Particulate matter sensor and air inducing equipment

Abstract

The utility model relates to a particulate matter sensor and induced draft equipment, which comprise a shell provided with an air inlet and an air outlet, a detection device arranged in the shell and a drainage air duct arranged in the shell, the drainage air duct comprises a first drainage air duct communicated with the air inlet, and a second drainage air duct communicated with the air outlet. The first drainage air duct is communicated with the air inlet, the second drainage air duct is communicated with the first drainage air duct, the third drainage air duct is communicated with the second drainage air duct and the air outlet, the included angle between the first drainage air duct and the second drainage air duct in the airflow direction is an obtuse angle, and the detection device is used for detecting particulate matter in the second drainage air duct. The problem that light in the external environment enters the second drainage air duct through the first drainage air duct and the detection accuracy is reduced can be avoided, the wind resistance of airflow flowing from the first drainage air duct to the second drainage air duct can be reduced through the arrangement of the obtuse angle, the problem that the airflow suddenly turns is avoided, and then the detection precision of the sensor is guaranteed.

Description

Technical Field

[0001] The utility model relates to the field of air quality detection, in particular to a particle sensor and air induction equipment. Background Art

[0002] With the popularization of air purification equipment, the application of air particle concentration sensors based on light scattering technology (hereinafter referred to as sensors) is becoming increasingly widespread, and the application scenarios are becoming more complex. The market has put forward higher precision, low cost, and long life requirements for such sensors. At present, due to structural and conditional limitations, most sensors on the market need to install a small fan inside the sensor, which not only increases the volume of the sensor and the complexity of the internal structure, but also increases the manufacturing cost. In addition, the fan is prone to aging, which directly shortens the service life of the sensor. In order to avoid light interference from the external environment, the fanless sensors in the existing technology have a longer air duct and a smaller turning angle of the airflow during the turning process, causing the airflow introduced from the air inlet to make a sharp turn, resulting in increased wind resistance and reduced airflow drainage efficiency. In addition, during the sharp turn of the airflow, the particles in the air will adhere to the side walls of the air duct due to the centrifugal force during the sharp turn, reducing the number of particles entering the test area and reducing the detection accuracy.

[0003] Therefore, eliminating the fan in the sensor and maintaining the same high detection accuracy as the sensor with a fan, that is, reducing the wind resistance when the airflow flows into the sensor while avoiding interference from external ambient light, and avoiding the problem of sudden changes in the airflow, is a technical problem that currently needs to be urgently solved by technical personnel in this field. Utility Model Content

[0004] In order to solve the above problems, the utility model provides a particulate matter sensor, which reduces the wind resistance when the airflow flows into the sensor while avoiding interference from external ambient light, avoids the problem of sudden changes in the airflow, and thus still has high detection accuracy after removing the fan.

[0005] To achieve the above purpose, the present invention provides the following solutions:

[0006] It includes a shell with an air inlet and an air outlet, a detection device arranged in the shell, and an air duct arranged inside the shell, the air duct includes a first air duct connected to the air inlet, a second air duct connected to the first air duct, and a third air duct connected to the second air duct and the air outlet, the angle between the first air duct and the second air duct along the air flow direction is an obtuse angle, the detection device is used to detect particulate matter in the second air duct, and the air outlet is used to be connected to the air ducting equipment.

[0007] Preferably, the caliber of the first drainage air duct is larger than the caliber of the second drainage air duct.

[0008] Preferably, a turning portion is provided between the second air guiding duct and the third air guiding duct.

[0009] Preferably, the detection device includes a light emitting device for emitting a light beam, and a photoelectric conversion unit for receiving a light signal scattered by particles.

[0010] Preferably, it also includes an extinction component, which includes a first wall surface arranged on the emission path of the light emitting device, a first reflection surface and a second reflection surface that are at least jointly formed with the first wall surface to form an extinction cavity, and are used to reflect the light beam. A reflection group for absorbing the light beam is provided in the extinction cavity, and a light inlet is provided on the first wall surface.

