JP3256756B2 - 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 an improvement in a fire detector employing a so-called pulse counting system, and more particularly to a fire detector capable of shortening an operation check time.

[0002]

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

The operation at this time is shown in a time chart of FIG. The light emission pulse shown in (a) is output at a period of t 'seconds, and the smoke density exceeds the predetermined threshold level in the pulse shown by oblique lines, and as shown in (b) to (c), the smoke density is continuously increased. Counting the number. Here, the fire alarm signal is output to the fire receiver for the first time when the pulse signal that has detected smoke is detected three times in succession (c). By using the pulse counting method in this way, it is no longer possible to determine that a fire has occurred due to a single external factor such as dust or insects entering the sensor. Can output a reliable fire alarm signal.

Although the fire detector is of the non-accumulation type, in the case of the accumulation type, the number of pulse signals for detecting smoke is larger (for example, 10 times) than that of the non-accumulation type, and the number of continuous pulses is larger. When this is detected, a fire alarm signal is output.

[0005]

However, in the above-mentioned conventional fire detector, when performing an operation check, a pulse signal is output a predetermined number of times in the same manner as when a fire actually occurs, and a fire alarm is generated. Since the signal is output, it takes time to complete the operation check of all the fire detectors.

In other words, in the case of the non-accumulation type, assuming that the light emission cycle is 3 seconds and the 3-pulse count method is adopted as in the conventional example, for example, after combining a smoke detector with a smoke tester, You have to wait at least 9 seconds (3 seconds × 3 times). In addition, in the case of the accumulation type, if a fire alarm signal is output when a pulse signal for detecting smoke is continuous 10 times, at least 30 seconds (3 seconds)
(Seconds x 10 times). Precisely, the smoke detector requires 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 has as its object to reduce the time required for operation inspection in a fire detector employing a pulse count system.

[0008]

According to a first aspect of the present invention, there is provided a fire detector, wherein the operation mode of the fire detector is switched between a normal monitoring mode and an inspection mode. Setting means, and pulse count value setting means for automatically changing and setting the count value of the pulse signal counting section in accordance with the operation mode set by the mode switching setting means, wherein the fire detector switches from the normal monitoring mode to the inspection mode. , The pulse count value set by the pulse count value setting means is changed and set to a small value.

This fire detector detects a fire by a pulse counting method. When a smoke density and a temperature level detected by a fire detection unit detect a smoke density and an environmental temperature, a pulse signal is output. The pulse signal is counted by a pulse signal counting unit, and when the continuously output pulse signal exceeds a preset count value, a fire alarm signal is output. Upon receiving this fire alarm signal, the fire receiver issues a fire alarm.

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

[0011] The fire detector according to the second aspect is the first aspect.
The mode switching setting means is provided with line voltage discriminating means for discriminating the magnitude of the voltage level supplied from the local line of the fire receiver to the fire detector, thereby providing a configuration for discriminating between the normal monitoring mode and the inspection mode. I have. Therefore,
The operation test can be performed by setting the fire receiver to the inspection mode without operating the fire detector.

The fire detector is connected to a district line derived from the fire receiver. When the fire receiver receives a fire alarm signal from the district line, it determines that a fire has occurred in the district line. Then, a configuration may be adopted in which a fire alarm is output, and this can be realized without using a multiplex transmission method. Switching of the operation mode of the fire detector is performed by changing the voltage level transmitted from the fire receiver to the local line,
For example, the voltage is 24 VDC in the normal monitoring mode, and 36 VDC in the inspection mode.

Since the fire detector is provided with a line voltage discriminating means, the normal monitoring mode and the inspection mode can be discriminated by the line voltage level supplied from the local circuit, and the pulse count value setting means is determined by the discrimination result. Change and set the count value. According to a third aspect of the present invention, there is provided a fire detector, wherein the mode switching setting means of the first aspect is provided with signal decoding means for decoding a multiplex signal transmitted from the fire receiver through a multiplex signal line. And the inspection mode. Therefore, the operation test can be performed by setting the fire receiver to the inspection mode without operating the fire detector.

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

According to a fourth aspect of the present invention, there is provided a fire detector according to the first aspect.
The mode switching setting means is constituted by a proximity switch which is activated by a magnetic force built in the fire detector.The fire tester which supplies heat and smoke to the fire detection unit by approaching the fire detector includes: It has a structure with a magnet for turning on the proximity switch. As a result, the mode can be changed only on the fire detector side without providing the fire receiver with the mode switching function. Note that a reed switch or the like is used as the mode changeover switch. If an actual inspection operation is performed by bringing the fire tester close to the fire detector, the mode is automatically switched to the inspection mode, which is convenient.

[0016]

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 the first and third aspects. In this figure, a smoke detector is shown as an example of the fire detector 1, and this fire detector 1 is connected to a multiplex signal line L derived from a 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 sound an acoustic device (not shown), or to a district connected by another multiplex signal line L. Sounding of an acoustic device (not shown) and interlocking with smoke prevention equipment (not shown) are performed.

Each of the fire detectors 1 (smoke detectors) has an address for multiplex transmission set therein.
A signal control unit 11 composed of a PU or the like, a transmission control unit 12 for performing multiplex transmission, a light emitting unit 13 and a light receiving unit 14 constituting a fire detecting unit, and a smoke detection amount at the light receiving unit 14 When the signal level exceeds a predetermined threshold level, the pulse signal counting section 15 counts the number of consecutive pulse signals, and operates as a pulse count value setting means to change and set the count value of the pulse signal counting section 15. A monitoring mode program P1, an inspection mode program P2, and a mode switching switch SW for switching the operation mode between the normal monitoring mode and the inspection mode are provided as mode switching setting means. Here, the light emitting section 13 outputs a light emission pulse at a predetermined frequency, and the light receiving section 14 receives this pulse signal and detects the presence of smoke (smoke density) inside the sensor.

