PASSENGER DOOR FRAME MODULE CONFIGURED TO BE CONNECTED TO AN AIRCRAFT FUSELAGE SKIN

Abstract

A frame module (M1) for a passenger door frame (5) configured to be connected to a skin (2) of an aircraft fuselage (1) (A), the frame module (M1) comprising a one-piece main body (6) having at least one corner portion (6d, 6e) curved at an angle between 70° and 110° so as to ensure the transition of forces between an upper and a lateral portion of the frame (5), the one-piece main body (6) having an open section defining an inner wall (P1), an outer wall (P2) and a connecting wall (P3) connecting the inner wall (P1) to the outer wall (P2), the inner wall (P1) having an inner tab (61) and the outer wall (P2) having an outer tab (62) configured to be fixed to the skin (2) so as to form a box with an inner cavity. Abstract figure: Figure 2

Description

Title of the invention: PASSENGER DOOR FRAME MODULE CONFIGURED TO BE CONNECTED TO A SKIN OF AN AIRCRAFT FUSELAGE technical field

[0001] The present invention relates to the field of manufacturing the structure of an aircraft, in particular, a frame for a passenger door of an aircraft.

[0002] In a known manner, with reference to [Fig. 1], an aircraft A comprises a fuselage 1 extending longitudinally along an axis X oriented from rear to front. The fuselage 1 has a skin 2 defining the outer surface of the aircraft A, which may be of the single or double curvature type. To allow passengers to enter and exit, the skin 2 has an opening 20, called the "exterior opening." The exterior opening 20 is configured to be closed by a passenger door (not shown) separating the aircraft's exterior environment EXT from its interior environment INT. The exterior opening 20 has an axis RP that is radial with respect to the longitudinal axis X, which is oriented from the interior INT to the exterior EXT.

[0003] The fuselage 1 further comprises an assembly of longitudinal stiffeners 11, called "strings," and transverse stiffeners 12, called "frames," which are fixed to the skin 2, as well as a door frame 105, hereinafter referred to as the "frame," to stiffen the circumference of the external opening 20 formed in the skin 2 and to resist the forces. In practice, a passenger door induces, at the level of the frame 105, forces that are primarily radial and directed outwards from the aircraft A, which are resisted by stops provided at the level of the frame 105.

[0004] In a known manner, a frame 105 comprises an edge frame having an upper longitudinal stiffener called a lintel, a lower longitudinal stiffener called a sill, vertical stiffeners on either side of the exterior opening 20 and connected to the longitudinal stiffeners. In addition, the frame 105 comprises a secondary frame consisting of at least two vertical stiffeners arranged on either side of the opening at a certain distance and two upper and lower longitudinal stiffeners located away from the lintel and the sill and connected to the vertical stiffeners. The frame 105 also includes ribs or reinforcements to connect the outer frame and the secondary frame. These ribs, known as intercostal ribs, form a ladder-like structure on either side of the outer opening 20, allowing for the diffusion of force flows within the skin. Such a ladder-like frame is described in patent application WO03 / 104080A1.

[0005] In practice, the numerous frame components are mounted in an individual manner This individual and sequential process requires significant assembly time and complicates any increase in production rate. Furthermore, it increases the weight and cost of such a frame.

[0006] Patent application WO2011 / 002081 proposed replacing the vertical stiffeners of the edge frame and secondary frame with a box-section structure comprising three composite walls connected together. In practice, connecting a box-section structure to the longitudinal stiffeners (threshold, lintel) is complex to implement, as it requires a precise connection at each end of the longitudinal stiffeners with a skin having a single or double curvature. Such a connection increases assembly time. Furthermore, the load transfer between the vertical and longitudinal structures is not optimal, as it is necessary to provide reinforcements or additional thickness at the interfaces (door corners), which increases the weight.Furthermore, the drainage of stresses at the door corners is not optimal, which generates thermal fatigue problems and necessitates the use of expensive materials.

