Improved system for guiding and driving a movable leading-edge flap for an aircraft wing

Abstract

The invention relates to a system (40) for guiding and driving a movable leading-edge flap (16), comprising: - a first assembly (52a) for guiding and driving the flap, comprising a first guide rail (54a), as well as a drive track (56); - a second guide rail (54b); - a device (64) for guiding the rails; - a device (70) for connecting the rails to the flap, comprising a structural element (72), this device forming first and second mechanical connections (80a, 80b) between first and second rail ends (82a, 82b) and the element (72), the system being configured such that, while they are moving, the rails undergo a relative movement causing the element (72) to move relative to the first rail end (82a).

Description

[0001] 51601 AP-P

[0002] Improved guidance and drive system for a leading-edge movable flap on an aircraft wing

[0003] DESCRIPTION

[0004] 5. TECHNICAL DOMAIN

[0005] The present invention relates to the field of aircraft wings, of the type comprising a fixed part of the wing carrying one or more movable leading edge flaps, also called "Slats" in English.

[0006] The invention relates more particularly to the guidance and drive systems of 10 of these leading-edge movable flaps.

[0007] It is noted that the invention applies to all types of aircraft, such as a flying wing, a tail-engine aircraft, a supersonic aircraft, etc.

[0008] STATE OF PRIOR ART

[0009] On aircraft, each of the two wings of the wing is generally equipped with 15 movable high-lift flaps, mounted on the leading edge and trailing edge of the wing.

[0010] As is well known, flaps are deployed during takeoff and landing to increase lift at low and medium speeds. Conversely, during high-speed cruise flight, the flaps are retracted to reduce drag. The movement and guidance of each flap are achieved conventionally using guidance and drive systems housed in the fixed wing section, also known as the wing center section.

[0011] In conventional designs, these systems include guide rails and / or drive rails for the flap, which usually have an arc shape, this shape therefore also corresponding to that of the trajectory of the flap during its movement relative to the fixed part of the wing.

[0012] With such a circular trajectory, the flap cannot, throughout its retraction / extension movement, adopt an optimal position relative to the fixed part of the wing, particularly in terms of angle of attack. For example, it might be desirable for the movable flap 51601 AP-P 2

[0013] The flap adopts an angle of attack that places its trailing edge flush with the fixed part of the wing when it is in its retracted position, and preferably also during the initial phase of its extension, for example, until it reaches its partially deployed position as adopted for takeoff. This helps to limit wing drag and thus reduce fuel consumption. However, it may also be desirable for the flap to adopt an angle of attack that places its trailing edge away from the fixed part of the wing when it is in its deployed position as adopted for landing. Indeed, the circulation of airflow between the flap and the fixed part of the wing during landing reduces the risk of stalling.

[0014] 10 More generally, it may be useful to be able to adapt the incidence of the flap in all or part of its positions during its extension and retraction movement.

[0015] There therefore remains a need for optimization of aircraft wing design, in order to meet the need expressed above, and preferably so that this design reduces drag as much as possible, and / or presents a so-called "Fail safe" function, and / or has a compact appearance.

[0016] DESCRIPTION OF THE INVENTION

[0017] To meet at least partially this need, the invention first relates to a guidance and drive system for a leading-edge movable flap for an aircraft wing, according to the characteristics of claim 1.

[0018] 20 The invention is advantageous in that it offers a design capable, during the outward movement of the flap relative to the fixed part of the wing, of applying an additional relative movement between the flap and the first rail, namely a pivoting movement around the first axis of rotation.

[0019] This design thus provides, in a reliable, simple, compact, and inexpensive way, an additional degree of freedom of movement to the flap, allowing control of its angle of attack in addition to its extension. This solution contrasts with a conventional one in which the flap is simply rotated relative to the fixed part of the wing, along a trajectory dictated by the same circular shape of all the flap's guide and / or drive rails. This degree of freedom of 51601 AP-P

[0020] Additional movement can be advantageously used to precisely control the relative position between the fixed wing section and the trailing edge of the flap. Furthermore, grouping the first and second guide assemblies within a single flap guidance and drive system allows for a compact design, reducing drag. This drag is further reduced because the two adjacent guide assemblies pass preferentially through a single opening in the leading edge of the fixed wing section. This again contrasts with conventional solutions in which each guide and / or drive rail passes through a specifically dedicated opening on the leading edge of the fixed wing section.Reducing the number of these openings advantageously reduces drag during flight phases when the flap is at least partially deployed, particularly during takeoff, which has a positive impact on fuel consumption. Finally, it should be noted that the design proposed by the invention remains perfectly compatible with the implementation of a fail-safe function for the transmission of forces between the flap and the fixed part of the wing.

