JPH0833558A - Cooking container for electromagnetic induction heating type cooker - Google Patents

Abstract

PURPOSE:To provide a cooking container of an electromagnetic induction heating type cooker which keeps favorable appearance while improving its anticorrosiveness. CONSTITUTION:A cooking container has an exothermic layer member 26 comprising a magnetic metal material given a rough shape of a plate joined on a lower external surface of the body 25 of the container comprising a nonmagnetic metal material by a molten metal forging method. Then, a step part 27 is formed at a peripheral part on the side of the upper end of the exothermic layer member as extending almost horizontally out ward therefrom and an border line C between the magnetic metal material of the exothermic layer member 26 and the non-magnetic metal material of the main body 25 of the container is positioned near the extended rim of the step part 27.

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,
The heat generating layer member made of a magnetic metal material having a substantially dish shape is provided in a portion extending from the outer bottom surface of the container body to the lower portion of the side surface, and has 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 manufactured by a molten metal forging method. In this molten metal forging method, as shown in FIG. 9, 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, and the upper mold b has a convex portion d having a shape corresponding to the inner shape of the cooking container.

First, a heat generating layer member e, which is formed in a predetermined shape by subjecting a magnetic metal material such as ferritic stainless steel to a pressing process in advance, 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 f is provided in advance on the upper surface of the member e by sintering or thermal spraying iron powder.

In this state, molten aluminum as a material of the container body is poured into the recess c of the lower mold a. Then, 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. Then, the molten aluminum is solidified. As a result, a cooking container in which the heat generating layer member e is integrally joined to the container body made of aluminum is completed.

[0009]

In such a conventional cooking container, a container body made of a non-magnetic metal material,
The heating layer member made of a magnetic metal material is in contact with the outer surface of the cooking container on the same surface, and the boundary line between the two is exposed on the outer surface of the cooking container.

However, when the cooking container is formed by the molten metal forging method, aluminum as the non-magnetic metal material is largely protruded to the outer surface side of the heat generating layer member as the magnetic metal material at the boundary line portion, and the appearance is deteriorated. It often drops. If the protruding aluminum is to be removed by cutting, the outer surface of the heat generating layer member will be scratched, and the scratch will deteriorate the appearance again.

Further, since the non-magnetic metal material of the container body and the magnetic metal material of the heating layer member are in contact with each other on the same outer peripheral surface of the cooking container, water is likely to accumulate at the boundary between the two. , This moisture penetrates from the boundary line to the inside, and the magnetic metal material is particularly apt to corrode with this moisture,
Corrosion resistance is reduced.

The present invention has been made in view of such a point, and an object of the invention is to provide a cooking container for an electromagnetic induction heating type cooker which maintains a good appearance and has improved corrosion resistance. To provide.

[0013]

In order to achieve such an object, the present invention has a heating layer made of a magnetic metal material having a substantially dish shape on the lower outer surface of a container body made of a nonmagnetic metal material by a molten metal forging method. A container in which members are joined,
A step portion that extends substantially horizontally outward is formed on the peripheral edge portion on the upper end side of the heat generating layer member, and the magnetic metal material of the heat generating layer member and the container body are formed in the vicinity of the extending edge of the step portion. The boundary line with the non-magnetic metal material is located.

[0014]

In such a cooking container, since a step portion extending substantially horizontally outward is formed at the peripheral edge of the upper end of the heating layer member, the boundary between the non-magnetic metal material and the magnetic metal material is formed. The lines are in an orderly straight line along the outer peripheral edge of the step, thus maintaining a good appearance of the cooking container.
When water adheres to the outer surface of the cooking container, since the boundary line is arranged along the outer peripheral edge of the step, so-called drainage is good due to this step, and therefore water is applied to the boundary. Is not accumulated, so that water is prevented from penetrating from the boundary line to the inside thereof, and corrosion resistance is improved.

[0015]

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 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 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, in order to prevent the leakage of the magnetic flux of the induction coils 4 and 5, a plurality of materials having a high magnetic permeability mainly composed of iron oxide are sintered. 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 ...

