A combined skin of a curved variable-sweep wing

Abstract

An embodiment of the present invention provides a combined skin that can be used on a curved variable-sweep wing. The combined skin of the curved variable-sweep wing includes: a first skin portion and a second skin portion. The first skin portion is installed in the portion from the wing main beam to the wing leading edge; the second skin portion is installed in the portion from the wing main beam to the wing trailing edge. The first skin portion is an integral structure. The second skin portion includes a plurality of strips; the length direction of the plurality of strips is along the fuselage direction; the plurality of strips are stacked in the wingspan direction. The combined skin provided by the embodiment of the present invention has a strong deformation capability and a wide range of applications.

Description

Technical Field

[0001] The present invention relates to the field of aerospace technology, and in particular to a combined skin that can be used on a curved variable-sweep wing. Background Art

[0002] This section introduces aspects that may be helpful in better understanding the present disclosure. Therefore, the statements in this section should be read in this manner and should not be understood as an admission that what is in the prior art or what is not in the prior art.

[0003] To meet the complex and ever-changing operating conditions encountered during flight missions, designers began experimenting with installing curved, variable-sweep wings on the fuselage to achieve the optimal aerodynamic layout under varying environmental conditions. To achieve this goal, the two main challenges required were the design and manufacture of the variable-sweep frame and the design and installation of the wing skin.

[0004] How to improve the installation design of the skin so that it can withstand the flight aerodynamic load while reducing the impact on the wing frame and meet various amplitudes of wing sweep angle deformation is a problem that needs to be solved urgently by technical personnel in this field. Summary of the Invention

[0005] This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

[0006] The purpose of the present invention is to provide a curved variable-sweep wing composite skin to solve the problems existing in the prior art such as serious influence on the skeleton and insufficient deformation capability.

[0007] An embodiment of the present invention provides a composite skin for a curved variable-sweep wing. The composite skin comprises a first skin portion and a second skin portion. The first skin portion is mounted from the wing main spar to the wing leading edge; the second skin portion is mounted from the wing main spar to the wing trailing edge. The first skin portion is a one-piece structure. The second skin portion comprises a plurality of straps, the lengths of which run along the fuselage, and the straps are stacked in the spanwise direction.

[0008] In an embodiment of the present invention, a trailing edge metal plate is provided at the trailing edge of at least one of the plurality of belts. A magnet mounting slot is provided at the trailing edge of the wing frame for receiving a magnet. The magnet is used to generate an attractive force on the trailing edge metal plate.

[0009] In an embodiment of the present invention, the first skin portion is an elastic skin comprising a silicone rubber film, and the second skin portion is a rigid skin comprising a polyimide film.

[0010] In an embodiment of the present invention, the plurality of straps includes a starting strap and a plurality of overlapping straps. The axis of symmetry of the starting strap coincides with and is fixedly connected to a starting rib near the center of the wing frame. One edge of one of the plurality of overlapping straps is fixedly connected to and coincides with the rib, and the other edge of the overlapping strap overlaps another strap.

[0011] In an embodiment of the present invention, the other strap is closer to the starting rib than one of the plurality of overlapping straps.

[0012] The beneficial effects of the present invention are:

[0013] 1. The combined skin has strong deformation capability and a wide range of applications. In actual use, it has successfully achieved 90-degree wing deformation.

[0014] 2. The rigid skin in the combined skin effectively avoids the problem of pre-stretching when using elastic skin on the shrinkage side, and has almost no impact on the skeleton.

[0015] 3. The combined skin material is light, simple in structure and easy to install. When used in small UAVs, it can be well connected to the frame even with 502 adhesive.

[0016] 4. The composite skin material is easy to obtain and inexpensive, and is particularly suitable for the curved variable-sweep wings of small UAVs. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The disclosure itself, the preferred mode of use and further objects are best understood by reference to the following detailed description of embodiments when read in conjunction with the accompanying drawings.

[0018] To more clearly illustrate the technical solutions of the specific embodiments of the present invention, the following briefly introduces the drawings required for describing the specific embodiments. Obviously, the drawings described below are some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive effort.

[0019] Figure 1 A schematic diagram of a rigid skin with overlapping plates of a combined skin provided by an embodiment of the present invention;

[0020] Figure 2 Schematic diagram of the elastic skin provided by an embodiment of the present invention

[0021] Figure 3 A three-dimensional diagram of the magnet mounting slots of the composite skin provided in an embodiment of the present invention.

[0022] Figure 4 A top view of the connection between the metal plate assembly of the composite skin and the rigid overlapped skin provided by an embodiment of the present invention;

[0023] Figure 5 A top view of the curved variable-sweep wing skeleton provided in an embodiment of the present invention.

