Underwater sealing bin based on shape memory alloy and sealing method thereof

Abstract

The invention discloses an underwater sealing bin based on shape memory alloy and a sealing method of the underwater sealing bin, and belongs to the technical field of underwater sealing. The underwater sealing bin comprises a bin body and a T-shaped plug blocking an opening of the bin body. A sealing groove is formed in the T-shaped plug, and a sealing ring is arranged in the sealing groove; a groove is further formed in the side face of the T-shaped plug, and an SMA-based supporting device is arranged in the groove. The supporting device based on the SMA is flexibly switched between the installation state and the sealing state through power-on and power-off control of the SMA spring, and the extrusion suction cup can be controlled to be adsorbed on the inner wall of the bin body. The SMA spring is connected with the water seal plug-in unit which is installed on the T-shaped plug. Preliminary sealing is formed through the sealing ring on the T-shaped plug, flexible switching of the supporting device based on the SMA between the mounting state and the sealing state is achieved through the shape memory characteristic of the SMA material, stable sealing of the T-shaped plug in the underwater high-pressure environment is ensured, and displacement of the T-shaped plug is prevented.

Description

Technical Field

[0001] This invention relates to the field of underwater sealing technology, specifically to an underwater sealing chamber based on shape memory alloy (SMA) and its sealing method. Background Technology

[0002] In fields such as marine resource development and deep-sea scientific research, underwater sealed enclosures play a crucial role and are frequently used for tasks such as deep-sea sampling and ocean observation. They need to operate stably in complex underwater environments, withstanding immense water pressure while ensuring that internal equipment and samples are not disturbed by seawater. Therefore, extremely high requirements are placed on their sealing performance and structural stability.

[0003] Currently, common underwater sealed chamber structures have many limitations when dealing with high-pressure environments. Some sealed chambers use simple bolt fastening or rubber sealing methods, which are prone to aging and deformation of sealing components under long-term high pressure, leading to seawater leakage, affecting normal equipment operation, and even damaging internal instruments. Furthermore, traditional sealed chambers lack effective mechanisms to cope with high-pressure deformation in their structural design. When subjected to deep-sea high pressure, the chamber body is prone to localized deformation, which not only reduces sealing reliability but may also cause structural safety issues. To improve the structural stability of sealed chambers, existing technologies often increase the wall thickness or use high-strength materials, but this significantly increases the equipment weight, raises manufacturing and transportation costs, and hinders flexible operation. In addition, some sealed chambers using mechanical support structures have complex adjustment and installation of support components, making it difficult to adapt to the rapidly changing needs of different underwater environments. Summary of the Invention

[0004] Based on the above-mentioned technical problems, this invention proposes an underwater sealing chamber based on shape memory alloy and its sealing method.

[0005] The technical solution adopted in this invention is:

[0006] An underwater sealing chamber based on shape memory alloy includes a chamber body and a T-shaped plug sealing the opening of the chamber body; the T-shaped plug includes a cylindrical plug body and a top cover, one end of the cylindrical plug body is connected to the top cover, and when the T-shaped plug seals the chamber body, the cylindrical plug body is embedded in the chamber body, and the top cover is in contact with the end face of the chamber body;

[0007] A sealing groove is provided around the other end of the cylindrical plug, and a sealing ring is provided in the sealing groove. The cylindrical plug forms a seal with the chamber through the sealing ring.

[0008] A groove is provided on the side of the cylindrical plug, and an SMA-based support device is provided in the groove; the SMA-based support device includes a support arm and an SMA spring. The support arm includes a fixed arm and a movable arm. One end of the fixed arm is fixedly connected to the inner wall of the groove, and one end of the movable arm is rotatably connected to the other end of the fixed arm. A suction cup is provided at the other end of the movable arm.