[0021] Other aspects of the invention will be described by enumerating the following optional features, which are intended to be implemented individually or in combination. Preferably, the first rail comprises two opposing guide tracks, each cooperating with the guide device, while the second rail comprises two opposing guide tracks, each cooperating with the guide device, with the first tracks having a different shape from the second tracks. It is this differentiation in shape between the adjacent rails of the system that makes it possible to generate the desired relative displacement between these rails, thus causing the additional movement of the shutter. Other solutions can, of course, be considered to generate this principle specific to the invention, such as providing, within the guide device, differentiated guide elements for the two rails, so that they follow distinct guide paths.

[0022] Preferably, the first two guide tracks are arc-shaped, and each of the two opposing second guide tracks has at least one non-circular portion. These two second guide tracks can therefore have a 51601 AP-P

[0023] a more complex curvilinear shape, dictated by the nature of the additional movement desired for the shutter relative to the first guide rail.

[0024] Preferably, the first mechanical link is located in front of the second mechanical link.

[0025] 5. Preferably, the guiding device comprises several guide rollers, each contributing to the guidance of the first and second rails. However, different rollers could be used to guide the first and second rails without departing from the scope of the invention.

[0026] Preferably, the first flap guide and drive assembly is supported against the second flap guide assembly, with a sliding layer possibly arranged between the first and second guide assemblies. Alternatively, a small clearance could be maintained between these two assemblies, in the flap's span direction.

[0027] Depending on different possible designs, the flap drive track is arranged between the first and second rails, in the span direction, or the first guide rail is arranged between the flap drive track and the second guide rail, also in the span direction.

[0028] Preferably, the drive track for the shutter is a toothed drive track. Preferably, the drive track for the shutter is fixed to the first guide rail, preferably using screws. A one-piece, i.e., monobloc, embodiment of both parts is also possible without departing from the scope of the invention.

[0029] Preferably, the structural element of the connecting device comprises a body, as well as a first and a second fixing lug projecting from this body towards the rear, and being spaced apart from each other along the span direction.

[0030] 25 According to a preferred embodiment envisaged, the first mechanical linkage comprises a first axle mounted on each of the first and second mounting lugs, and the second mechanical linkage comprises a second axle mounted on each of the first and second mounting lugs, and passing through a through-hole formed in the first front end of the first rail. 51601 AP-P

[0031] In this design, the connection device may include a spare structural piece, doubling the body, as well as each of the first and second fixing lugs.

[0032] According to another preferred embodiment, the structural element of the connection device also includes a third mounting tab projecting rearward from the body, arranged so that the second mounting tab is located between the first and third mounting tabs in the span direction. The first mechanical linkage then comprises a first axle mounted on each of the first and third mounting tabs, and passing through a through hole formed in the second mounting tab, and the second mechanical linkage comprises a second axle mounted on each of the second and third mounting tabs.

[0033] The invention also relates to an aircraft wing comprising a fixed wing section, a movable leading-edge flap, and such a guidance and drive system for the movable flap. The fixed wing section has a leading edge with an opening through which the first and second adjacent assemblies of the flap guidance and drive system pass. Preferably, the movable flap is associated with two guidance and drive systems spaced apart along the flap's span direction. The leading edge of the fixed wing section has two openings spaced apart along the span direction, each respectively traversed by one of the two flap guidance and drive systems.This contrasts with prior art solutions, in which four openings are usually made through the fixed part of the wing to connect a single flap, rather than two openings as proposed above. As previously mentioned, this arrangement reduces drag and lowers fuel consumption.

[0034] Moreover, it is noted that the wing may preferably comprise several movable flaps, each or only some of them being associated with guidance and drive systems having a design specific to the present invention.

[0035] Preferably, each movable shutter guidance and drive system is configured so that during the end of the shutter's travel towards its deployed position, the relative displacement 30 of the first and second rails drives the structural element of the device de51601 AP-P

[0036] The connection is moved relative to the first forward end of the rail, so that one trailing edge of the movable flap moves away from the fixed part of the wing. This allows the flap to be intentionally positioned and maintained at an angle of attack that places its trailing edge away from the fixed part of the wing, at least when the flap is in its deployed position as adopted during landing. With this trailing edge offset, airflow is advantageously directed between the rear of the movable flap and the fixed part of the wing during landing, thus reducing the risk of aerodynamic stall.

[0037] Finally, the invention relates to an aircraft comprising at least one wing of design as described above, and preferably two wings conforming to this same design.

[0038] Other advantages and features of the invention will appear in the detailed, non-limiting description below.

