Method of repairing a damaged area of ​​an external part of an aircraft and External part of the aircraft thus repaired

Abstract

Method for repairing a damaged area of ​​an external part of an aircraft and external part of an aircraft thus repaired. The repair method comprises forming a reinforcing element shaped to the initial shape of the external part of the aircraft, fixing the reinforcing element to the damaged area, drawing a resin into a mold whose shape corresponds to the initial shape of the external part of the aircraft so as to cover the reinforcing element and to give the resin the initial shape of the external part of the aircraft, polymerizing the resin, and checking the surface of the repaired damaged area. This repair method is quick, easy and inexpensive, and makes it possible to obtain an invisible repair which preserves the aerodynamic shape of the external part of the aircraft. Figure 3a

Description

Title of the invention: Method for repairing a damaged area of ​​an external part of an aircraft and External part of the aircraft thus repaired Technical field

[0001] The present application relates to a method for repairing a damaged area of ​​an external part of an aircraft, such as an air intake lip of an aircraft turbomachine. The present application also relates to an external part of the aircraft thus repaired. STATE OF THE PRIOR ART

[0002] In a known manner, an external part of an aircraft 1, as shown in [Fig. 1], may suffer damage in flight or on the ground, by the impact of a bird or another object. The damaged external part of the aircraft may be, in a non-limiting manner, an air intake lip 12 10 of an aircraft turbomachine as shown in [Fig. 2]. The air intake lip 12 has damage on a sector 14 of the air intake lip 12, which may have the form of a depression 16 on the air intake lip 12, and result in a boss 18 on the periphery of the depression 16 of the air intake lip 12. This depression 16 and this boss 18 can disrupt the circulation of the air flow F on the air inlet 10. Such damage must therefore be repaired.

[0003] Generally, when an air inlet lip shows damage, even localized, it is necessary to replace either the entire air inlet lip (depending on the location of the damage and its dimensions), or the segment of the air inlet lip showing the damage.

[0004] A current method of repairing an air inlet lip 12 consists of: - a step of cutting and removing a segment of the sector 14 of said air inlet lip 12 having the damage 16, 18, so as to obtain an air inlet lip sector without damage, but having a cutout; - a step of searching and cutting, on another air inlet lip, an air inlet lip segment showing no damage and corresponding to the segment previously cut; - a step of fixing the undamaged air inlet lip segment in place of the damaged inlet lip segment which has been previously cut out, by means of rivets, so as to obtain a repaired air inlet lip sector.

[0005] With this repair method, another air inlet lip must be cut out in order to provide an inlet segment to repair the damaged air inlet lip. This results in significant repair costs: the need to have another air inlet available for the repair, which is not necessarily reusable later for other repairs.

[0006] Furthermore, after the repair, the rivets for securing the undamaged air inlet lip segment are visible, and may cause a slight disturbance of the air flow F.

[0007] There is therefore a need for a new method for repairing an external part of an aircraft such as an air intake lip of an aircraft turbomachine. Summary of the invention

[0008] The present invention aims to propose a solution for repairing an external part of an aircraft which does not require cutting another external part of the aircraft to carry out the repair, and the repair of which does not cause disruption to the airflow.

[0009] To this end, the invention relates to a method for repairing a damaged area of ​​an external part of an aircraft whose shape differs from an initial shape of the external part of the aircraft, comprising: - a determination step, during which the initial shape of the external part of the aircraft, at the level of the damaged area, is determined, - a mold formation step, during which a mold whose shape corresponds to the determined initial shape of the external part of the aircraft is produced, - a step of forming a reinforcing element, during which at least one reinforcing element shaped to the initial determined shape of the external part of the aircraft is produced, - a fixing step, during which the reinforcing element is fixed to the damaged area, - a mold positioning step, during which the mold is positioned on the external part of the aircraft, at the level of the damaged area, around the reinforcement element, - a step of drawing a resin into the mold, during which the mold is filled with resin and the reinforcing element is covered with resin, so as to give the resin the initial determined shape of the external part of the aircraft, - a step of polymerizing the resin, during which the resin is polymerized, and - a control step, during which the surface of the repaired damaged area is checked.

[0010] Advantageously, this repair method is quick and easy to implement. In addition, this repair method makes it possible to limit the waste of material used during the repair, since no other external aircraft part needs to be used for said repair, without being able to be reused subsequently. This repair method is therefore less expensive to implement than those of the prior art. In addition, once repaired, the external aircraft part has the same shape as its initial shape before damage, which makes it possible to guarantee the aerodynamic shape of said external aircraft part.

[0011] According to another characteristic, the step of forming a reinforcing element comprises a cutting sub-step, during which a reinforcing material is cut so as to form the reinforcing element, the reinforcing element being cut to the dimensions of the damaged area, and a sub-step of drawing the reinforcing element, during which the reinforcing element is drawn into the mold whose shape corresponds to the determined initial shape of the external part of the aircraft, so as to give the reinforcing element the determined initial shape of the external part of the aircraft.

