Air-breathing fire smoke detector

Abstract

The invention discloses an air-breathing fire smoke detector, and relates to the technical field of smoke sensing detectors, and the air-breathing fire smoke detector achieves the real-time monitoring of the air inlet flow rate through the additional arrangement of a wind speed monitoring and regulation function, guarantees the stability of the airflow, optimizes the structural design of an air inlet pipeline and an air outlet pipeline, and improves the detection precision. Airflow is guided to pass through stably through the structural design of the flow guide cavity, and turbulent flow is prevented, so that the detection accuracy and stability of the detector are ensured; a multi-stage filtering mode is adopted, the structural design of the light scattering cavity assembly is optimized, an interference signal shielding function is added, dust and impurities can be effectively prevented from entering the laser assembly, and the stability of background signals in an initial state is guaranteed; according to the invention, a pulse width signal modulation technology design is adopted, stable emission of a laser source is ensured, a tiny signal amplification analog circuit processing technology is adopted, collected tiny signals are amplified, interference in the environment can be filtered, and high-precision detection is realized.

Description

Technical Field

[0001] The invention relates to the technical field of smoke detectors, and in particular to an aspirating fire smoke detector. Background Art

[0002] Among various disasters, fire is one of the most frequent and common major disasters that threaten public safety and social development. Therefore, effective fire prevention and control is of great significance to ensuring the safety of people's lives and property and promoting social stability and healthy development. The development of fire can be divided into four stages: 1. The initial stage with weak burning intensity, small area, visible smoke, small flame or flameless smoldering; 2. The growth stage with increasing burning intensity, gradually rising temperature, burning with flames, and rapid expansion of the burning area; 3. The fierce stage with the maximum burning intensity, sharp rise in temperature, strongest radiant heat, and rapid expansion of the burning area; 4. The decline stage with the decline of fire, temperature drop, smoke dissipation, and the gradual subsidence of fire. Among the four stages, the initial stage has low burning intensity and small harm, and also provides more time and opportunities to detect and control the development of fire, which is the best period for fire prevention and control.

[0003] In most cases, there is no open flame in the early stages of a fire, only a small amount of combustibles are in a smoldering state, and the temperature is low. It is difficult for temperature-sensitive fire detectors to detect fire dangers when they are far away from the fire source. In addition, the concentration of smoke particles generated in the early stages of a fire is extremely low, and the smoke particles diffuse slowly. Traditional point-type smoke detectors cannot actively collect smoke particles and have no reaction to extremely low concentrations of smoke particles in the early stages of a fire. Therefore, there is a need for an aspirating smoke detector that can actively collect smoke particles and detect low-concentration smoke particles, effectively detect and alarm fires in the early stages, and achieve efficient prevention and control of extremely early fires.

[0004] At present, most of the existing aspirating fire smoke detectors on the market have the ability to actively collect air for detection, but they do not have the wind speed control function and the gas pipeline structure is roughly designed. When the intake wind speed fluctuates, turbulence is easily generated, resulting in inaccurate smoke detection; the smoke detection component of the detector causes light interference or interference when no smoke enters, resulting in false alarms; in addition, the detector only has a single-stage dust filtration structure, which cannot filter dust and impurities with smaller particle sizes, and has poor anti-interference ability, causing dust and impurities to enter the smoke detection cavity and interfere with detection, or dust and other impurities are attached to the smoke detection cavity, thereby changing the background signal of the detector in the initial state, which will cause the detector's detection line for smoke concentration to change, thereby affecting the detector's detection accuracy. Summary of the invention

[0005] In view of the above technical problems, the present invention proposes an aspirating fire smoke detector, comprising a fan assembly, a filter box assembly, a laser assembly, a main control PCB board, a box cover assembly, a box body, a nylon gland, a wind speed test hose, a rubber hose, foam, a T-shaped nylon gasket and a plastic isolation column; a welding patch is provided on the back of the box body for installing and fixing the detector, and a three-point fixing method is adopted to enhance the installation stability of the detector; riveted studs are provided inside the box body for installing the fan assembly, the filter box assembly, the laser assembly and the main control PCB board; the nylon gland is installed on the side of the box body for introducing power lines and signal lines; the box cover assembly is installed on the box body, and the joint surface of the box cover assembly and the box body is pasted with foam for ensuring sealing.

