Energy-saving heat preservation device for silica sol storage tank

Abstract

The present application belongs to the technical field of silica sol storage tank, and relates to an energy-saving heat preservation device for a silica sol storage tank. The present application comprises a tank body, a first exhaust cavity and a second exhaust cavity are sequentially communicated with the lower part of the tank body; a discharge pipe is communicated with the lower part of the second exhaust cavity; a sieve plate is slidably arranged in each of the first exhaust cavity and the second exhaust cavity; a driving mechanism for driving the reverse movement of the two sieve plates is installed at the bottom of the tank body; and a negative pressure assembly for vacuumizing the first exhaust cavity and the second exhaust cavity is installed on the tank body. The silica sol is divided and thinned into multiple liquid columns through the through holes on the sieve plates, so as to greatly increase the contact area of the silica sol with the negative pressure environment. The reverse movement of the two sieve plates prolongs the flowing time of the silica sol in the negative pressure environment, which is beneficial to the escape of bubbles. Meanwhile, the silica sol is extruded by the movement of the sieve plates, so as to further break and separate the bubbles wrapped therein, thereby improving the quality of the silica sol.

Description

Technical Field

[0001] This invention belongs to the field of silica sol storage tank technology, and relates to an energy-saving and heat-insulating device for silica sol storage tanks. Background Technology

[0002] Silica sol, an inorganic colloidal material with high dispersibility and high specific surface area, is widely used in electronic packaging, precision casting, coatings, catalyst supports, and other fields. After preparation, silica sol needs to be transported to storage tanks. During this process, air can easily be drawn into the tank with the fluid flow, and tiny air bubbles become trapped within the silica sol, making them difficult to remove. The presence of these bubbles can severely affect the transparency, uniformity, coating performance, and mechanical strength of the final product.

[0003] Patent document CN119142670A discloses a storage device for processing thermally conductive silicone, including a sealed container for storing hot silicone. A stirring rod is rotatably mounted inside the sealed container, and a vacuum pump is installed on the container. A connecting pipe connects the vacuum pump to the sealed container. A discharge mechanism includes a discharge box connected to the bottom of the sealed container, with a guide frame plate at the bottom of the discharge box. An extraction pipe connects the connecting pipe to the top of the guide frame plate. This application primarily uses a trickle mechanism to allow hot silicone to flow into the guide frame plate in multiple trickle streams. Combined with the vacuum pump, this effectively removes air bubbles from the hot silicone inside the guide frame plate. Finally, a collection mechanism discharges the de-bubbled hot silicone. However, this degassing process mainly relies on static diversion and gravity flow, which has limited effectiveness in breaking up and extruding stubborn air bubbles within the silicone sol. There is still room for improvement in degassing efficiency and thoroughness.

[0004] To address the above problems, this invention proposes an energy-saving insulation device for silica sol storage tanks. Summary of the Invention

[0005] To address the problems existing in the background art, the present invention proposes an energy-saving and heat-insulating device for silica sol storage tanks.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] An energy-saving and heat-insulating device for a silica sol storage tank includes a tank body. The lower part of the tank body is sequentially connected to a first exhaust chamber and a second exhaust chamber. The lower part of the second exhaust chamber is connected to a discharge pipe. A perforated plate is slidably disposed in both the first and second exhaust chambers. A driving mechanism for driving the two perforated plates to move in opposite directions is installed at the bottom of the tank body. The two perforated plates move in opposite directions to receive, divert, and extrude the silica sol in the first and second exhaust chambers, respectively, thereby dynamically lengthening the flow path of the silica sol and increasing its contact area with the negative pressure environment. A negative pressure component for evacuating the first and second exhaust chambers is installed on the tank body.

[0008] Furthermore, the bottom of the tank is provided with a discharge hole, and a rotating disk is rotatably installed on the bottom of the tank. The rotating disk is provided with an adapter hole. When the discharge hole and the adapter hole are connected, the silica sol in the tank flows into the first exhaust chamber.

[0009] Furthermore, the upper end of the second exhaust chamber is provided with a first through hole connecting the first exhaust chamber and the second exhaust chamber; the lower end of the second exhaust chamber is fixedly connected to a discharge cylinder, and the lower end of the second exhaust chamber is provided with a second through hole communicating with the discharge cylinder; the discharge pipe is installed at the lower end of the discharge cylinder.