[0012] According to another characteristic, the step of forming a reinforcing element comprises an assembly sub-step, during which reinforcing rods are assembled so as to form the reinforcing element, and a sub-step of drawing the reinforcing element, during which the reinforcing element is drawn into the mold whose shape corresponds to the determined initial shape of the external part of the aircraft, so as to give the reinforcing element the determined initial shape of the external part of the aircraft.

[0013] According to another characteristic, the fixing step consists of fixing the reinforcing element to the damaged area by means of connecting elements, these connecting elements comprising a first end fixed to the damaged area and a second end opposite the first end and which passes through the reinforcing element, an interior zone being defined between the damaged area and the reinforcing element, the reinforcing element being fixed so that the second end of the connecting elements extends into an area outside the reinforcing element opposite said interior zone.

[0014] According to another characteristic, the fixing step consists of fixing the reinforcing element to the damaged area by means of connecting elements, these connecting elements comprising a first end fixed to the damaged area and a second end opposite the first end and which passes through the reinforcing element, an interior zone being defined between the damaged area and the element of reinforcement, the reinforcement element being fixed so that the second end of the connecting elements extends into said inner area.

[0015] According to another characteristic, the repair method also comprises, after the fixing step, a step of adjusting the position of the reinforcing element on the damaged area.

[0016] According to another characteristic, the repair method also comprises, before the step of forming a mold, a smoothing step, during which a bump resulting from the damaged area is smoothed so as to reduce it or make it disappear.

[0017] The invention also relates to an external aircraft part repaired by means of the repair method according to the invention, said external aircraft part comprising a reinforcing element fixed to said external part, and a resin in which said reinforcing element is embedded, the resin forming an external surface of said external aircraft part corresponding to the initial shape of the external aircraft part.

[0018] According to another characteristic, the reinforcing element comprises first and second reinforcing rods arranged so as to form a mesh.

[0019] According to another characteristic, the reinforcing element consists of a reinforcing blade or a reinforcing plate. Brief description of the drawings

[0020] Other characteristics and advantages will emerge from the description of the invention which follows, a description given by way of example only, with reference to the appended drawings, among which:

[0021] [Fig-1] is a schematic perspective view of an aircraft, already presented,

[0022] [Fig.2] is a schematic perspective view of a turbomachine air inlet aircraft, as well as an enlarged view of a part of said air intake whose air intake lip has a damaged area, already shown,

[0023] [Fig.3a] is a flowchart of a method of repairing an external part of a aircraft, such as an aircraft air intake lip, which illustrates an embodiment of the invention,

[0024] [Fig.3b] is a flowchart of part of the repair process of [Fig.3a], which illustrates an embodiment of the invention,

[0025] [Fig.3c] is a flowchart of part of the repair process of [Fig.3a], which illustrates an embodiment of the invention,

[0026] [Fig.4] is a schematic view of part of an aircraft air intake, during a step of the repair process of [Fig.3a],

[0027] [Fig.5] is a schematic view of an aircraft air intake portion, during a another step in the repair process of [Fig.3a],

[0028] [Fig.6] is a schematic sectional view of a mold of an aircraft air intake and a reinforcing element, during a step of the repair process of [Fig.3a],

[0029] [Fig.7] is a schematic sectional view of an aircraft air intake portion, during a step of the repair method of [Fig.3a],

[0030] [Fig.8] is a schematic sectional view of an aircraft air intake portion, during another step of the repair method of [Fig.3a],

[0031] [Fig.9] is a schematic sectional view of an aircraft air intake portion, and an enlarged view, during a step of the repair method of [Fig.3a],

[0032] [Fig. 10] is a schematic sectional view of an aircraft air intake portion, and an enlarged front view, during a step of the repair method of [Fig.3a],

[0033] [Fig. 11] is a schematic sectional view of an aircraft air intake portion, during a step of the repair method of [Fig.3a],

[0034] [Fig. 12] is a schematic sectional view of an aircraft air intake portion, during another step of the repair process of [Fig.3a],

[0035] [Fig. 13a] is a schematic top view of a reinforcing material used in the repair method of [Fig.3a], according to one embodiment,

[0036] [Fig. 13b] is a schematic top view of a reinforcing material used in the repair method of [Fig.3a], according to another embodiment,

[0037] [Fig. 14] is a schematic perspective view of a mold of an aircraft air intake, used during a step of the repair process of [Fig.3a],

[0038] [Fig. 15] is a flowchart of a portion of the repair method of [Fig.3a], which illustrates an alternative embodiment of the invention,

[0039] [Fig. 16] is a schematic view of an aircraft air intake portion, during a step of the repair process of [Fig. 15],