[0006] Furthermore, the fan assembly includes an air inlet duct, an air outlet duct and a centrifugal blower, the centrifugal blower is installed inside the box body by means of riveted studs, the air inlet duct and the air outlet duct are respectively arranged on both sides of the centrifugal blower, in order to reduce the generation of turbulence when the gas flows through the fan assembly and affect the stability and accuracy of the detection, a guide structure cavity is provided in the air inlet duct and the air outlet duct; a wind speed test hole and a sampling air outlet hole are provided on the air inlet duct, and a sampling air inlet hole is provided on the air outlet duct; in order to monitor the air intake wind speed in real time and keep the wind speed stable, the wind speed test hole is connected to the main control PCB board through a wind speed test hose, and the centrifugal blower is connected to the main control PCB board; the main control PCB board controls the rotation of the centrifugal blower to make air flow into the air inlet duct, and the air flows through the wind speed test hose and detects the wind speed through the main control PCB board, and when the wind speed fluctuation is large and affects the detection of the detector, the main control PCB board adjusts the speed of the centrifugal blower to keep the wind speed stable.

[0007] Furthermore, the filter box assembly includes a filter box body, a filter box cover, a plastic outer thread pagoda elbow, a coarse filter sponge, a fine filter sponge, and a filter box sealing strip; the filter box body is installed inside the box body through riveted studs, the filter pore diameter of the coarse filter sponge is 20-50um, and the filter pore diameter of the fine filter sponge is 10-15um, and they are placed in the coarse filter sponge cavity and the fine filter sponge cavity of the filter box body respectively; the filter box sealing strip is placed in a U-shaped groove on the filter box body, and two plastic outer thread pagoda elbows are connected to the coarse filter sponge cavity and the fine filter sponge cavity respectively; the filter box cover is installed on the filter box body to ensure sealing, and the plastic outer thread pagoda elbow connected to the coarse filter sponge cavity is connected to the sampling air inlet on the air outlet pipe through a rubber hose.

[0008] Furthermore, the laser assembly includes a laser cavity, a laser driving assembly, an astigmatism cavity assembly, an air duct, a smoke detection plate, a shielding box, a pagoda joint, an O-ring 2 and an O-ring 4. The laser cavity is installed inside the box by means of riveting studs. A hole is opened on the front of the laser cavity for installing the air duct. The air duct and the laser cavity are sealed by means of a plurality of O-rings 4. A hole is opened on the top of the laser cavity for installing the smoke detection plate. The smoke detection plate and the laser cavity are sealed by means of a plurality of O-rings 2. The shielding box is installed on the smoke detection plate. A hole is opened on one side of the laser cavity for installing the laser driving assembly. Two holes are opened on the other side of the laser cavity for installing the astigmatism cavity assembly and the pagoda joint. The laser driving assembly mounting hole on the laser cavity is coaxial with the astigmatism cavity assembly mounting hole. The air duct is connected to a plastic outer thread pagoda elbow connected to the fine filter sponge cavity through a rubber hose, and air enters the laser cavity through the air duct.

[0009] Furthermore, the laser driving component includes a support, a focusing sleeve, a light barrier, an isolation ring, a laser driving board, a focusing lens and an O-ring. A through hole is provided on the support, and the focusing sleeve, light barrier, isolation ring and focusing lens are sequentially arranged inside the through hole; the laser driving board is installed on one side of the support, and the other side of the support is installed on the laser cavity. The support and the laser cavity are sealed by multiple O-rings, and the laser driving board and the support are sealed by multiple O-rings; the laser driving board is designed with pulse width signal modulation technology to ensure stable emission of the laser source; the laser driving board is connected to the main control PCB board.

[0010] Furthermore, the astigmatism cavity assembly includes an astigmatism cavity, a focusing cone, an astigmatism cone and three O-rings to ensure the sealing of the cavity; the astigmatism cavity is installed on the laser cavity, the focusing cone and the astigmatism cone are placed in the astigmatism cavity, the astigmatism cone and the astigmatism cavity are sealed by multiple O-rings three, and the astigmatism cavity and the laser cavity are sealed by multiple O-rings three; the astigmatism cone has a bevel angle of 60° to ensure the stability of the background signal in the initial state and to have anti-interference performance.

