Curing mold for producing a turbomachine component made of composite material from a preform and method for producing a component using such a mold

Description

TECHNICAL FIELD

[0001] The invention relates to a baking mold for manufacturing a turbomachine part made of composite material from a preform, a method for manufacturing a turbomachine part made of composite material using such a baking mold and a turbomachine part made of composite material obtained by implementing such a method. STATE OF THE PRIOR ART

[0002] There are several known processes for manufacturing turbomachine parts from composite material.

[0003] For example, it is known to produce a preform of the turbomachine part by draping from pre-pregs, then to bake this preform in order to obtain the turbomachine part.

[0004] Here, the term "prepreg" is understood to mean a semi-finished product comprising reinforcing fibers and a thermosetting resin (matrix) in which the reinforcing fibers are impregnated. Such prepregs are generally packaged in the form of rolls of unidirectional and continuous fiber webs impregnated with the thermosetting resin.

[0005] The draping of prepregs is, for example, carried out by automated fiber placement, also called "AFP" for "Automated Fiber Placement" in English terminology, which is a draping technique particularly suited to turbomachine parts with complex geometry, particularly those with double curvature.

[0006] To achieve this, a robotic fiber placement head cuts strips from a prepreg sheet and then places these strips on the surface of a baking mold that is shaped to complement the surface of the turbomachine part to be manufactured. Several prepreg strips can be stacked on top of each other, particularly with different orientations of the reinforcing fibers, the reinforcing fibers remaining perpendicular to the stacking direction of the prepregs.

[0007] The preform thus produced is then positioned on the surface of a baking mold of complementary shape with a surface of the turbomachine part to be manufactured, then it is covered with a membrane and placed in an autoclave where the membrane is placed under vacuum. In the autoclave, the preform is baked under controlled conditions of temperature and pressure, so as to polymerize the resin and therefore consolidate the preform, and thus obtain the turbomachine part.

[0008] It is generally recognized that autoclave curing of the preform, due to the controlled temperature and pressure conditions, makes it possible to obtain turbomachine parts made of composite material with high mechanical performance.

[0009] However, when the turbomachine part to be manufactured only allows tight tolerance intervals for their geometry, as is the case for example with external low-pressure compressor casings for dual-flow turbomachines, autoclave curing of the preform cannot be used, since the vacuum membrane and the pressure inside the autoclave do not allow such tolerance intervals to be respected for the geometry of the turbomachine part to be manufactured.

[0010] Alternatively, after the prepregs have been draped, the preform can, for example, be molded by transfer molding the same qualified resin. This molding technique is known by the acronym "SQRTM" for "Same Qualified Resin Transfer Molding" in English terminology.

[0011] This molding technique uses a baking mold comprising a first and a second body whose internal surfaces together define a fixed air gap of complementary shape with the turbomachine part to be manufactured, a member for creating a vacuum in the air gap, as well as a piston for injecting resin into channels which are made in the first and second bodies and which communicate with the air gap.

[0012] When molding the preform, the latter is placed in the air gap of the curing mold, between the first and second bodies, so as to leave, in the air gap, empty spaces along the free edges of the preform with which the channels communicate. The first and second bodies are then pressed against each other, for example by means of a press, then the air gap is placed under vacuum. The curing mold is heated, for example by means of the press, while resin, identical to that of the prepregs forming the preform, is injected into the channels, so as to fill with resin the empty spaces in the air gap located along the free edges of the preform and thus put the preform under hydrostatic pressure in the air gap. This hydrostatic pressure is maintained during the curing of the preform, which is thus carried out under controlled conditions of temperature and pressure.

[0013] SQRTM thus not only makes it possible to obtain turbomachine parts with high mechanical performance, due to the curing of the preform under controlled temperature and pressure conditions, but also to maintain tight tolerance intervals for their geometry thanks to the fixed air gap curing mold. Using the same resin as the prepregs forming the preform also allows the implementation of SQRTM in the aeronautics field, without it being necessary to obtain a new qualification for the resin.

[0014] However, the SQRTM has the disadvantage of requiring an additional supply of resin to put the preform under hydrostatic pressure in the air gap, without this additional resin being retained once the turbomachine part is manufactured, the edge of the preform being removed after demolding. This therefore represents a loss of consumable material, generating a significant additional cost for the manufacture of turbomachine parts.

