An underwater wire displacement sensor

Abstract

This application relates to an underwater pull-cord displacement sensor, belonging to the field of sensor technology. It includes a sensor body, a reel, a pull rope, a self-winding spring, and a housing. The sensor body is rotatably connected to the reel, and the reel is connected to the self-winding spring. The pull rope is wound around the outside of the reel. Both the reel and the self-winding spring are housed within the housing. A water filter tank is fixedly connected inside the housing. Openings for the pull rope to pass through are provided on both sides of the water filter tank. A partition is fixedly connected inside the water filter tank, with a through-hole at the center for the pull rope to pass through. The openings and the through-hole are concentric. The partition is vertically positioned, and a layer of sodium polyacrylate for water absorption and expansion is provided on the outer side of the partition near the housing. This application has the effect of improving the sensor's service life.

Description

Technical Field

[0001] This application relates to the field of sensor technology, and in particular to an underwater wire displacement sensor. Background Technology

[0002] Currently, displacement sensors have extremely wide applications. They can be considered an indispensable "sensing organ" in modern industry, scientific research, and daily life. They are used to accurately measure the movement, expansion, contraction, vibration, or positional changes of objects. Their core function is to convert linear or rotational displacement into electrical signals that can be recognized and processed by the system. Underwater wire displacement sensors convert mechanical motion that cannot be directly observed underwater into reliable and accurate electrical signals, making remote control, automated operation, and intelligent monitoring possible. They are key sensing devices for developing the ocean, utilizing water resources, and maintaining the safety of underwater facilities.

[0003] Related technology can be found in Chinese Patent No. CN211147613U, which discloses an underwater pull-wire displacement sensor, including a pull-wire sensor housing. A spring mounting cavity is located on the left side of the pull-wire sensor housing, and a self-winding spring is installed inside the spring mounting cavity. A pull-wire cavity is located on the right side of the pull-wire sensor housing, and a reel is installed inside the pull-wire cavity. A pull-wire rope is wound around the reel. A pull-wire terminal is provided at the end of the pull-wire rope away from the reel. A displacement measuring device housing is located at the middle of the right side of the pull-wire sensor housing, and a Hall encoder is installed inside the displacement measuring device housing. A mechanical seal assembly is provided at the connection point between the connecting shaft and the right side of the pull-wire sensor housing.

[0004] Regarding the aforementioned technologies, underwater pull-wire displacement sensors are typically used in the deep sea. A sealing ring seals the outlet of the pull wire. However, with prolonged use of the pull wire, the pull wire wears down the sealing ring, causing it to lose its effectiveness. This allows seawater to enter the sensor and damage its internal components. Simply using a sealing ring for dynamic sealing is not ideal and reduces the sensor's lifespan. Therefore, there is an urgent need for an underwater pull-wire sensor to solve these problems. Summary of the Invention

[0005] To improve the service life of the sensor, this application provides an underwater wire displacement sensor.

[0006] This application provides an underwater wire displacement sensor, which adopts the following technical solution:

[0007] An underwater pull-cord displacement sensor includes a sensor body, a reel, a pull rope, a self-winding spring, and a housing. The sensor body is rotatably connected to the reel, and the reel is connected to the self-winding spring. The pull rope is wound around the outside of the reel. Both the reel and the self-winding spring are housed inside the housing. A water filter box is fixedly connected inside the housing. The water filter box has openings on both sides for the pull rope to pass through. A partition is fixedly connected inside the water filter box. A through hole for the pull rope to pass through is opened at the center of the partition. The opening and the through hole are concentric. The partition is vertically arranged. A layer of sodium polyacrylate for water absorption and expansion is provided on the outer side of the partition near the housing.

