JP3100645B2 - Combined fire 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 composite fire detector.

[0002]

2. Description of the Related Art Conventionally, a fire detector which independently detects a physical quantity (for example, smoke density, ambient temperature, temperature rise rate, amount of ultraviolet rays from a flame, etc.) which changes at the time of a fire and outputs a fire signal, In addition, there has been a composite fire detector that outputs a fire signal by detecting two or more types of physical quantities that change during a fire.

However, the conventional composite fire detector converts a plurality of physical quantities that change at the time of a fire into respective electrical quantities that change according to the magnitude of each physical quantity in each detection circuit, and detects each of the detected quantities. Each of the comparison circuits is connected to a circuit to determine whether or not each of the electric quantities is equal to or greater than a predetermined value, and a fire is generated by an AND (logical product) or OR (logical sum) output of the respective comparison results. It was a signal output.

FIG. 5 is a circuit block diagram showing a composite fire detector according to a conventional embodiment. In FIG. 5, the composite fire detector 10 includes a smoke detection circuit 11a, an ambient temperature detection circuit 12a, comparison circuits 11b and 12b, a logic circuit 13,
And an output circuit 14.

[0005] The smoke detection circuit 11a includes a smoke sensor (not shown), and outputs a smoke detection output that increases as the smoke density increases. The ambient temperature detection circuit 12a includes a temperature sensor (not shown), and outputs a temperature detection output that increases with an increase in the ambient temperature. The comparison circuit 11b compares the smoke detection output of the smoke detection circuit 11a with a predetermined value set in advance.
Output High. The comparison circuit 12b compares the temperature detection output of the ambient temperature detection circuit 12a with a predetermined value set in advance.
Is output.

The logic circuit 13 includes the comparators 11b, 1
The output of 2b is obtained by performing a logical operation, and may be an AND circuit or an OR circuit. Therefore, the logic circuit 13 executes the set logical operation and outputs the result to the output circuit 14. The output circuit 14 is a logic circuit 13
If the output from is high, a fire signal is output.

[0007]

By the way, the logic circuit 1
3 is set by the OR circuit, if the smoke density and the ambient temperature gradually increase and rise simultaneously due to the smoke and heat caused by the fire, the smoke detection output of the smoke detection circuit 11a exceeds the predetermined value of the comparison circuit 11b. Or the ambient temperature detection circuit 12a
The composite fire detector 1 does not output a fire signal unless the temperature detection output of the first embodiment becomes equal to or more than the predetermined value of the comparison circuit 12b. As a result, the measures against the occurrence of the fire may be delayed and cause serious damage. Further, when the logic circuit 13 is set by the AND circuit, the fire treatment is further delayed than when the logic circuit 13 is set by the OR circuit (A
The advantage of the ND circuit setting is that there are few false alarms).

As described above, the conventional composite fire detector has a problem that it is very inferior to human perception of a fire.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a hybrid type which accurately detects a fire and outputs a fire signal, which is close to human fire judgment. It is to provide a fire detector.

[0010]

Since the present invention SUMMARY OF] is to solve the above problems, a composite type fire detector a plurality of physical quantity which changes in a fire each detection and outputs a fire signal, each of said physical quantity A detection circuit that detects and outputs the variation of the detection output, a multiplication circuit that outputs a multiplication physical quantity obtained by multiplying each of the detection outputs, and a comparison circuit that determines whether the multiplication physical quantity is equal to or more than a predetermined value, The composite fire detector according to claim 1 is configured to output a fire signal when the physical quantity is equal to or greater than a predetermined value, wherein the composite fire detector according to claim 1 is configured to be suitable for analog processing. Is configured to be suitable for digital processing.
The composite fire detector according to claim 1, wherein the plurality of physical quantities are limited to smoke density and ambient temperature, and the composite fire detector according to claim 4 is configured to convert the plurality of physical quantities to smoke density and ambient temperature. It is suitable for analog processing that limits the relationship between the smoke density and the smoke detection output of the smoke detection circuit, the relationship between the ambient temperature and the temperature detection output of the ambient temperature detection circuit, and the preset predetermined value of the comparison circuit. The composite fire detector according to claim 5, wherein the plurality of physical quantities are limited to the smoke density and the ambient temperature, and the relationship between the smoke density and the smoke detection output of the smoke detection circuit and The configuration is suitable for digital processing, which limits the relationship between the ambient temperature and the temperature detection output of the ambient temperature detection circuit and the predetermined value set in advance by the comparison circuit.

