JP6800775B2 - smoke detector - Google Patents

Description

The present invention relates to a detector used in a fire alarm system or the like, and more particularly to a technique effective for using a smoke detector provided with a ringer.

Conventionally, the fire notification system installed inside the building includes a photoelectric smoke detector or the like as a fire detector, and the fire detection signal of the detector is transmitted to the fire receiver, and the fire receiver is used for an alarm. It is configured to ring a bell to notify the outbreak of a fire, or to send a signal to a smoke exhaust device or the like to operate it.
The detector in the conventional fire alarm system is generally not provided with a ringer such as a buzzer, but a speaker is built in the mounting base of the detector or a buzzer is built in the housing case of the detector. The invention has also been proposed (for example, Patent Documents 1 and 2).

The reason why the buzzer is not provided in the sensor is considered to be a decrease in the original sensing function due to the vibration of the ringer and a decrease in durability.
For example, in the invention of the smoke detector described in Patent Document 1, when a buzzer is provided in the housing case of the detector, a ventilation hole is formed in the case so that the buzzer sound can be clearly heard outside. However, when a vent is formed in the case, a part of the smoke flows into the case from the vent, so that the amount of smoke flowing into the smoke sensing unit is reduced and the detection sensitivity is lowered. Therefore, in order to prevent this, a smoke-proof projecting piece projecting downward is provided on the edge of the vent hole on the side far from the sensing portion.

Further, the invention described in Patent Document 2 is configured to provide a plurality of pressing ribs abutting on the peripheral surface of the piezoelectric buzzer on the inner surface of the housing case, and to regulate the movement of the piezoelectric buzzer by the pressing ribs. Is.
In addition, as an invention relating to a sensor having a sound generator built in a case, there is also one described in Patent Document 3.

Japanese Unexamined Patent Publication No. 06-333182 Japanese Unexamined Patent Publication No. 08-124058 International patent application WO2015032417 (A1)

The present inventors have studied that a ringer (piezoelectric sounder) using a piezoelectric element as an actuator is provided not in the housing case of the sensor in which the circuit board on which the detection circuit is mounted is housed, but in the head portion. As a result, even in a smoke detector provided with a piezoelectric sounder in the head portion, if the smoke concentration is measured while the piezoelectric sounder is operating, the measured value will deviate from the measured value when the measurement is performed while the piezoelectric sounder is not ringing. It became clear that there was a problem.
The present invention has been made by paying attention to the above-mentioned problems, and an object of the present invention is to provide a smoke detector capable of preventing an error in measured values even when a piezoelectric sounder is provided. To do.

In order to solve the above problems, the present invention
Inside the housing consisting of the main body base and the cover member covering the upper side of the main body base, an element for detecting a change in the monitoring target, a measuring circuit for measuring a physical quantity related to smoke concentration based on a signal from the element, and a measuring circuit. In a smoke detector in which a circuit board on which a control circuit is mounted is housed and a ringing means is provided on the cover member.
The circuit board is provided with a drive circuit for driving the ringing means and a transmission circuit capable of transmitting information between a predetermined device and an external device.
Between at least one of the plurality of syllables, a non-ringing period shorter than the ringing time of the shortest syllable is set.
The control circuit includes a storage device and controls the drive circuit in response to a ringing request from the outside to ring the ringing means according to a plurality of tunes, while controlling and measuring the measuring circuit during the non-ringing period. The measured value obtained by executing the above is stored in the storage device, and the transmission circuit is operated in response to the measurement value transmission request to transmit the measured value stored in the storage device. Is.

According to the above configuration, a short non-ringing period is provided between at least two of the plurality of tunes, and the control circuit stores the measured value obtained by executing the measurement during the non-ringing period in the storage device. However, since the measured value is transmitted in response to the measurement value transmission request, it is possible to avoid measuring the smoke concentration during the sounding when the smoke detector is provided with a sounding means such as a piezoelectric sounder. , It is possible to prevent the vibration of the piezoelectric sounder from being transmitted to the measurement circuit or the amplification circuit to cause an error in the measured value.

