Large-size bending-resistant round cross-section wing pipe beam butt joint structure

Abstract

The application belongs to the field of unmanned aerial vehicle wing beam design, and relates to a large-specification anti-bending circular-section wing beam butt joint structure, which comprises an inner circular beam, an outer circular beam, an inner butt joint connector sleeved at the end of the inner circular beam and an outer butt joint connector sleeved at the end of the outer circular beam. An inner end rib is arranged on the inner circular beam, and an outer end rib is arranged on the outer circular beam. The inner butt joint connector is used to connect the inner circular beam and the inner end rib, and the outer butt joint connector is used to connect the outer circular beam and the outer end rib. The inner butt joint connector and the outer butt joint connector can transmit large-specification bending moment and shear force. In addition, the inner butt joint connector and the outer butt joint connector are simple in cooperation with the inner end rib and the outer end rib, can realize quick disassembly and recovery installation of the structure, have excellent structural maintenance, have good implementation effect, are high in reliability, and have passed wing beam and butt joint selection static force test and flight verification of a solar unmanned aerial vehicle.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of unmanned aerial vehicle wing beam design, and particularly relates to a large-specification anti-bending circular cross-section wing beam butt joint structure. BACKGROUND

[0002] A certain large solar unmanned aerial vehicle has a wing span of 50 meters, and the wing beam thereof is a main load-bearing component. Considering production and manufacturing, component transportation restrictions and other factors, the wing must be segmented, and the separation surfaces of the wing segments must be quickly detachable and restorable. The certain large solar unmanned aerial vehicle is divided into five segments, including a 2-meter mission cabin segment, left and right 14-meter central wing segments and left and right 11-meter outer wing segments. The single-beam design maximum length of the wing beam is about 14 meters, and an integral composite circular pipe beam structure is adopted. For such a large wing span and aspect ratio wing structure, the wing beam is a main component for bearing wing bending moment and shear force. Under the premise of minimizing the structure weight, how to ensure the load transmission of the wing beam at the separation surfaces and achieve quick disassembly and restoration is a key problem faced by such aircraft design.

[0003] At present, there are not a few solar unmanned aerial vehicles that adopt a circular composite pipe beam structure as a main load-bearing component at home and abroad, but the pipe beam butt joint structures are different. Small load circular pipe beam butt joint adopts a shear pin, and large load circular pipe beam adopts a flange butt joint as a whole with the wing beam body.

[0004] The shear pin structure of the small load wing beam butt joint is not suitable for super large size and super large aspect ratio wing structures as the root bending moment increases with the increase of the wing span of the solar unmanned aerial vehicle. The flange butt joint structure of the large load circular pipe beam adopts a fastener connection, which increases the local thickness of the composite flange in the butt joint area, and the bolt and nut are directly connected with the composite wing beam. Frequent disassembly will inevitably cause delamination and other damages to the composite structure hole edge and hole wall, and the weight cost is large. In addition, the flange butt joint structure has different bending moments on the upper and lower surfaces of the wing under different load conditions, which results in different loads of the fasteners. If the diameters of the fasteners are different, force competition will occur, which is not conducive to the force of the structure. SUMMARY

[0005] The application aims to provide a large-specification anti-bending circular cross-section wing pipe beam butt joint structure to solve the technical problem that the pipe beam butt joint structure is difficult to achieve quick disassembly and assembly.

[0006] The technical scheme of the present application is: a large-specification anti-bending circular cross-section wing pipe beam butt joint structure, comprising an inner side circular pipe beam, an outer side circular pipe beam, an inner side butt joint connector sleeved at the end of the inner side circular pipe beam, and an outer side butt joint connector sleeved at the end of the outer side circular pipe beam; the inner side circular pipe beam is provided with an inner side end rib, the outer side circular pipe beam is provided with an outer side end rib, the inner side end rib is attached to the outer side end rib, the inner side butt joint connector and the outer side butt joint connector are both cylindrical, the connector body of the inner side butt joint connector is detachably connected with the inner side circular pipe beam, the end thereof is detachably connected with the inner side end rib, the connector body of the outer side butt joint connector is detachably connected with the outer side circular pipe beam, and the end thereof is detachably connected with the outer side end rib.

