Fire detector for locomotives

Abstract

The application discloses a locomotive fire detector, which comprises a shell and a special-shaped labyrinth structure arranged in the shell, and a smoke inlet is arranged on the shell; the special-shaped labyrinth structure comprises a plurality of special-shaped plates which are arranged in a circumferential interval and surround to form a detection cavity; a special-shaped channel which can communicate the smoke inlet and the detection cavity is formed between two adjacent special-shaped plates, the special-shaped channel comprises an outer channel and an inner channel which are communicated, the width of the outer channel gradually decreases from outside to inside, the width of the inner channel gradually decreases from outside to inside, and the minimum width of the inner channel is greater than that of the outer channel. The mechanical design of the special-shaped labyrinth structure can effectively solve the problem that dust is easily introduced into the detector when smoke is introduced, and the service life of the detector is improved.

Description

Technical Field

[0001] This invention relates to the field of locomotive fire prevention technology, and in particular to a fire detector for locomotives. Background Technology

[0002] Photoelectric smoke detectors have strong anti-interference capabilities and stable performance, and have gradually replaced ionization smoke detectors in the market. However, in recent years, various fields have increased their awareness and investment in fire prevention, and fire prevention in special scenarios has also been strengthened. For example, in large and open spaces such as airports, high-speed rail stations, and subway stations, if ordinary photoelectric smoke detectors are installed for smoke fire detection, when a fire occurs, the smoke often has difficulty spreading to the smoke detectors at the top. Even if it does spread, the fire has already entered the development stage, and it cannot achieve the effect of preventing fires before they start. Therefore, the need for smoke detectors in locomotives has emerged. When the locomotive is ventilated, the smoke particles in the air spread rapidly, which can greatly speed up the detection time.

[0003] However, because photoelectric smoke detectors cannot distinguish between particles, their application in locomotive smoke detectors has not yielded the expected results. Instead, frequent false alarms have caused adverse effects. Furthermore, ordinary photoelectric smoke detectors are quite sensitive to dust pollution, requiring maintenance. The installation and removal of detectors inside locomotives are not easy, and maintenance often requires significant manpower and resources. Summary of the Invention

[0004] The purpose of this invention is to provide a fire detector for locomotives, which utilizes a mechanical design of an irregularly shaped labyrinth structure to effectively solve the problem of dust easily entering the detector when smoke enters, thereby improving the service life of the detector.

[0005] The objective of this invention is achieved as follows: a fire detector for locomotives includes a housing and an irregularly shaped labyrinth structure disposed within the housing. The housing has a smoke inlet. The irregularly shaped labyrinth structure includes multiple irregularly shaped pieces arranged at circumferential intervals, which enclose a detection cavity. An irregularly shaped channel is formed between adjacent irregularly shaped pieces, connecting the smoke inlet and the detection cavity. This channel includes an outer channel and an inner channel that are connected. The length directions of the outer and inner channels, as well as the length directions of the outer and inner channels and their corresponding radial directions within the irregularly shaped labyrinth structure, have a first angle, a second angle, and a third angle, respectively. The first angle is less than or equal to 90°. The width of the outer channel gradually decreases from the outside to the inside, and the width of the inner channel also gradually decreases from the outside to the inside, with the minimum width of the inner channel being greater than the minimum width of the outer channel.

[0006] In a preferred embodiment of the present invention, a protrusion is provided at the connection position between the outer channel and the inner channel.

[0007] In a preferred embodiment of the present invention, the irregularly shaped piece includes a first baffle and a second baffle. The first baffle is arranged near the outer side of the irregularly shaped maze structure. The outer end of the second baffle is connected to the inner end of the first baffle, and a preset distance is left between the outer end of the second baffle and the inner end of the first baffle. The first baffle corresponding to the preset distance forms a protrusion.

[0008] In a preferred embodiment of the present invention, the irregular maze structure further includes a support disk, with irregularly shaped pieces spaced circumferentially on the disk surface of the support disk, and the surfaces of the first baffle and the second baffle are both perpendicular to the disk surface of the support disk.

