JPH07122915B2 - Fire alarm - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a fire alarm device, and more particularly to a fire alarm device itself, or a fire alarm caused by data sent from a fire sensor to a receiver via a transmission path. The present invention relates to a fire alarm device for judging.

[Prior Art and its Problems] As a detector or a sensor for detecting a fire, a photoelectric smoke sensor, a thermal sensor using a thermistor, and an ionization or radiation sensor are known. Each of these fire detectors detects a given smoke density, a given temperature, or a given radiant light from a fire,
I am trying to give a fire signal.

However, in such a system, even transient smoke such as cigarette smoke may operate beyond the predetermined detection level.

Therefore, there is also known a storage-type sensor or receiver that does not operate due to such a transient fire phenomenon and that does not operate unless a predetermined output continues for a certain period of time using a timer or the like. However, there was a drawback that fire detection was delayed.

Furthermore, in a room where a ventilator is working, the effect causes, for example, a gradual increase in smoke concentration, and the smoke concentration that finally activates the smoke detector is not reached, and a fire alarm is not issued, that is, a failure is reported. There were also cases such as.

[Problems to be Solved by the Invention] The present invention has been made to solve the above-mentioned problems, and does not malfunction in a transient, fire-like phenomenon such as cigarette smoke.
Another object of the present invention is to provide a fire alarm device capable of reliably and promptly detecting and issuing an alarm in the case of an actual fire even if the fire is a gradual rise.

[Means for Solving Problems] Therefore, according to the present invention, in a fire alarm device configured to judge a fire based on a sensor output level (SLV), the sensor is provided at predetermined time intervals (Δt). the difference between the means (step 101) that samples the output level, the first predetermined level (LV ₁₎ or more of the sampled sensor output level (SLV), the first predetermined (level (LV ₁₎ Is calculated at each of the predetermined time intervals (Δt), and a value (SI) integrated by the integrating means is compared with a predetermined integrated value (A). Discriminating means (steps 105 and 107) for discriminating when the value (SI) accumulated by the accumulating means has reached the predetermined accumulated value (A) and outputting a signal indicating an abnormality. Fire alarm device featuring To be done.

[Operation] The sensor output level is sampled at every predetermined time interval Δt by the sampling means, and from the time when the sensor output level SLV becomes equal to or higher than the first predetermined level LV ₁ , the sampled sensor output level is obtained. SLV
And the difference from the _first predetermined level LV ₁ is integrated by the integration means at each of the predetermined time intervals Δt. In this way, the portion of the sensor output level above the first predetermined level is integrated over time.

The determining means compares the value SI integrated by the integrating means with a predetermined integrated value A to determine when the value SI integrated by the integrating means reaches the predetermined integrated value A. A signal indicating an abnormality is output. As described above, since the signal indicating the abnormality is output only when the integrated value for the time of the first predetermined level or more reaches the predetermined integrated value A, it is possible to prevent the fire from suddenly rising. Therefore, the operating level of the sensor is raised, and the fire is detected at a low level for a fire with a gentle rise. Therefore, even if the rise of the sensor output level at the time of a fire occurs, It enables stable fire detection.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings. 1A
The figure shows the output level of the fire sensor with respect to time. In FIG. 1A, the horizontal axis shows the time t, and the vertical axis shows the output level SLV of the fire sensor. LV ₁ is the first predetermined level and LV ₂ is the second predetermined level. now,
Assuming that the sensor output level SLV rises along the straight line S, the description will proceed. The sensor output level SLV first exceeds the _first predetermined level LV ₁ at time t ₀ , and from this time point the sensor output level SLV is reached. The accumulation of the excess amount with respect to the first predetermined level LV ₁ is started over time. Specifically, this integration is obtained by subtracting the first predetermined level LV ₁ from the sensor output level SLV (SLV-LV ₁ ) at the time interval Δt.
To accumulate for each, that is, the formula Is calculated. Here, SLVk is the value of the sensor output level SLV at times t ₁ , t ₂ , t ₃ , ..., T _n for each time interval Δt. Therefore, i) when normal, SLV <LV ₁ , and ii) when SLV ≥ LV ₁ Iii) If SI ≧ A and SLV ≧ LV ₂ are satisfied within the time t _N , an abnormal signal is output.

iv) If SI does not reach A within time t _N , or
If SLV ≧ LV ₂ does not hold even if SI ≧ A, the integrated value SI is cleared and the integrating operation is performed from the beginning.

v) When SLV <LV ₁ , the integration operation is stopped at that point.

