Central wing box and electric tilting helicopter composite material wing

Abstract

The invention provides a central wing box and an electric tilting helicopter composite material wing, and belongs to the technical field of helicopter structural design, the central wing box adopts a double-beam type structure, the central wing box comprises a force-bearing covering cap, a front beam, a rear beam, a lower skin and wing ribs, and the front beam, the rear beam and the lower skin jointly form a battery installation room. The battery mounting room is divided into a plurality of battery cabins through a plurality of wing ribs, each battery cabin is provided with a plurality of battery mounting bases, and the force-bearing opening cover is positioned at the upper part of the battery mounting room; the front beam, the rear beam, the first central wing rib and the second central wing rib are connected with the fuselage. According to the invention, the integrated design of the wings is realized, the purpose of weight reduction is realized, the problem of difficult assembly and adjustment of the aircraft body and the wings is solved, the problem of large-opening load transfer caused by battery installation is solved, and the maintainability is greatly improved by adopting the bolt connection measures of the covering caps with uniform specifications.

Description

Technical Field

[0001] The present invention belongs to the technical field of helicopter structural design, and particularly relates to a central wing box and a composite wing of an electric tilt-rotor helicopter. Background Art

[0002] The wing is an important component of an aircraft, and its main function is to generate aerodynamic lift to ensure that the aircraft meets the aircraft performance and maneuverability specified by the technical requirements. The traditional fixed-wing wing is mainly composed of a left wing and a right wing, which are symmetrically arranged on both sides of the fuselage, powered by a fuel engine, and no installation interface for the battery needs to be provided.

[0003] The new electric tilt-rotor helicopter has both a rotor and a wing. In the fixed-wing mode of high-speed forward flight, the rotor tilts to act as a propeller, and in the fixed-wing mode, the wing provides lift for the whole aircraft. Since the new electric tilt-rotor helicopter adopts an electric drive mode, the central wing box of the wing needs to provide installation interfaces and space for the battery and cables, etc. The structure of the large opening of the central wing box caused by installing the battery brings great difficulties to the structural force transmission. At the same time, the all-composite wing has advantages in aspects such as weight reduction, high strength, and high durability. The design of the central wing box of all-composite wing structures is the focus of electric tilt-rotor helicopters. Summary of the Invention

[0004] In order to solve the installation space of the above battery pack and the problem that the large opening structure of the central wing box caused by installing the battery brings great difficulties to the structural force transmission, the present invention provides a central wing box and a composite wing of an electric tilt-rotor helicopter. The composite wing structure realizes the integrated design of the wing, achieves the goal of weight reduction, solves the problem of difficult assembly and adjustment between the airframe and the wing, solves the problem of large opening load transmission caused by battery installation, and the unified specification cover bolt connection measure greatly improves the maintainability. The technical solutions are as follows:

[0005] In the first aspect, a central wing box is provided. The central wing box adopts a double-beam structure and includes a load-bearing cover 20, a front beam 26, a rear beam 27, a lower skin 28, and wing ribs 21.

[0006] The front beam 26, the rear beam 27, and the lower skin 28 jointly form a battery installation space, and the battery installation space is divided into multiple battery compartments by a plurality of wing ribs 21. Each battery compartment is provided with a plurality of battery installation bases 29, and the load-bearing cover 20 is located above the battery installation space; the front beam 26, the rear beam 27, the first central wing rib 9, and the second central wing rib 10 are connected to the fuselage.

[0007] Optionally, the front beam 26 and the rear beam 27 are laminated composite parts with a C-shaped cross-section, which are used to reduce weight and transfer the aerodynamic load and axial load of the central wing box; the lower skin 28 is a honeycomb sandwich composite part, which is used to reduce weight and transfer the aerodynamic load and shear load of the central wing box; the lower skin 28 is provided with maintenance covers and pipeline fixing interfaces for the environmental control system pipeline layout to realize the disassembly, installation and maintenance inspection of the environmental control system.

[0008] The first central wing rib 9 and the second central wing rib 10 where the wing is docked with the fuselage are made of titanium alloy metal parts to ensure structural strength. The expansion coefficients during co-curing with composite parts are relatively close to ensure the quality of co-curing; the remaining wing ribs are laminated composite parts, which are used to reduce weight, increase structural stability and transfer the load of the central wing box. The composite wing structure design reduces structural connectors in terms of weight reduction, increases reliability, avoids the assembly difficulties caused by the original multi-part assembly, and reduces the overall processing difficulty and cost.

