JPH03238594A - fire detection device - Google Patents

Abstract

PURPOSE:To expand a monitoring range to be surely sensed by a sensor device by receiving the sensed result of the sensor device through a wireless means. CONSTITUTION:When a closed circuit 34 consisting of a low melting point material is closed, an LCX parallel resonance circuit consisting of a 2nd antenna 31, a capacitor 32 and a crystal oscillator 33 is closed in the sensor device 30. Thereby, the LCX parallel resonance circuit is resonated by a monitoring frequency signal received through the 2nd antenna 31 and a echo based upon a resonance current is wirelessly received by the 1st antenna 23 by means of electromagnetic coupling. When the circuit 34 is fused and disconnected by fire generation, the 2nd antenna 31 is disconnected and the echo disappears. Thereby, the echo is inputted to the detection part 22 of the main device 20 and the detection part 22 detects the existence of fire generation in the monitoring area. Thus, the monitoring range to be surely sensed by the sensor device 30 is widened.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a fire detection device for detecting the occurrence of a fire within a building.

[Prior art] A fire detection device in a building includes a main device placed at a certain position in the building, a sensor device placed at another position in the building, and a sensor device arranged between the main device and the sensor device. It is necessary to have a transmission path for transmitting power and control signals.

[Problems to be Solved by the Invention] However, conventional fire detection devices use wires as transmission paths. For this reason, it is necessary to wire a transmission line within the walls of the building or under the ceiling, making construction complicated.

Further, the sensor device detects the presence or absence of a fire using a bimetal heat-sensitive switch or the like placed in a local area such as the center of the ceiling panel material, and the range that can be monitored by the sensor switch is relatively narrow.

SUMMARY OF THE INVENTION An object of the present invention is to provide a fire detection device that can wirelessly receive sensing results of a sensor device and can widen the monitoring range that can be reliably sensed by the sensor device.

[Means for Solving the Problems] The present invention as set forth in claim 1 provides a fire detection device comprising a main device and a sensor device disposed at a specific position in a building remote from the main device, wherein the main device comprises: A signal generation section that generates a specific monitoring frequency signal, a detection section that detects the presence or absence of an echo from the sensor device, and a signal generated by the signal generation section is transmitted to the sensor device by electromagnetic coupling, and the echo from the sensor device is detected. a first antenna that receives the signal, a changeover switch that selectively connects the signal generation section and the detection section to the first antenna, and a control that switches the changeover switch to the signal generation section and the detection section at a constant cycle. The sensor device includes a closed circuit formed from a low melting point material and a display section that displays the detection results of the detection section, and a sensor device that is provided in the closed circuit and that generates a signal by electromagnetic coupling. A second antenna that receives a monitoring frequency signal from the signal generating section and transmits an echo resonated with the signal to the main device, and a resonant circuit that corresponds to the monitoring frequency signal from the signal generating section. It was designed so that

In the present invention as set forth in claim 2, the closed circuit formed from the low melting point material is routed along the periphery of the structural panel of the building.

According to a third aspect of the present invention, the resonant circuit is an L CX parallel resonant circuit including a second antenna, a capacitor, and a solid-state resonator.

The present invention according to claim 4 provides a fire detection device in which a sensor device is arranged at each of a plurality of positions in a building,
The signal generator of the main device cyclically sends out monitoring frequency signals with different frequencies at predetermined intervals, and each sensor device resonates with one of the frequency signals,
The detection section of the main device is designed to detect whether a fire has occurred at each location within the building based on the presence or absence of an echo transmitted by the sensor device and the frequency of the echo.

According to the present invention described in [Action-Claim], the above-mentioned effect (2) is achieved.

■When the closed circuit made of low melting point material is closed, the sensor device has a closed resonant circuit, so the resonant circuit resonates due to the monitoring frequency signal received via the second antenna, causing resonance. The signal is received by the first antenna wirelessly by an echo caused by a current or by electromagnetic coupling. When a closed circuit made of a low-melting point material melts and breaks due to a fire outbreak, the second antenna is disconnected and the echo disappears.

The echo received via the first antenna is input to the detection section of the main device, so the detection section can detect whether a fire has occurred in the monitoring area based on the presence or absence of this echo.

At this time, the closed circuit, which melts when a fire occurs, can be widely spread around a specific location in the building, making the entire area the monitoring range.

