Component for an aircraft and aircraft

Abstract

The present invention relates to an optimized design for a component (1) for an aircraft, the aircraft comprising a wing (2), an engine attachment pylon (4) and means for fixing a main structural member (28) of the engine attachment pylon to a wing box (14). These means include two lateral front fittings (42), each of these fittings comprising: a first connecting portion (46) fixed to the front spar (16); a second connecting portion (52) fixed to the main structural member (28) of the attachment pylon; at least one fixing member (54) connecting the first and second connecting portions (46, 52), the fixing member (54) being articulated to the first connecting portion (46) by a first pin system (56), the first pin system being oriented generally parallel to the front spar (16).

Description

Technical Field

[0001] The present invention relates to the field of aircraft, and more particularly, the present invention relates to an assembly including an aircraft wing and an engine attachment pylon fixed below the wing. Preferably, the present invention relates to such an assembly for supporting a large-diameter turbofan-type engine. Examples of this type of assembly are disclosed in documents such as FR2 887 522.

[0002] In particular, the present invention is applicable to commercial aircraft. Background Art

[0003] In existing aircraft, an engine such as a jet engine is suspended below the wing by a complex attachment device, also known as an EMS (Engine Mounting Structure), or by an attachment pylon. A commonly used attachment pylon has a main structure, also known as a rigid structure, which is usually in the form of a box, that is, the main structure is manufactured by assembling an upper spar and a lower spar, and the upper spar and the lower spar are connected together by a plurality of lateral stiffening ribs located inside and at the ends of the box. The spars are arranged on the lower surface and the upper surface of the box, while side panels close the box on the sides. In addition, the attachment pylon is arranged in the upper part of the engine located between the engine and the wing box. This is the so-called "12 o'clock" position.

[0004] As is known, the main structure of these pylons is designed to allow the transfer of static and dynamic loads imposed by the engine, such as weight, thrust, or different dynamic loads, to the wing, especially those loads associated with failure events, such as fan blade out (FBO), front landing gear collapse, hard landing, etc.

[0005] In the attachment pylons known from the prior art such as document FR 2 887 522, the load transfer between its main structure and the wing box is usually ensured by a set of fittings, which includes a front fitting, a rear fitting, and an intermediate fitting. In particular, the intermediate fitting is designed to react to the thrust load generated by the engine. Conventionally, these fittings are vertically inserted between the wing box and the main structure of the attachment pylon.

[0006] Recently developed engines have an increasingly large diameter. In particular, for turbofan engines such as jet engines, the high bypass ratio required results in a particularly large volume, because an increase in the bypass ratio inevitably leads to an increase in the engine diameter, and more particularly, to an increase in the diameter of its fan casing.

[0007] Thus, since the determined ground clearance is kept acceptable from a safety point of view, the remaining space between the wing and the engine is proven to be increasingly limited. Therefore, it is difficult to install the attachment pylon and various wing fittings into the remaining vertical space that is usually used for such installations. Considering that the passing loads are also high and a wing box of appropriate size is required, the connection of the two elements of the main structural member and the fittings is even more difficult. In particular, the fittings must have sufficient dimensions to provide mechanical strength that can withstand the load transfer from the engine to the wing and deform less under stress so as not to damage the aerodynamic performance of the propulsion system.

[0008] In the prior art, various solutions have been proposed to bring the engine as close as possible to the wing element that suspends the engine. In particular, efforts are made to maintain the required ground clearance despite the increase in engine size. In particular, some fittings can be installed at least partially in the leading edge area of the wing. However, the high loads borne by these fittings mean that the dimensions of these fittings must be determined accordingly, especially in the longitudinal direction. Therefore, the space usually used to accommodate systems and equipment in the leading edge area is limited.

