JP7592444B2 - Fire Receiver - Google Patents

Description

The present invention relates to a fire receiver that is connected to a sensor line to which fire detectors are connected, and issues a fire alarm for each sensor line.

In an alarm system connected to a P-type fire receiver that issues a fire alarm for each sensor line to which a fire detector is connected, the fire detector that detects a fire notifies the fire receiver by lowering its own impedance and increasing the current flowing through the sensor line (see, for example, Patent Document 1).

JP 2015-026323 A

Some P-type fire receivers have an external line connected to them in addition to the detector line. External devices such as smoke control devices are connected to the external line. The external devices connected to the external line change the current flowing through the external line by lowering or raising the impedance of the device itself, and notify the fire receiver of the device's normal or abnormal operating status based on the change in current.

As described above, P-type fire receivers have separate detector lines and external lines. For example, a fire receiver that can be connected to 30 detector lines needs to have a circuit board that can accommodate the 30 detector lines as well as a circuit board that can accommodate the external lines, and these circuit boards are costly. However, depending on the equipment being monitored, even if the fire receiver has a circuit board that can accommodate 30 lines, there are cases in which fewer than 30 lines are used. In such cases, the fire receiver will have a circuit board that monitors the external lines in addition to a circuit board that monitors the unused detector lines, and so improvements were desired from a cost perspective.

The present invention was developed in response to the above-mentioned problems, and aims to provide a fire receiver that can suppress the increase in costs of circuit boards for monitoring detector lines and external lines.

The fire receiver of the present invention is a fire receiver to which a plurality of sensor lines to which fire detectors are connected are connected, and comprises a plurality of state determination units connected to each of the plurality of sensor lines and monitoring the voltage of the sensor line to determine the state of the sensor line; a control unit that holds , for each of the sensor lines, either a first state in which the fire detector is connected or a second state in which an external device other than the fire detector is connected; a receiving resistor provided in each of the plurality of sensor lines for converting the current flowing through the sensor line into a voltage and inputting the voltage to the state determination unit; and a switch provided in each of the plurality of sensor lines for connecting or disconnecting the receiving resistor to the sensor line , and the switch provided in the sensor line to which the second state is set disconnects the receiving resistor from the sensor line .

The fire receiver of the present invention can set each detector line to either a first state in which a fire detector is connected, or a second state in which an external device is connected. The fire receiver is equipped with a control unit that, when a signal is input from a state determination unit that monitors the voltage of the detector line, operates according to whether the detector line is in the first state or the second state. In this way, the detector line can be used as an external line by setting it to the second state, thereby suppressing increases in costs associated with circuit boards.

1 is an explanatory diagram of a fire alarm system including a fire receiver according to a first embodiment. 11 is an explanatory diagram of a fire alarm system including a fire receiver according to a second embodiment. FIG.

The following describes an embodiment of the present invention with reference to the drawings. The present invention is not limited to the following embodiment, and various modifications are possible without departing from the spirit of the present invention. The present invention also includes all possible combinations of the configurations shown in the following embodiment. The device shown in the drawings is an example of the device of the present invention, and the device of the present invention is not limited to the device shown in the drawings. In addition, in each drawing, the same reference numerals are used to denote the same or equivalent parts, and this is common throughout the entire specification.

Embodiment 1.
(Configuration of fire alarm system 100)
FIG. 1 is an explanatory diagram of a fire alarm system 100 including a fire receiver 1 according to the first embodiment. The fire alarm system 100 is installed in buildings such as hotels, apartment buildings, office buildings, and commercial facilities, and monitors fires and issues an alarm when a fire is detected. The fire alarm system 100 includes a fire receiver 1, a sensor circuit 10 consisting of a common line 11 and a line line 12 drawn from the fire receiver 1, and a fire sensor 20 connected to the sensor circuit 10. A termination resistor 13 is connected to the end of the sensor circuit. The fire sensor 20 notifies the fire receiver 1 of the detection of a fire by lowering the line voltage of the sensor circuit 10 and increasing the current flowing through the sensor circuit 10. The sensor circuit 10 serves both as a power line for supplying power to the fire sensor 20 and as a signal line for transmitting and receiving signals between the fire sensor 20 and the fire receiver 1.

