JPH0833561A - Electromagnetic induction heating type cooker - Google Patents

Abstract

PURPOSE:To provide an electromagnetic induction heating type cooker which achieves ease of handling by keeping the internal bottom surface of a cooking container from protruding so much to accomplish operation smoothly when rice cooked up in the cooking container is scooped. CONSTITUTION:An electromagnetic induction type cooker comprises a cooking container 10, an induction coil and a temperature sensor and the cooking container 10 is made up of the main body 25 of a container comprising a nonmagnetic metal material and an exothermic layer member 26 comprising a magnetic metal material joined on a lower external surface thereof 25. The exothermic layer member 26 is made to generate heat by electromagnetic induction with the induction coil and heats the main body 25 of the container to cook. The cooking container 10 is not similar between the shapes of the internal surface and the external surface and a recessed part 27 is provided on the external bottom surface. The surface of the bottom of the recessed part 27 is made as a flat contact part 28 which the temperature sensor contacts.

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 cooker which heats a cooking container by electromagnetic induction to perform cooking.

[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. This electromagnetic induction heating type cooker is composed of a cooker main body provided with an induction coil as a heating means, and a cooking container detachably provided in the cooker main body. The cooking container has a composite structure of a container main body made of a non-magnetic metal material and a heating layer member made of a magnetic metal material joined to an outer surface of the container main body.

[0003] The induction coil is disposed so as to face the heat generating layer member of the cooking vessel at a predetermined interval.
At the time of cooking, the induction coil is excited, and the induction coil generates an eddy current in the heating layer member made of a magnetic metal material. I cook things.

[0004] As a material mainly for the container, lightweight aluminum having excellent thermal conductivity is generally used in order to efficiently conduct the heat of the heat generating layer member to the entire cooking container, and a ferrite-based material is used as the magnetic metal material. Stainless steel is used.

When manufacturing a cooking vessel having a composite structure, generally, a method is used in which a clad material obtained by joining an aluminum plate and a stainless plate is used as a raw material, and the clad material is pressed into a predetermined container shape. ing.

[0006]

However, since the clad material has a constant material thickness, the cooking container formed by pressing the clad material necessarily has the shape of the inner surface and the shape of the outer surface. Have similar shapes. The outer bottom surface of the cooking container is formed with a recessed portion that is recessed inward, and a temperature sensor as a temperature detecting means for detecting the temperature of the cooking container is brought into contact with the recessed portion.

This is because when the temperature sensor is brought into contact with the flat outer bottom surface of the cooking container, foreign matter adheres to the flat surface, and the foreign matter deteriorates the temperature detection accuracy of the temperature sensor. . Therefore, it is desirable to form the recess relatively deep. However, when a deep recess is formed on the outer bottom surface of the cooking container, conventionally, since the shape of the inner surface of the cooking container and the shape of the outer surface are similar to each other, the inner bottom surface of the cooking container largely protrudes, It becomes difficult to operate the rice cooked in the cooking container.

The present invention has been made by paying attention to such a point, and an object thereof is to prevent the inner bottom surface of the cooking container from largely protruding so that the rice cooked in the cooking container is served. An object of the present invention is to provide an electric induction heating type cooker that can be smoothly operated and has good usability.

[0009]

In order to achieve such an object, the present invention provides a cooking container removably housed in a cooker main body and a heating means provided in the cooker main body. Of the induction coil, and temperature detecting means for detecting the temperature of the cooking container in contact with the cooking container, and control for adjusting heating of the cooking container by the induction coil based on the temperature of the cooking container detected by the temperature detecting means. The cooking container comprises a container main body made of a non-magnetic metal material and a heating layer member made of a magnetic metal material joined to a lower outer surface of the container main body, and the cooking coil is electromagnetically induced by the induction coil. In the electromagnetic induction heating type cooker that heats the heating layer member and heats the container main body by this heat generation for cooking, the cooking container has an inner surface shape and an outer surface shape which are not similar to each other. A recess in the outer bottom surface, the surface of the bottom of the recess and the contact portion of the flat shape, in which so as to contact the temperature detecting means to the contact portion.

