JPS61181092A - Heating cooker - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a cooking device such as an electric stove or a gas stove.

Conventional technology Conventionally, when cooking tempura, the temperature of the oil has a large effect on the cooking result, and for good cooking, the oil temperature 1
Must be set at 180°C. For this reason, in order to cook tempura using a heating cooker such as an electric stove, the user must rely on their experience and intuition, or manually adjust the heat using a thermometer, etc. was.

There are also deep-fried food cookers intended exclusively for use with tempura; the output of the heating means is turned on and off using a thermostat attached to the bottom or side of the oil container, and the temperature is controlled to the temperature set by the thermostat. There was something to do.

Problems to be Solved by the Invention In such conventional techniques, the oil temperature is set at 180°C.
It can be controlled at , Thermal conductivity varies depending on the material of the pot.
There will be a difference in the temperature correlation between the oil temperature and the bottom of the pot. Therefore, when detecting the temperature at the bottom of the pot and controlling the temperature,
Even if you keep the settings constant, the amount of oil will vary depending on the pan you use.
The temperature was different, and it could not be applied to heating cookers like electric stoves. Even when applied, the temperature controlled by the pot changes, making it impossible to accurately control the temperature.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a heating cooking device having a temperature control function that can cook tempura while reducing the variation in set temperature depending on the material of the pot. do.

A heating means for heating the pot, a temperature detection means for detecting the temperature at the bottom of the pot, a degree setting means for manually inputting a temperature setting level from the outside and outputting a setting signal for the temperature to be controlled, heating control means for controlling the output of the heating means so that the temperature set by the setting means and the temperature detected by the temperature detection means are equal; and the temperature detected by the temperature detection means after heating is started. Initial temperature rise slope detection means for detecting the slope of rise; and correction means for correcting the output of the temperature setting means in correlation with the slope of the initial temperature rise to adjust the control temperature; ,
In other words, the material of the pot is detected from the delay in temperature rise that correlates to thermal conductivity, and the set temperature, that is, the temperature that occurs due to the pot material, which is the main cause of the temperature difference between the temperature detection means at the bottom of the pot and the oil temperature. By correcting the difference, temperature accuracy during control is improved.

Effect According to the above-described configuration, after starting heating with the heating means,
The temperature error caused by the pot can be reduced by determining the pot material mainly based on the delay time of temperature rise due to the thermal conductivity of the pot material, and by correcting the settings input from the temperature setting device using the correction means. This improves temperature accuracy.

Embodiments Hereinafter, embodiments of the present invention will be described based on the accompanying drawings. FIG. 1 shows a specific configuration of the present invention. In the figure, 1 is a pot into which oil or the like is put. 2 is pot 1
A heater 3 constitutes a heating control means for heating the pan 1, and a heater 3 constitutes a temperature detection means together with a temperature input means 4.
The temperature sensing element 6 and 6 together constitute the entire temperature setting means, the variable resistor 5 is for inputting the external setting temperature, and the setting input means 6
inputs the set temperature from the resistance value of the variable resistor 6. initial@
The temperature rise slope detection means 7 inputs the temperature signal from the @degree input means 4 and detects the temperature rise slope immediately after the start of heating.
A calculation is performed by inputting the delay information of the temperature increase, and a correction value is added to the set value inputted from the setting input means 6 and output. The output control means 9 constitutes a heating control means, and compares the pot bottom temperature output by the temperature input means 4 with the temperature input by the setting input means 6 and corrected by the correction means 8, so that the comparison values become equal. The temperature rise delay detection means 7 and the output control means 9 are configured to start operation upon input of the start switch 1o. The details of the heating cooking device of the present invention will be explained below.0 Figure 2 shows a conventional temperature control system, in which various pots are changed to adjust the temperature of the oil.
Is there a correlation between time and oil temperature when temperature control is performed? FIG. This FIG. 2 will be explained below.