[0008] By adopting the above technical solution, the pull rope extends outward from the sensor through the water filter tank. The pull rope continuously wears down the sealing ring, causing a small-diameter gap to appear in the sealing ring. When the sealing ring is damaged, seawater flows into the water filter tank through the opening. The seawater comes into contact with the sodium polyacrylate layer. The sodium polyacrylate molecular chains have a large number of sodium carboxylate groups. When they encounter water, these sodium ions dissociate into the water. The negatively charged polymer chains are fixed by the cross-linked network and cannot move. A huge ion concentration difference is formed between the inside of the polymer network and the pure water outside. In order to balance this concentration difference, water molecules will spontaneously and in large quantities permeate into the inside of the polymer network through the semi-permeable membrane. As water molecules continue to flow in, the polymer network is stretched like a sponge, and the three-dimensional molecular chains are stretched. As a result, the sodium polyacrylate layer expands and blocks the opening, which helps to reduce the amount of seawater entering the sensor. This, in turn, helps to reduce the damage to the internal components of the sensor and improves the service life of the sensor.

[0009] Optionally, a filter screen is slidably connected to the side of the partition near the outer shell. The filter screen is horizontally positioned above the sodium polyacrylate layer and has a gap for the pull rope to pass through.

[0010] By adopting the above technical solution, the filter screen filters seawater, and impurities and other substances in the seawater cannot easily pass through the filter screen. Sodium polyacrylate expands upon contact with water, which in turn helps to improve the water absorption effect of the sodium polyacrylate layer.

[0011] Optionally, the partition is fixedly connected with an elastic sealing layer, which is evenly arranged circumferentially at the through holes of the partition. The partition is provided with two squeezing claws for squeezing the elastic sealing layer toward the center of the through holes. The partition is also provided with a driving assembly for driving the squeezing claws to squeeze the elastic sealing layer. When the two squeezing claws collide, the elastic sealing layer squeezes the rope to seal.

[0012] By adopting the above technical solution, the pull rope passes through the center of the elastic sealing layer. Under normal working conditions, the elastic sealing layer and the pull rope do not come into contact, which helps to reduce the wear of the elastic sealing layer by the pull rope and improve the service life of the sensor. When the outer sealing ring leaks water, the squeezing claw squeezes the elastic sealing layer, and the elastic sealing layer contracts towards the center of the through hole and comes into contact with the pull rope, thereby sealing the through hole. This helps to reduce the phenomenon of seawater entering the sensor, reduce the phenomenon of damage to internal components, and improve the service life.

[0013] Optionally, the drive assembly includes a rotating rod, two rotating screws, and two connecting plates. The rotating rod is rotatably connected to the partition plate, and the rotating screws are coaxially fixedly connected to both ends of the rotating rod. The two rotating screws have opposite threads. The two connecting plates are threadedly connected to the two rotating screws respectively. The connecting plates are slidably connected to the partition plate. The two connecting plates are fixedly connected to the two squeezing claws respectively. When the rotating rod rotates, the two squeezing claws move towards each other. The filter tank is equipped with a linkage assembly for driving the rotating rod to rotate.

[0014] By adopting the above technical solution, the linkage component drives the rotating rod to rotate, the rotating rod drives the two rotating screws to rotate, the rotating screws drive the two connecting plates to move towards each other, and then drive the two squeezing claws to move towards each other. After the two squeezing claws come into contact with each other, the elastic sealing layer comes into contact with the pull rope, thereby completing the sealing of the through hole.

[0015] Optionally, the linkage assembly includes a pressure plate, a sliding plate, a drive rack, a drive gear, and a transmission rod. The pressure plate is horizontally positioned below the sodium polyacrylate layer. Both sides of the pressure plate are slidably connected to a partition and a water filter tank, respectively. The sliding plate is fixedly connected to the lower end face of the pressure plate and slidably connected to the water filter tank. Part of the sliding plate is positioned inside the water filter tank. The sliding plate is vertically positioned. The drive rack is fixedly connected to the lower end of the sliding plate and extends along the length of the sliding plate. The drive gear meshes with the drive rack and is fixedly connected to the transmission rod. The transmission rod is connected to the rotating rod through a bevel gear pair.