[0009] Therefore, it is necessary to optimize the existing design in order to reduce the volume of the fittings that connect the wing box to the pylon box. Summary of the Invention

[0010] To meet this need, an object of the present invention is a component for an aircraft, the component comprising:

[0011] An aircraft wing, the wing comprising a wing box, the wing box being partially formed by a front spar, an upper suction surface skin and a lower pressure surface skin;

[0012] An engine attachment pylon, the pylon being arranged below the wing and comprising a main structural member in the form of a pylon box, the pylon box having an upper spar that at least partially extends below the wing box, and

[0013] Devices for fixing the main structural member of the attachment pylon to the wing box.

[0014] According to the present invention, the fixing device comprises two lateral front fittings, each of these fittings comprising:

[0015] A first connection part that is fixed to the front spar;

[0016] A second connection part that is fixed to the main structural member of the attachment pylon;

[0017] At least one fixing member that connects the first connecting portion and the second connecting portion, and the at least one fixing member is hinged to the first connecting portion by a first pin system that is oriented substantially parallel to the front spar.

[0018] With the proposed arrangement, and in particular the specific orientation of the first pin system, the fixing member can be moved as close as possible to the front spar. Therefore, the first connecting portion fixed to the front spar can be more compact in the longitudinal direction.

[0019] In addition, the reduction in the thickness of the first connecting portion enables the reduction of the offset of the load introduced into the front spar of the wing box. Therefore, the connecting member no longer requires a specific size to withstand the cantilever effect - as is known, the cantilever effect is likely to introduce bending moments into the connecting member and the front spar, which helps to further reduce the thickness of the connecting member.

[0020] Advantageously, achieving these volume reductions enables a larger volume to be provided in front of the lateral front fitting for installing conventional systems and equipment in the leading edge region of the wing.

[0021] The present invention preferably provides at least one of the following alternative features: These features can be employed individually or in combination.

[0022] The at least one fixing member is hinged to the second connecting portion by a second pin system that is oriented substantially orthogonally to the front spar.

[0023] Each fixing member is arranged substantially parallel to the vertical direction of the assembly.

[0024] Each first connecting portion is a connecting member in the form of a bracket, and the bracket is simultaneously fixed to the front spar and the upper suction surface skin, and the connecting member in the form of a bracket is completely arranged in the leading edge region of the wing.

[0025] The two second connecting portions are integrally formed with the inner lateral stiffeners of the pylon box, and the two second connecting portions project outward from the pylon box and preferably partially penetrate into the leading edge region of the wing.

[0026] The fixing device further includes an intermediate front fitting that is configured to react to the loads applied in the lateral direction and the longitudinal direction of the assembly, and the intermediate front fitting preferably includes shear pins.

[0027] Each first connecting portion includes two side wings that carry the first pin system, and the at least one fixing member associated therewith is arranged between the two side wings, and the side wings are configured to: prevent the at least one fixing member from translating in the direction of the first pin system when the intermediate front fitting fails.

[0028] The assembly includes at least one system and / or equipment component arranged in the leading edge region of the wing, in front of the lateral front fitting.

[0029] Each lateral front fitting is designed to allow reaction to loads applied in the vertical direction of the assembly.

[0030] The fixing device further includes a rear fitting fixed to the rear closing rib of the pylon box, and the rear fitting is preferably designed to allow reaction to loads applied in the vertical direction and in the lateral direction of the assembly.

[0031] The fixing device forms a statically determinate load reaction system.

[0032] Finally, another subject of the present invention is an aircraft including at least one such assembly.

[0033] By the following non-limiting detailed description, other advantages and features of the present invention will become apparent. Description of the Drawings

[0034] The description will be made with reference to the drawings, in which:

[0035] - Figure 1 is a side view of an aircraft including an assembly according to the present invention;

[0036] - Figure 2 is Figure 1 an enlarged side view of the assembly carrying the engine in ;

[0037] - Figure 3 is Figure 2 a perspective view of a part of the assembly shown in ;

[0038] - Figure 4 is Figure 3 a sectional view of the assembly shown in along the section line IV-IV;

[0039] - Figure 5 is a view of the assembly in the foregoing views in a direction orthogonal to a single wing connection. Detailed Description of the Embodiment

[0040] Figure 1 An aircraft 100 including a fuselage 3 is shown, in which two wings 2 ( Figure 1 only one wing is visible in ) are fixed to the fuselage 3, and each wing is a part of the assembly 1 according to the present invention. The assembly 1 carries a twin-turbofan engine 10 such as a jet engine with an ultra-high bypass ratio (UHBR). The assembly 1 includes not only the wings 2 but also a pylon 4 for attaching the engine 10, and the pylon 4 is inserted between the wing 2 and the engine.