The conventional control method detects the temperature at the center of the bottom of the pot using a sensor or the like, and adjusts the output so that the detected temperature becomes the set temperature. Therefore, even if the temperature of the detection part is controlled to the set temperature, the detected temperature does not directly detect the oil temperature in the pot, but is the temperature at a distance equal to the thickness of the bottom of the pot, so the actual oil temperature is , as shown in Figure 2, the oil temperature will be different from the setting. For example, when using an aluminum pot and an iron pot, the oil temperature will be lower than the set temperature as shown in 11.12, and if a stainless steel pot with a large heat capacity is used. In this case, the oil temperature becomes higher than the set temperature as shown by 13. Further, the temperature difference between the set temperature and the oil temperature varies depending on the size and shape of the pot, the amount of oil, etc., but it is small compared to the influence of the material of the pot. In other words, the difference between the set temperature and the oil temperature is correlated with the heat transfer at the bottom of the pot, and is almost determined by the material of the pot.The material of the pot is determined and a temperature compensation TE is added depending on the material. By doing so, the accuracy of the oil temperature can be increased.

Next, a method for determining the material of the pot will be explained based on FIG. 3. Figure 3 shows the state where the pot etc. is not heated.
In other words, it is a diagram showing the correlation between the temperature at the center of the lower surface of the pot bottom and time at the initial stage when heating is started from room temperature.

The horizontal axis of the graph shows the passage of time, and heating by the heating means is started from 1=0. The vertical axis shows the temperature at the center of the lower surface of the pot bottom. As is clear from Fig. 3, the temperature rise at the center of the lower surface of the pot bottom immediately after heating starts is caused by the heating means heating the part of the pot bottom closest to the heating means, and the rise in temperature due to this heating occurs in the direction of the surface of the pot bottom. It is transmitted to the center of the lower surface of the bottom of the pot, and the transmission speed varies depending on the material of the pot, so the rise in temperature at the center also correlates with the material of the pot. In other words, if the material is made of a material with good heat conductivity, such as an aluminum pot, the temperature at the bottom of the pot will rise quickly.
A stainless steel pot with poor heat conductivity has a slow temperature rise, and by detecting the rate of temperature rise, the material of the pot can be detected.

That is, the tank bottom cooking device shown in FIG. 1 operates according to the principle described above, and its operation will be explained below.

A user fills the pot 1 with oil or the like and places the pot 1 on the heater 2. In addition, the cooking temperature is input through the variable resistor 5, the start switch 10''fc is turned ON, and a start signal is given to the device to start the operation of the device.When the start switch 1o is turned ○N, it is detected by the temperature sensing element 3. The temperature at the center of the lower surface of the pot bottom thus obtained is given to the output control means 9 via the temperature input means 4, and the temperature at the center of the lower surface of the pot bottom at this time is approximately room temperature. The setting @ degree is input to the correction means 8 via the setting input means 6. At this time, the correction means 8 is not given a correction signal, and the setting @ degree to be input is output to the gold production output control means 9. This output control means 9 compares the temperature input from the temperature input means 4 and the temperature input from the correction means 8, but since the pot bottom temperature from the degree input means 4 is lower than the set temperature from the correction means 8, At the same time, the output control means 9 controls the heater 2 to the maximum output. At the same time, the initial temperature rise slope detection means 7 inputs the pot bottom temperature signal from the temperature input means 4 in response to the signal from the start switch 10, and controls the initial temperature. Detects the differential of the temperature rise. The initial temperature rise slope detection means 7jFi outputs the output correlated to the temperature rise slope to the total correction means 8. That is, when the material of the pot 1 is aluminum etc., the slope is It outputs a dog signal, or a signal with a small slope in the case of stainless steel, etc. Based on this output signal, the correction means 8
Is there a correction to the above settings input? In addition, it is output to the output control means 9. For example, if the material of the pot 1 is aluminum or the like, and the signal indicates a large slope in the output of the initial temperature rise slope detection means 7, the correction means 8 adds a temperature corresponding to ΔT1 in FIG. 2 to the set temperature. In addition, if the pot 1 is made of stainless steel or the like and a signal indicating a small slope is output from the bottom of the initial temperature rise slope detection means, ΔT3 in FIG.
A correction is made by subtracting the temperature corresponding to the set temperature from the set temperature, and the result is output. Initial temperature rise slope detection means 7
After outputting the detected slope of the rise in degrees to the correction means 8, the correction means 8 outputs a temperature obtained by adding correction to the set temperature set by the variable resistor 5. Therefore, the output control means 9 works to compare the corrected set temperature and the temperature detected by the temperature sensing element 3 and control the output of the heater 2 so that the comparison matches, so that it is The temperature of the temperature sensing element 3 becomes stable at the corrected setting @ degrees, and when the temperature of the temperature sensing element 3 stabilizes at the corrected setting temperature, the temperature of the oil in the pot 1 becomes stable. is approximately equal to the set temperature set by the variable resistor 6. In addition, even if the material of the pot changes, the temperature of this oil is corrected by the correction means as explained above, so the temperature of the oil remains the same as the temperature set by the variable resistor 6. .

