Mold for manufacturing a fan case of a turbine engine from composite material

Abstract

The invention relates to a mold (1) for manufacturing a turbine engine fan case made of composite material, comprising: - a mandrel (2) on which a fiber preform of the fan case will be wound; - a plurality of counter-mold angular sectors (3) assembled on the outer contour of the mandrel for closing the mold (1) and compacting the fiber preform wound on the mandrel (2); characterized in that each angular sector (3) comprises, on the one hand, a first side flange (33) located at a first end of the angular sector (3) and, on the other hand, a second side flange (34) located at a second end of the angular sector (3) opposite the first end, the first side flange (33) and the second side flange (34) being configured to cooperate respectively with the second side flange (34) and the first side flange (33) of an adjacent angular sector (3); at least one angular sector (3) comprises a first recess (36) formed in at least one of the first side flange (33) and the second side flange (34), a first seal (5) being located in the first recess (36), the first seal (5) being configured to be compacted between the first side flange (33) and the second side flange (34) of two adjacent angular sectors (3).

Description

BACKGROUND

[0002] The present invention relates to the general field of manufacturing of turbine engine casings, and more particularly to containment casings of aero-engine gas turbine fans.

[0003] In aero turbine engines, the fan casing has multiple functions. It defines the intake flow of the turbine engine, supports the abradable material facing the tips of the fan blades, supports possible sound absorbing structures for acoustic treatment at the turbine engine inlet, and incorporates or supports a containment shroud.

[0004] The containment shroud forms a catcher that retains debris, such as ingested objects or fragments of damaged blades thrown under the influence of centrifugal force, to avoid these fragments passing through the casing and reaching other parts of the aircraft.

[0005] It is known to manufacture fan casings with composite materials, in particular organic-based composite materials. To do this, a fibrous weave is wound on a mandrel to form a fibrous preform having the shape of the casing to be manufactured. The fibrous preform is then densified by a matrix.

[0006] To achieve the densification of the fibrous preform by the matrix, the fibrous preform is wound on an impregnation mandrel, then an anti-mould angular sector is placed around the impregnation mandrel to form an injection mould. A precursor material of the matrix is then injected into the mould in order to densify the fibrous preform with the precursor material of the matrix. Once the fibrous matrix is densified, the precursor material is polymerized.

[0007] For example, the known document WO2017 / 089680 describes an injection mould for manufacturing a fan casing made of composite material, comprising a plurality of angular sectors arranged around an impregnation mandrel.

[0008] In the document WO2017 / 089680, the seal between the different angular sectors is provided by T-shaped parts attached by bolts between each angular sector and each compressing a flat seal overlapping the two adjacent angular sectors.

[0009] The drawback of this solution is the need for a relatively long processing time, in particular when tightening or unscrewing the bolts attaching the T-shaped parts to the angular sectors.

[0010] In addition, this type of injection mould can encounter stiffness problems, in particular at the junction between the angular sectors. SUMMARY

[0011] The main aim of the present application is therefore to attenuate this type of drawback, according to a first aspect of the application, a mold for manufacturing a fan case of a turbine engine made of composite material, more precisely of organic-based composite material, is proposed, comprising:

[0012] - a mandrel on which the fiber preform of the fan case will be wound;

[0013] - a plurality of counter-mold angular sectors assembled on the outer profile of the mandrel for closing the mold and compacting the fiber preform wound on the mandrel;

[0014] characterized in that each angular sector comprises, on the one hand, a first side flange at a first end of the angular sector and, on the other hand, a second side flange at a second end of the angular sector, opposite the first end, the first and second side flanges being configured to cooperate respectively with the second and first side flanges of an adjacent angular sector,

[0015] at least one angular sector comprising a first recess formed in at least one of the first and second side flanges, a first seal being located in the first recess, the first seal being configured to be compacted between the first and second side flanges of two adjacent angular sectors.

