An umbrella-shaped deployment and recovery mechanism based on shape memory alloy and a spacecraft

Abstract

This invention provides an umbrella-shaped deployment and retraction mechanism and spacecraft based on shape memory alloys, relating to the field of aerospace equipment technology. The umbrella-shaped deployment and retraction mechanism based on shape memory alloys includes a first tube, a second tube, a base, a tension lock mesh, radial ribs, an SMA drive spring, a propulsion plate, a slider, and a power supply. The first tube is fitted onto the second tube, and the lower ends of both tubes are connected to the base. The power supply is located inside the base and electrically connected to the SMA drive spring. A window communicating with a gap is provided on the second tube; the propulsion plate is hinged to the window, and the slider is slidably connected to the inner wall of the second tube. Multiple radial ribs are spaced around the first tube and hinged at one end to the base; each radial rib is connected to the slider via a tension lock mesh. Compared to existing technologies, the umbrella-shaped deployment and retraction mechanism based on shape memory alloys of this invention exhibits greater stability in the deployed state, and significantly improves energy conversion efficiency and the lightweight nature of the device.

Description

Technical Field

[0001] This invention relates to the field of aerospace equipment technology, and more specifically, to an umbrella-shaped unfolding and retracting mechanism and a spacecraft based on shape memory alloy. Background Technology

[0002] Spacecraft, also known as space vehicles or celestial vehicles, refer to various types of aircraft that operate in space according to the laws of celestial mechanics, performing specific missions such as exploring, developing, and utilizing space and celestial bodies. Currently, many spacecraft possess deployment and recovery mechanisms, such as exploration, meteorological, and communication satellites, as well as lunar rovers. During launch, the spacecraft's deployment and recovery mechanism is in a folded and stowed state, fixedly placed within the payload bay. After launch and reaching the designated location, the mechanism can be deployed as required by the ground control center or autonomously controlled by the spacecraft, reaching a preset configuration before locking and commencing normal operation.

[0003] Traditional antenna deployment solutions rely primarily on mechanical structure design and material selection to achieve antenna deployment, positioning, and retention. This requires comprehensive consideration of factors such as antenna type, size, weight, performance requirements, and application scenarios. These products typically use a mechanical drive source consisting of a motor and transmission mechanism. While offering advantages such as high stability and reliability, mechanical drive sources usually achieve propulsion by directly converting kinetic energy through mechanical components. Their relatively simple force application limits their adaptability to complex motion conditions. Furthermore, components such as motors and transmission mechanisms often have significant weight and volume, hindering the lightweight and miniaturized design of antennas.

[0004] Therefore, with the continuous development of aerospace technology, the performance requirements for space antennas are becoming increasingly higher, and traditional mechanical antenna structures can no longer meet the needs of modern aerospace missions. Summary of the Invention

[0005] The present invention aims to solve at least one of the above-mentioned technical problems.

[0006] This invention provides an umbrella-shaped unfolding and retracting mechanism based on shape memory alloy, comprising: a first tube, a second tube, a base, a tension lock mesh, radial ribs, an SMA drive spring, a push plate, a slider, and a power supply;

[0007] The first tube is sleeved on the second tube, and there is a gap between the inner wall of the first tube and the outer wall of the second tube. The lower ends of the first tube and the second tube are respectively connected to the base.

[0008] The power supply is located inside the base and is electrically connected to the SMA drive spring, which is used to be heated and generate high-temperature memory deformation.

[0009] The second tube has a window communicating with the gap. The push plate is hinged to the window. One end of the SMA drive spring is connected to the inner wall of the first tube, and the other end is used to pass through the window and connect to the push plate. The slider is slidably connected to the inner wall of the second tube. The SMA drive spring is used to drive the push plate to deflect when deformation occurs. The slider is used to slide along the length direction of the second tube under the extrusion force generated when the push plate deflects.

[0010] Multiple radial ribs are spaced around the first tube and one end is hinged to the base. Each radial rib is connected to the slider via a tension lock mesh. The slider is used to drive the multiple radial ribs to rotate relative to the base and to expand or contract through the multiple tension lock meshes.

