FR3009542A1 - AIRCRAFT ASSEMBLY COMPRISING A ACCESS PANEL TO THE JOINTS OF A MONO SWIVEL NACELLE HOOD ON AN AIRCRAFT ENGINE HANDLING DEVICE - Google Patents

Abstract

When opening a nacelle hood (33) for an aircraft engine, an articulated end of the hood can come into contact with an aircraft engine coupling device (4) and generate undesirable mechanical stresses. This contact may in particular relate to an access panel (40b) arranged between the nacelle hood and the attachment device and whose disassembly provides access to the hinges (46b) of the hood. The invention proposes an innovative solution to this problem, which is mechanically simple and reliable and offers easy mounting / dismounting of the access panel (40b). The invention is based on the movable character of the access panel (40b) and on a mounting of this access panel pivoting about a hinge axis (54) fixed relative to the attachment device (4).

Description

BACKGROUND OF THE INVENTION The present invention relates generally to an aircraft assembly provided with an airfoil engine coupling device and a nacelle for surrounding this engine.

Such a hooking device, also known as the "EMS" ("Sliding Mounting Structure"), can equally be used to suspend an engine below the wing of the aircraft, to mount this engine above the same wing, or to bring the engine back part of the fuselage of the aircraft. It generally comprises a rigid structure on which are articulated pod covers, such as thrust reverser covers. STATE OF THE PRIOR ART Such a coupling device is in fact provided to constitute the connection interface between a motor and a wing of the aircraft. It transmits to the structure of this aircraft the forces generated by its associated engine, and also allows the flow of fuel, electrical, hydraulic, and air between the engine and the aircraft. To ensure the transmission of forces, the attachment device comprises a rigid structure also called primary structure, usually of the "box" type, that is to say formed by the assembly of upper and lower rails and panels laterally connected via transverse ribs. On the other hand, the attachment device is provided with attachment means ensuring the mechanical connection between the engine and the rigid structure, these attachment means usually comprising two engine attachments and a device for taking up the thrust forces. generated by the engine, usually formed by two lateral rods. The attachment device also comprises another series of fasteners ensuring the mechanical connection between the rigid structure and the wing of the aircraft. Furthermore, the mast is provided with a plurality of secondary structures ensuring in particular the segregation and maintenance of the systems while supporting aerodynamic fairing elements, the latter generally taking the form of panels or cowlings integrated into these same structures. In a manner known to those skilled in the art, the secondary structures are different from the rigid structure in that they are not intended to ensure the transfer of forces from the engine and to be transmitted to the wing of the aircraft. Among the secondary structures, there is a front aerodynamic structure located at the front of the rigid structure of the suspension pylon, this aerodynamic front structure having not only an aerodynamic fairing function, but also allowing the introduction, the segregation and routing of different systems (air, electrical, hydraulic, fuel). In addition, this aerodynamic front structure carries the associated engine fan cowls, while the thrust reverser cowls are generally carried by the rigid structure of the attachment pylon. In this respect, the thrust reverser covers forming an integral part of the platform are generally articulated by means of a plurality of articulations attached to the rigid structure, among which there are so-called fixed joints in the sense that they are mounted rigidly on the rigid structure of the mast, and so-called floating joints in that they are mounted not rigidly on the rigid structure of the mast, having at least one degree of freedom with respect to this same structure. As an indicative example, it can be provided four joints distributed regularly along an articulated end of a thrust reverser cover, and more particularly two fixed joints followed by two floating joints for isostatic mounting of the cover concerned. . On the other hand, as is schematized in FIG. 1a showing a conventional embodiment of the prior art, the articulated end 102 of the thrust reverser cover 104 securely carries an access panel 106 whose function is to enable access to the hood joints 108, for inspection and maintenance. For this purpose, the access panel 106 is fixedly attached by means of brackets 114 to the articulated end 102, which it outcrops for reasons of maintaining the aerodynamic lines. In addition, when the inverter cover 104 is in the closed position as shown in Figure la, the access panel 106 is then also provided to be flush with an aerodynamic flange 112 of the attachment pylon 110, for same reasons for maintaining the aerodynamic lines. However, it has been observed that during the opening and closing of the reverser cover, it has a tendency to deform, especially at its articulated end, and in particular at the portion of this end connected to the floating joints. Thus, as shown schematically in FIG. 1b showing the theoretical maximum opening position of the cover taking into account the above-mentioned deformation, it can be seen that this cover 104 occupies locally a position that is too "raised" to allow the access panel 106 to slide correctly under the aerodynamic structure 112 of the attachment pylon 110. In fact, during the opening of the inverter cover 104, the deformation of the hinged end 102 carrying the panel 106 does not prevent it from becoming slide under the aerodynamic structure 112 as specifically provided, but the insertion of the panel 106 under this structure 112 takes place at the cost of an introduction of extremely high forces at the collision interface between these two elements 106, 112, likely to induce damage and / or permanent deformation thereof. The applicant's patent application FR 2 909 639 A1 proposes a solution to this problem.

