Sealing connection mechanism and gas sampling device

Abstract

The utility model belongs to the technical field of sealing devices, and discloses a sealing connecting mechanism and a gas sampling device.The sealing connecting mechanism comprises a connecting pipe, a connecting cap and a sealing assembly, a gas storage airbag is arranged at the groove bottom of a connecting groove, and an annular clamping airbag is arranged on the groove wall, so that when an external connecting pipe is connected to the connecting pipe in a threaded mode, the external connecting pipe is tightly clamped; the annular clamping air bag can be inflated when the air storage air bag is stressed and extruded, and the annular clamping air bag can be clamped on the outer wall of the external connecting pipe in a sleeving manner when the annular clamping air bag is inflated and expanded, so that the sealing strength of the sealing connecting mechanism is further improved on the basis of threaded connection; due to the adoption of the sealing connection mechanism, when the gas sampling device is connected with the external pipe of the gas valve on the electrical equipment for sampling, the leakage of sulfur hexafluoride gas in the electrical equipment can be effectively prevented, and the sulfur hexafluoride gas sampling can be realized only by screwing the connection pipe with the external pipe on the gas valve, so that the sampling efficiency is improved. The working difficulty of operators is reduced, and the sampling efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of sealing devices, in particular to a sealing connection mechanism and a gas sampling device. Background Art

[0002] Sulfur hexafluoride (SF6) is a colorless, odorless, tasteless, non-toxic, and non-flammable inert gas at room temperature and pressure. Due to its excellent insulation and arc-extinguishing properties, it is widely used in electrical equipment such as switchgear for gas-insulated, fully enclosed switchgear, large-capacity transformers, and high-voltage cables. However, the purity and quality of SF6 can deteriorate over time due to poor sealing or other external factors, potentially affecting the normal operation of electrical equipment. Therefore, regular sampling and testing of SF6 gas within electrical equipment is necessary.

[0003] In order to solve the above problems, some gas sampling devices have been designed in the prior art. When these gas sampling devices are connected to the external pipe of the gas valve of the electrical equipment for sampling, they mainly adopt two common methods: plug-in connection and threaded connection.

[0004] However, the plug-in connection requires a high degree of dimensional accuracy between the inserted component and the inserted component, otherwise a tight connection may not be achieved and the sealing is poor; and the connection achieved only by threads is easily affected by the vibration and temperature change of the electrical equipment, causing the thread tightening force to decay and gaps to appear in the originally tight thread fitting surface. In addition, since sulfur hexafluoride gas has high diffusivity, the existing gas sampling device is prone to leakage of sulfur hexafluoride during sampling, which in turn has an adverse impact on the stable operation of the electrical equipment, the surrounding environment and the safety of personnel. Utility Model Content

[0005] The purpose of the utility model is to provide a sealing connection mechanism and a gas sampling device, which can ensure the connection sealing while sampling the gas, effectively prevent the leakage of sulfur hexafluoride gas, and are simple and convenient to install and disassemble, and have high sampling efficiency.

[0006] To achieve this purpose, the present invention adopts the following technical solutions:

[0007] Sealing connection mechanism, comprising:

[0008] A connecting pipe, wherein the outer surface of the connecting pipe is provided with an external thread;

[0009] A connecting cap, wherein the connecting cap is provided with a connecting groove, and one end of the connecting pipe extends into the connecting groove from the bottom of the connecting groove;

[0010] The sealing assembly includes an air storage airbag and an annular clamping airbag that are interconnected. The air storage airbag is arranged at the bottom of the connecting groove, and the annular clamping airbag is arranged on the groove wall of the connecting groove. When the inner wall of the external tube is screwed to the external thread, it can press against the air storage airbag. When the air storage airbag is squeezed by force, it can inflate the annular clamping airbag. When the annular clamping airbag is inflated and expanded, it can be clamped on the outer wall of the external tube.

[0011] Preferably, the sealing assembly further comprises an extrusion piece, a placement cavity is provided at the bottom of the connecting groove, the placement cavity is connected to the connecting groove through a connecting channel, the air storage airbag is arranged in the placement cavity, the extrusion piece is passed through the connecting channel, and the external pipe can extrude the air storage airbag through the extrusion piece.

