JPH08273819A - Cooking pan - Google Patents

Abstract

PURPOSE: To solve the decrease of the quantity of heat generation due to a non magnetic metal in the bottom part of a cooking pan and heighten the heating efficiency regarding a cooking pan made of a non magnetic metal in which a magnetic metal is embedded. CONSTITUTION: As for a cooking pan 7 made of a non-magnetic metal in which a magnetic metal 11 is embedded in the bottom part and at the same time which is set on a heating coil 4 of a microwave cooking appliance to heat the magnetic metal 11 by induction heating: a plurality of cut parts 13 are formed by cutting the non-magnetic metal between the magnetic metal 11 and a face 8 to set a pan on in the way the magnetic metal is made to face to the face 8 and arranged radiantly from the center of the face 8 to the outer circumference. Of the cut parts 13, at least the non-magnetic metal between two cut parts 13a, 13b is cut to form a bridging part 14 to bridge these two cut parts 13a, 13b, so that eddy current 12' flowing in the direction inverse to the current flow in the heating coil 4 can be lessened and the quantity of the heat generation for a pan can be increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooking pot which can be heated by an electromagnetic cooker.

[0002]

2. Description of the Related Art A cooking pot of this type is disclosed in Japanese Patent Laid-Open No. 7-578.
No. 65 publication. This is an aluminum pot placed on the heating coil of an electromagnetic cooker, in which a magnetic metal that is heated by the magnetic flux of the heating coil is embedded in the bottom of the pot by casting aluminum, and eddy current flows in the magnetic metal. In order to generate the above, a slit, that is, a cutout portion for dividing the aluminum layer is provided on the outer bottom wall surface of the pot.

[0003]

In the electromagnetic cooker, the principle of heating the pan will be described. The magnetic flux generated in the heating coil enters the pan and follows the path returning to the heating coil via the bottom of the pan. The magnetic flux passing through the bottom of the pot causes an eddy current in the bottom of the pot in a clockwise direction with respect to the traveling direction of the magnetic flux, and this eddy current causes Joule loss, which causes the pot to generate heat.

The direction in which the magnetic flux at the bottom of the pot passes is a clockwise direction with respect to the direction of the current flowing through the heating coil, that is, the heating coil is spirally wound on a flat coil stand. It is parallel to the radial direction from the center of. Therefore, the eddy current flows counterclockwise with respect to the traveling direction of the magnetic flux, that is, in the concentric direction around the center of the pan bottom and in the direction opposite to the direction of the current flowing through the heating coil.

However, most of the magnetic flux passing through the bottom of the pan passes only in the portion facing the heating coil, that is, in the range of the size of the heating coil. Although there is some magnetic flux passing through the outer peripheral portion from this range, the magnetic flux does not contribute to heat generation because it is negligible compared to the portion facing the heating coil.

[0006] Therefore, magnetic metals such as iron and stainless steel have a large Joule loss and a large amount of heat generation from the pot because they have a lower conductivity than non-magnetic metals such as aluminum.

On the other hand, a non-magnetic metal such as aluminum has a high electric conductivity and a small Joule loss, so that the calorific value of the pan is reduced.

Therefore, when a magnetic metal is embedded in a non-magnetic metal as in the prior art, the non-magnetic metal exists between the heating coil and the magnetic metal, and an eddy current flows in this non-magnetic metal. become. A magnetic field is generated by this eddy current, but since it is generated in the direction opposite to the magnetic field of the heating coil, the magnetic field of the heating coil is canceled and the amount of Joule loss generated in the magnetic metal is reduced. Assuming that the amount of heat generated when heating a pot of magnetic metal is 100%, in a pot in which magnetic metal is embedded in non-magnetic metal, the eddy current flowing between the non-magnetic metal and the heating coil causes the eddy current to flow in the heating coil. The generated magnetic flux is canceled and the magnetic flux is reduced to 80% or less.

Further, when the magnetic metal is embedded in the non-magnetic metal, it is necessary to hold the magnetic metal in the mold for manufacturing, and since the non-magnetic metal is cast while holding it, the holding portion is the same as in the conventional case. It remains as a slit like a technique.