This embodiment is characterized in that it allows external devices other than fire detectors, such as a smoke control device 30, to be connected to a detector circuit 10 consisting of a common line 11 and a line line 12. In FIG. 1, a smoke control device 30 is connected to one detector circuit 10 as an example of an external device.

Here, FIG. 1 shows an example in which two sensor lines 10 are connected to a fire receiver 1, but the number of sensor lines 10 is not limited to the example shown. Also, FIG. 1 shows an example in which two fire sensors 20 are connected to one sensor line 10, and one smoke control device 30 is connected to the other sensor line 10, but the number of fire sensors 20 and smoke control devices 30 is also not limited to the example shown.

(Configuration of fire detector 1)
The fire receiver 1 comprises a main control unit 2, a sub-control unit 3, a power supply unit 4, a receiving resistor 5, a status determination unit 6, and a switch 7. The same number of sets each consisting of the sub-control unit 3, the power supply unit 4, the receiving resistor 5, the status determination unit 6, and the switch 7 are provided as the sensor lines 10. The main control unit 2 and the sub-control unit 3 form the control unit of the fire receiver 1, with the main control unit 2 controlling the entire fire receiver 1 and the sub-control unit 3 controlling the sensor lines 10.

The main control unit 2 transmits and receives signals to and from the sub-control unit 3. The main control unit 2 outputs control signals to the sub-control unit 3 and controls the sub-control unit 3. The main control unit 2 is composed of dedicated hardware or a CPU that executes a program stored in a memory (not shown).

The sub-controller 3 monitors one sensor line 10, receives output from the state determination unit 6 connected to that sensor line 10, and controls the power supply unit 4 and switch 7 connected to that sensor line 10. For the corresponding sensor line 10, the sub-controller 3 holds either a first state in which a fire sensor 20 is connected, or a second state in which an external device other than a fire sensor, such as a smoke control device 30, is connected. The first and second states are set by a dip switch or a program (not shown). The sub-controller 3 is composed of dedicated hardware, or a CPU that executes a program stored in a memory (not shown).

The power supply unit 4 converts the AC voltage supplied from a commercial power source (not shown) into a DC voltage of, for example, 24 V, and supplies it to the common line 11 of the sensor circuit 10.

The receiving resistor 5 is connected in parallel with the state determination unit 6 and the line 12. A current flows through the receiving resistor 5, which is supplied from the power supply unit 4 to the common line 11 and passes through the fire detector 20, the termination resistor 13, and the line 12. When a current flows through the receiving resistor 5, a voltage is generated across the receiving resistor 5. This voltage is called the receiving voltage. In this way, the receiving resistor 5 converts the current into a receiving voltage, and the receiving voltage is input to the state determination unit 6.

The power supply voltage supplied from the power supply unit 4 is divided into the impedance between the common line 11 and the line line 12, which is [line impedance of the sensor line 10]:[receiving resistance]. In other words, the power supply voltage is divided into a line voltage and a receiving voltage. Therefore, the receiving voltage is the value obtained by subtracting the line voltage from the power supply voltage. Here, the line impedance of the sensor line 10 is the composite impedance of the impedance of the fire sensor 20 connected to the sensor line 10 and the impedance of the termination resistor 13.

The state determination unit 6 determines the state of the sensor line 10. Specifically, it determines whether the sensor line 10 is in a normal state, a fire state, or a disconnection state, and outputs the determination result. The state determination unit 6 has a fire threshold for determining whether or not there is a fire state, and a disconnection threshold for determining whether or not there is a disconnection state, and determines the state of the sensor line 10 by comparing the input received voltage with the fire threshold and the disconnection threshold. The disconnection threshold is a value smaller than the fire threshold. The state determination unit 6 performs a delay operation to confirm the determination when the sensor line 10 continues in the same state for a predetermined delay time, so as not to be affected by momentary voltage changes in the sensor line 10 due to noise.

The switch 7 is connected between the line 12 and the receiving resistor 5, and is controlled by the sub-controller 3 to switch between an on state and an off state. When the switch 7 is in the on state, the receiving resistor 5 is connected to the line 12. When the switch 7 is in the off state, the receiving resistor 5 is disconnected from the line 12.

