Method for manufacturing intermediate casing of aircraft turbine engine and associated manufacturing method

Abstract

The invention relates to an annular intermediate casing (12) for an aircraft turbine engine (1), the intermediate casing (12) having an axis of rotation (X) and comprising:-an annular inner shroud (13) centered on the axis of rotation (X); -an annular outer shroud (14) arranged coaxially around the inner shroud (13); and-radial arms (15) connecting the inner and outer shields (13, 14), the intermediate housing (12) being characterized in that the outer shield (14) comprises:-an annular inner panel (18) centered on the axis of rotation (X) and extending around the arms (15); -an annular outer panel (19) arranged coaxially around the inner panel (18); and-an annular core (20) arranged coaxially between the inner and outer panels (18, 19).

Description

Technical Field

[0001] This invention relates to the field of intermediate housings for aircraft turbine engines.

[0002] The present invention also relates to the manufacture of these intermediate shells. Background Technology

[0003] Aircraft turbine engines typically have a longitudinal axis. An aircraft turbine engine, for example, includes, from upstream to downstream, a fan, a low-pressure compressor, a high-pressure compressor, a combustion chamber, a high-pressure turbine, a low-pressure turbine, and exhaust nozzles, in the direction of gas flow along the longitudinal axis.

[0004] The fan allows airflow to be drawn in, which is then split into a main stream and a secondary stream. The main stream flows through the main duct of the turbine engine, while the secondary stream is directed toward the secondary ducts surrounding the main duct.

[0005] The main stream is compressed in the compressor. The compressed air is then mixed with fuel and burned in the combustion chamber. The combustion gases pass through the turbine and are then expelled through nozzles whose cross-section allows the gases to be accelerated to produce propulsion.

[0006] A fan typically consists of a disc that can rotate about a longitudinal axis and blades mounted on the disc. The blades are surrounded by a fan housing centered on the longitudinal axis and configured to hold the blades in place, for example, in the event of blade damage.

[0007] The fan casing is typically surrounded by a nacelle that protects the fan. This type of fan is called a ducted fan, rather than a non-ducted fan where the blades are not enclosed by a casing.

[0008] The turbine engine also includes an intermediate casing located downstream of the fan casing. The intermediate casing typically includes an annular inner shroud centered on a longitudinal axis and an annular outer shroud arranged coaxially around the inner shroud. The outer shroud, together with the inner shroud, defines a portion of the secondary duct v2. The intermediate casing also includes a radial arm connecting the inner and outer shrouds. The radial arm is typically connected to the outer shroud via a platform arranged radially between the arm and the downstream annular portion of the outer shroud. The outer shroud also includes an upstream annular portion axially connected to the fan casing.

[0009] Turbine engines are a major source of noise pollution, and there is a strong demand to reduce this type of pollution. Therefore, it is recommended that the outer casing of the intermediate housing be equipped with sound-absorbing panels to reduce the noise generated by the turbine engine.

[0010] Sound-absorbing panels typically include a sandwich structure comprising an inner panel and an outer panel, with a core disposed between the inner and outer panels. This core may have, for example, a honeycomb structure configured to absorb sound waves. The inner panel also has pores to allow sound waves to propagate into the core, where they are absorbed.

[0011] These sound-absorbing panels are typically manufactured in the form of corner sectors, each of which is fitted and attached to the upstream portion of the outer casing. The sound-absorbing panels are secured to the outer casing of the intermediate housing using riveted attachment elements.

[0012] While this type of sound-absorbing panel significantly reduces noise pollution from turbine engines, it is not entirely satisfactory. The attachment devices tend to degrade acoustic performance because they are permeable to sound waves. These attachment devices also significantly increase the weight of the intermediate housing. The presence of the platform also prevents the sound-absorbing panel from being positioned in the downstream annular portion of the outer casing, further reducing the acoustic performance of the outer casing. Finally, the manufacture of this sound-absorbing panel and its installation in the intermediate housing are lengthy and cumbersome operations, making them expensive.

[0013] Therefore, there is a need for an intermediate housing for aircraft turbine engines that has good sound insulation properties, is lightweight, easy to manufacture, and inexpensive. Summary of the Invention

[0014] Therefore, the present invention proposes an annular intermediate housing for an aircraft turbine engine, the intermediate housing having a rotation axis and comprising: - An annular inner protective cover, centered on the axis of rotation. - An annular outer protective cover, which is arranged coaxially around the inner protective cover, and - A radial arm that connects the inner and outer protective covers. The notable feature of the intermediate shell is that the outer protective cover includes: - An annular inner panel that extends around the axis of rotation and around the arm. - An annular outer panel, which is arranged coaxially around the inner panel, and - An annular core, which is coaxially arranged between the inner panel and the outer panel.