[0011] Furthermore, the smoke detection board adopts a small signal amplification analog circuit processing technology to amplify the collected small signals, and at the same time can filter out interference in the environment to achieve high-precision detection. The smoke detection board is connected to the main control PCB board; in order to shield the accidental input of interference signals from affecting the detection results, a shielding box made of stainless steel is installed on the smoke detection board.

[0012] Furthermore, the pagoda joint is connected to the sampling air outlet on the air inlet pipe through a rubber hose, and the detected air or smoke is discharged through the sampling air outlet; the riveted stud of the laser assembly is placed on the outer cover of a plastic isolation column, and a T-shaped nylon gasket is placed on the upper part of the plastic isolation column to prevent accidental input of static electricity or interference signals.

[0013] Furthermore, the box cover assembly includes a box cover, a control display panel, a liquid crystal module shell, and a silk-screen mask; the box cover is installed on the box body, the control display panel is fixed to the back of the liquid crystal module shell, and the silk-screen mask is placed on the front of the liquid crystal module shell; the box cover has a hole on the front, and a rivet screw is provided on the back, and the liquid crystal module shell is fixed to the back of the box cover; the control display panel is connected to the main control PCB board to display, adjust and control the detector detection process and detection results.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention adds a wind speed monitoring and control function, which can monitor the intake air flow rate in real time to ensure the stability of the airflow, and optimizes the structural design of the intake duct and the outlet duct, and guides the airflow to pass smoothly through the guide cavity structure design to prevent the generation of turbulence, thereby ensuring the accuracy and stability of the detector detection; the present invention adopts a multi-stage filtering method to optimize the structural design of the astigmatism cavity component, and adds an interference signal shielding function, which can effectively prevent dust and impurities from entering the laser component and ensure the stability of the background signal in the initial state; the present invention adopts a pulse width signal modulation technology design to ensure the stable emission of the laser source, and at the same time adopts a small signal amplification analog circuit processing technology to amplify the collected small signal, which can filter out interference in the environment and achieve high-precision detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The invention is a general assembly of the aspirating fire smoke detector Figure 1 .

[0016] Figure 2 The invention is a general assembly of the aspirating fire smoke detector Figure 2 .

[0017] Figure 3 The invention is a general assembly of the aspirating fire smoke detector Figure 3 .

[0018] Figure 4 The fan assembly structure of the present invention is schematically shown in FIG. Figure 1 .

[0019] Figure 5 The fan assembly structure of the present invention is schematically shown in FIG. Figure 2 .

[0020] Figure 6 The structure of the filter box assembly of the present invention is schematically shown. Figure 1 .

[0021] Figure 7 The structure of the filter box assembly of the present invention is schematically shown. Figure 2 .

[0022] Figure 8 The structure of the laser assembly of the present invention is shown in FIG. Figure 1 .

[0023] Fig. 9 The structure of the laser assembly of the present invention is shown in FIG. Figure 2 .

[0024] Fig.10 It is a schematic diagram of the astigmatism cone structure of the present invention.

[0025] Fig.11 The structure of the box cover assembly of the present invention is shown in FIG. Figure 1 .

[0026] Fig.12 The structure of the box cover assembly of the present invention is shown in FIG. Figure 2 .

[0027] Fig.13 The structure of the box cover assembly of the present invention is shown in FIG. Figure 3 .

[0028] Figure numbers: 1-fan assembly; 2-filter box assembly; 3-laser assembly; 4-main control PCB board; 5-box cover assembly; 6-box; 7-nylon gland; 8-wind speed test hose; 9-rubber hose; 10-foam; 11-T-type nylon gasket; 101-inlet pipe; 102-outlet pipe; 103-centrifugal blower; 201-filter box body; 202-filter box cover; 203-plastic outer wire pagoda elbow; 204-coarse filter sponge; 205-fine filter sponge; 206-filter box sealing strip; 301-laser cavity; 3 02-support; 303-focusing shaft sleeve; 304-light bar; 305-isolating ring; 306-laser driving board; 307-scattering cavity; 308-focusing cone; 309-scattering cone; 310-air duct; 311-smoke detection board; 312-shielding box; 313-focusing lens; 314-pagoda connector; 315-O-ring one; 316-O-ring two; 317-O-ring three; 318-O-ring four; 501-box cover; 502-control display board; 503-LCD module housing; 504-silk screen mask. DETAILED DESCRIPTION

[0029] The present invention will be further described below in conjunction with specific embodiments. The illustrative embodiments and descriptions of the present invention are used to explain the present invention but are not intended to limit the present invention.