[0011]

According to the above structure, for example, in the combined fire detector according to the fifth aspect, the smoke density is 2%.
If the ambient temperature is 0 ° C./m and the ambient temperature is 25 ° C., the smoke density digitizing circuit that receives the smoke detection output of the smoke detection circuit outputs a smoke density value of 3, and receives the temperature detection output of the ambient temperature detection circuit. The temperature value output by the temperature digitizing circuit is 1
Becomes Therefore, the multiplication value output from the multiplication circuit is 3, and the comparison circuit compares the multiplication value 3 as the predetermined value and the multiplication value is equal to or larger than the predetermined value. Therefore, the composite fire detector outputs a fire signal.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a composite fire detector according to the present invention will be described below in detail with reference to FIGS. The combined fire detectors according to claims 1 to 3 more generally represent the combined fire detectors described in claims 4 and 5, and therefore, the following claims 4 and 5 will be described. The following description focuses on the composite fire detector.

First, the combined fire detector according to claim 4 will be described. FIG. 1 is a circuit block diagram showing a combined fire detector according to claim 4 of the present invention. In FIG. 1, the composite fire detector 20 includes a smoke detection circuit 21, an ambient temperature detection circuit 22, a multiplication circuit 23, a comparison circuit 24, and an output circuit 25.

The smoke detection circuit 21 is a smoke sensor (not shown)
And outputs a smoke detection output S that increases with the increase in smoke density and is approximated by the following [formula 1].

S = 1 + (T / 10) ·································································································································································· | The density is shown in units of% / m (dimming rate per meter). The ambient temperature detection circuit 22 includes a temperature sensor (not shown), and increases as the ambient temperature increases. ] Is output.

Q = １ ／ + (R / 50) ···································································································································································· | The temperature is indicated in units of ° C. (Celsius temperature). The multiplication circuit 23 takes in the smoke detection output S and the temperature detection output Q, respectively, and multiplies the smoke detection output S and the temperature detection output Q by an analog output (voltage of voltage). Such a physical physical quantity as well as a spatial physical quantity such as expansion and contraction of the dimension may be used, but the comparison circuit 24 at the next stage also has a configuration corresponding thereto.

The comparison circuit 24 calculates a two-unit value which is a predetermined value set in advance (the analog output amount output from the multiplication circuit 23 when the smoke detection output S is 1 V and the temperature detection output Q is 1 V). The output of the multiplication circuit 23 is compared with the output of the multiplication circuit 23, and if it is equal to or more than two unit values, a High output is output to the output circuit 25. Thus, the composite fire detector 20 outputs a fire signal.

FIG. 3 is a graph of a relational expression [1st expression] between the smoke detection output S and the smoke density T, and FIG. 4 is a graph showing a relational expression [1] of the temperature detection output Q and the ambient temperature R. 2] is a graph. Although the smoke detection output S and the temperature detection output Q have been described as voltages, it goes without saying that not only electrical physical quantities such as voltage but also spatial physical quantities such as expansion and contraction of dimensions may be used.

FIG. 2 shows [Equation 1] and [Equation 2].
The range in which the composite fire detector 20 outputs a fire signal (called the fire detection range) when the predetermined value predetermined and set by the comparison circuit 24 is set to 2 unit values in the relationship FIG. 7 is a graph showing the case where the axis is the ambient temperature R and the vertical axis is the smoke density T, and the hatched side, that is, the fire detection curve L
The upper right side of ₁ is a range in which the composite fire detector 20 outputs a fire signal. Note that fire curve L ₁ is showing a singularity when the ambient temperature R of -25 ° C., it is practically there is no problem without the use almost at -25 ° C..

