JPH0425823B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a gas cutoff device that prevents accidents involving fuel gases such as city gas and LP gas, and which can remotely open and close gas passages.

2. Description of the Related Art A conventional shutoff device of this type has a configuration as shown in FIG. 2, for example.

A magnet is provided in a portion of the gas meter 1 that responds to the measuring section 2, and a magnetic field detector that detects the magnetic field of this magnet is used as the flow rate sensor 3. The signal from the flow rate sensor 3 is a flow rate signal corresponding to the gas flow rate, and is inputted to the control unit 4. The controller 4 also receives an abnormal signal from an external sensor 5 that detects an abnormality such as a gas leak alarm or a seismic sensor and outputs an abnormal signal when an abnormality is detected.
is input. The control unit 4 determines the presence or absence of an abnormality in the flow rate and the presence or absence of an abnormality in the external environment from the flow rate signal and the abnormality signal, and when it is determined that there is an abnormality, drives the cutoff unit 6,
Cut off the gas passage. A self-holding manual return type solenoid valve is used for the shutoff section 6. Once in the cutoff state, the cutoff section 7 is returned to the open state by manually operating the return means. When a self-holding manual return type solenoid valve is manually reset, a back electromotive force is induced at both ends of its operating coil, and this back electromotive force is input to the control unit 4 as a return signal. The control unit 4 receives this return signal and if there is a flow rate signal within a predetermined time, it drives the shut-off unit 6 again to shut off the gas passage.If a gas appliance was in use at the time of the first shut-off, it will shut off in this state. If the section 6 is opened, raw gas will be released from the gas appliance, which is dangerous, so it is necessary to shut it off again in response to the presence of a flow rate signal within a predetermined period of time after this return.

The control section 4 had a configuration as shown in FIG.
The flow cutoff determination unit 8 receives the flow rate signal from the flow rate sensor 3 and determines whether or not the flow rate exceeds a predetermined criterion such as the maximum flow rate within a certain period of time or the longest duration time determined for each flow rate category. Determine the presence or absence of. That is, if the determination criteria are exceeded, it is determined that there is an abnormality and a flow cutoff signal is output. External cutoff determination section 9
receives the abnormality signal from the external sensor 5 and determines whether there is an abnormality in the external environment based on whether or not the abnormality signal duration time exceeds a predetermined criterion. That is, if the abnormality signal continues for longer than the above-mentioned abnormality signal duration time, it is determined that there is an abnormality and an external cutoff signal is output. Upon receiving a return signal indicating a change in the cutoff state of the cutoff section 6 to the open state, the return cutoff determination section 10 monitors the presence or absence of a flow rate signal from the flow rate sensor 3 within a predetermined period of time, and if there is a flow rate signal, performs a return cutoff. Output a signal. The drive signal generation section 11 outputs a drive signal to the cutoff section 6 when any of the above-mentioned cutoff signals is input. If the shutoff section 6 is a self-holding manual return type solenoid valve, this drive signal is a one-shot pulse. A battery 12 is used as a power source.

The above-mentioned flow rate sensor 3, control section 4, cutoff section 6, and return means 7 are integrated with the gas meter 1, and can be installed simply by replacing a normal gas meter with this gas meter 1 with a cutoff device, making installation work easy. It has become a thing. Further, if the external sensor 5 is not attached, wiring work is not required. Furthermore, since it uses a battery as a power source, it is always in operation regardless of whether there is a power outage or not, making it highly safe.

Problems to be Solved by the Invention However, the gas cutoff device having such a configuration cannot meet the following requirements. That is, a place far away from the gas meter 1,
For example, if you try to open and close a gas passage using this device from indoors, the following will happen. That is,
For example, if a remote switch is provided in place of the external sensor 5, and an attempt is made to open or close the gas passage using this switch, when closing the gas passage, the switch is set to the closed side and the same abnormal signal as the abnormal signal from the external sensor 5 is sent. This can be realized by generating and inputting this to the control section 4. However, it is necessary to manually operate the return means in order to open the cut-off section 6, which has once been in the cut-off state. Therefore, although it is possible to close the gas passage from inside the room, in order to open it, the return means 7 of the gas meter 1 must be manually operated, which is inconvenient.

