Photoelectric smoke detection device

Abstract

The present application relates to the technical field of fire detection devices, and discloses a detection device for photoelectric smoke, including a first cylinder, which is closed at the top, provided with an opening at the bottom, and provided with a smoke inlet hole in the circumferential direction; a second cylinder, which is arranged in the first cylinder and located on the side of the opening; a base, which is arranged below the first cylinder; a plurality of light shielding sheets, which are arranged on the top surface of the base and arranged along the radial direction of the base, and the second cylinder, the base and all the light shielding sheets jointly define a smoke-collecting cavity; a circuit board; a first transmitting tube; a second transmitting tube; a photosensitive receiving tube, wherein the first transmitting tube, the second transmitting tube and the photosensitive receiving tube are all connected to the circuit board, and the first transmitting tube, the second transmitting tube and the photosensitive receiving tube are arranged through the base and face the inside of the smoke-collecting cavity. The device can improve the sensitivity and accuracy of smoke detection, and reduce false alarms of non-fire interference sources.

Description

Technical Field

[0001] The present application relates to the technical field of fire detection devices, for example, to a detection device for photoelectric smoke sensing. Background Art

[0002] In recent years, frequent fires have caused great losses to people's lives and property. Therefore, timely detection of fires and alarms are the key to reducing losses. The basic principle of photoelectric smoke detectors is to detect the scattering of light by fire smoke particles. For smoke particle sizes, most are in the range of 0.1 microns to 1 micron, and the commonly used emission tube wavelength range is 460 nanometers to 940 nanometers. The scattering of smoke particles conforms to the Mie scattering principle, and its scattering parameter α = πd / λ, where d represents the particle diameter and λ represents the wavelength of the incident light. It can be seen that the scattering intensity is proportional to the particle diameter and inversely proportional to the wavelength of the incident light. For the gray-white smoke particles with larger particles produced by the burning of wood and cotton rope, red light and near-infrared light can be used for detection. For the black smoke with smaller particles produced by the burning of polyurethane and n-heptane, short-wavelength blue-violet light can be used for detection.

[0003] At present, the prerequisite for photoelectric smoke detectors to perform photoelectric detection is to gather smoke into the inside of the photoelectric smoke detector. Generally, the photoelectric smoke detector includes a base and a photoelectric detection component. The photoelectric detection component is arranged through the bottom of the base. A plurality of baffles are arranged on one side of the base. All baffles are arranged on the inner wall of the base. Although all baffles have a certain guiding effect on external smoke, due to the non-directional flow of smoke, the existing baffles cannot effectively gather external smoke into the inside of the base, thereby affecting the sensitivity of smoke detection of the photoelectric smoke detection device.

[0004] Most of the photoelectric smoke detection devices that are widely used in the market use a single forward scattering maze or a backscattering maze. It is difficult to distinguish black and white smoke particles by a single optical path detection, and it is difficult to eliminate interference from non-fire factors such as large particles of dust or water mist. Some manufacturers also use a combination of forward and backward scattering optical paths for smoke detection. Because the backscattering optical path has a large background light and the scattering intensity for black and white smoke is relatively weak, the accuracy of the photoelectric smoke detection devices on the market is relatively low. Summary of the invention

[0005] In order to provide a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. The summary is not an extensive review, nor is it intended to identify key / critical components or delineate the scope of protection of these embodiments, but rather serves as a prelude to the detailed description that follows.

[0006] The disclosed embodiment provides a detection device for photoelectric smoke sensing to enhance the gathering effect of external smoke and improve the smoke detection sensitivity of the photoelectric detection device.

[0007] In some embodiments, the detection device for photoelectric smoke sensing includes: a first cylinder with a closed top, an opening at the bottom, and smoke inlet holes arranged circumferentially; a second cylinder arranged in the first cylinder and located on the opening side; a base arranged below the first cylinder; a plurality of shading sheets arranged on the top surface of the base and arranged radially along the base, the second cylinder, the base and all the shading sheets jointly define a smoke-collecting cavity; a circuit board; a first transmitting tube; a second transmitting tube; a photosensitive receiving tube, the first transmitting tube, the second transmitting tube and the photosensitive receiving tube are all connected to the circuit board, the first transmitting tube, the second transmitting tube and the photosensitive receiving tube are arranged through the base and face the inside of the smoke-collecting cavity.

