figure 8 illustrates an example of a fibrous assembly 200 produced by assembling two platform fibrous preforms 210 and 220 and six aerodynamic profile fibrous preforms 230. The fibrous assembly has the shape of the bladed wheel sector 300 to be produced.

[0101] The platform fiber preforms 210 and 220 are oriented so that the extension direction DE corresponds to the axial direction D of the bladed wheel sector 300 to be produced. Similarly, the platform fiber preforms 210 and 220 are oriented so that the depth direction DP and the length direction DL correspond respectively to the radial direction DR and the circumferential direction De of the bladed wheel sector 300 to be produced.

[0102] According to a particularly interesting configuration illustrated in FIG. 8, the aerodynamic profile fiber preforms 230 are assembled in pairs to form the aerodynamic profiles. Each pair of aerodynamic profile fiber preforms 230 comprises a first aerodynamic profile fiber preform 231 and a second aerodynamic profile fiber preform 232. Each first aerodynamic profile fiber preform 231 is thus positioned with its back to the second aerodynamic profile fiber preform 232 belonging to the same pair. The central portion 230b of each first aerodynamic profile fiber preform 231 is thus in contact with the central portion 230b of the second aerodynamic profile fiber preform 232 belonging to the same pair.The end portions 230a of the first aerodynamic profile fiber preforms 231 are all oriented in the same first direction relative to the circumferential direction De and the end portions 230a of the second aerodynamic profile fiber preforms 232 are all oriented in the same second direction opposite to the first direction.

[0103] Thus, each pair of airfoil fiber preforms 230 has an “H” shape. Therefore, each pair of airfoil fiber preforms 230 has a trunk formed by the central portions 230b, from the upper end of which extend two legs and from the lower end of which extend two other legs, each leg being formed by an end portion 230a. The pairs of airfoil fiber preforms aerodynamic 230 are arranged so that one of the filling portions 212 of the first platform fiber preform 210 is present between two legs at the upper end of the “H” and one of the filling portions of the second platform fiber preform 220 is present between two legs at the lower end of the “H”. The filling portions are each in contact with two legs belonging to the same “H”.

[0104] Each aerodynamic profile fiber preform 230 is assembled so as to connect the first platform fiber preform 210 to the second platform fiber preform 220. Thus, each aerodynamic profile fiber preform 230 is in contact with the first platform fiber preform 210 and the second platform fiber preform 220. One of the end portions 230a of each aerodynamic profile fiber preform 230 is in contact with the first platform fiber preform 210 and the other end portion 230a of each aerodynamic profile fiber preform 230 is in contact with the second platform fiber preform 220. Each aerodynamic profile fiber preform 230 is in contact with one of the filling portions of the first platform fiber preform 210 and one of the filling portions of the second platform fiber preform 220.

[0105] Each pair of aerodynamic profile fiber preforms 230 covers one of the filling portions 212 of the first platform fiber preform 210 and covers one of the filling portions of the second platform fiber preform 220. Preferably, each pair of aerodynamic profile fiber preforms 230 completely covers one of the filling portions 212 of the first platform fiber preform 210 and completely covers one of the filling portions of the second platform fiber preform 220. Each filling portion is disposed between the first platform fiber preform 210 and the second platform fiber preform 220 of the same pair of platform fiber preforms. The filling portions are arranged so as to be in contact with the junction between the central portion 230b and one of the end portions 230a of the aerodynamic profile fiber preforms 230.

[0106] The preceding explanations in connection with Figures 7 and 8 are given in the context of the example of the bladed wheel sector. The preceding explanations in connection with Figures 7 and 8 are of course transposable to other types of part obtained by the method of the invention. In particular, the terms “aerodynamic profile fiber blank(s)” and “aerodynamic profile fiber preform(s)” can be replaced by “branch fiber blank(s)” and “branch fiber preform(s)” in the preceding explanations without departing from the scope of the invention.

[0107] The fibrous assembly 200 thus obtained is then subjected to a heat treatment so as to crosslink or consolidate the matrix. If the fibrous assembly 200 is formed by fibrous preforms 210, 220, 230 already impregnated with a matrix precursor, the heat treatment is carried out directly. If the fibrous assembly 200 is formed by fibrous preforms 210, 220, 230 without resin, it is possible to inject a resin into the fibrous assembly 200 after its formation.

[0108] The heat treatment of the fibrous assembly 200 is preferably carried out by applying pressure to said fibrous assembly 200, for example by means of an assembly of blocks around the fibrous assembly 200.

[0109] When the matrix is ​​formed in the porosities of the fibrous assembly 200, a bladed wheel sector 300 is obtained as illustrated in FIG. 1. The bladed wheel sector 300 is intended to be assembled with other bladed wheel sectors so as to obtain a complete bladed wheel. Such a bladed wheel is intended to be installed in an aircraft turbomachine.

