A controllable stretching device based on shape memory alloy

Abstract

The invention discloses a controllable extension device based on shape memory alloy, which relates to the field of aerospace technology. It includes a load seat, a first expandable middle seat, a second expandable middle seat, a third expandable middle seat, an extension base and a plurality of SMA circular arc elastic leaf springs. By inserting the adjustment cylinder into the sleeve groove of the fixed sleeve, the bottom of the adjustment cylinder squeezes the movable plate to drive the compression spring to compress, and after the cylinder groove of the outer wall of the adjustment cylinder completely enters the sleeve groove, the control block is twisted to drive the adjustment bolt to rotate, and the movable collar moves forward to drive the limit umbrella handles set on both sides to rotate and extend out of the cylinder groove under the support of the support rod, and the force squeezing the adjustment cylinder is released. The adjustment cylinder is reset under the elastic action of the compression spring, and the limit umbrella handle extending out of the cylinder groove is clamped at the connection between the sleeve hole and the sleeve groove. Under the elastic action of the compression spring, the clamping connection with the limit umbrella handle ensures the stability of the device installation, and the twisting limit umbrella handle is provided, which facilitates the installation and replacement of the SMA circular arc elastic leaf spring.

Description

Technical Field

[0001] The invention relates to the field of aerospace technology, and in particular to a controllable stretching device based on shape memory alloy. Background Art

[0002] Nowadays, the application of extension devices in the aerospace field is becoming more and more widespread. From the perspective of the driving source, extension devices are mainly divided into two categories: passive and active extension devices. Passive extension devices mostly use springs, torsion springs, rotating joints, bearings, etc. to achieve the deployment of the device. However, such passive extension devices generally have defects such as uncontrollable deployment and low stiffness. Active extension devices mostly use active components such as motors. Such devices have the disadvantages of complex structure, high weight, and low extension-to-retraction ratio. The defects of the above two traditional extension devices greatly limit their application scope in micro-satellite platforms, and further limit the development of platform payloads. Summary of the invention

[0003] The purpose of the present invention is to provide a controllable stretching device based on shape memory alloy, which solves the technical problems raised in the background technology.

[0004] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a controllable extension device based on shape memory alloy, comprising a load seat, a first expandable middle seat, a second expandable middle seat, a third expandable middle seat, an extension base and a plurality of SMA circular arc elastic leaf springs, wherein the outer walls of the load seat, the first expandable middle seat, the second expandable middle seat and the third expandable middle seat are all fixedly provided with adjustment plates, and the inner walls of the first expandable middle seat, the second expandable middle seat, the third expandable middle seat and the extension base are all provided with adjustment devices, wherein the adjustment devices comprise a plurality of elastic springs and connecting rods, wherein the plurality of elastic springs are respectively located on the first expandable middle seat, the second expandable middle seat, the third expandable middle seat and the extension base. The inner walls of the middle seat and the extension base, the connecting rod is located inside the elastic spring, and several of the connecting rods extend to the outside of the first expandable middle seat, the second expandable middle seat, the third expandable middle seat, and the extension base respectively. Several of the connecting rods are located at the first expandable middle seat, the second expandable middle seat, the third expandable middle seat, and the extension base, and one end of the outer wall is fixedly provided with a connecting block. Several of the connecting rods are located at the first expandable middle seat, the second expandable middle seat, the third expandable middle seat, and the extension base, and one end of the outer wall is fixedly provided with a limiting plate. The outer wall of each of the adjustment plates is provided with a placement groove, and the inner wall of each of the placement grooves is penetrated by a movable groove.