[0008] The photoelectric smoke detection device provided in the embodiments of the present disclosure can achieve the following technical effects:

[0009] Since a plurality of light shielding sheets are arranged on the top surface of the base and arranged along the radial direction of the base, smoke from different directions can enter the center of the base along the same diffusion path after entering the first cylinder through the smoke inlet hole, and has excellent azimuth consistency. In addition, since the second cylinder is located below the first cylinder with a closed top, the second cylinder, the base and all the light shielding sheets jointly define a smoke-gathering cavity for gathering smoke, so that the top and bottom of the smoke-gathering cavity are both closed, so that the smoke entering the center of the base is quickly and effectively diverted to the inside of the smoke-gathering cavity, enhancing the gathering effect of the smoke, and being more conducive to the photoelectric detection of the first transmitting tube, the second transmitting tube and the photosensitive receiving tube, thereby improving the sensitivity of smoke detection. At the same time, the first transmitting tube and the photosensitive receiving tube constitute the first detection optical path, and the second transmitting tube and the photosensitive receiving tube constitute the second detection optical path, and the two detection optical paths jointly detect the smoke entering the smoke-gathering cavity, and the first detection optical path and the second detection optical path are both vertical forward scattering optical paths. By analyzing and processing the two detection signals received by the photosensitive receiving tube, black and white smoke particles of different sizes and non-fire interference sources can be identified, thereby improving the smoke identification capability of the photoelectric smoke detection device, achieving higher detection accuracy and reducing false alarms of non-fire interference sources.

[0010] The above general description and the following description are exemplary and explanatory only and are not intended to limit the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] One or more embodiments are exemplarily described by corresponding drawings, which do not limit the embodiments. Elements with the same reference numerals in the drawings are shown as similar elements, and the drawings do not constitute a scale limitation, and wherein:

[0012] Figure 1 is a schematic diagram of the structure of a photoelectric smoke detection device provided by an embodiment of the present disclosure;

[0013] Figure 2 is a schematic structural diagram of another photoelectric smoke detection device provided by an embodiment of the present disclosure;

[0014] Figure 3 is a schematic structural diagram of another photoelectric smoke detection device provided by an embodiment of the present disclosure;

[0015] Figure 4 is a schematic structural diagram of a first cylinder and a second cylinder provided in an embodiment of the present disclosure;

[0016] Figure 5 is a schematic structural diagram of another first cylinder and a second cylinder provided in an embodiment of the present disclosure;

[0017] Figure 6 is a schematic structural diagram of another photoelectric smoke detection device provided by an embodiment of the present disclosure;

[0018] Figure 7 is a schematic structural diagram of another photoelectric smoke detection device provided by an embodiment of the present disclosure;

[0019] Figure 8 is a schematic structural diagram of another photoelectric smoke detection device provided by an embodiment of the present disclosure;

[0020] Fig. 9 is a schematic structural diagram of another photoelectric smoke detection device provided by an embodiment of the present disclosure;

[0021] Fig.10 It is a schematic diagram of the structure of another photoelectric smoke detection device provided in an embodiment of the present disclosure.

[0022] Reference numerals:

[0023] 1: first cylinder; 2: second cylinder; 3: base; 4: shading sheet; 11: open mouth; 1a: smoke inlet; 41: first shading section; 42: second shading section; 421: guide section; 43: third shading section; 51: first emitting tube; 52: second emitting tube; 53: receiving tube; 6: circuit board; 7: light guide column; 100: smoke collecting chamber; 301: first bracket; 302: second bracket; 303: third bracket. DETAILED DESCRIPTION

[0024] In order to be able to understand the features and technical contents of the embodiments of the present disclosure in more detail, the implementation of the embodiments of the present disclosure is described in detail below in conjunction with the accompanying drawings. The attached drawings are for reference only and are not used to limit the embodiments of the present disclosure. In the following technical description, for the convenience of explanation, a full understanding of the disclosed embodiments is provided through multiple details. However, one or more embodiments can still be implemented without these details. In other cases, to simplify the drawings, well-known structures and devices can be simplified for display.

