EVTOL aircraft wing skin

Abstract

The utility model discloses an eVTOL aircraft wing skin which comprises a longitudinal skin assembly, the longitudinal skin assembly is connected with a wing skin body and a motor arm, the wing skin body comprises an upper skin and a lower skin, the upper skin and the lower skin are connected at the front edge and the rear edge, each of the upper skin and the lower skin comprises a stringer, and the stringer is connected with the longitudinal skin assembly. The stringer is installed on the skin body, the two sides and the top of the skin body are connected with the sandwich area, and the sandwich area is located in the wing tip area, the front edge area and the rear edge area of a wing of the eVTOL aircraft. The wing skin is good in bearing capacity, bending moment generated by pulling force of the propellers on the motor arms is self-balanced in the longitudinal skin assemblies, only shearing force is transmitted to the wing skin body, the wing skin body bears bending moment generated by wing lift force and shearing force of the motor arms and does not bear the bending moment of the motor arms, and the bearing capacity is good.

Description

Technical Field

[0001] The utility model relates to the technical field of aviation equipment, and in particular to an eVTOL aircraft wing skin. Background Art

[0002] The development of eVTOL (Electric Vertical Takeoff and Landing) electric vertical takeoff and landing aircraft has attracted widespread attention from aerospace companies, the automotive industry, the transportation industry, the government, the military and academia. The potential future applications of eVTOL involve a variety of scenarios such as urban passenger transport, regional passenger transport, freight, personal aircraft, and emergency medical services. The American Vertical Flight Association believes that eVTOL technology is one of the most important technological changes in the aviation industry since the birth of the helicopter 75 years ago, and may be more revolutionary than the emergence of turbine engines. According to the "World Electric Vertical Takeoff and Landing (eVTOL) Aircraft Directory" published online by the association, there are currently more than 260 projects engaged in eVTOL development around the world. The use of electric propulsion systems instead of internal combustion engine power has gained many advantages and unique qualities. The most prominent advantages are energy saving and environmental protection, high efficiency and low energy consumption, while achieving near zero emissions, low noise and vibration levels, good ride comfort, and a truly environmentally friendly aircraft. In addition, it also has the characteristics of safety and reliability, simple structure, easy operation and use, good maintainability / low cost, and good economy. There are also many advantages in design: the overall layout is flexible, and both optimal layout and unconventional / innovative layout can be adopted; aircraft with extraordinary performance can be designed to meet special purpose requirements, etc.

[0003] The main function of an aircraft wing is to provide lift. The main external loads borne by the wing include shear force, bending moment and torque. All three loads are generated by the weight of the wing itself and the aerodynamic force. The position of the wing skin and the shape of the wing surface maintain the lift characteristics of the aircraft during flight, while bearing the loads generated by aerodynamic force. The skin is one of the main load-bearing components. Compared with traditional fixed-wing aircraft, the wings of eVTOL aircraft are connected to motor arms, and the tension generated by the motor is also transmitted to the wings. In addition to bearing its own aerodynamic force, the wings also need to withstand the tension generated by the propellers on the motor arms, so traditional wing skins cannot meet the needs of eVTOL aircraft. Utility Model Content

[0004] The purpose of the utility model is to provide an eVTOL aircraft wing skin to solve the problems mentioned in the background technology. To achieve the above purpose, the utility model provides the following technical solutions: an eVTOL aircraft wing skin, including a longitudinal skin assembly, the longitudinal skin assembly connects the wing skin body and the motor arm, the wing skin body includes an upper skin and a lower skin, the upper skin and the lower skin are connected at the leading edge and the trailing edge, the upper skin and the lower skin both include a long stringer, the long stringer is installed on the skin body, the two sides and the top of the skin body are connected to a sandwich area, and the sandwich area is located in the wing tip, leading edge, and trailing edge area of ​​the eVTOL aircraft.

[0005] Preferably, a maintenance cover is provided on the lower skin, and the maintenance cover is located in the sandwich area of ​​the lower skin and on the skin body.

[0006] Preferably, the long stringer is a T-shaped structure, and the long stringer and the skin body are formed in one step by a co-curing process.

[0007] Preferably, the longitudinal skin assembly comprises an outer upper longitudinal skin, an outer lower longitudinal skin, an inner upper longitudinal skin and an inner lower longitudinal skin, one end of which is connected to the wing skin body, and the other end is connected to the motor arm.

[0008] Preferably, the longitudinal skin component is made of one of aluminum alloy, carbon fiber composite material and glass fiber composite material.

[0009] Preferably, the longitudinal skin assembly is bonded to the wing skin body by means of structural adhesive, and rivets are used in local areas to increase strength.