[0009] Optionally, the central wing box is connected to the fuselage in a four-point connection form. The four-point connection form is specifically: the first connection point 5 is connected by a first bolt through the front fuselage frame, the center plane of the left web of the front beam, and the first central wing rib 9; the second connection point 6 is connected by a second bolt through the front fuselage frame, the center plane of the right web of the front beam, and the second central wing rib 10; the third connection point 7 is connected by a third bolt through the rear fuselage frame, the center plane of the left web of the rear beam, and the first central wing rib 9; the fourth connection point 8 is connected by a fourth bolt through the rear fuselage frame, the center plane of the right web of the rear beam, and the second central wing rib 10; the first central wing rib 9 and the second central wing rib 10 are provided with barrel nuts 16 for mating bolt connection; the head of the bolt is provided with a cap for facilitating the disassembly of the bolt 13. The force transmission path of the present invention is clear and simple, avoiding the additional bending moment generated by the bolt on the wing rib structure. The barrel nuts 16 participating in the bolt connection are installed in the integrated barrel nut supports of the two central wing ribs 9 and 10 where the wing is docked with the fuselage. This structural form has direct force transmission, simple installation and maintenance of the barrel nut, and improves the maintainability of the wing compared with the traditional wing structure. A cap is provided on the bolt head to facilitate the disassembly of the bolt.

[0010] Optionally, the bolts at each point in the four-point connection form are fitted with movable bushings.

[0011] The first bolt and the second bolt are both used in cooperation with the movable bushing 17 and the protective bushing 14, and are in clearance fit. The protective bushing 14 is in interference fit with the front and middle fuselage main frame 11.

[0012] The third bolt and the fourth bolt are both used in conjunction with the fixed bushing 15, and the fixed bushing 15 has an interference fit with the rear center fuselage main frame 12. The connection form of the fixed bushing at the rear end of the central wing box realizes the transmission of the course load, and the connection form of the movable bushing at the front end of the central wing box realizes the adjustment of the assembly clearance, avoiding the installation difficulty problem caused by structural deformation. The assembly scheme combining the fixed bushing and the movable bushing realizes the adjustment of the assembly clearance of the central wing box in the course direction, thus facilitating the connection and assembly.

[0013] Optionally, the load-bearing cover 20 is fixed to the front beam 26, the rear beam 27, and the wing rib 21 by bolts 19, clevis nuts 23, and clevis nut washers 22. The clevis nut washer 22 is used to adjust the clearance between the thread of the clevis nut 23 and the sandwich structure, facilitating the use of a single specification bolt for different thickness sandwich structures. The load-bearing cover realizes the transmission of the upper skin load and also meets the installation and disassembly requirements of the battery. The load-bearing cover uses unified specification connectors, reducing the maintenance cost and greatly improving the maintainability.

[0014] Optionally, the main body part 24 of the wing rib 21 is made of composite material, and the upper flange 25 of the wing rib 21 is a metal machined flange and is riveted to the main body part 24. The metal flange is beneficial to transmitting the extrusion load of the connecting bolt and plays a role in reducing the weight. The design of the adjustable position upper flange facilitates the adjustment of the assembly clearance size of the battery load-bearing cover, solving the problem of difficult structural assembly caused by non-uniform assembly clearance.

[0015] Optionally, the battery mounting base 29 is integrally designed with the battery wing rib to reduce the connecting parts of the battery mounting support;

[0016] The battery mounting holes on the battery base adopt a large clearance fit, and the bolts used for connecting the battery in the battery mounting holes adopt floating clevis nuts, facilitating the adjustment of the clearance and avoiding the problem of difficult battery installation.

