JPH0534075Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) The present invention is a dimming type smoke sensor that issues a fire alarm by detecting that the amount of light between the light emitting part and the light receiving part is attenuated due to smoke caused by a fire. Concerning vessels.

(Prior art) In recent years, dimming type smoke detectors for monitoring large spatial areas such as gymnasiums have been developed in which a light-emitting part that periodically emits light and a light-receiving part that receives light emitted from the light-emitting part are arranged at a predetermined interval. For example, if a smoke detection area of 20 m is placed facing each other, and smoke enters the smoke detection area, the light emitted from the light emitting part is dimmed by the smoke, and a fire judgment is made based on the dimmed light reception output of the light receiving part. A so-called dimming type separate smoke detector has been proposed.

By the way, when installing such a dimming type smoke detector on the ceiling etc., in order to improve the S/N ratio,
Adjust the optical axes of the light emitting section and the light receiving section so that the light receiving output of the light receiving section is maximized. After adjusting the optical axis, the level adjusting section adjusts the light receiving level so that the amount of light received by the light receiving section becomes a predetermined value when no smoke is present in the smoke detection area. When the adjustment is completed, switch to the monitoring state, set and register the reference value based on the initial amount of light received, calculate the threshold value based on the reference value, and compare the received light output attenuated by smoke with the threshold value to detect a fire. I was trying to make a decision.

However, once all adjustments are completed, once the dimming type smoke detector is switched to the monitoring state, even if an adjustment error occurs, the adjustment error will not be displayed and the abnormal light reception output will be automatically referenced. Since the setting is registered as a value, the threshold value calculated based on the reference value also becomes an abnormal value, and there is a problem that a normal fire judgment cannot be made, resulting in false alarms or missed alarms.

In addition, if an alarm is triggered even though the fire is not caused by cigarette smoke, etc., and if a recovery operation is performed on the receiver side by mistake, the dimming type smoke detector will automatically set the registered standard value. At the same time, the reference value is automatically set and registered when power supply starts from the receiver side, so the reference value has to be updated and registered while it is still full of cigarette smoke, and the reference value There was a risk of further false alarms due to the abnormality.

(Purpose of the invention) This invention was made in view of the above problems.
We provide a dimming type smoke detector that has a function that displays abnormal settings of reference values due to adjustment errors during installation adjustment of dimming type smoke detectors, and also detects abnormalities in updated and registered reference values during fire monitoring. The purpose is to

(Structure of the invention) In order to achieve this object, the present invention receives the emitted light from the light emitting part that periodically emits light with the light receiving part, and sets and registers the first light reception output of the light receiving part as a reference value. In dimming type smoke detectors, which determine whether there is a fire by comparing the received light output with a threshold value calculated based on a reference value each time a light receiving output is obtained in the light receiving part, the reference value registered in the memory part is a predetermined set value. A control unit is provided to determine whether the reference value is within the range of .

(Example) Hereinafter, an example of the present invention will be described based on the drawings.

FIG. 1 is an overall configuration diagram showing an embodiment of the present invention. First, the configuration will be described. Reference numeral 1 denotes a receiver, which supplies power to a dimming type smoke detector to be described later, and also receives detection information from the dimming type smoke detector and displays an alarm. From receiver 1 there is a fire signal L1 that also serves as a power source, an inspection signal L2, and a common line L.
3 is pulled out and connects a plurality of light receiving sections 2. A pair of light-receiving parts 2 and light-emitting parts 3 form a dimming type smoke detector, and the light-receiving parts 2 and light-emitting parts 3 are installed facing each other with a predetermined interval, for example, a smoke detection area 4 of 15 m. . A pair of traffic lights L4 and L5 are drawn out from the light receiving section 2 and connected to the light emitting section 3. 3a is a light emitting element, which emits light in response to a command from the light receiving section 2;
The emitted light is made incident on the light receiving element 2a. A reference value is set and registered in the light receiving unit 2 based on the first amount of light received after the installation adjustment is completed or the power is turned on again.The threshold value is calculated based on the reference value and every time a smoke detection signal is obtained. A fire judgment is made by comparing with a threshold value. In addition, the light receiving unit 2 determines whether the registered reference value is normal or not, and if the reference value is abnormal, it sends an inspection signal to the receiver 1 via the inspection signal L2. do.

