Fire detector

Abstract

The utility model relates to the technical field of fire detection, and provides a fire detector, which comprises a PCB (printed circuit board) provided with a transmitting tube, a receiving tube and a light insulation substrate. 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 utility model relates to the technical field of fire detection, and more particularly to a fire detector. Background Art

[0002] Existing fire detection technology primarily relies on infrared emitting and receiving devices combined with an optical darkroom structure 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 positioned opposite each other. When fire smoke particles are located between the two, the presence of fire smoke particles is detected by determining whether the optical signals between the two are disconnected, thereby achieving fire smoke particle detection. However, this existing optical darkroom structure is prone to objects such as fibers clinging to the surfaces of the infrared emitting and receiving devices' optical signal-sensitive areas, causing false alarms and low detection accuracy. Furthermore, this existing optical darkroom structure is generally complex, difficult to maintain and clean, and difficult to assemble. This leads to significant limitations in practical applications and is therefore in urgent need of improvement. Utility Model Content

[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 utility model 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 provided; a first groove and a second groove are provided in the light-isolating substrate, which are spaced apart, 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 member is further sealed on the light-isolating substrate, and the refractive index of the transparent member is greater than 1; the transparent member has a first inclined surface and a second inclined surface that are relatively outwardly inclined, 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 incidence 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 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 the 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 utility model are as follows: different from the prior art, the fire detector of the utility model 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 by the first inclined surface of the transparent member to sense smoke particles, and light scattered by the smoke particles is refracted by the second inclined surface of the transparent member to the receiving tube, and the light path for detecting smoke particles is planned according to the refractive index of the transparent member, and no optical darkroom with a complex structure is required, so that fire particle detection without an optical darkroom structure is effectively achieved, and the detection effect is better. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a structural diagram of a fire detector in an embodiment of the present utility model;

[0016] Figure 2 This is a schematic diagram of the circuit structure of the infrared transmitting circuit and the infrared receiving circuit in the embodiment of the utility model;

[0017] Figure 3 1 is a schematic diagram of the circuit structure of the bandpass circuit in the embodiment of the present utility model;

[0018] Figure 4 This is another structural diagram of a fire detector in an embodiment of the present utility model;

[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; flat surface 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, claims, and accompanying drawings of the present invention are used to distinguish between different items, not to describe a specific order. Furthermore, the terms "including," "having," and any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising a series of steps or elements is not limited to the listed steps or elements, but may optionally include steps or elements not listed, or may optionally include other steps or elements inherent to the process, method, product, or apparatus.

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

[0022] "Multiple" refers to two or more. "And / or" describes the relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can mean: A exists alone, A and B exist simultaneously, or B exists alone. The character " / " generally indicates that the associated objects are in an "or" relationship.

[0023] Moreover, the terms "up, down, front, back, left, right, upper end, lower end" and the like indicating directions are all based on the posture and position of the device or apparatus 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 more clear, the following will be described clearly and completely in conjunction with the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are some 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 are within the scope of protection of the present invention.

[0025] The present utility model is implemented as follows 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 provided; the light-isolating substrate 4 is provided with a first groove 401 and a second groove 402 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 further 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 that are inclined outwardly relative to each other, 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 above the light-isolating substrate 4. The transmitting tube 2 and the receiving tube 3 are parallel to each other. Light emitted by the transmitting tube 2 strikes the first inclined surface 51 and is refracted by the first inclined surface 51 to detect smoke particles 10. After detecting smoke particles 10, the light is scattered by the smoke particles 10. Part of the scattered light strikes the second inclined surface 52 and is refracted by the second inclined surface 52 to the receiving tube 3. After receiving the corresponding light, the receiving tube 3 undergoes photoelectric conversion and signal amplification, and then provides it to the main control MCU for processing, thereby realizing a smoke detection alarm. The PCB board 1 also includes a photoelectric conversion circuit, a signal amplification circuit, and a main control MCU circuit to process the signal received by the receiving tube 3. The more smoke particles in the detection area, the stronger the optical signal received by the receiving tube 3; conversely, the weaker the optical signal, thereby realizing fire detection based on the strength of the received signal.

[0027] In this embodiment, the three-dimensional area where the refracted emission range of light emitted by the transmitting tube 2 intersects the refracted incident range of light received by the receiving tube 3 constitutes the detection sensitive area 20 for detecting smoke particles 10. The refracted emission range of light emitted by the transmitting tube 2 is determined by the width of the first groove 401 to meet the reasonable range of light emitted by the transmitting tube 2. The refracted incident range of light received by the receiving tube 3 is determined by the width of the second groove 402 to meet the reasonable range of light received by the receiving tube 3. Within 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 the upper surfaces of the light-isolating substrate 4. 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 component 5. The greater the refractive index of the transparent component 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 component 5 is a transparent film or a transparent colloid. The refractive index of the transparent film or the transparent colloid is in the range of 1.5-3.0.

[0029] The light-isolating substrate 4 is made of a light-proof / light-isolating material. The width, depth, and spacing between the first and second grooves 401, 402 can be adjusted appropriately based on 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. The third angle m is greater than 60° and less than 180°. That is, 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 form a triangular cross-sectional structure.

[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, and the receiving tube 3 is an infrared receiving tube. 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 DC 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 as follows 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 the corresponding photoelectric conversion, signal amplification and main control signal processing. This embodiment does not make any specific limitations.

[0033] In this embodiment, light emitted by transmitting tube 2 enters first inclined surface 51 of transparent member 5, then refracts through first inclined surface 51. Transparent member 5 has a refractive index greater than 1, and the angle of refraction c1 at this point is greater than the angle of incidence b1 before entering the air. After being scattered by smoke particles 10, the light enters second inclined surface 52 of transparent member 5 from the air. Here, the angle of refraction c2 is less than the angle of incidence b2. The light is refracted by second inclined surface 52 of transparent member 5 and received by receiving tube 3. After undergoing photoelectric conversion and signal amplification, it is provided to the main control MCU for processing. By altering the optical path angle of transparent member 5, the higher refractive index of fire smoke particle detection is concentrated in the area sensitive to fire smoke particles, improving detection accuracy.

[0034] In other embodiments, Figure 4 As shown in , the transparent member 5 further includes a flat surface 53 located between the first inclined surface 51 and the second inclined surface 52. The width p of the flat surface 53 is equal to the linear distance between the adjacent groove walls of the first groove 401 and the second groove 402. This means that the first inclined surface 51, the flat surface 53, the second inclined surface 52 of the transparent member 5, and the upper surface of the light-isolating substrate 4 form a trapezoidal cross-sectional structure, which also concentrates the fire smoke particle sensitivity area, thereby improving detection accuracy.

[0035] The fire detector of this embodiment rationally plans the light path based on the refractive index of the transparent element 5. The primary light intensity comes from the scattered light from the emitted light. This eliminates the need for a complex optical darkroom, enabling fire particle detection without a darkroom. It can achieve both a single-transmit-one-receiver or multiple-transmit-multiple-receiver setup, resulting in superior detection effectiveness. The fire detector has a simple overall structure and assembly, facilitating automated production. The overall surface structure of the fire detector is also relatively flat, making it easy to maintain and clean.

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

Claims

1. A fire detector comprising a PCB, 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 provided 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 outward, 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 incidence 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 further has a plane 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 part 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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