[0011] The present invention provides an umbrella-shaped unfolding and retracting mechanism based on shape memory alloy, which, compared with the prior art, has, but is not limited to, the following beneficial effects:

[0012] The umbrella-shaped deployment and retraction mechanism based on shape memory alloy described in this invention uses shape memory alloy (SMA drive spring 6) and a mechanical structure to achieve deployment and retraction. It possesses a certain structural rigidity and stability, and can be deployed and retracted on-orbit, adjusting the deployment diameter, angle, and attitude without requiring replacement of parts or external auxiliary operations. In the deployed state, radial ribs provide tension, so compared to mechanisms relying solely on SMA material or SMPC (Shape Memory Polymer Composites) hinges, this invention significantly increases tension, resulting in greater stability in the deployed state and less susceptibility to external forces. Furthermore, compared to traditional mechanical deployment mechanisms, the use of a lighter SMA drive spring as the drive source significantly improves energy conversion efficiency and the device's lightweight design.

[0013] Optionally, the slider has a U-shaped groove along its side wall toward the center, and the push plate passes through the U-shaped groove and abuts against the inner wall of the U-shaped groove.

[0014] Optionally, a through-hole is provided in the middle section of the radial rib. After being pulled by the tension of the tensioned mesh, the radial ribs rotate and retract relative to the base, and elastically bend at the position of the through-hole until they fold.

[0015] Optionally, the first tube has a first through hole communicating with the gap at the end away from the base, and a second through hole communicating with the gap at the end near the base. The second tube has a third through hole communicating with the gap at the end away from the base. The tension lock net includes a first rope and a second rope. One end of the first rope is connected to the radial rib near the long slot, and the other end passes through the first through hole and the third through hole in sequence and is connected to the slider. One end of the second rope is connected to the radial rib away from the base, and the other end passes through the second through hole and the third through hole in sequence and is connected to the slider.

[0016] Optionally, the tension lock mesh is used to connect to the radial rib via a fixing bolt. The fixing bolt includes a base plate, a locking plate, a buckle, and a fixing rod. The base plate is connected to the radial rib. Two locking plates are hinged side by side to the base plate. Each locking plate is provided with a buckle. The ends of the two locking plates near each other are respectively provided with toothed holes. The tension lock mesh is used to pass through the toothed holes of the two locking plates. Two fixing rods are spaced apart on the base plate. When the two locking plates are rotated relative to the base plate until the two toothed holes clamp the tension lock mesh, the buckles on the two locking plates are respectively engaged with the two fixing rods.

[0017] Optionally, the umbrella-shaped unfolding and retracting mechanism based on shape memory alloy further includes a top seat connected to the end of the first tube and the second tube away from the base.

[0018] Optionally, the top seat has a first annular groove and a second annular groove, the end of the first tube away from the base is embedded in the first annular groove, and the end of the second tube away from the base is embedded in the second annular groove.

[0019] Optionally, the umbrella-shaped unfolding and retracting mechanism based on shape memory alloy also includes a controller. The base has a groove, and both the power supply and the controller are disposed in the groove. The controller is used to control the switching of the power supply.

[0020] Optionally, a distance sensor is provided in the groove. The distance sensor is communicatively connected to the controller to obtain the distance information between the slider and the base, and to feed the distance information back to the controller.

[0021] In addition, the present invention also provides a spacecraft including the umbrella-shaped deployment and retraction mechanism based on shape memory alloy as described above.

[0022] Since the technological improvements and effects achieved by the spacecraft are the same as those of the umbrella-shaped unfolding and retracting mechanism based on shape memory alloy, the technological effects of the spacecraft will not be described in detail. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the umbrella-shaped unfolding and retracting mechanism based on shape memory alloy in the unfolded state according to an embodiment of the present invention.

[0024] Figure 2 This is a schematic diagram of the umbrella-shaped unfolding and retracting mechanism based on shape memory alloy in the retracted state according to an embodiment of the present invention.

