JPH08224163A - Cooking container for electromagnetic induction heating cooker - Google Patents

Abstract

PURPOSE: To conduct heat generated by a heat generating layer member when it is heated into a container effectively and nearly uniformly. CONSTITUTION: A cooking container 10 comprising a container body 25 consisted of a non-magnetic metal material with high thermal conductivity, such as aluminum and the like, and a heat generating layer member 26 consisted of a magnetic metal material such as ferrite based stainless steel, disposed on the bottom outer face of the container body 25, wherein the thickness T of the container body 25 is made greater than the thickness t of the heat generating layer member 26, and a plurality of convex 27 is formed on the heat generating layer member.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a cooking container used in an electromagnetic induction heating type cooker.

[0002]

2. Description of the Related Art In recent years, there has been provided an electromagnetic induction heating type cooker which uses an induction coil as a heating means and heats a cooking container by electromagnetic induction by the induction coil to cook rice or the like.

A cooking container used in such an electromagnetic induction heating cooker includes a container body made of a non-magnetic metal material,
The heat generating layer member made of a magnetic metal material is provided on the outer surface of the lower portion of the container body to form a composite structure.

Then, an eddy current is generated in the heating layer member made of a magnetic metal material by the induction coil, and the container body is heated by the heat generated by the heating layer member based on this eddy current to cook the contents therein. ing.

As the material of the container body, aluminum or the like having excellent thermal conductivity is used in order to efficiently transfer the heat of the heat generating layer member to the entire cooking container, and the material of the heat generating layer member is ferritic stainless steel. Etc. are used.

The cooking container having such a structure is formed by pressing a clad material obtained by joining an aluminum plate and a stainless plate into a predetermined container shape, or by spraying a magnetic metal material on the outer surface of the aluminum container body. Manufactured by the method.

[0007]

However, in such a conventional cooking container, the thickness of the container body is too thin or, conversely, too thick with respect to the thickness of the heat generating layer member made of a magnetic metal material. Therefore, it is difficult to effectively and uniformly conduct the heat generated when the heat generating layer member generates heat to the container body.

The present invention has been made by paying attention to such a point, and an electromagnetic induction heating type cooker capable of effectively and almost uniformly conducting the heat when the heat generating layer member generates heat to the container body. To provide a cooking container.

[0009]

In order to achieve such an object, the present invention provides a container body made of a non-magnetic metal material such as aluminum having good heat conduction, and a lower outer surface of the container body. A cooking container composed of a heating layer member made of a magnetic metal material such as ferritic stainless steel, wherein the thickness of the container body is made thicker than the thickness of the heating layer member,
In addition, a plurality of convex portions are formed on the heat generating layer member. And in the invention according to claim 2,
The thickness T of the container body is approximately 4 to 1 of the thickness t of the heat generating layer member.
It is set as 0 times.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows an electromagnetic induction heating type cooker configured as a rice cooker, which is denoted by reference numeral 1
Is an outer frame, and an inner frame 2 formed of synthetic resin in a cylindrical shape with a bottom is housed in the outer frame 1. The inner frame 2 integrally has a flange portion 3 on the outer periphery of the upper part, and the flange portion 3 is locked to the opening edge portion of the upper end of the outer frame 1, and the inner frame 2 is locked inside the outer frame 1 by this locking. It is supported.

Induction coils 4 and 5 are attached to the outer bottom surface and the lower portion of the outer surface of the inner frame 2, and the induction coils 4 and 5 are covered with a coil cover 6. An opening 7 is formed in the center of the bottom surface of the inner frame 2, and a pan sensor 8 is attached to the center of the bottom surface of the coil cover 6. The pan sensor 8 is attached to the inner bottom of the inner frame 2 through the opening 7. It is protruding.