[0009] The SMA spring can be controlled to deform or recover by switching on and off power. It includes a first SMA spring, a second SMA spring, and a third SMA spring. One end of the first SMA spring is connected to the inner wall of one side of the groove, and the other end of the first SMA spring is connected to the movable arm. One end of the second SMA spring is connected to the inner wall of the other side of the groove, and the other end of the second SMA spring is connected to the movable arm. A cylindrical hole is provided at the end of the movable arm corresponding to the suction cup. The third SMA spring is placed in the cylindrical hole. When the third SMA spring deforms and elongates, it squeezes the suction cup and makes it adhere to the inner wall of the chamber.

[0010] The first SMA spring, the second SMA spring, and the third SMA spring are connected to an external power source through a water-sealing insert, so that the first SMA spring, the second SMA spring, and the third SMA spring are heated by the external power source to generate a shape memory effect. The water-sealing insert is installed on the T-shaped plug.

[0011] The present invention also provides a sealing method for an underwater sealing chamber based on shape memory alloy as described above, comprising the following steps:

[0012] S1. Assemble the SMA-based support device and the miniature camera in the groove of the T-shaped plug. After assembly, connect an external DC power supply to the water seal plug.

[0013] S2. First, the first SMA spring of the SMA-based support device in the T-shaped plug groove is heated by electricity. When the temperature required for it to transform into austenite is reached, the first SMA spring contracts and drags the movable arm of the support arm to rotate relative to the fixed arm to a vertical state. At this time, the cylindrical plug of the T-shaped plug is completely inserted into the chamber of the sealing chamber, and the miniature camera is turned on to observe the condition of the support arm inside the groove.

[0014] S3. Stop energizing the first SMA spring and allow it to slowly return to its original shape. If, through observation by the miniature camera, it is found that the movable arm still cannot return to a horizontal state after the first SMA spring is de-energized, then energize and heat the second SMA spring. The second SMA spring will contract and provide a counterforce to the movable arm, which will play a compensating role and allow it to return to a horizontal state. Then de-energize the second SMA spring.

[0015] S4. After the movable arm reaches the horizontal position, the suction cup at the tail end of the movable arm adheres to the inner wall of the chamber. At this time, the third SMA spring inside the tail end of the movable arm is energized and heated. After being heated, the third SMA spring extends to both sides, providing a squeezing force to the suction cup, so that it is tightly adhering to the inner wall of the chamber. After an appropriate time, the power to the third SMA spring is turned off.

[0016] The beneficial technical effects of the present invention are as follows:

[0017] This invention employs a dual-sealing design using a nitrile rubber sealing ring and a biomimetic suction cup at the end of an SMA support device. The nitrile rubber sealing ring serves as the basic seal, while the biomimetic suction cup at the end of the SMA support device effectively prevents T-plug displacement, significantly improving sealing reliability. The chamber body adopts a structure combining a cylinder and a hemispherical shell, effectively distributing external pressure evenly and avoiding stress concentration problems similar to flat-bottomed structures. The upper part features a reinforcing ring structure to ensure that the internal structure of the T-plug is not damaged when the chamber body is impacted under high underwater pressure, enhancing overall pressure resistance. Utilizing the shape memory characteristics of SMA, the support arm can be easily controlled to be horizontal or vertical by controlling the spring's contraction through electrical heating, facilitating T-plug installation and effectively preventing displacement, offering simple and flexible operation. The suction force generated by the biomimetic suction cup at the tail end of the SMA support device when in a horizontal state effectively resists external forces, ensuring the stability of the T-plug and guaranteeing the structural stability of the underwater sealing chamber in complex environments. Attached Figure Description

[0018] Figure 1 This is a schematic diagram illustrating the structural principle of the underwater sealing chamber based on shape memory alloy of the present invention;

[0019] Figure 2 This is a schematic diagram of the T-shaped plug in the underwater sealing chamber of the present invention;

[0020] Figure 3 This is a top view of the horizontal state of the support arm in the SMA-based support device of the present invention.

