Fire detector

Abstract

The invention relates to the technical field of fire detection, and provides a fire detector, which comprises a PCB (Printed Circuit Board), and a transmitting tube, a receiving tube and a light insulation substrate are arranged on the PCB; a first groove and a second groove which are distributed at an interval are formed in the light insulation base body, and groove openings of the first groove and the second groove face the same direction; the transmitting tube is located in the first groove, and the transmitting end of the transmitting tube corresponds to a notch of the first groove; the receiving tube is located in the second groove, and the receiving end of the receiving tube corresponds to the notch of the second groove; a transparent part is sealed on the light insulation substrate, and the refractive index of the transparent part is greater than 1; the transparent part is provided with a first inclined surface and a second inclined surface which are relatively inclined outwards, the first inclined surface is positioned above the first groove, and the second inclined surface is positioned above the second groove; the light path is reasonably planned based on the refractive index of the transparent part, the main light intensity comes from scattered emitted light, the optical darkroom without a complex structure is provided, fire particle detection without the optical darkroom structure is effectively achieved, and the detection effect is good.

Description

Technical Field

[0001] The present invention relates to the technical field of fire detection, and more particularly to a fire detector. Background Art

[0002] Existing fire detection technology mainly uses infrared emitting devices and infrared receiving devices combined with optical darkroom structures to detect fire smoke particles. For example, the emitting end of the infrared emitting device and the receiving end of the infrared receiving device are arranged relatively to each other. When fire smoke particles are between the two, the presence of fire smoke particles is detected by judging whether the optical signals of the two are disconnected, thereby realizing fire smoke particle detection. However, such existing optical darkroom structures are prone to objects such as fibers being attached to the surface of the sensitive areas of the infrared emitting device and the infrared receiving device optical signals, causing false alarms, and the detection accuracy is not high; moreover, such existing optical darkroom structures are usually more complicated, inconvenient to maintain and clean, and difficult to assemble, resulting in obvious limitations in practical applications, and therefore urgently need to be improved. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a fire detector in view of the above-mentioned defects of the prior art.

[0004] The technical solution adopted by the present invention to solve its technical problems is: a fire detector, including a PCB board, on which a transmitting tube, a receiving tube and a light-isolating substrate are arranged; a first groove and a second groove are arranged in the light-isolating substrate, and the notches of the first groove and the second groove are oriented in the same direction; the transmitting tube is located in the first groove, and the transmitting end of the transmitting tube corresponds to the notch of the first groove; the receiving tube is located in the second groove, and the receiving end of the receiving tube corresponds to the notch of the second groove; a transparent part is also sealed on the light-isolating substrate, and the refractive index of the transparent part is greater than 1; the transparent part has a first inclined surface and a second inclined surface that are relatively inclined outwards, the first inclined surface is located above the first groove, and the second inclined surface is located above the second groove.

[0005] In some embodiments, a three-dimensional area where the refraction emission range of the light emitted by the transmitting tube intersects with the refraction injection range of the light received by the receiving tube is a detection sensitive area.

[0006] In some embodiments, a first angle is formed between a surface of the light-isolating substrate facing the first inclined surface and the first inclined surface; a second angle is formed between a surface of the light-isolating substrate facing the second inclined surface and the second inclined surface.

[0007] In some embodiments, the first angle and the second angle are both less than 60°.

[0008] In some embodiments, a third angle is formed between the first inclined surface and the second inclined surface, and the third angle is greater than 60° and less than 180°.

[0009] In some embodiments, the transparent member further has a plane, and the plane is located between the first inclined surface and the second inclined surface.

[0010] In some embodiments, the width of the plane is equal to the straight-line distance between adjacent groove walls of the first groove and the second groove.

[0011] In some embodiments, the transparent member is a transparent film or a transparent colloid.

[0012] In some embodiments, the refractive index of the transparent film or transparent colloid is in the range of 1.5-3.0.

[0013] In some embodiments, the transmitting tube and the receiving tube are both plug-in devices or surface mount devices.