Therefore, the present invention aims to make it possible to easily open and close the gas passage using a remote switch, and to ensure the same safety as the conventional gas cutoff device.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention makes the cut-off section an energized-open type cut-off section, and the cut-off section is controlled by a remote switch installed indoors or the like and a switch section installed in the control section. The control unit includes a return detection unit that controls the power supply to the circuit, detects a change in the cutoff unit from closed to open, and outputs a return signal to the return cutoff determination unit and the switch unit,
The control section is provided with a reset signal generating section that outputs a reset signal to the switch section from the flow cutoff signal and the return cutoff signal.

Effects According to the present invention, with the above-described configuration, the cutoff section is opened and closed via the switch section of the control section using, for example, a remote switch provided indoors. That is, when the remote switch is turned from the open side to the closed side, power supply to the cutoff section via the switch section is stopped, so that the cutoff section cuts off the gas passage. In this state, when the remote switch is turned from the closed side to the open side, power supply to the cutoff section via the switch section is started, and the gas passage is opened. At the same time, this change from closed to open is detected by the return detection section, and a return signal is output. In response to this return signal, the return cutoff determination section starts operating and checks whether a flow rate signal is input within a predetermined time. If a flow rate signal is input, a return cutoff signal is output, and the reset signal generator receives this and outputs a reset signal. The switch section is reset by this reset signal, power supply to the cutoff section is stopped, and the gas passage is cut off again. In this state, when all the gas valves are closed and the remote switch is turned to the closed side and then to the open side, this change is detected by the return detection section and a return signal is output. This return signal becomes a set signal input to the switch section, the switch section is set, power supply to the cutoff section starts, and the gas passage becomes open again.

Embodiment FIG. 1 is a block diagram showing an embodiment of the gas cutoff device of the present invention. Reference numeral 13 denotes a remote switch installed indoors, etc., which includes a power source 14, a switch 15 that turns on and off the power supply from the power source 14 to the cutoff section 22, and a display section 16 that responds to display signals from the display control section 21 of the control section 17. Configure. The control unit 17 differs from the control unit 4 of the conventional device in the following points. A return detection section is provided which detects a change in the switch 15 from off (closed) to on (open) and outputs a return signal to the return cutoff determination section 10 and the switch section. A reset signal generating section 19 is provided which outputs a reset pulse upon receiving the flow cutoff signal from the flow cutoff determination section 8, the external cutoff signal from the external cutoff determination section 9, and the return cutoff signal from the return cutoff determination section 10. A latching relay 20 is provided as a switch section which receives a reset signal as a set input and a reset pulse as a reset input. A display control section 21 is provided which outputs a cut-off display signal when a reset pulse is input, and outputs a return display signal when a return signal is input. Reference numeral 22 denotes an energized open type solenoid valve as a cutoff section, which opens the gas passage in an open state during power supply, and enters a cutoff state when power supply is stopped.

Next, the operation in this embodiment will be explained. When the switch 15 is in the on state (open signal), the solenoid valve 2 is connected to the power supply 14 via the latching relay 20.
2, the solenoid valve 22 is open, and the gas passage is in an open state. When the switch 15 is turned off (close signal) in this state, the power supply 14 connects the solenoid valve 2.
2 is stopped, the electromagnetic valve 22 is closed, and the gas passage is cut off. When the switch 15 is turned on again from this state, power is supplied to the solenoid valve 22 and the gas passage becomes open. A change from the closed signal of the switch 15 to the closed signal is detected by the return detection section 18, and a return signal is output. Based on this return signal, the return cutoff determining section 10 checks whether a flow rate signal is input within a predetermined time. Further, since the return signal is inputted to the display control section 21, the display control section 21 outputs a return display signal, and in response to this signal, the display section 16 displays a return display to the outside to notify that the gas appliance should not be used yet. When a flow rate signal is input within a predetermined time, the return cutoff determination unit 10 outputs a cutoff signal, indicating that there is a gas appliance in an open state and that raw gas may be released. As a result, the reset signal generating section 19 generates a reset pulse. The latching relay 20, which is a switch section, is turned off by this reset pulse, and the power supply to the solenoid valve 22 is stopped. As a result, the solenoid valve 22
shuts off the gas passage. In response to the input of the reset pulse, the display control unit 21 outputs a shut-off display signal, whereby the display unit 16 indicates to the user that the shut-off unit 22
indicates that the gas passage is blocked. After closing the open gas appliance, turn on switch 15.
When it is turned on after being turned off, this change is detected by the return detector 18 and a return signal is output. This return signal is sent to the latching relay 20 which is the switch part.
This is the setting input for latching relay 20.
turns on again, power supply starts to the solenoid valve 22, and the gas passage becomes open. Return cutoff determination section 1
0 outputs a safety pulse if no flow rate signal is input within a predetermined time. On the other hand, since the return signal is input to the display control section 21, the display control section 21 outputs a return display signal and the display section 16 displays externally that the solenoid valve 22 has been returned. In response to the safety pulse from the return cutoff determination section 10 after a predetermined period of time, the display control section 21 stops outputting the display signal, and the display section 16 stops displaying.