[0009] In a preferred embodiment of the present invention, the fire detector for locomotives further includes a control circuit board, a detection optical path structure, and a light shield. The control circuit board, the detection optical path structure, the light shield, and the irregularly shaped labyrinth structure are arranged sequentially from the bottom to the top of the housing. The light shield is a cylindrical structure with an opening at the bottom and a mounting port on its top surface. The detection optical path structure is press-fitted onto the control circuit board through the light shield, and a portion of the detection optical path structure can be exposed through the mounting port. The irregularly shaped labyrinth structure is mounted on the top surface of the light shield. The detection optical path structure has multiple light sources, each capable of emitting light of different wavelengths into the detection cavity. A light receiver is also provided on the control circuit board, and both the light sources and the light receiver are electrically connected to the control circuit board.

[0010] In a preferred embodiment of the present invention, the plurality of light sources include a first light source, a second light source, and a third light source. The wavelength of the first light source is 470-475nm, the wavelength of the second light source is 597-577nm, and the wavelength of the third light source is 760-622nm. The locomotive fire detector has a system self-test state and a smoke particle detection state. When the locomotive fire detector is in the system self-test state, the second light source is activated. When the locomotive fire detector is in the smoke particle detection state, the first light source and the third light source are activated.

[0011] In a preferred embodiment of the present invention, a CAN communication interface and a temperature sensor are provided on the control circuit board.

[0012] In a preferred embodiment of the present invention, a power-on indicator and a working status indicator are provided on the control circuit board.

[0013] In a preferred embodiment of the present invention, an annular insect-proof net is also fitted on the outside of the irregular maze structure.

[0014] In a preferred embodiment of the present invention, the outer shell includes a top cover, a bottom cover and a fixed base. The top cover and the bottom cover can be snapped together and fixed. The control circuit board, the detection optical path structure, the light shield and the irregular maze structure are all disposed in the cavity enclosed by the top cover and the bottom cover. The bottom cover and the fixed base can be detachably connected.

[0015] As described above, this invention employs an irregularly shaped channel structure for the maze structure and designs the outer and inner channels within this irregular channel. After smoke enters the detector, the irregularly shaped channel creates a maze-like smoke entry method, ensuring that smoke particles enter the detection cavity while preventing dust particles from entering. Even if some dust particles enter the inner channel, the pressure drop caused by the irregular maze arrangement will create a small dust particle buffer zone within the inner channel, which will not affect the optical detection path, reducing dust contamination of the detector and improving its service life. Attached Figure Description

[0016] The accompanying drawings are intended only to illustrate and explain the present invention and do not limit the scope of the invention.

[0017] in:

[0018] Figure 1 This is a schematic diagram of the structure of the fire detector for locomotives provided by the present invention.

[0019] Figure 2 This is a cross-sectional schematic diagram of the fire detector for locomotives provided by the present invention.

[0020] Figure 3 This is an exploded schematic diagram of the fire detector for locomotives provided by the present invention.

[0021] Figure 4 This is a schematic diagram of the irregular maze structure provided by the present invention.

[0022] Figure 5 This is a cross-sectional schematic diagram of the irregular maze structure provided by the present invention.

[0023] Figure 6 This is a schematic diagram of the structure of the light shield provided by the present invention.

[0024] Figure 7 This is a cross-sectional schematic diagram of the light shield provided by the present invention.

[0025] Explanation of icon numbers:

[0026] 1. Outer casing; 11. Smoke inlet; 12. Top cover; 13. Bottom cover; 131. First spring clip; 14. Fixing base; 141. Second spring clip;

[0027] 2. Alien labyrinth structure; 21. Support plate; 22. Alien piece; 221. First baffle; 2211. Protrusion; 222. Second baffle; 23. Alien channel; 231. Outer channel; 232. Inner channel; 24. Detection cavity;

[0028] 3. Insect-proof netting;

[0029] 4. Sunshade; 41. Mounting port; 42. Mounting ring;

[0030] 5. Inspect the optical path structure;

[0031] 6. Control circuit board; 61. Power indicator light; 62. Working status indicator light. Detailed Implementation

[0032] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments of the present invention will now be described with reference to the accompanying drawings.

