JPH0449009B2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a heating cooking appliance, and more specifically, a heating device that detects the temperature of the bottom of the pot using a temperature sensor and adjusts the heating power according to the content of cooking. Regarding cooking utensils.

<Prior Art> The above heating cooking appliance is equipped with a temperature sensor made of a thermistor, bimetal, or the like that comes into contact with the center of the bottom of the pot to detect the temperature of the bottom of the pot. Then, the optimum cooking temperature is set according to the cooking content, and when the temperature sensor detects a temperature higher than the upper limit of the fixed temperature range that includes the above cooking temperature, the fire is reduced to low and the temperature lower than the lower limit of the same range is set. When detected, the fire is turned up to high and the fire power is adjusted accordingly. In addition, to prevent fires, we have set up an automatic extinguishing temperature that is a predetermined temperature lower than the ignition temperature based on the ignition temperature of oil, and when this automatic extinguishing temperature is reached, the gas supply to the burner is stopped. (Refer to Japanese Patent Publication No. 60-4734.) <Problems to be Solved by the Invention> In the above-mentioned heating cooking appliance, when there is little content to be cooked, the temperature does not reach the above-mentioned upper limit. When the value is reached, the fire becomes low. However, if you continue heating, the temperature detected by the temperature sensor will rise above the actual temperature of the bottom of the pot, reaching the automatic extinguishing temperature, which may turn off the burner and prevent you from cooking. The reason for this is explained as follows.

Figure 2 shows the flame 16 emitted from the burner 4 by the pot 15.
Indicates the state of being heated to . A temperature sensor 3 is disposed in the center of the burner 4 and comes into contact with the bottom of the pot 15 to measure the temperature of the bottom of the pot. When the flame 16 is a low flame as shown in FIG. 2a, the influence of heat radiation from the flame on the temperature sensor 3 in the center of the burner 4 is stronger than in the case of a strong flame as shown in FIG. 2b, and the detected temperature However, the temperature will be higher than the actual temperature at the bottom of the pot.

Therefore, when heating over low heat, the temperature detected by the temperature sensor will reach the automatic extinguishing temperature first, and if the actual temperature at the bottom of the pot has not yet reached the automatic extinguishing temperature, the fire will be extinguished. This caused problems with cooking.

<Purpose of the invention> This invention was made in view of the above problems, and provides a heating cooking method that can reliably automatically extinguish the flame when the bottom of the pot itself reaches the automatic extinguishing temperature even when heating on low heat. The purpose is to provide equipment.

<Means for Solving the Problems> In order to achieve the above object, the heating cooking appliance of the present invention includes a reference temperature setting means for setting a reference temperature for automatic extinguishing, and a detection temperature of the temperature sensor set to the above-mentioned temperature. The reference temperature is set by an automatic extinguishing means that automatically stops the supply of gas to the burner to extinguish the burner when the reference temperature is reached, and a determination means that determines whether heating is being performed with low heat or high heat. The means is to change the set reference temperature to a higher temperature by a temperature corresponding to the increase in detected temperature due to radiant heat during low heat when heating is being performed on low heat.

<Function> If the heating cooking appliance has the above configuration, the strength of the heating power currently being heated is known by the determination means, and the reference temperature for automatically extinguishing the fire is determined by the temperature detected by the radiant heat when the flame is low. The temperature is changed to a higher temperature by the amount corresponding to the increase. Therefore, even when the temperature sensor receives radiant heat from a low flame and the detected temperature rises above the actual temperature of the bottom of the pot, the fire can be extinguished when the temperature of the bottom of the pot itself reaches the automatic extinguishing temperature.

<Examples> Hereinafter, examples will be described in detail with reference to the accompanying drawings showing examples.

FIG. 1 is a perspective view showing a heating cooking appliance of the present invention. The cooking appliance 1 includes a left stove 2, a right stove 12, and a grill 11. The left stove 2 consists of a burner 4, a trivet 7 on which the pot is placed, a soup pan 6 placed under the trivet 7, etc., and a thermistor 3 as a temperature sensor that detects the temperature of the pot is located in the center of the burner 4, and a thermistor 3 is placed on the trivet 7. It is provided so as to protrude slightly from the top surface. A boiling liquid cover ring 5 is fitted around the burner 4 to prevent spilled liquid from entering the heating cooking appliance 1.

On the front of the left stove 2 side above, there is a stove ignition,
An appliance stopper knob 10 for extinguishing fire and adjusting fire power is provided. Further, on the front side, there are also attached a mode switching knob 8 for instructing the optimum cooking temperature according to the cooking content, and a timer knob 9 for setting the time until the fire is extinguished.

