Carbon dioxide filling device

By introducing buffer and positioning components into the carbon dioxide filling device, the problem of instability of gas cylinders during the filling process is solved, achieving efficient and accurate filling and weighing, and improving the safety and applicability of the equipment.

CN224339905UActive Publication Date: 2026-06-09TAIYUAN JINTENG GAS CO LTD

Patent Information

Authority / Receiving Office
CN · China
Patent Type
Utility models(China)
Current Assignee / Owner
TAIYUAN JINTENG GAS CO LTD
Filing Date
2025-04-14
Publication Date
2026-06-09

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Abstract

The application relates to the field of carbon dioxide filling equipment, in particular to a carbon dioxide filling device which comprises a support frame, a gas filling mechanism, a weighing mechanism and a display screen. The gas filling mechanism realizes safe and efficient gas filling of a gas cylinder through a gas storage tank, a communication pipe and a spray gun assembly; the weighing mechanism is equipped with a weighing plate provided with a buffer assembly and a positioning assembly, and in combination with an optimized multi-stage guiding and locking system, the weighing mechanism ensures stable placement and accurate measurement of the gas cylinder. The application achieves the technical effects of improving carbon dioxide filling precision, enhancing operation safety and improving user experience.
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Description

Technical Field

[0001] This application relates to the field of carbon dioxide filling equipment technology, and in particular to a carbon dioxide filling device. Background Technology

[0002] Carbon dioxide filling equipment is widely used in industrial production, food processing, and other fields, providing essential gas support for various devices. With the acceleration of industrialization and technological advancements, the requirements for the accuracy and efficiency of carbon dioxide filling are becoming increasingly stringent. Currently, various carbon dioxide filling devices exist on the market, which to some extent meet the needs of different scenarios, but still face many challenges in practical applications.

[0003] In food and industrial production, protective gases such as carbon dioxide are frequently used. These gases are typically pre-stored in cryogenic liquid tanks and then dispensed into smaller cylindrical cylinders via a gas filling system for easy transport and use. Currently, electronic scales are often used to weigh and fill these cylindrical cylinders. However, due to the weight of the cylinders, workers often bump or impact them during filling, leading to inaccurate weighing data and requiring frequent adjustments, severely impacting filling efficiency.

[0004] A common problem with the aforementioned technologies is that the lack of effective buffering and positioning measures during the filling process leads to unstable placement of gas cylinders, which can easily cause them to shift or tip over, affecting measurement accuracy and operational safety, and thus reducing overall work efficiency. At the same time, the weighing data may have some deviation due to the displacement of the cylinder placement position, and the existing buffering devices often only correspond to one type of cylinder, resulting in poor applicability. Therefore, there is an urgent need for a new solution that can effectively solve this problem and ensure that the entire process is carried out more reliably and smoothly. Utility Model Content

[0005] To address the aforementioned problems, this application provides a carbon dioxide filling device.

[0006] This application provides a carbon dioxide filling device, which adopts the following technical solution:

[0007] A carbon dioxide filling device includes: a support frame, an inflation mechanism disposed on the support frame for filling a gas cylinder, a weighing mechanism including a weighing device, a weighing plate disposed on the weighing device, a buffer assembly disposed on the weighing plate, a positioning assembly disposed on the buffer assembly, and a display screen electrically connected to the weighing mechanism.

[0008] By adopting the above technical solutions, this carbon dioxide filling device can achieve efficient and accurate filling while ensuring the safety and stability of the operation process. Specifically, during the filling of gas cylinders, the support frame provides a stable foundation for the entire equipment, effectively avoiding the risk of tipping over due to external environment or improper operation. The filling mechanism is rationally designed and directly installed on the support frame, allowing for precise control of gas flow and direction, thereby improving filling efficiency and reducing resource waste. In particular, the weighing mechanism integrates a design concept that includes buffer components and positioning components, making the placement of the gas cylinder to be filled more stable and reliable. When the gas cylinder is placed on the weighing plate, multiple springs in the buffer component work together to absorb the impact force, preventing damage caused by excessive instantaneous pressure; while the positioning component can quickly fix the gas cylinder in its axial position, eliminating the occurrence of displacement. This not only helps to improve weighing accuracy but also further ensures the smooth completion of subsequent steps. In addition, the display screen shows relevant data information in real time, allowing staff to monitor status changes at any time and adjust parameter settings in a timely manner, ultimately optimizing the overall process.