[0016] By adopting the above technical solution, the sodium polyacrylate expands and extrudes the pressure plate, which drives the slide plate to slide downwards. The slide plate drives the drive rack to descend, the drive rack drives the drive gear to rotate, the drive gear drives the transmission rod to rotate, and the transmission rod drives the rotating rod to rotate. In this way, the elastic sealing layer blocks the through hole during the expansion and blockage of the sodium polyacrylate layer, achieving a double sealing effect. This further reduces the phenomenon of seawater entering the sensor. At the same time, the mechanical transmission mode reduces the number of electronic control components, making it more suitable for use in seawater.

[0017] Optionally, two water-absorbing sponge layers are slidably connected to the side of the partition away from the sodium polyacrylate layer. The sponge layers are located at the through holes of the partition, and each of the two sponge layers has a pushing component on one side for pushing the sponge layer to block the through holes.

[0018] By adopting the above technical solution, a small amount of seawater will still pass through the perforations of the partition, and the sponge layer will absorb the small amount of seawater, further reducing the phenomenon of seawater entering the sensor.

[0019] Optionally, the pushing component includes a push plate and a moving plate. The push plate is disposed on the side of the sponge layer near the water filter tank and is fixedly connected to the sponge layer. The side of the push plate near the partition is fixedly connected to the moving plate, and the moving plate is fixedly connected to the connecting plate.

[0020] By adopting the above technical solution, under normal sensor operation, the sponge layer and the pull rope are separated, which helps to reduce the wear of the sponge layer by the pull rope. The moving plate moves synchronously with the connecting plate, which in turn drives the push plate to move. The push plate drives the two sponge layers to move towards each other, thereby sealing the through holes of the partition and the opening of the water filter box, and absorbing the small amount of seawater that enters. This achieves triple waterproofing, reduces the phenomenon of seawater entering the sensor, reduces the phenomenon of damage to internal components, and improves service life.

[0021] In summary, this application includes at least one of the following beneficial technical effects of underwater wire displacement sensors:

[0022] 1. By setting a sodium polyacrylate layer, a pull rope extends outward from the sensor through the water filter tank. The pull rope continuously wears down the sealing ring, creating a small-diameter gap. When the sealing ring is damaged, seawater flows into the water filter tank through the opening. The seawater comes into contact with the sodium polyacrylate layer. The sodium polyacrylate molecular chains have a large number of sodium carboxylate groups. When they encounter water, these sodium ions dissociate into the water. The negatively charged polymer chains are fixed by the cross-linked network and cannot move. A huge ion concentration difference is formed between the inside of the polymer network and the pure water outside. In order to balance this concentration difference, water molecules will spontaneously and in large quantities permeate into the inside of the polymer network through the semi-permeable membrane. As water molecules continue to flow in, the polymer network is stretched like a sponge, and the three-dimensional molecular chains are stretched. As a result, the sodium polyacrylate layer expands and blocks the opening, which helps to reduce the amount of seawater entering the sensor. This helps to reduce the damage to the internal components of the sensor and improves the service life of the sensor.

[0023] 2. By setting up a squeezing claw, the pull rope passes through the center of the elastic sealing layer. Under normal working conditions, the elastic sealing layer and the pull rope do not come into contact, which helps to reduce the wear of the elastic sealing layer by the pull rope and improve the service life of the sensor. When the outer sealing ring leaks water, the squeezing claw squeezes the elastic sealing layer, and the elastic sealing layer contracts towards the center of the through hole and comes into contact with the pull rope, thereby sealing the through hole. This helps to reduce the phenomenon of seawater entering the sensor, reduce the phenomenon of damage to internal components, and improve the service life.

[0024] 3. By setting up a sponge layer, a small amount of seawater will still pass through the perforations of the partition. The sponge layer absorbs this small amount of seawater, further reducing the phenomenon of seawater entering the sensor. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the overall structure of an underwater wire displacement sensor.

[0026] Figure 2 This is a schematic diagram of the structure of the water filter tank highlighted in this application.

[0027] Figure 3 This is a structural schematic diagram highlighting the filter screen, pressure plate, sodium polyacrylate layer, and sponge layer of this application.