[0040] [Fig. 17] is a schematic top view of a reinforcement rod used in the repair process of [Fig. 15],

[0041] [Fig. 18] is a schematic sectional view of an aircraft air intake portion, during a step of the repair method of [Fig. 15], according to a first embodiment,

[0042] [Fig. 19] is a schematic sectional view of an aircraft air intake portion, during a step of the repair method of [Fig. 15], according to a second embodiment,

[0043] [Fig.20] is a schematic perspective view of an aircraft air intake portion, during a step of the repair method according to another variant embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0044] As already presented with regard to Figures 1 and 2, an air inlet 10 of an aircraft turbomachine 1 comprises an air inlet lip 12, which has damage to a sector 14 of said air inlet lip 12, this damage taking the form of a depression 16 on the air inlet lip 12, and resulting in a boss 18 on the periphery of the depression 16 of said air inlet lip 12, which disrupts the circulation of the air flow F on the air inlet 10. The shape of the air inlet lip, at the level of the damage, therefore differs from the initial shape of the air inlet lip.

[0045] A method for repairing such an air intake 10 is illustrated in Figures 3a, 3b and 3c. Of course, this repair method is not limited to an application to an air intake of an aircraft turbomachine, but can be applied to any external part of an aircraft which would suffer damage which would require repair, and for example, in a non-exhaustive and non-limiting manner, to a fuselage 100, a wing 102 or a tailplane 104 of an aircraft 1.

[0046] Figures 4 to 12 illustrate the application of such a repair method according to the first embodiment of the invention.

[0047] A sector 34 of an air inlet lip 32 30 is shown in [Fig. 4]. This air inlet lip 32 has damage 36, also called damaged area 36, ​​which mainly corresponds to a depression (hollow) of the air inlet lip 32 30. A boss 37 (shown in dotted lines in [Fig. 4]), resulting from the depression, is also present near the damaged area 36. The damage 36 is here shown in elliptical shape, but can of course have any shape. This damage 36 has a maximum height H36, and a maximum length L36 (as well as a maximum depth P36 not shown in [Fig. 4]).The maximum height H36 (dimension along a first direction) and the maximum length L36 (dimension along a second direction orthogonal to the first direction) of the damage 36 are defined in a plane tangent to the surface of the air inlet lip 30 around the damaged zone 36 (excluding the boss 37).

[0048] The repair method comprises a step E02 of smoothing the boss 37, so as to make it disappear. This step E02 may correspond to a mechanical straightening of the boss 37. For example, a wooden hammer may be used to soften the boss(es) 37, and not damage other areas of the surface of the air inlet to be repaired. This step E02 makes it possible to repair, or at least to minimize, the boss 37 resulting from the depression. The application of this step E02 may also make it possible to minimize the depression, and therefore to reduce the surface area of ​​the damaged area 36.

[0049] The rest of the repair process mainly involves filling / filling the dent, so as to restore the air intake lip to its initial shape before damage.

[0050] The repair method then comprises a step E04 of preparing the surface of the damaged area 36, ​​so as to allow the following steps of the repair method to be carried out. This surface preparation step E04 may correspond to a mechanical and / or chemical action, in order to clean said damaged area and its surroundings, and allow better adhesion of the future repair.

[0051] According to a first embodiment, the repair method comprises a step E10 of positioning a reinforcing material 38 on the damaged area 36, ​​said reinforcing material 38 having dimensions greater than the dimensions of the damaged area 36. The reinforcing material 38 is here shown in [Fig. 4] in rectangular shape, but can of course have any shape. This reinforcing material 38 has a height H38, which is greater than the maximum height H36 of the damage 36, and a length L38, which is greater than the maximum length L36 of the damage 36. The height H38 (dimension along the first direction) and the length L38 (dimension along the second direction) of the reinforcing material 38 are taken in the plane tangent to the surface of the air inlet lip 30.According to this embodiment, the reinforcing material 38 takes the form of a substantially flat grid, and constitutes a safety structure, which makes it possible to reinforce the repair of the air intake which will be described subsequently. The reinforcing material 38 can be made of aluminum. For example, the reinforcing material 38 is made of the same material as the external part of the aircraft which it aims to repair, and therefore for example of the same material as the air intake lip. The reinforcing material 38 here comprises first reinforcing rods 39 which extend in the first direction as well as second reinforcing rods 41 which extend in the second direction, the first and second reinforcing rods 39, 41 crossing perpendicularly to each other so as to form an openwork grid of square 43 or rectangular meshes (i.e. a mesh 43).The dimensions of the meshes 43, and therefore the spacing between the first and second reinforcing rods 39, 41, may depend on the surface area of ​​the damaged area 36, ​​and on the location on the aircraft of the damage 36.