[0041] In the following description, by convention, the X direction corresponds to the longitudinal direction of component 1, which also corresponds to the longitudinal direction of engine 10. The longitudinal direction is parallel to the longitudinal axis of the engine. Additionally, the Y direction corresponds to the direction oriented transversely to component 1, which also corresponds to the lateral direction of the engine. Finally, the Z direction corresponds to the vertical direction or height direction, and these three directions X, Y, and Z are mutually orthogonal. Thus, engine 10 is suspended below component 1 in the Z direction.

[0042] Furthermore, the terms "front" and "rear" should be considered with respect to the direction of forward movement of the aircraft due to the thrust exerted by engine 10, which is schematically indicated by arrow 7.

[0043] Figure 2 Component 1, the longitudinal axis 12 of component 1, and engine 10 suspended below component 1 are now shown. The wing 2 of component 1 has a conventional design and is characterized in that the wing 2 has a wing box 14 extending in the spanwise direction of the wing. The wing box 14 is formed by a front spar 16, a rear spar or intermediate spar 17, an upper suction surface skin 20, and a lower pressure surface skin 22. Preferably, the two spars 16, 17 are generally parallel, extend in the spanwise direction, and are spaced apart from each other in the chordwise direction. Generally longitudinal internal stiffeners (not shown) may be received within the wing box 14 and fixed to each of the four box elements 16, 17, 20, 22 by rivets, bolts, or similar elements. Additionally, in front of the wing box 14, the wing 2 has a fairing 26 that forms the leading edge of the wing and defines a leading edge region 25 with the front spar 16.

[0044] Another element of component 1 - attachment hanger 4 - includes a main structural member 28 in the form of a box. Other constituent elements (not shown) of this hanger 4 of the type of secondary structural members that separate and hold the system while carrying an aerodynamic fairing are conventional elements similar to those encountered in the prior art. Thus, these conventional elements will not be described in detail.

[0045] The main structural member 28 or rigid structural member allows the static and dynamic loads imposed by engine 10 to be transmitted to the wing box 14. The box formed by this main structural member 28 extends in the X direction along the entire length of the main structural member. It has a conventional design as it is bounded upward by an upper spar 30, downward by a lower spar 32, and laterally by side panels 34. As Figure 2 can be seen, the upper spar 30 is at least partially located below the wing box 14. In this regard, it should be noted that each of the above elements 30, 32, 34 can be made in one piece or made by assembling a plurality of individual parts. Additionally, one part and the same part can form all or part of several of these elements 30, 32, 34.

[0046] The suspension box 28 is provided with lateral reinforcing ribs, some of which are generally arranged in the plane YZ and distributed in the X direction. They are the internal lateral ribs 36, the lateral reinforcing ribs 36b that close the rear part of the suspension box 28 - called the rear closing ribs, and the lateral reinforcing ribs 36a that close the front part of the box - called the front closing ribs. The ribs 36, 36a, 36b connect the external elements 30, 32, 34 of the box together. Another specifically defined lateral reinforcing rib 36c of the present invention is present inside the suspension box. This rib 36c is part of two lateral front fittings 42, and this rib 36c mechanically connects these wing fittings 42 to the rear engine fittings that will be described below. The rib 36c can extend in the plane YZ like the other internal ribs 36, but preferably, the rib 36c extends in a plane P' that is generally parallel to the plane in which the front spar 16 is located, and more specifically, the rib 36c extends in the plane defined by the front surface of the front spar.