[0016] The mold can also comprise the following additional features, which can be used individually or combined according to technically possible combinations:

[0017] - each angular sector comprises a front flange and a rear flange configured to cooperate respectively with an upstream flange and a downstream flange of the mandrel, the upstream and downstream flanges comprising respectively a second recess and a third recess, a second seal and a third seal being located respectively in the second and third recesses, the second seal being configured to be compacted between the upstream flange of the mandrel and the front flange of the angular sector, the third seal being configured to be compacted between the downstream flange of the mandrel and the rear flange of the angular sector, the first recess opening into the second recess on the one hand and into the third recess on the other hand;

[0018] - the mold comprises a first group of angular sectors in which the first recess is formed in the first and second side flanges, and a second group of angular sectors in which the first and second side flanges are smooth, one angular sector of the first group being located between two angular sectors of the second group;

[0019] - the first recess is formed in the first flange of each angular sector;

[0020] - the first recess has a wavy shape;

[0021] - the first recesses are crenelated, the first recesses comprising on the one hand a plurality of radially inward grooves and on the other hand a plurality of radially outward grooves;

[0022] - the first and second flanges of the angular sectors comprise holes, each angular sector being bolted to an adjacent angular sector, the bolted connection being on the one hand in a hole of the first side flange of the angular sector and on the other hand in a hole of the second side flange of the adjacent angular sector;

[0023] - the radially outward grooves are located between two holes;

[0024] - the first seal is made of an elastomer, for example a cold vulcanized elastomer.

[0025] According to a second aspect, the application proposes a method of manufacturing a turbine engine fan casing made of composite material using a mold according to any one of the preceding characteristics, the method comprising the following steps:

[0026] - winding a fiber preform of the fan casing around a mandrel;

[0027] - assembling a plurality of counter-mold angular sectors on the outer profile of the mandrel by connecting the first side flange of the angular sector to the second side flange of an adjacent angular sector;

[0028] - densifying the fiber preform by injecting a precursor material of a composite material matrix into the mold;

[0029] - polymerizing the precursor material to obtain a matrix of composite material;

[0030] - removing the plurality of angular sectors;

[0031] - demolding the fan casing. BRIEF DESCRIPTION OF DRAWINGS

[0032] Other characteristics and advantages of the application will be revealed by the description given below and with reference to the appended drawings, which show example embodiments, without any limiting character. In these drawings:

[0033] - Figure 1 is a schematic view of a mold for manufacturing a composite material turbine engine fan casing;

[0034] - Figure 2 is Figure 1 a schematic view of the fit between adjacent angular sectors of the mold;

[0035] - Figure 3a is a more precise view of the area A of Figure 2 , the seal not being shown;

[0036] - Figure 3b isFigure 2 A more accurate view of area B of FIG, without showing the seal;

[0037] - Figure 4 The different steps of a method for manufacturing a composite fan casing are schematically shown. DETAILED DESCRIPTION

[0038] like Figure 1 、 2 , 3 and 4 , a mold 1 for manufacturing a turbine engine fan case made of composite material comprises a core shaft 2 on which a fiber preform of the fan case is wound.

[0039] This mold 1 is used for impregnating a fibrous preform by a process of the RTM (“Resin Transfer Molding”) type.

[0040] The fiber preform can be produced by two-dimensional weaving of fibers (2D weaving) or, preferably, by three-dimensional weaving of fibers (3D weaving).

[0041] A “three-dimensional weaving” or “3D weaving” or even a “multi-layer weaving” as referred to herein is a weaving pattern in which at least some of the weft yarns connect the warp yarns over multiple warp yarn layers, or vice versa, according to a weave corresponding to a weaving pattern which can in particular be selected from one of the following patterns: interlock, multi-plain, multi-satin and multi-twill.

[0042] "Two-dimensional weaving" or "2D weaving" is understood to be a conventional weaving pattern in which each warp yarn passes from one side to the other of a single layer of weft yarns.

[0043] Fiber preforms can be made from carbon fibers, glass fibers, aramid fibers, and even ceramic fibers.

[0044] The outer wall of the mandrel 2 around which the fiber preform is wound has a profile that corresponds to the profile of the fan casing to be manufactured.

[0045] The mold 1 also comprises a plurality of counter-mold angular sectors 3 which are removably assembled on the outer contour of the mandrel 2. Once assembled on the outer contour of the mandrel 2, the angular sectors 3 close the mold 1 and compact the fiber preform.

[0046] By compacting the fiber preform via the angular sectors 3 , it is possible to compress the preform to the desired thickness and to obtain the desired fiber volume density in the fan housing.

