MOLD FOR MANUFACTURING A TURBINE MOTOR BLOWER HOUSING FROM A COMPOSITE MATERIAL

Description

Background of the invention

[0001] The present invention relates to the general field of manufacturing turbomachine housings, and more particularly to retention housings for gas turbine blowers for aircraft engines.

[0002] In an aeronautical turbomachine, a fan casing fulfills several functions. The fan casing defines the air intake duct of the turbomachine, supports an abradable material opposite the tips of the fan blades, supports a possible sound wave absorption structure for acoustic treatment at the turbomachine inlet, and incorporates or supports a retention shield.

[0003] The retention shield forms a trap that retains debris, such as ingested objects or fragments of damaged blades, projected by centrifugal force, to prevent this debris from passing through the casing and reaching other parts of the aircraft.

[0004] It is known to manufacture the blower housing from composite materials, and more specifically from organic matrix composite materials. To do this, a fibrous texture is wound around a mandrel to form a fibrous preform that has the shape of the housing to be manufactured. The fibrous preform is then densified by a matrix.

[0005] To densify the fibrous preform with the matrix, the fibrous preform is wound around an impregnation mandrel, and then angled counter-mold sectors are arranged around the impregnation mandrel to form the injection mold. A matrix precursor material is then injected into the mold to densify the fibrous preform with said matrix precursor material. Once the fibrous preform is densified, the precursor material is polymerized.

[0006] We know, for example, of document WO2017 / 089680 which describes an injection mold for the manufacture of a blower housing in composite material which includes a plurality of angular sectors arranged around an impregnation mandrel.

[0007] In document WO2017 / 089680, the sealing between the different angular sectors is ensured by T-shaped pieces which are fixed by bolts between each angular sector and which each compress a flat gasket overlapping two adjacent angular sectors.

[0008] Such a solution has the disadvantage of requiring a very significant amount of handling time, particularly for screwing or unscrewing the bolts that fix the T-shaped parts to the angular sectors.

[0009] Furthermore, such an injection mold can encounter a problem of rigidity, and in particular rigidity at the connection between the angular sectors. Object and summary of the invention

[0010] The main objective of the present invention is therefore to overcome such a drawback by proposing, according to a first aspect of the invention, a mold for manufacturing a turbomachine blower housing from composite material, and more specifically from an organic matrix composite material, comprising: a mandrel around which a fibrous preform of a blower housing is intended to be wound; a plurality of angular counter-mold sectors assembled on the outer contour of the mandrel which are intended to close the mold and compact the fibrous preform wound on the mandrel; characterized in that each angular sector comprises on the one hand a first lateral flange which is located at the first end of the angular sectors and on the other hand a second lateral flange which is located at a second end of the angular sectors and which is opposite to the first end, the first lateral flange and the second lateral flange being configured to cooperate respectively with the second lateral flange and the first lateral flange of the adjacent angular sectors, at least one angular sector comprising a first groove formed in at least one of the first lateral flange and the second lateral flange, a first joint being disposed in said first groove, said first joint being configured to be compressed between the first lateral flange and the second lateral flange of two adjacent angular sectors.

[0011] The mold may also include the following additional features, which may be taken alone or in combination depending on the technical possibilities: Each angular sector comprises a front flange and a rear flange which are configured to cooperate respectively with an upstream flange and a downstream flange of the chuck, the upstream flange and the downstream flange comprising respectively a second groove and a third groove, a second seal and a third seal being respectively disposed in the second groove and the third groove, said second seal being configured to be compressed between the upstream flange of the chuck and the front flange of the angular sectors, said third seal being configured to be compressed between the downstream flange of the chuck and the rear flange of the angular sectors, the first groove opening on one side into the second groove and on the other side into the third groove;the mold comprises a first group of angular sectors for which the first groove is formed on the first lateral flange and on the second lateral flange, and a second group of angular sectors for which the first lateral flange and the second lateral flange are smooth, an angular sector of the first group being disposed between two angular sectors of the second group; the first groove is formed on the first flange of each angular sector; the first groove comprises a wavy shape; the first groove is crenellated, the first groove comprising on one side a plurality of crenellations directed radially inwards and on the other side a plurality of crenellations directed radially outwards;The first and second flanges of the angular sectors include bores, each angular sector being fixed to an adjacent angular sector by bolts arranged on one side in the bores of the first lateral flange of the angular sector and on the other side in the bores of the second lateral flange of the adjacent angular sector; the slots directed radially outwards are located between two bores; the first seal is made of elastomer, for example a cold-vulcanizable elastomer.

