JPH07107450B2 - Gas combustor safety device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a gas combustor such as a gas stove and a water heater, and more specifically, for controlling gas supply to a burner in accordance with fire extinguishing, ignition, and thermal power adjustment operations. The present invention relates to a gas combustor configured to determine the presence or absence of a flame based on a signal from a thermocouple arranged near a burner flame hole.

<Prior Art> As a conventional safety device for a gas combustor, an electromagnetic valve interposed in a gas supply path to a burner, a flame detection sensor arranged near a burner flame hole, and a flame detection sensor signal,
Alternatively, there is one having a control circuit for controlling the stop of the gas supply and the like according to the fire extinguishing operation.

In the case of the above-described gas combustor safety device, the control circuit can close the solenoid valve to shut off the gas supply path to extinguish the fire in response to the fire extinguishing operation. In addition, if the fire is extinguished due to some cause such as spillage, it can be determined that there is no flame based on the signal from the flame detection sensor, and the control circuit can determine the solenoid valve based on the determination of no flame. Can be closed to shut off the gas supply path to prevent gas leakage.

The flame detection sensor may be a thermocouple or a frame rod. The flame rod detects the flame by the rectifying action of the flame, but there is a risk that the flame rectifying function may be deteriorated due to surface oxidation by the cooked waste, and it is expensive. Since the thermocouple generates an electromotive force in response to the temperature, it is not necessary to consider the boiling point and the like, and the price is low. From the above,
Thermocouples are used in gas combustors for cooking.

<Problems to be Solved by the Invention> However, since the thermocouple generates electromotive force in response to temperature as described above, it has a drawback that the response speed is slow, and even after extinguishing the fire for a while. There is enough electromotive force to judge that there is a flame. Therefore, if a pseudo-flame check is performed after the fire extinguishing operation is performed (whether or not there is a flame remaining is checked through the flame discrimination circuit. The same applies below.) There is a problem that it is difficult to judge whether there is any flame left in the disk or whether the flame discriminating circuit is abnormal.

This invention has been made in view of the above problems,
An object of the present invention is to provide a safety device for a gas combustor that enables checking of a pseudo flame after extinguishing a fire even when a thermocouple is used.

<Means for Solving Problems> In the safety device for a gas combustor according to the present invention for solving the above problems, a clocking time is set based on a response speed of a thermocouple, and the set time is set according to a fire extinguishing operation. And a control means for maintaining a fire extinguishing state even if an ignition operation is performed and for generating a warning signal when it is determined that there is a flame after the set time has been measured. Is.

<Operation> With the safety device for a gas combustor according to the present invention as described above, the gas supply to the burner is stopped in response to the fire extinguishing operation, and the flame is generated based on the signal from the thermocouple arranged near the burner flame hole. In the case of determining the presence or absence of the case, if the timekeeping means that the timekeeping time is set based on the response speed of the thermocouple measures the above time in response to the fire extinguishing operation, and if it is determined that there is a flame even after the timekeeping ends, Since the control means maintains the extinguishing state even if the ignition operation is performed, it is possible to determine that the flame determination circuit including the thermocouple is abnormal.

<Example> Hereinafter, detailed description will be given with reference to the accompanying drawings illustrating an example.

FIG. 1 is a diagram showing a safety device of a gas combustor when a gas stove is used as the gas combustor. The gas stove has stoves of the same configuration arranged on the left and right of a casing (not shown), and is provided in the gas supply path (1). The main solenoid valve (2), the governor (3), and the four-way branching device (4) are interposed in this order, and the gas supply amount regulating solenoid valve (5a) ( 5b) (5c) (5d) and orifices (6a) (6b) (6c) (6d) having different diameters are interposed, and the nozzle (6a) (6b) (6c) (6d) is provided with a nozzle ( The burner (8) is connected via 7), and the thermocouple (9) and the ignition plug (10) are arranged near the burner combustion hole. Then, the flame discrimination circuit (13) malfunctions in response to signals from the operation key panel (11) for inputting fire extinguishing, ignition, thermal power adjustment, etc. for the right and left stoves independently and the microcomputer (14) described later. A buzzer (12) for notifying that is is provided at an appropriate position on the side surface of the housing. Further, in a proper place in the housing, a flame discriminating circuit (13) for discriminating the presence or absence of flame on the basis of a signal output from the thermocouple (9), and an original solenoid valve ( 2), a spark plug (10), a gas supply amount adjusting solenoid valve (5a) (5b) (5c) (5d) and the like is provided with a control board equipped with a microcomputer (14) for controlling.