FIG. 2 is a block diagram showing the circuit configuration of the light receiving section 2 in FIG. 1. 6 is a constant voltage power supply, which receives the power supply from the receiver 1 and, for example,
Outputs 15V power supply voltage Vh. Reference numeral 7 denotes a light emission control section, which controls the light emission operation of the light emission section 3 based on commands from the control section 8 . 9 is a constant voltage power supply, which receives the power supply Vh from the constant voltage power supply 6 and adjusts the power supply voltage.
It is adjusted to a value Vl lower than Vh, for example, a voltage of 5V, and is continuously supplied to the control unit 8 to maintain the storage operation of the storage unit built in the control unit 8. Reference numeral 10 denotes a clock circuit that generates clock pulses of a predetermined pulse width at a predetermined cycle, and when the first clock pulse from the clock circuit 10 is input, the control section 8 starts a series of control operations based on preset program control. do. Reference numeral 11 denotes a constant voltage power supply, which receives power supply from the constant voltage power supply 6, adjusts it to a constant voltage Vm of, for example, 10V, and supplies power to the reception circuit 13 based on a control signal from the reception control section 12. The receiving circuit 13 includes a receiving circuit, an amplifier circuit, and a hold circuit, and the light receiving circuit receives the emitted light from the light emitting section 3, amplifies the received light output with the amplifier circuit, and holds it with the hold circuit. This held detection signal is sent to the A/D conversion circuit 16 based on a control signal from the control section 8. Reference numeral 15 denotes a power supply voltage monitoring circuit, which inputs the output voltage from the reception control unit 12 to monitor a drop in the power supply voltage Vh, detects interruption of power supply from the receiver 1, and starts power supply after restoration. monitors the rise in power supply voltage due to
It is sent to the control unit 8 via. A reference voltage circuit 17 receives power from the reception control section 12, adjusts it to a predetermined voltage, for example, 2.5V, and provides a reference voltage to the A/D conversion circuit 16. 18 is a sensitivity setting circuit that has two modes: adjustment state and monitoring state.
A plurality of resistors with different resistance values are switched and connected using a rotary switch, etc., and the reference voltage circuit 17
Input the reference voltage Vr from , divide the reference voltage Vr into a predetermined voltage division ratio determined by switching the rotary switch, and specify the adjustment state of the dimming type smoke detector and the detection sensitivity during monitoring. The A/D conversion circuit 16 converts the detection signal and a predetermined divided voltage from the sensitivity setting circuit 18 into an A/D converter based on the reference voltage Vr.
It is converted and sent to the control section 8. The control unit 8 inputs the divided voltage from the sensitivity setting circuit 18, recognizes a predetermined detection sensitivity corresponding to the divided voltage, and sets the monitoring state if the sensitivity is set, and adjusts if the sensitivity is not set. Determine the condition. When it is determined that the adjustment state is established, the control section 8 outputs a monitor signal to the monitor output section 19 every time the light reception output from the receiving circuit 13 is obtained, and also causes the reference value to be updated and registered in the storage section. When the control section 8 determines the monitoring state by switching from the adjustment state to the monitoring state by switching the sensitivity setting circuit 18, the control section 8 compares the updated and registered final reference value with the range of setting values provided in the control section 8. The determining means compares the values and determines whether or not they are normal. If there is an abnormality, the inspection signal output section 20 is activated to issue a command to send out an inspection signal. Note that, for example, the range of the set value provided in the control unit 8 is set in the range of 50% to 80% of the reference voltage Vr of the reference voltage circuit 17, which is the reference voltage of the A/D conversion circuit 16. In the monitoring state, the detection sensitivity set by the sensitivity setting circuit 18 and
A threshold value is calculated by multiplying by the registered reference value, and a fire judgment is made by comparing the threshold value and the received light output. When a fire is determined, the fire signal output unit 21 is activated and a command is sent to send out a fire signal. do.

FIG. 3 is a program flow diagram showing the control operation of the control section 8 shown in FIG. 2. To explain the operation with reference to the program flow diagram in FIG. 3, first, when installing a dimming type smoke detector, it is necessary to adjust the optical axis, light receiving level, etc. In block a, information from the sensitivity setting circuit 18 is adjusted. is input to determine whether it is in a monitoring state or an adjustment state, and when it is determined in block b that it is in an adjustment state, the process advances to block c, and each time the received light output from the receiving circuit 13 is obtained, it is updated and registered as a reference value. In block d, by activating the monitor signal output section 19 and outputting a monitor signal, the adjustment worker adjusts the optical axis of the light emitting section 3 and the light receiving section 2 and the level of the light receiving signal while checking the monitor signal. be able to. At the end of the adjustment work,
When the rotary switch built in the sensitivity setting circuit 18 is operated to switch to an arbitrary detection sensitivity, for example, 50%, the sensitivity setting circuit 18 has a preset value.
Since it is set that when the detection sensitivity is 50%, it is a monitoring state, the control section 8 determines that it is a monitoring state and proceeds from block b to block e. In block e, it is determined whether the monitoring information of the power supply voltage monitoring circuit 15 is normal or not, and if it is normal, the process proceeds to block f. In block f, it is determined whether or not the final reference value updated and registered at the time of adjustment, that is, in block c, is normal. Here, if the light reception signal level in a state where no smoke exists in the smoke detection area 4 is outside the range of the setting value to be adjusted due to an adjustment error by the adjustment worker, the reference value of the abnormal value will be set and registered. The process advances to block j, where the inspection signal output section 20 is activated to instruct transmission of an inspection signal.

