Combustible gas alarm

Abstract

The invention relates to the field of gas detection, in particular to a combustible gas alarm which comprises a detection cylinder and a columnar box coaxially arranged below the detection cylinder. The interior of the columnar box is divided into a plurality of fan-shaped cavities through a plurality of partition plates, a plurality of square cylinders are arranged at the bottom of the columnar box through first one-way valves, a fan-shaped plate is arranged in each fan-shaped cavity in a sliding mode, and a telescopic pipe communicated with the interior of the detection cylinder is arranged on each fan-shaped plate; a detection mechanism for detecting entering gas is arranged in the detection cylinder; the detection mechanism comprises an extrusion disc slidably arranged in the detection cylinder, and a detection sensor is further arranged on the extrusion disc; and the top of the columnar box is provided with a step-by-step adjusting mechanism capable of enabling the plurality of fan-shaped plates which are distributed in the circumferential direction to slide up and down in sequence along with the movement of the extrusion disc. According to the invention, step-by-step detection can be carried out in multiple directions, combustible gas can be monitored, and a leakage position can be positioned, so that a worker can carry out maintenance conveniently.

Description

Technical Field

[0001] The invention relates to the field of gas detection, and in particular to a combustible gas alarm. Background Art

[0002] Gas safety is extremely important in life. For flammable gases, it is easy to explode when they leak and encounter open flames, posing a great threat to life and property. In places where flammable gases are used, a flammable gas detector can be used to monitor the content of flammable gases in the air. When an abnormality is detected, relevant personnel can be reminded in time to deal with it, thereby reducing the occurrence of subsequent dangers.

[0003] Chinese Patent: CN114973608B A combustible gas detection alarm with good warning effect, including a connection box, an opening is arranged at the bottom of the connection box, a monitoring probe is installed on the outer wall of the connection box; a mobile detection mechanism is installed inside the connection box; the mobile detection mechanism includes a connection block, and both ends of the connection block are connected to the connection box through a mobile component; a sealing box is installed on the connection block, a processor is installed inside the sealing box, the processor is connected to the alarm through wires, the alarm is provided with a three-color alarm light and a voice announcer, a second rotating rod is installed on the sealing box, the second rotating rod is installed with a connecting plate, notches are opened at both ends of the connecting plate, and a rotating detection component is installed on the notch; sealing mechanisms are arranged at both ends of the opening.

[0004] In this patent, due to the fixed position, when the combustible gas leaks from the edge of the room and spreads to the connection box, its concentration may be high and dangerous, and the leakage location of the combustible gas is unknown. The staff needs to conduct a comprehensive investigation before they can carry out maintenance, resulting in low maintenance efficiency. Summary of the invention

[0005] The main purpose of the present invention is to provide a combustible gas alarm, which can gradually detect multiple directions through a square tube and a detection tube, and can not only monitor the combustible gas, but also locate the leakage position, so as to facilitate maintenance by staff.

[0006] To achieve the above-mentioned purpose, the present invention provides a combustible gas alarm, including a detection tube, a columnar box, a detection mechanism and a step-by-step adjustment mechanism; the detection tube is arranged in a horizontal state, a fixing plate is arranged in a mirror image on the outer wall of the detection tube, the columnar box is coaxially arranged below the detection tube through two connecting plates, a plurality of partition plates are arranged inside the columnar box along the axial direction, the plurality of partition plates divide the interior of the columnar box into a plurality of fan-shaped cavities, a plurality of square tubes are radially arranged on the bottom of the columnar box along the axial direction, the opening direction of each square tube is facing away from the axis of the columnar box, and each square tube is connected to the corresponding fan-shaped cavity through a first one-way valve; each fan-shaped cavity has a A fan-shaped plate is slidably arranged, each fan-shaped plate is provided with a telescopic tube extending vertically upward and passing through the columnar box, one end of each telescopic tube away from the fan-shaped plate is connected to the inside of the detection cylinder, and a second one-way valve is also arranged at one end of each telescopic tube away from the corresponding fan-shaped plate, and a third one-way valve is arranged at the bottom of the outer wall of the detection cylinder; the detection mechanism is arranged inside the detection cylinder and is used to detect the incoming gas; the detection mechanism includes an extrusion plate slidably arranged inside the detection cylinder, and a detection sensor is also arranged on the extrusion plate; the step-by-step adjustment mechanism is arranged at the top of the columnar box and can make multiple fan-shaped plates distributed circumferentially slide up and down in sequence with the movement of the extrusion plate.