That is, in FIGS. 1 and 11, 1 is an electromagnetic cooker main body, 2 is an exterior of the electromagnetic cooker 1, 3 is a ceramic top plate on which a cooking pot to be described later is placed, and 4 is a top plate. A circular heating coil disposed below the top plate 3 for generating a magnetic field, 5 is a heating coil base for mounting and supporting the heating coil, and 6 is a control for supplying a current to the heating coil 4 to generate a magnetic field. It is a device.

Reference numeral 7 denotes a cooking pot integrally formed by casting using a non-magnetic metal such as aluminum or an aluminum alloy. When placed on the top plate 3, a circular placing surface is in contact with the top plate surface. It is composed of a bottom portion 9 having a bottom surface 8 and a side portion 10 continuously rising from the periphery of the bottom portion 9.

Reference numeral 11 denotes a circular heating plate made of magnetic metal such as iron or stainless steel, which is buried in the bottom portion 9 of the pot 7 at the time of casting, and 12 denotes a handle provided facing the side portion 10 of the pot 7. Is.

The heating plate 11 is formed with a plurality of convex portions 13 which are provided so as to protrude downward from the center of the heating plate 11 in a rectangular shape whose longitudinal direction is the radial direction. The convex portion 13 is a portion that is held in contact with a mold when the pot 7 is molded, and this portion is not covered with a non-magnetic metal and can be exposed from the mounting surface 8. Therefore, since the non-magnetic metal is cut out at the portion where the convex portion 13 is provided, it corresponds to the notched portion in the claims.

In FIG. 12, a range shown by a dotted line is a range facing the heating coil 4, and a range shown by a chain line shows the size of the magnetic metal 11.

The eddy current generated in the shaded area A on the mounting surface 8 is
It flows to the adjacent shaded portion B via the non-magnetic metal portion 15 on the inner peripheral side or the non-magnetic metal portion 16 on the outer peripheral side of the cutout portion 13a.
In the shaded portion B, the eddy current flowing from the shaded portion A and the eddy current generated in the shaded portion B together with the non-magnetic metal portion 17 on the inner peripheral side or the non-magnetic metal portion on the outer peripheral side of the cutout portion 13b are included. 1
It flows via 8 further into the shaded area C next to it. By the same principle, the eddy current I1 flows through the nonmagnetic metal at the bottom of the pan and the eddy current I2 flows at the outer circumference of the bottom of the pan and the eddy current I2 flows at the center of the pan.

The eddy current generated in the non-magnetic metal has a higher conductivity in the non-magnetic metal, so that it flows only in the non-magnetic metal and does not easily flow to the magnetic metal side. Further, as described above, the eddy current generated at the bottom of the pan flows only within the one-dot chain line in FIG. Therefore, the eddy current generated in the non-magnetic metal on the bottom of the pan passes through the non-magnetic metal parts 15 and 17 on the inner peripheral side of the notch 13 and the non-magnetic metal parts 16 and 18 on the outer peripheral side of the notch 13, and the eddy current is concentric to the center of the pan bottom. An electric current will flow.

Since the eddy currents I1 and I2 flowing in the bottom of the pot flow in the direction opposite to the direction of the current flowing in the heating coil 4 as described above, the magnetic field generated by this eddy current cancels the magnetic field of the heating coil. It was the cause of the decrease in the calorific value of the pan.

The present invention solves this problem.

[0019]

A cooking pot according to the present invention is formed from a side portion and a bottom portion, at least the magnetic metal is embedded in the bottom portion, and the cooking pot is placed on a heating coil of an electromagnetic cooker and the magnetic material is placed on the heating coil. In a non-magnetic metal cooking pot capable of inductively heating a metal, a plurality of notches are formed by notching the non-magnetic metal between the magnetic metal and the bottom surface of the bottom so that the magnetic metal faces from the bottom surface. , Radially arranged from the center of the lower surface in the outer peripheral direction, and at least two of the notches
This is a configuration in which a non-magnetic metal between two cutouts is cut out to provide a connecting portion for connecting the two cutouts.

Further, the bridging portion is provided on the center side of the lower surface of the bottom portion among the end portions of the cutout portion.

Further, the bridging portion is provided on the outer peripheral side of the lower surface of the bottom portion among the end portions of the cutout portion.

Further, the bridging portion is provided on the center side and the outer peripheral side of the lower surface of the bottom portion of the end portion of the cutout portion.

