JP3922738B2 - Fire alarm - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fire alarm device that detects a physical quantity based on a fire phenomenon, for example, an environmental temperature rise, performs fire discrimination, and issues a fire alarm.
[0002]
[Prior art]
In the conventional fire alarm device, the fire signal when it is determined as a fire is self-held on the sensor side or the receiver side. This self-holding function is based on the premise that once a fire has been identified, the site must be checked with human eyes and then restored when there is no fire. In the case of a building, the manager checks the site. Perform recovery operation.
[0003]
[Problems to be solved by the invention]
On the other hand, when the installation target is a condominium, even if there is an administrator, it is often not possible to easily enter the house and check the site. Therefore, in such a case, it is proposed not to be a self-holding system, but to stop the alarm when it is no longer determined to be a fire as a so-called non-holding type having no self-holding function.
[0004]
An object of the present invention is to continue a fire signal for a predetermined time once it is determined that a fire has occurred in a non-holding system.
[0005]
[Means for Solving the Problems]
In view of the above points, the present invention provides detection means for capturing a sensor level using a fire detection unit that detects a physical quantity based on a fire phenomenon, and transmits a fire signal by determining a fire based on the sensor level. After determining the fire, a determination means for determining a non-fire defined separately and stopping the transmission of the fire signal, a fire alarm based on the fire signal, and by stopping the transmission of the fire signal a fire alarm system comprising an alarm unit to recover a fire alarm, a predetermined holding time from the fire discrimination of said discriminating means, the transmission of the fire signal before Symbol alarm means without discrimination of said discrimination means It has the holding means to continue, It is characterized by the above-mentioned.
[0007]
As described above, it is uneasy to immediately extinguish a fire alarm when a non-fire is immediately determined after a fire is determined. Even if it is a non-fire report, it is preferable to actually check it, and by continuing the fire alarm once given for a predetermined time, it is possible to surely call the attention of those concerned.
In addition, a fire detection system that detects a fire based on a defined fire discrimination and transmits a fire signal, and also detects a non-fire based on a separately defined non-fire discrimination and restores the fire signal. A detector that captures a sensor level using a fire detection unit that detects a physical quantity based on a fire phenomenon, a reference unit that stores a reference level to be compared with the sensor level, and a difference between the sensor level and the reference level Fire detection means for determining a fire when the value exceeds a predetermined determination value, sending means for outputting a fire signal when the fire determination means determines a fire, and sensor level after the fire determination means determines a fire Non-fire discrimination means for discriminating that the slope is negative, and the sending means stops sending the fire signal when it is judged as non-fire.
[0008]
Further, the non-fire determining means stores the sensor level when the fire determining means determines that it is a fire as a recovery reference level, and determines that it is non-fire when the sensor level from the detecting means falls below the recovery reference level, or When the difference value between the sensor level from the detection means and the reference level of the reference means or the recovery reference level exceeds a predetermined recovery determination value on a negative slope, it is determined that there is no fire. The reference means uses the stored sensor level before a predetermined time as a reference level, or uses a reference detection unit that detects the same physical quantity as the fire detection unit with delayed followability.
[0009]
As a result, a fire is detected based on the defined fire discrimination and a fire signal is transmitted, but a non-fire can be determined based on a separately defined non-fire discrimination and the fire signal can be recovered, which is useless. The fire alarm can be canceled without an administrator confirming the fire. At this time, the temperature or the like as the sensor level usually rises from the time when it is determined that the fire is normal, and it is certain that it falls below the current level or changes to a negative slope. Can be identified as non-fire.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a first embodiment of the present invention will be described. FIG. 1 is a circuit diagram of a thermistor type thermal sensor 4 as a specific example of the fire sensor of the first embodiment, and FIG. 2 is a flowchart showing the operation of the first embodiment.
[0011]
In FIG. 1, a heat detector 4 includes a constant voltage circuit B2 that supplies a stable voltage and current using terminals C and L to which power and signal lines wired from a fire receiver (not shown) are connected, respectively, An oscillation circuit B5 that inputs an interrupt to the microcomputer IC1 based on the charging time constant of the resistor R1 and the capacitor C1, a heat detection circuit B4 that detects heat due to a fire based on the temperature characteristics of the thermistor TH based on the control of the microcomputer IC1, The microcomputer IC1 includes a reset circuit B3 that performs a reset input when the microcomputer IC1 runs out of control, and a switching circuit B1 that switches between the terminals C and L to a low impedance substantially short-circuited state when the microcomputer IC1 determines that a fire has occurred.