[0007] The invention thus aims to eliminate at least some of these disadvantages by proposing a passenger door frame requiring little assembly. PRESENTATION OF THE INVENTION

[0008] The invention relates to a frame module for a passenger door frame configured to be connected to a skin of an aircraft fuselage, the skin having an external opening configured to be closed by a passenger door, the external opening having a circumference comprising an upper part, two opposing lateral parts and two corner parts connecting the upper part to the two lateral parts respectively, the frame module comprising: • a one-piece main body comprising at least one corner part configured to stiffen a corner part of the circumference of the external opening, the corner part being curved at an angle between 70° and 110° so as to ensure the transition of forces between an upper part and a lateral part of the frame, • the main one-piece body comprising an open section defining an inner wall, an outer wall and a connecting wall linking the inner wall to the outer wall, the inner wall comprising an inner tongue and the outer wall comprising an outer tongue configured to be fixed to the skin so as to form a box with an inner cavity.

[0009] A curved, one-piece main body allows for optimal drainage of the forces received by an upper and / or lateral part of the frame. In addition The reduced number of parts eliminates the need for complex connection operations between the lateral and longitudinal stiffeners of a frame, as required by prior art. Furthermore, the overall box-like shape effectively channels and distributes torsional forces optimally, allowing them to be absorbed within the fuselage. This also optimizes the thickness of the structure to reduce mass.

[0010] Advantageously, such a frame module can be manufactured remotely from the assembly site, thereby accelerating aircraft assembly rates. By reducing the number of interfaces, the number of parts and the mass are advantageously reduced. Furthermore, this avoids the need for multiple bulky assembly stations.

[0011] A curved, one-piece main body also avoids the need for additional thickness or the use of expensive materials to improve load transfer. By improving load transmission, a force received on an upper part of the frame can be optimally transmitted to a lateral part of the frame (and vice versa).

[0012] Preferably, the main one-piece body includes at least one lateral part configured to stiffen a lateral part of the circumference of the outer opening.

[0013] This optimally allows the forces to be drained between a corner part and a lateral part.

[0014] Preferably, the frame module includes a plurality of stop members configured to come into contact with the passenger door, the stop members being fixed to the lateral part of the main one-piece body.

[0015] The thrust forces are thus drained by the main monobloc body and distributed optimally.

[0016] Preferably, the stop members are fixed to the inner wall of the side portion of said main body. Preferably, the stop members are fixed to the inner wall of the side portions of said main body so as to protrude into the outer opening to cooperate with the passenger door in the closed position.

[0017] According to a preferred aspect, the framing module comprises a plurality of reinforcing members housed within the internal cavity of the monobloc main body and connected to said monobloc main body, one reinforcing member being positioned opposite each abutment member to absorb its forces. Such a reinforcing member makes it possible to dissipate abutment forces while being integrated within the internal cavity.

[0018] Preferably, each reinforcing member is fixed to the stop member with which it is positioned opposite in order to allow transmission of the stop forces.

[0019] Preferably, each reinforcing element has a belt-like shape connected to the inner and outer walls. This double connection allows the reinforcing element to dissipate stresses evenly throughout the main monolithic body, thereby reducing its structural weight. The reinforcing element 9 could also have an "I" shape for connecting the inner and outer walls.

[0020] According to one aspect of the invention, each reinforcing element comprises tabs fixed to the connecting wall of the monobloc main body. A connection to each wall of the monobloc main body allows the reinforcing element to dissipate stresses optimally within the monobloc main body, thereby reducing its structure.

[0021] Preferably, the main one-piece body includes at least one upper part configured to stiffen an upper part of the circumference of the outer opening.

[0022] This optimally allows the forces to be drained between a corner part and an upper part.

[0023] Preferably, the frame module includes connecting elements mounted in the internal cavity of the upper part of the main one-piece body configured to be fixed respectively to transverse stiffeners connected to the skin.

[0024] The use of such connecting elements makes it possible to drain the thrust forces also into the upper stiffeners by taking advantage of the box shape of the lintel.