[0033] like Figures 1 to 7 As shown, this embodiment provides a fire detector for locomotives, including a housing 1 and an irregularly shaped maze structure 2 disposed within the housing 1. The housing 1 has a smoke inlet 11. The irregularly shaped maze structure 2 includes multiple irregularly shaped pieces 22 arranged circumferentially, which enclose a detection cavity 24. An irregularly shaped channel 23 is formed between two adjacent irregularly shaped pieces 22, which can connect the smoke inlet 11 and the detection cavity 24. The irregularly shaped channel 23 includes an outer channel 231 and an inner channel 232 that are connected. The length directions of the outer channel 231 and the inner channel 232, as well as the length directions of the outer channel 231 and the inner channel 232, have a first angle, a second angle, and a third angle with the corresponding radial direction of the irregularly shaped maze structure 2, respectively. The first angle is less than or equal to 90°. The width of the outer channel 231 gradually decreases from the outside to the inside, and the width of the inner channel 232 gradually decreases from the outside to the inside. The minimum width of the inner channel 232 is greater than the minimum width of the outer channel 231.

[0034] During operation, the flue gas enters through the inlet 11 at a relatively high pressure. Due to the small size of the smoke particles, they easily diffuse through the irregularly shaped channel 23 into the detection chamber 24. However, the dust particles are larger and have poor diffusion. After entering the irregularly shaped channel 23, the width of the outer channel 231 gradually decreases from the outside to the inside, which can effectively block the entry of dust particles, allowing only a small number of dust particles to continue into the inner channel 232. Since the minimum width of the inner channel 232 is greater than the minimum width of the outer channel 231, the pressure drops after the dust particles enter the inner channel 232 from the outer channel 231, preventing the dust particles from being ejected too far forward. They can be deposited and remain stationary in the inner channel 232 (a portion of the inner channel 232 essentially forms a dust particle buffer zone). In addition, the width of the inner channel 232 gradually decreases from the outside to the inside (the degree of width reduction here can be relatively small), which further prevents the entry of dust particles, making it even more difficult for dust particles to diffuse into the detection chamber 24. This ensures that only smoke particles enter the detection chamber 24.

[0035] Therefore, in this embodiment, the detector adopts an irregularly shaped channel 23 structure for the maze structure, and designs the outer channel 231 and inner channel 232 in the irregularly shaped channel 23. After the smoke enters the detector, the irregularly shaped channel 23 can form an irregularly shaped maze smoke entry method, which can ensure that smoke particles enter the detection cavity 24 and prevent dust particles from entering the detection cavity 24. Even if some dust particles enter the inner channel 232, due to the arrangement of the irregularly shaped maze, the dust particles will form a small amount of dust particle buffer area in the inner channel 232 due to the pressure drop after entering the inner channel 232, which will not affect the optical detection optical path, reduce dust contamination of the detector, and improve the service life of the detector.

[0036] Preferably, a protrusion 2211 is provided at the connection position between the outer channel 231 and the inner channel 232.

[0037] The protrusion 2211 is generally an arc-shaped protrusion, which can further prevent dust particles from entering when they enter the inner channel 232 from the outer channel 231.

[0038] Specifically, refer to Figure 4 The irregular piece 22 includes a first baffle 221 and a second baffle 222. The first baffle 221 is arranged near the outer side of the irregular maze structure 2, and the second baffle 222 is arranged near the inner side of the irregular maze structure 2. The outer end of the second baffle 222 is connected to the inner end of the first baffle 221, and a preset distance is left between the outer end of the second baffle 222 and the inner end of the first baffle 221. The first baffle 221 corresponding to the preset distance forms a protrusion 2211.

[0039] Reference Figure 4 It can be understood that multiple irregularly shaped plates 22 are generally arranged evenly in the circumferential direction. The length direction of the outer channel 231 and the length direction of the first baffle 221 are inclined from the outside to the inside towards the corresponding radial side of the irregularly shaped maze structure 2. The length direction of the inner channel 232 and the length direction of the second baffle 222 are inclined from the outside to the inside towards the corresponding radial side of the irregularly shaped maze structure 2. The first baffle 221 and the second baffle 222 form a "human" shaped structure to effectively prevent dust particles.

