Wingtip folding and unfolding device based on shape memory alloy and aircraft
By using shape memory alloy actuation components and hinge components to achieve wingtip deflection, the problem of heavy mechanical wingtip camber adjustment mechanisms in existing aircraft has been solved, thus achieving lightweight aircraft design.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-30
- Publication Date
- 2026-04-10
AI Technical Summary
Existing aircraft use mechanical wingtip camber adjustment mechanisms driven by servo motors, resulting in heavy motors, reducers, and transmission mechanisms, which is not conducive to the lightweight design of aircraft.
Using shape memory alloy actuators as driving elements, the length change of the shape memory alloy actuators is activated by energizing them, and the change is converted into wingtip deflection by the hinge assembly, eliminating the need for the traditional mechanical wingtip camber adjustment mechanism driven by a servo motor.
The weight of the motor and reducer was reduced, which facilitated the lightweight design of the aircraft.
Smart Images
Figure CN121822800A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of aircraft technology, and in particular to a wingtip folding device and aircraft based on shape memory alloy. Background Technology
[0002] With the development of smart materials and structures, various smart material actuator concepts are constantly being proposed. In variability aircraft, many smart structure actuators are also present in the drive schemes for variability. Wingtip folding is also a current hot topic in the field of variability aircraft. By controlling the wingtip folding angle, induced drag during flight can be effectively reduced. Furthermore, wingtip folding indirectly controls the wing span, allowing the aircraft to adapt to more flight environments. On the ground, wingtip folding can also improve space utilization, enabling the parking of more aircraft.
[0003] However, existing aircraft use mechanical wingtip camber adjustment mechanisms driven by servo motors. The motors, reducers, and transmission mechanisms are heavy, which is not conducive to the lightweight design of aircraft. Summary of the Invention
[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a wingtip folding device based on shape memory alloy, so as to solve the technical problem that the existing mechanical wingtip camber adjustment mechanism driven by servo motor in aircraft has a large weight of motor, reducer and transmission mechanism, which is not conducive to the lightweight design of aircraft.
[0005] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a wingtip folding device based on a shape memory alloy, comprising: a wing body and a wingtip; a deformable connection mechanism connecting the wing body and the wingtip, the deformable connection mechanism including a shape memory alloy actuating component and a hinge component connected to the shape memory alloy actuating component; wherein, when the shape memory alloy actuating component is energized and activated, its length changes, and the hinge component is used to convert the length change of the shape memory alloy actuating component into a deflection of the deformable connection mechanism, so as to drive the wingtip to deflect relative to the wing body within a preset angle.
[0006] In some embodiments, the two ends of the hinge assembly are respectively connected to the wing body and the wingtip, and the shape memory alloy actuation assembly includes shape memory alloy actuators respectively arranged on both sides of the hinge assembly. When the shape memory alloy actuator on either side of the hinge assembly is activated, the deformable connection mechanism drives the wingtip to deflect in the corresponding direction.
[0007] In some embodiments, the two ends of the hinge assembly are respectively connected to the wing fuselage and the wingtip, and the shape memory alloy actuation assembly includes at least two sets of shape memory alloy actuators, the two sets of shape memory alloy actuators being respectively arranged on the side of the hinge assembly facing the upper surface of the wing fuselage and on the side facing the lower surface of the wing fuselage; wherein, each set of shape memory alloy actuators includes at least one shape memory alloy actuator; When the shape memory alloy actuator of the hinge assembly is activated on the side of the wing upper surface, the deformable connection mechanism causes the wingtip to deflect toward the wing upper surface. When the shape memory alloy actuator of the hinge assembly is activated near the lower wing surface of the wing fuselage, the deformable connection mechanism causes the wingtip to deflect towards the lower wing surface of the wing fuselage.
[0008] In some embodiments, the two ends of the shape memory alloy actuator are respectively connected to the wing body and the wingtip.
[0009] In some embodiments, the hinge assembly includes a plurality of rotating frames, which are rotatably connected in sequence.
[0010] In some embodiments, the rotating frame is provided with perforations on the side facing the upper wing surface and the side facing the lower wing surface, respectively, and the shape memory alloy actuators located on both sides of the hinge assembly pass through the corresponding perforations.
[0011] In some embodiments, the shape memory alloy actuator includes a shape memory alloy wire.