[0039] BRIEF DESCRIPTION OF THE DRAWINGS

[0040] This description will be made with reference to the attached drawings, among which are;

[0041] 15 [Fig. 1] represents a perspective view of an aircraft;

[0042] [Fig. 2] represents a schematic and partial cross-sectional view of a forward part of an aircraft wing, equipped with a movable leading-edge flap, which is shown in the retracted position;

[0043] [Fig. 2A] represents a simplified perspective view of the flap shown in Figure 2, with its two guidance and drive systems shown schematically only;

[0044] [Fig. 3] represents a perspective view of one of the two leading-edge flap guidance and drive systems shown on the wing in Figure 2A, and presented according to a first preferred embodiment of the present invention;

[0045] 25 [Fig. 4] represents another perspective view of the guidance and drive system shown in Figure 3, from a different viewing angle;

[0046] [Fig. 5] represents a cross-sectional view of the guidance and drive system shown in Figures 3 and 4, the section line following the general curvature of the rails equipping this guidance and drive system; 51601 AP-P

[0047] [Fig. 6] represents a cross-sectional view of the guidance and drive system shown in the previous figure, along line VI-VI of figure 5;

[0048] [Fig. 7] represents a cross-sectional view of the guidance and drive system shown in Figure 5, along line VII-VII of Figure 5;

[0049] 5 [Fig. 8] represents a cross-sectional view of the forward part of the wing, similar to that of Figure 2, with the flap in the position adopted during the beginning of the flap's outward movement;

[0050] [Fig. 9] represents a cross-sectional view similar to that of the previous figure, with the flap in the position adopted during takeoff;

[0051] [Fig. 10] represents a cross-sectional view similar to that of the previous figure, with the flap in the position adopted during landing;

[0052] [Fig. 11] is a schematic view of the movement of the two mechanical links associated with the front ends of the two rails equipping the guidance and drive system, during a movement of the flap from its retracted position to its deployed position, in a reference frame associated with the fixed part of the wing;

[0053] [Fig. 12] represents a cross-sectional view similar to that of figure 5, with the guidance and drive system being in the form of a second preferred embodiment of the invention;

[0054] [Fig. 13] represents a cross-sectional view of the guidance and drive system shown in Figure 12, along line XIII-XIII of Figure 12;

[0055] [Fig. 13A] represents a cross-sectional view similar to that of figure 13, with the guidance and drive system presented as an alternative;

[0056] [Fig. 14] represents a cross-sectional view similar to that of Figure 13, with the guidance and drive system presented as another alternative;

[0057] 25 [Fig. 15] represents a cross-sectional view similar to that of Figure 5, with the guidance and drive system presented in the form of a third preferred embodiment of the invention;

[0058] [Fig. 16] represents a cross-sectional view of the guidance and drive system shown in Figure 15, along line XVI-XVI of Figure 15.51601 AP-P

[0059] DETAILED EXPLANATION OF PREFERRED METHODS OF IMPLEMENTATION

[0060] With reference first to figure 1, an aircraft 1 is represented having a wing 2 made up of a plurality of wing elements, also called lifting aerodynamic surfaces.

[0061] 5. Throughout the following description, the terms "forward" and "rear" are to be understood in relation to the direction of forward movement of the aircraft encountered as a result of the thrust exerted by the aircraft's engines. This direction is schematically represented by arrow 3 and is also referred to as the "flight direction." The terms "upstream" and "downstream" could be substituted for the two preceding terms, with the same meaning. The wing components of aircraft 1 include two main wings, referred to as wings 4, a vertical stabilizer 6, and two horizontal stabilizers 7 located at the rear of the aircraft.

[0062] As regards the wings 4, as mentioned above, each of these includes a fixed part 8 of the wing, also called the fixed central wing body or main central portion 15, this fixed part constituting almost the entire wing, and being located behind a leading edge 10 of the wing.

[0063] As schematically shown in Figure 2, it is the leading edge 10 of each of the two wings 4 that can be equipped with at least one movable leading-edge flap 16, called a "slat" in English. Usually, several movable leading-edge flaps 16 are arranged successively along the fixed section 8, in a span direction 17 of the wing 4, which is also considered the span direction of the fixed section 8, and of each of the movable flaps 16 of the wing.

[0064] Each of these flaps 16 is intended to be connected to the fixed part 8 by guiding and driving systems 40, specific to the present invention and which will be described below. Figure 2 shows the leading-edge movable flap 16, having an aerodynamic part 19, for example box-shaped. Figure 2 represents the movable flap 16 in a retracted position, while the deployed, or extended, position is shown in Figure 10. In this regard, it is noted that by deployed position, it is understood that the flap 16 is fully extended, along a stroke / displacement of 51601 AP-P

[0065] Maximum deployment / extension. Consequently, during its deployment, and its retraction in the opposite direction, the movable flap 16 can adopt intermediate positions, in which it remains partially deployed / extended. These intermediate positions of flap 16 are shown in Figures 8 and 9.

[0066] 5 In the retracted / folded position of Figure 2, the flap 16, with its trailing edge 13, is flush with the leading edge 10a of the fixed part 8 of the wing 4. In such a case, the movable flap 16 is in its rearmost position.

[0067] In the deployed / extended position shown in Figure 10, the flap 16 is positioned forward of the leading edge 10a of the fixed section 8 and downwards. This fully deployed position is adopted particularly during the landing phase to increase lift at low and medium speeds. In this position, the trailing edge 13 of the flap is offset from the leading edge 10a of the fixed wing section to create a gap 5 between these two parts, allowing the circulation of an external airflow 77 and delaying wing stall. The method of generating this gap 5, specific to the invention, will be described later.