[0010] Furthermore, a push rod is fixed to the lower end of the sump plate, and the push rod on the sump plate in the first exhaust chamber is slidably inserted into the first through hole; the push rod on the sump plate in the second exhaust chamber is slidably inserted into the second through hole.

[0011] Furthermore, the driving mechanism includes a rotating rod, a sleeve and a tube sleeved on the rotating rod; the sleeve is fixedly connected to the vent plate in the first exhaust chamber, and the tube is fixedly connected to the lower vent plate in the second exhaust chamber; the rotating rod is driven by the sleeve and tube through a threaded structure with opposite rotation directions.

[0012] Furthermore, the rotating disk is sleeved on the sleeve, the sleeve has a second threaded groove, and a second protrusion is fixed on the rotating disk, the second protrusion being slidably disposed in the second threaded groove.

[0013] Furthermore, the tank body is fixedly connected to a fixing frame, and a motor that drives the rotating rod to rotate is installed on the fixing frame.

[0014] Furthermore, the inner diameter of the second exhaust chamber is larger than the inner diameter of the first exhaust chamber.

[0015] Furthermore, the exterior of the tank is provided with an insulation layer for introducing heat exchange water for heat preservation.

[0016] Furthermore, the inner wall of the sleeve is provided with a first threaded groove, and the inner wall of the tube is provided with a third threaded groove; and the first threaded groove and the third threaded groove have opposite directions of rotation; a first protrusion is slidably embedded in both the first threaded groove and the third threaded groove, and the first protrusion is fixedly connected to the rotating rod.

[0017] Compared with existing technologies, this invention has the following advantages: The silica sol is diverted and spread into multiple liquid columns through the through-holes in the perforations of the perforators, significantly increasing its contact area with the negative pressure environment. The counter-current movement of the two perforators prolongs the flow time of the silica sol in the negative pressure environment, facilitating the removal of air bubbles. Simultaneously, the movement of the perforators compresses the silica sol, further breaking down and separating the encapsulated air bubbles, thus improving the quality of the silica sol.

[0018] The movement of the sleeve drives the rotating disk to rotate, which in turn opens or closes the discharge port, achieving a synergistic effect between the discharge and degassing processes and improving degassing efficiency. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0020] Figure 2 In this invention Figure 1 Enlarged view of part A;

[0021] Figure 3 This is a partial sectional view of the tank body in this invention;

[0022] Figure 4 In this invention Figure 3 Enlarged view of part B;

[0023] Figure 5 In this invention Figure 4 Enlarged view of part C;

[0024] Figure 6 In this invention Figure 4 Enlarged view of part D;

[0025] Figure 7 This is a schematic diagram of the lower perforated plate in this invention;

[0026] Figure 8 This is a schematic diagram of the rotating rod in this invention;

[0027] Figure 9 This is a schematic diagram of the upper perforated plate in this invention;

[0028] Figure 10 This is a schematic diagram of the rotating disk in this invention;

[0029] Figure 11 This is a schematic diagram of the internal structure of the first and second exhaust chambers in this invention.

[0030] In the diagram: 1. Tank body; 2. Insulation layer; 3. Inlet pipe; 4. Outlet pipe; 5. Feed pipe; 6. First negative pressure pump; 7. Discharge hole; 8. Rotating disc; 9. Adaptor hole; 10. First exhaust chamber; 11. Second exhaust chamber; 12. First through hole; 13. Second through hole; 14. Discharge cylinder; 15. Discharge pipe; 16. Fixing frame; 17. Third threaded groove; 18. Sleeve; 19. Lower drain plate; 20. Rotating rod; 21. First protrusion; 22. Sleeve; 23. First threaded groove; 24. Spline; 25. Keyway; 26. Second threaded groove; 27. Second protrusion; 28. Upper drain plate; 29. ​​Top rod; 30. Second negative pressure pump; 31. Air pipe. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] like Figures 1-11 As shown, the technical solution adopted by the present invention is as follows: An energy-saving heat preservation device for a silica sol storage tank includes a tank body 1, a heat preservation layer 2, a first exhaust chamber 10, a second exhaust chamber 11, a drive mechanism, and a negative pressure component.