[0010]

A concave is formed on the outer bottom surface of the cooking container, and the bottom surface of the concave is a flat contact portion. However, the shape of the inner surface of the cooking container is different from the shape of the outer surface. There is a similar relationship, so the shape of the inner bottom surface of the cooking container can be made into a smooth curved surface shape without being restricted by the shape of the outer bottom surface.For this reason, scoop rice cooked in the cooking container. At that time, the rice scoop can be moved smoothly along the smooth curved surface of the inner bottom surface, which makes it easier to cook the rice and improves usability. Further, since the bottom surface of the concave portion of the outer bottom surface of the cooking container is made into a flat contact portion and the temperature detecting means is brought into contact with this contact portion, the temperature detecting means surely adheres to the contact portion. And good temperature detection is achieved.

[0011]

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, and reference numeral 1 is a cooker body. An inner frame 2 formed of a synthetic resin in a cylindrical shape with a bottom is housed in the cooking main body 1. The inner frame 2 integrally has a flange 3 on the outer periphery of the upper part. It is locked to the opening edge at the upper end. This inner frame 2
Is made of a relatively thick material with a heat resistance of 1.5 mm or more, such as polyamide resin containing glass fiber.

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 central portion of the bottom surface of the inner frame 2, and a temperature sensor 7 as a temperature detecting means is attached to the central portion of the bottom surface of the coil cover 6, and the temperature sensor 7 passes through the opening 2a. Is elastically projected by the urging force of the spring 7a.

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 ...

A cooking container 10 as a pan for cooking rice is housed inside the inner frame 2 in a removable manner. A flange portion 11 that is bent outward is integrally formed at the opening edge portion at the upper end of the cooking container 10. Then, the flange portion 11 is hooked on the opening edge portion at the upper end of the inner frame 2, whereby the cooking container 10 is supported inside the inner frame 2, and in this supported state, the outer surface of the cooking container 10 and the inner surface of the inner frame 2 are supported. A predetermined gap is secured between them.

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.

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 air inlet 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 main body 25 made of a non-magnetic metal material, and a heat generating layer member 26 made of a magnetic metal material joined to a portion extending from the bottom surface to the lower side surface of the container main body 25. .

The heating layer member 26 faces the induction coils 4 and 5 provided on the inner frame 2 with a predetermined space,
Further, the temperature sensor 7 is provided at the center of the outer bottom surface of the cooking container 10.
And the temperature of the cooking container 10 is detected by the temperature 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 the high-frequency current. Cooking container 1
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 detected by the temperature sensor 7.
Are sequentially detected by the control means, and based on the detected temperature, the heating amount of the cooking container 10 is adjusted by the control means in accordance with a predetermined sequence.

As the non-magnetic metal material forming the container main body 25 of the cooking container 10, aluminum having good heat conduction and light weight is used, and as the magnetic metal material forming the heating layer member 26, ferritic stainless steel (SUS430). Is used.

The heating layer member 26 has a substantially dish shape, and is embedded in a portion extending from the outer bottom surface to the lower side surface of the container main body 25 so that the outer surface is exposed to the outer surface of the cooking container 10.
It is integrally joined to the container main body 25.

FIG. 2 shows an enlarged cross section of a part of the cooking container 10. As shown in FIG.
A recess 27 is formed at the center of the bottom surface of the bottom. The recess 27 extends in a circular shape, and the bottom surface of the recess serves as a horizontal flat contact portion 28. The depth (height) H of the recess 27 is set to 2 mm or more, and the flatness of the flat surface 28 is set to 0.1 mm or less.

The heat generating layer member 26 has a side surface portion 29 which rises while curving in an arc shape at the peripheral edge thereof.
The bottom surface portion 30 of the cooking container 10 is between the portion 9 and the recess 27.
Then, the lowermost surface portion 30 has a horizontal flat shape.
The lowermost surface portion 30 is formed in a continuous annular shape along the outer periphery of the recess 27, and has a width L of 1 mm or more and a flatness of 0.2 mm or less.

