Quick-response long-optical-path infrared gas sensor

Abstract

The utility model provides a quick-response long-optical-path infrared gas sensor, which comprises a hardware circuit board, an infrared light source and an infrared detector, wherein the infrared light source and the infrared detector are arranged on the hardware circuit board; the second air chamber shell is connected with the hardware circuit board, the first air chamber shell is arranged on the second air chamber shell in a covering mode, the second air chamber shell comprises a second shell base and a detector via hole, and the detector via hole is formed in the second shell base and used for the infrared detector to stretch into. One of the first air chamber shell and the second air chamber shell is provided with a rice-shaped wall board extending towards the other one, and the rice-shaped wall board is arranged around the edge of the detector via hole. An air chamber is formed between the inner side of the right-hand-shaped wall plate and the right-hand-shaped wall plate and the first air chamber shell. And a double-gas exchange window leading to the gas chamber is arranged on the gas chamber shell 1. According to the utility model, the gas chamber shell I and the gas chamber shell II are utilized, and one of the gas chamber shell I and the gas chamber shell II is provided with the rice-shaped wall board to form an optical path structure, so that long optical path is realized, limited space is greatly utilized, and sensitivity of the sensor is improved; the area of the gas exchange windows is increased by arranging the double gas exchange windows, so that the ratio of the gas inlet area to the gas volume is increased, the gas replacement efficiency is greatly improved, and the response speed of the sensor is increased.

Description

Technical Field

[0001] The utility model relates to the technical field of gas sensors, in particular to a long optical path infrared gas sensor with fast response. Background Technique

[0002] In recent years, with the further development of the industrialization process, the emission of various waste gases and the large-scale combustion of fossil fuels, environmental pollution and the personal safety problems of operators in special places have always been the focus of people's attention. Among them, infrared detection technology is gradually replacing traditional sensors such as electrochemistry and catalytic combustion due to its advantages such as wide detection range, good selectivity, no poisoning, and long service life, and is widely used in places such as coal mines, petrochemical industries, metallurgy, and natural gas pipelines. More requirements are also put forward for the comprehensive performance of infrared gas sensors, such as volume, measurement accuracy, resolution, sensitivity, etc.

[0003] In the field of industrial detection, in order to facilitate the integrated installation of sensors, existing industrial 4-series infrared gas sensors have strict size requirements. The maximum outer shell size of the sensor is φ20mmx16.6mm. Affected by the outer shape size, the size of the optical path gas chamber housing structure of the sensor is also strictly restricted (the size of the optical path gas chamber housing structure is usually less than φ18.2mm). Due to the limited volume, the optical path is short, and the short optical path further affects the sensitivity, resolution, and measurement accuracy of the sensor. In order to improve the light efficiency in the optical path structure designed in a narrow volume space, the gas exchange window is usually opened very small, which results in a very slow gas exchange rate, further affecting the response time of the sensor and causing the sensor to respond slowly.

[0004] In view of the existing deficiencies, we propose a long optical path infrared gas sensor with fast response. Summary of the Invention

[0005] In view of the above technical problems, the utility model proposes a long optical path infrared gas sensor with fast response to solve the problem of slow response of gas sensors in the prior art.

[0006] In order to achieve the above purpose, the technical solution of the utility model is realized as follows:

[0007] A fast-response long optical path infrared gas sensor, comprising a hardware circuit board, an infrared light source and an infrared detector arranged on the hardware circuit board, and further comprising a second gas chamber housing connected to the hardware circuit board and a first gas chamber housing covering the second gas chamber housing. The second gas chamber housing includes a second housing base and a detector through hole provided on the second housing base for the infrared detector to extend into. One of the first gas chamber housing and the second gas chamber housing is provided with a block-shaped wall plate extending towards the other, and the block-shaped wall plate is arranged around the edge of the detector through hole; a gas chamber is formed inside the block-shaped wall plate and between the block-shaped wall plate and the first gas chamber housing. The first gas chamber housing is provided with a double gas exchange window leading to the gas chamber. The utility model utilizes the first gas chamber housing and the second gas chamber housing, and one of them is provided with a block-shaped wall plate to form an optical path structure, realizing a long optical path, greatly utilizing the limited space and improving the sensitivity of the sensor; and a gas exchange window with a large area is arranged through the double gas exchange window, the ratio of the intake area to the gas volume is increased, the gas replacement efficiency is greatly improved, and the response speed of the sensor is improved.