[0015] According to the present invention, the outer cover of the intermediate housing includes an inner panel and an outer panel, with a core disposed between the inner panel and the outer panel. In this way, the outer cover of the intermediate housing directly possesses sound insulation properties.

[0016] Because of this invention, sections of the soundproof panels and elements for attaching these panels can be eliminated, thus simplifying the methods for manufacturing and assembling these panels. Consequently, the intermediate housing is lighter and cheaper.

[0017] Due to this invention, the acoustic properties of the intermediate shell are also significantly improved.

[0018] This invention may include one or more of the following features, used individually or in combination with each other: - The outer shield includes an upstream annular portion and a downstream annular portion positioned around the arm, with the core located at least in the upstream annular portion; -The core is located in the upstream annular section and the downstream annular section; - The inner panel includes a first polymer matrix and reinforcing fibers embedded in the first matrix; -The outer panel includes a second polymer matrix and reinforcing fibers embedded in the second matrix; - The polymers of the first matrix and / or the second matrix are selected from thermoplastic or thermosetting plastics; - The inner panel has holes.

[0019] The present invention also relates to a method for manufacturing an annular intermediate shell according to any one of the foregoing features, the significant feature of which is that the method includes a step (c) of producing an outer protective cover, step (c) comprising the following sub-steps arranged in chronological order: (c1) Form an annular inner panel centered on the axis of rotation. (c2) An annular core is arranged coaxially around the inner panel. (c3) An outer panel is formed coaxially around the core, and (c4) Optionally, the inner panel and the outer panel are heat-treated.

[0020] The method may include one or more of the following features, which may be used individually or in combination: - Sub-steps (c1) and / or (c3) are performed using an automated fiber arrangement method. - Following sub-step (c4), the method includes a step of drilling holes in the inner panel (c5). - Drilling step (c5) is performed by mechanical drilling or laser drilling. - Sub-steps (c1) and (c3) include the following steps: -A tape of pre-impregnated fibers wound along the axis of rotation - Compact the material and heat it to a first temperature lower than the heat treatment temperature of step (c4). - The first temperature is between 20 o C to 500 o Between C, - Sub-step (c3) is performed via additive manufacturing. - Sub-step (c4) is performed in an autoclave. - The core has a honeycomb structure. Attached Figure Description

[0021] Other features and advantages will become apparent from the following description of non-limiting embodiments of the present invention, with reference to the accompanying drawings, in which: Figure 1 This is a schematic diagram of the longitudinal cross-section of one half of an aircraft turbine engine. Figure 2 This is a schematic perspective view of the intermediate housing according to the present invention. Figure 3 This is a schematic diagram of an outer protective cover fitted onto the intermediate housing according to the present invention. Figure 4 This is a schematic longitudinal cross-sectional view of the intermediate shell according to an embodiment of the present invention. Figure 5 This is a schematic longitudinal cross-sectional view of the intermediate housing according to another embodiment of the present invention. Figure 6 This is a block diagram of the manufacturing method according to the present invention. Figure 7 This is a schematic diagram of equipment used to manufacture the outer protective cover. Figure 8 This is a schematic diagram of the manufacturing station for the inner and outer panels of the outer protective cover. Detailed Implementation

[0022] Figure 1 An example of a turbine engine 1 for use in an aircraft is shown. The turbine engine 1 extends about and along the longitudinal axis X.

[0023] In this application, the terms "upstream" and "downstream" are defined relative to the direction of gas flow along the longitudinal axis X in the turbine engine 1.

[0024] The terms “axial,” “axially,” “radial,” and “radially” are defined relative to the longitudinal axis X.

[0025] The terms “internal,” “inside,” “inside,” “outside,” “external,” and “outer” are defined relative to the distance between the axis Z perpendicular to the longitudinal axis X and the longitudinal axis X.

[0026] Preferably, the turbine engine 1 is a turbojet engine, such as a turbojet engine with a dual-body and dual-flow configuration. The turbine engine includes, from upstream to downstream, a fan 2, at least one compressor (e.g., a low-pressure compressor 3 and a high-pressure compressor 4), a combustion chamber 5, at least one turbine (e.g., a high-pressure turbine 6 and a low-pressure turbine 7), and an exhaust nozzle.