[0021] Figure 4 This is a side view of the horizontal state of the support arm in the SMA-based support device of the present invention.

[0022] Figure 5 This is a side view of the support arm in the SMA-based support device of the present invention in a near-vertical state.

[0023] Figure 6 This is a side view of the biomimetic suction cup at the tail end of the SMA-based support device of the present invention.

[0024] Figure 7 This is a front view of the biomimetic suction cup at the tail end of the SMA-based support device of the present invention.

[0025] In the diagram: 1-Cavity body, 2-T-type plug, 3-Groove, 4-SMA-based support device, 5-Suction cup, 6-Water seal insert, 7-Miniature camera;

[0026] 101-Hollow cylinder; 102-Hemispherical shell; 103-Reinforcing ring;

[0027] 201-Cylindrical plug body, 202-Top cover, 203-Sealing groove;

[0028] 401-Fixed arm, 402-Moving arm, 403-First SMA spring, 404-Second SMA spring, 405-Third SMA spring, 406-Pin, 407-Connecting port;

[0029] 501 - Suction cup body, 502 - Tail connector, 503 - Oval independent groove. Detailed Implementation

[0030] Referring to the accompanying drawings, an underwater sealing chamber based on shape memory alloy (SMA) includes a chamber body 1 and a T-shaped plug 2 sealing the opening of the chamber body 1. The T-shaped plug 2 is used to seal the opening of the chamber body 1 to prevent gas and liquid from the underwater environment from entering the sealed chamber, ensuring the normal operation of the equipment inside. The T-shaped plug 2 includes a cylindrical plug body 201 and a top cover 202. One end of the cylindrical plug body 201 is connected to the top cover 202. When the T-shaped plug seals the chamber body, the cylindrical plug body 201 is embedded in the opening of the chamber body 1, and the top cover 202 is in contact with the end face of the chamber body 1. A sealing groove 203 is provided around the other end of the cylindrical plug body 201, and a sealing ring is provided in the sealing groove 203, forming a seal between the cylindrical plug body 201 and the chamber body 1 through the sealing ring. A groove 3 is also provided on the side of the cylindrical plug body 201, and a support device 4 based on SMA is provided in the groove 3. The SMA-based support device 4 includes a support arm and an SMA spring. The support arm includes a fixed arm 401 and a movable arm 402. One end of the fixed arm 401 is fixedly connected to the inner wall of the groove, and one end of the movable arm 402 is rotatably connected to the other end of the fixed arm 401. A suction cup 5 is provided at the other end of the movable arm 402. The SMA spring can be deformed or restored by controlling the switching on and off of electricity. It includes a first SMA spring 403, a second SMA spring 404, and a third SMA spring 405. One end of the first SMA spring 403 is connected to one side of the inner wall of the groove 3, and the other end of the first SMA spring 403 is connected to the movable arm 402. One end of the second SMA spring 404 is connected to the other side of the inner wall of the groove, and the other end of the second SMA spring 404 is connected to the movable arm 402. A cylindrical hole is provided at the end of the movable arm corresponding to the suction cup. The third SMA spring 405 is placed in the cylindrical hole. When the third SMA spring deforms and elongates, it squeezes the suction cup 5 to make it adhere to the inner wall of the chamber 1. The first SMA spring 403, the second SMA spring 404 and the third SMA spring 405 are all connected to the water seal plug 6, which is installed on the T-type plug 2.

[0031] After the SMA-based support device and sealing ring are installed, a DC power supply is used to energize the upper first SMA spring, causing it to contract due to heat. This lifts the support arm's tail end into a vertical position, ensuring the T-plug can be easily installed into the sealing chamber. Once the T-plug is fully inside the chamber, the upper SMA is de-energized, returning it to its original state. Simultaneously, the lower second SMA spring is energized, causing it to contract due to heat and pull the support arm into a horizontal position. After this process, the third SMA spring suspended inside the tail end of the support arm is energized, providing the heat required for its transformation into austenite. This causes the spring to extend, providing a compressive force to the bionic suction cup at the end. This creates micro-sealing spaces on the working surface of the bionic suction cup, allowing it to adhere more tightly to the inner wall of the chamber, preventing displacement of the T-plug and ensuring its stability.