[0007] Preferably, the detection mechanism also includes a reciprocating motor and a reciprocating screw; the reciprocating motor is arranged at the top center of the cylindrical box, the motor shaft of the reciprocating motor extends vertically upward through the detection tube and is provided with a reciprocating screw, a reciprocating hole is provided at the center of the extrusion disk, and the reciprocating hole is threadedly connected to the reciprocating screw; two guide grooves are mirror-imaged on the inner wall of the detection tube, and a guide block cooperating with the guide groove is mirror-imaged on the outer wall of the extrusion disk, and the guide block can be slidably arranged in the corresponding guide groove.

[0008] Preferably, the step-by-step adjustment mechanism includes a rotating ring, a driven wheel and a synchronous belt; each sector plate is also provided with an extension rod extending vertically upward and passing through the columnar box, and each extension rod is provided with a guide rod extending toward the axis of the columnar box at one end away from the corresponding sector plate; the rotating ring is coaxially rotatably arranged on the top of the columnar box, and the outer wall of the rotating ring is provided with a guide portion in an inverted V shape that cooperates with the corresponding guide rod; a driving wheel is provided on the motor shaft of the reciprocating motor, and the driven wheel is rotatably arranged at the bottom of the detection cylinder, and the driven wheel is connected to the driving wheel through a synchronous belt transmission, a driving gear is coaxially arranged at the bottom of the driven wheel, and a plurality of gear teeth are circumferentially arranged on the inner wall of the top of the rotating ring, and the driving gear meshes with the gear teeth on the inner wall of the rotating ring.

[0009] Preferably, a plurality of warning lights are arranged circumferentially on the outer wall of the detection tube.

[0010] Preferably, each extension rod is also sleeved with a downward pressure spring, and the downward pressure spring is located inside the corresponding fan-shaped cavity.

[0011] Preferably, a plurality of air-pushing mechanisms for evacuating the gas in the corresponding telescopic tube are further arranged at the bottom of the columnar box.

[0012] Preferably, each air-pushing mechanism includes a push rod, a return spring and a C-shaped plate; a plurality of moving holes are arranged along the axial direction at the bottom of the columnar box, the moving holes are coaxially arranged with the corresponding telescopic tube, the push rod is slidably arranged in the corresponding moving hole, and a rubber plug is arranged at one end of the push rod extending into the corresponding fan-shaped cavity; a limiting disc is arranged at one end of each push rod away from the rubber plug, the return spring is sleeved on the push rod and is located between the limiting disc and the bottom of the columnar box, the C-shaped plate is arranged at the bottom of the columnar box, a winding wheel is rotatably arranged inside the C-shaped plate, a first traction rope is wound on the winding wheel, and one end of the first traction rope away from the winding wheel is arranged on the limiting disc.

[0013] Preferably, a blocking block is slidably arranged in each square cylinder, a pushing spring is arranged between the blocking block and the inner wall of the bottom of the square cylinder, a second traction rope is arranged on one side of the blocking block close to the pushing spring, a traction hole for the second traction rope to pass through is arranged at the center of the bottom of the square cylinder, and the second traction rope passes through the traction hole and is wound on the corresponding winding wheel.

[0014] The beneficial effects of this application compared with the prior art are as follows:

[0015] 1. Through the cooperation of the square cylinder and the detection cylinder, and through the sequential reciprocating movement of a plurality of fan-shaped plates, this application can extract the gas at multiple positions around the detection cylinder. The extracted gas enters the detection cylinder in sequence for detection. It can not only monitor combustible gas, but also locate the position of combustible gas leakage through step-by-step detection in multiple directions, shortening the maintenance time of the staff and further ensuring the use safety.

[0016] 2. Through the cooperation of the fan-shaped plate and the extrusion disc, after a single detection is completed, this application can discharge the gas in the detection area through the movement of the extrusion disc through the third one-way valve, thus avoiding errors in the detection results caused by the mutual interference of the gas in different areas.

