JPH0833563A - Cooking container for electromagnetic induction heating type cooker - Google Patents

Abstract

PURPOSE:To provide a cooking container for an electromagnetic induction heating type cooker which enables the joining of a magnetic metal material on the body of the container firmly by a sufficient joining force. CONSTITUTION:This container has a magnetic metal material 26 formed in a plate having a side part joined on a portion from the external bottom surface to the side lower part of the body 25 of the container comprising a nonmagnetic metal material and the side of the body 25 of the container above the upper end rim of the magnetic metal material 26 is inclined by an angle of alpha. The side part 26a of the magnetic metal material 26 is inclined by an angle of betaand beta is 10 deg. while beta>alpha.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention 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,
It has a composite structure with a magnetic metal material provided on the outer surface of the container body.

[0004] An eddy current is generated in the magnetic metal material by the induction coil, and the heat generated by the magnetic metal material based on the eddy current heats the container body to cook the contents therein.

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 magnetic metal material to the entire cooking container, and as the magnetic metal material, ferritic stainless steel or the like is used. It is used.

As a method for producing such a cooking container, a method is known in which a clad material obtained by joining an aluminum plate and a stainless plate is pressed and processed into a predetermined container shape. Only a cooking container having an inner surface and an outer surface having similar shapes can be molded, which causes a restriction in shape.

There is also known a method of forming a container body from an aluminum casting or an aluminum plate and spraying a magnetic metal material such as stainless steel on the outer surface of the container body. In this case, the film thickness of the magnetic metal material layer is formed. It is difficult to finish the coating uniformly, and the sprayed surface is rough.

On the other hand, when the magnetic metal material is provided only on the outer bottom surface of the container body, the side surface of the container body is insufficiently heated and uneven heating occurs during cooking. Therefore, it is considered that the magnetic metal material is formed in a dish shape and the magnetic metal material is bonded to a portion extending from the outer bottom surface of the container body to the lower side surface. The cooking container having such a structure can be manufactured by a molten metal forging method. That is, a dish-shaped magnetic metal material is set in a mold, molten aluminum that is the material of the container body is poured into the lower mold, and the aluminum is pressed by the upper mold to mold the container body, In this method, the magnetic metal material is joined to a portion extending from the outer bottom surface of the container body to the lower portion of the side surface.

[0009]

However, in this case,
In the side surface of the container body, the force when aluminum is pressed to bond the magnetic metal material is in the direction orthogonal to the direction of gravity, so a sufficient bonding force cannot be obtained, and the reliability of the bonding decreases. There are difficulties.

The present invention has been made in view of such a point, and an object thereof is an electromagnetic induction heating type cooking capable of firmly bonding a magnetic metal material to a container body with a sufficient bonding force. The purpose is to provide a cooking container for a container.

[0011]

In order to achieve such an object, the present invention provides a dish-shaped magnetic metal material having a side surface portion from the outer bottom surface of a container body made of a non-magnetic metal material to the side surface lower portion. In the container joined to the part extending over, the side surface of the container body on the upper side of the upper edge of the magnetic metal material is inclined outwardly with respect to the vertical by an angle α, The side surface portion is inclined outward with respect to the vertical by an angle of β so that β is 10 ° or more and the relationship between α and β is β> α.

[0012]

In this way, the side surface of the container body above the upper edge of the magnetic metal material is set to the outside with respect to the vertical.
And the side surface of the magnetic metal material is inclined outward from the vertical by an angle β, and β is 1
When it is set to 0 ° or more and β> α, molten metal such as aluminum is poured into the lower mold for molding at the time of molten metal forging, and when the molten metal is pressed by the upper mold, the side surface portion of the magnetic metal material is formed. It is possible to apply a sufficient pressure to the portion, so that the magnetic metal material can be firmly joined to the container body formed of the molten metal.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 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, in which reference numeral 1 is an outer frame, and an inner frame 2 formed of synthetic resin in a bottomed tubular shape is provided in the outer frame 1. It is stored. The inner frame 2 integrally has a flange 3 on the outer periphery of the upper part, and the flange 3 is locked to the opening edge portion of the upper end of the outer frame 1, and the inner frame 2 is supported in the outer frame 1 by this locking. ing.