[0030] Example: Figure 1-Figure 13 The aspirating fire smoke detector shown in the figure comprises a fan assembly 1, a filter box assembly 2, a laser assembly 3, a main control PCB board 4, a box cover assembly 5, a box body 6, a nylon gland 7, a wind speed test hose 8, a rubber hose 9, foam 10, a T-type nylon gasket 11 and a plastic isolation column; a welding patch is provided on the back of the box body 6 for installing and fixing the detector, and a three-point fixing method is adopted to enhance the installation stability of the detector; riveted studs are provided inside the box body 6 for installing the fan assembly 1, the filter box assembly 2, the laser assembly 3 and the main control PCB board 4; the nylon gland 7 is installed on the side of the box body 6 for introducing the power line and the signal line; the box cover assembly 5 is installed on the box body 6, and the joint surface of the box cover assembly 5 and the box body 6 is pasted with foam 10 for ensuring sealing.

[0031] The fan assembly 1 includes an air inlet duct 101, an air outlet duct 102 and a centrifugal blower 103. The centrifugal blower 103 is installed inside the box body 6 by means of riveted studs. The air inlet duct 101 and the air outlet duct 102 are respectively arranged on both sides of the centrifugal blower 103. In order to reduce the generation of turbulence when the gas flows through the fan assembly and affect the stability and accuracy of the detection, a guide structure cavity is provided in the air inlet duct 101 and the air outlet duct 102; a wind speed test hole and a sampling air outlet hole are provided on the air inlet duct 101, and a sampling air inlet hole is provided on the air outlet duct 102; in order to monitor the intake wind speed in real time and keep the wind speed stable, the wind speed test hole is connected to the main control PCB board 4 through the wind speed test hose 8, and the centrifugal blower 103 is connected to the main control PCB board 4. The main control PCB board 4 controls the rotation of the centrifugal blower 103 to allow air to flow into the air intake duct 101. The air flows through the wind speed test hose 8 and the wind speed is detected by the main control PCB board 4. When the wind speed fluctuates greatly and affects the detector detection, the main control PCB board 4 adjusts the speed of the centrifugal blower 103 to maintain a stable wind speed.

[0032] The filter box assembly includes a filter box body 201, a filter box cover 202, a plastic outer thread pagoda elbow 203, a coarse filter sponge 204, a fine filter sponge 205, and a filter box sealing strip 206; the filter box body 201 is installed inside the box body 6 by means of riveted studs. To prevent dust and impurities with larger particle sizes from entering and affecting the detection results, the filter pores of the coarse filter sponge 204 have a pore size of 50um, and the filter pores of the fine filter sponge 205 have a pore size of 15um, and they are placed in the coarse filter sponge cavity and the fine filter sponge cavity of the filter box body 201, respectively; the filter box sealing strip 206 is placed in the U-shaped groove of the filter box body 201, and the two plastic outer thread pagoda elbows 203 are connected to the coarse filter sponge cavity and the fine filter sponge cavity, respectively; the filter box cover 202 is installed on the filter box body 201 to ensure sealing, and the plastic outer thread pagoda elbow 203 connected to the coarse filter sponge cavity is connected to the sampling air inlet 102 on the air outlet pipe through a rubber hose 9. Air flows into the filter box assembly 2 through the sampling air inlet, and after two-stage filtration, dust and impurities with larger particle sizes can be filtered out to ensure that only air and smoke with smaller particle sizes enter, thereby making the detection result more accurate.

