Wing surface deployment and sweep mechanism and method based on shape memory alloy wire actuator

Abstract

The present invention discloses a wing surface deployment and sweep mechanism and method based on a shape memory alloy wire actuator, and relates to the field of wing surface deployment and sweep control. In the mechanism, the wing surface can rotate around a fixed axis, and a guide rail is provided inside and outside the slider, and two pairs of block grooves are provided on the outer guide rail; a spring block controlled by an iron core coil is arranged in the block groove; the slider slides up and down under the tension of the alloy wire and the air load, and drives the wing surface to be deployed and swept back through a connecting rod; the alloy wire is wound on the surface of the outer guide rail. Before deployment, the first block pops out to prevent the slider from sliding down. When deploying, the first block is sucked in, and the slider slides down under tension to achieve deployment. After deployment, the second block that pops out clamps the slider to prevent it from sliding up; when sweeping back, the second block is sucked in, and the slider slides up under the action of the aerodynamic load. When the wing surface turns to a specified sweep angle, the slider is just stuck in the middle by the two pairs of pop-up blocks. The present invention is not only compact in structure, but also can greatly reduce the weight of the actuator.

Description

Technical Field

[0001] The invention relates to the field of wing surface deployment and sweep control, and in particular to a wing surface deployment and sweep mechanism and method based on a shape memory alloy wire actuator. Background Art

[0002] Before the flight, in order to save the space occupied by the wing surface, the aircraft needs to fold the wing surface before the flight and then unfold it during the flight. During the flight, in order to increase the flight speed and reduce air resistance, the wing surface needs to be swept back at a certain angle. However, the previous wing surface unfolding structure usually has the problem of complex structure and large mass. Using smart material actuators to replace the previous transmission methods such as motor transmission, hydraulic transmission and pneumatic transmission has become a new research hotspot. Shape memory alloy wire has functional characteristics such as large displacement, large driving force output and predetermined shape memory recovery, as well as advantages such as low voltage drive, no noise, light weight and no pollution. On the one hand, by combining the shape memory alloy actuator with the connecting rod slider mechanism, the linear contraction motion of the actuator can be converted into rotational motion, and the connecting rod slider also has the advantages of light weight and large rotational force. The combination of the two can well ensure the realization of the wing surface unfolding and sweeping functions under light weight. On the other hand, the characteristics of the core coil generating magnetic force when energized and the disappearance of electromagnetic force when disconnected are used to control the ejection and retraction of the card block with a spring in the card block slot. Before power is turned on, the block partially pops out of the block slot under the elastic force of the spring, which can block the sliding of the slider to fix the position of the slider. When the block retracts under the magnetic force generated by the core coil after power is turned on, the slider can slide freely. Therefore, the rotation and stop of the wing surface can be controlled by controlling the sliding and stopping of the slider, and different wing surface expansion angles and sweep angles can be obtained by designing the sizes of the slider, block and guide rail. Summary of the invention

[0003] In order to realize the precise deployment and sweeping functions of the wing surface with a smaller volume and lighter weight, the present invention provides a wing surface deployment and sweeping mechanism and control method based on a shape memory alloy wire actuator, which is novel, unique, easy to use, and can ensure that the wing surface is deployed at the beginning of takeoff while ensuring a lighter overall mass, and the wing surface is swept back to a specified angle during high-speed flight to reduce air resistance.

[0004] In order to meet the above requirements, the present invention has designed a method of using a power supply to heat a shape memory alloy wire actuator and generate tension, one end of the shape memory alloy wire actuator is fixed on the outer guide rail, and the other end is fixed to the bottom of the slider, the fixed rotating shaft of the wing surface, the inner guide rail and the outer guide rail are all fixed to the aircraft to maintain relative stillness, so that when the shape memory alloy wire contracts, a tension is generated on the slider in the connecting rod slider mechanism to make it slide along the inner and outer guide rails, and the wing surface is pulled by the connecting rod to rotate along the fixed axis to achieve unfolding; then, based on the relay effect of the magnetic force generated by the energization of the iron core coil and the spring elastic force, the two pairs of blocks installed in the block grooves are precisely ejected and retracted to achieve sliding and locking of the slider, ensuring that the slider can slide smoothly during the unfolding and sweeping process, and can be accurately locked after the unfolding and sweeping are completed.

[0005] The specific technical solutions adopted by the present invention are as follows:

[0006] In a first aspect, the present invention provides a wing surface deployment and sweep mechanism based on a shape memory alloy wire actuator, comprising a fixed shaft fixedly connected to a body, an inner guide rail and an outer guide rail;

[0007] The inner guide rail is fixed to the hollow inner cavity of the outer guide rail, and a slider capable of sliding axially along the inner guide rail is provided between the inner guide rail and the outer guide rail, and the slider and the outer guide rail are clearance-matched; the top of the slider is provided with concave grooves in four directions, and the third connecting hole of the concave groove in each direction is rotatably connected to one end of the connecting rod, and the other end of the connecting rod is rotatably connected to the wing rod; the wing rod is hinged to the fixed shaft and fixedly connected to the wing surface; the bottom of the slider is provided with a third boss, and a plurality of protruding second connectors are evenly distributed at the bottom of the third boss;

