JP3045645B2 - Flame detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flame detector, and more particularly, to a flame detector using a pyroelectric element for detecting infrared light having a wavelength specific to a flame.

[0002]

2. Description of the Related Art Conventionally, an infrared flame detector detects the characteristics of infrared light emitted from a flame to judge the occurrence of a fire. Since artificial infrared light is overflowing, selection of an infrared wavelength range to be detected and advanced fire judgment processing are required.

In a fire alarm (fire alarm system) using such a flame detector, a two-wire receiving line is provided corresponding to a security area (for example, each room) covered by the fire alarm. Is installed, and a plurality of flame detectors are connected to the receiving line. The flame detector connected to the receiving line has a high impedance in the normal monitoring state where no flame is detected, and when the flame is detected, the switching circuit is turned on.
As a result, the impedance becomes low.

In a fire alarm that covers one alert area, the allowable monitoring current in a normal monitoring state is as follows:
For example, since the current consumption in the monitoring state of the flame detector is 100 μA because it is suppressed to 800 μA,
Up to eight can be connected. For this reason, it is desirable that the flame sensor has as high an impedance as possible under normal monitoring conditions.

[0005]

However, in such a conventional flame detector connected to a two-wire receiving line, the allowable monitoring current amount of a fire alarm (fire alarm system) is specified. However, since the flame detector needs to have a high impedance in the monitoring state, there are the following problems.

That is, it is necessary to connect a plurality of flame sensors within the range of the allowable monitoring current amount specified in the fire alarm, and the consumption of the flame detector is high by using a flame sensor whose impedance in the monitoring state is high. Since the current is reduced, it is difficult to use a CPU (Central Processing Unit) with relatively large current consumption in the flame detector, and the infrared wavelength range is selected from the detection signals detected using the CPU. And it is difficult to perform advanced fire judgment processing.

[0007] Like the fire alarm, the function of the flame detector is required to be checked once every six months. In the function confirmation test using a flame detector, it is a quick method to confirm that it operates by burning the actual flame, but it is difficult to burn the flame due to the restrictions of the building where the flame detector is installed. In addition, there are many handling problems when bringing dangerous materials such as fuel to the site even when a flame can be burned.

Therefore, conventionally, a light emitting device provided with an appropriate light source for function confirmation has been brought near the flame detector,
Although the function check test of the sensor was performed by projecting light to the flame detector, the light of the light source projected as a substitute for the flame did not have the same characteristics and light output as the actual flame. It was difficult to realize a function confirmation test based on the occurrence of flame. Also,
If the flame detector was designed so that it would not be easily actuated by ambient ambient light, it would be necessary to bring the floodlight close to the flame detector mounted at a high altitude, and the tester's hands Was annoying.

[Purpose] The present invention suppresses the current consumption and reduces C
An object of the present invention is to provide a flame detector having a function of performing a high-level fire judgment process by enabling use of a PU and a function of performing a high-level function confirmation process using test light projected from a flame detection range. .

[0010]

According to a first aspect of the present invention, there is provided a flame detector for detecting a plurality of infrared rays having different wavelengths unique to the flame by detecting infrared rays having a wavelength unique to the flame and detecting the flame. And an infrared detecting means for outputting a detection signal corresponding to each wavelength, and amplifying each detection signal detected by the infrared detecting means with a predetermined amplification degree, converting the detection signal to a predetermined voltage level, and outputting the same. Level conversion means, and flame occurrence determination means for detecting level data from the detection signal of each wavelength output by the level conversion means, and determining the occurrence of the flame based on a comparison result of the detected level data, Flame generation notifying means for notifying the occurrence of a flame when the flame generation determining means determines that a flame has occurred , wherein the infrared detecting means includes a first flame specific to the flame.
Detecting infrared light of the wavelength and the second wavelength and responding to the first and second wavelengths.
And the level conversion means outputs the detected signal.
First and second wavelength detection signals detected by the line detection means
Is converted to a predetermined voltage level on the positive side,
Another means is a first signal output by the voltage level conversion means.
Of peak level data and peak of the first wavelength
Detecting the signal level of the second wavelength corresponding to the position,
A predetermined operation is performed on the detected level data of the first and second wavelengths.
Judgment of the occurrence of the flame based on the processing result
It is characterized by doing.

[0011]

Furthermore, as in the invention of claim 2, wherein the flame generation determination means, first, when the respective level data of the second wavelength for processing by a predetermined calculation process, the peak voltage of the first wavelength It is effective to calculate the ratio by taking the average of the difference between the value of the second wavelength at the peak of the first wavelength and the value of the second wavelength.

Furthermore, as in the invention of claim 3, wherein said flame generation determination means, when the level of the first wavelength is a predetermined value or more, together with the first, takes in each level data of the second wavelength, It is effective to perform the process of determining the occurrence of the flame every predetermined time.