As described above, according to the configuration shown in FIG. 1, it is possible to configure a high-precision cooking device that can control the oil in the pot to a set degree regardless of the type of pot. Moreover, since the temperature is high, the user can cook with peace of mind.

FIG. 4 shows a specific circuit diagram according to an embodiment of the present invention, in which 21 is an AC power source, 22 is a heater for heating a pot, etc., and 23 is a relay contact for controlling energization to the heater 22. It is turned on and off by the relay coil 24.

26 is a rectifier for inputting AC voltage and supplying DC voltage to each circuit. 26 is a thermistor,
Although not shown in the figure, it is installed to detect the temperature at the center of the lower surface of the bottom of the pot heated by the heater 22,
It exhibits a negative resistance change depending on temperature. 27 is a resistor connected in series with the thermistor 26 and divides the DC voltage; 28 is a variable resistor for externally inputting a set temperature; 29 is a resistor connected in series with the variable resistor 28 and divides the DC voltage; 30 is an A-D converter which inputs a voltage correlated to the temperature detected by the thermistor 26, which is divided by the thermistor 26 and the resistor 27, and outputs a digital signal correlated to this voltage. Further, 31 is an A-D converter, which inputs a voltage that is divided by a variable resistor 28 and a resistor 29 and that correlates to the set temperature that is input from the variable resistor 28, and outputs a digital signal that correlates to this input voltage. This is what is output. The resistor 32 and the switch 33 are connected in series between the DC power sources and are configured to convert an external switch operation into a voltage signal. 34 is the relay coil 2
4 is a transistor for switching the current flowing; 35 is a pace resistor that limits the heart flow based on the transistor 340; 36 is a protection diode for the relay coil 24;
37 includes an input section including input terminals I, , I, and I3, an output section including output terminals, and a storage section for storing various data and programs; It is a microcomputer that has an arithmetic control section that performs various calculations, etc., and the thermistor 26, resistor 27, and A-D converter 30 constitute a temperature detection means and an initial temperature rise slope detection means, and a variable resistor 28 , a resistor 29 and an A-D converter 31 constitute a temperature setting means, and a resistor 35, a transistor 34 and a relay coil 2
4, the relay contact 23, and the diode 36 constitute a heating control means, and the internal storage section and arithmetic control section constitute a correction means.

Figure 5 shows the difference between the set temperature and oil temperature shown in Figure 2, Δ
4 is a graph showing the correlation between T and an experimentally measured value of the slope of the temperature rise at the center of the lower surface of the pot bottom in FIG. 3, that is, the time Ts required for the temperature to rise by 2.5 degrees from the initial temperature.

FIG. 6 is a diagram showing the operation of the microcomputer 37 shown in FIG. 4.

The operation of the embodiment shown in FIG. 4 will be explained below using FIGS. 6 and 6.

The micro clone computer 37 starts from step 41 of the flowchart, and first performs initial settings in step 42.
In this case, each RAM is cleared. Next, in step 43, input terminal work is performed.