[0052] According to another configuration shown in [Fig. 13a], the reinforcing material 138 corresponds to a grid whose first and second reinforcing rods 139, 141 intersect non-perpendicularly, so as to form an openwork grid of meshes 143 in the shape of a parallelogram. The first reinforcing rods 139 extend in the first direction (here vertical), while the second reinforcing rods 141 extend in a second direction (here oblique) which is secant, but not orthogonal, to the first direction.

[0053] According to another configuration shown in [Fig. 13b], the reinforcing material 238 corresponds to a reinforcing plate 239 perforated with circular, oval, or elliptical, or even polygonal meshes 243.

[0054] According to another configuration not shown in the Figures, the reinforcing material corresponds to a solid plate, i.e. not perforated.

[0055] The repair method then comprises a step E12 of cutting the reinforcing material 38, so as to conform the reinforcing material 38 to the damage 36, and obtain a cut reinforcing element 40. More precisely, a reinforcing element 40 with the desired dimensions is cut from the reinforcing material 38, the dimensions of which are too large for the desired repair. The reinforcing element 40 is shown in [Fig. 5] with an elliptical shape, like the shape of the damage 36. Of course, the shape of the reinforcing element 40 may be different, as long as the shape of the reinforcing element 40 is substantially identical to the shape of the damage 36. The surface area of ​​the reinforcing element 40 obtained after cutting is substantially equal to the surface area of ​​the damage 36.The dimensions H40, L40 of the reinforcing element 40 are slightly smaller than the dimensions H36, L36 of the damaged area 36, ​​so that the cut reinforcing element 40 can be contained in the damaged area 36. The length L40 (dimension in the second direction) and the height H40 (dimension in the first direction) of the reinforcing element 40 are taken in a plane tangent to the surface of the air inlet lip 30. For example, the dimensions of the reinforcing element 40 are 5% smaller than the dimensions of the damage 36. According to another example, the dimensions of the reinforcing element 40 are 5 mm smaller than the dimensions of the damage 36. The reinforcing element 40 thus has dimensions equal to the dimensions of the damage 36 to within a homothety.This ensures that the reinforcing element 40 will not protrude beyond the limits of said damaged area 36, ​​and therefore will not be visible after the repair (and therefore will not disturb the air flow F circulating over the air inlet lip 32 30). The dimensions of the reinforcing element 40 are therefore substantially equal, to within a margin, to the dimensions of the damage 36 to be repaired.

[0056] The reinforcing element 40 obtained in step E12 is substantially flat, while the initial shape of the air inlet lip 32 is curved.

[0057] The repair method may comprise a step E102 of determining the initial shape of the lip 32 of the air inlet 30, at the damaged zone 36. For this determination step E102, the exact location of the damage 36 on the lip 32 of the air inlet 30 must be determined.

[0058] Then, the repair method may comprise a step E104 of forming a mold 42 whose shape corresponds to the initial shape of the damaged area 36. This mold 42 may be formed by any known molding method. For example, the mold 42 may be made using a thermoformable plate. In particular, the thermoformable plate is heated to a temperature above 50°C, for example in hot water, and is then positioned on an air inlet lip of an aircraft, exactly at the same location as the damaged area 36 on the air inlet lip to be repaired. The thermoformable plate, having taken the shape of the initial (undamaged) air inlet lip, is then cooled on this defect-free air inlet lip, and thus the theoretical (initial) profile of the air inlet lip is fixed. The thermoformable plate deformed to the shape of the initial air inlet lip can then be used as a mold 42.

[0059] Then, the repair method may comprise a step E106 of positioning a layer of material 44 in the mold 42, so as to create an excess thickness at the bottom of the mold 42. This layer of material 44 may be made of elastomer. Advantageously, this layer of material 44 is removable. These steps E102-E106, shown in [Fig.3b], may be carried out in parallel with steps E02-E12, and before step E14 of the repair method.

[0060] The repair method then comprises a step E14 of drawing the reinforcing element 40 into the mold 42, during which the reinforcing element 40 is placed in the mold 42 in order to give said reinforcing element 40 the shape of said mold 42. In particular, this step E14 makes it possible to bend the reinforcing element 40, in order to give it a curvature similar to the curvature of the air inlet section to be repaired. This drawing step E14 makes it possible to obtain a reinforcing element 40 with a shape corresponding substantially to the initial shape of the undamaged air inlet.

[0061] Between the reinforcing element 40 and the mold 42, the layer of material 44 can be added. This layer of material 44 corresponds to an excess thickness, arranged so that the reinforcing element 40, when positioned on the damaged zone 36, has dimensions slightly smaller than those of the initial (undamaged) air inlet lip. The mold 42 has an internal depth P42 (dimension in a third direction orthogonal to the first and second directions), which corresponds to the sum of the depth P40 of the reinforcing element 40 after drawing and the thickness E44 of the layer of material 44. For example, the depth P40 of the reinforcing element 40 is 5% less than the internal depth P42 of the mold 42. According to another example, the thickness E44 of the layer of material 44 is equal to 5 mm.The reinforcing element 40 thus has dimensions equal to the dimensions of the mold 42 to within a homothety (corresponding to the thickness E44 of the layer of material 44). This makes it possible to guarantee that the reinforcing element 40 will be contained in the repair, and will not disturb the air flow F circulating on the lip 32 of the air inlet 30. Thanks to the excess thickness formed by the layer of material 44, the reinforcing element 40 will have smaller dimensions than the final dimensions of the repaired air inlet lip, so that the reinforcing element 40 will not be visible after the repair.