[0009] Preferably, the inflation mechanism includes a gas storage tank, a connecting pipe, and a switch valve. The gas storage tank is connected to the spray gun assembly through the connecting pipe, the switch valve is disposed on the connecting pipe, and the spray gun assembly can point towards the weighing mechanism.

[0010] By adopting the above technical solution, the design of the connecting pipe between the gas storage tank and the spray gun assembly, along with the switch valve, not only achieves precise control of the filling process but also improves the safety and convenience of the filling operation. Simultaneously, the spray gun assembly can flexibly point towards the weighing mechanism, further optimizing the equipment's operational flexibility and improving work efficiency.

[0011] Preferably, the spray gun assembly includes a spray gun support frame and a spray gun nozzle, the spray gun nozzle is connected to the gas storage tank through the connecting pipe, and the spray gun nozzle is provided with a connecting component.

[0012] By adopting the above technical solution, the design of the spray gun assembly enables the spray gun nozzle to be stably connected to the gas storage tank. At the same time, the connection components improve the operational flexibility and sealing performance of the spray gun nozzle, effectively avoiding leakage problems caused by unstable connection during the filling process, and further improving the safety and efficiency of carbon dioxide filling.

[0013] Preferably, the connecting component includes a threaded rod, a pressing plate, and an operating handle. The threaded rod passes through the spray gun support frame, the pressing plate is located at one end of the threaded rod and can press against the tank body of the gas canister, and the operating handle is located at the end of the threaded rod away from the pressing plate.

[0014] By adopting the above technical solution, the design of the connecting components makes the connection between the spray gun assembly and the gas tank more stable and reliable. Specifically, the threaded rod structure allows for adjustment of the pressure plate position to accommodate gas tanks of different sizes, ensuring that the pressure plate fits tightly against the gas tank surface and improves sealing performance. Simultaneously, the operating handle allows operators to manually adjust the tightness of the threaded rod, improving ease of use and work efficiency. This design not only enhances equipment safety but also reduces the risk of gas leakage due to unstable connections.

[0015] Preferably, the buffer assembly includes a first buffer plate and several buffer springs. The first buffer plate is fixed on the support frame, and one end of each buffer spring is connected to the first buffer plate and the other end is connected to a second buffer plate.

[0016] By adopting the above technical solution, the design of the buffer assembly effectively mitigates the impact force generated during the placement of the gas cylinder, ensuring the stability of the weighing process. Specifically, the first buffer plate is fixedly connected to the support frame, forming a stable foundation structure, while the configuration of multiple sets of buffer springs absorbs excess vibration energy when the gas cylinder is placed, avoiding measurement errors caused by external vibrations or the weight of the gas cylinder itself, thereby improving the operational accuracy and reliability of the entire filling device. At the same time, this design also extends the service life of the weighing mechanism and reduces the frequency of equipment maintenance.

[0017] Preferably, the positioning assembly includes a support ring and at least three sets of positioning components. The support ring is disposed on the second buffer plate, and the positioning components are horizontally slidably connected to the support ring and pointing towards the axis of the support ring. The assembly also includes a plurality of rolling grooves disposed on the second buffer plate, wherein rolling balls are disposed in the rolling grooves, and the rolling grooves are disposed within the support ring.

[0018] By adopting the above technical solution, stable positioning of the gas cylinder is achieved. Specifically, the supporting ring, in conjunction with multiple sets of positioning components, ensures that the gas cylinder remains centered during filling, effectively preventing positional shifts caused by external vibrations or impacts. Simultaneously, the horizontal sliding connection design allows the positioning components to be flexibly adjusted according to the gas cylinder size, thereby improving the adaptability and ease of operation of the device. This precise positioning method not only improves filling efficiency but also significantly reduces safety hazards during the filling process, and the ball bearing design makes centering even more convenient.

[0019] Preferably, the positioning component includes a sliding rod and a guide slope, the sliding rod being slidably connected to the support ring, and the guide slope being disposed on the side of the sliding rod facing the axis of the support ring.