[0012]
Next, regarding the operation of the heat sensor 4, the capacitor C1 is always charged by the resistor R1 in the oscillation circuit B5, and when the charging voltage reaches a predetermined potential based on the time constant, the inverter IC4 operates to enter the interrupt port INT of the microcomputer IC1. A signal is sent. The microcomputer IC1 shifts from the stop state to the run state when an interrupt input is input to the port INT, and the flowchart of FIG. 2 starts. The number of inputs a to the port INT is counted (STEP 1). When a predetermined input constant A (for example, 10 times) is reached (STEP 2), the number of inputs a is cleared (STEP 6), and heat detection is performed. When the input number A is not the predetermined number A, the microcomputer IC1 sets the port Ps to the low level “L” (ground potential), and discharges the capacitor C1 to enter the stop state as the operation stop state (STEPs 3, 4, and 5). . Here, the stop state is a state in which the clock of the microcomputer is stopped, which is a very low consumption state of several μA, and in the run state, there is a large current consumption of several hundred μA, which is an economical state. It is.
[0013]
When performing heat detection, in order to discharge the charge of the capacitor C2 charged through the resistor R6 in the heat detection circuit B4 through the resistors R11, R12 and the thermistor TH, the port P7 is set to the low level “L”. (Ground potential) (STEP 11). At this time, the potential of the capacitor C2 is inputted to the port P6 of the comparator built in the microcomputer IC1 through the resistor R10 and monitored to fall below the predetermined voltage Vc, and the microcomputer IC1 measures the discharge time Ts (current discharge time). The temperature is measured at (STEP 12, 13, 14, 15). The reference potential of the comparator built in the microcomputer IC1 is determined by the resistors R7 and R8. Although not shown, the thermistor TH is provided so as to protrude from the sensor body and responds to the ambient temperature at the location where the sensor is installed. The discharge time from the capacitor C2 through the thermistor TH depends on the temperature. The temperature can be detected from the current discharge time Ts.
[0014]
Further, the number of times b of the heat detection operation is counted (STEP 21). When the predetermined operation constant B is reached (STEP 22), the number of times b is cleared (STEP 23), and the port P7 is set to the low level “L”. Instead, the port P8 is set to the low level “L” (STEP 24), the charge discharge of the capacitor C2 is discharged only by the resistor R11, and the discharge time Tc (corrected discharge time) that is not influenced by the temperature is measured to enter the stop state. (STEP 25, 26, 27, 28). Then, by taking the ratio of the current discharge time Ts including the thermistor TH and the corrected discharge time Tc not including the sensor level SLV (STEP 16), it is possible to eliminate variations due to individual differences of the capacitor C2. is there.
[0015]
After obtaining the sensor level SLV (STEP 16), the microcomputer IC1 counts the number of operations c of the sensor level SLV (STEP 31) and clears the number of operations c every predetermined calculation constant C (STEP 32) (STEP 33). And stored in a storage means RAM (not shown in detail) for use as a later-described reference level SLV '(STEP 34). The storage of the sensor level SLV in the storage means RAM may store all of the time t used as the reference level SLV ′ to be compared, but the capacity of the storage means RAM is reduced by storing every predetermined number of times C. Has been reduced. Then, the microcomputer IC1 obtains a difference value ΔSLV between the current sensor level SLV and the reference level SLV ′ that is a sensor level before a predetermined time t (STEP 41), and discriminates a fire set in the storage means or the like in advance. Is compared with the discriminant value SF as a reference of (STEP 42). If it is determined that there is a fire based on the result, the fire flag Fa and the holding flag Fc indicating the occurrence of fire are turned on in the storage means RAM (STEP 43), and the port Pf is set to the high level "H" (STEP 44). Then, it is stored in the storage means RAM as a recovery level SLVc for determining that it has recovered from a sensor level SLV described later (STEP 45), and a stop state is entered. By setting the port Pf to the high level “H” (STEP 44), the transistor Q4 of the switching circuit B1 is turned on to switch between the terminals C and L. At the same time, the transistor Q3 is turned on and a confirmation lamp by the light emitting diode LED is turned on. Light up. By switching between the terminals C and L, the power / signal line wired from the fire receiver (not shown) is substantially short-circuited, and the signal detection circuit of the fire receiver detects the substantially short-circuit state of this signal line as a fire signal. To do. The fire receiver that has received the fire signal in this way, the sound of the main sound such as a buzzer provided on its own, and the necessary sound device installed in each part of the building connected via the control line Activate and sound the district sound and fire alarm.