[0062] All of the steps E10, E12 and E14 make it possible to obtain a reinforcing element 40 shaped to the initial air inlet (without damage). These steps of the repair method therefore correspond to sub-steps of a step E20 of forming a reinforcing element 40 of the damaged zone 36 shaped to said damaged zone 36.

[0063] Some of these steps E10-E14 may be optional, depending on the reinforcing element 40 required for the repair, and the location of the damage 36 on the external part of the aircraft. For example, the reinforcing element 40 may be provided directly, and it is therefore not necessary to carry out step E10. Another example would be to have a surface of an external part of the aircraft to be repaired which is flat (and not curved like the air intake lip), and therefore it would not be necessary to carry out step E14.

[0064] The repair method then comprises a step E30 of positioning the reinforcing element 40 on the damaged area 36, ​​in order to determine the positions of connecting elements 50 between the reinforcing element 40 and the lip 32 of the air inlet 30 to be repaired. This step E30 corresponds to a step of pre-positioning the reinforcing element 40. In [Fig.7], the reinforcing element 40 is correctly positioned on the lip 32 of the air inlet 30, at the level of the damaged zone 36, and the dotted lines 46 correspond to the determined locations of the connecting elements 50 of the reinforcing element 40 to the lip 32 of the air inlet 30. The reinforcing element 40 taking the form of an openwork grid, the marking on the damaged zone 36 of the locations for the connecting elements 50 is possible through the meshes (openings) of the grid forming the reinforcing element 40.The marking of the location of the connecting elements 50 can be carried out by any known marking method.

[0065] Optionally, the repair method comprises a step E32 of drilling orifices 48 in the damaged area 36 at the locations determined for the connecting elements 50 between the reinforcing element 40 and the air inlet lip 32 30. For this step E32, shown in [Fig. 8], the reinforcing element 40 is previously removed from its position on the damaged area 36. The openings 48 are then drilled according to the marking of the damaged area 36.

[0066] The repair method then comprises a step E34 of fixing the reinforcing element 40 to the damaged area 36 by means of the connecting elements 50, optionally through the openings 48 previously drilled in the damaged area 36. As shown in [Fig. 9], the connecting elements 50 may be blind rivets with threaded shank. These connecting elements 50 comprise a first part 52 which extends inside Int36 of the air inlet lip 32 30, at the level of the damage 36, and a second part 54, connected to the first part 52, extending inside Int40 of the reinforcing element 40 (outside the air inlet lip 32 30), that is to say in the area delimited between the reinforcing element 40 and the damaged area 36, ​​and beyond the reinforcing element 40. The connecting elements 50 have a first end 57 from which the first part 52 extends and a second end 55 on which the second part 54 ends. The connecting elements 50 (the end 55 of the second part 54) can extend through the meshes 43 of the reinforcing element 40, and therefore protrude from the reinforcing element 40 in an external zone Ext40 (opposite to the internal zone Int40, the exterior Ext40 corresponds to the area beyond the reinforcing element 40 which is therefore in contact with the air flow F). The reinforcing element 40 is thus fixed to the damaged area 36 by riveting, or by gluing, or even by welding.

[0067] The repair method then comprises a step E36 of adjusting the position of the reinforcing element 40 on the damaged area 36. As shown in [Fig. 10], this adjustment can be carried out by means of nuts and / or locknuts 56 arranged inside Int40 of the reinforcing element 40 or outside Ext40 of the reinforcing element 40. The adjustment step E36 makes it possible to check, and possibly modify the position of the reinforcing element 40, so that the profile of the reinforcing element 40 corresponds to the profile of the initial shape of the lip 32 of the air inlet 30.

[0068] Furthermore, after this adjustment step E36, the repair method may include a step E38 of cutting any excess length (ends 55) of the connecting elements 50, which would protrude beyond the nuts / locknuts 56 in the outer zone Ext40.

[0069] The repair method then comprises a step E40 of drawing a resin into the mold 42 positioned on the air inlet lip 32 30, at the damaged zone 36, around the reinforcing element 40, so as to restore the air inlet lip to its initial shape (before damage). This step E40 is illustrated in [Fig.3c].