As is apparent from FIG. 2, for example, if the ambient temperature R is 0 ° C., the combined fire detector 20 does not output a fire signal unless the smoke density T becomes approximately 30% / m or more. However, if the ambient temperature R is 25 ° C., a fire signal is output if the smoke density T becomes approximately 10% / m or more.

That is, for example, if the conventional composite fire detector outputs a fire signal when the smoke density is 30% / m or more and outputs a fire signal when the ambient temperature R is 75 ° C. or more, FIG. outputs a fire signal at the upper right side that are separated by a straight line L ₂ and the straight line L ₃ shown by the two dashed lines (those aND circuits), or in the range of the upper right and the straight line L ₃ of the straight line L ₂ A fire signal was output (or an OR circuit), and a fire signal output range could not be set in a curved line. However, in the composite fire detector according to the present invention, the fire signal output range can be set in a curved manner, so that the fire perception can be made closer to human perception.

Next, a composite fire detector according to a fifth aspect will be described. Since the configuration and operation are substantially the same as those of the fourth aspect, they will be described with reference to FIGS.

A combined fire detector according to claim 5.
Has a smoke detection circuit 21, an ambient temperature detection circuit 22, a multiplication circuit 23, a comparison circuit 24, and an output circuit 25.

The smoke detection circuit 21 is a smoke sensor (not shown)
And outputs a smoke detection output that increases with an increase in smoke density. The ambient temperature detection circuit 22 is configured to include a temperature sensor (not shown), and outputs a temperature detection output that increases with an increase in the ambient temperature.

The multiplying circuit 23 receives the smoke detection output and the temperature detection output, approximates the smoke detection output to the following [Equation 3], and A / D converts the smoke detection output into a numerical value E (for example, a binary coded decimal number). An A / D conversion circuit (not shown) corresponding to a conversion circuit;
An A / D conversion circuit (not shown) corresponding to a temperature digitizing circuit for converting the temperature detection output into a numerical value F (for example, a binary-coded decimal number) by analog-to-digital conversion by approximating the following [Equation 4]; And E = 1 + (T / 10)... [Equation 3] where E is a smoke density value obtained by digitizing the smoke detection output. There is no unit. T indicates the smoke density, and the unit is% / m (dimming rate per meter). F = 1/2 + (R / 50)...... Here, F indicates a temperature numerical value obtained by digitizing the temperature detection output, and there is no unit. R indicates an ambient temperature and the unit is ° C. (Celsius temperature). An output unit for transferring and outputting a numerical value (for example, a binary-coded decimal number) to the comparison circuit 24 is provided.

The comparison circuit 24 compares the value 2 (stored in the storage area), which is a preset value, with the multiplication value output from the multiplication circuit 23. The output is output to the output circuit 25. Thus, the composite fire detector 20 outputs a fire signal.

FIG. 2 shows a case where the predetermined value set and determined in advance by the comparison circuit 24 under the relationship between [Equation 3] and [Equation 4] is 2. A graph in which the horizontal axis indicates the ambient temperature R and the vertical axis indicates the smoke density T, where the range in which the composite fire detector 20 outputs a fire signal (referred to as smoke detection range), is also shown. , i.e. that the upper right side of the fire curve L ₁ is in the range of composite fire detector 20 outputs a fire signal is the same as the composite fire sensor according to claim 4, wherein.

Therefore, in the composite fire detector according to the fifth aspect, similarly to the composite fire detector according to the fourth aspect, the fire signal output range can be set in a curved line, and the human perception of a fire can be further improved. You can get closer.

In the case of using digital arithmetic processing, it is also possible to directly store the fire detection curve in the storage device and compare the smoke detection output and the temperature detection output with the fire detection curve stored in the storage device. It is possible, and in this case, the fire detection curve can be set more freely.

[0030]

Since the present invention is configured as described above, a fire is detected while detecting a large number of physical quantities that change at the time of a fire, and only a specific physical quantity among the detected physical quantities increases. Does not output a fire signal until the specific physical quantity becomes very high, but if a large number of detected physical quantities increase in general, it outputs a fire signal even if each of the multiple physical quantities is not so high. This provides an effect that a composite fire detector that outputs a fire signal can be provided.