[0020] By adopting the above technical solution, the sliding connection structure between the sliding rod and the supporting ring allows the position of the positioning component to be flexibly adjusted according to the actual size of the gas tank, thereby improving the adaptability of the device. At the same time, the unique design of the guide slope reduces frictional resistance during sliding, ensuring a smoother and more stable positioning process, further enhancing the safety and efficiency of the filling operation.

[0021] Preferably, it further includes a first guiding mechanism, which includes a guide groove and a first rotating rod. The guide groove is disposed on the guide slope, the first rotating rod is rotatably connected to the sliding rod, and a first rotating wheel is disposed on the first rotating rod, the first rotating wheel being located within the guide groove.

[0022] By adopting the above technical solution, the position adjustment of the positioning component can be effectively guided during the placement of the gas cylinder. Specifically, the cooperation between the guide groove and the first rotating wheel allows the sliding rod to move smoothly along a predetermined trajectory when subjected to force, thereby improving positioning accuracy and reducing the risk of equipment damage due to deviation. At the same time, this structural design also has good adaptability, compatible with the filling requirements of gas cylinders of different specifications, further enhancing the overall practicality of the device.

[0023] Preferably, it further includes a second guide mechanism, which includes a second steering rod and a second rotating wheel. The second steering rod is rotatably connected to the side of the sliding rod near the axis of the supporting ring, and the second rotating wheel is disposed on the second steering rod and can press against the tank body of the gas tank.

[0024] By adopting the above technical solution, the second rotating wheel can provide a stable radial constraint force during the placement of the gas cylinder, ensuring that the gas cylinder is accurately positioned without deviation during the filling process. Simultaneously, thanks to the flexible adjustment capability of the second steering rod, this structure can adapt to gas cylinders of different diameters, significantly improving equipment compatibility and ease of operation, and reducing the need for manual adjustment while ensuring safety.

[0025] Preferably, the device further includes a locking mechanism, which includes a locking block, a locking rod, and a locking electromagnet. The locking block is disposed on the side of the sliding rod away from the axis of the supporting ring. The locking rod passes through the locking block and is connected to the supporting ring. The locking electromagnet is disposed at one end of the locking rod. A magnetic locking ring is disposed between the locking block and the locking electromagnet, and the locking ring is slidably connected to the locking rod.

[0026] By adopting the above technical solution, the locking mechanism can effectively fix the position of the positioning component. After the gas tank is positioned, the magnetic field generated by the locking electromagnet drives the locking ring to move along the locking rod, thereby pressing the locking block tightly against the sliding rod to prevent displacement or loosening. This ensures that the gas tank remains stable during the filling process, improving the operational safety and reliability of the equipment.

[0027] In summary, this application includes at least one of the following beneficial technical effects:

[0028] 1. By adding a buffer assembly consisting of a first buffer plate, a buffer spring, and a second buffer plate to the weighing plate, the impact force can be significantly reduced during the placement of the gas cylinder, effectively preventing fluctuations in weighing data or equipment damage caused by impact, and greatly improving the accuracy of weighing results and the stability of the system.

[0029] 2. The positioning assembly, utilizing multiple sets of horizontally positioned components that can slide along the supporting ring, can flexibly adapt to gas cylinders of various sizes, ensuring that the gas cylinder is always in the ideal position. Simultaneously, the rolling balls within the rolling groove reduce frictional resistance, making positioning adjustments smoother and more efficient, greatly improving operational safety and convenience.

[0030] 3. The spray gun assembly is rationally designed, with a threaded rod driving the pressing plate to tightly fit the surface of the gas canister, ensuring good sealing at the filling interface and reducing the risk of leakage. Furthermore, the display screen monitors real-time changes in weighing values, achieving precise control of the filling volume, optimizing the overall workflow, and enhancing the user experience. Attached Figure Description

[0031] Figure 1 This is a structural schematic diagram of an embodiment of this application;

[0032] Figure 2 This application Figure 1 An enlarged schematic diagram of point A.

