Aircraft comprising at least one removable compression energy absorption device

Abstract

Aircraft comprising at least one removable compression energy absorption device The invention relates to an aircraft comprising first and second elements (32, 34) spaced apart from each other as well as at least one compression energy absorption device, positioned between the first and second elements (32, 34), comprising at least one compression energy absorption module (30) as well as at least one attachment system (48) removably connecting each compression energy absorption module (30) to at least one element among the first and second elements (32, 34), at least one compression energy absorption module (30) comprising several first conduits (36) oriented in a compression direction (DC) and being independent of the first and second elements (32, 34). Figure 13

Description

Title of the invention: Aircraft comprising at least one removable device for absorbing energy by compression

[0001] The present application relates to an aircraft comprising at least one removable compression energy absorption device.

[0002] According to one embodiment, a panel comprises first and second skins as well as a honeycomb structure, interposed between the first and second skins, which comprises a plurality of conduits oriented perpendicular to the first and second skins. This honeycomb structure has a honeycomb geometry and comprises a plurality of identical, juxtaposed conduits of hexagonal sections. Generally, the conduits have a reduced section, which gives the panel a high resistance to compression (forces perpendicular to the skins). Such panels are not used as a compression energy absorption module.

[0003] According to an embodiment described in document US9,637,212, an aircraft comprises a compression energy absorption module positioned between the skin of the fuselage and a fairing. This module comprises a honeycomb structure comprising a plurality of ducts oriented parallel to the skin of the fuselage and to the fairing. This honeycomb structure has a honeycomb geometry and comprises a plurality of identical, juxtaposed ducts of hexagonal sections and oriented in a direction perpendicular to a direction of deformation. This embodiment does not allow a large amount of energy to be absorbed. According to the embodiment described in document US9,637,212, the fairing is dedicated to the energy absorption function and has shapes which fit the honeycomb structure to immobilize it, which leads to an increase in the mass of the aircraft and therefore its consumption.

[0004] According to another embodiment, an aircraft may comprise a ventral fairing designed to absorb energy in the event of an impact. Even if in this case the ventral fairing is not dedicated to the energy absorption function, the addition of this function leads to making it more complex.

[0005] The present invention aims to remedy all or part of the drawbacks of the prior art.

[0006] To this end, the invention relates to an aircraft comprising first and second elements spaced apart from each other as well as at least one compression energy absorption device positioned between the first and second elements and configured to be subjected to compression forces oriented in a compression direction, said device comprising at least one compression energy absorption module which comprises several first conduits oriented in the compression direction.

[0007] According to the invention, the compression energy absorption module is independent of the first and second elements. In addition, the compression energy absorption device comprises at least one attachment system removably connecting each compression energy absorption module to at least one element among the first and second elements.

[0008] This solution makes it possible to limit the impact of the compression energy absorption device on the elements that it separates.

[0009] According to another characteristic, each compression energy absorption module is connected to only one element among the first and second elements.

[0010] According to another characteristic, the first element being offset upwards relative to the second element, each compression energy absorption module is suspended under the first element.

[0011] According to another characteristic, each compression energy absorption module is spaced from the first and second elements.

[0012] According to another characteristic, each attachment system comprises a first wing pressed against the first or second element and connected to the latter by at least one first connecting element, a second wing pressed against the compression energy absorption module and connected to the latter by at least one second connecting element as well as a core connecting the first and second wings so as to form a single Z-shaped part, at least one of the first and second connecting elements being removable.

[0013] According to another characteristic, the aircraft comprises a fuselage, at least one tank, a ventral fairing spaced from the tank as well as at least one compression energy absorption device interposed between the tank and the ventral fairing and positioned under said tank.

[0014] According to another characteristic, each compression energy absorption module is only connected to the fuselage and / or to the tank.

[0015] According to another characteristic, the compression energy absorption device comprises several compression energy absorption modules positioned symmetrically with respect to the vertical longitudinal plane of symmetry of the aircraft.

[0016] According to another characteristic, the first conduits are spaced apart from each other. In addition, each compression energy absorption module comprises junction walls, parallel to the compression direction, connecting the first conduits so as to delimit at least one second conduit with the latter.

[0017] According to another characteristic, the junction walls are oriented in two or three directions so as to obtain an orthogrid or isogrid type network.