Here, preferably, the plurality of syllables are composed of a phrase including a syllable of a first frequency and a syllable of a second frequency different from the syllable of the first frequency, and the control circuit is provided with the sounding means. The drive circuit is controlled so as to repeat the phrase, and the syllable of the first frequency and the syllable of the second frequency are continuous, and the non-ringing period is provided between the phrases. ..

According to such a configuration, since the ringing means sounds by repeating a phrase including syllables of two frequencies, a clear alarm sound can be emitted, and since a non-ringing period is provided between the phrases, the alarm sound can be used. It is possible to secure time for performing highly accurate smoke concentration measurement during ringing without causing discomfort.

Further, preferably, the non-ringing period is set to 100 milliseconds or less, and the syllable of the first frequency and the syllable of the second frequency are set to 10 times or more of the non-ringing period, respectively. To do.
If the non-ringing period is 100 milliseconds or less, the melody can be heard by the human ear as an almost uninterrupted melody. Here, more preferably, the non-ringing period is set to 50 milliseconds or less.

Also, preferably, the ringing means is a piezoelectric sounder provided with a piezoelectric element.
The cover member includes a dome-shaped case having an opening in the center and being coupled to the main body base, and a head cover attached to the case so as to engage with the opening, and the piezoelectric sounder comprises. The configuration is provided inside the head cover.
According to this configuration, since the piezoelectric sounder is provided at the head portion which is the tip of the sensor, it is possible to generate a loud vibration sound with a relatively small power.

Further, preferably, the circuit board is fixed to the body base.
Inside the dome-shaped case, a box body containing an element for detecting a change in the monitoring target is arranged between the circuit board and the head cover.
A lead wire for electrically connecting the ringing means, the circuit board on which the driving circuit is mounted, and the ringing means is arranged so as to penetrate the box body.
According to such a configuration, the number of wirings penetrating the dark box can be reduced as compared with the case where the circuit board is arranged on the cover side, whereby the entire sensor can be compactly configured.

According to the present invention, there is an effect that it is possible to realize a smoke detector capable of preventing an error in measured values from occurring even when a piezoelectric sounder is provided.

An embodiment of a photoelectric smoke detector as an example of the smoke detector according to the present invention is shown, where (A) is a plan view and (B) is a front sectional view. It is a functional block diagram which shows the electric structure example of the smoke detector shown in FIG. The timing of the smoke concentration measurement operation of the smoke detector of the embodiment is shown, (A) is a smoke concentration measurement and measurement value collection timing chart when the present invention is not applied, and (B) is the smoke of the embodiment. It is a measurement of the smoke concentration in a sensor and the collection timing chart of the measured value. It is a flowchart which shows an example of the procedure in the case of measuring the smoke concentration according to the timing shown in FIG. 3B and transmitting to a fire receiver. It is a flowchart which shows an example of the procedure of the smoke concentration measurement process in the flowchart of FIG.

Hereinafter, an embodiment of a photoelectric smoke detector as an example of a smoke detector to which the present invention is applied will be described with reference to the drawings.
The photoelectric smoke detector (hereinafter, simply referred to as a detector) 10 of the present embodiment is a detector capable of detecting smoke generated by a fire, and is installed on the ceiling surface of a building or the like for use. It is configured in. In the following description, the upper side is the lower side and the lower side is the upper side when the sensor 10 is installed on the ceiling surface of the building.

As shown in FIG. 1, the sensor 10 of the present embodiment has a housing recess 11A for housing the sensing portion, has a cylindrical main body base 11 for mounting on the ceiling surface of a building, and has a dome shape. A sensor cover 12 that covers the entire upper side of the main body base 11 and a head cover 21 that covers an opening formed in the center of the sensor cover 12 are provided, and the main body base 11 and the sensor cover 12 provide an internal accommodation space. A housing having the above is formed.