[0025] Preferably, the main one-piece body comprises at least two corner parts configured to stiffen two corner parts of the circumference of the outer opening, each corner part being curved at an angle between 70° and 110° so as to ensure the transition of forces between an upper part and a lateral part of the frame.

[0026] A single-piece main body with an inverted U-shape optimally drains the forces received towards the skin, in particular, towards the transverse stiffeners. Besides reducing the number of parts, this eliminates all the necessary connecting operations between the lateral and longitudinal stiffeners of a frame, as in the prior art.

[0027] Preferably, the frame module also includes a lower portion forming the threshold, which is configured to stiffen a lower portion of the circumference of the outer opening. Preferably, the one-piece main body has a peripheral shape that absorbs the forces applied to the periphery of the outer opening. The number of parts required to form the frame is further reduced.

[0028] Preferably, the lower end of the lateral part of the main body monobloc is presented in the form of a fork having at least two teeth in order to allow a practical connection with the transverse stiffeners connected to the skin.

[0029] Preferably, the tines of a fork are configured to be fixed respectively to two transverse stiffeners connected to the skin. In other words, the forces applied to each lateral part of the main monobloc body are dissipated in two transverse stiffeners connected to the skin, which allows for efficient drainage and makes it possible to lighten the frame structure.

[0030] The invention relates to a passenger door frame configured to be connected to a skin of an aircraft fuselage, the skin having an external opening configured to be closed by a passenger door, the external opening having a circumference comprising an upper part, two opposing lateral parts and two corner parts connecting the upper part to the two lateral parts respectively, the frame comprising at least one frame module as previously described.

[0031] Preferably, the frame includes at least one auxiliary module having at least one lateral part configured to stiffen a lateral part of the circumference of the external opening, the auxiliary module being connected to at least one frame module.

[0032] Preferably, the auxiliary module is a single unit.

[0033] According to one aspect of the invention, the frame includes a lower longitudinal stiffener configured to stiffen a lower portion of the circumference of the outer opening, referred to as the threshold stiffener, which is mounted as an add-on. Due to the one-piece structure of the main body, the mounting space for the lower longitudinal stiffener is precisely defined, and the stiffener can be conveniently mounted. This add-on mounting provides flexibility during installation.

[0034] The invention also relates to an assembly comprising an aircraft fuselage skin, the skin having an external opening configured to be closed by a passenger door, and a passenger door frame module, as previously described, the inner and outer tabs of which are connected to the skin so as to form a box with an internal cavity.

[0035] The invention also relates to a method for mounting a frame module, as described above, on the skin of an aircraft fuselage, the skin having an external opening configured to be closed by a passenger door and transverse stiffeners, the method comprising steps consisting of • Attach the inner and outer tabs to the skin, then • Connect the frame module to the transverse stiffeners

[0036] Such an assembly allows the frame to be pre-assembled in order to define in a way its overall position. The frame can then be precisely mounted to the skin to allow for precise assembly, guaranteeing optimal stress distribution. PRESENTATION OF THE FIGURES

[0037] The invention will be better understood upon reading the following description, given by way of example, and referring to the following figures, given by way of non-limiting examples, in which identical references are given to similar objects.

[0038] Fig. 1 is a schematic representation of an aircraft fuselage according to the prior art.

[0039] Fig. 2 is a schematic representation of a passenger door frame comprising a one-piece frame module according to an embodiment of the invention, mounted on the fuselage of an aircraft.

[0040] Fig. 3 and Fig. 4 are further schematic representations of the passenger door frame of Fig. 2.

[0041] Fig. 5 is a schematic representation of a door frame with the passenger door in the open position.

[0042] Fig. 6 is a schematic representation of a door frame with the passenger door in the closed position.

[0043] The [Fig.7] is a schematic representation of a section of a main body of a one-piece door frame module.

[0044] Figures 8 and 9 are schematic representations of other embodiments of a one-piece door frame module

[0045] The [Fig. 10] is a schematic representation viewed from inside a stop member and a reinforcement member mounted on the main body.

