A dual-purpose gas path structure for a portable gas detector

Abstract

This invention provides a dual-purpose gas path structure for portable gas detectors, applicable to the field of gas detection device technology. It includes a cylindrical outer shell, a top coaxial air pump, an airflow pipe, a bottom gas chamber cover, a sliding exhaust / intake cover, a sensor, and a waterproof filter membrane. Multiple gas chambers are evenly distributed around the circumference of the gas chamber cover and connected by airflow guide channels. A return spring is provided between the exhaust / intake cover and the gas chamber cover, and a resistance cover is connected via a sliding rod. When the air pump starts, the airflow presses down on the resistance cover, overcoming the spring force of the return spring, causing the exhaust / intake cover to move down, closing the diffusion gap and opening the pump intake path. When the air pump stops, the return spring resets, automatically switching to diffusion intake mode. This invention achieves automatic switching between pump intake and diffusion modes without the need for a solenoid valve, offering the advantage of dual gas path detection switching, improving detection accuracy and equipment reliability, and is suitable for various portable multi-gas detection instruments.

Description

Technical Field

[0001] This application relates to the field of gas detection device technology, and in particular to a dual-purpose gas path structure for a portable gas detector. Background Technology

[0002] Gas detectors are core devices used to detect the concentration of harmful, toxic, and flammable gases in the environment, and are widely used in industrial production, environmental monitoring, mine rescue, public safety, and other fields. Based on the different gas intake methods, gas detectors are mainly divided into two categories: pump-suction and diffusion-type. Pump-suction detectors actively extract the gas to be tested using a pump, offering fast detection response, suitability for confined spaces, and long-distance sampling. Diffusion-type detectors rely on the natural diffusion of gas into the detection chamber, requiring no additional power, offering long operating time and a simple structure.

[0003] Currently, most portable gas detectors on the market use a single intake mode, which is only suitable for specific detection scenarios: pump-type detectors cannot be used in low-power scenarios, while diffusion-type detectors cannot meet the needs of rapid sampling. Some dual-mode detectors achieve mode switching through electromagnetic control valves, but electromagnetic control valves have problems such as complex structure, high cost, easy failure, and high power consumption, which do not meet the requirements of lightweight, low power consumption, and high reliability of portable devices.

[0004] Therefore, a dual-purpose gas path structure for portable gas detectors is proposed. Summary of the Invention

[0005] The purpose of this application is to solve the technical problems of existing gas detectors, such as a single gas intake mode, low automation of dual-mode switching, and poor convenience. Compared with the prior art, it provides a dual-purpose gas path structure for portable gas detectors, including:

[0006] The outer shell has a cylindrical shell structure.

[0007] An air pump is coaxially mounted on the top of the housing. The air inlet of the air pump is equipped with a grille cover, and the air inlet is connected to the outside through the grille cover.

[0008] An airflow duct is provided, wherein the air outlet of the air pump is connected to the air inlet of the airflow duct;

[0009] An air chamber cover is located on the inner bottom of the outer shell. The top of the air chamber cover has a connection port. The air outlet of the airflow pipe is connected to the connection port. The air chamber cover is provided with several air chambers at equal angles along the circumference of the airflow pipe. The air chamber cover and the air chambers are connected by airflow guide grooves.

[0010] An exhaust hood is installed on the top of the air chamber cover, and the top of the air chamber is provided with an exhaust port that communicates with the inside of the exhaust hood.

[0011] A sensor, wherein the gas detection end of the sensor extends to the bottom of the gas chamber for detecting gas in the air inlet;

[0012] A waterproof filter membrane is installed inside the air inlet and outlet ports.

[0013] Furthermore, the exhaust hood is slidably connected to the top of the air chamber hood in a vertical direction, and a return spring is clamped between the exhaust hood and the air chamber hood. The return spring has an elastic force that drives the exhaust hood to move upward away from the air chamber hood.

[0014] The exhaust hood has a C-shaped annular structure. An outer sealing plate is provided on the outer circumference of the exhaust hood. The top of the outer shell is provided with an upper ring edge that matches the outer sealing plate. When the return spring is in a free state, the outer sealing plate moves upward with the exhaust hood and away from the upper ring edge, and the outer sealing plate and the upper ring edge are separated to form an exhaust gap.

