JPH09129361A - Pot for electromagnetic induction heating cooking device and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To uniformly heat by good convection, suppress the secular change of pot dimension, and maintain the initial cooking performance for a long time by forming plural recessed and projecting parts in the position facing a heating coil of an electromagnetic induction heating cooking device made of a magnetic metal. SOLUTION: An electromagnetic induction heating cooking pot 4 is made of an outside magnetic metal 7 and an inside aluminum 8, has fluororesin coating 9 on the inner surface, and recessed and projecting work forming a recessed part 12a and a projecting part 12b is performed in the magnetic metal 7. An induction heating coil 5b is circularly arranged in the outer circumference of the cooking pot 4 through a protecting frame 10, and in driving, a line of magnetic force is concentrated on the projecting part 12b to locally generate a number of strong heat generating parts. A number of fine convection and large convection are generated in hot water in the cooking pot 4, and as a result, rice is uniformly heated. By hardening in recess and projection forming work, secular dimension change in actual use is suppressed for a long time.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a pan for an electromagnetic induction heating cooker such as a rice cooker and a heating cooker using electromagnetic induction heating.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 5, a pan for an electromagnetic induction heating cooker uses a non-magnetic metal aluminum plate 2 as a base material, and a ferritic stainless steel plate 2 which is a magnetic metal on the outside thereof. The clad plate used as the material was pressed into a pot shape, and then the inner surface of the electromagnetic induction heating and cooking pot 1 was subjected to surface treatment such as fluorine resin coating.

[0003]

However, in the above-mentioned conventional structure, the thickness of the pan 1 for electromagnetic induction heating and cooking formed by the clad material is substantially uniform, and the pan 1 for electromagnetic induction heating and cooking devices such as rice cookers is used. In order to cause good convection in the cooked food put in the pan 1, electromagnetic induction cooking, such as changing the mounting position of the induction heating coil or the number of windings of the induction heating coil, rather than modifying the pan itself The main controls were on the body side. For example, in the case of a rice cooker that uses electromagnetic induction heating, one example is control of the main body of the electromagnetic induction heating cooker, in which the induction heating coil has a two-stage configuration of an inner coil and an outer coil to obtain good convection. is there. Further, it is generally known that the convection changes by changing the thickness of the portion facing the induction heating coil, but such control is difficult in the case of a uniform plate thickness material such as a clad material.

Further, a considerable amount of heat is applied to the electromagnetic induction heating cooking pot 1 every time cooking is performed, but in the case of the electromagnetic induction heating cooking pot 1 formed by the clad material, it is combined with the aluminum 2 which is the base material. Due to the difference in the coefficient of thermal expansion of the magnetic metal 3, which is the material, the material gradually deforms over the years, resulting in a displacement in the positional relationship with the induction heating coil and a change in the calorific value, which reduces the initial cooking performance. There was also the problem of not being able to demonstrate it.

The present invention has been made in view of the above circumstances, and in a configuration in which an electromagnetic induction heating cooking pot generates heat by electromagnetic induction heating, good convection is caused in a cooked food in the electromagnetic induction heating cooking pot, The purpose is to achieve uniform heating and to suppress the aging of the pan size to a small extent to maintain the original cooking performance for a long time.

[0006]

In order to solve the above-mentioned problems, the present invention comprises an aluminum base material and a magnetic metal on its outer surface which generates heat by electromagnetic induction heating. A plurality of concave and convex portions are provided on the portion facing the induction heating coil.

Further, if necessary, the step per concave and convex section is set within a predetermined range, the area per concave section is about 4 cm ² or less, or the temperature sensor of the electromagnetic induction heating cooker body is used. The opposing portions are flat. Here, one section of unevenness means one concave portion generated by pressing and a raised convex portion around the concave portion.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 has a plurality of concaves and convexes formed on the magnetic metal of the portion of the main body of the electromagnetic induction heating cooker that faces the induction heating coil. Due to the nature of the magnetic field, the magnetic force lines are concentrated on the convex portion of the uneven processing, the heat generation of the convex portion is strengthened, a temperature difference occurs due to the unevenness, and many fine convections occur inside the electromagnetic induction heating cooking pot, causing convection of the cooked food. Results in more uniform heating. At the same time, the unevenness of the electromagnetic induction cooking pot, which has a minimal change in size due to work hardening, can maintain stable cooking performance for a long period of time and has high strength and excellent handleability. It becomes a pan for electromagnetic induction heating cooking.