[0017] In a second aspect, there is provided a composite material wing of an electric tilt-rotor helicopter, including the central wing box 1 according to any one of the first aspect, and a left wing assembly 2 and a right wing assembly 3. Among them, the wing skeleton is integrally designed, and the wing skeleton is formed by the central wing box 1, the left wing assembly 2, and the right wing assembly 3 respectively and then riveted together by a titanium alloy strip 4;

[0018] The central wing box 1 and the left wing assembly 2, the right wing assembly 3 adopt a secondary bonding and forming method, specifically: first, the front beam 26, the rear beam 27, the wing rib 21, and the lower skin 28 of the central wing box 1 are cured and formed into parts, and then these parts are assembled by adhesive film bonding and then put into the furnace for medium-temperature curing and forming as a whole. The strip plate has an installation clearance with the left and right wing boxes while meeting the strength and stiffness requirements, ensuring the adjustment of the installation clearance. Using the internal strip plate is overall beautiful, avoiding the corrosion problem brought by the harsh external environment of the external strip plate, and further improving the reliability of the structure.

[0019] Optionally, double-ear joints 30 are used to connect the two sides of the central wing box to the nacelle structure. A double-ear joint movable bushing 31 is arranged inside the double-ear joint to facilitate the adjustment of the installation clearance; the double-ear joint is also used to connect the equipment for hoisting the wing, avoiding the need to separately add a ground protection equipment joint, and the functional integration greatly reduces the weight of the structure.

[0020] Optionally, a detachable fairing 32 is arranged at the leading edge of the central wing box. The detachable fairing realizes the disassembly, installation and maintenance inspection functions of the cables inside the leading edge while realizing the aerodynamic fairing function;

[0021] Fixed fairings 33 are arranged at the front and rear flanges of the central wing box. The fixed fairings are formed by the connection method of press riveting the front and rear skins, providing a cable pipeline channel for the battery cables and realizing the disassembly and installation of the cables.

[0022] The beneficial effects of the present invention are at least as follows:

[0023] The integrated design of the wing skeleton, and the central wing box adopts a composite material structure, greatly reducing the weight;

[0024] The wing forming process design, and the secondary bonding forming method is adopted for each wing component, avoiding the assembly difficulty problem caused by the original multi-part assembly, and reducing the overall processing difficulty and cost;

[0025] The installation of the central wing box is simple and efficient, the disassembly and installation are convenient, the reliability is high, the force transmission path is clear and simple, and the additional bending moment of the bolt on the wing rib structure is avoided. The assembly scheme of the fixed bushing combined with the movable bushing realizes the adjustment of the assembly clearance of the wing in the heading direction, thus facilitating the connection and assembly;

[0026] The integrated design of the central wing rib of the central wing box connecting the fuselage, the barrel nut support and the battery installation support, and the titanium alloy metal parts ensure the structural strength;

[0027] While the load is transferred by the load-bearing cover of the central wing box, the battery pack is effectively integrated with the wing structure, facilitating the adjustment of the clearance and avoiding the problem of difficult battery installation. The installation bolts of the load-bearing cover of the central wing box have a single specification, which is convenient for disassembly and installation;

[0028] The design of the composite wing rib of the central wing box adopts a composite material main body riveted with a metal material flange, ensuring the connection strength and providing an assembly adjustment space. The design of the composite wing rib of the central wing box solves the problem of difficult structural assembly caused by inconsistent assembly clearances;

[0029] The two sides of the central wing box of the wing are connected to the nacelle structure by double-ear joints, avoiding the need to separately add a ground protection equipment joint, and the functional integration greatly reduces the weight of the structure;

[0030] The design of the central wing box fairing enables the disassembly, installation, maintenance, and inspection of the cables inside the leading edge while achieving aerodynamic fairing. The lower skin of the central wing box enables the disassembly, installation, maintenance, and inspection of the environmental control system.

[0031] The central wing box structure of the electric tilt-rotor helicopter of the present invention solves the installation space problem of the battery pack and ensures the strength and reliability of the connection between the central wing box and the fuselage. Brief Description of the Drawings

[0032] Figure 1 It is a schematic diagram of a wing skeleton structure provided by an embodiment of the present invention;

[0033] Figure 2 It is a schematic diagram of the connection between the central wing box and the fuselage provided by an embodiment of the present invention;

[0034] Figure 3 It is a schematic diagram of the connection between the protective bushing and the front and middle fuselage main frames provided by an embodiment of the present invention;

[0035] Figure 4 It is a schematic diagram of the connection between the fixed bushing and the rear and middle fuselage main frames provided by an embodiment of the present invention;

[0036] Figure 5 It is a schematic diagram of the connection points of the load-bearing hatch cover provided by an embodiment of the present invention;