[0005] Preferably, the outer walls of the load seat, the first expandable intermediate seat, the second expandable intermediate seat, the third expandable intermediate seat and the extension base are all provided with a plurality of seat holes, the inner wall of each of the seat holes is plugged with a fixing sleeve, the outer wall of one end of each of the fixing sleeves is provided with a sleeve hole, the inner wall of the sleeve hole is provided with a sleeve groove, the diameter of the sleeve hole is smaller than the diameter of the sleeve groove, the inner wall of the sleeve groove is fixedly provided with a compression spring, the outer wall of the other end of the compression spring is fixedly provided with a movable plate, the outer wall of each of the SMA circular arc elastic leaf springs is fixedly provided with a plurality of adjusting cylinders, the outer wall of each of the adjusting cylinders is provided with two cylinder grooves, the inner wall of each of the adjusting cylinders is fixedly provided with a fixing block, The outer walls on both sides of the fixed block are fixedly provided with a first rotating seat, and the outer wall of each of the first rotating seats is rotatably provided with a limited umbrella handle, and the outer walls on the side opposite to the two limited umbrella handles are fixedly provided with a second rotating seat, and the outer walls of the two second rotating seats are rotatably provided with a support rod, an adjusting bolt is inserted into the inner wall of the adjusting cylinder, one end of the adjusting bolt extends to the outside of the adjusting cylinder, the outer wall of one end of the adjusting bolt located inside the adjusting cylinder is rotatably connected to the bottom of the fixed block, and a control block is fixedly provided on the outer wall of one end of the adjusting bolt located outside the adjusting cylinder, and a movable ring is slidably provided on the outside of the adjusting bolt, and two third rotating seats are fixedly provided on the outer wall of the movable ring.

[0006] Preferably, the outer wall of each of the adjustment plates is provided with fixing bolts, and the load seat, the first expandable middle seat, the second expandable middle seat, the third expandable middle seat and the corresponding adjustment plate are fixedly connected by fixing bolts.

[0007] Preferably, a pull ring is fixedly provided on the outer wall of each of the limiting plates.

[0008] Preferably, the inner wall of each of the placement grooves is provided with two limiting holes, and the inner wall of each of the limiting holes is threadedly connected with a limiting bolt.

[0009] Preferably, the limiting plate is slidably connected to the placement slot.

[0010] Preferably, the support rod corresponds to the third rotating seat one by one, and the support rod is rotatably connected to the third rotating seat.

[0011] Preferably, a plurality of the SMA circular arc elastic leaf springs are evenly distributed in parallel around the load seat, and are fixedly connected to the extension base, the first expandable middle seat, the second expandable middle seat, and the third expandable middle seat.

[0012] Preferably, the SMA circular arc elastic leaf spring is made of TiNi binary memory alloy.

[0013] Compared with the related art, the controllable stretching device based on shape memory alloy provided by the present invention has the following beneficial effects:

[0014] 1. The present invention provides a controllable stretching device based on shape memory alloy, by pulling a pull ring to rotate the limit plate 90 degrees, after the pull ring is released, the limit plate is vertically stuck in the placement groove under the elastic action of an elastic spring, and the pull ring is pulled up and down to drag the device up and down to control the spacing of each intermediate seat, and after adjusting to a suitable position, the pull ring is pulled to drive the limit plate to extend from the inside of the placement groove, and the elastic spring is in a compressed and tightened state, and the limit plate is rotated 90 degrees to make the limit plate fall horizontally on the surface of the adjustment plate, and the first expandable intermediate seat, the second expandable intermediate seat, the third expandable intermediate seat, and the stretching base are completely fitted with the adjustment plate under the traction force of the limit plate, and under the elastic action of the elastic spring, the friction between the first expandable intermediate seat, the second expandable intermediate seat, the third expandable intermediate seat, the stretching base and the corresponding adjustment plate is increased to ensure the stability of the device, which is not only convenient for replacing or increasing or decreasing the number of intermediate seats, but also convenient for adjusting the spacing between the intermediate seats.

[0015] 2. The present invention provides a controllable extension device based on shape memory alloy. The adjusting cylinder is inserted into the sleeve groove of the fixed sleeve, and the bottom of the adjusting cylinder squeezes the movable plate to drive the compression spring to compress. When the sleeve groove of the outer wall of the adjusting cylinder completely enters the sleeve groove, the control block is turned to drive the adjusting bolt to rotate, and the movable sleeve ring moves forward to drive the limit umbrella handles set on both sides to rotate and extend out of the sleeve groove under the support of the support rod. The force squeezing the adjusting cylinder is released, and the adjusting cylinder is reset under the elastic action of the compression spring. At the same time, the limit umbrella handle extending out of the sleeve groove is clamped at the connection between the sleeve hole and the sleeve groove. Under the elastic action of the compression spring and the clamping connection with the limit umbrella handle, the stability of the device installation is guaranteed. The twistable limit umbrella handle is convenient for the installation and replacement of the SMA circular arc elastic leaf spring. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0017] Figure 2 It is a schematic diagram of the overall structure of the present invention after folding;

[0018] Figure 3 It is a structural schematic diagram of the load seat of the present invention;

[0019] Figure 4 It is a structural schematic diagram of the adjustment plate of the present invention;