[0033] Explanation of reference numerals in the attached drawings: 1. Support frame; 2. Inflation mechanism; 21. Gas storage tank; 22. Connecting pipe; 23. Switch valve; 24. Spray gun assembly; 241. Spray gun support frame; 242. Spray gun nozzle; 243. Connecting component; 2431. Threaded rod; 2432. Pressing plate; 2433. Operating handle; 3. Weighing mechanism; 31. Weighing device; 32. Weighing plate; 33. Buffer assembly; 331. First buffer plate; 332. Buffer spring; 333. Second buffer plate; 34. Positioning assembly; 341. Support ring; 342. Positioning component; 3421. Sliding rod; 3422. Guide slope; 343. Rolling groove; 344. Rolling ball; 4. Display screen; 5. First guide mechanism; 51. Guide groove; 52. First rotating rod; 53. First rotating wheel; 6. Second guide mechanism; 61. Second steering rod; 62. Second rotating wheel; 7. Locking mechanism; 71. Locking block; 72. Locking rod; 73. Locking electromagnet; 74. Locking ring. Detailed Implementation

[0034] The following is in conjunction with the appendix Figure 1-2 This application will be described in further detail.

[0035] This application discloses a carbon dioxide filling device. (Refer to...) Figure 1 as well as Figure 2 A carbon dioxide filling device includes: a support frame 1, an inflation mechanism 2, the inflation mechanism 2 being mounted on the support frame 1 for filling gas cylinders, a weighing mechanism 3, the weighing mechanism 3 including a weighing device 31, a weighing plate 32 mounted on the weighing device 31, a buffer assembly 33 mounted on the weighing plate 32, a positioning assembly 34 mounted on the buffer assembly 33, and a display screen 4 electrically connected to the weighing mechanism 3.

[0036] In practice, the cylindrical gas cylinder is first placed onto the weighing mechanism 3 manually or using external equipment. During placement, the buffer assembly 33 cushions the cylinder, with multiple springs working together to absorb impact and prevent damage from excessive instantaneous pressure. Simultaneously, the positioning assembly 34 also operates, quickly fixing the cylinder in its axial position to prevent displacement and further improve measurement accuracy. When the cylinder is placed on the weighing plate 32, this not only enhances weighing accuracy but also ensures the smooth completion of subsequent steps. Furthermore, the display screen 4 shows relevant data in real time, allowing staff to monitor status changes and adjust parameter settings promptly, ultimately optimizing the overall process.

[0037] Reference Figure 1 as well as Figure 2Specifically, the inflation mechanism 2 includes a gas storage tank 21, a connecting pipe 22, and a switch valve 23. The gas storage tank 21 is connected to the spray gun assembly 24, which includes a spray gun support frame 241 and a spray gun nozzle 242, through the connecting pipe 22. The spray gun nozzle 242 is connected to the gas storage tank 21 through the connecting pipe 22, and a connecting component 243 is provided on the spray gun nozzle 242. The connecting component 243 includes a threaded rod 2431, a pressing plate 2432, and an operating handle 2433. The threaded rod 2431 passes through the spray gun support frame 241. The pressing plate 2432 is provided at one end of the threaded rod 2431 and can press against the tank body of the gas tank. The operating handle 2433 is provided at the end of the threaded rod 2431 away from the pressing plate 2432. The switch valve 23 is provided on the connecting pipe 22. The spray gun assembly 24 can point towards the weighing mechanism 3.

[0038] In operation, gas is discharged from the gas storage tank 21 through the connecting pipe 22, and connected to the nozzle via the pressing connection assembly, thereby filling the gas tank with carbon dioxide gas. The design of the connecting pipe 22 between the gas storage tank 21 and the spray gun assembly 24, in conjunction with the switch valve 23, not only achieves precise control of the filling process but also improves the safety and convenience of the filling operation. The structure of the threaded rod 2431 allows adjustment of the position of the pressing plate 2432 to accommodate gas tanks of different sizes, ensuring that the pressing plate 2432 fits tightly against the gas tank surface, improving stability and sealing performance. Simultaneously, the operating handle 2433 allows operators to manually adjust the tightness of the threaded rod 2431, enhancing ease of use and work efficiency.

[0039] Reference Figure 1 as well as Figure 2 Specifically, the buffer assembly 33 includes a first buffer plate 331 and several buffer springs 332. The first buffer plate 331 is fixed on the support frame 1, and one end of the buffer spring 332 is connected to the first buffer plate 331 and the other end is connected to the second buffer plate 333.

[0040] In actual operation, the gas cylinder is placed on the second buffer plate 333, thereby compressing the buffer spring 332, which effectively alleviates the impact force generated during the placement of the gas cylinder, ensures the stability of the weighing process, extends the service life of the weighing mechanism 3, and reduces the frequency of equipment maintenance.