[0037] Figure 6 It is a schematic diagram of the connection of the load-bearing hatch cover provided by an embodiment of the present invention;

[0038] Figure 7 It is a schematic diagram of the upper flange of the wing rib provided by an embodiment of the present invention;

[0039] Figure 8 It is a schematic diagram of the double-ear joint provided by an embodiment of the present invention;

[0040] Figure 9 It is a schematic diagram of the lower skin of the wing provided by an embodiment of the present invention. Detailed Embodiments

[0041] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0042] The features and exemplary embodiments of various aspects of the present invention will be described in detail below. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced without some of these specific details. The following description of the embodiments is only intended to provide a better understanding of the present invention by showing examples of the present invention. The present invention is in no way limited to any specific arrangement and method presented below, but covers any improvements, substitutions, and modifications of structures, methods, and devices without departing from the spirit of the present invention. In the drawings and the following description, well-known structures and technologies are not shown to avoid unnecessarily obscuring the present invention.

[0043] It should be noted that, without conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other, and the various embodiments may be referred to and cited with each other.

[0044] The present invention will be further described in detail below through specific embodiments and drawings.

[0045] The present invention provides a central wing box and a composite wing of an electric tilt-rotor helicopter. The structure of the composite wing realizes the integrated design of the wing, achieves the goal of weight reduction, solves the problem of difficult assembly and adjustment between the fuselage and the wing, solves the problem of large-opening load transmission caused by battery installation, and the measures of bolt connection of covers with unified specifications greatly improve the maintainability.

[0046] In the present invention, the wing skeleton is integrally designed. The wing skeleton is composed of a central wing box 1, a left wing assembly 2, and a right wing assembly 3, which are respectively formed and then riveted together by a titanium alloy strip 4, as shown in Figure 1 , Figure 2 . The three-section design of the wing skeleton solves the requirements of the process for the size of the autoclave, avoids the assembly difficulty problem caused by large deformation of large-size parts, and is a trade-off design of function, performance, and economy. The titanium alloy strip 4 has an installation gap with the left and right wing boxes while meeting the strength and stiffness requirements, ensuring the adjustment of the installation gap. The use of the inner strip is overall beautiful, avoiding the corrosion problem brought by the harsh external environment of the outer strip, and further improving the reliability of the structure.

[0047] The central wing box molding process is designed to use a secondary bonding molding method for each section of the wing assembly, that is, the central wing box 1 and the left wing assembly 2 and the right wing assembly 3 are firstly respectively subjected to a secondary bonding molding method, specifically: the front beam 26, rear beam 27, wing rib 21 and lower skin 28 of the central wing box 1 are firstly subjected to part curing molding. The central wing box adopts a double-beam structure, the front beam 26 and rear beam 27 of the wing are laminated composite parts, the lower skin 28 of the wing is a honeycomb sandwich composite part, and the central wing ribs 9 and 10 where the wing and the fuselage are connected are laminated composite parts. The composite wing structure design reduces the structural connectors in terms of weight reduction, increases reliability, avoids the assembly difficulties caused by the original multi-part assembly, and reduces the overall processing difficulty and cost.

[0048] The central wing box is connected to the fuselage using a four-point connection. Figure 2 . The four-point connection form is specifically: the first connection point 5 is the front frame of the fuselage, the center plane of the left web of the front beam, and the central wing rib 9 are connected by the first bolt; the second connection point 6 is the front frame of the fuselage, the center plane of the right web of the front beam, and the central wing rib 10 are connected by the second bolt; the third connection point 7 is the rear frame of the fuselage, the center plane of the left web of the rear beam, and the central wing rib 9 are connected by the third bolt; the fourth connection point 8 is the rear frame of the fuselage, the center plane of the right web of the rear beam, and the central wing rib 10 are connected by the fourth bolt; the central wing rib 9 and the central wing rib 10 are provided with a cylindrical nut 16 connected with the matching bolt; the head of the bolt is provided with a card cap to facilitate the disassembly of the bolt 13. The force transmission path of this four-point connection form is clear and simple, and the bolt avoids the generation of additional bending moment on the wing rib structure. The central wing ribs 9 and 10 where the wing and the fuselage are connected are made of titanium alloy metal parts to ensure the structural strength, and the expansion coefficient is relatively close to that of the composite parts during co-curing molding, ensuring the quality of co-curing. This structural form transmits force directly, and the barrel nut is easy to install and maintain. Compared with traditional wing structures, the maintainability of the wing is improved.

