JP2002298242A - Flame detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flame detector allowing accurately measuring of the degree of stain of a light receiving glass of the flame detector and capable of preventing a cleaning cycle of the flame detector from being shortened. SOLUTION: This flame detector having an enclosure provided with a flat face part, a light receiving glass fixed to the enclosure protruding from the flat face part, a light receiving part provided inside the light receiving glass, a transparent member provided at the flat face part not protruding from the flat face part and forming a test window, and a light emitting element for detecting a stain provided in the enclosure and feeding a light to the light receiving part through the transparent member and the light receiving glass.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light-receiving element which receives light emitted by a light-emitting element for detecting a stain via a light-receiving glass. The present invention relates to a flame detector for detecting

[0002]

FIG. 3 is a schematic cross-sectional view showing a conventional flame detector FD10.

A conventional flame detector FD10 for tunnels
Is provided with a light receiving portion 30 in a light receiving glass 20 whose front surface is substantially elliptical or circular and whose cross section protrudes in a hemispherical shape, and this light receiving portion 30 monitors radiation light from a flame,
Identify the presence of a flame. The light receiving section 30 is a light receiving glass 2
0, the radiation light is monitored.
If the light is contaminated with dust or the like in the tunnel, the amount of the radiated light reaching the light receiving unit 30 may decrease, and the flame may not be detected normally.

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 the contamination becomes a predetermined level or more, the light receiving glass 20 of the flame detector FD10 is cleaned, Thereby, the flame detector FD1
The flame detection performance of 0 is maintained normally.

To detect the degree of contamination of the light receiving glass 20, a cylindrical globe 80 is provided outside the light receiving glass 20, and a light emitting element 81 for detecting dirt is provided in the cylindrical globe 80. Is provided with a dirt detection light-receiving element 83 which is also used as a fire detection element as the light-receiving section 30. Then, the dirt detection light emitting element 81 irradiates test light of a predetermined intensity from outside the light receiving glass 20, the light receiving element 83 in the light receiving glass 20 receives the test light, and determines the irradiation amount of the dirt detection light emitting element 81. Then, the degree of contamination of the light receiving glass 20 is calculated based on the amount of light received by the light receiving element 83.

[0006]

However, the glove 80
Is protruded from the housing 70 of the flame detector FD10, so that dust such as dust in the tunnel easily adheres to the airflow. Since 80 stains are added, the pollution degree measurement result becomes larger than the actual pollution degree, and there is a problem that the cleaning cycle of the flame detector FD10 is shortened.

[0007] The flame detector FD10 is generally installed on a wall having a height of 2.5 m from the road surface.
Above the center of the glass, dirt accumulates, dust and the like easily accumulate, and the globe 80 is further
, The light emitting element 81 for dirt detection
When the contamination of the light receiving glass 20 is measured by the
Is also detected above the center.

In the case of detecting a fire, a fire in a range below the center of the light receiving glass 20 up to a height of 2.5 m from the road surface is detected. Is almost generated in the range up to the height of the light receiving glass 20, so that the contamination on the lower side of the center of the light receiving glass 20 is important.

However, in the conventional example, the light receiving glass 20
Is measured between a lower side of the globe 80 disposed above the center of the light receiving glass 20 and an upper side of the light receiving glass 20. Therefore, the measured degree of pollution is not the degree of contamination below the light receiving glass 20 that is useful for actual fire detection, but is a value greater than the degree of contamination below the light receiving glass 20. There is a problem that the cleaning cycle of the FD 10 is shortened.

Further, there is a problem that the cylindrical globe 80 is difficult to clean in shape compared with the substantially hemispherical light receiving glass 20.

An object of the present invention is to provide a flame detector capable of accurately measuring the degree of contamination of the light receiving glass of the flame detector and preventing the cleaning cycle of the flame detector from being shortened. It is intended for.

Another object of the present invention is to measure the degree of contamination below the light receiving glass, which is useful for actual fire detection.

