Latch mechanism and manufacturing method thereof, latch system, aircraft wing and aircraft

Abstract

The invention relates to a latch mechanism and a method of manufacturing the same, a latch system, an aircraft wing and an aircraft, and more particularly to a latch mechanism (12) for locking an aircraft folding wing. The mechanism comprises at least one lug (13, 14) having an aperture (15a-15f) and a latch pin (16) movable within the aperture between a latched configuration in which the latch pin is received in the aperture and an unlatched configuration in which the latch pin is withdrawn from the aperture. At least a portion of one of the pin (16) and the aperture (15a-15f) has a hydrophobic coating. A hydrophobic coating may be applied to all apertures and / or latch pins in the mechanism. The provision of the hydrophobic coating helps prevent moisture formation on the latch pin and / or in the aperture and thus ice formation that can inhibit movement of the pin into and out of its latched position along the aperture.

Description

Technical Field

[0001] This invention relates to a latching mechanism for locking folding wings of an aircraft. The invention also relates to a latching system including such a latching mechanism; an aircraft wing including a latching mechanism; and an aircraft including a latching mechanism. The invention further relates to a method of manufacturing the latching mechanism. Background Technology

[0002] Civil aircraft design has evolved to meet the growing demand for larger and more efficient aircraft, which typically require larger wingspans. Folding wingtips have emerged as a compromise between larger wingspans and airport gate compatibility. In a typical wing design, the wing comprises a fixed wing section and a wingtip assembly at the tip of the fixed wing, which can rotate relative to the fixed wing between an extended configuration used during flight and a folded configuration used during ground-based operations. By allowing the outer wingtip to fold relative to the fixed wing, the effective wingspan can be reduced to accommodate gate and storage dimensions.

[0003] Known folding wings can have a releasable latching mechanism comprising a latching pin having at least one latching hole or orifice in the form of a lug or bushing. The latching mechanism can be configured between a latched configuration and an unlatched configuration, in which the latching pin is received in the latching orifice to lock the wingtip assembly in either a flight configuration or a ground configuration; and in an unlatched configuration, the latching pin is withdrawn from the latching orifice, allowing the wingtip assembly to move from either the flight or ground configuration to the other, respectively. Such a latching mechanism is arranged to ensure that each wingtip is securely locked in place during flight and is arranged to safely and efficiently release each wingtip for folding when the aircraft is on the ground.

[0004] A potential problem with conventional folding wingtip systems is ice formation on their components. Ice forms due to moisture from rain and other atmospheric conditions depositing on the wingtip system components and then freezing. Ice can form on components at any stage of flight or ground operation, and even when the aircraft is parked. Such ice buildup can prevent the proper operation of the latching mechanism by inhibiting the movement of the latch pins between the locked and unlocked positions. This can affect aircraft operation. For example, during landing, if the wings cannot fold, the aircraft may not be allowed to approach the gate. Similarly, if the wings cannot be extended in a flight configuration, the aircraft will be prevented from taking off. Summary of the Invention

[0005] A first aspect of the invention provides a latching mechanism including a lug and a latching pin. The lug has an orifice, and the latching pin is movable within the orifice between a latched configuration and an unlatched configuration. In the latched configuration, the latching pin is received in the orifice, while in the unlatched configuration, the latching pin is withdrawn from the orifice. At least a portion of either the pin or the orifice has a hydrophobic coating. The hydrophobic coating helps prevent the formation of moisture on the latching pin and / or in the orifice, and thus prevents the formation of ice, which could inhibit the pin from moving along the orifice into and from its latched position.

[0006] Preferably, the latching mechanism further includes a plurality of lugs having corresponding orifices, wherein at least some of the orifices have a hydrophobic coating. The orifice, or each orifice, may be in the form of a bushing.

[0007] Advantageously, the pin and the orifice or multiple orifices each have a hydrophobic coating.

[0008] Preferably, the hydrophobic coating comprises a wax. This may include natural waxes, such as carnauba wax and / or beeswax.

[0009] Hydrophobic coatings can include carbon or diamond-like carbon. Such coatings are highly elastic and typically also have a low coefficient of friction.

[0010] Advantageously, the hydrophobic coating includes pigments, making it possible to determine coating wear by visually inspecting the latching mechanism.

[0011] The present invention also provides a method for manufacturing a latching mechanism according to a first aspect of the invention, wherein at least a portion of a hydrophobic coating is applied by brushing, spraying or dipping.

