JPS6053811B2 - Gas supply safety device - Google Patents

Description

[Detailed description of the invention] The present invention relates to a gas supply safety device.

Conventionally, gas leakage due to a gas supply pipe failure has been detected by periodically measuring the difference between the gas pressure at the upstream end and the downstream gas pressure of the gas supply pipe, or by detecting gas odor.

However, since the former is an intermittent inspection, constant safety cannot be expected, and the latter is based on sensation, so it has the drawback of lacking reliability. Therefore, the present invention provides a gas supply safety device that automatically inspects the gas supply system at all times and can prevent gas accidents due to gas supply system failures.

Hereinafter, the present invention will be described in detail based on embodiments shown in the accompanying drawings. In the figure, 1 is a gas supply pipe, and one end is connected to a gas supply source, that is, the end of an outdoor pipe in the case of city gas, and a gas cylinder in the case of propane gas.

On the other hand, the other end (downstream side) of this gas supply pipe 1 is extended to gas valves B1, B2, .・・・・・・B
Gas appliances F1, F2, F3...Fn are connected to n via metal piping 5a or flexible hose 5b.
It is the same as before that the gas supply system is formed by connecting the two. A solenoid valve 2 that opens the gas supply pipe 1 when energized is disposed upstream of the gas supply pipe 1, preferably at an outdoor location.

Although '' is omitted in the figure, this electromagnetic valve 2 includes a valve, a spring that urges the valve in a direction to close the pipe, and a solenoid that pulls up the valve against the spring.
Further, the gas supply pipe 1 is provided with a pressure switch 3 downstream of the electromagnetic valve 2, which opens and closes in response to the internal pressure within the gas supply pipe 1. This pressure switch 3 has a switch operating piece erected on a diaphragm with one side facing the inside of the gas supply pipe 1, and when the inside of the gas supply pipe 1 is below a predetermined gas pressure, a switch circuit is opened and a pressure drop signal is generated. It is now being output. Note that the pressure switch 3 is not limited to the above example, and may be one that detects gas pressure as a current value and opens and closes a switch circuit at a predetermined gas pressure. On the other hand, the gas appliances Fl, F2, F3, which are connected to the gas supply pipe 1,
・ ...Fn part has operation switches 10, 10, 1
0...... are arranged. As shown most clearly in FIG.
It has a switch operation piece 11 connected to 1a, microswitches 12 and 13, and a timer mechanism 14,
When the switch cock 11a is turned to the left as shown in FIG. 1, the microswitch 12 is opened and the microswitch 13 is closed. When the switch operating piece 11 is turned 90 degrees to the right by the switch cock 11a, the micro switch 12 is closed and the output end 15
A switch signal is output, but at this time, the timer mechanism 14 intervenes, and this switch signal is first output instantaneously (about 1 second in the example), and then output for a predetermined period of time (5 to 1 circle 2 in the example). is stopped and then continues to be output. Furthermore, the switch operation piece 11
When the switch is turned 90 degrees to the right, the microswitch 13 is opened while the microswitch 12 remains closed.Then, by returning the switch operation piece 11 to the left by 90 degrees, the microswitch 13 is closed again, and the reset signal is output to the output terminal. 17
It is starting to output more. Note that 16 in FIG. 2 indicates a power input terminal. The operation switch 10 is connected to each gas appliance Fl, F. 2, F3...Incorporate into the frame of Fn or each gas appliance Fl, F2, F
3... It is placed on the wall near the Fn, but it does not necessarily require one operation switch 10 for each combustion port, and it can be used in gas appliances with multiple combustion ports and in nearby locations. ! It may be used for multiple gas appliances.

20 combines and organizes the pressure drop signal from the pressure switch 3 and the switch signal from the operation switch 10;
It consists of a control panel that controls the supply of electricity to the solenoid valve 2, as shown in FIG.

That is, 30 is a switch signal input terminal connected to the switch signal circuit C1 from the operation switch 10, 31 is a pressure drop signal input terminal connected to the pressure switch 3, and 32 is a reset signal input terminal connected to the reset signal circuit C2. end,
33 is a power input terminal, 34 is an output terminal connected to the solenoid valve 2, and a switch signal processing circuit 21 is connected between these terminals.
A pressure drop signal processing circuit, an alarm circuit 23, a solenoid valve power supply circuit 2 inhibition circuit 25, a power supply circuit 26, an alarm 27, and an indicator light 28 are interposed as shown. Each of these circuits will be explained below along with their functions. The switch signal processing circuit 21 combines and organizes the switch signal and the pressure drop signal and outputs the next control signal using a timer constituted by a NAND gate circuit of C-MOS-1C1 and an inverter circuit, and a logic circuit.

When the 1 switch signal is input, an energization signal is output to the solenoid valve power supply circuit 24.

2 If the pressure drop signal input does not disappear within a predetermined time (within 1 second as an example) after the switch signal is input, or if the pressure drop signal is input after this predetermined time, and the switch signal input disappears. If a pressure drop signal is input within a predetermined period of time (3 minutes in the example), a control signal is output to the inhibition circuit 25.

3 Specified time after switch signal input disappears (3 minutes above)
If a pressure signal is input after passing through, a control signal is output to the alarm display circuit 23.

