CN209992468U - Gas detection device - Google Patents

Abstract

The utility model discloses a gas detection device, which relates to the technical field of gas detection and comprises a gas conduit and a host casing with an air inlet interface, wherein the gas conduit comprises a hose section and a hard pipe section connected to one end of the hose section, which is close to the air inlet interface, the hard pipe section is arranged in the air inlet interface in a penetrating way, an elastic sealing element is also arranged on the inner wall of the air inlet interface and surrounds the hard pipe section, and the elastic sealing element tightly supports against the outer wall of the hard pipe section; and a connector for detachably connecting the air inlet connector is also fixed on the hard pipe section. The utility model provides a use and maintain the convenience, not fragile, life is longer, and the higher gaseous detection device of combustible gas concentration detection accuracy nature.

Description

Gas detection device

Technical Field

The utility model relates to a gaseous detection technology field, specifically speaking, it relates to a gaseous detection device.

Background

Common combustible gases include liquefied petroleum gas, natural gas, toluene, coal gas, methane and the like. The main components of the liquefied petroleum gas are propane, propylene, butane and butylene, and the liquefied petroleum gas is inflammable and explosive and has an anesthetic effect on the central nerve of a human body at a higher concentration; the main component of natural gas is methane, excessive methane cannot cause human poisoning, but suffocation is easily caused, and explosion with different scales can be caused when encountering fire; the main component of the gas is methane, and the methane is mixed with oxygen or air and then is possibly exploded when reaching a certain temperature; toluene is toxic and can cause acute poisoning of the human body; the coal gas is also toxic, which easily causes hypoxia of human body; the main components of the marsh gas are methane, carbon dioxide, oxygen, hydrogen sulfide and the like. The accumulated combustible gas is widely applied in actual production or engineering, in order to ensure safety, workers must pay attention to detecting the concentration of the combustible gas in relevant places all the time, and the combustible gas detection alarm is one of common instruments for the workers to detect the concentration of the combustible gas.

The existing combustible gas detection alarm generally comprises a host and a gas guide pipe, wherein the host is connected with the gas guide pipe, and a gas detection module is arranged in the host. In actual use, gas enters the host machine through the gas conduit, and the gas detection module can detect the components of combustible gas in the gas and display the components on the display screen of the host machine for a user to read. However, after the gas guide tube made of rubber is used for a long time, the stability and the sealing performance of the connection between the gas guide tube made of rubber and the corresponding interface are seriously reduced, so that in the subsequent use process, for example, when a user detects the concentration of combustible gas in the gas tank, external clean gas may permeate into the main machine through the gap between the gas guide tube and the corresponding interface, thereby affecting the accuracy of the detection result of the concentration of the combustible gas.

SUMMERY OF THE UTILITY MODEL

To the technical problem, the utility model aims at providing a gaseous detection device improves the stability and the leakproofness of gas conduit and the interface connection department that admits air, guarantees the accuracy nature that combustible gas concentration detected.

In order to achieve the above purpose, the utility model provides a following technical scheme:

a gas detection device comprises a gas conduit and a host shell with a gas inlet interface, wherein the gas conduit comprises a hose section and a hard pipe section connected to one end, close to the gas inlet interface, of the hose section, the hard pipe section is arranged in the gas inlet interface in a penetrating mode, an elastic sealing element is further arranged on the inner wall of the gas inlet interface and surrounds the hard pipe section, and the elastic sealing element abuts against the outer wall of the hard pipe section; and the hard pipe section is also fixedly provided with a connector for detachably connecting an air inlet interface.

Through adopting above-mentioned technical scheme, set the gas conduit into the structural style of hose section and stereoplasm pipeline section combination to connect the interface that admits air through stereoplasm pipeline section, can indirectly improve the stability of connecting. On the basis of realizing the stable connection of the gas conduit and the gas inlet interface by using the connector, the hard pipe section is inserted into the gas inlet interface, so that the gas absorbed in the gas conduit can directly enter the host machine through the hard pipe section; meanwhile, the elastic sealing element can tightly support the outer wall of the hard pipe section, so that the gap between the hard pipe section and the air inlet interface is effectively sealed, and the sealing performance of the connecting position of the hard pipe section and the air inlet interface is ensured. Through this kind of mode, guarantee the stability and the leakproofness of gas conduit and the interface connection department that admits air, avoid outside clean gas to get into inside the host computer to improve the accuracy nature of combustible gas concentration testing result.