[0027] The low-pressure compressor 3, the high-pressure compressor 4, the high-pressure turbine 6, and the low-pressure turbine 7 each include at least one rotor. The rotor of the low-pressure compressor 3 is connected to the rotor of the low-pressure turbine 7 via a low-pressure shaft 8, and the rotor of the high-pressure compressor 4 is connected to the rotor of the high-pressure turbine 6 via a high-pressure shaft 9. The high-pressure shaft 9 is arranged coaxially around the low-pressure shaft 8. The low-pressure shaft 8 and the high-pressure shaft 9 are centered on the longitudinal axis X.

[0028] The fan 2 includes a disk rotatable about a longitudinal axis X and blades 10 extending radially from the disk. The fan 2 also includes a fan shaft (not shown), which is connected to a low-pressure shaft 8, for example, via a speed reducer.

[0029] Fan 2 enables the intake of airflow F, which is divided into a primary airflow F1 and a secondary airflow F2. The primary airflow F1 passes through the main duct v1 of turbine engine 1, and the secondary airflow F2 flows into the secondary duct v2 of turbine engine 1. The secondary duct v2 surrounds the primary duct v1.

[0030] In mainstream F1 combustion, air is compressed in low-pressure compressor 3, and then in high-pressure compressor 4. The compressed air is then mixed with fuel and burned in combustion chamber 5. The combustion gases pass through high-pressure turbine 6 and low-pressure turbine 7. Finally, the gases escape through nozzles whose cross-section allows them to be accelerated to generate propulsion.

[0031] Fan 2 is ducted. Turbine engine 1 also includes fan housing 11. Fan housing 11 is annular and centered on the longitudinal axis X. The fan housing is arranged around blade 10. Fan housing 11 forms part of secondary duct v2.

[0032] The turbine engine 1 also includes an intermediate housing 12. The intermediate housing 12 is located downstream of the fan housing 11.

[0033] refer to Figure 2 When the intermediate housing 12 is installed in the turbine engine 1, the intermediate housing 12 has a rotation axis that coincides with the longitudinal axis X of the turbine engine 1. The intermediate housing 12 includes an inner shroud 13 and an outer shroud 14 connected by an arm 15.

[0034] The inner shield 13 is annular and centered on the longitudinal axis X. The inner shield 13 is made of metal, for example. The inner shield defines a portion of the main pipe v1 externally.

[0035] The outer casing 14 is annular and centered on the longitudinal axis X. The outer casing is arranged coaxially around the inner casing 13. The outer casing 14 and the inner casing 13 together form part of the secondary conduit v2.

[0036] The outer protective cover 14 has a thickness e between 10 mm and 50 mm, measured along the radial axis Z.

[0037] The outer casing 14 includes an upstream annular portion 16 and a downstream annular portion 17. Preferably, the downstream annular portion 17 is positioned around the arm 15. The upstream annular portion 16 is coaxially connected to the fan housing 11.

[0038] To reduce noise pollution generated by the turbine engine 1, the outer casing 14 has sound insulation properties. Advantageously, the outer casing 14 is capable of absorbing sound energy in the frequency range of 100Hz to 1500Hz.

[0039] The outer protective cover 14 has a sandwich structure. According to the present invention and with reference to... Figure 3 The outer protective cover 14 includes an annular inner panel 18, an annular outer panel 19, and an annular core 20, and advantageously has a honeycomb structure 21. Advantageously, the outer protective cover 14 is formed as a single piece.

[0040] The inner panel 18 is centered on the longitudinal axis X. The inner panel extends around the arm 15. The inner panel 18 is the innermost layer of the outer cover 14. The inner panel 18 includes a first composite material comprising a first polymer matrix and reinforcing fibers embedded in the first matrix.

[0041] The polymer material of the first matrix is ​​selected, for example, from thermoplastic plastics (such as polyolefins, such as polyethylene or polypropylene) or thermosetting plastics (such as epoxides) or thermosetting plastics (such as epoxides or polybismaleimide).

[0042] The reinforcing fibers are selected from carbon fibers, glass fibers, or polyamide fibers, for example.

[0043] Carbon fibers are, for example, polyaryletherketone (PAEK) fibers (such as polyetherketone (PEK) fibers, polyetheretherketone (PEEK) fibers, or polyetherketoneketone (PEKK) fibers) or polyacrylonitrile (PAN) fibers (such as HexTow® AS4, AS7, or IM7 fibers sold by Hextech).

