JP2022117536A - Fire sensor - Google Patents

Abstract

To provide a fire sensor capable of reliably detecting a fire without introducing smoke.SOLUTION: A sensor 1 for detecting a fire to occur in an object area comprises: a fire detection section 141 for detecting a fire to occur in the object area based on sonic speed information in the object area and an attenuation coefficient which indicates the degree of attenuation of a sonic wave in the object area; a wave transmission section 111 for transmitting a sonic wave to the object area; and a first wave reception section 112A and a second wave reception section 112B for receiving a sonic wave. The fire detection section 141 performs: first processing to calculate the sonic speed information and the attenuation coefficient based on the sonic waves received by the first wave reception section 112A and the second wave reception section 112B; second processing to specify a temperature of the object area based on the calculated sonic speed information and the attenuation coefficient; and third processing to detect a fire to occur in the object area based on the specified temperature.SELECTED DRAWING: Figure 2

Description

The present invention relates to fire detectors.

Conventionally, there has been known a fire detector that detects a fire based on smoke generated in a target area (see Patent Document 1, for example).

JP 2020-126700

By the way, in conventional fire detectors, it was necessary to introduce smoke into the fire detector, but there has been a demand for a technique for detecting fire without introducing smoke.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a fire sensor that can reliably detect a fire without introducing smoke.

In order to solve the above-mentioned problems and achieve the object, the fire sensor according to claim 1 is a fire sensor that detects a fire that occurs in a target area, and includes sound velocity information in the target area, and an attenuation coefficient indicating the degree of attenuation of sound waves in the target area.

In addition, the fire sensor according to claim 2 is the fire sensor according to claim 1, further comprising wave transmitting means for transmitting sound waves to the target area, wave receiving means for receiving sound waves, Further comprising, the fire detection means includes a first process of calculating the sound speed information and the attenuation coefficient based on the sound wave received by the wave receiving means, and based on the calculated sound speed information and the attenuation coefficient a second process of identifying the temperature of the target area; and a third process of detecting a fire occurring in the target area based on the identified temperature.

The fire sensor according to claim 3 is the fire sensor according to claim 2, wherein in the second process, the fire detection means specifies the temperature and humidity of the target area, The process detects a fire occurring in the area of interest based on the identified temperature and humidity.

Further, the fire sensor according to claim 4 is the fire sensor according to claim 2 or 3, wherein the wave receiving means is a first wave receiving means provided in the vicinity of the wave transmitting means, a second wave receiving means provided at a position farther than the first wave receiving means with respect to the wave transmitting means, wherein the fire detecting means, in the first processing, the first wave receiving means At least the attenuation coefficient is calculated based on the sound waves received by the means and the second wave receiving means.

The fire sensor according to claim 5 is the fire sensor according to any one of claims 2 to 4, wherein in the first process, the fire detection means transmits waves from the wave transmission means. The fire sensor further comprises correcting means for calculating the speed-of-sound information based on the propagation distance of the emitted sound wave until it is received by the wave receiving means, and correcting the propagation distance. .

According to the fire detector of claim 1, by detecting a fire occurring in the target area based on the sound speed information and the attenuation coefficient, for example, the fire can be reliably detected without introducing smoke into the fire detector. It becomes possible to detect

According to the fire sensor of claim 2, by detecting a fire occurring in the target area based on the temperature in the target area, for example, it is possible to reliably detect the fire.

According to the fire sensor of claim 3, by detecting a fire occurring in the target area based on the temperature and humidity in the target area, for example, it is possible to reliably detect a fire.

According to the fire sensor of claim 4, by calculating at least the attenuation coefficient based on the sound waves received by the first wave receiving means and the second wave receiving means, for example, the calculation accuracy of the attenuation coefficient can be improved. Since it can be improved, it becomes possible to reliably detect a fire.

According to the fire sensor according to claim 5, by correcting the propagation distance, for example, it is possible to calculate the speed-of-sound information using the propagation distance suitable for the environment in which the fire sensor is installed. , it becomes possible to reliably detect a fire.

It is a figure which shows the installation example of the sensor which concerns on this Embodiment. Fig. 3 is a block diagram showing a sensor; It is a flow chart of fire detection processing. It is the figure which illustrated the temporal change of propagation time. It is a figure which shows a jig|tool for correction.