Further, as in the invention according to claim 4 , each level data of the first and second wavelengths outputted by the level conversion means is compared, and when the ratio becomes a predetermined value,
It is effective to provide an operation confirmation notifying unit for notifying whether or not the infrared detecting unit is operating normally.

Further, as in the invention according to claim 5 , the process of judging the occurrence of the flame by the flame occurrence judging means is executed prior to the operation confirmation of the infrared detecting means by the operation confirmation notifying means. It is effective.

According to a sixth aspect of the present invention, after the operation confirmation notifying means executes the operation confirmation notification of the infrared ray detecting means, the process returns to the flame occurrence determining processing by the flame occurrence determining means. Is valid.

[0017] Furthermore, as in the invention of claim 7, wherein, in the said level converting means and flame generation determination means, a first power supply for supplying setting a first power supply voltage on the positive side, the first Approximately 1 / the first power supply voltage set by the power supply
A power supply voltage is supplied from a second power supply for setting and supplying a second power supply voltage, and the flame occurrence determination means is connected between the second power supply output stage and the common of the level conversion means. It is effective.

Further, as in the invention of claim 8, wherein the level converting means, first detected by the infrared detection means, the first and the second wavelength the detection signal is amplified by a predetermined amplification degree, Amplifying means for outputting an amplified signal of each of the second wavelengths; a signal corresponding to the fluctuation of the flame extracted from each of the amplified signals of the first and second wavelengths amplified by the amplifying means to extract each of the first and second wavelengths; Extraction means for outputting the signal, the signal amplification characteristic of the amplification means and the signal extraction characteristic of the extraction means are set to be equivalent, and the first and second wavelength detection signals are amplified and extracted at the same ratio. Is valid.

[0019]

According to the first aspect of the present invention, in a flame detector for detecting a flame by detecting infrared rays having a wavelength specific to the flame, the infrared detecting means detects a plurality of infrared rays having different wavelengths specific to the flame. A detection signal corresponding to each wavelength is output, and a level conversion unit amplifies each detection signal detected by the infrared detection unit with a predetermined amplification degree, converts the detection signal to a predetermined voltage level, and outputs it. When the flame occurrence determining means detects level data from the detection signal of each wavelength output by the level conversion means and determines the occurrence of the flame based on a comparison result of the detected level data, the flame occurrence notifying means , To that effect.

In this case, the infrared detecting means may include:
Detects first and second wavelengths of infrared light unique to the flame and outputs detection signals corresponding to the first and second wavelengths, and the level conversion means detects the first and second wavelengths detected by the infrared light detection means. Each of the two-wavelength detection signals is converted into a predetermined voltage level on the positive side, and the flame occurrence determination means determines the peak level data and the peak position of the first wavelength from the first detection signal output by the voltage level conversion means. Is detected, and the occurrence of the flame is determined based on the result of processing the detected level data of the first and second wavelengths by a predetermined arithmetic processing.

Accordingly, the first and second wavelength detection signals detected by the infrared detecting means can be processed by the level converting means in the positive half (0 to peak value), and the power supply voltage supplied to the determining means can be reduced. The amplification range that can be suppressed and the peak value can be handled without being saturated can be set large.

Further, as in the invention according to claim 2 ,
When processing the level data of the first and second wavelengths by a predetermined calculation process, the flame occurrence determining means determines the difference between the peak voltage of the first wavelength and the value of the second wavelength at the peak of the first wavelength. By taking the average of each of the difference value and the value of the second wavelength and calculating the ratio, common noise (for example, electromagnetic noise,
(Vibration noise, temperature change noise, etc.), and the reliability of the flame detector can be improved.

Further, as in the invention according to claim 3 ,
When the level of the first wavelength is equal to or more than a predetermined value, the flame occurrence determining means captures each level data of the first and second wavelengths and performs a process of determining the occurrence of the flame at predetermined time intervals. Even if a CPU is mounted in the flame detector, power consumption can be reduced.

Furthermore, as the serial mounting of the invention in claim 4,
The operation confirmation notifying means compares the level data of the first and second wavelengths outputted by the level converting means, and when the ratio becomes a predetermined value, whether or not the infrared detecting means is operating normally. , It is possible to perform a function check similar to a fire operation without changing the operation mode.

According to a fifth aspect of the present invention, the process of judging the occurrence of the flame by the flame occurrence judging unit is executed prior to the operation confirmation process of the infrared detecting unit by the operation confirmation notifying unit. By doing so, the function can be improved without causing a delay in the fire determination process due to the addition of the operation check function.

According to a sixth aspect of the present invention, after the operation confirmation notifying means executes the operation confirmation notification of the infrared detecting means, the process returns to the flame occurrence determining processing by the flame occurrence determining means. Accordingly, it is not necessary to perform an operation such as an operation mode change, and the function confirmation test can be easily performed.

