JPH0425824B2 - - 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 structure 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. Upon receiving this return signal, the control section 4 drives the cutoff section 6 again to cut off the gas passage if there is a flow rate signal within a predetermined time. If a gas appliance was in use at the time of the first shutoff, if the shutoff section 6 was left open in this state, raw gas would be released from the gas appliance, which would be dangerous. Therefore, it is necessary to shut off the power again.

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 the above-mentioned abnormality signal duration time or more, it is determined that an abnormality exists 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, shutoff 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 shutoff 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 batteries 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 causes the shutoff section to shut off the gas passage in response to a shutoff signal from the control section,
As a cutoff part that opens the gas passage by an opening signal,
A switch cutoff determination section is provided that receives a close signal from a remote switch installed indoors, etc. and outputs a switch cutoff signal to a cutoff signal generation section, and also detects the output of an open signal from the remote switch, and detects the output of an open signal from the remote switch, A return detection section is provided that outputs an open signal to the cutoff detection section.

Effects According to the present invention, with the above-described configuration, the gas passage can be opened and closed while maintaining safety by operating a remote switch installed indoors or the like. That is, when the remote switch is operated to output a close signal, the switch cutoff determination section outputs a switch cutoff signal.
The cutoff signal generating section 19 receives this signal and outputs a cutoff signal, and the cutoff section responds to this and cuts off the gas passage. When the remote switch is operated to output an open signal, the return detection section detects a change in the input from a no-signal input state to an open signal state and outputs an open signal. The shutoff section responds to this and opens the gas passage. On the other hand, the return cutoff determination section monitors the flow rate signal within a predetermined time after the open signal is input. If a flow rate signal is input, a return cutoff signal is output, and the cutoff signal generation section outputs a cutoff signal in response to this, so the cutoff section responds to this and cuts off the gas passage.

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., and is composed of an off switch 14 that generates an open signal, an on switch 15 that generates an open signal, and a display section 16 that displays an external display in response to a display signal from a display control section 21. . The control unit 17 is
It differs from the control section 4 of the conventional device in the following points. A switch cutoff determination section 18 is provided which receives a close signal from an off switch 14 and outputs a switch cutoff signal when the close signal satisfies a predetermined condition.
This predetermined condition includes a condition such as a continuous period of time or more, and in this case, the switch cutoff determination unit 1
8 is a timer. The cutoff signal generator 19 receives a switch cutoff signal as well as a flow cutoff signal, an external cutoff signal, a return cutoff signal, and outputs a cutoff signal when any of the signals is input. If the cutoff signal has a one-shot pulse waveform, the cutoff signal generator 19 is, for example, a monostable multivibrator with a 4-input OR gate. A return detection part 20 is provided which receives an open signal from an off switch 15, detects that there is no signal and changes to an open signal, and outputs an open signal. Note that this open signal is input to the cutoff section 22 and is also inputted to the return cutoff determination section 10 as a return signal. Reference numeral 21 denotes a display control unit which receives an open signal and outputs an open display signal, and receives a cutoff signal and outputs a cutoff signal.

Reference numeral 22 denotes a cutoff section, which cuts off the gas passage in response to a cutoff signal and shuts off the gas passage in response to an open signal. Such a shutoff section 22 may be a bistable self-holding solenoid valve, a combination of the shutoff section 6 shown in FIG. 2 and a solenoid or motor-driven return means, or the like. In the former case, in the case of a two-winding type, it is sufficient to input a one-shot pulse cut-off signal to the cut-off coil side and a one-shot pulse open signal to the open coil side. In the latter case, if the cutoff section 6 is a self-holding electromagnetic valve, a one-shot pulse cutoff signal may be input to its coil, and a one-shot pulse opening signal may be inputted to the solenoid or motor of the return means.