Inside the inner frame 2, a cooking container 10 serving as a rice cooking pot is removably housed. A flange 11 that bends outward is integrally formed at the opening edge of the upper end of the cooking container 10, and the flange 11 is attached to the inner frame 2.
The cooking container 10 is supported in the inner frame 2 by being hung on the opening edge of the upper end of the cooking container 10. A predetermined gap is secured between the outer surface of the cooking container 10 and the inner surface of the inner frame 2.

A lid 12 is rotatably attached to the upper surface of the outer frame 1 via a hinge (not shown).
A lid packing 13 and an inner lid 14 are attached to the lower surface of the cooking container 10, and the opening at the upper end of the cooking container 10 is opened and closed by the inner lid 14.

The inner lid 14 is formed with a plurality of small holes 15 for letting out the steam in the cooking container 10, and the lid 12 is provided with a steam port 16 for discharging the steam to the outside. Further, the lid 12 is provided with a lid heater 17 for heating the lower surface of the lid 12 and a lid sensor 18 for detecting the temperature of the lower surface. Further, a body heater 19 is provided in the middle part of the outer periphery of the inner frame 2.

A control board 20 is provided on the inner bottom of the outer frame 1, and an inverter circuit for supplying a high frequency current to the induction coils 4 and 5 is provided on the control board 20. A cooling fan 22 driven by a motor 21 is provided on the inner bottom portion of the outer frame 1, and an intake port 23 is formed on the bottom surface of the outer frame 1 so as to face the cooling fan 22.
An exhaust port 24 is formed in the lower part of the side surface of the.

By the rotation of the cooling fan 22, the air outside the outer frame 1 is sucked into the outer frame 1 through the intake port 23, and this air is blown toward the control board 20. The control board 20 is cooled.

The cooking container 10 is composed of a container body 25 made of a non-magnetic metal material and a heating layer member 26 made of a magnetic metal material provided in a portion extending from the bottom surface of the container body 25 to the lower side surface. .

A heating layer member 2 made of a magnetic metal material
6 is opposed to the induction coils 4 and 5 provided in the inner frame 2 at a predetermined interval, and the pan sensor 8 is in contact with the central portion of the outer bottom surface of the cooking container 10 for cooking by the pan sensor 8. The temperature of the container 10 is detected.

At the time of cooking, a high frequency current is supplied to the induction coils 4 and 5 by the inverter circuit of the control board 20, and an alternating magnetic field is generated in the induction coils 4 and 5 by the high frequency current. Cooking container 1 to be placed
Eddy current flows through the heating layer member 26 of 0, Joule heat due to this eddy current causes the heating layer member 26 to generate heat, and this heat is conducted to the container body 25, whereby the contents in the cooking container 10 are
That is, rice and water are heated.

The temperature of the cooking container 10 is sequentially detected by the pan sensor 8, and the heating amount of the cooking container 10 is adjusted according to a preset control sequence according to the detected temperature, and the rice cooking and the heat retention are performed by this adjustment. .

As the non-magnetic metal material forming the container body 25 of the cooking container 10, for example, aluminum having good heat conduction and light weight is used, and as the magnetic metal material forming the heat generating layer member 26, for example, ferritic stainless steel ( SUS4
30) is used.

As shown in FIG. 2, the heat generating layer member 26 has a substantially dish shape, and a plurality of bead-shaped convex portions 27 ... Are formed in the lower portion thereof. These protrusions 27 are formed in an annular shape centered on the center point of the bottom surface of the heat generating layer member 26.

The heat generating layer member 26 is embedded in the portion extending from the outer bottom surface of the container body 25 to the lower portion of the side surface so that the outer surface of the heat generating layer member 26 is exposed to the outer surface of the cooking container 10, and integrally joined to the container body 25. Has been done. The heating layer member 2
The peripheral portion of the upper end of 6 is embedded in the meat of the container body 25.

When the thickness of the container body 25 is T and the thickness of the heat generating layer member 26 is t at the portion where the heat generating layer member 26 and the container body 25 are joined, the thickness T is about the thickness t. Four
It is 10 times. The thickness T ′ of the side surface portion of the container body 25 where the heat generating layer member 26 is not joined is slightly smaller than the thickness T of the portion where the heat generating layer member 26 is joined, and is 1 / 3T to 2 / 3T.
Has become.