[0033] As attached Figure 4 As shown, the laser assembly 3 includes a laser cavity 301, a laser driving assembly, an astigmatism cavity assembly, an air duct 310, a smoke detection plate 311, a shielding box 312, a pagoda joint 314, an O-ring 2 316, and an O-ring 4 318. The laser cavity 301 is installed inside the box 6 by means of a riveting stud. The front of the laser cavity 301 is opened to install the air duct 310. The air duct 310 and the laser cavity 301 are sealed by a plurality of O-rings 4 318. The top of the laser cavity 301 is opened to install the smoke detection plate 311. The smoke detection plate 311 is sealed by means of a plurality of O-rings 4 318. 11 is sealed with the laser cavity 301 by multiple O-rings 316, and the shielding box 312 is installed on the smoke detection plate 311; a hole is opened on one side of the laser cavity 301 to install the laser drive component; two holes are opened on the other side of the laser cavity 301 to install the astigmatism cavity component and the pagoda connector 314; wherein, the laser drive component mounting hole on the laser cavity 301 is coaxial with the astigmatism cavity component mounting hole; the air duct 310 is connected to the plastic outer thread pagoda elbow 203 connected to the fine filter sponge cavity through the rubber hose 9, and the air enters the laser cavity 301 through the air duct 310.

[0034] The laser driving component generates laser light. To ensure the stability of the light source, the laser driving component includes a support 302, a focusing sleeve 303, a light barrier 304, an isolating ring 305, a laser driving board 306, a focusing lens 313 and an O-ring 315. A through hole is provided on the support 302. The focusing sleeve 303, the light barrier 304, the isolating ring 305 and the focusing lens 313 are sequentially arranged inside the through hole; the laser driving board 306 is installed on one side of the support 302, and the other side of the support 302 is installed on the laser cavity 301. The support 302 and the laser cavity 301 are sealed by multiple O-rings 315, and the laser driving board 306 and the support 302 are sealed by multiple O-rings 315; the laser driving board 306 is designed with pulse width signal modulation technology to ensure the stable emission of the laser source; the laser light enters the scattered light cavity component and then scatters to form a background signal in the initial state, and the laser driving board is connected to the main control PCB board 4.

[0035] The astigmatism cavity assembly includes an astigmatism cavity 307, a focusing cone 308, an astigmatism cone 309 and an O-ring 317 for ensuring the sealing of the cavity; the astigmatism cavity 307 is installed on the laser cavity 301, the focusing cone 308 and the astigmatism cone 309 are placed in the astigmatism cavity 307, the astigmatism cone 309 and the astigmatism cavity 307 are sealed by multiple O-rings 317, and the astigmatism cavity 307 and the laser cavity 301 are sealed by multiple O-rings 317; the bevel angle of the beveled surface of the astigmatism cone 309 is 60°, which can ensure the stability of the background signal in the initial state and has good anti-interference performance.

[0036] The smoke detection board 311 adopts tiny signal amplification analog circuit processing technology. When smoke enters the laser cavity 301, the collected tiny signal is amplified, and at the same time, it can filter out interference in the environment to achieve high-precision detection. The smoke detection board 311 is connected to the main control PCB board 4; in order to shield the accidental input of interference signals from affecting the detection results, a stainless steel shielding box 312 is installed on the smoke detection board 311.

[0037] The pagoda connector 314 is connected to the sampling outlet on the air inlet pipe 101 through the rubber hose 9, and the detected air or smoke is discharged through the sampling outlet. The pressure riveted studs of the laser assembly 3 are placed on the plastic isolation column, and a T-type nylon gasket 11 is placed on the top of the plastic isolation column to prevent the accidental input of static electricity or other interference signals.

[0038] The box cover assembly 5 includes a box cover 501, a control display panel 502, a liquid crystal module housing 503, and a silk screen mask 504. The box cover 501 is installed on the box body 6, the control display panel 502 is fixed to the back of the liquid crystal module housing 503, and the silk screen mask 504 is placed on the front of the liquid crystal module housing 503; the box cover 501 has a hole on the front, and a pressure riveting screw is provided on the back, and the liquid crystal module housing 503 is fixed to the back of the box cover 501; the control display panel 502 is connected to the main control PCB board 4 to display, adjust and control the detector detection process and detection results; the material of the box body 6 and the box cover 501 is preferably stainless steel or aluminum alloy; the material of the liquid crystal module housing 503 is preferably Q235 steel.