[0017] 3. Through the cooperation of the push rod and the blocking block, this application can push the residual gas in the telescopic tube into the detection cylinder, and through the movement of the blocking block, the residual gas sampled last time in the square cylinder can be discharged through the traction hole, avoiding the influence of the residual gas in the square cylinder and the residual gas in the telescopic tube on the subsequent results and ensuring the detection accuracy. Description of the Drawings

[0018] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention, so that other features, purposes and advantages of the present invention become more obvious. The accompanying drawings of the exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0019] Figure 1 The present invention is a three-dimensional Figure 1 ;

[0020] Figure 2 The present invention is a three-dimensional Figure 2 ;

[0021] Figure 3 yes Figure 2 A partial enlarged view of the middle part;

[0022] Figure 4 is a front view of the present invention;

[0023] Figure 5 yes Figure 4 Plane section view along BB direction;

[0024] Figure 6 yes Figure 5 A partial enlarged view of point C in the middle;

[0025] Figure 7 yes Figure 5 A partial enlarged view of point D in the middle;

[0026] Figure 8 It is a partial stereogram of the present invention;

[0027] Fig. 9 yes Figure 8 A partial enlarged view of point E in the middle;

[0028] Fig.10 The local stereo decomposition of the present invention Figure 1 ;

[0029] Fig.11 The local stereo decomposition of the present invention Figure 2 .

[0030] The numbers in the above figure are:

[0031] 1-detection cylinder; 11-fixing plate; 12-connecting plate; 13-partition plate; 14-sector-shaped cavity; 15-sector-shaped plate; 151-telescopic tube; 152-second one-way valve; 153-extension rod; 154-guide rod; 155-downward pressure spring; 16-third one-way valve; 17-guide groove; 18-warning light;

[0032] 2 - Columnar box; 21 - Square cylinder; 211 - Traction hole; 212 - Plugging block; 213 - Push spring; 214 - Second traction rope; 22 - First one - way valve; 23 - Moving hole;

[0033] 3 - Detection mechanism; 31 - Extrusion disc; 311 - Detection sensor; 312 - Reciprocating hole; 313 - Guide block; 32 - Reciprocating motor; 321 - Driving wheel; 33 - Reciprocating lead screw;

[0034] 4 - Step - by - step adjustment mechanism; 41 - Rotating ring; 411 - Guide part; 412 - Teeth; 42 - Driven wheel; 421 - Driving gear; 43 - Synchronous belt;

[0035] 5 - Air - pushing mechanism; 51 - Pushing rod; 511 - Rubber plug; 512 - Limiting disc; 52 - Return spring; 53 - C - shaped plate; 531 - Reel; 532 - First traction rope. Detailed implementation mode

[0036] In order to enable those skilled in the art of the present technology to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the scope of protection of the present invention.

[0037] See Figures 1 to 11As shown, a combustible gas alarm comprises a detection tube 1, a columnar box 2, a detection mechanism 3 and a step-by-step adjustment mechanism 4; the detection tube 1 is arranged in a horizontal state, and a fixing plate 11 is arranged in a mirror image on the outer wall of the detection tube 1; the columnar box 2 is coaxially arranged below the detection tube 1 through two connecting plates 12; a plurality of partition plates 13 are arranged inside the columnar box 2 along the axial direction, and the plurality of partition plates 13 divide the interior of the columnar box 2 into a plurality of fan-shaped cavities 14; a plurality of square tubes 21 are radially arranged at the bottom of the columnar box 2 along the axial direction, and the opening direction of each square tube 21 is oriented away from the axis of the columnar box 2, and each square tube 21 is connected to the corresponding fan-shaped cavity 14 through a first one-way valve 22; a fan plate 1 is slidably arranged in each fan-shaped cavity 14 5. Each sector plate 15 is provided with a telescopic tube 151 extending vertically upward and passing through the columnar box 2. One end of each telescopic tube 151 away from the sector plate 15 is connected to the inside of the detection cylinder 1. One end of each telescopic tube 151 away from the corresponding sector plate 15 is also provided with a second one-way valve 152. A third one-way valve 16 is provided at the bottom of the outer wall of the detection cylinder 1. The detection mechanism 3 is provided inside the detection cylinder 1 and is used to detect the incoming gas. The detection mechanism 3 includes a squeeze plate 31 slidably provided inside the detection cylinder 1, and a detection sensor 311 is also provided on the squeeze plate 31. The step-by-step adjustment mechanism 4 is provided on the top of the columnar box 2 and can make the plurality of sector plates 15 distributed circumferentially slide up and down in sequence with the movement of the squeeze plate 31.