[0015] Document JP2007253441A discloses a mold with a variable air gap by means of mandrels movable in translation and cooperating with bladders to bend the preform. STATEMENT OF THE INVENTION

[0016] The present invention aims to overcome the above-mentioned drawbacks, in particular by proposing a baking mold for manufacturing a turbomachine part, made of composite material, from a preform produced by draping pre-impregnated materials, inside which one or more inflatable bladders are provided to compress one or more edges of the preform by inflation, so as to expel the resin, previously heated, from the edge or edges of the preform and thus apply hydrostatic pressure to the preform.

[0017] More specifically, the subject of the invention is a baking mold for manufacturing a turbomachine part made of composite material, from a preform produced by draping pre-impregnated materials comprising reinforcing fibers impregnated in a thermosetting resin, the preform having a portion to be molded and at least one additional portion extending in the extension of the portion to be molded and forming an edge of the preform, the baking mold comprising: a first body and a second body designed to be attached to one another, the first and second bodies each comprising an internal surface itself comprising a peripheral zone at which the first and second bodies are in contact with one another and a central zone defining a fixed air gap between the first and second bodies, the air gap being intended to receive the preform and itself comprising: ∘ a molding part of complementary shape with the turbomachine part to be manufactured, the molding part being intended to receive the portion of the preform to be molded, and ∘ at least one additional part located in a peripheral space of the air gap, the or each of the additional parts being intended to receive an additional portion of the preform; a heating member designed to heat the preform in the air gap to a first temperature, so as to reduce the viscosity of the resin;at least one inflatable bladder housed in the central area of ​​the inner surface of the first or second body, opposite an additional portion of the air gap; a fluid injection member designed to inject fluid under pressure inside the bladder(s), so as to inflate the bladder(s) from a deflated state to an inflated state, the or each of the bladders being further designed to compress, in the inflated state, the additional portion of the preform, located in the additional portion of the air gap opposite said bladder, so as to expel the resin from the additional portion of the preform towards the portion of the preform to be molded and thus put the preform under hydrostatic pressure, when the preform is received in the air gap and the heating member heats the preform to the first temperature. ;

[0018] According to embodiment variants which can be taken together or separately: the reinforcing fibers of the preform are oriented perpendicularly to a stacking direction; the bladder(s) are housed in the central zone of the internal surface of the first or second body, locally aligned with the additional portion of the preform along the stacking direction of said additional portion, when the preform is received in the air gap of the baking mold; the injection member comprises a compressor designed to pressurize the fluid to be injected into the or each of the bladders and an injection pipe in communication on the one hand with the compressor, and on the other hand with the or each of the bladders, via one or more channels provided in the first and / or the second body; the fluid injected into the or each of the bladders is a heat transfer fluid; the injection member comprises a heat exchanger designed to heat the heat transfer fluid to be injected into the or each of the bladders;the heating member is designed to heat the preform to a second temperature, strictly higher than the first temperature, so as to cook the preform; the or each of the bladders is designed to continue, in the inflated state, the compression exerted on the additional portion of the preform, located in the additional part of the air gap opposite said bladder, when the preform is received in the air gap and the heating member heats the preform to the second temperature.;

[0019] The invention also relates to a method for manufacturing a turbomachine part made of composite material, using the baking mold as previously described, from a preform produced by draping pre-impregnated materials comprising reinforcing fibers impregnated in a thermosetting resin, the preform having a portion to be molded and at least one additional portion extending in the extension of the portion to be molded and forming an edge of the preform, the method comprising the steps of: placing the preform in the air gap, between the first and second bodies of the mold, the portion of the preform to be molded being housed in the molding part of the air gap, an additional portion of the preform being housed in the or each of the additional parts of the air gap; heating the preform to the first temperature; injecting the pressurized fluid into the or each of the bladders, so that the or each of the bladders swells to the inflated state and compresses the additional portion of the preform located in the additional part of the air gap opposite said bladder, the preform being maintained at the first temperature, the or each of the bladders expelling the resin from the additional portion of the preform towards the portion of the preform to be molded, the preform thus being put under hydrostatic pressure.

