JP3966537B2 - Flame detector - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a flame detector that receives light emitted from a dirt detection light emitting element via a light receiving glass, and that detects the degree of dirt on the light receiving glass based on the amount of light received by the light receiving part. .
[0002]
[Prior art]
FIG. 3 is a schematic cross-sectional view showing a conventional flame detector FD10.
[0003]
The conventional flame detector FD10 for tunnels has a light receiving part 30 provided in a light receiving glass 20 whose front surface is substantially elliptical or circular and whose section protrudes in a hemispherical shape. Monitor the radiation from and identify the presence of flames. Since the light receiving unit 30 monitors the radiated light through the light receiving glass 20, when the light receiving glass 20 is contaminated with dust or the like in the tunnel, the amount of the radiant light reaching the light receiving unit 30 is reduced and the flame is normally burned. It may become impossible to detect.
[0004]
In order to prevent the flame from being detected normally, the degree of contamination of the light receiving glass 20 is measured, and when the degree of contamination exceeds a predetermined level, the light receiving glass 20 of the flame detector FD10 is cleaned, thereby The flame detection performance of the flame detector FD10 is kept normal.
[0005]
When detecting the degree of contamination of the light receiving glass 20, a cylindrical glove 80 is provided outside the light receiving glass 20, and a dirt detection light emitting element 81 is provided in the cylindrical glove 80, and the light receiving glass 20 is provided inside. As the light receiving unit 30, a dirt detecting light receiving element 83 which is also used as a fire detecting element is provided. Then, the dirt detection light emitting element 81 emits test light having a predetermined intensity from the outside of the light receiving glass 20, and the light receiving element 83 in the light receiving glass 20 receives the test light. Based on the amount of light received by the light receiving element 83, the degree of contamination of the light receiving glass 20 is calculated.
[0006]
[Problems to be solved by the invention]
However, since the globe 80 protrudes from the housing 70 of the flame detector FD10, dirt such as dust in the tunnel is easily attached by the air current, and the result of measuring the degree of contamination of the light receiving glass 20 includes Since the dirt of the globe 80 is added to the dirt, the result of the degree of contamination measurement is larger than the actual degree of contamination, and there is a problem that the cleaning cycle of the flame detector FD10 is shortened.
[0007]
Further, the flame detector FD10 is generally installed on a wall surface at a height of 2.5 m from the road surface, and dirt is deposited on the upper side of the center of the light receiving glass 20, so that dust or the like easily accumulates. Since it is arranged on the upper side of the light receiving glass 20, when the dirt of the light receiving glass 20 is measured by the dirt detecting light emitting element 81, dirt accumulated on the upper side of the center of the light receiving glass 20 is also detected.
[0008]
When detecting a fire, it detects a fire in the lower part from the center of the light-receiving glass 20 up to a height of 2.5 m from the road surface, and the actual fire also reaches a height of 2.5 m from the road surface. Therefore, the contamination below the center of the light receiving glass 20 is important.
[0009]
However, in the conventional example, the degree of contamination is measured between the lower side of the globe 80 disposed above the center of the light receiving glass 20 and the upper side of the light receiving glass 20. Therefore, the measured degree of contamination is not the degree of contamination on the lower side of the light receiving glass 20 that is useful for actual fire detection, but is larger than the degree of contamination on the lower side of the light receiving glass 20, and thus the flame detector. There exists a problem that the cleaning period of FD10 becomes short.
[0010]
Further, the cylindrical globe 80 has a problem that it is difficult to clean in shape as compared with the substantially hemispherical light receiving glass 20.
[0011]
It is an object of the present invention to provide a flame detector that can accurately measure the degree of fouling of the light-receiving glass of the flame detector and that can prevent the cleaning cycle of the flame detector from being shortened. To do.
[0012]
Another object of the present invention is to measure the degree of contamination on the lower side of the light receiving glass that is useful for actual fire detection.
[0013]
[Means for Solving the Problems]
The present invention includes a housing having a flat portion, a light receiving glass protruding from the flat portion and fixed to the housing, a light receiving portion provided inside the light receiving glass, and protruding from the flat portion. And a transparent member for forming a test window, provided in the flat portion, and a dirt detecting light-emitting element that is provided in the casing and transmits light to the light receiving portion through the transparent member and the light receiving glass. A flame detector in which, when the flame detector is installed on a predetermined wall surface, the dirt detection light emitting element is installed below the center of the light receiving glass. .