The pressure signal processing circuit 22 outputs the pressure drop signal from the pressure switch 3 as a control signal to the switch signal processing circuit 21 through a one-shot multi-circuit formed by a combination of C-MOS-1C inverters. The prohibition circuit 25 receives the signal from the switch signal processing circuit 21 and stores it until it receives a reset signal using a flip-flop and logic circuit formed by a combination of C-MOS-1C NAND circuits, and then energizes the solenoid valve power supply circuit 24. It issues a prohibition signal and also issues a control signal to the alarm display circuit 23.

Note that the reset signal is received by turning off the power and then turning it on again while inputting the switch signal using the operation switch 10. The alarm display circuit 23 receives control signals from the switch signal processing circuit 21 and the prohibition circuit 25, and when receiving the control signal from the switch signal processing circuit 21, receives the control signal from the indicator lamp 28 and the prohibition circuit 25. If so, the alarm device 27 and indicator light 28 are energized. The electromagnetic valve power supply circuit 24 receives control signals from the switch signal processing circuit 21 and the inhibition circuit 25, and opens and closes the circuit of the output terminal 34 using a transistor.

The power supply circuit 26 has a transformer and a rectifier, and is connected to a reset signal input terminal, so as to supply power to each of the circuits described above.

Next, the operation of this embodiment will be explained.

First, when gas is not in use, the operation switch 10 is opened so that no switch signal is output. Then, since the solenoid valve 2 is closed, a gas accident will not occur downstream of this solenoid valve 2.

Next, when you want to use any of the gas appliances, turn the operation switch 10 first and send the switch signal to the control panel 2.
Output to 0. Then, the control panel 20 energizes the solenoid valve 2 and becomes ready to use gas, but at this time, the solenoid valve 2 is once opened and then closed for a predetermined period of time. When the gas pressure decreases and a gas pressure decrease signal is input, the solenoid valve 2 is electrically locked closed via the prohibition circuit 25 and an alarm is issued. Note that if the gas pressure reduction signal is not input while the solenoid valve 2 is temporarily closed, the solenoid valve 2 opens and the gas can then be used normally. Therefore, the gas supply system must be inspected every time gas is used to prevent gas leakage. If a large amount of gas leaks due to a hose disconnection or opening of a preliminary cock while gas is in use, the gas pressure may drop.

In this case, the pressure switch 3 is activated, the control panel 20 stops supplying power to the cutoff valve 2, and the gas supply pipe 1 is closed. After using gas, open the operation switch 10 and close the solenoid valve 2.
If there is no gas leak after solenoid valve 2, the pressure switch 3 will not operate due to residual gas, but if there is a crack in the hose, the residual gas will leak and the pressure switch 3 will not operate. It may work.

Therefore, the degree of gas leakage can be determined based on the time from when the solenoid valve 2 is closed until the pressure switch 3 is activated, and a safety inspection can be performed when the gas is not in use. In other words, if the residual gas pressure downstream of the shutoff valve 2 drops below the specified level within a certain period of time after gas has been used (in this case, there may be a significant gas leak due to faulty piping, cracks in the hose, faulty equipment, etc., and a danger is expected). )
The timer function in the control panel 20 is activated from the end of gas use, and the signal from the pressure switch 3 is stored in the prohibition circuit 25 within a certain period of time, and the alarm 27 and indicator light 28 are also activated.
The solenoid valve power supply circuit 15 is electrically locked, and the gas appliance cannot be used unless a predetermined return operation is performed. On the other hand, if the gas pressure drops below a predetermined value after a predetermined time after gas has been used, in this case only a small amount of gas leaks and there is very little danger, so only the indicator light 28 is turned on, and the gas appliance can then be used. Since the present invention has the above-described structure and operation, the safety inspection of the gas supply pipe 1 is always performed at the start of gas use and when gas is not used, which greatly contributes to the safe use of gas.

[Brief explanation of the drawing]

Fig. 1 is an explanatory external view showing one embodiment of the device of the present invention;
The figure is a wiring diagram of the operation switch used in this project, and Figure 3 is a block wiring diagram of the control panel. 1... Gas supply pipe, 2... Solenoid valve, 3
...Pressure switch, 10...Operation switch, 20...Control panel, Fl, F2, F3...
...Gas appliances.

Claims (1)

[Claims] 1. A solenoid valve 2 that opens the gas supply pipe 1 when electricity is applied to the upstream part of the gas supply pipe 1, and a solenoid valve 2 on the downstream side of the solenoid valve 2 that opens and closes in response to the internal pressure in the gas supply pipe 1. A gas appliance F equipped with a pressure switch 3 and connected to the gas supply pipe 1
1, F2, F3......The Fn portion includes operation switches 10, 10, which, when attempting to close the circuit, temporarily close the circuit and then close the circuit. 1
The pressure signal from the pressure switch 3 and the switch signal from the operation switch 10 are combined and organized in the control panel 20, and when the switch signal is input, the solenoid valve 2 to open the gas supply pipe 1,
If the pressure drop signal input does not disappear within a predetermined time after the switch signal input, or if the pressure drop signal is input after this predetermined time, and if there is a pressure drop signal input within the predetermined time after the switch signal input disappears. The gas supply safety device is configured to stop energizing the solenoid valve 2, issue an alarm, and lock the energization to the solenoid valve 2 in an electrically prohibited state.