Two-way shape memory alloy actuator for active regulation and control of antenna profile of cable net reflecting surface

Abstract

The invention discloses a two-way shape memory alloy actuator for actively regulating and controlling the antenna profile of a cable net reflecting surface, which comprises a cylindrical shell, an end cover I and an end cover II are respectively arranged at the two ends of the cylindrical shell, a shape memory alloy spring is arranged in the cylindrical shell, a sliding block is also arranged below the shape memory alloy spring in the cylindrical shell, and the sliding block is connected with the cylindrical shell. The two ends of the shape memory alloy spring are connected to the lower surface of the end cover II and the upper surface of the sliding block respectively and powered on, moving grooves are symmetrically formed in the inner side wall of the cylindrical shell and parallel to the axis of the cylindrical shell, the two ends, corresponding to the moving grooves, of the sliding block are slidably connected in the moving grooves, and the lower-section vertical cable penetrates through the end cover I and is connected with the bottom of the sliding block. And the upper-section vertical cable is connected with the top of the end cover II. According to the invention, the shape memory alloy spring is adopted, so that the cable force of the cable net reflector antenna can be regulated in real time, and the problem that in the prior art, when a tension structure system composed of a cable net frame is thermally deformed, the shape precision is deteriorated is solved.

Description

Technical Field

[0001] The invention belongs to the technical field of satellite-borne cable net reflector antennas, and relates to a two-way shape memory alloy actuator for active control of the shape of a cable net reflector antenna. Background Art

[0002] The space-borne cable net reflector antenna based on the tension structure system has the advantages of small size, large diameter and light weight, and has been widely studied and applied. The shape accuracy of its reflector is the decisive factor for the electrical performance of the antenna. If the shape accuracy is reduced, it will seriously affect the antenna gain and cause the communication quality to deteriorate. The tension structure system composed of cable net and frame has obvious thermal deformation. When the cable net antenna is in the space environment with alternating high and low temperatures, the shape accuracy will deteriorate, causing the antenna to fail to work properly.

[0003] Post content

[0004] The purpose of the present invention is to provide a two-way shape memory alloy actuator for active control of the shape of a cable net reflector antenna. The use of a shape memory alloy spring can achieve real-time control of the cable force of the cable net reflector antenna, solving the problem in the prior art that the shape accuracy of the tensioned structure system composed of a cable net and a frame will deteriorate when thermally deformed.

[0005] The technical solution adopted by the present invention is a two-way shape memory alloy actuator for active control of the shape of a cable net reflector antenna, which is connected to an upper vertical cable and a lower vertical cable at corresponding positions of the cable net reflector antenna, and comprises a cylindrical shell, and end caps I and II are respectively arranged at both ends of the cylindrical shell, a shape memory alloy spring is arranged in the cylindrical shell, and a slider is also arranged in the cylindrical shell below the shape memory alloy spring, and the two ends of the shape memory alloy spring are respectively connected to the lower surface of the end cap II and the upper surface of the slider and are energized, and the inner side wall of the cylindrical shell is symmetrically provided with moving grooves, and the moving grooves are parallel to the axis of the cylindrical shell, and the two ends of the slider corresponding to the moving grooves are slidably connected in the moving grooves, the lower vertical cable passes through the end cap I and is connected to the bottom of the slider, and the upper vertical cable is connected to the top of the end cap II.

[0006] The present invention is also characterized in that:

[0007] A hole I is provided on the end cover I, and the lower vertical cable passes through the hole I and is connected to the bottom of the slider; an annular handle II is provided on the top of the end cover II, and the upper vertical cable is connected to the annular handle II.

[0008] A ring handle I is arranged on a side of the slider away from the shape memory alloy spring, and a lower vertical cable passes through the hole I and is connected to the ring handle I.

[0009] Fixed grooves are also provided at both ends of each movable groove in the cylindrical shell, and the fixed grooves are connected with the corresponding movable grooves. Fixed blocks I and II are provided at the positions of the two movable grooves on the side walls of the upper end of the end cover I and the lower end of the end cover II. The upper end of the end cover I and the lower end of the end cover II are inserted into the cylindrical shell through the movable grooves, and the fixed blocks I and II are rotated at a certain angle so that the fixed blocks I and the fixed blocks II are inserted into the fixed grooves on the corresponding side to fix the end covers I and II.