[0008] Further, the outer side surface of the block-shaped wall plate and / or the upper side surface of the second housing base and / or the inner side surface of the first gas chamber housing are optical surfaces.

[0009] Further, the first gas chamber housing is provided with a concave structure, and the inner side surface of the concave structure forms a first reflecting surface.

[0010] Further, the first reflecting surface includes a flat surface on one side of the concave structure and an arc surface on the other side of the concave structure, and one end of the arc surface is smoothly transitioned with the inner side surface of the first gas chamber housing and the other end intersects with the flat surface through a short plane.

[0011] Further, the notch of the block-shaped wall plate corresponds to the concave structure so that a part of the concave structure can extend into the notch of the block-shaped wall plate.

[0012] Further, a second reflecting surface inclined towards the gas chamber is provided on one side of one of the double gas exchange windows.

[0013] Further, an anti-fooling positioning structure is provided between the second gas chamber housing and the first gas chamber housing.

[0014] Further, the anti-fooling positioning structure includes a mutually fitting anti-fooling positioning boss and an anti-fooling positioning groove, and one of the anti-fooling positioning boss and the anti-fooling positioning groove is arranged on the second housing base and the other is arranged on the side wall of the first gas chamber housing.

[0015] Further, a fixing structure is provided between the second gas chamber housing and the first gas chamber housing, and the fixing structure includes a threaded hole provided on the second housing base and a threaded through hole provided on the first gas chamber housing.

[0016] Furthermore, an infrared light source through-hole for the infrared light source to pass through is provided on the base of the second housing; a circuit board fixing structure for fixing the hardware circuit board is provided on the lower side of the base of the second housing.

[0017] Advantages of the present utility model:

[0018] 1. The present utility model utilizes the first air chamber housing and the second air chamber housing, and a notch-shaped wall plate is provided on one of them to form an optical path structure, achieving a long optical path, greatly making use of the limited space, and improving the sensitivity of the sensor;

[0019] 2. The present utility model is provided with a relatively large gas exchange window, increasing the ratio of the intake area to the gas volume, greatly improving the gas replacement efficiency, and enhancing the response speed of the sensor;

[0020] 3. The present utility model can effectively prevent the displacement of the positions of the air chamber housing and the air chamber housing through the anti-misalignment positioning structure, avoiding the influence on the optical path structure due to the displacement of the position, and further ensuring the consistency of the product

[0021] 4. The surfaces of the air chamber housing, the optical surface and the reflecting surface of the air chamber housing of the present utility model are coated with a film, improving the reflection efficiency of the optical surface, as well as the corrosion resistance and long-term stability of the optical surface;

[0022] 5. The hardware circuit board of the present utility model is reliably fixed through the fixing structure on the air chamber housing, and the fixing structures are distributed at a certain angle, thereby effectively increasing the stability of the product, solving the problem of poor stability caused by the change of the relative positions of the core components, and improving the output stability of the product;

[0023] 6. The present utility model is small in volume, light in weight, low in power consumption, and convenient for integrated use of the product. Description of the Drawings

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0025] Figure 1 is the structural schematic diagram of the present utility model;

[0026] Figure 2 is the structural schematic diagram of the first air chamber housing, the second air chamber housing and the hardware circuit board of the present utility model;

[0027] Figure 3 is Figure 2 the cross-sectional structural schematic diagram of;

[0028] Figure 4 It is a schematic structural diagram of the first gas chamber housing of the present utility model;

[0029] Figure 5 It is a schematic structural diagram of the second gas chamber housing of the present utility model;

[0030] Figure 6 It is a schematic structural diagram of another embodiment of the first gas chamber housing of the present utility model;

[0031] Figure 7 It is a schematic structural diagram of another embodiment of the second gas chamber housing of the present utility model.