The utility model discloses further set up to: the elastic sealing element is a rubber sealing sleeve which is fixedly arranged on the inner wall of the air inlet interface.

By adopting the technical scheme, after the hard pipe section is inserted into the rubber sealing sleeve, the rubber sealing sleeve can be tightly propped against the outer wall of the hard pipe section, so that the gap between the outer wall of the hard pipe section and the air inlet interface is effectively sealed, and the air tightness of the joint of the gas conduit and the air inlet interface is ensured.

The utility model discloses further set up to: the rubber sealing sleeve is internally provided with a through hole for penetrating the hard pipe section, the inner wall of the through hole is convexly provided with a sealing convex ring, and the sealing convex ring is provided with a plurality of groups at intervals along the extending direction of the through hole.

By adopting the technical scheme, when the hard pipe section is inserted into the rubber sealing sleeve, each sealing convex ring on the inner wall of the through hole can tightly support the outer wall of the hard pipe section, so that the air tightness between the hard pipe section and the hard pipe section is further improved.

The utility model discloses further set up to: one end of the hose section, which is close to the hard pipe section, is fixedly sleeved on the outer wall of the hard pipe section, and a plurality of anti-slip rings are convexly formed on the outer wall of the hard pipe section, which is used for connecting the hose section.

By adopting the technical scheme, the anti-disengaging ring can not only reduce the risk of disengagement of the hose section, but also help to improve the air tightness of the joint.

The utility model discloses further set up to: the outer side of the hose section is also spirally wound with a steel wire binding band for binding and fixing the sleeving part of the hose section and the hard pipe section; the outside cover of steel wire bandage is equipped with the protective sheath, the protective sheath can be dismantled and fix on the connector.

Through adopting above-mentioned technical scheme, utilize steel wire bandage ligature fixed hose section and stereoplasm pipeline section, not only can guarantee the stability of hose section and stereoplasm pipeline section connection, can also further improve its hookup location's gas tightness. And, when the user accidentally pulls the hose section, because the steel bandage has elastic restoring force, it can play the cushioning effect to the impact that pulls and produces, reduces the risk that the hose section is pulled apart.

The utility model discloses further set up to: the connector is in threaded connection with the outer side wall of the air inlet connector, the hard pipe section is fixedly arranged in the hard pipe section in a penetrating mode, and an elastic sealing gasket is arranged on the surface, opposite to the main machine shell, of the inner wall of the connector; when the connecting head is screwed, one end of the air inlet interface, which is far away from the main machine shell, abuts against the elastic sealing gasket.

Through adopting above-mentioned technical scheme, when the connector was screwed, the one end that the host computer casing was kept away from to the interface of admitting air supported tight elastic sealing pad, and elastic sealing pad can effectively seal the opening that the interface of admitting air kept away from the host computer casing to further improve the gas tightness of gas conduit and the interface connection department of admitting air.

The utility model discloses further set up to: a hexagonal rotating part is integrally formed on the outer side wall of the connector.

Through adopting above-mentioned technical scheme, with the help of setting up the hexagonal rotating part on the connector, convenience of customers rotates the connector, and indirect assurance user can be convenient the connector of screwing.

The utility model discloses further set up to: and a knurled section is further formed on the outer side wall of the connector in a machining mode.

Through adopting above-mentioned technical scheme, the annular knurl section can play skid-proof effect, can improve the convenience of this installation.

To sum up, the utility model discloses following beneficial effect has:

1. the gas guide pipe formed by combining the hose section and the hard pipe section is used for inserting the hard pipe section into the gas inlet interface, the gap between the outer wall of the hard pipe section and the inner wall of the gas inlet interface is effectively sealed by virtue of the elastic sealing element, the gas inlet interface is stably connected by matching with the connector, the stability and the airtightness of the joint of the gas guide pipe and the gas inlet interface are fully ensured, external clean gas is prevented from entering the interior of a host machine through a gap between the gas guide pipe and the gas inlet interface, and the accuracy of the detection of the concentration of the combustible gas;

2. the hose section and the hard pipe section are fixed by the steel wire binding band and matched with the protective sleeve, so that the stability of connection between the hose section and the hard pipe section can be ensured, the hose section can be protected, and the service life of the gas conduit can be indirectly prolonged;

3. through set up hexagonal rotating part and annular knurl section on the connector, improve the convenience of this gaseous detection device dismouting greatly, make things convenient for routine maintenance.