According to the second aspect of the present invention, in particular, by limiting the maximum step difference of one section of the unevenness, dirt sticking to the step can be easily removed and the aesthetic appearance can be maintained.

According to the third aspect of the present invention, the area of one section of the concave and convex portions is approximately 4 cm ² or less, and by providing a large number of relatively fine concave and convex portions, effective convection can be obtained.

According to the fourth aspect of the present invention, by limiting the maximum step of a section of the unevenness of the surface with respect to the object to be cooked, non-adhesiveness,
The abrasion resistance and the appearance can be made excellent.

According to a fifth aspect of the present invention, when a clad material formed by laminating stainless steel, which is a magnetic metal, and aluminum, which is a good thermal conductor, is used, the thickness of the stainless steel is approximately 0.45 mm to 1.0 mm. By setting the metal plate thickness ratio within a predetermined range, sufficient heat generation can be obtained, heat conduction can be improved, and an inappropriate increase in weight can be prevented.

According to a sixth aspect of the present invention, when the electromagnetic induction heating cooker main body is flat at least at a portion facing the temperature sensor, the temperature sensor and the electromagnetic induction heating cooking pot are brought into contact with each other. It improves and can detect the temperature accurately.

According to a seventh aspect of the present invention, in the manufacturing process of the pot for electromagnetic induction heating and cooking, the concavo-convex processing is performed in a flat plate state before press molding (drawing) into a pan shape, so that the concavo-convex processing is performed after the press molding. There is an advantage that processing is easier than in the case of applying.

According to the eighth aspect of the present invention, the relief processing is sacrificed by the uneven processing after the press molding (drawing processing) and before the surface non-adhesive coating treatment, but the uneven shape processed into a flat plate. Can be solved during press molding (drawing), and problems such as unevenness of unevenness can be eliminated.

Embodiments of the invention will be described below with reference to the accompanying drawings. (Embodiment) An electromagnetic induction heating cooker pot using the present invention, which is used for an electromagnetic induction heating type rice cooker, will be described with reference to FIGS. 1, 2 and 3. First, FIG.
The configuration of the electromagnetic induction cooking pan 4, the induction heating coil 5, and the temperature sensor 6 will be described with reference to FIG. Reference numeral 4 denotes an electromagnetic induction heating cooking pot of the present invention, which is composed of an outer magnetic metal 7 and an inner heat conductive metal 8, and the inner surface is coated with a fluorine resin coating 9 so that rice does not stick. The magnetic metal 7 is made of ferritic stainless steel or a steel plate, and the heat conductive metal 8 is made of aluminum or aluminum alloy. On the other hand, the fluorine resin coating or the silicone-based non-stick coating is applied to the outer surface of the electromagnetic induction cooking pot. It is possible. Reference numeral 5 denotes an induction heating coil, which has a two-stage configuration of an inner coil 5a and an outer coil 5b, and is annularly arranged on the outer periphery of the electromagnetic induction heating cooking pot with a protective frame 10 separated from the electromagnetic induction heating cooking pot, When driven, magnetic lines of force are generated, causing the magnetic metal 7 to generate heat. Further, 6 is a temperature sensor, which is indispensable for accurately performing the rice cooking process by coming into contact with the outer surface of the central portion of the bottom of the electromagnetic induction heating cooking pot to detect the temperature of the electromagnetic induction heating cooking pot.

Here, as shown in FIGS. 1 (b) and 1 (c), the inner coil 5a is provided on the outer surface of the pan 4 for electromagnetic induction heating and cooking.
From the facing portion of the outer coil 5b to the facing portion of the outer coil 5b, a large number of irregularities 12 are radially provided on a concentric circle whose center is the center of the bottom of the pot for electromagnetic induction heating and cooking. The number of concave-convex processing mentioned here means the number of concave portions 12a to be processed. FIG. 2 shows a concavo-convex process 1 in a pan 4 for electromagnetic induction heating cooking.
It is a cross-sectional view of the portion subjected to No. 2, the positional relationship with the outer coil 5b is also shown. Reference numeral 12b denotes a convex portion and 12a denotes a concave portion, but the number, shape, and arrangement of the concavo-convex processing to be provided are not particularly limited, and FIG. 3 (a) or FIG. 3) or a combination thereof may be used, and there is no problem even if adjacent recess patterns overlap each other as shown in FIG. 3C. In this embodiment, since the temperature sensor 6 of the rice cooker body is in contact with the central portion 11 of the outer surface of the pot bottom,
In order to make good contact with the pan 4 for electromagnetic induction heating and cooking, this portion is not provided with uneven processing 12, but in a cooker configured such that the temperature sensor 6 contacts the side surface of the pan, unevenness is formed at the center of the pan bottom. There is no problem even if it is processed. The portion to be unevenly processed is not limited to only the portion facing the induction heating coil, and the portion to be opposed to the inner coil 5a is provided with unevenness, while the portion to be opposed to the outer coil 5b is provided. It is also possible to change the convection by not providing it, or by dividing the portion facing the induction heating coil into the portion provided with the uneven processing and the portion not provided with the uneven processing.