[0008] The inner wall of the outer guide rail is laterally provided with a first block groove located at the top and a second block groove located at the bottom, and the first block groove and the second block groove are spaced apart along the axial direction of the outer guide rail and the distance between the two is not less than the height of the third boss; a first spring capable of providing a lateral elastic force and a first iron core coil capable of generating a ferromagnetic attraction force after being energized are provided in the first block groove; one end of the first spring is fixed to the inner wall of the first block groove, and the other end is fixed to a first block made of ferromagnetic material; the first block can slide laterally in the first block groove, can be partially located outside the first block groove when not subject to force, and can be completely retracted when subjected to a ferromagnetic attraction force. The first card block groove is in the first card block groove; the second card block groove is provided with a second spring capable of providing lateral elastic force and a second iron core coil capable of generating ferromagnetic attraction after being energized; one end of the second spring is fixed to the inner wall of the second card block groove, and the other end is fixed to a second card block made of ferromagnetic material; the second card block can slide laterally in the second card block groove, can be partially located outside the second card block groove when not subject to force, and can be completely retracted into the second card block groove when subjected to ferromagnetic attraction; a plurality of evenly arranged shape memory alloy wires are fixedly wound around the surface of the outer guide rail; and one end of the shape memory alloy wire is fixed to the second connector, and the other end is fixed to the outer guide rail.

[0009] Preferably, one end of the wing rod is connected to one end of the connecting rod through a first movable shaft and a bearing; the other end of the connecting rod is rotatably connected to the third connecting hole through a second movable shaft and a bearing.

[0010] Preferably, the main body of the inner guide rail is a sliding rod structure; the top and bottom of the sliding rod are respectively provided with a first boss and a second boss for axially limiting the sliding block, and the second boss is connected to a connecting block with a first connecting hole; a crossbeam is provided in the inner cavity of the outer guide rail below the second block groove, and a second connecting hole is provided on the crossbeam, and a fixed connection between the inner guide rail and the outer guide rail is achieved by a connecting piece between the first connecting hole and the second connecting hole; the distance between the first boss and the top of the first block groove, and the distance between the second boss and the bottom of the second block groove are not less than the height of the third boss.

[0011] Preferably, the sliding block is axially provided with an inner through hole and is sleeved on the outside of the inner guide rail, and the inner through hole is connected to the outer wall of the inner guide rail through ball sliding contact.

[0012] Preferably, the first iron core coil and the second iron core coil are connected to an external power source through a first wire groove and a second wire groove provided on the outer guide rail, respectively.

[0013] Preferably, there are four shape memory alloy wires which are evenly and vertically wound around the outer guide rail along the circumferential direction, and the shape memory alloy wires do not interfere with each other.

[0014] Preferably, the surface of the outer guide rail is provided with a plurality of threaded holes, and the bottom of the outer guide rail is provided with a plurality of bearing grooves and shaft grooves, and the threaded holes, bearing grooves and shaft grooves are all fixed with a protruding threaded shaft through a U-shaped bearing and a nut; the U-shaped bearing is used for winding the shape memory alloy wire.

[0015] Preferably, a protruding first connector is provided on the inner wall of the outer guide rail below the second block groove; one end of the shape memory alloy wire is fixed to the first connector, and the other end is fixed to the second connector.

[0016] Preferably, two of the first block slots and the second block slots are symmetrically arranged with the inner guide rail as the axis, the two first block slots are located on the same horizontal line, and the two second block slots are located on the same horizontal line.

[0017] In a second aspect, the present invention provides an actuation method of a wing surface deployment and sweep mechanism based on a shape memory alloy wire actuator according to any one of the first aspects, as follows:

[0018] When the wing surface is in a closed state, the first block partially leaks out of the first block groove under the elastic force of the first spring, and the second block partially leaks out of the second block groove under the elastic force of the second spring. The upper surface of the first block contacts the lower surface of the third boss and restricts its downward movement. At this time, the shape memory alloy wire has a pre-tension.

[0019] When the wing surface is ready to unfold, the power supply is first used to pass current through the shape memory alloy wire to heat it, and then the temperature of the shape memory alloy wire is measured by the thermistor and the output power of the power supply circuit is fed back to adjust the output power, and the temperature is controlled at a set value to control the tension of the shape memory alloy wire; when the temperature of the shape memory alloy wire is heated to a specified temperature, the shape memory alloy wire has a large contraction force, and current is passed through the first iron core coil and the second iron core coil, so that the first clamping block overcomes the elastic force of the first spring and is completely retracted into the first clamping block slot, so that the second clamping block overcomes the elastic force of the second spring The slider overcomes the rotational inertia of the wing surface and the smaller aerodynamic load under the contraction force of the shape memory alloy wire, and slides downward along the inner guide rail, driving the connecting rod to move and rotate, and the wing rod and the wing surface rotate along the fixed axis under the pulling force of the connecting rod; when the slider slides down to the bottom of the inner guide rail, the wing surface is unfolded to the maximum position, at which time the current on the first iron core coil and the second iron core coil is disconnected, the first clamping block and the second clamping block are ejected respectively under the elastic force of the first spring and the second spring, the second clamping block clamps the third boss and restricts its upward movement, the current on the shape memory alloy wire is disconnected, and the wing surface unfolding process is completed;

