JP2002049977A - Optical fire detection and annunciating system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical fire detection and annunciating system which is simple in constitution and high in reliability and dispenses with the power source of a detector. SOLUTION: Since a detection signal from detection parts 8a to 8d' is propagated to a light receiving circuit 5 through an optical fiber cable 4, the power source is unnecessitated. Since plural signal wires are not used but only one cable 4 is required through many detection parts are connected to the cable 4, constitution is simplified. Furthermore, since the cable 4 is used for connecting a light emitting circuit 2 and the circuit 5 influence from electromagnetic noise is not received and reliability is imporved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an optical fire detection and notification system.

[0002]

2. Description of the Related Art A conventional fire detection / notification system electrically detects fire heat, smoke, and the like of a building such as a building or a tunnel, and transmits and opens a signal to and from an electrical contact. This is done by:

[0003] When detecting fires at multiple points, signal lines are laid to the detectors, and two-core signal lines are used to address each detector. Further, since the voltage drop occurs when the signal line becomes longer, a repeater is used.

[0004]

However, the above-mentioned prior art has the following problems.

[0005] It is necessary to lay wires to sensors installed in fire alarm areas.

[0006] Coal mines and the like need to have an explosion-proof structure because they have electrical contacts.

[0007] It is necessary to arrange a detector for each fire alarm area and connect each detector by wiring. If the detector is long such as a tunnel, the fire alarm area is divided to identify a fire occurrence point. A core wire is required.

[0008] Even when a plurality of sensors connected by the sending wiring operate, it is unknown which sensor operates.

Since an electric signal is used, it is affected by electromagnetic noise.

[0010] Because of the electric system, there is a risk of electric shock, deterioration of the wire rod, dielectric breakdown, and the like.

Therefore, maintenance and inspection costs are required.

If one of the transmission lines fails (shorts), the sensing performance of the remaining sensing system is lost.

An object of the present invention is to provide an optical fire detection and notification system which solves the above-mentioned problems, has a simple structure, has high reliability, and does not require a power supply for a detector.

[0014]

In order to achieve the above object, an optical fire detection / notification system according to the present invention is connected between a light emitting circuit and a light receiving circuit and forms an outward route and a return route in a fire alarm area. Normally, a plurality of detectors are connected discretely to each other so that the propagating light propagates between the forward path and the return path, and in the event of a fire, light loss occurs in the propagating light due to smoke or heat. The light receiving circuit detects the dimming of the propagation light in the optical fiber due to the optical loss.

In addition to the above configuration, the optical fiber of the optical fire detection / informing system of the present invention is disposed so as to be folded at a predetermined point and be parallel to each other. May be connected respectively.

In addition to the above configuration, in the optical fire detection / informing system of the present invention, one end of the optical fiber is connected to the light emitting circuit and the light receiving circuit via the branching filter, and the other end returns the propagating light to the optical fiber. One end of each detection unit may be connected to an optical fiber via an optical coupler, and the other end may be connected to a reflector that returns propagating light to each detection unit.

In addition to the above configuration, the detection unit of the optical fire detection and notification system according to the present invention has a detection unit side optical fiber that is disposed to face the space so that the propagating light propagates in the space. When the light enters the inside, the propagation light may be scattered to cause light loss.

In addition to the above configuration, the detection unit of the optical fire detection and notification system according to the present invention includes a sensing optical fiber through which propagating light propagates, and an external force that generates an optical loss by applying an external force to the sensing optical fiber by heat. It may have additional means.

In addition to the above configuration, the detection unit of the optical fire detection and notification system according to the present invention includes: a detection unit side optical fiber disposed so as to oppose the propagating light to propagate in the space; Light blocking means for generating light loss by blocking the propagation light.

In addition to the above configuration, in the optical fire detection and notification system of the present invention, a plurality of notification units for adding light loss by a manual button for notifying a fire are discretely connected to the optical fiber. Is preferred.

In addition to the above configuration, the optical fire detection and notification system of the present invention may be a combination of at least two of the above systems.

According to the present invention, since the detection signal from the detection section is transmitted to the light receiving circuit by the optical fiber, no power supply is required. Even if a large number of detection units are connected to the optical fiber, the configuration is simplified because only one optical fiber is required without using a plurality of signal lines. Further, since the optical fiber is used for the connection between the light emitting circuit and the light receiving circuit, the optical fiber is not affected by the electromagnetic noise, and the reliability is improved.