[0010] The two ends of the slider corresponding to the two moving grooves are inserted into the moving grooves, so that the slider can move along the axis of the cylindrical shell.

[0011] A hole III is provided in the center of the slider, and an electrode sheet I is provided on the side of the slider close to the shape memory alloy spring. The wire passes through the end cap I.

[0012] The center hole I and hole III are connected to the electrode sheet I for power supply; an electrode sheet II is arranged at the bottom of the end cover II, and the wire is connected to the electrode sheet II through the hole II for power supply, and the two ends of the shape memory alloy spring are respectively connected to the electrode sheet I and the electrode sheet II.

[0013] The electrode sheet I and the electrode sheet II are completely identical in shape, and claws are provided on the connection surfaces with the shape memory alloy springs. The spring wires at both ends of the shape memory alloy springs are inserted into the corresponding claws for fixation.

[0014] The shape memory alloy spring is a nickel-titanium alloy spring with a two-way shape memory effect. When the power is turned on and the temperature rises to or above the austenite phase transformation starting temperature, the spring begins to stretch and pushes the slider to move toward end cover I. When the power is turned off and the temperature drops to or below the martensite phase transformation starting temperature, the spring shortens and pulls the slider to move toward end cover II. When the shape memory alloy spring is fully stretched, its length fills the entire inner cavity of the cylindrical shell.

[0015] The beneficial effects of the present invention are:

[0016] (1) The present invention heats the shape memory alloy spring by energizing it. This method has high control accuracy, high heating efficiency, and a simple structure. It is an ideal control scheme for the shape memory alloy actuator and has the advantage of enabling the shape memory alloy spring to stably output linear displacement.

[0017] (2) The driving element used in the present invention is a nickel-titanium alloy spring with a two-way memory effect. Compared with shape memory alloy wire, the shape memory alloy spring has the characteristics of large driving force and wide deformation range. Based on this, the cable force of the cable net reflector antenna can be adjusted in a large range, thereby providing reliable hardware conditions for antenna surface accuracy compensation.

[0018] (3) The shape memory alloy spring with two-way memory effect of the present invention realizes the function of bidirectional output displacement, consumes less energy and has a lighter weight than the method of using multiple one-way shape memory alloy springs to achieve driving, and can output the required displacement any number of times, meeting the demand for real-time active control of the cable net reflector antenna on track. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the state of the two-way shape memory alloy actuator used for active control of the shape of the cable net reflector antenna of the present invention being connected to the cable net reflector antenna;

[0020] Figure 2 It is a schematic diagram of the assembly of a two-way shape memory alloy actuator for active control of the shape of a cable net reflector antenna according to the present invention;

[0021] Figure 3 It is a schematic diagram of the parts structure of the two-way shape memory alloy actuator used for active control of the shape of the cable net reflector antenna of the present invention;

[0022] Figure 4 It is a structural schematic diagram of a cylindrical housing in a two-way shape memory alloy actuator for active control of the shape of a cable net reflector antenna according to the present invention;

[0023] Figure 5 It is a structural schematic diagram of a slider in a two-way shape memory alloy actuator for active control of the shape of a cable net reflector antenna according to the present invention;

[0024] Figure 6 It is a structural schematic diagram of the end cover I in the two-way shape memory alloy actuator for active control of the shape of the cable net reflector antenna of the present invention;

[0025] Figure 7 It is a structural schematic diagram of the end cover II in the two-way shape memory alloy actuator for active control of the shape of the cable net reflector antenna of the present invention;

[0026] Figure 8 It is a structural schematic diagram of electrode sheets I and II in a two-way shape memory alloy actuator for active control of the shape of a cable net reflector antenna according to the present invention;

[0027] Fig. 9 It is a structural schematic diagram of a shape memory alloy spring in a two-way shape memory alloy actuator for active control of the shape of a cable net reflector antenna according to the present invention.

