JPH0440606B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a combustion control device equipped with a valve-open holding circuit for a manually opened electromagnetic safety valve.

(Prior art) As a conventional device of this kind, a manually opened electromagnetic safety valve installed in a gas supply path to a burner is held open by a predetermined electromotive force from a thermoelectric generator heated by the burner. At the same time, the electromagnetic safety valve is kept open for a certain period of time until a predetermined electromotive force is generated from the thermoelectric generating element by a valve-open holding circuit installed in a circuit that connects the coil of the electromagnetic safety valve to a power source. Those who choose to hold are known.

(Problem to be Solved by the Invention) However, according to the above-mentioned conventional device, power from the power source is supplied to the coil by the valve-open holding circuit for a certain period of time regardless of whether the burner is ignited or not. Since the valve-type electromagnetic safety valve is held open, if the burner is not ignited for a certain period of time, raw gas is released, which is dangerous and wastes electricity, which is not desirable. If the burner is ignited after a delay in keeping the electromagnetic safety valve open for a certain period of time, the burner will be ignited explosively, which is dangerous, and electric power will be wasted until the burner is ignited, which is undesirable.

(Means for Solving the Problems) The present invention aims to provide a device that can eliminate the above-mentioned dangerous state of the burner and also eliminate wasteful power consumption, and which includes a gas supply path to the burner. A manually opened electromagnetic safety valve installed in the burner is held open by a predetermined electromotive force from the thermoelectric generator heated by the burner, and until a predetermined electromotive force is generated from the thermoelectric generator. In a device in which the electromagnetic safety valve is held open for a certain period of time by a valve-open holding circuit interposed in a circuit that connects the coil of the electromagnetic safety valve to a power source, the valve-open holding circuit is held open for a certain period of time. It consists of a timer circuit that operates and a flame detection circuit that is activated when the flame of the burner is detected, which is prepared for operation by the operation of the timer circuit, and the power from the power source is supplied to the coil only when both circuits are activated. It is characterized by being supplied.

(Function) The present invention has the above configuration. According to this, when the manual opening type electromagnetic safety valve is opened by the ignition operation of the burner and the ignition circuit is activated, the timer circuit is simultaneously activated for a certain period of time. As soon as the burner starts operating, the flame detection circuit is ready for operation, and if the burner ignites immediately, the flame detection circuit is activated and power from the power supply is supplied to the coil of the manual opening type electromagnetic safety valve. The opening type electromagnetic safety valve is held open for a certain period of time, and then the manually opening type electromagnetic safety valve is held open by a predetermined electromotive force from the thermoelectric generating element to continue combustion of the burner. If the flame does not ignite immediately, the flame detection circuit will not operate even if the timer circuit is activated, and power from the power supply will not be supplied to the coil. Therefore, the manual opening type electromagnetic safety valve will not be held open and the flame detection circuit will not operate even if the timer circuit is activated. The valve is closed and the burner remains stopped. Therefore, when the burner does not ignite immediately, raw gas will not be released or explosive ignition will occur, making it safe and preventing power from the power source from being wasted.

(Example) Next, embodiments of the present invention will be described based on the drawings.

In the drawing, reference numeral 1 indicates a manually opened electromagnetic safety valve installed in the gas supply path 3 to the burner 2.
has a compound winding coil 4 with low power consumption, one coil 4a is connected to a thermocouple 5 which is a thermoelectric generating element heated by the burner 2, and the other coil 4b is connected to a battery 6 which is a power source. The structure is as follows.

The circuit 7 connecting the coil 4b to the battery 6 includes an ignition circuit 8, a valve-open holding circuit 9, and a safety valve drive circuit 10.
I intervened.

The ignition circuit 8 operates an oscillation circuit 12 by a switch 11 that is closed when the burner 2 is ignited, generates a high voltage on the secondary side of the ignition transformer 13, and applies this high voltage to the ignition electrode 14 to create a voltage between the electrodes. A conventionally known spark generator was used.

The valve-open holding circuit 9 is composed of a timer circuit 15 and a flame detection circuit 16 downstream thereof.

The timer circuit 15 charges a capacitor 18 for a certain period of time by a switch 17 that is switched when the burner 2 is ignited, and during this time the transistors 19, 20,
21 is made conductive for a certain period of time and the flame detection circuit 16 at the subsequent stage is
The voltage of the battery 6 was applied to bring the flame detection circuit 16 into a state ready for operation.

The flame detection circuit 16 is of a flame rod type, and the oscillation circuit 2 is activated by the operation of the timer circuit 15.
2 is activated, an alternating voltage from the oscillation circuit 22 is applied to the flame rod 23, and when the burner 2 is ignited, the rectified current flowing through the flame to the flame rod 23 causes the transistor 24 to become non-conductive. I took it as a thing.