[0012] A third aspect of the invention provides a latching system arranged to control a latching mechanism according to a first aspect of the invention between a latched configuration and an unlocked configuration.

[0013] Preferably, the latching system includes an actuator arranged to move the latch pin between a latched configuration and an unlocked configuration. The operation of the actuator can be controlled by a control unit.

[0014] Another aspect of the invention provides an aircraft wing comprising a fixed wing portion and a wingtip assembly movable relative to the fixed wing between a flight configuration and a ground configuration, wherein the wing has an extended position in the flight configuration and a reduced wingspan in the ground configuration, and the aircraft wing further includes a latching mechanism according to a first aspect of the invention or a latching system according to a third aspect of the invention. The wing can form part of an aircraft. Attached Figure Description

[0015] The invention will now be described by way of example with reference to the accompanying drawings, in which: Figure 1a A perspective view of a swept wing of a passenger aircraft including a latching mechanism according to a first embodiment of the invention, constructed according to the invention, is shown, wherein the wingtip device of the wing is shown in both flight configuration (shown as dashed lines) and ground configuration (shown as solid lines). Figure 1b It shows Figure 1a A front view of a passenger aircraft, in which the wingtip devices are in flight configuration; Figure 2a This is a cross-sectional view of a latching system, which includes... Figure 1a and Figure 1b The latching mechanism of the aircraft shown is in a latching configuration; Figure 2b yes Figure 2a An axial view of the latching mechanism in a latching configuration; Figure 3 yes Figure 2a and Figure 2b A cross-sectional view of the latching mechanism in an unlocked configuration; Figure 4 This is a cross-sectional view of a latching mechanism constructed according to an alternative embodiment of the present invention; and Figure 5 This is a cross-sectional view of a latching mechanism constructed according to another embodiment of the present invention. Detailed Implementation

[0016] Reference Figure 1a and Figure 1b This illustration depicts an aircraft in the form of a typical commercial passenger plane, generally indicated by reference numeral 1. The aircraft 1 includes a fuselage 2, wings 3, main engines 4, and a tail 5. It should be understood that the invention is applicable to a wide variety of aircraft types. For example, the aircraft can be used for military purposes; can be used to transport passengers and / or cargo; can have jet, propeller, or other propulsion systems; and can have any of a variety of fuselage / wing configurations.

[0017] Each wing in wing 3 includes a fixed wing 3a and a wingtip assembly 3b. The fixed wing 3a extends outward from the fuselage 2 of the aircraft, from the root 6 along the wingspan direction to the tip 7. The fixed wing 3 also extends from the leading edge 8 along the chord direction to the trailing edge 9.

[0018] The wingtip device 3b is located at the outer tip of the fixed wing 3a. In the described embodiment, the wingtip device 3a is in the form of a planar wingtip extension, although the invention is also applicable to other types of wingtip devices such as wingtip fences, swept wingtips, split wingtips, and non-planar wingtip devices such as winglets.

[0019] The wingtip device 3b is capable of Figure 1b The flight configuration shown (and also) Figure 1a (shown as dashed lines) and ground configuration (in) Figure 1a (Shown as solid lines) The wingtip device 3b moves between these points. When the wingtip device 3a is in flight configuration, the wingtip device 3b extends outward along the wingspan. The wingtip device 3a also extends from the leading edge 8' along the chord direction to the trailing edge 9'. In flight configuration, the leading edge 8' and trailing edge 9' of the wingtip device 3b are continuations of the leading edge 8 and trailing edge 9 of the fixed wing 3a. Furthermore, the upper and lower surfaces of the wingtip device 3b are continuations of the upper and lower surfaces of the fixed wing 3a. Therefore, there is a smooth transition from the fixed wing 3a to the wingtip device 3b.

[0020] The position of the wingtip device 3b can be controlled to present a flight configuration for flight. In this configuration, the wingtip device 3b increases the wingspan of the aircraft wing, thereby providing beneficial aerodynamic effects, such as reducing the component of induced drag and increasing lift. In principle, this large wingspan can be maintained indefinitely, with only a large fixed wing. However, the maximum aircraft wingspan is actually limited by airport operating rules, which govern the various separations required when maneuvering around the airport (such as the wingspan and / or ground separation required for gate entry and safe taxiway use). In this respect, in the flight configuration, the wing span can exceed airport compatibility gate limits. Therefore, the wingtip device 3b can be moved to a ground configuration for use when the aircraft 1 is on the ground.