However, this solution requires adjustments making its implementation relatively complex. In addition, this solution is likely to cause jolts in operation, during the abutment of the arm secured to the access panel in contact with the protruding abutment integral with the bonnet joint. In addition, the access panel is relatively sensitive to the aerodynamic forces induced by the relative wind in flight. There is therefore a need for a simple and economical alternative solution to the problem described above, and does not have these disadvantages.

DISCLOSURE OF THE INVENTION The invention proposes for this purpose an assembly for aircraft comprising: a coupling device for supporting an engine; a nacelle for surrounding said engine and comprising at least one nacelle cover; first means for articulating an articulated end of said nacelle cover on said hooking device, said first means being designed to allow a displacement of said nacelle cover between a closed position and an open position relative to said device; hanging; and at least one access panel movable between a closed position in which said access panel extends between said attachment device and said articulated end of said nacelle cover when the latter is in its closed position, said panel access being then arranged opposite said first means, and an open position in which said access panel is spaced from its closed position. According to the invention, the assembly comprises: second means for articulating said access panel on said hooking device according to a hinge axis fixed with respect to said hooking device; and third means for connecting said access panel to said nacelle cover so that said third means cause a displacement of said access panel from its closed position to its open position under the effect of a displacement. said nacelle hood from its closed position to its open position, and vice versa. The invention thus proposes to mount the access panel not on the nacelle hood but on the attachment device, which provides better support of the access panel, particularly vis-à-vis the aerodynamic forces in flight . Said second means advantageously comprise at least one hinge fixed on said hooking device. Furthermore, said third means preferably comprise at least one connecting rod having a first end connected to said nacelle cover and an opposite second end connected to said access panel so that said connecting rod causes a displacement of said access panel from its position of closing in its open position under the effect of a displacement of said nacelle cover from its closed position to its open position, and vice versa. In this case, said first end of said connecting rod is preferably pivotally mounted on a structural beam of said nacelle cover connected to said coupling device via said first means.

In addition, said second end of said connecting rod is preferably connected to a connecting piece having a first part fixedly connected to said access panel, a second part articulated to said attachment device, and a third part on which said second end of said connecting rod is pivotally mounted.

Preferably, said connecting rod comprises two end portions displaceable with respect to each other and integrating respectively said first and second ends of the connecting rod, and elastic means interposed between said end portions of the connecting rod so that said resilient means is biased in compression when said nacelle hood is in its open position.

Furthermore, said nacelle hood advantageously comprises a support structure on which said access panel rests when said nacelle hood is in its closed position. Preferably, said attachment device comprises a lateral flange extending in the extension of said access panel when said nacelle hood is in its closed position. Where appropriate, said lateral flange preferably carries a seal which comes into contact with an internal face of said access panel when said nacelle cover is in its closed position.