[0046] Fig. 11 is a schematic representation of a stop member and a reinforcement member without the main body.

[0047] The [Fig. 12] is a schematic representation viewed from the outside of a stop member and a reinforcement member mounted on the main body.

[0048] The [Fig. 13] is a schematic representation of a connecting element linked to a transverse stiffener.

[0049] Fig. 14 is a schematic representation of an exploded view of a door frame.

[0050] Fig. 15 is a representation of a one-part door frame.

[0051] Fig. 16 is a representation of a two-part door frame.

[0052] Fig. 17 is a representation of a three-part door frame.

[0053] Fig. 18 is a representation of a four-part door frame.

[0054] It should be noted that the figures explain the invention in detail to put into works the invention, the said figures being of course able to better define the invention where appropriate. DETAILED DESCRIPTION OF THE INVENTION

[0055] With reference to [Fig. 2] representing the forward tip of an aircraft A, the aircraft A extends longitudinally along an axis X and comprises a fuselage 1 including a skin 2 which includes an external opening 20 allowing a passenger of the aircraft A to move between an interior environment INT and an exterior environment EXT of the aircraft A. The external opening 20 is configured to be closed by a passenger door P ([Fig. 6]) and has a circumference. The external opening 20 has an axis RP which is radial with respect to the longitudinal axis X and which is oriented from the interior INT to the exterior EXT.

[0056] In order to stiffen the skin 2, which may have a single curvature or a double curvature, the fuselage 1 has longitudinal stiffeners 11 extending along the X axis, called "strings", and transverse stiffeners 12 extending transversely to the X axis, called "frames", which are fixed to the skin 2. The external opening 20 forms a discontinuity in the transverse stiffeners 12. Preferably, the longitudinal stiffeners 11 and transverse stiffeners 12 are made of composite material but they could be made of metal.

[0057] In order to stiffen the outer opening 20 and to allow the mechanical forces induced by the passenger door P during the pressurization of the interior environment INT to be absorbed, the fuselage 1 further includes a door frame 5, hereafter referred to as "frame 5".

[0058] According to the invention, with reference to figures 2 to 4, the frame 5 comprises a frame module M1 which includes a main one-piece body 6 defining two lateral parts 6a, 6b configured to stiffen two opposite lateral parts of the circumference of the outer opening 20 and at least one upper part 6c configured to stiffen an upper part of the circumference of the outer opening 20.

[0059] The main one-piece body 6 has an open section defining a base, two arms and an open cavity facing the skin 2, the arms having free fixing ends configured to be fixed to the skin so as to form a box with an internal cavity as will be shown in detail in [Fig.5].

[0060] In this embodiment, with reference to Figures 3 to 4, the framing module comprises a single-piece main body 6 in the form of an inverted U to frame the lateral parts, the corner parts, and the upper part of the external opening 20 in order to stiffen it. Given that the main body monobloc 6 has a monobloc structure, it is no longer necessary to carry out operations in aircraft A to connect together the vertical and longitudinal elements of the frame 5, which ensures a saving of time and allows to significantly improve the transfer of forces between the lateral parts and the upper part.

[0061] In this embodiment, the frame 5 and the frame module M1 are identical. Other embodiments of the frame 5 will be shown in Figures 16 to 18.

[0062] A frame 5 with a box-shaped lintel is advantageous because it ensures continuity and homogeneity in the transmission of forces, particularly those generated by the passenger door P. This significantly reduces the number of parts that need to be installed in situ in the aircraft A. Thanks to the invention, the main one-piece body 6 of the frame 5 can be manufactured at a remote location and quickly assembled onto the skin 2 of the aircraft A. Such a frame 5 significantly improves the production rates of an aircraft A.

[0063] The two corner portions 6d, 6e ensure optimal force transfer between the lateral portions 6a, 6b and the upper portion 6c due to their monolithic nature. Preferably, each lateral portion 6a, 6b of the main body 6 is configured to completely stiffen one lateral edge of the circumference of the outer opening 20, that is, along its entire height. Even more preferably, the upper portion 6c extends along the entire length of the upper edge of the circumference of the outer opening 20.