[0012] Preferably, the extrusion member includes an extrusion plate, an extrusion rod and a push plate, the extrusion plate is located in the placement cavity, the push plate is located in the connecting groove, the extrusion rod is passed through the connecting channel, one end is connected to the extrusion plate, and the other end is connected to the push plate.

[0013] Preferably, a limiting groove is provided on a side of the push plate away from the extrusion rod, one end of the limiting groove passes through to an end of the push plate facing the connecting tube, and the external tube can extend into the limiting groove.

[0014] Preferably, the sealing assembly further includes an annular plate and an elastic member, the annular plate is connected to the inner wall of the placement cavity, the elastic member is located between the annular plate and the extrusion plate, one end of the air storage bag is connected to the connecting cap, and the other end is connected to the extrusion plate.

[0015] Preferably, the pushing plate is slidably connected to the groove wall of the connecting groove.

[0016] Preferably, an annular groove is provided on the groove wall of the connecting groove, and the annular clamping airbag is arranged in the annular groove.

[0017] Preferably, a sealing ring is provided on the connecting pipe, and when the external pipe is screwed to a set position on the external thread, the sealing ring is located between the inner wall of the external pipe and the outer wall of the connecting pipe.

[0018] Preferably, a plurality of air storage bags are provided at the bottom of the connecting groove, the plurality of air storage bags are evenly distributed along the circumference of the connecting pipe, and the plurality of air storage bags are all connected to the annular clamping bag.

[0019] A gas sampling device is used to sample sulfur hexafluoride gas from the gas valve of an electrical device. The gas valve is provided with an external pipe. The gas sampling device includes a gas storage tank and the sealing connection mechanism as described above. The connecting pipe is connected to the gas storage tank.

[0020] Beneficial effects of the utility model:

[0021] The sealing connection mechanism provided by the utility model is provided with a connecting tube and a connecting cap, and an air storage bag is provided at the bottom of the connecting groove, and an annular clamping air bag is provided on the groove wall, so that when the external tube is screwed to the connecting tube, it can press against the air storage bag, and when the air storage bag is squeezed by force, it can inflate the annular clamping air bag, and when the annular clamping air bag is inflated, it can be clamped on the outer wall of the external tube, so as to better adapt to the possible unevenness of the outer wall of the external tube, effectively fill the gap, improve the sealing strength on the basis of screw connection, reduce the risk of leakage, and the annular clamping air bag clamped on the outer wall of the external tube can also provide additional axial and radial support force between the connecting tube and the external tube. Compared with relying on threaded connection alone, it can prevent the connecting tube and the external tube from loosening due to factors such as vibration and pressure change, thereby enhancing the stability of the entire connection structure and further improving the sealing strength.

[0022] The gas sampling device provided by the present invention adopts the above-mentioned sealing connection mechanism, and when connected to the external pipe of the gas valve on the electrical equipment for sampling, it can effectively prevent the leakage of sulfur hexafluoride gas inside the electrical equipment. In addition, the gas sampling device provided by the present invention only needs to screw the connecting pipe to the external pipe on the gas valve to achieve sulfur hexafluoride gas sampling, which reduces the operator's work difficulty and workload and improves sampling efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a structural diagram of the gas sampling device according to an embodiment of the present utility model;

[0024] Figure 2 is a cross-sectional view of the sealing connection mechanism according to an embodiment of the present utility model;

[0025] Figure 3 yes Figure 2 Enlarged view of point A in the middle.

[0026] In the picture:

[0027] 1. Connecting pipe; 11. External thread; 12. Sealing ring; 13. Valve;

[0028] 2. Connecting cap; 20. Connecting groove;

[0029] 3. Sealing assembly; 31. Air storage airbag; 32. Annular clamping airbag; 33. Extrusion piece; 331. Extrusion plate; 332. Extrusion rod; 333. Push plate; 3330. Limiting groove; 34. Annular plate; 35. Elastic piece; 100. Air storage tank. DETAILED DESCRIPTION

[0030] The following describes in detail embodiments of the present invention. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar components or components having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present invention, and should not be construed as limiting the present invention.