[0025] The terms "first", "second", etc. in the specification and claims of the embodiments of the present disclosure and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchanged where appropriate, so that the embodiments of the embodiments of the present disclosure described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions.

[0026] In the embodiments of the present disclosure, the terms "upper", "lower", "inside", "middle", "outside", "front", "back" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. These terms are mainly intended to better describe the embodiments of the present disclosure and their embodiments, and are not intended to limit the indicated devices, elements or components to have a specific direction, or to be constructed and operated in a specific direction. Moreover, in addition to being used to indicate directions or positional relationships, some of the above terms may also be used to indicate other meanings. For example, the term "upper" may also be used to indicate a certain dependency or connection relationship in certain circumstances. For those of ordinary skill in the art, the specific meanings of these terms in the embodiments of the present disclosure can be understood according to specific circumstances.

[0027] In addition, the terms "disposed", "connected", and "fixed" should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection, or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, elements, or components. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present disclosure can be understood according to specific circumstances.

[0028] Unless otherwise stated, the term "plurality" means two or more.

[0029] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present disclosure may be combined with each other.

[0030] The explosion diagram of the photoelectric smoke detection device is as follows: Figure 1As shown, the cross-sectional view of the photoelectric smoke detection device is as follows Figure 3 The stereoscopic diagram of the photoelectric smoke detection device is shown in Figure 6 As shown. Combined Figure 1 , Figure 3 and Figure 6 As shown, the embodiment of the present disclosure provides a detection device for photoelectric smoke sensing, including a first cylinder 1, a second cylinder 2, a base 3, a circuit board 6, a first transmitting tube 51, a second transmitting tube 52 and a photosensitive receiving tube 53. The top of the first cylinder 1 is closed, and an opening 11 is provided at the bottom. The first cylinder 1 is circumferentially provided with a smoke inlet hole 1a. The second cylinder 2 is arranged in the first cylinder 1 and is located on the side of the opening 11. The base 3 is arranged below the first cylinder 1. A plurality of shading sheets 4 are arranged on the top surface of the base 3 and are arranged along the radial direction of the base 3. The second cylinder 2, the base 3 and all the shading sheets 4 together define a smoke collecting chamber 100. The first transmitting tube 51, the second transmitting tube 52 and the photosensitive receiving tube 53 are all connected to the circuit board 6. The first transmitting tube 51, the second transmitting tube 52 and the photosensitive receiving tube 53 are arranged through the base 3 and face the inside of the smoke collecting chamber 100.

[0031] In the detection device for photoelectric smoke sensing provided by the embodiment of the present disclosure, since a plurality of light shielding sheets are arranged on the top surface of the base and arranged along the radial direction of the base, smoke from different directions can enter the center of the base along the same diffusion path after entering the first cylinder through the smoke inlet hole, and has excellent azimuth consistency. In addition, since the second cylinder is located below the first cylinder with a closed top, the second cylinder, the base and all the light shielding sheets jointly define a smoke-gathering cavity for gathering smoke, so that the top and bottom of the smoke-gathering cavity are both closed, so that the smoke entering the center of the base is quickly and effectively diverted to the inside of the smoke-gathering cavity, enhancing the gathering effect of the smoke, and being more conducive to the photoelectric detection of the first transmitting tube, the second transmitting tube and the photosensitive receiving tube, thereby improving the sensitivity of smoke detection. At the same time, the first transmitting tube and the photosensitive receiving tube constitute the first detection optical path, and the second transmitting tube and the photosensitive receiving tube constitute the second detection optical path, and the two detection optical paths jointly detect the smoke entering the smoke-gathering cavity, and the first detection optical path and the second detection optical path are both vertical forward scattering optical paths. By analyzing and processing the two detection signals received by the photosensitive receiving tube, black and white smoke particles of different sizes and non-fire interference sources can be identified, thereby improving the smoke identification capability of the photoelectric smoke detection device, achieving higher detection accuracy and reducing false alarms of non-fire interference sources.