The flange portion 11 of the cooking container 10 is formed integrally with the opening edge portion of the upper end of the container body 25 so as to extend outward substantially horizontally. The connecting portion 28 between the flange portion 11 and the side surface of the container body 25 has an arc shape, and the radius R of this arc is about 2 to 4 times the thickness T '.

The cooking container 10 is manufactured by a molten metal forging method. In this molten metal forging method, a lower mold a and an upper mold b are used as shown in FIG. The lower mold a has a concave portion c having a shape corresponding to the outer shape of the cooking container 10, and the upper mold b has a convex portion d having a shape corresponding to the inner shape of the cooking container 10.

First, a heat generating layer member 26, which is formed in a predetermined shape by previously pressing a magnetic metal material such as ferritic stainless steel, is arranged on the inner bottom of the recess c of the lower mold a, and the heat generating layer is also formed. A bonding layer 26a is provided on the upper surface of the member 26 by spraying iron or the like.

In this state, molten aluminum as a material of the container body 25 is poured into the recess c of the lower mold a.
Next, the convex part d of the upper mold b is pushed into the concave part c of the lower mold a with a predetermined pressure to pressurize the aluminum to mold the container body 25. Then, the molten aluminum is solidified. As a result, the cooking container 10 in which the heating layer member 26 is integrally joined to the container body 25 is completed.

After the cooking container 10 is manufactured by the molten metal forging method, the inner surface of the cooking container 10 is roughened by blasting with an alumina grid or the like, and the roughened inner surface is coated with FEP resin. The coating film is dried in an air oven, a PFA resin is coated on the coating film, and the coating film is dried to form a non-adhesive coating layer on the entire inner surface of the cooking container 10.

The outer surface of the cooking container 10 is roughened by blasting with an alumina grid or the like, and then coated with a paint mainly composed of a polyether sulfone resin and a PTFE resin. Dry to form a coating layer for rust prevention.

In the cooking container 10 having such a structure, the thickness T of the container body 25 at the portion where the heating layer member 26 and the container body 25 are joined is about 4 with respect to the thickness t of the heating layer member 26. 10 times, and therefore the heating layer member 2
The heat generated when 6 heats up is effectively and almost uniformly conducted to the container body 25, so that there is no heating unevenness during cooking and it is possible to cook fluffy delicious rice.

Here, the following measurement test was conducted in order to confirm the heating efficiency of the cooking container. This measurement test
As shown in FIG. 4, the cooking container A has a relationship between the thickness T of the container body 25 and the thickness t of the heat generating layer member T = 8t.
(Invention) and a cooking container B (comparative example) in which T and t are almost the same are prepared, and the same amounts of rice and water are contained in these cooking containers A and B, respectively, and in this state, the heating layer is formed. The member is made to generate heat, and this heat is conducted to the container body to heat the rice and water, and when the temperature of one point in the cooking containers A and B reaches 100 ° C., the whole inside of the container The temperature distribution state of is measured.

As a result of this measurement, in the cooking container B (comparative example), the temperature distribution inside the container was high in the lower part and low in the upper part, and the difference was relatively large. In the container A, the temperature distribution inside the container A is almost uniform over the entire area,
It can be seen that the heat of the heat generating layer member is effectively and substantially uniformly conducted to almost the entire container body.

FIG. 5 shows the case of another measurement test. In this measurement test, the thickness T of the container body is compared with the thickness t of the heating layer member.
Creates various different cooking containers, stores a predetermined amount of rice and water in each cooking container, and determines the positions of three points A, B, and C from the bottom, and the internal temperature is 100 at the point A. The difference between the temperature at point A and the temperature at other points B and C was measured when the temperature reached ℃. As can be seen from the results of this measurement test, when the thickness T of the container body is sufficiently larger than the thickness t of the heat generating layer member, the temperature difference in the cooking container becomes small.