[0018] Other characteristics and advantages will emerge from the description of the invention which follows, a description given by way of example only, with reference to the appended drawings, among which:

[0019] [Fig-1] is a side view of an aircraft,

[0020] [Fig.2] is a perspective view of a lower portion of an aircraft illustrating a embodiment of the invention,

[0021] [Fig.3] is a longitudinal section of a lower part of an aircraft fuselage comprising compression energy absorption modules in the undeformed state illustrating an embodiment of the invention,

[0022] [Fig.4] is a longitudinal section of a lower part of an aircraft fuselage comprising compression energy absorption modules in the deformed state illustrating an embodiment of the invention,

[0023] [Fig.5] is a perspective view of energy absorption modules by com pressure illustrating an embodiment of the invention, in the undeformed state on part (A) and in the deformed state on part (B),

[0024] [Fig.6] is a side view of two compression energy absorption modules illustrating an embodiment of the invention, in the undeformed state on part (A) and in the deformed state on part (B),

[0025] [Fig.7] is a top view of compression energy absorption modules illustrating an embodiment of the invention,

[0026] [Fig.8] is a perspective view of energy absorption modules by com pressure illustrating an embodiment of the invention,

[0027] [Fig.9] is a perspective view of an energy absorption module by com pressure illustrating an embodiment of the invention,

[0028] [Fig. 10] is a side view of a compression energy absorption module illustrating one embodiment of the invention,

[0029] [Fig. 11] is a top view of a compression energy absorption module illustrating an embodiment of the invention,

[0030] [Fig. 12] is a perspective view of a compression energy absorption module illustrating an embodiment of the invention,

[0031] [Fig. 13] is a cross-section of a portion of an aircraft comprising a plurality of compression energy absorption modules suspended beneath a tank, illustrating one embodiment of the invention, and

[0032] [Fig. 14] is a perspective view of a connection connecting a compression energy absorption module and an element of the aircraft illustrating an embodiment of the invention.

[0033] According to an embodiment visible in [Fig.l], an aircraft 10 comprises a fuselage 12 which extends from a front tip 12.1 to a rear tip 12.2, wings 14 positioned on either side of the fuselage 12 as well as a tailplane 16 positioned at the level of the rear tip 12.2 of the fuselage 12.

[0034] For the remainder of the description, a longitudinal direction is a direction parallel to a substantially horizontal longitudinal axis when the aircraft is on the ground, which extends from the front tip 12.1 to the rear tip 12.2. The aircraft 10 has a vertical longitudinal plane of symmetry containing the longitudinal axis.

[0035] The fuselage 12 also comprises a primary structure 18 composed of frames and stringers as well as a skin 20 attached to the primary structure 18. It also comprises a central wing box 22 as well as a landing gear compartment 24 offset rearward relative to the central wing box 22. According to one configuration, the fuselage 12 comprises at least one tank 26 offset rearward relative to the landing gear compartment 24.

[0036] The aircraft 10 comprises a ventral fairing 28 which extends under the central wing box 22, the landing gear compartment 24 and the tank 26 and has a width substantially equal to that of the fuselage 12. At least in line with the tank 26, the ventral fairing 28 and the fuselage 12 (more particularly the skin 20 of the fuselage 12) are spaced apart. According to one configuration, the tank 26 is a structural tank integrated partly into the structure of the fuselage 12.

[0037] The aircraft 10 comprises at least one compression energy absorption device, interposed between the ventral fairing 28 and the fuselage 12 (more particularly the skin 20 of the fuselage 12), which comprises at least one compression energy absorption module 30 interposed between the ventral fairing 28 and the fuselage 12 (more particularly the skin 20 of the fuselage 12). According to one configuration, the aircraft 10 comprises at least one compression energy absorption module 30 interposed between the ventral fairing 28 and the tank 26, positioned under the latter. This configuration allows the addition of an additional tank 26 at the rear of the landing gear compartment 24, said tank 26 being protected by at least one compression energy absorption module 30 in the event of a vertical impact at the ventral fairing 28. Consequently, the latter is not necessarily designed to absorb such an impact and protect the tank 26.

[0038] Of course, the invention is not limited to this arrangement. Thus, the compression energy absorption device could be positioned in another location of the aircraft. More generally, the compression energy absorption device is configured to be positioned between first and second spaced elements 32, 34, more precisely between first and second spaced contact surfaces F32, F34, and to be subjected to compression forces oriented in a compression direction DC (visible in [Fig. 4]) intersecting with the first and second elements 32, 34. According to a first arrangement, the first and second contact surfaces F32, F34 are substantially parallel to each other and substantially perpendicular to the compression direction DC. According to another arrangement, the first and second contact surfaces F32, F34 are not parallel to each other, and one of them is perpendicular to the compression direction DC. The first element 32 is chosen from a structure, a fuselage, a fairing or a tank of the aircraft; the second element 34 being different from the first element 32, spaced from the latter and chosen from a structure, a fuselage, a fairing or a tank of the aircraft.