[0020] Figure 5 A top view of the first expandable intermediate seat structure of the present invention;

[0021] Figure 6 It is a sectional view of the structure of the fixing sleeve of the present invention;

[0022] Figure 7 This is a schematic diagram of the structure of the SMA circular arc elastic leaf spring of the present invention;

[0023] Figure 8 It is a partial structural cross-sectional view of the adjusting cylinder of the present invention;

[0024] Fig. 9 For the present invention Figure 4 A magnified view of the structure at center;

[0025] Fig.10 For the present invention Figure 3 A magnified view of the structure at B in the middle;

[0026] Fig.11 For the present invention Figure 5 Enlarged view of the structure at site C.

[0027] In the figure: 1. load seat; 101. seat hole; 2. first expandable middle seat; 3. second expandable middle seat; 4. third expandable middle seat; 5. extension base; 6. SMA circular arc elastic leaf spring; 7. adjustment plate; 701. placement slot; 702. movable slot; 703. fixing bolt; 704. limiting hole; 705. limiting bolt; 8. adjustment device; 801. connecting rod; 802. connecting block; 803. limiting plate; 804. pull ring; 805. elastic spring; 9. fixing sleeve; 10. sleeve hole; 11. sleeve slot; 12. compression spring; 13. movable plate; 14. adjusting cylinder; 1401. cylinder slot; 15. adjusting bolt; 16. control block; 17. fixing block; 18. first rotating seat; 19. limiting umbrella handle; 20. second rotating seat; 21. support rod; 22. movable sleeve ring; 23. third rotating seat. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. Embodiment 1

[0029] See also Figure 1-Figure 11The present invention provides a technical solution: a controllable extension device based on shape memory alloy, comprising a load seat 1, a first expandable middle seat 2, a second expandable middle seat 3, a third expandable middle seat 4, an extension base 5 and a plurality of SMA circular arc elastic leaf springs 6, the outer walls of the load seat 1, the first expandable middle seat 2, the second expandable middle seat 3, and the third expandable middle seat 4 are all fixedly provided with an adjustment plate 7, the inner walls of the first expandable middle seat 2, the second expandable middle seat 3, the third expandable middle seat 4, and the extension base 5 are all provided with an adjustment device 8, and the adjustment device 8 includes a plurality of Elastic spring 805 and connecting rod 801, several elastic springs 805 are respectively located on the inner wall of the first expandable middle seat 2, the second expandable middle seat 3, the third expandable middle seat 4, and the extension base 5, the connecting rod 801 is located inside the elastic spring 805, several connecting rods 801 extend to the outside of the first expandable middle seat 2, the second expandable middle seat 3, the third expandable middle seat 4, and the extension base 5, and several connecting rods 801 are respectively located on the outer wall of one end of the first expandable middle seat 2, the second expandable middle seat 3, the third expandable middle seat 4, and the extension base 5. A connecting block 802 is fixedly provided, and a plurality of connecting rods 801 are respectively located on the first expandable middle seat 2, the second expandable middle seat 3, the third expandable middle seat 4, and the outer wall of one end of the extension base 5 is fixedly provided with a limit plate 803, and the outer wall of each adjustment plate 7 is provided with a placement groove 701, and the inner wall of each placement groove 701 is penetrated with a movable groove 702, and the outer wall of each adjustment plate 7 is provided with a fixing bolt 703, and the load seat 1, the first expandable middle seat 2, the second expandable middle seat 3, the third expandable middle seat 4 and the corresponding adjustment plate 7 are fixed with the fixing bolt 703. 03 fixed connection, the outer wall of each limit plate 803 is fixedly provided with a pull ring 804, the inner wall of each placement groove 701 is provided with two limit holes 704, the inner wall of each limit hole 704 is threadedly connected with a limit bolt 705, the limit plate 803 is slidably connected to the placement groove 701, a plurality of SMA circular arc type elastic leaf springs 6 are evenly distributed in parallel around the load seat 1, and are fixedly connected with the extension base 5, the first expandable intermediate seat 2, the second expandable intermediate seat 3, and the third expandable intermediate seat 4, and the SMA circular arc type elastic leaf spring 6 is made of TiNi binary memory alloy.