[0070] More specifically, the repair method comprises a sub-step E42 of positioning the mold 42, around the reinforcing element 40 which is fixed on the damaged area 36, ​​the mold 42 having a shape corresponding to a correct shape for the air inlet lip, at the damaged area 36. This step E42 is illustrated in [Fig.l 1]. The inner face F42 of the mold 42 (facing the damaged area 36 and the reinforcing elements 40) may be previously covered with a mold release agent, in order to facilitate demolding after polymerization of the resin. Holding means (not shown in the Figures) may be used in order to maintain the position of the mold 42 on the area to be injected with resin. For example, the mold 42 may be held on the air inlet lip to be repaired by means of adhesive tape, so that it can be removed easily and without damaging or leaving any residue. traces on the air inlet 30 after repair. The mold 42 comprises at least one inlet orifice 58 for the resin, as well as at least one outlet orifice 60 for said resin. In particular, the mold 42 may be pierced with orifices 58, 60 which correspond to orifices for the passage of the resin (either for filling the interior Int42 of the mold 42, or in the event of resin overflow after filling said mold 42), or ventilation orifices for the polymerization of the resin. These orifices 58, 60 are arranged at opposite ends of the mold 42, for example on the periphery of the mold 42, so that the resin, which will be injected through the inlet orifice 58, travels throughout the interior Int42 (zone delimited between the mold 42 and the air inlet lip 30 on which the mold 42 is positioned) of the mold 42 before possibly exiting through the outlet orifice 60, in the event of excess resin.

[0071] According to another configuration shown in [Fig.14], the mold 142 comprises orifices 158 pierced around the center of the mold 142.

[0072] The repair method then comprises a sub-step E44 of filling the mold 42 with a resin 62, from the inlet orifice 58 of the mold 42. For example, the mold 42 is filled using an epoxy resin, or an expansive resin, for example two-component polyurethane. When filling the mold 42 with resin, the reinforcing element 40 is embedded in the resin 62. Optionally, if a quantity of resin greater than that necessary to fill the interior space Int42 of the mold 42 is injected into the mold 42, resin comes out through the outlet orifice 60 of the mold 42. The resin 62 thus makes it possible to fill the hollow space corresponding to the damaged zone 36, with the reinforcing element 40 making it possible to reinforce the adhesion of the resin to the air inlet lip. Thus, the reinforcing element 40 makes it possible to avoid a potential separation of the repair from the repaired air inlet lip.In the mold 42, the layer of material 44, constituting an excess thickness at the bottom of the mold 42, has been previously removed. This advantageously allows the mold 42 to have dimensions slightly greater than the dimensions of the reinforcing element 40, and therefore for the reinforcing element 40 to be well covered with resin 62 during injection into the mold 42, that is to say embedded in the resin 62. The molding of the reinforcing element 40 in the mold 42 with the presence of the layer of material 44, then the removal of this layer of material 44 for the molding of the resin, makes it possible to force the reinforcing element 40 to be included inside the resin 62 following step E44.The reinforcing element 40 thus has dimensions smaller than the damage 36 to be repaired, so that the reinforcing element 40 can be completely covered by the resin 62, and to allow the resin to take the shape and dimensions of the initial air inlet lip, that is to say safe and without damage.

[0073] The repair process then comprises a sub-step E46 of polymerization of the resin.

[0074] Then the repair method then comprises a sub-step E48 of removing the mold 42, in order to obtain the repaired air inlet lip, as shown in [Fig.12].

[0075] Following removal of the mold 42, resin may be passed through the outlet orifice 60, and therefore the surface of the repaired air inlet lip may not be smooth. The repair method also comprises a surface finishing step E50, during which the surface of the repaired air inlet lip is sanded, in order to remove any surface defects present due to excess resin resulting from overfilling of the mold, or to over-expansion of the resin. The surface of the repaired air inlet lip also undergoes the application of a surface treatment, and / or at least one layer of paint. The application of a surface treatment may correspond to the application of a sealing mastic, or an anti-corrosion solution, or a bonding primer.

[0076] Finally, the repair method comprises a step E60 of checking the final shape of the repaired air inlet, in order to verify that the shape of the repaired air inlet corresponds to the shape of the initial air inlet. This step E60 consists of different measurements of the surface of the repaired air inlet lip.

[0077] A variant of the method for repairing an air intake is illustrated in [Fig. 15]. Figures 16 to 19 illustrate the application of such a repair method according to this variant of the invention. Only the differences between the repair method described according to the first embodiment and this variant are described for the sake of brevity.

[0078] According to this variant, the step E20 of forming a reinforcing element 140 of the damaged zone 36 shaped to said damaged zone 36 comprises a sub-step E1 10 of assembling reinforcing rods 150a-b so as to form a reinforcing element 140 of the damaged zone 36. The reinforcing rods 150a-b can be replaced by reinforcing plates or sheets. The reinforcing rods 150a-b are made of metallic material. As shown in [Fig. 16], the reinforcing element 140 here comprises first reinforcing rods 150a extending in the first direction as well as second reinforcing rods 150b which extend in the second direction, the first and second reinforcing rods 150a-b crossing perpendicularly to each other so as to form a mesh 153.The first and second reinforcing rods 150a-b may be distinct, separate elements, or be secured to each other, at the junction between two first and second reinforcing rods 150a-b, by means of joining elements 152.