[0032] Optionally, the first transmitting tube 51 is a red light transmitting tube or an infrared light transmitting tube. The second transmitting tube 52 is a blue light transmitting tube or a purple light transmitting tube. In this way, the first transmitting tube and the receiving tube constitute a first detection optical path, and the second transmitting tube and the receiving tube constitute a second detection optical path, which can realize the detection of different types of smoke and achieve a balanced response to different types of smoke. In practical applications, the first transmitting tube and the second transmitting tube are transmitting tubes of two different wavelengths. The first transmitting tube is selected as a 940-nanometer infrared transmitting tube, and the second transmitting tube is selected as a 460-nanometer blue light transmitting tube. The receiving tube selects a wide-spectrum receiving tube that matches the first transmitting tube and the second transmitting tube.

[0033] Optionally, the base 3 is detachably arranged below the first cylinder 1. In this way, the assembly is convenient and the parts can be repaired or replaced conveniently.

[0034] Optionally, the base 3 is snap-fitted, threadedly connected or bonded to the first cylinder 1. In this way, quick disassembly and assembly of the base and the first cylinder can be achieved.

[0035] Combination Figure 2 and Figure 3 As shown, the embodiment of the present disclosure provides a detection device for photoelectric smoke, including a first cylinder 1, a second cylinder 2, a base 3, a circuit board 6, and a photoelectric smoke detection assembly. The top of the first cylinder 1 is closed, and an opening 11 is provided at the bottom. The first cylinder 1 is circumferentially provided with a smoke inlet 1a. The second cylinder 2 is arranged in the first cylinder 1 and is located on the side of the opening 11. The base 3 is arranged below the first cylinder 1. A plurality of light shielding sheets 4 are arranged on the top surface of the base 3 and arranged along the radial direction of the base 3. The second cylinder 2, the base 3 and all the light shielding sheets 4 together define a smoke collecting chamber 100. The first transmitting tube 51, the second transmitting tube 52 and the photosensitive receiving tube 53 are all connected to the circuit board 6. The first transmitting tube 51, the second transmitting tube 52 and the photosensitive receiving tube 53 are arranged through the base 3 and face the inside of the smoke collecting chamber 100. Each light shielding sheet 4 includes a first light shielding section 41 and a second light shielding section 42. The first light shielding section 41 is located at the edge of the base 3 and abuts against the inner wall of the first cylinder 1. The second light shielding section 42 is located inside the first light shielding section 41 and connected to the first light shielding section 41. The second light shielding section 42 faces the center of the base 3. The second barrel 2 abuts against the second light shielding section 42.

[0036] By using the detection device for photoelectric smoke sensing provided by the embodiment of the present disclosure, smoke can enter near the center of the base along the first light-shielding segment and the second light-shielding segment of any adjacent light-shielding sheets. Since the first light-shielding segment abuts against the inner wall of the first cylinder and the second cylinder abuts against the second light-shielding segment, the second cylinder, the base and all the first light-shielding segments and all the second light-shielding segments jointly define a smoke-gathering cavity for gathering smoke, thereby preventing the smoke that enters the first cylinder through the smoke inlet hole from diffusing, further enhancing the smoke gathering effect, and improving the sensitivity of the detection device for photoelectric smoke sensing.

[0037] Optional, combined Figure 2 As shown, the planes where all the second light shielding sections 42 are located intersect with the axis of the base 3. The axis of the base 3 is perpendicular to the top surface of the base 3. In this way, after the smoke passes through the adjacent first light shielding sections, the planes where all the second light shielding sections are located intersect with the axis of the base, so that smoke from different directions can enter the vicinity of the center of the base along the same diffusion path, so that the detection device for photoelectric smoke sensing has excellent azimuth consistency.

[0038] Optionally, the plane where all the first light shielding sections 41 are located is perpendicular to the top surface of the base 3. In this way, the smoke enters the vicinity of the center of the base along the adjacent first light shielding sections, with excellent azimuth consistency.

[0039] Optionally, a light guide column 7 is provided on the top surface of the base 3. The light guide column 7 is located at the first light shielding section 41 of any light shielding sheet 4 and passes through the first cylinder 1 to communicate with the outside. The light guide column 7 passes through the base 3 and is connected to the circuit board 6. In this way, when the smoke concentration obtained by the smoke detection exceeds the preset concentration value, the light guide column emits light to realize an alarm prompt.