Furthermore, as in the invention according to claim 7 , the level conversion means and the flame occurrence determination means include a first power supply for setting and supplying a first power supply voltage on the positive side, Approximately 1 / the first power supply voltage set by the power supply
A power supply voltage is supplied from a second power supply for setting and supplying a second power supply voltage, and the flame occurrence determination means is connected between the second power supply output stage and the common of the level conversion means. Thus, the common of the level conversion means and the common of the flame occurrence determination means can be set to the same potential, and the flame occurrence determination means only needs to detect the positive peak, thereby facilitating the construction of a fire determination processing program. can do.

Also, as in the invention according to claim 8 , the level conversion means amplifies the first and second wavelength detection signals detected by the infrared detection means with a predetermined amplification degree to obtain first and second wavelengths. Amplifying means for outputting an amplified signal of each of the second wavelengths; a signal corresponding to the fluctuation of the flame extracted from each of the amplified signals of the first and second wavelengths amplified by the amplifying means to extract each of the first and second wavelengths; Extraction means for outputting the signal, the signal amplification characteristic of the amplification means and the signal extraction characteristic of the extraction means are set to be equivalent, and the first and second wavelength detection signals are amplified and extracted at the same ratio. Accordingly, when the signal level of the first wavelength exceeds the saturation range of the amplification capability, the detection signals of both wavelengths can be attenuated at the same ratio, and the effects of environmental changes (temperature, various noises) can be canceled. To improve flame detector reliability It can be.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. 1 to 14 are views showing an embodiment of a flame detector according to the present invention.

First, the configuration will be described. FIG. 1 is a block diagram of the flame detector 1. In FIG. 1, a flame detector 1
Are sensors 2, 3, voltage amplification circuits 4, 5, filter circuits 6, 7, DC level conversion circuits 8, 9, comparator 1
0, CPU 11, fire output circuit 12, confirmation output circuit 1
3, operation indicator 14, constant voltage power supply I15, constant voltage power supply II
16 and a rectifier circuit 17.

Each of the sensors 2 and 3 is composed of, for example, a pyroelectric element having an infrared detecting function, generates a differential charge output with respect to incident light, and performs a differential proportional to thermal energy fluctuation generated from the flame. Output a signal. In the present embodiment, the sensor 2 detects a first wavelength (for example, 4.4 μm) indicating the carbon dioxide resonance radiation light peculiar to the flame.
Detects a second wavelength (for example, 3.9 μm) in the vicinity thereof.

The voltage amplifying circuits 4 and 5 amplify the first and second wavelength detection signals input from the sensors 2 and 3 at a predetermined amplification degree and output the amplified signals to the filter circuits 6 and 7. In the voltage amplification circuits 4 and 5, when the peak signals included in the first and second wavelength detection signals exceed the saturation region of the amplifier, the amplification is reduced at a fixed ratio (for example, 1/20). It is also possible.

The filter circuits 6, 7 include a voltage amplifying circuit 4,
5, a signal of several Hz to several tens of Hz corresponding to the fluctuation of the flame is extracted from the first and second wavelength detection signals amplified, and the first and second extracted signals are output to the DC level conversion circuits 8 and 9. I do.

The DC level conversion circuits 8 and 9 convert the first and second extracted signals extracted by the filter circuits 6 and 7 into DC-
By converting the signal to 0 V common, the first and second amplitude signals of DC + one-sided amplitude are generated and output to the input channels CH1 and CH2 of the CPU 11. Also, DC
The first amplitude signal generated by the level conversion circuit 8 is also output to the comparator 10.

The comparator 10 compares the peak voltage of the first amplitude signal input from the DC level conversion circuit 8 with a reference voltage Vth set based on the power supply voltage VDD2 input from the constant voltage power supply II. The result is output to an interrupt input of the CPU 11. That is, the comparator 10
For example, when the peak voltage of the first amplitude signal exceeds the reference voltage Vth, a logically inverted signal is output.

The CPU 11 has a built-in A / D converter and a buffer, executes a fire judgment process to be described later at the input timing of the inverted signal input from the comparator 10 to the interrupt input, and receives the input from the DC level conversion circuits 8 and 9. The signals are read into the channels CH1 and CH2, a peak voltage of the first wavelength and a voltage of the second wavelength corresponding to the peak position of the first wavelength are respectively detected, and the detected level data of the first and second wavelengths are respectively obtained. It is determined whether or not a fire has occurred based on the processing result of the predetermined arithmetic processing. If it is determined that a fire has occurred, a fire output signal is output to the fire output circuit 12.

When there is no interrupt input, the CPU 11 makes the following failure determination in the normal mode. C
Even if the PU 11 does not generate an interrupt and is in the normal mode, the first and second signals are input to the input channels CH1 and CH2 from the DC level conversion circuits 8 and 9 at regular time intervals (for example, 4.5 seconds). The amplitude signal is read into an A / D converter and converted into digital numerical data. The maximum value and the minimum value of the numerical data of the first wavelength and the second wavelength are respectively stored in a buffer. A maximum value and a minimum value of the wavelength and the second wavelength are calculated respectively, and a failure of the sensor or the circuit is determined based on a result of comparing the calculated values of the first wavelength and the second wavelength.

