JPH05253058A - Electrical rice cooking appliance - Google Patents

Abstract

PURPOSE:To allow adaptation to preference of taste from youth to aged men by discriminating cooking rice hard and soft inside a pot in an electrically rice cooking appliance by induction heating using a heating coil. CONSTITUTION:Among first and second heating coils 6 and 7 which supply a high-frequency current with an inverter circuit 10 to heat a pot 3 by induction heating. The first heating coil 6 for heating the bottom surface of the pot 3 is made up of a plurality of heating coil elements 6a-6d. A controller 9 for controlling heating outputs of the heating coils 6 and 7 allows changing of mutual heating outputs of the heating coil elements 6a-6d, thereby discriminating cooking of rice hard and soft by varying the temperature distribution in the pot 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric rice cooker for induction heating using a heating coil.

[0002]

2. Description of the Related Art Conventionally, an electric rice cooker of this type has been disclosed in Japanese Unexamined Patent Publication No.
What was described in the 24988 gazette was general. The configuration will be described below with reference to FIG.

As shown in the figure, the rice cooker main body (hereinafter referred to as the main body) 31 is provided with an accommodating portion 33 for accommodating a pan 32 therein, and the upper portion of the main body 31 is covered with an upper lid 34.
Can be taken out by opening and closing the upper lid 34. The 1st heating coil 35 is arrange | positioned in the position which opposes the central part of the bottom face of the pan 32, and induction-heats the central part of the bottom face of the pan 32. The 2nd heating coil 36 is arrange | positioned in the position which opposes the bottom face outer peripheral part and side surface lower part of the pan 32, and induction-heats the bottom face outer peripheral part and side surface lower part of the pan 32. The first heating coil 35 and the second heating coil 36 are provided along the outer peripheral portion of the pot 32, and the respective heating coils 35, 36 are placed on the support base 37 with a gap therebetween. Ferrite cores 38 that absorb leakage flux are radially provided on the side. The pan detection device 39 detects the presence or absence of the pan 32, and is provided so as to contact the center of the bottom surface of the pan 32. The signal from the pan detection device 39 is input to the control unit 40, which controls the inverter circuit 41 provided at the bottom of the main body 31 that supplies high-frequency current to the first heating coil 35 and the second heating coil 36. In addition to controlling the oscillation, the operation display unit 42 provided on the upper portion of the main body 31 is controlled.

In the above structure, when the pot 32 is inserted into the storage section 33, the pot detection device 39 is activated, and the control section 40 sends a heating start signal to the inverter circuit 41 to enter the heating standby state. Then, when the cooking mode is set by the cooking menu key of the operation display unit 42, the control unit 40 controls the operation of the inverter circuit 41, and the inverter circuit 41 causes the first heating coil 35 and the second heating coil 36 to operate. A high-frequency current is supplied, and the first heating coil 35 and the second heating coil 36 uniformly induction-heat the entire bottom surface and lower side surface of the pot 32, and a sequence according to the amount of rice and water in the pot 32. To cook rice.

[0005]

In such a conventional electric rice cooker, the first heating heater 35 and the second heating heater 36 uniformly induction-heat the entire bottom surface and lower side surface of the pot 32. Therefore, there is a problem in that the rice with almost uniform hardness is prepared in the pan 32 and cannot be matched with a plurality of consumers having different tastes.

The present invention is intended to solve the above problems, and it is an object of the present invention to cook hard and soft rice separately in a pot so that the tastes of young people to old people can be accommodated.

[0007]

In order to achieve the above object, the present invention controls a heating coil for induction heating a pot, an inverter circuit for supplying a high frequency current to the heating coil, and a heating output of the heating coil. And a controller for controlling at least a part of the heating coil that heats the bottom surface of the pot with a plurality of heating coil elements, and the controller can change the heating output between the heating coil elements. That is the means for solving the problem.

[0008]

According to the present invention, the temperature distribution in the pan can be changed by changing the heating outputs of the heating coil elements by the above-mentioned means for solving the problems. When the heating output is large, hard rice is cooked and the heating output is increased. In small areas, you can cook soft rice.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

As shown in the drawing, a lid 2 which is openable and closable is provided on an upper portion of a main body 1, and a pot storage portion 4 for storing a pot 3 is provided in the main body 1.
And an air layer 5 is formed between the pan 3 and the pan storage portion 4. The first heating coil 6 is for induction-heating the bottom surface of the pan 3, is provided on the bottom surface of the pan housing portion 4, and is composed of a plurality of donut-shaped heating coil elements 6a to 6d. A second heater 7 is provided on the outer bottom portion of the pan storage portion 4, and a third heater 8 is provided on the outer side portion thereof. The control device 9 is the first
The oscillating output of the inverter circuit 10 for supplying the high-frequency current to the heating coil 6, the second heating coil 8 and the third heating coil 8 is controlled. The temperature detecting means 11 is a pot storage unit 4.
It is configured to penetrate the hole provided at the bottom of the pot and contact the outer bottom of the pot 3 to detect the temperature of the object to be heated in the pot 3. The ferrite core 12 is arranged below the first heating coil 6 and the second heating coil 7 to prevent the magnetic flux from leaking downward. Similarly, leakage of magnetic flux from the third heating coil 8 is prevented by the ferrite core 13.

