JP2001283345A - Flame detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately detect the dirt/damage of a flame sensor. SOLUTION: A light emitting element is arranged in a glove projected from a body and the glove is a cylindrical body forming a smooth curved surface for an air current on the light receiving glass side. Through the smooth curved surface of the light receiving glass, the light emitted from a test light emitting element in dirt/damage detection operation is used to accurately detect the degree of dirt of the light receiving glass on the basis of the light receiving quantity of a light receiving element.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flame detector.

[0002]

2. Description of the Related Art Conventionally, a tunnel or the like is provided with a flame detector for detecting radiation emitted from a flame as ultraviolet rays or infrared rays in order to detect a fire. This flame detector has a structure in which a light receiving element is arranged on a light receiving glass projecting substantially hemispherically from the surface of the main body, and one flame detector can monitor in a direction of about 180 °. When the flame detector is installed in a road tunnel, in particular, the light-receiving glass for protecting the light-receiving element is contaminated by the adhesion of dust and the like contained in the airflow, and the light transmittance of the light-receiving glass is reduced. Therefore, in order to detect the degree of dirt, a test light emitting element for irradiating test light toward the light receiving glass is arranged, and the degree of dirt is checked by periodically receiving the test light with the light receiving element. .

[0003]

The test light-emitting element of such a flame detector is arranged to face the light-receiving element and is arranged in a covered cylindrical glove. Therefore, the light receiving element that detects the test light simultaneously detects the dimming due to the dirt on the light receiving glass and the dimming due to the dirt on the glove containing the test light emitting element.
This means that even if the light receiving glass is not dirty, only the glove is dirty, so that the flame detector is determined to be dirty although the flame can be normally detected.

In addition, when the degree of contamination is detected by the light receiving element and the test light emitting element which are opposed to each other with the light receiving glass interposed therebetween, the range of the light receiving glass which affects the intensity of the test light is narrow, and the test light emitting element is used. There is only a small range around the optical axis from to the light receiving element. Originally, the light-receiving glass is not uniformly contaminated, so that any position can be monitored, resulting in bias.However, if this range is narrow, flames can be detected normally if the degree of contamination in that range does not match the surroundings. Nevertheless, it may happen that the flame detector is determined to be fouled, or it is determined that the flame can be detected normally even though the flame detector is totally fouled.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to properly detect the contamination of a flame detector.

[0006]

According to a first aspect of the present invention, there is provided a flame detecting apparatus comprising a light receiving element for detecting a flame and a test light emitting element for irradiating test light from outside the light receiving glass in a convex light receiving glass. In the container, the light emitting element is disposed in a globe projecting from the main body, and the globe is a cylindrical body having a gentle curved surface formed on the light receiving glass side with respect to an air flow. is there. At this time, the light emitting element may be located at a position protruding from the surface of the main body, and a test light receiving element for receiving test light of the test light emitting element may be provided in the light receiving glass.

In a second aspect of the present invention, there is provided a light receiving element for flame detection in a convex light receiving glass, a test light emitting element for irradiating test light from outside the light receiving glass, and a test light receiving element in the light receiving glass. Wherein the light emitting element emits test light with the optical axis deviated from the test light receiving element. At this time, the flame detecting light receiving element may double as the test light receiving element.

In each of the above-mentioned inventions, the light receiving glass projects in a substantially elliptical front view with a slow rising angle, and is substantially perpendicular to the longitudinal direction of the light rising glass with a slow rising angle. The test light emitting element is arranged in the direction, and when the flame detector is installed on the wall, the longitudinal direction of the light receiving glass is the direction in which the air flow is coming in the horizontal direction, and the glove containing the test light emitting element is The gentle curved surface is arranged.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described. 1 and 2 are a front view and a longitudinal sectional view showing a flame detector D1 of the first embodiment. In the drawing, reference numeral 1 denotes a cylindrical case having a bottom and an open top, 2 denotes a cover having an opening at the center and covers the case 1 to form a main body, and 4 denotes frosted glass disposed at the opening of the cover 2. A light receiving glass 7 having a substantially bowl shape (or semi-rugby ball shape) is a fixing plate for airtightly fixing a flange portion of the light receiving glass 4 by sandwiching a packing (not shown). Also, cover 2
Is fixed to the case 1 from the front by screwing (not shown in detail), and a plurality of ears (not shown) of the case 1 are formed on an installation surface such as a tunnel wall surface and fixed by screwing there. By doing so, the cover 2 can be removed from the front at the site, and internal maintenance can be performed.