[0025] Figure 3 This is a cross-sectional view of an umbrella-shaped unfolding and retracting mechanism based on shape memory alloy according to an embodiment of the present invention;

[0026] Figure 4 for Figure 3 Enlarged view of a portion of point A in the middle;

[0027] Figure 5 for Figure 3 Enlarged view of a section at point B in the middle;

[0028] Figure 6 This is a schematic diagram of the structure of the first tube body according to an embodiment of the present invention;

[0029] Figure 7 This is a schematic diagram of the structure of the second tube body according to an embodiment of the present invention;

[0030] Figure 8 for Figure 7 Enlarged view of a section at point C;

[0031] Figure 9 This is a cross-sectional view of the push plate and slider inside the second tube according to an embodiment of the present invention;

[0032] Figure 10 This is a top view of the slider according to an embodiment of the present invention;

[0033] Figure 11 This is a schematic diagram of the base structure according to an embodiment of the present invention;

[0034] Figure 12 This is a schematic diagram of the top seat structure according to an embodiment of the present invention;

[0035] Figure 13 This is a schematic diagram of the radial ribs in the unfolded state according to an embodiment of the present invention;

[0036] Figure 14 This is a schematic diagram of the radial ribs in a retracted state according to an embodiment of the present invention;

[0037] Figure 15This is a perspective view of the fixing bolt according to an embodiment of the present invention;

[0038] Figure 16 This is a top view of the fixing bolt according to an embodiment of the present invention;

[0039] Figure 17 This is a schematic diagram illustrating the principle of the tensioned cable mesh driving the deformation of the radial ribs in an embodiment of the present invention.

[0040] Explanation of reference numerals in the attached figures:

[0041] First tube 1, first through hole 11, second through hole 12, second tube 2, window 21, third through hole 22, pin 23, base 3, groove 31, tension lock net 4, first rope 41, second rope 42, radial rib 5, long slot hole 51, SMA drive spring 6, push plate 7, slider 8, U-shaped groove 81, fixing bolt 9, base plate 91, locking plate 92, buckle 93, fixing rod 94, toothed hole 95, top seat 10, first annular groove 101, second annular groove 102. Detailed Implementation

[0042] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0043] In the description of this invention, the orientations or positional relationships indicated by terms such as "up," "down," "left," "right," "top," "bottom," "front," "back," "inner," and "outer" are based on the orientations or positional relationships shown in the accompanying drawings and are used only for the convenience of describing this invention. They are not intended to indicate or imply that the device referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the scope of protection of this invention.

[0044] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0045] In the description of this specification, references to terms such as "embodiment," "one embodiment," and "one implementation" indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or implementation is included in at least one embodiment or implementation of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or implementation. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or implementations.

[0046] Furthermore, in the attached diagram, the Z-axis represents the vertical direction, that is, the up and down position, and the positive direction of the Z-axis (that is, the direction the arrow of the Z-axis points) represents up, and the negative direction of the Z-axis (that is, the direction opposite to the positive direction of the Z-axis) represents down.

[0047] It should also be noted that the aforementioned Z-axis designation is only for the purpose of facilitating and simplifying the description of the present invention, and is not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of the present invention.

[0048] like Figures 1 to 11 As shown, the umbrella-shaped unfolding and retracting mechanism based on shape memory alloy according to an embodiment of the present invention includes: a first tube 1, a second tube 2, a base 3, a tension lock net 4, radial ribs 5, an SMA drive spring 6, a pusher plate 7, a slider 8, and a power supply.

[0049] The first tube 1 is sleeved on the second tube 2, and there is a gap between the inner wall of the first tube 1 and the outer wall of the second tube 2. The lower ends of the first tube 1 and the second tube 2 are respectively connected to the base 3.

[0050] The power supply is located inside the base 3 and is electrically connected to the SMA drive spring 6. The SMA drive spring 6 is used to be heated and generate high-temperature memory deformation.