[0015] Furthermore, the outer sealing plate is an overall elastic rubber structure, and the outer sealing plate has elasticity near the upper ring edge.

[0016] Furthermore, the inner wall of the exhaust hood is provided with an inner sealing plate that cooperates with the grille cover. The grille cover has a conical structure. When the return spring is in a free state, the inner sealing plate and the grille cover are aligned and close the air inlet.

[0017] Furthermore, the bottom of the exhaust hood is fixed with several sliding rods at equal angles, the top of the air chamber hood is provided with a sealing sleeve that cooperates with the sliding rods, and the bottom end of the sliding rod passes through the sealing sleeve and is fixed with a resistance cover.

[0018] Furthermore, the top of the air chamber shroud has a downward-facing bowl-shaped structure, and the resistance shroud has an upward-facing bowl-shaped structure.

[0019] Furthermore, the outlet end of the airflow duct passes through the connection port and extends to the top of the resistance shield, and the downward pressure exerted by the airflow output by the airflow duct on the resistance shield is greater than the elastic force of the return spring.

[0020] Furthermore, a lower sealing ring is fixed to the circumferential side of the resistance shield. When the reset spring is in a free state, the resistance shield moves upward along with the exhaust and intake shield, and at this time the lower sealing ring moves upward and blocks the intake end of the airflow guide groove.

[0021] Furthermore, the top of the air pump is encapsulated with a display screen, which houses a control unit. The bottom of the housing is detachably connected to a bottom sealing plate. The sensor is encapsulated between the air chamber and the bottom sealing plate, and the sensor is electrically connected to the control unit.

[0022] Furthermore, the sensor is one of a harmful gas sensor, a combustible gas sensor, or a toxic gas sensor, and both the sensor and the gas pump are electrically connected to the control unit.

[0023] Compared to existing technologies, the advantages of this application are:

[0024] This invention enables automatic dual-mode switching without a solenoid valve. It has a simple and reliable structure and relies entirely on the pressure of the airflow output by the gas pump and the elasticity of the return spring to achieve automatic switching between pumping and diffusion modes. It does not use any additional switching components, and its simplified structure makes it suitable for miniaturized design of portable and handheld gas detectors.

[0025] During the testing process, the gas path is completely isolated, eliminating cross-flow interference and resulting in higher testing accuracy. The triple-linked sealing structure is formed by sealing the pump port with the inner sealing plate, sealing the diffusion gap with the outer sealing plate, and sealing the airflow guide groove with the lower sealing ring, which significantly improves the accuracy and repeatability of the test. Attached Figure Description

[0026] Figure 1 This is a schematic diagram illustrating the state when switching between the two modes of this application;

[0027] Figure 2 This is a schematic diagram of the exploded structure of this application;

[0028] Figure 3 This is a cross-sectional structural diagram of the exhaust hood proposed in this application;

[0029] Figure 4 This is a cross-sectional structural diagram of the outer shell and air chamber cover proposed in this application;

[0030] Figure 5 This is a cross-sectional structural diagram of this application;

[0031] Figure 6 for Figure 5 Enlarged structural diagram of section A in the middle;

[0032] Figure 7 This is a schematic diagram of the gas flow direction under the pump-suction detection mode of this application;

[0033] Figure 8 This is a schematic diagram of the gas flow direction under the diffusion detection mode of this application.

[0034] Explanation of the labels in the diagram:

[0035] 1. Outer shell; 11. Bottom sealing plate; 12. Upper ring edge;

[0036] 2. Exhaust hood; 201. Exhaust gap; 21. Slide rod; 22. Resistance hood; 221. Lower sealing ring; 23. Inner sealing plate; 24. Outer sealing plate;

[0037] 3. Air pump; 301. Air inlet; 302. Air outlet; 31. Grille cover; 32. Display screen;

[0038] 4. Airflow duct;

[0039] 5. Return spring;

[0040] 6. Air chamber cover; 61. Connection port; 62. Sealing sleeve;

[0041] 7. Sensors;

[0042] 8. Air chamber; 81. Air inlet / outlet port; 82. Airflow guide groove;

[0043] 9. Waterproof filter membrane. Detailed Implementation

[0044] The embodiments will be described clearly and completely with reference to the accompanying drawings. All other embodiments obtained by those skilled in the art based on the embodiments in this application without creative effort are within the scope of protection of this application.