Claims

Claims

1. Method for manufacturing a part (300) made of organic matrix composite material, said part (300) comprising at least a first platform (310) and one or more branches (330) extending transversely from the first platform (310), the method comprising: - the arrangement of a first fibrous platform blank (111) in a mold (510) having an imprint, the imprint comprising a main portion (511) having the shape of the at least one first platform (310) to be produced and one or more grooves (512) extending in the same direction of extension (DE), the groove(s) (512) comprising one or more injection ports (513), the first fibrous platform blank (111) being arranged in the main portion (511) of the imprint, - injecting a filling material (112) through the injection port(s) (513) so as to fill the grooves (512) of the mold (510), - the heat treatment of the first fibrous platform blank (111) and the injected filling material (112) so as to obtain a first platform preform (210) to be produced comprising projecting filling portions (212) extending in the direction of extension (DE), - demolding of the first platform preform (210), - assembling the first platform preform (210) with one or more branch preforms (230) in order to obtain a fibrous assembly (200) having the shape of the part (300) to be obtained, the branch preform(s) (230) extending transversely from the first platform preform (210), each filling portion (212) being covered by one or more branch preforms (230), - densification by a matrix of the fibrous assembly (200) having the shape of the part (300) to be obtained so as to obtain said part (300) in composite material.

2. A method of manufacturing a part (300) according to claim 1, the part (300) further comprising a second platform (320), the branch(es) (330) extending between the first platform (310) and the second platform (320), the fibrous assembly (200) comprising a second platform preform (220) assembled with the branch preform(s) (230).

3. A method of manufacturing a part (300) according to claim 2, wherein the manufacturing of the second platform preform (220) to be produced comprises: - the arrangement of a second fibrous platform blank in a mold having an imprint, the imprint comprising a main portion having the shape of the second platform to be produced and one or more grooves extending in the same direction of extension, the groove(s) comprising one or more injection ports, the second fibrous platform blank being arranged in the main portion of the imprint, - the injection of a filling material through the injection port(s) so as to fill the grooves of the mold, - heat treatment of the second fibrous platform blank and the injected filling material so as to obtain the second platform preform (220) comprising projecting filling portions extending in the direction of extension, - demolding the second platform preform (220); assembling the second platform preform (220) with the branch preforms (230) being carried out such that each branch preform (230) connects one of the filling portions (212) of the first platform preform (210) to one of the filling portions of the second platform preform (220), each filling portion of the second platform preform (220) being covered by one or more branch preforms (230).

4. Method of manufacturing a part (300) according to any one of claims 1 to 3, in which the first platform blank (111), and where appropriate the second platform blank, is produced by superimposing pre-impregnated plies.

5. Method of manufacturing a part (300) according to any one of claims 1 to 4, in which the area of the section of the grooves (512) of the mold (510) is variable according to the direction of extension (DE), so as to obtain filling portions (212) having a variable cross-sectional area along the direction of extension (DE).

6. A method of manufacturing a part (300) according to any one of claims 1 to 5, in which the filling material (112) is a thermoplastic material and in which the first fibrous platform blank (210), the branch preforms (230) and, where appropriate, the second fibrous platform blank (220) are impregnated with a thermoplastic resin.

7. Method for manufacturing a part (300) according to any one of claims 1 to 5, in which the filling material (112) is a thermosetting material and in which the first fibrous platform blank (210), the branch preforms (230) and, where appropriate, the second fibrous platform blank (220) are impregnated with a thermosetting resin.

8. A method of manufacturing a part (300) according to any one of claims 1 to 7, wherein the filling material (112) is loaded with carbon particles.

9. Method for manufacturing a part (300) according to any one of claims 1 to 8, in which the branch preforms (230) have a “C” shape, a pair of branch preforms (231, 232) placed back to back forming the fibrous reinforcement of a single branch (330) of the part (300) to be produced, the filling portions (212) being arranged between two branch preforms (231, 232) belonging to the same pair.

10. A method of manufacturing a part (300) according to claim 9, wherein manufacturing the branch preforms (230) comprises: - the production of a fibrous branch blank (130) by superimposing pre-impregnated plies, - shaping the fibrous branch blank (130) by means of a vacuum membrane (602) so as to give a “C” shape to the fibrous branch blank (130), then - pre-consolidation of the shaped fibrous branch blank (130) so as to obtain the fibrous branch preform (230).

11. A method of manufacturing a part (300) according to any one of claims 1 to 10, wherein the part (300) is a stiffener.

12. A method of manufacturing a part (300) according to any one of claims 1 to 10, wherein the part (300) is a bladed wheel sector, the branch(es) being aerodynamic profiles extending radially, the filling portion(s) extending axially.

13. A bladed wheel comprising a plurality of sectors (300) produced according to the manufacturing method according to claim 12.

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