JP2000252053A - Induction heating cooker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate dispersion of electric characteristics of a control temperature element and an electric circuit in temperature control heating. SOLUTION: The induction heating cooker is operated in such a way that an actually measured temperature value Ti is inputted to detecting temperature Td detected with a temperature detecting element 31, and a correction value H is obtained from the difference between Td and Ti, stored in a memory circuit 33, and detecting temperature Th obtained by adding or subtracting the correction value H to or from the Td is used as a temperature value in a pan.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an induction heating cooker used in a commercial kitchen or the like.

[0002]

2. Description of the Related Art FIG. 5 is a block diagram of a conventional induction heating cooker. In the figure, 1 is an AC power supply, 2 is a rectifying circuit for rectifying the AC power supply 1, 4 is a heating coil, and 3 is an inverter circuit for supplying a high frequency current to the heating coil 4. 5 is an input current detection circuit, 6 is a power supply voltage detection circuit for detecting the voltage of the power supply supplied from the AC power supply 1, 7
Is a control unit for controlling the energization of the inverter circuit 3 with the power set by the input from the input current detection circuit 5 and the power supply voltage detection circuit 6, 8 is a top plate on which a pot 10 serving as a load is placed, and 9 is a heating coil 4. It is a temperature detecting element which is located above, is on the lower surface of the top plate 8 and measures the temperature of the lower surface of the top plate 8, and the detected temperature is transmitted to the controller 7.

[0003] Reference numeral 11 denotes a temperature detecting element for measuring the temperature inside the pot, which directly measures the temperature of the foodstuff, and the detected temperature is transmitted to the control unit 7. Reference numeral 12 denotes an operation display unit for setting and displaying the temperature of the ingredients in the pot, and the set control temperature is stored in the storage circuit 13. Further, the control unit 7 compares the control temperature set by the operation unit 12 and stored in the storage circuit 13 with the temperature inside the pot measured by the temperature detecting element 11, and the food temperature inside the pot maintains the control temperature. In this way, the inverter circuit 3 is driven and controlled.

The induction heating cooker constructed as described above will be described with reference to FIG.

First, when a heating start operation is performed by the operation unit 12 in Step 1, the process proceeds to Step 2 and the control unit 7 operates the inverter circuit 3 to start heating the pan 10 with a predetermined output. Thereafter, in Step 3, the temperature Td detected by the temperature detecting element 11 is compared with the control temperature Ts stored in the storage circuit 13. If Td is higher, Step 4 is performed.
And the heating is stopped. If Ts is higher, Step 2
And the heating is continued. After stopping the heating, in Step 5, Td is compared with Ts. If the control temperature Ts is higher, S5 is determined.
Returning to Step 2, heating is performed again, and if the detected temperature Td is high, the process shifts to Step 4 to stop heating.

As described above, the control temperature Ts and the detected temperature Td
And heating is controlled so as to maintain the temperature of the food inside the pot 10 by controlling the heating on / off.

[0007]

In the above conventional method,
The following problems are mentioned.

[0008] The thermistor, which is a temperature detecting element, has an error in resistance depending on the temperature range to be measured due to the temperature characteristics of the element. Therefore, if the temperature zone is wide, the error in the detected temperature increases. The control temperature range usually used for cooking is from about 70 ° C. to about 180 ° C., which is high-temperature cooking for tempura and fry, and needs to be 100 ° C. or more. In addition, there is further variation due to variations in circuit constants, electrical fluctuations, and the like.

When the user directly measures the temperature of the food, the temperature may not be equal to the control temperature. Also,
In the case of a device that can display the detected temperature on the operation display unit, the temperature may not be equal to the displayed temperature, which may cause inconvenience or distrust, and may cause a complaint.

[0010]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has a temperature correction function, and inputs a temperature Ti obtained by a thermometer or the like to obtain a true temperature. Is a Ti, the temperature difference between the detected temperature Td of the temperature detecting element and Ti is stored in the storage circuit as a correction value, and the correction value H is added to or subtracted from the detected temperature Td to perform the temperature correction. The detection temperature Th is obtained and Th is used as the detection temperature.

With the above configuration, it is possible to improve the variation in the detected temperature between the airframes and the detected temperature in a desired temperature range with high accuracy.

[0012]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of an induction heating cooker according to an embodiment of the present invention.

An AC power supply 21 and an AC power supply 22 are provided.
A rectifier circuit for rectifying 1, 24 is a heating coil, and 23 is an inverter circuit for supplying a high-frequency current to the heating coil 24. Reference numeral 25 denotes an input current detection circuit, reference numeral 26 denotes a power supply voltage detection circuit for detecting a voltage of a power supply supplied from the AC power supply 21, and reference numeral 27 denotes an inverter using power set by an input from the input current detection circuit 25 or the power supply voltage detection circuit 26 A control unit for controlling the energization of the circuit 23. Reference numeral 28 denotes a top plate on which a pot 30 serving as a load is placed. Reference numeral 29 denotes a temperature detection element which is located above the heating coil 24 and is located on the lower surface of the top plate 28 and measures the temperature of the lower surface of the top plate 28. The information is transmitted to the unit 27.

