JPH0962961A - Fire sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the time necessary for checking operation in a fire sensor adopting a pulse counting system. SOLUTION: This fire sensor 1 is provided with a mode switch setting means SW switch-setting the operation mode of the fire sensor 1 to be a normal monitoring mode or a check mode, and a pulse counting value setting means P1 and P2 automatically change-setting a counting value by means of a pulse signal counting part 15 corresponding to the operation mode set by the mode switch-setting means SW. Then when the fire sensor 1 is switched from the normal monitoring mode to the check mode, a pulse counting value set by the pulse counting value setting means P1 and P2 are differentially set to be a smaller one.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a fire detector adopting a so-called pulse counting method, and more particularly to a fire detector capable of shortening operation inspection time.

[0002]

2. Description of the Related Art Conventionally, in the case of a smoke detector using a so-called pulse counting method, a smoke detector emits light at a predetermined frequency (for example, 3 seconds), intermittently detects the smoke concentration, and detects the smoke concentration. Counts the pulse signals exceeding the threshold level, and outputs the fire alarm signal to the fire receiver when the pulse signals are output three times or more consecutively.

The operation at this time is shown in the time chart of FIG. The light emission pulse shown in (a) is output at a period of t'seconds, and the smoke density exceeds a predetermined threshold level in the pulse shown by diagonal lines, and as shown in (b) to Counting numbers. Here, the fire alarm signal is output to the fire receiver for the first time when the pulse signal for detecting smoke is detected three times in succession (c). If the pulse counting method is used in this way, it will not be judged as a fire due to a single external factor such as dust or insects entering the detector, and about T'seconds after the first detection of smoke. Can output a highly reliable fire alarm signal.

The case where the fire detector is of the non-accumulation type is shown here, but in the case of the accumulation type, the number of pulse signals for detecting smoke is larger (for example, 10 times) than in the non-accumulation type. The fire alarm signal is output when it is detected.

[0005]

However, in the above-described conventional fire detector, even when an operation check is performed, a pulse signal is output a predetermined number of times in the same manner as when an actual fire occurs, and a fire alarm is issued. Since a signal is output, it takes time to complete the operation inspection of all fire detectors.

That is, in the case of the non-accumulation type, assuming that the light emission period is 3 seconds and the 3 pulse counting method is adopted as in the above-mentioned conventional example, for example, after combining the smoke detector with the smoke tester, You will have to wait at least 9 seconds (3 seconds x 3 times). Further, in the case of the accumulation type, if the fire alarm signal is output when the smoke detection pulse signal continues 10 times, at least 30 seconds (3
It was supposed to take 10 seconds. To be precise, the smoke detector needs more time because it takes time for the smoke to flow inside.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to shorten the time required for operation inspection in a fire detector employing a pulse counting method.

[0008]

A fire detector according to claim 1, which is proposed to achieve the above object, is a mode switch for switching and setting an operation mode of the fire detector between a normal monitoring mode and an inspection mode. The fire detector is provided with a setting means and a pulse count value setting means for automatically changing and setting the count value by the pulse signal counter in accordance with the operation mode set by the mode switching setting means. When switched to, the pulse count value setting means changes and sets the pulse count value to a small value.

This fire detector detects a fire by the pulse counting method, and when the smoke concentration and temperature level detected by the fire detector such as smoke concentration and environmental temperature exceed a predetermined threshold level, a pulse signal is output. This pulse signal is counted by the pulse signal counter, and when the pulse signal continuously output exceeds the preset count value, the fire alarm signal is output. When the fire alarm signal is received, the fire receiver issues a fire alarm.

Here, the mode switching setting means can switch and set the fire detector between the normal monitoring mode and the inspection mode. When the mode is set to the normal monitoring mode, the count value of the pulse count value setting means is set to 3, for example, and the inspection is performed. When the mode is set, it is set to a smaller value, for example, 1. Therefore, in the inspection mode, the pulse count value is set to a value smaller than that in the normal monitoring mode, so that the operation inspection (test) can be performed quickly.