[0007] Preferably, the inner side butt joint connector and the outer side butt joint connector further comprise a butt flange provided at the end of the connector body, a single-ear butt ear provided on the butt flange, and double-ear butt ears; the butt flange is bolted with the inner side end rib or the outer side end rib, the single-ear butt ear is provided at the position of the aircraft structure horizontal plane, there are two groups of single-ear butt ears which are correspondingly provided along the circumference of the butt flange, and there are four groups of double-ear butt ears which are correspondingly provided along the circumference of the butt flange in pairs; a plurality of ear reinforcing ribs are provided on the side wall of the connector body, and the ear reinforcing ribs are integrally connected with the butt flange, the single-ear butt ear and the double-ear butt ear.

[0008] Preferably, the inner side wall of the end of the outer side butt joint connector and the inner side butt joint connector close to the butt flange is provided with an end chamfer, and the size of the end chamfer is 1mm.

[0009] Preferably, the end of the inner side butt joint connector and the outer side butt joint connector away from the butt flange is correspondingly provided with two groups of end notches along the circumference, the end notches are in W shape, and the end of the inner side butt joint connector and the outer side butt joint connector away from the butt flange is provided with an end flange on the side wall.

[0010] Preferably, a glass fiber fabric gasket is provided between the inner side end rib and the outer side end rib.

[0011] Preferably, a plurality of rows of fasteners are provided on the outer side butt joint connector and the inner side butt joint connector along the axial direction, a step is provided on the outer side wall of the end of the outer side butt joint connector and the inner side butt joint connector close to the butt flange, the wall thickness of the outer side butt joint connector or the inner side butt joint connector at the row of fasteners closest to the butt flange is 2mm, and the wall thickness of the outer side butt joint connector or the inner side butt joint connector at the remaining fasteners is 1.5mm.

[0012] Preferably, the inner side butt joint connector and the outer side butt joint connector are both made of TC4 material and are manufactured by 3D printing additive manufacturing process, the length of the inner side butt joint connector and the outer side butt joint connector is 240mm, and the local minimum wall thickness is 1.5mm.

[0013] Preferably, the inner side butt joint and the outer side butt joint are connected by glue and bolts.

[0014] The application provides a large-specification anti-bending circular cross-section wing beam butt joint structure, which comprises an inner side circular pipe beam, an outer side circular pipe beam, an inner side butt joint arranged at an end of the inner side circular pipe beam and an outer side butt joint arranged at an end of the outer side circular pipe beam; an inner side end rib is arranged on the inner side circular pipe beam, and an outer side end rib is arranged on the outer side circular pipe beam; the inner side butt joint is connected with the inner side circular pipe beam and the inner side end rib, respectively, and the outer side butt joint is connected with the outer side circular pipe beam and the outer side end rib, respectively; the inner side butt joint and the outer side butt joint can transmit large-specification bending moment and shear force; meanwhile, the inner side butt joint and the outer side butt joint are simple in cooperation with the inner side end rib and the outer side end rib, can realize quick disassembly and recovery installation of the structure, have excellent structural maintenance, have good implementation effect, are high in reliability, and have passed wing spar and butt joint selection static force test and flight verification of a solar unmanned aerial vehicle. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to more clearly illustrate the technical solutions provided by the application, the following will briefly introduce the drawings. Obviously, the drawings described below are only some embodiments of the application.

[0016] Figure 1 It is a schematic diagram of the pipe beam and the rib plate connection structure of the application;

[0017] Figure 2 It is an axonometric view of the overall structure of the application;

[0018] Figure 3 It is a sectional view of the overall structure of the application;

[0019] Figure 4 It is a front view of the outer side butt joint structure of the application;

[0020] Figure 5 It is an axonometric view of the outer side butt joint of the application.

