Unmanned aerial vehicle and manufacturing method thereof

Abstract

The invention provides the unmanned aerial vehicle which is low in cost and easy to operate and the manufacturing method thereof. Two main materials, namely a thin multi-layer plate and a KT plate, which are simplest and easy to obtain are utilized, and simple tools such as cutters, mucilage glue and abrasive paper are used for manufacturing the cheap model unmanned aerial vehicle. The strength of the machine body is guaranteed by means of a thin clamping plate framework, and the appearance and simulation of the machine body are achieved by cutting, grinding and shaping a KT plate. The strength requirement of the wing is met by bonding the carbon fiber tube with the wing rib and the KT plate. The invention is particularly suitable for rapid production and deployment of cost-sensitive application scenarios, such as consumable drones in military training. According to the invention, the consistency and reliability of products are ensured, the production cost is greatly reduced, and large-scale supply becomes possible.

Description

Technical Field

[0001] The invention relates to an unmanned aircraft and a manufacturing method thereof. Background Art

[0002] There are many types of drones with various uses. They are generally divided into drones that perform practical tasks (such as aerial photography, logistics, agriculture, military reconnaissance and strike), and model aircraft used for entertainment, competition, and sports. Model aircraft are different from aircraft models. Model aircraft are small flying aircraft, while aircraft models are proportional imitations of real aircraft. There are several ways to manufacture model aircraft:

[0003] 1. Paper and wood structure

[0004] This is the most common way to make early model airplanes. Figure 1 As shown in the figure, the fuselage and wing skeletons are constructed with thin wood slices, and then cotton paper (such as rice paper) or paper is pasted on the outer surface of the wooden skeleton. Parts that need to be strengthened (such as wings) will be pasted with thin wood slices to improve strength. This process follows the manufacturing process and materials of early aircraft before and after World War I, and is mainly limited by the fact that new materials (such as plastics, fiberglass, epoxy resin, etc.) had not yet appeared at the time. Its disadvantages include: complex process, difficult parts preparation, long manufacturing cycle, simple appearance, difficult trimming, low strength of finished products, inability to make streamlined simulation models, and easy damage. Despite this, it is still the mainstream choice for early aviation models and is suitable for handcraft enthusiasts who pursue traditional craftsmanship.

[0005] 2. Plastic foaming molding process

[0006] With the development of plastic materials, especially the emergence of lightweight foamed plastics, model aircraft manufacturing has entered a new stage. This type of model aircraft is molded by mold injection foaming, which has good shape retention and simulated appearance. However, this process relies on mold production and requires batch manufacturing, which is not suitable for self-assembly by enthusiasts, so it is mostly used for children's toys. Its core process is: first make a mold, inject plastic raw materials into the mold for foaming, and finally obtain standardized model parts.

[0007] 3. Foamed plastic sheet processing technology

[0008] like Figure 2 As shown in the figure, this method is based on foamed plastic sheets (such as expanded polystyrene EPS), and the wings and fuselage of standard airfoils are directly cut out in one piece by an electric wire cutting machine, and then the fine shape is shaped by grinding. After cutting, epoxy resin needs to be coated on the surface, and glass fiber or carbon fiber cloth needs to be laid to enhance the strength (the strength of the foamed plastic itself is insufficient). Although the process is complicated and costly, this technology is suitable for large model aircraft (wingspan is mostly more than 2 meters), because it is difficult for small model aircraft to achieve economical efficiency through this process.

[0009] 4. Foamed plastic sheet folding process

[0010] Currently, a manufacturing technology based on 2-4 mm foam plastic sheets is used for small model aircraft. Taking advantage of its bendable and foldable properties, the wings are formed by bending (such as Figure 3 ), the fuselage is bonded by splicing (such as Figure 4 ). The process is simple and low-cost, but it has significant defects: it cannot accurately reproduce the aircraft airfoil (wing profile shape), which affects flight performance; the overall strength is insufficient, and the shape cannot achieve the streamlined simulation effect of the real aircraft. Despite this, its low threshold characteristics make it a common choice for entry-level enthusiasts. Summary of the invention

[0011] The present invention provides an unmanned aircraft and a manufacturing method thereof, which has a simple process, readily available materials and low cost, and can manufacture model aircraft and commercial or military small and medium-sized unmanned aircraft with excellent structural strength, precise airfoil and good appearance shaping effect.

