High-lift device

Abstract

A high-lift device is provided that can sufficiently exert performance. The high-lift device includes a wing, a flap configured to be retracted in a storage communicating with a leading edge of the wing and to be extended to a front side of the leading edge, and a link mechanism configured to move the flap between a standby position where the flap is retracted in the storage and a deployment position where the flap is extended to the front side. The wing's leading edge includes an interference-avoidance aperture through which a link member in the link mechanism moves in and out when the link member moves between the standby and deployment positions.

Description

HIGH-LIFT DEVICE

[0001] The disclosure relates to a Krueger Flap as a high-lift device on the leading edge of an aircraft’s main wing.

[0002] As a high-lift device used during takeoff and landing of an aircraft, a slat mounted on the leading edge of a main wing is generally used. A Krueger Flap has attracted attention as a leading-edge high-lift device instead of a slat. The Krueger Flap has at least two distinctive features compared to the slat described below. To maintain laminar flow and reduce aerodynamic drag, the Krueger Flap can increase the smoothness of the front and upper surfaces of the main wing. When the smoothness is increased, the Krueger Flap can prevent turbulent transition due to contamination of the leading edge caused by insect adhesion and so on by being largely extended to protect the front and upper surfaces of the main wing from the lower surface side. The Krueger Flap has the potential to generate lower noise levels than the conventional slat during aircraft takeoff and landing. For example, PTL 1 discloses a high-lift device that can more appropriately set a flap’s position and angle based on an aircraft’s flight state. The high-lift device disclosed in PTL 1 includes a first link mechanism connected to a first rotary shaft and the flap and a second link mechanism connected to a second rotary shaft and the flap.

[0003] JP 2019-151200 A

[0004] A Krueger Flap has a complicated mechanical structure. Therefore, the Krueger Flap has a significant weight and requires space to store an intricate mechanism. Thus, the Krueger Flap is exclusively applied to a large aircraft or only to an inboard wing portion where space is relatively easily secured. The high-lift device disclosed in PTL 1 includes the two link mechanisms and the two rotary shafts. Therefore, the mechanical structure is complicated, and the weight is increased. As described above, the Krueger Flap cannot secure sufficient performance in some cases because an application target and an application location are limited. Therefore, the present disclosure aims to provide a high-lift device that can sufficiently exert its performance.

[0005] According to the present disclosure, a high-lift device includes a wing, a flap configured to be retracted in a storage communicating with a leading edge of the wing and extended to a front side of the leading edge, and a link mechanism configured to move the flap between a standby position where the flap is retracted in the storage and a deployment position where the flap is extended to the front side. The wing’s leading edge includes an interference-avoidance aperture through which a link member in the link mechanism moves in and out when the link member moves between the standby and deployment positions.

[0006] According to the high-lift device of the present disclosure, the wing’s leading edge includes the interference-avoidance aperture through which the link member in the link mechanism moves in and out when the link member moves between the standby and deployment positions. Thus, the high-lift device of the present disclosure allows the flap to be extended until maximum lift is achieved, enabling the flap to perform effectively.

[0007] FIG. 1 is a vertical cross-sectional view illustrating a high-lift device according to an embodiment;FIG. 2 is a perspective view of the high-lift device according to the embodiment as viewed from above;FIG. 3 is a perspective view of the high-lift device according to the embodiment as viewed from below;FIG. 4 is a vertical cross-sectional view illustrating the operation of the high-lift device according to the embodiment;FIG. 5 is a perspective view illustrating the operation of the high-lift device according to the embodiment as viewed from above;FIG. 6 is a perspective view illustrating the operation of the high-lift device according to the embodiment as viewed from below;FIG. 7 illustrates examples of an opening / closing structure for opening and closing an interference-avoidance aperture of the high-lift device according to the embodiment; andFIG. 8 illustrates examples of the opening / closing structure for opening and closing the interference-avoidance aperture of the high-lift device according to the embodiment.