[0033] The tank body 1 is covered with an insulation layer 2. The lower part of the insulation layer 2 is equipped with a water inlet pipe 3, and the upper part is equipped with a water outlet pipe 4. The water inlet pipe 3 and the water outlet pipe 4 are used to connect the heat exchange water circuit of the silicon powder hydrolysis reaction heat recovery system, so that the waste heat of the reaction can continuously keep the tank body 1 warm, effectively prevent the silica sol from solidifying, realize the recycling of energy, and achieve the purpose of energy saving.

[0034] The top of the tank 1 is equipped with a feed pipe 5 and a first negative pressure pump 6. The first negative pressure pump 6 is connected to the inside of the tank 1 and can draw negative pressure inside the tank 1 after feeding or during storage to initially remove air bubbles in the silica sol.

[0035] The bottom of the tank body 1 has multiple discharge holes 7. A rotating disk 8 is rotatably mounted on the bottom of the tank body 1. The rotating disk 8 has matching holes 9 that mate with the discharge holes 7. By rotating the rotating disk 8, the matching holes 9 and the discharge holes 7 can be aligned or misaligned, thereby opening and closing the discharge holes 7.

[0036] A first exhaust chamber 10 and a second exhaust chamber 11 are fixedly connected sequentially to the lower part of the tank body 1. Preferably, the inner diameter of the second exhaust chamber 11 is larger than the inner diameter of the first exhaust chamber 10. This allows the silica sol to spread over a larger area within the second exhaust chamber 11, which helps to reduce the flow rate of the silica sol, prolongs the residence time of the silica sol within the second exhaust chamber 11, and allows sufficient time for air bubbles in the silica sol to escape, thus improving the degassing effect. The first exhaust chamber 10 and the second exhaust chamber 11 are connected through a first through hole 12 at the upper end of the second exhaust chamber 11. A discharge cylinder 14 is fixedly connected to the lower end of the second exhaust chamber 11, and a second through hole 13 connecting the second exhaust chamber 11 and the discharge cylinder 14 is provided at the lower end of the second exhaust chamber 11.

[0037] A discharge pipe 15 is installed on the side of the discharge cylinder 14 for the final discharge of the processed silica sol.

[0038] Both the first exhaust chamber 10 and the second exhaust chamber 11 have slidably disposed permeable plates. For ease of description, the permeable plate disposed in the first exhaust chamber 10 is named the upper permeable plate 28, and the permeable plate disposed in the second exhaust chamber 11 is named the lower permeable plate 19. Both the upper permeable plate 28 and the lower permeable plate 19 have multiple through holes to disperse the flowing silica sol into multiple fine streams, thereby increasing their contact area with the vacuum environment.

[0039] A push rod 29 is fixedly connected to the lower end of both the upper drain plate 28 and the lower drain plate 19. When the upper drain plate 28 moves to the bottom of the first exhaust chamber 10, the push rod 29 on the upper drain plate 28 inserts into and blocks the first through hole 12. When the lower drain plate 19 moves to the bottom of the second exhaust chamber 11, the push rod 29 on the lower drain plate 19 inserts into and blocks the second through hole 13.

[0040] The drive mechanism is used to drive the upper perforator 28 and the lower perforator 19 to move in opposite directions.

[0041] The mechanism includes a rotating rod 20, a sleeve 22, and a tube 18. The sleeve 22 is slidably inserted into the first exhaust chamber 10 and the second exhaust chamber 11. The sleeve 22 is fixedly connected to the upper strainer plate 28. The tube 18 is slidably inserted into the second exhaust chamber 11 and the discharge cylinder 14, and the lower strainer plate 19 is fixedly connected to the tube 18.

[0042] The rotating rod 20 is movably inserted inside the sleeve 22 and the tube 18. The rotating rod 20 engages with the sleeve 22 and the tube 18 via oppositely helical threads. Specifically, the inner wall of the sleeve 22 has a first threaded groove 23, and the inner wall of the tube 18 has a third threaded groove 17. The first threaded groove 23 and the third threaded groove 17 have opposite helical directions. A first protrusion 21 is slidably embedded in both the first threaded groove 23 and the third threaded groove 17, and the first protrusion 21 is fixedly connected to the rotating rod 20.