[0021] 1, inner side butt joint; 2, outer side butt joint; 3, inner side circular pipe beam; 4, outer side circular pipe beam; 5, inner side end rib; 6, sock end rib; 7, butt joint bolt; 8, connecting bolt; 9, glass fiber fabric gasket; 10, end chamfer; 11, single-ear butt joint ear; 12, double-ear butt joint ear; 13, butt joint flange; 14, end notch; 15, reinforcing rib; 16, end flange. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solutions and advantages of the application clearer, the following will describe the technical solutions in the embodiments of the application in more detail with reference to the drawings in the embodiments of the application.

[0023] A large-scale, bending-resistant circular cross-section airfoil tube-beam butt joint structure, such as Figures 1-3 As shown, it includes an inner circular tube beam 3, an outer circular tube beam 4, an inner butt joint 1 sleeved at the end of the inner circular tube beam 3, and an outer butt joint 2 sleeved at the end of the outer circular tube beam 4; the inner circular tube beam 3 is provided with an inner end rib 5, and the outer circular tube beam 4 is provided with an outer end rib. The inner end rib 5 is in contact with the outer end rib. The inner butt joint 1 and the outer butt joint 2 are both cylindrical. The joint body of the inner butt joint 1 is detachably connected to the inner circular tube beam 3, and the end is detachably connected to the inner end rib 5. The joint body of the outer butt joint 2 is detachably connected to the outer circular tube beam 4, and the end is detachably connected to the outer end rib.

[0024] It should be noted that the end of the inner butt joint 1 and the outer butt joint 2 closest to the adjacent end rib is the front end of the butt joint, and the end away from the adjacent end rib is the rear end of the butt joint.

[0025] By using inner butt joint 1 to connect inner circular tube beam 3 and inner end rib 5 respectively, and outer butt joint 2 to connect outer circular tube beam 4 and outer end rib respectively, inner butt joint 1 and outer butt joint 2 can transmit large-scale bending moment and shear force. At the same time, since the inner butt joint 1 and inner end rib 5 and outer butt joint 2 and outer end rib are simple to match, the structure can be quickly disassembled and reinstalled. It also has excellent structural maintainability, good implementation effect, and high reliability. It has passed the static test of wing spars and docking selection, as well as the flight verification of solar-powered UAV.

[0026] Both the inner and outer butt joints 1 and 2 are made of TC4 material and manufactured using 3D printing additive manufacturing. Both joints are 240mm in diameter, with a minimum local wall thickness of 1.5mm, classifying them as large-diameter, thin-walled rotating structures. To avoid damaging the composite wing's main sparsity during frequent disassembly and assembly, traditional forging machining methods result in significant material removal, low material utilization, and severe deformation and springback issues associated with thin-walled structures. The metal 3D printing additive manufacturing process, however, achieves near-net-shape forming and high material utilization.

[0027] Combination Figures 4-5 Preferably, the inner butt joint 1 and the outer butt joint 2 further include a butt flange 13 located at the end of the joint body, a single-ear butt lug 11 and a double-ear butt lug 12 located on the butt flange 13; the butt flange 13 is connected to the inner end rib 5 or the outer end rib by butt bolts 7, the butt flange 13 is the wing butt mating area, the butt joint, end rib and gasket mating area, and the flange thickness is 8mm.

[0028] The single-ear butt lug 11 is arranged at the level of the aircraft structure plane, and there are two groups of single-ear butt lugs 11 arranged along the circumference of the butt flange 13, which are mainly used to bear and transmit the spar shear force. The double-ear butt lug 12 has four groups of double-ear butt lugs 12 arranged along the circumference of the butt flange 13, and each group of double-ear butt lugs 12 is arranged in pairs. Regarding the self-symmetry of the aircraft wing in the spanwise and chordwise directions, the double-ear butt lug 12 is mainly used to bear and transmit the spar bending moment.