[0011] Preferably, a first reflective group is provided on the first wall away from the light inlet, the angle between the first reflective surface and the second reflective surface is 75 degrees to 105 degrees, and a light extinction wall parallel to the first reflective surface is provided between the light inlet and the first reflective group.

[0012] Preferably, a second reflective group is provided on the first wall surface away from the first light inlet, the angle between the first reflective surface and the second reflective surface is 60 degrees to 90 degrees, at least one folding surface is provided on the first reflective surface, the angle between the folding surface and the optical axis of the light beam emitted by the light emitting device is 10 degrees to 20 degrees, and an extinction wall parallel to the first reflective surface is provided between the light inlet and the second reflective group.

[0013] Preferably, the first reflecting surface and the second reflecting surface are arranged in parallel, and the angle between the first reflecting surface and the second reflecting surface and the optical axis of the light beam emitted by the light emitting device is 30 degrees to 60 degrees, and the first reflecting surface and the second reflecting surface are respectively provided with a third reflecting group and a fourth reflecting group away from the light inlet.

[0014] Preferably, a heating component is provided on the shell near the air inlet.

[0015] Preferably, a reflective element is provided on the housing at a position directly opposite to the photoelectric conversion unit.

[0016] The utility model also discloses an air-inducing device, comprising the above-mentioned particle sensor, an air suction device arranged inside the air-inducing device to provide airflow adsorption power for the air-inducing device, and a ventilation hole connected to the air outlet is opened on the side wall of the air-inducing device.

[0017] Compared with the prior art, the utility model has achieved the following technical effects:

[0018] The angle between the first drainage air duct and the second drainage air duct along the air flow direction is an obtuse angle, that is, there is a bending portion between the first drainage air duct and the second drainage air duct, which can not only prevent the light from the external environment from passing through the first drainage air duct into the second drainage air duct, thereby reducing the accuracy of detection, but also, the setting of the obtuse angle can reduce the wind resistance of the airflow from the first drainage air duct to the second drainage air duct, avoid the problem of sudden changes in the airflow, and thus ensure the detection accuracy of the particulate matter sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0020] Attachment Figure 1 This is a schematic diagram of the internal drainage duct structure of the particle sensor disclosed in an embodiment of the present utility model;

[0021] Attachment Figure 2 This is a schematic structural diagram of the particulate matter sensor extinction component disclosed in the present utility model when the included angle between the first reflecting surface and the second reflecting surface is 75 degrees to 105 degrees;

[0022] Attachment Figure 3 This is a schematic structural diagram of the particulate matter sensor extinction component disclosed in the present utility model when the included angle between the first reflecting surface and the second reflecting surface is 60 degrees to 90 degrees;

[0023] Attachment Figure 4 This is a structural diagram of the particulate matter sensor extinction component disclosed in the present utility model when the first reflecting surface and the second reflecting surface are arranged in parallel;

[0024] Attachment Figure 5 A schematic diagram of the structure of a heating assembly provided in a particulate matter sensor disclosed in an embodiment of the present utility model;

[0025] Attachment Figure 6 A schematic diagram of the structure of a particulate matter sensor provided with a reflector according to an embodiment of the present utility model;

[0026] Attachment Figure 7 This is a schematic diagram of the structure of the particle sensor disclosed in an embodiment of the present utility model, which is arranged on the side wall of the drainage device;

[0027] Among them, 1. light emitting device; 2. photoelectric conversion unit; 3. extinction component; 4. first air duct; 5. second air duct; 6. third air duct; 7. first reflecting surface; 8. second reflecting surface; 9. first reflecting group; 10. second reflecting group; 11. third reflecting group; 12. fourth reflecting group; 13. light inlet; 14. extinction wall; 15. folding surface; 16. air inlet; 17. reflector; 18. air outlet; 19. heating component; 20. ventilation hole; 21. suction device. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0029] The purpose of this utility model is to provide a particulate matter sensor that reduces the wind resistance when the airflow flows into the sensor while avoiding interference from external ambient light, avoids the problem of sudden changes in the airflow, and thus still has high detection accuracy after removing the fan, and has lower cost and longer service life.