In FIG. 1A, it is shown that the integrated value reaches the predetermined integrated value A at the point P at the time t _n , and the sensor output SLV _n at this time is higher than the second predetermined level LV _2. Since it is large, an abnormal signal is generated at the time t _n .
Here, the role of the second predetermined level LV ₂ is as follows.
That is, in the explanation of FIG. 1A, when an abnormality occurs, the sensor output
Although the case where the SLV rises along the straight line S has been described as an example, the SLV does not always rise along the straight line, and when the integrated value reaches the predetermined integrated value A, for example, the abnormal state is resolved. In some cases, the sensor output SLV is decreasing, and for this reason, the predetermined integrated value A
The abnormal signal is output only when both the conditions of reaching the second predetermined level LV _{2 and} above are satisfied.

In FIG. 1B, the sensor output level SLV has various straight lines S ₁ ,
It shows the case of increasing along S ₂ , S _3, ..., The points on the graph at the time when the integrated value reaches the predetermined integrated value A are points P ₁ , P ₂ , P ₃ ,. .., and the locus of these points is indicated by the line L.

As shown in FIG. 1B, no matter what rate of increase in smoke concentration, each operating point P ₁ , P ₂ , P ₃ ... Is the apex and the first predetermined level LV ₁ is the base. If the area of each triangle was reached the same predetermined cumulative value a, that is, the total amount of smoke is to output an abnormality signal when it reaches a certain value, for example, linear S ₁ and S ₂ for relatively steep rise fire phenomena such as, becomes possible to output the abnormal signal in a high sensor output level as the point P ₁ and P _2, to realize the prevention of erroneous operation that the output of the abnormal signal due to non-fire It is also possible to output an abnormal signal at a low level such as points P ₆ and P ₇ for a relatively mild fire phenomenon such as straight lines S ₆ and S ₇ , which enables early fire detection. Has been realized. Also, since the outputs a fire abnormality when the second exceeds a predetermined level LV _2, even when it reaches the predetermined accumulated value A with a gentle rise, does not exceed a second predetermined level LV ₂ As long as the operation is suspended, the generation of a fire abnormality signal due to non-fire is suppressed in this way.

Since the line L shown in FIG. 1B is the operating point of the sensor, the first and second predetermined levels LV ₁ and LV ₂ are sufficiently lower than the level in the conventional sensor, that is, It is set to high sensitivity. Taking the smoke sensor as an example,
Conventionally, assuming that the smoke concentration is set to operate at 10% / m, for example, the first predetermined level LV ₁ is 2.5
.About.3% / m, and the second predetermined level LV ₂ is set to 5% / m.

FIG. 2 shows a block circuit diagram of a fire alarm device suitable for implementing the invention operatively described in FIG. 1A. In the figure, the fire alarm device is a summary, the sensor unit 10,
And a discrimination unit 11. The sensor unit 10 here is a photoelectric smoke sensor that operates by sensing smoke. In the smoke detecting chamber of the smoke sensor 10, a light emitting diode LED that is pulse-lighted at a predetermined cycle by an oscillation circuit 12 and a light emitting circuit 14, and a sun that receives scattered light in proportion to its concentration when smoke flows into the smoke detecting chamber. A battery SB is provided, and after the output from the solar battery SB is amplified by the amplifier 18 via the light receiving circuit 16,
The analog / digital (A / D) conversion circuit 20 converts the signal into a digital signal and sends it to the determination unit 11.

The microprocessor unit MPU is included in the determination unit 11 that receives signals from the sensor unit 10 and performs signal processing or determination.
And an interface I / that receives the signal from the sensor unit 10.
F, an oscillator OSC that oscillates a clock, and a program read-only program that stores a signal processing program.
Memory ROM1 and work random access memory RA
And M1, and the first and second predetermined level LV ₁ and LV first _{respectively 2} stores and second-level storage for read-only memory ROM2 and ROM 3, and stores the predetermined integrated value A Read-only memory ROM4 for storing the predetermined integrated value
Random access for sensor output storage to capture and store the sensor output SLV at predetermined time intervals Δt
A memory RAM2 and a random access memory RAM3 for storing an integrated value for storing an integrated value SI calculated at a predetermined time interval Δt based on the sensor output SLV fetched in the RAM2 are included. .

The values of the first predetermined level LV ₁ , the second predetermined level LV ₂ and the predetermined integrated value A are appropriately set depending on the degree of danger of the room, ventilation, air conditioning, density of people, time zone, height, volume, etc. Those skilled in the art will understand that the settings can be changed.

The operation of the block circuit diagram shown in FIG. 2 will be described with reference to the flowchart of FIG.