[0028] Figure 4 This is a schematic diagram highlighting the structure of the skateboard, drive rack, and drive gear in this application.

[0029] Figure 5 This is a structural schematic diagram highlighting the rotating rod, the rotating screw, and the connecting plate in this application.

[0030] Explanation of reference numerals in the attached drawings: 1. Sensing mechanism; 11. Sensor body; 12. Threaded reel; 13. Pull rope; 14. Housing; 131. Pull ring; 15. Water filter tank; 2. First sealing mechanism; 21. Sodium polyacrylate layer; 22. Partition plate; 23. Filter screen; 24. Slider; 3. Second sealing mechanism; 31. Elastic sealing layer; 32. Compression claw; 33. Drive assembly; 34. Linkage assembly; 331. Rotating rod; 332. Rotating screw; 333. Connecting plate; 341. Pressure plate; 342. Slide plate; 343. Drive rack; 344. Drive gear; 345. Transmission rod; 4. Third sealing mechanism; 41. Sponge layer; 42. Push assembly; 421. Push plate; 422. Moving plate. Detailed Implementation

[0031] The present application will be further described in detail below with reference to all the accompanying drawings.

[0032] This application discloses an underwater wire displacement sensor.

[0033] Reference Figures 1 to 3 An underwater wire displacement sensor includes a sensing mechanism 1, a first sealing mechanism 2, a second sealing mechanism 3, and a third sealing mechanism 4. When the sealing ring inside the sensing mechanism 1 wears and leaks water, the first sealing mechanism 2, the second sealing mechanism 3, and the third sealing mechanism 4 perform triple sealing, which helps to reduce the entry of seawater into the sensor, thereby reducing the damage to the internal components of the sensor and improving the service life of the sensor.

[0034] refer to Figure 1 and Figure 2The sensing mechanism 1 includes a sensor body 11, a reel 12, a pull rope 13, a self-winding spring, and a housing 14. The sensor body 11 and the self-winding spring are not shown in the prior art drawings. The sensor body 11 is rotatably connected to the reel 12, and the reel 12 is connected to the self-winding spring. The pull rope 13 is wound around the outside of the reel 12. The reel 12 and the self-winding spring are both located inside the housing 14. The housing 14 has a sealing opening, and a sealing ring is located at the sealing opening of the housing 14. One end of the pull rope 13 that passes through the sealing opening is connected to a pull ring 131. A water filter box 15 is fixedly connected inside the housing 14. Both sides of the water filter box 15 have openings that are connected to the sealing opening. Part of the pull rope 13 is located inside the water filter box 15. The first sealing mechanism 2, the second sealing mechanism 3, and the third sealing mechanism 4 are all located inside the water filter box 15.

[0035] refer to Figures 2 to 4 The first sealing mechanism 2 includes a sodium polyacrylate layer 21, a partition 22, a filter screen 23, and four sliders 24. The partition 22 is vertically installed inside the water filter tank 15 and is fixedly connected to the water filter tank 15. A through hole is opened at the center of the partition 22, which is directly opposite the opening. Both the partition 22 and the water filter tank 15 have two slide rails. The four sliders 24 are slidably connected to the slide rails of the partition 22 and the water filter tank 15, respectively. The four sliders 24 are respectively installed at both ends of the filter screen 23. The filter screen 23 is horizontally installed. The sodium polyacrylate layer 21 is installed below the filter screen 23. The filter screen 23 is installed on the side of the partition 22 near the sealing opening.