[0068] As is known, the aerodynamic part 19 of the flap 16 comprises a leading edge area 10b, from which extend, rearward, an intrados 24 and an extrados 26, the latter terminating in the trailing edge 13 of the flap. Also as is known, the intrados 24 and the extrados 26 are spaced apart along a direction of the height 21 of this flap.

[0069] Furthermore, the movable flap 16 has, in a plane orthogonal to the span direction 17 such as the cross-sectional plane of Figure 2, an axial line 23 passing through the leading edge of the flap, and also passing through a trailing edge of the wing (not shown) with the flap in its retracted position. This axial line 23, thus defined, can be considered a chord line of the movable flap 16, and it is noted that this line 23, as well as the two directions 17 and 21, are preferably orthogonal to each other. The aerodynamic part 19 can be closed at the rear by a closing skin 27, also called the rear skin, and designed to closely follow or approach 30 the leading edge 10a of the fixed wing part 8, when the flap 16 occupies 51601 AP-P

[0070] its retracted position. Such a closing coating 27 can constitute all or part of a flap spar, corresponding to a structural element of this flap 16. The closing element 27 extends from the intrados 24 to the trailing edge 13 of the flap.

[0071] Alternatively, a spar (not shown) could be added, extending 5 upstream of the closing skin 27 along the entire length of the flap in the wingspan direction 17, preferably parallel to it. The spar type has a web, for example with a generally C or E-shaped cross-section, and its two lower and upper edges are respectively fixed internally to the intrados 24 and the extrados 26.

[0072] 10 The fixed part 8 of the wing has a leading edge space 30, located in front of a wing box 31, the latter preferably being delimited forward by a leading edge spar 32 of this box. The space 30 forms a portion of the leading edge 10a of the fixed part 8 of the wing.

[0073] The forward spar 32 comprises a web 33 that is preferably flat, for example, also arranged in a plane parallel to the directions 17 and 21. The spar 32 of the fixed wing section is, for example, supplemented by ribs 35 integral with the web 33, and respectively fixed to the upper surface 34 and lower surface 36 of this fixed wing section 8. The forward spar 32, which has a structural function, thus extends parallel to the span direction 17, over substantially the entire length of the wing. It thus forms the fixed wing box 20 31 with the upper surface 34 and the lower surface 36, and a rear spar not visible in the figures. The wing box 31 conventionally provides a structural function to the wing, but it can also be at least partially filled with fuel.At the front of this box 31, the wall which forms the leading edge 10a of the fixed part 8 of the wing has a shape which is complementary or substantially complementary to that of the rear closing cover of the aerodynamic part of the flap 16.

[0074] As schematically illustrated in Figure 2A, each flap 16 is associated with two guidance and drive systems 40, spaced apart along the direction 17. These two systems 40 may be of identical or similar design. Thus, one of the features of the invention lies in the fact that the leading edge 10a of the fixed part 830 of the wing has only two openings 50 spaced apart along the direction 51601 AP-P

[0075] The wingspan is 17, and the two guide and drive systems 40 of the flap are respectively traversed by them. Only one of these two openings 50 is visible in Figure 2. They allow the flap to deploy and retract relative to the fixed part, and their reduced number limits drag and fuel consumption.

[0076] 5. The systems 40 allow the flap 16 to move from its retracted position to its deployed position, and vice versa. This preferably involves a rotational movement of the flap 16 about a rotation axis 18, combined with at least one other movement of the flap during at least part of this rotational movement, in particular to manage the flap's angle of attack and whether its trailing edge 13 is flush or not with the outer surface of the fixed part 8 of the wing. With reference now to Figures 2 to 11, one of the two guidance and drive systems 40 will be described according to a first preferred embodiment of the invention.

[0077] The system 40 comprises a moving part based on the implementation of a first assembly 52a for guiding and driving the flap, and a second assembly 52b for guiding this flap, this second assembly 52b being a follower assembly. The two assemblies 52a, 52b are adjacent along the span direction 17, for example, by bearing against each other, while allowing relative movement between them, preferably a sliding movement relative to each other in their interface plane. A sliding layer can be arranged between the first and second assemblies 52a, 52b to limit friction between them during their relative movement. Alternatively, a small clearance could be maintained between these two assemblies 52a, 52b in the span direction 17.

[0078] The first assembly 52a comprises a first guide rail 54a, and a drive track for the flap 56, which is integral with the first rail 54a. These two elements 54a and 56 are 25 pressed against each other along the span direction 17 and fixedly assembled to each other, preferably with screws 58. The drive track 56 is a toothed drive track, like a rack, with a general curvature identical or similar to that of the first rail 54a to which it is attached. It cooperates with a drive device also belonging to the system 40. The displacement device 51601 AP-P

[0079] includes a drive wheel 60 in contact with the track 56, this wheel 60 being set in motion by a motor 62 for example fixed on the front longitudinal member 32.