[0051] The second tube 2 has a window 21 communicating with the gap. The push plate 7 is hinged to the window 21. One end of the SMA drive spring 6 is connected to the inner wall of the first tube 1, and the other end is used to pass through the window 21 and connect to the push plate 7. The slider 8 is slidably connected to the inner wall of the second tube 2. The SMA drive spring 6 is used to drive the push plate 7 to deflect when deformation occurs. The slider 8 is used to slide along the length direction of the second tube 2 under the squeezing force generated when the push plate 7 deflects.

[0052] Multiple radial ribs 5 are spaced around the first tube 1 and one end is hinged to the base 3. Each radial rib 5 is connected to the slider 8 through the tension lock mesh 4. The slider 8 is used to drive the multiple radial ribs 5 to rotate relative to the base 3 and to expand or contract through the multiple tension lock mesh 4.

[0053] Specifically, in conjunction with the appendix Figures 7 to 9 As shown, window 21 may include two elongated slots symmetrically formed on the second tube 2, so that the push plate 7 can pass through the two elongated slots to achieve a greater degree of deflection; the upper end of the push plate 7 can be hinged to the upper position of one of the windows 21 by a pin 23, and one end of the SMA drive spring 6 (attached) Figure 4 As shown, it can pass through another window 21 and connect to the lower end of the push plate 7. In this way, the driving arm of the push plate 7 can be longer, so that the push plate 7 can be deflected by a small driving force generated when the SMA drive spring 6 extends and retracts.

[0054] The SMA drive spring 6 is a spring that is compressed at high temperature, then quenched and restored to room temperature. Its initial memory shape is that of a compressed spring, and its high-temperature memory shape is that of a stretched spring. The SMA drive spring 6 is made of shape memory alloys (SMA), such as nickel-titanium (NiTi) shape memory alloy.

[0055] In this embodiment, in conjunction with the appendix Figure 1 To be continued Figure 11 As shown, when this umbrella-shaped unfolding and retracting mechanism based on shape memory alloy switches from the unfolded state to the retracted state, the power is first turned on, and the SMA drive spring 6 begins to heat up. The SMA drive spring 6 gradually transforms into a stretched spring in a high-temperature memory shape, thereby gradually driving the push plate 7 to deflect. During the rotation, the push plate 7 will squeeze the slider 8. The pressure can be decomposed into vertical and horizontal pressures. The vertical pressure (see attached diagram) Figure 1 The pressure (in the Z-axis direction) causes the slider 8 to move downwards. Simultaneously, the tension lock mesh 4 fixed to the upper end of the slider 8 moves downwards with the slider 8, causing the traction radial ribs 5 to rotate relative to the base 3 towards the first tube 1. When the SMA drive spring 6 extends to its maximum stroke, the radial ribs 5 are approximately parallel to and close to the first tube 1, in a retracted state. At this time, the power supply remains on, keeping the SMA drive spring 6 extended. During this process, the support force transmitted to the slider 8 through the push plate 7 is always greater than the restoring force generated by the radial ribs 5 restoring the tension lock mesh 4 connected to the upper end of the slider 8 to its extended state, thus fixing the slider 8 in its current position. The entire mechanism is in a stable retracted state (see appendix). Figure 2(As shown); When this umbrella-shaped unfolding mechanism based on shape memory alloy switches from the folded state to the unfolded state, the power is first turned off, and the heating of the SMA drive spring 6 is stopped. The SMA drive spring 6 gradually becomes a compression spring in its initial memory shape, thereby driving the push plate 7 to gradually deflect in the opposite direction to reduce and eventually release the support force on the slider 8. At this time, the radial rib 5 can be driven to return to the unfolded state by the elastic restoring force of the elastic element provided between the radial rib 5 and the base 3, or by the restoring force generated by the bending deformation of the radial rib 5 itself (for example, the restoring force generated by the bending deformation of the radial rib 5 at the long slot 51 described later). At this time, the elastic restoring force will be transmitted to the slider 8 along the tension lock net 4, thereby gradually moving the slider 8 upward. In this process, the tension force of the radial rib 5 on the tension lock net 4 is greater than the support force provided to the slider 8 by the push plate 7 throughout the unfolding process. Therefore, the slider 8 can move upward slowly. In this process, the tension force provided by the radial rib 5 continuously decreases. After being fully unfolded, the slider 8 is stably maintained in the current state, and the overall mechanism is in a stable unfolded state (see appendix). Figure 1 (As shown). The umbrella-shaped deployment and retraction mechanism based on shape memory alloy of this invention, compared to existing technologies, utilizes shape memory alloy (SMA drive spring 6) and a mechanical structure to achieve deployment and retraction, possessing a certain structural rigidity and stability. Furthermore, it allows for on-orbit deployment and retraction operations, adjusting the deployment diameter, angle, and attitude without requiring parts replacement or external auxiliary operations. In the deployed state, the tension is provided by elastic force, thus significantly increasing the tension compared to mechanisms relying solely on SMA material or SMPC (Shape Memory Polymer Composites) hinges, resulting in greater stability in the deployed state and less susceptibility to external forces. Moreover, compared to traditional mechanical deployment mechanisms, the use of a lighter SMA drive spring as the drive source significantly improves energy conversion efficiency and the device's lightweight design.