[0041] Reference Figure 1 as well as Figure 2Specifically, the positioning component 34 includes a supporting ring 341 and at least three sets of positioning parts 342. The positioning parts 342 include a sliding rod 3421 and a guide slope 3422. The sliding rod 3421 is slidably connected to the supporting ring 341. The guide slope 3422 is located on the side of the sliding rod 3421 facing the axis of the supporting ring 341. The supporting ring 341 is located on the second buffer plate 333. The positioning parts 342 are horizontally slidably connected to the supporting ring 341 and point to the axis of the supporting ring 341. It also includes a plurality of rolling grooves 343 located on the second buffer plate 333. Rolling balls 344 are provided in the rolling grooves 343. The rolling grooves 343 are located in the supporting ring 341.

[0042] In operation, when the cylindrical gas cylinder is inserted, it is pressed against the guide slope 3422, which in turn moves the sliding rod 3421 away from the axis of the supporting ring 341. After the gas cylinder is fully inserted, the positioning rod pushes the gas cylinder through the elastic force of the buffer spring 332. Through simultaneous pushing in multiple directions, the gas cylinder is moved to the centered position. This achieves stable positioning of the gas cylinder and effectively avoids positional displacement caused by external vibration or impact. At the same time, the horizontal sliding connection design allows the positioning component 342 to be flexibly adjusted according to the size of the gas cylinder, thereby improving the adaptability and ease of operation of the device.

[0043] Reference Figure 1 as well as Figure 2 Specifically, it also includes a first guide mechanism 5, which includes a guide groove 51 and a first rotating rod 52. The guide groove 51 is set on the guide slope 3422, and the first rotating rod 52 is rotatably connected to the sliding rod 3421. A first rotating wheel 53 is set on the first rotating rod 52, and the first rotating wheel 53 is located in the guide groove 51.

[0044] In actual operation, when the cylindrical gas cylinder is placed in, the bottom of the cylindrical gas cylinder presses against the first rotating wheel 53. On the one hand, the cooperation between the guide groove 51 and the first rotating wheel 53 enables the sliding rod 3421 to move smoothly along the predetermined trajectory when under force, thereby improving the positioning accuracy and reducing the risk of equipment damage caused by deviation. On the other hand, it can provide initial buffering for the gas cylinder.

[0045] Reference Figure 1 as well as Figure 2 Specifically, it also includes a second guide mechanism 6, which includes a second steering rod 61 and a second rotating wheel 62. The second steering rod 61 is rotatably connected to the side of the sliding rod 3421 near the axis of the supporting ring 341. The second rotating wheel 62 is mounted on the second steering rod 61 and can press against the tank body of the gas tank.

[0046] In actual operation, after the cylindrical gas cylinder is placed in, the second guide wheel presses against the side of the gas cylinder body, which can provide a stable radial constraint force during the placement of the gas cylinder, ensuring that the position of the gas cylinder is accurate and without deviation during the filling process, and preventing the gas cylinder body from being damaged during displacement.

[0047] Reference Figure 1 as well as Figure 2 Specifically, it also includes a locking mechanism 7, which includes a locking block 71, a locking rod 72, and a locking electromagnet 73. The locking block 71 is located on the side of the sliding rod 3421 away from the axis of the supporting ring 341. The locking rod 72 passes through the locking block 71 and is connected to the supporting ring 341. The locking electromagnet 73 is located at one end of the locking rod 72. A magnetic locking ring 74 is provided between the locking block 71 and the locking electromagnet 73. The locking ring 74 is slidably connected to the locking rod 72.

[0048] In actual operation, after the gas tank is placed in, the locking electromagnet 73 works to generate a repulsive force on the locking ring 74. Then the locking ring 74 presses on the locking block 71. The locking mechanism 7 can effectively fix the position of the positioning component 342, prevent it from being displaced or loosened, and ensure that the gas tank remains stable during the filling process, thereby improving the operational safety and reliability of the equipment.

[0049] The implementation principle of a carbon dioxide filling device in this application embodiment is as follows: the original easily damaged electronic scale is modified by adding a positioning mechanism and a buffer mechanism, which gives it excellent impact resistance and load-bearing capacity. The buffer mechanism ensures that the impact force generated when the gas cylinder is placed can be evenly distributed, thereby effectively protecting the weighing sensor of the weighing structure from damage. The positioning mechanism can control the position of the gas cylinder to ensure the accuracy of the weighing data.