[0031] In the description of this utility model, unless otherwise expressly specified or limited, the terms "connected," "connect," and "fixed" should be understood in a broad sense. For example, they may refer to fixed or detachable connections, mechanical or electrical connections, direct or indirect connections through an intermediate medium, and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on specific circumstances.

[0032] In the description of the present utility model, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first feature and the second feature being in direct contact, or may include the first feature and the second feature being in contact not directly but through another feature between them. Moreover, a first feature being "above," "above," and "above" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature includes the first feature being directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0033] The technical solution of the present invention will be further described below with reference to the accompanying drawings and through specific implementation methods.

[0034] like Figure 2-Figure 3 As shown, the utility model provides a sealing connection mechanism, including a connecting tube 1, a connecting cap 2 and a sealing assembly 3. The outer surface of the connecting tube 1 is provided with an external thread 11; the connecting cap 2 is provided with a connecting groove 20, and one end of the connecting tube 1 extends into the connecting groove 20 from the bottom of the connecting groove 20; the sealing assembly 3 includes an air storage bag 31 and an annular clamping bag 32 that are interconnected. The air storage bag 31 is arranged at the bottom of the connecting groove 20, and the annular clamping bag 32 is arranged on the groove wall of the connecting groove 20. When the inner wall of the external tube is screwed to the external thread 11, it can press against the air storage bag 31. When the air storage bag 31 is squeezed by force, it can inflate the annular clamping bag 32. When the annular clamping bag 32 is inflated and expanded, it can be clamped on the outer wall of the external tube.

[0035] By arranging the connecting tube 1 and the connecting cap 2, and arranging the air storage bag 31 at the bottom of the connecting groove 20, and arranging the annular clamping air bag 32 on the groove wall, when the external tube is screwed to the connecting tube 1, it can press against the air storage bag 31, and when the air storage bag 31 is squeezed, it can inflate the annular clamping air bag 32, and when the annular clamping air bag 32 is inflated, it can be clamped on the outer wall of the external tube, so as to better adapt to the possible unevenness of the outer wall of the external tube, effectively fill the gap, improve the sealing strength on the basis of screw connection, reduce the risk of leakage, and the annular clamping air bag 32 is clamped on the outer wall of the external tube to provide additional axial and radial support between the connecting tube 1 and the external tube. Compared with relying solely on threaded connection, it can prevent the connecting tube 1 and the external tube from loosening due to factors such as vibration and pressure changes, thereby enhancing the stability of the entire connection structure and further improving the sealing strength.

[0036] In this embodiment, a connecting channel is provided in the connecting cap 2, and a connecting pipe is passed through the connecting channel. The air storage airbag 31 is connected to the annular clamping airbag 32 through the connecting pipe. The setting of the connecting channel can protect the connecting pipe and gas transmission from interference from external factors, reduce the possibility of damage to the connecting pipe and block the entry of impurities, ensure that the annular clamping airbag 32 can be inflated normally, thereby ensuring the sealing performance of the sealing connection mechanism.

[0037] Specifically, if Figure 2 As shown, the sealing assembly 3 further includes an extrusion member 33. A placement cavity is defined at the bottom of the connecting groove 20. The placement cavity is connected to the connecting groove 20 via a connecting passage. The air storage bag 31 is disposed within the placement cavity. The extrusion member 33 passes through the connecting passage, and the external pipe can squeeze the air storage bag 31 via the extrusion member 33. The placement cavity provides a specific accommodation space for the air storage bag 31, preventing the air storage bag 31 from moving or deforming arbitrarily, thereby allowing the air storage bag 31 to be stably positioned at the bottom of the connecting groove 20. When the external pipe squeezes the air storage bag 31 via the extrusion member 33, the placement cavity enables the squeezing force to act more concentratedly on the air storage bag 31, prompting gas to flow in a predetermined direction through the connecting passage to the annular clamping bag 32. Furthermore, the provision of the extrusion member 33 makes the squeezing of the air storage bag 31 by the external pipe more precise and stable, thereby achieving a higher degree of fit between the annular clamping bag 32 and the outer wall of the external pipe, and improving the sealing effect.