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a front view showing a flame detector FD1 according to a first embodiment of the present invention, and is a view of a state in which the flame detector FD1 is installed on a wall surface as viewed from the front.
[0015]
FIG. 2 is a schematic cross-sectional view of FIG.
[0016]
The flame detector FD1 includes a housing 10 having a flat surface portion 11, a light receiving glass 20 protruding from the flat surface portion 11 and fixed to the housing 10, and a light receiving portion 30 provided inside the light receiving glass 20. The transparent glass 40 that is provided on the flat surface portion 11 without projecting from the flat surface portion 11 and that forms the test window 41 and the housing 10, and passes through the transparent glass 40 and the light receiving glass 20 to the light receiving portion 30. And a dirt detecting light emitting element 50 for sending light. Here, the dirt detection light emitting element 50 is installed in the housing 10 near the transparent glass 40 with the direction thereof facing the light receiving unit 30.
[0017]
Further, when the flame detector FD1 is installed on a wall or the like, as shown in FIG. 1, the transparent glass 40 is installed below the center of the light receiving glass 20, and the dirt detecting light emitting element 50 is also provided. Similarly, it is installed below the center of the light receiving glass 20.
[0018]
Next, the operation of the first embodiment will be described.
[0019]
The flame detector FD1 measures the contamination of the light-receiving glass 20 once a day according to a command from a receiver (not shown), and if the measured contamination value exceeds a specified contamination value, a contamination alarm is given to the receiver. Send and notify that the specified monitoring range cannot be maintained. Cleaning is necessary at this time.
[0020]
By the way, in the first embodiment, since the test window 41 of the dirt detection light emitting element 50 is arranged on the same plane as the flat portion 11 of the housing 10, there is no air flow and dust is further collected. It does not get piled up, has a structure that is not easily contaminated with dust and the like in the tunnel, is easy to clean, and can lengthen the cycle for cleaning the flame detector FD1.
[0021]
Further, conventionally, when measuring the contamination of the light receiving glass 20, the contamination of the globe 80 contaminated by the air flow is added, so that the specified contamination value was reached quickly. Furthermore, since the measurement position is on the upper side of the light receiving glass 20, the specified fouling value was quickly reached due to the dirt accumulated on the light receiving glass 20. Furthermore, the installation height of the flame detector FD1 is 2.5 m above the road surface, and in the event of an actual fire, the fire actually fires from the bottom of the light receiving glass 20 to the vicinity of the center. Since the fire is monitored up to a height of 2.5m from the road surface where the rash occurs, the lower dirt is more important.
[0022]
Therefore, in the first embodiment, the test window 41 corresponding to the conventional globe 80 is flattened so as not to come out of the housing 10, and the entrance surface 42 of the test window 41 is cut obliquely. Yes. During the test, the test light is scattered inside the light receiving glass 20 (polished glass), and the light receiving unit 30 detects the light.
[0023]
In addition, since the dirt detection light emitting element 50 and the test window 41 are arranged below the center of the light receiving glass 20, the light receiving glass 20 is not affected by the dirt accumulated from above, and therefore, an actual fire is caused. Since only the degree of fouling on the lower side of the light receiving glass 20 useful for detection can be measured, the cleaning cycle of the flame detector FD1 can be made longer without affecting the detection of fire.
[0024]
Further, in the first embodiment, the incident surface 42 of the test window 41 is cut obliquely so that the optical axis of the light emitted from the dirt detecting light emitting element 50 and the incident surface 42 of the test window 41 are substantially the same. The test window 41 is formed so as to intersect perpendicularly, the amount of the test light reflected on the incident surface 42 of the test window 41 can be reduced, and the light receiving unit 30 (the dirt detecting light receiving element 83 in the light receiving glass 20). As a result, the degree of contamination of the light-receiving glass 20 can be accurately measured, and it is not necessary to increase the emission intensity of the dirt detecting light emitting element 50 more than necessary. Lower current consumption is possible.
[0025]
Moreover, if the dirt detection light receiving element 83 is also used as the fire detection element as the light receiving unit 30 as described above, a limited space in the light receiving glass 20 can be effectively used. The dirt detection light receiving element may be provided separately from the fire detection element.
