Antagonistic wing tip folding drive mechanism and wing based on shape memory alloy tube

Abstract

The present invention discloses an antagonistic wing tip folding drive mechanism and wing based on shape memory alloy tubes, which use two shape memory alloy torque tubes to interact with each other in the form of torsion, cooperate with the torsion transmission and amplification effect of the torque transmission device, and the temperature control device controls the temperature of the two shape memory alloy torque tubes respectively, so as to transmit the torsion torque of the shape memory alloy torque tube to the wing tip, realize full active control of the upper and lower folding angles of the wing tip, and can accurately control the torsion degree of each shape memory alloy torque tube, so that the aircraft can adapt to the current environment whether in flight or in a stopped state, and solves the disadvantage that most shape memory alloys have only one-way shape memory effect and need to be used with a biasing mechanism. The wing includes a wing body, a wing tip and the above-mentioned antagonistic wing tip folding drive mechanism based on the shape memory alloy tube, which can realize the functions of full-angle active folding control and angle maintenance of the wing tip.

Description

Technical Field

[0001] The invention relates to the technical field of aircraft, and in particular to an antagonistic wing tip folding drive mechanism based on a shape memory alloy tube and a wing. Background Art

[0002] With the development of smart materials and structures, various smart material drive concepts are constantly being proposed. In morphing aircraft, there are also many smart structure drives to achieve the drive scheme of the variant. Wingtip folding is a hot application in the current morphing aircraft field. By controlling the wingtip folding angle, the induced drag during flight can be effectively reduced. In addition, wingtip folding indirectly controls the span of the wing, which enables the aircraft to adapt to more flight environments. At the same time, wingtip folding on the ground can also improve space utilization and enable more aircraft to be parked.

[0003] The design and layout of the active folding mechanism of the wing tip is realized within the limited space of the wing. In terms of shape memory materials, there are also a variety of available drive types. Such as shape memory alloy wires, plates, springs, etc. As for the shape memory alloy torque tube drive technology alone, its structure is simple, the heating and heat dissipation methods during use are more efficient, and it has the characteristics of direct output torque, does not require other motion conversion structures, and can be directly integrated in the "hinge" position of the wing tip folding. While outputting torque to drive the wing tip to fold, the material itself is nickel-titanium alloy (shape memory alloy base material) and therefore has good mechanical properties, which can share part of the load at the hinge position, and is highly adaptable to the application scenario of wing tip folding.

[0004] Most of the existing shape memory alloy torsion tubes are tubular shape memory alloys, and it is difficult to train a stable two-way shape memory effect. They mainly use the one-way shape memory effect of the material to achieve semi-active wingtip folding and spreading control (that is, only one deflection direction can achieve active control), and the recovery process is a passive recovery process that relies on an additional bias spring to generate a restoring force. This not only increases the weight of the entire wingtip folding drive mechanism, but also increases the complexity of the wingtip folding drive mechanism, which cannot meet the goal of streamlined drive and limits the application scenarios of current wingtip folding technology to a certain extent. In order to solve the above problems, the present invention proposes an antagonistic wingtip folding drive mechanism and wing based on a shape memory alloy tube, which can realize full active folding drive of the wingtip, and has the characteristics of streamlined drive, and is suitable for a variety of flight environments. Summary of the invention

[0005] The purpose of the present invention is to provide an antagonistic wingtip folding drive mechanism and a wing based on a shape memory alloy tube, which can realize fully active folding drive of the wingtip and has the characteristics of streamlined drive and is adaptable to a variety of flight environments, so as to solve the problems existing in the above-mentioned prior art.

[0006] To achieve the above object, the present invention provides an antagonistic wing tip folding drive mechanism based on a shape memory alloy tube, which is used to be installed between a wing body and a wing tip, comprising:

[0007] The driving device comprises two coaxially arranged shape memory alloy torque tubes, and the two shape memory alloy torque tubes are twisted against each other; two ends of the two shape memory alloy torque tubes close to each other are connected by a connector, and two ends of the two shape memory alloy torque tubes far away from each other are used to be fixed on the wing body;

[0008] A torque transmission device, comprising an input gear, an output shaft and an output gear meshing with the input gear, wherein the input gear is arranged on the connecting head, and the rotating shaft of the input gear is coaxial with the shape memory alloy torque tube, and the output gear is arranged on the output shaft, and the output shaft is used to connect the wing tip;

[0009] A temperature control device is arranged on the driving device, and the temperature control device can heat the two shape memory alloy torque tubes so as to drive the wing tip to fold and deflect in two opposite directions relative to the wing body through the different directions of torque generated when the different shape memory alloy torque tubes are heated.