[0036] refer to Figures 1 to 4 The pull rope 13 extends outward from the sensor through the water filter tank 15. The pull rope 13 continuously wears down the sealing ring, causing a small-diameter gap to appear. When the sealing ring is damaged, seawater flows into the water filter tank 15 through the opening. The filter screen 23 filters the seawater, preventing impurities and other substances in the seawater from easily passing through. The sodium polyacrylate comes into contact with water, which helps improve the water absorption effect of the sodium polyacrylate layer 21. When seawater comes into contact with the sodium polyacrylate layer 21, the sodium polyacrylate molecular chains, which carry a large number of sodium carboxylate groups, dissociate into the water upon contact with the sodium ions. Meanwhile, the negatively charged polymer chains, fixed by the cross-linked network, cannot... The movement creates a huge ion concentration difference between the inside of the polymer network and the pure water outside. To balance this concentration difference, water molecules spontaneously and in large quantities permeate into the inside of the polymer network through the semi-permeable membrane. As water molecules continuously flow in, the polymer network is stretched like a sponge, the three-dimensional molecular chains are stretched, the sodium polyacrylate layer 21 expands, and pushes the filter screen 23. The filter screen 23 moves upward laterally in cooperation with the slider 24, and then the sodium polyacrylate layer 21 expands and blocks the opening, which helps to reduce the amount of seawater entering the sensor, thereby reducing the damage to the internal components of the sensor and improving the service life of the sensor.

[0037] refer to Figures 2 to 5The second sealing mechanism 3 includes an elastic sealing layer 31, two compression claws 32, a drive assembly 33, and a linkage assembly 34. The drive assembly 33 includes a rotating rod 331, two rotating screws 332, and two connecting plates 333. The linkage assembly 34 includes a pressure plate 341, a sliding plate 342, a drive rack 343, a drive gear 344, and a transmission rod 345. The pressure plate 341 is horizontally positioned below the sodium polyacrylate layer 21. The two sides of the pressure plate 341 are slidably connected to the partition plate 22 and the water filter box 15, respectively. The sliding plate 342 is fixedly connected to the lower end face of the pressure plate 341. A groove is provided at the lower end of the water filter box 15. The sliding plate 342 is slidably connected to the groove of the water filter box 15. Part of the sliding plate 342 is disposed inside the water filter box 15. The sliding plate 342 is vertically positioned. The drive rack 343 is fixedly connected to the sliding plate 342. At the lower end, the drive rack 343 extends along the length of the slide plate 342. The drive gear 344 meshes with the drive rack 343. The drive gear 344 is fixedly connected to the transmission rod 345. The transmission rod 345 is connected to the rotating rod 331 through a bevel gear pair. The rotating rod 331 is rotatably connected inside the partition plate 22. The rotating screw 332 is coaxially fixedly connected to both ends of the rotating rod 331. The two rotating screws 332 have opposite threads. The two connecting plates 333 are threadedly connected to the two rotating screws 332 respectively. The connecting plates 333 are slidably connected to the partition plate 22. The two connecting plates 333 are fixedly connected to the two pressing claws 32 respectively. The pressing claws 32 are arranged on both sides of the elastic sealing layer 31. The pressing claws 32 abut against the elastic sealing layer 31. The elastic sealing layer 31 is evenly arranged circumferentially at the through holes of the partition plate 22.

[0038] refer to Figures 2 to 5 When the outer sealing ring leaks water, the sodium polyacrylate layer 21 expands and squeezes the pressure plate 341. The pressure plate 341 drives the sliding plate 342 to slide downwards. The sliding plate 342 drives the drive rack 343 to descend. The drive rack 343 drives the drive gear 344 to rotate. The drive gear 344 drives the transmission rod 345 to rotate. The transmission rod 345 drives the rotating rod 331 to rotate. The rotating rod 331 drives the two rotating screws 332 to rotate. The rotating screws 332 drive the two connecting plates 333 to move towards each other, which in turn drives the two squeezing claws 32 to move towards each other. After the two squeezing claws 32 come into contact, the elastic sealing layer 31 comes into contact with the pull rope 13, thus completing the sealing of the through hole. This helps to reduce the phenomenon of seawater entering the sensor, reduce the damage to internal components, and improve service life. Under normal working conditions, the elastic sealing layer 31 does not come into contact with the pull rope 13, which helps to reduce the wear of the elastic sealing layer 31 by the pull rope 13 and improve the service life of the sensor. Simultaneously, during the expansion and blockage of the opening by the sodium polyacrylate layer 21, the elastic sealing layer 31 blocks the through hole, achieving a double sealing effect. This further reduces the phenomenon of seawater entering the sensor. Furthermore, the mechanical transmission mode reduces the number of electronic control components, making it more suitable for applications in seawater.