[0013]

According to the present invention, there is provided a housing having a flat portion, a light-receiving glass projecting from the flat portion and fixed to the housing, and provided inside the light-receiving glass. The light receiving portion, without protruding from the flat portion, provided on the flat portion, a transparent member forming a test window, and provided in the housing, through the transparent member and the light receiving glass, to the light receiving portion It is a flame detector having a dirt detecting light emitting element for transmitting light.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a front view showing a flame detector FD1 according to a first embodiment of the present invention.
It is the figure which looked at the state where the flame detector FD1 was installed in the wall surface from the front.

FIG. 2 is a schematic cross-sectional view of FIG.

The flame detector FD1 includes a housing 10 having a flat portion 11, a light-receiving glass 20 protruding from the flat portion 11, and fixed to the housing 10, and a light-receiving glass provided inside the light-receiving glass 20. A transparent glass 40 that is provided on the flat portion 11 without protruding from the flat portion 11 and forms the test window 41;
And a dirt detection light emitting element 50 for transmitting light to the light receiving section 30 through the light receiving glass 20. Here, the dirt detection light emitting element 50 is installed in the housing 10 near the transparent glass 40 with its direction facing the light receiving unit 30.

When the flame detector FD1 is installed on a wall or the like, a transparent glass 40 is installed below the center of the light receiving glass 20, as shown in FIG. The element 50 is also provided below the center of the light receiving glass 20.

Next, the operation of the first embodiment will be described.

The flame detector FD1 measures the contamination of the light receiving glass 20 once a day in accordance with a command from a receiver (not shown). Send a pollution warning to notify that the specified monitoring range cannot be maintained. At this time, cleaning is required.

In the first embodiment, since the test window 41 of the light emitting element 50 for dirt detection is arranged on the same plane as the flat portion 11 of the housing 10, the air flow does not hit the test window 41. Furthermore, the structure is such that dust does not accumulate and is hardly contaminated with dust and the like in the tunnel, and is easy to clean, and the cleaning cycle of the flame detector FD1 can be lengthened.

Further, conventionally, when measuring the contamination of the light receiving glass 20, the contamination of the glove 80, which is contaminated by the airflow, is added, so that the prescribed contamination value is reached quickly. Furthermore, since the measurement position is above the light-receiving glass 20, the prescribed contamination value was quickly reached by the dirt that accumulated on the light-receiving glass 20. Further, the flame detector FD
The installation height of 1 is 2.5 m above the road surface, and when a fire actually occurs, from the road surface where a fire actually occurs from below the light receiving glass 20 to near the center.
The lower dirt is more important, as it monitors fires up to a height of 5 m.

For this reason, in the first embodiment, the test window 41, which is a portion corresponding to the conventional glove 80, is flattened so as not to come out of the housing 10, and the entrance surface 4 of the test window 41 is formed.
2 is cut diagonally. At the time of the test,
The test light is scattered inside 0 (ground glass), and the light is detected by the light receiving unit 30.

The dirt detecting light emitting element 50 and the test window 4
1 is disposed below the center of the light receiving glass 20, so that the influence of dirt that accumulates from above is not affected by the light receiving glass 2
0 is not received, and therefore, only the degree of contamination on the lower side of the light receiving glass 20 useful for actual fire detection can be measured, so that the cleaning cycle of the flame detector FD1 can be made longer without affecting fire detection. .

Further, in the first embodiment, the test window 4
1 is cut obliquely, and the test window 41 is formed 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 intersect substantially perpendicularly. As a result, the amount of test light reflected on the entrance surface 42 of the test window 41 can be reduced, and the amount of light guided to the light receiving unit 30 (the dirt detection light receiving element 83) in the light receiving glass 20 can be increased. As a result, the degree of contamination of the light receiving glass 20 is accurately measured, and the contamination detecting light emitting element 50
It is not necessary to increase the emission intensity of the
Low current consumption can be achieved.

Further, as described above, if the dirt detecting light receiving element 83 is also used as a fire detecting element as the light receiving section 30, a limited space within the light receiving glass 20 can be effectively utilized. The light receiving element for detecting dirt may be provided separately from the fire detecting element.

Next, a second embodiment of the present invention will be described.

