High-aspect-ratio wing based on additive manufacturing

Abstract

The invention discloses a high aspect ratio wing based on additive manufacturing, and relates to the field of structural design of aircraft wings. According to the invention, the additive-manufactured high-aspect-ratio wing can also be conveniently connected and assembled, and all parts on the high-aspect-ratio wing can be accurately and efficiently mounted. The high-aspect-ratio wing comprises a wing body fusion part, wing sections and a winglet which are connected in sequence, one side of the wing body fusion part is used for being connected with a fuselage of the aircraft, the other side of the wing body fusion part is fixedly connected with the winglet through the two wing sections, and two control surfaces are installed on each wing section. And steering engines for controlling the control surfaces to rotate are mounted in the wing sections. According to the method, the high-aspect-ratio wing model can be processed and assembled by using the additive manufacturing technology, and the advantages brought by printing the airplane model by using the additive manufacturing technology can be applied to the high-aspect-ratio wing.

Description

Technical Field

[0001] The invention relates to the field of structural design of aircraft wings, and in particular to an additive manufacturing technology for large aspect ratio wings. Background Art

[0002] Flying wing aircraft have received extensive attention in the aviation industry due to their advantages such as good aerodynamic and stealth performance and light weight. Such aircraft generally use a wing structure with a large aspect ratio. Due to the light weight and high flexibility of such a wing, the wing will produce large bending and torsional deformations under the action of flight loads, which can easily cause flutter. Therefore, it is necessary to manufacture a large aspect ratio wing model to carry out aeroelastic tests in order to obtain the structural dynamics and aeroelastic characteristics of the wing.

[0003] In addition, with the continuous development of materials and manufacturing technology, the use of additive manufacturing technology to print aircraft models has become one of the important means of future aircraft design and manufacturing. Compared with traditional machining methods, additive manufacturing can directly form parts with complex structures without the support of fixtures and molds; and the material recovery rate is high, without a large number of cutting processes; due to the fast molding, it can also shorten the time required from completing the model design to obtaining the solid model. For flying wing layout aircraft, the use of additive manufacturing can also accurately control the position of the internal force structure of the aircraft, so that the mechanical properties of the model can be adjusted, which provides convenience for aeroelastic tests to study the aeroelastic properties of aircraft.

[0004] However, the use of additive manufacturing methods through 3D printers can achieve the overall printing of UAV parts, thus avoiding complex assembly work, but it will cause the problem of fewer separation surfaces available for connection; especially when facing large aspect ratio wings, because the wing length exceeds the size limit of the printer, it is necessary to print in sections and redesign the separation surface, which is quite difficult. In addition, in the measures for connecting the separation surface, if the traditional multi-nail mechanical connection is used, it is necessary to design a complex connection mechanism with many fasteners at the separation surface, making the wing segment difficult to install; if gluing is used, the glue will fail after the wing is disassembled, which is not conducive to the reuse of the UAV. Summary of the invention

[0005] In view of the above problems, the present invention proposes a high aspect ratio wing based on additive manufacturing, so that the high aspect ratio wing manufactured by additive manufacturing can also be easy to connect and assemble, and the installation of various parts on the high aspect ratio wing can be completed accurately and efficiently.

[0006] The technical solution of the present invention is as follows: the high aspect ratio wing comprises a wing-body fusion part 1, a wing section 2 and a winglet 4 which are connected in sequence, one side of the wing-body fusion part 1 is used to connect to the fuselage of the aircraft, and the other side is fixedly connected to the winglet 4 through two wing sections 2, two control surfaces 3 are respectively installed on each wing section 2, and a steering gear for controlling the rotation of the control surface 3 is installed inside the wing section 2;

[0007] The wing section 2 and the control surface 3 are processed by a 3D printer, and the interior thereof is filled with unit cells to form a lattice structure, and a skin is coated outside the lattice structure;

[0008] The wing-body fusion portion 1 and the wing section 2, adjacent wing sections 2, and the wing section 2 and the winglet 4 are all connected via a separation surface connection structure.