[0032] The underwater sealing chamber of this invention comprises the following components: The chamber body is barrel-shaped, or similar to a barrel-shaped cylinder, employing a combination of cylindrical and hemispherical shapes as its main structure; a T-shaped plug is used to seal the chamber body, and the T-shaped plug has a sealing groove, a recess, and a water-sealing insert; the sealing groove, located circumferentially at the end of the T-shaped plug, is used to install a rubber sealing ring for initial sealing; the recess, located on the side of the T-shaped plug, is used to install an SMA-based support device; and the water-sealing insert, located at the top of the T-shaped plug, is used to connect electrical wires to form a pathway for energizing and heating the SMA springs in the SMA-based support device. All the energizing connection wires of the SMA springs are placed close to the inner and side walls of the T-shaped plug's recess, converge through the internal pathway of the T-shaped plug, and finally connect to the water-sealing insert at the top of the T-shaped plug, enabling an external circuit to energize and heat the internal SMA springs using DC power.

[0033] This invention forms a preliminary seal through the sealing ring on the T-type plug, and utilizes the shape memory properties of SMA material to achieve flexible switching between the installation and sealing states of the SMA-based support device, ensuring stable sealing of the T-type plug under high-pressure underwater conditions and preventing displacement.

[0034] like Figure 1 As shown, the chamber 1 includes a hollow cylinder 101, a hemispherical shell 102 connected to the bottom end of the hollow cylinder 101, and a reinforcing ring 103 connected to the outer side of the upper end of the hollow cylinder 101. The inner diameter of the reinforcing ring 103 is equal to the inner diameter of the hollow cylinder, and the outer diameter of the reinforcing ring 103 is larger than the outer diameter of the hollow cylinder 101. The hollow cylinder 101, the hemispherical shell 102, and the reinforcing ring 103 are an integral structure, all made of titanium alloy, which has good pressure resistance and corrosion resistance, and can withstand underwater high pressure and resist seawater corrosion for a long time. The hemispherical shell ensures that the external pressure is evenly distributed when the chamber is in water, improving the pressure resistance of the bottom of the pressure chamber. The reinforcing ring structure set in the upper part of the chamber can also enhance the pressure resistance of this part and protect the internal T-type plug. It reduces the impact on the internal structure of the T-type plug in the underwater high-pressure environment and prevents it from being damaged.

[0035] like Figure 2 As shown, the sealing ring is an O-ring elastic rubber sealing ring made of nitrile rubber material; the sealing ring is tightly fitted into the sealing groove, slightly higher than the sealing groove, to enhance the sealing effect. When the T-shaped plug is fully inserted into the chamber, the nitrile rubber sealing ring is squeezed against the inner wall of the chamber, achieving a preliminary sealing effect and effectively preventing gas and liquid leakage.

[0036] like Figure 3-5As shown, the end of the movable arm 402 is connected to the fixed arm 401 via a pin 406. The fixed arm 401 is horizontally arranged, and the movable arm 402 can switch between vertical and horizontal states under the deformation or recovery conditions of the first SMA spring 403 and the second SMA spring 404. Connection ports 407 are provided at the upper and lower points of the movable arm 402, corresponding to the connections with the first SMA spring 403 and the second SMA spring 404, respectively. That is, there are two connection ports in total: a first connection port and a second connection port. The first connection port connects to the first SMA spring, and the second connection port connects to the second SMA spring.