[0023]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a block diagram showing an embodiment of a fire detection / notification apparatus to which the optical fire detection / notification system of the present invention is applied.

The fire detecting / notifying device 1 shown in FIG. 1 is arranged in a fire alarm area with one end connected to the light emitting circuit 2 and a light emitting circuit 2 and is turned back at a predetermined point (end part) 3. Optical fiber cable 4 arranged in parallel
A light receiving circuit 5 connected to the other end of the optical fiber cable 4, a plurality of detectors 8 connected by optical couplers 6a to 6d and 7a to 7d between the outward path and the return path of the optical fiber cable 4, It comprises a plurality of notification units 11 connected by optical couplers 9a to 9d and 10a to 10d between the outward path and the return path of the fiber cable 4.

Although the number of the detectors 8 and 11 is five in the figure, the number is not limited. Also, 8d, 8d ', 11
Not only one but also a plurality of couplers may be provided between the couplers as in d and 11d '.

The detecting section 8 has a pair of optical fibers (not shown) on the detecting section side facing each other so that the propagating light propagates in the space, and smoke at the time of fire enters the space. Then, it is a kind of light transmission type sensor (smoke detector) in which propagation light is scattered and light loss occurs.

The notifying unit 11 includes, for example, a sensing optical fiber and a manual button (both not shown) arranged outside the sensing optical fiber and applying a predetermined pressure to the sensing optical fiber. By pressing a manual button to notify the occurrence of a fire, light loss is added to the sensing optical fiber.

Next, the operation of the fire detection / notification device will be described.

(1) Light emitting circuit 2 to optical fiber cable 4
The optical pulse incident on the outward path (upper side in the figure) is branched by each of the optical couplers 6a to 6d, and each of the detectors 8a to 8d '.
Through the optical couplers 7a to 7d, and the light receiving circuit 5 via the return path (the lower side in the figure) of the optical fiber cable 4.
The optical pulses received by the optical couplers 9a to 9d pass through the notification units 11a to 11d ', and pass through the optical couplers 1a to 11d'.
The light is multiplexed at 0a to 10d and received by the light receiving circuit 5 via the return path of the optical fiber cable 4.

(2) From the light emitting circuit 2 of the above (1) to the detector 8a
Although the optical path length to the light receiving circuit 5 via .about.8d 'differs depending on each of the detection units 8a to 8d', the light pulse received by the light receiving circuit 5 is time-series because the light speed is constant.
Therefore, when the transmission loss of the specific detection units 8a to 8d 'changes suddenly due to the smoke of the fire, the light intensity of the specific pulse in the pulse train decreases, and the occurrence of the fire can be notified with an address.

(3) The soundness of the forward path and the return path of the optical fiber cable 4 is confirmed by an optical pulse passing through the terminal section 3.

In the above, according to the present optical fire detection and notification system, the detection signals from the detection units 8a to 8d 'are transmitted to the light receiving circuit 5 via the optical fiber cable 4, so that no power supply is required and the detection unit Even if many 8a to 8d 'are connected, only one optical fiber cable 4 is required without using a plurality of signal lines, so that the configuration is simplified. Further, since the present system uses the optical fiber cable 4, the system is not affected by electromagnetic noise, and the reliability is improved.

Here, in the present embodiment, the principle of the smoke detector is used as the detector, but the optical fiber is deformed due to mechanical deformation due to heat of a fire such as a bimetal, a diaphragm, or the like, thereby causing light loss. (Transmission loss) may be added. In addition, the detection by heat and smoke is not only one of them, but by detecting both heat and smoke by connecting two detection units in series, one of the methods is quicker to react,
A fire may be detected.

FIG. 2 is a block diagram showing another embodiment of a fire detection / notification apparatus to which the optical fire detection / notification system of the present invention is applied. The same reference numerals are used for members similar to those of the embodiment shown in FIG.

The difference from the embodiment shown in FIG. 1 is that a reflector is provided in the optical fiber cable, the detection section and the notification section.