[0009] Furthermore, two adjacent structural members are connected by means of the separation surface connection structure, wherein a slot 12 is provided on one of the structural members along the chord direction of the wing, and a ridge 13 is provided on the other structural member along the chord direction of the wing. After the ridge is assembled in the slot along the chord direction, it is locked by means of a vertically arranged fixing screw passing through the ridge 13.

[0010] Furthermore, the top surface and the bottom surface of the convex ridge 13 are parallel planes to each other;

[0011] The ends of the slot 12 and the ridge 13 are in a broken line shape, and the surface of the separation surface connection structure is arc-shaped after the two are plugged in.

[0012] Furthermore, each wing section 2 has two steering gear cabins in the middle of the lower surface for installing steering gears for controlling the deflection of the control surface, and a steering gear cabin cover 5 for sealing is fixedly installed outside the cabin.

[0013] Furthermore, a receiving groove for receiving the control surface 3 is provided at the trailing edge of the wing section 2 , and the control surface 3 is rotatably connected in the receiving groove of the wing section 2 .

[0014] Furthermore, the wingtip winglet 4 is divided into two half winglets in the vertical direction from the chord, and bolt holes are arranged around the side edges of the two half winglets for connecting the two half winglets.

[0015] Compared with the prior art, the present invention can realize the use of additive manufacturing technology to process a high aspect ratio wing model and complete the assembly, and can apply the advantages of printing aircraft models using additive manufacturing technology to high aspect ratio wings. The separation surface connection structure provided by the present invention can reduce the number of fasteners used in connecting wing sections, making the installation of wing sections simpler; and the wing sections connected using this method can be repeatedly disassembled. The connection structure between the control surface and the wing section provided by the present invention is relatively simple to assemble, requires fewer separation surfaces, and can be realized through additive manufacturing processing, so that the high aspect ratio wing model can be equipped with a control surface and a control system, which is convenient for conducting research on active aeroelastic control. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a top view of the structural layout of the high aspect ratio wing model;

[0017] Figure 2 This is a bottom view of the high aspect ratio wing model structure layout;

[0018] Figure 3 This is a schematic diagram of the dot matrix structure used inside the wing;

[0019] Figure 4 It is the top view and side view of the control surface shape;

[0020] Figure 5 It is a schematic diagram of the assembly of the control surface and the wing section connection structure;

[0021] Figure 6a This is a schematic diagram of the structure of the two halves of the wingtip winglet. Figure 1 , Figure 6b This is a schematic diagram of the structure of the two halves of the wingtip winglet. Figure 2 ;

[0022] Figure 7a This is a schematic diagram of the structure on one side of the separation surface connection structure Figure 1 , Figure 7b This is the structural diagram of this side. Figure 2 ;

[0023] Figure 8a This is a schematic diagram of the structure on the other side of the separation surface connection structure Figure 1 , Figure 8b This is the structural diagram of this side. Figure 2 ;

[0024] Fig. 9 It is a schematic diagram of a circular shaft with a spring used in the control surface and wing section connection mechanism.

[0025] In the figure, 1 is the wing-body fusion part, 2 is the wing section, 3 is the control surface, 4 is the wingtip winglet, 5 is the servo cabin cover, 6 is the hinge hole, 7 is the limit hole, 8 is the threaded hole, 9 is the mounting hole, 10 is the bearing, 11 is the reinforcement rib, 12 is the groove, 13 is the convex ridge, 17 is the aluminum alloy round shaft, and 18 is the spring. DETAILED DESCRIPTION

[0026] In order to clearly illustrate the technical features of this patent, this patent is elaborated in detail below through a specific implementation method and in combination with its accompanying drawings.

[0027] The wing is Figure 1 and Figure 2 As shown, the model includes a wing-body fusion part 1, two wing sections 2, four control surfaces 3 and a winglet 4. The span of the whole model is 1.6m.