[0080] In this first preferred embodiment, the second flap guide assembly 52b includes a second guide follower rail 54b, having a rail web bearing 5 against a web of the second rail 54b. The two rails 54a, 54b can have a general C shape, arranged back-to-back in the span direction 17. Consequently, the first rail 54a is arranged between the drive track 56 and the second guide rail 54b, according to the span direction 17 in which these three elements are stacked.

[0081] As for the "follower" nature of the second guide rail 54b, which also characterizes the entire second assembly 52b, this is understood in a conventional manner. Indeed, the extension and retraction of the second rail 54b relative to the fixed part of the wing, during the extension and retraction of the flap, are caused by the movement of the flap, and not the other way around. In other words, the second rail 54b, nor any other element of the second assembly 52b, is associated with any drive means such as a rack, drive wheel, or similar elements, unlike the first rail 54a, and more generally the first assembly 52a. More precisely, it is the extension and retraction movement of the first drive rail 54a that is transmitted to the second rail 54b, via a connecting device 70 for the two rails, which is attached to the flap and will be described below.

[0082] It is noted that screws 59 can also pass through the second rail 54b, but simply for safety and with play, so that they do not hinder the relative movement capacity between the two rails, during the deployment and retraction movements of the shutter.

[0083] The system 40 also includes a guide device for the rails 54a, 54b, mounted on the fixed part 8 of the wing. This device is preferably implemented by guide rollers 25 64, distributed on either side of the two rails along the vertical direction, each of these rollers 64 contributing to the guidance of each of the first and second rails 54a, 54b. The rollers 64 may be common to both rails or separate for each rail, particularly in the case of an overhang of the training track 56 as shown in Figure 13A, which will be described below. 51601 AP-P

[0084] It is noted that the first rail 54a has two first guide tracks 66a facing opposite directions 21, and that the second rail 54b has two second guide tracks 66b also facing opposite directions 21. The first tracks 66a are preferably identical and parallel to each other, as are the second tracks 66b. However, the first tracks 66a have a different shape from the second tracks 66b. The first two guide tracks 66a are arc-shaped, while the two second guide tracks 66b may have a more complex curvilinear shape, dictated by the nature of the additional movement desired for the flap 16 relative to the first guide rail 54a, as will be explained below.

[0085] 10 Thus, each of the two opposing second guide tracks 66b has at least one part with a shape different from an arc of a circle, that is to say at least one part with a non-circular shape, of course intended to cooperate with the rollers as an integral part of the second guide tracks 66b.

[0086] For example, it is planned that two upper rollers 64 will each cooperate with the two upper tracks 66a, 66b of the rails, and two lower rollers 64 will each cooperate with the two lower tracks 66a, 66b of the rails.

[0087] One or more other guide rollers 68 may be provided for guiding the drive track 56, as can be seen in figures 3 and 4.

[0088] The system 40 also includes a connection device 70, allowing the 20 connection of the first and second rails 54a, 54b on the shutter.

[0089] More specifically, the connecting device 70 comprises a structural element 72 integral with the flap, with a body 74, corresponding, for example, to a plate fixed to the flap's closing cover 27 by means of screws, rivets, bolts, or other conventional fasteners. The structural element 72 can be considered a connecting rib, and even extend into the aerodynamic part 19 to form a transverse inner flap rib. Alternatively, its body 74, in addition to being fixed to the closing cover 27, can be attached directly to such a transverse inner flap rib. According to yet another alternative, the body 74 can be fixed to such a transverse inner flap rib by simply passing through the closing cover 27. Similar designs are also conceivable with a 51601 AP-P

[0090] fixing of body 74 on a flap spar, rather than on its closing cover 27.

[0091] In addition to the plate-forming body 74, the structural element 72 comprises first and second mounting lugs 76a, 76b, projecting rearward from this body and spaced 5 apart along the span direction 17. The structural element 72 thus takes the form of a two-headed yoke 76a, 76b. To ensure a fail-safe function, the connection device 70 may include a backup structural piece 78, for example, generally U-shaped, so as to double the body 74, as well as each of the first and second mounting lugs 76a, 76b. Such a piece, preferably made in one piece like the structural element 72 it doubles, is schematically represented in Figure 5. It is arranged here between the two lugs 76a, 76b.