Further, the sensor 10 has a circuit board 13 accommodated and fixed in the accommodation space formed by the main body base 11 and the sensor cover 12, and a light-shielding wall having a labyrinth structure, and is mounted on the circuit board 13. A dark box base 14 and a dark box cover 15 that engages with the dark box base 14 to form a dark box are provided, and these components are housed in the housing and the main body base 11 and the sensor cover 12 are combined. The sensor is configured by being done.

The main body base 11 constitutes the lower housing wall of the sensor 10, and the lower surface of the main body base 11 is connected to a mounting base (not shown) previously installed on the ceiling surface, and the sensor 10 is attached. Three connecting metal fittings 17 for fixing to the ceiling surface are provided (two of them are visible in FIG. 1). Further, the main body base 11 is provided with a boss portion 11b through which a screw 18 for fixing the circuit board 13 accommodated in the accommodating recess 11A is inserted (one of them is visible in FIG. 1).

The dark box base 14 is provided with a storage portion for storing a light emitting element 19A such as an LED (light emitting diode) and a storage portion for storing a light receiving element 19B such as a photodiode, and is provided on the bottom wall of the storage portion. Is formed with pores (not shown) through which the lead terminals 19a and 19b of the light emitting element 19A and the light receiving element 19B can be inserted, and the tip of the lead terminal of each element protruding from the lower surface of the dark box base 14 is a circuit. It penetrates the substrate 13 and is connected by flow soldering or the like.

The circuit board 13 is composed of a printed wiring board on which electronic components such as resistors, capacitances, and ICs (semiconductor integrated circuits) that form an electronic circuit for fire detection are mounted on the upper surface and the lower surface, and a screw is inserted into the board. A hole is formed, and it is fixed to the bottom wall of the main body base 11 by a screw hole 18 inserted through a screw hole of the connecting metal fitting 17 and a boss portion 11b of the bottom wall of the main body base 11 and inserted into a screw insertion hole of the circuit board 13. Will be done.

On the other hand, as shown in FIG. 1A, a plurality of openings 12B communicating with the smoke detection portion in the dark box are formed in the dome-shaped peripheral wall portion of the sensor cover 12 along the circumferential direction, and the openings are formed. The 12B is configured to function as a smoke inlet that allows outside smoke to flow into the case. Further, as shown in FIG. 1B, a circular opening 12A in which the upper part of the dark box can be exposed is formed in the center of the sensor cover 12, and the dark box cover 16 exposed from the opening 12A. The head cover 21 is engaged with the edge of the disk-shaped lid portion of the above.

Further, a light emitting member 23 made of a transparent member formed in a ring shape is fitted to the edge of the opening 12A in the center of the sensor cover 12. A pair of rod-shaped light guide portions (not shown) formed so as to hang downward are connected to the light emitting member 23, and the tip (lower end) of one of the light guide portions is connected. The light incident portion (end face) of the above is configured to face a light emitting diode (LED) for notifying an operating state mounted on the circuit board 13. The light emitting diode and the light emitting member 23 constitute an indicator lamp 22 described later.

Further, the head cover 21 is provided with a piezoelectric sounder 24 on a disk made of a piezoelectric element, and a light-shielding wall portion 14A projecting upward is formed in the center of the dark box base 14, and the light-shielding wall is formed. Inside the portion 14A, a lead wire 25A extending from the circuit board 13 and a lead wire 25B extending from the piezoelectric sounder 24, and a connector 26 for connecting these lead wires are housed and leads. The drive signal of the piezoelectric sounder 24 is transmitted from the circuit board 13 via the wires 25A and 25B, and the piezoelectric sounder 24 is sounded. Further, a sound hole 21A is provided between the head cover 21 and the upper wall of the sensor cover 12, and is configured so that the ringing sound of the piezoelectric sounder 24 can easily spread to the outside.