Inside the inner frame 2, a cooking container 10 serving as a pan for cooking rice is removably housed. A flange 11 which is bent outward is integrally formed at the opening edge of the upper end of the cooking container 10, and the flange 11 is hooked on the opening edge of the upper end of the inner frame 2, whereby the cooking container 10 is formed.
Are supported in the inner frame 2. And this cooking container 10
A predetermined gap is secured between the outer surface of the 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. 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.

The outer frame 1 is provided with a lid clamp 12a on the side opposite to the hinge 1a, and the lid clamp 12a is provided.
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 portion 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 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 heating layer member 26 made of a magnetic metal material provided in a portion extending from the bottom surface to the lower portion of the side surface of the container body 25. .

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 with a predetermined gap, and the pan sensor 7 is in contact with the central portion of the outer bottom surface of the cooking container 10 for cooking by the pan sensor 7. The temperature of the container 10 is detected.

During cooking, a high frequency current is supplied to the induction coils 4, 5 by the inverter circuit of the control board 20, and an alternating magnetic field is generated in the induction coils 4, 5 by this high frequency current. And the cooking container 10 arranged in the magnetic field
An eddy current flows through the heating layer member 26, and Joule heat due to the eddy current causes the heating layer member 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, for example, aluminum, which has good heat conduction and is lightweight, is used, and as the magnetic metal material forming the heat generating layer member 26, for example, ferritic stainless steel ( SUS4
30) is used.

The heat generating layer member 26 has a substantially dish shape, as shown in FIG.
As shown in enlarged form, a step portion 27 that extends substantially horizontally outward is formed on the peripheral edge portion of the upper end of the heat generating layer member 26, and is substantially perpendicular to the extending edge portion of the step portion 27. A standing portion 28 that stands upright is formed.

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 thereof is exposed to the outer surface of the cooking container 10 and integrally joined to the container body 25. Has been done.

The outer peripheral surface of the container main body 25 is inclined in a taper shape that widens outward toward the upper side, and the outer peripheral surface of the container main body 25 and the outer peripheral surface of the rising portion 28 of the heat generating layer member 26 are The angle α formed by is 30 ° or less.

When the thickness of the container body 25 is A and the thickness of the heat generating layer member 26 is B at the portion where the heat generating layer member 26 and the container body 25 are joined, the thickness B is 1 / 6
It is ~ 1/8. For example, the thickness A of the container body 25 is 5
mm, the thickness B of the heat generating layer member 26 is 0.7 mm.

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, the heat generating layer member 26, which is formed in a predetermined shape by subjecting a magnetic metal material such as ferritic stainless steel to a pressing process in advance, 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 sintering or spraying iron powder.

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 then 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 such a cooking container 10, a step portion 27 extending substantially horizontally outward is formed at the peripheral edge of the upper end of the heat generating layer member 26, and therefore the cooking container 10 is formed.
At the time of molding, as shown in FIG. 3, the lower surface of the stepped portion 27 adheres to the substantially horizontal receiving portion of the lower die, so that the aluminum as the material of the container body 25 protrudes to the outer peripheral side of the rising portion 28. However, this aluminum is blocked by the contact portion between the step portion 27 and the receiving portion, and the protrusion of the step portion 27 to the lower surface side is reliably prevented.

Therefore, the boundary line C between the aluminum and the magnetic metal material is in an orderly linear state along the outer peripheral edge of the step portion 27, so that the appearance of the cooking container 10 can be kept good. Since the boundary line C between the aluminum and the magnetic metal material is arranged along the outer peripheral edge of the step portion 27, the boundary line C is visually inconspicuous with the contour of the step portion 27, which makes cooking even more difficult. The appearance of the container 10 becomes good.

By the way, in the unlikely event that aluminum is stepped 27
If the lower surface of the cooking container 10 is cut off and removed, and the lower surface of the stepped portion 27 is scratched by the cutting, the lower surface of the stepped portion 27 may cause the cooking container 10 to be obliquely upward or upward. When viewed from the side, a blind spot is formed, so that the scratches are not conspicuous, and therefore the overall appearance of the cooking container 10 can be kept good.