[0064] Preferably, the one-piece main body 6 is made of composite material, in particular from reinforcing fibers embedded in a thermoplastic matrix. The one-piece main body 6 thus has a lightweight and robust structure.

[0065] In this example, with reference to [Fig. 6], the monolithic main body 6 comprises three walls: an inner wall PI, an outer wall P2, and a connecting wall P3 linking the inner wall PI to the outer wall P2. The inner wall PI is located near the outer opening 20 and is preferably orthogonal to the skin 2 or inclined with respect to it. The outer wall P2 is radially external to the inner wall PI, at a distance from the outer opening 20. The outer wall P2 is here orthogonal to the skin 2 but could also be inclined. The connecting wall P3 is preferably parallel to the skin 2. The monolithic main body 6 thus has a U-shaped or omega-shaped cross-section.

[0066] Preferably, with reference to [Fig. 5], the inner wall PI comprises an inner tab 61 intended to bear flat against the skin 2 and fixed to the latter, for example, by riveting / welding / co-consolidation or otherwise. By conso In the context of pressure bonding, pressure is applied to layers of composite material at a temperature exceeding 400°C. Co-consolidation refers to the joining of two parts by consolidation using a press or local tooling. Similarly, the outer wall P2 includes an outer tab 62 designed to bear flat against the skin 2 and fixed to it. Referring to [Fig. 5], the inner tab 61 and the outer tab 62 project towards each other, i.e., beneath the bonding wall P3. In an alternative, the inner tab 61 and the outer tab 62 project towards each other and join to form a single tab 63, as illustrated in [Fig. 8]. It goes without saying that the inner tongue 61 and the outer tongue 62 could also extend in projection opposite each other as illustrated in [Fig.9].In this variant, the inner tongue 61 and the outer tongue 62 are not located opposite the connecting wall P3.

[0067] With reference to Figures 3 and 4, the frame module M1 includes stop members 8 against which the passenger door P can bear, in particular to ensure the absorption of outwardly directed forces EXT as illustrated in [Fig. 6]. These stop members 8 are preferably positioned at the lateral parts 6a, 6b of said monobloc main body 6.

[0068] In this example, with reference to Figures 5 to 7, the stop members 8 are fixed to the inner wall PI of the lateral parts 6a, 6b of said main body 6 and extend projecting towards the outer opening 20. Due to its monobloc structure, the forces are distributed throughout the monobloc main body 6, which can thus have a lightweight structure. It is not necessary to reinforce the joint areas as in the prior art.

[0069] As illustrated in Figures 10 and 11, a stop member 8 comprises a base 80 fixed to the inner wall PI and projecting inward into the outer opening 20 in order to cooperate with a passenger door P in the closed position. The stop member 8 also comprises a contact surface 81 intended to come into contact with the passenger door P in the closed position. The contact surface 81 is substantially orthogonal to the door axis RP.

[0070] In order to allow optimal transmission of forces to the monobloc main body 6, with reference to Figures 10 and 11, the frame 5 comprises a plurality of reinforcing members 9 housed within the cavity of the monobloc main body 6. Preferably, a reinforcing member 9 is positioned opposite each stop member 8 to absorb its forces. In other words, each stop member 8 is associated with a reinforcing member 9. It is understood, however, that the number of reinforcing members 9 could be greater to locally increase mechanical strength.

[0071] In this example, the stop member 8 and the reinforcing member 9 are connected together, in particular, via the inner wall PI of the main body 6. Thus, the thrust forces are optimally transmitted from the thrust member 8 to the reinforcement member 9.