[0021] In the ground configuration, the wingtip device 3b folds from the aforementioned flight configuration, causing it to rotate upwards. When the wingtip device 3b is in the ground configuration, the wingspan of the wing 3 decreases. To enable the movement of the wingtip device 3b between the flight and ground configurations, a rotating connection 10 is provided (in... Figure 2a (Schematably shown as box 10). The rotatable connection 10 rotatably connects the wingtip device 3b to the fixed wing 3a, allowing the wingtip device 3b to rotate between flight and ground configurations. An example of a wingtip device 3b capable of rotating in this manner is shown in WO 2015 / 150835 (Airbus Operations Ltd.), the contents of which are incorporated herein by reference.

[0022] The aircraft wing 3 also includes a latching system 11 configured to selectively lock the wingtip device 3b in both flight and ground configurations. The latching system 11 includes a latching mechanism 12 constructed according to the invention, and... Figure 2a It is shown schematically in the middle.

[0023] The latching mechanism 12 includes a first bushing or lug group 13, in this case, four lugs 13a, 13b, 13c, 13d arranged in two adjacent pairs, the lugs 13a, 13b, 13c, 13d being fixedly attached to a portion of the outer end of the wing box that fixes the wing 3a. The latching mechanism also includes a second lug group 14, in this case, two lugs 14a, 14b, the lugs 14a, 14b being arranged in pairs and fixedly attached to a portion of the inner end of the wingtip device 3b, such that the lugs 14a, 14b can rotate about a hinge line (not shown) as the wingtip device 3b moves between ground configuration and flight configuration.

[0024] Each of the lugs 13a, 13b, 13c, 13d, 14a, 14b includes a generally circular hole or aperture 15a, 15b, 15c, 15d, 15e, 15f extending through the thickness of the respective lug. The lug groups 13, 14 are arranged such that the lugs are staggered and the apertures 15a to 15f of the lugs are aligned to collectively form a hole or aperture 15 for the movement of the latch pin 16 between a latched configuration and an unlocked configuration.

[0025] In these embodiments, orifices 15a to 15f are shown in the form of bushings inserted into lugs, wherein one bushing is used to mate orifices 15b and 15c of adjacent lugs 13b and 13c together. Orifices 15a to 15f may alternatively take the form of bearings or other cylindrical bushings, or may simply be holes in lugs.

[0026] The latching pin 16 is substantially cylindrical, meaning that the latching pin 16 has a diameter that is substantially constant along its length. The pin 16 is mounted on a support structure (not shown in these figures) for use in the latched position (in... Figure 2a and Figure 2b (shown in) and the unlatched position (in) Figure 3 (As shown in the figure) They slide and reciprocate between each other.

[0027] The latching system 11 includes an actuator 17 connected to a latching pin 16 to move the pin between a latched position and an unlocked position. The actuator 17 may be, for example, an electromechanical actuator in the form of a solenoid, or any other suitable type of actuator, such as a mechanical, pneumatic, or electric actuator. The latching system 11 also includes a control unit 18 arranged to control the operation of the actuator 17. The control unit 18 may be connected at an input to a pilot-operable control for the pilot to lock the wingtip device 3a. Alternatively, the control unit 18 may be automatically configured to lock the wingtip device in a desired configuration.

[0028] When latch pin 16 is in Figure 3 In the unlocked position, one end portion of the pin is located in the aperture 15d of the farthest lug 13d of the fixed wing 3a. In this position, the pin does not protrude into the aperture 15f of the adjacent lug 14b attached to the wingtip assembly 3b, and thus the wingtip assembly moves freely between its flight configuration and ground configuration.

[0029] It should be noted that a small gap exists between the outer surface of the latch pin 16 and the surfaces of the orifices 15a to 15f of the lugs 13 and 14. It has been found that ice can form in this area. The accumulation of ice can prevent the proper operation of the latching mechanism 12 by hindering the movement of the latch pin 16 between the latched and unlatched configurations, and thus prevent the proper operation of the aircraft 1. If the latching mechanism 12 is iced over, the wing 3 may not be able to move from the extended configuration to the folded configuration upon landing, preventing the aircraft 1 from approaching the gate. Similarly, if the accumulation of ice prevents the latch pin 16 of the latching mechanism 12 from being unlatched so that the wing can deploy and adopt the extended configuration for flight, the takeoff of the aircraft 1 may be delayed.