[0045] Example:

[0046] This invention provides a dual-purpose gas path structure for a portable gas detector; please refer to [link / reference]. Figure 1 - Figure 8 ,include:

[0047] The outer shell 1 has a cylindrical shell structure, which provides support and external protection for the whole machine;

[0048] Air pump 3 is coaxially mounted on the top of housing 1. Air pump 3 has a grille cover 31 at its air inlet 301, and the air inlet 301 is connected to the outside atmosphere through the grille cover 31.

[0049] The airflow duct 4 and the air outlet 302 of the air pump 3 are connected to the airflow duct 4, which is used to deliver the gas output by the air pump 3 downward to the lower air passage structure.

[0050] The air chamber cover 6 is located at the bottom inner side of the outer shell 1. The top of the air chamber cover 6 is provided with a connection port 61, and the air outlet of the airflow pipe 4 is connected to the connection port 61. The air chamber cover 6 is provided with several air chambers 8 evenly distributed at equal angles along the circumference of the airflow pipe 4. The air chamber cover 6 and the air chambers 8 are connected by an airflow guide groove 82. The exhaust air cover 2 is located on the top of the air chamber cover 6. The top of the air chambers 8 is provided with exhaust air holes 81 that are connected to the inside of the exhaust air cover 2. The multiple air chambers 8 are evenly distributed around the circumference, and the air intake is uniform and consistent. The pumping and diffusion air intake are evenly distributed, so that the air path environment of each sensor 7 is consistent. This effectively avoids the detection deviation caused by uneven air intake between multiple sensors 7, and the overall detection consistency and stability are greatly improved.

[0051] Sensor 7, with its gas detection end extending to the bottom of gas chamber 8, is used to detect the concentration of gas entering the inlet / outlet port 81 and gas chamber 8. A waterproof filter membrane 9, located inside the inlet / outlet port 81, prevents moisture and dust from entering gas chamber 8 while allowing gas molecules to pass freely. The built-in waterproof filter membrane 9 forms a waterproof filtration structure, effectively blocking external moisture, dust, and oil from entering gas chamber 8, preventing the sensor 7 probe from becoming damp or contaminated and malfunctioning. Simultaneously, it does not affect the normal diffusion of gas molecules, improving the protection level without reducing the detection response speed. The equipment is more adaptable to harsh working conditions such as humidity and dust.

[0052] Please refer to this first. Figure 5 Furthermore, the exhaust hood 2 is slidably connected to the top of the air chamber hood 6 in a vertical direction, and a return spring 5 is clamped between the exhaust hood 2 and the air chamber hood 6. The return spring 5 has an elastic force that drives the exhaust hood 2 to move upward and away from the air chamber hood 6.

[0053] Please refer to this first. Figure 2 The exhaust hood 2 has a C-shaped annular structure. An outer sealing plate 24 is provided on the outer circumference of the exhaust hood 2. The top of the outer shell 1 is provided with an upper ring edge 12 that matches the outer sealing plate 24. When the return spring 5 is in the free state, the outer sealing plate 24 moves upward with the exhaust hood 2 and separates from the upper ring edge 12, forming an exhaust gap 201 between the outer sealing plate 24 and the upper ring edge 12, which serves as the main channel for the entry of external gas in the diffusion mode.

[0054] Furthermore, the outer sealing plate 24 is an elastic rubber structure. The outer sealing plate 24 has an inward contraction and is close to the upper ring edge 12, so that it can fit tightly against the upper ring edge 12 when the exhaust hood 2 moves down, achieving a reliable seal. At the same time, in the pumping mode, the gas in the air chamber 8 will push the outer sealing plate 24 outward, so that an exhaust gap is generated between the outer sealing plate 24 and the upper ring edge 12, which facilitates the improvement of the pumping efficiency of the air pump 3.

