Flame detector light path self-checking condenser lens

Abstract

This utility model discloses a self-testing focusing cover for a flame detector optical path, including a focusing cover body. The focusing cover body has a through stepped hole inside. The surface of the stepped hole has a small hole surface and a large hole surface. A parabolic surface is machined on the small hole surface, and a C1 chamfer is provided on the large hole surface. The stepped hole is located in the middle of the focusing cover body. An infrared light source is installed in the stepped hole. The infrared light source is mounted on an analog circuit board through pins. The analog circuit board is located at the bottom of the focusing cover body. The bottom of the focusing cover body and the analog circuit board are fixedly connected by glue. The light source position is located at the focal length of the parabolic surface.

Description

Technical Field

[0001] This utility model belongs to the field of flame detection technology, and more specifically, it relates to a self-testing focusing cover for the optical path of a flame detector. Background Technology

[0002] Optical path self-test devices generally refer to a combination of an infrared light source, a pyroelectric sensor, and a specular reflector. The infrared light source emits an infrared signal, which penetrates the viewing window and illuminates the specular reflector. The specular reflector then reflects the infrared signal, which penetrates the viewing window again and illuminates the pyroelectric sensor. The pyroelectric sensor determines the degree of contamination of the viewing window by the amount of energy absorbed by the infrared signal. When the energy of the infrared self-test signal emitted by the instrument decreases to a certain threshold after being absorbed by the pyroelectric sensor, the instrument issues a "viewing window contamination" fault signal, prompting on-site personnel to clean the instrument viewing window.

[0003] Currently, traditional self-testing light sources (such as infrared LEDs) are mostly wide-angle emitters with low light energy utilization. Scattered light is easily affected by environmental interference, resulting in insufficient noise ratio at the receiver. Furthermore, wide-angle light sources have low sensitivity to local contamination, requiring a large area of ​​contaminants to trigger an alarm, delaying maintenance. They also have poor structural adaptability, with conventional lens or reflector structures being difficult to accommodate installation requirements in narrow spaces and unable to effectively match infrared wavelength characteristics. Utility Model Content

[0004] To address the shortcomings of existing technologies, this invention provides a self-testing focusing cover for a flame detector optical path. By directional focusing, it improves the concentration of the self-testing light source and the sensitivity of contamination detection, while also adapting to the compact installation requirements of flame detectors, thereby solving the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a self-testing focusing hood for a flame detector optical path, comprising a focusing hood body, wherein a through stepped through hole is provided inside the focusing hood body, the surface of the stepped through hole is provided with a small hole surface and a large hole surface, a parabolic surface is machined on the small hole surface, and a C1 chamfer is provided on the large hole surface; the stepped through hole is located in the middle of the focusing hood body, an infrared light source is provided inside the stepped through hole, the infrared light source is mounted on an analog circuit board via pins, the analog circuit board is located at the bottom of the focusing hood body, the bottom of the focusing hood body and the analog circuit board are fixedly connected by adhesive, and the light source position is provided at the focal length of the parabolic surface.

[0006] Preferably, a viewing window is provided on one side of the focusing illumination, a specular reflector is provided on the outer side of the viewing window, and a pyroelectric sensor is provided below the main body of the focusing cover.

[0007] Preferably, the surface of the light-concentrating cover body is provided with a nickel plating layer and a gold plating layer, the surface thickness of the nickel plating layer is 13μm, and the surface thickness of the gold plating layer is 1.27μm.

[0008] Preferably, the aperture size of the small hole is 2.4 mm, and the aperture size of the large hole is 3 mm.

[0009] Preferably, the main body of the light-concentrating cover is cylindrical and made of 304 material.

[0010] Preferably, the surface roughness of the parabolic surface is required to be <Ra0.8.

[0011] This invention provides a self-testing focusing cover for a flame detector, which has the following advantages: its polished reflective surface acts as a focusing surface for the scattered light from the infrared light source, increasing the signal strength of the self-testing receiver; the focused light illuminates contaminants on the viewing window, causing significant light attenuation, thus improving the sensitivity to contaminants and enhancing the ability to judge contamination of the viewing window. Attached Figure Description

[0012] Fig. 1 This is a cross-sectional view of the flame detector assembly of this utility model.

[0013] Fig. 2 This is a cross-sectional view of the light-concentrating cover structure of this utility model.

[0014] Fig. 3 This is a cross-sectional view of the light-concentrating cover structure of this utility model.

[0015] In the diagram, 1. View window; 2. Concentrator body; 3. Infrared light source; 4. Mirror reflector; 5. Pyroelectric sensor; 6. Stepped through hole; 7. Analog circuit board; 8. Large hole surface; 9. Small hole surface; 10. Parabolic surface; 11. C1 chamfer; 12. Light source position. Detailed Implementation

[0016] The embodiments of this utility model will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and should not be construed as limiting the scope of this utility model.

