JPS6247377A - gas cutoff device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a gas cutoff device that automatically cuts off a gas flow path.

2. Description of the Related Art A conventional gas cutoff device is shown in FIG. 4, for example. In the figure, reference numeral 1 denotes a network control device that connects and controls switching of a telephone line 2, which is an external communication line, to a general telephone 3 in the house and a gas cutoff device 4 installed in a gas make. Of the main control section 5, 6 is a determination section consisting of a microcomputer that receives signals sent from the flow rate sensor 7 through the flow rate sensor input section 8 and integrates, stores, and evaluates the gas flow rate. Compare the data with the signal from the flow rate sensor 7, and if the flow rate of passing gas is determined to be abnormal by more than a predetermined amount, or if the gas utility center (hereinafter abbreviated as the center) is determined to be abnormal, the telephone line 2/communication control is When a shutdown command is received via the section 9, a shutdown signal is sent to the shutdown control section 10. Furthermore, the shutoff unit 11 is composed of a self-holding manual return type solenoid valve, and is connected to a manual return operation unit 12 that allows the user to easily open the flow path manually when the gas flow path is blocked for the above reason. has been done.

Problems to be Solved by the Invention However, with the above configuration, it is difficult to quickly and reliably supply gas as a countermeasure against emergencies such as large earthquakes and fires, as well as for gas meters that are confirmed not to use gas. Even if the center sends a cutoff signal via an external communication line to cut off the gas flow path, there is a risk that the gas manufacturer may be unaware of the emergency situation or intentionally restore the cutoff state. The problem was that there was.

The present invention solves such conventional problems, and in response to a cutoff output such as a so-called abnormal flow rate generated based on a signal from a flow rate sensor installed in a gas meter, all return operations by the user are accepted as before. However, it is an object of the present invention to provide a device in which when a cutoff signal is sent from the center, the gas meter cannot return to cutoff unless a signal for permission to return to cutoff is issued from the center again.

Means for Solving the Problems In order to solve the above problems, the gas shutoff device of the present invention determines an abnormality depending on the gas flow rate situation, or detects an abnormality in response to a shutoff command signal from an external communication line. When a cutoff command is issued from the center to the main control unit that drives the gas cutoff unit, the gas manufacturer independently sends a signal to prohibit the shutoff and return, and receives a return signal based on the signal from the prohibition unit. This includes a configuration in which a return signal input section whose availability is controlled is added.

Effects The present invention produces the following effects due to the above-mentioned configuration.

In other words, when a cutoff signal is sent from the cutoff control unit to the cutoff unit, it is determined whether the issued cutoff signal is based on the judgment result of the judgment unit itself or whether it is based on a command from the center via an external communication line. If this is due to a command from the center, a signal is sent from the prohibition section to prohibit the return of the cut-off. As a result, if the center wants to quickly and forcibly shut off the gas flow path, the gas meter will be unable to open and restore the shutoff section unless the center again releases a control signal from the prohibited section. It will become.

Embodiments Hereinafter, embodiments of the present invention will be described based on the accompanying drawings. In FIG. 1, 4 is a block diagram of the gas cutoff device installed in the system, and FIG. 2 is a specific example of its configuration. It is connected to a certain telephone line 2 and receives control signals from the center. Now, the switch of the flow rate sensor 7 is turned on and off every time a unit volume of gas passes through the gas flow path, so that the gas flow rate signal is transmitted through the entire flow rate sensor input section 8.
It is sent to the judgment section 6 consisting of a microcomputer,
This determination unit 6 integrates and stores the flow rate signal, and determines whether there is an abnormality by comparing it with flow rate data of normal limit values registered in advance in the ROM. Reference numeral 11 denotes a shutoff unit consisting of a solenoid valve that can be opened and closed by electrical signals, and is used when the determination unit 6 determines that there is an abnormality in the flow rate, or when a signal is sent from the center via the network control device 1 and the communication control unit 9. When receiving a shutoff command, a shutoff signal is sent to the shutoff control section 10 to drive the solenoid valve to shut off. Therefore, the gas flow path is blocked and the flow of gas can be stopped. Conversely, when the cutoff section 11 is in the cutoff state, the determination section 6 is configured to receive a return command signal from the return signal input section 13 and send a signal to the cutoff control section 1o to return the cutoff section 11 to full open state. ing. As shown in FIGS. 1 and 2, the return signal input section 13 issues a return command (low) to the determination section 6 by turning on the return switch 14, which is a return operation section, and turning on the return signal input section 1a. This is the case when high is applied to . Reference numeral 15 denotes a prohibition section that completely prohibits the sending of a return signal when the cutoff section 11 is closed not because the judgment section 6 itself judges that there is an abnormality in the gas flow rate, but because a cutoff command is issued from an external center. . In other words, when prohibiting the return command from the return signal input section 13, by changing the output from the determination section 6 to the prohibition section 15 from low to high, the transistor (between the collector and emitter) in the prohibition section 15 is turned on. Return switch 1
4 is turned on, the voltage applied to the recovery signal input section 13 is
Since the transistor in the prohibition section 15 does not turn high, the return signal input section 13 cannot issue a return command, and the cutoff section 1
1 is maintained in the closed state. In order to open the cutoff section again from this state, the output from the determination section 6 to the prohibition section 15 is returned to low by a control signal from the center, and the return signal input section 13 accepts the signal from the return switch 14. It is necessary to make it possible to do so. Incidentally, such an operation of the prohibition section 15 can of course be equivalently replaced by software processing within the determination section 6.