EMBODIMENT OF THE INVENTION Below, embodiment of the fire sensor which concerns on this invention is described in detail based on drawing. In addition, this invention is not limited by this embodiment.

[Basic concept of the embodiment]
First, the basic concept of this embodiment will be explained. This embodiment generally relates to a fire detector.

A "fire detector" is a device that detects a fire that occurs in a target area, and is a concept that includes, for example, a reflective fire detector and a counter-type fire detector. Moreover, as a system for detecting fire by the fire sensor, for example, a quantitative system and a differential system are assumed.

A “target area” is an area that is a target for fire detection, and is a concept that includes arbitrary areas such as parking spaces in parking lots and rooms in buildings, for example.

"Reflective fire detector" is a concept that includes, for example, those that detect fire using sound waves reflected by a reflective surface within a target area. "Opposite type fire detector" is a device on the transmitting side and a device on the receiving side that are separated from each other, provided with the target area sandwiched, for example, after being output from the device on the transmitting side This is a concept that includes the detection of fire using sound waves directly received on the receiving side.

The “quantitative formula” is a concept that includes a method of detecting a fire based on the value of the physical quantity of the target area (for example, temperature value, humidity value, etc.) itself. “Differential method” is a concept that includes a method of detecting a fire based on the temporal change (for example, inclination) of the physical quantity of the target area.

In the embodiment shown below, the "target area" is a parking space in a parking lot, and a case where a quantitative formula is adopted in a reflective fire sensor will be described. will be explained.

[Specific contents of the embodiment]
Next, specific contents of the embodiment will be described.

(Constitution)
First, the configuration of the sensor according to this embodiment will be described. FIG. 1 is a diagram showing an installation example of a sensor according to this embodiment, and FIG. 2 is a block diagram showing the sensor. In FIG. 1, some constituent elements of the sensor 1 are illustrated as rectangles, and the overall shape of the sensor 1 is illustrated in an enlarged manner.

The detector 1 in FIG. 1 is a reflective fire detector, for example, a device for detecting fires occurring in a parking space (that is, a target area) of a parking lot. The sensor 1 is of a quantitative type (more specifically, constant temperature type) that detects a fire based on the temperature value of the parking space itself. and receive the sound waves reflected on the floor side.

The sensor 1 includes, for example, a sound wave unit 11, an alarm unit 12, a recording unit 13, and a control unit 14, as shown in FIG.

(Configuration - sound wave section)
The sound wave unit 11 transmits or receives sound waves, and includes, for example, a wave transmission unit 111, a first wave reception unit 112A, and a second wave reception unit 112B. In the present application, although sound waves of any frequency band may be used, for example, a case of using sound waves of a frequency band corresponding to ultrasonic waves will be described.

(Construction-sound wave unit-transmitting unit)
The wave transmitting unit 111 is wave transmitting means for transmitting sound waves to a target area, and is provided at a predetermined position in the housing of the sensor 1, for example, as shown in FIG. As the wave transmitting section 111, for example, a known ultrasonic wave transmitter using a piezoelectric ceramic vibrator can be used.

(Configuration-sound wave unit-first wave receiving unit)
The first wave receiving section 112A is wave receiving means for receiving sound waves, and is, for example, the first wave receiving means provided near the wave transmitting section 111 as shown in FIG. As the first wave receiving section 112A, for example, a known ultrasonic wave receiver using a piezoelectric ceramic vibrator can be used (the same applies to the second wave receiving section 112B).

(Configuration-sound wave unit-second wave receiving unit)
The second wave receiving section 112B is a wave receiving means for receiving sound waves, and is provided at a position farther from the wave transmitting section 111 than the first wave receiving section 112A, as shown in FIG. is the second wave receiving means.

(Configuration - alarm unit)
The alarm unit 12 is alarm means for outputting an alarm. As the alarm unit 12, for example, an indicator lamp or a speaker (none of which is shown) can be used.

(Configuration - recording unit)
The recording unit 13 is recording means for recording programs and various data necessary for the operation of the sensor 1, and can be configured using a flash memory or the like, for example. Distance information is stored in the recording unit 13 .