[0020] When the wing surface is swept back, current is only passed through the second iron core coil, so that the second clamping block overcomes the elastic force of the second spring and is completely retracted into the second clamping block groove; the wing surface rotates backward around the fixed axis through the wing rod under the action of the aerodynamic load, and drives the connecting rod to move and rotate, and the connecting rod generates an upward pulling force on the slider, and the slider overcomes the downward contraction force of the shape memory alloy wire and slides upward; when the upper surface of the third boss contacts the lower surface of the first clamping block, it stops moving upward under the limiting action of the first clamping block, and the wing surface is swept back to a specified angle; at this time, the current on the second iron core coil is disconnected, and the second clamping block pops out under the elastic force of the second spring and limits the downward movement of the third boss, completing the sweeping process of the wing surface.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The present invention uses a shape memory alloy wire actuator to replace the previous motor drive, hydraulic drive and pneumatic drive, and cooperates with a slider connecting rod mechanism to convert the linear contraction movement of the shape memory alloy wire into the rotation of the wing surface. Under the premise of ensuring the driving force, the complexity of the mechanism is reduced and the volume and weight of the mechanism are reduced; the magnetic force change before and after the core coil is powered on and off is used to control the ejection and retraction of the card block with a spring in the card block groove. Before power is turned on, the card block partially pops out of the card block groove under the elastic force of the spring, which can block the sliding of the slider; after power is turned on, the card block retracts under the attraction of the magnetic force, and the slider can slide freely. Therefore, the rotation and stop of the wing surface are controlled by controlling the sliding and stopping of the slider, and then different wing surface expansion angles and sweep angles are obtained by designing the sizes of the slider, the card block and the guide rail. In addition, a concave bearing is installed on the outer guide rail, and the shape memory alloy wire is wound on the concave bearing, which can not only increase the length of the alloy wire to increase the contraction amount, but also reduce the friction and material wear between the wire and the winding device during the wire contraction process, and also save the extra space occupied by the shape memory alloy wire. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the structure of the mechanism of the present invention when it is folded;

[0024] Figure 2 It is a schematic diagram of the structure of the present invention when the mechanism is unfolded;

[0025] Figure 3 It is a schematic diagram of the structure of the mechanism of the present invention when it is swept back;

[0026] Figure 4 It is a schematic diagram of the structure of the inner guide rail;

[0027] Figure 5 It is a schematic diagram of the structure of the outer guide rail;

[0028] Figure 6 This is a schematic diagram of the structure after the U-shaped bearing is installed on the outer guide rail;

[0029] Figure 7 It is the axonometric view of the outer rail;

[0030] Figure 8 It is a structural diagram of the slider;

[0031] In the figure, wing surface 1, wing rod 2, fixed shaft 3, first movable shaft 4, connecting rod 5, second movable shaft 6, inner guide rail 7, first boss 7-1, sliding rod 7-2, second boss 7-3, connecting block 7-4, first connecting hole 7-5, outer guide rail 8, threaded hole 8-1, first block groove 8-2-1, first wire groove 8-3-1, second block groove 8-2-2, second wire groove 8-3-2, crossbeam 8-4, second connecting hole 8-5, first connector 8- 6, bearing groove 8-7, shaft groove 8-8, first clamping block 9-1, first spring 10-1, first iron core coil 11-1, second clamping block 9-2, second spring 10-2, second iron core coil 11-2, slider 12, concave groove 12-1, third connecting hole 12-2, third boss 12-3, inner through hole 12-4, second connecting head 12-5, shape memory alloy wire 13, connecting piece 14, U-shaped bearing 15, nut 16, threaded shaft 17. DETAILED DESCRIPTION

[0032] The present invention is further described and illustrated below in conjunction with the accompanying drawings and specific embodiments. The technical features of each embodiment of the present invention can be combined accordingly without conflicting with each other.

[0033] like Figures 1 to 3 As shown, a wing surface unfolding and sweeping mechanism based on a shape memory alloy wire actuator provided by the present invention is provided. The mechanism mainly includes a fixed shaft 3, an inner guide rail 7 and an outer guide rail 8. The fixed shaft 3, the inner guide rail 7 and the outer guide rail 8 are all fixedly connected to other components on the fuselage, and remain relatively stationary during the entire process of the wing surface unfolding and sweeping of the mechanism.

[0034] In the mechanism of the present invention, the inner guide rail 7 is fixed in the hollow inner cavity of the outer guide rail 8, the inner guide rail 7 and the outer guide rail are arranged coaxially and spaced apart, and a slider 12 is provided at the interval between the inner guide rail 7 and the outer guide rail 8. The slider 12 can slide axially along the outer wall of the inner guide rail 7, and is in surface contact or clearance fit with the outer guide rail 8. Four concave grooves 12-1 are evenly arranged on the top of the slider 12, each concave groove 12-1 faces a different direction, and the axes of adjacent concave grooves 12-1 are perpendicular to each other. A third connecting hole 12-2 is opened on each concave groove 12-1, and the third connecting hole 12-2 is rotatably connected to one end of the corresponding connecting rod 5, and the other end of the connecting rod 5 is rotatably connected to the wing rod 2. The wing rod 2 is hinged to the fixed shaft 3 and is fixedly connected to the wing surface 1. A third boss 12-3 is provided at the bottom of the slider 12, and a plurality of second connectors 12-5 protruding downward are evenly arranged at the bottom of the third boss 12-3.