[0020] According to embodiment variants which can be taken together or separately: the manufacturing method comprises a subsequent step of heating the preform to a second temperature, strictly higher than the first temperature, so as to bake the preform and thus obtain the turbomachine part, the compression applied by the bladder(s) in the inflated state on the additional portion(s) of the preform being continued; the manufacturing method comprises the subsequent steps of: ∘ releasing the compression applied by the bladder(s) on the additional portion(s) of the preform thus baked; ∘ demolding the preform thus baked; ∘ removing the additional portion(s) of the preform thus baked and demolded, so as to obtain the turbomachine part; the preform is for example placed under a hydrostatic pressure of between 3 and 10 bar inclusive, preferably between 3 and 7 bar inclusive, during the step of injecting the pressurized fluid into the or each of the bladders;the reinforcing fibers of the preform are oriented perpendicularly to a stacking direction; the bladder(s) are housed in the central zone of the internal surface of the first or second body, in alignment with the additional portion of the preform following the stacking direction of said additional portion, when the preform is received in the air gap of the baking mold; the fluid injected into the or each of the bladders is a heat transfer fluid and the injection member comprises a heat exchanger designed to heat the heat transfer fluid to be injected into the or each of the bladders. ; BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Other aspects, aims, advantages and characteristics of the invention will appear better on reading the following detailed description of preferred embodiments thereof, given by way of non-limiting example, and made with reference to the appended drawings in which: there figure 1is a schematic sectional view of a baking mold for manufacturing a turbomachine part made of composite material, from a preform, according to one embodiment of the invention, the baking mold being shown without the preform and with a bladder in the deflated state; figure 2 is a sectional view of the baking pan shown in figure 1 , the preform being received in the baking mold and the bladder being in the deflated state; the figure 3 is a sectional view of the baking pan shown in Figures 1 and 2 , the preform being received in the baking mold and the bladder being in the inflated state; the figure 4 is a partial top view of the baking pan shown in figures 1 to 3 ; there Figure 5 is a flowchart of a manufacturing process for a turbomachine part made of composite material, using the baking mold illustrated in figures 1 to 4 ; there figure 6is a perspective view of an example of a turbomachine part obtained by implementing the manufacturing method illustrated in Figure 5 ; there figure 7 is a perspective view of another example of a turbomachine part obtained by implementing the manufacturing method illustrated in Figure 5 ; there figure 8 is a schematic longitudinal sectional view of an aircraft turbomachine comprising the turbomachine part illustrated in figure 6 . DETAILED DESCRIPTION

[0022] THE figures 1 to 4 show a baking mold 10 for manufacturing a turbomachine part in composite material, from a preform 200, according to one embodiment of the invention.

[0023] The preform 200 is produced by draping pre-impregnated materials comprising reinforcing fibers impregnated in a thermosetting resin.

[0024] The preform 200 is for example produced by draping prepregs comprising unidirectional carbon fibers impregnated in an epoxy thermosetting resin. These prepregs comprise for example 34% by mass of epoxy thermosetting resin. In the remainder of the description, the values ​​provided are in particular adapted to a preform 200 produced by draping such prepregs.

[0025] The preform 200 is for example produced by draping by automated fiber placement, also called “AFP” which is the acronym for “Automated Fiber Placement” in English terminology. The preform 200 may alternatively be produced by manual draping or automated draping by tape laying, also called “ATL” which is the acronym for “Automated Tape Laying” in English terminology. These draping techniques are well known to those skilled in the art.

[0026] The reinforcing fibers of the preform 200 are oriented perpendicularly to a stacking direction DE which defines a thickness of the preform 200. The reinforcing fibers are thus stacked in the stacking direction DE. It will be understood that depending on the geometry of the preform 200, in particular its curvature(s), the stacking direction DE of the reinforcing fibers of the preform 200 may have an orientation which varies from one zone to another of the preform 200.

[0027] The preform 200 has a molding portion 201 and at least one additional portion 202 extending in the extension of the molding portion 201 and forming an edge of the preform 200. The molding portion 201 and the or each of the additional portions 202 are therefore in one piece. They also each have reinforcing fibers impregnated with the resin.