[0038] More specifically, if Figure 3As shown, the extrusion member 33 includes an extrusion plate 331, an extrusion rod 332, and a push plate 333. The extrusion plate 331 is located in the placement cavity, the push plate 333 is located in the connection groove 20, and the extrusion rod 332 is disposed in the connection channel, with one end connected to the extrusion plate 331 and the other end connected to the push plate 333. When interacting with the external tube, the push plate 333 effectively converts the axial thrust of the external tube into axial pressure on the extrusion rod 332, which is then transmitted to the extrusion plate 331, thereby squeezing the air storage bag 31 and avoiding force dispersion and loss during the transmission process. Furthermore, the extrusion plate 331, with its large contact area, evenly applies the received pressure to the air storage bag 31, preventing damage to the air storage bag 31 due to excessive local pressure, thereby ensuring that the air storage bag 31 can stably and continuously supply gas to the annular clamping bag 32.

[0039] More specifically, if Figure 3 As shown, a limiting groove 3330 is defined on the side of the push plate 333 away from the extrusion rod 332. One end of the limiting groove 3330 extends through the end of the push plate 333 facing the connecting tube 1, allowing the external tube to extend into the limiting groove 3330. The limiting groove 3330 not only provides a precise insertion position for the external tube, but also constrains and guides the direction of force transmission, allowing the force to act on the push plate 333 in a predetermined direction, reducing force dispersion and loss, thereby ensuring that the extrusion rod 332 receives stable and sufficient axial pressure, further ensuring that the extrusion plate 331 effectively squeezes the air storage bag 31.

[0040] More specifically, if Figure 3 As shown, the sealing assembly 3 further includes an annular plate 34 and an elastic member 35. The annular plate 34 is connected to the inner wall of the placement cavity, and the elastic member 35 is located between the annular plate 34 and the extrusion plate 331. One end of the air storage bag 31 is connected to the connection cap 2, and the other end is connected to the extrusion plate 331. When the extrusion plate 331 is not squeezing the air storage bag 31, the annular plate 34 can restrain the air storage bag 31 in a relatively fixed position. The elastic member 35 can use its own elastic force to provide a certain pre-tightening force on the air storage bag 31. Under the combined action of the annular plate 34 and the elastic member 35, the air storage bag 31 can be prevented from wrinkling or local deformation when it is in a relaxed state. When the external tube is removed from the connecting tube 1, the elastic potential energy of the elastic member 35 begins to be released. The annular plate 34 provides a stable support base for the elastic member 35, enabling the elastic member 35 to push the extrusion plate 331 away from the air storage bag 31, pulling the air storage bag 31, thereby restoring the air storage bag 31 to its original shape and storing air. Without the auxiliary return function of the elastic member 35, the air storage bag 31 may not fully recover its shape after each squeeze. After repeated use, it may easily wrinkle, deform, or even damage, resulting in its inability to properly store and transport gas, which in turn affects the sealing effect of the annular clamping bag 32.

[0041] In this embodiment, when the extrusion member 33 is not pushed by the external tube, the extrusion plate 331 is located in the first position. When the external tube is screwed to the set position on the external thread 11, the extrusion plate 331 moves to the second position by squeezing the air storage bag 31. The second position is located between the first position and the position of the annular plate 34, which can allow the air storage bag 31 to produce an appropriate amount of deformation to provide sufficient gas to expand the annular clamping bag 32 and achieve sealing and clamping, and ensure that the air storage bag 31 will not be over-extruded, avoiding problems such as bag rupture and gas extrusion abnormalities due to excessive extrusion, so that the air storage bag 31 can continuously and stably provide an appropriate amount of gas to the annular clamping bag 32, thereby achieving good sealing and clamping effects.