[0037] As a further design of the invention, multiple grooves 3 are provided on the cylindrical plug body 201 and arranged at intervals along the circumference of the cylindrical plug body. A support device 4 based on SMA is provided in each groove. A miniature camera 7 is also provided inside the groove 3 for observing the internal conditions of the groove. An LED lighting device is integrated into the miniature camera 7. The miniature camera 7 can be glued to the side wall of the groove. After the T-shaped plug is fully inserted into the chamber, the detailed situation of the internal support device of the T-shaped plug can be observed in real time. The LED lighting device integrated into the miniature camera turns on when the miniature camera is working, providing sufficient light to achieve clear observation of the internal conditions of the groove. Two grooves 3 can be provided, symmetrically arranged on the left and right sides of the cylindrical plug body 201.

[0038] The first SMA spring 403, the second SMA spring 404, and the third SMA spring 405 are each connected to an electrical path, enabling them to be heated by an external DC power supply to generate a shape memory effect. Both the first SMA spring 403 and the second SMA spring 404 contract when energized. As the first SMA spring 403 and the second SMA spring 404 deform or return to their original shape, the tail end of the support arm switches between vertical and horizontal states. The third SMA spring 405 performs the reverse training; it is in an extended state when energized and contracts back to its original shape after cooling.

[0039] The first, second, and third SMA springs mentioned above can be selected from NiTi shape memory alloy springs, etc., as needed. The third SMA spring is a reverse-training SMA spring, which is heat-treated under compression to make the spring's memory shape elongated with a larger pitch. When heated, this spring elongates, thereby squeezing the bionic suction cup and generating a squeezing force for the bionic suction cup to adhere to the inside of the chamber.

[0040] Furthermore, such as Figure 6 , Figure 7As shown, the suction cup 5 is a biomimetic suction cup, comprising a suction cup body 501 and a tail connector 502. The tail connector 502 is inserted into the end of the movable arm, i.e., into the cylindrical hole, and contacts one end of the third SMA spring 405. The working surface of the suction cup body 501 is provided with several elliptical independent grooves 503 spaced around its perimeter, forming a biomimetic non-smooth shape. During the adsorption process, multiple micro-sealed chambers are formed, improving the sealing performance of the biomimetic suction cup. The suction cup 5 is made of a flexible material, such as silicone rubber, which has excellent properties such as resistance to high and low temperatures and aging.

[0041] The present invention also provides a sealing method for an underwater sealing chamber based on shape memory alloy as described above, comprising the following steps:

[0042] S1. Assemble the SMA-based support device 4 and the miniature camera 7 in the groove 3 of the T-shaped plug. After assembly, connect an external DC power supply to the water seal plug 6.

[0043] S2. First, the first SMA spring 403 of the SMA-based support device in the T-shaped plug groove is energized and heated. When the temperature required for its transformation into austenite is reached, the first SMA spring 403 contracts, dragging the movable arm of the support arm to rotate relative to the fixed arm to a vertical position. At this time, the cylindrical plug body of the T-shaped plug 2 is completely inserted into the chamber of the sealing chamber, and the miniature camera 7 is turned on to observe the condition of the support arm inside the groove.

[0044] S3. Stop energizing the first SMA spring 403 and allow it to slowly return to its original shape. If, as observed through the miniature camera 7, the movable arm 402 still cannot return to a horizontal state after the first SMA spring 403 is de-energized, then the second SMA spring 404 is energized and heated. The second SMA spring 404 contracts, providing a counterforce to the movable arm 402 to compensate and restore it to a horizontal state; then the second SMA spring 404 is de-energized.

[0045] S4. After the movable arm 402 reaches a horizontal position, the suction cup 5 at the tail end of the movable arm 402 adheres to the inner wall of the chamber 1. At this time, the third SMA spring 405 inside the tail end of the movable arm is energized and heated. This spring is designed for reverse training, allowing it to be in an extended state during heating and contract back to its original shape after cooling. After being heated, the third SMA spring 405, being in a suspended state, extends to both sides, providing a squeezing force to the suction cup 5. The elliptical grooves on the working surface of the suction cup adhere to the inner wall of the chamber, forming several micro-sealed spaces, increasing the adsorption force of the bionic suction cup, making it tightly adhered to the inner wall of the chamber, preventing the T-shaped plug from shifting, and improving its stability. After an appropriate time, the energization of the third SMA spring inside the support arm is stopped to prevent its performance from being damaged by prolonged energization.