[0092] The connecting device 70 first forms a first mechanical link 80a between a first front end of rail 82a provided on the first guide rail 54a, and the lugs 76a, 76b of the structural element 72. This first mechanical link 80a defines a first axis of rotation 84a, preferably parallel or substantially parallel to the span direction 17. To this end, the first mechanical link 80a includes a first pin 86a, centered on the first axis of rotation 84a. This pin 86a, for example formed using a bolt as shown in Figure 7, is mounted on each of the first and second fixing lugs 76a, 76b, which it passes through. The pin 86a is also mounted in an opening in the first front end of rail 82a, located between the two fixing lugs 76a, 76b. It can be ball-jointed, i.e. associated with a radial ball joint 88, allowing to accommodate the small parasitic movements of the flap.A slip can also be tolerated for the first front end of rail 82a, between the two fixing lugs 76a, 76b, along the rotation axis 84a.

[0093] It is noted that the first axis 86a also passes through the tabs of the spare part 78. In addition, the connecting device 70 forms a second mechanical link 80b between a second front rail end 82b provided on the second guide rail 54b, and the tabs 76a, 76b of the structural element 72. This second mechanical link 80b defines a second axis of rotation 84b, preferably parallel or substantially parallel to the span direction 17, and therefore parallel to the first axis of rotation 84a and distinct from 51601 AP-P

[0094] To achieve this, the second mechanical linkage 80b includes a second axis 86b, or pin, centered on the second axis of rotation 84b. This axis 86b, for example formed using a bolt, is mounted on each of the first and second mounting lugs 76a, 76b, which it passes through. The axis 86b is also mounted in an opening in the second front end of rail 82b, located between the two mounting lugs 76a, 76b, to the rear of the first axis 86b. In other words, the second front end of rail 82b stops before the first front end 82a, and also before the first axis 86a. Here too, the second axis 86b can be hinged, in the same way as the first axis 86a shown in Figure 7. In addition, the second axis 86b passes with play through a passage 90 made through the first front end of rail 82a.The play is large enough not to hinder the desired relative movement between the two rails 54a, 54b, during the opening and closing of the shutter.

[0095] As mentioned previously, Figure 2 shows flap 16 in the PO position, corresponding to the retracted position, adopted for example during cruise. Figure 9 shows flap 16 in a partially deployed P2 position, adopted for example during takeoff, while the PI position in Figure 8 corresponds to an intermediate position between PO and P2. Finally, Figure 10 shows flap 16 in the P3 position, corresponding to the fully deployed position, at the end of its deployment travel, adopted during landing.

[0096] 20. Preferably, in and between positions P0 to P2, the trailing edge 13 of the flap is in contact with the leading edge 10a of the fixed part of the wing, in order to prevent the circulation of the aforementioned external airflow 77 between these two parts. Also, preferably, it is only from the movement of the flap from position P2, towards and into position P3, that the space 5 is provided between the trailing edge 13 of the flap and the leading edge 10a of the fixed part of the wing, for the circulation of the external airflow 77.

[0097] These four positions P0-P3 have been plotted in Figure 11, illustrating the movement of the two mechanical linkages 80a, 80b during the flap's movement from its retracted to its deployed position. For clarity, the evolution of the position of their respective axes of rotation 84a, 84b has been represented in an X, Z coordinate system associated with the fixed part of the wing. 51601 AP-P

[0098] Furthermore, two trajectories 92a, 92b have been represented on this figure 11, corresponding respectively to the trajectories of the two rotation axes 84a, 84b in the X,Y frame. The first trajectory 92a has a shape identical to that of the first two guide tracks 66a of the first rail, while the second trajectory 92b has a shape identical to that of the second two guide tracks 66b of the second rail.

[0099] The system 40 is configured such that during at least a determined portion of the movement of the first and second rails 54a, 54b relative to the rollers 64, and more precisely during the end of the flap's travel towards its deployed position, the distinct interactions between the rollers 64 and the tracks 66a, 66b generate a relative displacement 10 of the two rails 54a, 54b relative to each other. This relative displacement, corresponding to a sliding motion of one relative to the other in their interface plane, causes the second rotation axis 84b to move upward relative to the first rotation axis 84b, by pivoting between the second front end of rail 82b and the tabs 76a, 76b. This pivoting generates another pivoting of the tabs 76a, 76b relative to the first front end of rail 82a, around the rotation axis 84a.This last movement causes the entire structural element 72 to pivot about the first forward end of the rail 82a, along the first axis of rotation 84a. With this pivoting, the entire flap 16 is rotated / pivoted about the axis 84a, in such a way that its trailing edge 13 moves away from the outer surface of the fixed part of the wing. It is this outward movement 20, observed at the end of the deployment stroke, that creates the gap 5 between the rear of the flap and the fixed part of the wing, as shown in Figure 10.

[0100] In Figure 11, the first trajectory 92a is represented as an arc of a circle centered on the rotation axis 18 of the flap. The second trajectory 92b can also be largely in the form of an arc of a circle centered on the rotation axis 18, before adopting at the end of its travel a more complex non-circular shape, triggering the desired relative displacement between the rails 54a, 54b.

[0101] The second trajectory 92b could be more complex, over a greater extent, particularly if necessary to keep the trailing edge 13 of the flap flush with the leading edge 10a of the fixed part of the wing, between positions PO and P2. More generally, the shape of this trajectory 92b allows control, in any case, of AP-P.