The safety valve drive circuit 10 includes two transistors 2
5, 26, a current limiting resistor 27, and a coil 4b, and when the transistor 24 of the flame detection circuit 16 is non-conductive, the transistors 25, 26 are made conductive to apply the voltage of the battery 6 to the coil 4b. And so.

When doing so, open the manual opening type electromagnetic safety valve 1 by igniting the burner 2, and turn the switch 11.
When the ignition circuit 8 is activated by closing the switch 17 and the timer circuit 15 is started for a certain period of time by switching the switch 17, the voltage of the battery 6 is changed to the voltage of the transistor 2.
1 to the flame detection circuit 16, and the flame detection circuit 16 is ready for operation. Here, when the burner 2 is immediately ignited by the spark of the ignition circuit 8, a rectified current flows through the flame rod 23, the flame detection circuit 16 is activated, and the voltage of the battery 6 is transmitted to the electromagnetic safety valve via the transistor 26 of the safety valve drive circuit 10. 1 to the coil 4b of the electromagnetic safety valve 1.
is maintained in the open state for a certain period of time by the timer circuit 15, and then the manual opening type electromagnetic safety valve 1 is energized by a predetermined electromotive force from the thermocouple 5 heated by the burner 2, and the coil 4a is turned into the open state. The burner 2 continues to burn. Further, when the burner 2 does not ignite due to a spark in the ignition circuit 8 or due to a failure in the ignition circuit 8, no current flows to the flame rod 23, the flame detection circuit 16 becomes inactive, and no voltage is supplied to the voltage coil 4b of the battery 6. , the electromagnetic safety valve 1 that was manually opened is immediately closed, and the burner 2 is maintained in a stopped state.

It should be noted that the switch 11 in the above embodiment is closed only when the ignition is performed, and the switch 17 is returned to its original position when the fire is extinguished.

Incidentally, in the above embodiment, one thermocouple 5 as a thermoelectric generating element is disclosed, but the present invention is not limited to this, and for example, two thermocouples 5 facing the flame or the exhaust and the flame may be used.
5 with opposite polarities and connected to the coil 4a so that when the combustion flame lifts due to lack of oxygen in the burner 2, the electromotive force of both thermocouples 5, 5 cancels out and closes the electromagnetic safety valve 1. It's okay.

(Effects of the Invention) As described above, according to the present invention, the valve-open holding circuit that holds the manually opened electromagnetic safety valve in the open state for a certain period of time until a predetermined electromotive force is generated from the thermoelectric generating element is operated for the certain period of time. It consists of a timer circuit that operates, and a flame detection circuit that is prepared for operation by the operation of the timer circuit and is activated when the flame of the burner is detected, and only when both circuits are activated, the power from the power source is supplied to the electromagnetic safety valve. Since the electromagnetic safety valve is supplied to the coil, the electromagnetic safety valve can be kept open to continue burning the burner only when the burner is immediately ignited during the burner ignition operation, and when the burner is not ignited immediately. Compared to the conventional method, which can stop the burner without holding the electromagnetic safety valve open and maintains the electromagnetic safety valve in the intermediate valve state for the certain period of time even when the burner is not immediately ignited, In particular, a timer circuit is used to set a ready state in which power is supplied for the required time, and after that time the ready state is released, so the flame is removed from the power supply. There is no wasteful consumption of the power supplied to the detection circuit, and this has the effect of further saving energy.

[Brief explanation of drawings]

The drawing is a circuit diagram showing an example of implementation of the present invention. 1...Manual opening type electromagnetic safety valve, 2...Burner,
3... Gas supply path, 4... Coil, 4a, 4b...
...Coil, 5...Thermocouple (thermoelectric generating element), 6...
Battery (power supply), 7...circuit, 9...valve open holding circuit,
15...Timer circuit, 16...Flame detection circuit.

Claims (1)

[Claims] 1. A manually opened electromagnetic safety valve installed in the gas supply path to the burner is held open by a predetermined electromotive force from the thermoelectric generator heated by the burner, and the electromagnetic safety valve is The electromagnetic safety valve is held in an open state by a valve-open holding circuit installed in a circuit that connects the coil of the electromagnetic safety valve to a power source for a certain period of time until a predetermined electromotive force is generated. The valve-open holding circuit is composed of a timer circuit that operates for a certain period of time and a flame detection circuit that is prepared for operation by the operation of the timer circuit and is activated when the flame of the burner is detected, and only when both circuits are activated. A combustion control device characterized in that electric power from the power source is supplied to the coil.