FIG. 2 shows a functional block diagram of a smoke detector composed of electronic components such as ICs mounted on the circuit board 13.
As shown in FIG. 2, the smoke detector is controlled by a CPU (central processing unit), a memory such as a ROM or RAM, an oscillator, and an MCU (microcomputer unit) that operates according to a program stored in the ROM. A constant voltage circuit (voltage regulator) 32 as a power supply circuit that receives a voltage from a transmission line 40 extended from a fire receiver (not shown) and generates an operating voltage of an internal circuit including a control circuit 31. Via a smoke concentration measuring circuit 33 that measures the smoke concentration based on the signal of the light receiving element 19B arranged in the dark box, an amplifier circuit 34 that amplifies the output signal of the smoke concentration measuring circuit 33, and a transmission line 40. A transmission circuit (I / F) 35 for transmitting and receiving signals to and from a fire receiver is provided.

The control circuit 31 periodically operates the smoke concentration measuring circuit 33 and the amplifier circuit 34 to calculate the smoke concentration value based on the signal from the amplifier circuit 34, convert it into a digital value, store it in the memory, and store the stored smoke. The concentration value is transmitted from the fire receiver to the fire receiver from the transmission circuit (I / F) 35 as requested.
Further, the smoke detector of the present embodiment is a sounder drive that rings and drives an indicator light drive circuit 36 that lights up and drives an indicator light 22 composed of a light emitting diode and a light emitting member 23, and a piezoelectric sounder 24 as a speaker (SP). It includes a circuit 37 and a tone color selection circuit 38 that externally selects a tone color to be sounded from the piezoelectric sounder 24.

The tone color selection circuit 38 is configured to make a selection depending on whether a resistor is mounted or not mounted. The control circuit 31 is configured to operate the sounder drive circuit 37 to ring the piezoelectric sounder 24 when the fire receiver receives a ringing command via the transmission line 40.
The transmission line 40 is composed of two wires, and an operating voltage is supplied from the fire receiver via the transmission line 40. Multiple (for example, 255) detectors can be connected to one transmission line 40, and addresses are assigned to each detector so as not to overlap, and the fire receiver uses the addresses for polling. Smoke concentration measurement values are sequentially acquired from each sensor. Further, the fire receiver can ring or stop the piezoelectric sounder 24 by transmitting a command to each sensor via the transmission line 40.

When the fire receiver receives the smoke concentration measurement value from the detector, it judges that a fire has occurred when the smoke concentration value or its rate of change exceeds a preset threshold value, and performs warning display processing and sounder ringing processing. Execute interlocking processing to notify the occurrence of a fire.
Further, the transmission line 40 includes a fire detector having a form different from that of the smoke detector of the above embodiment, and an SCI (short circuit) that detects a short circuit when the transmission line is short-circuited and electrically disconnects the transmission line on the downstream side. A repeater to which peripheral devices such as a circuit isolator), bell, and smoke evacuator are connected may be connected.

Next, the smoke concentration measurement operation by the control circuit 31 will be described with reference to the timing chart of FIG. 3 and the flowchart of FIG.
FIG. 3A shows the collection timing of the smoke concentration measurement value when the present invention is not applied. In FIG. 3A, when the smoke detector receives the sounder ringing command at the timing t1, the sounding control signal is output from the control circuit 31 to the sounder drive circuit 37. As a result, the piezoelectric sounder 24 repeats the operation of ringing at a frequency of 677 Hz for 500 ms (milliseconds) and then ringing at a frequency of 938 Hz for 500 ms. Further, completely asynchronous with the sound control of the sounder, when a concentration measurement request is generated by a timer interrupt, a measurement control signal is transmitted from the control circuit 31 to the smoke concentration measurement circuit 33, and smoke concentration measurement is performed at that timing (t2). Will be done.