In addition, on the front side of the right stove 12, the right stove 12
Also attached are appliance plug knobs 13 and 14 for igniting, extinguishing, and adjusting the firepower of the grill 11.

FIG. 3 is a block diagram of the automatic fire extinguishing system in the heating cooking appliance of the present invention.

Gas introduction path 26 that guides gas from the gas introduction port 23
is divided into two paths, a gas introduction path 24 and a gas introduction path 25, both of which communicate with the burner 4. A safety valve 21 is provided in the gas introduction path 26,
Control the entire gas supply. One of the two gas introduction paths 24 is provided with a thermovalve 22 that adjusts high heat and low heat. When the thermovalve 22 is open, gas flows through both inlets 24,
Since it is introduced from 25, it will be a strong fire. When the thermovalve 22 is closed, gas flows through one of the inlet channels 25.
Since the gas is introduced only from the source, the amount of gas supplied is reduced and the heat is low.

The safety valve 21 is opened and closed by a coil 27. The coil 27 is connected to the relay switch 31
It is connected to the thermocouple 30 via. The coil 27 maintains the safety valve 21 in an open state by the electromotive force of the thermocouple 30 heated by the flame of the burner 4.

The relay switch 31 is driven by keep-type relay coils 32 and 33. When the relay coil 32 is energized for a moment, the relay switch 31 is opened, and when the relay coil 33 is energized for a moment, the relay switch 31 is closed.

Valve coils 28 and 29 drive the thermovalve 22. When the relay coil 28 is momentarily energized, the thermovalve 22 opens, and when the relay coil 29 is momentarily energized, the thermovalve 22 is closed.

A constant bias voltage is applied to one end of the thermistor 3 from a battery 39 via a switch 40. Since the thermistor 3 shows a voltage drop according to the detected temperature, a voltage corresponding to the voltage drop appears at the other end of the thermistor 3. This voltage is input to comparator 37. On the other hand, D/A converter 3
A plurality of sweep digital signals are inputted to 8 from the microcomputer 36. and,
The D/A converter 38 outputs an analog signal that changes over a predetermined period and a predetermined amplitude range in accordance with the sweep digital signal, and the comparator 37
is input as a reference voltage to the comparison terminal of Therefore, by knowing the digital signal at the time when the output of the comparator 37 changes, the temperature detected by the thermistor 3 can be known.

The microcomputer 36 has a driver 34,
35 and are connected to relay coils 32 and 33, respectively. The excitation signal has already been momentarily supplied to the relay coil 33, and the relay switch 31 is kept in a normally closed state. However, as will be described later, when the temperature detected by the thermistor 3 reaches a temperature corresponding to the set reference value θ, the relay coil 32 is momentarily excited and the relay switch 31 is turned on.
will be opened.

On the other hand, the microcomputer 36 uses the driver 4
1 to the valve coil 28.
The valve coil 28 is momentarily supplied with an excitation signal that opens the thermovalve 22 in the case of high flame. It is also connected to a valve coil 29 through a driver 42, and an excitation signal is momentarily supplied to the valve coil 29 when the thermovalve 22 is closed in the case of low heat.

Microcomputer 36 as determination means
However, if it remembers that the valve coil 28 has been excited, the microcomputer 36 as a setting means sets the value θ ₀ corresponding to the automatic extinguishing temperature as the reference value θ corresponding to the reference temperature for automatically extinguishing the fire.
Set. This automatic extinguishing temperature is, for example, a temperature that is a predetermined temperature lower than the ignition temperature of oil. The predetermined temperature was lowered because
This is because when heating over high heat, the temperature of the contents inside the pot will be slightly higher than the temperature detected at the bottom of the pot, and safety was taken into consideration. Also, valve coil 2
If you remember that 9 was excited, the reference value θ is a value θ ₀ + which is a predetermined value Δθ higher than the above value θ ₀
Set Δθ. The predetermined value Δθ corresponds to the temperature increase due to radiant heat that the thermistor 3 receives from the flame when the flame is low.

Reference numeral 43 denotes a code changeover switch, which is linked to the mode changeover knob 8 to set the cooking temperature. A timer 44 sets the extinguishing time in conjunction with the timer knob 9, and sends a predetermined signal to the microcomputer 36 to close the safety valve 21 when the set time elapses. The microcomputer 36 includes a dry battery 39.
Power is supplied from the switch 40 through the switch 40.

To explain the operation of the above configuration, first, the mode changeover switch 43 is used to set the cooking temperature. Next, when the device stopper knob 10 is pushed and turned, the switch 40 is closed. Along with that,
The safety valve 21 opens and gas is supplied,
An ignition means (not shown) is driven to ignite the burner. The open state of the safety valve 21 is maintained by the electromotive force of the thermocouple 30 heated by the flame.