[0072] In this example, the reinforcing member 9 has a belt shape connected to the inner wall PI and the outer wall P2 to allow the transmission of forces received by the stop member 8 to several walls PI, P2 of the monobloc main body 6. Preferably, with reference to [Fig. 11], the reinforcing member 9 comprises four walls: a front wall RI in contact with the inner wall PI, a rear wall R2 in contact with the outer wall P2, and two side walls R3, R4. In this example, the side walls R3, R4 have tabs 91 for attachment to the connecting wall P3 of the main body 6 to allow the transmission of forces received by the stop member 8 to all the walls PI, P2, P3 of the monobloc main body 6. The distribution of forces is thus optimal. The reinforcing member 9 could also have an "I" shape.

[0073] Preferably, the tabs 91 extend between the inner wall PI and the outer wall P2 of the main body 6. [Fig.7] schematically represents the mounting of a reinforcing member 9 and a stop member 8 in a lateral part 6a of the one-piece main body 6. In this figure, the black dots represent connections which can be of different kinds, for example, by riveting / welding / co-consolidation or other.

[0074] In one configuration, the connecting wall P3 of the monobloc main body 6 is open at the reinforcing members 9 in order to limit the mass of the monobloc main body 6 in a reinforced area and to allow the connection of the monobloc main body 6 with the reinforcing member 9. This also facilitates access for repair or maintenance. It can also be positioned on walls PI and P2.

[0075] In an embodiment not shown, the frame 5 further comprises a lower longitudinal stiffener, designated threshold stiffener, which is mounted in a manner attached to the one-piece main body 6 at the lower edge of the circumference of the outer opening 20. Advantageously, due to the one-piece nature of the main body 6, the spacing between the lateral parts 6a, 6b of the main body 6 is perfectly defined and the mounting of a threshold stiffener is convenient for operators.

[0076] According to one embodiment of the invention, the one-piece main body 6 also includes a lower portion forming the threshold. In other words, the one-piece main body 6 has a peripheral shape to completely rigidify the circumference of the outer opening 20.

[0077] In this example, with reference to Figures 3 and 4, each lower end of a lateral part 6a, 6b of the main one-piece body 6 is presented in the form of a In particular, a fork 63a, 63b has two tines. A slot is formed at the lower end of each lateral part 6a, 6b so that each tine can be conveniently connected to a transverse stiffener 12 located under the frame 5, as illustrated in [Fig. 2]. Specifically, the inner wall P1 of a fork 63a, 63b is connected to a first transverse stiffener 12, while the outer wall P2 of said fork 63a, 63b is connected to a second transverse stiffener 12. This improves the transmission of forces between the frame 5 and the skin 2 and its stiffeners 12.

[0078] As illustrated in Figures 13 and 14, the frame 5 further comprises connecting members 4 mounted in the internal cavity of the upper part 6c of the main body 6, i.e., in the part forming the lintel. The connecting members 4 are positioned opposite the transverse stiffeners 12, called "frames," located above the frame 5 so as to ensure optimal transmission of forces between the frame 5 and the transverse stiffeners 12.

[0079] Each connecting member 4 comprises a lower wall SI in contact with the inner wall PI, an upper wall S2 in contact with the outer wall P2, and a side wall S3 connecting the lower wall SI to the upper wall S2. The lower wall SI is connected to the inner wall PI, while the upper wall S2 is connected to the outer wall P2. The transverse stiffeners 12 are connected to the upper wall S2 via the outer wall P2 so as to ensure optimal load transfer between the door frame 5 and the transverse stiffeners 12, and to allow the transmission of forces between the upper part 6c and the transverse stiffeners 12 located above the frame 5.

[0080] With reference to [Fig. 12], the side portions 6a, 6b and the upper portion 6c of the main monobloc body 6 have through-openings in one of the connecting walls P3 to allow access for inspection and maintenance. Depending on certain configurations, connecting openings may be present in walls P1 and / or P2.

[0081] An example of the implementation of a method for mounting a door frame module Ml will now be presented.

[0082] First, the longitudinal stiffeners 11 and the transverse stiffeners 12 are fixed to the inner face of the skin 2 including the outer opening 20.