[0008] An embodiment is described below with reference to the accompanying drawings. A high-lift device 1 includes a flap 2 on the leading edge 51 of the main wing 50 of an aircraft. When the flap 2 is extended forward during takeoff or landing, as illustrated in S03 in each of FIG. 4, FIG. 5, and FIG. 6, the high-lift device 1 can enhance a lift coefficient. The flap 2 includes two elements: the first flap element 5 and the second flap element 6. During a cruising flight of the aircraft, as illustrated in S01 in each of FIG. 4, FIG. 5, and FIG. 6, the first flap element 5 is retracted in the storage 55 of the main wing 50, and the second flap element 6 forms a part of the lower surface 57 of the main wing 50. As illustrated in FIG. 3 and FIG. 6, an interference-avoidance aperture 53 is provided in the leading edge 51 of the main wing 50, which makes it possible to enlarge the movable range of the flap of the high-lift device 1.

[0009] <Configuration of High-lift Device 1: See FIG. 1, FIG. 2, and FIG. 3> The high-lift device 1 forms the flap 2 at a deployment position by transmitting the operation of standard rotation or reverse rotation of a driving shaft 3 through a link mechanism 10. Each of the first flap element 5 and the second flap element 6 forming the flap 2 serves as one of the components of the link mechanism 10. In other words, the link mechanism 10 includes the function of the flap by itself.

[0010] <Flap 2 (First Flap Element 5)> The flap 2 is a member with a wing shape that is long in one direction and installed along the spanwise direction W of the main wing 50 on the leading edge 51. As described above, the flap 2 includes the first flap element 5 and the second flap element 6. The first flap element 5 includes a flap main body 5A and a coupling arm 5B. When the high-lift device 1 is at the deployment position, the flap main body 5A contributes to lift improvement. The coupling arm 5B is provided integrally with the flap main body 5A, which is pin-coupled to a second driven link 15 of the link mechanism 10 that extends the flap 2. The coupling arm 5B is provided inside the flap main body 5A on the lower surface side when the flap 2 is extended. The flap main body 5A of the first flap element 5 is also pin-coupled to a first driven link 13 of the link mechanism 10. The flap main body 5A includes a first flap-forming surface 5C.

[0011] <Link Mechanism 10: See FIG. 1, FIG. 2, and FIG. 3> First, the members included in the link mechanism 10 are described. In the link mechanism 10, both the driving link and the two driven links swing. As will be explained in detail below, the first driven link 13 and the second driven link 15 of the link mechanism 10 perform their swinging motion due to the motion of the driving link 11.

[0012] The link mechanism 10 includes the driving link 11 performing a swinging motion caused by standard rotation or reverse rotation of the driving shaft 3, and the first driven link 13 and the second driven link 15 swinging in response to the motion of the driving link 11. The driving link 11 and the first driven link 13 are coupled by a transmission link 17, and the driving link 11 and the second driven link 15 are also coupled by the transmission link 17. In other words, the first driven link 13 and the second driven link 15 are coupled to the driving link 11 through the common transmission link 17. The flap 2 is coupled between the first driven link 13 and the second driven link 15. The flap 2 is also a link member interposed between the first driven link 13 and the second driven link 15.

[0013] Next, a configuration of each of the link members is described. The driving link 11 has a shape straightly extending in a radial direction RD (see FIG. 1) relative to the driving shaft 3. The second driven link 15 has a shape substantially straightly extending even though a part thereof is bent. The transmission link 17 also has a similar shape.

[0014] The first driven link 13 includes three elements: a first link element 13A to which the transmission link 17 is coupled, a second link element 13B coupled to the flap 2, and a third link element 13C connecting the first link element 13A and the second link element 13B. Each of the first link element 13A, the second link element 13B, and the third link element 13C has a straight shape. The third link element 13C intersects with the first link element 13A, and the third link element 13C intersects with the second link element 13B. The first link element 13A and the third link element 13C are connected in an L-shape, and the second link element 13B and the third link element 13C are connected in a T-shape.

[0015] A part of the first driven link 13 functions as the flap at the deployment position. More specifically, the second link element 13B and the first flap element 5 form the flap 2. Therefore, the second link element 13B forms the second flap element 6.

[0016] Next, a coupling state of the link members is described. The term "coupling of the link members" herein means that the link members form a rotating pair and are connected in an oscillating manner. The driving link 11 is fixed to the driving shaft 3. It performs a swinging motion within a predetermined rotation angle around the driving shaft 3 by standard rotation or reverse rotation of the driving shaft 3. The driving shaft 3 is rotatably supported by the main wing 50.