Next, a description will be given of the operation when a recovery operation is performed after a predetermined time has elapsed due to power cutoff from the receiver side in a normal monitoring state. First, when the power supply is cut off for a predetermined period of time, the power supply from the constant voltage power supply 9 is cut off, thereby erasing the reference value set and registered in the storage section. When the power is turned on again, block a
The state is determined by , and it is determined that the power is turned on again in the monitoring state, and blocks from block b to block e
Proceed to. In block e, the power supply voltage monitoring circuit 15
monitors the rise in the power supply voltage, and it is determined that it is not in a normal monitoring state until the specified power supply voltage is reached, and the process proceeds to block c, where the light reception signal from the receiving circuit 13 is input and updated and registered as a reference value. . In block d, the monitor signal output section 19 is activated to issue a command to send out a monitor signal. Power supply voltage monitoring circuit 15
When it is determined that the power supply voltage has reached the specified voltage based on the monitoring information from Determine whether or not. If the reference value at this time is abnormal, the process advances to block j and a check signal is output. Further, if the reference value is normal in the determination of block f, the process proceeds from block f to block g, and the reference value is multiplied by the detection sensitivity to calculate the threshold value. In block h, fire judgment is made by comparing the threshold value and the received light output from the receiving circuit 13. If the amount of light reduction is small, that is, if the received light output is greater than the threshold value, it is determined to be normal and the block a is returned to. Return and continue monitoring operation. When the amount of light attenuation increases due to the intrusion of smoke into the smoke detection area 4 and the received light output becomes smaller than the threshold value, it is determined that there is a fire, the process proceeds to block i, and the fire signal output section 21 is activated to command the transmission of a fire signal. .

In the above embodiment, a separate dimming type smoke detector is provided in which a light emitting part that periodically emits light and a light receiving part that receives light emitted from the light emitting part are arranged facing each other at a predetermined interval. Although the present invention has been described above, it can also be applied to an integrated dimming type smoke detector in which a light emitting part and a light receiving part are built into the same housing.

(Effects of the invention) As explained above, according to the invention, the light emitted from the light emitting part is received by the light receiving part, and the first received light output of the light receiving part is set and registered as a reference value. In dimming type smoke detectors, which calculate a threshold value based on the threshold value and compare the received light output attenuated by smoke with the threshold value to determine a fire, the reference value registered in the memory unit is within the range of the predetermined setting value. By installing a control unit that determines whether or not the smoke detector is inside the room and determines whether the reference value is normal, it is possible to prevent abnormality in the reference value due to a mistake in the installation adjustment of the dimming type smoke detector. The settings can be easily identified, and even if the registration of the reference value is deleted due to a power cut in the fire monitoring state, it can be checked again after the power supply starts to see if the updated and registered reference value is normal. Monitoring prevents malfunctions of dimming smoke detectors and greatly improves their reliability.

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram showing an embodiment of the present invention;
FIG. 2 is a block diagram showing the circuit configuration of the light receiving section in FIG. 1, and FIG. 3 is a program flow diagram of the control section in FIG. 2. DESCRIPTION OF SYMBOLS 1... Receiver, 2... Light receiving part, 2a... Light receiving element, 3... Light emitting part, 3a... Light emitting element, 4... Smoke detection area, 6, 9, 11... Constant voltage power supply, 7... ...Emission control section, 8...Control section, 10...Clock circuit, 12...Reception control section, 13...Reception circuit, 1
5... Power supply voltage monitoring circuit, 16... A/D conversion circuit, 17... Reference voltage circuit, 18... Sensitivity setting circuit, 19... Monitor signal output section, 20... Inspection signal output section, 21... Fire signal output section.

Claims (1)

[Scope of utility model registration request] The light emitted from the light emitting part is received by the light receiving part, and the first light reception output from the light receiving part is set and registered in the memory part as a reference value.The threshold value is calculated based on the reference value, and the received light that has been attenuated by smoke is calculated. In a dimming type smoke detector that makes a fire judgment by comparing the output with the threshold value,
Determining whether or not the reference value registered in the storage unit is within a predetermined set value range;
A dimming type smoke detector characterized by being provided with a control unit that determines whether the reference value is normal and outputs an alarm if there is an abnormality.