[0014] The beneficial effects of the present invention are as follows: different from the prior art, the fire detector of the present invention is provided with a transmitting tube, a receiving tube and a light-isolating substrate on a PCB board; a first groove and a second groove are provided in the light-isolating substrate, so that the transmitting tube is located in the first groove, and the receiving tube is located in the second groove; a transparent member sealed on the light-isolating substrate has a first inclined surface and a second inclined surface, and the refractive index of the transparent member is greater than 1; light emitted by the transmitting tube is refracted through the first inclined surface of the transparent member to sense smoke particles, and light scattered by the smoke particles is refracted through the second inclined surface of the transparent member to the receiving tube, and the planning of the light path for detecting smoke particles is realized according to the refractive index of the transparent member, and there is no optical darkroom with a complex structure, so that fire particle detection without an optical darkroom structure is effectively realized, and the detection effect is better. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a structural schematic diagram of a fire detector in an embodiment of the present invention;

[0016] Figure 2 Schematic diagram of the circuit structure of an infrared transmitting circuit and an infrared receiving circuit in an embodiment of the present invention;

[0017] Figure 3 is a schematic diagram of the circuit structure of a bandpass circuit in an embodiment of the present invention;

[0018] Figure 4 is another structural schematic diagram of a fire detector in an embodiment of the present invention;

[0019] Names and numbers in the figure: PCB board-1; transmitting tube-2; receiving tube-3; light-isolating substrate-4; first groove-401; second groove-402; transparent member-5; first inclined surface-51; second inclined surface-52; plane-53; infrared transmitting circuit-21; infrared receiving circuit-31; smoke particles-10; detection sensitive area-20. DETAILED DESCRIPTION

[0020] The terms "first", "second", "third" and "fourth" etc. in the specification and claims of the present invention and the drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units that are not listed, or may optionally include other steps or units that are inherent to these processes, methods, products or devices.

[0021] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0022] "Multiple" means two or more. "And / or" describes the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the related objects are in an "or" relationship.

[0023] Moreover, the terms "up, down, front, back, left, right, upper end, lower end" etc. indicating directions are all based on the posture and position of the device or equipment described in this solution during normal use.

[0024] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the following will be described clearly and completely in combination with the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are partial embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the protection scope of the present invention.

[0025] Embodiments of the present invention Figure 1As shown in the figure, a fire detector includes a PCB board 1, on which a transmitting tube 2, a receiving tube 3 and a light-isolating substrate 4 are arranged; the light-isolating substrate 4 is provided with a first groove 401 and a second groove 402 which are spaced apart from each other, and the notches of the first groove 401 and the second groove 402 are oriented in the same direction; the transmitting tube 2 is located in the first groove 401, and the transmitting end of the transmitting tube 2 corresponds to the notch of the first groove 401; the receiving tube 3 is located in the second groove 402, and the receiving end of the receiving tube 3 corresponds to the notch of the second groove 402; a transparent member 5 is also sealed on the light-isolating substrate 4, and the refractive index of the transparent member 5 is greater than 1; the transparent member 5 has a first inclined surface 51 and a second inclined surface 52 which are inclined relatively outwardly, the first inclined surface 51 is located above the first groove 401, and the second inclined surface 52 is located above the second groove 402.

[0026] In this embodiment, for example, the notches of the first groove 401 and the second groove 402 are both facing upward, and the transparent member 5 is sealed and arranged above the light-isolating substrate 4; the transmitting tube 2 and the receiving tube 3 are parallel to each other. The light emitted by the transmitting tube 2 is emitted to the first inclined surface 51 and refracted by the first inclined surface 51 to detect the smoke particles 10. After the light detects the smoke particles 10, it is scattered by the smoke particles 10. Part of the scattered light is emitted to the second inclined surface 52 and refracted to the receiving tube 3 by the second inclined surface 52. After the receiving tube 3 receives the corresponding light, it undergoes photoelectric conversion and signal amplification and is provided to the main control MCU for processing, thereby realizing smoke detection alarm. Among them, the PCB board 1 is also provided with a photoelectric conversion circuit, a signal amplification circuit and a main control MCU circuit, which are used to realize the signal processing of the light received by the aforementioned receiving tube 3. The more smoke particles there are in the detected space area, the stronger the optical signal received by the receiving tube 3, and vice versa, the weaker the optical signal, thereby realizing fire detection according to the strength of the received signal.