[0035] In this embodiment, the airfoil 1, wing bar 2 and connecting rod 5 are provided with four groups, facing different directions respectively, and connected with the concave groove 12-1 facing the corresponding direction. Specifically, the rotation center of the airfoil 1 is fixed to the wing bar 2, and can rotate around the fixed axis 3 with the wing bar 2. The wing bar 2 extends a distance along the chord length direction of the airfoil 1, and the top of the extended section is a concave groove. The concave groove at the top of the extended section is connected to one end of the connecting rod 5 through the first movable shaft 4 and the bearing. The other end of the connecting rod 5 extends into the concave groove 12-1 at the top of the slider 12, and is rotatably connected to the third connecting hole 12-2 through the second movable shaft 6 and the bearing. The up and down sliding of the slider can drive the connecting rod to move and rotate, and then pull the airfoil to achieve expansion and sweeping through the connecting rod.

[0036] In this embodiment, if Figure 4 As shown, the inner guide rail 7 can adopt a structure in which the main body is a columnar sliding rod 7-2, and a matching structure, such as Figure 8 As shown, the slider 12 is provided with a cylindrical inner through hole 12-4 in the axial direction, and the slider 12 is sleeved on the sliding rod 7-2 of the inner guide rail 7 through the inner through hole 12-4. Specifically, the top of the sliding rod 7-2 is provided with a first boss 7-1, and the bottom is provided with a second boss 7-3. The first boss 7-1 and the second boss 7-3 are both used to limit the axial position of the slider 12 to prevent the slider 12 from detaching from the sliding rod 7-2. Specifically, the second boss 7-3 is used to prevent the wing from continuing to unfold after it is unfolded to the maximum; the first boss 7-1 can be added after the slider 12 is installed on the inner guide rail 7 to prevent the slider 12 from sliding upward and to fix it to the aircraft body.

[0037] In this embodiment, the second boss 7-3 is connected to a connecting block 7-4, and a first connecting hole 7-5 is provided on the connecting block 7-4. A crossbeam 8-4 is provided in the inner cavity of the outer guide rail 8 below the second clamping block groove 8-2-2, and a second connecting hole 8-5 is provided on the crossbeam 8-4. The first connecting hole 7-5 and the second connecting hole 8-5 are connected by a connecting member 14 to realize the fixed connection between the inner guide rail 7 and the outer guide rail 8. The connecting member 14 can be a bolt and nut fixing assembly. The spacing between the first boss 7-1 and the top of the first clamping block groove 8-2-1, and the spacing between the second boss 7-3 and the bottom of the second clamping block groove 8-2-2 are not less than the height of the third boss 12-3. The third boss 12-3, as the clamping part of the first clamping block 9-1 and the second clamping block 9-2, can adopt a square boss structure, which is in contact with the outer guide rail 8 or has a little gap. By adjusting the length of the inner guide rail, the slider stops moving when it slides downward to the second boss 7-3 at the bottom of the inner guide rail. At this time, the slider reaches the lowest point, and the wing surface is just fully unfolded under the action of the connecting rod slider.

[0038] In order to realize the sliding connection between the slider 12 and the sliding rod 7-2, a plurality of rotating balls can be embedded in the inner wall of the inner through hole 12-4, and the sliding connection between the inner wall of the inner through hole 12-4 and the outer wall of the sliding rod 7-2 can be realized by the balls. This structure can ensure a small friction force during the sliding process. Of course, other structures can also be used to realize the sliding connection between the slider 12 and the sliding rod 7-2, such as setting an axial slide rail or opening a sliding groove, which are all commonly used sliding methods in the prior art and will not be described here.

[0039] In the mechanism of the present invention, Figure 5 and Figure 6 As shown, the inner wall of the outer guide rail 8 is provided with a first block groove 8-2-1 located at the top and a second block groove 8-2-2 located at the bottom. The first block groove 8-2-1 and the second block groove 8-2-2 are both opened transversely along the outer guide rail 8, and the axial directions of the two grooves are perpendicular to the axial direction of the outer guide rail 8. The first block groove 8-2-1 and the second block groove 8-2-2 are arranged at intervals, and the interval between the two is not less than the height of the third boss 12-3.

[0040] In an optimal embodiment of the present invention, the spacing between the first boss 7-1 and the top of the first block slot 8-2-1, the spacing between the second boss 7-3 and the bottom of the second block slot 8-2-2, and the spacing between the bottom of the first block slot 8-2-1 and the top of the second block slot 8-2-2 are all equal to the height of the third boss 12-3, so that the mechanism can better engage and limit during execution. Specifically, the distance from the upper surface of the first block to the second boss is the maximum effective travel distance of the slider, and the distance between the lower surface of the first block and the upper surface of the second block is equal to the distance between the lower surface of the second block and the second boss, and is equal to or slightly greater than the thickness of the second boss. The slider can be just stuck between the first block and the second block, and between the second block and the second boss, that is, only two pairs of blocks are used to achieve the blocking and conduction of the slider when the wing surface is unfolded and swept back. The sum of the thickness of the second block and the thickness of the second boss is just equal to the distance the slider needs to slide up when the wing surface changes from the deployed state to the specified swept angle state, so as to ensure that when the slider slides up from between the second pair of sliders and the second boss to between the first block and the second block, the wing surface can just be swept back from the deployed state to the specified angle.