That is, the sensing results of the sensor device can be wirelessly received, and the monitoring range that can be reliably sensed by the sensor device can be widened.

According to the present invention as set forth in claim 2, there is the following effect (2).

■A closed circuit that melts in the event of a fire is routed along the periphery of the building's ceiling material, for example.

Therefore, the range along the periphery of the ceiling surface material, in other words, the entire range of the living room, etc., which is the area to be monitored, can be set as the monitoring range that can be reliably sensed by the sensor device.

According to the present invention as set forth in claim 3, there is the following effect (2).

■By generating an echo for the monitoring frequency signal in the LCX parallel resonant circuit, the echo attenuation becomes gradual, and as a result, the echo level increases after the same period of time has elapsed, extending the detection distance. It is possible to increase the wireless distance between the device and the sensor device. Therefore, the degree of freedom regarding the location of the main device and the sensor device is increased, and the construction of the fire detection device can be simplified.

According to the present invention as set forth in claim 4, there is the following effect (2).

■When there are multiple objects to be monitored and multiple sensor devices, each sensor device resonates at its own assigned frequency. Can identify the condition.

At this time, when using an LCX parallel resonant circuit, its Q
Since the number of sensor devices is large, the frequency width required to identify the same number of sensor devices is narrower than when using an LC parallel resonant circuit. Therefore, it is possible to inscribe a large number of sensor devices into one main device, and the identification ability is improved.

[Example] Fig. 1 is a block diagram showing the fire detection device of the present invention, and Fig. 2 is a block diagram showing the fire detection device of the present invention.
Figure is an electrical circuit diagram showing the fire detection device, Figure 3 is a schematic diagram showing transmitted waves and echo waves, Figure 4 is a schematic diagram showing echo attenuation characteristics, and Figure 5 is the main equipment and sensor equipment in the building unit. FIG.

As shown in FIGS. 1 and 2, the fire detection device 10 includes a main device 20 and sensor devices 30 (30A, 3
0B, 30C-...).

The manufactured W20 includes a signal generating section 21, a detecting section 22, and a first
The antenna 23 (inductance Ll), a changeover switch 24, a control section 25, and a display section 26 are configured.

The signal generator 21 generates different frequencies fl by switching the oscillation circuit or by performing frequency modulation.
f2. Monitoring frequency signals f3... are sent out sequentially and cyclically at a predetermined period.

The detection unit 22 takes in a signal from the sensor device 30, performs signal amplification, etc., and detects the presence or absence of an echo. At this time, the detection unit 22 detects whether a fire has occurred in each monitoring target area from the presence or absence of echoes and the frequency.

The first antenna 23 is, for example, a loop antenna,
The signal generated by the signal generator 21 is transmitted and the echo is received by electromagnetic coupling.

The changeover switch 24 selectively connects the signal generation section 21 and the detection section 22 to the first antenna 23 .

The control unit 25 controls starting and stopping of the signal generation unit 21, and also controls the changeover switch 24 every time the signal generation unit 21 sends out a frequency signal for monitoring, immediately before the echo from the sensor device 30 attenuates. is switched to the detection unit 22 side.

The display unit 26 displays the detection result of the detection unit 22 by, for example, turning on or off a light emitting element, or by sounding a buzzer.

The sensor device 30 (30A, 30B, 30C...) includes a second antenna 31 (inductance L2), a capacitor 32 (capacitance C2), a crystal oscillator 33 (X),
The closed circuit 34 is formed from a low melting point material such as AI2 wire.

The second antenna 31 of each sensor device 30 is connected to a closed circuit 34
The monitoring frequency signals fl, f2, f3 from the signal generating section 21 of the main device 20 are generated by electromagnetic coupling.
... and transmits an echo that resonates with any one of those frequencies.

In each sensor device 30, the second antenna 31, capacitor 32, and crystal oscillator 33 constitute an LCX parallel resonant circuit, and the frequencies f1, f2, f3, . . . of the monitoring frequency signals sent out by the signal generator 21 are The values of L2, C2, and X are selected so as to resonate with any one specific one.

FIG. 3 shows a transmission wave sent out by the signal generator 21 of the main device 20 and an echo wave sent out by the sensor device 30.