[0027] In this embodiment, the three-dimensional area where the refraction emission range of the light emitted by the transmitting tube 2 and the refraction injection range of the light received by the receiving tube 3 intersect is the detection sensitive area 20 for detecting smoke particles 10. Among them, the refraction emission range of the light emitted by the transmitting tube 2 depends on the slot width of the first slot 401, so as to meet the reasonable range of the light emitted by the transmitting tube 2. The refraction injection range of the light received by the receiving tube 3 depends on the slot width of the second slot 402, so as to meet the reasonable range of the light that the receiving tube 3 can receive. In this detection sensitive area 20, smoke particles 10 can be detected more accurately.

[0028] Specifically, a first angle a1 is formed between a surface of the light-isolating substrate 4 facing the first inclined surface 51 and the first inclined surface 51; a second angle a2 is formed between a surface of the light-isolating substrate 4 facing the second inclined surface 52 and the second inclined surface 52. A surface of the light-isolating substrate 4 facing the first inclined surface 51 and a surface of the light-isolating substrate 4 facing the second inclined surface 52 are both upper surfaces of the light-isolating substrate 4. Among them, the first angle a1 and the second angle a2 are the same and are both less than 60°. The selection and setting of the first angle a1 and the second angle a2 are related to the refractive index of the transparent part 5. The larger the refractive index of the transparent part 5, the smaller the first angle a1 and the second angle a2 can be, so as to achieve an ultra-thin and miniaturized structure. The transparent part 5 is a transparent film or a transparent colloid. The refractive index range of the transparent film or the transparent colloid is 1.5-3.0.

[0029] The light-isolating substrate 4 is made of opaque / light-isolating material. In the light-isolating substrate 4, the width and depth of the first groove 401 and the second groove 402 and the interval between the first groove 401 and the second groove 402 can be appropriately adjusted according to the light-isolating effect.

[0030] In this embodiment, a third angle m is formed between the first inclined surface 51 and the second inclined surface 52, and the third angle m is greater than 60° and less than 180°. That is, a structure with a triangular cross-section is formed between the first inclined surface 51, the second inclined surface 52 of the transparent member 5 and the upper surface of the light-isolating substrate 4.

[0031] In this embodiment, the transmitting tube 2 and the receiving tube 3 are both plug-in devices or surface mount devices. Specifically, the transmitting tube 2 is an infrared transmitting tube, the receiving tube 3 is an infrared receiving tube, and the corresponding infrared transmitting circuit 21 and infrared receiving circuit 31 are as shown in FIG. Figure 2 As shown in . In practical applications, the infrared transmitting circuit 21 and the infrared receiving circuit 31 are also combined with a bandpass circuit, which has the effect of resisting the influence of external interference light, and effectively forms an optical detection structure without a darkroom. Specifically, the bandpass circuit adopts a bandpass isolation design, and external stable or non-same frequency interference light has no effect on the signal. The specific circuit structure of the bandpass circuit is shown in Figure 3 shown.

[0032] It should be noted that the technology of setting a photoelectric conversion circuit, a signal amplification circuit and a main control MCU circuit on the PCB board 1 is relatively existing. In practical applications, any existing suitable photoelectric conversion circuit, signal amplification circuit and main control MCU circuit can be set on the PCB board 1 to achieve corresponding photoelectric conversion, signal amplification and main control signal processing, and this embodiment does not make any specific limitations.