[0028] In the figure: 1. cylindrical housing, 2. shape memory alloy spring, 3. slider, 4. end cover I, 5. end cover II, 6. electrode sheet I, 7. electrode sheet II, 8. claw;

[0029] 21. Mobile slot, 22. Fixed slot;

[0030] 31. Ring handle I, 32. Hole III;

[0031] 41. hole I, 42. fixing block I;

[0032] 51. Ring handle II, 52. Hole II, 53. Fixing block II. DETAILED DESCRIPTION

[0033] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0034] Example 1

[0035] The present invention is a two-way shape memory alloy actuator for actively controlling the shape of a cable net reflector antenna. Figure 1 As shown, the upper vertical cable and the lower vertical cable corresponding to the position of the cable net reflector antenna are connected, such as Figure 2-3 As shown, it includes a cylindrical shell 1, and end caps I4 and II5 are respectively provided at both ends of the cylindrical shell 1. A shape memory alloy spring 2 is provided in the cylindrical shell 1. A slider 3 is also provided below the shape memory alloy spring 2 in the cylindrical shell 1. Both ends of the shape memory alloy spring 2 are respectively connected to the lower surface of the end cap II5 and the upper surface of the slider 3 and are energized. Figure 4 As shown, the inner wall of the cylindrical shell 1 is symmetrically provided with a moving groove 21, and the moving groove 21 is parallel to the axis of the cylindrical shell 1. The two ends of the slider 3 corresponding to the moving groove 21 are slidably connected in the moving groove 21, the lower vertical cable passes through the end cover I4 and is connected to the bottom of the slider 3, and the upper vertical cable is connected to the top of the end cover II5.

[0036] The working principle of embodiment 1 of the present invention is:

[0037] The shape memory alloy spring 2 is a nickel-titanium alloy spring with a two-way shape memory effect. When the shape memory alloy spring 2 is energized and the temperature is raised to or above the austenite transformation start temperature, the spring begins to stretch and pushes the slider 3 to move toward the end cover I4. When the power is turned off and the temperature drops to or below the martensite transformation start temperature, the spring shortens and pulls the slider 3 to move toward the end cover II5. When the shape memory alloy spring 2 is fully extended, its length occupies the entire inner cavity of the cylindrical shell. When it is not fully expanded, it is only stretched to a certain length by the tension of the vertical cable of the cable net antenna.

[0038] Example 2

[0039] On the basis of Example 1, Figure 5-7 As shown, a hole I41 is provided on the end cover I4, and the lower vertical cable passes through the hole I41 and is connected to the bottom of the slider 3; an annular handle II51 is provided on the top of the end cover II5, and the upper vertical cable is connected to the annular handle II51.

[0040] An annular handle I31 is provided on a side of the slider 3 facing away from the shape memory alloy spring 2, and the lower vertical cable passes through the hole I41 and is connected to the annular handle I31.

[0041] Fixed grooves 22 are also provided at both ends of each movable groove 21 in the cylindrical outer shell 1, and the fixed grooves 22 are connected with the corresponding movable grooves 21. Fixed blocks I42 and fixed blocks II53 are provided at the positions of the upper end of the end cover I4 and the lower end of the end cover II5 corresponding to the two movable grooves 21. The upper end of the end cover I4 and the lower end of the end cover II5 are inserted into the cylindrical outer shell 2 through the movable grooves 21, and rotated at a certain angle so that the fixed blocks I42 and the fixed blocks II53 are inserted into the fixed grooves 22 on the corresponding side to fix the end cover I4 and the end cover II5.

[0042] The two ends of the slider 3 corresponding to the two moving grooves 21 are inserted into the moving grooves 21 , so that the slider 3 can move along the axis of the cylindrical housing 1 .

[0043] Example 3

[0044] On the basis of Example 2, a hole III32 is provided in the center of the slider 3, and an electrode sheet I6 is provided on a side of the slider 3 close to the shape memory alloy spring 2. The wire is connected to the electrode sheet I6 through the hole I41 and the hole III32 in the center of the end cover I4 for power supply; an electrode sheet II7 is provided at the bottom of the end cover II5, and the wire is connected to the electrode sheet II7 through the hole II52 for power supply, and the two ends of the shape memory alloy spring 2 are respectively connected to the electrode sheet I6 and the electrode sheet II7.