In the above configuration, when there is a cutoff command from the center, the cutoff signal is sent out and the return signal 't-Fl from the return switch 14 is not accepted. This has the effect that the gas meter cannot independently open the shutoff section 11.

Next, another embodiment of the present invention will be described with reference to FIG. In FIG. 3, the solenoid valve of the shutoff section 11 is not open/close controlled by electric signals, but is different from the previous embodiment.
The point is that it is a self-holding manual return type similar to that shown in the conventional example. Shutoff s11 from the claw 9 shutoff control unit 10
Although it is possible to only send a signal to close the solenoid valve, it is possible to manually open the solenoid valve, and when opening the solenoid valve, the back electromotive force generated in the coil installed in the solenoid valve can be sent as a return signal. The input unit 13 can receive it as a return signal. In this case, as shown in FIG. 3, the prohibition section 15 and the return signal input section 13 are logically summed, and when the logical sum is established, a cutoff output is performed. However, the input/output relationship of the logic element AND in FIG. 3 is assumed to be active-high. When the shut-off section 11 is closed by a shut-off command from the terminal, the prohibition section 15 issues a signal prohibiting the return of the shut-off as in the embodiment described above. 12, the blocking part 11
When an attempt is made to manually return the switch, a return signal is input due to the generation of a back electromotive force by the coil I of the solenoid valve of this cutoff section 11.
If the logical sum is established, the shutoff signal is issued again, so it is the same as not being able to open the shutoff section 11 after all.

According to this configuration, during a shutdown due to a shutdown command from the center, a shutdown signal is sent each time the shutdown unit 11 is manually reset, so that the return operation on the Smake side becomes invalid as a result. There is.

Effects of the Invention As described above, according to the gas cutoff device of the present invention, when a center issues a cutoff command to the Smake,
Since the gas meter is configured to be unable to independently return to shutoff unless the center sends a signal again to fully permit shutoff return, the following effects can be obtained.

(1) Cases in which it is necessary to quickly and reliably stop gas supply plans over a wide area, such as a major earthquake or fire, to prevent secondary disasters; (2) Cases in which gas is not used (or not permitted) for any reason. In cases where you want to quickly and reliably shut off the gas flow path for a gas make that has been damaged, by preventing general users from accidentally (or intentionally) shutting off the gas flow path, it is possible to prevent the gas supply from the center from being restored. This has the effect of ensuring thorough management.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a gas cutoff device according to a first embodiment of the present invention, Fig. 2 is a specific circuit configuration diagram of Fig. 1, and Fig. 3 is a gas cutoff device according to another embodiment of the present invention. 10
FIG. 72 and FIG. 4 are block diagrams showing a conventional gas cutoff device. 4...Gas cutoff device, 5...Main control section,
7...Flow rate sensor, 11...Shutoff part, 1
2...Manual return operation section, 14...Return switch. Name of agent: Patent attorney Toshio Nakao and 1 other person7
Round lid t) Su l θ Figure 3 No. 4

Claims (1)

[Claims] A flow rate sensor provided in the gas meter and measuring the flow rate of gas flowing in a gas flow path, a shutoff section for opening and closing the gas flow path, a return operation section for opening the shutoff section, and a connection to the flow rate sensor. A flow rate sensor input section to which a signal from the flow rate sensor is applied; a cutoff control section connected to the cutoff section and sending out an opening/closing signal for the cutoff section; a determination section comprised of a microcomputer that compares and determines with flow rate data registered in the circuit and sends a shutoff signal to a shutoff control section; and a return signal input section that receives a signal from the return operation section and sends a return signal to the determination section. a communication control section connected to the determination section and connected to an external communication line; and a communication control section that sends a cutoff return prohibition signal to the return signal input section when the gas flow path is cut off by a cutoff signal from the communication control section. Gas cutoff device equipped with a prohibition section for sending out gas.