[0026]
Next, a second embodiment of the present invention will be described.
[0027]
The second embodiment includes the flame detector FD1 shown in the first embodiment, in which the dirt detection light emitting element 50 and the test window 41 protrude from the flat portion 11 of the housing 10. It is. That is, the second embodiment is an embodiment in which the dirt detection light emitting element 50 and the test window 41 are disposed below the center of the light receiving glass 20.
[0028]
That is, the second embodiment includes a housing having a flat portion, a light receiving glass protruding from the flat portion and fixed to the housing, a light receiving portion provided inside the light receiving glass, A test window provided in the housing; and a dirt detection light emitting element that transmits light to the light receiving section through the test window and the light receiving glass, the dirt detection light emitting element, and the test window. Is a flame detector disposed below the center of the light receiving glass.
[0029]
In the second embodiment, the test window 41 may be provided on the flat portion 11 without protruding from the flat portion 11 as in the first embodiment, even if the test window 41 protrudes from the flat portion 11. It is possible to measure the degree of contamination on the lower side of the light receiving glass 20 that is useful for actual fire detection.
[0030]
In addition, when the test window 41 is a globe formed so as to protrude from the housing 10, the globe can be viewed from above if the globe is arranged so as to be hidden behind the light receiving glass 20 in a ceiling view. As a result, the degree of contamination on the lower side of the light receiving glass 20 can be confirmed accurately, and the cleaning cycle of the flame detector FD1 can be lengthened.
[0031]
If the globe is hidden behind the light receiving glass 20, it may be directly below or at the end of the light receiving glass, and the light receiving portion in the light receiving glass is provided at a position corresponding to the dirt detecting light emitting element in the globe. At this time, as the light receiving portion, the dirt detecting light receiving element and the fire detecting element may be used together, or may be provided separately.
[0032]
Further, the glove is also soiled by dust and the like that accumulates obliquely from above due to the airflow in the tunnel. However, since the wide light-receiving glass 20 is present on the upper side of the glove, the glove is not easily soiled.
[0033]
Further, when the position of the globe is not easily hidden by the light receiving glass 20, a configuration may be adopted in which the wiper, watering cleaning, or the like is added to remove the dirt on the globe.
[0034]
Instead of the transparent glass 40, a transparent member other than glass may be provided.
[0035]
【The invention's effect】
According to the present invention, it is possible to accurately measure the degree of fouling of the light receiving glass of the flame detector, and further it is possible to prevent the cleaning cycle of the flame detector from being shortened. In addition, it is possible to measure the degree of fouling on the lower side of the light receiving glass, which is useful for actual fire detection.
[Brief description of the drawings]
FIG. 1 is a front view showing a flame detector FD1 according to a first embodiment of the present invention, and shows a state in which the flame detector FD1 is installed on a wall surface as viewed from the front.
FIG. 2 is a schematic cross-sectional view of FIG.
FIG. 3 is a schematic cross-sectional view showing a conventional flame detector FD10.
[Explanation of symbols]
FD1 ... Flame detector,
10: housing,
11 ... plane part,
20: Light-receiving glass,
30. Light receiving part,
40 ... Transparent glass,
41 ... test window,
42 ... entrance surface of test window,
50: Light-emitting element for detecting dirt.

Claims (2)

A housing having a flat surface;
A light-receiving glass that protrudes from the flat surface and is fixed to the housing;
A light receiving portion provided inside the light receiving glass;
A transparent member that does not protrude from the flat part and is provided on the flat part and forms a test window;
A dirt-detecting light-emitting element that is provided in the housing and transmits light to the light-receiving portion through the transparent member and the light-receiving glass;
In a flame detector having
The flame detector, wherein when the flame detector is installed on a predetermined wall surface, the dirt detecting light emitting element is installed below the center of the light receiving glass. A housing having a flat surface;
A light-receiving glass that protrudes from the flat surface and is fixed to the housing;
A light receiving portion provided inside the light receiving glass;
A transparent member that does not protrude from the flat part and is provided on the flat part and forms a test window;
A dirt-detecting light-emitting element that is provided in the housing and transmits light to the light-receiving portion through the transparent member and the light-receiving glass;
The flame detector is characterized in that the test window is formed so that the optical axis of the light emitted from the dirt detection light emitting element is substantially orthogonal to the incident surface of the test window. .

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