[0045] like Figure 8 As shown, the electrode sheet I6 and the electrode sheet II7 are exactly the same in shape, and claws 8 are provided on the connection surfaces with the shape memory alloy spring 2. The spring wires at both ends of the shape memory alloy spring 2 are inserted into the corresponding claws 8 for fixation, thereby realizing the push-pull action of the slider 3.

[0046] The shape memory alloy spring 2 is a nickel-titanium alloy spring with a two-way shape memory effect. When the power is turned on and the temperature rises to or above the austenite phase transformation starting temperature, the spring begins to stretch and pushes the slider 3 to move toward the end cover I4. When the power is turned off and the temperature drops to or below the martensite phase transformation starting temperature, the spring shortens and pulls the slider 3 to move toward the end cover II5. When the shape memory alloy spring 2 is fully stretched, its length occupies the entire inner cavity of the cylindrical shell 1. When it is not fully expanded, it is only stretched to a certain length by the tension of the vertical cable of the cable net antenna.

[0047] The working process of this embodiment is divided into two stages: the elongation stage and the contraction stage, specifically:

[0048] In the elongation stage, the slider 3 is moved toward the end cover I4. The movement of the slider 3 drives the distance between the upper vertical cable and the lower vertical cable to increase, and the vertical cable as a whole shows an elongation trend. The control method is that the two ends of the shape memory alloy spring 2 are respectively connected to the electrode sheet I6 at the bottom of the slider 3 and the electrode sheet II7 at the bottom of the end cover II5. The electrode sheets I6 and II7 are connected to an external power supply. The shape memory alloy spring is energized for a certain period of time, so that the shape memory alloy spring 2 undergoes an austenite phase transformation and then elongates. When the shape memory alloy spring 2 is elongated, it will push the slider 3 to move toward the end cover I4.

[0049] In the contraction stage, the slider 3 is moved from the end cap I4 to the end cap II5. The movement of the slider 3 reduces the distance between the upper vertical cable and the lower vertical cable, and the vertical cable as a whole shows a contraction trend. The control method is to cut off the power to the electrode sheets I6 and II7 to reduce the temperature of the shape memory alloy spring 2, thereby generating a martensitic phase transformation and then contracting. When the shape memory alloy spring 2 contracts, it will pull the slider 3 to move from the end cap I4 to the end cap II5.

[0050] The above-mentioned elongation and contraction stages are based on the length of the shape memory alloy spring 2 at natural temperature due to the internal tension of the vertical cable as the initial state, so the adjustable range of the vertical cable is the deformation range of the shape memory alloy spring 2 based on the initial state. The initial state of the shape memory alloy spring 2 can also be customized according to actual needs. For example, the shape memory alloy spring 2 is energized to maintain it at a certain temperature, and the length of the shape memory alloy spring 2 at this temperature is used as the initial state. Therefore, the adjustable range of the vertical cable becomes based on the initial state, and it can be extended to the maximum length, or it can be contracted to the length of the shape memory alloy spring 2 when it is at ambient temperature. Since the shape memory alloy spring 2 has a two-way memory effect, the actuator can complete any number of bidirectional displacement outputs.

[0051] The two-way shape memory alloy actuator for active control of the shape of a cable net reflector antenna of the present invention has the characteristics of simple control, space saving, light weight, large driving force, large deformation range, and reusability, and can provide reliable pre-hardware conditions for the shape accuracy compensation of the cable net reflector antenna.

