METHOD FOR PRODUCE A PREFORM FOR A TURBO MACHINE COMPONENT AND ARRANGEMENT FOR WEAVING SUCH A PREFORM

Description

Field of invention

[0001] The present invention relates to the field of manufacturing a turbomachine part made of composite material from a preform. It also relates to a weaving installation for manufacturing such a preform. Technical background

[0002] It is known to produce various turbomachine parts, in particular aircraft turbomachine parts, from a composite material in order to improve their thermomechanical resistance capabilities and reduce their masses. The composite material is produced from a preform or fabric intended to form a fibrous reinforcement and which is embedded in a matrix. The preform is obtained by three-dimensional weaving (or 3D weaving) or two-dimensional weaving (or 2D weaving).

[0003] Generally, the weaving of the preform is carried out using a weaving installation with a Jacquard loom. The weaving installation is fed with several weft and warp threads which are made to intertwine or interlace according to a predetermined weave to form the preform. The nature of the weft and warp threads as well as the selected reinforcement will define the mechanical properties of the preform and also of the turbomachine part. For this purpose, the installation includes a weaving comb which is located in a weaving zone where the preform (where the threads are woven) is obtained at the outlet. The preform (thus woven) is wound and stored on a storage roller known as a "take-up" and which is arranged downstream of the weaving comb.The storage roller is rotated around a rotation axis using a motor so as to pull the preform while applying tension to it following the installation. In order to facilitate the pulling and conveying of the preform to the storage roller, a first take-up roller known by the English expression "puller" is mounted just at the exit of the weaving zone and upstream of the storage roller. Examples of weaving installations are described in documents FR-A 13066429 and WO-A1-2017 / 149252.

[0004] When weaving the preform, it happens that the preform slips on the first take-up roller which causes a spacing (or loosening) or a tightening (or contraction) of the stitches, in particular the weft stitches (known as "pick spacing" in English). This anomaly also occurs almost exclusively when the weaving installation is stopped, which can occur for maintenance of the installation, during an incident during the operation of the installation, or when replenishing yarns, etc. Preforms made with a non-woven fabric such as in document FR-A1-3085126 do not encounter pick spacing problems. When stopped, a drop in tension at the storage roller has been observed which is reflected on the first take-up roller which causes the meshes to loosen or tighten. Summary of the invention

[0005] The objective of the present invention is to provide a solution that makes tension reliable throughout the weaving process while being economical and simple.

[0006] We achieve this objective in accordance with the invention by means of a method for manufacturing a preform of a turbomachine part with a weaving installation comprising at least a first take-up roller and a storage roller, the method comprising the following steps: feeding the weaving installation with weft and warp threads, weaving the weft and warp threads so as to form a preform, driving the preform in a direction of movement towards the storage roller which applies a predetermined tension to the preform, and winding and storing the preform around the storage roller, the method comprising a step of immobilizing the preform on the first take-up roller arranged upstream of the storage roller in the direction of movement of the preform.

[0007] Thus, this solution makes it possible to achieve the aforementioned objective. In particular, immobilizing the preform, which comes out of the loom, on the first take-up roller prevents the preform from sliding towards the comb (located upstream of the first take-up roller) or towards the storage roller which applies tension to the preform. The stitches of the preform (between the weft and warp threads), in particular the weft stitches ("spick spacing") are controlled and uniform; they are no longer too tight or too spaced (in particular in the event of relaxation of the tension on one of the two sides of the preform) and possible mechanical weaknesses once the composite material part from this preform is obtained are avoided.

[0008] The method also comprises one or more of the following steps and / or features, taken alone or in combination: the immobilization step is carried out by means of a flange arranged near the first take-up roller. the flange is removable. the flange moves towards the first take-up roller so that the preform is compressed between the first take-up roller and the flange. the flange moves substantially in a direction orthogonal to the direction of movement of the preform. the movement of at least the movable part of the flange is manual. the movement of at least the movable part of the flange is motorized. the installation is connected to an electronic control system configured to control the stopping and starting of the installation, the electronic control system being connected to a member for moving the flange so that when it receives information to stop the installation, a control order is sent to the member for moving it. the flange applies a pressure to the first take-up roller of between 0.1 and 2 MPa.the preform is made using a three-dimensional interlock weave, a three-dimensional weave, or a two-dimensional weave.