[0017] One end of the transmission link 17 is pin-coupled to the driving link 11 by a first pin 21. The other end of the transmission link 17 is coupled to the second driven link 15 by a second pin 22 and to the third link element 13C of the first driven link 13 by a third pin 23. The first driven link 13 is pin-coupled to the main wing 50 by a fourth pin 24. Therefore, a fixed link (unillustrated) of the link mechanism 10 is present between the driving shaft 3 and the first driven link 13. One end of the second driven link 15 is coupled to the transmission link 17 by the second pin 22, and the other end of the second driven link 15 is coupled to the coupling arm 5B of the flap 2 by a fifth pin 25. In the flap 2, one end of the coupling arm 5B is coupled to the second driven link 15 by the fifth pin 25, and one end of the flap main body 5A is coupled to the first driven link 13 by a sixth pin 26.

[0018] An outline of the operation of the link mechanism 10 is described. The driving shaft 3 is rotated counterclockwise in the drawing in the standard rotation to extend the flap 2. As a result, the driving link 11 is rotated counterclockwise, and the transmission link 17 is accordingly displaced leftward in the drawing. When the transmission link 17 is displaced leftward, the first driven link 13 is rotated clockwise in the drawing through the third pin 23. With the rotation, the first flap element 5 coupled to the second link element 13B of the first driven link 13 through the sixth pin 26 is also rotated clockwise. Since the coupling arm 5B of the first flap element 5 is coupled to the second driven link 15, the first flap element 5 is rotated clockwise for extension while being restrained by the second driven link 15. In an above-described manner, the link mechanism 10 converts the rotation operation of the driving shaft 3 into the extension operation of the flap 2 through the two link members, namely, the first driven link 13 and the second driven link 15. Since the transmission link 17 is coupled to both the first driven link 13 and the second driven link 15, the transmission link 17 realizes the swinging motion of the first flap element 5 and the second flap element 6 (second link element 13B) from the rotation operation of the driving shaft 3.

[0019] <Interference-avoidance aperture of Main Wing 50 for Link Mechanism 10: See FIG. 3> In the process of rotating the flap 2 to the deployment position by the link mechanism 10, interference of the link members included in the link mechanism 10 with the main wing 50 is anticipated. The rotation angle can be suppressed to avoid interference with the main wing 50; however, when the rotation angle is suppressed, the lift generated by the flap 2 is insufficient, and the contamination of the leading edge caused by insect adhesion cannot be managed. Therefore, to avoid interference with the link mechanism 10, the main wing 50 includes the interference-avoidance aperture 53 at a necessary portion of the leading edge 51 of the main wing 50.

[0020] The interference-avoidance aperture 53 is bored through the front and back of the main wing 50 on the underside of the leading edge 51 of the main wing 50. The interference-avoidance aperture 53 is formed along the chordwise direction L of the main wing 50. Dimensions of the opening in the chordwise direction L and the spanwise direction W are determined such that the link mechanism 10 does not interfere with the main wing 50 even when the link mechanism 10 reaches the deployment position.

[0021] The entire interference-avoidance aperture 53 is preferably located below a stagnation point 59 on the leading edge 51 of the main wing 50. The interference-avoidance aperture 53 and flap 2 create irregularities on the surface of the main wing 50 when they are in the standby position. When the interference-avoidance aperture 53 is positioned below the stagnation point, the irregularities do not affect the laminarization process on the upper surface 58.

[0022] <Extension Operation of Link Mechanism 10: See FIG. 4 to FIG. 6> Next, the extension operation of the link mechanism 10 is described. In FIG. 4 to FIG. 6, S01 illustrates the standby position, S02 illustrates a middle position, and S03 illustrates the deployment position. When the driving shaft 3 is rotated at the standby position (S01), the driving link 11 is rotated counterclockwise, and the transmission link 17 rotates the first driven link 13 and the second driven link 15 in the clockwise direction. The first flap element 5 is coupled to the first driven link 13 and the second driven link 15 and is rotated clockwise while being supported by the first driven link 13 and the second driven link 15 (S02). At this time, the second link element 13B forming the second flap element 6 is also rotated. The driving shaft 3 is further rotated until the driving link 11 and the transmission link 17 form a linear shape (S03). As a result, the link mechanism 10 reaches the deployment position where the first flap-forming surface 5C of the first flap element 5 and a second flap-forming surface 13D of the second link element 13B are flush with each other to form a flap surface 4. At the deployment position, the transmission link 17 is inserted into the interference-avoidance aperture 53 of the leading edge 51 (S03 in FIG. 6). This prevents the transmission link 17 from interfering with the leading edge 51.