Next, the operation in this embodiment will be explained. When the off switch 14 of the remote switch 13 is pressed to output a close signal while the gas passage is opened in the cutoff section 22, the switch cutoff determination section 18 monitors the state of the close signal in response to this close signal and makes a predetermined determination. When the conditions are satisfied, a switch cutoff signal is output. As a result, the cutoff signal generating section 19 outputs a cutoff signal, and the cutoff section 22 responds to this and cuts off the gas passage. The cutoff signal is input to the display control section 21,
The display control section 21 thereby outputs a cutoff display signal, and the display section 16 accordingly displays that it is cut off. In this state, when the on switch 15 is pressed to open the gas passage, a close signal is output. The return detector 20 detects a change from the previous no-signal state to the input of a closed signal, and outputs an open signal. The cutoff section 22 opens the gas passage in response to this signal. On the other hand, the return cutoff determination unit 10 monitors the flow rate seismic signal for a predetermined period of time after inputting this signal. On the other hand, the display control section 21 outputs an opening display signal upon input of the opening signal, and the display section 16 thereby performs an opening display. If the flow rate signal is not input within a predetermined period of time, the return cutoff determination unit 10 outputs a reset pulse, the display control unit 21 thereby stops outputting the display signal, and the display unit 16 stops displaying. If the flow rate signal is input within the predetermined time, the return cutoff determination unit 1
0 outputs a return cutoff signal, the cutoff signal generating section 19 outputs a cutoff signal, and the cutoff section 22 thereby cuts off the gas passage again. In addition, the display control unit 2
1 outputs a cutoff display signal, and the display section 16 displays a cutoff display.

Note that the shutoff based on the flow rate signal from the flow rate sensor 3 and the abnormality signal from the external sensor is performed in the same manner as in the conventional gas shutoff device.

As a result, with only the operation of switches 14 and 15,
Not only can you open and close the gas passage, but you can also
2 changes from closed to open, that is, the gas passage changes from being blocked to open, that is, each time the input to the return detecting unit 20 changes from a null state to an open signal, the return shutoff determining unit 10 starts operating. Therefore, it is safe because raw gas can be prevented from being released due to forgetting to close the gas valve after shutting off. Also, even if raw gas is released while the on switch 15 is intentionally held down,
First, the cutoff is performed based on the flow rate signal. Secondly, the on switch 15 continues to be pressed, that is, the open signal is maintained, so there is no change from no signal to the open signal, so the return detection unit 20 detects the open signal. Since no signal is output and the gas passage is not opened, the shutoff state can be maintained and it is safe.

Furthermore, if a device capable of one-shot pulse drive, such as a bistable self-holding solenoid valve, is used for the shutoff section 22, a sufficiently long operation can be achieved using the battery 12.

Further, the display control section 21 and the display section 16 make it easy to know whether the gas passage is closed or open, which is convenient.

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 away from the gas meter, such as indoors, and the gas passage can be changed from closed to open in this way. It also prevents raw gas from being released from gas appliances, which can sometimes occur, and provides safety similar to 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...switch cutoff determination unit, 19...cutoff signal generation unit, 20...
...return detection section, 22... cutoff section.

Claims (1)

[Claims] 1. A flow rate sensor that outputs a flow rate signal according to the gas flow rate, a remote switch that outputs an open/close signal for opening and closing the gas passage, and a remote switch that receives the flow rate signal and the open/close signal as input, and sends a shut-off signal to the shut-off part, The control unit includes a control unit that outputs an opening signal, and a blocking unit that blocks the gas passage in response to the cutoff signal and opens the gas passage in response to the opening signal, and the control unit includes:
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 it is determined that there is an abnormality; a switch cutoff determination unit that outputs a switch cutoff signal in response to a closing signal from the remote switch;
a return detection unit that detects a change from no signal to a closed signal from the remote switch and outputs an open signal;
a return cutoff determination unit that monitors whether or not a flow rate signal is input at a predetermined time after receiving the opening signal, and outputs a return cutoff signal when the flow rate signal is input; and the flow cutoff signal, the switch cutoff signal, and the return cutoff signal. A gas cutoff device includes a cutoff signal generator that outputs a cutoff signal when any of the signals is input, and a power source.