[0010] Preferably, the temperature control device comprises an air guide tube, and any one of the shape memory alloy torque tubes is provided with an air guide tube, and the air guide tube comprises:

[0011] An air supply inner pipe, comprising an air inlet pipe section and an air outlet pipe section connected to the air inlet pipe section, wherein the air outlet pipe section is sleeved inside the shape memory alloy torque tube, and a pipe wall of the air outlet pipe section is provided with an air vent, the air inlet pipe section is located outside the shape memory alloy torque tube, and the air inlet pipe section can introduce a high-temperature airflow or a low-temperature airflow into the air outlet pipe section;

[0012] The return pipe is sleeved on the outside of the intake pipe section and forms an annular return channel between the return pipe and the intake pipe section. The return pipe is also sealed and plugged with the end of the shape memory alloy torque tube to connect the annular return channel with the inside of the shape memory alloy torque tube.

[0013] Preferably, the temperature control device further comprises an air supply source, and the air supply source adopts an environmental control system of the aircraft, and the environmental control system can provide a high-temperature airflow or a low-temperature airflow to the air intake pipe section.

[0014] Preferably, the antagonistic wingtip folding drive mechanism also includes a braking device, which is used to be installed on at least one of the wingtip and the wing body, and the braking device is used to apply a braking force to the connecting head when the wingtip is folded and deflected to a specified position relative to the wing body.

[0015] Preferably, the braking device comprises:

[0016] A base, used for being mounted on at least one of the wing tip and the wing body, wherein the base is provided with a sliding guide rod;

[0017] The locking assembly comprises a first brake member, a second brake member, a pre-tightening nut, a first spring and a second spring, wherein the first spring, the first brake member, the second spring and the second brake member are sequentially slidably mounted on the sliding guide rod, and the pre-tightening nut is threadedly connected to the end of the sliding guide rod; a connector clamping area is formed between the first brake member and the second brake member, and the end of the connector passes through the connector clamping area;

[0018] The electromagnetic adsorption component includes a first adsorption electromagnet and a second adsorption electromagnet, wherein the first adsorption electromagnet and the second adsorption electromagnet are respectively arranged on the first brake member and the second brake member, and the first brake member and the second brake member can be clamped or loosened by synchronously turning on and off the power of the first adsorption electromagnet and the second adsorption electromagnet.

[0019] Preferably, the antagonistic wingtip folding drive mechanism further comprises a fixed support, and two ends of the two shape memory alloy torque tubes that are away from each other are respectively connected to a fixed support, and the fixed support is used to be fixed on the wing body.

[0020] Preferably, any one of the shape memory alloy torque tubes is spline-connected to the corresponding fixed support.

[0021] Preferably, any one of the shape memory alloy torque tubes is spline-connected to the connector.

[0022] Preferably, the antagonistic wingtip folding drive mechanism further includes a bearing support device, which includes:

[0023] A bearing seat, used for fixing on the wing body;

[0024] An input bearing, wherein the outer ring of the input bearing is fixed on the bearing seat, and the connector is arranged to penetrate the inner ring of the input bearing;

[0025] An output bearing, wherein the outer ring of the output bearing is fixed on the bearing seat, and the output shaft passes through the inner ring of the output bearing.

[0026] Preferably, an integrated shaft sleeve is also sleeved on the output shaft, and the integrated shaft sleeve is spline-connected to the output shaft, and the integrated shaft sleeve is used to connect the wing tip.

[0027] Preferably, the antagonistic wingtip folding drive mechanism also includes a heat insulation structure, and the heat insulation structure is provided at at least one of position one and position two; wherein, position one is between the two ends of the two shape memory alloy torque tubes that are close to each other, and position two is the outer wall of the shape memory alloy torque tube.

[0028] The present invention also proposes a wing, comprising a wing body and a wingtip, and also comprising the antagonistic wingtip folding drive mechanism described in any one of the above items, wherein the two ends of the two shape memory alloy torque tubes that are away from each other are fixed on the wing body, and the output shaft is connected to the wingtip to drive the wingtip to fold and deflect relative to the wing body.

[0029] Compared with the prior art, the present invention has achieved the following technical effects:

[0030] The present invention proposes an antagonistic wingtip folding drive mechanism based on shape memory alloy tubes, in which two shape memory alloy torque tubes interact with each other in the form of torsion, cooperate with the torsion transmission and amplification effect of the torque transmission device, and the temperature control device respectively controls the temperatures of the two shape memory alloy torque tubes, thereby transmitting the torsional torque of the shape memory alloy torque tube to the wingtip, realizing full active control of the upper and lower folding angles of the wingtip, and can accurately control the torsion degree of each shape memory alloy torque tube, so that the aircraft can adapt to the current environment regardless of whether it is in flight or in a parked state, thereby solving the problem that most shape memory alloys have only one-way shape memory effect and need to be used in conjunction with a biasing mechanism.