[0012] In a first aspect, a method for manufacturing an unmanned aircraft comprises manufacturing a wooden fuselage using plywood; manufacturing a fuselage skin using a foamed plastic board; and bonding the skin to the fuselage to form a complete fuselage shell.

[0013] In some examples, different portions of the skin are manufactured separately by foam molding and the portions are bonded to the fuselage.

[0014] In some examples, the left and right side skins and the lower skin of the fuselage are molded and manufactured in the same mold; the fuselage is embedded and fixed between the left and right side skins and the upper skin; and then the upper skin is added to complete the overall assembly.

[0015] In some examples, left and right side skins and an upper skin of a fuselage are molded and manufactured in the same mold; the fuselage is embedded and fixed between the left and right side skins and the upper skin; and then a lower skin is added to complete the overall assembly.

[0016] In a second aspect, a method for manufacturing an unmanned aircraft includes: wing manufacturing steps: a. selecting multiple layers of foamed plastic plates for lamination and bonding according to the designed thickness of the wing, applying glue between the layers and pressurizing and curing, and ensuring that the fiber texture of the foamed plastic plates is consistent with the span direction of the wing; b. when bonding the wings made of the multiple layers of foamed plastic plates, simultaneously installing carbon fiber tube wing beams and wing ribs made of the multiple layers of plates inside; c. performing heat cutting or grinding on the bonded wings to form an airfoil profile; d. covering the wing surface with a reinforcement material layer; fuselage manufacturing steps: e. Stack and bond multiple foam plastic boards to form the fuselage body, and adjust the number of layers to adapt to the curvature changes in different parts; f. When bonding the fuselage made of multiple layers of foam plastic boards, it is necessary to install a wooden frame inside to fix the engine bracket, landing gear bracket and / or magazine bracket; g. Cut and polish the bonded foam plastic boards to form a smooth fuselage shape; Assembly steps of the whole machine: h. Insert the wing beam into the corresponding mounting hole of the fuselage to complete the connection between the wing and the fuselage; i. Trim the connection between the wing and the fuselage to ensure a smooth transition of the aerodynamic shape.

[0017] A third aspect provides an unmanned aircraft manufactured using the unmanned aircraft manufacturing method. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of an early model aircraft.

[0019] Figure 2 It is a schematic diagram of processing model airplane expanded polystyrene (EPS) sheet using electric heating wire cutting technology.

[0020] Figure 3 It is a schematic diagram of a wing structure formed by bending a foamed plastic sheet.

[0021] Figure 4 It is a schematic diagram of the fuselage structure formed by splicing and bonding foam plastic sheets.

[0022] Figure 5 This is a schematic diagram of a model aircraft fuselage frame assembled by laser cutting three-ply plywood and gluing it together.

[0023] Figure 6 This is a schematic diagram of the assembly structure of the fuselage frame and the foamed plastic molded skin.

[0024] Figure 7 It is a schematic diagram of the fuselage side skin and upper skin structure which are made up of multiple KT plates glued together.

[0025] Figure 8 This is a cross-sectional view of the middle section of a model airplane fuselage after multiple layers of KT boards have been bonded together and then cut, polished and shaped.

[0026] Fig. 9It is a schematic diagram of a wing bonded with multiple layers of KT panels. DETAILED DESCRIPTION

[0027] The invention relates to a simple and economical process method, which is suitable for manufacturing model aircraft or commercial and military small and medium-sized unmanned aerial vehicles with high-strength structure and precise airfoil. The method uses two basic materials: thin three-ply board and foamed plastic (KT) board.

[0028] Example 1

[0029] For thin plywood applications, 1.5-2mm thickness is usually used for small model aircraft, while for larger models, 3-5mm thick sheets may be required. Figure 5 As shown, these three-ply plates are mainly used to construct the main load-bearing structures of the fuselage, such as engine brackets, landing gear brackets, wing brackets and magazine brackets, etc. In order to reduce weight, all frames are designed in a hollow form, but at the same time ensure sufficient strength to withstand various stresses during flight.