[0041] In the mechanism of the present invention, a first spring 10-1 and a first iron core coil 11-1 are provided in the first block slot 8-2-1, and the first spring 10-1 can provide a lateral elastic force, and the first iron core coil 11-1 can generate a ferromagnetic attraction force after being energized. One end of the first spring 10-1 is fixed to the inner wall of the first block slot 8-2-1, and the other end is fixed with a first block 9-1. The first block 9-1 should be made of ferromagnetic material, and can be attracted and moved after the first iron core coil 11-1 is energized. The first block 9-1 can slide laterally in the first block slot 8-2-1, and can be partially located outside the first block slot 8-2-1 to limit the third boss 12-3 when not subject to force (i.e., the first iron core coil 11-1 is not energized and the first spring 10-1 is at its original length), and can overcome the elastic force of the first spring 10-1 and be completely retracted into the first block slot 8-2-1 when subjected to ferromagnetic attraction force (i.e., the first iron core coil 11-1 is energized).

[0042] In practical applications, the thickness of the third boss 12-3 at the bottom of the slider, the thickness of the first clamping block 9-1 and the thickness of the second clamping block 9-2 can be flexibly designed after determining the effective stroke and the sweep angle.

[0043] In the mechanism of the present invention, a second spring 10-2 and a second iron core coil 11-2 are provided in the second block slot 8-2-2, and the second spring 10-2 can provide a lateral elastic force, and the second iron core coil 11-2 can generate a ferromagnetic attraction force after being energized. One end of the second spring 10-2 is fixed to the inner wall of the second block slot 8-2-2, and the other end is fixed with a second block 9-2. The second block 9-2 should be made of ferromagnetic material, and can be attracted and moved after the second iron core coil 11-2 is energized. The second block 9-2 can slide laterally in the second block slot 8-2-2, and can be partially located outside the second block slot 8-2-2 to limit the third boss 12-3 when not subject to force (i.e., the second iron core coil 11-2 is not energized and the second spring 10-2 is at its original length), and can overcome the elastic force of the second spring 10-2 and be completely retracted into the second block slot 8-2-2 when subjected to ferromagnetic attraction force (i.e., the second iron core coil 11-2 is energized).

[0044] In this embodiment, the outer guide rail 8 is further provided with a first wire groove 8-3-1 and a second wire groove 8-3-2. The first wire groove 8-3-1 is connected to the first block groove 8-2-1, and the first iron core coil 11-1 is connected to the external power supply through the first wire groove 8-3-1. The second wire groove 8-3-2 is connected to the second block groove 8-2-2, and the second iron core coil 11-2 is connected to the external power supply through the second wire groove 8-3-2. A plurality of first block grooves 8-2-1 and second block grooves 8-2-2 can be provided to better limit the slider, for example: two first block grooves 8-2-1 and second block grooves 8-2-2 can be provided symmetrically with the inner guide rail 7 as the axis, the two first block grooves 8-2-1 are located on the same horizontal line, and the two second block grooves 8-2-2 are located on the same horizontal line.

[0045] In the mechanism of the present invention, a plurality of evenly arranged shape memory alloy wires 13 are fixedly wound around the surface of the outer guide rail 8, and one end of the shape memory alloy wire 13 is fixed to the second connector 12-5, and the other end is fixed to the outer guide rail 8. In this embodiment, the number of shape memory alloy wires should be an even number to better pull the slide block to slide symmetrically, and four wires are preferably used. Figure 7 As shown, there are four shape memory alloy wires 13, which are evenly and vertically wound on the outer guide rail 8 along the circumferential direction, and the shape memory alloy wires 13 do not interfere with each other. Specifically, a plurality of threaded holes 8-1 are provided on the surface of the outer guide rail 8, which are mainly distributed in the upper and lower parts. A plurality of bearing grooves 8-7 and shaft grooves 8-8 are provided at the bottom of the outer guide rail 8, and the threaded holes 8-1, the bearing grooves 8-7 and the shaft grooves 8-8 are all fixed with a protruding threaded shaft 17 through a U-shaped bearing 15 and a nut 16. Among them, the U-shaped bearing 15 is used to wind the shape memory alloy wire 13. A raised first connector 8-6 is provided on the inner wall of the outer guide rail 8 located below the second block groove 8-2-2. One end of the shape memory alloy wire 13 is fixed on the first connector 8-6 and serves as a starting point, and then it is wound on the U-shaped bearing 15 in sequence, and the other end is fixed on the second connector 12-5. The U-shaped bearing 15 can play a role in insulation and preventing the wound shape memory alloy wire from falling off. The four shape memory alloy wires 13 are wound in exactly the same manner without interfering with each other, so as to ensure that the four shape memory alloy wires 13 contract normally and the contraction forces generated at the same temperature are completely symmetrical.

[0046] In practical application, the threaded shaft 17 with threads at both ends can be screwed into the threaded hole 8-1, and then the U-shaped bearing 15 is installed on the threaded shaft 17 by interference fit and then tightened by the nut 16. A wire ring is installed between the nut 16 and the bearing 15 and between the nut 16 and the outer surface of the outer guide rail 8. The inner diameter of the wire ring is the same as the diameter of the threaded shaft 17, and the outer diameter is slightly smaller than the outer diameter of the inner ring of the U-shaped bearing 15, so as to ensure that the outer ring of the U-shaped bearing 15 does not generate friction with objects on both sides when rotating.

