JPH07106172B2 - Electromagnetic heating container - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic heating container such as a rice cooker in which a bottomed cylindrical heating container is heated by high frequency electromagnetic induction heating.

[0002]

2. Description of the Related Art A typical prior art is JP-A-2-1216.
08 publication. This prior art relates to a rice cooker that uses electromagnetic induction heating, such as near the center of the bottom of a bottomed cylindrical pot made of a material with high relative permeability and resistivity such as iron, and from the edge of the bottom to the side. A heating coil is arranged at each of the corners to reach, and a high-frequency current is individually supplied to each heating coil. An eddy current is generated in the pan by the high-frequency magnetic field from the heating coil, and the contents of the pan are heated by the eddy current generating heat in the pan.

With this configuration, uniform heating from the bottom of the pan is realized, and even rice can be cooked evenly, and the current supplied to each heating coil is individually controlled according to the amount of rice cooked. We are trying to cook delicious rice by setting an appropriate amount of heating according to the amount of rice cooked.

[0004]

However, in the above-mentioned prior art, since basically the heating is performed only from the bottom, especially when the amount of cooked rice is large, the pan is separated from the bottom relatively. The heated portion is not always well heated. For this reason, the contents of the pan cannot be heated uniformly, which may result in uneven cooking.

An object of the present invention, the amount of the contents of the container pressurized heat discriminated within a short time after the start of heating, the contents
An object of the present invention is to provide an electromagnetic heating container capable of uniformly heating the contents by heating according to the amount .

[0006]

The electromagnetic heating container of the present invention for achieving the above object is an electromagnetic heating container in which the contents of the heating container are heated by induction heating. , Along the outer surface of the heating container,
A plurality of heating coils arranged in a region extending from the bottom to the side, and for a certain period of time after the start of heating,
High-frequency power is supplied only to the heating coil, and the heating capacity in between
Based on the temperature rise characteristics of the vessel, determine the amount of contents in the heating container.
And means for determining, according to the amount of the contents of the discriminated heating container, is intended to include a power supply control means for supplying a high frequency power by selecting a part or all of the plurality of heating coils.

[0007]

According to the above construction, a plurality of heating coils are arranged along the outer surface of the heating container from the bottom to the side . Heating the bottom for a certain time after starting heating
High-frequency power is supplied only to the coil, and the heating container in between
The amount of contents in the heating container can be determined based on the temperature rise characteristics of the
Be separated. Then , according to the amount of the determined contents, the power supply control means selects a part or all of the plurality of heating coils to supply high-frequency power, so that the heating container of the heating container is selected according to the amount of the contents of the heating container. Heating from the side can also be performed.

[0008]

Embodiments will be described in detail below with reference to the accompanying drawings showing embodiments. FIG. 1 is a cross-sectional view showing the basic structure of an electromagnetic heating type rice cooker which is an embodiment of the electromagnetic heating container of the present invention.
This rice cooker includes a tubular main body 1 and a lid body 2 that is openably and closably connected to the main body 1 by a hinge mechanism 9. In the main body 1, a storage container 4 for detachably storing the rice cooker 3 which is a bottomed cylindrical heating container is provided. The rice cooker 3 is made of a material having a high resistivity and a high relative magnetic permeability such as iron and stainless steel. At the center of the bottom of the storage container 4, the presence or absence of the rice cooker 3 is detected, and the temperature of the rice cooker 3 is detected.
A sensor 5 for detecting the degree is arranged. Contents of rice cooker 3
Detection of the amount of goods (rice amount) is achieved by Rukoto issuing detects the gradient of the temperature rise curve of the rice unit 3 by the sensor 5.
That is, if the heating amount is constant, the temperature rise of the rice cooker 3
The slope of the oven is inversely proportional to the amount of rice cooked. That is, the temperature rise
The steeper the slope of the oven, the less rice is cooked
The amount of rice cooked is large. Therefore, the slope of this temperature rise curve
Is measured for a certain short time after the rice is cooked,
To be determined.

A bottom coil L0, which is a heating coil for inductively heating the bottom of the rice cooker 3, is provided outside the storage container 4 at a portion corresponding to the bottom of the rice cooker 3. Further, on the outside of the storage container 4 and at the portion corresponding to the side portion of the rice cooker 3, the horizontal coils L1, L2, L3, which are heating coils for inductively heating the side portion of the rice cooker 3, are arranged from below. They are arranged in order. Thus, along the outer surface of the storage container 4, the plurality of heating coils L0, L1, L2, L3 arranged in the region extending from the bottom to the side of the rice cooker 3,
High frequency power is supplied from the inverter circuit unit 7 controlled by the control signal from the control unit 6. The output of the sensor 5 is given to the control unit 6 to prevent the high frequency power from being supplied when the rice cooker 3 is not set. Reference numeral 10 is a fan for cooling the inverter circuit unit 7.

