A wing surface continuous deformation mechanism based on slide bar-flexible truss-skin

Abstract

The application discloses a wing surface continuous deformation mechanism based on a slide bar-flexible truss-skin, which comprises a rigid wing box (40% of the terminal chord length), a flexible upper skin, four independent flexible trusses, a slide bar and a rigid trailing edge. The trusses are connected with the upper skin together, and the whole driving system serves as the lower skin of the wing. The slide bar slides back and forth at the leading edge of the wing, the deformation mechanism is stretched or bent, and the curved surface of the wing is changed. The upper surface skin of the wing is made of a skin prepared from a material capable of bearing large deformation. The motor drives the slide bar to generate a driving force, when the driving force is applied to the leading edge direction, the trailing edge deflects downward, and when the driving force is applied to the trailing edge direction, the trailing edge deflects upward, so that the deformation is completed.

Description

Technical Field

[0001] This invention relates to the field of unmanned aerial vehicle (UAV) technology, and more specifically to a wing surface continuous deformation mechanism based on a slide bar-flexible truss-skin. Background Technology

[0002] The wing is an important component of an aircraft. Conventional wings employ a relatively complex hinge system and control surfaces, resulting in a larger aircraft mass. This makes the aircraft prone to vibration and noise during operation, as well as fatigue damage to the wing structure and a relatively small lift-to-drag ratio, which can even limit the aircraft's handling and maneuverability.

[0003] Continuous seamless deformable wings based on smart materials and structural design offer numerous advantages, including improved wing surface handling efficiency, active flutter suppression, and stealth performance. Various countries have conducted extensive research and experimentation on flexible deformable wings. Currently, flexible deformable wings mainly fall into three categories: in-plane deformable wings, out-of-plane deformable wings, and variable airfoil wings. In-plane deformable wings primarily involve variable sweep, variable span, and variable chord length; out-of-plane deformable wings mainly involve wing folding, spanwise bending, and wing twisting; and airfoil adjustments mainly include variable camber wings and variable thickness wings.

[0004] Smooth trailing edge continuously variable camber wings can significantly improve the aerodynamic characteristics of aircraft, which is of great significance for low-speed cruise, takeoff and landing. They can reduce drag during cruise, thereby saving fuel and increasing range. They can also replace traditional control surfaces for flight control to improve performance. By continuously changing the trailing edge camber, the lift and drag characteristics throughout the cruise phase can be improved. Therefore, it is necessary to carry out research on new flexible deformable wings, explore new deformation methods, and provide technical support for the design of new flexible deformable wings for future UAVs. Summary of the Invention

[0005] In order to achieve continuous deformation of wing camber, this invention provides a continuous wing deformation mechanism based on a slide bar-flexible truss-skin. This deformation mechanism has a simple structure, high reliability, good controllability, and simple maintenance.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] This invention provides a continuously deformable wing surface mechanism based on a slide bar-flexible truss-skin structure, specifically including a rigid leading-edge wing box (40% of the trailing chord length), a flexible upper skin, four independent flexible trusses, a slide bar, and a rigid trailing edge. The trusses are connected to the upper skin, and the entire drive system serves as the lower skin of the wing. The slide bar passes through a fixed plate of the flexible truss. To prevent interference between connected trusses, such as... Figure 2As shown, the apex angle at the bottom of the truss is designed to be 60 degrees. The number of fixing plates is the same as that of the truss, and they are arranged at equal intervals along the sliding rods. The truss is 0.5 mm thick, and the material can be carbon fiber reinforced plastic; the sliding rods are cylindrical rods with a diameter of 1 mm, and the material can be carbon fiber reinforced plastic rods; the upper skin is 0.25 mm thick, and the material is carbon fiber reinforced plastic sheet; the fixing plates are set at 5 mm x 3 mm, and the material is carbon fiber reinforced plastic sheet.

[0008] like Figure 3 As shown, a series of small holes are designed on the flat surface of the leading edge, through which the sliding rod can pass smoothly, thus enabling deformation. The length of the leading edge is 40% of the chord length, and the width is 50mm.

[0009] Figure 4 and Figure 5 This is a model diagram of the upper skin, in which... Figure 4 This is the isometric view of the upper skin. Figure 5 The diagram shows the dimensional parameters of the upper skin. The thickness of the upper skin is 0.25 mm.