Further, the side portion and the bottom portion are formed of a non-magnetic metal, and the magnetic metal is embedded in at least the bottom portion,
In a cooking pot that can be placed on a heating coil of an electromagnetic cooker to inductively heat the magnetic metal, the non-magnetic metal between the magnetic metal and the bottom surface of the bottom is cut out to cut the magnetic metal from the bottom surface. A plurality of notches arranged so as to face each other are arranged radially from the center of the lower surface in the outer peripheral direction, and at least one of the notches extends outside the outer periphery of the heating coil.

Further, the cutout portion has a substantially rectangular shape whose longitudinal direction is substantially parallel to the radial direction from the center of the bottom surface of the bottom portion.

Further, the non-magnetic metal is aluminum or an aluminum alloy, and the magnetic metal is stainless steel or iron.

[0026]

Function: That is, the eddy current flowing through the non-magnetic metal at the bottom of the pan is
By the connecting portion provided between the plurality of notches, it is possible to prevent the passage of the flow in the direction opposite to the heating coil from being taken, and to prevent the magnetic field of the heating coil from being canceled by the magnetic field due to the eddy current,
Prevents the decrease of the calorific value of the pan.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the above description, the components having the same numbers as those described above have the same functions, and therefore their explanations are omitted.

In FIG. 2, reference numeral 14 designates convex portions 13a and 13b.
Is a position connecting the inner peripheral side end of the pan 7, and the non-magnetic metal between the mounting surface 8 at the bottom of the pan 7 and the magnetic metal 11 is cut out to pass the convex portions 13a and 13b. It is a transfer section to be established.

In FIG. 3, an eddy current I2 'tends to flow to the bottom of the pot due to the magnetic field of the heating coil 4, but by providing the connecting portion 14, the shaded portion A surrounded by the convex portions 13a and 13b. The eddy current generated in 1 does not flow in the eddy current I2 '. As the eddy current in the shaded area A stops flowing, the eddy current I
The magnetic field that cancels the magnetic field of the heating coil 4 generated by 2'becomes small, and the amount of heat generated by the pot 7 increases.

Another embodiment of the pattern of the mounting surface 8 is shown in FIG.
Shown in In this embodiment, the connecting portion 14 is connected to the convex portions 13a and 1a.
It is provided at a position connecting the outer peripheral side end with 3b.

In FIG. 5, an eddy current I1 'is generated and flows at the bottom of the pot, but the eddy current generated at the shaded portion A surrounded by the convex portions 13a and 13b is separated by the connecting portion 14 and stops flowing. . When the eddy current in the shaded area A stops flowing, the eddy current I
1'is decreased, and the magnetic field that cancels the magnetic field generated in the heating coil 4 is decreased, so that the heat generation amount of the pan 7 is increased.

FIG. 6 is a view in which the connecting portion 14 of FIG. 2 is provided at a position connecting all the inner peripheral side end portions between the respective convex portions 13.
The eddy current I2 'is not allowed to flow to eliminate the magnetic field generated by the eddy current.

FIG. 7 shows the connecting portion 14 of FIG. 4 provided at a position connecting all the outer peripheral side end portions between the respective convex portions 13.
The eddy current I1 'is not allowed to flow to eliminate the magnetic field generated by this eddy current.

FIG. 8 shows a connecting portion 14 provided on the inner peripheral side of FIG.
And the connecting portion 14 provided on the outer peripheral side of FIG. 7 are both provided.

That is, since the connecting portions 14 are provided so as to connect the inner peripheral side end portions and the outer peripheral side end portions of the respective convex portions 13,
The amount of heat generated by the pan 7 is increased by stopping the flow of eddy currents I1 ′ and I2 ′ generated at the bottom of the pan 7.

FIG. 9 shows a structure in which the above-mentioned connecting portion 14 is eliminated and the length of the convex portion 13a among the plural convex portions 13 in the longitudinal direction is increased. The convex portion 13 a has a length that extends outside the outer circumference of the heating coil 4 and extends inside the inner circumference of the heating coil 4.

That is, since the eddy current generated at the bottom of the pot is generated only in the portion facing the heating coil 4 (the range of the one-dot chain line), the eddy currents I1 and I2 shown in FIG. The eddy current flowing in the direction opposite to the heating coil 4 is prevented from flowing.