On the other hand, in the case of inspecting the quality of the bonding state between aluminum and the magnetic metal material at the boundary C,
Since the boundary line C is arranged along the outer peripheral edge of the step portion 27, the position of the boundary line C can be easily determined based on the step portion 27, and therefore the boundary line C can be determined by using a magnet or the like.
Without the troublesome work of detecting the position of
The quality of the joined state can be inspected efficiently.

When water adheres to the outer surface of the cooking container 10,
Since the boundary line C is arranged along the outer peripheral edge portion of the step portion 27, so-called drainage becomes good by the step portion 27,
Therefore, water does not collect at the boundary line C,
Therefore, the permeation of water from the boundary line C into the inside can be surely prevented, and thereby the corrosion resistance can be improved.

In particular, in this embodiment, the standing portion 28 is formed on the extending edge portion of the step portion 27, and the standing portion 28 is embedded in the meat of the container body 25, so that water further penetrates. Therefore, it is possible to reliably prevent corrosion at the upper edge of the upright portion 28. Since the upright portion 28 is embedded inside the meat of the container body 25, the heating layer member 26
Has an advantage that it can be more firmly bonded to the container body 25 and its peeling can be reliably prevented.

At the portion where the heat generating layer member 26 and the container body 25 are joined, the thickness B of the heat generating layer member 26 is set to the container body 2
The thickness A is 1/6 to 1/8 of the thickness A. Therefore, the heat generating layer member 26 can efficiently generate heat and the heat can be efficiently conducted to the entire container body 25.

If the thickness of the heat generating layer member 26 is increased, the amount of heat generated increases, but the thickness of the container body 25 must be reduced accordingly, and as a result, the amount of heat conduction of the container body 25 increases. It becomes less and local overheating occurs, causing uneven heating over the entire cooking container 10. On the contrary, when the thickness of the heat generating layer member 26 is reduced, the amount of heat generated decreases, the amount of heat conducted to the container body 25 decreases, and not only the efficiency decreases, but also the heat generating layer member 26 easily heats and cools. The heat generation layer member 26 becomes easier due to its expansion and contraction.
Will be easily peeled off.

According to the results of the experiment, the thickness B of the heat generating layer member 26 is set to 1/6 to 1/8 of the thickness A of the container body 25 at the portion where the heat generating layer member 26 is joined. It has been found that the heating efficiency is improved and the exothermic layer member 26 can be reliably prevented from peeling off.

FIG. 4 shows a cooking container 10 according to a second embodiment of the present invention. In the cooking container 10 according to the second embodiment, a step portion 27 extending substantially horizontally outward is formed at the peripheral edge of the upper end of the heat generating layer member 26 made of a magnetic metal material, and this step portion is further formed. A bent portion 29 that greatly bends inward is formed at the extended edge portion of 27. The bent portion 29 is embedded inside the meat of the container body 25.

In such a structure, the heat generating layer member 2
Since the bent portion 29 of No. 6 is arranged so as to fit into the inside of the meat of the container body 25, the joint strength of the heat generating layer member 26 to the container body 25 is further improved, and peeling of the heat generating layer member 26 is reliably prevented. can do.

FIG. 5 shows a cooking container 10 according to a third embodiment of the present invention. In the cooking container 10 according to the third embodiment, a step portion 27 extending substantially horizontally outward is formed at the peripheral edge of the upper end of the heat generating layer member 26 made of a magnetic metal material, and this step portion is further formed. A rising portion 28 is formed on the extended edge portion of 27. The upright portion 28 is slightly inclined with respect to the vertical line at the same angle as the outer peripheral side surface of the container body 25. Then, the end surface 28 at the upper end of the standing portion 28
As a is enlarged and shown in FIG. 6, it is inclined so as to face upward toward the inside of the cooking container 10 with respect to the horizontal line.