Said gasket advantageously comprises at least one notch through which said connecting piece extends. The invention also relates to an aircraft comprising at least one assembly of the type described above.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be better understood, and other details, advantages and characteristics thereof will appear on reading the following description given by way of nonlimiting example and with reference to the accompanying drawings in which: FIGS. 1a and 1b, already described, schematize the design of conventional assemblies encountered in the prior art; Figure 2 is a partial schematic perspective view of an aircraft engine assembly including an assembly according to a preferred embodiment of the present invention; Figure 3 is a partial schematic perspective view of the assembly of Figure 2; Figure 4 is a partial schematic perspective view of the assembly of Figure 2, illustrating the joints of a thrust reverser cover; Figure 5 is a partial schematic cross-sectional view of the assembly of Figure 2, illustrating the thrust reverser cover in the closed position; Figure 6 is a view similar to Figure 5, illustrating the thrust reverser cover in the open position. In all of these figures, identical references may designate identical or similar elements.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT Referring firstly to FIG. 2, there is seen a portion of a motor assembly 1 intended to be fixed under a wing of an aircraft (not shown), this engine assembly comprising an attachment device 4, a motor 6 such as a turbojet engine hung under this device 4, and a nacelle 3, the rear portion has been partially omitted for reasons of clarity. The attachment device 4 and the nacelle 3 together form an assembly 15 for an aircraft according to a first embodiment of the invention. Throughout the following description, by convention, X is the longitudinal direction of the attachment device 4 which is also comparable to the longitudinal direction of the turbojet engine 6, this direction X being parallel to a longitudinal axis 5 of the turbojet engine 6. On the other hand, the direction transversely oriented relative to the device 4 and also comparable to the transverse direction of the turbojet engine 6 is called Y, and Z is the vertical or height direction, these three directions X, Y and Z being orthogonal to each other. they.

On the other hand, the terms "front" and "rear" are to be considered in relation to a direction of advancement of the aircraft encountered following the thrust exerted by the turbojet engine 6, this direction being represented schematically by the arrow 7. Overall, the attachment device 4 comprises a rigid structure 8, also called primary structure, carrying means for attaching the motor 6, these attachment means comprising for example a plurality of engine attachments 12 (only a rear attachment being visible in FIG. 2) and a device 14 for taking up the thrust forces generated by the motor 6.

The attachment device 4 comprises another series of fasteners (not shown) attached to the rigid structure 8 and to ensure the suspension of the engine assembly 1 under the wing of the aircraft. In addition, the attachment device 4 comprises a plurality of secondary structures reported on the rigid structure 8. These secondary structures, which will be described in the following, ensure the segregation and maintenance of the systems while supporting aerodynamic fairing elements . The turbojet engine 6 comprises at the front a large fan casing 18 delimiting an annular fan duct 20, and comprises at the rear a central casing 22 of smaller size, enclosing the heart of this turbojet engine. The rigid structure 8 takes the form of a box extending from the front to the rear, substantially in the direction X. The rigid structure 8 shown in FIG. 2 takes the form of a mast of similar design to that usually observed for the turbojet latches, in particular in that it is provided with transverse ribs 9 each taking the form of a rectangle oriented in a plane YZ. As an indication, although this has only been very partially represented, it is noted that among the secondary structures of the attachment device 4 is an aerodynamic structure before 24 (the only one represented in FIG. 2), a structure aerodynamic rear, a streamlined front and rear aerodynamic structures, and a lower rear aerodynamic fairing. Overall, these secondary structures are conventional elements identical or similar to those encountered in the prior art, and known to those skilled in the art. More specifically, the front aerodynamic structure 24 is usually placed at the front of the wing and performs an aerodynamic function between an upper portion of the fan cowls articulated thereon, and the leading edge of the wing. This aerodynamic front structure 24 also performs a function of supporting the fan cowls, and ensures the introduction, segregation and routing of various systems (air, electrical, hydraulic, fuel).