[0024] Reference numerals:

[0025] 1-rear end metal plate; 2-lap strap; 3-starting strap; 4-elastic skin; 5-limiting block; 6-rib; 7-magnet mounting slot; 8-wing root rib; 9-wingtip rib; 10-starting rib; 11-skeleton main beam. DETAILED DESCRIPTION

[0026] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0027] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0028] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0029] To meet the complex and ever-changing operating conditions encountered during flight missions, designers began experimenting with installing curved, variable-sweep wings on the fuselage to achieve the optimal aerodynamic layout under varying environmental conditions. To achieve this goal, the two main challenges required were the design and manufacture of the variable-sweep frame and the design and installation of the wing skin.

[0030] A commonly used method currently involves pre-stretching an elastic material and then attaching it to a curved, variable-sweep frame to form an elastic skin. This method is simple in principle: it leverages the elastic material's inherent ability to adapt to changes in the wing's sweep angle, ensuring the skin remains essentially intact regardless of the variable sweep state.

[0031] However, the aforementioned technical solution presents a problem: during actual flight, the elastic skin deforms under aerodynamic loads, thus affecting the wing's aerodynamic performance. To minimize this deformation, it is necessary to increase the thickness of the elastic material or replace the skin with one with a higher elastic modulus. This can significantly impact the wing's structure, and in severe cases, can even cause partial damage. Furthermore, elastic materials have a deformation limit, and when installed on a wing with a sweep angle exceeding 60 degrees, the material's elastic limit is easily exceeded, making it difficult to ensure structural integrity and functional performance.

[0032] Therefore, how to improve the installation design of the skin so that it can withstand the flight aerodynamic load while reducing the impact on the wing frame and meet various amplitudes of wing sweep angle deformation is an urgent problem to be solved by technical personnel in this field.

[0033] An exemplary embodiment of the present invention provides a curved variable-sweep wing composite skin.

[0034] Figure 1 A schematic diagram of a rigid skin with overlapping plates of a combined skin provided by an embodiment of the present invention; Figure 2 A schematic diagram of an elastic skin provided by an embodiment of the present invention; Figure 3 A three-dimensional diagram of the magnet mounting slot of the composite skin provided in an embodiment of the present invention; Figure 4 A top view of the connection between the metal plate assembly of the composite skin and the rigid overlapped skin provided by an embodiment of the present invention; Figure 5 A top view of the curved variable-sweep wing skeleton provided in an embodiment of the present invention.

[0035] like Figures 1 to 5 As shown, the composite skin includes an elastic skin 4, a rigid lap skin (including a trailing edge (rear end) metal plate 1, a lap band 2, and a starting band 3), and a magnet mounting slot 7 and a micro-neodymium magnet provided on the wing frame in coordination with the rigid lap skin. Specifically, the elastic skin 4 is mounted on the front end of the frame main beam 11 (i.e., covering the portion from the frame main beam 11 to the leading edge of the wing); the rigid lap skin is mounted on the rear end of the frame main beam 11 (i.e., covering the portion from the frame main beam 11 to the trailing edge of the wing); the magnet mounting slot 7 is manufactured together with the frame, and the magnet is mounted in the slot; the trailing edge metal plate 1 is mounted on the rear end of the rigid lap skin, generating an attractive force with the micro-neodymium magnet in the magnet mounting slot 7.

[0036] The combined skin provided by the present invention can better solve the problems existing in the prior art of the skin, such as serious impact on the skeleton, insufficient deformation ability, etc.: First, the combined skin has strong deformation ability and a wide range of applications. In actual use, it has successfully achieved 90-degree wing deformation. Secondly, the rigid skin in the combined skin effectively avoids the problem of pre-stretching when using elastic skin on the contraction side, and has almost no impact on the skeleton. Thirdly, the combined skin material is light, simple in structure, and easy to install. When applied to small UAVs, it can be well connected to the skeleton even with 502 adhesive. Finally, the combined skin material is easy to obtain and low in cost, and is particularly suitable for small UAV curved variable-sweep wings.

[0037] Building on the above embodiment, the elastic skin 4 is further constructed from a silicone rubber film, and the rigid overlapping skin is constructed from a polyimide film. The technical benefits of this solution are: first, the material exhibits excellent processability, enabling efficient and convenient installation on various curved variable-sweep wings; second, the material exhibits stable properties and rarely reacts with other substances, greatly facilitating various installation methods; third, the material is inexpensive and readily available, facilitating rapid prototyping and economical operation; and fourth, the material exhibits low density and light weight, making it suitable for manufacturing aircraft components.