The fire detector according to claim 2 is the fire detector according to claim 1.
The mode switching setting means is provided with a line voltage determination means for determining the level of the voltage level supplied to the fire detector from the local line of the fire receiver, and as a configuration for determining the normal monitoring mode and the inspection mode. There is. Therefore,
The operation test can be performed by setting the inspection mode from the fire receiver side without operating the fire detector.

This fire detector is connected to a district line derived from the fire receiver, and when the fire receiver receives a fire alarm signal from the district line, it is determined that a fire has occurred in the district line. Then, the fire alarm may be output, which can be realized without using the multiplex transmission system. Switching the operation mode of the fire detector is performed by changing the voltage level sent from the fire receiver to the district line,
For example, DC 24V is used in the normal monitoring mode, and DC 36V is used in the inspection mode.

Since the fire detector is provided with the line voltage discriminating means, the normal monitoring mode and the inspection mode can be discriminated by the line voltage level supplied from the district line, and the pulse count value setting means can be discriminated by the discrimination result. Change and set the count value. In the fire detector according to claim 3, the mode switching setting means according to claim 1 is provided with a signal decoding means for decoding a multiple signal transmitted from the fire receiver through the multiple signal lines, whereby the normal monitoring mode is provided. And the inspection mode. Therefore, the operation test can be performed by setting the inspection mode from the fire receiver side without operating the fire detector.

This fire detector is connected to the multiple signal lines derived from the fire receiver. When the fire receiver receives a fire alarm signal specifying an address from the fire detector through the multiple signal line, it determines that a fire has occurred in the fire detector at the address and outputs a fire alarm. The switching of the operation mode of the fire detector is performed by sending a multiple signal from the fire receiver to the multiple signal line. If this multiple signal includes, for example, a mode setting code, it is provided in the fire detector. It can be easily decoded by the signal decoding means. As a result, the fire detector can distinguish between the normal monitoring mode and the inspection mode, and the count value of the pulse count value setting means is changed and set.

A fire detector according to claim 4 is the fire detector according to claim 1.
The mode switching setting means of is composed of a proximity switch that operates with magnetic force built in the fire detector, and the fire tester that supplies heat and smoke to the fire detection part when brought close to the fire detector, The structure is such that a magnet for turning on the proximity switch is attached. As a result, even if the fire receiver does not have a mode switching function, the mode can be changed only on the fire detector side. A reed switch or the like is used as the mode changeover switch, and it is convenient to automatically switch to the inspection mode when the fire tester is brought close to the fire detector and an actual inspection operation is performed.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an example of the configuration of the fire detector 1 according to claims 1 and 3. In this figure, a smoke detector is shown as an example of the fire detector 1, and the fire detector 1 is connected to the multiple signal line L led by the fire receiver 2. In the fire alarm system having such a configuration, the fire receiver 2 receives a fire alarm signal from the fire detector 1 to ring an audio device (not shown) or connect with another multiple signal line L. Sounding of an audio device (not shown) and interlocking of a smoke proof device (not shown) are performed.

An address for multiplex transmission is set in each of the fire detectors 1 (smoke detectors).
A signal control unit 11 including a PU or the like, a transmission control unit 12 for executing multiplex transmission, a light emitting unit 13 and a light receiving unit 14 forming a fire detection unit, and a smoke detection amount in the light receiving unit 14 are When a predetermined threshold level is exceeded, the pulse signal counting unit 15 that counts the number of consecutive pulse signals, and as pulse count value setting means, operates to change and set the count value by the pulse signal counting unit 15. The monitoring mode program P1 and the inspection mode program P2 are provided, and the mode switching switch SW for switching the operation mode between the normal monitoring mode and the inspection mode is provided as the mode switching setting means. Here, the light emitting unit 13 outputs a light emission pulse at a predetermined frequency, and the light receiving unit 14 receives the pulse signal and detects the presence of smoke (smoke concentration) inside the sensor.

