JP2000300425A - Electromagnetic induction heat type rice cooker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make fluffy and delicious cooked rice without having cores by uniformly and strongly heating inner parts of an inner pot in a rice cooker to boil rice by electromagnetic induction heating. SOLUTION: An inner container 2 is installed inside a main body 1 of this rice cooker, an inner pot 4 is detachably contained in the inner container 2, an induction heating coil 6 spirally formed on an outer bottom surface of the inner pot 4, and plural coil units 5A, 5B, 5C and 5D comprising several ferrite rods 7, etc., roughly radially provided on a lower surface of it are installed, and the plural coil units 5A, 5B, 5C and 5D are separately energized to strongly heat the respective parts, thereby insufficient heating is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic induction heating type rice cooker with improved rice cooking heating.

[0002]

2. Description of the Related Art As shown in FIGS. 4 and 5, a conventional electromagnetic induction heating rice cooker has a spiral induction heating coil 10 provided on almost the entire outer bottom surface of an inner pot 4 for storing rice and water. A coil unit 12 composed of several rod-shaped ferrites 11 and the like provided radially on the lower surface of the coil 10 is provided.

In this rice cooker, an induction heating coil 1 is provided.
When electricity is applied to 0, a magnetic field is generated at the bottom of the inner pot 4 to cause an electromagnetic induction phenomenon, and the bottom of the inner pot 4 generates heat. Since the magnetic field at this time is concentrated on the upper part of the ferrite 11, the heating of the bottom part of the inner pot 4 corresponding to the upper part of the ferrite 11 becomes stronger, and the heat is transmitted from the side of the inner pot 4 as shown by arrow A in FIG. The rice is cooked by creating a convection that entrains in the center.
(For example, JP-A-6-86631)

[0004]

In the above-mentioned conventional rice cooker, as shown in FIG. 5, the heat generated at the bottom of the inner pot 4 always causes convection from the side of the inner pot 4 toward the center. Therefore, the heating near the center part a of the inner pot indicated by the dotted line tends to be insufficient.

[0005] To prevent this, conventionally, ferrite 1
1 is moved toward the center of the inner pot 4 or the ferrite 11 itself is extended toward the center of the inner pot 4 so that the magnetic field is concentrated at the center part a of the inner pot 4 so that insufficient heating near the center part a is prevented. However, since the convection of heat is always convection from the side of the inner pot 4 toward the center, insufficient heating near the center a cannot be completely compensated for, and the core remains in the cooked rice. there were.

[0006]

In order to solve the above-mentioned problems, the present invention provides an induction heating coil formed in a spiral shape,
A plurality of coil units made of a plurality of ferrites and the like provided substantially radially on the lower surface are prepared, and these are installed on the outer bottom surface of the inner pot in a well-balanced manner. Due to this, heat convection occurs from a plurality of places in the inner pot corresponding to the plurality of coil units, and the inside of the inner pot is uniformly heated to cook plump delicious rice with no core left. .

[0007]

According to a first aspect of the present invention, an inner container is installed in a rice cooker main body, an inner pot is removably accommodated in the inner pot, and a spiral is provided on an outer bottom surface of the inner pot. An induction heating coil formed in a shape and a plurality of coil units composed of several rod-like ferrites provided substantially radially on the lower surface of the coil are installed. And eliminates insufficient heating near the center.

According to a second aspect of the present invention, a plurality of coil units can be energized independently of each other, thereby enabling high-heat heating of the portions and eliminating insufficient heating. .

[0009]

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

FIG. 1 is a sectional view of a rice cooker according to an embodiment of the present invention, FIG. 2 is an explanatory view showing the configuration of the coil unit, and FIG. 3 is a convection diagram of heat in an inner pot using the coil unit. is there.

In FIG. 1, reference numeral 1 denotes a rice cooker main body having an upper surface opening, in which an inner container 2 divided into a side surface and a bottom surface is installed. Reference numeral 3 denotes a lid, which covers the upper opening of the rice cooker main body 1 so as to be freely opened and closed. Reference numeral 4 denotes an inner pot. The outer layer is made of an electromagnetic stainless steel material, and the inner layer is made of an aluminum material having good heat conductivity. 5A, 5B,
5C and 5D are independent coil units (four in the figure, but not limited to four), and
It is composed of a spiral induction heating coil 6 and several rod-like ferrites 7 provided substantially radially on its lower surface, and is arranged in a well-balanced manner on the outer bottom surface of the inner container 2 with its central portion removed. . The coil units 5A, 5A
B, 5C, and 5D can be independently energized, and can be attached to the inner container 2 using the ferrite 7 or may be attached by another method. Reference numeral 8 denotes a temperature sensor, which penetrates the center of the bottom
It is in close contact with the center of the bottom of the.