Thus, the end surface 28a of the upper end of the rising portion 28 is
Is inclined, the inclined end surface 28a becomes an edge portion, and the effect of preventing the exothermic layer member 26 from peeling is further improved.
FIG. 7 shows a cooking container 10 according to a fourth embodiment of the present invention.
Is shown. In the cooking container 10 according to the fourth embodiment, a step portion 27 extending substantially horizontally outward is formed at the peripheral edge of the upper end of the heat generating layer member 26 made of a magnetic metal material, and this step portion is further formed. Standing portion 28 on the extended edge of 27
Are formed. The upright portion 28 is slightly inclined with respect to the vertical line at the same angle as the outer peripheral side surface of the container body 25.

The uppermost end of the heat generating layer member 26, that is, the rising portion 28.
The distance D between the position of the upper edge of the above and the position of the uppermost end of the induction coil 5 provided on the outer side of the heat generating layer member 26 is 5 mm or more.

An opening 30 is formed at the center of the bottom surface of the heat generating layer member 26, and an upright portion 31 which stands up substantially vertically is formed above the opening 30 at the periphery of the opening 30. Further, at the bottom of the heat generating layer member 26 on the outer peripheral side of the opening 30, two rows of beads 31, 31 protruding upward are formed in an annular shape so as to surround the opening 30.

The central portion of the outer bottom surface of the container body 25 is exposed to the outside through the opening 30. This exposed portion is processed into a recess 25a by cutting, and the pan sensor 7 contacts the flat surface of this recess 25a. Is configured.

If the uppermost position of the heat generating layer member 26 and the uppermost position of the induction coil 5 are separated by 5 mm or more, the heat generation amount of the heat generating layer member 26 due to induction heating decreases at the upper end portion thereof, and expansion / contraction occurs. This is effective in preventing the exothermic layer member 26 from peeling due to the above.

The bead 3 is formed on the bottom of the heat generating layer member 26.
1,31 are formed, these beads 31,3
1, the mechanical strength of the heat generating layer member 26 is reinforced, the joint area between the heat generating layer member 26 and the container body 25 is increased to improve the joint strength, and the heat generated in the heat generating layer member 26 is applied to the container body 25. Good conduction to.

Since the cooking container 10 of the present invention is formed by the molten metal forging method, it can be formed into a circular shape as shown in FIG.
It can also be formed in a square shape as shown in FIG. In this case, it is also possible to make the upper end portion into a square shape and round the shape toward the lower end side.

[0057]

As described above, according to the cooking container of the present invention, it is possible to maintain a good appearance and surely improve the corrosion resistance.

[Brief description of drawings]

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

FIG. 2 is a sectional view showing a part of the cooking container according to the first embodiment of the present invention.

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

FIG. 4 is a sectional view showing a part of the cooking container according to the second embodiment of the present invention.

FIG. 5 is a sectional view showing a part of a cooking container according to a third embodiment of the present invention.

FIG. 6 is an enlarged cross-sectional view showing a part of the cooking container.

FIG. 7 is a sectional view showing a part of a cooking container according to a fourth embodiment of the present invention.

FIG. 8 is a perspective view showing a cooking container formed in a rectangular shape.

FIG. 9 is a cross-sectional view for explaining a method of manufacturing a cooking container by a molten metal forging method.

[Explanation of symbols]

 10 ... Cooking container 25 ... Container body 26 ... Exothermic layer member 27 ... Step C ... Boundary line

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

Claims (1)

[Claims] 1. A container comprising a container main body made of a non-magnetic metal material and a heating layer member made of a substantially dish-shaped magnetic metal material joined to the lower outer surface of the container body by a molten metal forging method, the upper end side of the heating layer member. A step portion that extends substantially horizontally outward is formed on the peripheral portion of the heat generating layer member and the non-magnetic metal material of the container body in the vicinity of the extending edge of the step portion. A cooking container of an electromagnetic induction heating type cooking device, characterized in that the boundary line of the cooking device is located.