JPH01265479A - Cooker - Google Patents

Abstract

PURPOSE:To make it possible to increase the wattage at the time of cooking and to prevent radio interference at the time of keeping warmth by heating a pan by induction at the time of cooking such as of boiling rice or the like and by energizing a heater at the time of keeping warmth. CONSTITUTION:When a cooking switch is pressed, a triac 16 is turned off to de-energize a heater 15, an inverter control circuit 10 is driven to oscillate an inverter circuit 9 and a high frequency dc current is supplied to an induction coil 2. When the temperature at a temperature sensor element 12 reaches a cooking finish temperature, a signal according to the temperature is issued to the circuit 10 to stop the oscillation of the circuit 9. When the temperature at the element 12 lowers below a warmth-keeping temperature, the triac 16 is turned on the energize the heater 15 to keep warmth. This constitution makes it possible to cook with an intense heat without limiting wattage and to prevent radio interference at the time of keeping warmth.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a cooking device such as a jar rice cooker or a pressure cooker for cooking food such as rice, water, etc. and keeping it warm.

2. Description of the Related Art Conventional cooking devices of this type include, for example, the Utility Model No. 53-1
Like the rice cooker shown in Publication No. 64964, the pot is heated by induction using two induction coils installed on the side and bottom of the pot, and AC power is applied to each induction coil one by one. There was one in which a pot was removably placed on top of a hot plate having an electric heater, and the heat of the electric heater was transferred from the hot plate to the bottom of the pot to cook rice.

Problems to be Solved by the Invention The rice cooker configured as described above requires a switch to switch the induction coil, and since the oscillation voltage of the induction coil may reach eooV to 8oov, the withstand voltage between the contacts of the switch is Also, something expensive was needed. In addition, since high-frequency current is passed through the induction coil, noise is emitted outside the device, and in this case, the time for cooking rice is relatively short, so there is not much actual damage.
If the induction coil is used to heat the pot while it is being kept warm, it will last all day, which can cause real damage. Therefore, it required filling with large coils and capacitors, making it expensive. However, the watt density per unit area of electric heaters is too high, and if a foreign object such as a grain of rice gets between the pot and the electric heater, the heating plate will melt, creating a risk of fire or burns. , the capacity of the electric heater is 600W ~ 1o
I could only do it up to oow.

In this case, if the capacity of the electric heater was increased to 1ooOW or more, the heating plate would be made larger and the watt density would be lowered, so there was no choice but to make a rice cooker with a larger diameter.

An object of the present invention is to provide a cooking device that solves these problems.

Means for Solving the Problems In order to solve the above problems, the cooking device of the present invention includes a pot for storing food to be cooked, water, etc., an induction coil for induction heating the pot, and an alternating current applied to the induction coil. An inverter circuit that applies voltage, a heater that heats the pot, and drives the inverter circuit when cooking food, water, etc. in the pot, and energizes the heater when keeping it warm after cooking. It is constructed by a control means to

Function According to the above configuration, when cooking such as rice, the pot is heated by induction using the induction coil.
It is not limited to 00W, but the wattage can be increased, which allows cooking such as rice with strong heat, making it possible to cook delicious rice. Furthermore, since the heater is energized to perform the heat retention operation during heat retention, it is possible to eliminate noise caused by induction heating. As described above, according to the structure of the present invention, it is possible to cook with a simple structure and with strong heat, and since heat is kept by the heater, there is no noise, and the cooker is easy to use. It is something that can be provided.

EXAMPLE Hereinafter, an example of the present invention will be described based on FIGS. 1 to 3.

FIG. 1 shows a circuit diagram of a rice cooker according to an embodiment of the present invention, and FIG. 2 shows a sectional view of the same rice cooker.
is a pot for storing rice, water, etc. This pot 1 is heated by induction by an induction coil 2, and this induction coil 2 is located at the bottom and lower side of the pot 1 and is arranged to heat the pot 1 evenly. It is set up.

3 is a diode bridge that performs full-wave rectification of the AC power source 4, and an input capacitor 6 is connected to the output that has been full-wave rectified by this diode bridge 3.

Reference numeral 6 denotes a resonant capacitor, which is connected in parallel with the induction coil 2. 7 is a transistor, this transistor 7
The collector is connected to the induction coil 2, and the series circuit of the transistor 7 and the induction coil 2 is connected in parallel to the input capacitor 5. A diode 8 has a cathode connected to the collector of the transistor 7 and an anode connected to the emitter of the transistor 7. In addition, the input capacitor 6, the resonant capacitor 6, the transistor 7, and the diode 8 form an induction coil 2.
An inverter circuit 9 is configured to supply high-frequency alternating current to. 1o is an inverter control circuit that controls the inverter circuit 9, and its output is connected to the gate of the transistor 7.