[0028] The or each of the edges of the preform 200 forms for example an additional portion 202.

[0029] In the example illustrated in figures 1 to 4 , the preform 200 has the shape of a rectangular plate and only comprises an additional portion 202 which forms an edge rectangularly framing the portion to be molded 201. The preform 200 has, as a variant (not shown), the shape of a shell.

[0030] The baking mold 10 comprises a first body 11 and a second body 12 designed to be attached to one another. The first and second bodies 11, 12 each comprise an internal surface 13, 14 itself comprising a peripheral zone 15, 16 at which the first and second bodies 11, 12 are in contact with one another in a clamping direction DS, for example vertical, and a central zone 17, 18. The central zones 17, 18 of the internal surface 13, 14 of the first and second bodies 11, 12 together define or delimit a fixed air gap 19 intended to receive the preform 200 ( figure 1 ).

[0031] The air gap 19 itself comprises a molding part 20 and at least one additional part 21.

[0032] The molding portion 20 of the air gap 19 is of complementary shape with the turbomachine part to be manufactured. The molding portion 20 is further intended to receive the portion to be molded 201 of the preform 200.

[0033] The additional part or parts 21 of the air gap 19 are located in a peripheral space of the air gap 19. By "peripheral space" is meant a space of the air gap 19 extending along the peripheral zones 15, 16 of the internal surfaces 13, 14 of the first and second bodies 11, 12. The or each of the additional parts 21 of the air gap 19 is further intended to receive an additional portion 202 of the preform 200.

[0034] In the example illustrated in figures 1 to 4 , the air gap 19 only comprises an additional part 21 which forms a rectangular frame surrounding the molding part 20.

[0035] The baking mold 10 further comprises a heating member 22 designed to heat the preform 200 in the air gap 19 to a first temperature, so as to reduce the viscosity of the resin ( figure 4 ). This allows, for example, the resin of the preform 200 to be distributed homogeneously in the air gap 19 of the baking mold 10.

[0036] The first temperature is for example between 80 and 110°C inclusive. The first temperature is for example maintained for a period of between 30 and 60 minutes inclusive. This period corresponds in particular to a level of homogenization of the temperature of the baking mold 10.

[0037] The cooking mold 10 further comprises at least one inflatable bladder 23 housed in the central zone 17, 18 of the internal surface 13, 14 of the first or second body 11, 12, opposite an additional part 21 of the air gap 19, as well as a fluid injection member 24 designed to inject fluid under pressure inside the bladder(s) 23, so as to inflate the bladder(s) 23 from a deflated state to an inflated state ( figures 2 to 4 ).

[0038] The or each of the bladders 23 is further designed to compress, in the inflated state, the additional portion 202 of the preform 200, which is located in the additional part 21 of the air gap 19 opposite said bladder 23, so as to expel the resin from the additional portion 202 of the preform 200 towards the portion to be molded 201 of the preform 200 and thus put the preform 200 under hydrostatic pressure, when the preform 200 is received in the air gap 19 and the heating member 22 heats the preform 200 to the first temperature ( figure 3 ). The preform 200 is for example placed under a hydrostatic pressure of between 3 and 10 bar inclusive, preferably between 3 and 7 bar inclusive.

[0039] By "fluid under pressure" is meant that the fluid injected into the bladder(s) is at a pressure such that it causes the inflation of the bladder(s) 23 in the air gap 19 and the compression of the additional portion(s) 202 by the bladder(s) 23.

[0040] Thus, the baking mold 10 uses the resin of the additional portion(s) 202 of the preform 200 to put the preform 200 under hydrostatic pressure. This or these additional portions 202 being in any case intended, during the production of the preform 200, to be removed after demolding, there is therefore no loss of resin beyond that already contained in the additional portion(s) 202. The baking mold 10 thus makes it possible to avoid a significant additional cost which would be linked to an additional supply of resin to put the preform 200 under hydrostatic pressure. Furthermore, to the extent that this or these additional portions 202 are removed after demolding, it is not inconvenient to dry this or these additional portions 202 of the preform 200 of their resin.