[0040] Combination Figure 2 and Figure 3 As shown, the embodiment of the present disclosure provides a detection device for photoelectric smoke, including a first cylinder 1, a second cylinder 2, a base 3, a circuit board 6, and a photoelectric smoke detection assembly. The top of the first cylinder 1 is closed, and an opening 11 is provided at the bottom. The first cylinder 1 is circumferentially provided with a smoke inlet 1a. The second cylinder 2 is arranged in the first cylinder 1 and is located on the side of the opening 11. The base 3 is arranged below the first cylinder 1. A plurality of light shielding sheets 4 are arranged on the top surface of the base 3 and arranged along the radial direction of the base 3. The second cylinder 2, the base 3 and all the light shielding sheets 4 together define a smoke collecting chamber 100. The first transmitting tube 51, the second transmitting tube 52 and the photosensitive receiving tube 53 are all connected to the circuit board 6. The first transmitting tube 51, the second transmitting tube 52 and the photosensitive receiving tube 53 are arranged through the base 3 and face the inside of the smoke collecting chamber 100. Each light shielding sheet 4 includes a first light shielding section 41 and a second light shielding section 42. The first light shielding section 41 is located at the edge of the base 3 and abuts against the inner wall of the first cylinder 1. The second light shielding section 42 is located at the inner side of the first light shielding section 41 and connected to the first light shielding section 41. The second light shielding section 42 faces the center of the base 3. The second barrel 2 abuts against the second light shielding section 42. The second light shielding section 42 of the partial light shielding sheet 4 includes a guide section 421. The guide section 421 is arranged at the inner side of the second light shielding section 42. The height of the guide section 421 is less than the height of the second light shielding section 42. The second barrel 2 abuts against the top of the guide section 421.

[0041] With the photoelectric smoke detection device provided by the embodiment of the present disclosure, since the height of the guide section is smaller than the height of the second light-shielding section, the smoke entering the smoke collection chamber is not blocked by the guide section, and the guide section will not block the smoke detection, which is more conducive to smoke detection.

[0042] Optionally, the front end surface of the guide section 421 is an inclined surface. The front end surface of the guide section refers to the surface of the guide section facing the axis of the base. In this way, the orientation consistency of the detection device for photoelectric smoke sensing is further improved.

[0043] Optional, combined Figure 3 As shown, the cross section of any shading sheet 4 is Y-shaped. In this way, it is possible to prevent external stray light from entering. At the same time, the light emitted by the first emitting tube and the second emitting tube is reflected multiple times, so that the intensity of the light after multiple reflections is reduced.

[0044] Optional, combined Figure 2 As shown, there are at least three light shielding sheets 4 provided with guide sections 421 and they are evenly arranged along the radial direction of the base 3. In this way, the second cylinder can be stably arranged above the light shielding sheet, thereby improving the stability of the detection device for photoelectric smoke sensing.

[0045] Optionally, there are eight light shielding sheets 4 provided with guide sections 421 and they are evenly arranged along the radial direction of the base 3. In this way, all the light shielding sheets form an optical maze, which can quickly guide the smoke into the smoke collecting chamber. At the same time, the eight light shielding sheets provided with guide sections allow the smoke to enter the smoke collecting chamber from different directions and along the same trajectory, ensuring the directionality of the optical maze.

[0046] Combination Figure 2As shown, the embodiment of the present disclosure provides a detection device for photoelectric smoke, including a first cylinder 1, a second cylinder 2, a base 3, a circuit board 6, and a photoelectric smoke detection assembly. The top of the first cylinder 1 is closed, and an opening 11 is provided at the bottom. The first cylinder 1 is circumferentially provided with a smoke inlet 1a. The second cylinder 2 is arranged in the first cylinder 1 and is located on the side of the opening 11. The base 3 is arranged below the first cylinder 1. A plurality of light shielding sheets 4 are arranged on the top surface of the base 3 and arranged along the radial direction of the base 3. The second cylinder 2, the base 3 and all the light shielding sheets 4 together define a smoke collecting chamber 100. The first transmitting tube 51, the second transmitting tube 52 and the photosensitive receiving tube 53 are all connected to the circuit board 6. The first transmitting tube 51, the second transmitting tube 52 and the photosensitive receiving tube 53 are arranged through the base 3 and face the inside of the smoke collecting chamber 100. Each light shielding sheet 4 includes a first light shielding section 41 and a second light shielding section 42. The first light shielding section 41 is located at the edge of the base 3 and abuts against the inner wall of the first cylinder 1. The second light shielding section 42 is located inside the first light shielding section 41 and connected to the first light shielding section 41. The second light shielding section 42 faces the center of the base 3. The second barrel 2 abuts against the second light shielding section 42. A third light shielding section 43 is provided at the connection between the first light shielding section 41 and the second light shielding section 42, and the third light shielding section 43 forms an acute angle with the inner wall of the second barrel 2. The second barrel 2 abuts against the second light shielding section 42.