[0039] The present invention designs an aspirating smoke detector, which realizes real-time monitoring and regulation of the intake air velocity by adding a wind speed monitoring function, thereby ensuring the stability of the airflow; the airflow is guided to pass smoothly through the guide cavity structure design to prevent the generation of turbulence, thereby ensuring the accuracy and stability of the detector detection; the present invention adopts a multi-stage filtering method to optimize the structural design of the scattered light cavity component, and adds an interference signal shielding function, which can effectively prevent dust and impurities from entering the laser component and ensure the stability of the background signal in the initial state; the present invention adopts a pulse width signal modulation technology design to ensure the stable emission of the laser source, and adopts a small signal amplification analog circuit processing technology to amplify the collected small signal, which can filter the interference in the environment and achieve high-precision detection.

[0040] The above contents are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, various changes and modifications may be made according to the present invention. Any modifications, equivalent substitutions and improvements made within the design principles of the present invention should be covered within the protection scope of the present invention.

Claims

1. An aspirating fire smoke detector, characterized in that: The invention comprises a fan assembly (1), a filter box assembly (2), a laser assembly (3), a main control PCB board (4), a box cover assembly (5), a box body (6), a nylon gland (7), a wind speed test hose (8), a rubber hose (9), foam (10), a T-shaped nylon gasket (11) and a plastic isolation column; the box body (6) is provided with a welding patch on the back side for mounting and fixing the detector; the box body (6) is provided with a rivet stud inside for mounting the fan assembly (1), the filter box assembly (2), the laser assembly (3) and the main control PCB board (4); the nylon gland (7) is installed on the side of the box body (6) for introducing a power line and a signal line; the box cover assembly (5) is installed on the box body (6), and the joint surface of the box cover assembly (5) and the box body (6) is pasted with foam (10) for ensuring sealing.

2. An aspirating fire smoke detector as claimed in claim 1, characterized in that: The fan assembly (1) comprises an air intake duct (101), an air outlet duct (102) and a centrifugal blower (103); the centrifugal blower (103) is installed inside the box (6) by means of riveted studs; the air intake duct (101) and the air outlet duct (102) are respectively arranged on both sides of the centrifugal blower (103); in order to reduce the generation of turbulence when the gas flows through the fan assembly, thereby affecting the stability and accuracy of the detection, a flow guide structure cavity is provided in the air intake duct (101) and the air outlet duct (102); a wind speed test hole and a sampling air outlet hole are provided on the air intake duct (101); and the air outlet hole is provided on the air intake duct (101). A sampling air inlet hole is provided on the pipe (102); in order to monitor the air intake wind speed in real time and maintain a stable wind speed, the wind speed test hole is connected to the main control PCB board (4) through a wind speed test hose (8); the centrifugal blower (103) is connected to the main control PCB board (4); the main control PCB board (4) controls the rotation of the centrifugal blower (103) to allow air to flow into the air intake pipe (101); the air flows through the wind speed test hose (8) and the main control PCB board (4) to detect the wind speed; when the wind speed fluctuates greatly and affects the detection of the detector, the main control PCB board (4) adjusts the rotation speed of the centrifugal blower (103) to maintain a stable wind speed.

3. An aspirating fire smoke detector as claimed in claim 2, characterized in that: The filter box assembly comprises a filter box body (201), a filter box cover plate (202), a plastic outer thread pagoda elbow (203), a coarse filter sponge (204), a fine filter sponge (205), and a filter box sealing strip (206); the filter box body (201) is installed inside the box body (6) by means of riveted studs; the filter pores of the coarse filter sponge (204) are 20-50 um in diameter, and the filter pores of the fine filter sponge (205) are 10-15 um in diameter, and are respectively placed on the filter box body (2 01); the filter box sealing strip (206) is placed in the U-shaped groove on the filter box body (201), and two plastic outer thread pagoda elbows (203) are respectively connected to the coarse filter sponge cavity and the fine filter sponge cavity; the filter box cover (202) is installed on the filter box body (201) to ensure the sealing performance, and the plastic outer thread pagoda elbow (203) connected to the coarse filter sponge cavity is connected to the sampling air inlet hole on the air outlet pipe (102) through a rubber hose (9).