[0046] In summary, this invention proposes an underwater sealing chamber device and its sealing method based on shape memory alloy (SMA). The chamber body adopts a structure similar to a barrel cylinder, combining cylindrical and hemispherical shapes. A reinforcing ring is provided on the upper periphery of the cylinder body to effectively enhance structural strength. A T-plug is used for sealing, with a sealing groove on the T-plug, and a rubber sealing ring is installed in the groove to achieve initial sealing. A groove is also provided for installing the SMA-based support device, and a water-sealing insert is used to connect the passage to heat the SMA spring in the SMA-based support device. The SMA-based support device is composed of SMA springs, etc. When energized, the upper first SMA spring heats and contracts, keeping the tail end of the support device vertical, facilitating the installation of the T-plug into the cylinder body. When de-energized, the upper first SMA spring returns to its original position, while the lower second SMA spring heats and contracts, making the support device horizontal and supporting the inner side of the barrel wall. Once the support device is fully horizontal, the third SMA spring built into the tail end of the support arm is energized. The built-in third SMA spring uses different pre-training methods and has the effect of elongation upon heating. It squeezes the bionic suction cup installed at the tail end, so that the bionic suction cup can be tightly attached to the inner wall of the sealing chamber when the support arm is horizontal. This prevents the T-plug from shifting under high pressure underwater. Together with the rubber sealing ring, it ensures a reliable seal of the underwater sealing chamber, effectively solving the sealing and component displacement problems of the underwater sealing chamber under high pressure. It is suitable for various underwater operation equipment.

[0047] For any parts not mentioned above, existing technologies can be adopted or referenced.

[0048] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. An underwater sealed chamber based on shape memory alloy, characterized in that: It includes a chamber body and a T-shaped plug that seals the opening of the chamber body; the T-shaped plug includes a cylindrical plug body and a top cover, one end of the cylindrical plug body is connected to the top cover, and when the T-shaped plug seals the chamber body, the cylindrical plug body is embedded in the chamber body, and the top cover is in contact with the end face of the chamber body; A sealing groove is provided around the other end of the cylindrical plug, and a sealing ring is provided in the sealing groove. The cylindrical plug forms a seal with the chamber through the sealing ring. A groove is provided on the side of the cylindrical plug, and an SMA-based support device is provided in the groove; the SMA-based support device includes a support arm and an SMA spring. The support arm includes a fixed arm and a movable arm. One end of the fixed arm is fixedly connected to the inner wall of the groove, and one end of the movable arm is rotatably connected to the other end of the fixed arm. A suction cup is provided at the other end of the movable arm. The SMA spring can be controlled to deform or recover by switching on and off power. It includes a first SMA spring, a second SMA spring, and a third SMA spring. One end of the first SMA spring is connected to the inner wall of one side of the groove, and the other end of the first SMA spring is connected to the movable arm. One end of the second SMA spring is connected to the inner wall of the other side of the groove, and the other end of the second SMA spring is connected to the movable arm. A cylindrical hole is provided at the end of the movable arm corresponding to the suction cup. The third SMA spring is placed in the cylindrical hole. When the third SMA spring deforms and elongates, it squeezes the suction cup and makes it adhere to the inner wall of the chamber. The first SMA spring, the second SMA spring, and the third SMA spring are connected to an external power source through a water-sealing insert, so that the first SMA spring, the second SMA spring, and the third SMA spring are heated by the external power source to generate a shape memory effect. The water-sealing insert is installed on the T-shaped plug.