[0016]
In addition, after being determined as a fire as described above, the heat detector 4 continues to send out a fire signal when it is not actually a fire, or when the fire is in a non-fire state such that the fire has been subsided in the initial stage. There is no need. Therefore, after determining the above fire, the non-fire is determined from the sensor level SLV.
[0017]
In addition, if the fire signal is stopped immediately in the case of a non-fire, the fire alarm that has been started will not alert the relevant personnel, and the dangerous situation may continue. It is preferable to confirm that there is. Therefore, after the fire is determined, the stop state is continued for a predetermined holding time D without performing the determination.
[0018]
That is, when it is determined that there is a fire, the retention flag Fc is turned on in the storage means RAM (STEP 43), and when the microcomputer IC1 enters an interrupt input to this port INT and shifts from the stop state to the run state, When the holding flag Fc is on (STEP 61), the holding count d is counted by inputting to the port INT (STEP 62). When a predetermined holding time D (for example, a value of 2 to 5 minutes) is reached (STEP 63), the number of times of input d is cleared and the holding flag Fc is turned off (STEP 64, 65), and heat detection is performed. When it is not the holding time D, the microcomputer IC1 sets the port Ps to the low level “L” (ground potential) and discharges the charge of the capacitor C1 in the stop state as the operation stop state, as in the case of counting the number of inputs a. (STEP 3, 4, 5). This stop state is also a clock stop state of the microcomputer and is an economical state. Therefore, during the predetermined holding time D, heat detection is not performed and fire discrimination is not performed, so the substantially short circuit state of the switching circuit B1 is maintained, and a fire alarm by a fire receiver (not shown) is also maintained.
[0019]
Then, the holding flag Fc is turned off as the holding time D elapses, but the fire flag Fa is held. Therefore, when calculating the sensor level SLV, the state of the fire flag Fa in the storage means RAM is confirmed (STEP 51). When the flag Fa is on, a flow for determining non-fire is performed.
[0020]
The non-fire determination is made when the recovery level SLVc, which is the current sensor level stored in the storage means RAM when it is determined that there is a fire, is compared with the current sensor level SLV (STEP 52) and falls below the recovery level SLVc. In addition, since the sensor level SLV has a negative slope, it is determined that the fire is not fired or sedated. Then, the fire flag Fa of the storage means RAM is turned off (STEP 53), the port Pf is set to low level “L” (STEP 54), the transistor Q4 of the switching circuit B1 is turned off, and the terminals C and L are connected. The switching is restored, and at the same time, the transistor Q3 is turned off and the confirmation lamp by the light emitting diode LED is turned off. And it will be in a stop state. By restoring the switching between the terminals C and L, the power / signal line wired from the fire receiver (not shown) is restored to the normal state, and the signal detection circuit of the fire receiver detects the restoration of the signal line. At this time, the fire receiver stops the activation of the necessary sound equipment arranged in each part of the building connected via the control line at the same time as the main sound of the buzzer etc. provided in itself stops. Stop the sound of the district sound and restore the fire alarm.
[0021]
Here, the microcomputer IC1 uses a thermistor TH that detects the environmental temperature as a physical quantity based on a fire phenomenon, and detects the sensor level SLV using the thermistor TH. Based on the sensor level SLV, the microcomputer IC1 distinguishes between fire and non-fire, Is a determination unit that sends out a fire signal from the switching circuit B1, and a holding unit that continues to send a fire signal to a predetermined holding time alarm unit from the time of fire determination of the determination unit, and a fire receiver (not shown) It is an example of the alarm means which performs a fire alarm based on the fire signal by the substantially short-circuit state.
[0022]
This non-fire determination is a definition different from the definition of fire determination. However, as long as a fire signal can be held, a non-fire may be determined when a fire is not determined by the same definition as the fire determination. However, once it is determined that there is a fire, if it is not determined that there is a fire in the same way, there is anxiety about immediately making it non-fire, so it is determined that there is no fire and the fire signal is canceled separately. The fire alarm can be canceled in consideration of safety in terms of hysteresis.
[0023]
Further, in this embodiment, during the holding time D, neither fire discrimination nor non-fire discrimination is performed. However, either determination may be performed during the holding time D, and the operation as a conclusion is performed. It is only necessary to hold the fire signal from a certain switching circuit B1 for a predetermined period.
[0024]
Next, a second embodiment of the present invention will be described. FIG. 3 is a flowchart showing the operation of the second embodiment. Specifically, the same circuit diagram as that of the first embodiment is used, and the same circuit diagram as FIG. 1 is used.