[0102] desired, the impact of the shutter at every point during its extension / retraction movement.

[0103] With reference now to Figures 12 and 13, a second preferred embodiment of the invention is shown, which differs from the previous embodiment essentially in that the drive track 56 is arranged between the first and second rails 54a, 54b. The sliding between the two assemblies 52a, 52b therefore takes place between the second rail 54b and the drive track 56.

[0104] In an alternative design shown in Figure 13A, the drive track 56 is partially arranged within the space defined between the webs of the two guide rails 54a, 54b. This track 56 can be designed to have a support portion 56a, with a reduced thickness along the span direction 17, so as to be positioned between the webs of the two rails and thus limit the lever arm between these guide rails 54a, 54b. The track 56 also includes an active portion 56b, equipped with teeth, and supported by the support portion 56a. The active portion 56b projects inward from the two rails relative to their curvature 15, so as to offset the teeth from the volume swept by the guide rails 54a, 54b. This active part 56b can therefore have, in the span direction, a thickness greater than that of the support part 56a.

[0105] In an alternative design shown in Figure 14, the first assembly 52a includes an additional rail 54a', for example, made in one piece with the first rail 54a. This design provides a recess between the two rails 54a, 54a', so as to accommodate the drive track 56. To achieve this, the double rail 54a, 54a' can take a general U or n shape. This allows the second rail 54b to slide along the additional rail 54a' of the first assembly.

[0106] Furthermore, in this second preferred embodiment, the emergency structural part 78 is 25 arranged externally with respect to the legs 76a, 76b.

[0107] Finally, with reference to Figures 15 and 16, a third preferred embodiment is shown, in which the change lies in the design of the connecting device 70. In this embodiment, the stacking order of elements 54a, 54b, 56 can be any one of those considered previously. 51601 AP-P

[0108] Here, the connecting device 70 also includes a third mounting lug 76c projecting rearward from the body, arranged so that the second lug 76b lies between the first and third lugs 76a, 76c, along the span direction 17. It is therefore a three-headed clevis-shaped rib, the two lugs 76b, 76c extending 5 meters rearward beyond the shorter first lug 76a. In this configuration, the first mechanical linkage 80a comprises the first shaft 86a mounted on each of the first and third mounting lugs, and passing through a through-hole 94 formed through the second mounting lug 76b. Alternatively, the first shaft 86a could be mounted on each of the first and second mounting lugs 76a, 76b, and passing through a through-hole formed through the third mounting lug 76c.In all cases, this axle 86a is also mounted on the first front end of rail 82a, located between lugs 76a and 76b, in a manner similar to that described for the preceding configurations. Furthermore, further back, the second mechanical linkage 80b includes the second axle 86b, mounted on each of the second and third mounting lugs 76b and 76c. This axle 86b is also mounted on the second front end of rail 82b, located between lugs 76b and 76c, in a manner similar to that described in the preceding configurations.

[0109] In this third preferred embodiment, the third fixing tab 76c enables the "Fail Safe" backup function to be formed in case of failure of either of the other two tabs 76a, 76b.

[0110] As mentioned previously, the invention can be implemented by allowing relative movement of the movable flap 16 with respect to the rail ends, sliding on the mechanical connecting axes 84a and 84b, in the span direction. Conversely, the invention can be designed to block these relative movements in this span direction, between the flap and the rail ends.

[0111] 25 Where such relative movements are permitted by the design, they can be used to accommodate the pivoting effects of the rails observed during their extension. Within the same guide system 40, the sliding directions between the two elements can then be reversed at the two mechanical connecting axes 84a, 84b of the system 40.51601 AP-P 19

[0112] Of course, various modifications can be made by a person skilled in the art to the invention just described, by way of non-limiting examples only. In particular, the elements of the different embodiments and their alternatives are interchangeable or combinable. For example, if two guide systems 40 have been described for equipping the same movable flap, it should be noted that the number of these systems 40 could be greater.

[0113] 10

Claims

1. 51601 AP-P DEMANDS 1. A system (40) for guiding and driving a movable leading-edge flap (16) for an aircraft wing, the flap being intended to be mounted on a fixed part (8) of the wing, 5 so as to be able to be moved between a retracted position and a deployed position relative to the fixed part (8) of the wing, characterized in that the system comprises: - a first assembly (52a) for guiding and driving the shutter, comprising a first guide rail (54a), as well as a drive track (56) for the shutter, the first guide rail (54a) and the drive track (56) being integral; characterized in that the system also includes: - a second assembly (52b) for guiding the flap, adjacent to the first assembly (52a) along a span direction (17) of the flap, the second assembly comprising a second guide follower rail (54b); - a guide device (64) for the first and second rails, intended to be mounted on the fixed part 15 of the wing; - a connecting device (70) for connecting the first and second guide rails (54a, 54b) to the movable shutter, the connecting device comprising a structural element (72) intended to be integral with the shutter, this device (70) forming: - a first mechanical link (80a) between a first front end of rail (82a) of the first rail and the structural element (72), the first mechanical link (80a) defining a first axis of rotation (84a); and - a second mechanical link (80b) between a second front end of rail (82b) of the second rail and the structural element (72), the second mechanical link (80b) defining a second axis of rotation (84b) distinct from the first axis of rotation (84a) and parallel to it - 25 ci, the system being configured such that during at least a determined part of a displacement of the first and second rails (54a, 54b) relative to their guiding device (64), the first and second rails undergo a relative displacement with respect to each other, causing the structural element (72) of the connecting device (70) to move by 51601 AP-P relative to the first front end of rail (82a), pivoting relative to this first front end of rail, along the first axis of rotation (84a).