On the other hand, the shape of the inner surface of the cooking container 10 is not similar to the shape of the outer surface. That is, the shape of the inner surface of the container main body 25 has a portion corresponding to the recess 27,
That is, in the central portion of the inner bottom surface of the cooking container 10, there is a spherical portion 31 having a gentle radius of curvature R and convex upward.
A smooth curved surface portion 32 is formed between the spherical surface portion 31 and the side surface of the container main body 25.

As shown in FIG. 3, the flange portion 11 of the cooking container 10 is integrally formed with the opening edge portion of the upper end of the container main body 25 so as to extend outward substantially horizontally, and this flange portion is further formed. A handling portion 11a is formed integrally with the outer peripheral edge of the lower portion 11 and is bent downward at a substantially right angle.

As shown in FIG. 3B, a plurality of ribs 35 having a width of about 2 mm are integrally formed on the lower surface of the flange portion 11 at regular intervals along the circumferential direction of the opening of the container main body 25. Has been done.

On the other hand, as shown in FIG. 1, a plurality of projections 2a are formed on the upper end surface of the inner frame 2 at regular intervals, and the projections 2a are formed on the flange portion 11 between the ribs 35. Of the cooking container 10 is supported by this contact.

The relationship of the gap between the inner surface of the inner frame 2 and the outer surface of the cooking container 10 will be described. In the portion where the induction coil 4 provided on the outer bottom surface of the inner frame 2 and the outer surface of the cooking container 10 face each other. The gap is A, the gap between the induction coil 5 provided on the lower part of the outer surface of the inner frame 2 and the outer surface of the cooking container 10 is B, the outer surface of the middle part of the cooking container 10 and the inner surface of the inner frame 2. C is the gap between the upper surface of the cooking container 10 and the inner surface of the inner frame 2 is D, the gap A and the gap B are substantially the same, and the gap C is the gap A and The gap D is smaller than the gap B, and the gap D is smaller than the gap C.

The gap A and the gap B are preferably set within a range of 2 to 6 mm, for example, 4 mm. The gap C is set to 3 mm and the gap D is set to 2-1 mm. Cooking container 1 having a composite structure including a container body 25 and a heating layer member 26
0 is manufactured by, for example, a molten metal forging method. In this molten metal forging method, a lower mold and an upper mold are used, and a concave portion having a shape corresponding to the outer shape of the cooking vessel 10 is formed in the lower mold, and the inner shape of the cooking vessel 10 is formed in the upper mold. A convex part having a shape is formed.

First, the heat generating layer member 26, which is formed into 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 of the lower mold. Molten aluminum as a material of the container main body 25 is poured into the concave portion of the container. Then, the convex portion of the upper die is pressed into the concave portion of the lower die at a predetermined pressure to press the aluminum, thereby forming the container main 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,
The inner surface of the cooking vessel 10 is roughened by blasting with an alumina grid or the like, the roughened inner surface is coated with FEP resin, the coating film is dried in an air oven, and then PFA is coated on the coating film.
The resin is coated, 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 vessel 10 is roughened by blasting with an alumina grid or the like, and then coated with a paint mainly composed of polyether sulfone resin and PTFE resin, and this coating film is formed. Dry to form a coating layer for rust prevention.

The electromagnetic induction heating type cooker having such a structure has the following effects. The abutting portion 28 on the outer bottom surface of the cooking container 10 has a flat shape, and therefore the temperature sensor 7 surely comes into close contact with the abutting portion 28, so that the heat of the cooking container 10 is satisfactorily transferred to the temperature sensor 7 to detect the temperature. Accuracy is improved. The abutment portion 28 is located at a level above the lowermost surface portion 30 of the cooking container 10, so that even when the cooking container 10 is placed on the table, the abutment portion 28 may directly contact the table. Therefore, the contact portion 28 is not scratched, dented, or foreign matter is attached to the contact portion 28. Therefore, the adhesion between the contact portion 28 and the temperature sensor 7 can be kept good for a long time. . Since the lowermost surface portion 30 has a flat shape, when the cooking container 10 is placed on a table, the stability is good and the usability is good.