Induction coils 4, 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, 5 are covered with a coil cover 6. An opening 2a is formed in the center of the bottom surface of the inner frame 2, and a pan sensor 7 is attached to the center of the bottom surface of the coil cover 6. The pan sensor 7 projects through the opening 2a to the inner bottom of the inner frame 2. ing.

On the outer side of the induction coils 4 and 5, a plurality of materials having a high magnetic permeability mainly composed of iron oxide are sintered in order to prevent the leakage of the magnetic flux of the induction coils 4 and 5. Are provided so as to be orthogonal to the winding direction of the induction coils 4 and 5. Further, a magnetic shield plate 9 made of aluminum is provided on the outer peripheral side of the ferrite cores 8 ...

A cooking container 10 as a pan for cooking rice is housed inside the inner frame 2 in a removable manner. A flange 11 which is bent outward is integrally formed at an opening edge portion of an upper end of the cooking container 10, and a grip portion 11a having a substantially triangular cross section is integrally formed at an outer peripheral edge portion of the flange 11. There is. Then, the flange 11 is hooked on the opening edge portion at the upper end of the inner frame 2, whereby the cooking container 10
Are supported in the inner frame 2, and in this supported state, 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 1a, a heat radiating plate 13 is provided on the lower surface of the lid 12, and the lower surface of the heat radiating plate 13 is covered with a lid packing. 14 and an inner lid 15 are attached, and the opening at the upper end of the cooking container 10 is opened and closed by the inner lid 15.

A lid clamp 12a is provided on the outer frame 1 on the side opposite to the hinge 1a.
The lid 12 is releasably locked by means of this locking, the opening at the upper end of the cooking container 10 is closed by the inner lid 15, and the lid packing 14 is in close contact with the upper surface of the flange 11 of the cooking container 10. Further, when the lock is released, the lid 12 is pivoted upward with the hinge 1a as a fulcrum to rotate the cooking vessel 10
The opening at the top of the can be opened.

The inner lid 15 is formed with a plurality of small holes 15a for allowing the steam in the cooking container 10 to flow out, and the lid 12 is provided with a steam port 16 for discharging the steam to the outside. Further, the heat radiation plate 13 of the lid 12 is provided with a lid heater 17 for heating the heat radiation plate 13 and a lid sensor 18 for detecting the temperature of the heat radiation plate 13. 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 and the like for supplying a high-frequency current to the induction coils 4 and 5 are 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.

The rotation of the cooling fan 22 causes air outside the outer frame 1 to be sucked into the outer frame 1 from 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 magnetic metal material 26 joined to a portion extending from the bottom surface of the container body 25 to the lower side surface.

The magnetic metal material 26 faces the induction coils 4 and 5 provided on the inner frame 2 with a predetermined space, and the pan sensor 7 contacts the central portion of the outer bottom surface of the cooking container 10. The temperature of the cooking container 10 is detected by the pan sensor 7.

During 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 this high frequency current. And the cooking container 10 arranged in the magnetic field
An eddy current flows through the magnetic metal material 26, and Joule heat due to the eddy current causes the magnetic metal material 26 to generate heat, which is conducted to the container body 25, whereby the contents in the cooking container 10, that is, rice and water. Is heated.

The temperature of the cooking container 10 is sequentially detected by the pan sensor 7, 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, aluminum having good heat conduction and light weight is used, and as the magnetic metal material 26, ferritic stainless steel (SUS430) is used. The plate thickness of this ferritic stainless steel is 0.3 to 0.8 mm, preferably
It is 0.5 to 0.6 mm. Further, the thickness of the container body 25 is 4 mm (set within the range of 2.5 to 6 mm) at the joint portion with the magnetic metal material 26, and is about 3 mm at other portions.

The magnetic metal material 26, as shown in FIG.
It is formed in a dish shape having an inclined side surface portion 26a. Further, a grip portion 25a protruding outward is integrally formed at the opening edge portion of the container body 25.