[0041] The heating member 22 is for example also designed to heat the preform 200 to a second temperature, strictly higher than the first temperature, so as to cure the preform 200, when said preform 200 is received in the air gap 19. The curing of the preform 200 makes it possible to polymerize the resin of the preform 200 and therefore to consolidate it, in order to obtain the turbomachine part. The second temperature corresponds in particular to a polymerization temperature of the resin of the preform 200. The second temperature is for example between 170 and 190°C inclusive, in particular equal to 180°C. The second temperature is for example maintained for a duration equal to 2 hours.

[0042] The or each of the bladders 23 can then be designed to continue, in the inflated state, the compression exerted on the additional portion 202 of the preform 200, located in the additional portion 21 of the air gap 19 opposite said bladder 23, when the preform 200 is received in the air gap 19 and the heating member 22 heats the preform 200 to the second temperature. The baking of the preform 200 thus takes place under controlled conditions of temperature and pressure, making it possible to obtain a turbomachine part with high mechanical performance. The compression exerted on the additional portion 202 of the preform 200 by the or each of the bladders 23 is for example maintained during baking. Alternatively, it is modified for and / or during baking.

[0043] The heating member 22 is for example designed to heat the preform 200 via the first and second bodies 11, 12 of the cooking mold 10, when the preform 200 is received in the air gap 19 ( figure 4 ). The heating member 22 comprises, for example, a press as described below, a heating system using heat transfer fluid, such as oil, or one or more heating cartridges integrated into the first and second bodies 11, 12 of the cooking mold 10.

[0044] The or each of the bladders 23 extends along an extension line LE which can be closed or open.

[0045] In the example illustrated in figures 1 to 4 , the extension line LE of the bladder 23 is closed and forms a rectangle.

[0046] The or each of the bladders 23 has, for example, in the inflated state and in the deflated state, a cross-section, taken perpendicular to the extension line LE, of rectangular shape ( figures 1 to 3 ).

[0047] The or each of the bladders 23 comprises, for example, an extensible membrane forming a pocket receiving the pressurized fluid injected by the injection member 24. The membrane of the or each of the bladders 23 is, for example, made from silicone.

[0048] The baking mold 10 comprises for example one or more bladders 23 housed in the central zone 17 of the internal surface 13 of the first body 11, opposite the or an additional part 21 of the air gap 19. The bladder(s) 23 are further designed to compress, in the inflated state, the additional portion 202 of the preform 200, located in said additional part 21 of the air gap 19, against the central zone 18 of the internal surface 14 of the second body 12, when the preform 200 is received in the air gap 19. The or the additional portions 202 of the preform 200 are then held in a vice between a bladder 23 and the central zone 18 of the internal surface 14 of the second body 12, which is opposite the bladder 23 with respect to the preform 200 ( figure 3 ).

[0049] Additionally or alternatively, the baking mold 10 comprises at least one pair of bladders 23, a first bladder 23 of the pair being housed in the central zone 17 of the inner surface 13 of the first body 11, opposite the or an additional portion 21 of the air gap 19, and a second bladder 23 of the pair being housed in the central zone 18 of the inner surface 14 of the second body 12, opposite said additional portion 21 of the air gap 19 and the first bladder 23. The first and second bladders 23 then face each other so as to take the or the additional portions 202 of the preform 200 in a vice between said first and second bladders 23, when the preform 200 is received in the air gap 19.

[0050] The or each of the bladders 23 is for example designed to compress, in the inflated state, the or an additional portion 202 of the preform 200, located in the additional part 21 of the air gap 19 opposite said bladder 23, generally perpendicular to the orientation of the reinforcing fibers of said additional portion 202, when the preform 200 is received in the air gap 19. The or each of the bladders 23 thus compresses the additional portion 202 of the preform 200, which is associated with them, in the stacking direction DE of said additional portion 202 ( figure 3 ) of said additional portion 202. This makes it possible to avoid damaging the portion to be molded 201 of the preform 200.

[0051] For this, the or each of the bladders 23 is for example housed in the central zone 17, 18 of the internal surface 13, 14 of the first or second body 11, 12, in alignment with the additional portion 202 of the preform 200, located in the additional part 21 of the air gap 19 opposite said bladder 23, in the stacking direction DE of said additional portion 202, when the preform 200 is received in the air gap 19.