[0044] Advantageously, the fiber is a continuous fiber, that is, a roving composed of a continuous assembly of parallel or twisted filaments.

[0045] Advantageously, the fiber is a high-strength and / or medium-modulus fiber (e.g., having a modulus between 200 GPa and 250 GPa) or a high-modulus fiber (e.g., having a modulus up to 350 GPa).

[0046] The inner panel 18 has a hole 18a. Hole 18a is a through hole. In this way, the hole passes through the entire thickness of the inner panel 18. Hole 18a has, for example, a circular cross-section. The diameter of the hole is, for example, between 0.1 mm and 5 mm, less than 1 mm, and advantageously between 0.1 mm and 0.8 mm. The diameter of hole 18a reduces the aerodynamic drag of the turbine engine 1. The inner panel 18 is in contact with the secondary flow F2, and the presence of the inner panel interferes with the flow of the secondary flow F2. This interference generates aerodynamic drag that reduces the performance of the turbine engine 1. Hole 18a is made by laser drilling or mechanical drilling.

[0047] For example, the thickness of the inner panel 18 is between 0.5 mm and 2 mm, preferably between 0.8 mm and 2 mm.

[0048] Advantageously, the inner panel 18 is made by automatic fiber arrangement.

[0049] The outer panel 19 is arranged coaxially around the inner panel 18. The outer panel 19 is the outermost layer of the outer cover 14.

[0050] The outer panel 19 includes a second composite material. The second composite material includes a second polymer matrix and reinforcing fibers embedded in the second matrix.

[0051] The polymer material of the second matrix is ​​selected from thermoplastic or thermosetting plastics. This thermoplastic or thermosetting material may be the same as or different from the thermoplastic or thermosetting material of the first polymer matrix. For example, the thermoplastic material of the second matrix is ​​selected from polyolefins (such as polyethylene, polypropylene), fluorinated polymers, polyamides, or polyaryletherketones (such as polyetheretherketone (PEEK)). According to another example, the thermosetting material of the second matrix is ​​selected from epoxy resins or polybismaleimide.

[0052] Reinforcing fibers, for example, are selected from carbon fiber, glass fiber and polyamide fiber.

[0053] Carbon fibers are, for example, polyaryletherketone (PAEK) fibers (such as polyetherketone (PEK) fibers, polyetheretherketone (PEEK) fibers, or polyetherketoneketone (PEKK) fibers) or polyacrylonitrile (PAN) fibers (such as HexTow® AS4, AS7, or IM7 fibers sold by Hextech).

[0054] Advantageously, the fiber is a continuous fiber, that is, a roving composed of a continuous assembly of parallel or twisted filaments.

[0055] Advantageously, the fiber is a high-strength and / or medium-modulus fiber (e.g., having a modulus between 200 GPa and 250 GPa) or a high-modulus fiber (e.g., having a modulus up to 350 GPa).

[0056] The reinforcing fibers may be the same as or different from the reinforcing fibers of the inner panel 18.

[0057] Advantageously, the outer panel 19 is made by an automated fiber arrangement method.

[0058] Advantageously, the thickness of the outer panel 19 is between 1 mm and 20 mm, or even more advantageously between 1 mm and 15 mm. Advantageously, the inner panel 18 and the outer panel 19 have the same thickness.

[0059] The core 20 is annular and centered on the longitudinal axis X. The core is coaxially arranged between the inner panel 18 and the outer panel 19. The core 12 may, for example, have a honeycomb structure 21, or have a rectangular, square, or rhomboid cross-section. The core 20 includes honeycomb cells 21a. Each honeycomb cell 21a has, for example, a hexagonal, triangular, square, or rhomboid cross-section. The cross-sections of the honeycomb cells 21a may differ from each other. Each honeycomb cell 21a is hollow and has an inner cavity 21b communicating with at least one hole 18a. This allows each honeycomb cell 21a to absorb a portion of the acoustic energy emitted by the turbine engine 1.

[0060] Advantageously, the core 20 comprises radially stacked honeycomb cells 21a. The core 20 includes, for example, a first ring and a second ring (not shown) of honeycomb cells 21a. The first and second rings are separated by a diaphragm. In this art, a diaphragm is a perforated membrane that is permeable to certain frequency ranges but impermeable to others. This configuration of the core 20 allows the outer sheath 14 to absorb acoustic energy over a wider frequency range. The first ring enables absorption of acoustic energy in a first frequency range, while the second ring enables absorption of acoustic energy in another frequency range.