[0010] Figure 6 , Figure 7 , Figure 8 This is a model diagram of a flexible truss, in which... Figure 6 This is a side view of the flexible truss, showing its approximate arrangement. Figure 7 This is a diagram showing the lateral arrangement of flexible trusses. In the middle, the flexible trusses are arranged symmetrically on the left and right sides to prevent adjacent flexible trusses from interfering with each other. Figure 8 This is a diagram showing the dimensional parameters of the flexible truss.

[0011] Figure 9 This is a side view of the fixed plate and its dimensional parameters. Figure 10 The main view and dimensions of the fixing plate are shown. The fixing plate is designed as a cuboid structure, and the number of the flexible trusses is the same, four in total. Small holes are provided on the horizontal side of the fixing plate.

[0012] Figure 11 This is a side view of the slide bar and its dimensions. The slide bar is a rod-shaped object with a circular cross-section. The cross-section is a circle with a diameter of 1 mm and a length of 185 mm, with a portion located inside the leading edge.

[0013] Figure 12 This is a detailed drawing of a continuously deformable wing surface mechanism based on a slide bar-flexible truss-skin.

[0014] Figure 13This is a side view of a continuously deformable wing mechanism based on a sliding bar-flexible truss-skin according to an embodiment of the present invention. Using NACA4418 as the reference, the designed deformable wing has a chord length of 280 mm and a wingspan of 50 mm. The entire deformable mechanism is a carbon fiber composite material deformable mechanism.

[0015] The present invention has the following beneficial effects:

[0016] 1. In this invention, the truss is connected to the upper skin, and the drive system serves as the lower skin of the wing. The carbon fiber rod passing through the flexible truss fixing plate is driven by a motor to achieve continuous bending deformation at the trailing edge, thereby improving the aerodynamic characteristics of the aircraft.

[0017] 2. The use of carbon fiber materials is lightweight, which can reduce the weight of the aircraft, save fuel, and increase the range. This is of great significance for the aircraft's cruise, takeoff, and landing. Attached Figure Description

[0018] Figure 1 This is a conceptual design diagram of the sliding flexible truss mechanism in an embodiment of the present invention;

[0019] Figure 2 For structural design scheme drawings;

[0020] Figure 3 This is a detailed view of the leading edge;

[0021] Figure 4 This is an isometric view of the upper skin.

[0022] Figure 5 Design dimensional parameter diagram for the upper skin;

[0023] Figure 6 This is a side view of the flexible truss.

[0024] Figure 7 This is a diagram showing the lateral arrangement of the flexible trusses.

[0025] Figure 8 This is a diagram showing the dimensional parameters of the flexible truss.

[0026] Figure 9 This is a side view of the fixed plate;

[0027] Figure 10 This is a horizontal view of the fixed plate;

[0028] Figure 11 This is a side view of the slide bar;

[0029] Figure 12 A detailed drawing of a continuously deformable wing surface mechanism based on a sliding bar-flexible truss-skin;

[0030] Figure 13 A side view of a continuously deformable wing surface mechanism based on a sliding bar-flexible truss-skin;

[0031] Figure 14 This is a schematic diagram illustrating the principle of downward deflection of the trailing edge.

[0032] Figure 15 This is a schematic diagram illustrating the principle of upward deflection of the trailing edge.

[0033] Reference numerals: 1. Leading edge of wing; 2. Elastic skin on the upper surface of wing; 3. Flexible truss; 4. Trailing edge of wing; 5. Slide bar; 6. Fixing plate. Detailed Implementation

[0034] To make the objectives and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0035] Reference Figure 12 This invention provides a continuous deformation mechanism for an airfoil based on a slide bar-flexible truss-skin, including a leading edge 1 (hereinafter referred to as the wing box), an elastic skin 2 on the upper surface of the wing, a flexible truss 3, a trailing edge 4, a slide bar 5, and a fixed plate 6. The slide bar 5 can pass through the fixed plate 6. One end of the flexible truss 3 is connected to the upper surface skin of the wing, and the other end is fixedly connected to the fixed plate 6. The upper surface skin of the wing needs to be made of a material capable of withstanding large deformations, as the upper surface experiences the greatest deformation during the trailing edge bending deformation of the wing. The slide bar 5 can slide on the leading edge 1, and its sliding motion drives the trailing edge to deflect vertically. The deformation mechanism involves a motor providing a driving force to the slide bar 5. When the driving force is applied towards the leading edge, the trailing edge deflects downwards; when the driving force is applied towards the trailing edge, the trailing edge deflects upwards, thus completing the deformation. A detailed deformation principle diagram is shown below. Figure 14 and Figure 15 As shown.