[0030] The external covering of the fuselage is made of foam plastic board. Figure 6 As shown, first, different parts of the fuselage (upper skin, lower skin, left and right skin) are manufactured separately through a foaming mold, and then these parts are bonded to a wooden frame to form a complete fuselage shell. Alternatively, the left and right skins and the lower skin (or upper skin) of the fuselage can be molded and manufactured in the same mold, and then the wooden frame is embedded and fixed, and finally the upper (or lower) skin is added to complete the overall assembly. This technology enables the design of complex curved surfaces and transition areas, thereby producing an aircraft model that conforms to more aerodynamic characteristics.

[0031] Example 2

[0032] In addition, the present invention also proposes an improved process specifically for small batch production, which constructs the fuselage (such as Figure 7 As shown). The material of the foamed plastic board may include polyethylene (PE), polyvinyl chloride (PVC) and the like. The following is a specific description taking KT board as an example.

[0033] Adjust the number of KT board layers according to specific needs to adapt to the curvature changes in different parts. Figure 8 This is a cross-sectional view of the middle section of the fuselage of a model aircraft made by this process. After the initial forming is completed, the shape is further trimmed by cutting and grinding to eliminate edges and corners, making the surface smoother and more fluent, and reducing resistance and turbulence during flight. When bonding the fuselage made of multiple layers of KT board, a wooden frame needs to be installed inside to fix the engine bracket, landing gear bracket and / or magazine bracket. The wooden frame adopts a hollow design to reduce weight.

[0034] like Fig. 9 As shown in the figure, the same principle of multi-layer KT board bonding is followed for the manufacture of the wing. First, select the appropriate KT board thickness according to the maximum thickness of the required airfoil. For example, when the maximum thickness is 16 mm, four 4 mm thick KT boards can be selected for stacking. The internal structure of the wing includes wing beams made of carbon fiber tubes and other key supporting components (such as ribs). The entire wing needs to be hot cut or ground to obtain the accurate airfoil profile, and finally covered with a layer of reinforcing material (such as kraft paper or thermoplastic film) to improve the surface strength.

[0035] like Fig. 9 As shown in the figure, when cutting multi-layer foamed plastic (KT) boards, special attention should be paid to the direction of their fiber grain. When manufacturing wings, it should be ensured that the fiber direction of the foamed plastic (KT) board is compatible with the main stress of the wing, that is, the direction of its grain is consistent with the span direction of the wing to enhance the structural strength.

[0036] When bonding a wing made of multiple layers of KT plates, the following components must be securely fixed at the same time: wing spars (made of carbon fiber tubes, divided into front and rear spars), wing ribs (divided into root ribs, wing tip ribs and other ribs, which can be made of multiple layers of plates, such as plywood). Specifically, Figure 5 As shown, the spar passes through the wing root rib, and a length of the mounting hole that can be inserted into the fuselage is reserved at the outer end of the wing root. The other end of the spar is embedded in the half-wing rib in the mounting hole of the wing servo. When bonding, it is necessary to ensure that the inner side of the wing root rib and the half-wing rib are firmly bonded to the end face of the laminated foam plastic (KT) board. At the same time, the spar should also be glued and securely fixed in the reserved groove of the wing. In addition, it is necessary to ensure that the wing servo is reliably bonded to the end face of the foam plastic (KT) board.

[0037] The foamed plastic (KT) boards also need to be glued and pressed with heavy objects between the layers to make them firmly bonded. When the glue is completely cured and firmly bonded, the wing surface is thermally cut, or the excess part of the rib is removed by grinding, so as to obtain a wing with a perfect and precise airfoil. Finally, a thin layer of kraft paper or thermoplastic film is covered on the entire wing surface to strengthen the strength of the outer surface of the wing.