[0030] According to the invention, at least a portion of the latching mechanism 12 has a hydrophobic coating 19. Figure 2a , Figure 2b and Figure 3 In the embodiment shown, the hydrophobic coating 19 covers the entire outer cylindrical surface of the latch pin 16. Of course, the coating may be applied only to selected areas of the pin 16. The hydrophobic coating 19 is indicated by dashed lines on the surface of the pin 16.

[0031] Hydrophobic coatings are thin layers of material that repel water. These coatings cause water droplets to simply “bead” and roll off. The way a water droplet interacts with a surface determines whether the surface is hydrophobic. This is measured by the static contact angle between the surface and the droplet. The higher the contact angle, the more hydrophobic the surface. When the water contact angle is less than 90°, the surface can be considered “hydrophilic”; when the water contact angle is greater than 90°, the surface can be considered “hydrophobic”; and when the water contact angle is greater than 150°, the surface can be considered “superhydrophobic”. The coating 19 of the latching mechanism can be hydrophobic or superhydrophobic: the term “hydrophobic” is used in this specification to cover materials that have hydrophobic or superhydrophobic properties.

[0032] Examples of suitable materials for forming the hydrophobic coating 19 are polymers, such as polytetrafluoroethylene (PTFE), silicon-based compounds, ceramics, waxes, and oils. Carbon coatings and diamond-like carbon (DLC) coatings can also be used. DLC is formed when ionized carbon is bombarded on a surface with high energy. The resulting coating is hydrophobic, exhibits excellent abrasion and corrosion resistance, and has a low coefficient of friction.

[0033] Natural waxes such as carnauba wax, beeswax, or paraffin wax are particularly suitable for this invention because they are natural materials, readily available and applicable, and have a low environmental impact. The waxes suitable for this invention are solid at the operating temperatures of the aircraft and soften upon heating. The waxes used in this invention are preferably insoluble in water. Other waxes such as animal waxes, plant waxes, mineral waxes, and petroleum waxes, as well as synthetic waxes, can be used. Blends of hydrophobic materials, such as mixtures of beeswax and carnauba wax, can be employed.

[0034] The hydrophobic coating 19 can be applied to the latch pin 16 by various methods. For example, the selected hydrophobic material or mixture can be heated to a liquid phase or simply softened and then simply brushed or wiped onto the latch pin 16. Other suitable applications include spray coating, slot die coating, dip coating, and any other method capable of depositing thin films such as chemical vapor deposition (CVD) or physical vapor deposition (PVD), depending on the type of coating selected. The coating material can be in the form of powder or paint. Several coating layers can be applied to the pin 16.

[0035] During maintenance of aircraft 1, ground crew can easily reapply the hydrophobic coating 19 after a period of wear. The coating mixture may include pigments to color the hydrophobic coating 19; therefore, wear on the coating can be determined by a simple visual inspection of the latching mechanism 12.

[0036] A hydrophobic coating is applied to prevent ice formation on the latch pin. This inhibits moisture deposition on the pin, making it impossible for moisture to remain in place for a sufficient time to freeze. If ice does form, the surface structure of the hydrophobic coating reduces the contact area with the ice to a level that does not impede latching operation. Furthermore, the hydrophobic coating 19 reduces the adhesion strength of the ice, making it easier to remove than previously possible.

[0037] The hydrophobic coating 19 also provides a protective barrier against moisture ingress, thereby reducing corrosion of the latch pin 16 and other damage and degradation caused by contact with water and other chemicals.

[0038] It has also been found that moisture can attract dust and debris. By inhibiting moisture deposition on the latch pin 16, the latch pin 16 can be kept relatively dust-free. Accumulated dust and debris can prevent the operation of the latching mechanism 12. Furthermore, as water beads up and rolls off the latch pin 16, the water carries away dust and contaminants, making the latching mechanism 12 self-cleaning.

