JP3107897B2 - Cooking pots and plates for electromagnetic - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to fire prevention and temperature control of a pot or a metal plate without using a temperature controller.

[0002]

2. Description of the Related Art Conventionally, when controlling the temperature of a pan by electromagnetic induction heating, a sensor of a temperature controller is installed in a place not affected by the magnetic flux of a work coil, that is, on the outer peripheral surface of the pan, or a sensor is mounted on the pan. There is only a method of putting directly into the inside (foodstuff), and if it is installed on the outer peripheral surface, the temperature control will be inaccurate,
In addition, when placed in a pot, it hindered cooking, and had problems with hygiene and cleaning.

It is generally well known that a magnetic metal pot is heated by an electromagnetic cooker, and several kinds of dedicated pots are commercially available. The pot ingredients also have their respective Curie points, but at 700-800 ° C, they are not suitable for cooking. Permalloy can change the Curie point by adjusting the nickel content, and can produce a permalloy suitable for the cooking temperature. In addition, permalloy (JIS C25) which is generally sold as a core material for transformers
31PD) can also be used for cooking, taking into account the degree of bonding to the pot bottom, and can maintain a constant cooking temperature.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to accurately control cooking temperature without using a temperature controller and to prevent a fire by controlling the temperature of the pot itself.

[0005]

According to the present invention, a permalloy is provided on the bottom of a metal pot used for electromagnetic induction heating, and the permalloy sets its Curie point to a cooking temperature. Adapted and temperature controlled and above
A gap is provided between the bottom surface and the top surface of Permalloy,
The cooking pot for electromagnetic use according to the invention, wherein the welding area between the bottom surface of the metal cooking pot and the top surface of the permalloy is adjusted by changing the heating temperature of the pot. Instead of the metal pan, the electromagnetic cooker according to the first or second aspect of the present invention has a permalloy disposed on the bottom surface of a metal plate.

[0006]

According to the present invention, when permalloy 2 is placed on electromagnetic cooker 4 by electromagnetic induction heating, magnetic flux generated from work coil 5 causes magnetic material permalloy 2 to generate eddy current and generate heat due to its own electric resistance. . As the temperature rises, the atoms that carry the magnetic moment vibrate violently, so that the parallelism of the magnetic moment is disturbed and the spontaneous magnetization decreases. When the Curie point is reached, magnetism is no longer exhibited, and eddy current is also reduced and no heat is generated. With this operation, the temperature of cooking can be controlled.

A gap t is interposed between the bottom surface of the metal plate or the pot 1 and the upper surface of the permalloy 2 by welding 3, and radiant heat from the permalloy 2 at a certain temperature is adjusted by the size of the gap t. The conduction heat from the three weld portions can be adjusted by adjusting the area of the weld 3.

[0008]

EXAMPLE A permalloy 2 is placed on the bottom of a commercially available iron plate or iron pan 1 (FIG. 1). The spot welding 3 is used as an arrangement example, and the spot position and the number of the spot welding 3 are set so as to reach the cooking temperature.

[0009] Heat conduction is based on Fourier's law.

[0010]

(Equation 1)

Q ‥ Heat quantity flowing in unit time (Kcal / h) Q ‥ Heat quantity flowing in θ time (Kcal) A ‥ Cross section (m ² ) x ‥ Thickness (m) Δt ‥ Temperature difference (° C) λ ‥ Heat Deform the conductivity

[0012]

(Equation 2)

When λ and q are fixed, as can be seen from the above equation, when the contact surface, that is, the cross-sectional area A is increased, Δ
Since t becomes smaller and the cross-sectional area becomes smaller, Δt becomes larger, and the temperature difference Δt between the heat generation temperature of the permalloy 2 and the pot temperature can be obtained by the gap t between the bottom surface of the pot 1 and the upper surface of the permalloy 2 and the number of spot welds 3. The temperature of the pan 1 can be made variable by changing the gap t even if the heat generation temperature of 2 is constant.

When the iron pot 1 or the iron plate on which the permalloy 2 is disposed is placed on the electromagnetic cooker 4 (FIG. 2) and the power is turned on, the permalloy 2 on the bottom surface generates heat and heats the pot 1 or the iron plate from the spot welding 3 part. A part of the non-welded portion where the heat is conducted receives heat by radiation. When the permalloy 2 reaches the Curie point p, the output of the inverter 4 'decreases to maintain the cooking temperature, but when the temperature falls below the Curie point p due to a load or the like, the output of the inverter 4' increases to keep the set temperature constant. Cooking is performed.

In FIG. 5, reference numeral 6 denotes a ceramic plate, FIG. 3 shows an experimental state of Permalloy 2, 5 'denotes a central space of the work coil 5, and e in FIG. The range in which the Curie point p (magnetic transformation point) changes, a, b, and c in FIG.
In FIG. 6, a ', b', and c 'are measured temperatures at the temperature measurement points a, b, and c, and a "and b" are fluctuation points due to load.

[0016]

According to the present invention, the permalloy 2 is disposed on the bottom of the metal pot 1 or the metal plate, and the heat of the permalloy 2 is transmitted to the pot 1 or the plate by electromagnetic induction heating. The cooking temperature can be set, and the temperature required for cooking can be set by setting the Curie point p of the permalloy 2 to the cooking temperature. Therefore, there is no fear of fire and the effect of eliminating the inaccuracy of the temperature sensor and the complexity of the device can be eliminated.

[Brief description of the drawings]

FIG. 1 is a side view showing an electromagnetic cooking pot according to the present invention.

FIG. 2 is an enlarged side view of a weld and a gap.

FIG. 3 is a side view of the experimental apparatus.

FIG. 4 is a plan view along the line AA in FIG. 3;

FIG. 5 is a susceptibility / Curie point curve diagram.

FIG. 6 is a temperature-time curve diagram.

[Explanation of symbols]

 Reference Signs List 1 metal plate or pot 2 permalloy p Curie point t gap 3 welding

Claims (3)

(57) [Claims] 1. A result by arranging the permalloy on the bottom surface of the metal pan to be used for electromagnetic induction heating, and the permalloy is temperature adjusted by adapting its Curie point the cooking temperature, and
A gap is provided between the bottom surface and the top surface of Permalloy,
Adjust the gap to change the heating temperature of the pan
A cooking pot for electromagnetic use. 2. The electromagnetic cooking pot according to claim 1, wherein a welding area between a bottom surface of the metal pot and a top surface of the permalloy is adjusted. 3. The electromagnetic cooking plate according to claim 1, wherein a permalloy is provided on a bottom surface of the metal plate instead of the metal pan.