[0040] The general irregular maze structure 2 also includes a support disk 21, with irregularly shaped pieces 22 spaced circumferentially on the disk surface of the support disk 21. The surfaces of the first baffle 221 and the second baffle 222 are both perpendicular to the disk surface of the support disk 21. Each irregularly shaped piece 22 and the support disk 21 can be integrally formed.

[0041] Furthermore, refer to Figure 3The fire detector for locomotives also includes a control circuit board 6, a detection optical path structure 5, and a light shield 4. The control circuit board 6, the detection optical path structure 5, the light shield 4, and the irregularly shaped labyrinth structure 2 are arranged sequentially from the bottom to the top of the outer shell 1. The light shield 4 is a cylindrical structure with an opening at the bottom and an installation port 41 on its top surface. The detection optical path structure 5 is press-fitted onto the control circuit board 6 through the light shield 4, and part of the detection optical path structure 5 can be exposed through the installation port 41. The irregularly shaped labyrinth structure 2 is installed on the top surface of the light shield 4. The detection optical path structure 5 has multiple light sources, which can emit light of different wavelengths into the detection cavity 24 respectively. A light receiver is also provided on the control circuit board 6. Both the light source and the light receiver are electrically connected to the control circuit board 6.

[0042] The light receiver is located inside the detection cavity 24 and is used to receive light emitted by various light sources and scattered by smoke particles or air in the detection cavity 24.

[0043] Preferably, the system is equipped with three light sources: a first light source, a second light source, and a third light source. The wavelength of the first light source is 470-475nm, the wavelength of the second light source is 597-577nm, and the wavelength of the third light source is 760-622nm. The locomotive fire detector has a system self-test state and a smoke particle detection state. When the locomotive fire detector is in the system self-test state, the second light source is activated. When the locomotive fire detector is in the smoke particle detection state, the first and third light sources are activated.

[0044] The first, second, and third light sources mentioned above correspond to blue light, yellow light, and red light, respectively. After the detector is powered on, the second light source is activated first. At this time, the detection cavity 24 is filled with air, and the locomotive fire detector is in a system self-test state. If the light receiver can receive the light emitted by the second light source and scattered by the air in the detection cavity 24, it indicates that the detector is in normal condition. If the light receiver cannot receive the light, it indicates that there is an abnormality in the detector, and the operator needs to perform corresponding maintenance or replacement.

[0045] When the fire detector on the locomotive is in a self-test state and the detection is normal, the first and third light sources will be turned on and the second light source will be turned off to detect smoke particles. The working principle is based on optical principles, utilizing the difference in diffuse signal intensity generated by suspended particles of different sizes on red and blue light beams of different wavelengths. Specifically, when detecting particles that have entered the detection cavity 24 of the irregular maze structure 2, smoke particles are uniformly distributed and their particle size is mostly between 0.5-0.9 μm, while dust and water vapor particles often have a particle size of 1-5 μm or even larger. The different particle sizes, quantities, and distributions result in different light scattering. Detecting the current values ​​generated by the light scattering using the two light sources will yield two different values. By comparing this difference, it is possible to analyze and determine whether it is smoke particles (the specific analysis and judgment process is existing technology and will not be elaborated here). Only when it is determined to be smoke particles will a smoke alarm be triggered, providing a reliable basis for smoke alarm judgment, thereby achieving anti-interference capability against dust particles and water vapor particles. In the complex environment of a locomotive, the detector only issues an alarm signal for smoke particles.

[0046] Furthermore, a CAN communication interface is provided on control circuit board 6, which facilitates data analysis and acquisition. Information exchange adopts a CAN bus communication architecture to acquire relevant parameters in real time, combined with software algorithms and other technologies for judgment. The specific analysis and judgment process is existing technology and will not be elaborated here.

[0047] A temperature sensor is also provided on the control circuit board 6. The temperature sensor is located inside the detection cavity 24 and is used to detect the temperature inside the detection cavity 24.

[0048] The control circuit board 6 is equipped with a power indicator 61 and a working status indicator 62. When the detector is powered on, the power indicator 61 lights up green, indicating that it is powered on; when the detector is powered off, the power indicator 61 does not light up, indicating that it is powered off. When the detector is in working condition, the working status indicator 62 flashes once per second and lights up green, indicating that it is always working; when an abnormal smoke alarm is detected, the working status indicator 62 turns red and stays on, indicating that an abnormality has occurred.