The side surface of the container body 25 located above the upper edge of the magnetic metal material 26 is inclined outwardly with respect to the vertical by an angle α, and the side surface portion 2 of the magnetic metal material 26 is inclined.
6a is inclined outward from the vertical by an angle β. And β> α.

Α is 3 to 10 °, and in this embodiment α =
It is set at 5 °. Β is 10 to 45 °, preferably 3
Set to 0 °. However, the relation of β> α is always established.

The side surface of the container body 25 that inclines at an angle α does not have a linear inclination, but has a very gentle curved line, and the approximate straight line inclines at an angle α, and at an angle β. The side surface portion 26a of the inclining magnetic metal material 26 is not linearly inclined but has a gentle curved shape, and its approximate straight line is inclined at an angle β.

In the container body 25, the magnetic metal material 26
The side surface of the portion to be joined to the side surface portion 26a of the
Sakai is inclined in a shape similar to a, and the side surface of this portion and the side surface of the portion inclined at the angle α on the upper side are finished into a smooth curved surface.

Such a cooking container 10 is manufactured by a molten metal forging method. Next, this molten metal forging method will be described. In this molten metal forging method, as shown in FIG. 3, a lower die a and an upper die b are used. The lower mold a has a concave portion c having a shape corresponding to the outer shape of the cooking container 10, and the lower mold b has a convex portion d having a shape corresponding to the inner shape of the cooking container 10.

First, a ferritic stainless steel plate is pressed, and this is molded into a dish shape corresponding to the portion extending from the outer bottom surface to the lower portion of the side surface of the cooking container 10 to form the container body 10.
The magnetic metal material 26 to be bonded to The inner surface of the magnetic metal material 26 is roughened by a blasting treatment, and after this treatment, iron (Fe) is sprayed on the inner surface to 100 to 150 μm.
An Fe layer having a thickness of m is formed, and the Fe layer is further sintered by vacuum heat treatment to be bonded to the inner surface of the magnetic metal material 26.

Next, the magnetic metal material 26 is inserted into the recess c of the lower mold a with the Fe layer facing upward, and set in the inner bottom of the recess c. In this state, aluminum such as AC4CH as the material of the container body 25 is melted at about 800 ° C., and the melted aluminum is poured into the recess c of the lower mold a by a predetermined amount. Then, the convex portion d of the upper die b is pushed into the concave portion c of the lower die a to press the molten aluminum at a pressure of about 350 t. At this time, the Fe layer acts as a binder for binding the magnetic metal material 26 and aluminum,
As a result, the magnetic metal material 25 is firmly bonded to aluminum.

The aluminum eventually solidifies to become the container body 25, and the magnetic metal material 26 is added to the container body 25.
The cooking container 10 in which the are integrally joined is completed. After the cooking container 10 is manufactured, the inner surface and the outer surface of the cooking container 10 are roughened by a blasting process, and a primer made of FEP resin is applied to the inner surface, and then a predetermined pattern is applied to the cooking container 10.
Printing is performed by T printing or the like, and a coating mainly composed of PFA resin is further coated thereon, the coating film is dried and baked in an air oven, and the outer surface is coated with a fluororesin-based coating.

In the cooking container 10 having such a structure, since the side surface portion 26a of the magnetic metal material 26 is inclined at an angle (β) of 10 ° or more, the molten aluminum is made into a convex portion of the upper die b at the time of molten metal forging. When pressed with d, the side surface 2
Sufficient pressure is applied even to the portion 6a, and the side surface portion 2
6a and molten aluminum can be firmly joined.

According to the result of the experiment, when the inclination angle (β) of the side surface portion 26a of the magnetic metal material 26 is less than 10 °,
When molten aluminum is pressed by the convex portion d of the upper mold b,
The pressure force at the side surface portion 26a was insufficient, a stable joining force could not be obtained, and the joining force between the side surface portion 26a and the molten aluminum varied.

