Aircraft comprising at least one flexible profile made of composite material forming at least one element between a coupling shaft of a moving surface and a moving surface

Abstract

Aircraft comprising at least one flexible profile of composite material forming at least one element among a coupling shaft of a moving surface and a moving surface. The invention relates to an aircraft comprising at least one moving surface (20) connected to a fixed structure (22) by at least one articulation system (24) which has a pivot axis (A24), at least one actuation system configured to rotate the moving surface (20) around the pivot axis (A24) and at least one profile (32) of composite material comprising reinforcing fibers embedded in a resin matrix, at least 50% of the reinforcing fibers of the profile (32) forming with a longitudinal direction an angle between [-60° and -45°] and between [+45° and +60°], less than 40% of the reinforcing fibers of the profile (32) forming with the longitudinal direction an angle between [-30° and +30°].This profile (32) can form the moving surface (20) and / or a coupling shaft (28) connecting the moving surface (20) and the fixed structure (22) or the moving surface (20) and the actuation system. This arrangement of reinforcing fibers gives the profile very high torsional strength while allowing it to deform in bending. Figure 5.

Description

Title of the invention: Aircraft comprising at least one flexible profile made of composite material forming at least one element between a coupling shaft of a moving surface and a moving surface

[0001] The present application relates to an aircraft comprising at least one flexible profile of composite material forming at least one element among a coupling shaft of a movable aerodynamic surface and a movable aerodynamic surface.

[0002] An aircraft includes several movable surfaces to control its movements such as ailerons provided at the rear edges of the wings or elevators and rudders provided at the tail assembly.

[0003] Each movable surface is configured to pivot about a pivot axis relative to a fixed structure of the aircraft. To this end, the movable surface is attached to a coupling shaft having an axis coinciding with the pivot axis and connected to the fixed structure of the aircraft by several joints.

[0004] Given the wing deformations during flight, each aileron can only be connected to the fixed wing structure by two joints. This configuration is not suitable for large ailerons.

[0005] According to a first embodiment, each moving surface is associated with an actuation device comprising a first actuator connecting the moving surface and the fixed structure, configured to rotate the moving surface in a first direction, and a second actuator connecting the moving surface and the fixed structure, configured to rotate the surface in a second direction opposite to the first. The first and second actuators are linear actuators, such as jacks, located at the moving surface, between the latter and the fixed structure.

[0006] According to this first embodiment, the fixed structure has a significant thickness to house the first and second actuators of the actuation device, which tends to increase drag. Another drawback is that the actuation device occupies a significant volume within the wing's fixed structure, to the detriment of other components such as the fuel tanks.

[0007] According to a second embodiment described in document EP2234877, the joint comprises a coupling shaft whose pivoting movements are controlled by an actuation device positioned at one end of the coupling shaft, in its extension.

[0008] This second embodiment makes it possible to reduce the size of the actuation device at the right of the moving surface.

[0009] However, it can hardly be implemented when the moving surface is connected to a fixed structure which deforms, such as an aircraft wing for example, unless the coupling shaft is divided into several segments connected to each other by universal joints to allow the coupling shaft to adapt to the curvature of the wing, which would lead to a more complex coupling system between the actuation device and the moving surface and to a significant increase in the aircraft's onboard mass.

[0010] The present invention aims to remedy all or part of the drawbacks of the prior art.

[0011] To this end, the invention relates to an aircraft comprising at least one fixed structure, at least one movable surface, at least one articulation system linking the movable surface and the fixed structure and having a pivot axis, at least one actuation system configured to rotate the movable surface around the pivot axis in at least one first direction, as well as at least one profile extending in a longitudinal direction and forming at least one element among the movable surface, a coupling shaft linking the movable surface and the fixed surface, a coupling shaft linking the actuation system and the movable surface.