[0047] The suspension box 28 has a cross-section YZ with an overall shape of a square, rectangle, or parallelogram. The cross-section varies in the X direction but still has a constant shape along the overall length of the suspension box 28, thus allowing for better discharge of the load inside the suspension box. In other words, the cross-section of the suspension box 28 does not suddenly change shape. Preferably, the cross-section gradually narrows when extending forward and backward from the middle part of the box. The rib 36c for a part of the suspension box is located in this middle part, or behind the middle part.

[0048] The engine 10 is fixed to the suspension box 28 in a conventional manner, which will now be briefly described. An engine front fitting 9a is provided to connect the front closing rib 36a to the fan casing 11 of the engine or to the casing ring 11' of the intermediate casing. An engine rear fitting 9b connected to the casing 13 is also provided, and engine gases are ejected through the casing 13 to the bottom part of the suspension box 28. Preferably, the body of the engine rear fitting 9b is fixed to the lower spar 32 and near the bottom end of the internal lateral reinforcing rib 36c, thereby facilitating a more direct load path between the engine and the wing. In addition, the two engine fittings 9a, 9b are complemented by two conventional linkages 9c to react to the thrust load, and these linkages 9c connect the base 15 of the intermediate casing to the body of the engine rear fitting 9b.

[0049] These engine fittings 9a, 9b, 9c are produced in a conventional manner known to those skilled in the art. They jointly form a statically determinate or nearly statically determinate load reaction system, just like the device specifically defined in the present invention for fixing the suspension box 28 to the wing box 14, and will now be described with reference to Figures 2 to 5 be described.

[0050] In the present text, these fixtures are formed by two side front fittings 42, a rear fitting 44 and an intermediate front fitting 43.

[0051] The two side front fittings 42 have the same or similar design and are arranged substantially symmetrically with respect to the above-mentioned plane P' and are inclined with respect to the intermediate plane XZ of the assembly 1, the intermediate plane XZ being Figure 3 marked as "P" in the [description]. Therefore, only one of the two side front fittings 42 will now be described.

[0052] The side front fitting 42 is designed to react to loads in the Z direction. Firstly, the side front fitting 42 has a first connecting portion 46. Preferably, the first connecting portion 46 is formed by a connecting member in the form of a bracket, which bracket includes a first bottom surface 46a fixed and pressed against the front spar 16 and a second bottom surface 46b fixed and pressed against the suction surface skin 20. Preferably, the first bottom surface 46a is substantially parallel to the plane P'. Fixing is effected by means of fixing means 50a corresponding to conventional means of the bolt, rivet or similar element type.

[0053] The connecting member 46 is made in one piece and is entirely arranged in the leading edge region 25. The connecting member 46 also has two flank portions 80 arranged substantially orthogonally to the front spar 16. As will be described in detail below, these flank portions 80 serve as reinforcing ribs at the angle between the two bottom surfaces 46a, 46b and also as stops.

[0054] The connecting member 46 extends over a large part of the height of the front spar 16, or even over the whole of the front spar 16, in order to reduce the load at each fixing element 50a.

[0055] The side front fitting 42 also includes a second connecting portion 52, which second connecting portion 52 is part of a rib 36c made in one piece. The second connecting portion 52 is in the form of an eyelet, or in the form of a plurality of eyelets stacked and / or spaced apart, in order to ensure a safety function in the event of a failure, such a function generally being referred to as fail-safe. In the depicted embodiment, there are three eyelets 52 spaced apart from one another. Each eyelet 52 projects laterally and upwards from the hanger box 28 such that the end portion of said eyelet is received in the leading edge region 25.

[0056] In order to connect the two parts 46, 52, the side front fitting 42 includes at least one fixing member in the form of a shackle 54. Here, only one shackle 54 is provided with a double bottom end in order to ensure the fail-safe function.