In the CPU 11, a constant voltage power supply II 16
The reference voltage Vref that sets the + side voltage V + and the resolution of the built-in A / D converter by the power supply voltage VDD2 supplied from the
Set.

The fire output circuit 12 latches the fire output signal input by the fire judgment processing of the CPU 11 and causes the operation indicator lamp 14 to display a fire occurrence. The confirmation output circuit 13 drives an active element (transistor) according to a failure output signal input by the failure determination processing of the CPU 11 or an operation confirmation signal input by the operation confirmation function, and displays a failure occurrence display or operation by the operation indicator lamp 14. Make confirmation display momentary.

The constant voltage power supply I15 generates the power supply voltage VDD1 and supplies it to the sensors 2, 3, the voltage amplifier circuits 4, 5, the filter circuits 6, 7 and the constant voltage power supply II16. Constant voltage power supply
II16 is a power supply voltage V supplied from the constant voltage power supply I15.
A power supply voltage VDD2 is generated based on DD1 and supplied to the comparator 10 and the CPU 11.

In this embodiment, since only the positive signals of the first and second wavelengths are detected, the power supply voltage of the CPU 11 can be kept low. The CPU 11 stops the processing until it exceeds, operates only the timer part built in the CPU 11, monitors the status of the first and second wavelengths (judgment of failure) by time-up (timer interrupt) every 4.5 seconds, Even after the signal of the first wavelength exceeds the comparison voltage Vth of the comparator 10, the second wavelength is not monitored until the peak value of the first wavelength is detected, thereby reducing the number of times the A / D converter is started. , Power consumption can be reduced. Thus, power consumption can be reduced by making the processing operation of the CPU 11 intermittent.

In the present embodiment, the relationship between the power supply voltage VDD1 and the power supply voltage VDD2 is designed so that VDD1 ≧ 2VDD2. In this way, the power supply voltage VDD1 and the power supply voltage VDD2 are set to suppress the power supply voltage value supplied to the comparator 10 and the CPU 11, and the comparator 10 and the C
The current consumption in the PU 11 is suppressed.

Although not shown in FIG. 1,
The power supply voltage VDD2 generated by the constant voltage power supply II16 is
It is also connected to the common side (signal: 0 V) of the voltage amplification circuits 4 and 5.

The rectifier circuit 17 makes the output of the detector non-polar in consideration of workability. The rectifier circuit 17 is connected to a receiving line of a fire alarm installed at a disaster prevention center (not shown). The power is rectified and supplied to the constant voltage power supply I15 and the operation indicator lamp 14.

Next, a function test apparatus for performing a function confirmation test of the flame detector 1 will be described with reference to the block diagram shown in FIG.

In FIG. 2, the function test apparatus 20 comprises a charger switch 21, a charging circuit 22, a nickel-cadmium battery 23, a tester switch 24, a test light source 25, a condenser mirror 26, a test start switch 27, and an optical chopper 28. Have been.

The charger switch 24 is connected to an external AC 100
This is a switch for connecting the V line to the charging circuit 22. The charging circuit 22 is a circuit that generates a charging voltage by AC100V supplied through the charger switch 21 and charges the NiCd battery 23. The NiCd battery 23 is
The battery is charged by the charging circuit 22 to generate a predetermined voltage, and supplies a power supply voltage to each unit in the function test apparatus 20.

The tester switch 24 is connected to the function tester 20
When the switch is turned on, the power supply voltage supply line from the NiCd battery 23 is connected to the test light source 25 and the test start switch 27. The test light source 25 is constituted by a halogen lamp or a visible or near-infrared laser light source, is turned on by the power supply voltage supplied from the nickel cadmium battery 25 when the tester switch 24 is turned on, and is condensed by the condensing mirror 26 to emit light. I do.

The test start switch 27 is connected to the optical chopper 2
8 is a switch for starting, and supplies a power supply voltage supplied via the tester switch 24 to the optical chopper 28 when it is turned on. The optical chopper 28 is constituted by rotating blades having slits formed therein,
, The rotating blade is rotated by the power supply voltage supplied when the test start switch 27 is turned on, and the light collected by the focusing mirror 26 is intermittently passed through the slit of the rotating blade. A test light having actual flame-like fluctuation is emitted to the outside.

Since the function test apparatus 20 includes the charger switch 21, the charging circuit 22, and the nickel cadmium battery 23, it is portable and can be used in places where no AC 100V line is installed.

Next, the operation of this embodiment will be described. First,
The main flow executed by the CPU 11 in the flame sensor 1 of the present embodiment will be described based on the flowcharts shown in FIGS.