Directly in the rear extension of this structure, mounted above the rigid structure 8, is the connecting fairing, also called "karman". Then, still towards the rear, the connecting fairing is extended by the rear aerodynamic structure, attached under the wing of the aircraft. Finally, under the rigid structure 8 and the rear aerodynamic structure, is the lower rear aerodynamic fairing, also called "shield" or "Aft Pylon Fairing". Its essential functions are the formation of a fire barrier, and the formation of an aerodynamic continuity between the engine output and the rigging mast. Furthermore, we can see part of the nacelle 3 having at its front end an air inlet 32 fixed to the front of the fan casing 18, this air inlet 32 being directly followed back by two fan cowls 34 (only one visible due to the perspective view) each hingedly mounted to the secondary aerodynamic structure 24 described above. In addition, two other nacelle hoods 33, also called thrust reverser hoods (one hood being partially visible due to the perspective view), are also provided in the rear aerodynamic continuity of the fan cowlings 34, the latter pod covers 33 being articulated on the attachment device 4 as will now be detailed with reference to Figures 3 and 4. Figure 3 illustrates a portion of the assembly for aircraft 15, and more particularly one of the hoods of nacelle 33, occupying a closed position. The cover 33 has an articulated end 36, generally constituting an upper end of the cover, and incorporating a structural beam (not visible in FIG. 3) making it possible to ensure reliable mechanical connection of this cover 33 to the attachment device 4, and more specifically on the rigid structure 8 thereof via a plurality of joints defining a hood hinge axis, as will be detailed below. In the terminology of the invention, these articulations form first means for articulating the articulated end 36 of the nacelle cover 33 on the attachment device 4. These first means allow movement of the cover 33 with respect to the attachment device 4, between the closed position of the cover and an open position thereof, as will become clearer in what follows. At this articulated end 36 of the cover 33, a hood outer skin 38 forming an aerodynamic surface is extended in the direction of the attachment device 4 by one or more aerodynamic elements 40a, 40b, each constituting a removable access panel allowing access to the hood 33 joints, for maintenance or inspection. It is sufficient for an operator to dismantle and remove these access panels to access the joints, without it being necessary to dismantle the entire cover 33. When several access panels are provided, they are then arranged in the extension of each other along the articulated end of the nacelle cover 33. This is particularly the case on the embodiment of Figure 3 incorporating two access panels 40a, 40b arranged one in the extension of the other, substantially in the direction X, each of them taking the form of a substantially flat and rectangular plate extending from the front to the rear. When the cover 33 is in its closed position illustrated in Figure 3, each access panel 40a, 40b occupies an aerodynamic junction position in which it is flush, on one side, the outer skin 38 of the hood 33, at the the articulated end 36 of the latter, and on the other side, the attachment device 4, so as to ensure the maintenance of the aerodynamic lines in flight. More specifically, the part of the attachment device 4 concerned by this outcrop is a secondary aerodynamic structure, and more particularly the aforementioned connection fairing, referenced 42 in Figure 3. For this purpose, the connecting fairing 42 has two lateral flanges 44 or side walls of junction, extending substantially in the direction X, respectively on either side of the rigid structure 8, each side flange 44 is therefore in the aerodynamic continuity of the adjacent access panels 40a, 40b when the cover 33 is in its closed position, as is also visible in FIG. 4.

In this figure 4 where the nacelle hood 33 is not shown, we can see the fixed parts of the joints 46a, 46b for mounting the cover 33 on the rigid structure 8 of the attachment device 4. As an example a plurality of articulations 46a, 46b attached to the rigid structure 8 are provided, among which are articulations 46a, said to be fixed in the sense that they are rigidly mounted on the rigid structure 8, as well as articulations 46b, said floating in that they are mounted not rigidly on the rigid structure 8, that is to say having at least one degree of freedom with respect to this rigid structure. More specifically, four articulations are provided distributed regularly along the hinged end 36 of the cover 33, namely substantially in the longitudinal direction X, and more particularly two fixed joints 46a followed forward of two floating joints 46b, l assembly allowing an isostatic mounting of the cover 33. In this respect, the rearmost access panel 40a is arranged opposite the two fixed joints 46a, thus allowing easy access after disassembly of the same rear panel 40a, while the other access panel 40b, located foremost, is arranged opposite the two floating joints 46b, so as to allow access to these floating joints 46b by disassembly of the front panel 40b. In the context of the invention, at least one of the access panels 40b is movable between a closed position corresponding to its position shown in Figures 3 and 4, where the access panel 40b extends between the hooking device and the hinged end 36 of the cover 33 when the latter is in its closed position, and an open position in which the access panel 40b is spaced from its closed position.

This specificity, which aims to allow a reconciliation of the cover 33 during its opening relative to the attachment device 4, without the risk of deforming the access panel 40b, preferably applies to the two covers 33, but preferably only for the front access panel 40b, the rear access panel 40a remaining then rigidly fixed on its cover 33, and therefore simply following the movement of the latter during its opening or closing phase.