[0057] The shackle 54 extends generally parallel to the Z direction. The shackle 54 has a top end of the lug hinged to the connecting member 46 by a first pin system 56, and the first pin system 56 has a specific feature oriented generally parallel to the front spar 16. This enables the first pin system 56 to be moved as close as possible to the front spar. The side wings 80 of the connecting member carry the first pin system 56, so that the connecting member 56 can be more compact in the X direction.

[0058] In addition, the reduction in the thickness of the connecting member 46 enables the offset of the load introduced into the front spar 16 to be reduced. Therefore, the connecting member no longer requires a specific size to withstand the cantilever effect - as is known, the cantilever effect is likely to introduce bending moments into the connecting member and the front spar 16, which helps to further reduce the thickness of the connecting member.

[0059] These measures are aimed at aligning all the elements constituting the front fitting 42 in a continuous plane generally parallel to the plane P'. These measures ensure a compact design in the X direction, enabling a larger volume to be provided in front of the side front fitting 42 in the leading edge region 25 for the installation of systems and equipment 72, as Figure 2 schematically shown for one of the systems and equipment 72. These systems and equipment can be, for example, de-icing elements, fuel ducts, hydraulic control lines or movable flap actuating members of the leading edge.

[0060] Finally, it should be noted that due to the side front fittings 42 installed in the leading edge region 25, the overall dimensions of the assembly 1 are reduced in the Z direction. This allows the assembly 1 to define a sufficiently high hanger box 28 in the Z direction to support an engine with a larger diameter while maintaining a satisfactory ground clearance.

[0061] Furthermore, the bottom end of the shackle 54 is hinged to the lug 52 by a second pin system 58, and the second pin system 58 is oriented generally orthogonal to the plane P' of the front spar 16. Therefore, the second pin system 58 is inclined at 90° with respect to the first pin system 56.

[0062] It is clearly visible from the above that the lugs 52 of the two side front fittings 42 are made of a single part formed by the internal rib 36c. The rib 36c has a lower bottom surface 60 fixed to the lower spar 32 of the hanger box, and two opposite lower side surfaces 59 respectively fixed to the two opposite side panels 34. The lugs 52 are located in the continuation of the two opposite lower side surfaces 59. Finally, the rib 36c includes an upper bottom surface 61 fixed to the upper spar 30 inside the hanger box 28. Therefore, the two side fittings 42 are closely fitted by sharing the internal rib 36c with each other, thereby allowing the reaction to the load associated with the torque applied around the X direction.

[0063] Alternatively, the lug 52 can be made independently of the rib 36c and attached to the outside of the hanger box 28 at the upper edge corners of the hanger box 28. In this case, the lugs 52 are likewise respectively located in the continuations of the two opposite lower side faces 59 of the rib 36c and aligned with the two opposite lower side faces 59 of the rib 36c, which rib 36c, like the other ribs 36, is located inside the hanger box 28.

[0064] The intermediate front fitting 43 includes the shear pin 74 illustrated in Figure 5 which is oriented in the Z direction and fixed to the connecting member attached to the hanger box and in line with the rib 36c. The shear pin 74 cooperates with the connecting member 76 attached below the pressure surface skin 22.

[0065] The intermediate front fitting 43 is preferably arranged in the same transverse plane as the two side front fittings 42 and is designed to react against the shear loads known to be applied in the Y and X directions. This reaction occurs at or in the plane defined by the lower pressure surface skin. In the event of a failure of this fitting 43, the two side front fittings 42 can react against the loads in the Y direction through the shackles 54 and the connecting members 42. In particular, the top end of each shackle 54 is slidably mounted on its pin system 56 and arranged between the two side wings 80 of the connecting member 46 supporting the system. Only a small clearance is maintained in the span direction between each shackle 54 and each of the two side wings 80 associated with the shackle 54. Thus, in the event of a failure of the intermediate front fitting 43, the side wings 80 are configured to prevent translational movement of the shackle 54 in the span direction. Preventing said translational movement can thus ensure a fail-safe function with respect to reacting against loads in the Y direction.