[0061] The core 20 may include, for example, a metallic material such as aluminum or a polymeric material such as a thermoplastic or composite material.

[0062] Advantageously, the core 20 is manufactured by additive manufacturing directly on the inner panel 18 or the outer panel 19. In this way, the manufacture of the outer cover 14 according to the invention can be fully automated without any manual assembly steps.

[0063] Alternatively, the core 20 is manufactured parallel to the inner panel 18 and then arranged on the inner panel 18.

[0064] The core 20 is located at least in the upstream portion 17 of the outer casing 14.

[0065] exist Figure 4 In the first preferred embodiment shown, the core 20 is located in the upstream portion 16 and the downstream portion 17 of the outer casing 14.

[0066] according to Figure 5 In the second embodiment shown, the core 20 is located in the upstream portion 16, and the downstream portion 17 does not have the core 20.

[0067] Arms 15 are evenly spaced around the longitudinal axis X. The arms are connected to the inner shroud 13 and the outer shroud 14, for example, by inner bolts 15a and outer bolts 15b. Arms 15 may take the form of flow straightening blades (referred to as "outlet guide vanes (OGV)").

[0068] The outer cover 14 according to the invention directly possesses sound insulation properties. Due to this invention, the need for sound-absorbing panel sections assembled and attached to the outer cover is eliminated. Therefore, the acoustic characteristics of the outer cover 14 are greatly improved. The outer cover 14 is also lighter and cheaper.

[0069] As a result of the present invention, the entire outer cover 14 (i.e., the upstream portion 16 and the downstream portion 17 of the outer cover 14) can also be acoustically separated.

[0070] Now refer to Figure 6 A method for manufacturing the intermediate shell 12 is described. The manufacturing method includes the following steps: (a) Provide inner protective cover 13, (b) Connect arm 15 to inner cover 13. (c) Provide an outer protective cover 14, (d) Connect the outer cover 14 to the arm 15.

[0071] According to the present invention, step (c) includes the following sub-steps performed in chronological order: (c1) Forming the inner panel 18, (c2) The core 20 is arranged coaxially around the inner panel. (c3) An outer panel 19 is formed coaxially around the core 20. (c4) Optionally, the inner panel 18 and the outer panel 19 are heat-treated, and (c5) Drill hole 18a in inner panel 18.

[0072] Advantageously, sub-steps (c1) and (c3) are performed by an automated fiber placement method (also known as AFP, Automated Fiber Placement).

[0073] In sub-steps (c1) and (c3), for example, a robotic arm 140 is used to wind multiple strips 110 of pre-impregnated fibers onto an annular support 120. Advantageously, the strips 110 are compacted and heated to induce adhesion between them. When the matrix of the strips 110 is thermoplastic, the heating temperature of the strips 110 is between 400°C and 400°C. o C to 500 o Between C, preferably between 400o C to 450 o Between C, or even more preferably 420 o C.

[0074] When the substrate with 110 is thermosetting, the heating temperature is between 20°C and 30°C. o C to 120 o Between C.

[0075] In sub-step (c2), the core 20 is preferably arranged on the inner panel 18 by additive manufacturing. This method offers the advantage of simplifying sub-step (c2) and enabling a wider variety of honeycomb cell geometries 21a. This example is preferred when the matrix of the inner panel 18 is thermoplastic.

[0076] In another example, in sub-step (c2), the core is manually arranged on the inner panel 18.

[0077] In yet another example, in sub-step (c2), the core is arranged on the inner panel 18 by a pick-and-place device.

[0078] Sub-step (c4) is particularly advantageous for polymerizing the thermosetting polymer matrix and thus consolidating the inner panel 18 and the outer panel 19. Sub-step (c4) is a baking step. For example, sub-step (c4) is carried out in an autoclave.

[0079] In sub-step (c5), hole 18a is drilled, for example, using mechanical drilling or laser drilling.

[0080] For example, laser drilling uses a laser. This laser can be a short-pulse power laser or an ultrashort-pulse power laser. Advantageously, the laser produces radiation with wavelengths between 1 nm and 1 mm. Therefore, the produced radiation is in the infrared, visible, or ultraviolet range.

[0081] According to the present invention, the manufacturing method for the outer cover 14 can be fully automated, which reduces the manufacturing time of the outer cover 14 and significantly reduces the manufacturing cost. Furthermore, due to the implementation of the automated fiber arrangement method, the outer cover 14 can be produced in the form of an annular panel with sound-insulating properties.

