JP2002147755A - Burning appliance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a burning appliance, in which shut-off of combustion is ensured for occasion of abnormal conditions. SOLUTION: When a burner is carelessly left in a firing state or flamed-off state according to judgement of S10, current-carrying to a magnetic operated safety valve is turned off in S11 to close the valve. Gas-supply to the burner is stopped, and fire of burner is put out. The state of off-energization to the valve is continued for two seconds in S12. Even if an operation button is pushed on in this period, or noises corresponding to a reset signal are accidentally made, the current is not passed to the valve.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a burner such as a table stove provided with a safety valve in a gas supply path to a burner.

[0002]

2. Description of the Related Art For example, in a table stove, a safety valve is provided in a gas supply path to a stove section and a grill section, and during normal combustion, the valve is held open by energization control by a safety valve control circuit. When the flame goes out or overheat occurs, and the thermocouple or thermistor as the abnormality detection means detects this, the safety valve control circuit cuts off the current to the safety valve, closes it, and releases the gas. Stop supply. When such an abnormality occurs, the control shifts to an abnormal state control state in which the normal combustion control is stopped.However, if a reset signal such as an ON signal of an igniter switch or an OFF signal of a cock switch is obtained by operating an operation button, The abnormal state control state is reset and re-ignition is possible.

[0003]

However, even if the energization is turned off, the safety valve in the energized state cannot be closed instantaneously due to the attraction force of the attraction surface or a magnetic delay.
There may be a delay of about s. Therefore, if the noise corresponding to the reset signal accidentally enters after the safety valve has been turned off and before the safety valve has been disconnected in the event of an abnormality, the safety valve must be restarted and the safety valve closed. And the combustion may be continued.

Accordingly, an object of the present invention is to provide a combustion apparatus excellent in safety by reliably stopping combustion when an abnormality occurs.

[0005]

To achieve the above object, according to the first aspect of the present invention, when an abnormality is detected by the abnormality detecting means, the safety valve control means determines whether the abnormality resetting means is executed or not. The power supply to the safety valve is stopped for a predetermined time during which the safety valve can be reliably closed. The invention according to claim 2 is
In addition to the object of claim 1, in the abnormality detecting means for detecting by a temperature sensor that a combustion part heated by a burner has reached a predetermined fire extinguishing temperature, in order to improve usability while ensuring safety. In addition, when the burner is re-ignited after the safety valve is closed due to the reaching of the extinguishing temperature, the extinguishing temperature is switched to the higher second extinguishing temperature for a predetermined time.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram of a table stove 1 as an example of a burning appliance.
A burner main body 5 to which the gas pipe 7 is connected
And a burner head 6 mounted on the head of the burner main body 5. The gas pipe 7 is provided with a main valve 9 and a magnet safety valve 10 that can be opened by pressing an operation button 8. . In the center of the burner head 6, a thermistor 11 as a temperature sensor for detecting a pan bottom temperature is provided.
Near the flame hole of the burner head 6, there is a thermocouple 1 for detecting a flame.
2 are provided and connected to the controller 13. 14 is a dry battery serving as a power supply for the controller 13, 15
Is an LED lamp indicating the battery life. On the other hand, in the grill section 3, a pair of grill burners 16, 16 is disposed, and the gas pipe 1 connected to the grill burners 16, 16 is provided.
7 is also provided with a main valve 19 and a magnet safety valve 20 that can be opened by pressing the operation button 18. A thermocouple 21 for detecting a flame is provided near the grill burner 16, and is also connected to the controller 13.

FIG. 2 is a circuit block diagram of the controller 13, in which a microcomputer 22 and a dedicated IC 23 for providing a safety function are provided, and the thermoelectromotive force of the thermocouples 12, 21 is detected by flame detection. Is amplified by the circuit 24 and
C, the dedicated IC operates the safety valve control circuit 25 to control the opening and closing of the magnet safety valves 10 and 20 (falling safety device). On the other hand, the resistance value of the thermistor 11 is converted into a voltage by the thermistor input circuit 26 and input to the microcomputer 22. The microcomputer 22 operates the safety valve control circuit 25 via the dedicated IC 23 to control the opening and closing of the magnet safety valves 10 and 20. (Tempura fire prevention device). Reference numeral 27 denotes a display circuit for the LED lamp 15, reference numeral 28 denotes a power supply circuit for generating power in the circuit, reference numeral 29 denotes a voltage monitoring circuit, and reference numeral 30 denotes a pulse monitoring circuit for obtaining a pulse signal from the microcomputer 22 and monitoring runaway of the microcomputer 22.