[0047] The photoelectric smoke detection device provided in the embodiment of the present disclosure is used to prevent the smoke entering the base through the smoke inlet from flowing back to the outside of the first cylinder, so that as much smoke as possible flows unidirectionally to the vicinity of the center of the base after passing through the smoke inlet.

[0048] Optional, combined Figure 4 and Figure 5 As shown, the base 3 is in the shape of a circular plate. The second cylinder 2 is coaxial with the first cylinder 1 and coaxial with the base 3. In this way, the contact area between the first cylinder and the outside world can be increased, so that as much smoke as possible can flow into the base through the smoke inlet hole. At the same time, the second cylinder is coaxial with the first cylinder, so that smoke can enter the vicinity of the center of the base through any angle, thereby improving the sensitivity of smoke detection.

[0049] Optional, combined Figure 5 As shown, the smoke inlet holes 1a are arranged in an array around the first cylinder 1. In this way, since the smoke flow is uncertain, by arranging the smoke inlet holes in an array around the first cylinder 1, smoke from any direction can enter the first cylinder, thereby improving the sensitivity of smoke detection and the versatility of smoke detection.

[0050] Optionally, the smoke inlet hole 1a is a square hole, so that the particulate smoke can enter the smoke collecting chamber more conveniently.

[0051] Optional, combined Figure 5As shown, the top wall and / or side wall of the second barrel 2 are provided with conical convex stripes. In this way, the absorption effect of background stray light is enhanced, which is conducive to the elimination of stray light.

[0052] Optionally, the top wall and / or side wall of the second barrel 2 are provided with conical convex stripes. In this way, the absorption effect of background stray light is enhanced, which is conducive to eliminating stray light.

[0053] Combination Figure 7 As shown, the embodiment of the present disclosure provides a detection device for photoelectric smoke, including a first cylinder 1, a second cylinder 2, a base 3, a circuit board 6, and a photoelectric smoke detection assembly. The top of the first cylinder 1 is closed, and an opening 11 is provided at the bottom. The first cylinder 1 is circumferentially provided with a smoke inlet 1a. The second cylinder 2 is arranged in the first cylinder 1 and is located on the side of the opening 11. The base 3 is arranged below the first cylinder 1. A plurality of light shielding sheets 4 are arranged on the top surface of the base 3 and arranged along the radial direction of the base 3. The second cylinder 2, the base 3 and all the light shielding sheets 4 together define a smoke collecting chamber 100. The first transmitting tube 51, the second transmitting tube 52 and the photosensitive receiving tube 53 are all connected to the circuit board 6. The first transmitting tube 51, the second transmitting tube 52 and the photosensitive receiving tube 53 are arranged through the base 3 and face the inside of the smoke collecting chamber 100. Each light shielding sheet 4 includes a first light shielding section 41 and a second light shielding section 42. The first light shielding section 41 is located at the edge of the base 3 and abuts against the inner wall of the first cylinder 1. The second light shielding section 42 is located on the inner side of the first light shielding section 41 and is connected to the first light shielding section 41. The second light shielding section 42 faces the center of the base 3. The second cylinder 2 abuts against the second light shielding section 42. The angle a between the axis of the first transmitting tube 51 and the axis of the photosensitive receiving tube 53 is an obtuse angle. The angle b between the axis of the second transmitting tube 52 and the axis of the photosensitive receiving tube 53 is an obtuse angle (not shown in the figure). The first transmitting tube 51 and the photosensitive receiving tube 53 constitute a first forward scattering detection light path, and the second transmitting tube 52 and the photosensitive receiving tube 53 constitute a second forward scattering detection light path. Combined Figure 8 As shown, the projection of the axis of the first transmitting tube 51 along the base 3 is collinear with the projection of the axis of the photosensitive receiving tube 53 along the base 3 .