[0079] According to another configuration not shown in the Figures, the reinforcing element 140 corresponds to a grid whose first and second reinforcing rods 150a-b intersect non-perpendicularly.

[0080] According to another configuration not shown in the Figures, the reinforcing element corresponds to a single first reinforcing rod, such as the first reinforcing rod 150a and / or a single second reinforcing rod, such as the second reinforcing rod 150b.

[0081] The first and second reinforcing rods 150a-b are intended to be fixed in the damaged zone 36, and therefore have dimensions smaller than those of the damaged zone 36.

[0082] The forming step E20 then comprises a sub-step E112 of drawing the reinforcing element 140 into the mold 42, during which the reinforcing element 140 is placed in the mold 42 in order to bend the reinforcing element 140, and therefore the reinforcing rods 150a-b, and to give it a curvature similar to the curvature of the air inlet section to be repaired.

[0083] Each first or second reinforcing rod 150a-b comprises, as shown in [Fig. 17], a core 154 and at each end of the core 154, a plate 156. A core 154 has a tapered shape. Each plate 156 is intended for fixing the first or second reinforcing rod 150a-b to the damaged area, by any known fixing means. The plates 156 here have a substantially rectangular shape, but can of course have any shape allowing the fixing of said plate 156 to the damaged area 36.

[0084] According to a configuration shown in [Fig. 18], each first or second reinforcing rod 150a-b can be folded, at the junction between the core 154 and the plates 156, for its attachment to the air inlet lip 32 30. For example, each first or second reinforcing rod 150a-b can be folded so that the plates 156 are positioned in the interior space Intl40 (space located between the reinforcing element 140 and the damaged area 36) of the reinforcing element 140 and attached to the damaged area 36 by means of connecting elements 158. In the folded position of a first or second reinforcing rod 150a-b, the plates 156 are positioned towards each other. According to this configuration, the connecting elements 158 are included in the interior space Intl40 of the reinforcing element 140.

[0085] According to another configuration shown in [Fig. 19], each first or second reinforcing rod 150a-b can be folded so that the plates 156 are positioned in the outer space Extl40 (space located opposite the inner space Int40, the exterior Ext40 corresponds to the area beyond the reinforcing element 140 which is therefore in contact with the air flow F) of the reinforcing element 140 and fixed to the damaged area 36 by means of connecting elements 158. In the folded position of a first or second reinforcing rod 150a-b, the plates 156 are oriented in opposite directions to each other. According to this configuration, the connecting elements 158 are included in the outer space Extl40 of the reinforcement element 140, and will be covered with resin so as not to be visible after the repair.

[0086] Another variant of the method for repairing an air inlet is illustrated in [Fig. 20]. Only the differences between the repair method described according to the first embodiment and this variant are described for the sake of brevity.

[0087] According to this variant, the step E20 of forming a reinforcing element 240 of the damaged area 36 consists of forming a reinforcing element 240 of the damaged area 36 by means of at least one metal reinforcing blade, and possibly drawing the reinforcing blade 240 into the mold 42 so as to curve the reinforcing blade 240 to give it a curvature similar to the curvature of the air intake section to be repaired. The dimensions of the reinforcing blade 240 depend on the dimensions of the damaged area 36 and the location of the damage 36 on the aircraft. For example, as shown in [Fig. 20], the damage 36 is of substantially elliptical shape, and has a greater maximum length L36 than its maximum height H36. According to this configuration, the reinforcing blade 240 has a length L240 greater than a height H240, and extends mainly along the length L36 of the damage 36.The reinforcing blade 240 can be previously cut from a reinforcing material, so as to have the desired dimensions.

[0088] This repair method thus makes it possible to obtain an aircraft whose external part which was damaged is repaired. This repaired external part of the aircraft has a shape corresponding to the initial shape of the external part of the aircraft, that is to say before (and without) damage. In the repaired area, there is a reinforcing element fixed to said external part of the aircraft, and embedded in a resin. The reinforcing element is therefore not visible from the outside, but its presence can be identified by any known non-destructive testing method for example.

[0089] The invention has been described in the context of a repair of an aircraft air intake lip, but can of course be applied to other parts of the air intake, without departing from the scope of the invention, and also to other external parts of the aircraft, such as, in a non-limiting manner, the fuselage 100, the wings 102, the empennage 104, etc.

[0090] This repair is particularly effective for any external part of an aircraft made of aluminum, or steel for example.