[0039] refer to Figures 2 to 5 The third sealing mechanism 4 includes two sponge layers 41 and two pushing components 42. The pushing components 42 include a push plate 421 and a moving plate 422. The two sponge layers 41 are arranged in parallel. The push plate 421 is located on the side of the sponge layer 41 near the water filter tank 15. The push plate 421 is fixedly connected to the sponge layer 41. The side of the push plate 421 near the partition 22 is fixedly connected to the moving plate 422. The moving plate 422 is fixedly connected to the connecting plate 333. The sponge layer 41 is located at the through hole of the partition 22.

[0040] refer to Figures 2 to 5 A small amount of seawater passes through the perforation of the partition 22. The moving plate 422 moves synchronously with the connecting plate 333, which in turn drives the push plate 421 to move. The push plate 421 causes the two sponge layers 41 to move towards each other, thereby sealing the perforation of the partition 22 and the opening of the filter tank 15, and absorbing the small amount of seawater that enters. This achieves triple waterproofing, reducing the phenomenon of seawater entering the sensor, reducing damage to internal components, and improving service life. Under normal sensor operation, the sponge layer 41 is separated from the pull rope 13, which helps to reduce the wear of the sponge layer 41 by the pull rope 13.

[0041] The implementation principle of an underwater pull-wire displacement sensor according to an embodiment of this application is as follows: The pull rope 13 is pulled outward from the sensor through the water filter box 15. The pull rope 13 continuously wears down the sealing ring, and a small diameter gap appears in the sealing ring due to wear. When the sealing ring is damaged, seawater flows into the water filter box 15 through the opening. The filter screen 23 filters the seawater, and impurities and other substances in the seawater cannot easily pass through the filter screen 23. Sodium polyacrylate comes into contact with water. The sodium polyacrylate molecular chain has a large number of sodium carboxylate groups. When it comes into contact with water, these sodium ions will dissociate into the water. The negatively charged polymer chains cannot move because they are fixed by the cross-linked network. A huge ion concentration difference is formed between the inside of the polymer network and the pure water outside. In order to balance this concentration difference, water molecules will spontaneously and in large quantities permeate into the inside of the polymer network through the semi-permeable membrane. As water molecules continue to flow in, the polymer network is stretched like a sponge, the three-dimensional molecular chains are stretched, the sodium polyacrylate layer 21 expands, and pushes the filter screen 23. The filter screen 23 moves upward laterally with the help of the slider 24, and then the sodium polyacrylate layer 21 expands and blocks the opening.

[0042] The sodium polyacrylate layer 21 expands and synchronously extrudes the pressure plate 341. The pressure plate 341 drives the slide plate 342 to slide downwards. The slide plate 342 drives the drive rack 343 to descend. The drive rack 343 drives the drive gear 344 to rotate. The drive gear 344 drives the transmission rod 345 to rotate. The transmission rod 345 drives the rotating rod 331 to rotate. The rotating rod 331 drives the two rotating screws 332 to rotate. The rotating screws 332 drive the two connecting plates 333 to move towards each other, which in turn drives the two extrusion claws 32 to move towards each other. After the two extrusion claws 32 come into contact, the elastic sealing layer 31 comes into contact with the pull rope 13, achieving a double sealing effect.

[0043] The movable plate 422 moves synchronously with the connecting plate 333, which in turn drives the push plate 421 to move. The push plate 421 drives the two sponge layers 41 to move towards each other, thereby blocking the through holes of the partition plate 22 and the opening of the filter tank 15, and absorbing the small amount of seawater that enters, thus achieving triple waterproofing.