The operation of the table stove 1 constructed as described above will be described with reference to the flowchart of FIG. When the operation button 8 is pressed, an igniter switch (not shown) is turned on at S1, and at S2
The main valve 9 and the magnet safety valve 10 are forcibly opened to supply fuel gas to the stove burner 4, and
The igniter is operated to continuously discharge the ignition electrode (not shown) near the burner head 6, and is ignited in S3. When the burner 4 burns and it is confirmed in S4 that the thermoelectromotive force of the thermocouple 12 has reached the flame detection level or higher (if the flame electromotive force has not reached the flame detection level, the combustion is stopped in S5), the safety valve is released in S6. By operating the control circuit 25, the magnet safety valve 10 is energized to be kept open, and the combustion control is executed (S7). S
When the operation button 8 is pressed again at 8, the power to the magnet safety valve 10 is turned off at S9, and the burner 4 burns out.

On the other hand, if there is no fire extinguishing operation and an abnormality such as forgetting to turn off the stove burner 4 or misfiring occurs while the stove section 2 is in use (S10), the power supply to the magnet safety valve 10 is turned off in S11 and the magnet is turned off. Since the safety valve 10 is closed and the supply of gas to the burner burner 4 is shut off, the burner burner 4 is extinguished. Next, in S12, the power supply OFF state to the magnet safety valve 10 is continued for 2 seconds. Therefore, even if a reset signal such as an operation of pressing the operation button 8 to turn on the igniter switch as an abnormal resetting means or a noise corresponding to the reset signal is accidentally input during this time, the magnet safety valve 1 is not operated.
0 is not supplied, and the valve is securely closed even if the separation is delayed due to the suction force of the suction surface or the magnetic delay.

After waiting for 2 seconds, the igniter switch is turned on or the cock switch is turned off in accordance with the re-ignition operation in step S13.
When a reset signal such as F is input, in S14, the setting of the automatic extinguishing temperature of the thermistor 11 in the tempura fire prevention device is changed to 270 ° C. as the second extinguishing temperature, and in S1
At 5, the ignition control is performed to keep the magnet safety valve 10 energized. Then, when the elapse of 120 seconds is confirmed in the determination of S16, the setting of the automatic fire extinguishing temperature is switched to 250 ° C. as the normal fire extinguishing temperature in S17. Therefore, before the elapse of 120 seconds, the automatic fire extinguishing temperature remains at 270 ° C. (S18). S
In the determination of 19, the temperature of the thermistor 11 becomes the automatic fire-extinguishing temperature (1
When the temperature reaches 250 ° C. before the elapse of 20 seconds and 270 ° C. after the elapse, the process returns to S11 to turn off the magnet safety valve 10 and stop the combustion of the stove burner 4. Also in this case, the power supply OFF state to the magnet safety valve 10 is continued for 2 seconds (S12), and the control after the re-ignition operation is repeated from S13.

The reason why the automatic extinguishing temperature of the thermistor 11 is switched to the second extinguishing temperature for only 120 seconds upon re-ignition after the operation of the tempura fire prevention device is as follows. When the temperature of the pot bottom rises in the combustion state of the stove burner 4 and reaches 250 ° C. and the fire is automatically extinguished, the thermistor 1
1 further rises in temperature due to preheating. Here, even if the user needs further cooking and immediately performs a relighting operation, since the temperature of the thermistor has already reached 250 ° C., it cannot be used until the temperature of the thermistor decreases, and the usability deteriorates. Therefore, at the time of re-ignition, the re-ignition is enabled by raising the automatic extinguishing temperature by 20 ° C. for only 2 minutes. By the way, cooking that requires relighting is supposed to be a stir-fry in a frying pan or the like. From the cooking process of putting ingredients and adding water, the thermistor temperature drops to 250 ° C or less in at least 2 minutes, so cooking Can be continued. In addition, in tempura cooking, there is no danger of ignition even if the automatic extinguishing temperature is set to 270 ° C. for only 2 minutes.