[0049] Generally, multiple smoke inlets 11 are provided circumferentially on the side wall of the outer shell 1. The tops of multiple irregularly shaped pieces 22 are connected to the support plate 21, and the bottoms can abut against the top surface of the light shield 4. An annular insect-proof net 3 is also fitted on the outside of the irregularly shaped maze structure 2 for insect protection. When in use, the smoke enters through the smoke inlet 11, passes through the insect-proof net 3, and then enters the irregularly shaped channel 23.

[0050] For easier processing and installation, the outer casing 1 includes a top cover 12, a bottom cover 13 and a fixed base 14. The top cover 12 and the bottom cover 13 can be snapped together and fixed. The control circuit board 6, the detection optical path structure 5, the light shield 4 and the irregular maze structure 2 are all located in the cavity formed by the top cover 12 and the bottom cover 13. The bottom cover 13 and the fixed base 14 can be detachably connected.

[0051] The aforementioned control circuit board 6 can be fixed to the bottom cover 13 by multiple fasteners (e.g., four screws), and the bottom of the detection optical path structure 5 is clipped onto the control circuit board 6. (Refer to...) Figure 3 , Figure 6 and Figure 7 A mounting ring 42 is provided on the inner top surface of the light shield 4, surrounding the mounting opening 41. The mounting opening 41 is generally rectangular, and the detection optical path structure 5 is also rectangular. The mounting ring 42 can be pressed onto the outer periphery of the detection optical path structure 5 to press the detection optical path structure 5 onto the control circuit board 6. The irregularly shaped maze structure 2 is placed on the outer top surface of the light shield 4, and the insect-proof net 3 is fitted over the irregularly shaped maze structure 2. By fastening the top cover 12 to the outside and snapping it into the bottom cover 13, the irregularly shaped maze structure 2 and the insect-proof net 3 can be pressed tightly onto the light shield 4.

[0052] The entire detector is circular. The bottom cover 13 and the fixed base 14 can be detachably connected in any manner. For example, multiple first spring clips 131 (e.g., six) can be provided at the bottom of the bottom cover 13, and multiple second spring clips 141 (e.g., five) can be provided at the top of the fixed base 14. The bottom cover 13 and the fixed base 14 can be screwed together and disassembled through the action of the first spring clips 131 and the second spring clips 141. In use, the fixed base 14 is fixed in a fixed position. If the detector needs to be replaced, simply disassemble the bottom cover 13 and the fixed base 14; there is no need to replace the fixed base 14, making it simple and convenient.

[0053] In an optional embodiment, the components, resistors, etc., in the EMC circuit on the control circuit board 6 (PCB) can also be optimized to improve the detector's resistance to strong electromagnetic interference.

[0054] In summary, the fire detector for locomotives in this embodiment is a photoelectric smoke detector, a type of intelligent dual-light source fire detector for locomotives, which has the following advantages:

[0055] (1) By utilizing the mechanical design of the optical irregular maze, the method of smoke inlet through the irregular maze can effectively solve the problem of dust entering the smoke inlet.

[0056] (2) Utilizing the light scattering principle of photoelectric smoke detectors and the different distributions of dust, smoke, and water mist particles, and based on the differences in scattering characteristics of the same particles at different wavelengths, the detector employs dimensionless particle size parameter calculation and analysis. A multi-source wavelength comparison method is used, and the control circuit calculates the anti-interference capability against dust and water mist particles. Furthermore, the PCB board is optimized to achieve electromagnetic interference resistance. The detector's components can be made of high-temperature resistant materials. In complex environments like locomotives, the detector only issues alarm signals for smoke, filtering out interference from dust, high temperatures, and strong electromagnetic fields.

[0057] (3) Three light sources are used for detection, each emitting light of a different wavelength. One light source, when activated, does not distinguish between particle states and is only used for system self-checking to determine whether the detector is functioning correctly. The other two light sources can be used to detect smoke particles in the detection cavity 24. By using the combination of these three light sources, the detector's working status is first checked, and then smoke particles are detected, providing a reliable basis for alarm judgment while ensuring the detector's normal operation. The principle of light scattering is used to compare the scattering characteristics of dust, water mist, and smoke particles, and a wide-range multi-light source comparison method is adopted to judge, thereby achieving anti-interference against dust and water mist, and issuing alarm signals only for smoke particles.