[0052] The cooking mold 10 comprises for example at least one groove 25 formed in the central zone 17, 18 of the internal surface 13, 14 of the first or second body 11, 12 and receiving the or one of the bladders 23. The groove(s) 25 are furthermore of complementary shape with the bladder(s) 23, when the bladder(s) 23 are in the deflated state.

[0053] A fastening system (not shown) is for example provided for fastening the bladder(s) 23 in the groove(s) 25. The fastening system may comprise a frame or several frame portions which are received in the or each in one of the grooves 25 and which are designed to clamp or even to compress edges of the bladder(s) 23 in the groove(s) 25.

[0054] The fluid injected into the bladder 23 includes, for example, air, oil, etc.

[0055] The fluid injected inside the bladder 23 is for example a heat transfer fluid, such as oil, so that it participates, in addition to the heating member 22, in heating the preform 200. The term "heat transfer fluid" is understood to mean a fluid capable of transporting and evacuating heat.

[0056] The injection member 24 comprises for example a compressor 26 designed to pressurize the fluid to be injected into the or each of the bladders 23 and an injection pipe 27 in communication on the one hand with the compressor 26, and on the other hand with the or each of the bladders 23 via one or more channels 28 arranged in the first and / or the second body 11, 12 ( figure 4 ).

[0057] The injection member 24 may further comprise a heat exchanger 29 designed to heat the heat transfer fluid to be injected into the or each of the bladders 23 ( figure 4 ). The heat exchanger 29 is for example located between the compressor 26 and the channel(s) 28 communicating with the bladder(s) 23. The heat transfer fluid thus makes it possible to heat, via the channel(s) 28, the first and / or second body 11, 12 which then themselves heat the preform 200.

[0058] The baking mold 10 may also comprise a press 30 designed to compress the first and second bodies 11, 12 against each other in the clamping direction DS, when the first and second bodies 11, 12 are attached to each other ( figure 2 ). The press 30 thus makes it possible to ensure the clamping of the first and second bodies 11, 12 of the baking mold 10 against each other, and to overcome the swelling of the preform 200. The press 30 also makes it possible to ensure the contact of the peripheral zones 15, 16 of the internal surfaces 13, 14 of the first and second bodies 11, 12 of the baking mold 10, and thus to avoid resin leaks.

[0059] There Figure 5 shows a manufacturing method 300 for manufacturing a turbomachine part made of composite material using the baking mold 10. The manufacturing method 300 comprises the steps of: placing 301 of the preform 200 in the air gap 19, between the first and second bodies 11, 12 of the baking mold 10, the portion to be molded 201 of the preform 200 being housed in the molding part 20 of the air gap 19, an additional portion 202 of the preform 200 being housed in the or each of the additional parts 21 of the air gap 19; if necessary, pressing 302 of the first and second bodies 11, 12 of the baking mold 10 against each other in the clamping direction DS; heating 303 of the preform 200 to the first temperature; injection 304 of the pressurized fluid into the or each of the bladders 23, so that the or each of the bladders 23 inflates to the inflated state and compresses the additional portion 202 of the preform 200 located in the additional part 21 of the air gap 19 opposite said bladder 23, the preform 200 being maintained at the first temperature.

[0060] The preform 200 is for example placed under a hydrostatic pressure of between 3 and 10 bar inclusive, preferably between 3 and 7 bar inclusive.

[0061] The manufacturing method 300 may further comprise the subsequent steps of: heating 305 of the preform 200 to the second temperature, so as to bake the preform 200, the compression applied by the bladder(s) 23 in the inflated state on the additional portion(s) 202 of the preform 200 being continued; releasing 306 of the compression applied by the bladder(s) 23 on the additional portion(s) 202 of the preform 200 thus baked; demolding 307 of the preform 200 thus baked; removal 308 of the additional portion(s) 202 of the preform 200 thus baked and demolded, in particular by machining, so as to obtain the turbomachine part.

[0062] The release step 306 occurs, for example, as soon as the resin of the preform 200 freezes in the baking mold 10.

[0063] THE figures 6 and 7 each show an example of a turbomachine part 101 made of composite material obtained by implementing the manufacturing method 300. The figure 8 shows a turbomachine 100 for an aircraft comprising the turbomachine part 101.