[0012] In some embodiments, the deformable connection mechanism further includes a power supply device and an angle sensor, the power supply device being electrically connected to the angle sensor, the power supply device being used to provide electrical power to the shape memory alloy actuation assembly, and the angle sensor being used to detect the folding angle of the wingtip relative to the wing body.
[0013] In some embodiments, the deformable connection mechanism further includes a flexible skin that surrounds the wing body and the wingtip, wherein the shape memory alloy actuation component and the hinge component are both disposed within the enclosure area of the flexible skin.
[0014] Secondly, the present invention also provides an aircraft, including the wingtip folding device based on shape memory alloy described in the first aspect; wherein the aircraft is an electric vertical take-off and landing aircraft with fixed wings.
[0015] The wingtip camber device based on shape memory alloy of the present invention uses a shape memory alloy actuation component as the driving element. The length change can be achieved simply by energizing it. The length change of the shape memory alloy actuation component is converted into the deflection of the wingtip relative to the wing body through the hinge component. This eliminates the mechanical wingtip camber adjustment mechanism driven by servo motors used in traditional aircraft, reduces the weight of motors and reducers, and promotes the lightweight design of aircraft.
[0016] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention, it can be implemented according to the contents of the specification. In order to make the above and other objects, features and advantages of the present invention more obvious and understandable, preferred embodiments are described in detail below. Attached Figure Description
[0017] Figure 1 This is a three-dimensional structural schematic diagram of the wingtip folding device based on shape memory alloy according to an embodiment of the present invention; Figure 2 This is a side view of the wingtip folding device based on shape memory alloy according to an embodiment of the present invention; Figure 3 This is a first-view internal structure schematic diagram of the wingtip folding device based on shape memory alloy according to an embodiment of the present invention; Figure 4 This is a second-view internal structure diagram of the wingtip folding device based on shape memory alloy according to an embodiment of the present invention; Figure 5 This is a third-view internal structure diagram of the wingtip folding device based on shape memory alloy according to an embodiment of the present invention; Figure 6 This is a cross-sectional view of the internal structure of the wingtip folding device based on shape memory alloy according to an embodiment of the present invention.
[0018] Explanation of reference numerals in the attached figures: 1. Wing body; 2. Deformable connection mechanism; 21. Rotating frame; 211. Hinge; 22. Shape memory alloy actuator; 23. Flexible skin; 3. Wing tip. Detailed Implementation
[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.
[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0021] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.
[0022] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.
[0023] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.
[0024] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.
[0025] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. The illustrative expressions of the above terms in this specification should not be construed as necessarily referring to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0026] Please see Figures 1-4 This invention provides a wingtip folding device based on shape memory alloy, comprising: a wing body 1 and a wingtip 3; a deformable connection mechanism 2 connecting the wing body 1 and the wingtip 3, the deformable connection mechanism 2 including a shape memory alloy actuation component and a hinge component connected to the shape memory alloy actuation component; wherein, when the shape memory alloy actuation component is energized and activated, its length changes, and the hinge component is used to convert the length change of the shape memory alloy actuation component into a deflection of the deformable connection mechanism 2, so as to drive the wingtip 3 to deflect relative to the wing body 1 within a preset angle.
[0027] It is understood that this embodiment uses a shape memory alloy actuation component as a driving element, which can achieve length change simply by energizing it. The length change of the shape memory alloy actuation component is converted into the deflection of the wingtip 3 relative to the wing body 1 through the hinge component. This eliminates the mechanical wingtip camber adjustment mechanism driven by the servo motor used in traditional aircraft, reduces the weight of the motor and reducer, and promotes the lightweight design of the aircraft.
[0028] It should be explained that shape memory alloys (SMA) are materials composed of two or more metallic elements that exhibit shape memory effect (SME) through thermoelasticity and martensitic phase transformation and its inverse phase transformation. In this embodiment, when the wingtip 3 needs to be deflected, the shape memory alloy actuation component is activated by energizing it. When the current flows through the shape memory alloy actuation component, Joule heating is generated, causing its temperature to rise. When the temperature exceeds its austenitic phase transformation point, the shape memory alloy actuation component will undergo a significant change in its macroscopic length based on the shape memory effect. For example, in this embodiment, the shape memory alloy actuation component shortens in length when the temperature exceeds its austenitic phase transformation point. This change in length of the shape memory alloy actuation component is transmitted as a driving displacement to the hinge component. The hinge component, as a motion conversion mechanism, effectively converts the linear displacement generated by the shape memory alloy actuation component into the rotational deflection motion required by the wingtip 3. When the power supply to the shape memory alloy actuation component is stopped, its temperature drops due to natural cooling or forced heat dissipation. When the temperature drops below the martensitic phase transformation completion temperature, the deformation connection mechanism 2 will drive the wingtip to move in the opposite direction or return to its original position under the action of the restoring force, preparing for the next activation drive of the shape memory alloy actuation component.