[0023] <Effects Achieved by High-lift Device 1> The high-lift device 1 includes, in the main wing 50, the interference-avoidance aperture 53 into which the transmission link 17 is inserted as one element of the link mechanism 10 when the link mechanism 10 is at the deployment position. Therefore, the flap 2 as the high-lift device 1 can be extended until the maximum lift is obtained, which makes it possible to exert the performance of the flap 2 sufficiently. In addition, according to the high-lift device 1, it is possible to prevent leading-edge contamination.

[0024] Since the link mechanism 10 of the high-lift device 1 contains only one driving shaft 3, its mechanical structure is simple, allowing for reduced weight. Therefore, the high-lift device 1 can be utilized on large, middle, or small aircraft.

[0025] In the high-lift device 1, the flap 2 includes two elements: the first flap element 5 and the second flap element 6. At the standby position, the first flap element 5 and the second flap element 6 are folded. The first flap element 5 is retracted in the storage 55 of the main wing 50, and the second flap element 6 forms part of the lower surface 57 of the main wing 50. On the other hand, when the flap 2 is extended, the first flap-forming surface 5C and the second flap-forming surface 13D are flush with each other to generate sufficient lift. Accordingly, the high-lift device 1 can be applied to a middle or small aircraft or an outboard wing portion with narrow storage space.

[0026] <Opening and Closing of Interference-avoidance aperture 53: See FIG. 7 and FIG. 8> The interference-avoidance aperture 53 is desirably closed when the high-lift device 1 is at the standby position. Therefore, in the present embodiment, any opening / closing structures 60 for opening and closing the interference-avoidance aperture 53 are preferably provided. In the following, several exemplary opening / closing structures 60 are described. Although opening / closing structures 61, 62, 63, and 64 are exemplified, these opening / closing structures are collectively referred to as the opening / closing structures 60.

[0027] The opening / closing structure 61 extends one end of the second flap element 6. When the illustrated flap 2 is at the deployment position, the opening / closing structure 61 is moved away from the interference-avoidance aperture 53 to open the interference-avoidance aperture 53. The opening / closing structure 61 closes the interference-avoidance aperture 53 when the flap 2 is at the standby position. With the movement of the flap 2 from the standby position to the deployment position, the opening / closing structure 61 closing the interference-avoidance aperture 53 moves away from the interference-avoidance aperture 53 to open the interference-avoidance aperture 53.

[0028] The opening / closing structure 62 includes a door performing a swinging motion, as illustrated by a double-pointed arrow. The opening / closing structure 62 moves outward from the leading edge 51. When the illustrated flap 2 is at the deployment position, the opening / closing structure 62 is moved away from the interference-avoidance aperture 53 to open the interference-avoidance aperture 53. The opening / closing structure 62 closes the interference-avoidance aperture 53 when the flap 2 is at the standby position. With the movement of the flap 2 from the standby position to the deployment position, the opening / closing structure 62 moves away from the interference-avoidance aperture 53 by being rotated clockwise in the drawing to open the interference-avoidance aperture 53. In contrast, with the movement of the flap 2 from the deployment position to the standby position, the opening / closing structure 62 is rotated counterclockwise in the drawing to close the interference-avoidance aperture 53.

[0029] The upper part of FIG. 8 illustrates a specific example of the opening / closing structure 62. The opening / closing structure 62 includes a door 62A, first supporting links 62B, each having one end supported, with a revolute pair, to an upper side of the door 62A in the drawing, and second supporting links 62C, each having one end supported, with a revolute pair, to a lower side of the door 62A in the drawing. The other end of each of the first supporting links 62B and the second supporting links 62C is supported, with a revolute pair, to any of the structures of the wing 50. As described above, the opening / closing structure 62 forms a quadric link mechanism, particularly in which the first supporting links 62B and the second supporting links 62C swing.