It has indeed been observed that, during the opening and closing of the thrust reverser cover in the engine assemblies of the prior art, this cover tends to deform, particularly at the part of the articulated end 36 connected to the floating joints 46b. It is therefore with regard to these floating joints 46b, that is to say at the level of the front access panel 40b, that the opening movement of the hood 33 is likely to cause a problematic introduction of efforts to the within the attachment device, and more particularly in the side flanges 44 of the connecting fairing 42. Nevertheless, it is also possible to make the rear access panel 40a movable in a similar manner to the front access panel 40b, without departing from the scope of the invention. Figure 5 illustrates the front access panel 40b in its closed closed position when the cover 33 is itself in the closed position.

At one of its lateral ends, the access panel 40b is substantially flush with the outer skin 38 of the articulated end 36 of the cover 33, while at the other lateral end, it substantially flushes the flange lateral 44 of the connecting fairing 42 belonging to the attachment device 4. To improve the tightness of the aerodynamic junction between the access panel 40b and the lateral flange 44, the latter advantageously carries a seal 48 in the form of elastically deformable blade having a free end 50 which comes into contact with an inner face 52 of the access panel 40b, that is to say its face on the side of the interior of the nacelle. According to the invention, the aircraft assembly 15 comprises second means for articulating the access panel 40b on the attachment device 4 according to a hinge axis 54 fixed with respect to the attachment device 4 and for example substantially parallel to the longitudinal direction X, and third means for connecting the access panel 40b to the nacelle cover 33 so that these third means cause a displacement of the access panel 40b from its closed position to its position d opening under the effect of a displacement of the nacelle cover 33 from its closed position to its open position, and vice versa. The second aforementioned means comprise for example two hinges 56 substantially aligned in the longitudinal direction X and defining the hinge axis 54. One of these hinges is masked by the other in Figures 5 and 6 in cross section. These second means further comprise two connecting pieces or fittings 58, one of which is also masked by the other in FIGS. 5 and 6. These connecting pieces 58 are for example of arcuate shape and thus comprise a first part 60 fixed on the inner face 52 of the access panel 40b, and a second portion 62 provided with a passage hole of a hinge pin 64 to the corresponding hinge 56. Each connecting piece 58 further comprises a third portion 66 arranged between the first and second parts 60 and 62 and forming a bend or an apex of the arc formed by the connecting piece.

The first part 60 of each connecting piece 58 extends through a notch provided for this purpose in the free end 50 of the gasket 48. The third aforementioned means comprise for example two rods 68, one of which is also each of these connecting rods 68 has a first end connected to said nacelle hood 33 and an opposite second end connected to the access panel 40b. More specifically, the first end of each connecting rod 68 is pivotally articulated to a hinge 72 carried by the structural beam 74 of the nacelle cover 33, while the second end of each connecting rod 68 is articulated to the third part 66 of the part connecting link 58, by means of an axis 76 mounted in the orifice of said third portion 66. By definition, the connecting pieces 58 are also part of said third means. In the embodiment of Figures 5 and 6, each rod 68 has two end portions 80, 82 movable relative to each other and integrating respectively said first and second ends of the rod. Each connecting rod 68 further comprises elastic means 84, such as a coil spring. These elastic means are interposed between the end portions 80 and 82 of the connecting rod. The elastic means 84 are designed to be at rest in the position illustrated in FIG. 5, and to be stressed in compression when the ends of the connecting rod 68 approach one another. In operation, the opening of the nacelle hood 33 is effected by a rotation of the latter around the hinge axis of the hood 76, in the clockwise direction R in FIG.

The rotation of the nacelle cover 33 causes a displacement of each connecting rod 68 which tends to push the corresponding connecting piece 58 in rotation in the clockwise direction R about the hinge axis 54, while compressing the elastic means 84. connecting piece 58 then moves within the corresponding notch formed in the seal 48.

This results in a displacement of the access panel 40b in rotation in the clockwise direction R about the articulation axis 54. The access panel 40b thus passes from its closed position (FIG. 5) to its position of opening (Figure 6), the latter being reached when the nacelle cover 33 reaches its own opening position. The stiffness of the elastic means 84 determines the amplitude of the displacement of the access panel 40b, and thus allows to define the opening position of the latter. The closure of the nacelle hood 33 operates in the same process in the opposite direction. The access panel 40b is then returned to its closed position under the effect of elastic means 84 which tend to return to their rest position.