[0030] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0031] refer to Figure 1 The particle sensor disclosed in the embodiment of the present utility model comprises at least a shell, a detection device and a drainage duct arranged inside the shell, an air inlet 16 and an air outlet 17 are provided on the shell, a detection device is provided inside the shell, the drainage duct comprises a first drainage duct 4 connected to the air inlet 16, a second drainage duct 5 connected to the first drainage duct 4, and a third drainage duct 6 connected to the second drainage duct 5 and the air outlet 18 at the same time, the angle between the first drainage duct 4 and the second drainage duct 5 along the air flow direction is an obtuse angle, the detection device is used to detect particulate matter in the second drainage duct 5, the air outlet 17 is used to communicate with the air induction device, and the air flow is transported by means of the suction device 21 inside the air induction device;

[0032] In this embodiment, after the air flow flows from the air inlet 16 into the first drainage duct 4, since the angle between the first drainage duct 4 and the second drainage duct 5 along the air flow direction is an obtuse angle, that is, there is a bend between the first drainage duct 4 and the second drainage duct 5, not only can the light from the external environment be prevented from passing through the first drainage duct 4 and entering the second drainage duct 5, thereby reducing the accuracy of detection, but also, the obtuse angle setting can reduce the wind resistance of the air flow from the first drainage duct 4 to the second drainage duct 5, thereby avoiding the problem of a sharp turn of the air flow, thereby improving the detection accuracy;

[0033] It should be noted that the included angle between the first air guiding duct 4 and the second air guiding duct 5 along the air flow direction is 100 degrees to 160 degrees, as long as no external light is incident on the second air guiding duct 5 .

[0034] refer to Figure 1 As an implementation method, the diameter of the first drainage duct 4 is larger than that of the second drainage duct 5. When the air volume at the air inlet 16 is unstable, the air flow velocity can be increased through the diameter reduction section, making the air flow through the second drainage duct 5 more stable, which helps to improve the accuracy of particle measurement. In addition, the diameter reduction of the flow channel can reduce the deposition of particulate matter inside the second drainage duct 5, thereby reducing the maintenance requirements of the particulate matter sensor and extending its service life.

[0035] As an embodiment, the diameter of the air inlet 16 is the same as or slightly larger than the diameter of the first drainage air duct 4, so that as many particles as possible enter the first drainage air duct 4 through the air inlet 16, the diameter of the third drainage air duct 6 is the same as the diameter of the second drainage air duct 5, and the diameter of the third drainage air duct 6 is the same as or slightly larger than the diameter of the air outlet 18.

[0036] refer to Figure 1 As an embodiment, a turning portion is provided between the second air duct 5 and the third air duct 6, which can further avoid external light interference, and the angle between the second air duct 5 and the third air duct 6 along the air flow direction can also be set to an obtuse angle, preferably 100 degrees to 160 degrees, as long as external light does not enter the second air duct 5.

[0037] refer to Figure 1As an embodiment, the shell includes an upper shell and a lower shell, the upper shell is provided with an air inlet 16 for air flow in, and the lower shell is provided with an air outlet 18 for air flow out, and a detection device is provided between the upper shell and the lower shell, the detection device includes a light emitting device 1 for emitting a light beam and a photoelectric conversion unit 2 for receiving a light scattered by particulate matter, and also includes a circuit board electrically connected to the light emitting device 1 and the photoelectric conversion unit 2, the circuit board is provided between the upper shell and the lower shell, and a drainage duct is provided between the circuit board and the lower shell, the second drainage duct 5 is provided opposite to the photoelectric conversion unit 2, the light beam emitted by the light emitting device 1 is emitted into the air flow of the second drainage duct 5, the particulate matter in the air flow scatters the light, and the scattered light signal of the particulate matter is received by the photoelectric conversion unit 2 corresponding to the second drainage duct 5, thereby performing particulate matter detection.