With the above structure, when the rice cooker body is driven, the magnetic lines of force generated from the induction heating coil 5 are
As a result of the large number of locally generated strong heat generating portions concentrated on the convex portions of the uneven processing, as shown in FIG. 2, many fine and complicated convections are generated in the hot water in the electromagnetic induction cooking pot, resulting in rice. Will be heated uniformly. At the same time, the work hardening due to the unevenness processing brings about an effect that the dimensional change over time in actual use for a long time can be suppressed to an extremely small extent.

Next, a specific method of manufacturing the rice cooker pot of this embodiment, which has been subjected to the uneven processing, will be described.

First, a clad flat plate having a plate thickness ratio of 3.0, a thickness of 2 mm, and a diameter of 400 mm, in which aluminum, which is a good heat conductor of the base material, and stainless steel, which is a magnetic metal that bears heat, is laminated, is prepared. As shown in (a), a cylindrical press having a diameter of 10 mm and a plurality of punches 14 each having a spherical end surface R = 25 mm was used to press the center of the flat plate from the inner coil to the portion facing the outer coil. Radial concavo-convex machining with a maximum depth of 0.4 mm on the concentric circles 1
Apply 2 to the stainless steel side. Next, the punch is pressed against the stainless steel side and pressed, so that the portion pressed with the punch is processed into a concave shape 12a in the tip shape of the punch, as shown in FIG. 4 (b). The portion extruded to the periphery rises to form the convex shape 12b. Note that each punch may be covered with an elastic material such as urethane rubber in order to suppress distortion of the flat plate. In this step, the flat plate is warped, but it can be corrected by a press equipped with a leveler or a flat die. In addition, due to the processing method of uneven processing, the unevenness may float on the aluminum side of the inner surface,
When the unevenness of the inner surface is unnecessary, the aluminum surface can be smoothed by polishing or the like.

Next, a press machine equipped with a predetermined die and punch was used to perform drawing to a desired pot shape, and then the inner surface of the electromagnetic induction heating and cooking pot was coated with a fluororesin. The outer surface of the pan for electromagnetic induction heating can be polished to give a metallic luster, and can be painted in various color tones.

In the present embodiment, the concavo-convex processing is performed on the flat plate, but it is also possible to process the flat plate by drawing it into a pot shape. In this case, the concavo-convex processing is performed before the fluororesin coating treatment. If applied, it is possible to reduce adverse effects on the fluororesin coating, such as residual stress and scratches.

[0023]

As described above, according to the first aspect of the invention, since the magnetic metal of the portion facing the induction heating coil of the electromagnetic induction heating cooker body is provided with a plurality of irregularities, the heat generation area is increased. In addition, due to the nature of the magnetic force lines, the magnetic force lines concentrate on the convex portions of the uneven processing, so the heat generation at the convex portions intensifies, a temperature difference occurs due to the unevenness, and many small convections occur inside the electromagnetic induction cooking pot. More uniform convection of the food product results in uniform heating. At the same time, the unevenness of the electromagnetic induction cooking pot, which has a minimal change in size due to work hardening, can maintain stable cooking performance for a long period of time and has high strength and excellent handleability. It becomes a pan for electromagnetic induction heating cooking.

Further, according to the second aspect of the invention, particularly, by limiting the maximum step difference of one section of the unevenness, it is possible to easily remove the dirt stuck to the step and maintain the aesthetic appearance.

According to the third aspect of the present invention, the area of one section of the concave and convex portions is about 4 cm ² or less, and by providing a large number of comparatively fine concave and convex portions, effective convection can be obtained.