[0058] The above are merely illustrative embodiments of the present invention and are not intended to limit the scope of the invention. Any equivalent changes and modifications made by those skilled in the art without departing from the concept and principles of the present invention should fall within the scope of protection of the present invention.

Claims

1. A fire detector for locomotives, characterized in that, It includes an outer shell and an irregularly shaped labyrinth structure disposed within the outer shell, and the outer shell has a smoke inlet; The irregularly shaped maze structure includes multiple irregularly shaped pieces arranged circumferentially, which together form a detection cavity. A irregularly shaped channel is formed between two adjacent irregularly shaped pieces, connecting the smoke inlet and the detection cavity. This channel includes an outer channel and an inner channel. The length directions of the outer and inner channels, as well as the length directions of the outer and inner channels and their respective radial directions relative to the irregularly shaped maze structure, form a first angle, a second angle, and a third angle, respectively. The first angle is less than or equal to 90°. The width of the outer channel gradually decreases from the outside in, and the width of the inner channel also gradually decreases from the outside in, with the minimum width of the inner channel being greater than the minimum width of the outer channel.

2. The locomotive fire detector as described in claim 1, characterized in that, A protrusion is provided at the connection point between the outer channel and the inner channel.

3. The locomotive fire detector as described in claim 2, characterized in that, The irregularly shaped piece includes a first baffle and a second baffle. The first baffle is arranged near the outer side of the irregularly shaped maze structure. The outer end of the second baffle is connected to the inner end of the first baffle, and a preset distance is left between the outer end of the second baffle and the inner end of the first baffle. The first baffle corresponding to the preset distance constitutes the protrusion.

4. The locomotive fire detector as described in claim 3, characterized in that, The irregular maze structure also includes a support disk, with the irregular pieces circumferentially spaced on the surface of the support disk, and the surfaces of the first baffle and the second baffle are perpendicular to the surface of the support disk.

5. The locomotive fire detector as described in claim 1, characterized in that, The locomotive fire detector also includes a control circuit board, a detection optical path structure, and a light shield. The control circuit board, the detection optical path structure, the light shield, and the irregularly shaped labyrinth structure are arranged sequentially from the bottom to the top of the housing. The light shield is a cylindrical structure with an opening at the bottom and a mounting port on its top surface. The detection optical path structure is pressed onto the control circuit board through the light shield, and a portion of the detection optical path structure can be exposed through the mounting port. The irregularly shaped labyrinth structure is mounted on the top surface of the light shield. The detection optical path structure has multiple light sources, each of which can emit light of different wavelengths into the detection cavity. A light receiver is also provided on the control circuit board, and both the light sources and the light receiver are electrically connected to the control circuit board.

6. The locomotive fire detector as described in claim 5, characterized in that, The plurality of light sources include a first light source, a second light source, and a third light source. The wavelength of the first light source is 470-475nm, the wavelength of the second light source is 597-577nm, and the wavelength of the third light source is 760-622nm. The locomotive fire detector has a system self-test state and a smoke particle detection state. When the locomotive fire detector is in the system self-test state, the second light source is activated. When the locomotive fire detector is in the smoke particle detection state, the first light source and the third light source are activated.

7. The locomotive fire detector as described in claim 5, characterized in that, The control circuit board is equipped with a CAN communication interface and a temperature sensor.

8. The locomotive fire detector as described in claim 5, characterized in that, The control circuit board is equipped with a power indicator and a working status indicator.

9. The locomotive fire detector as described in claim 5, characterized in that, An insect-proof net is also fitted around the outside of the irregularly shaped maze structure.

10. The locomotive fire detector as described in claim 5, characterized in that, The outer casing includes a top cover, a bottom cover, and a fixed base. The top cover and the bottom cover can be snapped together and fixed. The control circuit board, the detection optical path structure, the light shield, and the irregular maze structure are all located in the cavity formed by the top cover and the bottom cover. The bottom cover and the fixed base can be detachably connected.

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