[0030] In this embodiment, an adjustment plate 7 is provided on the outer walls of the load seat 1, the first expandable middle seat 2, the second expandable middle seat 3, and the third expandable middle seat 4. A placement groove 701 is provided on the outer wall of the adjustment plate 7. A movable groove 702 is provided through the inner wall of the placement groove 701. The top of the adjustment plate 7 is hollowed out to facilitate the replacement and increase and decrease of the middle seat. An adjustment device 8 is provided on the outer walls of the first expandable middle seat 2, the second expandable middle seat 3, the third expandable middle seat 4, and the extension base 5. The adjustment device 8 corresponds to the adjustment plate 7 one by one. When the distance between the middle seats needs to be adjusted, such as Fig.10 The limit plate 803 is in a rotated state, and the limit plate 803 at the adjusting device 8 is initially horizontally located on the outer surface of the adjusting plate 7. Pull the pull ring 804 to rotate the limit plate 803 by 90 degrees. After releasing the pull ring 804, the limit plate 803 is vertically stuck in the placement groove 701 under the elastic action of the elastic spring 805. Pull the pull rings 804 set at the upper and lower parts of the first expandable middle seat 2, the second expandable middle seat 3, the third expandable middle seat 4, and the extension base 5 up and down respectively to drag the first expandable middle seat 2, the second expandable middle seat 3, the third expandable middle seat 4, and the extension base 5 to move up and down, so as to control the spacing between the middle seats. After adjusting to a suitable position, pull the pull ring 804 to drive the limit plate 803 to extend from the inside of the placement groove 701, and the elastic spring 805 set The elastic spring 805 is in a compressed and tightened state, and the limit plate 803 is rotated 90 degrees so that the limit plate 803 falls horizontally on the surface of the adjustment plate 7. The first expandable middle seat 2, the second expandable middle seat 3, the third expandable middle seat 4, and the extension base 5 are completely fitted with the adjustment plate 7 under the traction force of the limit plate 803. Under the elastic action of the elastic spring 805, the friction between the first expandable middle seat 2, the second expandable middle seat 3, the third expandable middle seat 4, the extension base 5 and the corresponding adjustment plate 7 is increased to ensure the stability of the device. At the same time, a limit hole 704 is opened on the inner wall of the placement groove 701, and a limit bolt 705 is set in the inner thread of the limit hole 704 to prevent the limit plate 803 from being over-adjusted, and it is also convenient to replace or increase or decrease the number of the middle seats. Embodiment 2

[0031] See also Figure 1-Figure 8As shown, on the basis of the first embodiment, the present invention provides a technical solution: the outer walls of the load seat 1, the first expandable intermediate seat 2, the second expandable intermediate seat 3, the third expandable intermediate seat 4, and the extension base 5 are all provided with a plurality of seat holes 101, the inner wall of each seat hole 101 is plugged with a fixing sleeve 9, the outer wall of one end of each fixing sleeve 9 is provided with a sleeve hole 10, the inner wall of the sleeve hole 10 is provided with a sleeve groove 11, the diameter of the sleeve hole 10 is smaller than the diameter of the sleeve groove 11, the inner wall of the sleeve groove 11 is fixedly provided with a compression spring 12, the outer wall of the other end of the compression spring 12 is fixedly provided with a movable plate 13, the outer wall of each SMA circular arc elastic leaf spring 6 is fixedly provided with a plurality of adjusting cylinders 14, the outer wall of each adjusting cylinder 14 is provided with two cylinder grooves 1401, the inner wall of each adjusting cylinder 14 is fixedly provided with a fixing block 17, and both sides of the fixing block 17 A first rotating seat 18 is fixedly provided on the outer wall, and a limited umbrella handle 19 is rotatably provided on the outer wall of each first rotating seat 18. A second rotating seat 20 is fixedly provided on the outer wall on the side opposite to the two limited umbrella handles 19, and a support rod 21 is rotatably provided on the outer wall of the two second rotating seats 20. An adjusting bolt 15 is inserted into the inner wall of the adjusting cylinder 14, and one end of the adjusting bolt 15 extends to the outside of the adjusting cylinder 14. The outer wall of one end of the adjusting bolt 15 located inside the adjusting cylinder 14 is rotatably connected to the bottom of the fixed block 17, and the outer wall of one end of the adjusting bolt 15 located outside the adjusting cylinder 14 is fixedly provided with a control block 16, and a movable ring 22 is slidably provided on the outside of the adjusting bolt 15. Two third rotating seats 23 are fixedly provided on the outer wall of the movable ring 22, and the support rod 21 corresponds to the third rotating seat 23 one by one, and the support rod 21 is rotatably connected to the third rotating seat 23.