[0038] As an embodiment, a middle frame is provided between the circuit board and the lower housing. The middle frame has multiple plate-like structures extending toward the lower housing to form a first drainage duct 4, a second drainage duct 5, and a third drainage duct 6. The middle frame is provided with a first opening at a position directly opposite the photoelectric conversion unit 2, a second opening at a position directly opposite the light emitting device 1, and multiple plate-like structures are provided with a third opening at a position directly opposite the light emitting device 1 emitting a light beam. The light beam emitted by the light emitting device 1 passes through the third opening and enters the airflow of the second drainage duct 5. Particles in the airflow scatter the light, and the scattered light signal of the particles is received by the photoelectric conversion unit 2 corresponding to the second drainage duct 5, thereby performing particle detection. By providing the middle frame, the guidance of the airflow in the drainage duct can be improved.

[0039] refer to Figure 1 As an embodiment, a light extinction component 3 is further provided on the path of the light beam emitted by the light emitting device 1 after passing through the third opening and the second air duct 5. The light extinction component 3 includes a first wall surface provided on the emission path of the light emitting device 1, a first reflecting surface 7 and a second reflecting surface 8 for reflecting the light beam. The first reflecting surface 7, the second reflecting surface 8, and the first wall surface are jointly arranged to form an light extinction cavity. The first reflecting surface 7, the second reflecting surface 8, and the first wall surface can also be jointly arranged with other plate surfaces to form an light extinction cavity. The first reflecting surface 7 or the second reflecting surface 8 has an intersection with the light beam emitted by the light emitting device 1 to ensure that the incident light beam can be reflected. A reflection group for absorbing the light beam is provided in the light extinction cavity. A light inlet 13 is provided on the first wall surface for the light beam emitted by the light emitting device 1 to enter. The light extinction component 3 can eliminate stray light reflected by particulate matter through the second air duct 5, thereby preventing stray light from being reflected back into the measurement area and affecting the detection accuracy of the sensor.

[0040] refer to Figure 1 As a preferred embodiment, the first wall is arranged perpendicular to the optical axis of the light beam emitted by the light emitting device 1.

[0041] refer to Figure 2 As a preferred embodiment, a first reflection group 9 is provided on the first wall away from the light inlet 13. The included angle between the first reflection surface 7 and the second reflection surface 8 is 75 degrees to 105 degrees, preferably 94 degrees to 96 degrees. A light extinction wall 14 parallel to the first reflection surface 7 is provided between the light inlet 13 and the first reflection group 9. The stray light beam is reflected by the first reflection surface 7 onto the second reflection surface 8, and then reflected by the second reflection surface 8 to the first reflection group 9 for absorption. The first reflection group 9 is composed of a plurality of protrusions with an included angle of 30 degrees to 50 degrees between the two surfaces. The included angle of the protrusions of the first reflection group 9 is preferably 38 degrees to 40 degrees.

[0042] In this embodiment, an extinction cavity is formed by the first wall surface, the first reflecting surface 7, the second reflecting surface 8, the first connecting surface for connecting the first reflecting surface 7 and the first wall surface, and the second connecting surface for connecting the second reflecting surface 8 and the first wall surface. Without increasing the length of the cavity, stray light is reflected by the first reflecting surface 7 and the second reflecting surface 8 into the first reflecting group 9 in the extinction cavity and then diffusely reflected, thereby effectively increasing the optical path, significantly reducing the proportion of stray light escaping, and improving the absorption rate of stray light. In addition, the provision of the extinction wall 14 can prevent stray light that has not been absorbed after multiple reflections from returning to the detection area, effectively reducing interference with the sensor sampling signal and improving the sensor detection accuracy.

[0043] refer to Figure 3 As an embodiment, a second reflection group 10 is provided on the first wall away from the first light inlet 13, the angle between the first reflection surface 7 and the second reflection surface 8 is 60 degrees to 90 degrees, preferably 75 degrees to 77 degrees, the first reflection surface 7 is provided with at least one folding surface 15, and the angle between the folding surface 15 and the optical axis of the light beam emitted by the light emitting device 1 is 10 degrees to 20 degrees, and an extinction wall 14 parallel to the first reflection surface 7 is provided between the light inlet 13 and the second reflection group 10, the second reflection group 10 is composed of a plurality of protrusions with an angle of 30 degrees to 50 degrees between the two surfaces, and the angle of the protrusions of the second reflection group 10 is preferably 38 degrees to 40 degrees. The stray light beam entering from the light inlet 13 is reflected by the folding surface 15, the first reflection surface 7 and the second reflection surface 8 to enter the second reflection group 10 in the extinction cavity, and then undergoes diffuse reflection, which greatly reduces the proportion of stray light escaping, improves the absorption rate of stray light, effectively reduces the interference of the sensor sampling signal, and improves the detection accuracy of the sensor.