In FIG. 3, when the power of the flame detector 1 is turned on, each input port, a start-up timer (4.5 seconds) is started, and initialization processing such as interruption processing is executed (step S1). The time-up of 4.5 seconds is checked based on the timing of the regular start timer (step S).
2). If 4.5 seconds have not elapsed, it is determined whether or not the fire processing mode is set by setting the fire processing mode setting flag (step S3). If the fire processing mode setting flag is not set, Step S
Return to 2.

That is, as shown in the flowchart of FIG. 5, the CPU 11 determines whether or not to set the fire processing mode based on the inverted signal input from the comparator 10 to the interrupt input (step S21). A fire processing mode setting flag is set (step S22).

Here, the operation of the comparator 10 and the CPU
FIG. 6 shows the relationship between the 11 AD conversion operations. When the amplitude signal of the first wavelength exceeds the reference voltage Vth (for example, 0.5 V) in the comparator 10, the CPU 11 starts the fire processing mode and starts the conversion operation by the built-in A / D converter. For example, as shown by a broken line in FIG. 6, a point where the first wavelength data input to the input channel CH1 is fetched every 10 msec and the wavelength signal changes from increasing to decreasing is found. Then, when the peak position of the first wavelength in the figure is found, the input channel CH2
, The conversion operation by the A / D converter is performed, and the digital numerical data of the first and second wavelengths are stored in an integrating buffer for obtaining an average value.

When the fire processing mode setting flag is set, as shown in FIG. 7 and FIG.
3, the first and second wavelengths are detected from the flame-specific infrared rays, and are amplified and extracted by the voltage amplifier circuits 4, 5 and the filter circuits 6, 7 as shown in FIG.
As shown in (1), each level data of the first and second wavelength amplitude signals input to the input channels CH1 and CH2 as the + side amplitude signal by the DC level conversion circuits 8 and 9 is taken (step S4), and the peak of the first wavelength is obtained. Is the voltage amplification circuit 4
(Step S5). If it does not exceed the saturation region, the process proceeds to step S7, and if it does exceed the saturation region, the amplification is set to 1 / N (for example, 1/20) (step S7).
6) In step S7, it is determined whether or not a process of returning the amplification degree of the amplifier of the voltage amplification circuit 4 is necessary. If it is determined that the process of returning the amplification is not necessary, the process immediately returns to step S2. If it is determined that the process of returning the amplification is necessary, the process returns to step S2 after returning the amplification to the standard in step S8. Return.

If it is determined in step S2 that 4.5 seconds have elapsed and the time is up, the flow shifts to step S9 in FIG. 4 to determine whether the fire processing mode has been set or not. Is determined by the set of If the fire processing mode setting flag is set, a fire determination process described later is executed (step S1).
0), a fire level is determined based on the processing result (step S11). When the fire level is determined as a result of the fire determination process, a fire occurrence output signal corresponding to the fire level is output to the fire output circuit 12 (step S1).
2) The operation indicator lamp 14 is caused to display a message indicating the occurrence of a fire, and the process is terminated. In addition, as a result of the fire determination processing, that is, as shown in FIGS. 9 and 10, a fire caused by the influence of the place where the flame detector 1 is installed (for example, a moving heat source, an artificial light source, sunlight reflection, etc.) It is determined whether the peaks are the first and second wavelength peaks when different wavelengths are detected, and if it is not abnormal, it is determined that a state other than the fire level has been determined, and the process returns to step S2.

If the fire processing mode setting flag has not been set in step S9, a process for judging abnormalities of the sensors 2 and 3 is performed, and the input channels CH1 and CH
The maximum value and minimum value data of the first and second wavelength amplitude signals input to 2 are fetched (step S13), and it is determined whether the maximum and minimum levels are abnormal (step S14).
If it is determined that the sensor is not abnormal, the process immediately returns to step S2. If it is determined that the sensor is abnormal, a failure output signal indicating a failure of the sensors 2 and 3 is output to the confirmation output circuit 13 (step S15), and the operation display is performed. The light 14 is displayed for a moment to indicate the failure of the sensors 2 and 3, and the process returns to step S2.

If it is not determined in step S11 that the fire level is attained, it is input to the input channels CH1 and CH2 by the test light projected from the function test apparatus 20 shown in FIG. 2 accompanying the function test. It is determined whether or not the condition for comparing the level values of the first and second wavelength amplitude signals and the condition for confirming the operation of the sensors 2 and 3 are satisfied (step S16).

That is, in the function test state as shown in FIG. 11, the test light from the function test apparatus 20 installed on the stand 30 in the flame sensing area of the flame detector 1 (a conical area shown by a broken line in the figure). Is projected,
Unlike the relationship between the first wavelength level and the second wavelength level of the infrared light included in the actual flame shown in FIG. 6, the relationship between the first wavelength level and the second wavelength level of the infrared light included in the test light is as follows.
As shown in FIG.