[0043] The upper end of the sleeve 22 slides into the tank body 1. The rotating disk 8 is fitted onto the sleeve 22. A second threaded groove 26 is formed on the top outer wall of the sleeve 22. A second protrusion 27 is fixed to the rotating disk 8, and the second protrusion 27 is slidably embedded in the second threaded groove 26. When the sleeve 22 moves relative to the rotating disk 8, it drives the rotating disk 8 to rotate through the second protrusion 27, thereby opening or closing the discharge hole 7.

[0044] The lower end of the rotating rod 20 passes through the bottom of the discharge cylinder 14. A fixed frame 16 is fixedly connected to the bottom of the tank body 1. A motor is installed on the fixed frame 16, and the output shaft of the motor is fixedly connected to the lower end of the rotating rod 20.

[0045] When the rotating rod 20 rotates, it drives the sleeve 22 and the tube 18 to move axially in opposite directions, thereby causing the upper drain plate 28 and the lower drain plate 19 to move in opposite directions. At the same time, the axial movement of the sleeve 22 drives the rotating disk 8 to rotate through the engagement of the second threaded groove 26 and the second protrusion 27.

[0046] To ensure that the sleeve 22 and the tube 18 can only move and not rotate, splines 24 are fixed on the outside of both the sleeve 22 and the tube 18, and keyways 25 for the splines 24 to slide are opened at the upper and lower ends of the corresponding second exhaust chamber 11.

[0047] like Figure 1 , Figure 2 As shown, the negative pressure assembly includes a second negative pressure pump 30 fixed on the tank body 1. The second negative pressure pump 30 is connected to both the first exhaust chamber 10 and the second exhaust chamber 11 through an air pipe 31, and is used to evacuate the first exhaust chamber 10 and the second exhaust chamber 11 during the discharge process to create a negative pressure environment to facilitate the precipitation and removal of bubbles.

[0048] Working principle: During use, the waste heat generated by the hydrolysis of silicon powder is continuously introduced into the insulation layer 2 through the heat exchange water circuit from the inlet pipe 3, flows through the outer wall of the tank 1, and then flows out from the outlet pipe 4. This process utilizes the waste heat generated by the hydrolysis of silicon powder to continuously insulate the tank 1, effectively preventing the silica sol from solidifying due to excessively low temperatures, thus achieving energy recycling and energy saving.

[0049] During storage, the adapter hole 9 on the rotating disk 8 is misaligned with the discharge hole 7 at the bottom of the tank 1, and the solid part of the rotating disk 8 completely blocks the discharge hole 7 to prevent silica sol leakage.

[0050] At this time, the upper drain plate 28 is located above the first exhaust chamber 10, and the lower drain plate 19 is located below the second exhaust chamber 11. The push rod 29 on the lower drain plate 19 is inserted into and blocks the second through hole 13.

[0051] During and after the process of filling the tank 1 with silica sol through the feed pipe 5, the first negative pressure pump 6 can be activated to create negative pressure inside the tank 1. This helps to extract air bubbles generated during mixing or storage, and provides preliminary pretreatment for the silica sol.

[0052] When silica sol needs to be used, the second negative pressure pump 30 is first started. The second negative pressure pump 30 simultaneously evacuates the first exhaust chamber 10 and the second exhaust chamber 11 through the air pipe 31. This removes the air from the first exhaust chamber 10 and the second exhaust chamber 11, creating a negative pressure environment inside, which creates favorable conditions for the rapid precipitation and extraction of bubbles when silica sol flows in.

[0053] Then, the motor on the fixed frame 16 is started, driving the rotating rod 20 to start rotating. The rotating rod 20 causes the sleeve 22 to move down and the sleeve 18 to move up, which in turn causes the upper drain plate 28 to move down and the lower drain plate 19 to move up.

[0054] As the sleeve 22 moves downward, the rotating disk 8 rotates due to the cooperation of the second protrusion 27 and the second threaded groove 26. This causes the adapter hole 9 on the rotating disk 8 to gradually align with the discharge hole 7 at the bottom of the tank 1, opening the discharge hole 7 and allowing the silica sol inside the tank 1 to flow out.