Drawings

Fig. 1 is an axial view of the overall structure of an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a host in an embodiment of the present invention;

fig. 3 is a schematic structural view of an elastic protection sleeve according to an embodiment of the present invention;

fig. 4 is a schematic view of the inner structure of the elastic protection sleeve according to an embodiment of the present invention;

fig. 5 is a schematic view of an exploded structure of a gas conduit according to an embodiment of the present invention;

fig. 6 is a schematic cross-sectional view of a gas conduit according to an embodiment of the present invention;

fig. 7 is a schematic cross-sectional view of an air inlet interface according to an embodiment of the present invention;

FIG. 8 is an enlarged view of portion A of FIG. 7, primarily illustrating the connection of the rigid pipe segment to the flexible pipe segment;

fig. 9 is an axial view of a connector according to an embodiment of the present invention;

fig. 10 is a schematic cross-sectional view of a rubber sealing boot according to an embodiment of the present invention.

Reference numerals: 100. a host; 110. a main housing; 111. an air inlet interface; 112. a USB interface; 113. a charging jack; 114. a recessed portion; 1141. a positioning groove; 1142. a label display projection; 115. a host portion; 116. a transition shoulder; 120. an alarm lamp; 130. a display screen; 140. an operation panel; 150. an elastic protective sleeve; 151. anti-skid lines; 152. positioning the convex ring; 153. receiving the strips; 154. a label through opening; 155. a rubber layer; 156. a steel wire mesh reinforcing layer; 160. an elastic protective layer; 200. a gas conduit; 210. a metal probe tube section; 211. a first tube section; 212. a second tube section; 220. a hose section; 230. a pollution discharge filter; 231. an outer tubular body; 2311. a thread extension; 232. an inner tube body; 233. a vacuum compartment; 234. a first filter layer; 235. a second filter layer; 236. a filter disc; 240. a first screw cap; 250. a second screw cap; 260. weaving a protective layer; 300. a hard pipe section; 310. a slip-off preventing ring; 400. a steel wire binding band; 500. a connector; 510. a protective sleeve; 520. a hexagonal rotary part; 530. a knurling section; 540. an elastic sealing gasket; 600. a rubber sealing sleeve; 610. perforating the hole; 611. and sealing the convex ring.

Detailed Description

The present invention will be described in detail with reference to the accompanying drawings and examples.

Referring to fig. 1, a gas detection device is provided for detecting the concentration of combustible gas in a gas. The gas detection device comprises a detection component and a collection component connected with the detection component; in actual use, the collection assembly can collect the gas to be detected and transmit the gas to the detection assembly, and the detection assembly can detect the concentration of combustible gas in the gas and display the related concentration parameters to a user for the user to read.

With reference to fig. 2, the detecting assembly is a main body 100, which includes a main body housing 110, and an air inlet 111 for connecting an acquiring assembly is fixed on the top of the main body housing 110; meanwhile, the alarm lamp 120, the display screen 130 and the operation panel 140 are sequentially disposed along the central line of the same side of the main body case 110. When the host 100 is in an upright state, one side of the alarm lamp 120 is the top of the host 100, and the other side of the host 110 opposite to the top naturally forms the bottom of the host 110, and the bottom of the host 110 is further provided with a USB interface 112 and a charging socket 113.

Referring to fig. 2, the top and bottom of the main body case 110 are both injection molded with a recess 114, and a portion of the main body case 110 between the two recesses 114 constitutes a main body part 115; the surface of the recess 114 is lower than the surface of the main portion 115, creating a "recess" like effect, and a transition shoulder 116 is formed at the intersection of any recess 114 with the main portion 115. The elastic protection sleeve 150 is sleeved on the two recessed portions 114 of the host housing 110, an opening for sleeving the corresponding recessed portion 114 is formed on the elastic protection sleeve 150, and the edge of the opening of the elastic protection sleeve 150 extends to the transition shoulder 116 and abuts against the transition shoulder 116. To ensure the overall aesthetics of the host 100, the outer surface of the elastic protection sleeve 150 can be flush with the outer surface of the host portion 115 when the elastic protection sleeve 150 is sleeved on the recess 114.