The fire detecting / notifying device 20 includes a light emitting circuit 2, a duplexer 21 connected to the light emitting circuit 2, and an optical fiber cable 22 having one end connected to the duplexer 21 and arranged in a fire alarm area. Is connected to the other end (termination portion) 23 of the optical fiber cable 22 and transmits the propagation light to the optical fiber cable 22.
, A plurality of optical couplers 6a to 6d discretely connected to the optical fiber cable 22, one end of each of the detectors 8a to 8d 'connected to the optical couplers 6a to 6d, and one end of each optical coupler. Notification units 11a to 11 connected to 9a to 9a
d ′ and a reflector 25 connected to the other end of the detection unit and returning the propagation light transmitted through the detection units 8a to 8d ′ to the detection units 8a to 8d ′
a to 25d and the propagation light connected to the other ends of the notification units 11a to 11d 'and propagated through the notification units 11a to 11d'.
It comprises reflectors 26 a to 26 d returning to 1 a to 11 d ′ and a light receiving circuit 5 connected to the duplexer 21.

When the fire detecting / notifying device 20 operates, the light pulse from the light emitting circuit 2 propagates through the optical fiber cable 22 through the branching filter 21, and the optical couplers 6a to 6a
d, 9a to 9d, and reach the detection units 8a to 8d 'and the notification units 11a to 11d'. Each detector 8a-8
Propagation light propagating through d 'and the notification units 11a to 11d' are reflected by the reflectors 25a to 25d and 26a to 26d, respectively, and are again detected by the detection units 8a to 8d 'and the notification units 11a to 11d.
The light passes through 11d ', is multiplexed by the optical couplers 6a to 6d, 9a to 9d, and is again received by the light receiving circuit 5 via the optical fiber cable 22 and the duplexer 21. That is, the optical path from the duplexer 21 to the reflector 24 through the terminal end 23 of the optical fiber cable 22 is the outward path, and the optical path from the reflector 24 to the duplexer 21 through the terminal end 23 of the optical fiber cable 22. The light path is the return path.

Each of the detection units 8a to 8d 'and each of the notification units 11a to
Although the optical path lengths of the light pulses passing through 11d 'are different, the light speed is constant, so that the light pulses received by the light receiving circuit 5 are time-series. Therefore, as described above, when the transmission loss of a specific detection unit (notification unit) suddenly changes due to smoke from a fire, the light intensity of a specific pulse in the pulse train decreases, and the occurrence of a fire is reported with an address. It is possible to do.

Therefore, such a fire detecting / notifying device 2
0, the same effect as in the embodiment shown in FIG. 1 can be obtained.

FIG. 3 is a block diagram showing another embodiment of a fire detection / notification apparatus to which the optical fire detection / notification system of the present invention is applied. The same reference numerals are used for members similar to those of the embodiment shown in FIG.

The difference from the embodiment shown in FIG. 1 is that the detector generates light loss due to heat of a fire.

The fire detecting / notifying device 30 includes a light emitting circuit 2, a parallel optical fiber cable 4 having one end connected to the light emitting circuit 2, disposed in a fire alarm area, and folded at a predetermined point; A light receiving circuit 5 connected to the other end of the optical fiber cable 4, a plurality of detectors 31a to 31d connected by optical couplers 6a to 6d and 7a to 7d between the forward path and the return path of the optical fiber cable 4, It comprises a plurality of notification units 11a to 11d connected by optical couplers 9a to 9d and 10a to 10d between the forward path and the return path.

The detectors 31a to 31d are provided with a sensing optical fiber through which the propagating light propagates and an external force applying means (for example, bimetal, shape memory alloy) for applying an external force to the sensing optical fiber by heat of a fire to generate an optical loss. (Both are not shown).

The same effects as those of the embodiment shown in FIG. 1 can be obtained in such a fire detecting / notifying device 30 as well.

Here, in the fire detecting / notifying apparatus shown in FIGS. 1 to 3, the intensity of the light pulse propagating through the optical fiber cable is reduced by the optical coupler. In addition, it is necessary to increase the number of cores of the optical fiber cable and to additionally provide a light emitting circuit and a light receiving circuit.

In addition, by using the optical fire detection and notification system in combination with the distributed optical fiber temperature measuring device, it is possible to detect a fire early even when there is a wind speed in the shaft of the tunnel or in the tunnel.

Further, diffuse reflection by smoke particles occurs,
By providing a mechanism in which the light path is blocked by a bimetal, a diaphragm, or the like, which is deformed by heat, in a space where light is attenuated, combined detection of heat and smoke becomes possible.

(Application System) (a) Fire monitoring in a long distance section such as a tunnel can also be performed by detecting smoke (heat can be measured by a distributed optical fiber temperature measuring device).

