JPH08135975A - Heating cooker - Google Patents

Abstract

PURPOSE: To provide a simple and inexpensive overheat preventing mechanism, in a heating cooker, detecting the temperature of bottom of an oven to prevent overheat. CONSTITUTION: When the bottom 7 of an oven is overheated, the displacement of a temperature detecting sensor unit 10 closes the flow passage of gas in a pilot burner 5 to put off the flame of the pilot burner 5. A solenoid type control valve 1 is closed due to the deterioration of the electromotive force of a thermocouple 2 provided in the pilot burner 5 to stop the combustion in the pilot burner 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating cooker such as a table hob, and more particularly to a heating cooker for detecting overheat temperature by detecting the bottom temperature of a cooking pot placed on the upper part of a burner.

[0002]

2. Description of the Related Art Conventionally, in order to prevent a tempura fire, burning, etc., a heating cooker that detects the temperature of the bottom of a cooking pot with a sensor and stops combustion when the detected temperature reaches a predetermined temperature or higher. Are known. For example, as shown in FIG. 3, a sensor unit 30 for detecting the pot bottom temperature of the cooking pot 7 is provided in the central portion of the main burner 36, and the pot bottom temperature of the cooking pot 7 placed on Gotoku is set to a preset temperature. When it reaches
A heating cooker is known in which a push rod 32 integrated with a magnet 39 is pushed downward to close a gas flow path 34. Specifically, the temperature-sensitive ferrite 38 and the magnet 39, which are biased in the separating direction by the return spring 31, constitute the sensor unit 30,
Utilizing the fact that the temperature-sensitive ferrite 38 changes from ferromagnetic to paramagnetic when it reaches a temperature near the Curie point, the magnet 3 is used when the force of the return spring 31 exceeds the attraction force of both.
9 is released. When the magnet 39 is removed, the push rod 32
Lowers to close the main valve 21 of the main switch 20 provided in the main gas flow path 34 via the interlocking rod 33 to stop combustion. At the time of reuse, the reset button (not shown) is pushed to magnet 39, push rod 32, interlocking rod 33.
To the initial state. In addition to such an overheat prevention mechanism, the heating cooker has a thermocouple 22 that senses the flame of the main burner 36, and an electromagnetic control valve 23 that opens and closes the main gas flow path 34 by the electromotive force generated by the thermocouple 22. (For example, a magnet safety valve) and is configured to close the main gas flow passage 34 when the flame of the main burner 36 is extinguished due to spillage or wind from the cooking pot 7 and raw gas is emitted.
In the figure, reference numeral 35 is a pressing spring, and 37 is a non-magnetic cover.

[0003]

However, in such a conventional heating cooker, a large load is required on the valve of the switch in order to extinguish the flame clearly without causing gas leakage. That is, since the switch of the main burner flows a large flow rate at a constant pressure, the diameter of the valve is large and the opening / closing stroke is long. Therefore, the interlocking with the sensor part and the opening / closing mechanism were complicated and expensive. It is an object of the heating cooker of the present invention to solve the above problems and provide a heating cooker that reliably prevents overheating with a simple configuration.

[0004]

A heating cooker according to the present invention for solving the above-mentioned problems includes a main burner for burning a fuel gas, a pilot burner for branching and burning from a gas passage of the main burner, and the pilot. When a thermocouple that generates electromotive force by heating with the combustion flame of the burner and the electromotive force of the thermocouple drops below a predetermined value, close the main gas flow path to the main burner and the pilot burner and stop combustion. In a heating cooker equipped with an electromagnetic control valve for contacting a bottom surface of a cooking pot and displacing when a predetermined pan bottom temperature is reached, the thermocouple is interlocked with the displacement of the sensor unit. The gist of the present invention is to provide a pilot valve for closing the gas flow path of the pilot burner to be heated.

[0005]

In the heating cooker of the present invention having the above-mentioned structure, when the temperature of the bottom of the cooking pot heated by the burner reaches a predetermined value, the sensor section is displaced in a predetermined manner, and the displacement causes the gas passage of the pilot burner. Close and extinguish the combustion flame of the pilot burner. When the electromotive force of the thermocouple generated by the heating of the pilot combustion flame decreases at the same time as the extinction and falls below a predetermined value, the electromagnetic control valve is closed and combustion is stopped. In other words, since the gas flow rate of the pilot burner is small, it is possible to reduce the pilot valve itself, and at the time of heating, securely close this pilot valve to extinguish the pilot flame and close the electromagnetic control valve to extinguish the main burner. .