[0042] It should be noted that the set position is a predetermined position on the external thread 11. When the external tube is screwed to this position on the external thread 11, it cannot continue to rotate, which can ensure that the sealing connection mechanism achieves a good sealing effect. If the external tube is not screwed to this position on the external thread 11, the annular clamping airbag 32 cannot be fully expanded, resulting in a poor seal; if it exceeds this position, the air storage airbag 31 will be over-squeezed, causing problems such as airbag rupture.

[0043] In this embodiment, the elastic member 35 is a spring tube, which is sleeved on the air storage bag 31 .

[0044] In other embodiments, the elastic member 35 may also be a rubber elastic tube.

[0045] More specifically, if Figure 3 As shown, the push plate 333 is slidably connected to the groove wall of the connecting groove 20. When the external tube applies axial thrust, the push plate 333 can slide smoothly along the groove wall, thereby efficiently converting the thrust into axial pressure on the extrusion rod 332. In this process, due to the stability of the sliding connection, the force transmission direction can be well maintained, avoiding the dispersion and offset of force due to unstable connection, and ensuring that the subsequent extrusion plate 331 can receive stable and accurate direction pressure to extrude the air storage bag 31, thereby ensuring that the sealing function of the entire sealing connection mechanism is effectively realized.

[0046] In this embodiment, a sliding bar is provided on the groove wall of the connecting groove 20, and a groove adapted to the sliding bar is provided on the pushing plate 333, so that the pushing plate 333 can only slide along the direction limited by the sliding bar, strictly restricting its freedom in other directions, avoiding lateral deviation, torsion, etc., so that the direction of force transmission can always remain stable and accurately in the direction of the extrusion rod 332, laying the foundation for the subsequent extrusion plate 331 to stably squeeze the air storage airbag 31.

[0047] In other embodiments, a guide rail and slider structure can be used to achieve a sliding connection between the push plate 333 and the wall of the connecting groove 20. The guide rail is installed on the wall of the connecting groove 20. Its shape is usually long and has high-precision straightness and surface finish. The slider is installed on the push plate 333 and matches the guide rail.

[0048] Specifically, if Figure 2 As shown, an annular groove is opened on the groove wall of the connecting groove 20, and the annular clamping airbag 32 is arranged in the annular groove. The annular groove provides a precise installation position for the annular clamping airbag 32, so that the annular clamping airbag 32 can be accurately positioned in the connecting groove 20, and the annular groove can fix the annular clamping airbag 32 and limit the movement of the annular clamping airbag 32, thereby ensuring the structural stability of the entire sealing connection mechanism.

[0049] In this embodiment, the annular clamping airbag 32 is clamped in the annular groove and partially extends into the connecting groove 20. When the external tube does not squeeze the air storage airbag 31, the annular clamping airbag 32 fits with the outer surface of the external tube. When the external tube begins to squeeze the air storage airbag 31, gas enters the annular clamping airbag 32 to inflate it, and it can fit more tightly and evenly on the outer surface of the external tube and the relevant parts of the connecting groove 20, forming a reliable sealing interface to ensure that gas or liquid will not leak from the connection part.

[0050] Specifically, if Figure 3 As shown, a sealing ring 12 is provided on the connecting pipe 1. When the external pipe is screwed to the set position on the external thread 11, the sealing ring 12 is located between the inner wall of the external pipe and the outer surface of the connecting pipe 1, which can fill the gap between the external pipe and the connecting pipe 1, preventing gas from overflowing through the small gap of the thread, and further improving the sealing of the connection part.

[0051] Specifically, a plurality of air storage bags 31 are provided at the bottom of the connecting groove 20, and the plurality of air storage bags 31 are evenly distributed along the circumference of the connecting tube 1. The plurality of air storage bags 31 are all connected to the annular clamping bags 32. When the external tube squeezes these air storage bags 31, it can ensure that the annular clamping bags 32 can obtain gas supply synchronously and evenly at various parts in the circumferential direction. The annular clamping bags 32 can expand evenly in the entire circumferential direction, thereby generating uniform radial pressure on the connection part between the external tube and the connecting tube 1, achieving an all-round, dead-angle-free sealing effect.