In the second embodiment, in the flame detector FD1 shown in the first embodiment, the dirt detecting light emitting element 50 and the test window 41 protrude from the flat portion 11 of the housing 10. This is an embodiment including: That is, in the second embodiment, the dirt detection light emitting element 50 and the test window 41 are
This is an embodiment in which it is arranged below the center of 0.

That is, in the second embodiment, a housing provided with a flat portion, a light-receiving glass projecting from the flat portion and fixed to the housing, and a light-receiving glass provided inside the light-receiving glass are provided. Unit, a test window provided in the housing, through the test window and the light receiving glass, having a dirt detection light emitting element that sends light to the light receiving unit, the dirt detection light emitting element, The test window is a flame detector disposed below the center of the light receiving glass.

In the second embodiment, even if the test window 41 protrudes from the flat portion 11, it does not protrude from the flat portion 11 as in the first embodiment, but is provided on the flat portion 11. Alternatively, it is possible to measure the degree of contamination on the lower side of the light receiving glass 20, which is useful for actual fire detection.

When the test window 41 is a glove formed so as to protrude from the housing 10, this glove is
By arranging the glove so as to be hidden behind the light receiving glass 20 when viewed from the ceiling, the glove is hardly contaminated with dust or the like that accumulates from above. As a result, the degree of contamination on the lower side of the light receiving glass 20 can be accurately confirmed. The cleaning cycle of the flame detector FD1 can be lengthened.

If the globe is hidden behind the light-receiving glass 20, it may be directly below or at the edge of the light-receiving glass, and the light-receiving portion in the light-receiving glass may be provided at a position corresponding to the dirt detecting light emitting element in the glove. I do. At this time, the light receiving unit may serve both as the light detecting element for detecting dirt and the fire detecting element, or may be provided separately.

Also, by the flow of the air current in the tunnel,
The glove is stained by dust or the like that accumulates diagonally from above, but since the wide light receiving glass 20 exists above the glove, the glove is not easily stained.

Further, when the position of the glove is hard to be hidden by the light receiving glass 20, a configuration may be adopted in which a dirt on the glove can be removed by adding a separate wiper, watering and washing.

In place of the transparent glass 40, a transparent member other than glass may be provided.

[0035]

According to the present invention, the degree of contamination of the light receiving glass of the flame detector can be accurately measured, and further, the cleaning cycle of the flame detector can be prevented from being shortened. Play. Further, there is an effect that the degree of contamination on the lower side of the light receiving glass, which is useful for actual fire detection, can be measured.

[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 is a view of a state in which the flame detector FD1 is installed on a wall, 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: flat part, 20: light receiving glass, 30: light receiving part, 40: transparent glass, 41: test window, 42: entrance surface of the test window, 50: light emission for detecting dirt element.

 ────────────────────────────────────────────────── ─── Continued on the front page F term (reference) 2G051 AA90 AB01 AB20 CB05 EA11 2G065 AB24 AB26 BA02 BC14 BD06 CA29 DA05 DA06 DA15 5C085 AA11 AB01 BA31 CA14 FA16 FA35

Claims (4)

[Claims] 1. A housing having a flat portion; a light-receiving glass projecting from the flat portion and fixed to the housing; a light-receiving portion provided inside the light-receiving glass; A transparent member provided on the flat portion and forming a test window without projecting; a dirt detecting light emitting element provided in the housing and transmitting light to the light receiving portion through the transparent member and the light receiving glass. And a flame detector. 2. The method according to claim 1, wherein when the flame detector is installed on a predetermined wall surface, the dirt detecting light emitting element is installed below a center of the light receiving glass. Features a flame detector. 3. The test window according to claim 1, wherein the test window is formed such that an optical axis of light emitted from the dirt detecting light emitting element and an incident surface of the test window are substantially orthogonal to each other. Features a flame detector. A housing provided with a flat portion; a light-receiving glass projecting from the flat portion and fixed to the housing; a light-receiving portion provided inside the light-receiving glass; A test window provided; and a dirt detection light-emitting element that transmits light to the light receiving unit through the test window and the light-receiving glass; and the dirt detection light-emitting element and the test window, A flame detector, wherein the flame detector is arranged below a center of the light receiving glass.