[0028] One side of the wing-body fusion part 1 is used to connect to the fuselage of the aircraft, and the other side is fixedly connected to the wingtip winglet 4 through two wing sections 2. Two control surfaces 3 are respectively installed on each wing section 2, and a servo for controlling the rotation of the control surface 3 is installed inside the wing section 2.

[0029] Among them, the wing uses Figure 3 The lattice structure composed of a unit cell is filled, the wing skin is placed at the lattice, and the part where the lattice and the skin intersect is cut to obtain the internal filling structure of the wing. The wing section 2 and the control surface 3 are made by additive manufacturing process, and after forming, they include unit cells and skin.

[0030] Each wing section 2 has two steering gear compartments in the middle of the lower surface. Figure 2 As shown, the interior is used to install a steering gear for controlling the deflection of the control surface, and a steering gear cabin cover 5 for sealing is fixedly installed outside the cabin.

[0031] like Figure 5 As shown, the trailing edge of the wing section 2 is provided with a receiving groove for accommodating the control surface 3, and the inner wall of the receiving groove is provided with a mounting hole 9 along the span direction, the diameter of the mounting hole is 10 mm, and each hole is provided with a rolling bearing 10 for rotationally connecting with the shaft head of the control surface 3.

[0032] The shape of the control surface 3 is as follows: Figure 4 As shown. The airfoil of the control surface 3 is obtained by dividing the airfoil into two parts near the trailing edge of the wing airfoil and taking the part including the trailing edge. The front part of the control surface 3 has a hinge hole 6 along the span direction, with a hole diameter of 6.8mm; after the rotating shaft is installed in the hinge hole 6 and the mounting hole 9, the control surface 3 is rotatably connected to the receiving groove of the wing section 2.

[0033] There is a tapered limit hole 7 at each end of the control surface 3, which points to the rotating shaft. After the limit pin is installed in the limit hole 7, the control surface 3 and the rotating shaft are relatively fixed; three threaded holes 8 distributed in a triangular shape are also opened in the middle of the control surface 3, which are used to install the transmission mechanism of the steering gear so as to accept the control of the steering gear to flip up and down.

[0034] The wingtip winglet 4 is divided into two half winglets in the vertical direction from the chord. Figure 6a , 6b As shown, bolt holes are arranged around the side edges of the two half winglets for connecting the two half winglets. The interior of the two half winglets is provided with reinforcing ribs 11, as shown in FIG. Figure 6a As shown, a transition section for connecting the wing sections is provided on the outer wall of one of the half winglets.

[0035] In addition, this embodiment also includes a connection structure between a control surface and a wing section and an assembly diagram thereof as shown in FIG. Figure 5 The rotating shaft comprises two identical aluminum alloy round shafts 17 and a spring 18, as shown in FIG. Fig. 9 The diameter of the round shaft 17 is 6 mm, and a long slot for connecting a limit pin is provided on the aluminum alloy round shaft 17 , and the spring 18 is fixedly connected between the two aluminum alloy round shafts 17 .

[0036] When installing the control surface 3, first install the two aluminum alloy round shafts 17 equipped with springs 18 into the hinge holes 6 along the span direction of the control surface 3, and press the two ends of the aluminum alloy round shafts 17 by hand so that they are completely located inside the through holes; then move the control surface 3 so that the axis of the hinge hole 6 is aligned with the axis of the hinge hole 6. Figure 5 The axes of the mounting holes 9 in the control surface 3 coincide with each other, and then release the grip, so that the two aluminum alloy round shafts 17 extend into the mounting holes 9 at both ends of the wing section mounting part along the span direction under the action of the restoring force of the springs 18; finally, limit pins are placed in the limit holes 7 at both ends of the surface of the control surface 3, and the pins are inserted into the long grooves on the surface of the aluminum alloy round shafts 17 at the same time, and the installation of the control surface can be completed.

[0037] In this case, adjacent wing sections 2 are connected by a separation surface connection structure, and the connection structure and its assembly effect diagram are shown in FIG. Figure 7a , 7b , Figure 8a , 8b shown.