[0052] In this embodiment, Figure 2 As shown, two air storage bags 31 are provided at the bottom of the connecting groove 20. Specifically, two placement cavities are symmetrically provided at the bottom of the connecting groove 20. A sealing assembly 3 is provided in each of the two placement cavities. The annular clamping bag 32 is respectively connected to the two air storage bags 31 through two connecting tubes 8.

[0053] In other embodiments, three, four or more air storage bags 31 are provided at the bottom of the connecting groove 20. For example, when three air storage bags 31 are provided, three placement cavities are provided at the bottom of the connecting groove 20 at 120-degree intervals along the circumference of the connecting tube 1. A sealing assembly 3 is provided in each of the three placement cavities. The annular clamping air bag 32 is respectively connected to the three air storage bags 31 through three connecting tubes 8. When the three air storage bags 31 are squeezed, gas can be respectively delivered to the annular clamping air bag 32, thereby collaboratively ensuring the inflation uniformity of the annular clamping air bag 32 from three directions, enhancing the sealing effect and improving the structural stability.

[0054] like Figure 1 As shown, the present invention also provides a gas sampling device for sampling sulfur hexafluoride gas from a gas valve of electrical equipment. The gas valve is provided with an external pipe. The gas sampling device includes a gas storage tank 100 and the above-described sealing connection mechanism. The connecting pipe 1 is connected to the gas storage tank 100. Due to the use of the above-described sealing connection mechanism, the gas sampling device provided by the present invention can effectively prevent the leakage of sulfur hexafluoride gas inside the electrical equipment when connected to the external pipe of the gas valve on the electrical equipment for sampling. During sampling, sulfur hexafluoride gas sampling can be achieved by simply threading the connecting pipe 1 to the external pipe on the gas valve, thereby reducing the difficulty and workload of the operator and improving sampling efficiency.

[0055] In this embodiment, a valve 13 is provided on the connecting pipe 1 , and the valve 13 is a one-way valve that can prevent the sulfur hexafluoride gas from flowing back, ensuring that the sulfur hexafluoride gas flows into the gas storage tank 100 in one direction.

[0056] In this embodiment, a handle is further provided on the gas storage tank 100, which provides a stable gripping position for the operator, making it convenient for the operator to move the gas sampling device.

[0057] In this embodiment, the working process of the gas sampling device for sampling sulfur hexafluoride gas from the gas valve of the electrical equipment is as follows:

[0058] Preparation stage: The operator first holds the handle on the gas storage tank 100 and moves the gas sampling device to the vicinity of the gas valve of the electrical equipment. He then checks whether all components of the device are in normal condition, especially the external thread 11 of the connecting pipe 1 and the one-way valve 13, to ensure that they are not damaged or blocked. At the same time, he confirms that the gas storage bag 31 and the annular clamping bag 32 in the sealing connection mechanism are not abnormally deformed or damaged.

[0059] Connection stage: The operator aligns the connecting cap 2 with the external tube on the gas valve of the electrical equipment and starts the screw connection operation. As the connecting tube 1 rotates and advances, the external tube gradually inserts into the connecting groove 20. During this process, the external tube first contacts the pushing plate 333 and squeezes it. The pushing plate 333 slides along the sliding strip on the wall of the connecting groove 20 toward the squeezing rod 332, squeezing the air storage bag 31 through the squeezing plate 331. The gas in the air storage bag 31 flows to the annular clamping bag 32 through the connecting pipe. After being inflated, the annular clamping bag 32 begins to expand and gradually fits tightly to the outer surface of the external tube to form a good sealing state.

[0060] Sampling stage: After the connecting pipe 1 is connected to the external pipe and sealed, the gas valve of the electrical equipment is opened. Under the action of the pressure difference, the sulfur hexafluoride gas inside the electrical equipment flows through the connecting pipe 1 to the gas storage tank 100. The operator can determine whether the sampling is completed according to the pre-set sampling volume or by monitoring the pressure change in the gas storage tank 100.