[0009] The invention also relates to a weaving installation for manufacturing a preform of a turbomachine part, the installation comprising: a fixed structure, at least one preform storage roller mounted in rotation about a first axis of rotation relative to the structure, the storage roller being intended to apply tension to the preform which is intended to be driven in a direction of movement towards the storage roller and to be wound around it, at least one first take-up roller mounted upstream of the storage roller and movable in rotation about a second axis of rotation relative to the structure, and a flange configured so as to immobilize the preform on the first take-up roller when the installation is stopped.

[0010] The facility also includes one or more of the following features, taken alone or in combination: the flange is removably attached to the fixed structure. at least a portion of the flange is movable relative to the first take-up roller via at least one displacement member which is attached to the structure and connected to the flange. the flange comprises a bearing surface oriented towards the first roller and which has a complementary shape with a peripheral surface of the first roller or of the preform. the flange comprises a support member and a movable member or a flexible member relative to the support member, the flexible or movable member carrying the bearing surface. the bearing surface comprises a coating made of a polymer material. the first take-up roller is intended to drive the preform at a predetermined speed.

[0011] The invention also relates to a method for manufacturing a turbomachine part made of composite material comprising a fibrous reinforcement densified by a matrix, the method comprising the following steps: manufacturing a preform as mentioned above, placing the preform around a mandrel forming a mold, installing a counter mold around the preform placed on the mandrel so as to form an injection chamber, injecting a matrix into the injection chamber, polymerizing the matrix, demolding the composite material part.

[0012] The invention also relates to a turbomachine casing made of composite material comprising a fibrous reinforcement densified by a matrix, the casing being produced by the method having any one of the steps and / or characteristics above.

[0013] The invention further relates to a turbomachine comprising at least one casing made of composite material as mentioned above.

[0014] The invention also relates to an aircraft comprising at least one turbomachine as mentioned above. Brief description of the figures

[0015] The invention will be better understood, and other aims, details, characteristics and advantages thereof will appear more clearly on reading the detailed explanatory description which follows, of embodiments of the invention given as purely illustrative and non-limiting examples, with reference to the appended schematic drawings in which: [ Fig. 1 ] There figure 1 is a partial axial sectional view of an example of a turbomachine to which the invention applies; [ Fig. 2 ] There figure 2 is a very schematic view of a weaving installation for the manufacture of a preform according to the invention; [ Fig. 3 ] There figure 3is a schematic and axial sectional view of another part of the weaving installation which comprises at least one storage roller for the preform obtained at the outlet of a weaving loom according to the invention; [ Fig. 4 ] There figure 4 is a schematic and detailed view of a first take-up roller of the weaving installation cooperating with a flange which is intended to immobilize the preform in the event of the weaving installation according to the invention being stopped; and [ Fig. 5 ] There Figure 5 is a schematic and detailed view of another embodiment of a first take-up roller of the weaving installation equipped with a flange intended to immobilize the preform in the event of the weaving installation stopping according to the invention. Detailed description of the invention

[0016] There figure 1shows an axial and partial sectional view of a turbomachine 1 with longitudinal axis X which comprises various components which can be made of composite materials. The invention is particularly concerned with turbomachine components or parts which have an axis of revolution such as fan casings, compressor casings, turbine casings, etc.

[0017] The turbomachine of the figure 1 is a double-flow, double-spool turbomachine intended to be mounted on an aircraft. The turbomachine 1 comprises a fan 2 which is mounted upstream of a gas generator 3 or engine following the circulation of the gases in the turbomachine and here along the longitudinal axis X (and even from left to right on the figure 1 ). The gas generator comprises, from upstream to downstream, a low-pressure compressor 4a, a high-pressure compressor 4b, a combustion chamber 5, a high-pressure turbine 6a and a low-pressure turbine 6b.