[0050] 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. A carbon dioxide filling device, characterized in that, include Support frame (1); An inflation mechanism (2) is mounted on the support frame (1) and is used to inflate the gas cylinder. Weighing mechanism (3), the weighing mechanism (3) includes a weighing device (31), a weighing plate (32) is provided on the weighing device (31), a buffer component (33) is provided on the weighing plate (32), and a positioning component (34) is provided on the buffer component (33). The display screen (4) is electrically connected to the weighing mechanism (3).

2. The carbon dioxide filling device according to claim 1, characterized in that, The inflation mechanism (2) includes a gas storage tank (21) mounted on the support frame (1). A connecting pipe (22) is mounted on the gas storage tank (21), and a switch valve (23) is mounted on the connecting pipe (22). A spray gun assembly (24) is mounted on one end of the connecting pipe (22) away from the gas storage tank (21), and the spray gun assembly can point towards the weighing mechanism (3).

3. A carbon dioxide filling device according to claim 2, characterized in that, The spray gun assembly (24) includes a spray gun support frame (241), on which a spray gun nozzle (242) is provided. The spray gun nozzle (242) is connected to the connecting pipe (22), and a connecting component (243) is provided on the spray gun nozzle (242).

4. A carbon dioxide filling device according to claim 3, characterized in that, The connecting component (243) includes a threaded rod (2431) passing through the spray gun support frame (241). A pressing plate (2432) is provided at one end of the threaded rod (2431) pointing towards the spray gun nozzle (242). The pressing plate (2432) can press against the tank body of the gas tank. An operating handle (2433) is provided at the end of the threaded rod (2431) away from the pressing plate (2432).

5. A carbon dioxide filling device according to claim 1, characterized in that, The buffer assembly (33) includes a first buffer plate (331) disposed on the support frame (1), a plurality of buffer springs (332) disposed on the first buffer plate (331), a second buffer plate (333) disposed at the end of the buffer springs (332) away from the first buffer plate (331), and the positioning assembly (34) disposed on the second buffer plate (333).

6. A carbon dioxide filling device according to claim 5, characterized in that, The positioning component (34) includes a support ring (341) disposed on the second buffer plate (333), at least three sets of positioning components (342) are slidably connected on the support ring (341), the positioning components (342) are horizontally disposed, one end of the positioning component (342) points to the axis of the support ring (341), and also includes a plurality of rolling grooves (343) disposed on the second buffer plate (333), the rolling grooves (343) are provided with rolling balls (344), and the rolling grooves (343) are disposed in the support ring (341).

7. A carbon dioxide filling device according to claim 6, characterized in that, The positioning component (342) includes a sliding rod (3421) slidably connected to the support ring (341), and a guide slope (3422) is provided on the side of the sliding rod (3421) pointing towards the axis of the support ring (341).

8. It also includes a carbon dioxide filling device according to claim 7, characterized in that, It also includes a first guide mechanism (5), which includes a guide groove (51) provided on the guide slope (3422), a plurality of first rotating rods (52) rotatably connected to the sliding rod (3421), a first rotating wheel (53) provided on the first rotating rod (52), the first rotating wheel (53) being provided in the guide groove (51), and the first rotating wheel (53) being able to press on the tank body of the gas tank.

9. A carbon dioxide filling device according to claim 8, characterized in that, It also includes a second guide mechanism (6), which includes a second steering rod (61) rotatably connected to the sliding rod (3421). The second steering rod (61) is located on the side of the sliding rod (3421) near the axis of the support ring (341). A second rotating wheel (62) is provided on the second steering rod (61), and the second rotating wheel (62) can press against the tank body of the gas tank.

10. A carbon dioxide filling device according to claim 9, characterized in that, It also includes a locking mechanism (7), which includes a locking block (71) disposed on the side of the sliding rod (3421) away from the axis of the supporting ring (341). A locking rod (72) is passed through the locking block (71). One end of the locking rod (72) is connected to the supporting ring (341). A locking electromagnet (73) is disposed at the other end of the locking block (71). A locking ring (74) is disposed between the locking electromagnet (73) and the locking block (71). The locking ring (74) is magnetic and is slidably connected to the locking rod (72).