[0012] According to a second aspect, the invention proposes a method for manufacturing a turbomachine blower housing made of composite material with the mold according to any one of the preceding characteristics, the method comprising the following steps: wrap a fibrous preform of the blower housing around the mandrel; assemble the plurality of angular counter-mold sectors on the outer contour of the mandrel by fixing the first lateral flange of the angular sectors with the second lateral flange of an adjacent angular sector; densify the fibrous preform by injecting a precursor material of a matrix of the composite material into the mold; polymerize the precursor material to obtain the matrix of the composite material; remove the plurality of angular sectors; demold the blower housing. Brief description of the drawings

[0013] Other features and advantages of the present invention will become apparent from the description below, with reference to the accompanying drawings, which illustrate an example of an embodiment without being limiting in any way. In the figures: there figure 1is a schematic representation of a mold for manufacturing a turbomachine blower housing from composite material; the figure 2 is a schematic representation of the cooperation between adjacent angular sectors of the mold of the figure 1 ; there figure 3a is a more accurate representation of zone A of the figure 2 the joint not being shown; the figure 3b is a more accurate representation of zone B of the figure 2 the joint not being shown; the figure 4 schematically represents the different stages of a manufacturing process for a blower housing made of composite material. Detailed description of the invention

[0014] As illustrated on the Figures 1 , 2 , 3 And 4 , a mold 1 for manufacturing a turbomachine blower housing from composite material includes a mandrel 2 around which a fibrous preform of the blower housing is wound.

[0015] Mold 1 is intended to be used for impregnation by an RTM (Resin Transfer Molding) type process of the fibrous preform.

[0016] The fibrous preform can be made by two-dimensional weaving of fibers (2D weaving), or preferably by three-dimensional weaving of fibers (3D weaving).

[0017] By "three-dimensional weaving" or "3D weaving" or even "multilayer weaving", we mean here a method of weaving in which at least some of the weft yarns link warp yarns over several warp layers, or vice versa, according to a weave corresponding to a weave structure, said weave structure being able to be chosen in particular from one of the following weaves: interlock, multi-plain, multi-satin and multi-twill.

[0018] By "two-dimensional weaving" or "2D weaving" we mean here a classic weaving method in which each warp thread passes from one side to the other of threads in a single layer of weft.

[0019] The fibrous preform can be made from carbon fibers, glass fibers, aramid fibers, or even ceramic fibers.

[0020] The outer wall of the mandrel 2 around which the fibrous preform is wound has a profile which corresponds to the profile of the blower housing to be manufactured.

[0021] The mold 1 also includes a plurality of angular counter-mold 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 compress the fibrous preform.

[0022] The compression of the fibrous preform by the angular sectors 3 allows the preform to be compacted to the desired thickness and to obtain the desired volumetric ratio of fibers in the blower housing.

[0023] In order to fix the angular sectors 3 to the mandrel 2, the mandrel 2 includes an upstream flange 21 located at a front end of the mandrel 2 and a downstream flange 22 located at a rear end of the mandrel 2, and each angular sector 3 includes on the one hand a front flange 31 which is configured to cooperate with the upstream flange 21, and on the other hand a rear flange 32 which is configured to cooperate with the downstream flange 22.

[0024] In the variant illustrated on the figures 1 to 4, the front flange 31 and the rear flange 32 of the angular sectors 3 are respectively fixed to the upstream flange 21 and the downstream flange 22 by bolts which are arranged in holes formed in said front flange 31, rear flange 32, upstream flange 21 and downstream flange 22.

[0025] Furthermore, the angular sectors 3 are fixed to each other, each angular sector 3 being fixed to the two angular sectors adjacent to it.