Claims

Claims

1. Method for repairing a damaged area (36) of an external part of an aircraft whose shape differs from an initial shape of the external part of the aircraft, characterized in that said repair method comprises: - a determination step (E102), during which the initial shape of the external part of the aircraft, at the damaged area (36), is determined, - a step of forming (E104) a mold (42; 142), during which a mold (42; 142) whose shape corresponds to the determined initial shape of the external part of the aircraft is produced, - a step of forming (E20) a reinforcing element (40; 140; 240), during which at least one reinforcing element (40; 140; 240) shaped to the determined initial shape of the external part of the aircraft is produced, - a fixing step (E34), during which the element reinforcement (40; 140; 240) is fixed on the damaged area (36), - a step of positioning the mold (42;142), during which the mold (42; 142) is positioned on the external aircraft part, at the damaged area (36), around the reinforcing element (40; 140; 240), - a step (E40) of drawing a resin (62) into the mold (42; 142), during which the mold (42; 142) is filled with resin (62) and the reinforcing element (40; 140; 240) is covered with resin (62), so as to give the resin (62) the determined initial shape of the external aircraft part, - a step (E46) of polymerization of the resin (62), during which the resin (62) is polymerized, and - a control step (E60), during which the surface of the repaired damaged area is controlled.;

2. A repair method according to claim 1, characterized in that the step of forming (E20) a reinforcing element (40; 240) comprises a cutting sub-step (El2), during which a reinforcing material (38) is cut so as to form the reinforcing element (40; 240), the reinforcing element (40; 240) being cut to the dimensions of the damaged area (36), and a sub-step of pulling (E14) the reinforcing element (40; 240), during which the reinforcing element (40; 240) is drawn into the mold (42) whose shape corresponds to the determined initial shape of the external part of the aircraft, so as to give the reinforcing element (40; 240) the determined initial shape of the external part of the aircraft.

3. Repair method according to claim 1, characterized in that the step of forming (E20) a reinforcing element (140) comprises an assembly sub-step (El 10), during which reinforcing rods (150a, 150b) are assembled so as to form the reinforcing element (140), and a sub-step of drawing (El 12) of the reinforcing element (140), during which the reinforcing element (140) is drawn into the mold (42; 142) whose shape corresponds to the determined initial shape of the external part of the aircraft, so as to give the reinforcing element (140) the determined initial shape of the external part of the aircraft.

4. Repair method according to one of claims 1 to 3, characterized in that the fixing step (E34) consists of fixing the reinforcing element (40; 140; 240) to the damaged area (36) by means of connecting elements (50; 158), these connecting elements (50; 158) comprising a first end (57) fixed to the damaged area (36) and a second end (55) opposite the first end (57) and which passes through the reinforcing element (40; 140; 240), an inner zone (Int40; Intl40) being defined between the damaged area (36) and the reinforcing element (40; 140; 240), the reinforcing element (40; 140; 240) being fixed so that the second end (55) of the connecting elements (50; 158) extends in an outer zone (Ext40; Extl40) to the reinforcing element (40; 140; 240) opposite said inner zone (Int40; Intl40).

5. Repair method according to one of claims 1 to 3, characterized in that the fixing step (E34) consists of fixing the reinforcing element (40; 140) to the damaged area (36) by means of connecting elements (50; 158), these connecting elements (50; 158) comprising a first end (57) fixed to the damaged area (36) and a second end (55) opposite the first end (57) and which passes through the reinforcing element, an inner zone being defined between the damaged area (36) and the reinforcing element (40; 140), the reinforcing element (40; 140) being fixed so that the second end (55) of the connecting elements (50; 158) extends into said inner zone (Int40; Intl40).

6. Repair method according to one of claims 1 to 5, characterized in that said repair method also comprises, after the fixing step (E34), a step of adjusting (E36) the position of the reinforcing element (40; 140; 240) on the damaged area (36).

7. Repair method according to one of the preceding claims, characterized in that said repair method also comprises, before the step of forming (E104) a mold (42; 142), a smoothing step (E02), during which a boss (37) resulting from the damaged area (36) is smoothed so as to reduce it or make it disappear.

8. External part (10; 100; 102; 104) of aircraft (1) repaired by means of the repair method according to one of the preceding claims, characterized in that said external part of aircraft comprises a reinforcing element (40; 140; 240) fixed on said external part, and a resin (62) in which said reinforcing element (40; 140; 240) is embedded, the resin (62) forming an external surface of said external part of aircraft corresponding to the initial shape of the external part of aircraft.

9. External part (10; 100; 102; 104) of aircraft (1) according to claim 8, characterized in that the reinforcing element (40; 140) comprises first and second reinforcing rods (39, 41; 139, 141; 150a, 150b) arranged so as to form a mesh (43; 143; 153).

10. External part (10; 100; 102; 104) of aircraft (1) according to claim 8, characterized in that the reinforcing element (240) consists of a reinforcing blade or a reinforcing plate (239).

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