[0031] The wing proposed in the present invention includes a wing body, a wingtip and the above-mentioned antagonistic wingtip folding drive mechanism based on a shape memory alloy tube. Two shape memory alloy torque tubes integrated at the hinges of the wing body and the wingtip interact with each other in the form of torsion, and cooperate with a torque transmission device, a temperature control device, a braking device, and high and low temperature environmental control airflow to achieve precise temperature control of the torque tube, thereby realizing functions such as active control of full-angle folding of the wingtip and angle maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0033] Figure 1 It is an overall structural diagram of the antagonistic wing tip folding drive mechanism based on the shape memory alloy tube disclosed in an embodiment of the present invention;

[0034] Figure 2 for Figure 1 Exploded view of;

[0035] Figure 3 A schematic diagram of an air duct in a temperature control device disclosed in an embodiment of the present invention;

[0036] Figure 4 A partial cross-sectional view of an air guide tube in a temperature control device disclosed in an embodiment of the present invention;

[0037] Figure 5 It is an overall structural diagram of the braking device disclosed in the embodiment of the present invention;

[0038] Figure 6 It is an overall assembly diagram of the braking device and the connector disclosed in the embodiment of the present invention;

[0039] Figure 7 It is a front view of the assembly of the braking device and the connector disclosed in the embodiment of the present invention;

[0040] Figure 8 It is a side view of the assembly of the braking device and the connector disclosed in the embodiment of the present invention;

[0041] Fig. 9 An exploded view of a braking device disclosed in an embodiment of the present invention;

[0042] Fig.10 A schematic diagram of a wing structure disclosed in an embodiment of the present invention;

[0043] Fig.11 This is a front view of a wing disclosed in an embodiment of the present invention.

[0044] In the figure: 100, antagonistic wing tip folding drive mechanism based on shape memory alloy tube; 200, wing body; 300, wing tip;

[0045] 1. driving device; 11. shape memory alloy torque tube; 12. connector; 13. catheter connector;

[0046] 2. Torque transmission device; 21. Input gear; 22. Output shaft; 23. Output gear;

[0047] 3. Temperature control device; 31. Air inlet pipe section; 32. Air outlet pipe section; 33. Air vent; 34. Return pipe; 35. Annular return channel;

[0048] 4. Braking device; 41. Base; 42. Sliding guide rod; 43. First spring; 44. First braking member; 45. Second spring; 46. Second braking member; 47. Connector clamping area; 48. Electromagnet mounting hole;

[0049] 5. Fixed support;

[0050] 6. Bearing support device; 61. Bearing seat; 62. Input bearing; 63. Output bearing;

[0051] 7. Integrated sleeve;

[0052] 8. Insulation pad;

[0053] 9. Thermal insulation sleeve. DETAILED DESCRIPTION

[0054] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0055] One of the objects of the present invention is to provide an antagonistic wingtip folding drive mechanism based on a shape memory alloy tube, which can realize fully active folding drive of the wingtip and has the characteristics of streamlined drive, and is adaptable to a variety of flight environments, so as to solve the problems existing in the above-mentioned prior art.

[0056] Another object of the present invention is to provide a wing comprising the above-mentioned antagonistic wingtip folding drive mechanism.

[0057] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0058] Example 1

[0059] Aiming at the demand for active control of the bidirectional folding angle of the wing tip, this embodiment provides an antagonistic wing tip folding drive mechanism 100 based on a shape memory alloy tube, which can be integrated between the wing body 200 and the wing tip 300 as a hinge structure. Specifically, Figure 1 and Figure 2As shown, the above-mentioned antagonistic wingtip folding drive mechanism 100 based on shape memory alloy tubes includes a drive device 1, a torque transmission device 2 and a temperature control device 3. The drive device 1 includes two coaxially arranged shape memory alloy torque tubes 11, and the two shape memory alloy torque tubes 11 are twisted; the two ends of the two shape memory alloy torque tubes 11 close to each other are connected by a connector 12, and the two ends of the two shape memory alloy torque tubes 11 away from each other are used to be fixed on the wing body 200; the torque transmission device 2 includes an input gear 21, an output shaft 22 and a temperature control device 3 connected to the input gear 21. The output gear 23 is meshed with the gear 21, and the input gear 21 is arranged on the connecting head 12, and the rotating shaft of the input gear 21 is coaxial with the shape memory alloy torque tube 11, and the output gear 23 is arranged on the output shaft 22, and the output shaft 22 is used to connect the wing tip 300; the temperature control device 3 is arranged on the driving device 1, and the temperature control device 3 can heat the two shape memory alloy torque tubes 11, so that the torque directions generated by different shape memory alloy torque tubes 11 when heated are different, and the wing tip 300 is driven to fold and deflect in two opposite directions relative to the wing body 200. The two shape memory alloy torque tubes 11 of the present solution interact with each other in the form of torsion, cooperate with the torsion transmission and amplification effect of the torque transmission device 2, and the temperature control device 3 controls the temperature of the two shape memory alloy torque tubes 11 respectively, to transmit the torsion torque of the shape memory alloy torque tube 11 to the wing tip 300, thereby realizing full active control of the upper and lower folding angles of the wing tip (a two-way active control), and can accurately control the torsion degree of each shape memory alloy torque tube 11, so that the aircraft can adapt to the current environment whether it is in flight or in a parked state.