[0032] In the figure: 1. Outer shell, 11. Anti-fool positioning structure, 12. Fixing structure, 13. Optical gas chamber for the gas to be measured, 2. First gas chamber housing, 21. Optical surface, 22. First reflection surface, 23. Second reflection surface, 24. Anti-fool positioning groove, 25. Fixing structure boss, 26. Gas exchange window, 27. Third optical surface, 3. Second gas chamber housing, 31. First optical surface, 32. Second optical surface, 33. Threaded hole, 34. Anti-fool positioning boss, 35. Detector through hole, 36. Infrared light source through hole, 37. Circuit board fixing structure, 4. Hardware circuit board, 5. Infrared light source, 6. Infrared detector, 7. Fixing screw. Specific embodiments

[0033] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0034] Such as Figures 1 to 5As shown in the figure, a fast-response long optical path infrared gas sensor according to Embodiment 1 of the present utility model includes a hardware circuit board 4, an infrared light source 5 and an infrared detector 6 disposed on the hardware circuit board 4, and further includes a second gas chamber housing 3 connected to the hardware circuit board 4 and a first gas chamber housing 2 covering the second gas chamber housing 3. The second gas chamber housing 3 includes a second housing base, and a detector through hole 35 for the infrared detector 6 to extend into is provided in the middle of the second housing base. An infrared light source through hole 36 for the infrared light source 5 to pass through is further provided on one side of the second housing base where the detector through hole 35 is located. A notch-shaped wall plate extending towards the other one is provided on one of the first gas chamber housing 2 and the second gas chamber housing 3, and the notch-shaped wall plate surrounds the edge of the detector through hole 35. In this embodiment, the notch-shaped wall plate is vertically connected to the second housing base, and the upper end of the notch-shaped wall plate abuts against the top of the first gas chamber housing 2. The notch-shaped wall plate is an annular wall plate with a notch on one side, and the infrared light source through hole 36 is provided at the edge near the notch side of the notch-shaped wall plate. A gas chamber 13 is formed inside the notch-shaped wall plate and between the notch-shaped wall plate and the first gas chamber housing 2. The first gas chamber housing 2 is provided with a double gas exchange window 26 leading to the gas chamber 13. By means of the double gas exchange window 26, the intake area can be increased, the gas replacement efficiency is greatly improved, and the response speed of the sensor is improved. Among them, the double gas exchange window 26 is two crescent-shaped windows or bow-shaped windows. In another embodiment, the double gas exchange window 26 is of other shapes.

[0035] Further, the outer side surface of the notch-shaped wall plate, the upper side surface of the second housing base and the inner side surface of the first gas chamber housing 2 are optical surfaces. Among them, as Figure 4 and Figure 5 shown, the outer side surface of the notch-shaped wall plate is the first optical surface 31, the upper side surface of the second housing base is the second optical surface 32, and the inner side surface of the first gas chamber housing 2 is the optical surface 21.

[0036] In addition, a housing 1 is further covered outside the first gas chamber housing 2.

[0037] In a preferred embodiment, the long optical path infrared gas sensor is improved on a cylindrical structure with a diameter of φ18.2 mm. By using the first gas chamber housing 2 and the second gas chamber housing 3 to form an optical path structure, a long optical path of 58 mm is realized, which greatly utilizes the limited space and improves the sensitivity of the sensor. And for the gas exchange window in the first gas chamber housing 2, the intake area reaches 76 mm², and the ratio of the intake area to the gas volume is 6%, which greatly improves the gas replacement efficiency and the response speed of the sensor.

[0038] Embodiment 2 is different from Embodiment 1 in that, as Figure 1 and Figure 5 shown, the first gas chamber housing 2 is provided with an inner concave structure, and the inner side surface of the inner concave structure forms a first reflecting surface 22.