Reference numeral 10 denotes a light receiving portion mounting base projecting in a triangular cross section. Cylindrical light receiving element cases 11 are provided on both slopes. An optical filter 12 is mounted at the tip of the light receiving element case 11, and although not shown, two light receiving elements, for example, a pyroelectric element and a photodiode are arranged in combination as a flame detecting light receiving element. In this case, the flame is determined from the outputs of the two types of elements. For example, the flame is determined by calculating the magnitude and ratio of the two outputs. Further, by combining the two light receiving element cases 11 and disposing the light receiving element cases 11 in the convex light receiving glass 4, the monitoring range can be made substantially 180 ° around the flame detector D1. Reference numeral 15 denotes a printed circuit board, and the light receiving unit mounting base 10 is fixed on the printed circuit board 15, and the printed circuit board 15 is fixed to the cover 2 via the support 3 by screws. As for the power supply lines and signal lines from the printed circuit board 15, lead wires (not shown) are drawn out of the printed circuit board 15 to the outside of the case 1 and are air-tightly connected by an insulating sleeve or the like.
The outlet (not shown) is also kept airtight by putting putty or the like.

Reference numeral 18 denotes a light-emitting element for detecting contamination, such as a light-emitting diode as a test light-emitting element. The light-emitting element 18 stands on the printed circuit board 15 via a support 51 and protrudes from the cover 2. It is located in the glove 32. FIG. 3 is a partial cross-sectional view showing the structure of the light-emitting element 18. The light emitting element 18 is mounted on the upper surface of the support table 51, and a locking piece (not shown) is formed below the support table 51, and is erected by engaging with a locking hole (not shown) formed in the printed circuit board 15. ing. In addition, the printed circuit board 15 includes
A light-receiving element 19 for detecting contamination as a test light-receiving element protruding into the light-receiving glass 4 is provided. Glove 32
Is formed in a substantially cylindrical shape, and the light receiving glass 4
A light projecting portion 32a having a gentle curved surface is formed on the side,
It is a transparent or translucent resin or glass having a flange 32b at its lower end. The flange 3 of the glove 32 is inserted into the screw hole opened in the cover 2 through the packing 33a.
The fixing screw 34 is screwed in so as to hold the packing 2b with the packing 33b interposed therebetween, and is fixed to the cover 2 in an airtight manner.
Further, around the globe 32, a protection portion 2 a is raised from the cover 2 so as to cover the globe 32.

By the way, when such a flame detector D1 is installed in a tunnel, for example, it is a poor environment in which exhaust gas, dust, and the like from a traveling vehicle are always present, and therefore, the flame detector D1 is contaminated. . If the contamination is severe, a light receiving element (not shown) in the light receiving element case 11 cannot perform accurate detection output. In order to detect the degree of contamination of the light receiving glass 4 at this time, light is emitted from the light emitting element 18 to the light receiving element 19 with the light receiving glass 4 interposed therebetween, and the degree of contamination can be detected from the amount of received light. It is possible to perform output correction and pollution alarm.