The voltage divided by the resistor 32 and the start signal switch 33, that is, when the switch 33 is turned on, the voltage is connected to GND.
If the voltage remains off, the VDD voltage is input, and the input signal is determined in step 44. This discrimination result is VD
If the voltage is D, it is determined that the switch 33 is not turned on, and steps 43 and 44 are repeated until the switch 33 is turned on. When the switch 33 is turned on, the process moves to step 46 and the device begins to operate. Steps 45 to 49 are the differential value of the initial temperature rise of the thermistor 26, that is, the initial temperature T in FIG. 1s of time to rise by 12.5 degrees
It is for measuring. In step 46, a signal obtained by digitally converting the voltage divided by the thermistor 26 and the resistor 27 by the A-D converter 3o is inputted to the input terminal as the detected temperature of the thermistor 26. The input temperature at this time is stored in the storage section of the microcomputer 37 as the initial temperature T0, and at the same time, in step 46, a 1s timer is started to count 1s according to the program of the microcomputer 37, and the output terminal 01
Then, the VDD voltage is outputted and energization to the heater 22 is started. When the output of the output terminal 51 reaches the VDD voltage, a current flows through the resistor 35 to the transistor 34.
As a result, conduction occurs between the collector and emitter of the b transistor 34, current flows through the relay coil 24, and the relay contact 23 closes.Therefore, current flows through the heater 22, heating the pot, and the output from the output terminal 251 is also increased. If the voltage is GND, the base current of the transistor 34 will not flow, so
Relay contact 23 is turned off, so no current flows through heater 22. Next, in step 47, the temperature detected by the thermistor 26 is input as the temperature Ts from the input terminal 11 in the same manner as above, and in step 48, the input temperature Ts is compared with the initial temperature T0+2, 5 degrees. , the temperature of T3 is T. The operations of steps 47 and 48 are repeated until the value is equal to or greater than +2.5deg. During this time, the tli timer is kept UP as time passes. The temperature of the pot and the oil in the pot rises due to heating by the heater 22, and the temperature of the thermistor 2 increases.
When the detected temperature Ts of No. 6 becomes higher than or equal to To+2.5 degrees, the process proceeds to step 49 and the operation of the t8 timer is stopped. At this time, the timer value becomes 18. Note that the tl configured by the program
Although not shown, the i timer is accurate because it counts based on the oscillation of the ceramic resonator and the command cycles of the operating microcomputer 37.

In step 5o, a signal obtained by digitally converting the voltage divided by the variable resistor 28 and the resistor 29 by the A-D converter 31 is inputted as the set temperature T of the variable resistor 28 from the input terminal I2, and in step 51, ET Calculates the 1s time of the initial temperature rise differential value and the set temperature TSET. This calculation is performed by approximation based on the regression line from the experimental data in FIG. 5, and in this example, the regression equation is T, i, = 0.45
2, the correction value is (TSET-T□,)
=180-(0,46xt +162), and the correction calculation formula is the set temperature after correction "H5="SET+18-',5
×ts+. That is, in step 51, the rise time t input in steps 46 to 49 is
8 and the TSET data input in step 50, TH5=T sE 727 +0.9 X t
, and calculate the corrected set temperature "H?5". In step 52, the temperature of the thermistor 26 is inputted as the current temperature Tn in the same way as above, and in step 53, the current temperature T and the corrected set temperature are calculated. The set temperature "H5" is compared, and if the current temperature Tn is low, in step 64, the output of the output terminal ci1 is set to VDD voltage to energize the heater 22 and heat the pot. If the current temperature Tn becomes equal to or higher than the corrected set temperature TH5, the output of the output terminal d1 is set to the GND voltage in step 65, and the heater 22 is de-energized to stop heating the pot. This step 52
By repeating the operations from to 65, the temperature of the thermistor 26 becomes equal to the corrected set temperature TH5 and is stably controlled. As a result, the temperature of the oil becomes the set temperature "SET" set by the variable resistor 28 from the outside of the pot.For example, when using an aluminum pot with a double bottom thickness, the set temperature Even if the temperature is 180″C, the oil temperature is 1
According to the heating cooking apparatus of this embodiment, the rising time tll is 12 seconds, and the set temperature after correction is 192.6°C, which is 12.6 deg from the set temperature.
g Since the temperature at the bottom of the pot is controlled in a high state, the oil temperature remains at approximately 180.6°C.