[0010] Preferably, three long girders are provided in the upper skin, and two long girders are provided in the lower skin.

[0011] The technical effects and advantages of the utility model are as follows: the wing skin has good bearing capacity: the bending moment generated by the pulling force of the propeller on the motor arm is self-balanced inside the longitudinal skin assembly, and only the shear force is transmitted to the wing skin body. The wing skin body bears the bending moment generated by the wing lift and the shear force of the motor arm, but does not bear the bending moment of the motor arm, and has good bearing capacity;

[0012] Light weight: The longitudinal force of the motor arm is borne by the longitudinal skin assembly, and the spanwise force generated by the wing is borne by the wing skin body, avoiding the complex force transmission route in the intersection area between the two, and the structure is light in weight;

[0013] Good maintainability: A large number of maintenance covers are designed on the lower skin, which can facilitate the maintenance of the internal structure and equipment of the wing; the upper and lower skins are designed as sandwich structures at the tip area where the load is less, and the root area is designed as a non-sandwich area reinforced by long girders. When there is damage, it is convenient to check and ultrasonically detect, and easy to repair;

[0014] Good manufacturability: The longitudinal skin components subjected to longitudinal forces and the wing skin body subjected to spanwise forces are designed as separate parts with simple part surfaces and are easy to manufacture. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is an axonometric drawing of the utility model;

[0016] Figure 2 It is an exploded view of the utility model;

[0017] Figure 3 It is an exploded view of the wing skin body of the utility model;

[0018] Figure 4 It is an axonometric view of the upper skin of the utility model;

[0019] Figure 5 It is an axonometric view of the lower skin of the utility model;

[0020] Figure 6 It is a cross-sectional view of the upper skin of the utility model at the long stringer;

[0021] Figure 7 It is a cross-sectional view of the connection between the longitudinal skin assembly and the wing skin body of the utility model;

[0022] Figure 8 It is an axonometric view of the utility model in the position of an eVTOL aircraft.

[0023] In the figure, 1. wing skin assembly; 11. longitudinal skin assembly; 111. outer upper longitudinal skin; 112. outer lower longitudinal skin; 113. inner upper longitudinal skin; 114. inner lower longitudinal skin; 12. wing skin body; 121. upper skin; 1211. sandwich area; 1212. long stringer; 1213. skin body; 122. lower skin; 1221. maintenance cover; 2. eVTOL aircraft. DETAILED DESCRIPTION

[0024] In order to make the technical means for realizing the utility model, creative features, objectives and effects easy to understand, the utility model is further explained below in conjunction with specific diagrams. In the description of the utility model, it should be noted that, unless otherwise clearly stipulated and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, an integral connection or a mechanical connection, or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be internal communication between two components.

[0025] Example

[0026] like Figure 8 As shown, the wing skin assembly 1 serves as the outer surface part of the wing (left and right wings, only the left side is described in this example, and the right and left sides are symmetrical parts), maintains the aerodynamic shape of the wing, and bears the aerodynamic force received by the wing. At the same time, the pulling force generated by the propeller is transmitted to the wing skin assembly 1 through the motor arm.

[0027] like Figure 1 , Figure 2 As shown, the wing skin assembly 1 includes a longitudinal skin assembly 11 and a wing skin body 12. The longitudinal skin assembly 11 includes an outer upper longitudinal skin 111, an outer lower longitudinal skin 112, an inner upper longitudinal skin 113 and an inner lower longitudinal skin 114. The longitudinal skin assembly 11 is connected to the wing skin body 12 and the motor arm. The bending moment generated by the propeller tension is self-balanced on the longitudinal skin assembly 11, and only the shear force is transmitted to the wing skin body 12. The outer upper longitudinal skin 111, the outer lower longitudinal skin 112, the inner upper longitudinal skin 113, and the inner lower longitudinal skin 114 can be made of aluminum alloy, carbon fiber composite material, or glass fiber composite material. This example uses carbon fiber composite material. The loads received are in the direction of tension and compression. The outer upper longitudinal skin 111 and the inner upper longitudinal skin 113 are mainly in compressive stress, and the proportions of 0 degree, 45 degree, and 90 degree are 40%, 50%, and 10%; the outer lower longitudinal skin 112 and the inner lower longitudinal skin 114 are mainly in tensile stress, and the proportions of 0 degree, 45 degree, and 90 degree are 60%, 30%, and 10%. The wing skin body 12 bears the aerodynamic force of the wing and also bears the shear load transmitted by the motor arm.