[0026] Each angular sector 3 comprises a first lateral flange 33 which is located at the first end of the angular sectors 3 and a second lateral flange 34 which is located at a second end of said angular sectors 3, the second end being opposite to the first end.

[0027] For each angular sector 3, the first lateral flange 33 is configured to cooperate with the second lateral flange 34 of the adjacent angular sector 3, and thus the second lateral flange 34 is configured to cooperate with the first lateral flange 33 of the other adjacent angular sector 3.

[0028] Thus, to fix the plurality of angular sectors 3 onto the contour of the mandrel 2, each angular sector 3 is fixed with the following elements: the front flange 31 of the angular sector 3 is fixed to the upstream flange 21 of the chuck 2; the rear flange 32 of the angular sector 3 is fixed to the downstream flange 22 of the chuck; the first lateral flange 33 of the angular sector 3 is fixed to the second lateral flange 34 of the first adjacent angular sector 3; the second lateral flange 34 of the angular sector 3 is fixed to the first lateral flange 33 of the second adjacent angular sector 3.

[0029] The fact that the angular sectors 3 are directly fixed to each other, and not with an intermediate piece placed between each angular sector, makes it possible to reinforce the rigidity of the mold 1 at the level of the connection between the angular sectors 3, and thus limits the deformation of the mold 1 at the level of the connection between the angular sectors 3.

[0030] In order to fix the first side flange 33 and the second side flange 34, said first side flange 33 and second side flange 34 include holes 35 which allow the passage of bolts.

[0031] In order to ensure the seal between the different angular sectors 3, a first groove 36 is formed in at least one of the first lateral flange 33 and the second lateral flange 34.

[0032] More specifically, the first groove 36 is formed in the flat portion of the first lateral flange 33 and / or the second lateral flange 34 which rests against the complementary flat part of the second lateral flange 34 or the first lateral flange 33 of the adjacent angular sector 3.

[0033] A first seal 5 is disposed inside the first groove 36, said first seal 5 being thus compressed between, on the one hand, the first lateral flange 33 and, on the other hand, the second lateral flange 34, thereby sealing the connection between the angular sectors 3. The first seal 5 is not shown in the figures 3a and 3b in order to leave the first groove 36 visible.

[0034] The first seal 5 can be made of elastomer, which is a material suitable for the stresses encountered by the first seal 5, and in particular of cold-vulcanizable elastomer (or RTV for "Room-Temperature-Vulcanizing" according to Anglo-Saxon terminology), such as for example a cold-vulcanizable silicone, thus offering good resistance to the stresses to which the first seal 5 is subjected as well as simple use.

[0035] In the embodiment shown on the figure 2 , the first groove 36 is not formed on all angular sectors 3, but on only a part of said angular sectors 3.

[0036] More specifically, in the variant illustrated on the figure 2, the mold 1 comprises on the one hand a first group of angular sectors 3 for which a first groove 36 is formed both on the first lateral flange 33 and on the second lateral flange 34, and on the other hand a second group of angular sectors 3 for which the first lateral flange 33 and the second lateral flange 34 are smooth, that is to say that the first lateral flange 33 and the second lateral flange 34 are without a first groove 36.

[0037] An angular sector 3 from the first group is positioned between two angular sectors 3 from the second group. Thus, in this variant, the seal between the different angular sectors 3 is achieved as follows: the first seal 5 disposed in the first groove 36 formed in the first lateral flange 33 of the angular sectors 3 of the first group is compressed between on the one hand the first lateral flange 33 of the angular sectors 3 of the first group and on the other hand the second lateral flange 34 of the angular sectors 3 of the second group; the first seal 5 disposed in the first groove 36 formed in the second lateral flange 34 of the angular sectors 3 of the first group is compressed between on the one hand the second lateral flange 34 of the angular sectors 3 of the first group and on the other hand the first lateral flange 33 of the angular sectors 3 of the second group.