[0039] Figure 4 An alternative embodiment of the invention is shown in the figure. In this embodiment, the orifices 15a to 15f of the lugs 13, 14 of the latching mechanism 12 have a hydrophobic coating 20. In this figure, all orifices 15a to 15f are shown with the hydrophobic coating 20, but of course, the coating can be applied only to selected orifices if desired. Different coatings can be used for different orifices 15a to 15f. The hydrophobic material can be one of the coatings of the aforementioned types. The coating can be applied (and reapplied during maintenance) by simply brushing it into the orifices of the lugs 13, 14 or by any of the other methods mentioned above regarding the coating of the latch pin 16.

[0040] The application of a hydrophobic coating to some or all of the orifices 15a to 15f has the aforementioned benefits: preventing ice formation and reducing its adhesion to the lugs 13 and 14, as well as inhibiting moisture ingress and suppressing the accumulation of dust and debris in the orifices 15a to 15f. Therefore, the latching pin 16 can easily slide through the orifice 15 as it moves between the latched and unlocked configurations, thus facilitating the operation of the aircraft between folding wing and extended wing configurations.

[0041] Figure 5Another alternative embodiment of the invention is shown. In this embodiment, both the latch pin 16 and the orifices 15a to 15f have hydrophobic coatings 19 and 20, respectively. The hydrophobic coating 19 for the latch pin 16 may be the same as the hydrophobic coating 20 on the orifices 15a to 15f, or they may have coatings composed of different hydrophobic materials or mixtures. The hydrophobic material, or each hydrophobic material, may include one of the coating types mentioned above regarding coating only the latch pin 16. The coating may be applied by any of the methods mentioned above or a combination of methods for different components.

[0042] Applying a coating to both the latch pin 16 and the orifices 15a to 15f includes the aforementioned benefits and also helps to further lubricate the movement of the latch pin 16 through the orifice 15 as it moves into and out of its latch configuration. The hydrophobic coatings 19 and 20 are thin enough not to cause significant changes in the overall dimensions of the components of the latch mechanism 12.

[0043] Other modifications can be made without departing from the scope of the invention. For example, the hydrophobic coating may include one or more additives such as non-fiber reinforcing materials, elastomers, and / or lubricants. The hydrophobic coating may have a microtextured or nanotextured surface, which further reduces water contact and promotes droplet roll-off. Other modifications of the invention will be apparent to those skilled in the art.

Claims

1. A latching mechanism for latching the wingtip of a folding wing of an aircraft, the mechanism comprising a lug and a latching pin, the lug having an orifice, and the latching pin being movable within the orifice between a latched configuration and an unlatched configuration, wherein, in the latched configuration, the latching pin is received in the orifice, and in the unlatched configuration, the latching pin is retracted from the orifice, wherein, At least a portion of either the pin or the orifice has a hydrophobic coating.

2. The latching mechanism according to claim 1 further includes a plurality of lugs having corresponding openings, wherein, At least some of the orifices have a hydrophobic coating.

3. The latching mechanism according to claim 1 or claim 2, wherein, The pin and the orifice or multiple orifices each have a hydrophobic coating.

4. The latching mechanism according to claim 1, 2 or 3, wherein, The hydrophobic coating comprises wax.

5. The latching mechanism according to claim 4, wherein, The waxes include natural waxes.

6. The latching mechanism according to claim 5, wherein, The wax includes carnauba wax.

7. The latching mechanism according to claim 5 or 6, wherein, The wax includes beeswax.

8. The latching mechanism according to any one of claims 1, 2 or 3, wherein, The hydrophobic coating comprises carbon or diamond-like carbon.

9. The latching mechanism according to any of the preceding claims, wherein, The hydrophobic coating includes pigments.

10. A method of manufacturing a latching mechanism according to any of the preceding claims, wherein, At least a portion of the hydrophobic coating is applied by brushing, spraying, or dipping.

11. A latching system arranged to control the latching mechanism according to any one of claims 1 to 9 between a latched configuration and an unlocked configuration.

12. The latching system of claim 11, further comprising an actuator arranged to move the latch pin between a latched configuration and an unlocked configuration.

13. The latching system of claim 12, further comprising a control unit arranged to control the operation of the actuator.

14. An aircraft wing comprising a fixed wing portion and a wingtip device, the wingtip device being movable relative to the fixed wing between a flight configuration and a ground configuration, wherein the wing has an extended position in the flight configuration and a reduced wingspan in the ground configuration, and the aircraft wing further comprising a latching mechanism according to any one of claims 1 to 9 or a latching system according to any one of claims 11 to 13.

15. An aircraft comprising an aircraft wing according to claim 14.

Images