More specifically, the original solenoid valve (2) opens the gas supply passage (1) according to an ignition operation and closes the gas supply passage (1) according to a fire extinguishing signal.

The above-mentioned cover (3) is for adjusting the pressure of the gas, and the gas whose pressure is adjusted by the cover (3) is sent to the adjusting valve (5) via the four-way branching device (4).

Solenoid valve for adjusting gas supply amount (5a) (5b) (5c) (5d)
Is for controlling the gas supply amount by opening / closing in accordance with a thermal power adjustment operation signal and selectively combining branch paths branched in four directions. That is, the gas supplied from the governor (3) is selectively combined with the orifices (6a) (6b) (6c) (6d) having different diameters to adjust the diameter of the gas supply passage, that is, the gas supply amount. Theoretically, 16 kinds of thermal power can be adjusted including the case where all the gas supply amount adjusting solenoid valves (5a) (5b) (5c) (5d) are shut off, but in this embodiment, 7
It is set according to the street. The original solenoid valve (2) and the gas supply amount adjusting solenoid valves (5a) (5b) (5c) (5d) open the branch passage when energized, and shut off when not energized. Is used.

The key panel (11) includes a fire extinguishing key (111), fire power adjustment keys (112) to (118) for setting ignition power and seven levels of heat power from low heat to high heat, and the respective heat power adjustment keys ( It has LEDs (11a) to (11g) which are arranged on the upper part of 112) to (118) and which are turned on in response to the input of the heat power adjustment key. It should be noted that the ignition operation is performed by the first heat power adjustment key input operation after extinguishing the fire, and the heat power adjustment operation is performed by the next heat power adjustment key (112) to (118) position.

The flame discrimination circuit (13) compares the electromotive force of the thermocouple (9) with the reference voltage, and when the electromotive force of the thermocouple (9) is equal to or higher than the reference voltage, determines that there is a flame. When the electromotive force of the thermocouple (9) becomes equal to or lower than the reference voltage, it is determined that there is no flame. FIG. 2 is a circuit diagram showing an example of the flame discrimination circuit (13), in which the electromotive force of the thermocouple (9) is divided by resistors (R1) and (R2), and the divided voltage is input to the inverting input terminal of the comparator (131). The power supply voltage supplied and divided by the volume (132) is further divided by the resistors (R3) and (R4) and supplied to the non-inverting input terminal of the comparator (131). Then, the output terminal of the comparator (131) is supplied to the microcomputer (14) via the resistor (R7), and the comparator (13) is supplied.
A part of the output is fed back by the resistor (R5) connected between the output terminal of 1) and the non-inverting input terminal to give the hysteresis characteristic. Furthermore, a capacitor (C) is connected between the inverting and non-inverting input terminals of the comparator (131).
1) is connected.

In the case of the flame discrimination circuit (13), the electromotive force of the thermocouple (9) is divided by the resistors (R1) and (R2), and the potential of the signal is divided by the volume (132) and the resistors (R3) and (R4). The presence or absence of a flame is determined by comparing it with the compressed power supply voltage, and the microcomputer (1
4) can be output to. And the comparator (1
By giving 31) hysteresis characteristics, it is possible to prevent the output from frequently switching in the vicinity of the threshold value.

The microcomputer (14) includes a main solenoid valve (2), an ignition plug (10), and a solenoid valve for adjusting a gas supply amount (in accordance with signals from the fire extinguishing, ignition, and thermal power adjustment operations and the flame discrimination circuit (13). 5a), (5b), (5c), (5d), etc. are controlled, and processing is performed based on the monitor program shown in FIG. That is, in the step, it is determined whether or not the ignition operation has been performed, and when it is determined that the ignition operation has not been performed, the operation of the step is repeated, and when it is determined that the ignition operation has been performed, the original Open the solenoid valve (2). In the step, after the start of the clocking time described later,
It is determined whether or not a fixed time (approximately 2 minutes) has passed. If it is determined that the fixed time has passed, the process proceeds to step. In step, if the flame determination circuit (13) determines that there is a flame, At step, the original solenoid valve (2) is closed, and at step, a warning signal is output by the buzzer (12) and LE.
Output to D and return to step.