[0056] Optionally, the slider 8 has a U-shaped groove 81 along its side wall toward the center, and the push plate 7 passes through the U-shaped groove 81 and abuts against the inner wall of the U-shaped groove 81.

[0057] In this embodiment, in conjunction with the appendix Figure 5 and attached Figure 10 As shown, the slider 8 is a cylindrical structure with a notch, which is a U-shaped groove 81 opened along the side wall of the slider 8 towards the center. Figure 9 As shown, the push plate 7 can pass through the U-shaped groove 81 and abut against the inner wall of the U-shaped groove 81. The U-shaped groove 81 provides limiting and rotational guidance for the push plate 7. When this umbrella-shaped unfolding and retracting mechanism based on shape memory alloy switches from the unfolded state to the retracted state, the SMA drive spring 6 drives the push plate 7 to deflect, and the push plate 7 will squeeze the slider 8 during the rotation, causing the slider 8 to move downwards (see attached diagram). Figure 1 (Move in the opposite direction of the Z-axis) Conversely, when the umbrella-shaped unfolding mechanism based on shape memory alloy switches from the folded state to the unfolded state, the SMA drive spring 6 drives the push plate 7 to deflect in the opposite direction, and the radial rib 5 provides tension force due to its own bending deformation recovery, which is transmitted to the slider 8 along the tension lock net 4, thereby gradually moving the slider 8 upward.

[0058] Optionally, a through-hole 51 is provided in the middle section of the radial rib 5. After being pulled by the tension of the tensioned net 4, the radial ribs 5 rotate and retract relative to the base 3, and elastically bend at the position of the through-hole 51 until they fold.

[0059] In this embodiment, in conjunction with the appendix Figure 13 and attached Figure 14 As shown, the radial rib 5 can be made of carbon fiber material, and the radial rib 5 has the characteristic of restoring its original shape after deformation. A through-hole 51 is provided in the middle section of the radial rib 5. When the radial rib 5 is subjected to the tension of the tensioned mesh 4, it can not only retract relative to the first tube 1, but also elastically bend at the position of the through-hole 51 to achieve folding (see attached diagram). Figure 2 and attached Figure 14 As shown in the figure, the length of the radial rib 5 after being folded can be further reduced. Furthermore, the radial rib 5 is in an elastic deformation state when folded. Therefore, when the device switches from the folded state to the unfolded state, the elastic restoring force of the radial rib itself can provide the tension force in the unfolded state. Thus, compared to mechanisms relying solely on SMA material or SMPC (Shape Memory Polymer Composites) hinges, the tension force of this invention is significantly increased, the stability of the unfolded state is greater, and it is less susceptible to changes from external forces.

[0060] Optionally, the first tube 1 has a first through hole 11 communicating with the gap at the end away from the base 3, and a second through hole 12 communicating with the gap at the end near the base 3. The second tube 2 has a third through hole 22 communicating with the gap at the end away from the base 3. The tension lock net 4 includes a first rope 41 and a second rope 42. One end of the first rope 41 is connected to the radial rib 5 near the long slot 51, and the other end passes through the first through hole 11 and the third through hole 22 in sequence and is connected to the slider 8. One end of the second rope 42 is connected to the radial rib 5 away from the base 3, and the other end passes through the second through hole 12 and the third through hole 22 in sequence and is connected to the slider 8.