(Configuration of Fire Detector 20)
The fire detector 20 is a heat detector, a smoke detector, or a flame detector. When multiple fire detectors 20 are connected to one detector line 10, the fire detectors 20 are connected by a feeder wiring. When the end of the detector line 10 is a fire detector 20, a termination resistor 13 is connected to the fire detector 20 at the end. The fire detector 20 has a built-in contact 21 connected to the detector line 10. The contact of the fire detector 20 is normally open. Therefore, during normal times when the fire detector 20 does not detect a fire, only a weak current flows through the detector line 10. When the fire detector 20 detects a fire, it closes the contact 21 connected to the detector line 10, lowering the voltage of the detector line 10 and allowing a current larger than normal to flow through the detector line 10. This current larger than normal becomes a fire signal and notifies the fire receiver 1 of the occurrence of a fire.

(Configuration of the smoke control device 30)
The smoke control and exhaust device 30 is an example of an external device. The smoke control and exhaust device 30 is, for example, a fire door, a fire damper, an emergency door, a smoke exhaust machine, or the like. Note that the specific devices of the external devices connected to the sensor line 10 are not limited to those shown here. The smoke control and exhaust device 30 operates by receiving power from an external power source (not shown). For the smoke control and exhaust device 30, the sensor line 10 is a signal line.

Here, like the fire detector 20, the smoke control device 30 has contacts 31 connected to the detector line 10. The smoke control device 30 has contacts 31 that are normally open and contacts 31 that are normally closed. The smoke control device 30 changes the impedance by changing the contacts 31 from a closed state to an open state, or from an open state to a closed state, thereby changing the current flowing through the detector line 10. In this way, the smoke control device 30 notifies the fire receiver 1 whether the smoke control device 30 is operating or not. It is also possible to notify the fire receiver 1 of a state, such as a normal state or an abnormal state.

(Operation of fire alarm 1)
The fire receiver 1 is preset with a first state in which the fire detector 20 is connected and a second state in which the external device, the smoke control device 30, is connected for each of the connected detector lines 10. In this embodiment, the sub-control unit 3 holds the settings of the first state and the second state.

The sub-controller 3 connected to the sensor line 10 set to the first state turns on the switch 7. This connects the receiving resistor 5 to the line 12, and the receiving voltage is input from the receiving resistor 5 to the state determination unit 6. The state determination unit 6 periodically compares the receiving voltage with the fire threshold and the disconnection threshold described above to determine the fire state and the disconnection state. If it is determined that there is a fire state or a disconnection state, a detection signal is input to the sub-controller 3. When the sub-controller receives the detection signal, it notifies the main control unit 2, and if the main control unit 2 determines that there is a fire state, it performs an alarm operation at the time of fire detection. After that, when a recovery switch (not shown) provided on the fire receiver 1 is operated to input a recovery signal, the main control unit 2 of the fire receiver 1 disconnects the power supply unit 4 from the sensor line 10 and cuts off the power supply to the fire detector 20. This causes the fire detector 20 to return to the normal state. By returning to the normal state, the contact 21 of the fire detector 20 becomes open.

The sub-controller 3 connected to the sensor line 10 set to the second state can set the switch 7 to either the on or off state. This is explained in detail below.

In the case where the contact 31 of the smoke control device 30 is a type that is in a closed state during normal operation when the smoke control device 30 is not in operation, as an example of the second state, the switch 7 is turned off and the receiving resistor 5 is disconnected from the sensor line 10. The sub-controller 3 then periodically turns on the switch 7 to connect the receiving resistor 5 to the sensor line 10. When the switch 7 is in the on state, the state determination unit 6 determines that the sensor line 10 is in a fire state from the receiving voltage generated in the receiving resistor 5, and inputs a fire detection signal to the sub-controller 3. However, the sub-controller 3 connected to the sensor line 10 set to the second state determines that the smoke control device 30 is not in operation because the smoke control device 30 is not intended for fire detection, unlike the fire detector 20, and does not notify the main control unit 2. Also, when the contact 31 is in an open state and the state determination unit 6 determines that there is no fire state when the switch 7 is in the on state, the sub-controller 3 detects that the smoke control device 30 is in operation and notifies the main control unit 2.