[0060] The shape memory alloy torque tube 11 used in this embodiment has high energy density, simple structure, and sufficient driving stroke. Combined with the temperature control function of the temperature control device 3, the metal phase change process of the shape memory alloy can be controlled to achieve the purpose of controlling the torque output of the shape memory alloy torque tube 11, thereby realizing the fully active and controllable folding of the wing tip and adapting to various flight environments. The torque output principle of the shape memory alloy torque tube 11 in this embodiment is as follows: in a low temperature state, that is, in a martensitic state, torsion can be generated at a lower torque and a certain torsion angle can be maintained. At this time, the shape memory alloy torque tube 11 is heated to transform it into a high temperature state, that is, an austenitic state. The torsional deformation recovery of the shape memory alloy torque tube 11 can provide a higher torque than that in the low temperature state, thereby producing a torque output effect. The driving principle of the two shape memory alloy torque tubes 11 in this embodiment is: the two shape memory alloy torque tubes 11 are twisted against each other, so as to Figure 1As shown in the example, the shape memory alloy torque tube 11 on the left is heated, and the torque tube generates deflection to drive the connector 12 to rotate, and then transmits through the torque transmission device 2, so that the wing tip 300 is folded, and the shape memory alloy torque tube 11 on the right (the other one) is twisted to obtain a certain residual angle; at this time, if the wing tip 300 is to be folded in the opposite direction, it is necessary to first cool the shape memory alloy torque tube 11 on the left, and then heat the shape memory alloy torque tube 11 on the right, so that the shape memory alloy torque tube 11 on the right is transformed into a high-temperature austenite state, so that the wing tip 300 is deflected in the opposite direction, and the shape memory alloy torque tube 11 on the left also obtains a residual angle. In essence, this solution is to achieve active deflection control of the wing tip 300 in both directions by alternating heating of the two shape memory alloy torque tubes 11.

[0061] In this embodiment, Figure 3 and Figure 4 As shown, the temperature control device 3 includes an air guide pipe, and any shape memory alloy torque tube 11 is provided with an air guide pipe, the air guide pipe includes an air supply inner pipe and a return pipe 34, the air supply inner pipe includes an air inlet pipe section 31 and an air outlet pipe section 32 connected to the air inlet pipe section 31, the air outlet pipe section 32 is sleeved inside the shape memory alloy torque tube 11, and the pipe wall of the air outlet pipe section 32 is provided with an air vent 33, the air inlet pipe section 31 is located outside the shape memory alloy torque tube 11, and the air inlet pipe section 31 can introduce high-temperature airflow or low-temperature airflow into the air outlet pipe section 32; the return pipe 34 is sleeved on the outside of the air inlet pipe section 31, and an annular return channel 35 is formed between the air inlet pipe section 31, and the return pipe 34 is also sealed and plugged with the end of the shape memory alloy torque tube 11 to make the annular return channel 35 connected to the inside of the shape memory alloy torque tube 11. Among them, the air supply inner tube is mainly used to introduce external airflow into the shape memory alloy torque tube 11 to heat or cool the shape memory alloy torque tube 11, and the formation of the annular return channel 35 is mainly used to guide the return flow of the airflow in the shape memory alloy torque tube 11. The above-mentioned air guide tube adopts the principle of air intake temperature control and uses inner and outer double-layer nested pipelines to make the inner wall of the shape memory alloy torque tube 11 evenly heated by the airflow while recovering the heated airflow to reflux the gas, which can recycle the hot air and prevent the airflow from being released to affect other components. Each shape memory alloy torque tube 11 is respectively equipped with an independent air guide tube to reduce the interference of external environmental temperature changes on the temperature control of the shape memory alloy torque tube 11.

[0062] As a preferred solution, a plurality of circles of air holes 33 are arranged at intervals in the axial direction of the air outlet pipe section 32, and each circle of air holes 33 is cross-arranged in the circumferential direction of the air outlet pipe section 32, that is, four air holes 33 are arranged in each circle of air holes 33, and the four air holes 33 are divided into two groups, and the two air holes 33 in each group are aligned, and the axes of the air holes 33 in the two groups are perpendicularly crossed. Such flute-like distributed air holes 33 have uniform heat dissipation, so that the shape memory alloy torque tube 11 can achieve the effect of uniform heating.