[0055] The inner wall of the exhaust hood 2 is provided with an inner sealing plate 23 that cooperates with the grille cover 31. The grille cover 31 has a conical structure. When the return spring 5 is in the free state, the inner sealing plate 23 and the conical grille cover 31 fit together to seal the air inlet 301 of the air pump 3, preventing gas from flowing back or leaking from the end of the air pump 3.

[0056] Several sliding rods 21 are evenly fixed at the bottom of the exhaust hood 2. The top of the air chamber hood 6 is provided with a sealing sleeve 62 that cooperates with the sliding rods 21. The bottom end of the sliding rod 21 passes through the sealing sleeve 62 and is fixedly connected to the resistance cover 22. The sealing sleeve 62 can radially limit and axially seal the sliding rod 21 to prevent gas from leaking from the mating gap of the sliding rod 21.

[0057] The top of the air chamber shroud 6 is a bowl-shaped structure with the opening facing downwards, and the drag shroud 22 is a bowl-shaped structure with the opening facing upwards. The two form opposing chambers, which facilitates the concentrated airflow acting on the top surface of the drag shroud 22 to generate stable downforce.

[0058] The air outlet of the airflow duct 4 passes through the connection port 61 and extends to the top of the resistance cover 22. The downward pressure generated by the airflow output from the airflow duct 4 on the resistance cover 22 is greater than the elastic force of the return spring 5, ensuring that the air pump 3 can reliably push the exhaust cover 2 down after starting, and automatically complete the mode switching.

[0059] A lower sealing ring 221 is fixed on the circumferential side of the resistance shield 22; when the return spring 5 is in the free state, the resistance shield 22 moves upward with the exhaust and intake shield 2, and the lower sealing ring 221 moves upward synchronously and blocks the air inlet end of the airflow guide groove 82, cutting off the pump suction path and preventing gas from entering the airflow pipe 4 in the diffusion mode and causing crossflow.

[0060] The top of the air pump 3 is encapsulated with a display screen 32, which has a built-in control unit. The bottom of the housing 1 is detachably connected to a bottom sealing plate 11. The sensor 7 is encapsulated between the air chamber 8 and the bottom sealing plate 11, which facilitates the replacement and calibration of the sensor 7 and the waterproof filter membrane 9. The gas circuit structure has a high degree of modularity and is compatible with various types of sensors such as combustible gas, toxic gas, and oxygen. It can adapt to different detection needs, has strong versatility, is easy to mass-produce, and is convenient to disassemble and maintain.

[0061] Sensor 7 is electrically connected to the control unit to realize the acquisition, processing and display of detection signals. It should be noted that sensor 7 is one or more of the following: combustible gas sensor, toxic gas sensor, oxygen sensor or volatile organic compound sensor. Both sensor 7 and air pump 3 are electrically connected to the control unit and are powered and controlled by the control unit.

[0062] This invention achieves automatic switching between pump-suction detection and diffusion detection modes by dynamically balancing the airflow pressure of the air pump 3 and the elastic force of the return spring 5, without requiring solenoid valves, motors or other electrically operated switching components throughout the entire process.

[0063] In diffusion detection mode, when the air pump 3 is off, there is no airflow output in the airflow pipe 4, and the resistance cover 22 is not subjected to downward airflow pressure. At this time, the return spring 5 pushes the exhaust cover 2 upward under its own elastic force, causing the exhaust cover 2 to slide upward along the slide rod 21 to the limit position.

[0064] In this position, the outer sealing plate 24 moves upward with the exhaust hood 2 and separates from the upper ring edge 12 of the outer shell 1, forming an annular exhaust gap 201. External gas can naturally diffuse into the internal cavity of the exhaust hood 2 through the exhaust gap 201. The inner sealing plate 23 moves upward with the exhaust hood 2 and fits tightly with the conical grille cover 31, completely sealing the air inlet 301 of the air pump 3, preventing gas from entering or exiting the air pump 3 channel, and avoiding interference of the air pump 3 cavity with the diffusion air path. At the same time, the resistance cover 22 moves upward synchronously with the slide bar 21, and its outer lower sealing ring 221 presses upward and seals the air inlet end of the airflow guide groove 82, disconnecting the air path between the airflow pipe 4 and the air chamber 8, and preventing gas crossflow.