[0061] In this embodiment, in conjunction with the appendix Figure 6 and attached Figure 7As shown, the upper end of the first pipe body 1 (attached Figure 6 Multiple first through holes 11 are opened in the positive Z-axis direction, multiple second through holes 12 are opened at the lower end, and multiple third through holes 22 are opened at the upper end of the second tube body 2, in conjunction with the attached... Figure 17 As shown, one end of the first rope 41 is connected to the radial rib 5 near the elongated slot 51, and the other end passes through the first through hole 11 and the third through hole 22 in sequence and is connected to the upper end of the slider 8. One end of the second rope 42 is connected to the end of the radial rib 5 away from the base 3, and the other end passes through the second through hole 12 and the third through hole 22 in sequence and is connected to the slider 8. That is, the second rope 42 first passes through the second through hole 12, then extends upward along the gap between the first tube 1 and the second tube 2, finally passes through the second through hole 12 and extends into the interior of the second tube 2, and finally connects to the upper end of the slider 8. Figure 17 As shown, when slider 8 moves downward, the first rope 41 and the second rope 42 will move according to the attached... Figure 17 Bend in the direction indicated by the middle arrow until it becomes an attachment. Figure 2 Or attached Figure 14 The state shown.

[0062] Optionally, the tension lock net 4 is used to connect to the radial rib 5 via a fixing bolt 9. The fixing bolt 9 includes a base plate 91, a locking plate 92, a buckle 93, and a fixing rod 94. The base plate 91 is connected to the radial rib 5. Two locking plates 92 are hinged side by side to the base plate 91. Each locking plate 92 is provided with a buckle 93. The ends of the two locking plates 92 close to each other are respectively provided with toothed holes 95. The tension lock net 4 is used to pass between the toothed holes 95 of the two locking plates 92. Two fixing rods 94 are spaced apart on the base plate 91. When the two locking plates 92 are rotated relative to the base plate 91 until the two toothed holes 95 clamp the tension lock net 4, the buckles 93 on the two locking plates 92 are respectively engaged with the two fixing rods 94.

[0063] In this embodiment, in conjunction with the appendix Figure 13 As shown, the tensioned cable net 4 (first rope 41 and second rope 42) can be connected to the radial ribs 5 via fixing bolts 9, combined with the attached... Figure 15 and attached Figure 16As shown, the fixing bolt 9 includes a base plate 91, a locking plate 92, a buckle 93, and a fixing rod 94. When not locked, the two locking plates 92 can rotate flexibly relative to the base plate 91. When locking is required, the tension lock net 4 is passed through the toothed holes 95 of the two locking plates 92. By pulling the tension lock net 4, the locking plates 92 are rotated. When the locking plates 92 are rotated to the horizontal position, the buckle 93 above the locking plates 92 engages with the fixing rod 94. At this time, the rotation of the locking plates 92 is restricted by the buckle 93, and the two locking plates 92 remain parallel. The teeth of the toothed holes 95 of the two locking plates 92 are inserted into the tension lock net 4 to clamp the tension lock net 4. At this time, the fixing bolt 9 and the tension lock net 4 are locked. The fixing bolt 9 is fixed to the radial rib 5 by screws or rivets, thus fixing the tension lock net 4 to the radial rib 5. The fixing bolt 9 adopts a unique animal trap design, which makes it highly reliable and can be unlocked for easy disassembly and maintenance and replacement of the tension lock net 4.

[0064] Optionally, the umbrella-shaped unfolding and retracting mechanism based on shape memory alloy further includes a top seat 10, which is connected to the end of the first tube 1 and the second tube 2 away from the base 3.