[0044] refer to Figure 4In one embodiment, the first and second reflective surfaces 7 and 8 are arranged parallel to each other, and the angle between the first and second reflective surfaces 7 and 8 and the optical axis of the light beam emitted by the light emitting device 1 is 30 to 60 degrees. A third reflective group 11 and a fourth reflective group 12 are respectively disposed on the first and second reflective surfaces 7 and 8 away from the light inlet 13. The third and fourth reflective groups 11 and 12 are composed of a plurality of obtuse protrusions, preferably with an angle of 120 to 130 degrees. Stray light beams entering the light inlet 13 are absorbed by the extinction structure after multiple reflections by the two reflective surfaces and the third and fourth reflective groups 11 and 12.

[0045] refer to Figure 5 As an embodiment, a heating component 19 is provided on the upper shell near the air inlet 16. The heating component 19 is preferably a thermistor. By arranging the thermistor at the air inlet 16, the thermistor generates heat to obtain a hot air flow. The rising hot air flow drives the surrounding air flow. Under the condition of zero wind speed, a trace wind speed is established, and the sensor can work normally to measure and feedback signals. The thermistor is low in cost and durable. The thermistor is provided at the air inlet and outlet 18 of the sensor to drive the air flow inside the sensor.

[0046] refer to Figure 6 In one embodiment, a reflective element 17 is provided on the housing at a position directly opposite to the photoelectric conversion unit 2;

[0047] In this embodiment, the reflector 17 is arranged on the lower shell. At this time, the second air duct 5 is between the photoelectric conversion unit 2 and the reflector 17. By setting the reflector 17, the light signal scattered toward the lower shell can be reflected and concentrated on the photoelectric conversion unit 2, thereby increasing the measurement of scattered light signals, improving the sampling rate, and reducing measurement data fluctuations.

[0048] refer to Figure 7 The present invention also discloses an air-inducing device, which includes the particulate matter sensor in any one of the above embodiments, and also includes a suction device 21 arranged inside the air-inducing device to provide airflow adsorption power for the air-inducing device. A ventilation hole 20 connected to the air outlet 18 is opened on the side wall of the air-inducing device. When the suction device 21 of the air-inducing device rotates, the air flow is driven from the air inlet 16 of the particulate matter sensor, through the drainage air duct, and into the air duct inside the air-inducing device. That is, with the help of the suction device 21 inside the air-inducing device, there is no need to set a fan inside the particulate matter sensor, which reduces costs without affecting the detection effect, and can eliminate the influence of the fan on the life of the entire sensor, thereby improving the overall service life of the sensor, eliminating the noise and maintenance problems caused by the fan, and reducing energy consumption.

[0049] As an embodiment, the air suction device 21 is a fan.

[0050] It should be noted that the induced draft equipment can be air purifiers, fresh air systems, vacuum cleaners and other equipment.

[0051] The present invention is used as follows: When the air inlet device is in operation, the suction force of the air suction device 21 draws suspended particulate matter from the air inlet 16 of the particle sensor into the air inlet duct, the air outlet 18, the vent 20, and the interior of the air inlet device. After the airflow containing particulate matter enters the air inlet duct, the first air inlet duct 4 and the second air inlet duct 5 are at an obtuse angle. This not only prevents light from the external environment from passing through the first air inlet duct 4 and entering the second air inlet duct 5, thereby reducing detection accuracy, but also reduces the wind resistance of the airflow from the first air inlet duct 4 to the second air inlet duct 5 by setting the obtuse angle, thereby avoiding the problem of sudden changes in the airflow, thereby improving detection accuracy. After the airflow enters the second air inlet duct 5, the light beam emitted by the light emitting device 1 illuminates the airflow of the second air inlet duct 5. The particulate matter in the airflow scatters the light, and the photoelectric conversion unit 2 corresponding to the second air inlet duct 5 receives the scattered light signal of the particulate matter, thereby detecting the particulate matter. The other stray light passing through the second air duct 5 enters the light extinction component 3 through the light inlet 13, thereby eliminating the stray light, effectively reducing the interference of the sensor sampling signal, and improving the detection accuracy of the sensor.