[0063] In this embodiment, the shape memory alloy torque tube 11 has a shape memory effect, and the key condition for producing the shape memory effect is to have a system that can accurately and efficiently control the temperature of the shape memory alloy torque tube 11. Considering that conventional aircraft have a corresponding environmental control system, the control of the ambient temperature is achieved by introducing high-temperature (low-temperature) airflow. Based on this, in this solution, the air supply source of the aforementioned air duct is preferably the environmental control system of the aircraft, and the environmental control system is used to provide high-temperature airflow or low-temperature airflow to the air intake section 31 to control the temperature of the shape memory alloy torque tube 11. Combined with the brake device 4, the control of the wing tip folding angle can be achieved.

[0064] In this embodiment, after ensuring that the shape memory alloy torque tube 11 has the corresponding torsion driving capability, in order to produce a control effect on the wing tip structure, not only driving force but also braking force is required. Therefore, a braking device 4 needs to be provided in the corresponding structure to lock the position so that the wing tip 300 can be braked in time when it moves to the specified position, thereby achieving the required flight effect. The structure of the braking device 4 is as follows: Figure 1 , Figure 2 , Figures 5 to 9As shown, the brake device 4 is used to be installed on at least one of the wing tip 300 and the wing body 200, and the brake device 4 is used to apply a braking force to the connector 12 when the wing tip 300 is folded and deflected to a specified position relative to the wing body 200. Specifically, the above-mentioned braking device 4 includes a base 41, a locking assembly and an electromagnetic adsorption assembly. The base 41 is used to be installed on at least one of the wing tip 300 and the wing body 200, and a sliding guide rod 42 is arranged on the base 41; the locking assembly includes a first brake member 44, a second brake member 46, a pre-tightening nut, a first spring 43 and a second spring 45, the first spring 43, the first brake member 44, the second spring 45 and the second brake member 46 are slidably mounted on the sliding guide rod 42 in sequence, and the pre-tightening nut is threadedly connected to the end of the sliding guide rod 42; a connector clamping area 47 is formed between the first brake member 44 and the second brake member 46, and the end of the connector 12 passes through the connector clamping area 47; the electromagnetic adsorption assembly includes a first adsorption electromagnet and a second adsorption electromagnet, the first adsorption electromagnet and the second adsorption electromagnet are respectively arranged on the first brake member 44 and the second brake member 46, and the first brake member 44 and the second brake member 46 can be clamped or loosened by synchronously turning on and off the power to the first adsorption electromagnet and the second adsorption electromagnet.

[0065] In this embodiment, it is preferred that each shape memory alloy torque tube 11 is braked by an independent braking device 4, and the first brake member 44 and the second brake member 46 are attracted to each other and clamp the connector 12 by utilizing the energized adsorption effect of the electromagnet, so that friction is formed between the inner walls of the first brake member 44 and the second brake member 46 and the connector 12, thereby producing a braking effect. Specifically: the connector clamping area 47 formed between the first brake member 44 and the second brake member 46 is a circular area, but it is not a complete circle. The first brake member 44 and the second brake member 46 always maintain a certain distance between them under the support of the second spring 45. This structure can ensure that the inner walls of the first brake member 44 and the second brake member 46 can fully contact and rub with the connector 12 when braking is required. As a preferred solution, the first brake member 44 and the second brake member 46 are made of high-carbon steel material, which can ensure the braking accuracy while ensuring the structural strength of the first brake member 44 and the second brake member 46, and have high temperature stability and wear resistance; at the same time, the inner walls of the first brake member 44 and the second brake member 46 are made of high friction coefficient materials, such as ceramic composite materials, which can further enhance their clamping and braking effects on the connector 12. In addition, if Figures 5 to 9As shown, the first brake member 44 and the second brake member 46 are sleeved on the sliding guide rod 42 of the base 41. The sliding guide rod 42 is preferably arranged in two groups in parallel. The second brake member 46 is pre-tightened by a pre-tightening bolt, so that the first spring 43 and the second spring 45 are both in a compressed state, wherein the elastic coefficient of the first spring 43 is greater than the elastic coefficient of the second spring 45. The first spring 43 is used to support the first brake member 44 and the second brake member 46 at the same time. When the first brake member 44 and the second brake member 46 are in a non-braking state, they are suspended on the periphery of the connector 12 under the support of the second spring 45. By adjusting the position of the pre-tightening nut, the first brake member 44 and the second brake member 46 can be prevented from contacting the connector 12 in a non-braking state. When braking is required, the adsorption electromagnets of the first brake member 44 and the second brake member 46 are energized to make the first brake member 44 and the second brake member 46 adsorb each other and clamp the connector 12 to achieve braking.

[0066] The first brake member 44 and the second brake member 46 are preferably brake pads, and the inner wall profiles thereof are arc-shaped to match the outer wall profile of the connector 12 .