[0065] In this embodiment, in conjunction with the appendix Figures 1 to 3 As shown, at the upper ends of the first tube 1 and the second tube 2 (attached) Figure 1 Or attached Figure 3 A top seat 10 is connected to the Z-axis (positive direction). The top seat 10 is similar to an end cap and serves to protect the first tube 1 and the second tube 2.

[0066] Optionally, the top seat 10 is provided with a first annular groove 101 and a second annular groove 102, the end of the first tube 1 away from the base 3 is embedded in the first annular groove 101, and the end of the second tube 2 away from the base 3 is embedded in the second annular groove 102.

[0067] In this embodiment, in conjunction with the appendix Figure 12 As shown, the top seat 10 has a first annular groove 101 and a second annular groove 102, and the upper end of the first tube 1 (attached) Figure 1 Or attached Figure 3 The first tube 1 and the second tube 2 (in the positive Z-axis direction) can be embedded in the first annular groove 101, and the upper end of the second tube 2 can be embedded in the second annular groove 102, so that the first tube 1 and the second tube 2 can remain coaxial.

[0068] Optionally, the umbrella-shaped unfolding and retracting mechanism based on shape memory alloy also includes a controller. The base 3 has a groove 31, and both the power supply and the controller are disposed in the groove 31. The controller is used to control the switching of the power supply.

[0069] In this embodiment, in conjunction with the appendix Figure 11 As shown, the outer periphery of the base 3 is provided with multiple pins for hinged connection with the radial ribs 5, and a groove 31 is provided in the middle position. The power supply and controller are both located in the groove 31. The power supply and controller are directly connected and the controller controls the power supply switch. Based on controlling the power supply status, the mechanism realizes the repeated deployment and retraction task in the operating environment, i.e., the spacecraft during operation, by utilizing the shape memory alloy (SMA drive spring 6) which changes shape due to temperature.

[0070] In other embodiments, the controller can be equipped with an intelligent control computer and a voltage output control device. Measurement data is fed back to the intelligent control computer, which analyzes the data to calculate the extension and retraction status of the mechanism and adjusts the power supply voltage to the SMA drive spring 6. This finely adjusts the return shape of the SMA drive spring 6, ensuring stability during the extension or retraction process. Simultaneously, the intelligent control computer analyzes the data to determine the real-time progress of the extension or retraction process.

[0071] Optionally, a distance sensor is provided in the groove 31. The distance sensor is communicatively connected to the controller to obtain the distance information between the slider 8 and the base 3, and to feed the distance information back to the controller.

[0072] In this embodiment, the groove 31 is connected to the interior of the second tube 2. The distance sensor in the groove 31 can obtain the distance information between the slider 8 and the base 3 and feed the distance information back to the controller. The deformation characteristics of the SMA drive spring 6 can be determined by the distance change, thereby calculating the unfolding and retraction of the mechanism, thus serving as a feedback device for unfolding and retraction.

[0073] In addition, the present invention also provides a spacecraft including the umbrella-shaped deployment and retraction mechanism based on shape memory alloy as described above.

[0074] Since the technological improvements and effects achieved by the spacecraft are the same as those of the umbrella-shaped unfolding and retracting mechanism based on shape memory alloy, the technological effects of the spacecraft will not be described in detail.

[0075] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature.

[0076] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. An umbrella-shaped unfolding and retracting mechanism based on shape memory alloy, characterized in that, include: First tube (1), second tube (2), base (3), tension lock net (4), radial rib (5), SMA drive spring (6), push plate (7), slider (8) and power supply; The first tube (1) is sleeved on the second tube (2), and there is a gap between the inner wall of the first tube (1) and the outer wall of the second tube (2). The lower ends of the first tube (1) and the second tube (2) are respectively connected to the base (3). The power supply is located inside the base (3) and is electrically connected to the SMA drive spring (6). The SMA drive spring (6) is used to be heated and generate high-temperature memory deformation. The second tube (2) has a window (21) communicating with the gap. The push plate (7) is hinged to the window (21). One end of the SMA drive spring (6) is connected to the inner wall of the first tube (1), and the other end is used to pass through the window (21) and connect with the push plate (7). The slider (8) is slidably connected to the inner wall of the second tube (2). The SMA drive spring (6) is used to drive the push plate (7) to deflect when deformation occurs. The slider (8) is used to slide along the length direction of the second tube (2) under the squeezing force generated when the push plate (7) deflects. Multiple radial ribs (5) are spaced around the first tube (1) and one end is hinged to the base (3). Each radial rib (5) is connected to the slider (8) through the tension lock net (4). The slider (8) is used to drive the multiple radial ribs (5) to rotate relative to the base (3) and to expand or contract through the multiple tension lock nets (4).