[0047] In the mechanism of the present invention, the shape memory alloy wire 13 is wound on the U-shaped bearing 15 of the outer guide rail 8, which makes the structure compact on the one hand, and can save extra space when using a longer length to meet a larger stroke; on the other hand, it greatly reduces the friction and material wear during the contraction process. Before the wing surface is unfolded, there is a pre-tension in the shape memory alloy wire 13, which can make the contraction force and contraction amount after heating greater than when there is no pre-tension; during the sweep process, it can be judged whether the shape memory alloy wire needs to be heated according to the size of the aerodynamic load, and the size of its contraction force can be appropriately adjusted to achieve a better buffering effect on the slider.

[0048] In actual application, the first block in the first block slot is initially ejected only under the elastic force of the first spring, and the third boss 12-3 at the bottom of the slider is clamped to prevent the block from sliding downward. After the coils of the two core coils are energized, the coils generate magnetic flux and magnetic force, and the two blocks respectively overcome the spring elastic force and retract into the slot under the action of the magnetic force, so that the slider can slide up and down under the external force. One end of the shape memory alloy wire is fixed to the bottom of the slider, and is wound on the bearing on the outer guide rail, and finally the other end is fixed to the outer guide rail. Initially, the shape memory alloy wire has an initial pre-tension to increase the contraction force and contraction amount during the actuation process. Before unfolding, it is necessary to use a power supply to energize and heat it to a specified temperature, so that the material properties of the shape memory alloy wire change from martensite to austenite, and produce a contraction trend.

[0049] The actuation method of the wing surface deployment and sweep mechanism based on the shape memory alloy wire actuator is as follows:

[0050] When the wing surface 1 is in a closed state (i.e., the wing surface is in a completely closed vertical state), the first clamping block 9-1 partially leaks out of the first clamping block groove 8-2-1 under the elastic force of the first spring 10-1, and the second clamping block 9-2 partially leaks out of the second clamping block groove 8-2-2 under the elastic force of the second spring 10-2, and the upper surface of the first clamping block 9-1 contacts the lower surface of the third boss 12-3 and restricts its downward movement. At this time, the shape memory alloy wire 13 has a pre-tension to ensure that the shape memory alloy wire transforms from twinned martensite to non-twinned martensite.

[0051] In this embodiment, the closed state is as follows Figure 1 As shown, the first block 9-1 and the second block 9-2 are both in a pop-up state, and the lower surface of the bottom boss 12-3 of the slider 12 contacts the upper surface of the first block 9-1. At this time, the shape memory alloy wire 13 has a certain pre-tension to increase the subsequent contraction force and contraction amount.

[0052] When the wing surface 1 is ready to unfold, the power supply is first used to pass current through the shape memory alloy wire 13 to heat it, so that the temperature of the shape memory alloy wire rises rapidly, and the material properties change from martensite to austenite, causing it to shrink as a whole, and generating a downward pulling force on the slider. Then, the temperature of the shape memory alloy wire 13 is measured by the thermistor and the output power of the power supply circuit is adjusted by feedback, and the tension of the shape memory alloy wire 13 is controlled by controlling the temperature at a set value. When the temperature of the shape memory alloy wire 13 is heated to the specified temperature, the shape memory alloy wire 13 has a large contraction force. By passing current through the first iron core coil 11-1 and the second iron core coil 11-2, the coils generate magnetic flux and magnetic force. Under the action of magnetic force, the first clamp 9-1 overcomes the elastic force of the first spring 10-1 and is completely retracted into the first clamp slot 8-2-1, and the second clamp 9-2 overcomes the elastic force of the second spring 10-2 under the action of magnetic force and is completely retracted into the second clamp slot 8-2-2. Under the contraction force of the shape memory alloy wire 13, the slider 12 overcomes the rotational inertia and the smaller aerodynamic load of the wing surface 1, and slides downward along the inner guide rail 7, driving the connecting rod 5 to move and rotate. The wing rod 2 rotates along the fixed axis 3 together with the wing surface 1 under the pulling force of the connecting rod 5. When the slider 12 slides down to the bottom of the inner guide rail 7, the wing surface 1 is unfolded to the maximum position. At this time, the current on the first iron core coil 11-1 and the second iron core coil 11-2 is disconnected, the magnetic force disappears, the first clamping block 9-1 and the second clamping block 9-2 are quickly ejected under the elastic force of the first spring 10-1 and the second spring 10-2 respectively, the second clamping block 9-2 clamps the third boss 12-3 and restricts its upward movement, and the slider is completely locked under the obstruction of the second clamping block and the second boss. The current on the shape memory alloy wire 13 is disconnected, and the unfolding process of the wing surface 1 is completed.

[0053] In this embodiment, the structure of the unfolded airfoil 1 is as follows: Figure 2 shown.

[0054] Before the wing surface 1 starts to sweep back, if the flight speed is low and the aerodynamic load of the air on the wing surface is not large, the shape memory alloy wire can be left unheated, that is, the current passed into the shape memory alloy wire is disconnected, the temperature drops, and the contraction force drops; if the flight speed is high and the aerodynamic load generated by the air on the wing surface is large, the shape memory alloy wire needs to be heated to maintain its contraction force, so that the contraction tension of the shape memory alloy wire plays a certain deceleration and buffering effect during the upward sliding process of the slider. Then, only the second iron core coil 11-2 is passed through the current, so that the second clamping block 9-2 overcomes the elastic force of the second spring 10-2 and is completely retracted into the second clamping block slot 8-2-2. Under the action of the aerodynamic load, the wing surface 1 rotates backward around the fixed axis 3 through the wing rod 2, and drives the connecting rod 5 to move and rotate. The connecting rod 5 generates an upward pulling force on the slider 12, and the slider 12 overcomes the downward contraction force of the shape memory alloy wire 13 and slides upward. When the upper surface of the third boss 12-3 contacts the lower surface of the first clamping block 9-1, the upward movement stops under the limiting action of the first clamping block 9-1, and the wing surface 1 is swept back to a specified angle. At this time, the current on the second core coil 11-2 is disconnected, the magnetic force disappears, and the second clamping block 9-2 pops out under the elastic force of the second spring 10-2 and limits the downward movement of the third boss 12-3. The slider is completely stuck under the action of the first clamping block 9-1 and the second clamping block 9-2, completing the sweeping process of the wing surface 1.