[0025]
The operation of the heat detector 4 is the same as that of the first embodiment, and is always in a stop state when a signal is sent to the interrupt port INT of the microcomputer IC1 based on the time constant of the oscillation circuit B5 and an interrupt input is received. 3 shifts to the run state, and the flowchart of FIG. 3 starts.
[0026]
The flowchart of FIG. 3 showing the operation of the second embodiment is also substantially the same as the flowchart of FIG. 2 showing the operation of the first embodiment, and heat detection is performed by counting the number of inputs a to the port INT. When the predetermined number of times A is not reached, the charge of the capacitor C1 is discharged to enter a stop state as an operation stop state (STEP 1 to 6), and the current discharge time Ts when the potential of the capacitor C2 falls below the predetermined voltage Vc is measured. (STEPs 11 to 16), measuring the corrected discharge time Tc that is not affected by the temperature of the capacitor C2 for each predetermined operating constant B (STEPs 21 to 28), and a reference every predetermined calculation constant C Storing the sensor level SLV as the level SLV ′ (STEPs 31 to 34) is the same.
[0027]
In the flowchart of the second embodiment, a predetermined number of times (accumulation constants X and Y) are continuously performed during the fire determination (STEP 41 and 42) and the non-fire determination (STEP 41 and 42) of the first embodiment. This is the first storage function to make a fire or non-fire by determining whether it is fire or non-fire.
[0028]
That is, when the state of the fire flag Fa in the storage means RAM is off (STEP 81), the microcomputer IC1 performs a fire discrimination flow, and the current sensor level SLV and the reference level that is the sensor level before a predetermined time t. A difference value ΔSLV from SLV ′ is obtained (STEP 71), and compared with a discrimination value SF as a reference for discriminating a fire set in the storage means or the like in advance (STEP 72). As a result, the number of fires x determined to be a fire is counted (STEP 73). When a predetermined fire accumulation constant X (for example, 10 to 60 seconds) is reached (STEP 74), the fire number x is cleared. (STEP 75), the fire flag Fa indicating the occurrence of fire is turned on in the storage means RAM (STEP 76), the port Pf is set to the high level "H" (STEP 77), and the sensor level SLV described later is restored. The recovery level SLVc for determining this is stored in the storage means RAM (STEP 78), and a stop state is entered. By setting the port Pf to the high level “H” (STEP 77), the transistor Q4 of the switching circuit B1 is turned on to switch between the terminals C and L. At the same time, the transistor Q3 is turned on and a confirmation lamp by the light emitting diode LED is turned on. Light up. By switching between the terminals C and L, the power / signal line wired from the fire receiver (not shown) is substantially short-circuited, and the signal detection circuit of the fire receiver detects the substantially short-circuit state of this signal line as a fire signal. To do. The fire receiver that has received the fire signal in this way, the sound of the main sound such as a buzzer provided on its own, and the necessary sound device installed in each part of the building connected via the control line Activate and sound the district sound and fire alarm. If it is not determined that a fire has occurred before the fire count x reaches the predetermined fire accumulation constant X (STEP 72), the fire count x is cleared (STEP 79). As a result, even if it is determined again as a fire, the number of fires x is counted from the beginning.
[0029]
Then, the microcomputer IC1 confirms the state of the fire flag Fa in the storage means RAM (STEP 51), and if the flag Fa is turned on, performs a non-fire determination flow. The determination of non-fire is made when the recovery level SLVc, which is the current sensor level stored in the storage means RAM when it is determined that there is a fire, is compared with the current sensor level SLV (STEP 82) and falls below the recovery level SLVc The number of non-fire times y determined as non-fire is counted (STEP 83), and when a predetermined non-fire accumulation constant Y (for example, a constant corresponding to 2 to 5 minutes) is reached (STEP 84), the number of non-fire times y is cleared (STEP 85), the fire flag Fa of the storage means RAM is turned off (STEP 86), the port Pf is set to the low level (L) (STEP 87), the transistor Q4 of the switching circuit B1 is turned off, and the terminal C , L is restored, and at the same time, the transistor Q3 is turned off and the confirmation lamp by the light emitting diode LED is turned off. And it will be in a stop state. By restoring the switching between the terminals C and L, the power / signal line wired from the fire receiver (not shown) is restored to the normal state, and the signal detection circuit of the fire receiver detects the restoration of the signal line. At this time, the fire receiver stops the activation of the necessary sound equipment arranged in each part of the building connected via the control line at the same time as the main sound of the buzzer etc. provided in itself stops. Stop the sound of the district sound and restore the fire alarm. If the fire is not judged before the non-fire count y reaches the predetermined non-fire accumulation constant Y (STEP 82), the non-fire count y is cleared (STEP 88). Thereby, even if it is determined again that there is no fire, the non-fire frequency y is counted from the beginning.