One of the fire receivers 2 has a signal processing unit 21.
, Transmission control unit 22, and operation unit 2 including various operation keys
3 and a display unit 24 composed of a liquid crystal screen, LEDs, and the like. In the fire detector 1, usually, the monitoring mode program P1 operates to execute fire detection by a pulse count method, and the light emitting unit 13 outputs a light emitting pulse output at a predetermined frequency (for example, 3 seconds) to the light receiving unit 14. Received at
Intermittently detect physical changes (smoke density) 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 counted to a predetermined number (for example, three times). If 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 mode switch SW of the fire detector 1 is operated or the operation unit 23 of the fire receiver 2 is operated.
, A signal indicating the inspection mode is transmitted, and the inspection mode program P2 of the fire detector 1 is operated. In the inspection mode program P2, the count value in the pulse count method is made smaller than that in the operation in the normal monitoring mode. That is, the predetermined number serving as the output reference of the fire alarm signal is changed to, for example, one time to shorten the time from the start of the inspection to the output of the fire alarm signal.

The signal multiplex-transmitted from the fire receiver 2 is
The signal is decoded by the signal processing unit 11 as signal decoding means via the transmission control unit 12. The signal instructing the switching of the operation mode includes a command indicating the mode switching, a line number, an address of the fire detector 1, a 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. The configuration of this signal is not limited to this, and a configuration may be employed in which the count number of the pulse count method is directly specified.

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 FIG.
In the pulse indicated by the oblique line, the smoke density exceeds a predetermined level, and as shown in (b) to (b), the pulse signal counting unit 1
5 is counting the continuous number. Here, a fire alarm signal is output if a pulse signal that has detected smoke is detected even once (c). In this way, the operation check can be performed in a shorter time than in the related art (see FIG. 6).

Next, a fire detector 1 according to a second aspect will be described. FIG. 3 is a block diagram showing an example of the configuration of the fire detector 1. In place of the mode changeover switch SW of the configuration of claim 1 (see FIG. 1), a voltage detection circuit 16 is provided as line voltage determination means. ing. The fire receiver 2 is provided with a voltage changing circuit 25. When the operation unit 23 is operated to check the operation, the voltage level supplied to the district line L1 is changed to, for example, a normal DC 24V.
To 36 VDC. 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 instantaneous. If the voltage level is instantaneously changed again by the voltage changing circuit 25 of the fire receiver 2, the operation mode can be returned to the normal monitoring mode.

Next, a fire detector 1 according to a fourth aspect will be described. FIG. 4 shows an example of use of the fire detector 1 at the time of an operation check. The fire detector 3 that supplies heat and smoke is approached to detect a fire in a pseudo manner. At this time, the proximity switch SW1 built in the fire detector 1 is turned on by the magnet 3a attached to the fire tester 3, so that 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).

Thus, simultaneously with the operation check, the operation mode of the fire detector 1 can be automatically switched from the normal monitoring mode to the check mode. The example in which the normal monitoring mode and the inspection mode can be freely changed by mode switching has been described above. However, in addition to these, the operation mode can be switched to a sensitivity setting mode or the like, and a corresponding program can be operated. .

[0025]

As can be understood from the above description, according to the fire detector according to 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 count method can be reduced, the output of the fire alarm signal is quickened, and the time required for inspection can be reduced.

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 of the fire receiver supplying the local line. According to the fire detector of claim 3,
By the multiplex transmission from the fire receiver, the operation mode of the fire detector can be changed to the inspection mode. Therefore,
When performing a simultaneous inspection of a fire detector, a signal indicating mode switching may be transmitted in order from the fire receiver.

According to the fourth aspect of the present invention, the operation mode can be changed to the inspection mode only by changing the configuration of the fire detector without changing the configuration of the fire receiver. I can do it. Therefore, when the mode switching function is added to the fire alarm system, only the fire detector needs to be replaced. In addition, since the inspection mode can be set by an external magnetic force, it is only necessary to attach a magnet to the fire tester. At the time of the actual test, the mode can be automatically switched to shorten the inspection time. .

[Brief description of the 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.

FIGS. 2A to 2C 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 a configuration of a fire detector according to claim 2 of the present invention.

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

FIGS. 5A to 5C are time charts showing an example of the operation of a conventional fire detector.

[Explanation of symbols]

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

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G08B 17/10 G08B 17/00 G08B 25/00 520 G08B 29/12

Claims (4)

(57) [Claims] A pulse signal counting section for counting a pulse signal output from a fire detection section, wherein when the pulse signal counting section continuously counts a predetermined number of pulse signals, a fire signal is generated. And a mode switching setting means for switching the operation mode of the fire detector between a normal monitoring mode and an inspection mode, and setting the count value of the pulse signal counting unit to the mode switching. 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 is provided. A fire detector configured to change the numerical value to a smaller value. 2. The mode switching setting means includes a line voltage discriminating means for discriminating a level of a voltage level supplied to a fire detector from a local line of a fire receiver. The fire detector according to claim 1, wherein the fire detector is configured to determine a mode and an inspection mode. 3. The mode switching setting means includes signal decoding means for decoding a multiplex signal transmitted from a fire receiver through a multiplex signal line, and the signal decoding means switches between a normal monitoring mode and an inspection mode. The fire detector according to claim 1, wherein the fire detector is configured to determine. 4. The mode switching setting means is constituted by a proximity switch built in the fire sensor and operated by a magnetic force.
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.