[0006]

EXAMPLES In order to further clarify the constitution and operation of the present invention described above, preferred examples of the heating cooker of the present invention will be described below. FIG. 1 is a schematic configuration diagram of a heating cooker as an example. The heating cooker of the present embodiment has a main gas conduit 3 that branches from the original gas conduit 14 and supplies fuel gas to the main burner 16 that heats the cooking pot 7, and a center of the main burner 16 that branches from the main conduit 3. A pilot gas conduit 6 for supplying fuel gas to a pilot burner 5 provided nearby, a thermocouple 2 for generating an electromotive force due to combustion heat of the pilot burner 5, and a source gas conduit 14 upstream of a branch point are provided. It is composed of an electromagnetic control valve 1 (a magnet valve is used in this embodiment) that opens and closes the original gas flow path, and a sensor unit 10 that detects the pot bottom temperature.

The sensor portion 10 is provided so as to be urged upward by a pressing spring 15, and is brought into contact with the bottom of the cooking pot 7 placed on Gotoku to detect the pot bottom temperature. A non-magnetic cover 17 is provided on a portion of the cooking pot 7 that comes into contact with the bottom face of the cooking pot 7, and a temperature-sensitive ferrite 18 whose magnetism changes according to the temperature inside the cover 17.
And a magnet 19 facing the temperature-sensitive ferrite 18 and attracting and desorbing. Further, one end is fixed to the magnet 19, and the pilot valve 12 that moves up and down integrally with the magnet 19 is provided. The pilot valve 12 includes a return spring 1 for urging the magnet 19 away from the temperature-sensitive ferrite 18.
1 is provided. During operation, the return spring 11 works to press the pilot valve 12 against the valve seat 13 provided on the upper portion of the pilot conduit 6 to shut off the gas to the pilot burner 5.

The operation of the heating cooker when the cooking pot 7 is boiled will be described. When the main burner 16 is ignited, the pot bottom temperature is lower than the predetermined temperature, and the attracting force of the temperature-sensitive ferrite 18 and the magnet 19 of the sensor unit 10 is larger than the force of the return spring 11, so the sensor unit 10 maintains the initial state. Then, as the pot bottom temperature gradually rises, the temperature of the sensor unit 10 also rises accordingly. At that time, when abnormal overheating occurs due to empty heating or the like, when the temperature of the temperature-sensitive ferrite 18 reaches a predetermined temperature (temperature near the Curie point in this embodiment), the magnetism of the temperature-sensitive ferrite 18 changes from ferromagnetic to paramagnetic. It changes and the attraction force with the magnet 19 weakens rapidly. Then, the force of the return spring 11 overcomes the attracting force to separate the magnet 19 from the temperature-sensitive ferrite 18. At the same time, the pilot valve 12 is pressed against the valve seat 13 by the force of the return spring 11, the gas to the pilot burner 5 is shut off, the flame of the pilot burner 5 is extinguished, and the thermocouple 2 heated by the pilot burner 5 When the electromotive force is reduced to a predetermined voltage or less, the electromagnetic control valve 1 is closed and combustion is stopped.

When the main burner 16 extinguishes and the temperature of the bottom of the pot falls below a predetermined temperature, the magnetism of the temperature-sensitive ferrite 18 returns to ferromagnetic, and the attraction force between the temperature-sensitive ferrite 18 and the magnet 19 overcomes the force of the return spring 11. Then, the temperature-sensitive ferrite 18 and the magnet 19 automatically return to the original attracted state. At that time, the pilot valve 12 is in the original valve opening position apart from the valve seat 13.