[0038] Furthermore, the elastic skin 4 and the rigid skin are divided by the main beam 11. The elastic skin 4 is installed on the portion of the main beam 11 close to the leading edge of the wing (i.e., toward the nose) (hereinafter referred to as the "stretching side"), and the rigid skin is installed on the portion of the wing main beam 11 close to the trailing edge (i.e., toward the tail) (hereinafter referred to as the "contraction side"). The technical effect of this solution is that the elastic skin 4 is easy to stretch and deform but almost impossible to contract, and the rigid lap skin is easy to contract but impossible to stretch. When the curved variable sweep wing changes, the wing length on the stretching side gradually increases, and the wing length on the contraction side gradually decreases. The main beam length remains basically unchanged and can be regarded as the boundary between the stretching side and the contraction side. Arranging the two skins with this as the boundary is conducive to the integrity of the wing shape and the realization of its function.

[0039] Furthermore, after the elastic skin is processed according to the shape and size of the wing, it can be directly installed on the stretched side of the wing. The technical effect of this solution is that the direct installation process is simple and the effect is reliable. The rigid overlapping skin is stacked and installed on the wing in the form of armor plates on ancient armor, and the installation steps are as follows: the first step is to select a rib near the center of the wing frame and determine it as the "starting rib 10" of the rigid overlapping skin, and process the polyimide into a strip (hereinafter referred to as the "starting strip 3") with a width slightly greater than twice the rib spacing and a length equal to the distance from the main beam to the trailing edge of the wing, so that the symmetry axis of the strip coincides with the starting rib 10 and the two are fixedly connected; the second step is to process the polyimide into a strip (hereinafter referred to as the "lapping strip 2") with the same length as the starting strip 3 and a width slightly greater than the rib spacing, and overlap one side of the lapping strip 2 with the rib adjacent to the starting rib 10 and fix the two together, and the other side of the lapping strip 2 is overlapped on the starting strip without any processing; the third step is to repeat the second step, starting from the starting rib 10, fixing the lapping strip 2 on the ribs in the two directions of the wing root and wingtip respectively, until the lapping strip 2 is fixed to the wing root and wingtip ribs 8 and 9. The technical effect of this solution is that by stacking polyimide sheets on the retracted side in the form of armor plates on ancient armor, the rigid skin will not be damaged or deformed when the wing is bent and swept back, and the sealing integrity of the skin is guaranteed.

[0040] Furthermore, the trailing edge metal plate 1 is mounted on the polyimide strip near the trailing edge of the wing; the magnet and the metal plate attract each other at the trailing edge, securing the strip's end. This solution's technical advantage is that the metal plate attached to the strip's end and the micro-neodymium magnets in the magnet mounting slots 7 on the frame attract each other, restraining the polyimide strip's end and preventing it from fluttering due to airflow disturbances during flight, thus maintaining the skin's seal and the wing's aerodynamic performance.

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A combined skin of a curved variable-sweep wing, comprising: a first skin portion, a second skin portion; The first skin portion (4) is installed on the portion from the wing main beam (11) to the leading edge of the wing; the second skin portion is installed on the portion from the wing main beam (11) to the trailing edge of the wing; wherein the first skin portion (4) is an integrated structure; The second skin portion comprises a plurality of strips (2, 3); the length direction of the plurality of strips (2, 3) is along the fuselage direction; the plurality of strips (2, 3) are stacked in the wingspan direction; wherein a trailing edge metal plate (1) is provided at at least one trailing edge of the plurality of belts (2, 3); Wherein, a magnet installation groove (7) is provided at the rear edge of the wing frame for placing the magnet; Wherein, the magnet is used to generate an attractive force on the trailing edge metal plate (1); wherein the first skin portion (4) is an elastic skin; wherein the second skin portion is a rigid skin; Wherein, the plurality of belts (2, 3) include a starting belt (3) and a plurality of overlapping belts (2); The symmetry axis of the starting belt (3) coincides with and is fixedly connected to a starting rib (10) near the center of the wing frame; One side of one of the plurality of overlapping straps (2) overlaps and is fixedly connected to the rib, and the other side (2) of the overlapping strap overlaps on another strap (2, 3).

2. The combined skin according to claim 1, in, The first skin portion (4) comprises a silicone rubber film; Wherein, the second skin portion comprises a polyimide film.

3. The combined skin according to claim 1 or 2, in, The further band (2, 3) is closer to the starting rib (10) than one of the plurality of overlapping bands (2).

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