[0067] In this embodiment, the aforementioned antagonistic wingtip folding drive mechanism 100 based on shape memory alloy tubes also includes a fixed support 5, and the two ends of the two shape memory alloy torque tubes 11 that are far away from each other are respectively connected to a fixed support 5, and the fixed support 5 is used to be fixed on the wing body 200; any shape memory alloy torque tube 11 is spline-connected to the corresponding fixed support 5; any shape memory alloy torque tube 11 is spline-connected to the connector 12. Specifically: spline-type joints are used at both ends of the shape memory alloy torque tube 11. This structure has a better matching effect. The fixed support 5 is used to fix one end of the shape memory alloy torque tube 11, and the other end of the shape memory alloy torque tube 11 is connected to the built-in spline in the connector 12.

[0068] In this embodiment, the input gear 21 is preferably a local gear structure with a certain number of teeth set according to the torsion limit of the shape memory alloy torque tube 11. The output gear 23 is sleeved on the center of the output shaft 22 and connected to the output shaft 22 by a spline.

[0069] In this embodiment, an integrated sleeve 7 is also sleeved on the output shaft 22, and the integrated sleeve 7 is spline-connected to the output shaft 22, and the integrated sleeve 7 is used to connect the wing tip 300. The integrated sleeve 7 is preferably made of high carbon steel, which can ensure sufficient strength during torque transmission while having high temperature stability and wear resistance.

[0070] In this embodiment, the aforementioned antagonistic wing tip folding drive mechanism 100 based on shape memory alloy tube further includes a bearing support device 6, which includes a bearing seat 61, an input bearing 62 and an output bearing 63. The bearing seat 61 is used to be fixed on the wing body 200, the bearing outer ring of the input bearing 62 is fixed on the bearing seat 61, and the connector 12 is set through the bearing inner ring of the input bearing 62; the bearing outer ring of the output bearing 63 is fixed on the bearing seat 61, and the output shaft 22 is set through the bearing inner ring of the output bearing 63. Specifically: the corresponding positions of the connector 12 and the output shaft 22 are both set with shaft shoulder positions, which are used for the installation and positioning of the above-mentioned input bearing 62 and output bearing 63 respectively; the bearing seat 61 adopts an integrated structure, and the input bearing 62 and the output bearing 63 are integrated and installed, which can ensure that the relative position of the connector 12 and the output shaft 22 is correct, thereby ensuring that the axis of the shape memory alloy torque tube 11 and the axis of the output shaft 22 are always parallel.

[0071] In this embodiment, the aforementioned antagonistic wingtip folding drive mechanism 100 based on shape memory alloy tube also includes a heat insulation structure, and a heat insulation structure is provided at at least one of position one and position two; wherein, position one is between the two ends of the two shape memory alloy torque tubes 11 that are close to each other, and position two is the outer wall of the shape memory alloy torque tube 11. Specifically, in this embodiment, it is preferred that both position one and position two are provided with thermal insulation structures, and the thermal insulation structure at position one is a thermal insulation pad 8. The two ends of the two shape memory alloy torque tubes 11 that are close to each other are blocked by the thermal insulation pad 8, which can ensure that the internal spaces of the two shape memory alloy torque tubes 11 are independent of each other, avoid mutual temperature interference, and realize independent temperature control of the two shape memory alloy torque tubes 11; position two is a thermal insulation sleeve 9 mounted on the outside of the shape memory alloy torque tube 11, and it is preferred that the thermal insulation sleeve 9 is also provided with a temperature sensor that can monitor the temperature change of the shape memory alloy torque tube 11 in real time, so as to transmit the real-time temperature information of the shape memory alloy torque tube 11 to the control system, so as to realize accurate control of the heating effect of the shape memory alloy torque tube 11.

[0072] In this embodiment, an angle monitoring device, such as a ring encoder, can also be configured on the output shaft 22 to monitor the rotation angle of the output shaft 22 in real time, and use this as feedback to guide the temperature control range of the temperature control device 3 and the start and stop of the braking device 4, so as to achieve real-time and accurate regulation of the folding angle of the wing tip 300 relative to the wing body 200.

[0073] In this embodiment, Figure 1 and Figure 2As shown, the above-mentioned antagonistic wingtip folding drive mechanism 100 based on shape memory alloy tubes preferably adopts a highly symmetrical structural arrangement, specifically: the two shape memory alloy torque tubes 11 are symmetrically arranged with the connecting head 12 as the center, and the aforementioned thermal insulation pad 8 is located at the center of the two shape memory alloy torque tubes 11; the temperature control device 3, the braking device 4, the fixed support 5, the bearing support device 6 and the integrated shaft sleeve 7 are all arranged symmetrically on the left and right with the thermal insulation pad 8 as the center, wherein: the two integrated shaft sleeves 7 are combined into the wing beam structure of the wing tip 300, which can transmit the rotation angle output of the shape memory alloy torque tube 11 to the wing tip 300.