[0054] The detection device for photoelectric smoke sensing provided by the embodiment of the present disclosure is used, the first transmitting tube is an infrared transmitting tube, the first transmitting tube and the photosensitive receiving tube form a first detection optical path, the second transmitting tube is a blue light transmitting tube, the second transmitting tube and the receiving tube form a second detection optical path. Since the detection angles of the two detection optical paths are different, and two different wavelengths of detection light, infrared light and blue light, are used respectively, and a and b are both obtuse angles and the projection of the axis of the first transmitting tube along the base is collinear with the projection of the axis of the photosensitive receiving tube along the base, by analyzing and processing the two detection signals received by the photosensitive receiving tube, black and white smoke particles of different particle sizes and non-fire interference sources can be identified, thereby improving the ability to distinguish smoke, the detection accuracy is higher, and the false alarms of non-fire interference sources can be reduced.

[0055] Optionally, the first emitting tube 51 is an infrared emitting tube. The second emitting tube 52 is a blue light emitting tube or an ultraviolet emitting tube. The wavelength of the light wave corresponding to the infrared emitting tube is 850nm to 1050nm. The wavelength of the light wave corresponding to the blue light emitting tube is 400nm to 480nm. The wavelength corresponding to the ultraviolet emitting tube is 250nm to 400nm. In which, nm is a unit of length measurement, representing nanometers.

[0056] Optionally, the first emitting tube 51 is a blue light emitting tube or an ultraviolet emitting tube, and the second emitting tube 52 is an infrared emitting tube.

[0057] Optionally, the axis of the first transmitting tube 51, the axis of the second transmitting tube 52 and the axis of the photosensitive receiving tube 53 intersect with the axis of the base 3. In this way, the smoke discrimination capability is further improved, and the detection accuracy is further improved.

[0058] Optionally, 100°≤a≤140° and 100°≤b≤140°.

[0059] Optional, combined Figure 8 and Fig. 9 As shown, 20°<α=β=γ<30°. Among them, α represents the angle between the axis of the first transmitting tube 51 and the top surface of the base 3, β represents the angle between the axis of the second transmitting tube 52 and the top surface of the base 3, and γ represents the angle between the axis of the photosensitive receiving tube 53 and the top surface of the base 3. In this way, it is possible to effectively prevent external stray light from entering the smoke collecting chamber, reduce the influence of external stray light on the scattering of smoke by the first detection optical path and the second detection optical path, and improve the detection accuracy of the detection device for photoelectric smoke sensing.

[0060] Optional, combined Fig.10As shown, the base 3 includes a first bracket 301, a second bracket 302 and a third bracket 303. A first transmitting tube 51 is arranged inside the first bracket 301. A second transmitting tube 52 is arranged inside the second bracket 302. A photosensitive receiving tube 53 is arranged inside the third bracket 303. The first bracket 301, the second bracket 302 and the third bracket 303 are all arranged through the base 3. In this way, the first transmitting tube, the second transmitting tube and the photosensitive receiving tube are firmly fixed to the bottom of the frame by the first bracket, the second bracket and the third bracket, thereby improving the structural firmness of the detection device for photoelectric smoke sensing.

[0061] Optionally, the angle between the axis of the first transmitting tube and the axis of the second transmitting tube is greater than 0° and less than or equal to 40°. In this way, the light emitted by the first transmitting tube and the second transmitting tube is generally directed toward the photosensitive receiving tube, further improving the detection accuracy of the photoelectric smoke detection device.

[0062] Optionally, the angle between the axis of the first transmitting tube and the axis of the second transmitting tube is greater than 25° and less than or equal to 35°. In this way, the light emitted by the first transmitting tube and the second transmitting tube is directed toward the photosensitive receiving tube, further improving the detection accuracy of the photoelectric smoke detection device.