2. The underwater sealing chamber based on shape memory alloy according to claim 1, characterized in that: The hopper body includes a hollow cylinder, with a hemispherical shell connected to the bottom end of the hollow cylinder, and a reinforcing ring provided at the top end of the hollow cylinder; the inner diameter of the reinforcing ring is equal to the inner diameter of the hollow cylinder, and the outer diameter of the reinforcing ring is greater than the outer diameter of the hollow cylinder.

3. The underwater sealing chamber based on shape memory alloy according to claim 2, characterized in that: The hollow cylinder, hemispherical shell, and reinforcing ring are an integral structure, all made of titanium alloy.

4. The underwater sealing chamber based on shape memory alloy according to claim 1, characterized in that: The sealing ring is an O-ring elastic rubber sealing ring, made of nitrile rubber material; after the sealing ring is embedded in the sealing groove, the top surface of the sealing ring is exposed.

5. An underwater sealing chamber based on shape memory alloy according to claim 1, characterized in that: The end of the movable arm is connected to the fixed arm via a pin. The fixed arm is arranged horizontally. The movable arm can switch between vertical and horizontal states under the deformation or recovery conditions of the first SMA spring and the second SMA spring. The movable arm is provided with a first connection port and a second connection port. The first connection port is connected to the first SMA spring, and the second connection port is connected to the second SMA spring.

6. An underwater sealing chamber based on shape memory alloy according to claim 1, characterized in that: Multiple grooves are provided on the cylindrical plug body and are arranged at intervals along the circumference of the cylindrical plug body; a support device based on SMA is provided in each groove.

7. An underwater sealing chamber based on shape memory alloy according to claim 1, characterized in that: A miniature camera is also installed inside the groove, and an LED lighting device is integrated on the miniature camera.

8. An underwater sealing chamber based on shape memory alloy according to claim 1, characterized in that: The first and second SMA springs contract when energized, while the third SMA spring undergoes reverse training, being in an extended state when heated and contracting back to its original shape after cooling.

9. An underwater sealing chamber based on shape memory alloy according to claim 1, characterized in that: The suction cup is a biomimetic suction cup, comprising a suction cup body and a tail connector. The tail connector is inserted into the end of the movable arm and contacts one end of the third SMA spring. The working surface of the suction cup body is provided with several independent elliptical grooves spaced around its perimeter. The suction cup is made of flexible material.

10. The sealing method for an underwater sealed chamber based on shape memory alloy as described in any one of claims 1-9, characterized in that... Includes the following steps: S1. Assemble the SMA-based support device and the miniature camera in the groove of the T-shaped plug. After assembly, connect an external DC power supply to the water seal plug. S2. First, the first SMA spring of the SMA-based support device in the T-shaped plug groove is heated by electricity. When the temperature required for it to transform into austenite is reached, the first SMA spring contracts and drags the movable arm of the support arm to rotate relative to the fixed arm to a vertical state. At this time, the cylindrical plug of the T-shaped plug is completely inserted into the chamber of the sealing chamber, and the miniature camera is turned on to observe the condition of the support arm inside the groove. S3. Stop energizing the first SMA spring and allow it to slowly return to its original shape. If, through observation by the miniature camera, it is found that the movable arm still cannot return to a horizontal state after the first SMA spring is de-energized, then energize and heat the second SMA spring. The second SMA spring will contract and provide a counterforce to the movable arm, which will play a compensating role and allow it to return to a horizontal state. Then de-energize the second SMA spring. S4. After the movable arm reaches the horizontal position, the suction cup at the tail end of the movable arm adheres to the inner wall of the chamber. At this time, the third SMA spring inside the tail end of the movable arm is energized and heated. After being heated, the third SMA spring extends to both sides, providing a squeezing force to the suction cup, so that it is tightly adhering to the inner wall of the chamber. After an appropriate time, the power to the third SMA spring is turned off.

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