[0047] In order to attach the angular sectors 3 to the core shaft 2, the core shaft 2 includes an upstream flange 21 located at the front end of the core shaft 2 and a downstream flange 22 located at the rear end of the core shaft 2, and each angular sector 3 includes, on the one hand, a front flange 31 configured to cooperate with the upstream flange 21, and on the other hand, a rear flange 32 configured to cooperate with the downstream flange 22.

[0048] In Figures 1 to 4 In the variant illustrated, the front flanges 31 and the rear flanges 32 of the corner sectors 3 are attached to the upstream flanges 21 and to the downstream flanges 22, respectively, by means of bolted connections arranged in the holes made in the front flanges 31, in the rear flanges 32, in the upstream flanges 21 and in the downstream flanges 22.

[0049] Furthermore, the corner sectors 3 are attached to each other, each corner sector 3 being attached to the two corner sectors adjacent thereto.

[0050] Each corner sector 3 comprises a first side flange 33 at a first end of the corner sector 3 and a second side flange 34 at a second end of said corner sector 3, the second end being opposite the first end.

[0051] For each corner sector 3, the first side flange 33 is configured to cooperate with the second side flange 34 of the adjacent corner sector, and therefore the second side flange 34 is configured to cooperate with the first side flange 33 of the other adjacent corner sector 3.

[0052] Therefore, in order to connect the plurality of corner sectors 3 to the profile of the mandrel 2, each corner sector 2 is connected to the following elements:

[0053] - the front flange 31 of the corner sector 3 is connected to the upstream flange 21 of the mandrel 2;

[0054] - the rear flange 32 of the corner sector 3 is connected to the downstream flange 22 of the mandrel;

[0055] - the first side flange 33 of the corner sector 3 is connected to the second side flange 34 of the first adjacent corner sector 3;

[0056] - the second side flange 34 of the corner sector 3 is connected to the first side flange 33 of the second adjacent corner sector 3.

[0057] The fact that the corner sectors 3 are directly connected to each other, instead of placing intermediate parts between each corner sector, allows to reinforce the stiffness of the mould 1 at the connections between the corner sectors 3, thus limiting the deformation of the mould at the connections between the corner sectors 3.

[0058] In order to connect the first side flange 33 and the second side flange 34, said first side flange 33 and third side flange 34 comprise holes 35 allowing the passage of a bolt.

[0059] In order to ensure the sealing between the different corner sectors 3, a first recess 36 is made in at least one of the first side flange 33 and the second side flange 34.

[0060] More precisely, the first recess 36 is made in a flat portion of the first side flange 33 and / or of the second side flange 34, which rests on a complementary flat portion of the second side flange 34 or of the first side flange 33 of the adjacent corner sector 3.

[0061] The first seal 5 is located in the first groove 36, which is thus compressed between the first side flange 33 and the second side flange 34, so as to be able to seal the connection between the corner sectors 3. The first seal 5 is not shown in Figures 3a and 3b, so as to make the first groove 36 visible.

[0062] The first seal 5 can be made of an elastomer suitable for the stresses encountered by the first seal 5, in particular a cold vulcanized (or room temperature vulcanized (RTV)) elastomer, such as a cold vulcanized silicone, so as to have good resistance to the stresses to which the first seal 5 is subjected, and simple to use.

[0063] In Figure 2 In the variant embodiment shown, the first grooves 36 are not formed on all the corner sectors 3, but only on a part of said corner sectors.

[0064] More precisely, in Figure 2 In the variant shown, the mold 1 comprises, on the one hand, a first group of corner sectors 3 in which the first grooves 36 are formed on the first side flange 33 and on the second side flange 34, and, on the other hand, a second group of corner sectors 3 for which the first side flange 33 and the second side flange 34 are smooth, i.e. the first side flange 33 and the second side flange 34 do not have the first grooves 36.

[0065] One of the corner sectors 3 of the first group is located between two corner sectors 3 of the second group. Thus, in this variant, the sealing between the different corner sectors 3 is obtained:

[0066] - the first seal 5 located in the first groove 36 formed in the first side flange 33 of the corner sectors 3 of the first group is compressed between the first side flange 33 of the corner sectors 3 of the first group and the second side flange 34 of the corner sectors 3 of the second group;

[0067] - the first seal 5 located in the first groove 36 formed in the second side flange 34 of the corner sectors 3 of the first group is compressed between the second side flange 34 of the corner sectors 3 of the first group and the first side flange 33 of the corner sectors 3 of the second group.