However, as described above, in a smoke detector provided with a piezoelectric sounder having a piezoelectric element as an actuator in the head portion, when the smoke concentration is measured while the piezoelectric sounder is ringing, the measurement is performed while the piezoelectric sounder is not ringing. There is a problem that deviation from the measured value occurs. Therefore, in the smoke detector of the present embodiment, as shown in FIG. 3 (B), during the sounding of the piezoelectric sounder, silent periods T1, T2 ... For example, 30 ms are provided when the sound frequency is switched. At the timing, the control circuit 31 outputs a concentration measurement command to the smoke concentration measurement circuit 33 to perform concentration measurement, stores the measured concentration value in the internal memory, and transmits it to the receiver in response to the smoke concentration (measurement) request. It is configured to do.

The timing of transmitting the measured concentration value may be the timing of receiving a transmission request from the fire receiver, or may be periodic transmission by a timer interrupt. Further, although not particularly limited, in the present embodiment, the ringing period of each frequency is shortened from 500 ms to 485 ms by providing the silent periods T1, T2 ... Such as 30 ms.
FIG. 4 shows an example of a procedure in which the control circuit 31 measures the smoke concentration according to the timing as shown in FIG. 3B and transmits the smoke concentration to the fire receiver. Hereinafter, the control procedure will be described with reference to the flowchart of FIG.

In this embodiment, the smoke detector executes sound control of the sounder by command processing. Specifically, first, it is determined whether or not a command has been received from the fire receiver (step S1). Here, if it is determined that the command has been received (Yes), the process proceeds to step S2, it is determined whether or not the sounder ringing command has been received, and if it is determined that the sounder ringing command has been received (Yes), the process proceeds to step S3 to measure the smoke concentration. It is determined whether or not the smoke concentration is being measured by the circuit 33.

Then, if it is determined that the smoke concentration is not being measured (No), the process proceeds to step S4, and the selection setting state of the tone color selection circuit 38 is read. For example, if tone 1 is selected, the sounder drive circuit 37 is first set to 677 Hz. A command to ring at a frequency is output, a measurement prohibition is commanded to the smoke concentration measuring circuit 33, and a timer is activated (step S5). If another tone is selected by the tone color selection circuit 38, a ringing command corresponding to the other tone is output.

Next, it is determined whether or not the timer has clocked 485 ms (step S6), and if it is determined that the timer has clocked 485 ms (Yes), the process proceeds to step S7, and a command to sound the sounder drive circuit 37 at a frequency of 677 Hz. Is output and the timer is restarted. Subsequently, it is determined whether or not the timer has clocked 485 ms (step S8), and if it is determined that the timer has clocked 485 ms (Yes), the process proceeds to step S9, and a command to stop the ringing is output to the sounder drive circuit 37. At the same time, a command for permitting measurement is output to the smoke concentration measuring circuit 33. After that, the timer is set to 30 ms, the smoke concentration measurement (step S10) is performed by the smoke concentration measurement circuit 33, and the process proceeds to step S11.

In step S11, it is determined whether or not the sounder ringing stop command has been received, and if it is determined that the command has not been received (No), the process returns to step S3 and the above operation is repeated. On the other hand, if it is determined in step S11 that the sounder ringing stop command has been received (Yes), the process proceeds to step S12, a command for prohibiting ringing is output to the sounder drive circuit 37, and measurement is performed on the smoke concentration measuring circuit 33. Outputs a command to allow and ends command processing.

On the other hand, if it is determined in step S2 that the reception command is not a sounder ringing command (No), the process proceeds to step S13, and it is determined whether or not the command is a measurement value request command. Then, if it is determined that the command is a measurement value request command (Yes), the process proceeds to step S14, the smoke concentration measurement value measured and stored in step S10 is transmitted to the receiver, and the command process is completed. Further, if it is determined that the command is not the measured value request command in step S13 (No), the process proceeds to step S15 and other command processing is executed.