In order to reduce the risk that the host 100 falls off from the user's hand, the two sides of the elastic protection sleeve 150 in the width direction are provided with anti-slip stripes 151. Meanwhile, to prevent the elastic protection cover 150 from peeling off from the host housing 110, a positioning groove 1141 is further formed on the outer sidewall of the corresponding recess 114, and the positioning groove 1141 is circumferentially arranged along the outer sidewall of the host housing 110. Correspondingly, as shown in fig. 3, the inner side wall of the elastic protection sleeve 150 is convexly formed with a positioning convex ring 152. When the elastic protection cover 150 is properly fitted on the host housing 110, the positioning protruding ring 152 is just inserted into the corresponding positioning groove 1141. In addition, in the embodiment, a plurality of positioning grooves 1141 are disposed at intervals along the length direction of the host housing 110, and the positioning protruding rings 152 on the elastic protection sleeve 150 are disposed in one-to-one correspondence with the positioning grooves 1141. In addition, considering that the user may carelessly peel off the elastic protection sleeve 150 from the corresponding recess 114, a receiving strip 153 is integrally formed at the opening edge of the elastic protection sleeve 150, and the receiving strip 153 is convexly formed at the outer side of the elastic protection sleeve 150 and has a contraction type structure, so that the elastic protection sleeve 150 can be tightly sleeved on the corresponding recess 114.

A label display projection 1142 is further protrudingly formed on one side surface of the recess 114 at the bottom of the main body case 110; the label display projection 1142 is located on the same side of the main housing 110 as the display 130, and can be used for displaying the model of the device and detecting the object gas. Correspondingly, the elastic protection sleeve 150 at the bottom of the host casing 110 is provided with a label through hole 154; when the elastic protection sleeve 150 is properly sleeved on the corresponding concave part 114, the label display protrusion 1142 is just embedded in the label through hole 154.

Referring to fig. 4, to ensure that the elastic protection sleeve 150 can sufficiently protect the main housing 110, the elastic protection sleeve 150 includes a rubber layer 155, and a steel wire mesh reinforcing layer 156 is laid in the rubber layer 155, and the rubber layer 155 and the steel wire mesh reinforcing layer 156 are vulcanized and fixed together. In practical use, the rubber layer 155 can not only buffer impact, but also increase the friction force between the host 100 and human hands; the steel wire mesh reinforcing layer 156 can improve the strength of the elastic protection sleeve 150, reduce the risk of damage to the elastic protection sleeve 150, and also contribute to improving the stability of the elastic protection sleeve 150 sleeved on the host casing 110.

In addition, as shown in fig. 2, two sides of the main housing 110 in the width direction are also fixedly attached with an elastic protection layer 160, and the elastic protection layer 160 may be made of a common rubber material or the same material as the elastic protection cover 150.

Referring to fig. 5, the collection assembly is a gas conduit 200, the gas conduit 200 includes a metal detection pipe section 210 and a hose section 220 for connecting to the air inlet 111 of the main housing 110, a drain filter 230 is disposed at an end of the metal detection pipe section 210 close to the hose section 220, and the metal detection pipe section 210 is connected to an end of the hose section 220 far from the main housing 110 through the drain filter 230. In practical use, the gas to be detected enters the main machine shell 110 after sequentially flowing through the metal detection pipe section 210, the pollution discharge filter 230 and the hose section 220 until the concentration detection of the combustible gas is completed; in this process, the filth discharge filter 230 can effectively filter moisture and dust in the gas.

The metal detection pipe section 210 comprises a first pipe section 211 and a second pipe section 212, and the first pipe section 211 is inserted into the second pipe section 212, so that the first pipe section 211 can flexibly extend and retract in the second pipe section 212, the length of the metal detection pipe section 210 is convenient to change, and the detection requirements of containers with different depths are met. A first screw cap 240 is fixed to an end of the second pipe section 212 far away from the first pipe section 211, an internal thread is formed inside the first screw cap 240, and the second pipe section 212 can be detachably connected to an adjacent end of the pollution discharge filter 230 through the first screw cap 240.