[0029] In the first feasible implementation, the two ends of the articulated assembly are connected to the wing body 1 and the wingtip 3 respectively. The shape memory alloy actuation assembly includes shape memory alloy actuators 22 respectively arranged on both sides of the articulated assembly. When the shape memory alloy actuator 22 on either side of the articulated assembly is activated, the deformable connection mechanism 2 drives the wingtip 3 to deflect in the corresponding direction.
[0030] Optionally, the shape memory alloy actuation assembly in this embodiment mainly includes two sets of shape memory alloy actuators 22 distributed on both sides of the hinge assembly. Each set of shape memory alloy actuators 22 contains at least one shape memory alloy actuator 22, that is, the shape memory alloy actuation assembly includes at least two shape memory alloy actuators 22 located on both sides of the hinge assembly. Optionally, each set of shape memory alloy actuators 22 may include multiple shape memory alloy actuators 22, which are evenly arranged at equal intervals.
[0031] Furthermore, based on the folding and unfolding requirements of the wingtip 3, the shape memory alloy actuation assembly in this embodiment includes at least two sets of shape memory alloy actuators 22. The two sets of shape memory alloy actuators 22 are respectively arranged on the side of the hinge assembly facing the upper wing surface 1 and the side facing the lower wing surface 1; wherein, each set of shape memory alloy actuators 22 includes at least one shape memory alloy actuator 22. Therefore, when the shape memory alloy actuator 22 of the articulated assembly is activated on the side of the upper surface of the wing fuselage 1, the deformable connection mechanism 2 causes the wingtip 3 to deflect towards the upper surface of the wing fuselage 1; when the shape memory alloy actuator 22 of the articulated assembly is activated on the side of the lower surface of the wing fuselage 1, the deformable connection mechanism 2 causes the wingtip 3 to deflect towards the lower surface of the wing fuselage 1; when the shape memory alloy actuators 22 on both sides of the articulated assembly are not activated, the deformable connection mechanism 2 will return to its initial state, that is, cause the wingtip 3 to remain in a neutral position that is basically aligned with the spanwise extension direction of the wing fuselage 1.
[0032] It should be noted that the activation in the above embodiments refers to electrical activation, that is, heating the shape memory alloy actuator 22 by energizing it, thereby shortening the shape memory alloy actuator 22. It is important to note that activation in the above embodiments refers to an energizing power greater than the activation preset value. That is, the shape memory alloy actuator 22 can be activated even when not activated, but during activation, the energizing power must be greater than the activation preset value. For example, in the unactivated state, the shape memory alloy actuators 22 on both sides of the hinge assembly are connected to electrical energy of the same magnitude but less than the activation preset value. At this time, the wingtip 3 remains in a neutral position substantially aligned with the spanwise extension direction of the wing body 1. However, when it is necessary to bend the wingtip 3 towards the upper or lower wing surface, it is only necessary to ensure that the electrical energy supplied to the shape memory alloy actuator 22 on the corresponding side is greater than the activation preset value.
[0033] Please see Figures 3-6 Furthermore, the hinge assembly includes multiple rotating frames 21, which are rotatably connected in sequence to form a mechanism capable of transmitting and converting motion.