[0038] The staff fixes the detection cylinder 1 to the ceiling through expansion bolts and a fixing plate 11 arranged on the outer wall of the detection cylinder 1, thereby fixing the position of the detection cylinder 1. Subsequently, the squeezing plate 31 moves along its axial direction, thereby squeezing the residual gas between the detection cylinder 1 and the squeezing plate 31. The setting of the third one-way valve 16 allows the gas to flow only from the inside of the detection cylinder 1 to the outside, so that there is no residual gas in the detection cylinder 1, avoiding mutual interference between gases, thereby improving the detection accuracy; at this time, with the cooperation of the step-by-step adjustment mechanism 4, a plurality of circumferentially distributed sector plates 15 can slide up and down step by step, and gases in multiple directions are extracted in sequence through the square cylinder 21. The setting of the first one-way valve 22 allows the gas to The gas can only flow from the square tube 21 toward the inside of the columnar box 2, so that the extracted gas can enter the fan-shaped cavity 14; the setting of the second one-way valve 152 allows the gas to flow only from the fan-shaped cavity 14 toward the inside of the detection tube 1; thereby, the gas in multiple directions can flow in turn between the bottom inner wall of the detection tube 1 and the extrusion disk 31, and be discharged in turn through the third one-way valve 16; in this process, the detection sensor 311 arranged on the extrusion disk 31 can detect the incoming gas in turn; it can not only monitor the leakage of combustible gas, but also locate the position of the combustible gas leakage through gradual detection in multiple directions, thereby shortening the maintenance time of the staff and further ensuring the safety of use.

[0039] See also Figures 8 to 11 As shown, the detection mechanism 3 also includes a reciprocating motor 32 and a reciprocating screw 33; the reciprocating motor 32 is arranged at the top center of the columnar box 2, the motor shaft of the reciprocating motor 32 extends vertically upward through the detection tube 1 and is provided with a reciprocating screw 33, a reciprocating hole 312 is provided at the center of the extrusion disk 31, and the reciprocating hole is threadedly connected with the reciprocating screw 33; the inner wall of the detection tube 1 is mirror-imaged with two guide grooves 17, and the outer wall of the extrusion disk 31 is mirror-imaged with a guide block 313 that cooperates with the guide groove 17, and the guide block 313 can be slidably arranged in the corresponding guide groove 17.

[0040] The reciprocating motor 32 rotates, thereby driving the reciprocating screw 33 to rotate. As the reciprocating screw rotates, the extrusion disk 31 threadedly connected to it can move back and forth along its axial direction. The extrusion disk 31 can fit with the inner wall of the bottom of the detection tube 1, so that the gas inside the detection tube 1 can be completely discharged, avoiding the gas from affecting subsequent detection and improving the detection accuracy.

[0041] See also Figures 8 to 10 As shown, the step-by-step adjustment mechanism 4 includes a rotating ring 41, a driven wheel 42 and a synchronous belt 43; each sector plate 15 is also provided with an extension rod 153 extending vertically upward and passing through the columnar box 2, and each extension rod 153 is provided with a guide rod 154 extending toward the axial direction of the columnar box 2 at one end away from the corresponding sector plate 15; the rotating ring 41 is coaxially rotatably arranged on the top of the columnar box 2, and the outer wall of the rotating ring 41 is provided with a guide portion 411 in an inverted V shape that cooperates with the corresponding guide rod 154; a driving wheel 321 is arranged on the motor shaft of the reciprocating motor 32, and the driven wheel 42 is rotatably arranged at the bottom of the detection cylinder 1, and the driven wheel 42 and the driving wheel 321 are connected by a synchronous belt 43, and a driving gear 421 is coaxially arranged at the bottom of the driven wheel 42, and a plurality of gear teeth 412 are circumferentially arranged on the inner wall of the top of the rotating ring 41, and the driving gear 421 meshes with the gear teeth 412 on the inner wall of the rotating ring 41.

[0042] During the rotation of the reciprocating motor 32, the driving wheel 321 arranged on the motor shaft drives the driven wheel 42 to rotate through the synchronous belt 43. As the driven wheel 42 rotates, the driving gear 421 coaxially arranged therewith is driven to rotate. The driving gear 421 meshes with the gear teeth 412 on the rotating ring 41, so that the rotating ring 41 can rotate. The outer wall of the rotating ring 41 is provided with an inverted V-shaped guide portion 411, and the guide portion 411 can contact the corresponding guide rod 154 in turn, so that the multiple fan-shaped plates 15 can move in turn toward the direction close to the detection tube 1, so as to extract the gas in multiple areas around the detection tube 1. While judging whether it contains combustible gas, it can also detect the leakage position of the combustible gas, so that the staff can handle it in time.

[0043] See Figure 1 As shown, a plurality of warning lights 18 are circumferentially arranged on the outer wall of the detection cylinder 1.