In such a tunnel, the flame detector D1
In many cases, there is always an airflow from one side to the other, and at least one of them tends to be in the longitudinal direction of the tunnel, and the airflow contains exhaust gas and dust. ing. Therefore, the light receiving glass 4
Is formed into a cylindrical shape or a hemispherical shape, the air current collides with the side surface, and the air flow is retained on the opposite side, so that the air flow is easily contaminated. Therefore, the shape of the light-receiving glass 4 makes the angle of the contact surface with respect to the airflow, that is, the rising angle from the cover 2 gradual, thereby flowing the airflow and preventing the light-receiving glass 4 from being stained. Further, the globe 32 is placed on the light receiving glass 4.
Are arranged at a distance in a direction perpendicular to the airflow direction so that the turbulence of the airflow in the globe 32 does not affect the light receiving glass 4.

Further, in the shape of the globe 32, a light projecting portion 32a through which light emitted from the light emitting element 18 on the light receiving glass 4 side is transmitted at a substantially cylindrical outer periphery is formed to have a gentle curved surface against an air flow. This prevents contamination of the light emitting part 32a. The contamination of the light projecting portion 32a of the globe 32 causes the light emission of the light emitting element 18 to pass through the light projecting portion 32a of the globe 32 until reaching the light receiving element 19 in the above-described contamination detecting operation of the light receiving glass 4. The receiving glass 4
Therefore, if the light projecting portion 32a is dirty, the degree of contamination of the light receiving glass 4 cannot be accurately detected.

From this, it is only necessary to prevent the light projecting portion 32a from being stained if the front portion through which the light emitted from the light emitting element 18 is transmitted is not stained.
It doesn't matter much about the back of the camera. However, in this embodiment, by making the whole substantially cylindrical, it is possible to prevent dirt from accumulating as much as possible due to some roundness, and at the same time, it is difficult for airflow turbulence to occur. this is,
It can not affect the light receiving glass 4,
The smooth flow of the air flow on the light emitting portion 32a side does not cause disturbance of the air flow on the light receiving glass 4 side.

Here, the position of the globe 32 is arranged in a direction substantially perpendicular to the longitudinal direction of the light-receiving glass 4, but it is sufficient that the position is shifted in the perpendicular direction. It may be inclined at 60 ° or the like. Then, the gentle curved surface of the light projecting portion 32a may be formed with respect to the airflow, and the light emitting element 18 may be directed so as to pass through a clean position.

Therefore, according to the first embodiment, since the globe 32 has the light projecting portion 32a on the light receiving glass 4 side formed with a gentle curved surface against the airflow, the light projecting portion 32a is not stained. Light emitting element 1 in the contamination detection operation
It is possible to irradiate the light-receiving glass 4 with the light emitted from the light-receiving element 8 without attenuation, and it is possible to accurately detect the degree of contamination of the light-receiving glass 4 based on the amount of light received by the light receiving element 19. At the same time, since the light projecting portion 32a has a gentle curved surface with respect to the air flow, the air flow near the globe 32 is not disturbed on the light receiving glass 4 side, and the air flow toward the light receiving glass 4 is not affected. Can flow smoothly without hitting the light receiving glass 4.

Next, a second embodiment of the present invention will be described. 4 and 5 are a front view and a longitudinal sectional view showing a flame detector D2 according to the second embodiment. The basic structure of the flame detector D2 is the same as that of the first embodiment, and the same members are denoted by the same reference numerals and description thereof will be omitted.
The different parts will be described below. In the figure, 48
Is a light-emitting element for detecting fouling similar to the light-emitting element 18, and is erected on the printed circuit board 15 via a support 41 similar to the support 51, and protrudes from the cover 2. Is located within. This light emitting element 48
The difference from the light-emitting element 18 is that the height from the surface of the cover 2 is slightly higher in the light-emitting element 48 than in the light-emitting element 18. Therefore, the height of the support 41 and the globe 42 is slightly different. The difference is that the globe 42 has a cylindrical shape. Further, a light receiving element 49 for detecting contamination similar to the light receiving element 19 is provided on the printed circuit board 15 so as to face the light receiving glass 4.