[0083] Preferably, the door frame 5 is pre-assembled at a remote location, away from the mounting location. The one-piece main body 6 is made of a single piece, in particular, of composite material. The reinforcing members 9, the stop 8, and the connecting members 4 are preferably assembled to the one-piece main body 6 so as to form a pre-assembled frame module M1 that can be mounted directly to the aircraft A, i.e., at the mounting location.

[0084] According to a particular aspect, the reinforcing members 9 could be formed with the main one-piece body 6, for example, by a co-consolidation process, overinjection, welding or riveting.

[0085] During assembly, the frame 5 is connected to the skin 2 by joining the inner tongue 61 and the outer tongue 62, and then connected to the transverse stiffeners 12, in particular, via the connecting members 4 and the forks 63a, 63b. This ensures optimal alignment of the frame 5. The threshold can then be attached to the frame 5.

[0086] Thanks to the invention, the assembly of a frame 5 is practical and can be largely carried out at a remote location, thus accelerating assembly rates at the assembly site. The use of reinforcing elements 9 improves the transfer of forces from the stop elements 8, which are thus optimally transferred to the skin 2 and the longitudinal stiffeners 11. Due to its monobloc structure, the main monobloc body 6 acts as a torsion box and, overall, captures the various forces to which the external opening 20 is subjected and distributes them evenly throughout the fuselage 1.

[0087] The time saved at the assembly site is estimated at at least 50% compared to traditional framing. Furthermore, the number of part numbers required for assembly is significantly reduced.

[0088] As illustrated in [Fig.15], a frame 5 comprising a single frame module Ml having a monobloc main body 6 having successively a lateral part 6a, a corner part 6d, an upper part 6c, a corner part 6e and a lateral part 6b was previously presented. Thus, the frame 5 and the frame module Ml according to the invention are identical.

[0089] According to another embodiment, with reference to [Fig. 16], the frame 5 may comprise a first frame module M2 and a second frame module M3 which are attached together. The first frame module M2 has a side portion 6a, a corner portion 6d, and a portion of the upper portion 6c1. The second frame module M3 has a side portion 6b, a corner portion 6e, and a portion of the upper portion 6c2. The two frame modules M2 and M3 may have similar shapes within a single curvature (standard section) or non-similar shapes within a double-curvature leading edge area. A two-part frame 5 facilitates the formation of the two frame modules M2 and M3 by requiring only smaller manufacturing equipment compared to a one-part frame 5.

[0090] According to another embodiment, with reference to [Fig. 17], the frame 5 may include a frame module M4 comprising a corner part 6d, a upper part 6c and a corner part 6e, as well as two auxiliary modules MA, MB. The first auxiliary module MA corresponds to the side part 6a and is preferably a single piece. Similarly, the second auxiliary module MB corresponds to the side part 6b and is preferably a single piece. According to an alternative, with reference to [Fig. 18], instead of a single framing module M4, this could be made in two parts to include, on the one hand, a first framing module M5 comprising a corner part 6d and a portion of the upper part 6c1 and, on the other hand, a second framing module M6 comprising a corner part 6e and a portion of the upper part 6c2 as illustrated in [Fig. 18].

[0091] A multi-module frame 5 allows the modules to be manufactured with less complex and expensive equipment. The assembly of the frame 5 remains simple and practical. In all embodiments, the frame 5 comprises at least one frame module with a main body defining at least one corner portion, which optimizes the transfer of forces between the upper and longitudinal portions of the frame 5, without the need for connecting elements that are complex to assemble, heavy, and bulky.