[0068] According to another possible variant, the first grooves 36 can be formed on the first side flange 33 of each corner sector 3, so that the first seal 5 is compressed between the first side flange 33 and the second side flange 34, the second side flange 34 being smooth for itself. It should be noted that likewise, the first grooves 36 can be formed in the second side flange 34 of each corner sector 3, while the first side flange 33 is smooth. What is meant here by "smooth" can also be understood as the first side flange 33 or the second side flange 34 not having the first grooves 36.

[0069] To ensure the sealing between the mandrel 2 and the angular sector 3, the upstream flange 21 of the mandrel 2 comprises a second groove 23 and the downstream flange 22 comprised in the mandrel 2 comprises a third groove 24.

[0070] The second groove 23 is an annular groove which is located on the profile of the upstream flange 21, more precisely on a flat surface of the upstream flange 21 which is in contact with a complementary flat surface of the front flange 31 of the angular sector 3.

[0071] The third groove 24 is also an annular groove which is located on the profile of the downstream flange 22, more precisely on a flat surface of the downstream flange 22 which is in contact with a complementary flat surface of the rear flange 32 of the angular sector 3.

[0072] The second seal 6 is located inside the second groove 23 and the third seal 7 is located inside the third groove 24.

[0073] The second seal 6 is configured to be compressed between the upstream flange 21 of the mandrel 2 and the front flange 31 of the angular sector 3, thereby ensuring the sealing of the connection between the upstream flange 21 of the mandrel 2 and the front flange 31 of the angular sector 3.

[0074] The third seal 7 is configured to be compressed between the downstream flange 22 of the mandrel 2 and the rear flange 32 of the angular sector 3, thereby ensuring the sealing of the connection between the downstream flange 22 of the mandrel 2 and the rear flange 32 of the angular sector 3.

[0075] The second seal 6 and the third seal 7 can be made of an elastomer, which is a material suitable for the stresses encountered by the second seal 6 and the third seal 7. The second seal 6 and the third seal 7 can be made of a cold vulcanized (or room temperature vulcanized (RTV)) elastomer, in particular a cold vulcanized silicone.

[0076] As illustrated on figures 3a and 3b, when the angular sector 3 is connected to the mandrel 2, the first groove 36 formed in the first side flange 34 opens on the third groove 23 formed in the upstream flange 21 on the one hand and on the third groove 24 formed in the downstream flange 22 on the other hand.

[0077] The first groove 36 opens on the second groove 23 and on the third groove 24, which makes it possible to ensure the continuity of the sealing.

[0078] Moreover, as illustrated on figure 3a, the first groove 36 has a wavy shape, which makes it possible to limit the risk of the first seal 5 leaving said first groove 36. Figure 2

[0079] The wavy shape of the first groove 36 is advantageously a zigzag shape, said first groove 36 comprising a radially inward groove and a radially outward groove. This type of zigzag makes it possible to limit the risk of the first seal 5 leaving the first groove 36. ​

[0080] It can be understood here that a radially inward groove refers to a portion of the first groove 36 where the first groove 36 approaches the mandrel 2, and a radially outward groove refers to a portion of the first groove 36 where the first groove 36 moves away from the mandrel 2.

[0081] As Figure 2 illustrated, the radially outward groove from the first groove 36 can advantageously be positioned between two holes 35.

[0082] The mold 1 can be used to implement a manufacturing method of a composite material fan case as Figure 4 illustrated, the method comprising the following steps:

[0083] - E1 : winding a fan case fiber preform around a mandrel 2;

[0084] - E2: assembling a plurality of counter-mold angular sectors 3 on the outer profile of said mandrel by connecting the first side flange 33 of an angular sector 3 to the second side flange 34 of an adjacent angular sector 3. The angular sectors 3 are also connected to the mandrel 2 by connecting the front flange 31 and the rear flange 32 of a sector 3 to the upstream flange 21 and to the downstream flange 22 of the mandrel 2;

[0085] - E3: densifying said fiber preform by injecting a precursor material of a composite material matrix into the mold 1, said mold 1 comprising injection openings for injecting said precursor material;

[0086] - E4: polymerizing said precursor material to obtain a matrix of a composite material;

[0087] - E5 removing said plurality of angular sectors 3, this step being done by separating the first side flange 33 from the second side flange 34, the front flange 31 from the upstream flange 21 and the rear flange 32 from the downstream flange 32;

[0088] - E6: demolding said fan case.