This is because if the thickness T is smaller than the thickness t, when the heat of the heating layer member is transferred to the bottom of the container body, the heat quickly exchanges heat with the water inside. However, if the thickness T is sufficiently larger than the thickness t, the heat transmitted to the bottom of the container body is further sufficiently transmitted to the side surface of the container body to heat the entire water in the container.

On the other hand, if the thickness T of the container body 25 is sufficiently large, the so-called molten metal flow of molten aluminum is improved when the cooking container 10 is formed by the molten metal forging method. Poor flow of molten aluminum may cause defects such as cracks and sink marks in the container body 25.
In addition, there is a possibility that the heating layer member 26 may be joined poorly due to insufficient pressurization of the molten aluminum. However, in the cooking container 10 of the present invention, the thickness T of the container body 25 is sufficiently large. Can be prevented.

The connecting portion 28 between the flange portion 11 extending from the opening edge portion of the upper end of the container body 25 and the side surface of the container body 25 has an arc shape, and the radius R of the arc of the connecting portion 28 is , About 2 to 4 of the thickness T'of the side surface of the container body 25
It is twice as much, and for this reason the cooking container 1 is made by the molten metal forging method.
When forming 0, the flow of aluminum from the connecting portion 28 to the flange portion 11 is improved.

The radius R of the arc of the connecting portion 28 and the container body 2
When the relationship between the thickness T'of the side surface of No. 5 and the thickness T'is R <2T ', as shown in FIG. 6 (A), the connecting portion 28 is bent so that the convex portion d of the upper die b is formed during the forging of the molten metal. Even if pressure is applied to the aluminum melted in the above step, the molten aluminum does not reach the area where the flange 11 is to be formed. R> 4
At T ′, as shown in FIG. 6 (B), the bending of the connecting portion 28 becomes too large, and when the flange portion 11 extending substantially horizontally is to be formed, the extending length L thereof is considerably increased. It becomes necessary to increase the material cost, which is economically disadvantageous.

In the embodiment described here, R is about 2 to 4 times T ', and therefore, the aluminum runoff to the portion of the region where the flange portion 11 is to be formed is good,
In addition, the economy is good.

On the other hand, the heat generating layer member 26 is integrally formed by a thin plate of ferritic stainless steel, and therefore, there is a problem such as cracking or peeling due to mechanical shock or thermal shock, which occurs when it is formed by metal spraying. It never happens.

[0041]

As described above, according to the present invention,
The heat generated when the heat generating layer member generates heat can be effectively and almost uniformly conducted to the container body, and therefore, it is possible to cook fluffy and delicious rice without uneven heating during rice cooking.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing the structure of an electromagnetic induction heating cooker.

FIG. 2 is a partially cutaway side view showing a cooking container according to an embodiment of the present invention.

FIG. 3 is a sectional view for explaining a method for manufacturing the cooking container.

FIG. 4 is a diagram for explaining the operation of the embodiment.

FIG. 5 is a diagram for explaining the operation of the embodiment.

FIG. 6 is a diagram for explaining the operation of the embodiment.

[Explanation of symbols]

 10 ... Cooking container 25 ... Container body 26 ... Heating layer member 27 ... Convex portion

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masayuki Onishi 2570, Gosuda, Kamo City, Niigata Prefecture 1 Toshiba Home Techno Co., Ltd.

Claims (2)

[Claims] 1. A container body made of a non-magnetic metal material such as aluminum having good heat conduction, and a heating layer member made of a magnetic metal material such as ferritic stainless steel provided on the lower outer surface of the container body. A cooking container for an electromagnetic induction heating cooker, characterized in that the thickness of the container body is made thicker than the thickness of the heating layer member, and a plurality of convex portions are formed on the heating layer member. 2. The cooking container of the electromagnetic induction heating type cooker according to claim 1, wherein the thickness T of the container body is about 4 to 10 times the thickness t of the heat generating layer member.