Claims

Claims

1. Framing module (M1-M6) for a passenger door frame (5) configured to be connected to a skin (2) of an aircraft fuselage (1) (A), the skin (2) comprising an external opening (20) configured to be closed by a passenger door (P), the external opening (20) having a circumference comprising an upper part, two opposite lateral parts and two corner parts respectively connecting the upper part to the two lateral parts, the framing module (M1-M6) comprising: • a single-piece main body (6) comprising at least one corner part (6d, 6e) configured to stiffen a corner part of the circumference of the external opening (20), the corner part (6d, 6e) being curved at an angle of between 70° and 110° so as to ensure the transition of forces between an upper part and a lateral part of the frame (5),• the main one-piece body (6) comprising an open section defining an inner wall (PI) defined relative to the outer opening (20), an outer wall (P2) defined relative to the outer opening (20) and a connecting wall (P3) connecting the inner wall (PI) to the outer wall (P2), the inner wall (PI) comprising an inner tab (61) and the outer wall (P2) comprising an outer tab (62) configured to be fixed to the skin (2) so as to form a box with an inner cavity when it is fixed to the skin (2).,

2. Framing module (M1-M6) according to claim 1, wherein the one-piece main body (6) comprises at least one lateral portion (6a, 6b) configured to stiffen a lateral portion of the circumference of the external opening (20).

3. Frame module (M1-M6) according to claim 2, comprising a plurality of stop members (8) configured to come into contact with the passenger door (P), the stop members being fixed to the lateral part (6a, 6b) of the main one-piece body (6).

4. Framing module (M1-M6) according to claim 3, wherein the stop members (8) are fixed to the inner wall (PI) of the lateral part (6a, 6b) of said main body (6).

5. Framing module (M1-M6) according to one of claims 3 to 4, comprising a plurality of reinforcing members (9) housed in the interior cavity of the main monobloc body (6) and connected to said main monobloc body (6), a reinforcing member (9) being positioned opposite each stop member (8) to take up its forces.

6. Framing module (M1-M6) according to claim 5, wherein each reinforcing member (9) is fixed to the stop member (8) with which it is positioned opposite.

7. Framing module (M1-M6) according to one of claims 5 to 6, in which each reinforcing member (9) has a belt shape which is connected to the inner wall (PI) and to the outer wall (P2).

8. Framing module (M1-M6) according to claim 7, in which each reinforcing member (9) comprises tabs (91) fixed to the connecting wall (P3) of the main single-piece body (6).

9. Framing module (M1-M6) according to one of claims 1 to 8, wherein the single-piece main body (6) comprises at least one upper part (6c) configured to stiffen an upper part of the circumference of the external opening (20).

10. Framing module (M1-M6) according to one of claims 1 to 9, wherein the one-piece main body (6) comprises at least two corner portions (6d, 6e) configured to stiffen two corner portions of the circumference of the outer opening (20), each corner portion (6d, 6e) being curved at an angle of between 70° and 110° so as to ensure the transition of forces between an upper portion and a lateral portion of the frame (5).

11. Passenger door frame (5) configured to be connected to a skin (2) of a fuselage (1) of an aircraft (A), the skin (2) comprising an external opening (20) configured to be closed by a passenger door (P), the external opening (20) having a circumference comprising an upper part, two opposite lateral parts and two corner parts respectively connecting the upper part to the two lateral parts, the frame (5) comprising at least one frame module (M1-M6) according to one of claims 1 to 10.

12. Frame (5) according to claim 11, comprising at least one auxiliary module (MA, MB) comprising at least one lateral part configured to stiffen a lateral part of the circumference of the external opening (20), the auxiliary module (MA, MB) being connected to at least one framing module (M1-M6).

13. Assembly comprising a skin (2) of a fuselage (1) of an aircraft (A), the skin (2) comprising an external opening (20) configured to be closed by a passenger door (P), and a passenger door (5) frame module (M1-M6), according to one of claims 1 to 10, the inner tab (61) and the outer tab (62) of which are connected to the skin (2) so as to form a box with an inner cavity.

14. Method for mounting a framing module (M1-M6) according to one of claims 1 to 10 on a skin (2) of a fuselage (1) of an aircraft (A), the skin (2) comprising an external opening (20) configured to be closed by a passenger door (P) and transverse stiffeners (12), the method comprising steps consisting of: • Connecting the inner tab (61) and the outer tab (62) to the skin (2) then • Connecting the framing module (M1-M6) to the transverse stiffeners (12).

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