FIG. 10 shows four protrusions 13a, 13b, 13c and 13d arranged at 90 ° intervals.
It is long only in the outer peripheral direction and is provided outside the outer peripheral portion of the heating coil 4. This effect is the same as that of the embodiment shown in FIG. 9, and the path of the eddy current flowing in the opposite direction to the current flowing through the heating coil 4 is cut off so that the magnetic field generated in the heating coil 4 is not canceled.

As described above, the magnetic field generated by the heating coil 4 enters the pot 7 to generate an eddy current.
By reducing or eliminating the eddy currents I1 and I2 as shown in Fig. 1, the magnetic field generated by this eddy current is reduced or eliminated, and the amount of cancellation of the magnetic field generated in the heating coil 4 is reduced. The amount of heat generation is increased.

[0040]

According to the present invention, the calorific value of the non-magnetic metal pot in which the magnetic metal is embedded is increased, and the decrease in heating efficiency is alleviated.

[Brief description of drawings]

FIG. 1 is a block diagram showing a basic configuration of the present invention.

FIG. 2 is a diagram showing a pattern of convex portions of a pan showing an embodiment of the present invention.

FIG. 3 is a diagram in which paths of eddy currents flowing in FIG. 2 are overlapped.

FIG. 4 is a view showing a pattern of convex portions of a pot showing another embodiment of the present invention.

5 is a diagram in which the paths of the eddy currents flowing in FIG. 4 are superimposed.

FIG. 6 is a view showing a pattern of convex portions of a pot showing another embodiment of the present invention.

FIG. 7 is a view showing a pattern of convex portions of a pot showing another embodiment of the present invention.

FIG. 8 is a view showing a pattern of convex portions of a pot showing another embodiment of the present invention.

FIG. 9 is a view showing a pattern of convex portions of a pot showing another embodiment of the present invention.

FIG. 10 is a view showing a pattern of convex portions of a pot showing another embodiment of the present invention.

FIG. 11 is a view showing a pattern of convex portions of a conventional pot.

12 is a diagram in which the paths of the eddy currents flowing in FIG. 10 are superimposed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electromagnetic cooker body 4 Heating coil 7 Cooking pot 11 Magnetic metal 13 Convex part (notch part) 14 Transfer part

Claims (7)

[Claims] 1. A cooking pot made of a non-magnetic metal, which is formed of a side part and a bottom part, and in which at least the bottom part is filled with a magnetic metal, and which is placed on a heating coil of an electromagnetic cooker to induction-heat the magnetic metal. In, a plurality of notches are formed by notching the non-magnetic metal between the magnetic metal and the bottom surface of the bottom so that the magnetic metal faces the bottom surface, and are arranged radially from the center of the bottom surface toward the outer peripheral direction. The cooking pot is characterized in that a non-magnetic metal between at least two cutouts of the cutouts is cut out to provide a connecting portion for connecting the two cutouts. 2. The cooking pot according to claim 1, wherein the connecting portion is provided on the center side of the lower surface of the bottom portion among the end portions of the cutout portion. 3. The cooking pot according to claim 1, wherein the connecting portion is provided on an outer peripheral side of a lower surface of the bottom portion among end portions of the cutout portion. 4. The cooking pot according to claim 1, wherein the connecting portion is provided on the center side and the outer peripheral side of the lower surface of the bottom portion among the end portions of the cutout portion. 5. The side portion and the bottom portion are formed of a non-magnetic metal,
In a cooking pot in which magnetic metal is embedded at least in the bottom portion and which can be placed on a heating coil of an electromagnetic cooker to inductively heat the magnetic metal, the non-magnetic material between the magnetic metal and the bottom surface of the bottom portion. A plurality of notches formed by notching metal so that the magnetic metal faces from the lower surface are arranged radially from the center of the lower surface in the outer peripheral direction, and at least one of the notches is formed from the outer periphery of the heating coil. A cooking pot characterized by being extended to the outside. 6. The cooking device according to claim 1, wherein the cutout portion has a substantially rectangular shape whose longitudinal direction is substantially parallel to a radial direction from a center of a bottom surface of the bottom portion. pot. 7. The cooking pot according to claim 1, wherein the non-magnetic metal is aluminum or an aluminum alloy, and the magnetic metal is stainless steel or iron.