Furthermore, when an inspection or maintenance operation of the joints 46b is necessary, it is sufficient to separate the access panel 40b of each connecting piece 58 and then remove the access panel to access the joints 46b.

FIG. 6 also makes it possible to see a support structure 86 carried by the structural beam 74 of the nacelle hood 33 and on which the access panel 40b is resting when the nacelle hood 33 is in its closed position.

In general, the invention provides a mechanism for driving the access panel 40 which is simple and reliable, which is particularly free of jerks. Because the access panel 40b is mounted on the attachment device 4 and not on the nacelle cover 33, the invention allows an improvement of the resistance of the access panel to the aerodynamic forces induced by the relative wind. which bathes the engine assembly in flight. In addition, in the embodiment described above, in which the opening is effected in the direction going from the inside to the outside of the nacelle, the second and third aforementioned means, namely the connecting pieces. 58 and connecting rods 68, contribute to the support of the access panel 40b against these aerodynamic forces. In the illustrated embodiment, the support structure 86 also contributes to this support of the access panel.

Claims (10)

REVENDICATIONS1. An aircraft assembly (15) comprising: an attachment device (4) for supporting a motor (6); a nacelle (3) intended to surround said motor and comprising at least one nacelle hood (33); first means (46b) for articulating an articulated end (36) of said nacelle cover on said hooking device, said first means being designed to allow a displacement of said nacelle cover (33) between a closed position and a position of opening with respect to said hooking device (4); at least one access panel (40b) movable between a closed position in which said access panel extends between said attachment device (4) and said articulated end (36) of said platform cover when the latter is in its closed position, said access panel (40b) then being arranged opposite said first means (46b), and an open position in which said access panel (40b) is spaced from its closed position; said assembly being characterized in that it comprises: second means (56, 58) for articulating said access panel (40b) on said hooking device (4) along an axis of articulation (54) fixed relative to said hooking device; third means (68) for connecting said access panel (40b) to said nacelle hood (33) so that said third means causes said access panel (40b) to move from its closed position to its position d opening under the effect of a displacement of said nacelle cover (33) from its closed position to its open position, and vice versa. 2. Assembly according to claim 1, wherein said second means comprise at least one hinge (56) fixed on said hooking device (4). An assembly according to claim 1 or 2, wherein said third means comprise at least one connecting rod (68) having a first end connected to said nacelle hood (33) and an opposite second end connected to said access panel (40b) of whereby said connecting rod causes said access panel to move from its closed position to its open position under the effect of a displacement of said nacelle cover from its closed position to its open position, and Conversely. 4. An assembly according to claim 3, wherein said first end of said link (68) is pivotally mounted on a structural beam (74) of said nacelle hood (33) connected to said hooking device (4) via said first means (46b). An assembly according to claim 3 or 4, wherein said second end of said link (68) is connected to a connecting piece (58) having a first portion (60) fixedly connected to said access panel (40b), a second portion (62) hinged to said hooking device (4), and a third portion (66) on which said second end of said link is pivotally mounted. 6. An assembly according to any one of claims 3 to 5, wherein said connecting rod (68) has two end portions (80, 82) movable relative to each other and integrating respectively said first and second ends. of the connecting rod, as well as elastic means (84) interposed between said end portions (80, 82) of the connecting rod so that said elastic means are biased in compression when said nacelle hood (33) is in its position d 'opening. An assembly according to any one of the preceding claims, wherein said nacelle hood (33) comprises a support structure (86) on which said access panel (40b) rests when said nacelle hood (33) is in its closing position. 8. Assembly according to any one of the preceding claims, wherein said attachment device (4) comprises a lateral flange (44) extending in the extension of said access panel (40b) when said nacelle hood (33). ) is in its closed position. An assembly according to the combination of claims 5 and 8, wherein said lateral flange (44) carries a seal (48) which contacts an inner face (52) of said access panel (40b) when said cover nacelle (33) is in its closed position, said seal comprising at least one notch through which extends said connecting piece (58). 10. Aircraft, comprising at least one assembly (15) according to any one of the preceding claims.