[0018] The fan 2 is surrounded by a fan casing 7 which is extended downstream by an intermediate casing shroud (known by the acronym “ICV”) 8. This intermediate casing shroud is fixed to the fan casing 7. This shroud 8 can also be made of composite material and thus fall within the scope of the invention. The intermediate casing shroud 8 is connected to an inter-stream casing 12 of the turbomachine via several structural arms 14 arranged regularly around the longitudinal axis. The intermediate casing shroud 8 supports the fan casing 7 and also an external nacelle 13. The nacelle 13 and the fan casing 7 are centered on the longitudinal axis. The blower 2 divides the air entering the turbomachine into a primary air flow which passes through the gas generator 3 and in particular into a primary vein 9, and into a secondary air flow which circulates around the gas generator in a secondary vein 10.The gas generator is housed inside an inner casing 11. The inter-vein casing 12 surrounds the inner casing 11. The inter-vein casing 12 delimits the radially inner wall of the secondary vein 10. The primary and secondary veins 9, 10 are concentric. This inter-vein casing 12 and the inner casing 11 comprise various structural casings surrounding the compressors and the turbines.

[0019] At least one of the turbomachine casings or shells is produced by a method of manufacturing a part in composite materials with a fiber reinforcement embedded in a matrix. The fiber reinforcement is obtained by a method of manufacturing a preform 15 (or fiber texture or fabric) produced in a three-dimensional weave (or 3D weave) of threads. In the present invention, we understand by the expression "three-dimensional weave" or "3D weave" a weaving mode in which warp threads are linked to weft threads on several layers. The preform could also be produced according to a three-dimensional interlock weave or "3D interlock weave". We understand by the expression "3D interlock weave" a weaving mode in which several layers (formed of warp and weft threads) are linked together. The preform 15 can also be obtained with a two-dimensional weave (or 2D weave).

[0020] The weaving of the preform 15 is carried out by means of a weaving installation 16 comprising a loom 17 configured for three-dimensional and / or two-dimensional weaving. The fibrous reinforcement comprises a plurality of warp threads and a plurality of weft threads which are respectively oriented in directions which are perpendicular. The weaving is advantageously carried out flat so that at the outlet of the loom 17, the preform 15 obtained also has the general shape of a flat strip with varying thicknesses.

[0021] In the present example, the threads or strands for carrying out the weaving comprise fibers made of carbon, glass, ceramic, silica, silicon carbide, Kevlar, polyamide, alumina or a mixture of these fibers. Preferably, but not limited to, the threads are made of carbon.

[0022] On the figure 2An example of a weaving installation 16 is shown which extends in a longitudinal direction L, has a height in a radial direction R and a width in a transverse direction T. The directions are perpendicular to each other. The weaving installation 16 comprises a system 18 for feeding yarns intended to serve as warp yarn Cn and which are stored on several bobbins. The feeding system allows for better distribution of the warp yarns which are arranged in several layers and in a superimposed manner in the radial direction R (so as to give thickness to the fabric). The warp yarns are also arranged in the transverse direction (so as to give width to the fabric). The loom 17 shown is of the Jacquard type and is arranged on a first structure 19 which extends in the radial direction.The weaving loom 17 comprises in particular a loom head 20 which surmounts in the radial direction a harness 21 which is made up of a perforated weaving board 22 and several heddles 23 which pass through the weaving board. The weaving board is arranged above the connection / weaving zones, in the vertical direction. Each heddle 23 is connected on the one hand, at a first end to the loom head 20 and on the other hand, at a second opposite end to return springs 24 which are integral with a frame 25 of the first structure 19 of the weaving loom. Each heddle 23 is in the form of a metal rod and comprises at least one eyelet 26 which is crossed by a warp thread coming from the supply system 18. Alternatively, each heddle consists of a flexible thread which is attached to a metal rod comprising the eyelet. This configuration allows the 23 heddles to support the Cn warp threads.

[0023] During weaving, the harness 21 is set in motion in the vertical direction and in a connection zone 27 of the warp threads and the heddles (with the eyelets) so as to allow the introduction of the weft threads later after the opening of the shed. The vertical amplitude of the movements of the heddles 23 determines the different layers and thicknesses of the preform. When the harness 21 is set in motion, some heddles rise vertically while the others descend and vice versa.