[0029] A plurality of lug stiffeners 15 are arranged on the side wall of the joint body, and the lug stiffeners 15 are integrally connected with the butt flange 13, the single-ear butt lug 11 and the double-ear butt lug 12. Three lug stiffeners 15 are arranged side by side at the position corresponding to the double-ear butt lug 12, and two lug stiffeners 15 are arranged side by side at the position corresponding to the single-ear butt lug 11. The thickness of the lug stiffeners 15 is 3 mm, and the height of the lug stiffeners 15 is locally reduced from the front end to the rear end along the axial direction, and finally the lug stiffeners 15 are flush with the end flange 16, thereby providing local strength and rigidity of the lug connection area.

[0030] Preferably, a plurality of rows of fasteners are arranged on the outer side butt joint 2 and the inner side butt joint 1 along the axial direction. The outer side wall of the inner side butt joint 1 and the outer side wall of the outer side butt joint 2 near one end of the butt flange 13 are provided with a step. The wall thickness of the outer side butt joint 2 or the inner side butt joint 1 at the row of fasteners closest to the butt flange 13 is 2 mm, and the wall thickness of the outer side butt joint 2 or the inner side butt joint 1 at the remaining fasteners is 1.5 mm. The step can effectively improve the connection strength between the outer side butt joint 2 and the inner side butt joint 1 and the corresponding end rib.

[0031] The butt joint area between the inner side butt joint 1 and the inner side circular tube beam 3 and the butt joint area between the outer side butt joint 2 and the outer side circular tube beam 4 are connected by using a common structure formed by adhesive bonding and connecting bolts 8, which are stable in connection and have small gaps. The theoretical single-side gap is 0.3 mm. J133C structure adhesive bonding is adopted, and bolts with a diameter of 5 mm are used for connection. HB1-103-5 bolts are matched with HB1-801LA-M5 nuts. The nuts are installed inside the composite circular tube beam. A structural gasket HB1-521LB5X12X1.5 is arranged on one side of the nut installation side to ensure the installation angle of the nut.

[0032] The inner side butt joint 1 and the inner side end rib 5, and the outer side butt joint 2 and the outer side end rib are connected by using butt bolts 7 with a diameter of 10 mm and YTSA101-10-18+YTSA503-10 self-locking nuts, and the bolts are fixed to ensure the installation requirements.

[0033] Preferably, the butt joint area between the inner side butt joint 1 and the inner side circular tube beam 3 and the butt joint area between the outer side butt joint 2 and the outer side circular tube beam 4 are not flush on the end face. The end face of the inner side circular tube beam 3 or the outer side circular tube beam 4 is smaller than the end face of the corresponding joint by 2 mm. Considering the assembly tolerance of the tube beam ±1 mm accuracy, the tube beam is prevented from protruding from the end face of the joint to affect the assembly of the wing rib.

[0034] Preferably, the outer butt joint and the inner butt joint 1 are provided with end chamfers 10 on the inner side wall near one end of the butt flange 13, specifically a round chamfer, the size of the end chamfer 10 is 1mm, the setting of the end chamfer 10 can prevent the local extrusion of the hole wall after the wing beam bending deformation, resulting in stress concentration.

[0035] Preferably, according to the stress distribution, the inner butt joint 1 and the outer butt joint 2 are provided with two groups of end notches 14 corresponding to the circumferential direction away from one end of the butt flange 13, the end notches 14 are W-shaped to reduce the structure weight. The inner butt joint 1 and the outer butt joint 2 are provided with end flanges 16 on the side wall away from one end of the butt flange 13 to increase the local rigidity and strength of the inner butt joint 1 or the outer butt joint 2, the flange thickness is 4mm.

[0036] Preferably, the inner end rib 5 and the outer end rib are provided with a glass fiber fabric gasket 9 therebetween to adjust the polishing gasket thickness when adjusting the fit clearance between the two components, and to ensure the installation requirements.