[0039] Specifically, asFigure 5 As shown, the first reflecting surface 22 includes a flat surface on one side of the concave structure and an arc surface on the other side of the concave structure. One end of the arc surface is smoothly transitioned with the inner side surface of the air chamber housing 2, and the other end intersects with the flat surface through a short plane.

[0040] Furthermore, the notch of the block-shaped wall plate corresponds to the concave structure, so that a part of the concave structure can extend into the notch of the block-shaped wall plate.

[0041] Embodiment 3 is different from Embodiment 1 in that, as Figure 5 shown, on one side of one of the double gas exchange windows 26, there is an inclined plate inclined towards the air chamber 13, and the lower side surface of the inclined plate is the second reflecting surface 23. Specifically, the inclined plate is arranged in the middle of the double gas exchange window 26. The upper end of the inclined plate is close to one of the double gas exchange windows 26, and the lower end of the inclined plate is close to the other of the double gas exchange windows 26 and is inclined towards the air chamber 13. Both sides of the inclined plate are connected to the top of the air chamber housing 2 through straight plates, and the back surface, i.e., the upper side surface, of the inclined plate is an open surface, that is, the position of the top of the air chamber housing 2 corresponding to the back surface of the inclined plate is hollowed out.

[0042] Embodiment 4 is different from Embodiment 1 in that, as Figure 2 , Figure 4 and Figure 5 shown, there is an anti-fooling positioning structure 11 between the air chamber housing 2 and the air chamber housing 3.

[0043] Furthermore, as Figure 4 and Figure 5 shown, the anti-fooling positioning structure 11 includes a mutually fitting anti-fooling positioning boss 34 and an anti-fooling positioning groove 24. The anti-fooling positioning boss 34 is arranged on the outer periphery of the base of the housing 2, and the anti-fooling positioning groove 24 is arranged on the side wall of the air chamber housing 2. The outer periphery of the base of the housing 2 is also provided with a bearing edge that cooperates with the lower end surface of the side wall of the air chamber housing 2. Both sides of the anti-fooling positioning boss 34 are connected to the bearing edge, and the outer side of the anti-fooling positioning boss 34 is aligned with the outer side of the bearing edge.

[0044] Embodiment 5 is different from Embodiment 4 in that, as Figure 2 , Figure 3 , Figure 4 and Figure 5As shown, a fixing structure 12 is provided between the second air chamber housing 3 and the first air chamber housing 2. The fixing structure 12 includes a threaded hole 33 provided on the base of the second housing and a threaded through-hole provided on the first air chamber housing 2. Among them, at least two notches are provided at the edge of the bearing platform, and a fixing structure boss 25 extending downward is provided on the lower end surface of the side wall of the first air chamber housing 2, and the fixing structure boss 25 fits with the notches at the edge of the bearing platform. The threaded through-hole is provided at the junction of the fixing structure boss 25 and the side wall of the first air chamber housing 2, and the threaded hole 33 is provided at the corresponding position on the outer periphery of the base of the second housing.

[0045] Embodiment 6, the difference from Embodiment 1 is that, as Figure 4 shown, a circuit board fixing structure 37 for fixing the hardware circuit board 4 is provided on the lower side of the base of the second housing. In this embodiment, the circuit board fixing structure 37 is a plurality of fixing columns provided on the lower side of the base of the second housing.

[0046] Embodiment 7, the difference from Embodiment 3 is that the first air chamber housing 2, the second air chamber housing 3, and the surfaces of each optical surface and reflecting surface are coated with a film, which improves the reflection efficiency of the optical surface and the corrosion resistance and long-term stability of the optical surface.

[0047] Embodiment 8, the difference from Embodiment 2 is that, as Figure 6 and Figure 7 shown, an optical surface 27 is added to the first air chamber housing 2, and the first optical surface 31 is removed from the second air chamber housing 3, that is, the arcuate wall plate is connected to the first air chamber housing 2 to achieve the same effect. After the first optical surface 31 is removed from the second air chamber housing 3, as Figure 7 shown, that is, the arcuate wall plate of the second air chamber housing 3 is omitted. When the third optical surface 27 is added to the first air chamber housing 2, as Figure 6 shown, an arcuate wall plate connected to the concave structure is provided in the first air chamber housing 2, and the outer side surface of the arcuate wall plate is the third optical surface 27. Among them, one side edge of the notch of the arcuate wall plate is butted against the short flat surface of the concave structure, and the outer side of the arcuate wall plate is smoothly and transitionally connected to the arc surface of the first reflecting surface 22.