Claims

1. A two-way shape memory alloy actuator for active control of the shape of the cable net reflector antenna is connected to the upper vertical cable and the lower vertical cable at the corresponding position of the cable net reflector antenna, characterized in that: The invention comprises a cylindrical shell (1), wherein two ends of the cylindrical shell (1) are respectively provided with an end cover I (4) and an end cover II (5), a shape memory alloy spring (2) is arranged inside the cylindrical shell (1), and a slider (3) is also arranged inside the cylindrical shell (1) below the shape memory alloy spring (2), the two ends of the shape memory alloy spring (2) are respectively connected to the lower surface of the end cover II (5) and the upper surface of the slider (3) and are energized, the inner side wall of the cylindrical shell (1) is symmetrically provided with moving grooves (21), the moving grooves (21) are parallel to the axis of the cylindrical shell (1), the two ends of the slider (3) corresponding to the moving grooves (21) are slidably connected in the moving grooves (21), the lower section vertical cable passes through the end cover I (4) and is connected to the bottom of the slider (3), and the upper section vertical cable is connected to the top of the end cover II (5).

2. The two-way shape memory alloy actuator for active control of the shape of a cable net reflector antenna according to claim 1, characterized in that: The end cover I (4) is provided with a hole I (41), and the lower vertical cable passes through the hole I (41) and is connected to the bottom of the slider (3); the top of the end cover II (5) is provided with an annular handle II (51), and the upper vertical cable is connected to the annular handle II (51).

3. The two-way shape memory alloy actuator for active control of the shape of a cable net reflector antenna according to claim 2, characterized in that: A circular handle I (31) is provided on a side of the slider (3) facing away from the shape memory alloy spring (2), and the lower vertical cable passes through a hole I (41) and is connected to the circular handle I (31).

4. The two-way shape memory alloy actuator for active control of the shape of a cable net reflector antenna according to any one of claims 1 to 3, characterized in that: The cylindrical outer shell (1) is further provided with fixed grooves (22) at both ends of each movable groove (21), the fixed grooves (22) being in communication with the corresponding movable grooves (21), and the upper end of the end cover I (4) and the lower end of the end cover II (5) are provided with fixed blocks I (42) and fixed blocks II (53) at positions corresponding to the two movable grooves (21), the upper end of the end cover I (4) and the lower end of the end cover II (5) are inserted into the cylindrical outer shell (2) through the movable grooves (21), and are rotated at a certain angle so that the fixed blocks I (42) and the fixed blocks II (53) are snapped into the fixed grooves (22) on the corresponding side, thereby fixing the end cover I (4) and the end cover II (5).

5. The two-way shape memory alloy actuator for active control of the shape of a cable net reflector antenna according to claim 3, characterized in that: The two ends of the slider (3) corresponding to the two movable grooves (21) are inserted into the movable grooves (21), so that the slider (3) can move along the axis of the cylindrical shell (1).

6. The two-way shape memory alloy actuator for active control of the shape of a cable net reflector antenna according to claim 3, characterized in that: The slider (3) is provided with a hole III (32) at the center, and an electrode sheet I (6) is provided on a side of the slider (3) close to the shape memory alloy spring (2). A wire is connected to the electrode sheet I (6) through a hole I (41) at the center of the end cover I (4) and the hole III (32) to conduct electricity. An electrode sheet II (7) is provided at the bottom of the end cover II (5), and the wire is connected to the electrode sheet II (7) through a hole II (52) to conduct electricity. Both ends of the shape memory alloy spring (2) are respectively connected to the electrode sheet I (6) and the electrode sheet II (7).

7. The two-way shape memory alloy actuator for active control of the shape of a cable net reflector antenna according to claim 5, characterized in that: The electrode sheet I (6) and the electrode sheet II (7) are completely identical in shape, and are both provided with claws (8) on the connection surfaces with the shape memory alloy spring (2). The spring wires at both ends of the shape memory alloy spring (2) are inserted into the corresponding claws (8) for fixation.

8. The two-way shape memory alloy actuator for active control of the shape of a cable net reflector antenna according to claim 1, characterized in that: The shape memory alloy spring (2) is a nickel-titanium alloy spring with a two-way shape memory effect. When the power is turned on and the temperature is raised to or above the austenite phase transformation starting temperature, the spring begins to stretch and pushes the slider (3) to move in the direction of the end cover I (4). When the power is turned off and the temperature is lowered to or below the martensite phase transformation starting temperature, the spring shortens and pulls the slider (3) to move in the direction of the end cover II (5). When the shape memory alloy spring (2) is fully stretched, its length fills the entire inner cavity of the cylindrical housing (1).

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