[0032] In this embodiment, a plurality of adjustment cylinders 14 are arranged on the outer wall of the SMA circular arc elastic leaf spring 6, and a fixing sleeve 9 is arranged on the outer wall of the load seat 1, the first expandable intermediate seat 2, the second expandable intermediate seat 3, the third expandable intermediate seat 4, and the extension base 5. Figure 2 The device is shown in the folded state. The device is provided with a plurality of parallel SMA circular arc elastic leaf springs 6. The number of SMA circular arc elastic leaf springs 6 can be adjusted according to the actual use. In the unfolded state, the SMA circular arc elastic leaf spring 6 is in a straight line. In the folded state, the SMA circular arc elastic leaf spring 6 is in a segmented Ω compressed state, such as Figure 2As shown, when the SMA circular arc elastic leaf spring 6 is installed on the device, the adjusting cylinder 14 arranged on the outer wall of the SMA circular arc elastic leaf spring 6 is inserted into the sleeve groove 11 of the fixing sleeve 9 on the outer wall of the load seat 1, the first expandable intermediate seat 2, the second expandable intermediate seat 3, the third expandable intermediate seat 4, and the extension base 5. The outer wall of the fixed sleeve 9 is provided with a sleeve hole 10, and the sleeve hole 10 is provided with a sleeve groove 11. The diameter of the sleeve hole 10 is smaller than the sleeve groove 11. The bottom of the adjusting cylinder 14 squeezes the movable plate 13 to drive the compression spring 12 to compress. When the cylinder groove 1401 on the outer wall of the adjusting cylinder 14 completely enters the sleeve groove 11, the control block 16 is turned to drive the adjusting bolt 1 5 rotates, and as the adjusting bolt 15 rotates, the movable collar 22 moves forward. As the movable collar 22 moves forward, the limit umbrella handles 19 arranged on both sides of the movable collar 22 rotate and extend out of the cylinder groove 1401 under the support of the support rod 21, and the force of squeezing the adjusting cylinder 14 is released. The adjusting cylinder 14 is reset under the elastic action of the compression spring 12, and at the same time, the limit umbrella handles 19 extending out of the cylinder groove 1401 are clamped at the connection between the sleeve hole 10 and the sleeve groove 11. Under the elastic action of the compression spring 12 and the clamping connection with the limit umbrella handle 19, the stability of the device installation is ensured. At the same time, the twistable limit umbrella handle 19 is convenient for the installation and replacement of the SMA circular arc elastic leaf spring 6.