[0012] According to the invention, the profile is made of composite material and comprises reinforcing fibers embedded in a resin matrix, at least 50% of the reinforcing fibers of the profile forming with the longitudinal direction an angle between [-60° and -45°] and between [+45° and +60°], less than 40% of the reinforcing fibers of the profile forming with the longitudinal direction an angle between [-30° and +30°].

[0013] This arrangement of reinforcing fibers gives the profile very high torsional strength while allowing it to deform in bending. Thus, in operation, the profile can follow the deformations of the fixed structure to which it is connected.

[0014] According to another characteristic, the resin of the profile has a Young's modulus of less than 3.5 GPa.

[0015] According to another characteristic, the profile is a hollow profile.

[0016] According to another characteristic, the profile has a thickness between 0.5 and 40 mm.

[0017] According to another feature, the profile has a wing-shaped cross-section and forms at least part of the moving surface.

[0018] According to another feature, the profile has a circular cross-section and forms a coupling shaft connecting the moving surface and the fixed surface or the actuation system and the moving surface.

[0019] Other features and advantages will become apparent from the description of the invention which will follow, description given as an example only, with regard to the attached drawings, among which:

[0020] [Fig. 1] is a top view of an aircraft,

[0021] [Fig.2] is a front view of an aircraft wing,

[0022] [Fig.3] is a top view of part of an aircraft wing illustrating a mode of realization of the invention,

[0023] [Fig.4] is a cross-section of a coupling shaft illustrating a mode of realization of the invention,

[0024] [Fig. 5] is a perspective view of a coupling shaft illustrating a mode of realization of the invention,

[0025] [Fig.6] is a cross-section of a moving surface illustrating a mode of realization publication of the invention,

[0026] [Fig.7] is a perspective view of a moving surface illustrating a mode of realization implementation of the invention.

[0027] As illustrated in [Fig.1], an aircraft 10 comprises a fuselage 12, two wings 14 positioned on either side of the fuselage 12 and an empennage 16 positioned at the rear of the fuselage 12. This empennage 16 comprises a vertical plane 16.1 (also called fin) and two horizontal planes 16.2 (also called stabilizers) positioned on either side of the vertical plane 16.1.

[0028] As illustrated in Figures 1 and 2, a wing 14 comprises a first end 14.1 connected to the fuselage 12, a second end 14.2 opposite the first end, a leading edge F14 and a trailing edge F14', as well as a vertical median plane PM14 substantially equidistant from the leading and trailing edges F14, F14'. In flight, the wing 14 can deform in the vertical median plane PM14 and follow a curved profile, as illustrated by dashed lines in [Fig. 2].

[0029] The aircraft 10 also includes several movable surfaces 20 positioned at the rear of the wings 14, vertical and horizontal planes 16.1, 16.2 of the tail assembly 16 or positioned at the front of the wings 14, such as leading edge slats.

[0030] As illustrated in [Fig. 3], each movable surface 20 is connected to a fixed structure 22 of the aircraft by at least one articulation system 24 which has a pivot axis A24. In one application, the movable surface 20 corresponds to an aileron of a wing and the fixed structure 22 corresponds to the structure of a wing. Of course, the invention is not limited to this application. The movable surface 20 could be an elevator or a rudder, and the fixed structure a horizontal plane 16.2 or a vertical plane 16.1 of the tail assembly 16.

[0031] As illustrated in [Fig. 3], the movable surface 20 comprises a first end 20.1 oriented towards the first end 14.1 of wing 14 and a second end 20.2 oriented towards the second end 14.2 of wing 14.

[0032] The aircraft includes at least one actuation system 26 configured to rotate the movable surface 20 around the pivot axis A24 in at least one first direction.

[0033] According to a first configuration visible on [Fig.3], the actuation system 26 includes an actuator configured to rotate the movable surface 20 around the pivot axis A24 in a first direction and in a second direction opposite to the first direction.

[0034] According to a second configuration visible in [Fig.7], the actuation system 26 comprises a first actuator configured to rotate the mobile surface 20 around the pivot axis A24 in a first direction and a second actuator configured to rotate the mobile surface 20 around the pivot axis A24 in a second direction opposite to the first direction.