[0055] In this embodiment, the swept structure of the airfoil 1 is as follows: Figure 3 shown.

[0056] The above-described embodiment is only a preferred solution of the present invention, but it is not intended to limit the present invention. A person skilled in the relevant technical field may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, any technical solution obtained by equivalent replacement or equivalent transformation falls within the protection scope of the present invention.

Claims

1. A wing surface deployment and sweep mechanism based on a shape memory alloy wire actuator, characterized in that: It comprises a fixed shaft (3) fixedly connected to the machine body, an inner guide rail (7) and an outer guide rail (8); The inner guide rail (7) is fixed to the hollow inner cavity of the outer guide rail (8); a slider (12) capable of sliding along the axial direction of the inner guide rail (7) is provided between the inner guide rail (7) and the outer guide rail (8); the slider (12) and the outer guide rail (8) are clearance-matched; the top of the slider (12) is provided with concave grooves (12-1) in four directions; the third connecting hole (12-2) of the concave groove (12-1) in each direction is rotatably connected to one end of the connecting rod (5); the other end of the connecting rod (5) is rotatably connected to the wing rod (2); the wing rod (2) is hinged to the fixed shaft (3) and fixedly connected to the wing surface (1); the bottom of the slider (12) is provided with a third boss (12-3); the bottom of the third boss (12-3) is evenly provided with a plurality of protruding second connectors (12-5); The inner wall of the outer guide rail (8) is laterally provided with a first card block groove (8-2-1) located at the top and a second card block groove (8-2-2) located at the bottom. The first card block groove (8-2-1) and the second card block groove (8-2-2) are spaced apart along the axial direction of the outer guide rail (8) and the spacing between the two is not less than the height of the third boss (12-3); a first spring (10-1) capable of providing a lateral elastic force and a first iron core coil (11-1) capable of generating a ferromagnetic attraction force after being energized are provided in the first card block groove (8-2-1); one end of the first spring (10-1) is fixed to the inner wall of the first card block groove (8-2-1), and the other end is fixed with a first card block (9-1) made of ferromagnetic material; the first card block (9-1) can slide laterally in the first card block groove (8-2-1), can be partially located outside the first card block groove (8-2-1) when not subject to force, and can be completely located outside the first card block groove (8-2-1) when subject to ferromagnetic attraction force. retracted into the first clamping block slot (8-2-1); a second spring (10-2) capable of providing lateral elastic force and a second iron core coil (11-2) capable of generating ferromagnetic attraction when energized are provided in the second clamping block slot (8-2-2); one end of the second spring (10-2) is fixed to the inner wall of the second clamping block slot (8-2-2), and the other end is fixed with a second clamping block (9-2) made of ferromagnetic material; the second clamping block (9-2) can slide laterally in the second clamping block slot (8-2-2), can be partially located outside the second clamping block slot (8-2-2) when not subject to force, and can be completely retracted into the second clamping block slot (8-2-2) when subject to ferromagnetic attraction; a plurality of evenly arranged shape memory alloy wires (13) are fixedly wound around the surface of the outer guide rail (8); one end of the shape memory alloy wire (13) is fixed to the second connector (12-5), and the other end is fixed to the outer guide rail (8).

2. The wing surface deployment and sweep mechanism based on shape memory alloy wire actuator according to claim 1, characterized in that: One end of the wing rod (2) is connected to one end of the connecting rod (5) via a first movable shaft (4) and a bearing; the other end of the connecting rod (5) is rotatably connected to the third connecting hole (12-2) via a second movable shaft (6) and a bearing.

3. The wing surface deployment and sweep mechanism based on shape memory alloy wire actuator according to claim 1, characterized in that: The main body of the inner guide rail (7) is a sliding rod (7-2) structure; the top and bottom of the sliding rod (7-2) are respectively provided with a first boss (7-1) and a second boss (7-3) for axially limiting the sliding block (12); the second boss (7-3) is connected to a connecting block (7-4) provided with a first connecting hole (7-5); a crossbeam (8-4) is provided in the inner cavity of the outer guide rail (8) below the second clamping block groove (8-2-2); a second connecting hole (8-5) is provided on the crossbeam (8-4); the first connecting hole (7-5) and the second connecting hole (8-5) are connected to each other via a connecting piece (14) to realize fixed connection between the inner guide rail (7) and the outer guide rail (8); the spacing between the first boss (7-1) and the top of the first clamping block groove (8-2-1), and the spacing between the second boss (7-3) and the bottom of the second clamping block groove (8-2-2) are not less than the height of the third boss (12-3).

4. The wing surface deployment and sweep mechanism based on shape memory alloy wire actuator according to claim 1, characterized in that: The slider (12) is provided with an inner through hole (12-4) in the axial direction and is sleeved on the outside of the inner guide rail (7); the inner through hole (12-4) and the outer wall of the inner guide rail (7) are connected via ball sliding contact.