[0039] Each compression energy absorption module 30 comprises several first conduits 36 spaced apart from each other, oriented in the compression direction DC and each having a first cross-section (perpendicular to the compression direction DC) as well as junction walls 38 parallel to the compression direction DC and connecting the first conduits 36 so as to delimit, with the latter, at least one second conduit 40 which has a second cross-section (perpendicular to the compression direction DC).

[0040] Each first conduit 36 ​​has a side wall 42 and extends between first and second ends 42.1, 42.2 oriented respectively in the direction of the first and second elements 32, 34.

[0041] According to an embodiment visible in [Fig.l 1], the first conduits 36 of the same compression energy absorption module 30 all have the same cross-section.

[0042] According to an embodiment visible in [Fig.9], the first conduits 36 of the same compression energy absorption module 30 have different cross-sections.

[0043] According to the different embodiments, the first cross sections of the first conduits 36 may be prismatic, square, rectangular, triangular, in the shape of a circle or a semicircle. Of course, the invention is not limited to these geometries for the first cross sections of the first conduits 36.

[0044] According to an embodiment visible in Figures 5 to 8, a compression energy absorption module 30 comprises first conduits 36 having first cross sections in the shape of a circle or a semicircle which have substantially the same diameter.

[0045] The first conduits 36 have, for example, a first cross-section of between 20 and 200 cm2.

[0046] According to embodiments visible in particular in Figures 9 and 10, each junction wall 38 is substantially rectangular and extends between first and second edges 38.1, 38.2 oriented respectively in the direction of the first and second elements 32, 34 as well as the third and fourth edges 38.1, 38.2 connected to first conduits 36.

[0047] Depending on the configurations, the junction walls 38 are planar. Some junction walls 38 may be non-planar and have at least one hollow shape to at least partially house a first conduit 36 ​​of another compression energy absorption module 30.

[0048] According to one embodiment, the joining walls 38 of the compression energy absorption modules 30 are oriented in two or three directions so as to obtain a network of joining walls of the orthogrid type as illustrated in FIGS. 5, 7, 8 and 12 or of the isogrid type as illustrated in [Fig. 6]. This solution makes it possible to obtain a crushing of the first conduits 36 which ensures energy absorption and not a spillage of said first conduits 36.

[0049] According to one arrangement, the junction walls 38 form an orthogrid type network and are oriented in a first direction parallel to the longitudinal direction and in a second direction perpendicular to the longitudinal direction.

[0050] According to one configuration, the compression energy absorption device comprises several compression energy absorption modules 30 positioned symmetrically relative to the vertical longitudinal plane of symmetry of the aircraft.

[0051] The first ends 42.1 of the first conduits 36 as well as the first edges 38.1 of the joining walls 38 of the same compression energy absorption module 30 are positioned in the same first plane or the same first almost flat surface.

[0052] In addition, the second ends 42.2 of the first conduits 36 as well as the second edges 38.2 of the joining walls 38 of the same compression energy absorption module 30 are positioned in the same second plane or the same second almost flat surface.

[0053] The joining walls 38 are connected to the first conduits 36 by any suitable means, such as by welding for example. Alternatively, the joining walls 38 and the first conduits 36 of a compression energy absorption module 30 are produced in one piece by an additive manufacturing process for example.

[0054] According to one embodiment, the junction walls 38 and the first conduits 36 of a compression energy absorption module 30 are made of aluminum alloy, in particular from aluminum alloy sheets.

[0055] For each second conduit 40, its second cross-section corresponds to an area delimited by the junction walls 38 and a part of the side walls 42 of the first conduits 36 and does not include the first cross-sections of the first conduits 36 bordering it.

[0056] According to one embodiment of the invention, for each compression energy absorption module 30, the second cross-section of the second conduit 40 is greater than that(s) of the first conduits 36. According to one configuration, the second cross-section of the second conduit 40 is at least twice as large as the first cross-section of each first conduit 36 ​​bordering the second conduit 40. Such a compression energy absorption module makes it possible to absorb a greater quantity of energy.

[0057] According to one configuration, the second cross-section of the second conduit 40 is greater than the sum of the first cross-sections of the first conduits 36 bordering the second conduit 40 and less than 10 times the sum of the first cross-sections of the first conduits 36 bordering the second conduit 40.