[0049] The center wing box assembly clearance adjustment, the first bolt and the second bolt are used in conjunction with the movable bushing 17 and the protective bushing 14, and are clearance fit, the protective bushing 14 and the front center fuselage main frame 11 are interference fit, see Figure 3 The third bolt and the fourth bolt are used in conjunction with the fixing bushing 15, and the fixing bushing 15 and the rear middle fuselage main frame 12 are interference fit, see Figure 4 The connection form of the fixed bushing at the rear end of the wing realizes the transmission of the heading load, and the connection form of the movable bushing at the front end of the wing realizes the adjustment of the assembly gap, avoiding the installation difficulties caused by structural deformation. The assembly scheme of the fixed bushing combined with the movable bushing realizes the adjustment of the assembly gap of the wing in the heading, thus facilitating the connection and assembly.

[0050] The central wing box load-bearing cover design, the battery is installed in the wing rib cavity of the central wing assembly, the load-bearing cover connection point 18, see Figure 5 To meet the requirements of battery pack disassembly and assembly, the load-bearing cover 20 is fixed to the front beam 26, the rear beam 27 and the wing rib 21 by means of bolts 19, support plate nuts 23 and support plate nut washers 22. Figure 6 . In order to standardize the parts, a support plate nut gasket 22 is used to adjust the gap between the support plate nut 22 thread and the sandwich structure, so that a single specification of bolts can be used for sandwich structures of different thicknesses. The load-bearing port cover realizes the transmission of the upper skin load and meets the installation and disassembly requirements of the battery. The load-bearing port cover uses connectors of uniform specifications, which reduces maintenance costs and greatly improves maintainability.

[0051] The central wing box has a composite wing rib design, and the battery mounting base 29 is integrated with the central wing ribs 9 and 10 where the wing and fuselage are connected to reduce the number of connectors for the battery mounting bracket. Figure 2 The battery mounting hole on the battery base adopts a large clearance fit, and the bolts used to connect the battery in the battery mounting hole adopt a floating support nut, which is convenient for gap adjustment and avoids the problem of difficult battery installation. The main part of the wing rib 21 of the central wing assembly is a composite material. The upper flange 25 of the wing rib 21 is riveted to the main part 24 by riveting metal machine flanges. Figure 7 The metal flange is conducive to transmitting the extrusion load of the connecting bolts, which plays a role in reducing weight. The upper flange design with adjustable position facilitates the adjustment of the assembly gap size of the battery load-bearing cover, solving the problem of structural assembly difficulties caused by inconsistent assembly gaps.

[0052] The two sides of the central wing box are connected to the nacelle structure by double-ear joints 30. Double-ear joint movable bushings 31 are arranged in the double-ear joints to facilitate the adjustment of the installation gap. The double-ear joints 30 are also used to connect the equipment for hoisting the wing, avoiding the need to add a separate ground protection equipment joint. The functional integration greatly reduces the weight of the structure. Figure 8 .

[0053] A detachable fairing 32 is provided at the leading edge of the central wing box. The detachable fairing not only realizes the aerodynamic fairing function but also realizes the disassembly and maintenance inspection functions of the cables in the leading edge. A fixed fairing 33 is provided at the front and rear flanges of the central wing box. The fixed fairing 33 is formed by riveting the front and rear skins, and a cable pipeline channel is provided for the battery cable, realizing the disassembly and assembly of the cable. Figure 8 Because the battery is prone to high temperature after long-term use, the environmental control system is required to achieve temperature control. The wing lower skin 28 is provided with a maintenance cover and a pipeline fixing interface 34 for the environmental control system pipeline, which enables the disassembly and maintenance inspection of the environmental control system. Figure 9 .

[0054] The above only expresses the embodiments of the present invention, which are described in a relatively specific and detailed manner, but should not be construed as a limitation on the scope of the patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can be made, and these all fall within the protection scope of the present invention. In addition, the parts not elaborated in the present invention are all conventional techniques.