In the case where the contact 31 of the smoke control device 30 is in an open state under normal circumstances and is in a closed state when a signal is sent to the fire receiver 1 to notify the state, the switch 7 may be in an off state as described above and periodically in an on state, as an example of the second state. When the switch 7 is in an on state, the receiving resistor 5 is connected to the sensor line 10. The contact 31 of the smoke control device 30 is in an open state at all times, but when the device is to inform the fire receiver 1 that it is in operation, the contact 31 is in a closed state. When the switch 7 is in an on state, if the state determination unit 6 determines that the sensor line 10 is not in a fire state based on the received voltage, the sub-control unit 3 determines that the smoke control device 30 is not in operation and does not notify the main control unit 2. Also, when the switch 7 is in an on state, if the state determination unit 6 determines that a fire state is present, the sub-control unit 3 determines that the smoke control device 30 is in operation and notifies the main control unit 2.
When the contacts 31 of the smoke control and exhaust device 30 are normally open, the switch 7 is turned on as an example of the second state. After the state determination unit 6 determines that a fire exists because the contacts 31 are closed, the switch 7 may be turned off, or the switch 7 may be periodically connected.
Moreover, the smoke control device 30 can inform the fire receiver 1 of its own state by intermittently closing the contact 31 and changing the current in a pulsed manner. In this case, as an example of the second state, the switch 7 is periodically turned on, and when a pulsed change in the current is detected, the switch 7 is turned on for a predetermined time to detect a pulse signal from the smoke control device 30. The smoke control device 30 can notify the fire receiver 1 of the state by changing the timing of closing the contact 31 between the normal state and the abnormal state. The state determination unit 6, which detects the change in current caused by the state change of the contact 31, inputs the determination result to the sub-control unit 3. Depending on the operating state of the contact 31, the state determination unit 6 can input to the sub-control unit 3 a detection signal that is the same as the fire state or the disconnection state when the fire detector 20 detects a fire. However, since the sensor line 10 is set to the second state, the sub-control unit 3 does not perform the operation upon detection of a fire or a broken line, and determines whether the state is normal or abnormal, assuming that the state has been notified by the smoke control device 30.

In this way, the sub-controller 3 of the sensor line 10 set to the second state will perform a different operation even if the state determination unit 6 inputs a signal that is the same as a fire state or a broken wire state in the sensor line 10 in the first state.

As described above, the fire receiver 1 of this embodiment can set each detector line 10 to either a first state in which the fire detector 20 is connected, or a second state in which the smoke control device 30 is connected. The sub-controller 3 is provided with a sub-controller that operates according to whether the detector line 10 is in the first state or the second state when a signal is input from the state determination unit 6 that monitors the voltage of the detector line 10. In this way, by setting the detector line 10 to the second state, it can be used as an external line to which external devices other than fire detectors, such as the smoke control device 30, are connected, thereby suppressing increases in costs associated with circuit boards.

In addition, in this embodiment, the switch 7 connected to the sensor line 10 set to the second state is turned off to disconnect the receiving resistor 5 from the sensor line 10. Therefore, when a smoke control device 30 having a normally closed contact 31 is connected to the sensor line 10, no current flows through the receiving resistor 5 at all times, so that the receiving resistor 5 can be prevented from becoming too hot.

In a conventional fire receiver 1 without a switch 7, when a smoke control device 30 with a contact 31 in a normally closed state is connected to a sensor line 10, the receiving resistor 5 is always connected to the sensor line 10, so that a current always flows through the receiving resistor 5, causing it to become hot. In a sensor line 10 in a first state in which a fire sensor 20 is connected, when the fire sensor 20 detects a fire, a current flows through the receiving resistor 5, but when the fire sensor 20 returns to a normal state, the current stops flowing through the receiving resistor 5, so the high temperature of the receiving resistor 5 is not a major problem. However, when a smoke control device 30 with a normally closed contact 31 is connected, the receiving resistor 5 becomes hot due to the current always flowing through it, so that heat countermeasures are required. Here, it is also possible to suppress the current flowing through the receiving resistor 5 by increasing the resistance value of the receiving resistor 5. However, as described above, the power supply voltage supplied from the power supply unit 4 to the sensor line 10 is divided into a line voltage and a receiving voltage. If the resistance value of the receiving resistor 5 is increased, when a fire detector 20 is connected to this detector line 10, the receiving voltage generated by the receiving resistor 5 due to the current flowing through the fire detector 20 and the termination resistor 13 under normal conditions increases, causing the line voltage of the detector line 10 to decrease. As a result, the voltage supplied to the fire detector 20 decreases, causing the operation of the fire detector 20 to become unstable. Therefore, if the same detector line 10 is to be used for both the fire detector 20 and the smoke control device 30, the resistance value of the receiving resistor 5 cannot be increased.