Although the abutting portion 28 and the lowermost surface portion 30 of the outer bottom surface of the cooking container 10 are flat, the inner bottom surface of the cooking container 10 is in a state not similar to the outer bottom surface, that is, the spherical surface portion 31 and the curved surface. It is in a state of a smooth curved surface consisting of the portion 32. Therefore, when the rice cooked in the cooking container 10 is to be scooped, the scoop should be smoothly moved along the smooth curved surface of the inner bottom surface of the container body 25. Therefore, the rice is easily cooked, the usability is improved, and the smooth curved surface provides a good appearance of the inner surface of the cooking container 10.

Ribs 35 are provided on the lower surface of the flange portion 11, which improves the strength of the flange portion 11. Further, when the flange portion 11 is set to the gate position during the casting of the main body 25, the flow of molten aluminum is improved and the formability is improved.

A plurality of protrusions 2a are formed on the upper end surface of the inner frame 2 at regular intervals, and these protrusions 2a abut on the lower surfaces of the flanges 11 between the ribs 35 to form the cooking container 10 The ribs 35 are supported in the inner frame 2, and therefore, even if the cooking container 10 is rotated when the rice in the cooking container 10 is picked up, the rib 35 is attached to the protrusion 2a according to the rotation. Immediately contact with each other to prevent rotation, so that the rice becomes even easier to serve in combination with the shape of the inner bottom surface of the cooking container 10.

The gap between the outer surface of the cooking container 10 and the inner surface of the inner frame 2 is kept substantially uniform in the portion where the induction coils 4, 5 and the cooking container 10 face each other, and therefore the induction coil 4 , 5 acts on the entire heating layer member 26, so that the heating layer member 26 can be uniformly heated. And the outer surface of the cooking container 10 and the inner frame 2
The gap between the inner surface of the inner wall and the inner surface of the inner wall gradually becomes narrower toward the upper side. Therefore, the heat insulation effect by the air layer in this gap is improved, and the material of the inner frame 2 is relatively large (compared to the iron plate). Since it is a thick synthetic resin, it has a high heat insulation effect,
Therefore, when the cooked rice is kept warm, it can be kept warm evenly. For this reason, the side surface (body) heater for heat retention, which is conventionally required, is not required, and the component structure can be simplified.

Further, since the gap between the outer surface of the cooking container 10 and the inner surface of the inner frame 2 gradually expands from the top to the bottom of the cooking container 10, the cooking container 10 is pulled upward to raise the inner frame. When removing the cooking container 10 from the inside, the cooking container 10 can be tilted halfway, which facilitates the removal of the cooking container 10 and also facilitates the same operation when the cooking container 10 is inserted into the inner frame 2. There is an advantage that can be.

[0043]

As described above, according to the present invention,
It is possible to reduce the weight of the cooking container, to appropriately heat the container main body of the cooking container to prevent uneven heating, and to prevent peeling of the heating layer member for a long time. .

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing the structure of an electromagnetic induction heating cooker according to one embodiment of the present invention.

FIG. 2 is a sectional view showing a part of a cooking container in the electromagnetic induction heating type cooking device.

FIG. 3 is a sectional view showing a portion where a flange portion of the cooking container is formed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Cooker main body 4 ... Induction coil 5 ... Induction coil 7 ... Temperature sensor 10 ... Cooking container 25 ... Container main body 26 ... Exothermic layer member 27 ... Recessed part 28 ... Contact part

Claims (1)

[Claims] 1. A cooking container removably housed in the cooker main body, an induction coil as a container heating means provided in the cooker main body, and a temperature of the cooking container in contact with the cooking container. And a control means for adjusting the heating of the cooking container by the induction coil based on the temperature of the cooking container detected by the temperature detecting means,
The cooking container is composed of a container main body made of a non-magnetic metal material and a heat generating layer member made of a magnetic metal material bonded to a lower outer surface of the container main body, and the heating layer member generates heat by electromagnetic induction by the induction coil. In the electromagnetic induction heating type cooker that heats the container main body by this heat generation for cooking, the cooking container has an inner surface shape and an outer surface shape which are not similar to each other, and has a concave portion on the outer bottom surface. An electromagnetic induction heating cooker characterized in that the bottom surface of the recess is a flat contact portion, and the contact portion is in contact with the temperature detecting means.