[0074] Although other forms of shape memory materials can currently provide the driving force required for wingtip folding, in the application scenario of wingtip folding, the above-mentioned antagonistic wingtip folding drive mechanism 100 based on shape memory alloy tube proposed in the present invention adopts a shape memory alloy torsion tube drive scheme with a simpler structure, which can achieve the wingtip folding effect in a smaller space and at a smaller weight, and can also use the aircraft's own environmental control system for temperature control, thereby simplifying the design of the foldable wingtip structure, reducing the overall weight of the wing, and also improving the overall flight efficiency of the aircraft.

[0075] The above-mentioned antagonistic wingtip folding drive mechanism 100 based on shape memory alloy tube proposed by the present invention adopts an antagonistic driver design scheme, which solves the disadvantage that most shape memory alloys only have a one-way shape memory effect and need to be used in conjunction with a biasing mechanism, and realizes full-range active control. The key to driving the wingtip folding of the aircraft lies in the driver. According to the characteristics of shape memory materials, even if it is a two-way shape memory effect, even if a certain displacement can be generated during the cooling process, as a torque output, from an energy perspective, the torque tube does not have continuous energy input during the cooling process, and the torque provided to the outside is naturally limited. Therefore, the present invention adopts an antagonistic dual torque tube driver. During the heating drive process, the torque tube not only provides torque and angle output for the wingtip folding, but also enables the other torque tube to obtain a certain pre-twisted angle. During the next heating, the other tube can produce an effect in the opposite direction, realizing active control of the whole process.

[0076] Although the twisting method of the two shape memory alloy torque tubes 11 can better realize the active control of the whole process of wingtip folding, the two shape memory alloy torque tubes 11 are stacked together, which inevitably reduces the effective length of the torque tube (compared with the offset method). Therefore, in the present invention, a gear amplification mechanism based on the meshing of the input gear and the output gear is provided to amplify the torsion angle of the torque tube, thereby realizing full-angle control of the wingtip folding.

[0077] Therefore, during the recovery process, the use of two or more shape memory alloy torque tubes 11 can also enable the torque tube-based driver to generate continuous torque output. However, the control of multiple torque tubes requires a complex temperature control solution, and the heating and heat dissipation of each tube requires an additional design process. It is also necessary to consider the temperature influence between each tube during the heating and heat dissipation process, thereby increasing the weight of the entire mechanism and the control difficulty, and also increasing the difficulty of reliability design. Therefore, the design of two shape memory alloy torque tubes 11 in the present invention is currently the optimal solution.

[0078] Example 2

[0079] like Fig.10 and Fig.11 As shown, this embodiment proposes a wing, including a wing body 200, a wing tip 300 and the antagonistic wing tip folding drive mechanism 100 based on the shape memory alloy tube disclosed in Example 1, the two ends of the two shape memory alloy torque tubes 11 of the antagonistic wing tip folding drive mechanism 100 based on the shape memory alloy tube are fixed to the wing body 200, and the output shaft 22 is connected to the wing tip 300. As can be seen from the above, the two shape memory alloy torque tubes 11 integrated at the hinge of the wing body 200 and the wing tip 300 interact with each other in the form of torsion, cooperate with the torque transmission device 2, the temperature control device 3, the brake device 4, and the high and low temperature environmental control airflow to achieve precise temperature control of the torque tube, thereby realizing the full-angle active control of the wing tip 300, angle maintenance and other functions.

[0080] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. An antagonistic wing tip folding drive mechanism based on a shape memory alloy tube, used for installation between a wing body (200) and a wing tip (300), characterized in that: include: The driving device (1) comprises two coaxially arranged shape memory alloy torque tubes (11), wherein the two shape memory alloy torque tubes (11) are twisted against each other; two ends of the two shape memory alloy torque tubes (11) close to each other are connected via a connector (12), and two ends of the two shape memory alloy torque tubes (11) far from each other are used to be fixed on the wing body (200); A torque transmission device (2), comprising an input gear (21), an output shaft (22) and an output gear (23) meshing with the input gear (21), wherein the input gear (21) is arranged on the connector (12), and the rotating shaft of the input gear (21) is coaxial with the shape memory alloy torque tube (11), and the output gear (23) is arranged on the output shaft (22), and the output shaft (22) is used to connect the wing tip (300); A temperature control device (3) is arranged on the driving device (1), and the temperature control device (3) is capable of heating the two shape memory alloy torque tubes (11) so as to drive the wing tip (300) to fold and deflect in two opposite directions relative to the wing body (200) by generating different torque directions when the different shape memory alloy torque tubes (11) are heated. The temperature control device (3) comprises an air guide tube, and any one of the shape memory alloy torque tubes (11) is provided with an air guide tube, and the air guide tube comprises an air supply inner tube and a return pipe (34), and the air supply inner tube comprises an air inlet pipe section (31) and an air outlet pipe section (32) connected to the air inlet pipe section (31), and the air outlet pipe section The shape memory alloy torque tube (11) is provided with a vent hole (33) on its wall, and the intake pipe section (31) is located outside the shape memory alloy torque tube (11). The intake pipe section (31) can introduce a high-temperature airflow or a low-temperature airflow into the outlet pipe section (32). The return pipe (34) is sleeved on the outside of the intake pipe section (31) and an annular return channel (35) is formed between the return pipe (34) and the intake pipe section (31). The return pipe (34) is also sealed and plugged with the end of the shape memory alloy torque tube (11) so that the annular return channel (35) is connected to the inside of the shape memory alloy torque tube (11).