However, according to this embodiment, the receiving resistor 5 corresponding to the sensor line 10 to which the smoke control device 30 having the normally closed contacts 31 is connected is disconnected from the sensor line 10 by the switch 7, so that the receiving resistor 5 can be prevented from becoming too hot, as described above. Therefore, the convenience of using the sensor line 10 as an external line to connect external equipment such as the smoke control device 30 can be improved.

Embodiment 2.
In this embodiment, an example will be described in which the switch 7 is provided at a position different from that in embodiment 1. In this embodiment, the differences from embodiment 1 will be mainly described.

Figure 2 is an explanatory diagram of a fire alarm system 100 including a fire receiver 1 according to embodiment 2. The fire receiver 1 of this embodiment has a switch 7A instead of the switch 7 of embodiment 1. The function and structure of switch 7A are the same as those of switch 7 of embodiment 1, but the connection position is different. Specifically, switch 7A is connected in series with the state determination unit 6 and the receiving resistor 5 in line 12.

A first state or a second state is set for each sensor line 10, and in the first state, switch 7A is turned on, and in the second state, switch 7A is turned off, as in embodiment 1.

The operation of the fire receiver 1 when the sensor line 10 is set to the second state will be described. When the switch 7A is turned off, the sensor line 10 is no longer a closed circuit, and no current flows through the sensor line 10. In other words, no received voltage is input to the state determination unit 6. In this case, the state determination unit 6 determines that the sensor line 10 is in a disconnected state and inputs a disconnection signal to the sub-control unit 3. However, the sub-control unit 3 connected to the sensor line 10 set to the second state does not notify the main control unit 2 of the detection of the disconnection. Furthermore, the sub-control unit 3 may periodically turn on the switch 7 to connect the receiving resistor 5 to the sensor line 10. By connecting the receiving resistor 5 to the sensor line in this way, as described in embodiment 1, the state determination unit 6 detects different currents depending on whether the contact 31 is in an open state or a closed state, and the state of the smoke control device 30 can be detected.

In this way, even in the second embodiment, in which the switch 7A is connected in series with the receiving resistor 5 and the state determination unit 6, the same technical effect as in the first embodiment can be obtained.

In the first and second embodiments, a smoke control and exhaust device has been used as an example, but the external device may also be an emergency broadcast system used in conjunction with the fire receiver 1 to broadcast the occurrence of a fire, or a general control panel that displays the location of a fire on a map, and the status of these devices can be displayed on the fire receiver 1.
The external device may also be a fire control panel that controls a sprinkler system or a gas fire extinguishing system, or a pressure monitoring device that is part of such a system.
Furthermore, the external device may be an emergency notification device or an emergency stop device that is operated by a person who discovers an abnormality to notify the abnormality.
Furthermore, the external device may be a power supply facility that supplies power to a building or an emergency power supply facility that supplies power in the event of a power outage.
Furthermore, the external device may be a lighting device, an automatic door, an elevator, or an escalator.

1 Fire receiver, 2 Main control unit, 3 Sub-control unit, 4 Power supply unit, 5 Receiving resistor, 6 Status determination unit, 7 Switch, 7A switch, 10 Sensor line, 11 Common line, 12 Line line, 13 Terminating resistor, 20 Fire sensor, 21 Contact, 30 Smoke control device, 31 Contact, 100 Fire alarm system.

Claims (2)

A fire receiver to which a plurality of detector lines to which fire detectors are connected,
A plurality of state determination units each connected to a plurality of the sensor lines, each monitoring a voltage of the sensor line and determining a state of the sensor line;
a control unit that holds, for each of the sensor lines, either a first state in which the fire sensor is connected or a second state in which an external device other than the fire sensor is connected;
a receiving resistor provided in each of the plurality of sensor lines, converting a current flowing through the sensor line into a voltage and inputting the voltage to the state determination unit;
a switch provided in each of the plurality of sensor lines for connecting or disconnecting the receiving resistor to the sensor line ;
The switch provided in the sensor line in which the second state is set disconnects the receiving resistor from the sensor line.
Fire receiver. The fire receiver according to claim 1 , wherein the switch provided in the sensor line in which the second state is set disconnects the receiving resistor from the sensor line and then periodically connects the receiving resistor to the sensor line.

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