[0024] The installation 16 also comprises a weaving comb 28 which is arranged in the direction of advancement of the warp threads between the connection zone 12 and a weaving zone 29 where the preform 15 is obtained (the weft and warp threads are interlaced). At the level of the comb 28 there is also an insertion zone 30 for the weft threads Tn (the shed) which are conveyed by a shuttle (not shown). The weft threads Tn extend in this insertion zone 30 in the transverse direction. The weaving comb 28 comprises a plurality of teeth each traversed by the warp threads Cn. Typically, the weaving comb 28 is driven by an upstream-downstream movement relative to the longitudinal direction making it possible to pack the weft threads Tn which interlace the warp threads Cn on the preform 15 already woven in the weaving zone 29.

[0025] On the figure 3is shown an axial section of another part of the weaving installation 16 where the preform 15 which has been previously woven in the form of a strip of fabric is wound onto a storage roller 34. This other part is a storage unit 31 which is located downstream of the weaving zone. The storage unit 31 comprises a second structure 32 with a first partition 33 and a second partition 33' (cf. figure 4 ) which are opposite in the transverse direction. The storage roller 34 is mounted on the second structure 32 and extends transversely between the first and second partitions 33, 33'. The storage roller 34 is also movable in rotation about a first axis of rotation A and in a first direction of rotation. This first axis of rotation A is perpendicular to the longitudinal direction L (according to the reference frame indicated on the figure 3). During weaving, the preform 15 is wound onto this storage roller 34 which applies a tension thereto. For this, the storage roller is connected to a motor (not shown) which is driven by an electronic control system 35. The storage roller applies a tension of between 1500 and 4500 Newton. The motor delivers a torque which drives the storage roller 34 in rotation and which makes it possible to apply the tension to the preform which is coupled to the storage roller 34. The angular speed of the storage roller 34 is discontinuous (the roller 34 advances in jerks). In particular, for 2D weaving, the roller 34 advances in increments with each insertion of a weft thread and potentially in a constant manner.For multi-layer weaving, the roller 34 stops while all the weft threads of the column are inserted (so that they are well above each other) and then advances by one increment for the insertion of n weft threads of the next column.

[0026] The installation 16 is also connected to the electronic control system which controls its stopping and starting.

[0027] At least one first take-up roller 36 called a “puller” in English is located upstream of the storage roller 34 so as, on the one hand, to drive the preform (make it advance) and on the other hand, to guide the preform towards the storage roller and to better distribute the tension of the storage roller 34. The first take-up roller 36 is arranged downstream of the weaving loom. In the present example, the first take-up roller 36 is carried by the second structure 32 as can be seen in the figure 3and extends transversely between the first and second partitions 33, 33'. Alternatively (not shown), the first take-up roller 36 is mounted on the first structure 19.

[0028] The first take-up roller 36 is also driven in rotation via a motor around a second axis of rotation B. The second axis of rotation B is parallel to the first axis of rotation A. The roller 36 is, in particular, driven at a determined speed (the speed determines the weft stitches). Then, the storage roller 34 is tension-controlled (direct application or servo-control with a feedback loop thanks to a tension measurement on intermediate rollers described below). The tension applied by the storage roller 34 makes it possible to press the preform onto the first take-up roller 36. The first take-up roller 36 still has a sufficient coefficient of friction to allow adequate adhesion with the preform. Advantageously, the take-up roller 36 is equipped with a coating with a high coefficient of friction to better pull the fabric. Its direction of movement is advantageously identical to that of the storage roller 34.According to another exemplary embodiment, the take-up roller 36 can rotate in the opposite direction to the storage roller 34. In this embodiment, for example, the preform can pass under the storage roller to be wound.

[0029] At least one second take-up roller 37, called a “reverser” in English, is also mounted to rotate on the second structure 32 along a third axis of rotation C, which is parallel to the axis B. Several second take-up rollers 37 (called intermediate rollers) can be installed between the take-up roller 36 and the storage roller 34. Each second roller 37 allows for uniform application of the tension. Indeed, the preform can have a different length between each second roller (preform woven “in shape” using the “contour weaving” process – i.e. the preform is non-developable), which involves an adjustment of the length traveled by the preform between the first take-up roller 36 and the storage roller 34. In this way, thanks to the second take-up roller(s) (intermediate rollers), the length of the preform is different at each axial position of a second roller.In the absence of this or these second roller(s) 37, the tension applied by the storage roller 34 can concentrate in an area where the preform is the shortest and generate slippage.