Incidentally, the fire detection device 10 is applied to a building in which a plurality of building units 11 as shown in FIG. 5 are joined together, and a sensor device 30 is installed in each building unit 11 serving as a monitoring target area. At this time, the first antenna 23 of the main device 20 is routed along the outer edge of the ceiling panel of the building unit 11, and the second antenna 31 of the sensor device 30
is routed along the inner periphery of the ceiling surface material of the building unit 11.

Next, the operation of the fire detection device 10 will be explained.

In the fire detection device 10, monitoring frequency signals of frequencies f1, f2, f3, . cyclically oscillates.

A fire has now broken out in the monitoring target area (building unit 11) where a sensor device 30n that resonates at frequency fn is installed.
Assume that the low melting point material forming the closed circuit 34 in the monitoring target area melts and breaks.

At this time, the fire detection device 10 detects the following (A) (B)
It works like this.

(A) Frequencies f1, f2, f3-f (n-1
) is sent out from the signal generator 21, the changeover switch 24 is set to the signal generator 21 side (contact a), and the signal generator 21 sends the frequencies f1 and f2 to the first switch 23. , f 3 ...f (n-1) currents flow.

■ Due to the above ■, magnetic flux is generated from the first antenna 23, and among the sensor devices 130, the sensor devices 30 other than the sensor device 30n whose closed circuit 34 is in a closed state resonate in parallel, and the resonant current The signal flows to the antenna 31 of No. 2.

(2) The changeover switch 24 is switched to the detecting section 22 side (contact b) in synchronization with the end of the oscillation in (2) above.

(2) Due to the above (2), the magnetic flux from the first antenna 23 disappears, and an echo (alternating magnetic flux) is generated from the second antenna 31.

■Through the mutual inductance M, the first antenna 23
and the second antenna 31 are electromagnetically coupled, and an induced current flows through the first antenna 23.

(2) That is, the echo generated in the sensor device 30 in response to the monitoring frequency signal is received by the first antenna 23 by electromagnetic coupling, and this received signal is input to the detection unit 22 through the changeover switch 24, where it is amplified. be done.

- The detection unit 22 determines the monitoring target area to which this frequency is assigned based on the frequency of the input received echo, and monitors information regarding the presence or absence of a break in the closed circuit 34 in the monitoring target area, in other words, the presence or absence of a fire outbreak. is displayed on the display section 26.

(B) The monitoring frequency signal of frequency fn is transmitted to the signal generator 21
When the sensor device 30 other than the sensor device 3130n has a closed circuit 34, the first antenna 23 and the second antenna 31 are electromagnetically coupled. However, it does not perform resonance operation.

(2) The sensor device 30n does not operate because the closed path 34 is disconnected and open.

(2) Based on the absence of a received echo for the monitoring frequency signal fn, the detection unit 22 of the main device 20 determines the monitoring target area to which this frequency is assigned, and detects the occurrence of disconnection of the closed circuit 34 in the monitoring target area; In other words, information on the occurrence of a fire is displayed on the display section 26.

At the timing when the signal processing and discrimination processing in the detection section 22 are completed, the control section 25 switches the changeover switch 24 to the signal generation section 21 side (contact a), and the signal generation section 21 switches to the monitoring frequency f1. Send a signal.

By the way, the resonant current of the LC parallel resonant circuit is rapidly attenuated, but the resonant current of the LCX parallel resonant circuit is
3, as shown in FIG. 4(A), the attenuation becomes more gradual than in the case of the LC parallel resonant circuit, and the time TO required for the attenuation to reach a receivable critical level becomes longer. In addition, since the LCX parallel resonant circuit has a high Q, the resonant waveform becomes sharp, and the frequency band required to identify received echoes is narrow, making it easy to identify multiple echoes in different frequency ranges without interference. becomes.

Next, the operation of the fire detection device 10 will be explained.

■When the closed circuit 34 made of a low melting point material is closed, the sensor device aF30 connects the second antenna 31 and the capacitor 3.
Since the LCX parallel resonant circuit consisting of the second antenna 31 and the crystal resonator 33 is closed, the LCX parallel resonant circuit resonates due to the monitoring frequency signal received through the second antenna 31, and an echo due to the resonant current or electromagnetic coupling causes the LCX parallel resonant circuit to resonate. The signal is received by the first antenna 23 wirelessly. When the closed path 34 made of a low melting point material melts and breaks due to a fire outbreak,
The second antenna 31 is disconnected and the echo disappears.