The fire receiver 2 has a signal processing section 21.
, A transmission control unit 22, and an operation unit 2 including various operation keys
3, a display unit 24 including a liquid crystal screen, LEDs, and the like. In the fire detector 1, the monitoring mode program P1 normally operates to execute fire detection by the pulse counting method, and the light emitting unit 13 outputs a light emission pulse at a predetermined frequency (for example, 3 seconds). Received at
Intermittently detect the amount of physical change (smoke concentration) due to fire. When the physical change amount detected by the light receiving unit 14 exceeds the threshold level, the pulse signal counting unit 15 counts the number of consecutive pulse signals, and the number is a predetermined number (for example, 3 times). When it exceeds, a fire alarm signal is interrupted and output to the fire receiver 2 via the transmission control unit 12.

When performing an operation check, the transmission control unit 22 operates the multiple signal line L by operating the mode selector switch SW of the fire detector 1 or the operating unit 23 of the fire receiver 2.
A signal indicating the inspection mode is transmitted via the to activate the inspection mode program P2 of the fire detector 1. In the inspection mode program P2, the count value in the pulse counting method is made smaller than that in the operation in the normal monitoring mode. That is, the predetermined number serving as the output standard of the fire alarm signal is changed to, for example, once to shorten the time from the start of inspection to the output of the fire alarm signal.

The signal multiplexed from the fire receiver 2 is
The signal is decoded by the signal processing unit 11, which is a signal decoding unit, via the transmission control unit 12. The signal instructing the switching of the operation mode has a command indicating the mode switching, the line number, the address of the fire detector 1, the mode setting code (normal monitoring mode or inspection mode), and other control data,
When returning from the inspection mode to the normal monitoring mode,
The mode type may be set to the normal monitoring mode, and the fire receiver 2 may transmit to the fire detector 1. Note that the configuration of this signal is not limited to this, and the configuration may be such that the count number of the pulse counting method is directly designated.

Next, an example of the operation in the inspection mode will be described with reference to the time chart of FIG. The light emission pulse from the light emitting unit 13 shown in (a) is output at a T second cycle,
When the smoke density exceeds a predetermined level in the pulse shown by the diagonal lines, the pulse signal counting unit 1
5 counts the number of consecutive times. Here, if the pulse signal that detects smoke is detected even once, the fire alarm signal is output (c). By doing so, the operation inspection can be performed in a shorter time than in the conventional case (see FIG. 6).

Next, the fire detector 1 according to claim 2 will be described. FIG. 3 is a block diagram showing an example of the configuration of the fire detector 1, and a voltage detection circuit 16 is provided as line voltage determination means instead of the mode changeover switch SW having the configuration of claim 1 (see FIG. 1). ing. One of the fire receivers 2 is provided with a voltage changing circuit 25, and when the operation unit 23 is operated when performing an operation check, the voltage level supplied to the district line L1 is, for example, a normal DC24V.
To 36V DC. Then, the voltage detection circuit 16 of the fire detector 1 detects this change and changes the operating program from the normal monitoring mode program P1 to the inspection mode program P2. The change of the voltage level at this time may be momentary, and the operation mode can be returned to the normal monitoring mode by once again changing the voltage level by the voltage changing circuit 25 of the fire receiver 2.

Next, the fire detector 1 according to claim 4 will be described. FIG. 4 shows an example of use of the fire detector 1 at the time of operation inspection, in which a fire test device 3 that supplies heat and smoke is brought close to detect a fire in a pseudo manner. At this time, since the proximity switch SW1 built in the fire detector 1 is turned on by the magnet 3a attached to the fire tester 3, the signal processing unit 11 changes the operating program from the normal monitoring mode program P1 to the inspection mode. Program P2
(See FIG. 1).

With this, at the same time as the operation inspection, the operation mode of the fire detector 1 can be automatically switched from the normal monitoring mode to the inspection mode. In the above, the example in which the normal monitoring mode and the inspection mode can be freely changed by the mode switching has been shown. However, in addition to these, the operation mode can be switched to the sensitivity setting mode and the corresponding program can be operated. .