Reference numeral 11 denotes a microcomputer, and this microcomputer 11 is a so-called one-chip microcomputer composed of a CPU, ROM, RAM, input/output ports, and the like. Reference numeral 12 denotes a temperature sensing element attached to the center of the bottom of the pot 1, and this temperature sensing element 12 is connected to an input port of the microcomputer 11 via an A/D converter 13. As a result, the temperature signal from the temperature sensing element 12 is converted into a binary code and read into the microcomputer 11.

14 is a rice cooking switch, and this rice cooking switch 14 is controlled by the microcomputer 1 to determine whether it is pressed or not.
1 is entered. A heater 16 is located on the side of the pot 1 and heats the pot 1 from the side. 16 is bidirectional 3
This triac 16 is a terminal thyristor (hereinafter referred to as a triac), and the signal from the output port of the microcomputer 11 is input to the gate via the resistor 17.
Controls energization to the heater 16. 18 is a DC power supply for operating the circuit described above.

Here, the inverter control circuit 10 is configured to receive a signal from the output port of the microcomputer 11 and cause the inverter circuit 9 to oscillate.

Next, the operation of this rice cooker with the above configuration will be explained.

FIG. 3 shows a flowchart of the program stored in the ROM in the microconbeater 11, and its operation will be explained according to the steps of the program shown in this flowchart.

First, in step 1, it is determined whether the rice cooking switch 14 has been pressed, and if it has not been pressed, the process proceeds to step 2. In step 2, it is determined whether the temperature of the thermosensor 12 is higher than the heat retention temperature, and If it is higher than the temperature, the triac 16 is turned off in step 3 to stop energizing the heater 16, and the process returns to step 1. If the temperature of the temperature sensing element 12 is lower than the heat retention temperature in step 2, the triac 16 is turned on in step 4 to energize the heater 15, and the process returns to step 1.

Next, in step 1, if it is determined that the rice cooking switch 14 has been pressed, in step 6, the triac 16 is turned off to stop power supply to the heater 15, and the inverter control circuit 10 is further driven to is oscillated to supply a high frequency alternating current to the induction coil 2, and the process proceeds to step 6. In step 6, a drive signal is output to the inverter control circuit 10 according to the temperature of the temperature sensing element 12, and the process proceeds to step 7. In step 7, it is determined whether the temperature of the thermosensor 12 has reached the rice cooking completion temperature. If it has not reached the rice cooking completion temperature, the process returns to step 6. If it has reached the rice cooking completion temperature, a signal is output to the inverter control circuit 1o in step 8, and the inverter The oscillation of the circuit 9 is stopped, the supply of high frequency alternating current to the induction coil 2 is stopped, and the process returns to step 1.

In this way, when rice is cooked, the induction coil 2 heats the pot 1 by induction, so the rice can be cooked with strong heat, and when the rice is kept warm, the heater 15 heats it, so no noise is generated.

In the above embodiment π, the heater 15 is located on the side surface of the pot 1, but it may also be provided at the bottom of the pot 1 near the induction coil 2, and the location where it is installed is not limited. do not have.

Effects of the Invention As is clear from the description of the above embodiments, according to the present invention,
When cooking rice, etc., the pot is heated by induction using a single wound induction coil, so it uses 1000W like an electric heater.
As a result, the wattage can be increased, so you can cook rice with strong heat and cook delicious rice. Moreover, since the heater is energized only to carry out the heat-keeping operation during the heat-keeping operation, it is possible to eliminate noise caused by induction heating.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram of a rice cooker showing one embodiment of the present invention;
The figure is a sectional view of the rice cooker, and FIG. 3 is a flowchart showing an example of a program of the rice cooker. 1...Pot, 2...Induction coil, 6...
...Input capacitor, 6...Resonance capacitor,
7...Transistor, 8...Diode, 9...Inverter circuit, 16...
Heater, 16... Bidirectional 3-terminal thyristor. To death emotion be>he 臥 concave - 1- value Figure 2 Figure 3

Claims (1)

[Claims] A pot that stores food to be cooked, water, etc., an induction coil that heats the pot by induction, an inverter circuit that applies alternating current to the induction coil, a heater that heats the pot, and a pot that accommodates the food and water in the pot. A cooking appliance comprising a control means that drives the inverter circuit when cooking water or the like, and energizes the heater when keeping it warm after cooking.