The end of the hose segment 220 away from the air inlet 111 is fixedly connected with a second screw cap 250, an internal thread is formed inside the second screw cap 250, and the hose segment 220 can be detachably connected with the adjacent end of the pollution discharge filter 230 through the second screw cap 250. And, for guaranteeing this collection subassembly whole life, above-mentioned hose section 220 outside still evenly coats and has woven protective layer 260, should weave protective layer 260 and can adopt the warp and weft knitting structure commonly used among the wire and cable, and it can play effective protection to hose section 220, reduces the damaged risk of hose section 220.

Referring to fig. 6, the pollution discharge filter 230 includes an outer body 231, both ends of the outer body 231 are opened in a shrinking type structure, and both ends are extended along a length direction thereof to form a thread extension 2311, and outer side walls of both the thread extensions 2311 are formed with outer threads. In actual installation, the first screw cap 240 and the second screw cap 250 are respectively screwed on the two screw extensions 2311.

An inner tube 232 is coaxially arranged inside the outer tube 231, and the opening edges at two ends of the inner tube 232 are bent towards the inner wall of the outer tube 231 and fixedly connected with the inner side wall of the outer tube 231; thus, a vacuum compartment 233 is enclosed between the inner tube 232 and the outer tube 231.

Meanwhile, the inner tube 232 is further embedded with a first filter layer 234 and a second filter layer 235, and the first filter layer 234 and the second filter layer 235 are arranged at intervals along the length direction of the inner tube 232. In this embodiment, the first filter layer 234 may be an air desiccant layer, which is used to remove moisture from the detection gas and is disposed inside the inner tube 232 at a side close to the first screw cap 240; the second filter layer 235 may be a non-woven fabric layer, which may be used for a filter belt to detect particles such as dust in the gas, and may be arranged in 2 or more layers at intervals in the inner tube 232 as required; the non-woven fabric layer is integrally arranged on the side of the air drying agent layer, which is far away from the first screwing cover 240, and the non-woven fabric layer and the air drying agent layer can be separated by adopting a partition plate with vent holes.

In addition, in order to further improve the filtering effect, a filter 236 is further embedded in the second screwing cover 250, the filter 236 may be made of non-woven fabric or activated carbon, and the opening of the adjacent end of the outer tube 231 is directly faced with the filter, so as to further filter the particles in the gas to be detected.

Referring to fig. 7 and 8, a hard pipe segment 300 is further connected to an end of the hose segment 220 away from the second screw cap 250, the hard pipe segment 300 may be made of metal, and an end of the hard pipe segment 300 away from the hose segment 220 extends into the main housing 110 through the air inlet 111 and is connected to a gas detection module (not shown) in the main housing 100. In order to ensure the connection stability of the hose segment 220 and the hard pipe segment 300, the outer side wall of the hard pipe segment 300 is convexly formed with anti-release rings 310, the anti-release rings 310 are located at one end of the hard pipe segment 300 close to the hose segment 220, and a plurality of groups can be arranged at intervals along the length direction, and the adjacent end of the hose segment 220 is sleeved at the position of each anti-release ring 310 on the hard pipe segment 300. And, the outer side of the hose segment 220 is further spirally wound with a steel wire bandage 400, and the steel wire bandage 400 tightly binds and fixes the section of the hose segment 220 for sleeving the hard tube segment 300 on the hard tube segment 300, thereby effectively preventing the hose segment 220 from being disconnected from the hard tube segment 300.

Referring to fig. 9, the hard pipe segment 300 is further provided with a connector 500, the connector 500 is similar to a cap in structure and can be screwed on the air inlet 111, and the hard pipe segment 300 is inserted and fixed in the center of the connector 500. A protective sleeve 510 is arranged on one side of the connector 500 close to the hose section 220, and the protective sleeve 510 is made of metal and can be directly welded and fixed on the connector 500; the protective sleeve 510 is sleeved on the outer side of the steel wire bandage 400, so that the steel wire bandage 400 can be effectively hidden and protected. A hexagonal rotating part 520 is formed on one side of the outer side wall of the connector 500 close to the hose section 220, so that a user can rotate the connector 500 conveniently; meanwhile, a knurled section 530 is formed on the outer side wall of the connector 500 on the side close to the main housing 110, so that the connector 500 is prevented from falling off from a human hand when being taken and placed. Moreover, an elastic gasket 540 is further attached to the inner wall of the connector 500 facing the surface of the main housing 110, and the elastic gasket 540 may be a rubber gasket; when the connector 500 is screwed on the air inlet 111, the air inlet 111 will abut against the elastic sealing pad 540, so as to greatly improve the air tightness at the opening of the air inlet 111.