[Brief description of the drawings]

FIG. 1 is a circuit block diagram showing one embodiment of a composite fire detector according to the present invention.

FIG. 2 is a graph showing a fire detection curve of one embodiment of the combined fire detector of the present invention.

FIG. 3 is a graph showing the relationship between smoke density and smoke detection circuit output of one embodiment of the composite fire detector of the present invention.

FIG. 4 is a graph showing a relationship between an ambient temperature and an output of an ambient temperature detection circuit of one embodiment of the composite fire detector of the present invention.

FIG. 5 is a circuit block diagram showing one embodiment of a conventional composite fire detector.

[Explanation of symbols]

 Reference Signs List 20 composite fire detector 21 smoke detection circuit (detection circuit) 22 ambient temperature detection circuit (detection circuit) 23 multiplication circuit 24 comparison circuit

Claims (5)

(57) [Claims] 1. A composite fire detector for detecting a plurality of physical quantities that change during a fire and outputting a fire signal,
A detection circuit that detects and outputs a change in each of the physical quantities, a multiplication circuit that outputs a multiplication physical quantity obtained by multiplying each of the detection outputs, and a comparison circuit that determines whether the multiplication physical quantity is equal to or greater than a predetermined value. A composite fire detector for outputting a fire signal when the multiplied physical quantity is equal to or greater than a predetermined value. 2. A composite fire sensor for detecting a plurality of physical quantities that change during a fire and outputting a fire signal.
A detection circuit for detecting and outputting a change in each of the physical quantities ; a digitization circuit for digitizing each of the detection outputs; and a multiplication circuit for multiplying each of the digitized values and outputting the multiplied value And a comparing circuit for determining whether the multiplied value is equal to or greater than a predetermined value, and outputs a fire signal when the multiplied value is equal to or greater than a predetermined value. 3. The composite fire detector according to claim 1, wherein the plurality of physical quantities are smoke density and ambient temperature. 4. The plurality of physical quantities are a smoke density and an ambient temperature, and a smoke detection output which is detected by detecting the smoke density and increases with an increase in the smoke density is S = 1 + (T / 10), where S is smoke The detection output is shown and the unit is V (volts). T is the smoke density and the unit is a smoke detection circuit approximated by% / m (dimming rate per meter). The ambient temperature is detected and the ambient temperature rises. The temperature detection output that increases with Q is: Q = 1/2 + (R / 50) where Q is the temperature detection output and the unit is V (volts) R is the ambient temperature and the unit is ° C (degrees Celsius) An ambient temperature detection circuit approximated by, a multiplication circuit that outputs a multiplied physical quantity obtained by multiplying the smoke detection output and the temperature detection output, and a comparison circuit that determines whether the multiplied physical quantity is substantially equal to or more than two unit values. Wherein the multiplied physical quantity is approximately two unit values or less.
2. The composite fire detector according to claim 1, wherein a fire signal is output in the above case. 5. A smoke detection circuit for detecting a smoke density and outputting a smoke detection output which increases with an increase in the smoke density, wherein the plurality of physical quantities are a smoke density and an ambient temperature; An ambient temperature detection circuit that performs a temperature detection output that increases with an increase in temperature, and the smoke detection output is E = 1 + (T / 10), where E is a smoke density value obtained by digitizing the smoke detection output, and the unit is: None T indicates smoke density, and the unit is% / m (dimming rate per 1 m). A smoke density digitizing circuit for digitizing to a smoke density numerical value, and the temperature detection output is F = 1/2 + (R / 50 However, F is a temperature numerical value obtained by digitizing the temperature detection output, and there is no unit. R is an ambient temperature, and the unit is a temperature numerical circuit for converting into a numerical value in degrees Celsius (Celsius), and the smoke density numerical value. And a multiplication circuit that multiplies the temperature value and outputs the multiplied value. And a comparator circuit for arithmetic value to determine whether it is substantially more, the composite fire sensor according to claim 2, wherein the multiplication value is and outputs a fire signal when approximately 2 or more.