[0082] This allows for improved acoustic properties of the outer casing 14 and reduced weight of the outer casing 14.

[0083] Now refer to Figure 7 Describes the equipment used to manufacture the outer protective cover 14.

[0084] The equipment includes a first station 100 for manufacturing inner panel 18 and outer panel 19, a station 200 for arranging core 20, an optional baking station 300, and a drilling station 400.

[0085] refer to Figure 8 The first station 100 includes, for example, an unwinding machine 130 for pre-impregnating the fiber tape 110. The unwinding machine 130 enables the tape 110 to be arranged on a support 120. For example, the unwinding machine 130 is a robotic arm for winding the tape 110 onto the annular support 120. For example, the support 120 is a chuck.

[0086] The first station 100 also includes compaction rollers 140. Advantageously, the first station 100 includes a plurality of compaction rollers 140 evenly distributed around the support 120. The compaction rollers 140 enable pressure to be applied to the belts 110 arranged on the support 120 to promote adhesion between the belts 110.

[0087] The first station 100 also includes a device 150 for heating the belt 110. The heating device 150 heats the belt as it is deposited on the support 120. This helps to adhere the belts 110 to each other by melting the matrix. Thus, the combination of pressure and temperature promotes the adhesion of the belts 110 to each other.

[0088] For example, the heating device 150 is a laser, such as an infrared laser. For example, the heating device 150 can rotate about the support 120.

[0089] For example, the layout station 200 includes additive manufacturing equipment or "pick-and-place" layout equipment.

[0090] For example, an additive manufacturing apparatus includes a first filament distributor and a first extruder.

[0091] For example, baking station 300 includes an autoclave.

[0092] The drilling station 400 also includes components for drilling holes in the inner panel 18. For example, the drilling component is a laser or a mechanical drill. For example, the laser is a short-pulse power laser or an ultrashort-pulse power laser. Advantageously, the laser produces radiation with wavelengths between 1 nm and 1 mm. Therefore, the produced radiation is in the infrared, visible, or ultraviolet range.

[0093] Therefore, the device according to the invention enables the outer protective cover 14 to be manufactured online.

Claims

1. A method for manufacturing an annular intermediate housing (12) for an aircraft turbine engine (1), the intermediate housing (12) having a rotation axis (X) and comprising: - Annular inner protective cover (13), the annular inner protective cover being centered on the rotation axis (X), - An annular outer protective cover (14), which is arranged coaxially around the inner protective cover (13), and -Radial arm (15), which connects the inner shield and the outer shield (13, 14), The outer protective cover (14) includes: - An annular inner panel (18), the annular inner panel extending about the rotation axis (X) and around the arm (15), the inner panel (18) comprising a first polymer matrix and reinforcing fibers embedded in the first matrix, - An annular outer panel (19), the annular outer panel being coaxially arranged around the inner panel (18), the outer panel (19) comprising a second polymer matrix and reinforcing fibers embedded in the second matrix; and - An annular core (20), said annular core being coaxially arranged between said inner panel and said outer panel (18, 19), characterized in that the method includes step (c) of producing said outer cover (14), said step (c) comprising the following sub-steps arranged in chronological order: (c1) An annular inner panel (18) centered on the axis of rotation (X) is formed by automatic fiber arrangement. (c2) An annular core (20) is arranged coaxially around the inner panel (18). (c3) An outer panel (19) is formed coaxially around the core (20) by automatic fiber arrangement, and (c4) The inner panel and the outer panel (18, 19) are subjected to heat treatment.

2. The method according to the preceding claim, characterized in that, After sub-step (c4), the method includes a step (c5) of drilling holes in the inner panel (18).

3. The method according to the preceding claim, characterized in that, The drilling step (c5) is performed by mechanical drilling or laser drilling.

4. The method according to any one of the preceding claims, characterized in that, Sub-steps (c1) and (c3) include the following steps: - A strip (110) of pre-impregnated fibers is wound along the axis of rotation (X). - Compact the strip (110) and heat it to a first temperature lower than the heat treatment temperature of step (c4).

5. The method according to the preceding claim, characterized in that, The first temperature is between 20 o C to 500 o Between C.

6. The method according to any one of the preceding claims, characterized in that, Sub-step (c3) is performed via additive manufacturing.

7. The method according to any one of the preceding claims, characterized in that, Sub-step (c4) is performed in an autoclave.

8. The method according to any one of the preceding claims, characterized in that, The core (20) has a honeycomb structure (21).

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