[0030] The link mechanism 10 is operated from the standby position toward the deployment position. As a result, the transmission link 17 pushes up a lower end 62F of the door 62A, and the door 62A moves away from the interference-avoidance aperture 53 to open the interference-avoidance aperture 53. When the transmission link 17 returns to the standby position, the door 62A returns to a position where gravity closes the interference-avoidance aperture 53. To smoothly return the door 62A to the position where the interference-avoidance aperture 53 is closed when the transmission link 17 returns to the standby position, for example, a torsion spring 62D may be provided on each of the second supporting links 62C. The torsion springs 62D apply loads in the counterclockwise direction in the drawing to the second supporting links 62C. The torsion springs 62D apply to the opening / closing structure 63 described below. The lower end 62F of the door 62A is pushed up by the transmission link 17. A roller 62E can be provided on the lower end 62F to reduce resistance. The roller 62E applies to the opening / closing structure 63 described below.

[0031] The opening / closing structure 63 includes a shutter that moves upward and downward, as illustrated by a double-pointed arrow. When the illustrated flap 2 is at the deployment position, the opening / closing structure 63 is moved away from the interference-avoidance aperture 53 to open the interference-avoidance aperture 53. The opening / closing structure 63 closes the interference-avoidance aperture 53 when the flap 2 is at the standby position. With the movement of the flap 2 from the standby position to the deployment position, the opening / closing structure 63 moves upward in the drawing to be away from the interference-avoidance aperture 53 to open the interference-avoidance aperture 53. In contrast, with the movement of the flap 2 from the deployment position to the standby position, the opening / closing structure 63 moves downward in the drawing to close the interference-avoidance aperture 53.

[0032] A lower part in FIG. 8 illustrates a specific example of the opening / closing structure 63. The opening / closing structure 63 includes a shutter 63A, a pair of swing arms 63B supporting the shutter 63A, and a pair of guides 63C guiding the movement of the shutter 63A. The swing arms 63B are each supported, with a revolute pair, to any of the structures of the wing 50.

[0033] The link mechanism 10 is operated from the standby position toward the deployment position. As a result, the transmission link 17 pushes up a lower end 63F of the shutter 63A, and the shutter 63A moves away from the interference-avoidance aperture 53 to open the interference-avoidance aperture 53. When the transmission link 17 returns to the standby position, the shutter 63A returns to a position where gravity closes the interference-avoidance aperture 53.

[0034] The opening / closing structure 64 includes a pair of seals 64A and 64B, each made of, for example, a rubber. It closes the interference-avoidance aperture 53 by the pair of seals 64A and 64B, as illustrated by a solid line in the drawing. Each of the seals 64A and 64B is cantilever-supported to face the interference-avoidance aperture 53. The seals 64A and 64B are easily elastically deformable. Therefore, for example, when the transmission link 17 pushes the seals 64A and 64B, the seals 64A and 64B are deflected to enable the transmission link 17 to enter the interference-avoidance aperture 53.

[0035] The opening / closing structures 60 described above have in common that the opening / closing structures 60 close the interference-avoidance aperture 53 when the flap 2 is in the standby position and open the interference-avoidance aperture 53 when the flap 2 is in the deployment position. In addition, these opening / closing structures 60 have in common that the opening / closing structures 60 open the interference-avoidance aperture 53 with the movement of the flap 2 from the standby position to the deployment position and close the interference-avoidance aperture 53 with the movement of the flap 2 from the deployment position to the standby position.

[0036] <Notes> The present disclosure can be understood as follows. <Note 1> A high-lift device (1) of the present disclosure, including: a wing (50); a flap (2) configured to be retracted in a storage (55) communicating with a leading edge (51) of the wing (50) and to be extended to a front side of the leading edge (51); and a link mechanism (10) configured to move the flap (2) between a standby position where the flap (2) is retracted in the storage (55) and a deployment position where the flap (2) is extended to the front side, in which the leading edge (51) of the wing (50) includes an interference-avoidance aperture (53) through which a link member (17) included in the link mechanism (10) moves in and out when the link member (17) moves between the standby and deployment positions.