[0061] Finishing stage: When the predetermined sampling requirements are met, the operator closes the gas valve of the electrical equipment, and then rotates the connecting pipe 1 in the reverse direction to remove the gas sampling device from the external pipe to complete the sampling work.

[0062] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the implementation methods of the present invention. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation methods here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. Sealed connection mechanism, characterized in that: include: A connecting pipe (1), wherein the outer surface of the connecting pipe (1) is provided with an external thread (11); A connecting cap (2), wherein the connecting cap (2) is provided with a connecting groove (20), and one end of the connecting pipe (1) extends into the connecting groove (20) from the bottom of the connecting groove (20); The sealing assembly (3) comprises an air storage bag (31) and an annular clamping bag (32) which are interconnected. The air storage bag (31) is arranged at the bottom of the connecting groove (20), and the annular clamping bag (32) is arranged at the groove wall of the connecting groove (20). When the inner wall of the external pipe is screwed to the external thread (11), it can press against the air storage bag (31). When the air storage bag (31) is squeezed by force, it can inflate the annular clamping bag (32). When the annular clamping bag (32) is inflated and expanded, it can be clamped on the outer wall of the external pipe.

2. The sealing connection mechanism according to claim 1, characterized in that: The sealing assembly (3) further comprises an extrusion piece (33); a placement cavity is provided at the bottom of the connecting groove (20); the placement cavity is connected to the connecting groove (20) via a connecting channel; the air storage bag (31) is arranged in the placement cavity; the extrusion piece (33) is passed through the connecting channel; and the external pipe can extrude the air storage bag (31) via the extrusion piece (33).

3. The sealing connection mechanism according to claim 2, characterized in that: The extrusion member (33) comprises an extrusion plate (331), an extrusion rod (332) and a push plate (333); the extrusion plate (331) is located in the placement cavity; the push plate (333) is located in the connection groove (20); the extrusion rod (332) is arranged in the connection channel, one end of the extrusion rod is connected to the extrusion plate (331), and the other end is connected to the push plate (333).

4. The sealing connection mechanism according to claim 3, characterized in that: A limiting groove (3330) is provided on a side of the pushing plate (333) away from the extrusion rod (332), one end of the limiting groove (3330) passes through an end of the pushing plate (333) facing the connecting tube (1), and the external tube can extend into the limiting groove (3330).

5. The sealing connection mechanism according to claim 3, characterized in that: The sealing assembly (3) further comprises an annular plate (34) and an elastic member (35), wherein the annular plate (34) is connected to the inner wall of the placement cavity, and the elastic member (35) is located between the annular plate (34) and the extrusion plate (331), and one end of the air storage bag (31) is connected to the connection cap (2), and the other end is connected to the extrusion plate (331).

6. The sealing connection mechanism according to claim 3, characterized in that: The pushing plate (333) is slidably connected to the groove wall of the connecting groove (20).

7. The sealing connection mechanism according to claim 1, characterized in that: An annular groove is provided on the groove wall of the connecting groove (20), and the annular clamping airbag (32) is arranged in the annular groove.

8. The sealing connection mechanism according to claim 1, characterized in that: A sealing ring (12) is sleeved on the connecting pipe (1); when the external pipe is screwed onto the external thread (11) to a set position, the sealing ring (12) is located between the inner wall of the external pipe and the outer wall of the connecting pipe (1).

9. The sealing connection mechanism according to any one of claims 1 to 8, characterized in that: A plurality of air storage bags (31) are provided at the bottom of the connecting groove (20), the plurality of air storage bags (31) are evenly distributed along the circumference of the connecting pipe (1), and the plurality of air storage bags (31) are all connected to the annular clamping bag (32).

10. A gas sampling device for sampling sulfur hexafluoride gas from a gas valve of an electrical device, wherein the gas valve is provided with an external pipe, characterized in that: The gas sampling device comprises a gas storage tank (100) and a sealing connection mechanism according to any one of claims 1 to 9, and the connecting pipe (1) is connected to the gas storage tank (100).

Images