FIG. 5 shows an example of a specific procedure of the smoke concentration measurement process executed in step S10 in the flowchart of FIG.
In this smoke concentration measurement, first, a command for prohibiting ringing is output to the sounder drive circuit 37 (step S21). Subsequently, after outputting a command to perform measurement to the smoke concentration measuring circuit 33, the measured concentration value is stored in the memory (steps S22 and S23). After that, a command for permitting ringing is output to the sounder drive circuit 37 (step S24).

On the other hand, the smoke detector of the embodiment is configured so that the measurement by the smoke concentration measurement circuit 33 is performed by a timer interrupt separately from the above command processing, and is controlled when the smoke concentration measurement interrupt is input. The circuit 31 determines whether or not the sounder is ringing (step S25), does nothing if it is ringing, proceeds to step S21 if it is not ringing, and executes the above operations S21 to S24. Has been done.

Although the present invention has been described above based on the embodiment, the present invention is not limited to that of the above embodiment. For example, in the smoke detector of the above embodiment, the one using a piezoelectric sounder as the sounding means is shown, but the smoke detector may be applied to one using a buzzer or a speaker.
Further, in the above embodiment, the present invention has been described in which the present invention is applied to a smoke detector having a light emitting element and a light receiving element, but the present invention is not limited thereto, and the present invention is not limited thereto, such as a pyroelectric element for detecting infrared rays and a thermistor. It can be widely used when a sounder is provided in an element such as a heat-sensitive element or a gas sensor that detects harmful gas such as CO, and a smoke detector equipped with an amplifier circuit that amplifies signals from these elements.

10 Smoke detector (photoelectric smoke detector)
11 Main body base 12 Sensor cover 13 Circuit board 14 Dark box base 16 Dark box cover 19A Light emitting element 19B Light receiving element 21 Head cover 24 Piezoelectric sounder (sounding means)
25A, 25B lead wire 26 connector

Claims (5)

Inside the housing consisting of the main body base and the cover member covering the upper side of the main body base, an element for detecting a change in the monitoring target, a measuring circuit for measuring a physical quantity related to smoke concentration based on a signal from the element, and a measuring circuit. In a smoke detector in which a circuit board on which a control circuit is mounted is housed and a ringing means is provided on the cover member.
The circuit board is provided with a drive circuit for driving the ringing means and a transmission circuit capable of transmitting information between a predetermined device and an external device.
Between at least one of the plurality of syllables, a non-ringing period shorter than the ringing time of the shortest syllable is set.
The control circuit includes a storage device and controls the drive circuit in response to a ringing request from the outside to ring the ringing means according to a plurality of tunes, while controlling and measuring the measuring circuit during the non-ringing period. The measured value obtained by executing the above is stored in the storage device, and the transmission circuit is operated in response to the measurement value transmission request to transmit the measured value stored in the storage device. A smoke detector characterized by being present. The plurality of syllables consist of a phrase containing a first frequency syllable and a second frequency syllable different from the first frequency syllable.
The control circuit controls the drive circuit so that the ringing means repeats the phrase.
The smoke detector according to claim 1, wherein the syllable of the first frequency and the syllable of the second frequency are continuous, and the non-ringing period is provided between the phrases. The claim is characterized in that the no-ring period is set to 100 milliseconds or less, and the syllable of the first frequency and the syllable of the second frequency are each set to 10 times or more of the no-ring period. 2. The smoke detector according to 2. The ringing means is a piezoelectric sounder provided with a piezoelectric element.
The cover member includes a dome-shaped case having an opening in the center and being coupled to the main body base, and a head cover attached to the case so as to engage with the opening.
The smoke detector according to any one of claims 1 to 3, wherein the piezoelectric sounder is provided inside the head cover. The circuit board is fixed to the main body base and
Inside the dome-shaped case, a box body containing an element for detecting a change in the monitoring target is arranged between the circuit board and the head cover.
4. The fourth aspect of the present invention is characterized in that a lead wire for electrically connecting the ringing means, a circuit board on which the driving circuit is mounted, and the ringing means is arranged so as to penetrate the box body. The smoke detector described.

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