[0038] According to another possible variant, the first groove 36 can be formed on the first lateral flange 33 of each angular sector 3, so that the first joint 5 is compressed between the first lateral flange 33 and the second lateral flange 34, the second lateral flange 34 being smooth. It should be noted that, equivalently, the first groove 36 can be formed in the second lateral flange 34 of each angular sector 3 while the first lateral flange 33 is smooth. "Smooth" here also means that the first lateral flange 33 or the second lateral flange 34 lacks the first groove 36.

[0039] To ensure a seal between the mandrel 2 and the angular sectors 3, the upstream flange 21 of the mandrel 2 includes a second groove 23 and the downstream flange 22 of the mandrel 2 includes a third groove 24.

[0040] The second groove 23 is an annular groove which runs along the contour of the upstream flange 21, and more precisely on the flat surface of the upstream flange 21 which comes into contact with the complementary flat surface of the front flange 31 of the angular sectors 3.

[0041] The third groove 24 is also an annular groove which runs along the contour of the downstream flange 22, and more precisely on the flat surface of the downstream flange 22 which comes into contact with the complementary flat surface of the rear flange 32 of the angular sectors 3.

[0042] A second seal 6 is arranged inside the second groove 23, and a third seal 7 is arranged inside the third groove 24.

[0043] The second seal 6 is configured to be compressed between the upstream flange 21 of the chuck 2 and the front flange 31 of the angular sectors 3, thus ensuring the sealing of the fixing between the upstream flange 21 of the chuck 2 and the front flange 31 of the angular sectors 3.

[0044] 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 sectors 3, thus ensuring the sealing of the fixing between the downstream flange 22 of the mandrel 2 and the rear flange 32 of the angular sectors 3.

[0045] The second seal 6 and the third seal 7 can be made of 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 cold-vulcanizable elastomer (or RTV for "Room-Temperature-Vulcanizing" according to Anglo-Saxon terminology), and in particular of cold-vulcanizable silicone.

[0046] As shown in detail on the figures 3a and 3b , when an angular sector 3 is fixed on the mandrel 2, the first groove 36 formed in the first lateral flange 34 opens on one side into the second groove 23 formed in the upstream flange 21, and on the other side into the third groove 24 formed in the downstream flange 22.

[0047] The fact that the first groove 36 opens into the second groove 23 and the third groove 24 ensures continuity of sealing.

[0048] Furthermore, as illustrated on the figure 2, the first groove 36 includes a corrugated shape, thus limiting the risk of the first seal 5 coming out of said first groove 36.

[0049] The corrugated shape of the first groove 36 is advantageously a crenellated shape, said first groove 36 comprising crenellations directed radially inwards, and crenellations directed radially outwards. Such a crenellated shape limits the risk of the first seal 5 coming out of the first groove 36.

[0050] By slot directed radially inwards we understand here a portion of the first groove 36 on which the first groove 36 approaches the mandrel 2, and by slot directed radially outwards we understand here a portion of the first groove 36 on which the first groove 36 moves away from the mandrel 2.

[0051] As illustrated on the figure 2, the slots directed radially outwards from the first groove 36 can be advantageously located between two holes 35.

[0052] Mold 1 can be used to implement the manufacturing process for the blower housing made of composite material as illustrated in the figure 4 The process includes the following steps: E1: wrap the fibrous preform of the blower housing around the mandrel 2; E2: assemble the plurality of angular sectors 3 of the counter-mold onto the external contour of the mandrel 2 by fixing the first lateral flange 33 of the angular sectors 3 with the second lateral flange 34 of an adjacent angular sector 3.The angular sectors 3 are also fixed to the mandrel 2 by fixing the front flanges 31 and rear flanges 32 of the sectors 3 to the upstream flanges 21 and downstream flanges 22 of the mandrel 2; E3: densify the fibrous preform by injecting a precursor material of a matrix of the composite material into the mold 1, the mold 1 comprising injection ports for the injection of said precursor material; E4: polymerize the precursor material to obtain the matrix of the composite material; E5: remove the plurality of angular sectors 3, this step being carried out by decoupling the first lateral flanges 33 from the second lateral flanges 34, the front flanges 31 from the upstream flange 21, as well as the rear flanges 32 from the downstream flange 32; E6: demold the blower housing.