[0030] In reference to the figure 3 , the second roller 37 is mounted free to rotate (unlike the take-up roller 36 and the storage roller 34). In particular, the second roller 37 is located in the longitudinal direction L between the first roller 36 and the storage roller 34. This second roller is also located at a radial height different from that of the first roller 36 and that of the storage roller 34. It can be lower or higher depending on requirements.

[0031] There figure 4shows in more detail the first call roller 36. The latter here has an axial section of general hourglass shape. The first roller 36 can have all types of shapes with different curvilinear, conical or truncated portions more or less pronounced. In other words, the shape of the first roller 36 is said to be scalable. Typically, the shape of the axial section of the roller corresponds to the profile of the casing or the shell to be manufactured. In the example shown very schematically of the figure 4, the first call roller has a first cylindrical part 38 centered on the axis A and a second conical or frustoconical part 39 which extends the first part, the base of the second part being connected to the first part. The first roller also comprises a third conical or frustoconical part 40 whose apex is connected to that of the second part. Alternatively, the second part is cylindrical and the first and third parts which extend transversely on either side of the second roller are of frustoconical shape. The first call roller 36 is manufactured in a single piece (made from the same material or in a single piece). Alternatively, the first call roller 36 is manufactured using several parts which are assembled with suitable fixing means (welding, screws, bolts, studs, etc.).

[0032] The installation 16 comprises an immobilizing element 41 for immobilizing the preform on the first take-up roller 36 when the installation is stopped (in particular during prolonged stops). This immobilizing element 41 prevents the preform from sliding upstream (toward the weaving zone 29) or downstream of the first roller 36 (toward the storage roller 34) due to a drop in tension on one of the two sides of the first roller 36 (either on the side of the storage roller 34, or on the side of the weights which are located on the bobbins mounted in the feed system 18). The tension on the side of the storage roller occurs because it pulls the preform downstream. Upstream there is also a resistant tension due to the weights of the bobbins and the weights, and friction of the threads on the different parts of the installation (eyelet, comb, etc.).

[0033] In the present example, the immobilizing element 41 comprises a wedge or a flange 42 which is mounted near the first take-up roller 36. Advantageously, the flange 42 is arranged at a support table 43 of the preform 15 at the outlet of the weaving loom. In particular, as can be seen in the figure 4 , a space 44 is provided in the support table 43 to receive at least part of the first roller 36. The preform is supported by the first take-up roller 36 at this space 44. Alternatively, the flange can be placed at another location in the second structure. The flange must not prevent the rotation of the first roller during operation of the installation.

[0034] The flange 42 has a bearing surface 45 which has a shape complementary to a peripheral surface 46 of the first roller 36. In the present example, the bearing surface 45 is intended to adapt to the shape of the first roller and / or to the preform. The bearing surface 46 is in other words arranged opposite the roller 36 (with the preform). In this example, the flange 42 also comprises a support member 48 which carries the bearing surface 45. Advantageously, the flange 42 is made of a metallic material. An example of a metallic material envisaged is aluminum which is light and economical. This has a thickness of the order of 5 cm so as to have sufficient rigidity. The flange also has a width l in the transverse direction (relative to the reference frame of the figure 4 ) between 70 cm and 190 cm. In particular, the flange has a width substantially identical to that of the first roller 36.

[0035] Following the example shown on the figure 4 , the bearing surface 45 comprises a coating 47 which makes it possible to respect the physical integrity of the preform and to better distribute the pressure of the flange 42 applied to the preform 15 or the first roller 36. The coating 47 is made of a polymer material such as an elastomer (neoprene, silicone). This coating 47 can allow the bearing surface 45 to adapt to the shape and / or the thickness of the preform which runs on the first take-up roller 36.

[0036] Alternatively as shown in the Figure 5, the flange 42 comprises a movable member 42a which carries the bearing surface 45. In particular, the movable member is in the form of a flexible metal sheet 42a (very thin) so as to adapt to the shape of the roller 36 and / or the preform 15. The metallic material is for example aluminum or steel. The sheet 42a is held by the support member 48 which is here in the form of a transverse bar (along the transverse direction T), rigid. The support member 48 is made of a metallic material. The sheet 42a, for its part, extends mainly along the transverse direction T.