[0063] The above description and the accompanying drawings sufficiently illustrate the embodiments of the present disclosure to enable those skilled in the art to practice them. Other embodiments may include structural and other changes. The embodiments represent only possible variations. Unless explicitly required, individual components and functions are optional, and the order of operations may vary. Portions and features of some embodiments may be included in or replace portions and features of other embodiments. The embodiments of the present disclosure are not limited to the structures described above and shown in the accompanying drawings, and various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A photoelectric smoke detection device, characterized in that: include: The first cylinder has a closed top, an open bottom, and smoke inlet holes arranged around the circumference; A second cylinder is disposed inside the first cylinder and located on the open side, and the top wall and / or side wall of the second cylinder are provided with conical stripes; A base, disposed below the first cylinder; A plurality of light shielding sheets are arranged on the top surface of the base and arranged radially along the base, and the second cylinder, the base and all the light shielding sheets together define a smoke collecting cavity; Circuit boards; The first launch tube; The second launch tube; Photosensitive receiving tube, the first transmitting tube, the second transmitting tube and the photosensitive receiving tube are all connected to the circuit board, the first transmitting tube, the second transmitting tube and the photosensitive receiving tube are arranged through the base and face the inside of the smoke collecting chamber, the first transmitting tube and the photosensitive receiving tube constitute a first detection optical path, the second transmitting tube and the photosensitive receiving tube constitute a second detection optical path, the two detection optical paths jointly detect the smoke entering the smoke collecting chamber, and the first detection optical path and the second detection optical path are both vertical forward scattering optical paths; The angle between the axis of the first transmitting tube and the axis of the photosensitive receiving tube is an obtuse angle, the angle between the axis of the second transmitting tube and the axis of the photosensitive receiving tube is is an obtuse angle; Among them, the projection of the axis of the first transmitting tube along the base is collinear with the projection of the axis of the photosensitive receiving tube along the base; the first transmitting tube is an infrared transmitting tube, and the second transmitting tube is a blue light transmitting tube or an ultraviolet transmitting tube; or, the first transmitting tube is a blue light transmitting tube or an ultraviolet transmitting tube, and the second transmitting tube is an infrared transmitting tube.

2. The device according to claim 1, characterized in that Each shade sheet includes: A first light shielding section, located at the edge of the base and abutting against the inner wall of the first cylinder; The second light-shielding section is located at the inner side of the first light-shielding section and connected to the first light-shielding section, facing the center of the base, and the second cylinder abuts against the second light-shielding section.

3. The device according to claim 2, characterized in that The planes where all the second light-shielding segments are located intersect with the axis of the base; wherein the axis of the base is perpendicular to the top surface of the base.

4. The device according to claim 3, characterized in that The planes where all the first light-shielding segments are located are perpendicular to the top surface of the base.

5. The device according to claim 2, characterized in that The second shading section of the partial shading sheet includes: The guide section is arranged at the inner side of the second light-shielding section, the height of the guide section is smaller than the height of the second light-shielding section, and the second cylinder is against the top of the guide section.

6. The device according to claim 5, characterized in that There are at least three shading sheets provided with the guide sections and the shading sheets are evenly arranged along the radial direction of the base.

7. The device according to any one of claims 2 to 6, characterized in that A third light-shielding section is provided at the connection between the first light-shielding section and the second light-shielding section, and the third light-shielding section forms an acute angle with the inner wall of the second cylinder.

8. The device according to any one of claims 1 to 6, characterized in that The base is in the shape of a circular plate, and the second cylinder is coaxial with the first cylinder and the base.

9. The device according to any one of claims 1 to 6, characterized in that: The smoke inlet holes are arranged in an array in the circumference of the first cylinder.

10. The device according to any one of claims 1 to 6, characterized in that The axis of the first transmitting tube, the axis of the second transmitting tube and the axis of the photosensitive receiving tube intersect at the axis of the base.

11. The device according to any one of claims 1 to 6, characterized in that ； in, represents the angle between the axis of the first launch tube and the top surface of the base, represents the angle between the axis of the second launching tube and the top surface of the base, It represents the angle between the axis of the photosensitive receiving tube and the top surface of the base.

12. The device according to any one of claims 1 to 6, characterized in that The base comprises: a first bracket, in which the first launching tube is arranged; A second bracket, in which the second launching tube is arranged; A third bracket, in which the photosensitive receiving tube is arranged; Wherein, the first bracket, the second bracket and the third bracket are all disposed through the base.

13. The device according to any one of claims 1 to 6, characterized in that The included angle between the axis of the first launching tube and the axis of the second launching tube is greater than 0° and less than or equal to 40°.

Images