[0044] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. An underwater pull-wire displacement sensor, comprising a sensor body (11), a reel (12), a pull rope (13), a self-winding spring, and a housing (14), wherein the sensor body (11) is rotatably connected to the reel (12), the reel (12) is connected to the self-winding spring, the pull rope (13) is wound around the outside of the reel (12), and both the reel (12) and the self-winding spring are disposed within the housing (14), characterized in that: A water filter box (15) is fixedly connected inside the outer shell (14). Both sides of the water filter box (15) have openings for the passage of a pull rope (13). A partition plate (22) is fixedly connected inside the water filter box (15). A through hole for the pull rope (13) is opened at the center of the partition plate (22). The opening and the through hole are concentric. The partition plate (22) is vertically arranged. A layer of sodium polyacrylate (21) for water absorption and expansion is provided on the outer side of the partition plate (22) near the outer shell (14). A filter screen (23) is slidably connected to the side of the partition plate (22) near the outer shell (14). The filter screen (23) is horizontally arranged on the sodium polyacrylate layer. Above the sodium layer (21), the filter screen (23) has a gap for the pull rope (13) to pass through. The partition (22) is fixedly connected to an elastic sealing layer (31). The elastic sealing layer (31) is evenly arranged around the through holes of the partition (22). The partition (22) is provided with two squeezing claws (32) for squeezing the elastic sealing layer (31) to shrink towards the center of the through holes. The partition (22) is provided with a driving assembly (33) for driving the squeezing claws (32) to squeeze the elastic sealing layer (31). When the two squeezing claws (32) collide, the elastic sealing layer (31) squeezes the pull rope (13) to seal.

2. The underwater wire displacement sensor according to claim 1, characterized in that: The drive assembly (33) includes a rotating rod (331), two rotating screws (332) and two connecting plates (333). The rotating rod (331) is rotatably connected to the partition plate (22). The rotating screws (332) are coaxially fixedly connected to both ends of the rotating rod (331). The two rotating screws (332) have opposite threads. The two connecting plates (333) are threadedly connected to the two rotating screws (332) respectively. The connecting plates (333) are slidably connected to the partition plate (22). The two connecting plates (333) are fixedly connected to the two squeezing claws (32) respectively. When the rotating rod (331) rotates, the two squeezing claws (32) move towards each other. The filter tank (15) is provided with a linkage assembly (34) for driving the rotating rod (331) to rotate.

3. The underwater wire displacement sensor according to claim 2, characterized in that: The linkage assembly (34) includes a pressure plate (341), a sliding plate (342), a drive rack (343), a drive gear (344), and a transmission rod (345). The pressure plate (341) is horizontally positioned below the sodium polyacrylate layer (21). The two sides of the pressure plate (341) are slidably connected to the partition plate (22) and the water filter tank (15), respectively. The sliding plate (342) is fixedly connected to the lower end face of the pressure plate (341), and the sliding plate (342) is slidably connected to the water filter tank (15). Next, a portion of the slide plate (342) is installed inside the water filter tank (15). The slide plate (342) is vertically installed. The drive rack (343) is fixedly connected to the lower end of the slide plate (342). The drive rack (343) extends along the length of the slide plate (342). The drive gear (344) meshes with the drive rack (343). The drive gear (344) is fixedly connected to the transmission rod (345). The transmission rod (345) is connected to the rotating rod (331) through a bevel gear pair.

4. The underwater wire displacement sensor according to claim 3, characterized in that: Two water-absorbing sponge layers (41) are slidably connected to the side of the partition (22) away from the sodium polyacrylate layer (21). The sponge layers (41) are located at the through holes of the partition (22). Each of the two sponge layers (41) is provided with a pushing component (42) for pushing the sponge layers (41) to block the through holes.

5. An underwater wire displacement sensor according to claim 4, characterized in that: The pushing component (42) includes a push plate (421) and a moving plate (422). The push plate (421) is disposed on the side of the sponge layer (41) near the water filter tank (15). The push plate (421) is fixedly connected to the sponge layer (41). The side of the push plate (421) near the partition (22) is fixedly connected to the moving plate (422). The moving plate (422) is fixedly connected to the connecting plate (333).

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