[0034] It is understood that within the framework of this solution, the number of rotating frames 21 is not fixed, but can be adjusted according to actual needs. Generally speaking, increasing the number of rotating frames 21 can improve the design freedom of the articulated assembly, which may help to achieve more complex motion trajectories or a larger displacement amplification ratio. However, increasing the number of rotating frames 21 will inevitably introduce more moving joints, which may lead to a corresponding increase in structural complexity, overall weight, and cumulative motion error. Conversely, reducing the number of rotating frames 21 helps to simplify the structure, reduce weight, and improve rigidity, but may limit the flexibility of motion planning and the displacement amplification effect. Therefore, this embodiment does not limit the specific number of rotating frames 21. In practical applications, those skilled in the art can adaptively select an appropriate number of rotating frames 21 to constitute the articulated assembly of the present invention based on the specific model of the target aircraft, the load required to be borne by the wingtip folding device, and the specific drive requirements of the wingtip 3. This selection of the number is a design trade-off made by those skilled in the art under the guidance of the principles of the present invention, and will not be exhaustively listed here.
[0035] Specifically, the rotating frame 21 has perforations on the side facing the upper surface of the wing fuselage 1 and the side facing the lower surface of the wing fuselage 1, and the shape memory alloy actuators 22 located on both sides of the hinge assembly pass through the corresponding perforations.
[0036] Understandably, the rotating frame 21 is provided with perforations and hinges 211. The perforations are for the shape memory alloy actuators 22 to pass through, allowing them to move freely within the perforations. The perforations position, guide, and isolate the shape memory alloy actuators 22, preventing unnecessary interference or friction with the hinge components during operation, ensuring effective transmission of driving force, and improving the reliability and lifespan of the mechanism. The hinges 211 are used to form a rotational connection with adjacent rotating frames 21, allowing each end of a single rotating frame 21 to be rotatably connected to two adjacent rotating frames 21, thus transmitting motion sequentially. It is important to note that the perforations should be located on the side of the hinges 211 facing the upper wing surface 1 and the side facing the lower wing surface 1, respectively. This ensures that when the shape memory alloy actuators 22 on both sides of the rotating frame 21 are activated, they can rotate the rotating frame 21, causing the deformable connection mechanism 2 to rotate the wingtip 3.
[0037] Optionally, the hinge 211 in this embodiment can be a hinge hole and hinge shaft fit, or a ball joint or other rotational connection. Optionally, the rotating frame 21 in this embodiment is connected to the flexible skin 23 in the deformable connection mechanism 2 on the side near the front flange and the side near the rear flange, respectively.
[0038] In some embodiments, the shape memory alloy actuator 22 in the above embodiments includes a shape memory alloy wire, one end of which is connected to the wing body 1 and the other end of which is connected to the wingtip 3.
[0039] In some embodiments, the deformable connection mechanism 2 in the above embodiments further includes a power supply device and an angle sensor. The power supply device is electrically connected to the angle sensor. The power supply device is used to provide electrical energy to the shape memory alloy actuation component. The angle sensor is used to detect the folding angle of the wingtip 3 relative to the wing body 1.
[0040] Optionally, the power supply device can be located at the wingtip 3, the wing-body 1, or both. Preferably, the power supply device is located at the wing-body 1.
[0041] In some embodiments, the deformable connection mechanism 2 in the above embodiments further includes a flexible skin 23, which is disposed between the wing body 1 and the wingtip 3, and the shape memory alloy actuation component and the hinge component are both disposed within the enclosure area of the flexible skin 23.
[0042] Furthermore, the flexible skin 23 in this embodiment adopts a double-layer structure, that is, the flexible skin 23 in this embodiment includes a first skin disposed on the outer layer and a second skin disposed on the inner layer.
[0043] The first skin is made of aluminum alloy. Specifically, the first skin is made of 0.5 mm thick aluminum alloy plate with an elastic modulus of 71 GPa and a yield strength of 195 MPa. When the wingtip 3 deflects, it undergoes elastic bending, which not only bears part of the aerodynamic load, but also provides restoring force during the cooling stage of the shape memory alloy actuator 22, so that the wingtip 3 quickly returns to the neutral position that is basically aligned with the spanwise extension direction of the wing body 1.
[0044] The second skin is made of shape memory polymer (SMP), specifically a 0.1 mm thick SMP with a glass transition temperature (Tg) of 60°C. When the wingtip deflects, the second skin is heated to 70°C via resistance wire to enter a rubber state, capable of withstanding a maximum tensile strain of 10% without cracking. When the temperature drops to room temperature, the second skin returns to the glass state, maintaining an aerodynamically smooth surface.