[0033] In this embodiment, the light emitted by the transmitting tube 2 enters the first inclined surface 51 of the transparent member 5, and then refracts and emits through the first inclined surface 51 of the transparent member 5. The refractive index of the transparent member 5 is greater than 1, and the refraction angle c1 here is greater than the incident angle b1 to enter the air; when the light is scattered by the smoke particles 10, the light enters the second inclined surface 52 of the transparent member 5 from the air, and the refraction angle c2 here is less than the incident angle b2. The light is refracted through the second inclined surface 52 of the transparent member 5 to be received by the receiving tube 3, and after photoelectric conversion and signal amplification, it is provided to the main control MCU for processing. By changing the optical path angle through the transparent member 5 with a higher refractive index, the fire smoke particle sensitive area is concentrated, and the detection accuracy is improved.

[0034] In other embodiments, Figure 4 As shown in , the transparent member 5 further has a plane 53, and the plane 53 is located between the first inclined surface 51 and the second inclined surface 52. The width p of the plane 53 is equal to the linear distance between the adjacent groove walls of the first groove 401 and the second groove 402. That is, the first inclined surface 51, the plane 53, the second inclined surface 52 of the transparent member 5 and the upper surface of the light-isolating substrate 4 form a structure with a trapezoidal cross-section shape, which can also concentrate the fire smoke particle sensitive area, thereby improving the detection accuracy.

[0035] The fire detector of this embodiment rationally plans the light path based on the refractive index of the transparent part 5. The main light intensity comes from the light scattered by the emitted light. There is no optical darkroom with complex structure, and the fire particle detection without darkroom can be realized. It can realize one-shot and one-receive, and can also realize multiple shots and multiple receivables, and the detection effect is better. The overall structure of the fire detector is simple, the assembly is simple, and it is convenient for automated production. The overall surface structure of the fire detector is also relatively flat, which is convenient for maintenance and cleaning.

[0036] It should be understood that, for ordinary technical workers in the field, improvements or changes can be made based on the above description, and all these improvements and changes should fall within the scope of protection of the claims attached to the present invention.

Claims

1. A fire detector, comprising a PCB board, characterized in that: The PCB board is provided with a transmitting tube, a receiving tube and a light-isolating substrate; a first groove and a second groove are arranged in the light-isolating substrate at intervals, and the notches of the first groove and the second groove are oriented in the same direction; the transmitting tube is located in the first groove, and the transmitting end of the transmitting tube corresponds to the notch of the first groove; the receiving tube is located in the second groove, and the receiving end of the receiving tube corresponds to the notch of the second groove; a transparent part is also sealed on the light-isolating substrate, and the refractive index of the transparent part is greater than 1; the transparent part has a first inclined surface and a second inclined surface that are relatively inclined outwards, the first inclined surface is located above the first groove, and the second inclined surface is located above the second groove.

2. The fire detector according to claim 1, characterized in that: The three-dimensional area where the refraction emission range of the light emitted by the transmitting tube intersects with the refraction injection range of the light received by the receiving tube is the detection sensitive area.

3. The fire detector according to claim 2, characterized in that: A first angle is formed between a surface of the light-isolating substrate facing the first inclined surface and the first inclined surface; a second angle is formed between a surface of the light-isolating substrate facing the second inclined surface and the second inclined surface.

4. The fire detector according to claim 3, characterized in that: The first angle and the second angle are both smaller than 60°.

5. The fire detector according to claim 4, characterized in that: A third angle is formed between the first inclined surface and the second inclined surface, and the third angle is greater than 60° and less than 180°.

6. The fire detector according to claim 4, characterized in that: The transparent member also has a plane, and the plane is located between the first inclined surface and the second inclined surface.

7. The fire detector according to claim 6, characterized in that: The width of the plane is equal to the straight-line distance between adjacent groove walls of the first groove and the second groove.

8. The fire detector according to claim 1, characterized in that: The transparent member is a transparent film or a transparent colloid.

9. The fire detector according to claim 8, characterized in that: The refractive index of the transparent film or transparent colloid is in the range of 1.5-3.

0.

10. The fire detector according to any one of claims 1 to 9, characterized in that: The transmitting tube and the receiving tube are both plug-in devices or surface mount devices.

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