Claims

1. A mold for manufacturing a turbine engine fan case made of composite material, comprising: - a mandrel on which a fiber preform of a fan case will be wound; - a plurality of counter-mold angular sectors assembled on the outer profile of the mandrel for closing the mold and compacting the fiber preform wound on the mandrel; characterized in that each angular sector comprises, on the one hand, a first side flange at a first end of the angular sector and, on the other hand, a second side flange at a second end of the angular sector opposite the first end, the first and second side flanges being configured to cooperate respectively with the second and first side flanges of an adjacent angular sector, at least one angular sector comprising a first groove formed in at least one of the first and second side flanges, a first seal being located in the first groove, the first seal being configured to be compacted between the first and second side flanges of two adjacent angular sectors; wherein the first groove is zigzag-shaped, comprising on the one hand a plurality of radially inward grooves and on the other hand a plurality of radially outward grooves.

2. The mold of claim 1, wherein, each angular sector comprising a front flange and a rear flange configured to cooperate respectively with an upstream flange and a downstream flange of the mandrel, the upstream and downstream flanges comprising respectively a second groove and a third groove, a second seal and a third seal being respectively located in the second and third grooves, the second seal being configured to be compacted between the upstream flange of the mandrel and the front flange of the angular sector, the third seal being configured to be compacted between the downstream flange of the mandrel and the rear flange of the angular sector, the first groove opening on the one hand into the second groove and on the other hand into the third groove.

3. The mold of claim 1, wherein, the mold comprising a first group of angular sectors in which the first groove is formed on the first and second side flanges, and a second group of angular sectors in which the first and second side flanges are smooth, one angular sector of the first group being located between two angular sectors of the second group.

4. The mold of claim 1, wherein, the first groove is formed on the first side flange of each angular sector.

5. The mold of claim 1, wherein, the first and second side flanges of the angular sectors comprise holes, each angular sector being bolted to an adjacent angular sector, the bolted connection being located on the one hand in a hole of the first side flange of the angular sector and on the other hand in a hole of the second side flange of the adjacent angular sector.

6. The mold of claim 5, wherein, the radially outward grooves are located between two holes.

7. The mold of any one of claims 1 to 6, wherein, the first seal is made of elastomer.

8. The mold of any one of claims 1 to 6, wherein, the first seal is made of cold vulcanized elastomer.

9. A method for manufacturing a composite turbine engine fan case using the mold according to any one of claims 1 to 8, the method comprising: - winding a fiber preform of a fan case around a mandrel; - assembling a plurality of counter-mold angular sectors on the outer profile of the mandrel (2) by connecting the first side flange of an angular sector to the second side flange of an adjacent angular sector; - densifying the fiber preform by injecting a precursor material of a composite matrix into the mold; - polymerizing the precursor material to obtain a matrix of composite material; - removing the plurality of angular sectors; - demolding the fan case.

10. A method for manufacturing a composite turbine engine fan case using the mold according to any one of claims 1 to 8, the method comprising: - winding a fiber preform of a fan case around a mandrel; - assembling a plurality of counter-mold angular sectors on the outer profile of the mandrel (2) by connecting the first side flange of an angular sector to the second side flange of an adjacent angular sector; - densifying the fiber preform by injecting a precursor material of a composite matrix into the mold; - polymerizing the precursor material to obtain a matrix of composite material; - removing the plurality of angular sectors; - demolding the fan case.

11. A method for manufacturing a composite turbine engine fan case using the mold according to any one of claims 1 to 8, the method comprising: - winding a fiber preform of a fan case around a mandrel; - assembling a plurality of counter-mold angular sectors on the outer profile of the mandrel (2) by connecting the first side flange of an angular sector to the second side flange of an adjacent angular sector; - densifying the fiber preform by injecting a precursor material of a composite matrix into the mold; - polymerizing the precursor material to obtain a matrix of composite material; - removing the plurality of angular sectors; - demolding the fan case.

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