For this reason, the CPU 11 of this embodiment performs a level comparison process different from the fire judgment process,
When the ratio between the wavelength level and the second wavelength level is "1: 0.5 to
When it becomes 1 ", a confirmation output signal indicating the operation confirmation of the sensors 2 and 3 is outputted to the confirmation output circuit 13 and the step S
After the operation indicator lamp 14 is turned on instantaneously in step 17,
Return to 2.

In the case of this embodiment, the amplification characteristics of the voltage amplifier circuits 4 and 5 and the filter characteristics of the filter circuits 6 and 7 shown in FIG. 1 are designed to be equivalent, and the influence of humidity and electromagnetic field noise is reduced. Since the first and second outputs appear equally, it is possible to avoid determining the peak of the abnormality as a fire. Further, when the signal level of the first wavelength exceeds the saturation range of the voltage amplifier circuits 4 and 5, the first and second wavelengths can be attenuated at the same ratio, and changes in the environment (temperature, various noises). The effect can be canceled.

The first and second wavelength detection signals of the sensors 2 and 3 shown in FIGS. 7 and 8 (a) greatly fluctuate. In this example, even if the sensors 2 and 3 are installed in an environment subject to disturbance, if there is an input based on a fire in the first wavelength detection signal, a difference voltage between the first wavelength detection signal and the second wavelength detection signal is obtained. Occurs, and the occurrence of a fire can be reliably determined.

Next, the fire judgment process executed in step S10 of FIG. 4 will be described with reference to the flowchart shown in FIG.

In FIG. 13, first, the peak value of the first wavelength and the average value of the level values of the second wavelength stored in the buffer in the CPU 10 are calculated (step P1).
The level ratio of the second wavelength is calculated (Step P2). Next, it is determined whether the average value of the first and second wavelength levels calculated in step P1 is smaller than a certain value (step P1).
3) If the number is small, the fire determination process is terminated (step P4). If the number is large, it is determined whether the number of peak data is large (for example, 2 or less per second) (step P4).
5). If the number of peak data is large, it is determined whether the first wavelength peak value and the second wavelength peak value are equal to or more than a certain value (step P6). It is determined whether the ratio of the peak values is equal to or greater than a certain value (step P7). If the ratio is equal to or greater than the certain value, it is determined that a fire has occurred and a fire output signal is output (step P7).
8). In addition, FIG.
In the case of the ratio between the first wavelength and the second wavelength shown in (1), it is determined that the operation is at the operation test level (Step P9), and the operation indicator lamp 14 is turned on instantly (Step P10).

If the number of peak data is small in Step P5, it is determined whether or not a value obtained by subtracting the second wavelength peak value from the first wavelength peak value is not less than a certain value (Step P10). In the case of, it is determined whether or not the ratio of the first wavelength peak value to the second wavelength peak value is equal to or more than a certain value (step P11). Output an output signal (Step P1
2). In addition, FIG.
In the case of the ratio between the first wavelength and the second wavelength shown in (1), it is determined that the operation is at the operation test level (step P13), and the operation indicator lamp 14 is turned on instantly (step P14).

FIG. 14 is a timing chart showing the operational relationship of the function confirmation process executed in the fire judgment process. That is, in the flame sensor 1 of the present embodiment, when the test light is projected from the function test device 20 and the sensors 2 and 3 are turned on (see FIG. 3A), the fire determination process is started (see FIG. (B)), operation indicator 1
4 is turned on instantaneously (see FIG. 3 (c)). When it is determined that an actual flame is generated, the operation indicator lamp 14 is continuously turned on as shown by a broken line in FIG.

In the above-described fire judgment processing, in the present embodiment, the following three fire level judgment conditions are set according to the correlation between the fire judgment time and the first and second wavelength peak data.

(High level fire I) Judgment time 4.5 seconds (1 frame) A Voltage amplification degree Low amplification level B First wavelength peak voltage integrated value ≧ 5 × Second wavelength voltage integrated value C Peak frequency ≧ 3 times / Second D First wavelength average peak signal level ≥ 0.2 V (High level fire II) Judgment time 9.0 seconds (2 frames) A Voltage amplification High amplification level B First wavelength peak voltage integrated value ≥ 6 x second wavelength Voltage integrated value C First wavelength average peak signal level ≥ 0.5 V D Peak frequency ≥ 3 times / second (normal level fire) Judgment time 14.5 seconds (3 frame) i Voltage amplification high amplification level B 1st wavelength peak Voltage integrated value ≧ 4 × second wavelength voltage integrated value c First wavelength average peak signal level ≧ 0.2V d Peak frequency ≧ 3 times / second In the flame detector 1 of this embodiment, the comparator 10 and the CPU
11 to suppress the current consumption, the comparator 10 and the CPU 11 perform advanced fire judgment processing based on the above set conditions, and output a fire output signal corresponding to each fire level to the fire output circuit 12. Then, it is displayed on the operation indicator lamp 14 and notified.