[0037] In another variant not shown, so that the bearing surface adapts to the shape of the first roller and / or to the preform, the flange comprises a flexible member. The flexible member is formed by a flexible bladder which is mounted on the support member. The bladder is arranged in the radial direction between the rigid support member 48 and the preform. The bladder forms a closed chamber and which is intended to be inflated (to fill its volume) by a fluid. The bladder is kept under pressure by the fluid inside it or by an external pressurization system connected to the bladder. The bladder is also made of a polymer material such as a silicone.

[0038] When stopping the loom, or even during installation, the operator places the flange on the first roller so that a portion of the preform is compressed or compressed between the first take-up roller 36 and the flange 42. For this purpose, fixing members 50 such as screws, studs, nuts are used to fix the flange in position on the second structure and / or in particular here on the support table 43.

[0039] According to another embodiment, the flange 42 comprises at least one part which is mounted to move relative to the first roller 36. Advantageously, but not limitingly, at least one part of the flange moves substantially in a direction orthogonal to the direction of movement of the preform. For this, and as can be seen in the figure 4, the flange is equipped with a displacement member 49 which is fixed on the second structure. This displacement member comprises a first cylinder 51 which is connected to a first end 48a of the support member 48 of the flange and a second cylinder 51' which is connected to a second end 48a of the flange. The first and second cylinders 51, 51' operate according to a vertical translation in the radial direction. The cylinders are controlled by the electronic control system 35. In this way, when information to stop the installation is received by the electronic control system, the latter sends a control order to the displacement member 49 of the flange to move the flange towards the first take-up roller 36. In this way, the preform 15 is compressed between the first take-up roller 36 and the flange 42.

[0040] In the example of realization of the Figure 5, a member for moving at least a portion of the flange 42 is also provided. In this case, the movement is manual following a vertical translation (along the radial direction) as represented by the arrows DV. The flexible metal sheet 42a is removable and movable relative to the support member 48 and also relative to the roller 36. For this, the movement member 49 comprises adjustment screws 52 which are each received in a bore of the support member 48. Here, the bores comprise an internal thread. By screwing each adjustment screw 52 into their bores, their free ends come into abutment against an external surface 53 of the sheet 42a (radially opposite the bearing surface 45 carried here by the sheet).According to an alternative of this embodiment, the displacement member comprises adjustment rods which are integral with the external surface of the sheet metal and which are intended to each pass through a bore of the support member. A nut is mounted on the side of the free ends of the rods to fix the position of the sheet metal on the preform 15.

[0041] In the case of the Figure 5 , at least the metal sheet 42a is attached and removable. This is preferably put in place manually. The tab 54 then presses the flange onto the preform.

[0042] According to yet another embodiment, at least a portion of the flange moves in a rotation whose axis of rotation is orthogonal to the direction of movement of the preform. For this purpose, each first and second end of the flange or of the movable member (or flexible member (metal sheet)) is connected to an arm which is mounted in rotation about an axis parallel to the axis of the first roller. The arms are pivotally mounted on the second structure (or the support table). The arms are controlled by the electronic control system to move them towards the first roller when the latter receives information to stop the installation. The rotational movement of the arm would allow a greater range of movement and better clearance of the area comprising the space 44 when the flange 42 is not in use.

[0043] According to a variant of this embodiment, it is the operator who lowers the flange manually towards the first roller when the installation is stopped.

[0044] The flange can apply a compression or compaction pressure on the first call roller which is between 0.1 Mpa and 2 Mpa.

[0045] Once the preform is obtained, it is cut (end of weaving scrap) then unrolled from the storage roll 34.

[0046] The manufacturing process for the turbomachine part further includes a step of placing the preform around a mandrel that has the shape of the turbomachine casing. This mandrel has an axis of revolution and forms the injection mold into which the resin intended to densify the preform and obtain the desired part will be injected. The injection mold has a geometry identical to that of the final part. After wrapping around the injection mold, the preform is cut to the correct length to fill part of the injection chamber. A counter mold is applied around the preform to form the injection chamber.