[0038] The separation surface connection structure is as follows: a slot 12 is provided along the chord direction on one of the wing segments 2, and a ridge 13 is provided along the chord direction on the other wing segment 2. After the ridge is assembled in the slot along the chord direction, it is locked by a vertically arranged fixing screw passing through the ridge 13.

[0039] The top and bottom surfaces of the ridge 13 are parallel planes; the ends of the slot 12 and the ridge 13 are in a broken line shape, and the surface of the separation surface connection structure is arc-shaped after the two are plugged in.

[0040] In this way, the ridges 13 and slots 12 arranged in the chord direction are assembled and then locked by the vertical fixing screws. Finally, the structural members on both sides of the separation surface can be fully positioned in the chord direction, span direction and vertical direction through the separation surface connection structure, which is not only simple to assemble, but also accurate in positioning and can be repeatedly disassembled.

[0041] The wing-body fusion part 1 and the wing section 2 are also connected by the above-mentioned separation surface connection structure. Specifically, a slot 12 can be set on the wing-body fusion part 1, and a ridge 13 can be set on the adjacent wing section 2, and finally locked by fixing screws.

[0042] The wing section 2 and the winglet 4 are also connected by the separation surface connection structure. Specifically, a slot 12 can be provided on the wing section 2, and a ridge 13 can be provided on the winglet 4, and finally locked by fixing screws.

[0043] There are many specific implementation ways of the present invention. The above is only the preferred implementation mode of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements can be made without departing from the principle of the present invention. These improvements should also be regarded as the protection scope of the present invention.

Claims

1. A high aspect ratio wing based on additive manufacturing, characterized in that: The high aspect ratio wing comprises a wing-body fusion part (1), a wing section (2) and a winglet (4) which are connected in sequence, one side of the wing-body fusion part (1) is used to connect to the fuselage of the aircraft, and the other side is fixedly connected to the winglet (4) through two wing sections (2), each wing section (2) is respectively equipped with two control surfaces (3), and a steering gear for controlling the rotation of the control surface (3) is installed inside the wing section (2); The wing section (2) and the control surface (3) are processed by a 3D printer, the interior of which is filled with unit cells to form a lattice structure, and the lattice structure is covered with a skin; The wing-body fusion portion (1) and the wing section (2), adjacent wing sections (2), and the wing section (2) and the winglet (4) are all connected via a separation surface connection structure.

2. The high aspect ratio wing based on additive manufacturing according to claim 1, characterized in that: Two adjacent structural members are connected by means of the separation surface connection structure, wherein the separation surface connection structure comprises: a slot (12) along the chord direction of the wing is provided on one of the structural members, and a ridge (13) along the chord direction of the wing is provided on the other structural member, and after the ridge is assembled in the slot along the chord direction, it is locked by means of a fixing screw vertically arranged through the ridge (13).

3. The high aspect ratio wing based on additive manufacturing according to claim 1, characterized in that: The top surface and bottom surface of the convex ridge (13) are parallel planes to each other; The ends of the slot (12) and the ridge (13) are in a broken line shape, and the surface of the separation surface connection structure is arc-shaped after the two are plugged in.

4. The high aspect ratio wing based on additive manufacturing according to claim 1, characterized in that: Each wing section (2) has two steering gear cabins in the middle of the lower surface for installing steering gears for controlling the deflection of the control surface, and a steering gear cabin cover (5) for sealing is fixedly installed outside the cabin.

5. The high aspect ratio wing based on additive manufacturing according to claim 1, characterized in that: The trailing edge of the wing section (2) is provided with a receiving groove for receiving the control surface (3), and the control surface (3) is rotatably connected in the receiving groove of the wing section (2).

6. The high aspect ratio wing based on additive manufacturing according to claim 1, characterized in that: The winglet (4) is divided into two half winglets in the vertical direction from the chord, and bolt holes are arranged around the side edges of the two half winglets for connecting the two half winglets.

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