Therefore, in the flame detector 1 of this embodiment,
The first and second wavelength detection signals detected by the sensors 2 and 3 are processed by the voltage amplification circuits 4 and 5, the filter circuits 6 and 7, and the DC level conversion circuits 8 and 9 in the positive half (0 to peak value). As a result, the power supply voltage supplied to the CPU 11 can be kept low, and the amplification range that can be handled without saturating the peak value can be set large.

The commons of the voltage amplification circuits 4 and 5 and the CP
By connecting U11 to the power supply voltage VDD2 of the low-voltage power supply II and setting it at the same potential, signal processing only needs to detect the peak on the plus side, and a fire judgment processing program processed by the CPU 11 can be easily constructed. be able to.

Further, in the fire judgment processing of the present embodiment, the processing is performed focusing on the movement of the first wavelength, so that unnecessary processing of the CPU 11 can be reduced and current consumption can be suppressed. It has become possible.

In the fire judgment processing of this embodiment, the first
By calculating the ratio by taking the average of the value of the difference between the peak voltage of the wavelength and the value of the second wavelength at the peak of the first wavelength and the value of the second wavelength, a common noise (for example, electromagnetic wave noise) is obtained. , Vibration noise, temperature change noise, etc.), and the reliability of the flame detector 1 can be improved.

Further, in the fire judgment processing of this embodiment, the first
The ratio between the wavelength level and the second wavelength level is "1: 0.5 to 1"
In this case, a confirmation output signal indicating the operation confirmation of the sensors 2 and 3 is output to the confirmation output circuit 13 and the operation indicator 14
Is turned on instantaneously, when artificial test light projected from the function test apparatus 20 is received, a function check similar to a fire operation can be performed without changing the operation mode.

Further, in the flame detector 1, an operation confirmation process is included in the fire judgment process. However, when an actual flame signal level is detected, a fire occurrence notification is given priority, so that an operation confirmation function is performed. The function can be improved without delay in the fire judgment processing by the addition of.

In addition, since the flame detector 1 automatically returns to the normal processing mode after performing the function confirmation processing, the tester does not need to change the operation mode or the like, and can easily confirm the function. Testing can be performed.

Therefore, the operation of the flame detector can be confirmed without using an actual flame, and since a general light source can be used as a functional test device, the operation can be performed safely and simply without being restricted by the installation place. Can be.

[0077]

According to the first aspect of the present invention, the first and second wavelength detection signals detected by the infrared detecting means can be processed by the level converting means in the plus half (0 to peak value). Thus, the power supply voltage supplied to the determination means can be kept low, and the amplification range that can be handled without saturating the peak value can be set large.

According to the second aspect of the invention, it is possible to reduce the influence of common noise (for example, electromagnetic noise, vibration noise, temperature change noise, etc.), and to improve the reliability of the flame detector. Can be.

According to the third aspect of the present invention, power consumption can be reduced even if a CPU is mounted in the flame detector.

According to the fourth aspect of the present invention, a function check similar to a fire operation can be performed without changing the operation mode.

According to the fifth aspect of the present invention, the function can be improved without delaying the fire judgment processing by adding the operation check function.

According to the sixth aspect of the present invention, it is not necessary to perform an operation such as an operation mode change, and a function confirmation test can be easily performed.

According to the invention of claim 7, the common of the level conversion means and the common of the flame occurrence judging means can be set to the same potential, and the flame occurrence judging means only needs to detect a positive peak in signal processing. Thus, a fire judgment processing program can be easily constructed.

According to the eighth aspect of the present invention, when the signal level of the first wavelength exceeds the saturation range of the amplifying ability, both wavelength detection signals can be attenuated at the same ratio, and environmental change (temperature , Various noises) can be canceled, and the reliability of the flame detector can be improved.

[Brief description of the drawings]

FIG. 1 is a block diagram of a flame detector to which the present invention is applied.

FIG. 2 is a block configuration diagram of a function test device that performs a function test of the flame detector of FIG. 1;

FIG. 3 is a flowchart of a main process executed by a CPU of FIG. 1;

FIG. 4 is a flowchart of a main process following FIG. 2;

FIG. 5 is a flowchart of a comparator input process executed by the CPU of FIG. 1;

FIG. 6 shows the comparator operation of FIG.
The figure which shows the relationship with a converter operation | movement.

FIG. 7 is a diagram showing an example of an output signal of a first wavelength output by the sensor 2, the voltage amplifying circuit 4, the filter circuit 6, and the DC level conversion circuit 8 of FIG.

FIG. 8 is a diagram showing an example of an output signal of a second wavelength output by the sensor 3, the voltage amplification circuit 5, the filter circuit 7, and the DC level conversion circuit 9 of FIG.