[0028] like Figure 3 As shown, the wing skin body 12 includes an upper skin 121 and a lower skin 122. According to the flight envelope of the eVTOL aircraft, the upper skin 121 is mainly subjected to compressive stress, and the lower skin 122 is subjected to tensile stress. The bending moment generated by the lift increases from small to large from the wing tip direction to the wing root direction. The upper skin 121 and the lower skin 122 are bonded at the leading edge and the trailing edge by structural adhesive. In addition to considering the compressive strength of the material, the upper skin 121 also needs to consider the compression stability, and the lower skin 122 only considers the tensile strength.

[0029] like Figure 4 As shown, the upper skin 121 and the lower skin 122 have a similar structure, including a sandwich area 1211, a long stringer 1212, and a skin body 1213. The long stringer 1212 is installed on the skin body 1213. The two sides and the top of the skin body 1213 are connected to the sandwich area 1211. The sandwich area 1211 is distributed in the wing tip, leading edge, and trailing edge areas where the load is relatively small. The laminate is thin, and a sandwich is used to increase the out-of-plane stiffness. The core can be made of honeycomb or foam material. In this example, it is PET foam with a thickness of 5 mm, which effectively improves the out-of-plane stiffness of these areas. There is no need to increase the long stringer, thereby reducing the number of parts. The area of ​​the skin body 1213 below the long stringer 1212 is a laminate area with a thicker layer. This area is subjected to greater force and is the main force transmission path on the upper skin 121 and the lower skin 122. If damaged, it will cause serious consequences. Therefore, the long stringer 1212 is used for reinforcement to improve the compression strength. In addition, it needs to be easy to repair. When damaged, it can be easily repaired and ultrasonically inspected to ensure the safety of the eVTOL aircraft. The long stringer 1212 plays a role in reinforcing the skin body 1213. The ply is mainly 0-degree ply, which improves the strength along the span direction and reduces the amount of carbon fiber composite materials.

[0030] like Figure 5 As shown, in addition to the core area 1211, the long stringer 1212 and the skin body 1213, the lower skin 122 is also designed with a large number of maintenance covers 1221 on the core area 1211 and the skin body 1213 to maintain the internal equipment, structure and wiring harness of the wing. Since the maintenance covers 1221 may have tolerances during the manufacturing and assembly processes, which will affect the aerodynamic characteristics, the aerodynamic characteristics of the lower skin 122 are not as critical as those of the upper skin 122. Therefore, the maintenance covers 1213 are designed on the lower skin 122.

[0031] like Figure 6 As shown, the long stringer 1212 is a T-shaped long stringer, which effectively reduces the difficulty of the mold and simplifies the manufacturing process. The long stringer 1212 and the skin body 1213 are formed at one time using a co-curing process. In this example, the upper skin 121 is designed with three long strings 1212, and the lower skin 122 is provided with two long strings 1212.

[0032] like Figure 7 As shown, the longitudinal skin assembly 11 and the wing skin body 12 are separately manufactured parts, which are bonded together by structural adhesive. Rivets are added in local areas to improve the connection strength. The area between the two parts is an empty area, which can ensure that the two parts bear forces in different directions respectively, reducing the complexity of the force in this area.

[0033] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An eVTOL aircraft wing skin, comprising a longitudinal skin assembly, characterized in that: The longitudinal skin assembly connects the wing skin body and the motor arm. The wing skin body includes an upper skin and a lower skin. The upper skin and the lower skin are connected at the leading edge and the trailing edge. The upper skin and the lower skin both include long spars. The long spars are installed on the skin body. The two sides and the top of the skin body are connected to a sandwich area. The sandwich area is located in the wing tip, leading edge, and trailing edge areas of the eVTOL aircraft.

2. The eVTOL aircraft wing skin according to claim 1, characterized in that: The lower skin is provided with a maintenance cover, and the maintenance cover is located in the sandwich area of ​​the lower skin and on the skin body.

3. The eVTOL aircraft wing skin according to claim 1, characterized in that: The long stringer is a T-shaped structure, and the long stringer and the skin body are formed at one time by a co-curing process.

4. The eVTOL aircraft wing skin according to claim 1, characterized in that: The longitudinal skin assembly includes an outer upper longitudinal skin, an outer lower longitudinal skin, an inner upper longitudinal skin and an inner lower longitudinal skin, one end of which is connected to the wing skin body, and the other end is connected to the motor arm.

5. The eVTOL aircraft wing skin according to claim 1, characterized in that: The longitudinal skin component is made of one of aluminum alloy, carbon fiber composite material and glass fiber composite material.

6. The eVTOL aircraft wing skin according to claim 1, characterized in that: The longitudinal skin assembly is bonded to the wing skin body by structural adhesive, and rivets are used in local areas to increase strength.

7. The eVTOL aircraft wing skin according to claim 3, characterized in that: The upper skin is provided with three long girders, and the lower skin is provided with two long girders.

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