[0036] As the slide bar 5 slides along the fixed plate 6, the deformation mechanism will stretch or bend, and the curvature of the wing will also change. During deformation, the slide bar 5 on the upper and lower skins of the flexible composite material will maintain a smooth curvature to ensure aerodynamic efficiency. During deformation, the flexible truss unit 3 undergoes small elastic deformation, which can be adjusted through its flexibility. Simultaneously, the carbon fiber reinforced plastic truss structure has relatively high specific stiffness and specific strength, providing relatively high load-bearing capacity. Due to approximation, the structure is allowed to have relatively low bending stiffness and low resistance to bending deformation.

[0037] In summary, by adopting the aforementioned continuous deformation wing surface mechanism based on a slide bar-flexible truss-skin, the lift-drag characteristics of the entire cruise phase can be improved through a smooth, continuously variable camber wing at the trailing edge. This significantly improves the aerodynamic characteristics of the aircraft, reduces drag during cruise, saves fuel, and increases range.

[0038] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A continuously deformable wing surface mechanism based on a sliding bar-flexible truss-skin, characterized in that, include: The wing leading edge is a wing box, the upper surface of the wing is an elastic skin, a flexible truss, the wing trailing edge, several sliding rods, a fixed plate and a motor; The wing is a NACA4418 airfoil. One end of the elastic skin on the upper surface of the wing is connected to the upper edge of the leading edge of the wing, and the other end extends to the rear of the wing and connects to the trailing edge. The tail of the leading edge of the wing is flat. Several small holes are provided through the lower edge of the box wall. The number of small holes is the same as the number of sliding rods and they are arranged one-to-one. There are two or more flexible trusses, which are distributed adjacent to each other along the fore-and-aft direction between the leading and trailing edges of the wing. They are all plate trusses and are arranged symmetrically from left to right. The number of fixed plates is the same as the number of flexible trusses and they are arranged one-to-one. Several fixed plates are also distributed sequentially adjacent to each other along the fore-and-aft direction of the wing. The flexible truss includes a first tension plate and a second tension plate. The first and second tension plates of the same flexible truss The plate is located on the two sides of the first included angle of the truss. The vertices of the first included angle of all flexible trusses are downward. The upper plate joint of the first pull plate of all flexible trusses is close to the trailing edge of the wing. Conversely, the lower plate joint of the first pull plate of all flexible trusses is close to the leading edge of the wing. The plate joints of the upper ends of the first and second pull plates of the same flexible truss are far apart from each other and are fixed to the elastic skin of the upper surface of the wing at intervals. The plate joints of the lower ends are close to each other and are fixed to a fixed plate corresponding to the flexible truss. The flexible truss closest to the trailing edge of the wing is the first truss. The flexible truss adjacent to it on its front side is the second truss. The second truss is located outside the first truss. The upper plate joint of the first pull plate of the second truss is close to the upper plate joint of the second pull plate of the first truss. One end of the sliding rod is located inside the wing box, and the other end passes through a small hole through the wing box, passes through several fixing plates in sequence, and is fixed to the tail of the trailing edge of the wing. The sliding rod slides in the small hole and the fixing plates. The sliding rod is deformable. The motor is used to drive the sliding rod to slide along the fore-and-aft direction of the wing. When the sliding rod is subjected to force and slides towards the front of the wing, the fixing plate is subjected to force and moves forward. The elastic skin of the upper surface of the wing deforms through its own elasticity, and the flexible truss deforms elastically through its own flexibility adjustment. The trailing edge of the wing deflects downward. When the sliding rod is subjected to force and slides towards the rear of the wing, the elastic skin of the upper surface of the wing deforms, and the flexible truss deforms elastically through its own flexibility adjustment. The trailing edge of the wing deflects upward. During the sliding process of the sliding rod, the elastic skin of the upper surface of the wing deforms but always maintains a smooth curvature.

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