[0052] It should be noted that the dotted arrows in the drawings of the present utility model specification represent the emission path and reflection path of the light beam emitted by the light emitting device 1, and the solid arrows represent the flow path of the airflow.

[0053] Adaptive changes based on actual needs are all within the protection scope of this utility model.

[0054] It should be noted that it is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, from all perspectives, the embodiments should be considered as illustrative and non-restrictive. The scope of the present invention is defined by the appended claims, not the foregoing description, and it is intended that all variations within the meaning and range of equivalents of the claims be included within the present invention. Any reference signs in the claims should not be construed as limiting the claim to which they relate.

Claims

1. A particulate matter sensor, characterized in that: It includes a shell with an air inlet and an air outlet, a detection device arranged in the shell, and an air duct arranged inside the shell, the air duct includes a first air duct connected to the air inlet, a second air duct connected to the first air duct, and a third air duct connected to the second air duct and the air outlet, the angle between the first air duct and the second air duct along the air flow direction is an obtuse angle, the detection device is used to detect particulate matter in the second air duct, and the air outlet is used to be connected to the air ducting equipment.

2. A particulate matter sensor according to claim 1, characterized in that: A turning portion is provided between the second air guiding duct and the third air guiding duct.

3. The particulate matter sensor according to claim 1, characterized in that: The detection device includes a light emitting device for emitting a light beam, and a photoelectric conversion unit for receiving a light signal scattered by particles.

4. The particulate matter sensor according to claim 3, characterized in that: It also includes an extinction component, which includes a first wall surface arranged on the emission path of the light emitting device, a first reflection surface and a second reflection surface that are at least jointly formed with the first wall surface to form an extinction cavity, and are used to reflect the light beam. A reflection group for absorbing the light beam is provided in the extinction cavity, and a light inlet is provided on the first wall surface.

5. The particulate matter sensor according to claim 4, characterized in that: A first reflection group is provided on the first wall away from the light inlet, the angle between the first reflection surface and the second reflection surface is 75 degrees to 105 degrees, and an extinction wall parallel to the first reflection surface is provided between the light inlet and the first reflection group.

6. The particulate matter sensor according to claim 4, characterized in that: A second reflection group is provided on the first wall surface away from the light inlet, the angle between the first reflection surface and the second reflection surface is 60 degrees to 90 degrees, at least one folding surface is provided on the first reflection surface, the angle between the folding surface and the optical axis of the light beam emitted by the light emitting device is 10 degrees to 20 degrees, and an extinction wall parallel to the first reflection surface is provided between the light inlet and the second reflection group.

7. The particulate matter sensor according to claim 4, characterized in that: The first reflecting surface and the second reflecting surface are arranged in parallel, and the angle between the first reflecting surface and the second reflecting surface and the optical axis of the light beam emitted by the light emitting device is 30 degrees to 60 degrees. The first reflecting surface and the second reflecting surface are respectively provided with a third reflecting group and a fourth reflecting group away from the light inlet.

8. The particulate matter sensor according to claim 1, characterized in that: A heating component is provided on the shell near the air inlet.

9. The particulate matter sensor according to claim 3, characterized in that: A reflective element is provided on the housing at a position directly facing the photoelectric conversion unit.

10. An air induction device comprising the particle sensor according to any one of claims 1 to 9 and an air suction device for providing airflow adsorption power to the air induction device, characterized in that: A ventilation hole communicating with the air outlet is provided on the side wall of the air inducing device.

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