2. The antagonistic wing tip folding drive mechanism according to claim 1, characterized in that: The temperature control device (3) also includes an air supply source, wherein the air supply source is an environmental control system of an aircraft, and the environmental control system is capable of providing a high-temperature airflow or a low-temperature airflow to the air intake pipe section (31).

3. The antagonistic wing tip folding drive mechanism according to claim 1 or 2, characterized in that: It also includes a braking device (4), which is used to be installed on at least one of the wing tip (300) and the wing body (200), and the braking device (4) is used to apply a braking force to the connecting head (12) when the wing tip (300) is folded and deflected to a specified position relative to the wing body (200).

4. The antagonistic wing tip folding drive mechanism according to claim 3, characterized in that: The braking device (4) comprises: A base (41) for being mounted on at least one of the wing tip (300) and the wing body (200), wherein a sliding guide rod (42) is provided on the base (41); A locking assembly, comprising a first brake member (44), a second brake member (46), a pre-tightening nut, a first spring (43) and a second spring (45); the first spring (43), the first brake member (44), the second spring (45) and the second brake member (46) are sequentially slidably mounted on the sliding guide rod (42); the pre-tightening nut is threadedly connected to the end of the sliding guide rod (42); a connector clamping area (47) is formed between the first brake member (44) and the second brake member (46); the end of the connector (12) passes through the connector clamping area (47); The electromagnetic adsorption component comprises a first adsorption electromagnet and a second adsorption electromagnet, wherein the first adsorption electromagnet and the second adsorption electromagnet are respectively arranged on the first brake member (44) and the second brake member (46), and the first brake member (44) and the second brake member (46) can be clamped or loosened by synchronously turning on and off the power of the first adsorption electromagnet and the second adsorption electromagnet.

5. The antagonistic wing tip folding drive mechanism according to claim 1 or 2, characterized in that: It also comprises a fixed support (5), two ends of the two shape memory alloy torque tubes (11) that are away from each other are respectively connected to a fixed support (5), and the fixed support (5) is used to be fixed on the wing body (200); Any one of the shape memory alloy torque tubes (11) is spline-connected to the corresponding fixed support (5); Any one of the shape memory alloy torque tubes (11) is spline-connected to the connector (12).

6. The antagonistic wing tip folding drive mechanism according to claim 1 or 2, characterized in that: Also included is a bearing support device (6), which includes: A bearing seat (61) used for being fixed on the wing body (200); An input bearing (62), wherein the outer ring of the input bearing (62) is fixed on the bearing seat (61), and the connector (12) is disposed through the inner ring of the input bearing (62); An output bearing (63), wherein the outer ring of the output bearing (63) is fixed on the bearing seat (61), and the output shaft (22) is arranged to penetrate the inner ring of the output bearing (63).

7. The antagonistic wing tip folding drive mechanism according to claim 1 or 2, characterized in that: An integrated shaft sleeve (7) is also sleeved on the output shaft (22), and the integrated shaft sleeve (7) is spline-connected to the output shaft (22), and the integrated shaft sleeve (7) is used to connect the wing tip (300).

8. The antagonistic wing tip folding drive mechanism according to claim 1 or 2, characterized in that: It also includes a heat insulation structure, which is provided at at least one of position one and position two; wherein position one is between the two ends of the two shape memory alloy torque tubes (11) that are close to each other, and position two is the outer wall of the shape memory alloy torque tube (11).

9. A wing, comprising a wing body (200) and a wing tip (300), characterized in that: It also includes the antagonistic wingtip folding drive mechanism as described in any one of claims 1 to 8, wherein the two ends of the two shape memory alloy torque tubes (11) that are away from each other are fixed to the wing body (200), and the output shaft (22) is connected to the wing tip (300) to drive the wing tip (300) to fold and deflect relative to the wing body (200).

Images