By the way, like the flame detector D1, the flame detector D2 projects light from the light-emitting element 48 to the light-receiving glass 4 to detect the degree of contamination of the light-receiving glass 4. The degree of contamination is detected from the amount of received light, and the detection output due to the contamination can be corrected and a contamination alarm can be performed. In the fouling detection operation of the flame detector D2, since the light emitting element 48 and the light receiving element 49 are arranged with their optical axes shifted, strong light from the light emitting element 48 does not directly enter the light receiving element 49. Therefore, as schematically shown in FIG. 6, the light flux L of the light emitting element 48 has a spread, so that the light receiving glass 4 is irradiated with a predetermined size. The light receiving element 49 is
The arrangement is such that the light flux L from the light emitting element 48 does not directly hit the light receiving glass 4 and the inner surface of the light receiving glass 4 is frosted glass, so that only the scattered light Ls from the light receiving glass 4 is received by the light receiving element 49.
Will be incident. Therefore, the amount of light received by the light receiving element 49 reflects the dirt on a predetermined area of the light receiving glass 4, and the more uniform detection of dirt than the detection of dirt at almost one point between the opposing elements. It can be performed. In particular, the light receiving glass 4 of this embodiment
Is not a hemispherical shape but a semi-rugby ball shape, so that the surface area is large, and it is preferable to detect fouling in as wide a range as possible. When only the light scattered by the light receiving glass 4 is incident on the light receiving element 49, the amount of received light is small. Therefore, the amount of received light may be increased by applying some direct light. The ratio between such direct light and scattered light may be variously selected.

Therefore, according to the second embodiment, by shifting the optical axis of the light emitting element 48 and the light receiving element 49, the light receiving element 49 can be uniformly stained with the light receiving glass 4 within a predetermined size range. , And it is possible to prevent the occurrence of contamination abnormality due to accidental dust or the like.

Next, a third embodiment of the present invention will be described. 7 and 8 are a front view and a longitudinal sectional view showing a flame detector D3 according to the third embodiment. The basic structure of the flame detector D3 is the same as the first embodiment or the second embodiment.
In this embodiment, the same members are denoted by the same reference numerals, and description thereof is omitted. In the figure, the stain detection operation mechanism performs the same operation as in the second embodiment using the light emitting element 48 and the light receiving element 49, and protects the light emitting element 48 using the globe 32 and changing its shape to the first. This is the same as in the embodiment.

Therefore, according to the third embodiment, similarly to the first embodiment, the globe 32 has the light projecting portion 32a on the light receiving glass 4 side formed with a gentle curved surface. 32a is capable of irradiating the light-receiving glass 4 with the light emitted from the light-emitting element 48 without attenuating in the contamination detection operation without being stained, and accurately detecting the degree of contamination of the light-receiving glass 4 by the amount of light received by the light-receiving element 49. At the same time, the light projecting portion 32a has a gentle curved surface, so that the air flow near the globe 32 is not disturbed on the light receiving glass 4 side, and the air flow toward the light receiving glass 4 is not affected. It can flow smoothly without hitting the light receiving glass 4. Further, similarly to the second embodiment, by shifting the optical axis of the light emitting element 48 and the light receiving element 49, the light receiving element 49 can detect dirt in the predetermined size range of the light receiving glass 4 on average. It is possible to prevent the occurrence of a stain abnormality due to accidental dust or the like.

Further, a fourth embodiment of the present invention will be described. 9 and 10 are a front view and a longitudinal sectional view showing a flame detector D4 according to the fourth embodiment. The basic structure of the flame detector D4 is the same as that of the first embodiment or the second embodiment, and the same members are denoted by the same reference numerals and description thereof will be omitted. In the figure, the stain detection operation mechanism is configured such that the light emitting element 48 is
In the figure, a light receiving element for fire detection (not shown) is used, and since the light receiving element (not shown) is disposed with the optical axis of the light emitting element 48 shifted, strong light does not directly enter from the light emitting element 48. . Therefore, similarly to the second and third embodiments, it is possible to reflect dirt on a predetermined area of the light receiving glass 4. The protection of the light emitting element 48 is as follows.
The globe 32 is used and the shape is the same as that of the first embodiment.