[0064] The turbomachine 100 is a double-flow turbomachine. It comprises a fan 102 intended for sucking in an air flow dividing downstream of the fan 102 into a primary flow circulating in a primary flow channel, called primary vein 103, within a core of the turbomachine 100, and a secondary flow bypassing this core in a secondary flow channel, called secondary vein 104.

[0065] The heart of the turbomachine 100 comprises, from upstream to downstream in the direction of air flow, a low pressure compressor 105, also called a “booster”, a high pressure compressor 106, a combustion chamber 107, a high pressure turbine 108 and a low pressure turbine 109.

[0066] Respective rotors of the high pressure compressor 106 and the high pressure turbine 108 are connected by a shaft called the "high pressure shaft", while respective rotors of the low pressure compressor 105 and the low pressure turbine 109 are connected by a shaft called the "low pressure shaft" surrounded by the high pressure shaft.

[0067] The turbomachine 100 is shrouded by a nacelle 110 surrounding the secondary vein 104.

[0068] Furthermore, the rotors of the turbomachine 100 are rotatably mounted around a longitudinal direction 111 of the turbomachine 100.

[0069] The low pressure compressor 105 comprises, in addition to one or more rotors, one or more stators arranged alternately with the rotors in the longitudinal direction 111.

[0070] The stators comprise blades extending radially with respect to the longitudinal direction 111 between an inner shell and an outer shell (not shown) by means of which said blades are carried by an outer casing 112.

[0071] The turbomachine part 101 forms, for example, the external casing 112 of the low-pressure compressor 105 ( figure 6 ). The turbomachine part 101 can also form a sector of the external casing 112 of the low pressure compressor 105 ( figure 7 ). By “sector” is meant an angular sector of the external casing around the longitudinal direction 111. As a variant (not shown), the turbomachine part 101 forms a rotor drum.

Claims

1. Curing mold (10) for manufacturing a turbomachine component made of a composite material, starting from a preform (200) made by laying up prepregs comprising reinforcing fibers impregnated in a thermosetting resin, the preform (200) having a portion to be molded (201) and at least one additional portion (202) extending into the prolongation of the portion to be molded (201) and forming an edge of the preform (200), the curing mold (10) comprising: - a first body (11) and a second body (12) designed to be fitted together, the first and second bodies (11, 12) each comprising an internal surface (13, 14) itself comprising a peripheral area (15, 16) at which the first and second bodies (11, 12) are in contact with each other and a central area (17, 18) defining a fixed air gap (19) between the first and second bodies (11, 12), the air gap (19) being intended to accommodate the preform (200) and itself comprising: ∘ a molding part (20) with a shape complementary to the component to be manufactured, the molding part (20) being intended to accommodate the portion to be molded (201) of the preform (200), and ∘ at least one additional part (21) located in a peripheral space of the air gap (19), the or each additional part (21) being intended to accommodate an additional portion (202) of the preform (200); - a heating member (22) designed to heat the preform (200) in the air gap (19) to a first temperature, so as to reduce the viscosity of the resin; - at least one inflatable bladder (23) housed in the central area (17, 18) of the internal surface (13, 14) of the first or second body (12, 13), facing an additional part (21) of the air gap (19); - an injection member (24) designed to inject fluid under pressure inside the bladder(s) (23), so as to inflate the bladder(s) (23) from a deflated state to an inflated state, and the or each bladder (23) also being designed so that, in the inflated state, it compresses the additional portion (202) of the preform (200) located in the additional part (21) of the air gap (19) facing said bladder (23), so as to flush the resin from the additional portion (202) of the preform (200) towards the portion to be molded (201) of the preform (200) and thus put the preform (200) under hydrostatic pressure, when the preform (200) is located in the air gap (19) and the heating member (22) heats the preform (200) to the first temperature.

2. Curing mold (10) according to claim 1, wherein: - the reinforcing fibers of the preform (200) are oriented perpendicular to a stacking direction (DE); - the bladder(s) (23) is (are) located in the central area (17, 18) of the internal surface (13, 14) of the first or second body (11, 12), in alignment with the additional portion (202) of the preform (200) along the stacking direction (DE) of said additional portion (202), when the preform (200) is located in the air gap (19) of the curing mold (10).