(Construction-Recording section-Distance information)
“Distance information” is information for specifying the distance that sound waves propagate (that is, the propagation distance). Specify the distance propagated by the transmitted sound wave when it reaches the second wave receiving unit 112B after being reflected by a reflection target (that is, an object on which the sound wave is reflected) in the target area. It is information for

As this distance information, in the present embodiment, information corresponding to the length of the distance L between the ceiling and the floor surface in the vertical direction (vertical direction in the drawing) is stored as the initial value of the distance information. will be described as an example.

(Configuration - control unit)
The control unit 14 in FIG. 2 is also a control means for controlling the sensor 1, and specifically, includes a CPU, various programs interpreted and executed on the CPU (a basic control program such as an OS, and a and an internal memory such as a RAM for storing programs and various data.

The control unit 14 includes, for example, a fire detection unit 141 and a correction unit 142 functionally. The fire detection unit 141 is fire detection means for detecting a fire occurring in a target area based on sound velocity information in the target area and an attenuation coefficient indicating the degree of attenuation of sound waves in the target area. The correction unit 142 is correction means for correcting the propagation distance. The processing performed by each part of this control part 14 will be described later.

The "sound velocity information" is information indicating the sound velocity in the target area. "Attenuation coefficient" is information indicating the degree of attenuation of a sound wave in a target region, for example, the ratio between the amplitude of the sound wave before propagation in the target region and the amplitude of the sound wave after propagation in the target region It is information determined according to

(process)
Next, fire detection processing executed by the sensor 1 configured in this manner will be described. FIG. 3 is a flowchart of fire detection processing (steps are abbreviated as "S" in the following description of each processing). “Fire detection processing” is processing for detecting a fire in a parking space. The timing for executing this fire detection process is arbitrary, but for example, when the power of the sensor 1 is turned on, repeated execution is started, and the description will start from the start of execution of the fire detection process.

First, at SA1 in FIG. 3, the fire detection unit 141 causes the wave transmitting unit 111 to transmit sound waves, and causes the first wave receiving unit 112A and the second wave receiving unit 112B to receive sound waves. Here, for example, the first wave receiving unit 112A receives a pre-propagation sound wave (hereinafter also referred to as a “pre-propagation sound wave”) transmitted from the wave transmitting unit 111 in the target region. Further, the second wave receiving unit 112B receives, in the target area, the sound wave after propagation (hereinafter, also referred to as “post-propagation sound wave”) that is transmitted from the wave transmitting unit 111 and reflected by a reflection target (for example, a floor surface). do.

Next, at SA2 in FIG. 3, the fire detection unit 141 measures the propagation time and amplitude and stores the measurement results. The “propagation time” is a concept indicating the time it takes for a sound wave transmitted by the sensor 1 to return to the sensor 1, and is a concept corresponding to TOF (Time of Flight), for example.

Specifically, the time from when the wave transmitting unit 111 transmits the sound wave to when the second wave receiving unit 112B receives the “post-propagation sound wave” is measured as the propagation time. The amplitude of the "pre-propagation sound wave" received by the first wave receiving section 112A and the amplitude of the "post-propagation sound wave" received by the second wave receiving section 112B are also measured. Then, these measurement results are stored in the recording unit 13 .

Next, at SA3 in FIG. 3, the fire detection unit 141 determines whether or not the propagation time and amplitude values measured in the most recent SA2 are different from the propagation time and amplitude values measured in the past SA2. If it is determined that they are different (YES in SA3), the process proceeds to SA4. On the other hand, if it is determined that they are not different (that is, they are the same) (NO in SA3), the process proceeds to SA1, and repeats the above. process.

Here, for example, the temperature or humidity of the parking space in FIG. (top surface of the antenna) may change the propagation distance. In such a case, the values of the propagation time and amplitude measured in the most recent SA2 are different from the values of the propagation time and amplitude measured in the past SA2. transition to

Next, at SA4 in FIG. 3, the fire detection unit 141 measures the propagation time and amplitude N times (for example, 5 to 10 times, or 50 to 100 times, etc.), and the measurement results for N times ( That is, N sets of measurement results) are stored in the recording unit 13 . Note that the specific processing is the same as the processing of SA1 and SA2.