Therefore, according to the fourth embodiment, similarly to the third embodiment, in addition to the same operation and effect as those of the first and second embodiments, the light reception for detecting the contamination is performed. There is an effect that the element can be omitted.

As described above, the first aspect of the present invention provides a flame detector including a flame detecting light receiving element in a convex light receiving glass and a test light emitting element for irradiating test light from outside the light receiving glass. In, the light-emitting element is disposed in a globe protruding from the main body, the globe is a cylindrical body having a gentle curved surface against the air flow formed on the light-receiving glass side, the gentle curved surface without contamination In the stain detection operation, light emitted from the test light emitting element can be irradiated to the light receiving glass without attenuation, and the degree of contamination of the light receiving glass can be accurately detected based on the amount of light received by the light receiving element. At the same time, on the gentle curved surface, the airflow near the globe is not disturbed on the light receiving glass side, and the airflow can be smoothly flowed without affecting the light receiving glass without affecting the airflow toward the light receiving glass.

According to a second aspect of the present invention, there is provided a light receiving element for detecting a flame in a convex light receiving glass, a light emitting element for a test for irradiating test light from outside the light receiving glass, and a light receiving element for a test in the light receiving glass. In the flame detector provided with, the light emitting element is irradiated with the test light with the optical axis deviated from the test light receiving element. At this time, the test light receiving element averages the contamination of the light receiving glass within a predetermined size range. This can prevent the occurrence of contamination abnormality due to accidental dust or the like.

[Brief description of the drawings]

FIG. 1 is a front view showing a first embodiment of the present invention.

FIG. 2 is a sectional view of FIG.

FIG. 3 is a partial sectional view of FIG. 1 at a position different from that of FIG. 2;

FIG. 4 is a front view showing a second embodiment of the present invention.

FIG. 5 is a sectional view of FIG. 4;

FIG. 6 is a schematic diagram showing a light emitting state of the contamination detection operation of FIG. 4;

FIG. 7 is a front view showing a third embodiment of the present invention.

FIG. 8 is a sectional view of FIG. 7;

FIG. 9 is a front view showing a fourth embodiment of the present invention.

FIG. 10 is a sectional view of FIG. 9;

[Explanation of symbols]

 D1, D2, D3, D4 Flame detector 4 Light receiving glass 18, 48 Light emitting element 19, 49 Light receiving element 32 Globe

Claims (9)

[Claims] 1. A flame detector comprising a light receiving element for flame detection and a test light emitting element for irradiating test light from outside of the light receiving glass in a convex light receiving glass, wherein the light emitting element comprises a main body. A flame detector which is arranged in a glove projecting from the light-receiving glass side, wherein the glove is a cylindrical body having a gentle curved surface with respect to an airflow formed on the light receiving glass side. 2. The flame detector according to claim 1, wherein the light emitting element is located at a position protruding from the surface of the main body. 3. The flame detector according to claim 1, wherein a test light receiving element for receiving test light from the test light emitting element is provided in the light receiving glass. 4. A light receiving element for detecting a flame, a light emitting element for test for irradiating test light from outside of the light receiving glass, and a light receiving element for test in the light receiving glass. In the flame detector, the light emitting element emits a test light with an optical axis deviated from the test light receiving element. 5. The flame detector according to claim 4, wherein the flame detecting light receiving element also serves as a test light receiving element. 6. The flame detector according to claim 1, wherein the light receiving glass protrudes in a substantially elliptical shape in front with a rising angle being slow. 7. The flame detector according to claim 1, wherein the test light emitting element is arranged in a direction substantially perpendicular to a longitudinal direction of the light receiving glass whose rising angle is slow. 8. The flame detector according to claim 1, wherein when the flame detector is installed on a wall surface, a gentle curved surface of a glove containing the test light emitting element faces downward. 9. The flame detector according to claim 1, wherein the longitudinal direction of the light receiving glass is horizontal when the flame detector is installed on a wall surface.