[0058] According to one configuration, the joining walls 38 and the first conduits 36 of the same compression energy absorption module 30 are arranged so that the second conduit 40 has a prismatic, square, rectangular, triangular or circular cross-section. Of course, the invention is not limited to these geometries for the cross-sections of the second conduit 40.

[0059] According to one embodiment, the compression energy absorption module 30 comprises at least one second conduit 40. According to another embodiment, the compression energy absorption module 30 comprises several second conduits 40. According to one arrangement, the second conduits 40 of the same compression energy absorption module 30 are all identical, as illustrated in [Fig.11].

[0060] According to arrangements visible in Figures 9 and 11, the compression energy absorption module 30 comprises at least one second conduit 40 having a second triangular cross-section, the first conduits 36 being positioned at the apexes of the cross-section of each second conduit 40.

[0061] According to another arrangement visible in Figures 5 to 8, the compression energy absorption module 30 comprises at least one second conduit 40 having a second square or rectangular cross-section, the first conduits 36 being spaced from the vertices of the cross-section of each second conduit 40.

[0062] According to the arrangement visible in Figures 5 to 8, the compression energy absorption module 30 comprises at least one second conduit 40 which has a second substantially square or rectangular cross-section bordered by first conduits 36 positioned at the sides of the second substantially square or rectangular cross-section and spaced from the vertices of this second cross-section. In addition, the compression energy absorption module 30 comprises, at each side of the second conduit 40, two or three first cylindrical and / or semi-cylindrical conduits 36.

[0063] The second conduit 40 has a second cross-section of between 200 and 2000 cm2.

[0064] The dimensions and the material(s) of the first conduits 36 and the joining walls 38 are determined so as to obtain a progressive crushing of the first conduits 36, promoting the absorption of energy and not a spillage of the latter.

[0065] According to one embodiment, the compression energy absorption module 30 comprises at least one first end wall 44 configured to close the first end 42.1 of at least one first conduit 36 ​​and at least partially clearing the second conduit 40 as well as at least one second end wall 46 configured to close the second end 42.2 of at least one first conduit 36 ​​and at least partially clearing the second conduit 40. According to one arrangement, the compression energy absorption module 30 comprises one or more first end walls 44 closing the first end 42.1 of all the first conduits 36 and at least partially clearing the second conduit 40 as well as one or more second end walls 46 closing the second end 42.2 of all the first conduits 36 and at least partially clearing the second conduit 40.

[0066] According to one configuration, a first end wall 44 is configured to close the first ends 42.1 of several first conduits 36 of the compression energy absorption module 30. A second end wall 46 is configured to close the second ends 42.2 of several conduits 36 of the compression energy absorption module 30.

[0067] According to one arrangement, the first end wall 44 is configured to close the first ends 42.1 of all the first conduits 36 of the compression energy absorption module 30. This first end wall 44 forms a frame delimited by an inner edge 44.1 as well as an outer edge 44.2 spaced from the inner edge 44.1 by a sufficient distance to close the first conduits 36 of the compression energy absorption module 30. The second end wall 46 is configured to close the second ends 42.2 of all the first conduits 36 of the compression energy absorption module 30. This second end wall 46 forms a frame delimited by an inner edge as well as an outer edge spaced from the inner edge by a sufficient distance to close the first conduits 36 of the compression energy absorption module 30.

[0068] Of course, the invention is not limited to this number and to this geometry for the first and second end walls 44, 46. Thus, each of the first and second end walls 44, 46 can be formed from a single wall or from several juxtaposed walls.

[0069] According to one embodiment, the first and second end walls 44, 46 are part of the compression energy absorption module 30 and are connected to the first conduits 36 and to the junction walls 38 by any suitable means, such as by welding for example. Of course, the invention is not limited to this embodiment. Thus, at least one of the first and second end walls 44, 46 could not be part of the compression energy absorption module 30 and be integral with the first or second element 32, 34 between which said compression energy absorption module 30 is positioned.

[0070] According to an embodiment visible in Figures 5, 12 to 13, the compression energy absorption device comprises at least one attachment system 48 removably connecting each compression energy absorption module 30 to at least one element among the first and second elements 32, 34 between which said compression energy absorption module 30 is positioned. This attachment system 48 is configured to allow rapid assembly or disassembly of the compression energy absorption module 30.

[0071] In the case of an aircraft, each compression energy absorption module 30 comprises several attachment systems 48 for connecting it to the fuselage 12 (more particularly to the skin 20 of the fuselage 12) and / or to the ventral fairing 28. According to one configuration, each compression energy absorption module 30 is connected to only one element among the first and second elements 32, 34. According to one arrangement, the first element 32 being offset upwards relative to the second element 34, each compression energy absorption module is suspended under the first element 32, namely the fuselage 12 or the tank 26.