(B) The longer the tunnel, the higher the cost merit of this system.

(C) The present invention can be applied to fire monitoring of manholes, handholes, and the like scattered over a wide area without a power source.

(D) It can also be used as a non-powered push button type emergency alarm (road, railway “for example, railroad crossing”, tunnel, sewer, coal mine, etc.).

(E) It is possible to express the effect of smoke extinction in numerical values, and it can be an analog smoke detector.

As described above, according to the present invention, (1) the equipment installed in the fire alarm area has no power supply,
By using light, a long-distance, wide-area fire detection and notification system can be constructed.

(2) Because it is an optical type, it is essentially an explosion-proof type, is resistant to electromagnetic noise, and has no risk of electric shock.

(3) Since address information can be added at the time of fire detection / notification, early countermeasures are possible.

(4) A plurality of fire detections / alerts can be recognized.

(5) Since light is used, real-time long-distance remote monitoring is possible.

(6) The detection mechanism using diffuse reflection by smoke is simple, and the intensity of light pulses can be directly modulated, so that the reliability is high.

(7) Fire detection due to heat and smoke can be realized only by the phenomenon of “dimming (shielding)”.

(8) The existing optical fiber cable core can be used (one or two cores may be used).

[0062]

In summary, according to the present invention, the following excellent effects are exhibited.

It is possible to provide an optical fire detection / informing system which has a simple configuration and high reliability and does not require a power supply for the detector.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a fire detection and notification device to which an optical fire detection and notification system of the present invention is applied.

FIG. 2 is a block diagram showing another embodiment of a fire detection and notification device to which the optical fire detection and notification system of the present invention is applied.

FIG. 3 is a block diagram showing another embodiment of a fire detection and notification device to which the optical fire detection and notification system of the present invention is applied.

[Explanation of symbols]

2 light emitting circuit 4 optical fiber cable 5 light receiving circuit 6a-6d, 7a-7d, 9a-9d, 10a-10d
Optical couplers 8a to 8d 'Detection units 11a to 11d' Notification units

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2G059 BB02 CC19 EE01 EE04 FF04 HH01 HH02 JJ17 JJ22 KK01 MM05 5C085 AA01 AA03 AB03 BA25 BA32 BA33 CA17 FA06 FA20 5F089 AA10 AC13 AC17 AC26 CA11 CA21

Claims (8)

[Claims] 1. An optical fiber connected between a light emitting circuit and a light receiving circuit and arranged so as to form a forward path and a return path in a fire alarm zone, normally propagates light between the forward path and the return path. However, in the event of a fire, a plurality of detectors that generate light loss in propagating light due to smoke or heat are discretely connected, and the dimming of the propagating light in the optical fiber due to the light loss is detected by the light receiving circuit. Optical fire detection and notification system characterized by the following. 2. The optical fiber according to claim 1, wherein the optical fiber is folded back at a predetermined point and arranged so as to be parallel to each other, and each detecting unit is connected by an optical coupler between the forward path and the return path. Optical fire detection and notification system. 3. One end of the optical fiber is connected to the light emitting circuit and the light receiving circuit via a branching filter, and the other end is connected to a reflector that returns the propagating light to the optical fiber. The optical fire detection and notification system according to claim 1, wherein one end of the detection unit is connected to the optical fiber via an optical coupler, and the other end is connected to a reflector that returns propagating light to each detection unit. 4. The detecting section has a detecting section side optical fiber which is disposed to face the propagating light so that the propagating light propagates in a space.
The optical fire detection and notification system according to any one of claims 1 to 3, wherein when the smoke enters the space, the propagation light is scattered to cause light loss. 5. The sensing unit has a sensing optical fiber through which propagating light propagates, and an external force applying means for applying an external force to the sensing optical fiber by the heat to generate an optical loss. The optical fire detection and notification system according to any one of the above. 6. The detection section includes: a detection section-side optical fiber disposed so as to oppose the propagating light to propagate in the space; and an optical loss caused by blocking the propagation light in the space by the heat. The optical fire detection and notification system according to any one of claims 1 to 3, further comprising a light blocking means for causing the fire to occur. 7. The optical fire according to claim 1, wherein a plurality of alarm units for adding light loss by a manual button for alarming the fire are discretely connected to the optical fiber. Detection and notification system. 8. An optical fire detection system, wherein at least two systems according to claim 1 are combined.
Notification system.