Almost equal to the set temperature. The same applies to other types of pots. In addition, in the flowchart of Fig. 6,
In addition to repeating steps 52-55, step 5
o to 51 and steps 56 to 57 at the same time, in steps 50 to 51, if the user changes the variable resistor 28 for inputting the set temperature midway through, and in steps 56 to 57, This is to provide a response so that when the user turns off the switch 33 to stop the device, the device can be stopped in step 58.

As described above, according to the embodiment shown in FIG. 4, it is possible to construct a high-performance cooking apparatus that can control the temperature of oil to be equal to the set temperature. Furthermore, this allows the user to easily cook tempura or the like.

In the embodiment shown in FIG. 4, the initial temperature rise differentiating means is a means for detecting the time t8 until the temperature rises by 2.5 degrees after the start of heating, but the present invention is not limited to this. As shown in a diagram similar to Figure 3 in Figure 7, there is also a correlation based on the temperature rise ΔTs after a predetermined period of time after the start of heating, and it is possible to identify the pot. It goes without saying that the same effect can be obtained by finding the differential value of . Further, the heater of the heating means is the same for a stove and a high-frequency heating device that use gas or the like as fuel.

Effects of the Invention As described above, according to the present invention, the temperature of the ingredients in the pot can be controlled to the set temperature in a stable state and with high precision, regardless of the material of the pot, with an extremely simple circuit configuration, and it can be put into practical use. This provides an extremely useful cooking device.

[Brief explanation of drawings]

Fig. 1 is a configuration diagram showing an embodiment of the heating cooking device according to the present invention, Fig. 2 is a correlation diagram of oil temperature and time in a conventional heating cooking device, and Fig. 3 is a diagram showing the relationship between time and the lower surface of the bottom of the pot in the initial stage of heating. FIG. 4 is a specific circuit diagram of an embodiment of the heating cooking device according to the present invention. FIG. 6 is a correlation diagram between the difference between the set temperature and oil temperature and the temperature rise time at startup. Figure 6 is the fourth
FIG. 7 is a flowchart showing the operation of the microcomputer shown in the figure, and is a correlation diagram similar to that of FIG. 3 but with a different correlation. 1...Pot, 2...Heater, 311.・
...g@element, 4...Temperature input means, 5...
...Variable resistor, 6...Setting input means, 7...
. . . Initial temperature rise slope detection means, 8 . . . Correction means, 9 . . . Output control means. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 3
Fig. 4 Fig. 5

Claims (2)

[Claims] (1) A heating means for heating a pot, etc., a temperature detection means for detecting the temperature at the bottom of the pot, and a temperature setting for manually inputting a temperature setting level from the outside and outputting a setting signal for the temperature to be controlled. heating control means for controlling the output of the heating means so that the temperature set by the temperature setting means and the temperature detected by the temperature detection means are equal;
initial temperature increase slope detection means for detecting the slope of temperature rise of the temperature detected by the temperature detection means after heating starts, and correcting and controlling the output of the temperature setting means in correlation with the slope of the initial temperature rise. A heating cooking device comprising a correction means for adjusting temperature. (2) The initial temperature rise slope detection means uses the heating means to
an initial value storage means for temporarily storing the temperature detected by the temperature detection means before or at the time of starting heating of a pot, etc., and a temperature preset to the temperature stored by this initial value storage means. temperature comparison means that compares the added temperature and the temperature detected by the temperature detection means and outputs a signal when the detected temperature of the temperature detection means is higher; and the temperature comparison means that starts timing when the heating starts; 2. The heating cooking apparatus according to claim 1, comprising: a timer for stopping timekeeping in response to a signal; and arithmetic means for performing arithmetic operations on the timekeeping results of the timer means and outputting the results to the correction means.