As shown in FIG. 2, the control device 9 comprises a control means 14, a switching element driving means 15, a first relay driving means 16, a second relay driving means 17 and a third relay driving means 18. The switching element driving means 15 drives the switching element (not shown) of the inverter circuit 10, and the first relay driving means 16 operates the relay contact 19 to switch the heating output of the heating coil element 6a. And the second relay drive means 17
Is to operate the relay contact 20 to switch the heating output of the heating coil element 13b. The third relay driving means 18 operates the relay contact 21 during heat retention to switch between the first heating coil 6 and the second heating coil 7 and the third heating coil 8. Heating output setting means 2
Reference numeral 2 sets the heating output of the heating coil elements 6a to 6d, which is input to the control means 14 to control the operations of the first relay driving means 16 and the second relay driving means 17. When the relay contacts 19 and 20 are connected to the normally closed contact b, the heating outputs of the heating coil elements 6a to 6d are the same, and when connected to the normally open contact a, the heating output of the heating coil element 6a is The heating output of the heating coil element 6b is small and large. The inverter circuit 10 is operated by the output of the rectifier 25 connected from the commercial power source 23 via the switch 24, and the control device 9 is applied with a voltage from the DC power source 27 connected via the transformer 26.

To explain the operation in the above configuration, the inverter circuit 10 controls the oscillation output by controlling the on-time of the switching element driven by the switching drive means 15. Now, when cooking rice normally, if the heating output setting means 22 is set to "normal cooking", the control means 14 will make the first and second relay driving means 1
6, 17 to connect the relay contacts 19 and 20 to the normally-closed contact b, and the respective heating coil elements 6a to 6a of the first heating coil 6 to
6d has the same heating output and the first from the inverter circuit 10.
Of high frequency current is supplied to the heating coil 6 and the second heating coil 7 in order to induction-heat the pot 3 according to a predetermined sequence,
Cook almost uniform rice in the entire pan 3. When the rice cooking is completed, the control unit 14 shortens the ON time of the switching element by the switching drive unit 15, and the first
The heating output of the second heating coils 6 and 7 is reduced, and the third relay driving means 18 is driven to switch the relay contact 21 at a predetermined cycle, thereby the first heating coil 6 and the second heating coil are switched. Insulation is maintained by 7 and the third heating coil 8.

Next, when changing the cooked rice in the pan 3, the "heated rice" is set by the heating output setting means 22.
When set to 1, the control means 14 connects the relay contacts 19 and 20 to the normally open contact a by the first and second relay drive means 16 and 17, and outputs the heating output of the heating coil element 6a of the first heating coil 6. Is set to be small and the heating output of the heating coil element 6b is set to be large, and a high frequency current is supplied from the inverter circuit 10 to the first heating coil 6 and the second heating coil 7 to induction-heat the pot 3 in a predetermined sequence. To do. At this time, since the heating output of the heating coil element 6a is small in the portion of the pan 3 which is heated by the heating coil element 6a,
The temperature changes as indicated by the broken line in FIG.
Since the heating output of the heating coil element 6b is large in the portion heated by b, the temperature changes as shown by the solid line in FIG. Further, the temperature of the portion heated by the heating coil elements 6c and 6d becomes an intermediate temperature change. As a result, in the cooked rice, the portion heated by the heating coil element 6a is cooked softly and the portion heated by the heating coil element 6b is cooked hard in the pan 3. as a result,
It can be adapted to the taste of young people to old people.

In the above embodiment, the heating outputs of the heating coil element 6a and the heating coil element 6b of the first heating coil 6 are driven by the first relay driving means 16 and the second relay driving means. However, different heating outputs may be used. Further, the number of heating coil elements and the switching method are not limited to those in the above embodiment.

[0015]

As is apparent from the above embodiments, according to the present invention, a heating coil for induction heating a pot, an inverter circuit for supplying a high frequency current to the heating coil, and a heating output of the heating coil are controlled. And a control device, wherein, of the heating coil, at least a portion for heating the bottom surface of the pot is configured by a plurality of heating coil elements, the control device,
Since the heating outputs of the heating coil elements can be changed, it is possible to cook hard and soft rice separately in the pot, and it is possible to cope with the taste of young people to old people.

[Brief description of drawings]

FIG. 1A is a vertical cross-sectional view of an electric rice cooker according to an embodiment of the present invention. FIG. 1B is a perspective view of first and second heating coils of the electric rice cooker.

[Fig. 2] Block circuit diagram of the electric rice cooker

[Fig. 3] Temperature characteristic diagram of the electric rice cooker during rice cooking

FIG. 4 is a vertical sectional view of a conventional electric rice cooker.

[Explanation of symbols]

 3 Pan 6 First Heating Coil (Heating Coil) 6a Heating Coil Element 6b Heating Coil Element 6c Heating Coil Element 6d Heating Coil Element 7 Second Heating Coil (Heating Coil) 9 Controller 10 Inverter Circuit

Claims (1)

[Claims] 1. A heating coil for induction-heating a pot, an inverter circuit for supplying a high-frequency current to the heating coil, and a control device for controlling a heating output of the heating coil,
An electric rice cooker in which at least a portion of the heating coil that heats the bottom surface of the pot is composed of a plurality of heating coil elements, and the control device can change the heating output between the heating coil elements.