Claims

1. A mold (1) for the manufacture of a turbomachine fan casing of composite material comprising: - a mandrel (2) around which a fibrous preform of the fan casing is intended to be wound; - a plurality of counter-mold angular sectors (3) assembled on the external contour of the mandrel (2), which are intended to close the mold (1) and to compact the fibrous preform wound on the mandrel (2); each angular sector (3) comprising, on the one hand, a first lateral flange (33) which is positioned at the first end of the angular sectors (3), and on the other hand, a second lateral flange (34) which is positioned at a second end of the angular sectors (3) and which is opposite to the first end, the first lateral flange (33) and the second lateral flange (34) being configured to cooperate respectively with the second lateral flange (34) and the first lateral flange (33) of the adjacent angular sectors, at least one angular sector (3) comprising a first groove (36) formed in at least one of the first lateral flange (33) and the second lateral flange (34), a first seal (5) being positioned in said first groove (36), said first seal (5) being configured to be compressed between the first lateral flange (33) and the second lateral flange (34) of two adjacent angular sectors (3).

2. The mold (1) according to claim 1, wherein each angular sector (3) comprises a front flange (31) and a rear flange (32) which are configured to cooperate respectively with an upstream flange (21) and a downstream flange (22) of the mandrel (2), the upstream flange (21) and the downstream flange (22) comprising respectively a second groove (23) and a third groove (24), a second seal (6) and a third seal (7) being respectively positioned in the second groove (23) and the third groove (24), said second seal (6) being configured to be compressed between the upstream flange (21) of the mandrel (2) and the front flange (31) of the angular sectors (3), said third seal (7) being configured to be compressed between the downstream flange (22) of the mandrel (2) and the rear flange (32) of the angular sectors (3), the first groove (36) leading, on the one hand, into the second groove (23) and, on the other hand, into the third groove (24).

3. The mold (1) according to any one of claims 1 to 2, wherein the mold (1) comprises a first group of angular sectors (3) for which the first groove (36) is formed on the first lateral flange (33) and on the second lateral flange (34), and a second group of angular sectors (3) for which the first lateral flange (33) and the second lateral flange (34) are smooth, one angular sector (3) of the first group being positioned between two angular sectors (3) of the second group.

4. The mold (1) according to any one of claims 1 to 2, wherein the first groove (36) is formed on the first lateral flange (33) of each angular sector (3).

5. The mold (1) according to any one of claims 1 to 4, wherein the first groove (36) comprises an undulated shape.

6. The mold (1) according to claim 5, wherein the first groove (36) is crenelated, the first groove (36) comprising, on the one hand, a plurality of slots directed radially inward and, on the other hand, a plurality of slots directed radially outward.

7. The mold (1) according to any one of claims 1 to 6, wherein the first flange and the second flange of the angular sectors (3) comprise bores (35), each angular sector (3) being attached to an adjacent angular sector (3) by boltwork positioned, on the one hand, in the bores of the first lateral flange (33) of the angular sector (3) and, on the other hand, in the bores (35) of the second lateral flange (34) of the adjacent angular sector (3).

8. The mold (1) according to claim 7, taken in combination with claim 6, wherein the slots directed radially outward are positioned between two bores (35).

9. The mold (1) according to any one of claims 1 to 8, wherein the first seal (5) is made of elastomer, for example a cold-vulcanizing elastomer.

10. A manufacturing method of a turbomachine fan casing of composite material with the mold (1), according to any one of claims 1 to 9, the method comprising the following steps: - (E1): winding a fibrous preform of the fan casing around the mandrel (2); - (E2): assembling the plurality of counter-mold angular sectors (3) on the external contour of the mandrel (2) by attaching the first lateral flange (33) of the angular sectors (3) to the second lateral flange (34) of an adjacent angular sector (3); - (E3): densifying the fibrous preform by injection of a precursor material of a matrix of the composite material into the mold (1); - (E4): polymerizing the precursor material to obtain the matrix of the composite material; - (E5): withdrawing the plurality of angular sectors (3); - (E6): de-molding the fan casing.