[0055] The outflowing silica sol, after passing through the discharge hole 7 and the adapter hole 9, first falls onto the upper sprue plate 28. The silica sol spreads out on the surface of the upper sprue plate 28 and flows downwards through the through-holes in the upper sprue plate 28. This spreading out of the silica sol on the surface of the upper sprue plate 28 extends the flow path and exposure area, facilitating the removal of air bubbles. The silica sol is dispersed by the upper sprue plate 28 into multiple downward-flowing liquid columns, increasing the contact area (exposure area) between the silica sol and the negative pressure environment within the first exhaust chamber 10, allowing air bubbles inside the silica sol to be extracted efficiently and quickly.

[0056] The silica sol that falls to the bottom of the first exhaust chamber 10 flows to the second exhaust chamber 11 through the first through hole 12. However, since the flow rate of the first through hole 12 is less than that of the upper sprue 28, the silica sol accumulates at the bottom of the first exhaust chamber 10.

[0057] As the upper vent plate 28 continues to move downwards, it exerts a squeezing effect on the silica sol accumulated at the bottom of the first venting chamber 10. This also pushes some of the silica sol into the second venting chamber 11.

[0058] As the upper sprue plate 28 moves downward, the push rod 29 on the upper sprue plate 28 is inserted into the first through hole 12, sealing the first through hole 12. Subsequently, as the upper sprue plate 28 moves downward, the silica sol accumulated at the bottom of the first exhaust chamber 10 flows through the upper sprue plate 28 to the top of the upper sprue plate 28. Through the squeezing action of the upper sprue plate 28 and the diversion effect of the through hole on the upper sprue plate 28, the bubbles in the silica sol are further broken and separated, promoting the expulsion of the bubbles. Simultaneously, the flow path of the silica sol is lengthened, prolonging the residence time of the silica sol in the first exhaust chamber 10, which helps the bubbles to escape.

[0059] The silica sol flowing into the second exhaust chamber 11 is received by the gradually upward-moving lower drain plate 19. The silica sol flowing onto the lower drain plate 19 automatically spreads out under natural flow and flows downward through the through-holes in the lower drain plate 19. This extends the flow path and exposure area of ​​the silica sol, facilitating the removal of air bubbles. It also allows the silica sol to be fully exposed again in the negative pressure environment of the second exhaust chamber 11, further removing residual air bubbles. Furthermore, because the lower drain plate 19 is larger than the upper drain plate 28, the area on the lower drain plate 19 where the silica sol is distributed is larger. And as the lower drain plate 19 moves upward, the flow path of the silica sol is lengthened.

[0060] After the upper duct plate 28 moves to the bottom of the first exhaust chamber 10, it rises, while the lower duct plate 19 begins to move downward. During its downward movement, the lower duct plate 19 squeezes the silica sol accumulated at the bottom of the second exhaust chamber 11, causing it to flow through the second through hole 13 to the discharge cylinder 14, and finally be discharged through the discharge pipe 15.

[0061] When the lower duct plate 19 moves to the bottom of the second exhaust chamber 11, the push rod 29 below the lower duct plate 19 inserts and blocks the second through hole 13. The upper duct plate 28 moves up to the upper part of the first exhaust chamber 10. At this time, the adapter hole 9 is misaligned with the discharge hole 7, and the discharge hole 7 is closed.