[0065] After the outside gas enters the exhaust hood 2 through the exhaust gap 201, it continues to diffuse downward through the exhaust port 81 at the top of the gas chamber 8. The waterproof filter membrane 9 inside the exhaust port 81 filters the gas, blocking water vapor, oil mist, and dust. The clean gas enters the gas chamber 8 and comes into full contact with the detection end of the sensor 7. The sensor 7 converts the gas concentration signal into an electrical signal and transmits it to the control unit. After processing, the concentration value is displayed in real time on the display screen 32, completing the diffusion detection.

[0066] In diffusion detection mode, there is no power consumption of the air pump 3, and the sensor 7 works statically only, resulting in extremely low power consumption of the whole machine, which can achieve long-term continuous monitoring.

[0067] In the pump-suction detection mode, when the control unit starts the air pump 3, the air pump 3 draws in the outside air through the air inlet 301, sends it into the airflow pipe 4 through the air outlet 302, and sprays it downwards from the end of the airflow pipe 4 onto the top surface of the resistance shield 22.

[0068] Because the downward pressure generated by the airflow on the drag shield 22 is greater than the elastic force of the return spring 5, the drag shield 22 moves downward against the elastic force of the return spring 5 under the action of the airflow thrust, which drives the slide rod 21 to slide downward along the sealing slide sleeve 62, thereby driving the exhaust and intake shield 2 to move downward as a whole.

[0069] During this process, the outer sealing plate 24 on the outside of the exhaust hood 2 moves downward to fit against the upper ring edge 12. Since the outer sealing plate 24 is made of elastic rubber, it can produce slight deformation and tightly seal the exhaust gap 201, completely closing the intake channel of the diffusion intake channel. The inner sealing plate 23 moves down with the exhaust hood 2 and separates from the conical grille cover 31, so that the air inlet 301 of the air pump 3 is reconnected to the outside, ensuring that the air pump 3 can pump air normally. The resistance cover 22 drives the lower sealing ring 221 to move down synchronously, so that the lower sealing ring 221 is separated from the air inlet end of the airflow guide groove 82, and the airflow pipe 4 and the air chamber 8 form a complete pump suction path through the airflow guide groove 82.

[0070] The gas to be tested, continuously drawn by the air pump 3, passes sequentially through the air inlet 301, the airflow pipe 4, the airflow guide 82, and the air chamber 8. Under the pump's suction, the gas quickly fills the air chamber 8 and comes into contact with the detection end of the sensor 7, achieving rapid, high-flow-rate sampling and detection. Because the gas path is completely closed, with no cross-contamination or leakage, the sensor has a fast response speed, and the detection data is stable and reliable.

[0071] When the air pump 3 is turned off, the airflow thrust disappears, and the exhaust hood 2 automatically moves upward and resets under the action of the reset spring 5, returning to the diffusion detection mode, realizing the automatic cyclic switching between the two modes.

[0072] This invention enables automatic dual-mode switching without a solenoid valve. It has a simple and reliable structure and relies entirely on the pressure of the airflow output by the air pump 3 and the elasticity of the return spring 5 to achieve automatic switching between pumping and diffusion modes. It does not use any additional switching components, and its structure is simplified, making it suitable for miniaturized design of portable and handheld gas detectors.

[0073] During the testing process, the gas path is completely isolated, eliminating cross-flow interference and resulting in higher testing accuracy. A triple-linked sealing structure is formed by sealing the pump port with the inner sealing plate 23, sealing the diffusion gap with the outer sealing plate 24, and sealing the airflow guide groove 82 with the lower sealing ring 221. The diffusion channel is completely closed in pump suction mode and completely closed in diffusion mode. The two gas paths do not interfere with each other, do not cross-flow, and do not depressurize, effectively avoiding problems such as detection drift and zero-point offset caused by gas backflow and gas mixing. This significantly improves the accuracy and repeatability of the test, combining the advantages of low power consumption of diffusion type and high speed of pump suction type. It can cover a variety of scenarios such as open environment monitoring, confined space detection, emergency inspection, and pipeline sampling.

[0074] The above description is only the best implementation method adopted in this application in combination with current practical needs, but the scope of protection of this application is not limited thereto.