First, the determination unit including the microprocessor unit MPU constantly samples the sensor output level SLV based on the program stored in the ROM 1. That is, the sensor output level S sent from the sensor unit 10 through the interface I / F at every predetermined time interval Δt counted based on the clock pulse from the oscillator unit OSC.
The LV is being read into RAM2 (step 101). Also, R
The sensor output level SLV read into AM2 compares first the predetermined level LV ₁ stored in the ROM 2, are subjected to determination of whether or not was the first predetermined level LV ₁ or more at all times (step 102 ). When the sensor output level SLV is lower than the first predetermined level LV ₁ , or when SLV ≧ LV ₁ and the sampling circuit n for each time interval ΔT becomes a predetermined number of times N or more ( In step 102, N, that is, "no", the accumulated value SI up to the previous time stored in the RAM 3 is cleared (step 103). RAM2 to increase the sensor output level SLV stored is higher than the first predetermined level LV _1, and if the sampling number n is a predetermined number of times smaller than N (step 102 in Y, i.e., "YES"),
Next, the accumulated value SI up to the previous time stored in RAM3 (SL
V-LV ₁ ) is added and this is stored in RAM 3 as a new integrated value SI (step 104). Next, it is determined whether or not the integrated value SI newly stored in the RAM3 is equal to or larger than a predetermined integrated value A stored in the ROM4 (step 105), S
If I is not equal to or more than A, a new SLV is read (step 101), the integration operation is further continued in step 104, and in this way, until the number of sampling times is determined to be N in step 102, step 105 Then, it is determined whether or not the integrated value reaches A. If it is determined that the latest integrated value SI stored in RAM3 is greater than or equal to the predetermined integrated value A stored in ROM4, then the SLV stored in RAM2 is stored.
Is determined to be LV ₂ or more stored in the ROM 3, and if the SLV is LV ₂ or more (Y in step 106),
A fire abnormality signal will be output (step 10).
7).

In the above embodiments, the sensor output level is described as a signal obtained from the photoelectric smoke sensor, but the sensor output level can be obtained from a thermal type, ionization type or radiation type fire sensor using a thermistor. Even in the case of a signal, the same effect as that of the above-described embodiment is obtained.

Further, in the above embodiment, the description has been made assuming that the sensor unit and the fire determination unit of the fire alarm device are integrated.
The fire sensor output digitized by the conversion circuit may be transmitted to a remote receiver via a modem or the like, and the fire judgment may be performed there.

As described above, according to the present invention, the sensor output level
Since the portion above the first predetermined level is integrated and the abnormal signal is output only when the integrated value reaches the predetermined integrated value, the operation level of the sensor can be increased in case of a sudden fire. It is possible to detect a fire at a low level for a fire with a high rise and a gentle rise. Therefore, although it does not malfunction for a transient fire phenomenon, it is possible to detect a fire with a gradually increasing smoke concentration. On the other hand, there is an effect that it is possible to obtain a fire alarm device that can be reliably operated.

[Brief description of drawings]

1A and 1B are graphs for explaining the operation of the present invention, FIG. 2 is a configuration diagram showing a fire alarm device according to an embodiment of the present invention, and FIG. 3 is an operation of FIG. 4 is a flowchart for explaining In the figure, 10 is a smoke sensor section, 11 is a discrimination section, MPU is a microprocessor unit, ROM 1 is a read-only memory for program storage,
RAM1 is working random access memory, SLV sensor output level, LV ₁ is a first predetermined level, LV ₂ is a second predetermined level, A is a predetermined cumulative value, △ t is a predetermined time interval,
N is a predetermined number of times.

Claims (3)

[Claims] 1. A fire alarm device adapted to judge a fire on the basis of a sensor output level, and means for sampling the sensor output level at predetermined time intervals, and the sampling at a first predetermined level or higher. An integrating means for integrating the difference between the sensor output level and the first predetermined level at each of the predetermined time intervals, and comparing the value integrated by the integrating means with the predetermined integrated value. A fire alarm device, comprising: a determining unit that determines when the value integrated by the integrating unit reaches the predetermined integrated value and outputs a signal indicating an abnormality. 2. The determination means adds a second value larger than the first predetermined level to the sensor output level so as to be added to the comparison between the value integrated by the integrating means and the predetermined integrated value. Is also compared with a predetermined level, the signal indicating the abnormality when the value integrated by the integrating means is greater than or equal to the predetermined integrated value and the sensor output level is greater than or equal to the second predetermined level. The fire alarm device according to claim 1, wherein the fire alarm device outputs. 3. A value integrated by the integrating means when the number of samplings of the sensor output level equal to or higher than the first predetermined level performed at each of the predetermined time intervals reaches a predetermined number (N). And the sampled sensor output level above the first predetermined level,
The fire alarm device according to claim 1 or 2, wherein integration of the difference from the first predetermined level at each of the predetermined time intervals is started from the beginning.