Claims

1. A central wing box, characterized in that, The central wing box adopts a double-beam structure. The central wing box includes a load-bearing cover (20), a front beam (26), a rear beam (27), a lower skin (28), and wing ribs (21). The front beam (26), the rear beam (27), and the lower skin (28) jointly form a battery installation compartment. The battery installation compartment is divided into multiple battery compartments by a plurality of wing ribs (21). Each battery compartment is provided with a plurality of battery installation bases (29). The load-bearing cover (20) is located above the battery installation compartment. The front beam (26), the rear beam (27), the first central wing rib (9), and the second central wing rib (10) are connected to the fuselage. The central wing box is connected to the fuselage in a four-point connection form. The specific four-point connection form is as follows: The first connection point (5) is that the front fuselage frame, the center plane of the left web of the front beam, and the first central wing rib (9) are connected by a first bolt; the second connection point (6) is that the front fuselage frame, the center plane of the right web of the front beam, and the second central wing rib (10) are connected by a second bolt; the third connection point (7) is that the rear fuselage frame, the center plane of the left web of the rear beam, and the first central wing rib (9) are connected by a third bolt; the fourth connection point (8) is that the rear fuselage frame, the center plane of the right web of the rear beam, and the second central wing rib (10) are connected by a fourth bolt. The first central wing rib (9) and the second central wing rib (10) are provided with barrel nuts (16) for bolt connection. The head of the bolt is provided with a cap for facilitating the disassembly of the bolt (13). The bolts at each point in the four-point connection form are fitted with bushings. The first bolt and the second bolt are both used in cooperation with a movable bushing (17) and a protective bushing (14), and are in clearance fit. The protective bushing (14) is in interference fit with the front and middle fuselage main frame (11). The third bolt and the fourth bolt are both used in cooperation with a fixed bushing (15). The fixed bushing (15) is in interference fit with the rear and middle fuselage main frame (12).

2. The central wing box according to claim 1, characterized in that, The front beam (26) and the rear beam (27) are laminated composite parts, and their cross-sections are C-shaped; the lower skin (28) is a honeycomb sandwich composite part; the lower skin (28) is provided with a maintenance cover and a pipeline fixing interface for the environmental control system pipeline layout. The first central wing rib (9) and the second central wing rib (10) for the docking of the wing and the fuselage are made of titanium alloy metal parts; the remaining wing ribs are laminated composite parts.

3. The central wing box according to claim 1, characterized in that, The load-bearing cover (20) is fixed on the front beam (26), the rear beam (27), and the wing ribs (21) through bolts (19), plate nuts (23), and plate nut gaskets (22).

4. The central wing box according to claim 1, characterized in that, The main body part (24) of the wing rib (21) is made of composite material. The upper flange (25) of the wing rib (21) is a metal machined flange and is riveted to the main body part (24).

5. The central wing box according to claim 1, characterized in that, The battery installation base (29) is integrally designed with the battery wing rib. The battery installation holes on the battery base adopt a large clearance fit, and the bolts used for connecting the battery in the battery installation holes adopt floating plate nuts.

6. A composite wing of an electric tilt-rotor helicopter, characterized in that, Comprising the central wing box (1) as described in any one of claims 1 to 5, and a left wing assembly (2) and a right wing assembly (3), wherein the wing skeleton is integrally designed, and the wing skeleton is formed by the central wing box (1), the left wing assembly (2), and the right wing assembly (3) respectively, and then riveted together by a titanium alloy strip (4); The central wing box (1) and the left wing assembly (2) and the right wing assembly (3) adopt a secondary bonding and forming method, specifically: first, the front beam (26), the rear beam (27), the wing rib (21), and the lower skin (28) of the central wing box (1) are cured and formed into parts, and then these parts are assembled by film adhesive bonding and then put into the furnace for medium-temperature curing and forming as a whole; Both sides of the central wing box are connected to the nacelle structure by double-ear joints (30), and a double-ear joint movable bushing (31) is arranged inside the double-ear joints; the double-ear joints are also used to connect the equipment for hoisting the wings.

7. The composite wing of an electric tilt-rotor helicopter according to claim 6, characterized in that, A detachable fairing (32) is arranged at the leading edge of the central wing box; Fixed fairings (33) are arranged on the front and rear flanges of the central wing box, and the fixed fairings are formed by the connection method of press riveting the front and rear skins.

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