FIG. 4 is a graph showing the time course of the temperature detected by the thermistor 3 after ignition.

First, a case will be described in which heating is performed in a so-called "temperature control" mode in which the cooking temperature is set. After ignition, the temperature rises due to high heat heating, but when the cooking temperature reaches the cooking temperature set by the mode changeover switch 43, the valve coil 29 is energized, the thermovalve 22 is closed, and the heat becomes low.
FIG. 5 is a flowchart showing the procedure for automatically extinguishing a fire, and the microcomputer 36
In the step shown in the figure, it is determined whether or not it is remembered that the valve coil 29 was energized. In this case, since it is remembered that the valve coil 29 has already been excited, the process proceeds to step and sets a value θ ₀ +Δθ which is a predetermined value Δθ higher than the value θ ₀ corresponding to the automatic extinguishing temperature.

If the amount of food to be cooked is appropriate, the temperature will drop after reaching the cooking temperature. When the temperature reaches a predetermined temperature lower than the cooking temperature, the valve coil 28 is excited, the thermovalve 22 is opened, and the heat is turned on. At the time when the valve coil 28 is energized, the microcomputer 36 erases the memory of the previous energization of the valve coil 29. Then, in the step shown in FIG. 5, it is determined whether or not it is remembered that the valve coil 29 was energized. In this case, since we do not remember that the valve coil 29 was energized, we proceed to step and set the value θ ₀ corresponding to the automatic extinguishing temperature.
Thereafter, the above process is repeated, and the detected temperature repeatedly rises and falls as indicated by the broken line in the figure.

However, if the amount of food to be cooked is small, the heat capacity is small, so even when the heat is switched to low, the temperature continues to rise as shown by the solid line in the figure. As mentioned above, the microcomputer 36 has already set the value θ ₀ +Δθ when the heat is switched to low heat, so when the temperature rises and the thermistor 3 detects a temperature corresponding to the above value θ ₀ +Δθ, Relay coil 32 is momentarily energized and relay switch 31 is opened. the result,
The current flowing through the coil 27 is immediately cut off, the safety valve 21 is closed, the gas supply is cut off, and the fire is automatically extinguished. At the time when this automatic extinguishing is performed, the temperature of the bottom of the pot is almost at the automatic extinguishing temperature.

In addition, when heating in manual mode without setting the cooking temperature, heating is performed only with high heat,
The temperature continues to rise as indicated by the dashed line in the figure. Since the microcomputer 36 does not remember that the valve coil 29 was excited, it sets a value θ ₀ corresponding to the automatic extinguishing temperature. Therefore,
Once the automatic extinguishing temperature is reached, follow the steps above.
The safety valve 21 is closed and automatic extinguishing is performed.

It should be noted that the present invention is not limited to the above-mentioned embodiments. For example, the opening and closing stages of the thermovalve 22 can be set to three or more stages, and the reference value for automatically extinguishing the fire can be switched based on a certain stage. Various design changes may be made without departing from the gist of the invention.

<Effects of the Invention> As described above, the present invention allows the reference temperature for automatic extinguishing to be set higher when heating on low heat by an amount corresponding to the increase in detected temperature due to radiant heat during low heat. It has the unique effect of being able to automatically extinguish the fire when it reaches the actual automatic extinguishing temperature.

[Brief explanation of the drawing]

Figure 1 is a perspective view of the heating cooking appliance of the present invention, Figure 2 is a diagram explaining the heating state of the bottom of the pot, Figure 3 is a block diagram of the automatic fire extinguishing system, and Figure 4 shows the transition of detected temperature after ignition. The graph shown in FIG. 5 is a flowchart showing the automatic fire extinguishing procedure. 1...Heating cooking utensil, 3...Temperature sensor, 4...
...Burner, 36...Microcomputer constituting determination means and setting means.

Claims (1)

[Claims] 1. A heating cooking appliance in which a temperature sensor for detecting the temperature at the bottom of the pot is installed in the center of the burner and the firepower is adjusted based on a preset cooking temperature depending on the cooking content, for automatic extinguishing. a reference temperature setting means for setting a reference temperature of the burner; an automatic extinguishing means for automatically stopping gas supply to the burner and extinguishing the burner when the temperature detected by the temperature sensor reaches the reference temperature; and a determination means for determining whether heating is being performed on high heat, and the reference temperature setting means detects the set reference temperature using radiant heat during low heat when the determination means determines that heating is being performed on low heat. A heating cooking appliance characterized by changing the temperature to a higher temperature in response to a rise in temperature.