[0062] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An energy-saving insulation device for a silica sol storage tank, comprising a tank body (1), characterized in that: The lower part of the tank (1) is connected to a first exhaust chamber (10) and a second exhaust chamber (11) in sequence; the lower part of the second exhaust chamber (11) is connected to a discharge pipe (15); a slidable baffle is provided in both the first exhaust chamber (10) and the second exhaust chamber (11); a driving mechanism for driving the two baffles to move in opposite directions is installed at the bottom of the tank (1); the two baffles move in opposite directions to receive, divert and squeeze the silica sol in the first exhaust chamber (10) and the second exhaust chamber (11) respectively, thereby dynamically lengthening the flow path of the silica sol and increasing its contact area with the negative pressure environment; a negative pressure assembly for evacuating the first exhaust chamber (10) and the second exhaust chamber (11) is installed on the tank (1); The upper end of the second exhaust chamber (11) is provided with a first through hole (12) connecting the first exhaust chamber (10) and the second exhaust chamber (11); the lower end of the second exhaust chamber (11) is fixedly connected to a discharge cylinder (14), and the lower end of the second exhaust chamber (11) is provided with a second through hole (13) communicating with the discharge cylinder (14); the discharge pipe (15) is installed at the lower end of the discharge cylinder (14); The drain plate in the first exhaust chamber (10) is named the upper drain plate (28), and the drain plate in the second exhaust chamber (11) is named the lower drain plate (19); the upper drain plate (28) and the lower drain plate (19) disperse the flowing silica sol into multiple fine streams; When taking silica sol, the upper drain plate (28) is moved downward and the lower drain plate (19) is moved upward. The silica sol in the tank (1) falls onto the upper drain plate (28) and spreads out on the upper drain plate (28). The silica sol is dispersed into multiple downward flowing liquid columns by the upper drain plate (28). The silica sol at the bottom of the first exhaust chamber (10) flows to the second exhaust chamber (11). As the upper drain plate (28) moves downward, it exerts a squeezing effect on the silica sol accumulated at the bottom of the first exhaust chamber (10). The silica sol flowing into the second exhaust chamber (11) is received by the gradually moving lower drain plate (19) and then flows downward through the lower drain plate (19). As the lower drain plate (19) moves upward, the flow path of the silica sol is lengthened.

2. The energy-saving and heat-insulating device for the silica sol storage tank according to claim 1, characterized in that: The bottom of the tank (1) is provided with a discharge hole (7), and a rotating disk (8) is rotatably installed on the bottom of the tank (1). An adapter hole (9) is provided on the rotating disk (8). When the discharge hole (7) and the adapter hole (9) are connected, the silica sol in the tank (1) flows into the first exhaust chamber (10).

3. The energy-saving and heat-insulating device for the silica sol storage tank according to claim 1, characterized in that: The lower end of the sluice plate is fixed with a top rod (29). The top rod (29) on the sluice plate in the first exhaust chamber (10) is slidably inserted into the first through hole (12); the top rod (29) on the sluice plate in the second exhaust chamber (11) is slidably inserted into the second through hole (13).

4. The energy-saving and heat-insulating device for the silica sol storage tank according to claim 2, characterized in that: The driving mechanism includes a rotating rod (20), a sleeve (22) and a tube (18) sleeved on the rotating rod (20); the sleeve (22) is fixedly connected to the vent plate in the first exhaust chamber (10), and the tube (18) is fixedly connected to the vent plate in the second exhaust chamber (11); the rotating rod (20) is driven by the sleeve (22) and the tube (18) through a threaded structure with opposite rotation direction.

5. The energy-saving and heat-insulating device for the silica sol storage tank according to claim 4, characterized in that: The rotating disk (8) is sleeved on the sleeve (22), and the sleeve (22) has a second threaded groove (26). The rotating disk (8) has a second protrusion (27) fixed on it, and the second protrusion (27) is slidably disposed in the second threaded groove (26).

6. The energy-saving and heat-insulating device for the silica sol storage tank according to claim 5, characterized in that: The tank (1) is fixedly connected to a fixed frame (16), and a motor that drives the rotating rod (20) to rotate is installed on the fixed frame (16).

7. The energy-saving and heat-insulating device for the silica sol storage tank according to claim 1, characterized in that: The inner diameter of the second exhaust chamber (11) is larger than the inner diameter of the first exhaust chamber (10).

8. The energy-saving and heat-insulating device for the silica sol storage tank according to claim 1, characterized in that: The tank (1) is provided with an insulation layer (2) for heat exchange water to be introduced for heat preservation.

9. The energy-saving and heat-insulating device for the silica sol storage tank according to claim 4, characterized in that: The inner wall of the sleeve (22) is provided with a first threaded groove (23), and the inner wall of the sleeve (18) is provided with a third threaded groove (17); and the first threaded groove (23) and the third threaded groove (17) have opposite directions of rotation; a first protrusion (21) is slidably embedded in both the first threaded groove (23) and the third threaded groove (17), and the first protrusion (21) is fixedly connected to the rotating rod (20).

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