[0044] By providing the warning lights 18, when the detection sensor 311 detects data, the warning lights 18 at the corresponding positions can flash, which is conducive to the staff to judge the leakage position of combustible gas and improve the maintenance efficiency.

[0045] See Fig.10 As shown, a compression spring 155 is also sleeved on each extension rod 153, and the compression spring 155 is located inside the corresponding sector cavity 14.

[0046] By providing the compression spring 155, after the guiding part 411 is separated from the guiding rod 154, under the elastic force of the compression spring 155, the sector plate 15 can be attached to the inner wall of the bottom of the columnar box 2, so as to squeeze the gas in the sector cavity 14 into the detection cylinder 1, thus facilitating the detection of combustible gas.

[0047] See Figure 1 、 Figures 5 to 7 As shown, a plurality of air pushing mechanisms 5 for evacuating the gas in the corresponding telescopic pipe 151 are further arranged at the bottom of the columnar box 2; each group of air pushing mechanisms 5 includes a pushing rod 51, a return spring 52 and a U-shaped plate 53; a plurality of moving holes 23 are arranged along the axial direction at the bottom of the columnar box 2, the moving holes 23 are coaxially arranged with the corresponding telescopic pipe 151, the pushing rod 51 is slidably arranged in the corresponding moving hole 23, and a rubber plug 511 is arranged at one end of the pushing rod 51 extending into the corresponding sector cavity 14; a limiting disc 512 is arranged at one end of each pushing rod 51 away from the rubber plug 511, the return spring 52 is sleeved on the pushing rod 51 and is located between the limiting disc 512 and the bottom of the columnar box 2, the U-shaped plate 53 is arranged at the bottom of the columnar box 2, a winding wheel 531 is rotatably arranged inside the U-shaped plate 53, and a first traction rope 532 is wound around the winding wheel 531, and one end of the first traction rope 532 away from the winding wheel 531 is arranged on the limiting disc 512.

[0048] An adjustment motor for driving the reel 531 to rotate is also provided on each U-shaped plate 53. The adjustment motor drives the reel 531 to rotate. The reel 531 enables the push rod 51 to move against the elastic force of the return spring 52 through the first traction rope 532. After the sector plate 15 contacts the inner wall of the bottom of the columnar box 2, the rubber plug 511 can be pushed into the corresponding telescopic tube 151, so as to completely push the residual gas inside the telescopic tube 151 into the detection cylinder 1, thereby avoiding the influence of the residual gas in the telescopic tube 151 on the subsequent monitoring results and ensuring the monitoring accuracy. After the pushing is completed, the reel 531 loosens, and under the elastic force of the return spring 52, the rubber plug 511 is reset, so that the residual gas in the telescopic tube 151 can be continuously processed.

[0049] See Figure 6 As shown, a blocking block 212 is slidably arranged in each square cylinder 21. A pushing spring 213 is arranged between the blocking block 212 and the inner wall of the bottom of the square cylinder 21. A second traction rope 214 is arranged on one side of the blocking block 212 close to the pushing spring 213. A traction hole 211 for the second traction rope 214 to pass through is arranged at the center of the bottom of the square cylinder 21. The second traction rope 214 passes through the traction hole 211 and is wound around the corresponding reel 531.

[0050] In order to further improve the detection accuracy, through the blocking block 212 arranged in the square cylinder 21, when the gas needs to be detected at the corresponding position, as the reel 531 rotates, the blocking block 212 can move towards the bottom of the square cylinder 21, so as to discharge the residual gas in the square cylinder 21 through the traction hole 211 at its bottom. Guide plates for guiding the first traction rope 532 and the second traction rope 214 are also arranged on both sides of the U-shaped plate 53, so as to avoid friction between the first traction rope 532 and the second traction rope 214 and the reel 531. When the blocking block 212 moves to between the corresponding first one-way valve 22 and the inner wall of the bottom of the square cylinder 21, the gas at the open end of the square cylinder 21 can enter the sector cavity 14 along the square cylinder 21, so as to complete the detection of the gas in different directions.