With reference to fig. 10, an elastic sealing element, which may be a rubber sealing sleeve 600, is further disposed inside the air inlet 111, and the rubber sealing sleeve 600 may be vulcanized and fixed on an inner wall of the air inlet 111, and is provided with a through hole 610 for passing through the hard pipe segment 300; when the hard pipe section 300 passes through the rubber sealing boot 600, the rubber sealing boot 600 can effectively seal the gap between the outer wall of the hard pipe section 300 and the inner wall of the air inlet joint 111. In order to further improve the air tightness, sealing convex rings 611 are further formed on the inner walls of the through holes 610 in a protruding manner, and the sealing convex rings 611 may be arranged in 2 or more groups at intervals along the extending direction of the through holes 610.

The working principle of the embodiment is as follows: the hard pipe section 300 is arranged at one end of the hose section 220, the anti-drop ring 310 is arranged at the part of the hard pipe section 300 for connecting the hose section 220, and the stability of the connection between the hose section 220 and the hard pipe section 300 is fully ensured by matching the steel wire binding band 400 and the protective sleeve 510. Meanwhile, the hard pipe section 300 is connected with the main unit 100, a rubber sealing sleeve 600 is filled in a gap between the hard pipe section 300 and the air inlet 111, and an elastic sealing gasket 540 arranged inside the connector 500 is matched, so that the air tightness of the joint of the air conduit 200 and the air inlet 111 is fully ensured.

The present embodiment is only for explaining the present invention, and it is not limited to the present invention, and those skilled in the art can make modifications to the present embodiment without inventive contribution as required after reading the present specification, but all of them are protected by patent laws within the scope of the claims of the present invention.

Claims (8)

1. A gas detection device comprises a gas guide pipe (200) and a main machine shell (110) with an air inlet interface (111), and is characterized in that the gas guide pipe (200) comprises a hose section (220) and a hard pipe section (300) connected to one end, close to the air inlet interface (111), of the hose section (220), the hard pipe section (300) is arranged in the air inlet interface (111) in a penetrating mode, an elastic sealing element is further arranged on the inner wall of the air inlet interface (111) and surrounds the hard pipe section (300), and the elastic sealing element abuts against the outer wall of the hard pipe section (300); and a connector (500) for detachably connecting the air inlet interface (111) is also fixed on the hard pipe section (300).

2. A gas detection device according to claim 1, wherein the elastic sealing member is a rubber sealing sleeve (600), and the rubber sealing sleeve (600) is fixedly arranged on the inner wall of the air inlet interface (111).

3. The gas detection device according to claim 2, wherein a through hole (610) for penetrating the hard pipe segment (300) is formed in the rubber sealing sleeve (600), a sealing convex ring (611) is formed on the inner wall of the through hole (610) in a protruding manner, and the sealing convex ring (611) is provided with a plurality of groups at intervals along the extending direction of the through hole (610).

4. The gas detection device according to claim 1, wherein the end of the flexible pipe section (220) close to the rigid pipe section (300) is fixedly sleeved on the outer wall of the rigid pipe section (300), and the outer wall of the rigid pipe section (300) for connecting the flexible pipe section (220) is further convexly formed with a plurality of anti-slip rings (310).

5. The gas detection device according to claim 4, wherein a steel wire binding band (400) for binding and fixing the sleeved part of the hose section (220) and the hard pipe section (300) is further spirally wound on the outer side of the hose section (220); the outside cover of steel wire bandage (400) is equipped with protective sheath (510), protective sheath (510) can be dismantled and fix on connector (500).

6. The gas detection device according to claim 1, wherein the connector (500) is screwed on the outer sidewall of the air inlet (111), the hard pipe segment (300) is fixedly inserted into the hard pipe segment (300), and an elastic gasket (540) is arranged on the inner wall of the connector (500) facing the surface of the main housing (110); when the connector (500) is screwed, one end of the air inlet interface (111) far away from the main machine shell (110) abuts against the elastic sealing gasket (540).

7. A gas detecting device according to claim 6, characterized in that the hexagonal rotary portion (520) is integrally formed on the outer side wall of the connecting head (500).

8. A gas detection device according to claim 6, characterized in that the outer side wall of the connection head (500) is further formed with a knurled section (530).

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