5. The wing surface deployment and sweep mechanism based on shape memory alloy wire actuator according to claim 1, characterized in that: The first iron core coil (11-1) and the second iron core coil (11-2) are respectively connected to an external power source through a first wire slot (8-3-1) and a second wire slot (8-3-2) opened on the outer guide rail (8).

6. The wing surface deployment and sweep mechanism based on shape memory alloy wire actuator according to claim 1, characterized in that: There are four shape memory alloy wires (13), which are evenly and vertically wound on the outer guide rail (8) along the circumferential direction, and the shape memory alloy wires (13) do not interfere with each other.

7. The wing surface deployment and sweep mechanism based on shape memory alloy wire actuator according to claim 1, characterized in that: The surface of the outer guide rail (8) is provided with a plurality of threaded holes (8-1), the bottom of the outer guide rail (8) is provided with a plurality of bearing grooves (8-7) and shaft grooves (8-8), and the threaded holes (8-1), the bearing grooves (8-7) and the shaft grooves (8-8) are all fixed with an outwardly protruding threaded shaft (17) via a U-shaped bearing (15) and a nut (16); the U-shaped bearing (15) is used for winding the shape memory alloy wire (13).

8. The wing surface deployment and sweep mechanism based on shape memory alloy wire actuator according to claim 1, characterized in that: A protruding first connector (8-6) is provided on the inner wall of the outer guide rail (8) below the second clamping block slot (8-2-2); one end of the shape memory alloy wire (13) is fixed to the first connector (8-6), and the other end is fixed to the second connector (12-5).

9. The wing surface deployment and sweep mechanism based on shape memory alloy wire actuator according to claim 1, characterized in that: Two of the first clamping block slots (8-2-1) and the second clamping block slots (8-2-2) are symmetrically arranged with the inner guide rail (7) as an axis, the two first clamping block slots (8-2-1) are located on the same horizontal line, and the two second clamping block slots (8-2-2) are located on the same horizontal line.

10. An actuation method of a wing surface deployment and sweep mechanism based on a shape memory alloy wire actuator according to any one of claims 1 to 9, characterized in that: The details are as follows: When the wing surface (1) is in a closed state, the first clamping block (9-1) partially leaks out of the first clamping block groove (8-2-1) under the elastic force of the first spring (10-1), and the second clamping block (9-2) partially leaks out of the second clamping block groove (8-2-2) under the elastic force of the second spring (10-2), and the upper surface of the first clamping block (9-1) contacts the lower surface of the third boss (12-3) and restricts its downward movement, and at this time, the shape memory alloy wire (13) has a pre-tension; When the wing surface (1) is ready to unfold, a power supply is first used to pass current through the shape memory alloy wire (13) to heat it, and then the temperature of the shape memory alloy wire (13) is measured through a thermistor and the output power of the power supply circuit is fed back to adjust the temperature, thereby controlling the tension of the shape memory alloy wire (13) at a set value; when the temperature of the shape memory alloy wire (13) is heated to a specified temperature, the shape memory alloy wire (13) has a large contraction force, and current is passed through the first iron core coil (11-1) and the second iron core coil (11-2), so that the first clamping block (9-1) overcomes the elastic force of the first spring (10-1) and is completely retracted into the first clamping block slot (8-2-1), and the second clamping block (9-2) overcomes the elastic force of the second spring (10-2) and is completely retracted into the second clamping block slot (8-2-2 ); the slider (12) overcomes the rotational inertia and smaller aerodynamic load of the wing surface (1) under the contraction force of the shape memory alloy wire (13), and slides downward along the inner guide rail (7), driving the connecting rod (5) to move and rotate, and the wing rod (2) together with the wing surface (1) rotates along the fixed axis (3) under the pulling force of the connecting rod (5); when the slider (12) slides down to the bottom of the inner guide rail (7), the wing surface (1) is unfolded to the maximum position, at which time the current on the first iron core coil (11-1) and the second iron core coil (11-2) is disconnected, the first clamping block (9-1) and the second clamping block (9-2) are ejected under the elastic force of the first spring (10-1) and the second spring (10-2), respectively, the second clamping block (9-2) clamps the third boss (12-3) and restricts its upward movement, the current on the shape memory alloy wire (13) is disconnected, and the wing surface (1) unfolding process is completed; When the wing surface (1) is swept backward, current is only passed through the second iron core coil (11-2), so that the second clamping block (9-2) overcomes the elastic force of the second spring (10-2) and is completely retracted into the second clamping block slot (8-2-2); under the action of the aerodynamic load, the wing surface (1) rotates backward around the fixed axis (3) through the wing rod (2), and drives the connecting rod (5) to move and rotate, the connecting rod (5) generates an upward pulling force on the slider (12), and the slider (12) overcomes the shape memory alloy wire (13 ) downward contraction force and slides upward; when the upper surface of the third boss (12-3) contacts the lower surface of the first clamping block (9-1), it stops moving upward under the limiting action of the first clamping block (9-1), and the wing surface (1) is swept back to a specified angle; at this time, the current on the second iron core coil (11-2) is disconnected, and the second clamping block (9-2) pops out under the elastic force of the second spring (10-2) and limits the downward movement of the third boss (12-3), completing the sweeping process of the wing surface (1).

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