The echo received via the first antenna 23 is input to the detection unit 22 of the main device 20, so the detection unit 22 determines whether a fire has occurred in the monitoring area based on the presence or absence of this echo. can be detected.

At this time, the closed passage 34, which melts when a fire occurs, can be widely spread over a specific position in the building, making the entire range the monitoring range.

That is, the sensing results of the sensor device W30 can be received wirelessly, and the monitoring range that can be reliably sensed by the sensor device 30 can be widened.

■The closed circuit 34, which melts when a fire occurs, is routed along the periphery of the ceiling panel of the building. Therefore, the monitoring range that can be reliably sensed by the sensor device 30 can be the range along the periphery of the ceiling surface material, in other words, the entire range of the living room, etc., which is the monitoring target area.

■By generating an echo for the monitoring frequency signal using the LCX parallel resonant circuit, the attenuation of the echo becomes gradual, and as a result, the echo level increases after the same amount of time has elapsed, making it possible to extend the detection distance. The wireless distance between the device 20 and the sensor device 30 can be increased. Therefore, the main device 20 and the sensor device 30
The degree of freedom regarding the location of the fire detection device 10 is increased, and the construction of the fire detection device 10 can be simplified.

■When there are multiple objects to be monitored and multiple sensor devices 30, each sensor device resonates at its own assigned frequency. The physical condition can be identified.

At this time, since the Q of the LCX parallel resonant circuit is large, the frequency width required to identify the same number of sensor devices 30 is narrower than when using the LC parallel resonant circuit. Therefore, one main device 20 is used for a large number of sensor devices 30.
This will improve identification ability.

[Effects of the Invention] As described above, according to the present invention, the sensing results of the sensor device can be wirelessly received, and the monitoring range that can be reliably sensed by the sensor device can be widened.

[Brief explanation of drawings]

Figure 1 is a block diagram showing the fire detection device of the present invention, Figure 2 is a block diagram showing the fire detection device of the present invention.
Figure is an electrical circuit diagram showing the fire detection device, Figure 3 is a schematic diagram showing transmitted waves and echo waves, Figure 4 is a schematic diagram showing echo attenuation characteristics, and Figure 5 is the main equipment and sensor equipment in the building unit. FIG. DESCRIPTION OF SYMBOLS 10... Fire detection device, 11... Building unit, 12... Ceiling surface material, 20... Main device, 21... Signal generation part, 22... Detection part, 23... No. 1 antenna, 24... Selector switch, 25... Control unit, 26... Display unit, 30... Sensor device, 31... Second antenna, 32... Capacitor, 33...・Crystal oscillator, 34...Closed circuit.

Claims (4)

[Claims] (1) In a fire detection device consisting of a main device and a sensor device placed at a specific location in a building separated from the main device, the main device includes a signal generator that generates a specific monitoring frequency signal, and a sensor device that generates a specific frequency signal for monitoring. a first antenna that transmits the signal generated by the signal generator to the sensor device and receives the echo from the sensor device by electromagnetic coupling; each first
A control section that switches the switch to the signal generation section and the detection section at a constant cycle, and a display section that displays the detection results of the detection section. , the sensor device includes a closed circuit formed from a low-melting point material, and is provided within the closed circuit, and receives a monitoring frequency signal from a signal generator by electromagnetic coupling;
A fire detection device comprising: a second antenna that transmits an echo resonated with the signal to the main device; and a resonant circuit corresponding to a monitoring frequency signal from a signal generating section. (2) The fire detection device according to claim 1, wherein the closed circuit formed from the low melting point material is routed along the periphery of a structural panel of the building. (3) Claim 1, wherein the resonant circuit is an LCX parallel resonant circuit comprising a second antenna, a capacitor, and a solid resonator.
Or the fire detection device described in 2. (4) In a fire detection system in which sensor devices are arranged at multiple locations in a building, the signal generating section of the main device cyclically sends out monitoring frequency signals with different frequencies at predetermined intervals, and The sensor device resonates with one of the frequency signals, and the detection section of the main device detects whether a fire has occurred at each location within the building based on the presence or absence of an echo transmitted by the sensor device and the frequency of the echo. A fire sensing device according to any one of claims 1 to 3.