FIG. 9 is a view showing an example of a detection signal when a non-fire first wavelength is detected by the sensor 2 of FIG. 1;

FIG. 10 is a view showing an example of a detection signal when a non-fire second wavelength is detected by the sensor 3 of FIG. 1;

FIG. 11 is a diagram showing an example of an installation state when a function test is performed on the flame detector of FIG. 1 by the function test device of FIG. 2;

FIG. 12 is a diagram illustrating a relationship between a first wavelength level and a second wavelength level of infrared light included in test light projected from the function test apparatus of FIG. 2;

FIG. 13 is a flowchart of a fire determination process executed by the CPU of FIG. 1;

FIG. 14 is a timing chart of a function confirmation process executed by the CPU of FIG. 1;

[Description of Signs] 1 Flame detector 2, 3 Sensor 4, 5 Voltage amplification circuit 6, 7 Filter circuit 8, 9 DC level conversion circuit 10 Comparator 11 CPU 12 Fire output circuit 13 Confirmation output circuit 14 Operation indicator 15 Constant voltage Power supply I 16 Constant voltage power supply II 17 Rectifier circuit 20 Function test device 21 Charger switch 22 Charging circuit 23 NiCd battery 24 Tester switch 25 Test light source 26 Condenser mirror 27 Test start switch 28 Optical chopper

Continuation of front page (56) References JP-A-4-18698 (JP, A) JP-A-54-149498 (JP, A) JP-A-6-259675 (JP, A) JP-A-1-243199 (JP) , A) (58) Field surveyed (Int. Cl. ⁷ , DB name) G08B 17/00-17/02

Claims (8)

(57) [Claims] 1. A flame detector for detecting a flame by detecting infrared rays having a wavelength specific to a flame, and detecting a plurality of infrared rays having different wavelengths specific to the flame, and outputting a detection signal corresponding to each wavelength. An infrared detecting unit, a level converting unit that amplifies each detection signal detected by the infrared detecting unit with a predetermined amplification degree, converts the signal to a predetermined voltage level, and outputs the voltage level, and an output from the level converting unit. Flame generation determining means for detecting level data from the detection signal of each wavelength, and determining the occurrence of the flame based on a comparison result of the detected level data, and determining that a flame has occurred by the flame generation determining means. when in, provided with a flame generating informing means for informing to that effect, wherein the infrared detecting means includes first and second wavelengths peculiar to flames
And detects detection signals corresponding to the first and second wavelengths.
Output, and the level conversion means is detected by the infrared detection means.
The detected signals of the first and second wavelengths are supplied to a predetermined voltage on the positive side.
Level, and the flame occurrence determination means outputs the voltage by the voltage level conversion means.
The peak level data and the first
The signal level of the second wavelength corresponding to the peak position of the wavelength
Each level data of the detected first and second wavelengths detected
On the basis of the result of processing the
A flame detector characterized by determining occurrence of a fire. 2. The method according to claim 1, wherein the flame occurrence determining means is configured to perform processing on the level data of the first and second wavelengths by a predetermined arithmetic processing.
2. The flame detector according to claim 1, wherein the ratio is calculated by averaging the difference between the wavelength and the value of the second wavelength. 3. When the level of the first wavelength is equal to or more than a predetermined value, the flame generation determining means fetches each level data of the first and second wavelengths and determines the occurrence of the flame at predetermined time intervals. 2. The method according to claim 1 , wherein the processing is performed.
2. The flame detector according to 2 . 4. A method for comparing each level data of the first and second wavelengths outputted by the level converting means, and when the ratio becomes a predetermined value, whether or not the infrared detecting means is operating normally. flame detector of claim 1 to claim 3, wherein further comprising an operation confirmation informing means for informing a. 5. The determination processing of the flame generated by the flame generating discriminating means, claims 1 to, characterized in that the run priority over operation confirmation processing of said infrared detection means according to the operation confirmation notification means Item 4. The flame detector according to Item 4 . After operation confirmation notification of the infrared detecting means is performed by wherein said operation confirmation notification unit, according to claim 1 to claim and returning to the determination process of the flame generated by the flame generating discriminating means 4. The flame detector according to 4 . 7. A first power supply for setting and supplying a first power supply voltage on the positive side, and a first power supply voltage set by the first power supply. A power supply voltage is supplied from a second power supply for setting and supplying approximately half the second power supply voltage, and the flame generation determination means is provided between the second power supply output stage and the common of the level conversion means. claim 1 or claim, characterized in that connected
Item 3. The flame detector according to Item 2 . 8. The amplification means for amplifying the first and second wavelength detection signals detected by the infrared detection means with a predetermined amplification degree and outputting the first and second wavelength amplification signals. Means, the first and second signals amplified by the amplification means.
Extraction means for extracting a signal corresponding to the fluctuation of the flame from each amplified signal of the wavelengths and outputting first and second extracted signals of the respective wavelengths. The signal amplification characteristic of the amplification means and the signal extraction characteristic of the extraction means are made equivalent. set, the first, flame detector of claim 1 to claim 5, wherein in that the second wavelength the detection signals to amplify and extracted in the same ratio.