[0045] Optionally, the neutral position where the wingtip 3 is basically aligned with the spanwise extension direction of the wing body 1 is taken as the 0° position. In the above embodiment, the maximum angle of the wingtip 3 deflecting upward towards the wing surface is 15°, and the maximum angle of the wingtip 3 deflecting downward towards the wing surface is also 15°.
[0046] The present invention also provides an aircraft, including the aforementioned wingtip folding device based on shape memory alloy; wherein the aircraft is an electric vertical take-off and landing (eVTOL) aircraft with fixed wings. It is understood that an electric vertical take-off and landing aircraft refers to an aircraft that uses an electric drive system and can achieve vertical take-off and landing without relying on a conventional runway, which will not be elaborated upon here.
[0047] The above examples are merely illustrative of the technical content of the present invention to facilitate easier understanding by the reader, but do not imply that the implementation of the present invention is limited to these examples. Any technical extensions or re-creations made based on the present invention are protected by the present invention. The scope of protection of the present invention is defined by the claims.
Claims
1. A wingtip folding and unfolding device based on shape memory alloy, characterized in that, include: Wing body and wingtip; A deformable connection mechanism connecting the wing body and the wingtip, the deformable connection mechanism including a shape memory alloy actuation component and a hinge component connected to the shape memory alloy actuation component; When the shape memory alloy actuation component is energized and activated, its length changes. The hinge component is used to convert the length change of the shape memory alloy actuation component into the deflection of the deformable connection mechanism, so as to drive the wingtip to deflect relative to the wing body within a preset angle.
2. The wingtip folding device based on shape memory alloy according to claim 1, characterized in that, The two ends of the hinge assembly are respectively connected to the wing body and the wingtip. The shape memory alloy actuation assembly includes shape memory alloy actuators arranged on both sides of the hinge assembly. When the shape memory alloy actuator on either side of the hinge assembly is activated, the deformable connection mechanism drives the wingtip to deflect in the corresponding direction.
3. The wingtip folding device based on shape memory alloy according to claim 2, characterized in that, The hinge assembly is connected to the wing body and the wingtip at both ends, respectively. The shape memory alloy actuation assembly includes at least two sets of shape memory alloy actuators. The two sets of shape memory alloy actuators are respectively arranged on the side of the hinge assembly facing the upper surface of the wing body and on the side facing the lower surface of the wing body. Each set of shape memory alloy actuators includes at least one shape memory alloy actuator. When the shape memory alloy actuator of the hinge assembly is activated on the side of the wing upper surface, the deformable connection mechanism causes the wingtip to deflect toward the wing upper surface. When the shape memory alloy actuator of the hinge assembly is activated near the lower wing surface of the wing fuselage, the deformable connection mechanism causes the wingtip to deflect towards the lower wing surface of the wing fuselage.
4. The wingtip folding device based on shape memory alloy according to claim 2 or 3, characterized in that, The two ends of the shape memory alloy actuator are respectively connected to the wing body and the wingtip.
5. The shape memory alloy-based shape unfolding device according to claim 2 or 3, characterized in that, The hinge assembly includes multiple rotating frames, which are rotatably connected in sequence.
6. The wingtip folding device based on shape memory alloy according to claim 5, characterized in that, The rotating frame has perforations on the side facing the upper surface of the wing and the side facing the lower surface of the wing, and the shape memory alloy actuators located on both sides of the hinge assembly pass through the corresponding perforations.
7. The wingtip folding device based on shape memory alloy according to any one of claims 2 or 3, characterized in that, The shape memory alloy actuator includes a shape memory alloy wire.
8. The wingtip folding device based on shape memory alloy according to any one of claims 2 or 3, characterized in that, The deformable connection mechanism also includes a power supply device and an angle sensor. The power supply device is electrically connected to the angle sensor. The power supply device is used to provide electrical energy to the shape memory alloy actuation component. The angle sensor is used to detect the folding angle of the wingtip relative to the wing body.
9. The wingtip folding device based on shape memory alloy according to any one of claims 2 or 3, characterized in that, The deformable connection mechanism also includes a flexible skin, which is arranged between the wing body and the wingtip. The shape memory alloy actuation component and the hinge component are both arranged within the enclosed area of the flexible skin.
10. An aircraft, characterized in that, Includes the wingtip folding device based on shape memory alloy as described in any one of claims 1-9; wherein the aircraft is an electric vertical takeoff and landing aircraft with fixed wings.