[0037] <Note 2> The high-lift device (1), according to Note 1, in which the link mechanism (10) preferably includes a driving link (11), a first driven link (13) and a second driven link (15), and a transmission link (17) configured to couple the driving link (11) and the first driven link (13) and to couple the driving link (11) and the second driven link (15), the first driven link (13) and the second driven link (15) perform swinging motion by swinging motion of the driving link (11) and the transmission link (17) moves in and out through the interference-avoidance aperture (53).

[0038] <Note 3> The high-lift device (1), according to Note 2, in which the flap (2) preferably includes a first flap element (5) pin-coupled to both the first driven link (13) and the second driven link (15) and a second flap element (6) serving as a part of the first driven link (13).

[0039] <Note 4> The high-lift device (1), according to Note 3, in which, preferably, at the standby position, the first flap element (5) and the second flap element (6) are folded, the first flap element (5) is retracted in the storage (55), and the second flap element (6) forms a part of a lower surface (57) of the wing (50), and at the deployment position, the first flap element (5) and the second flap element (6) are extended to the front side of the leading edge (51) to form a flush flap surface (4).

[0040] <Note 5> The high-lift device (1), according to any one of Note 1 to Note 4, preferably further including an opening / closing structure (60) configured to close the interference-avoidance aperture (53) at the standby position and to open the interference-avoidance aperture (53) at the deployment position. The opening / closing structure (60) is preferably configured to close the interference-avoidance aperture (53) when the flap (2) is at the standby position and to open the interference-avoidance aperture (53) when the flap (2) is at the deployment position.

[0041] <Note 6> The high-lift device (1), according to Note 5, in which the opening / closing structure (60) preferably opens the interference-avoidance aperture (53) with movement of the flap (2) from the standby position to the deployment position and closes the interference-avoidance aperture (53) with movement of the flap (2) from the deployment position to the standby position.

[0042] Other than the above description, the configurations described in the above-described embodiment can be selected or appropriately changed to different configurations.

[0043] 1 high-lift device 2 flap 3 driving shaft 4 flap surface 5 first flap element 5A flap main body 5B coupling arm 5C first flap-forming surface 6 second flap element 10 link mechanism 11 driving link 13 first driven link 13A first link element 13B second link element 13C third link element 13D second flap-forming surface 15 second driven link 17 transmission link 21 first pin 22 second pin 23 third pin 24 fourth pin 25 fifth pin 26 sixth pin 50 main wing 51 leading edge 53 interference-avoidance aperture 55 storage 57 lower surface 58 upper surface 59 stagnation point 60,61,62,63,64 opening / closing structure 62A door 62B first supporting links 62C second supporting links 62D torsion spring 62E roller 62F lower end 63A shutter 63B swing arms 63C guides 63F lower end

Claims

1. A high-lift device comprising: a wing; a flap configured to be retracted in a storage communicating with a leading edge of the wing and to be extended to a front side of the leading edge and a link mechanism configured to move the flap between a standby position where the flap is retracted in the storage and a deployment position where the flap is extended to the front side, wherein the leading edge of the wing includes an interference-avoidance aperture through which a link member in the link mechanism moves in and out when the link member moves between the standby and deployment positions.

2. The high-lift device, according to claim 1, wherein the link mechanism includes a driving link, a first driven link, a second driven link, and a transmission link configured to couple the driving link and the first driven link and to couple the driving link and the second driven link, the first and second driven links perform swinging motion by swinging motion of the driving link and the transmission link moves in and out through the interference-avoidance aperture.

3. The high-lift device, according to claim 2, wherein the flap includes a first flap element pin-coupled to both the first and second driven links and a second flap element serving as a part of the first driven link.

4. The high-lift device, according to claim 3, wherein at the standby position, the first and second flap elements are folded, the first flap element is retracted in the storage, and the second flap element forms a part of a lower surface of the wing and at the deployment position, the first and second flap elements are extended to the front side of the leading edge to form a flush flap surface.

5. The high-lift device, according to claim 1, further comprising an opening / closing structure configured to close the interference-avoidance aperture when the flap is at the standby position and to open the interference-avoidance aperture when the flap is at the deployment position.

6. The high-lift device, according to claim 5, wherein the opening / closing structure opens the interference-avoidance aperture with movement of the flap from the standby position to the deployment position and closes the interference-avoidance aperture with movement of the flap from the deployment position to the standby position.

Images