[0033] Working principle: The outer walls of the load seat 1, the first expandable middle seat 2, the second expandable middle seat 3, and the third expandable middle seat 4 are all provided with adjustment plates 7, the outer wall of the adjustment plate 7 is provided with a placement groove 701, and the inner wall of the placement groove 701 is provided with a movable groove 702, and the top of the adjustment plate 7 is in a hollow state, which is convenient for the replacement and increase and decrease of the middle seat, and the outer walls of the first expandable middle seat 2, the second expandable middle seat 3, the third expandable middle seat 4, and the extension base 5 are provided with adjustment devices 8, and the adjustment devices 8 correspond to the adjustment plates 7 one by one, and the distance between the middle seats needs to be adjusted. When the limit plate 803 at the adjusting device 8 is initially located horizontally on the outer surface of the adjusting plate 7, the pull ring 804 is pulled to rotate the limit plate 803 90 degrees. After the pull ring 804 is released, the limit plate 803 is vertically stuck in the placement groove 701 under the elastic action of the elastic spring 805. The pull rings 804 arranged at the upper and lower parts of the first expandable middle seat 2, the second expandable middle seat 3, the third expandable middle seat 4, and the extension base 5 are pulled up and down respectively to drag the first expandable middle seat 2, the second expandable middle seat 3, the third expandable middle seat 4, and the extension base 5 to move up and down, so as to control each After the spacing of the middle seats is adjusted to a suitable position, the pull ring 804 is pulled to drive the limiting plate 803 to extend from the inside of the placement groove 701, and the elastic spring 805 is in a compressed and tightened state. The limiting plate 803 is rotated 90 degrees to make the limiting plate 803 fall horizontally on the surface of the adjustment plate 7. The first expandable middle seat 2, the second expandable middle seat 3, the third expandable middle seat 4, and the extension base 5 are completely fitted with the adjustment plate 7 under the traction force of the limiting plate 803. Under the elastic action of the elastic spring 805, the first expandable middle seat 2, the second expandable middle seat 3, the third expandable middle seat 4, and the extension base 5 are increased. The friction between the three expandable intermediate seats 4, the extension base 5 and the corresponding adjustment plate 7 ensures the stability of the device. At the same time, a limit hole 704 is opened on the inner wall of the placement groove 701, and a limit bolt 705 is set in the inner thread of the limit hole 704 to prevent the limit plate 803 from being over-adjusted, and it is also convenient to replace or increase or decrease the number of intermediate seats. A plurality of adjustment cylinders 14 are arranged on the outer wall of the SMA circular arc elastic leaf spring 6, and a fixing sleeve 9 is arranged on the outer wall of the load seat 1, the first expandable intermediate seat 2, the second expandable intermediate seat 3, the third expandable intermediate seat 4, and the extension base 5, wherein Figure 2 The device is shown in the folded state. The device is provided with a plurality of parallel SMA circular arc elastic leaf springs 6. The number of SMA circular arc elastic leaf springs 6 can be adjusted according to the actual use. In the unfolded state, the SMA circular arc elastic leaf spring 6 is in a straight line. In the folded state, the SMA circular arc elastic leaf spring 6 is in a segmented Ω compressed state, such as Figure 2As shown, when the SMA circular arc elastic leaf spring 6 is installed on the device, the adjusting cylinder 14 arranged on the outer wall of the SMA circular arc elastic leaf spring 6 is inserted into the sleeve groove 11 of the fixing sleeve 9 on the outer wall of the load seat 1, the first expandable intermediate seat 2, the second expandable intermediate seat 3, the third expandable intermediate seat 4, and the extension base 5. The outer wall of the fixed sleeve 9 is provided with a sleeve hole 10, and the sleeve hole 10 is provided with a sleeve groove 11. The diameter of the sleeve hole 10 is smaller than the sleeve groove 11. The bottom of the adjusting cylinder 14 squeezes the movable plate 13 to drive the compression spring 12 to compress. When the cylinder groove 1401 on the outer wall of the adjusting cylinder 14 completely enters the sleeve groove 11, the control block 16 is turned to drive the adjusting bolt 1 5 rotates, and as the adjusting bolt 15 rotates, the movable collar 22 moves forward. As the movable collar 22 moves forward, the limit umbrella handles 19 arranged on both sides of the movable collar 22 rotate and extend out of the cylinder groove 1401 under the support of the support rod 21, and the force of squeezing the adjusting cylinder 14 is released. The adjusting cylinder 14 is reset under the elastic action of the compression spring 12, and at the same time, the limit umbrella handles 19 extending out of the cylinder groove 1401 are clamped at the connection between the sleeve hole 10 and the sleeve groove 11. Under the elastic action of the compression spring 12 and the clamping connection with the limit umbrella handle 19, the stability of the device installation is ensured. At the same time, the twistable limit umbrella handle 19 is convenient for the installation and replacement of the SMA circular arc elastic leaf spring 6.

[0034] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions. The sentence "includes an element defined by ... does not exclude the existence of other identical elements in the process, method, article or device including the element".

[0035] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A controllable extension device based on shape memory alloy, comprising a load seat (1), a first expandable intermediate seat (2), a second expandable intermediate seat (3), a third expandable intermediate seat (4), an extension base (5) and a plurality of SMA circular arc elastic leaf springs (6), characterized in that: The outer walls of the load seat (1), the first expandable middle seat (2), the second expandable middle seat (3), and the third expandable middle seat (4) are all fixedly provided with adjustment plates (7); the inner walls of the first expandable middle seat (2), the second expandable middle seat (3), the third expandable middle seat (4), and the extension base (5) are all provided with adjustment devices (8); the adjustment devices (8) include a plurality of elastic springs (805) and connecting rods (801); the plurality of elastic springs (805) are respectively located on the inner walls of the first expandable middle seat (2), the second expandable middle seat (3), the third expandable middle seat (4), and the extension base (5); the connecting rods (801) are located inside the elastic springs (805); the plurality of connecting rods (801) extend to the first expandable middle seat (2), the second expandable middle seat (3), the third expandable middle seat (4), and the extension base (5); The first expandable middle seat (2), the second expandable middle seat (3), the third expandable middle seat (4), and the stretchable base (5) are arranged outside the first expandable middle seat (2), the second expandable middle seat (3), the third expandable middle seat (4), and the stretchable base (5); a plurality of connecting rods (801) are respectively located inside the first expandable middle seat (2), the second expandable middle seat (3), the third expandable middle seat (4), and the stretchable base (5); one end of the outer wall is fixedly provided with a connecting block (802); a plurality of connecting rods (801) are respectively located outside the first expandable middle seat (2), the second expandable middle seat (3), the third expandable middle seat (4), and the stretchable base (5); a limiting plate (803) is fixedly provided on the outer wall of each of the adjusting plates (7); a placement groove (701) is provided on the outer wall of each of the placement grooves (701); and a movable groove (702) is provided through the inner wall of each of the placement grooves (701).