[0025]

As can be understood from the above description, according to the fire detector of the first aspect of the present invention, the operation mode is changed from the normal normal monitoring mode to the inspection mode when the operation is inspected. Since the count value in the pulse counting method can be reduced, the fire alarm signal is output faster and the time required for inspection can be shortened.

According to the fire detector of the second aspect, the operation mode of the fire detector can be changed to the inspection mode by changing the voltage level supplied by the fire receiver to the local line. According to the fire detector of claim 3,
The operation mode of the fire detector can be changed to the inspection mode by the multiplex transmission from the fire receiver. Therefore,
When performing a simultaneous inspection of fire detectors, a signal indicating mode switching may be transmitted sequentially from the fire receiver.

According to the fire detector of the fourth aspect, the operation mode can be changed to the inspection mode by changing only the configuration of the fire detector without changing the configuration of the fire receiver. I can. Therefore, when adding the mode switching function to the fire alarm system, only the fire detector needs to be replaced. Also, because the inspection mode can be set by the magnetic force from the outside, all you have to do is to attach a magnet to the fire tester, and during the actual test, the mode can be automatically switched to shorten the inspection time. .

[Brief description of drawings]

FIG. 1 is a block diagram showing an example of the configuration of a fire detector according to claims 1 and 3 of the present invention.

2 (a) to 2 (c) are time charts showing an example of the operation of the fire detector according to the present invention.

FIG. 3 is a block diagram showing an example of the configuration of a fire detector according to claim 2 of the present invention.

FIG. 4 is a diagram showing an example of use of the fire detector according to claim 4 of the present invention.

5 (a) to (c) are time charts showing an example of the operation of the conventional fire detector.

[Explanation of symbols]

 1 ... Fire detector (smoke detector) 11 ... Signal processing unit 12 ... Transmission control unit 13 ... Light emitting unit 14 ... Light receiving unit 15 ... Pulse signal counting unit 16 ... Voltage detection circuit SW ... Mode change switch P1 ... Monitoring mode program P2 ... Inspection mode program 2 ... Fire receiver 21 ... Signal processing unit 22 ... Transmission control unit 23 ... Operation Part 24 ... Display part 25 ... Voltage change circuit 3 ... Fire tester 3a ... Magnet L ... Multiple signal line L1 ... District line T ... Operation check time

Claims (4)

[Claims] Claims: 1. A pulse signal counting unit for counting pulse signals output from a fire detection unit, wherein when the pulse signal counting unit continuously counts a predetermined number of preset pulse signals In a fire detector configured to output a warning signal, a mode switch setting means for switching and setting the operation mode of the fire detector between a normal monitoring mode and an inspection mode, and a count value by the pulse signal counting section for the mode switching setting. Pulse count value setting means for automatically changing and setting according to the operation mode set by the means, and when the fire detector is switched from the normal monitoring mode to the inspection mode, the pulse counter by the pulse count value setting means. A fire detector configured to change the value to a smaller value. 2. The mode switching setting means is provided with a line voltage determining means for determining the magnitude of the voltage level supplied from the district line of the fire receiver to the fire detector, and is normally monitored by this line voltage determining means. The fire detector according to claim 1, wherein the fire detector is configured to discriminate between a mode and an inspection mode. 3. The mode switching setting means is provided with a signal decoding means for decoding a multiple signal transmitted from a fire receiver through a multiple signal line, the normal decoding mode and the inspection mode being provided by the signal decoding means. The fire detector according to claim 1, wherein the fire detector is configured to determine. 4. The mode switching setting means is composed of a proximity switch which is operated by magnetic force built in the fire detector, and is brought close to the fire detector to heat the fire detector.
The fire detector according to claim 1, wherein the fire tester for supplying smoke has a structure in which a magnet for turning on the proximity switch is attached.