Claims

1. A dual-purpose gas path structure for a portable gas detector, characterized in that, include: The outer shell (1) has a cylindrical shell structure; An air pump (3) is coaxially mounted on the top of the outer casing (1). The air pump (3) has a grille cover (31) at its air inlet (301), and the air inlet (301) is connected to the outside through the grille cover (31). The airflow duct (4) is connected to the air inlet (302) of the air pump (3); An air chamber cover (6) is located at the bottom inside the outer shell (1). The top of the air chamber cover (6) is provided with a connection port (61). The air outlet of the airflow pipe (4) is connected to the connection port (61). The air chamber cover (6) is provided with several air chambers (8) at equal angles along the circumference of the airflow pipe (4). The air chamber cover (6) and the air chambers (8) are connected through an airflow guide groove (82). An exhaust hood (2) is provided on the top of the air chamber hood (6), and the top of the air chamber (8) is provided with an exhaust hood (81) that communicates with the interior of the exhaust hood (2). Sensor (7), the gas detection end of which extends to the bottom of the gas chamber (8) for detecting gas in the exhaust port (81); A waterproof filter membrane (9) is installed inside the air inlet / outlet port (81); The exhaust hood (2) is slidably connected to the top of the air chamber hood (6) in a vertical direction. A return spring (5) is clamped between the exhaust hood (2) and the air chamber hood (6). The return spring (5) has an elastic force that drives the exhaust hood (2) to move upward away from the air chamber hood (6). The exhaust hood (2) has a C-shaped annular structure. An outer sealing plate (24) is provided on the outer circumference of the exhaust hood (2). The top of the outer shell (1) is provided with an upper ring edge (12) that matches the outer sealing plate (24). When the return spring (5) is in a free state, the outer sealing plate (24) moves upward with the exhaust hood (2) and moves away from the upper ring edge (12), and the outer sealing plate (24) and the upper ring edge (12) are separated to form an exhaust gap (201). The inner wall of the exhaust hood (2) is provided with an inner sealing plate (23) that cooperates with the grille cover (31). The grille cover (31) has a conical structure. When the return spring (5) is in a free state, the inner sealing plate (23) and the grille cover (31) are relatively merged to close the air inlet (301). The bottom of the exhaust hood (2) is fixed with several sliding rods (21) at equal angles. The top of the air chamber hood (6) is provided with a sealing sleeve (62) that cooperates with the sliding rods (21). The bottom end of the sliding rod (21) passes through the sealing sleeve (62) and is fixed with a resistance cover (22). The outlet end of the airflow duct (4) passes through the connection port (61) and extends to the top of the resistance shield (22). The downward pressure generated by the airflow output by the airflow duct (4) on the resistance shield (22) is greater than the elastic force of the return spring (5). The lower sealing ring (221) is fixed on the circumferential side of the resistance shield (22). When the reset spring (5) is in a free state, the resistance shield (22) moves upward with the exhaust air shield (2), and at this time the lower sealing ring (221) moves upward and blocks the air inlet end of the airflow guide groove (82).

2. The dual-purpose gas path structure for a portable gas detector according to claim 1, characterized in that, The outer sealing plate (24) is an elastic rubber structure, and the outer sealing plate (24) has elasticity near the upper ring edge (12).

3. The dual-purpose gas path structure for a portable gas detector according to claim 1, characterized in that, The top of the air chamber shroud (6) is a bowl-shaped structure with the opening facing downwards, and the resistance shroud (22) is a bowl-shaped structure with the opening facing upwards.

4. The dual-purpose gas path structure for a portable gas detector according to claim 1, characterized in that, The top of the air pump (3) is encapsulated with a display screen (32), which has a built-in control unit. The bottom of the housing (1) is detachably connected to a bottom sealing plate (11). The sensor (7) is encapsulated between the air chamber (8) and the bottom sealing plate (11). The sensor (7) is electrically connected to the control unit.

5. The dual-purpose gas path structure for a portable gas detector according to claim 4, characterized in that, The sensor (7) is one of the following: a harmful gas sensor, a combustible gas sensor, or a toxic gas sensor. The sensor (7) and the gas pump (3) are both electrically connected to the control unit.

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