[0072] According to one arrangement, each compression energy absorption module 30 is only connected to the fuselage 12 and / or to the tank 26 and is not connected to the ventral fairing 28. According to this arrangement, each compression energy absorption module 30 is suspended under the fuselage 12. Insofar as each compression energy absorption module 30 is only connected to a single element among the fuselage 12 and the ventral fairing 28, it does not ensure any transmission of forces between the fuselage 12 and the ventral fairing 28, which makes it possible to simplify its design.

[0073] According to one embodiment, each compression energy absorption module 30 is independent of the first and second elements 32, 34 (fuselage 12 or ventral fairing 28) between which it is positioned and connected to at least one of these first and second elements 32, 34 by the removable attachment system(s) 48. By a removable connection, it is meant that each compression energy absorption module 30 can be assembled or disassembled several times, without impacting the characteristics of the first and second elements 32, 34. In this sense, each attachment system 48 is designed to be connected to the first or second element 32, 34 without any modification of the latter.

[0074] According to an arrangement visible in [Fig. 13], each energy absorption module by compression 30 is spaced from the first and second elements 32, 34. According to an embodiment visible in [Fig. 14], each attachment system 48 comprises an angle iron 50 which has a first wing 50.1 pressed against the first or second element 32, 34 and connected to the latter by at least one first connecting element 52, a second wing 50.2 pressed against the compression energy absorption module 30 and connected to the latter by at least one second connecting element 52' as well as a web 50.3 connecting the first and second wings 50.1, 50.2 so as to form a single Z-shaped part. At least one of the first and second connecting elements 52, 52' is removable and is in the form of a bolt for example. Of course, the invention is not limited to this embodiment for the attachment systems 48. Thus, the attachment systems could have a C-shaped section.

Claims

Claims

1. An aircraft comprising first and second elements (32, 34) spaced apart from each other and at least one compression energy absorption device positioned between the first and second elements (32, 34) and configured to be subjected to compression forces oriented in a compression direction (DC), said device comprising at least one compression energy absorption module (30) which comprises several first conduits (36) oriented in the compression direction (DC); characterized in that the compression energy absorption module (30) is independent of the first and second elements (32, 34) and in that the compression energy absorption device comprises at least one attachment system (48) removably connecting each compression energy absorption module (30) to at least one element among the first and second elements (32, 34).

2. Aircraft according to the preceding claim, characterized in that each compression energy absorption module (30) is connected to only one element among the first and second elements (32, 34).

3. Aircraft according to the preceding claim, characterized in that the first element (32) is offset upwards relative to the second element (34) and in that each compression energy absorption module (30) is suspended below the first element (32).

4. Aircraft according to one of the preceding claims, characterized in that each compression energy absorption module (30) is spaced from the first and second elements (32, 34).

5. Aircraft according to the preceding claim, characterized in that each attachment system (48) comprises a first wing (50.1) pressed against the first or second element (32, 34) and connected to the latter by at least one first connecting element (52), a second wing (50.2) pressed against the compression energy absorption module (30) and connected to the latter by at least one second connecting element (52') as well as a core (50.3) connecting the first and second wings (50.1, 50.2) so as to form a single Z-shaped part, at least one of the first and second connecting elements (52, 52') being removable.

6. Aircraft according to one of the preceding claims, characterized in that the aircraft comprises a fuselage (12), at least one tank (26), a ventral fairing (28) spaced from the tank (26) as well as at least one compression energy absorption device interposed between the tank (26) and the ventral fairing (28) and positioned under said tank (26).

7. Aircraft according to the preceding claim, characterized in that each compression energy absorption module (30) is only connected to the fuselage (12) and / or to the tank (26).

8. Aircraft according to one of the preceding claims and having a vertical longitudinal plane of symmetry, characterized in that the compression energy absorption device comprises several compression energy absorption modules (30) positioned symmetrically with respect to the vertical longitudinal plane of symmetry of the aircraft.

9. Aircraft according to one of the preceding claims, characterized in that the first ducts (36) are spaced apart from each other and in that each compression energy absorption module (30) comprises joining walls (38), parallel to the compression direction (DC), connecting the first ducts (36) so as to delimit at least one second duct (40) with the latter.

10. Aircraft according to the preceding claim, characterized in that the junction walls (38) are oriented in two or three directions so as to obtain an orthogrid or isogrid type network.

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