[0017] In the description of this utility model, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. In addition, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0018] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0019] Please see Figs. 1 to 3 This utility model provides a technical solution: a self-testing optical path focusing cover for a flame detector, comprising a focusing cover body 2, which is a cylinder made of 304 stainless steel. The surface of the focusing cover body 2 is provided with a nickel plating layer and a gold plating layer. The surface thickness of the nickel plating layer is 13μm, and the surface thickness of the gold plating layer is 1.27μm. The nickel plating is performed according to standard ML-C-26074, grade B, level 4, and the gold plating is performed according to standard ML-G-45204, TYPE II, CL1.

[0020] The main body 2 of the focusing cover has a through-hole 6. The surface of the through-hole 6 has a small-aperture surface 9 and a large-aperture surface 8. The diameter of the small-aperture surface 9 is 2.4 mm, and the diameter of the large-aperture surface 8 is 3 mm. A parabolic surface 10 is machined on the small-aperture surface 9, and the cross-sectional equation of the parabolic surface 10 is X. 2 =2×2y, with a C1 chamfer 11 on the large hole surface 8. The surface roughness requirement for the parabolic surface 10 is <Ra0.8.

[0021] A stepped through-hole 6 is located in the middle of the condenser body 2. An infrared light source 3 is installed inside the stepped through-hole 6. The infrared light source 3 is mounted on the analog circuit board 7 via pins. The analog circuit board 7 is located at the bottom of the condenser body 2. The bottom of the condenser body 2 and the analog circuit board 7 are fixedly connected by glue. A light source position 12 is located at the focal length of the parabolic surface 10. A viewing window 1 is provided on one side of the condenser body 2. A specular reflector 4 is provided on the outer side of the viewing window 1. A pyroelectric sensor 5 is provided below the condenser body 2.

[0022] The specific usage and function of this embodiment: The reflective surface of the focusing cover body 2 is a parabolic surface 10, with the focal point of the parabolic surface 10 on the axis of the focusing cover body 2. The light source position 12 is installed at the focal point of the parabolic surface 10. The infrared light source 3 emitted from the focal point will be reflected by the parabolic surface 10 and become parallel light. Using this parabolic surface 10 reflection method can greatly reduce the scattering of the infrared light source 3. The concentration of the light path can amplify the attenuation effect of contaminants (such as dust and oil film) on the light signal, making it easier to identify light path contamination earlier. The focusing cover is made of stainless steel, and its plating includes a nickel layer and a gold layer. The surface thickness of the nickel layer is 13μm. Nickel plating can fill the defects of the substrate and enhance the surface adhesion of the gold layer. The thickness of the gold layer is 1.27μm. The gold layer has a good reflective effect in the infrared band, and its reflectivity can reach 95-98%.

[0023] The infrared light emitted by the infrared light source 3 is originally scattered light at a large angle, but after being reflected by the condenser, its scattering angle is greatly reduced, and the intensity of the light source signal is enhanced. The light reflected by the condenser penetrates the window 1 and shines on the mirror reflector 4. The mirror reflector 4 then reflects the infrared signal, which penetrates the window 1 and shines on the pyroelectric sensor 5. The pyroelectric sensor 5 judges the degree of contamination of the window 1 by the amount of energy of the absorbed infrared signal. Because the light signal received by the sensor is enhanced after being reflected by the condenser, it can better judge the degree of contamination of the window 1.

[0024] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A self-testing focusing hood for a flame detector optical path, comprising a focusing hood body (2), characterized in that: The main body (2) of the light condenser has a through stepped hole (6) inside. The surface of the stepped hole (6) has a small hole surface (9) and a large hole surface (8). A parabolic surface (10) is machined on the small hole surface (9), and a C1 chamfer (11) is provided on the large hole surface (8). The stepped hole (6) is located in the middle of the main body (2). An infrared light source (3) is provided in the stepped hole (6). The infrared light source (3) is mounted on the analog circuit board (7) through pins. The analog circuit board (7) is located at the bottom of the main body (2). The bottom of the main body (2) and the analog circuit board (7) are fixedly connected by glue. The light source position (12) is provided at the focal length of the parabolic surface (10).

2. The self-testing focusing cover for a flame detector optical path according to claim 1, characterized in that: The main body (2) of the light-concentrating cover has a viewing window (1) on one side, a mirror reflector (4) is provided on the outside of the viewing window (1), and a pyroelectric sensor (5) is provided below the main body (2).

3. The self-testing focusing cover for a flame detector optical path according to claim 1, characterized in that: The surface of the light-concentrating cover body (2) is provided with a nickel plating layer and a gold plating layer. The surface thickness of the nickel plating layer is 13 μm, and the surface thickness of the gold plating layer is 1.27 μm.

4. The self-testing focusing cover for a flame detector optical path according to claim 1, characterized in that: The aperture size of the small hole surface (9) is 2.4 mm, and the aperture size of the large hole surface (8) is 3 mm.

5. The self-testing focusing cover for a flame detector optical path according to claim 1, characterized in that: The main body (2) of the light-concentrating cover is cylindrical and made of 304 material.

6. The self-testing focusing cover for a flame detector optical path according to claim 1, characterized in that: The surface roughness requirement of the parabolic surface (10) is <Ra0.8.

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