3. Curing mold (10) according to claim 1 or claim 2, wherein the injection member (24) comprises a compressor (26) designed to pressurize the fluid to be injected into the or each bladder (23) and an injection conduit (27) in communication, on the one hand, with the compressor (26) and on the other hand, with the or each bladder (23), via one or more channels (28) formed in the first and / or second body (11, 12).

4. Curing mold (10) according to one of claims 1 to 3, wherein the fluid injected into the or each bladder (23) is a heat transporting fluid and wherein the injection member (24) comprises a heat exchanger (29) designed to heat the heat transporting fluid to be injected into the or each bladder (23).

5. Curing mold (10) according to one of claims 1 to 4, wherein the heating member (22) is designed to heat the preform (200) to a second temperature, higher than the first temperature so as to cure the preform (200) and wherein the or each bladder (23) is designed so that, in the inflated state, the compression exerted on the additional portion (202) of the preform (200) located in the additional part (21) of the air gap (19) facing said bladder (23) is maintained when the preform (200) is located in the air gap (19) and the heating member (22) heats the preform (200) to the second temperature.

6. Method (300) for manufacturing a turbomachine component made of composite material, making use of the curing mold (10) according to one of claims 1 to 5, starting from a preform (200) made by laying up prepregs comprising reinforcing fibers impregnated in a thermosetting resin, the preform (200) having a portion to be molded (201) and at least one additional portion (202) extending into the prolongation of the portion to be molded (201) and forming an edge of the preform (200), the manufacturing method (300) comprising the following steps: - place (301) the preform (200) in the air gap (19), between the first and second bodies (11, 12) of the curing mold (10), the portion to be molded (201) of the preform (200) being located in the molding part (20) of the air gap (19), an additional portion (202) of the preform (200) being located in the or in each additional part (21) of the air gap (19); - heat (303) the preform (200) to the first temperature; - inject (304) pressurized fluid into the or each bladder (23), so that the or each bladder (23) is inflated to the inflated state and compresses the additional portion (202) of the preform (200) located in the additional part (21) of the air gap (19) facing said bladder (23), the preform (200) being maintained at the first temperature, the or each bladder (23) flushing resin from the additional portion (202) of the preform (200) to the portion to be molded (201) of the preform (200), thus putting the preform (200) under hydrostatic pressure.

7. Manufacturing method (300) according to claim 6, comprising the subsequent step (305) to heat the preform (200) to a second temperature, higher than the first temperature, so as to cure the preform (200), the compression applied by the bladder(s) (23) in the inflated state on the additional portion(s) (202) of the preform (200) being maintained.

8. Manufacturing method (300) according to claim 7, comprising subsequent steps to: - release (306) the compression applied by the bladder(s) (23) on the additional portion(s) (202) of the preform (200) thus cured; - unmould (307) the preform (200) thus cured; - remove (308) the additional portion(s) (202) of the preform (200) thus cured and demoulded, so as to obtain the turbomachine component.

9. Manufacturing method (300) according to one of claims 6 to 8, wherein the preform (200) is put under a hydrostatic pressure between 3 and 10 bar inclusive, during the step to inject pressurized fluid into the or each bladder.

10. Manufacturing method (300) according to one of claims 6 to 9, wherein the preform (200) is put under a hydrostatic pressure between 3 and 7 bar inclusive, during the step to inject pressurized fluid into the or each bladder.

11. Manufacturing method (300) according to one of claims 6 to 10, wherein: - the reinforcing fibers of the preform (200) are oriented perpendicular to a stacking direction (DE); - the bladder(s) (23) is (are) located in the central area (17, 18) of the internal surface (13, 14) of the first or second body (11, 12), in alignment with the additional portion (202) of the preform (200) along the stacking direction (DE) of said additional portion (202), when the preform (200) is located in the air gap (19) of the curing mold (10).

12. Manufacturing method according to one of claims 6 to 11, wherein the fluid injected into the or each bladder (23) is a heat transporting fluid and wherein the injection member (24) comprises a heat exchanger (29) designed to heat the heat transporting fluid to be injected into the or each bladder (23).