2. The umbrella-shaped unfolding and retracting mechanism based on shape memory alloy according to claim 1, characterized in that, The slider (8) has a U-shaped groove (81) along its side wall toward the center position, and the push plate (7) passes through the U-shaped groove (81) and abuts against the inner wall of the U-shaped groove (81).

3. The umbrella-shaped unfolding and retracting mechanism based on shape memory alloy according to claim 1, characterized in that, The radial ribs (5) have a through slot (51) in the middle section. When the radial ribs (5) are subjected to the tension of the tensioned net (4), they rotate and retract relative to the base (3), and elastically bend at the slot (51) until they fold.

4. The umbrella-shaped unfolding and retracting mechanism based on shape memory alloy according to claim 3, characterized in that, The first tube (1) has a first through hole (11) communicating with the gap at one end away from the base (3), and a second through hole (12) communicating with the gap at one end near the base (3). The second tube (2) has a third through hole (22) communicating with the gap at one end away from the base (3). The tension lock net (4) includes a first rope (41) and a second rope (42). One end of the first rope (41) is connected to the radial rib (5) near the long slot (51), and the other end passes through the first through hole (11) and the third through hole (22) in sequence and is connected to the slider (8). One end of the second rope (42) is connected to the radial rib (5) away from the base (3), and the other end passes through the second through hole (12) and the third through hole (22) in sequence and is connected to the slider (8).

5. The umbrella-shaped unfolding and retracting mechanism based on shape memory alloy according to claim 1, characterized in that, The tensioned cable mesh (4) is used to connect to the radial rib (5) via fixing bolts (9). The fixing bolts (9) include a base plate (91), locking plates (92), buckles (93), and fixing rods (94). The base plate (91) is connected to the radial rib (5). Two locking plates (92) are hinged side by side to the base plate (91). Each locking plate (92) is provided with a buckle (93). The ends of the two locking plates (92) that are close to each other are... The tension lock net (4) is provided with toothed holes (95) for passing through the toothed holes (95) of the two locking plates (92); the two fixing rods (94) are spaced apart on the base plate (91). When the two locking plates (92) are rotated relative to the base plate (91) to clamp the tension lock net (4) with the two toothed holes (95), the buckles (93) on the two locking plates (92) are respectively engaged with the two fixing rods (94).

6. The umbrella-shaped unfolding and retracting mechanism based on shape memory alloy according to claim 1, characterized in that, It also includes a top seat (10), which is connected to the end of the first tube (1) and the second tube (2) away from the base (3).

7. The umbrella-shaped unfolding and retracting mechanism based on shape memory alloy according to claim 6, characterized in that, The top seat (10) is provided with a first annular groove (101) and a second annular groove (102). The end of the first tube (1) away from the base (3) is embedded in the first annular groove (101), and the end of the second tube (2) away from the base (3) is embedded in the second annular groove (102).

8. The umbrella-shaped unfolding and retracting mechanism based on shape memory alloy according to claim 1, characterized in that, It also includes a controller. The base (3) has a groove (31) and the power supply and the controller are both located in the groove (31). The controller is used to control the switching of the power supply.

9. The umbrella-shaped unfolding and retracting mechanism based on shape memory alloy according to claim 8, characterized in that, A distance sensor is provided in the groove (31). The distance sensor is connected to the controller and is used to obtain the distance information between the slider (8) and the base (3) and to feed the distance information back to the controller.

10. A spacecraft, characterized in that, Including the umbrella-shaped unfolding and retracting mechanism based on shape memory alloy as described in any one of claims 1 to 9.

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