JPH0133971Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to a safety device for a combustor used in a gas water heater or other gas appliances.

(Prior Art) Conventionally, this type of device has connected an operating circuit including a thermocouple and a solenoid coil, a gas detection circuit including a gas sensor and a battery, and a circuit for forcibly holding an electromagnetic safety valve open. When the gas sensor detects carbon monoxide gas, the battery applies a voltage in the opposite direction to the electromotive force of the thermocouple to the solenoid coil to close the electromagnetic safety valve installed in the gas supply path and supply gas. It is common practice to block the
However, in the above device, even after the electromagnetic safety valve is closed when carbon monoxide gas is detected, a large current flows through the gas detection circuit at once, causing the solenoid coil to become heated, and current continues to flow through the thyristor to maintain the input state. Therefore, there is a drawback that the battery consumption is significant.
Furthermore, since there is no switch even when the combustor is not in use, there is a problem that a small current constantly flows through this circuit and consumes the battery.The power switch is mechanically opened in conjunction with the closing of the electromagnetic safety valve to drain the battery. It is desirable to be able to prevent wear and tear.

(Problems to be Solved by the Invention) The object of the present invention is to provide a safety device for a combustor that meets such demands.

(Means for solving the problem) The present invention is a system that uses a battery as a driving source to close an electromagnetic safety valve when a carbon monoxide sensor or other gas sensor installed in a gas detection circuit detects carbon monoxide gas. The gas detection circuit is characterized in that a power switch that opens in conjunction with the closing of the electromagnetic safety valve is disposed in the gas detection circuit.

(Example) The present invention will be explained below with reference to the drawings.

FIG. 1 shows an example of implementing the present invention.
In the figure, 1 indicates an operating circuit that connects a thermocouple 2 and a solenoid coil 3, and 4 indicates a gas detection circuit that includes a gas sensor 5, a battery 6, and a power switch 8. A thermocouple 2 that generates an electromotive force when ignited is connected to a solenoid coil 3, and an electromagnetic safety valve 7 is arranged in a gas supply path 10 to a burner 9. When the burner 9 is in a normal combustion state, The electromotive force of the thermocouple 2 energizes the solenoid coil 3 to keep the electromagnetic safety valve 7 open.

Further, the gas detection circuit 4 connects a battery 6 as a driving source via a power switch 8 to a gas sensor 5 such as a carbon monoxide sensor and a variable resistor 11 for level adjustment.
The end of the voltage dividing circuit 12 on the gas sensor 5 side is connected to the anode of the thyristor 13, and the gas sensor 5 and the variable resistor 11 are connected to each other.
The connection point A of the thyristor 13 is connected to the gate of the thyristor 13, and the cathode of the thyristor 13
A pair of output terminals 14, 14 are provided which are connected to the end of the variable resistor 11 of the second variable resistor 11, and the pair of output terminals 14, 14 are connected to the solenoid coil 3 of the operating circuit 1.

The electromagnetic safety valve 7 includes, for example, as shown in FIG. 2, a solenoid coil 3, an attraction piece 17 that opens the safety valve 15 against a spring 16 that attracts the solenoid coil 3 and pushes the safety valve 15 in the closing direction when the solenoid coil 3 is energized, and the safety valve 15. It is composed of an interlocking rod 18 that is linked to opening and closing. In the present invention, this is disposed in the gas supply path 10, and the interlocking rod 18 is disposed in contact with the switch lever 8a of the power switch 8, which is a normally open type micro switch, as shown in the second figure. When the valve is completely closed, the interlocking rod 18 is pushed out to press the switch lever 8a and open the power switch 8.

The gas sensor 5 was arranged at an appropriate location exposed to combustion exhaust gas.

Thus, in the gas detection circuit 4, when the power switch 8 is closed and a voltage corresponding to a predetermined value of the carbon monoxide gas concentration, for example 300 ppm, is obtained at the connection point A of the voltage dividing circuit 12, the thyristor 13 is activated. If the carbon monoxide gas concentration in the exhaust gas reaches a predetermined value, the resistance value of the gas sensor 5 will decrease from the usual 10 to 100 kΩ to around 500 kΩ, and the resistance will be applied to the gate of the thyristor 13. As the voltage increases, the thyristor 13 becomes conductive, and a voltage approximately equal to the voltage of the battery 6 is obtained between the pair of output terminals 14 and 14, and the superpower of the thermocouple 2 is applied to the solenoid coil 3 in the opposite direction. The solenoid coil 3 is demagnetized by applying a voltage of Then, the gas supply to the burner 9 is cut off to stop its combustion, and the generation of superpower by the thermocouple 2 is stopped, and in conjunction with the closing of the safety valve 15, the switch lever 8a is pressed by the interlocking rod 18, and the electromagnetic switch is activated. 8 is opened to cut off the conduction of current from the battery 6 to the solenoid coil 3 and thyristor 13, thereby preventing battery 6 from being exhausted.

In addition, 19 in the figure is a power supply 20, a switch 21,
a capacitor 22, and a forced open holding circuit for the electromagnetic safety valve 4, which operates until a predetermined electromotive force is generated from the thermocouple 2 within a certain period of time after ignition of the burner 9;
23 is the gas detection circuit 4 and the solenoid coil 3
24 is a manual valve that opens and closes in conjunction with the opening and closing of the safety valve 15 via the seesaw lever 25 to supply and stop gas to the burner 9; 26 supports the manual valve 24; The rod 27 indicates a gas inlet of the electromagnetic safety valve 7, and 28 indicates a gas outlet of the electromagnetic safety valve 7.

FIG. 3 shows another embodiment of the present invention, which differs from the embodiment in FIG. The solenoid coil 3 and the coil 29 are double coils, but the gas detection circuit 4 is operated only by the first coil 29.
This is not different from the embodiment shown in the figure, and according to this, when the carbon monoxide gas concentration reaches a predetermined value, the coil 29 is energized and the electromagnetic safety valve 7 is closed by reverse magnetic force, thereby supplying gas to the burner 9. is stopped, and the power switch 8 is opened to cut off the conduction of current to the coil 29 to prevent battery 6 from being exhausted.

(Effect of the invention) As described above, according to the invention, a combustor equipped with an operating circuit that operates an electromagnetic safety valve includes a carbon monoxide sensor and other gas sensors, and a battery that is a driving source for closing the electromagnetic safety valve. When adding a gas detection circuit for combustible gases, it is sufficient to install a power switch in advance in this gas detection circuit and configure the power switch to open in conjunction with the closing of the electromagnetic safety valve, and it is sufficient to detect carbon monoxide gas. Then, the closing of the electromagnetic safety valve and the opening of the power switch are mechanically performed in conjunction with each other, which completely cuts off the fuel supply to ensure gas safety, and prevents battery consumption by cutting off the conduction of current to the circuit. It has the advantage of being simple in structure and easy to manufacture.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention.
The figure is an explanatory circuit diagram of the first embodiment of the present invention, and the second figure is a cutaway side view showing one example of the electromagnetic safety valve used in the present invention.
FIG. 3 is an explanatory circuit diagram of another embodiment of the present invention. 4...Gas detection circuit, 5...Gas sensor, 6...
...Battery, 7...Solenoid safety valve, 8...Power switch.

Claims (1)

[Scope of utility model registration request] Carbon monoxide sensors and other gas sensors installed in gas detection circuits use a battery as a drive source to close an electromagnetic safety valve when carbon monoxide gas is detected. A combustor safety device characterized by having a power switch installed in the gas detection circuit.