4. An aspirating fire smoke detector as claimed in claim 3, characterized in that: The laser assembly (3) comprises a laser cavity (301), a laser driving assembly, an astigmatism cavity assembly, an air duct (310), a smoke detection plate (311), a shielding box (312), a pagoda joint (314), a second O-ring (316), and a fourth O-ring (318); the laser cavity (301) is installed inside the box (6) by means of riveting studs; a hole is opened on the front of the laser cavity (301) for installing the air duct (310); the air duct (310) and the laser cavity (301) are sealed by means of a plurality of fourth O-rings (318); a hole is opened on the top of the laser cavity (301) for installing the smoke detection plate (311); The smoke detection plate (311) and the laser cavity (301) are sealed by a plurality of O-rings (316), and the shielding box (312) is mounted on the smoke detection plate (311); a hole is opened on one side of the laser cavity (301) for mounting a laser driving component; two holes are opened on the other side of the laser cavity (301) for mounting an astigmatism cavity component and a pagoda connector (314); the laser driving component mounting hole on the laser cavity (301) is coaxial with the astigmatism cavity component mounting hole; the air guide pipe (310) is connected to a plastic outer thread pagoda elbow (203) connected to the fine filter sponge cavity through a rubber hose (9), and air enters the laser cavity (301) through the air guide pipe (310).

5. An aspirating fire smoke detector as claimed in claim 4, characterized in that: The laser driving assembly comprises a support (302), a focusing sleeve (303), a light barrier (304), an isolating ring (305), a laser driving plate (306), a focusing lens (313) and an O-ring (315); a through hole is provided on the support (302); the focusing sleeve (303), the light barrier (304), the isolating ring (305) and the focusing lens (313) are sequentially arranged inside the through hole; the laser driving plate (306) is mounted on the support (302) and the laser driving plate (306) is mounted on the support (302). The support (302) is mounted on one side of the laser cavity (301); the support (302) and the laser cavity (301) are sealed by a plurality of O-rings (315); the laser driving board (306) and the support (302) are sealed by a plurality of O-rings (315); the laser driving board (306) is designed with pulse width signal modulation technology to ensure stable emission of the laser source; and the laser driving board is connected to a main control PCB board (4).

6. An aspirating fire smoke detector as claimed in claim 5, characterized in that: The astigmatism cavity assembly comprises an astigmatism cavity (307), a focusing cone (308), an astigmatism cone (309), and an O-type sealing ring (317) for ensuring the sealing of the cavity; the astigmatism cavity (307) is mounted on a laser cavity (301); the focusing cone (308) and the astigmatism cone (309) are placed in the astigmatism cavity (307); the astigmatism cone (309) and the astigmatism cavity (307) are sealed by a plurality of O-type sealing rings (317); the astigmatism cavity (307) and the laser cavity (301) are sealed by a plurality of O-type sealing rings (317); the beveled surface of the astigmatism cone (309) has a beveled angle of 60°, so as to ensure the stability of the background signal in an initial state and to have anti-interference performance.

7. An aspirating fire smoke detector as claimed in claim 6, characterized in that: The smoke detection board (311) adopts a tiny signal amplification analog circuit processing technology to amplify the collected tiny signal and can filter out interference in the environment to achieve high-precision detection. The smoke detection board (311) is connected to the main control PCB board (4). In order to shield the accidental input of interference signals from affecting the detection results, a shielding box (312) made of stainless steel is installed on the smoke detection board (311).

8. An aspirating fire smoke detector as claimed in claim 7, characterized in that: The pagoda connector (314) is connected to the sampling outlet on the air inlet pipe (101) through a rubber hose (9), and the detected air or smoke is discharged through the sampling outlet; the laser assembly (3) is placed on a plastic isolation column with a riveted stud jacket, and a T-shaped nylon gasket (11) is placed on the top of the plastic isolation column to prevent accidental input of static electricity or interference signals.

9. An aspirating fire smoke detector as claimed in claim 8, characterized in that: The box cover assembly (5) comprises a box cover (501), a control display panel (502), a liquid crystal module housing (503), and a silk-screen mask (504); the box cover (501) is mounted on the box body (6); the control display panel (502) is fixed to the back of the liquid crystal module housing (503); and the silk-screen mask (504) is placed on the front of the liquid crystal module housing (503); the box cover (501) has an opening on the front, and a rivet screw is provided on the back; the liquid crystal module housing (503) is fixed to the back of the box cover (501); the control display panel (502) is connected to the main control PCB board (4) to display, adjust and control the detector detection process and detection results.

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