Next, at SA5 in FIG. 3, the fire detection unit 141 determines whether or not the N sets of measurement results measured at SA4 are stable after a rapid change in the propagation time. If it is determined that the propagation time is stable after a rapid time change (YES in SA5), the process proceeds to SA6, while it is determined that the propagation time is not stable after a rapid time change. If yes (that is, other than YES in SA5) (NO in SA5), the process proceeds to SA7.

FIG. 4 is a diagram illustrating temporal changes in propagation time. For example, when a car is parked in an empty parking space at timing t1, as shown in FIG. 4(a), the propagation time changes relatively significantly at timing t1 and then becomes a constant value. . Further, for example, when a fire breaks out at timing t1 and the temperature of the parking space gradually rises, as shown in FIG. 4B, the propagation time gradually changes from timing t1. will continue.

In the processing of SA5, for example, when the propagation time transitions as shown in FIG. 4(b)), a method of determining "NO in SA5" is applied. More specifically, for example, if the propagation time changes within a second width (a width that is significantly smaller than the first width) after the propagation time has changed by the first width or more, the "YES in SA5 , and on the other hand, in cases other than this case, a method of determining "NO in SA5" may be applied.

Next, at SA6 in FIG. 3, the correction unit 142 performs distance information correction processing. The "distance information correction process" is a process of correcting and updating the distance information stored in the recording unit 13 of FIG. 2, that is, a process of correcting the propagation distance.

In the processing of SA6, for example, using the propagation time in the case of being stable after a rapid time change, among the measurement results of SA5, a predetermined calculation (propagation distance is the value of the speed of sound (here, for example, in advance The propagation distance is calculated based on the calculation based on the product of the determined predetermined value) and the propagation time), and the information for specifying the calculated propagation distance is the corrected propagation distance. The distance information is stored in the recording unit 13 and updated.

In addition, as the propagation time used in the calculation here, the propagation time in a stable state after a rapid time change among the N propagation times in the N sets of measurement results measured in SA4 is used. . That is, in the example of FIG. 4A, the propagation time measured after the timing t1 is used. After that, it shifts to SA1 and repeats the above-described processes.

Next, in SA7 after NO in SA5 in FIG. 3, the fire detection unit 141 detects N sets of measurement results (that is, N sets of propagation time, amplitude of "pre-propagation sound wave", and "post-propagation sound wave" ) to identify the temperature. A specific method for specifying the temperature here is arbitrary, but for example, the following first to third methods may be used.

<First method>
The first method is to use the first equation for obtaining the speed of sound with temperature and humidity as variables, and the second equation for obtaining the attenuation coefficient with temperature and humidity as variables.

When using this first method, first, after acquiring the distance information of the recording unit 13, the propagation distance (propagation distance specified by the acquired distance information) ÷ propagation time (measurement result) is calculated. Calculate the result as the speed of sound.

Next, "(20/distance) x log (amplitude of "pre-propagation sound wave"/amplitude of "post-propagation sound wave")" (the base of log is "10") is calculated. Calculate the result as the damping coefficient. The "distance" in this formula indicates the propagation distance of the sound wave from the first wave receiving section 112A to the second wave receiving section 112B with respect to the sound wave reflected by the reflection target as shown in FIG. . This "distance" is the distance indicated by the distance information recorded in the recording unit 13 in FIG. Later, the distance that the sound wave propagates up to the second wave receiving portion 112B (hereinafter also referred to as “the distance from the wave transmitting portion 111 to the second wave receiving portion 112B”), a predetermined distance (For example, a distance predetermined as the propagation distance of the sound wave from the wave transmitting unit 111 to the first wave receiving unit 112A) (hereinafter referred to as “from the wave transmitting unit 111 to the first (also referred to as "the distance to the wave receiving unit 112A") may be used. As the predetermined distance, a numerical value obtained by predetermined experiments, simulations, or the like may be used.

Alternatively, as a modified example, the "distance from the wave transmitting section 111 to the second wave receiving section 112B" is much longer than the "distance from the wave transmitting section 111 to the first wave receiving section 112A". Ignoring the distance from the first wave receiving portion 112A from the portion 111, the distance from the transmitting portion 111 to the second receiving portion 112B is used as the distance in the equation for calculating the attenuation coefficient. may be used.