Next, the complicated interlocking mechanism (push rod 32, interlocking rod 33, etc.) in FIG.
Since it is possible to directly link the displacement of 0 to the main valve 21 of the main switch 20, a reference example will be described with reference to FIG. In this reference example, the switch 43 provided in the main gas passage 44 of the main burner 53 is opened and closed by utilizing the same displacement of the sensor unit 40 as in the present embodiment (FIG. 1). In this reference example, since the switch 43 is provided in the main gas flow path 44 of the main burner 53 having a large flow rate, a large load is required to seal the main opening / closing valve 46, and the displacement of the sensor unit 40 is changed by a simple interlocking mechanism. Cannot be transmitted. This is because the main valve 46 of the main switch 43 requires a load of a predetermined value or more that does not cause gas leakage, and the load is obtained by the return spring 41. On the other hand, if the load of the return spring 41 is less than the attraction force between the temperature-sensitive ferrite 48 and the magnet 49 at room temperature, the return spring 41 cannot be set and cannot function as an overheat prevention sensor. In this way, it is difficult to set the load of the return spring 41 that is subject to the upper and lower limits, and the main valve 46
This is because it becomes more difficult as the load required for sealing is increased.

Further, the opening / closing stroke of the main valve 46 must be ensured by the distance required to supply the gas to the main burner 53. In particular, if the reset is the automatic return type as in the embodiment shown in FIG. The opening / closing stroke of the valve 46, that is, the distance between the temperature-sensitive ferrite 48 and the magnet 49 needs to be small so that the attraction force of the magnet 49 can overcome the return spring 41. Therefore, in the main burner switch 43 with a large flow rate. It is difficult to set the distance.

Further, it is conceivable that a micro switch (not shown) connected in series to the thermocouple circuit of the electromagnetic control valve 23 is provided in place of the switch 20 in FIG. 3 of the conventional example to prevent overheating. The contact resistance of the microswitch increases and the current of the thermocouple circuit decreases due to secular change or the like, which deteriorates the valve opening performance of the electromagnetic control valve 23 and causes a problem such as ignition failure.

According to the embodiment shown in FIG. 1 described above, the sensor section 10 which senses the pot bottom temperature and causes a predetermined displacement, and the opening / closing mechanism which is interlocked with the sensor section 10 are provided especially in the gas conduit 6 of the pilot burner 5. By providing the above, it is possible to provide a heating cooker capable of reliably preventing overheating with a simple mechanism. That is, since the overheat detection mechanism and the opening / closing mechanism are integrally formed, and the return spring that causes the displacement also serves as the seal of the pilot valve, the number of parts is small and the structure is simple. Further, since the spring load can be small, the automatic return type configuration as in the present embodiment can be realized, and the user can save the time and effort of resetting the next time to use it, which is convenient. Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments and may be applied to a gas appliance using a pot such as a rice cooker. Needless to say, the present invention can be implemented in various modes without departing from the scope of the invention.

[0014]

As described in detail above, according to the heating cooker of the present invention, the temperature of the pot bottom is detected and the displacement of the sensor portion is transmitted to the pilot valve which may have a small sealing load.
It has an excellent effect that it is possible to surely prevent overheating with a simple mechanism.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a stove as an embodiment.

FIG. 2 is an enlarged view of a main part of FIG.

FIG. 3 is a schematic configuration diagram of a stove according to a conventional example.

FIG. 4 is a schematic configuration diagram showing a reference configuration for comparison with an example.

[Explanation of symbols]

 1, 23, 51 ... Electromagnetic control valve 2, 22, 54 ... Thermocouple 3, 34, 44 ... Main conduit 5 ... Pilot burner 6 ... Pilot gas conduit 7 ... Cooking pot 10, 30, 40 ... Sensor part 11, 31 , 41 ... Return spring 12 ... Pilot valve 13 ... Valve seat 14 ... Original gas conduit 15, 35, 45 ... Pressing spring 16, 36, 53 ... Main burner 17, 37, 47 ... Non-magnetic material cover 18, 38, 48 ... Temperature-sensitive ferrite 19, 39, 49 ... Magnet 20, 43 ... Main switch 21, 46 ... Main valve 32 ... Push rod 33 ... Interlocking rod

Claims (1)

[Claims] 1. A main burner that burns fuel gas, a pilot burner that branches and burns from a gas flow path of the main burner, a thermocouple that generates electromotive force by heating by a combustion flame of the pilot burner, In a heating cooker equipped with an electromagnetic control valve that closes the main gas passage to the pilot burner and stops combustion when the electromotive force of the thermocouple drops below a predetermined value, A sensor part that comes into contact with the bottom surface and is displaced when reaching a predetermined pan bottom temperature, and a pilot valve that closes the gas flow path of the pilot burner that heats the thermocouple in conjunction with the displacement of the sensor part are provided. Cooker characterized by.