JPH0626653A - Gas control circuit for gas range - Google Patents

Abstract

PURPOSE:To permit the easy and sure control of temperature for preventing the outflow of gas due to discontinued burning and preventing the ignition of oil. CONSTITUTION:A thermocouple 4, generating an electromotive force by heating the same by flame, a safety valve 24, retained in opened condition by the electromotive force of the thermocouple 4, and a temperature detecting element 13, provided for detecting the temperature of bottom of a pot and having positive characteristic whose resistance value is increased when the temperature is raised, are connected in series. The safety valve 24 is otherwise connected to the parallel circuit of the temperature detecting element 13, having negative characteristic in which the resistance value is reduced when the temperature is raised, and the thermocouple 4 to operate the safety valve 24 by the change of a value of current conducted through the safety valve 24 due to the change of the value of the electric resistance of the temperature detecting element 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas control circuit for controlling the flow of gas in a gas stove.

[0002]

2. Description of the Related Art In a gas stove, a thermocouple heated by a flame and a safety valve held open by an electromotive force generated by the thermocouple are provided in order to prevent gas from flowing out in the case of extinction. Conventionally, there has been provided a device which shuts off a gas by closing a safety valve when the extinguishing occurs.

In addition, in recent years, in consideration of the occurrence of fire due to the ignition of the tempura oil, a heat collecting plate is provided in contact with the bottom of the pan, and a mechanical switch using bimetal is attached to the heat collecting plate. It is provided that the safety valve is connected between the thermocouple and the safety valve so that when the pot bottom temperature exceeds a predetermined value, the switch is turned off and the safety valve is closed.

[0004]

However, since the switch has a mechanical contact and has a large electric resistance, it may be difficult to open the safety valve when the electromotive force of the thermocouple is small. there were. Further, since this contact is under severe heat conditions, there is an increase in electrical resistance due to corrosion, which easily causes the above problems.

The present invention has been made in view of the above points, and an object thereof is to easily and surely perform temperature control for preventing outflow of gas due to extinguishment and prevention of oil ignition. It is possible to provide a gas control circuit for a gas stove.

[0006]

DISCLOSURE OF THE INVENTION In the present invention, however, a thermocouple that generates an electromotive force by being heated by a flame, a safety valve that is held in an open state by the electromotive force of the thermocouple, and a temperature detection of the pot bottom. For use and having a temperature detection element having a positive characteristic in which the resistance value increases as the temperature rises, the thermocouple, the temperature detection element, and the safety valve are connected in series or heated by a flame. Equipped with a thermocouple that generates an electromotive force, a safety valve that is kept open by the electromotive force of the thermocouple, and a temperature detection element for detecting the temperature of the pan bottom and having a negative characteristic that the resistance value decreases as the temperature rises. The safety valve is connected to the parallel circuit of the thermocouple and the temperature detecting element.

[0007]

According to the present invention, the value of the current flowing through the safety valve is changed by the change of the electric resistance value of the temperature detecting element, and the safety valve is activated. It is possible to sufficiently secure the current value flowing through the safety valve when the temperature is low.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the illustrated embodiments. A nozzle 23 is provided at one end of the mixing tube 20, and a burner cap 21 is attached to the other end of the mixing tube 20 to provide a burner. Flame holes 22 are arranged on the periphery of the cap 21. Then, in the gas flow path leading to the nozzle 23,
An electromagnetic safety valve 24 is provided.

A thermocouple 4 heated by a flame is arranged near the burner cap 21. Also,
At the center of the burner cap 21, a temperature detecting device 1 for detecting the temperature of the bottom of the pan is arranged. The temperature detecting device 1 includes a shaft 10 supported by a fixed plate 15 attached to a mixing pipe 20, a cylinder 11 that is vertically movable with respect to the shaft 10, and a collector provided on the upper end of the cylinder 11. The temperature detecting element 13 attached to the lower surface of the heat plate 12 is disposed between the upper end of the shaft 10 and the lower surface of the heat collecting plate 12 to urge the heat collecting plate 12 and the cylinder 11 upward. And a spring 14 which is a coil spring.

The temperature detecting element 13 here is one having a positive characteristic such that the resistance value increases as the temperature rises, for example, a positive characteristic thermistor, and the thermocouple 4, the temperature detecting element 13 and the safety valve 24 are shown in FIG. They are connected in series as shown in. When the gas stove 2 is ignited, the resistance value of the temperature detection element 13 at this time is low, so the electromotive force of the thermocouple 4 keeps the safety valve 24 open. Then, the temperature of the temperature detecting element 13, which is in contact with the bottom surface of the pot 3 via the heat collecting plate 12 by the bias of the spring 14, rises, and a certain temperature, for example, tempura oil, ignites 3.
If the resistance value suddenly rises around 20 ° C,
The current flowing through the safety valve 24 decreases, and the safety valve 24 closes the gas flow path and shuts off the gas supply.

When the temperature detecting element 13 is a thermistor having negative characteristics (preferably a critical temperature thermistor), the thermocouple 4 and the temperature detecting element 13 are connected in parallel as shown in FIG. If a safety valve 24 is connected to the temperature detection element 13 and the temperature detected by a certain temperature detection element 13 reaches or exceeds a predetermined value, the resistance value of the temperature detection element 13 sharply decreases, and the current generated by the electromotive force of the thermocouple 4 changes to the temperature. It suffices that a large amount of current flow to the side of the detection element 13 and a small amount of current flow to the side of the safety valve 13 so that the safety valve 24 closes.

[0012]

As described above, in the present invention, the temperature detecting element for detecting the temperature of the bottom of the pot and having a positive characteristic that the resistance value increases with the temperature rise, the thermocouple and the safety valve are connected in series, Alternatively, since the safety valve is connected to the parallel circuit of the temperature detection element and the thermocouple, which has a negative characteristic that the resistance value decreases as the temperature rises, the safety valve changes depending on the detected temperature of the temperature detection element. The safety valve operates by changing the value of the current flowing through, and reliability can be increased because it can be configured without a contact, and a sufficient value of the current flowing through the safety valve when the pot bottom temperature is low is secured. In addition, thermal corrosion does not pose a problem, and for this reason, temperature control can be performed easily and reliably to prevent gas outflow and oil ignition due to extinction. Can.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment.

FIG. 2 is a schematic circuit diagram of the above.

FIG. 3 is a schematic circuit diagram of another embodiment.

[Explanation of symbols]

 4 Thermocouple 13 Temperature detection element 24 Safety valve

Claims (2)

[Claims] 1. A thermocouple that generates an electromotive force when heated by a flame, a safety valve that is held in an open state by an electromotive force of the thermocouple, a temperature detector for detecting the temperature of the bottom of the pot, and a resistance value that increases as the temperature rises. A gas control circuit for a gas stove, comprising a temperature detection element having an increasing positive characteristic, and a thermocouple, a temperature detection element, and a safety valve connected in series. 2. A thermocouple that generates an electromotive force when heated by a flame, a safety valve that is held in an open state by an electromotive force of the thermocouple, a temperature detector for detecting the temperature of the bottom of the pot, and a resistance value that increases as the temperature rises. A gas control circuit for a gas stove, comprising a temperature detecting element having a negative characteristic that deteriorates, and a safety valve connected to a parallel circuit of a thermocouple and the temperature detecting element.