The shutoff based on the flow rate signal from the flow rate sensor 3 and the abnormality signal from the external sensor is similar to the conventional gas shutoff device.

As a result, not only can the gas passage be opened and closed simply by operating the switch 15, but also the solenoid valve 2 in the shutoff section can be opened and closed.
2 changes from closed to open, the return cutoff determination unit 10
operates, so there is no danger of raw gas being released. In addition, when the power source 14 is formed from a commercial power source, the solenoid valve 22 of the cut-off section will be in a cut-off state due to a power outage.
When the power is restored, the solenoid valve 22 returns to the open state, but since the change from the close signal to the open signal is input to the return detection section 18 via the switch 15, the return cutoff determination section 10 operates, so in the unlikely event that Even if the gas appliance remains open and there is a power outage re-energization, the gas passage can be shut off by the solenoid valve 22 of the shut-off part, making it safe.

Further, the display unit 16 is convenient because it displays the shutoff state of the gas passage and the return monitoring state within a predetermined time period during which the return cutoff determining unit 10 monitors the flow rate signal after the solenoid valve 22 returns.

Effects of the Invention As described above, according to the present invention, it is convenient to be able to easily open and close the gas passage from a place far away from the gas meter, such as indoors, and in this way, the gas passage can be changed from closed to open. It is possible to prevent raw gas from being released from gas appliances that may occur when such a gas appliance is used, and the safety level can be made to be the same as that of conventional gas shutoff devices.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a gas cutoff device according to an embodiment of the present invention, FIG. 2 is a schematic diagram of a conventional gas cutoff device, and FIG. 3 is a block diagram of the same device. 3...Flow rate sensor, 8...Flow rate cutoff determination unit, 1
0...Return cutoff determination unit, 12...Battery, 13...
Remote switch, 17...control unit, 18...return detection unit, 19...reset signal generation unit, 20...switch unit, 22...cutoff unit.

Claims (1)

[Claims] 1 A remote switch equipped with a flow rate sensor that outputs a flow rate signal corresponding to the gas flow rate, a switch that outputs an opening/closing signal to turn on/off the power supply to the cutoff section, and a remote switch that receives the flow rate signal and the opening/closing signal from the remote switch as input. , a control unit that outputs on/off of power supply to the cutoff unit, and a cutoff unit that opens a gas passage when power is supplied from the control unit and cuts off the gas passage when power is not supplied, the control unit a flow cutoff determination unit that determines whether there is an abnormality based on the flow rate signal and outputs a flow cutoff signal when an abnormality is determined; and a return unit that detects a change in power supply from the remote switch from no to present and outputs a return signal. a detection section, a return cutoff determination section that outputs a return cutoff signal to which a flow rate signal from a flow rate sensor is input for a predetermined time after the return signal is input; a reset signal generating section that outputs a reset signal when the reset signal is input, turns off the power supply from the remote switch to the shutoff valve when the reset signal is input, and turns off the power supply from the remote switch to the shutoff valve when the reset signal is input. A gas cutoff device that includes a switch that turns on and a power source for the control unit.