When high frequency power is supplied to the coils L0, L1, L2, L3, an eddy current is generated in the rice cooker 3 by electromagnetic induction due to a high frequency magnetic field generated by the coils L0, L1, L2, L3, and this eddy current is generated. This causes the rice cooker 3 to generate heat. The heat generated in the rice cooker 3 heats the contents. FIG. 2 is an electric circuit diagram showing an electric configuration of the electromagnetic heating type rice cooker. The power from the commercial AC power source 20 is rectified by the rectifier 21, smoothed by the choke coil 22 and the smoothing capacitor 23, and supplied to the coils L0, L1, L2, L3 connected in parallel. A power element P0 including a transistor Q0 and a reverse current diode D0 is provided between the bottom coil L0 and the rectifier 21.
And an inverter circuit I0 configured by a parallel circuit of the resonance capacitor C0 and the resonance capacitor C0. Transistor Q0
Is turned on / off at a predetermined cycle by a control signal from the control unit 6.
Turned off. The horizontal coils L1, L2, L3 have the same structure, and the respective parts corresponding to the structure for the bottom coil L0 are shown with the same alphabet with the subscripts 1, 2, 3 of the coils. Each coil L0, L
1, L2, L3 transistors Q0, Q1, Q2, Q3
Are independently controlled by the control unit 6.

Transistor Q0 corresponding to bottom coil L0
When is turned on, a current flows from the bottom coil L0 through the transistor Q0. When the transistor Q0 is turned off from this state, the current flowing in the bottom coil L0 charges the resonance capacitor C0. Due to the discharging of the charged resonance capacitor C0, a reverse current flows in the bottom coil L0. The current in the reverse direction suddenly becomes 0 even after the voltage between both terminals of the resonance capacitor C0 becomes 0.
Cannot be the diode D in the power device P0.
Flow through 0. In this way, the high frequency current is supplied to the bottom coil L0. Horizontal coil L1, L
The operations regarding 2 and L3 are similar.

The control unit 6 controls the bottom for a certain time from the start of rice cooking.
A current is supplied only to the coil L0. And in the meantime
Rice cooked based on the temperature rise curve slope detected by SA5
Determine the amount. Then, according to the amount of cooked rice , the high frequency current is selectively supplied to the bottom coil L0 and the horizontal coils L1, L2 and L3. That is, when the amount of cooked rice is small as shown in FIG. 3, a control signal is applied only to the transistor Q0 so that the high frequency current is supplied only to the bottom coil L0.
No control signal is given to the transistors Q1, Q2, Q3 corresponding to the remaining coils L1, L2, L3. Similarly, when the amount of cooked rice is medium as shown in FIG. 4, for example, the high frequency current is supplied only to the bottom coil L0 and the lateral coil L1, and when the amount of cooked rice is large as shown in FIG.
0 and the horizontal coils L1, L2 and L3 are supplied with high frequency current.

In the rice cooker 3, an eddy current is generated in the vicinity of the coil to which the high frequency current is supplied, and the rice cooker 3 starts from such a portion.
Since the contents of the above will be heated, the bottom coil L0 and the horizontal coils L1, L corresponding to the above-mentioned rice cooking amount
By supplying power to 2 and L3, the contents of the rice cooker 3 can be uniformly heated from the position of an appropriate heat source. In this way, in this embodiment, the plurality of heating coils L0, L1, L2, L3 are arranged side by side in the region extending from the bottom to the sides of the rice cooker 3, and the power supply to each heating coil is adjusted according to the amount of cooked rice. Since the cooking is performed, the contents of the rice cooker 3 can be uniformly heated according to the amount of cooked rice, and delicious rice can be cooked. Moreover, depending on the amount of cooked rice,
Since a high frequency current is supplied to a part or all of the bottom coil L0 and the lateral coils L1, L2, L3, useless power consumption does not occur.