As described above, according to the above embodiment, when an abnormality is detected, the power supply is stopped for a predetermined time (two seconds) during which the magnetic safety valve 10 can be reliably closed regardless of the presence or absence of the reset signal. Thus, even when noise corresponding to the reset signal accidentally enters, the magnet safety valve 10 can be reliably closed. Therefore,
When an abnormality occurs, the combustion can be reliably stopped, and safety is improved. Here, in the case where the stove burner 4 is re-ignited after the magnet safety valve 10 is closed due to the reaching of the fire extinguishing temperature in the tempura fire prevention device, a predetermined time (120
Second fire extinguishing temperature (270 ° C)
Therefore, it is possible to reignite the burner burner 4 while ensuring safety, thereby improving usability.

The reason why the magnet safety valve is turned off for two seconds after the occurrence of an abnormality in the above-described embodiment is that if the magnet safety valve is too short, the magnet safety valve cannot be reliably closed. 2 seconds is selected in consideration of the balance between the two, and the time during which the magnet safety valve can be reliably closed is desirably 1 second or more. In addition, the setting of the second fire extinguishing temperature and the predetermined time for maintaining the temperature are not limited to 270 ° C. and 120 seconds, and can be appropriately changed.

[0014]

According to the first aspect of the present invention, when an abnormality is detected by the abnormality detection means, the safety valve control means determines whether the safety valve can be reliably closed regardless of the execution of the abnormality reset means. By stopping the energization of the safety valve during the time period, the safety valve can be reliably closed even when noise corresponding to the reset signal of the abnormal resetting unit accidentally enters. Therefore, when an abnormality occurs, combustion can be reliably stopped, and safety is improved.
According to the second aspect of the present invention, in addition to the effect of the first aspect, the abnormality detecting means detects that the temperature of the combustion portion heated by the burner reaches a predetermined fire extinguishing temperature by the temperature sensor. Therefore, if the burner is re-ignited after the safety valve is closed due to the reaching of the fire extinguishing temperature, the fire extinguishing temperature is switched to the higher second fire extinguishing temperature for a predetermined period of time, thereby ensuring safety while ensuring safety. Re-ignition is enabled to improve usability.

[Brief description of the drawings]

FIG. 1 is a schematic view of a table stove.

FIG. 2 is a circuit block diagram of a controller.

FIG. 3 is a flowchart showing an operation in the cooking stove;

[Explanation of symbols]

1. Table stove, 2. Stove section, 3. Grill section, 4. Stove burner, 10, 20, Magnet safety valve, 11, Thermistor, 13, Controller, 1
6. Grill burner, 22 microcomputer, 25 safety valve control circuit.

Claims (2)

[Claims] 1. A burner, a safety valve provided in a gas supply path to the burner, and held open by energization, a safety valve control means for controlling energization of the safety valve, and an abnormality detection means capable of detecting an abnormality When the abnormality detection unit detects an abnormality, the safety valve control unit stops energization of the safety valve, and the combustion appliance provided with abnormality reset unit that enables re-ignition of the burner. When the abnormality detection unit detects an abnormality, the safety valve control unit stops energizing the safety valve for a predetermined time during which the safety valve can be reliably closed regardless of whether the abnormality reset unit is executed. A burning appliance characterized by being made to make it. 2. An abnormality detecting means for detecting, by a temperature sensor, that a combustion portion heated by a burner has reached a predetermined fire extinguishing temperature, wherein the safety valve is closed after the fire extinguishing temperature is reached. If the burner is re-ignited,
The combustion appliance according to claim 1, wherein the fire extinguishing temperature is switched to a higher second fire extinguishing temperature for a predetermined time.