Further, according to the invention of claim 4, by limiting the maximum step of a section of the unevenness of the surface with respect to the object to be cooked, non-adhesiveness when the inner surface is subjected to non-adhesive coating treatment, The abrasion resistance and the appearance can be made excellent.

According to the fifth aspect of the invention, when a clad material formed by laminating stainless steel, which is a magnetic metal, and aluminum, which is a good thermal conductor, is used, the thickness of the stainless steel is approximately 0.45 mm to 1. By setting the plate thickness ratio of both metals to 0 mm and setting the plate thickness ratio of both metals within a predetermined range, sufficient heat generation can be obtained, heat conduction can be improved, and an inappropriate increase in weight can be prevented.

Further, according to the invention of claim 6, if at least the portion of the main body of the electromagnetic induction heating cooker facing the temperature sensor is made flat, the temperature sensor and the electromagnetic induction heating cooker are used. The contact of the pan is improved and the temperature can be detected accurately.

According to the invention of claim 7, in the manufacturing process of the pan for electromagnetic induction heating and cooking, the concavo-convex processing is performed in a flat plate state before press forming (drawing) into a pan shape, thereby performing the pressing. There is an advantage that the processing is easy as compared with the case where the uneven processing is performed after the molding.

Further, according to the invention of claim 8, the unevenness is processed after the press molding (drawing) and before the surface non-adhesive coating treatment, but the ease of processing is sacrificed. It is possible to solve the problem that the processed uneven shape is deformed at the time of press molding (drawing) and the unevenness of the unevenness becomes small.

[Brief description of the drawings]

FIG. 1A is a sectional view showing a positional relationship between a pan for an electromagnetic induction heating cooker, a temperature sensor, and an induction heating coil according to an embodiment of the present invention. FIG. The side view (c) is the same as the bottom view of the electromagnetic induction cooking pot.

FIG. 2 is a partial cross-sectional view of the same pot for electromagnetic induction heating cooking.

[Fig. 3] (a) is the same as the shape diagram of the concavo-convex processing of the pot for electromagnetic induction heating and cooking (b) is the same as the shape diagram of another concavo-convex processing of the pot for electromagnetic induction heating and cooking (c) is the same Shape drawing of another uneven processing of the cooking pot

FIG. 4A is a sectional view showing the same before the concavo-convex processing of the electromagnetic induction heating cooking pot, and FIG. 4B is a sectional view showing the same after concavo-convex processing of the electromagnetic induction heating cooking pot.

FIG. 5 is a cutaway sectional view of a conventional pot for an electromagnetic induction heating cooker.

[Explanation of symbols]

 4 Electromagnetic induction cooking pot 7 Magnetic metal 8 Aluminum 12a Recess 12b Convex

Claims (8)

[Claims] 1. An electromagnetic induction comprising aluminum and a magnetic metal provided on an outer surface thereof, wherein the magnetic metal is provided with a plurality of irregularities at least at a portion facing an induction heating coil of an electromagnetic induction heating cooker body. Pan for heating cooker. 2. The pot for an electromagnetic induction heating cooker according to claim 1, wherein the plurality of unevennesses have a maximum step difference of one section being approximately 1/30 to 1/2 of the magnetic metal plate thickness. 3. The pan for an electromagnetic induction heating cooker according to claim 1 or 2, wherein each of the plurality of concaves and convexes has an area of one concave portion of about 4 cm ² or less. 4. The maximum step difference of one section of the unevenness of the surface containing the food to be cooked is set to be smaller than the maximum step difference on the surface on the opposite side. Electromagnetic induction heating cooker pot. 5. The plate thickness of the magnetic metal is approximately 0.45 mm.
The pan for an electromagnetic induction heating cooker according to any one of claims 1 to 4, wherein the clad material has a plate thickness ratio of aluminum to the magnetic metal of about 2.0 to 3.5 and is about 1.0 mm. 6. The magnetic metal has a flattened portion facing the temperature sensor of the main body of the electromagnetic induction heating cooker.
A pan for an electromagnetic induction heating cooker according to any one of items 1 to 5. 7. After providing a plurality of irregularities on the magnetic metal surface,
The method for producing a pan for an electromagnetic induction heating cooker according to any one of claims 1 to 6, which is obtained by press forming into a pan shape. 8. The electromagnetic induction cooking according to claim 1, wherein a plurality of irregularities is provided after press-forming into a pot shape and before performing a non-adhesive coating treatment. Method of manufacturing pot for cooking.