Next, by substituting the value of the speed of sound calculated above into the first formula, and substituting the damping coefficient calculated above into the second formula, the two variables of temperature and humidity are mutually independent. We derive two equations. Next, the calculated temperature is specified by calculating the temperature and the humidity based on the derived two equations.

For the first and second equations described above, known equations may be used, or equations defined based on predetermined experiments or simulations may be used.

<Second method>
A second method is a method using another formula showing the relationship between temperature and sound speed. When using this second method, the speed of sound is calculated in the same manner as in the case described above, and the temperature is calculated by applying the calculation result to the other equation, and the calculated temperature is specified.

<Third method>
A third technique is to use predetermined table information indicating the relationship between temperature and humidity, sound velocity and attenuation coefficient. When using this third method, the speed of sound and the attenuation coefficient are calculated in the same manner as described above, and the temperature and humidity corresponding to the calculated speed of sound and the attenuation coefficient are obtained by referring to the table information. temperature.

Next, at SA8 in FIG. 3, the fire detection unit 141 determines whether or not a fire has occurred based on the temperature specified at SA7. Specifically, it is assumed that a temperature threshold, which serves as a criterion for judging the occurrence of fire, is determined in advance. If the temperature identified in SA7 is less than the temperature threshold, it is determined that no fire has occurred (NO in SA8), and the process ends without detecting a fire. On the other hand, if the temperature specified in SA7 is equal to or higher than the temperature threshold, it is determined that a fire has occurred (YES in SA8), the fire is detected, and the process proceeds to SA9.

Here, for example, in SA7, N temperatures are specified based on N sets of measurement results, but if a predetermined number or more of the N temperatures exceed the temperature threshold, fire Alternatively, it may be determined that a fire has occurred when the average value of the N temperatures is greater than or equal to the temperature threshold.

Next, at SA9 in FIG. 3, the fire detection unit 141 transmits a fire signal indicating that a fire has occurred to a disaster prevention receiver (not shown) or outputs an alarm via the alarm unit 12. to notify the occurrence of fire.

Next, at SA10 in FIG. 3, when the fire detection unit 141 receives a recovery signal (that is, a signal for recovering to a state for reporting the occurrence of a fire) transmitted from the disaster prevention receiver side, Terminate the fire alarm and restore. This concludes the description of the fire detection process.

(Effect of Embodiment)
As described above, according to the present embodiment, by detecting a fire that occurs in the target area based on the sound velocity information and the attenuation coefficient, for example, the fire can be reliably detected without introducing smoke into the sensor 1. It becomes possible to

Further, by detecting a fire occurring in the target area based on the temperature in the target area, for example, it is possible to reliably detect the fire.

Further, by calculating at least the attenuation coefficient based on the sound waves received by the first wave receiving unit 112A and the second wave receiving unit 112B, for example, it is possible to improve the calculation accuracy of the attenuation coefficient. It is possible to reliably detect it.

[Modification to Embodiment]
Although the embodiments according to the present invention have been described above, the specific configuration and means of the present invention can be arbitrarily modified and improved within the scope of the technical ideas of each invention described in the claims. can be done. Such modifications will be described below.

(Problem to be solved and effect of invention)
First, the problems to be solved by the invention and the effects of the invention are not limited to the contents described above, and may differ depending on the details of the implementation environment and configuration of the invention. or only part of the effects described above.

(Regarding decentralization and integration)
Also, the configuration described above is functionally conceptual, and does not necessarily have to be physically configured as shown in the drawing. That is, the specific form of distribution or integration of each part is not limited to the illustrated one, and all or part of them can be functionally or physically distributed or integrated in arbitrary units.

(About the wave receiving part)
Also, in the above embodiment, the case where the first wave receiving section 112A is provided has been described, but this component may be omitted. When omitted, for example, a predetermined value may be used as the value of the amplitude of the “pre-propagation sound wave”.

(About judgment of fire)
Further, in the above-described embodiment, the case of judging the occurrence of a fire (that is, detecting a fire) based on the temperature in SA8 of FIG. 3 has been described, but the present invention is not limited to this. For example, SA7 may be configured to specify humidity in addition to temperature, and SA8 may be configured to use humidity in addition to temperature to determine the occurrence of a fire. With this configuration, it is possible to reliably detect a fire, for example, by detecting a fire occurring in the target area based on the temperature and humidity in the target area.