[0051] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

Claims

1. A combustible gas alarm, characterized in that: It includes a detection cylinder, a columnar box, a detection mechanism and a step-by-step adjustment mechanism; The detection cylinder is arranged in a horizontal state, and a fixing plate is arranged in a mirror image on the outer wall of the detection cylinder. The columnar box is coaxially arranged below the detection cylinder through two connecting plates. A plurality of partition plates are arranged inside the columnar box along the axial direction, and the plurality of partition plates divide the inside of the columnar box into a plurality of fan-shaped cavities. A plurality of square cylinders are radially arranged along the axial direction at the bottom of the columnar box, and the opening direction of each square cylinder is facing away from the axis of the columnar box, and each square cylinder is connected with the corresponding fan-shaped cavity through a first one-way valve; A sector plate is slidably arranged in each sector cavity, and a telescopic tube extending vertically upward and passing through the columnar box is arranged on each sector plate, and one end of each telescopic tube away from the sector plate is connected to the inside of the detection cylinder, and one end of each telescopic tube away from the corresponding sector plate is also provided with a second one-way valve, and a third one-way valve is arranged at the bottom of the outer wall of the detection cylinder; The detection mechanism is arranged inside the detection cylinder and is used to detect the incoming gas; the detection mechanism includes a pressing plate slidably arranged inside the detection cylinder, and a detection sensor is also arranged on the pressing plate; The step-by-step adjustment mechanism is arranged on the top of the columnar box and can make a plurality of sector plates distributed in the circumferential direction slide up and down in sequence along with the movement of the squeezing disk.

2. A combustible gas alarm according to claim 1, characterized in that: The detection mechanism also includes a reciprocating motor and a reciprocating screw rod; The reciprocating motor is arranged at the center of the top of the columnar box, the motor shaft of the reciprocating motor vertically extends upward through the detection tube and is provided with a reciprocating screw rod, a reciprocating hole is arranged at the center of the extrusion disk, and the reciprocating hole is threadedly connected with the reciprocating screw rod; The inner wall of the detection tube is mirror-imaged with two guide grooves, and the outer wall of the extrusion disk is mirror-imaged with guide blocks matched with the guide grooves, and the guide blocks can be slidably arranged in the corresponding guide grooves.

3. A combustible gas alarm according to claim 2, characterized in that: The step-by-step adjustment mechanism includes a rotating ring, a driven wheel and a synchronous belt; Each sector plate is also provided with an extension rod extending vertically upward and passing through the columnar box, and one end of each extension rod away from the corresponding sector plate is provided with a guide rod extending toward the axis direction of the columnar box, and a rotating ring is coaxially rotatably provided on the top of the columnar box, and an outer wall of the rotating ring is provided with a guide portion in an inverted V shape that cooperates with the corresponding guide rod; A driving wheel is arranged on the motor shaft of the reciprocating motor, and a driven wheel is rotatably arranged at the bottom of the detection tube. The driven wheel and the driving wheel are connected by a synchronous belt transmission. A driving gear is coaxially arranged at the bottom of the driven wheel, and a plurality of gear teeth are circumferentially arranged on the inner wall at the top of the rotating ring. The driving gear meshes with the gear teeth on the inner wall of the rotating ring.

4. A combustible gas alarm according to claim 1, characterized in that: A plurality of warning lights are arranged around the outer wall of the detection tube.

5. A combustible gas alarm according to claim 3, characterized in that: Each extension rod is also sleeved with a downward pressure spring, which is located inside the corresponding fan-shaped cavity.

6. A combustible gas alarm according to claim 1, characterized in that: The bottom of the columnar box is also provided with a plurality of gas pushing mechanisms for emptying the gas in the corresponding telescopic tubes.

7. A combustible gas alarm according to claim 6, characterized in that: Each set of air pushing mechanism includes a pushing rod, a return spring and a shaped plate; A plurality of movable holes are arranged along the axial direction at the bottom of the columnar box. The movable holes are arranged coaxially with the corresponding telescopic tubes. The push rods are slidably arranged in the corresponding movable holes. A rubber plug is arranged at one end of the push rods extending into the corresponding fan-shaped cavity. A limiting disk is provided at one end of each push rod away from the rubber plug. A return spring is sleeved on the push rod and is located between the limiting disk and the bottom of the columnar box. A C-shaped plate is provided at the bottom of the columnar box. A winding wheel that can rotate is arranged inside the C-shaped plate. A first traction rope is wound around the winding wheel. One end of the first traction rope away from the winding wheel is arranged on the limiting disk.

8. A combustible gas alarm according to claim 7, characterized in that: A blocking block is slidably arranged in each square cylinder. A pushing spring is arranged between the blocking block and the inner wall of the bottom of the square cylinder. A second traction rope is arranged on one side of the blocking block close to the pushing spring. A traction hole for the second traction rope to pass through is arranged at the center of the bottom of the square cylinder. The second traction rope passes through the traction hole and is wound around the corresponding winding wheel.

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