[0035] According to a first arrangement visible on [Fig.7], the actuation system 26 is positioned between the first and second ends 20.1, 20.2 of the moving surface 20.

[0036] According to a second arrangement visible in [Fig.3], the actuation system 26 is offset relative to the moving surface 20. According to one embodiment, the actuation system 26 can be identical to that described in document EP2234877.

[0037] According to a first embodiment visible in [Fig.5], the articulation system 24 comprises a coupling shaft 28 fixed to the moving surface 20 and bearings 30 fixed to the fixed structure 22, the coupling shaft 28 and the bearings 30 being arranged so that the coupling shaft 28 has an axis coinciding with the pivot axis A24 of the articulation system 24.

[0038] According to the second arrangement visible in [Fig.3], the coupling shaft 28 includes an extension projecting from the first or second end 20.1, 20.2 of the moving surface 20.

[0039] As illustrated in Figures 4 and 5, the coupling shaft 28 is a profile 32 made of composite material comprising reinforcing fibers embedded in a resin matrix.

[0040] By profile, we mean a long, thin element which extends along a direction called longitudinal.

[0041] This profile 32 is hollow and has a circular cross-section, with first and second ends 32.1, 32.2 and a longitudinal axis A32 connecting the first and second ends 32.1, 32.2, which coincides with the pivot axis A24 during operation. This profile 32 has constant cross-sections in transverse planes perpendicular to the longitudinal axis A32.

[0042] According to a particular feature, when the profile 32 is not deformed, at least 50% of the reinforcing fibers of the profile 32 form with the longitudinal direction (parallel to the longitudinal axis A32) an angle between [-60° and -45°] and between [+45° and +60°] and less than 40% of the reinforcing fibers of the profile 32 form with the longitudinal direction an angle between [-30° and +30°].

[0043] According to another feature, the resin of the profile 32 has a Young's modulus of less than 3.5 GPa.

[0044] The reinforcing fibers of the profile 32 are selected from the following materials: carbon, glass, quartz, aramid, boron, or basalt. This list is not exhaustive; other materials may be suitable for the fibers, such as polymer fibers or metallic fibers, for example.

[0045] The profile 32 can be obtained from reinforcing fibers in the same material or from a mixture of reinforcing fibers of different materials.

[0046] These orientations for the reinforcing fibers make it possible to obtain a profile 32 which is very resistant to torsion but able to deform in bending.

[0047] Thus, as illustrated in [Fig. 5], in operation, the coupling shaft 28 can follow the deformations of the fixed structure 22 to which it is connected by means of the bearings 30. It is also possible to provide a greater number of bearings 30, which allows for a better distribution of the forces transmitted between the coupling shaft 28 and the fixed structure 22. Due to this greater number of bearings 30, it is possible to lengthen the moving surface 20 and / or the coupling shaft 28 and thus to position the actuation system 26 in areas less constrained in terms of overall dimensions.

[0048] Depending on the configuration, the hollow profile 32 has a thickness between 0.5 and 40 mm. The thickness of the hollow profile 32 depends on the loads to be transferred as well as the optimization of the orientation of the reinforcing fibers.

[0049] According to a second embodiment shown in Figures 6 and 7, the articulation system 24 does not include any coupling shaft ensuring the connection between the moving surface 20 and the fixed structure 22. According to this second embodiment, the moving surface 20 is connected by bearings 30 to the fixed structure 22. For this purpose, the moving structure 20 includes, at each bearing 30, a bearing surface allowing the moving surface 20 to pivot relative to the bearing 30.

[0050] According to this second embodiment, the movable surface 20 comprises a hollow profile 32' having first and second ends 32.1', 32.2' and a longitudinal axis A32' connecting the first and second ends 32.1', 32.2'. This hollow profile 32' has constant cross-sections in planes transverse and perpendicular to the longitudinal axis A32. The cross-sections of the hollow profile 32' can also vary, i.e., widen or narrow, for example, as a result of changes homothetic.