[0037] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited to this, any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A butt joint structure of a large-sized, bend-resistant, round cross-section wing tube beam, characterized by: The application relates to a double-sided butt joint structure of a circular tube beam, which comprises an inner circular tube beam (3), an outer circular tube beam (4), an inner butt joint (1) sleeved on the end of the inner circular tube beam (3) and an outer butt joint (2) sleeved on the end of the outer circular tube beam (4); the inner circular tube beam (3) is provided with an inner end rib (5), the outer circular tube beam (4) is provided with an outer end rib, the inner end rib (5) is attached to the outer end rib, the inner butt joint (1) and the outer butt joint (2) are both cylindrical, the butt joint body of the inner butt joint (1) is detachably connected with the inner circular tube beam (3), the end of the butt joint body of the inner butt joint (1) is detachably connected with the inner end rib (5), the butt joint body of the outer butt joint (2) is detachably connected with the outer circular tube beam (4), and the end of the butt joint body of the outer butt joint (2) is detachably connected with the outer end rib. The inner butt joint (1) and the outer butt joint (2) further comprise butt flanges (13) arranged at the ends of the butt joint bodies, single-ear butt ear plates (11) and double-ear butt ear plates (12) arranged on the butt flanges (13); the butt flanges (13) are connected with the inner end rib (5) or the outer end rib through butt bolts (7), the single-ear butt ear plates (11) are arranged at the positions of the aircraft structure horizontal planes, the single-ear butt ear plates (11) are arranged in correspondence along the circumferences of the butt flanges (13) in two groups, the double-ear butt ear plates (12) are arranged in correspondence along the circumferences of the butt flanges (13) in four groups, and the double-ear butt ear plates (12) are arranged in two groups each; the side walls of the butt joint bodies are provided with a plurality of ear plate reinforcing ribs (15), and the ear plate reinforcing ribs (15) are integrally connected with the butt flanges (13), the single-ear butt ear plates (11) and the double-ear butt ear plates (12). The ends, away from the butt flanges (13), of the inner butt joint (1) and the outer butt joint (2) are correspondingly provided with two groups of end notches (14) along the circumferences, the end notches (14) are in W shapes, and the side walls of the ends, away from the butt flanges (13), of the inner butt joint (1) and the outer butt joint (2) are provided with end flanges (16).

2. The large size, bend-resistant, round cross-section, wing tube beam butt joint structure of claim 1, wherein: The inner side walls of the ends, close to the butt flanges (13), of the outer butt joint (2) and the inner butt joint (1) are both provided with end chamfers (10), and the size of the end chamfers (10) is 1 mm.

3. The large size, bend-resistant, round cross-section, wing tube beam butt joint structure of claim 1, wherein: Glass fiber fabric gaskets (9) are arranged between the inner end rib (5) and the outer end rib.

4. The large size, bend-resistant, round cross-section, wing tube beam butt joint structure of claim 1, wherein: A plurality of fasteners are arranged on the outer butt joint (2) and the inner butt joint (1) along the axial direction, the outer side walls of the ends, close to the butt flanges (13), of the inner butt joint (1) and the outer butt joint (2) are provided with steps, the wall thickness of the outer butt joint (2) or the inner butt joint (1) at the fastener closest to the butt flanges (13) is 2 mm, and the wall thickness of the outer butt joint (2) or the inner butt joint (1) at the remaining fasteners is 1.5 mm.

5. The large size, bend-resistant, round cross-section, wing tube beam butt joint structure of claim 1, wherein: The inner butt joint (1) and the outer butt joint (2) are made of TC4 material and are manufactured by a 3D printing additive manufacturing process, and the inner butt joint (1) and the outer butt joint (2) are 240 mm, and the local minimum wall thickness is 1.5 mm.

6. The large size, bend-resistant, round cross-section, wing tube beam butt joint structure of claim 1, wherein: The inner butt joint (1) and the outer butt joint (2) are connected by glue and connecting bolts (8).

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