[0066] Finally, the rear fitting 44 has a conventional design and is provided with a triangular shackle 82 that cooperates with the rear closing rib 36b of the hanger box 28. The triangular shackle is designed to react against loads in the Y and Z directions, thereby allowing the fittings 42, 43, 44 to form a statically determinate or nearly statically determinate load reaction system.

[0067] Of course, those skilled in the art can make various modifications to the present invention, which is only described by way of non-limiting examples, and the scope of the present invention is defined by the appended claims.

Claims

1. A component (1) for an aircraft, the component comprising: An aircraft wing (2), the wing comprising a wing box (14), the wing box being formed in part by a front spar, an upper suction surface skin (20), and a lower pressure surface skin (22); An engine attachment pylon (4), the pylon being arranged below the wing (2) and comprising a main structural member in the form of a pylon box, the main structural member having an upper spar (30), the upper spar at least partially extending below the wing box (14), and A fixing device for fixing the main structural member (28) of the attachment pylon to the wing box (14), Wherein the fixing device comprises two side front fittings (42), each of the side front fittings comprising: A first connection part (46), the first connection part being fixed to the front spar (16); A second connection part (52), the second connection part being fixed to the main structural member (28) of the attachment pylon; At least one fixing member connecting the first connection part and the second connection part, the at least one fixing member being hinged to the first connection part (46) by a first pin system (56), the first pin system being oriented generally parallel to the front spar (16), Wherein the at least one fixing member is hinged to the second connection part (52) by a second pin system (58), the second pin system (58) being oriented generally orthogonal to the front spar (16).

2. The component according to claim 1, wherein, Each of the fixing members is arranged generally parallel to the vertical direction (Z) of the component.

3. The component according to claim 1 or claim 2, wherein Each of the first connection parts (46) is a connector in the form of a bracket, the connector being fixed to both the front spar (16) and the upper suction surface skin (20) simultaneously, and the connector in the form of the bracket being entirely arranged in the leading edge region (25) of the wing.

4. The component according to claim 1 or claim 2, wherein, The two second connection parts (52) are integrally formed with an internal transverse stiffening rib (36c) of the main structural member (28), and the two second connection parts (52) project outward from the main structural member.

5. The component according to claim 1 or claim 2, wherein The fixing device further comprises an intermediate front fitting (43), the intermediate front fitting (43) being configured to react to loads applied in the lateral direction (Y) and the longitudinal direction (X) of the component.

6. The component according to claim 5, wherein, Each of the first connection parts (46) comprises two side wings (80), the side wings (80) carrying the first pin system (56) and having the at least one associated fixing member arranged therebetween, the side wings being configured to: prevent the at least one fixing member from translating in the direction of the first pin system (56) in the event of a failure of the intermediate front fitting (43).

7. The component according to claim 1 or claim 2, the component comprising at least one equipment part arranged in the leading edge region (25) of the wing and in front of the side front fitting (42).

8. The component according to claim 1 or claim 2, wherein Each of the said front side fittings (42) is designed to allow reaction to a load applied in the vertical direction (Z) of the said assembly.

9. The component according to claim 1 or claim 2, wherein, The said fixing means further includes a rear fitting (44) which is fixed to the rear closing rib (36b) of the said main structural member (28).

10. The component according to claim 1 or claim 2, wherein, The said fixing means forms a statically determinate load reaction system.

11. The component according to claim 4, wherein Two of the said second connecting portions (52) penetrate partially into the leading edge region (25) of the said wing.

12. The component according to claim 5, wherein, The said intermediate front fitting (43) includes a shear pin (74).

13. The component according to claim 9, wherein, The said rear fitting (44) is designed to allow reaction to a load applied in the vertical direction (Z) of the said assembly and in the lateral direction (Y) of the said assembly.

14. An aircraft (100) comprising at least one assembly (1) according to any one of claims 1 to 13.

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