In Table 1 below, the inclination angle (β) of the side surface portion 26a of the magnetic metal material 26 is variously changed, and each side surface portion 26 is formed.
Aluminum is joined to a by a molten metal forging method, and the joined aluminum is pulled in one direction to be peeled off,
The result when the force required for this peeling is measured as the bonding force is shown. For this measurement, as shown in FIG. 4, a test piece having a width L of 10 mm in which aluminum was joined to the side surface portion 26a of the magnetic metal material 26 was used.

[0039]

[Table 1]

As shown in Table 1, when the inclination angle (β) of the side surface portion 26a is less than 10 °, the joining force is weak, but 1
It can be seen that when the angle is 0 ° or more, the joining force increases and a sufficient and stable joining force can be obtained.

The inclination angle (β) of the side surface portion 26a is 4
If it exceeds 5 °, the volumetric efficiency at the time of molten metal forging deteriorates, which is economically disadvantageous. Therefore, the inclination angle (β) of the side surface portion 26a is preferably in the range of 10 to 45 °.

The inclination angle (α) of the side surface of the container body 25 above the upper edge of the magnetic metal material 26 is smaller than the inclination angle (β) of the side surface portion 26a of the magnetic metal material 26. The inner volume of the cooking container 10 can be efficiently secured.

On the inner surface of the container body 25, the magnetic metal material 26
The portion corresponding to the side surface portion 26a is inclined at a relatively large angle similar to the side surface portion 26a. Therefore, for example, rice cooked in the cooking container 10 can be scooped along the inclined inner surface. Sometimes the operation is easy.

The side surface portion 26a of the magnetic metal material 26 has an angle of 10 °.
Since it is inclined at a relatively large angle as described above, it is easy to perform the work of performing the blast treatment on the upper surface of the magnetic metal material 26 or the work of spraying the iron powder as the pretreatment during the molten metal forging. You can do it efficiently. Further, the work of coating the inner surface and the outer surface of the cooking container 10 after the cooking container 10 is manufactured can be performed easily and efficiently.

On the other hand, since the cooking container 10 is manufactured by the molten metal forging method, the inner surface and the outer surface of the cooking container 10 can be formed into different shapes. For example, the grip portion 11a is formed on the outer peripheral edge of the flange 11. And this grip part 11
The shape of a can be selected in various ways, such as by making the cross section of a substantially triangular.

Since the magnetic metal material 26 is formed into a dish shape by pressing, its outer surface can be made smooth, and the thickness of each part can be kept constant to obtain uniform heating characteristics. it can.

Since the magnetic metal material 26 has a dish shape and is joined to a portion extending from the outer bottom surface of the container body 25 to the lower side surface, the induction coils 4 and 5 are provided so as to face the magnetic metal material 26. It is possible to effectively heat the side surface portion from the bottom portion without locally heating the bottom portion of the cooking container 10 to suppress the occurrence of uneven heating during cooking.

[0048]

As described above, according to the present invention,
There is an advantage that the magnetic metal material can be firmly bonded to the container body with a sufficient bonding force.

[Brief description of drawings]

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

FIG. 2 is a cross-sectional view showing a cooking container according to an embodiment of the present invention.

FIG. 3 is a sectional view showing a mold for manufacturing the cooking container.

FIG. 4 is a perspective view for explaining a joining force measuring unit for magnetic metal materials.

[Explanation of symbols]

 10 ... Cooking container 25 ... Container body 26 ... Magnetic metal material 26a ... Side part

Front page continuation (72) Inventor Masayuki Onishi 2570, Gosuda, Kamo City, Niigata Prefecture 1 Toshiba Home Techno Co., Ltd.

Claims (1)

[Claims] 1. A container in which a dish-shaped magnetic metal material having a side surface portion is joined to a portion extending from an outer bottom surface of a container body made of a non-magnetic metal material to a lower portion of the side surface, wherein the magnetic metal material The side surface of the container main body on the upper side of the upper end edge is inclined outwardly with respect to the vertical by an angle α, and the side surface portion of the magnetic metal material is outwardly with respect to the vertical by an angle β. A cooking container for an electromagnetic induction heating cooker, which is inclined, β is 10 ° or more, and the relationship between α and β is β> α.