2. System according to claim 1, characterized in that the first rail (54a) comprises two first opposing guide tracks (66a) each cooperating with the guide device (64), in that the second rail (54b) comprises two second opposing guide tracks (66b) each cooperating with the guide device (64), and in that the first tracks (66a) have a different shape from that of the second tracks (66b).

3. System according to claim 2, characterized in that the first two guide tracks (66a) are in the shape of an arc of a circle, and in that each of the two second 10 opposite guide tracks (66b) has at least one part of non-circular shape.

4. System according to any one of the preceding claims, characterized in that the first mechanical linkage (80a) is located in front of the second mechanical linkage (80b).

5. System according to any one of the preceding claims, characterized in that the guidance device comprises several guide rollers (64), each participating in the guidance of the first and second rails (54a, 54b).

6. System according to any one of the preceding claims, characterized in that the first guide and drive assembly (52a) of the flap is supported against the second guide assembly (52b) of the flap, a sliding layer being able to be arranged between the first and second guide assemblies.

7. System according to any one of the preceding claims, characterized in that the drive track (56) of the flap is arranged between the first and second rails (54a, 54b), in the span direction (17), or in that the first guide rail (54a) is arranged between the drive track (56) of the flap and the second guide rail (54b), in the span direction (17).

8. System according to any one of the preceding claims, characterized in that the drive track (56) of the flap is a toothed drive track.

9. A system according to any one of the preceding claims, characterized in that the drive track (56) of the shutter is fixed to the first guide rail (54a), preferably by means of screws (58). 51601 AP-P 10. System according to any one of the preceding claims, characterized in that the structural element (72) of the connecting device (70) comprises a body (74), as well as a first and a second fixing lug (76a, 76b) projecting from this body (74) towards the rear, and being spaced from each other along the span direction (17). 5 11. System according to claim 10, characterized in that the first mechanical link (80a) comprises a first axis (86a) mounted on each of the first and second fixing lugs (76a, 76b), and in that the second mechanical link (80b) comprises a second axis (86b) mounted on each of the first and second fixing lugs (76a, 76b), and passing through a passage hole (90) made through the first front end of rail 10 of the first rail (82a).

12. System according to claim 10 or 11, characterized in that the connecting device (70) comprises a structural backup part (78), doubling the body (74), as well as each of the first and second fixing lugs (76a, 76b).

13. System according to claim 10, characterized in that the structural element (72) of the connecting device (70) also comprises a third fixing lug (76c) projecting from the body (74) towards the rear, and arranged so that the second fixing lug (76b) is located between the first and third fixing lugs (76a, 76c) along the span direction (17), in that the first mechanical linkage (80a) comprises a first axis (86a) mounted on each of the first and third fixing lugs (76a, 76c), and 20 passing through a passage orifice (94) made through the second fixing lug (76b), and in that the second mechanical linkage (80b) comprises a second axis (86b) mounted on each of the second and third fixing lugs (76b, 76c).

14. Aircraft wing (4) comprising a fixed wing portion (8), a movable leading-edge flap (16), and a guidance and drive system (40) for the movable flap (16) according to any one of the preceding claims, the fixed wing portion having a leading edge (10a) with an opening (50) through which the first and second adjacent assemblies (52a, 52b) of the flap guidance and drive system pass, and, preferably, the movable flap (16) is associated with two guidance and drive systems (40) spaced apart along the wingspan direction (17) of the flap, the leading edge (10a) of the fixed wing portion having two openings (50) spaced apart. the other along the span direction (17), and respectively crossed by the two systems (40) for guiding and driving the flap.

15. Wing according to the preceding claim, characterized in that each guidance and drive system (40) of the movable flap (16) is configured so that during the end of the flap's travel towards its deployed position, the relative displacement of the first and second rails (54a, 54b) causes the structural element (72) of the connecting device (70) to move relative to the first forward end of the rail (82a), so that a trailing edge (13) of the movable flap (16) moves away from the fixed part (8) of the wing.

16. Aircraft (1) comprising at least one wing (4) according to any one of the 10 claims 14 and 15.

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