[0038] The advantage of the present invention is that it uses the two most simple and readily available main materials - thin multilayer boards (e.g., 2-3 mm thick) and foamed plastic (KT) boards, and uses simple tools such as knives, glue and sandpaper to manufacture a cheap model aircraft drone. The fuselage strength is guaranteed by the thin plywood structure, while the fuselage shape and simulation are achieved by cutting and grinding the KT board. The strength requirements of the wing are met by the carbon fiber tube and its bonding with the wing ribs and the foamed plastic (KT) board. At the same time, the precisely manufactured wing ribs ensure the accuracy of the airfoil.

[0039] Model airplanes, commercial and military drones manufactured using the materials and processes of the present invention will not be deformed during placement and use, thereby ensuring the consistency of the product's flight quality. This provides quality assurance for small drones used on the battlefield. Due to the simplicity of materials and the simple manufacturing process, the cost is low, and a large number of continuous supply of combat disposable consumables can be provided for the battlefield.

[0040] In summary, the present invention provides a low-cost, easy-to-operate solution that is particularly suitable for the rapid production and deployment of cost-sensitive application scenarios, such as consumable drones in military training. This approach not only ensures product consistency and reliability, but also greatly reduces production costs, making large-scale supply possible.

Claims

1. A method for manufacturing an unmanned aircraft, characterized in that: The wooden fuselage is manufactured by using three-ply plywood; the skin of the fuselage is manufactured by using a foamed plastic board; and the skin is bonded to the fuselage to form a complete fuselage shell.

2. The method for manufacturing an unmanned aircraft according to claim 1, characterized in that: The different parts of the skin are manufactured separately by means of a foaming mould and these parts are bonded to the fuselage.

3. The method for manufacturing an unmanned aircraft according to claim 1, characterized in that: The left and right side skins and the lower skin of the fuselage are molded and manufactured in the same mold; the fuselage is embedded and fixed between the left and right side skins and the upper skin; and the upper skin is added to complete the overall assembly.

4. The method for manufacturing an unmanned aircraft according to claim 1, characterized in that: The left and right side skins and the upper skin of the fuselage are molded and manufactured in the same mold; the fuselage is embedded and fixed between the left and right side skins and the upper skin; and the lower skin is added to complete the overall assembly.

5. An unmanned aircraft, characterized in that: The unmanned aircraft is manufactured by the unmanned aircraft manufacturing method described in any one of claims 1 to 4.

6. A method for manufacturing an unmanned aircraft, characterized in that: include: Wing manufacturing steps: a. According to the designed thickness of the wing, select multiple layers of foam plastic sheets for lamination and bonding, apply glue and pressurize to cure between the layers, and ensure that the fiber texture of the foam plastic sheets is consistent with the span direction of the wing; b. When bonding the wing made of multi-layer foamed plastic sheets, the carbon fiber tube wing beam and the wing rib made of multi-layer sheets are installed inside at the same time; c. Perform thermal cutting or grinding on the bonded wing to form an airfoil profile; d. Cover the wing surface with a layer of reinforcement material; Fuselage manufacturing steps: e. The fuselage body is formed by stacking and bonding multiple foam plastic sheets, and the number of layers is adjusted to adapt to the curvature changes in different parts; f. When gluing the fuselage made of multi-layer foamed plastic sheets, it is also necessary to install a wooden frame inside to fix the engine bracket, landing gear bracket and / or magazine bracket; g. Cut and polish the bonded foam plastic sheets to form a smooth fuselage shape; Machine assembly steps: h. Insert the wing spar into the corresponding mounting hole of the fuselage to complete the connection between the wing and the fuselage; i. Trim the connection between the wing and the fuselage to ensure a smooth transition of the aerodynamic shape.

7. The method for manufacturing an unmanned aircraft according to claim 6, characterized in that: The reinforcement material layer on the wing surface is made of kraft paper or thermoplastic film.

8. The method for manufacturing an unmanned aircraft according to claim 6, characterized in that: The reinforcement material layer covers the entire wing surface by gluing or hot pressing.

9. The method for manufacturing an unmanned aircraft according to claim 6, characterized in that: The foamed plastic board adopts KT board.

10. An unmanned aircraft, characterized in that: The unmanned aircraft is manufactured using the unmanned aircraft manufacturing method described in any one of claims 6-7.

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