[0047] The method comprises a step of injecting a matrix using RTM technology, this acronym meaning Resin Transfer Molding. In this description, the terms "resin" and "matrix" are equivalent. The matrix allowing densification of the fiber reinforcement can be a polymer matrix such as an epoxy-based thermosetting resin. The polymer matrix can also be a thermoplastic resin. The impregnation of the preform by the resin is optimized by applying pressure in the injection chamber. Other methods such as infusion, resin transfer molding known by the English acronym "RTM light" or injection molding of a resin between the preform and a flexible membrane known by the term "Polyflex" are of course conceivable.

[0048] We obtain a rigid part after hardening or polymerization of the matrix and without excessive tightening or loosening of the meshes in the fiber reinforcement. The final part in composite material is then demolded. Optionally, machining and drilling operations of the resulting casing are carried out at the end of the process.

Claims

1. A method for manufacturing a preform (15) for a turbomachine component using a weaving installation (16) comprising at least a first delivery roll (36) and a take-up roll (34), the method comprising the following steps: - feeding the weaving installation with weft (Tn) and warp (Cn) filaments, - weaving the weft and warp filaments together to form the preform (15), - driving the preform (15) in a direction of travel towards the take-up roll (34) which applies a predetermined tension on the preform (15), and - winding and storing the preform (15) around the take-up roll (34), characterised in that it comprises a step of immobilising the preform (15) on the first delivery roll (36) arranged upstream of the take-up roll (34) in the direction of travel of the preform (15) when the installation is stopped.

2. The manufacturing method according to the preceding claim, characterised in that the immobilisation step is carried out by means of a flange (42) arranged close to the first delivery roll (36).

3. The manufacturing method according to the preceding claim, characterised in that at least one portion of the flange (42) moves towards the first delivery roll (36) so that the preform (15) is compressed between the first roll and the flange.

4. The manufacturing method according to the preceding claim, characterised in that the movement of at least the movable portion of the flange (42) is manual or motorised.

5. The manufacturing method according to claim 3 or 4, characterised in that the installation is connected to an electronic control system (35) configured to control the stopping and the starting of the installation (16), the electronic control system (35) being connected to a moving member (49) for setting in motion the flange (42) so that when it receives an information about stopping the installation, a control command is sent to the moving member (49).

6. The manufacturing method according to any one of the preceding claims, characterised in that the flange (42) applies a pressure to the first delivery roll (36) of between 0.1 Mpa and 2 Mpa.

7. A weaving installation (16) for manufacturing a preform (15) for a turbomachine component, the weaving installation (16) comprising: - a stationary structure (32, 33, 43), - at least one take-up roll (34) for the preform (15) mounted so as to rotate about a first axis of rotation (A) with respect to the structure, the take-up roll (34) being intended to apply a tension to the preform (15) which is intended to be driven in a direction of movement towards the take-up roll (34) and to be wound around the latter, - at least one first delivery roll (36) mounted upstream of the take-up roll (34) and movable in rotation about a second axis of rotation (B) relative to the structure, and, - a flange (42) configured so as to immobilise the preform (15) on the first delivery roll (36) when the installation stops.

8. The weaving installation (16) according to the preceding claim, characterised in that at least a portion of the flange (42) is movable relative to the first delivery roll (36) via at least one moving member (49) which is attached to the structure (32, 33, 43) and which is connected to the flange (42).

9. The weaving installation (16) according to one of claims 7 and 8, characterised in that the flange (42) comprises a bearing surface (45) oriented towards the first delivery roll (36) and which has a complementary shape with a peripheral surface (46) of the first delivery roll (36) or of the preform (15).

10. The weaving installation (16) according to one of claims 7 to 9, characterised in that the flange (42) comprises a support member (48) and a movable member (42a) or flexible member relative to the support member (48), the movable or flexible member carrying the bearing surface (45).

11. The weaving installation (16) according to the preceding claim, characterised in that the bearing surface (45) comprises a coating (47) made of a polymeric material.

12. A method for manufacturing a turbomachine component of composite material comprising a fibrous reinforcement densified by a matrix, the method comprising the following steps: - manufacturing a preform according to the method of any one of claims 1 to 6, - placing the preform around a mandrel forming a mould, - installing a counter-mould around the preform placed on the mandrel so as to form an injection chamber, - injecting a matrix into the injection chamber, - polymerising the matrix, - demoulding the composite material component.