(Regarding the corrector)
Further, the processing performed by the correction unit 142 may be configured to perform the following first to third correction processing. Note that each of these correction processes may be executed, for example, when the sensor 1 is installed, or may be executed at any other timing.

<First Correction Processing>
The first correction process is a process of correcting based on a user's operation. In this case, for example, after providing an operating means (for example, a dip switch, etc.) for inputting distance information to the sensor 1, when the user inputs the distance information through the operation of the operating means, , the correction unit 142 acquires the input distance information and stores it in the recording unit 13 to correct it.

<Second Correction Processing>
A second correction method is a method of correcting based on communication. In this case, for example, when distance information is transmitted from an external device (user's terminal device, disaster prevention receiver, etc.) to the sensor 1, the correction unit 142 receives the distance information and the recording unit 13 Correction is performed by storing in The method of transmitting the distance information here is arbitrary, but for example, the distance information may be transmitted by a signal for wired communication, radio waves for wireless communication, or sound wave communication.

<Third Correction Processing>
A third correction method is a method of correcting using a correction jig. FIG. 5 is a diagram showing a correction jig. A correction jig 900 is a device used to correct distance information, and includes a reflector 901 that reflects sound waves that are at a predetermined distance from the sensor 1 . Correction propagation distance information for specifying the sound wave propagation distance when the correction jig 900 is installed is stored in advance in the recording unit 13 .

Then, when the user presses the operation button (not shown) for correction of the sensor 1 after installing the correction jig 900, the correction unit 142 performs the same processing as SA4 in FIG. , N sets of propagation times and amplitudes are measured, and the measurement results are stored. Next, the correcting unit 142 calculates the propagation distance specified by the correcting propagation distance information of the recording unit 13÷the measured propagation time (specifically, the average value of N measured propagation times), and the calculation result is is calculated as the speed of sound in the current environment. Next, when the user detaches the correction jig 900 and presses the correction operation button (not shown) of the sensor 1 again, the correction unit 142 performs the same processing as SA4 in FIG. to measure N sets of propagation times and amplitudes and store the measurement results. Next, the correction unit 142 calculates the above-described calculated sound speed value×measured propagation time (more specifically, the average value of N measured propagation times), and applies the calculation result to the target area (for example, 1 parking space), and information specifying the calculated propagation distance is stored in the recording unit 13 as distance information for correction.

When configured in this way, by correcting the propagation distance, for example, it is possible to calculate the sound velocity information using the propagation distance suitable for the environment in which the sensor 1 is installed, so that the fire can be reliably detected. It becomes possible to

(About differential type)
Further, the sensor 1 described above may be configured as a differential type. In this case, for example, even if the absolute value of the propagation distance deviates, the fire can be detected, so SA6 in FIG. 3 may be omitted. In this case, after YES in SA5, the process may proceed to SA1 without executing SA6. In addition, in the case of such a configuration, in SA8, for the N temperatures specified in SA7, the slope of the straight line showing the temperature change when the horizontal axis is the time and the vertical axis is the temperature value is calculated. may be calculated, the calculated slope may be compared with a predetermined slope for fire determination, and whether or not a fire has occurred may be determined based on the comparison result.

(About opposed type)
Further, the sensor 1 described above may be configured as a facing type. In this case, for example, after separating the first device having at least the wave transmitting unit 111 and the first wave receiving unit 112A and the second device having the second wave receiving unit 112B, each of these devices is divided into the target area are provided so as to face each other with the . In such a configuration, after YES in SA3 of FIG. 3, SA4 to SA6 may be omitted and SA7 to SA10 may be executed.

(For other application examples)
Further, based on the measurement result of the propagation time or amplitude described above, the detection of the target in the target region or the detection of the distance to the target may be performed.

(About features)
Also, the features of the above embodiment and the features of the modifications may be combined arbitrarily.

(Appendix)
The fire sensor of Supplementary Note 1 is a fire sensor that detects a fire that occurs in a target area, based on sound velocity information in the target area and an attenuation coefficient that indicates the degree of attenuation of sound waves in the target area. and fire detection means for detecting a fire occurring in the target area.