[0051] This hollow profile 32' has a wing-shaped cross-section and includes a leading edge 34.1, a trailing edge 34.1 and upper and lower faces 34.3, 34.4.

[0052] According to a first variant, the profile 32' forms the entire moving surface 20 or only a part of it.

[0053] As for the profile 32 of the coupling shaft 28, at least 50% of the reinforcing fibers of the profile 32' form with the longitudinal direction (parallel to the longitudinal axis A32') an angle between [-60° and -45°] and between [+45° and +60°], less than 40% of the reinforcing fibers of the profile 32' form with the longitudinal direction an angle between [-30° and +30°], the Young's modulus of the resin of the profile 32' being less than 3.5 GPa.

[0054] Depending on the configurations, the 32' hollow profile has a thickness between 0.5 and 40 mm.

[0055] Of course, the invention is not limited to the embodiments described. According to another configuration, the movable surface 20 is a hollow profile 32' connected to the fixed structure 22 by a coupling shaft 28 also in the form of a profile 32. This coupling shaft 28 can serve to connect the movable surface 20 to the fixed structure 22 and / or to ensure the transmission of pivoting movements between an actuation system 26 and the movable surface 20.

[0056] According to another configuration, the moving surface 20 is a hollow profile 32' connected directly to the bearings 30 attached to the fixed structure 22. According to this configuration, the moving surface 20 can be coupled to the actuation system 26 by a coupling shaft which may or may not be a hollow profile 32.

[0057] According to another configuration, the movable surface 20 is not a hollow profile 32'. According to this configuration, the movable surface 20 can be connected to the fixed structure 22 by a coupling shaft 28 in the form of a hollow profile 32 and / or be connected to an actuation system 26 by a coupling shaft in the form of a hollow profile 32.

[0058] Different operating methods can be used to obtain the profiles 32, 32'. By way of example, a process for obtaining a profile 32, 32' includes a step of placing layers of reinforcing fibers on a core, these reinforcing fibers being able to be pre-impregnated with resin or not, a polymerization step possibly preceded by a resin injection step, and then a core removal step.

Claims

Demands

1. Aircraft comprising at least one fixed structure (22), at least one movable surface (20), at least one articulation system (24) connecting the movable surface (20) and the fixed structure (22) and having a pivot axis (A24), at least one actuation system (26) configured to rotate the movable surface (20) about the pivot axis (A24) in at least one first direction, and at least one profile (32, 32') extending in a longitudinal direction and forming at least one element among the movable surface (20), a coupling shaft (28) connecting the movable surface (20) and the fixed structure (22), and a coupling shaft (28) connecting the actuation system (26) and the movable surface (20), characterized in that the profile (32, 32') is made of composite material and comprises reinforcing fibers embedded in a resin matrix, at least 50% of the profile's reinforcing fibers (32,32') forming with the longitudinal direction an angle between [-60° and -45°] and between [+45° and +60°], less than 40% of the reinforcing fibers of the profile (32, 32') forming with the longitudinal direction an angle between [-30° and +30°].,

2. Aircraft according to the preceding claim, characterized in that the resin of the profile (32, 32') has a Young's modulus of less than 3.5 GPa.

3. Aircraft according to any one of the preceding claims, characterized in that the profile (32, 32') is a hollow profile.

4. Aircraft according to the preceding claim, characterized in that the profile (32, 32') has a thickness between 0.5 and 40 mm.

5. Aircraft according to any one of the preceding claims, characterized in that the profile (32') has a wing-shaped cross-section and forms at least part of the movable surface (20).

6. Aircraft according to any one of the preceding claims, characterized in that the profile (32) has a circular cross-section and forms a coupling shaft (28) connecting the moving surface (20) and the fixed structure (22) or the actuation system (26) and the moving surface (20).

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