[0030]
Here, the microcomputer IC1 uses a thermistor TH that detects the environmental temperature as a physical quantity based on a fire phenomenon, and detects the sensor level SLV using the thermistor TH. Based on the sensor level SLV, the microcomputer IC1 distinguishes between fire and non-fire, As an example of storage means for counting the non-fire time of the determination result of the determination means when the fire signal is sent from the switching circuit B1, and stopping the fire signal transmission when the non-fire continues for a predetermined time. A fire receiver (not shown) is an example of alarm means for performing a fire alarm based on a fire signal due to a substantially short-circuit state of a signal line.
[0031]
This non-fire discrimination is different from the fire discrimination definition as in the first embodiment. However, if a fire signal can be retained, it is not determined that a fire is detected by the same definition as the fire discrimination. It may be non-fire. However, once it is determined that there is a fire, if it is not determined that there is a fire in the same way, there is anxiety about immediately making it non-fire, so it is determined that there is no fire and the fire signal is canceled separately. The fire alarm can be canceled in consideration of safety in terms of hysteresis.
[0032]
In the first or second embodiment, in the operation for determining a fire, the sensor level SLV ′ to be compared with the sensor level SLV is not used as the reference level SLV ′ but is provided inside the housing. Alternatively, the reference level SLV ′ may be obtained from the temperature of the environment based on the temperature characteristics of the base voltage _VBE of the transistor as the temperature detecting element.
[0033]
Furthermore, for fire discrimination, when a storage-type fire receiver is used, storage is not necessary, and the signal transmission of the fire detector is not a short circuit of the signal line by the switching circuit, but a code signal using a transmission circuit The status signal may be sent by the Further, when the sensor is an analog type and the detection level is transmitted as a code signal, the above-described various fire discrimination and non-fire discrimination may be performed in the fire receiver.
[0034]
【The invention's effect】
As described above, the present invention is a detection means that captures a sensor level using a fire detection unit that detects a physical quantity based on a fire phenomenon, and detects a fire based on the sensor level and sends a fire signal. Once the fire is determined, a non-fire defined separately is determined to stop sending the fire signal, a fire alarm is issued based on the fire signal, and the fire is stopped by stopping sending the fire signal. a fire alarm system having a warning means to recover an alarm, continued transmission of the fire signal before Symbol warning means from the time of the fire discrimination of the discriminating means predetermined holding time, without discrimination of said discrimination means Since the fire signal is canceled by discriminating that the discrimination means is a non-fire separately, the fire alarm can be canceled in consideration of safety in terms of hysteresis. If a non-fire is determined immediately after a fire is determined, the fire alarm is not immediately extinguished, but the fire alarm once performed is continued for a certain period of time to ensure the attention of relevant parties. Can be aroused.
[0036]
In addition, a fire is detected based on the defined fire discrimination and a fire signal is transmitted, and a non-fire is determined based on a separately defined non-fire discrimination and the fire signal is restored. Based on the defined fire discrimination, fire is detected and a fire signal is sent out, but a non-fire can be determined based on a separately defined non-fire discrimination and the fire signal can be recovered. You can rest assured even if you do not perform the fire confirmation act. At this time, the temperature or the like as the sensor level usually rises from the point of time when it is determined that the fire is normal, and it becomes non-existent when the level falls below that point or the sensor level changes to a negative slope. Can be identified as a fire.
[Brief description of the drawings]
FIG. 1 is a circuit diagram of a thermistor type heat detector as a specific example of a fire detector.
FIG. 2 is a flowchart showing the operation of the fire detector of FIG.
3 is a flowchart showing the operation of the fire detector of FIG. 1 as in FIG. 2;
[Explanation of symbols]
IC1 Microcomputer B1 Switching circuit B4 Heat detection circuit

Claims (1)

A detection means for capturing a sensor level using a fire detection unit that detects a physical quantity based on a fire phenomenon, and a fire signal is transmitted by determining a fire based on the sensor level. a determining means to determine the non-fire defined stops sending of the fire signal, performs fire alarm based on the fire signal, the alarm means to recover the fire alarm by stopping the transmission of the fire signals, the a fire alarm system having a feature in that it has holding means for the predetermined holding time from the fire discriminating the discrimination means, to continue the transmission of the fire signal before Symbol alarm means without discrimination of said discrimination means Fire alarm device.

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