The fire sensor according to Supplementary Note 2 is the fire sensor according to Supplementary Note 1, further comprising wave transmitting means for transmitting sound waves to the target area and wave receiving means for receiving sound waves, wherein the fire The detecting means performs a first process of calculating the sound velocity information and the attenuation coefficient based on the sound wave received by the wave receiving means, and the temperature of the target region based on the calculated sound velocity information and the attenuation coefficient. and a third process of detecting a fire occurring in the target area based on the identified temperature.

The fire sensor according to Supplementary Note 3 is the fire sensor according to Supplementary Note 2, wherein the fire detection means specifies the temperature and humidity of the target area in the second process, and detects the specified temperature in the third process. and based on humidity to detect fires occurring in the area of interest.

The fire sensor according to Supplementary Note 4 is the fire sensor according to Supplementary Note 2 or 3, wherein the wave receiving means includes first wave receiving means provided near the wave transmitting means and and a second wave receiving means provided at a position farther than the first wave receiving means, wherein the fire detecting means, in the first processing, includes the first wave receiving means and the second wave receiving means. At least the attenuation coefficient is calculated based on the sound waves received by the wave means.

The fire sensor according to Supplementary Note 5 is the fire sensor according to any one of Supplementary Notes 2 to 4, wherein, in the first processing, the fire detection means receives sound waves transmitted from the wave transmission means. The fire sensor further comprises correcting means for calculating the speed-of-sound information based on the propagation distance propagated until the wave is received by the wave means, and for correcting the propagation distance.

(Effect of Supplementary Note)
According to the fire detector described in Supplementary Note 1, by detecting a fire occurring in a target area based on sound velocity information and an attenuation coefficient, for example, a fire can be reliably detected without introducing smoke into the fire detector. detection becomes possible.

According to the fire sensor described in Supplementary Note 2, by detecting a fire occurring in the target area based on the temperature in the target area, for example, it is possible to reliably detect a fire.

According to the fire sensor described in Supplementary Note 3, by detecting a fire occurring in the target area based on the temperature and humidity in the target area, for example, it is possible to reliably detect a fire.

According to the fire sensor described in Supplementary Note 4, by calculating at least the attenuation coefficient based on the sound waves received by the first wave receiving means and the second wave receiving means, for example, the calculation accuracy of the attenuation coefficient is improved. Therefore, it is possible to reliably detect a fire.

According to the fire sensor described in appendix 5, by correcting the propagation distance, for example, it is possible to calculate the speed-of-sound information using the propagation distance suitable for the environment in which the fire sensor is installed. It becomes possible to reliably detect a fire.

1 sensor 11 sound wave unit 12 alarm unit 13 recording unit 14 control unit 111 wave transmitting unit 112A first wave receiving unit 112B second wave receiving unit 141 fire detection unit 142 correction unit 900 correction jig 901 reflector L distance

Claims (5)

A fire detector for detecting fires occurring in an area of interest,
Fire detection means for detecting a fire occurring in the target area based on sound velocity information in the target area and an attenuation coefficient indicating the degree of attenuation of sound waves in the target area;
Fire detector with. wave transmitting means for transmitting sound waves to the target area;
and a receiving means for receiving sound waves,
The fire detection means is
a first process of calculating the sound velocity information and the attenuation coefficient based on the sound wave received by the wave receiving means;
a second process of identifying the temperature of the target region based on the calculated sound velocity information and the attenuation coefficient;
performing a third process of detecting a fire occurring in the target area based on the specified temperature;
A fire sensor according to claim 1. The fire detection means is
In the second process, specifying the temperature and humidity of the target area,
In the third process, detecting a fire occurring in the target area based on the specified temperature and humidity;
A fire sensor according to claim 2. The wave receiving means is
a first wave receiving means provided in the vicinity of the wave transmitting means;
a second wave receiving means provided at a position farther from the wave transmitting means than the first wave receiving means;
The fire detection means is
In the first processing, at least the attenuation coefficient is calculated based on the sound waves received by the first wave receiving means and the second wave receiving means;
The fire sensor according to claim 2 or 3. The fire detection means is
In the first processing, calculating the speed-of-sound information based on the propagation distance that the sound wave transmitted from the wave transmitting means is propagated until the wave is received by the wave receiving means;
The fire sensor is
Further comprising correction means for correcting the propagation distance,
A fire sensor according to any one of claims 2 to 4.

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