When it is determined in the above step that the fixed time has not elapsed and when the flame determination circuit (13) determines that there is no flame in the step, all the gas supply amount adjusting solenoid valves (5a) are determined in the step. ) (5b) (5
c) Open (5d) and supply gas to the burner (8).
In step, the spark plug (8) is energized to ignite. In step, stop energizing to the specified solenoid valve among all gas supply amount adjusting solenoid valves (5a) (5b) (5c) (5d) that have already been energized in step according to the input of the thermal power adjustment key Then, the amount of gas, that is, the heating power is adjusted. In the step, it is determined whether or not there is any one of the digestion key input signal and the no-discrimination signal, and when neither is present, the processing of the step is repeated, and when there is any signal, , In step, start counting a certain time, and in step, stop energizing the original solenoid valve (2) and all solenoid valves (5a) (5b) (5c) (5d) for adjusting gas supply amount. , Stop the gas supply to the burner (8) and return to the step.

The operation of stopping the gas supply in the step is performed almost simultaneously with the step.

The operation of the above embodiment is as follows. That is, the microcomputer (14) determines whether or not a predetermined time (approximately 2 minutes) has elapsed from the previous extinguishing operation according to the ignition operation, and further, a flame presence signal is output from the flame determining circuit (13). If it is determined whether or not it is being output, and a certain time (approximately 2 minutes) has elapsed since the previous extinguishing operation, and a signal indicating that a flame is being output, the solenoid valve for adjusting the gas supply amount (5a) ( 5b) (5c)
The warning signal is output to the buzzer (12) and LED (13h) while keeping (5d) closed. And fixed time (approximately 2 minutes)
Ignition is performed according to the ignition operation in both cases where the time has not elapsed and the case where the flame determination circuit (13) outputs the no flame signal.

Therefore, if the ignition operation is performed within a certain time after extinguishing the fire, it is possible to cope with the slow response time of the thermocouple (9) by igniting. When the flame discrimination circuit (13) discriminates that there is a flame within a certain time after extinguishing the fire, the flame discrimination circuit (13) is output by outputting a buzzer (12) warning signal from the mylocomputer (14). ) Can inform that it is making an erroneous determination, and can check for pseudo flames.

Note that the present invention is not limited to the above-described embodiment, and for example, an LED that blinks and notifies an abnormality of the flame discrimination circuit.
Can be provided on the key panel (11), the number of gas stoves can be increased or decreased, and other various design changes can be made without departing from the scope of the invention.

<Effects of the Invention> As described above, according to the present invention, the timekeeping means in which the timekeeping time is set on the basis of the response speed of the thermocouple measures the set time according to the fire extinguishing operation, and the flame is generated even after the timekeeping ends. If it is determined that there is, since the control means maintains the extinguishing state even if there is an ignition operation, even if the thermocouple has a slow response speed, the flame determination circuit makes an incorrect determination. There is a unique effect that you can see that

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of a safety device for a gas combustor of the present invention, FIG. 2 is a circuit diagram showing an example of a flame discrimination circuit, and FIG. 3 is a flowchart of the safety device for a gas combustor. (2) …… Original solenoid valve, (5a) (5b) (5c) (5d) …… solenoid valve for gas supply adjustment, (9) …… thermocouple, (12) …… buzzer, (13)… … Flame discriminating circuit, (14) …… Microcomputer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Takuo Ohara 3 201 Minamiyoshikata, Tottori City, Tottori Prefecture Tottori Sanyo Electric Co., Ltd. (72) Seiichiro Kobayashi 3 201 Minamiyoshikata, Tottori City, Tottori Prefecture Sanyo Tottori Electric Machinery Co., Ltd. (72) Inventor Yoshifumi Ozaki 3-201 Minamiyoshikata, Tottori City, Tottori Prefecture Tottori Sanyo Electric Co., Ltd. (56) Bibliography Sho 61-23060 (JP, U)

Claims (2)

[Claims] 1. A flame discrimination system for controlling gas supply to a burner in response to fire extinguishing, ignition, and thermal power adjustment operations, and for determining the presence or absence of a flame based on a signal from a thermocouple arranged near a burner flame hole. In a gas combustor having means, a timekeeping time is set based on the response speed of the thermocouple, and a timekeeping means for starting the timekeeping of the set time according to a fire extinguishing operation, and the flame discrimination means after the time measurement of the set time is completed. A safety device for a gas combustor, which has a control means for prohibiting ignition and maintaining a fire extinguishing state even if there is an ignition operation and generating a warning signal when it is determined that there is a flame. 2. The control means ignites when the ignition operation is performed before the time measurement of the set time is completed, and when it is determined that there is no flame due to the ignition operation after the time measurement of the set time is completed. The safety device for a gas combustor according to claim 1, wherein the safety device is provided.