[0048] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: Any modification to the technical solutions described in the foregoing embodiments, or equivalent replacement of some or all of the technical features, without departing from the spirit and principle of the present invention, shall fall within the protection scope of the technical solutions of the present invention.

Claims

1. A fast-response long-light-path infrared gas sensor, comprising a hardware circuit board (4), an infrared light source (5) and an infrared detector (6) arranged on the hardware circuit board (4), characterized in that: The invention also comprises an air chamber housing (2) connected to the hardware circuit board (4) and an air chamber housing (2) covered on the air chamber housing (3); the air chamber housing (3) comprises a housing base and a detector through hole (35) arranged on the housing base for the infrared detector (6) to extend into; one of the air chamber housing (2) and the air chamber housing (3) is provided with a ring-shaped wall plate extending toward the other, and the ring-shaped wall plate is arranged around the edge of the detector through hole (35); an air chamber (13) is formed on the inner side of the ring-shaped wall plate and between the ring-shaped wall plate and the air chamber housing (2); and the air chamber housing (2) is provided with dual gas exchange windows (26) leading to the air chamber (13).

2. The fast-response long-path infrared gas sensor according to claim 1, characterized in that: The outer side surface of the ring-shaped wall plate and / or the upper side surface of the second shell base and / or the inner side surface of the air chamber shell one (2) are optical surfaces.

3. The fast-response long-path infrared gas sensor according to claim 1 or 2, characterized in that: The air chamber shell 1 (2) is provided with an inner concave structure, and the inner side surface of the inner concave structure forms a first reflection surface (22).

4. The fast-response long-path infrared gas sensor according to claim 3, characterized in that: The first reflecting surface (22) comprises a straight surface located on one side of the concave structure and a curved surface located on the other side of the concave structure, and one end of the curved surface smoothly transitions to the inner side surface of the air chamber shell (2), and the other end intersects with the straight surface via a short plane.

5. The fast-response long-path infrared gas sensor according to claim 4, characterized in that: The notch of the ring-shaped wall panel corresponds to the concave structure so that part of the concave structure can extend into the notch of the ring-shaped wall panel.

6. The fast-response long-light-path infrared gas sensor according to claim 1, 2, 4 or 5, characterized in that: A second reflecting surface (23) inclined toward the inside of the gas chamber (13) is provided on one side of one of the dual gas exchange windows (26).

7. The fast-response long-optical-path infrared gas sensor according to claim 1, 2, 4 or 5, characterized in that: An anti-mistake positioning structure (11) is provided between the air chamber shell 2 (3) and the air chamber shell 1 (2).

8. The fast-response long-path infrared gas sensor according to claim 7, characterized in that: The foolproof positioning structure (11) comprises a matching foolproof positioning boss (34) and a foolproof positioning groove (24), wherein one of the foolproof positioning boss (34) and the foolproof positioning groove (24) is arranged on the second housing base, and the other is arranged on the side wall of the air chamber housing (2).

9. The fast-response long-optical-path infrared gas sensor according to claim 1 or 2 or 4 or 5 or 8, characterized in that: A fixing structure (12) is provided between the air chamber shell 2 (3) and the air chamber shell 1 (2), and the fixing structure (12) comprises a threaded hole (33) provided on the base of the shell 2 and a threaded through hole provided on the air chamber shell 1 (2).

10. The fast-response long-optical-path infrared gas sensor according to claim 1 or 2 or 4 or 5 or 8, characterized in that: An infrared light source through hole (36) for the infrared light source (5) to pass through is provided on the second base of the housing; and a circuit board fixing structure (37) for fixing a hardware circuit board (4) is provided on the lower side of the second base of the housing.

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