Reference numeral 31 denotes a temperature detecting element for measuring the temperature inside the pot, which directly measures the temperature of the foodstuff, and the detected temperature is transmitted to the control unit 27. Reference numeral 32 denotes an operation display unit for setting and displaying the temperature of the food inside the pot, and the set control temperature is stored in the storage circuit 33. Further, the operation unit 32 can input a temperature actually measured by a thermometer or the like.

Numeral 34 denotes a correction value calculating circuit. The correction value calculating circuit 34 calculates a correction value from the temperature detected by the temperature detecting element 31 and the actually measured temperature inputted from the operation display unit 32, and calculates a correction value. To communicate.

Next, the operation of this embodiment will be described with reference to FIG.

First, food (for example, tempura oil) is put in the pot 30 and the control display 32 displays the control temperature Ts (Ts = 180).
C.), and a heating start operation is performed (Step 1).

The control section 27 operates the inverter circuit 23 to start heating the pan 30 at a predetermined output (Step Ste).
p2). Thereafter, the temperature T detected by the temperature detecting element 31
d is compared with the control temperature Ts stored in the storage circuit 33 (Step 3). If the detected temperature Td is higher, the heating is stopped (Step 4). If the control temperature Ts is higher, the heating is continued.

After the heating is stopped, the detected temperature Td and the control temperature T
s is compared (Step 5). If the control temperature Ts is higher, the process returns to Step 2 and heating is performed again. If the detected temperature Td is higher, the heating is stopped.

As described above, the control temperature Ts and the detected temperature T
Heating is performed so as to maintain the temperature of the foodstuff inside the pot 30 by comparing the values of d and turning on and off the heating.

Here, the user directly measures the temperature of the food with a thermometer or the like, and if the measured temperature is different from the displayed detected temperature or control temperature, the measured temperature T is used.
i is input to the operation display unit 32. Then, the correction value calculation circuit 34 calculates a correction value H from the temperature detected by the temperature detection element 31 and the actually measured temperature Ti input from the operation display unit 32, and transmits the correction value H to the control unit 27.

Next, a method of calculating the correction value H by the correction value calculation circuit 34 will be described with reference to FIG.

In step 1, the detected temperature Td is compared with the measured temperature input value Ti. If Td is larger, the correction value H is obtained in step 2 by H = Td-Ti, and the minus flag is turned on. Conversely, if Ti is larger, Step
At 3, H = Ti−Td is obtained and the minus flag is turned off. As described above, the correction value H and the minus flag, which is a flag indicating whether the correction value H is to be added or subtracted, are obtained. The correction value H and the minus flag are stored in the storage circuit 33 via the control unit 27.

Next, the temperature correction method will be described with reference to FIG.

The detected temperature Th after the temperature correction is first determined in Step
At 1, it is checked whether the minus flag is on. If it is on, the correction value H is subtracted from the detected temperature Td, and Th = Td−
Find with H. On the other hand, if the minus flag is off, the correction value H is added to the detected temperature Td to obtain Th = Td + H.

The detected temperature Th obtained after the temperature correction obtained as described above is used as a detected temperature for heating by controlling the temperature so as to maintain the control temperature or for displaying the food temperature. As a result, an accurate control temperature can be maintained, and for example, the temperature of the tempura oil or the like is also maintained at 180 ° C., so that delicious cooking can be obtained.

[0028]

As described above, according to the present invention, variation in the detected temperature of the temperature detecting element can be eliminated by obtaining the correction value from the measured temperature input on the operation display unit, and the temperature of the food material can be accurately maintained. , Delicious cooking is possible.

[Brief description of the drawings]

FIG. 1 is a block diagram of an induction heating cooker according to an embodiment of the present invention.

FIG. 2 is a flowchart of temperature control of the induction heating cooker of the present invention and a conventional example.

FIG. 3 is a flowchart showing a temperature correcting means of the present invention.

FIG. 4 is a flowchart showing a temperature correction unit.

FIG. 5 is a block diagram of a conventional induction heating cooker.

[Explanation of symbols]

23: Inverter circuit, 24: Heating coil, 27: Control unit, 31: Pot internal temperature detecting element, 32: Operation display unit,
33: storage circuit, 34: correction value calculation circuit.

Claims (2)

[Claims] A rectifier circuit for converting an AC power supply to a DC power;
An inverter circuit that supplies the DC power to a resonance circuit including a heating coil and a capacitor and generates a high-frequency resonance current in the resonance circuit by the switching element; and changes output power by changing a driving frequency of the switching element according to input power. Control circuit, temperature detecting means for detecting the temperature inside the pot to be heated, input means for setting and selecting the control temperature inside the pot, and displaying the control temperature and the temperature inputted by the temperature detecting means. Display means, and control means for comparing the detected temperature detected by the temperature detecting means with the control temperature set by the input means to adjust the output, and placed on the heating coil by a high-frequency magnetic field generated in the heating coil In the induction heating cooker which heats by the eddy current loss generated in the heated object,
In actual use, the measured temperature measured by the temperature detecting means such as a thermometer is input by the input means, and the difference between the temperature obtained by the temperature detecting means and the detected temperature is used as a correction value to determine the detected temperature in actual use. An induction heating cooker having a function of setting a subsequent detected temperature to a value obtained by increasing or decreasing a correction value with respect to the detected temperature in accordance with the measured temperature. 2. The induction heating cooker according to claim 1, further comprising storage means for storing a correction value which is a difference between the control temperature and the detected temperature and the measured value.