Reference numeral 9 denotes a control board for controlling the whole rice cooking process based on the temperature detected by the temperature sensor 8.

In the above configuration, the rice cooking operation will be described.

First, the polished rice and water are put into the inner pot 4 and stored in the inner container 2 through the opening on the upper surface of the rice cooker body 1.
After closing the lid 3, the power is turned on. When the power is turned on, a current flows through the induction heating coil 6 by the control board 9, thereby generating a magnetic field on the bottom portion of the inner pot 4 and an eddy current flows on the outer layer of the stainless steel layer of the inner pot 4. Then, heat ([eddy current] 2 × [resistance]) is generated due to the resistance of the stainless steel layer, and this heat is transmitted to the inner aluminum layer of the inner pot 4 to start heating rice and water inside. At this time, the magnetic field concentrates on the upper part of the ferrites 7 of the individual coil units 5A, 5B, 5C, and 5D.
Heating of the bottom portion of the inner pot 4 becomes strong, and heat convection occurs from a plurality of places as shown by arrow B in FIG. 3, thereby uniformly heating the entire inside of the inner pot 4.

In the present invention, a plurality of coil units 5
A, 5B, 5C, and 5D can be energized independently, and while one coil unit 5A is energized, the other coil units 5B, 5C, and 5D are stopped. The unit 5B is energized to stop the other coil units 5A, 5C and 5D, and the energization is repeated one after another to heat the rice in the inner pot 4 partially and sequentially along the circumferential direction. Can be heated uniformly.

Further, a plurality of coil units 5A, 5A
By energizing B, 5C and 5D individually, the volume of rice to be heated by one coil unit is reduced. For example, as shown in FIG.
If there are four A, 5B, 5C, and 5D, the volume of rice to be heated by one coil unit is 1/4 of the whole, and the burden of heating is reduced. In other words, high-heat heating is possible, albeit partially. Thereby, the inside of the inner pot 4 can be uniformly heated by high heat, and the rice without the core can be cooked. Note that the number of coil units is not limited to four, and the plurality of coil units can achieve the above-described functions and effects.

[0017]

As described above, according to the present invention, a plurality of coil units composed of an induction heating coil and a ferrite or the like are installed in a well-balanced manner on the outer bottom surface of the inner container, so that a plurality of heat convections can be generated in the inner pot. It can be woken up from a single place, and the rice inside the inner pot can be heated evenly by high heat to cook plump rice with no core left in the center.

In addition, by energizing a plurality of coil units individually and independently, the volume of rice to be heated by one coil unit is reduced, so that the burden of heating per coil unit is reduced. Can be heated over high heat, eliminating insufficient heating and making delicious rice with no core left over.

[Brief description of the drawings]

FIG. 1 is a sectional view of a rice cooker according to one embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a configuration of the coil unit.

FIG. 3 is a convection diagram of heat in an inner pot using the coil unit.

FIG. 4 is an explanatory diagram showing a configuration of a conventional coil unit.

FIG. 5 is a convection diagram of heat in an inner pot using the coil unit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rice cooker main body 2 Inner container 4 Inner pot 5A coil unit 5B coil unit 5C coil unit 5D coil unit 6 Induction heating coil 7 Ferrite

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Naoki Mikami 3-1, Shinjugoji, Kashiwa-shi, Chiba F-term in Hitachi Home Tech Co., Ltd. 4B055 AA02 AA09 BA26 BA63 CA02 CA16 CA71 CB27 CC04 DA02 DB14 DB21

Claims (2)

[Claims] An inner container (2) is installed in a rice cooker main body (1), and an inner pot (4) is removably accommodated in the inner container (2). On the outer bottom surface, a plurality of coil units (5A), including a spirally formed induction heating coil, (6), and several rod-like ferrites (7) provided substantially radially on the lower surface thereof, 5B),
(5C) An electromagnetic induction heating type rice cooker characterized by having ... 2. A plurality of coil units (5A), (5A).
The electromagnetic induction heating type rice cooker according to claim 1, wherein power can be supplied to each of B), (5C) ... independently.