2. The controllable stretching device based on shape memory alloy according to claim 1, characterized in that: The outer walls of the load seat (1), the first expandable intermediate seat (2), the second expandable intermediate seat (3), the third expandable intermediate seat (4), and the extension base (5) are all provided with a plurality of seat holes (101); the inner wall of each seat hole (101) is plugged with a fixing sleeve (9); the outer wall of one end of each fixing sleeve (9) is provided with a sleeve hole (10); the inner wall of the sleeve hole (10) is provided with a sleeve groove (11); the diameter of the sleeve hole (10) is smaller than the diameter of the sleeve groove (11); the inner wall of the sleeve groove (11) is fixedly provided with a compression spring (12); the outer wall of the other end of the compression spring (12) is fixedly provided with a movable plate (13); the outer wall of each SMA circular arc elastic leaf spring (6) is fixedly provided with a plurality of adjustment cylinders (14); the outer wall of each adjustment cylinder (14) is provided with two cylinder grooves (1401); the inner wall of each adjustment cylinder (14) is fixedly provided with a fixing block (17); The outer walls of both sides of the fixed block (17) are fixedly provided with first rotating seats (18), the outer wall of each of the first rotating seats (18) is rotatably provided with a limit umbrella handle (19), the outer walls of the two limit umbrella handles (19) on one side opposite to each other are fixedly provided with a second rotating seat (20), the outer walls of the two second rotating seats (20) are rotatably provided with a support rod (21), the inner wall of the adjusting cylinder (14) is plugged with an adjusting bolt (15), one end of the adjusting bolt (15) extends to the outside of the adjusting cylinder (14), the outer wall of one end of the adjusting bolt (15) located inside the adjusting cylinder (14) is rotatably connected to the bottom of the fixed block (17), the outer wall of one end of the adjusting bolt (15) located outside the adjusting cylinder (14) is fixedly provided with a control block (16), the outer wall of the adjusting bolt (15) is slidably provided with a movable collar (22), and the outer wall of the movable collar (22) is fixedly provided with two third rotating seats (23).

3. The controllable stretching device based on shape memory alloy according to claim 1, characterized in that: The outer wall of each of the adjustment plates (7) is provided with a fixing bolt (703), and the load seat (1), the first expandable middle seat (2), the second expandable middle seat (3), the third expandable middle seat (4) and the corresponding adjustment plate (7) are fixedly connected via the fixing bolt (703).

4. The controllable stretching device based on shape memory alloy according to claim 1, characterized in that: A pull ring (804) is fixedly provided on the outer wall of each of the limiting plates (803).

5. The controllable stretching device based on shape memory alloy according to claim 1, characterized in that: The inner wall of each placement slot (701) is provided with two limiting holes (704), and the inner wall of each limiting hole (704) is threadedly connected with a limiting bolt (705).

6. The controllable stretching device based on shape memory alloy according to claim 1, characterized in that: The limiting plate (803) is slidably connected to the placement groove (701).

7. The controllable stretching device based on shape memory alloy according to claim 2, characterized in that: The support rod (21) corresponds to the third rotating seat (23) in a one-to-one manner, and the support rod (21) is rotatably connected to the third rotating seat (23).

8. The controllable stretching device based on shape memory alloy according to claim 1, characterized in that: A plurality of the SMA circular arc elastic leaf springs (6) are evenly distributed in parallel around the load seat (1), and are fixedly connected to the extension base (5), the first expandable middle seat (2), the second expandable middle seat (3), and the third expandable middle seat (4).

9. The controllable stretching device based on shape memory alloy according to claim 8, characterized in that: The SMA circular arc elastic leaf spring (6) is made of TiNi binary memory alloy.

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