FIG. 6 is an electrical circuit diagram showing the electrical configuration of another embodiment of the present invention. 6, parts corresponding to the respective parts shown in FIG. 2 are designated by the same reference numerals. In this embodiment, both the bottom coil L0 and the lateral coils L1, L2, L3 are connected in series, and each coil L0, L1, L2, L3 is connected to a parallel circuit of an inverter circuit I0 and a resonance capacitor C0. Relays R0, R1, R2, R3 are provided. The control unit 6 is a bottom coil for a certain time from the start of rice cooking.
Above the temperature detected by sensor 5 when heating only with L0
The amount of cooked rice is determined based on the rising curve. And the control unit 6
Are relays R0, R1, R based on the determined amount of cooked rice.
Any one of R2 and R3 is made conductive. That is, when the amount of cooked rice is small, the relay R0 is conducted, and when the amount of cooked rice is medium, for example, the relay R1 is conducted.
When the amount of cooked rice is large, the relay R3 is turned on. With this, a heating state corresponding to the amount of cooked rice can be realized by using one inverter circuit I0 and one resonance capacitor C0, which is advantageous for cost reduction.

The output P of the coil is expressed as P = A × (I · L) ² (where A is a constant), where I is the current flowing through the coil and L is the self-inductance of the coil. Therefore, if the larger the amount of rice cooked, the more coils are connected in series as described above, and the larger the amount of rice cooked, the larger the total self-inductance. it can. As a result, an output corresponding to the amount of cooked rice can be given, good heating can be performed, and delicious rice can be cooked.

The present invention is not limited to the above embodiment. For example, in the above embodiment, the case where one bottom coil and three horizontal coils are provided is taken as an example, but the bottom coil may be divided into two or more, and the number of horizontal coils is The number may be one or a plurality other than three. Further, in the above embodiment, the heating coils L0 to L1 are arranged outside the storage container 4 which stores the rice cooker 3, but the heating coil is arranged on the outer surface of the rice cooker 3 without using the storage container 4. You may.

Furthermore, a temperature sensor for detecting the temperature of the rice cooker 3 in the course of cooking rice may be provided, and the heating coils L0 to L3 may be selectively supplied with electric power according to the output of the temperature sensor. Further, the power supply amount to each of the coils L0 to L3 may be changed discretely or continuously.

[0018] Also, in the above embodiment describes the cooker as an example, the present invention can be widely implemented in an electromagnetic heating vessel other than rice cooker.

In addition, various design changes can be made without changing the gist of the present invention.

[0020]

As described above, according to the electronic heating container of the present invention, the temperature rise characteristic of the heating container within a fixed time after the start of heating is increased.
Based on the sex, the amount of contents of the heating container is determined. So
The heating from the side portion of the heating container is also performed in accordance with the determined amount of the content. Thereby, the contents can be uniformly heated regardless of the amount of the contents in the heating container, and a good heating condition can be realized. Moreover, the heating container
The amount of contents in the
It is performed based on the output of the server 5. Therefore, the amount of contents can be determined
It does not require any special sensor and can be constructed at low cost. Furthermore
In addition, since the high frequency power is supplied to some or all of the heating coils according to the amount of the contents of the heating container, there is no waste of power consumption.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a basic configuration of an electromagnetic heating type rice cooker which is an example of an electromagnetic heating container of the present invention.

FIG. 2 is an electric circuit diagram showing an electric configuration of the electromagnetic heating type rice cooker.

FIG. 3 is a cross-sectional view for explaining the relationship between the amount of cooked rice and the power supply status to the heating coil.

FIG. 4 is a cross-sectional view for explaining the relationship between the amount of cooked rice and the power supply status to the heating coil.

FIG. 5 is a cross-sectional view for explaining the relationship between the amount of cooked rice and the power supply status to the heating coil.

FIG. 6 is an electric circuit diagram showing an electric configuration of another embodiment of the present invention.

[Explanation of Codes] 3 Rice Cooker (Heating Vessel) 5 Sensor 6 Control Unit (Power Supply Control Means) 7 Inverter Circuit Unit L0 Bottom Coil L1 Transverse Coil L2 Transverse Coil L3 Transverse Coil I0 Inverter Circuit I1 Inverter Circuit I2 Inverter Circuit I3 Inverter Circuit R0 relay R1 relay R2 relay R3 relay

Claims (1)

[Claims] 1. An electromagnetic heating container in which the contents of the heating container are heated by induction heating, the heating container being arranged in a region extending from the bottom to the side along the outer surface of the heating container. Multiple heating coils and the heating coils in the bottom area for a certain time after the start of heating.
High frequency power is supplied only to the temperature of the heating container in between.
A hand to determine the amount of contents in the heating container based on the rising characteristics.
And stage, depending on the amount of the contents of the discriminated heating vessel, electromagnetic heating, characterized in that it comprises a power supply control means for selecting a part or all of the plurality of heating coils to power the high-frequency power container.