JPH0779858A - Induction-heating type cooking unit - Google Patents

Abstract

PURPOSE:To provide a cooking unit in which a cooking pot itself is heated in its entirety by an induction coil so as to uniformly raise the temperature thereof. CONSTITUTION:This induction-heating type cooling unit is composed of a cooking pot 7 formed by baking a mixture of magnetic powder and carbon powder, a frame 3 storing therein the cooling pot 7, and an induction coil 5 provided in the inner bottom part of the frame 3 and having a ring-like planar part on which the cooking pot 7 is set. Further, the cooling pot 7 is set on the induction coil 5, which is then energized so as to heat the cooling pot 7 by current running through the magnetic powder. When the coil 5 is energized, magnetic fluxes flow through the magnetic powder in the cooling pot 7, which is therefore heated in its entirety. Further, thus obtained heat is transmitted in a short-time through the carbon powder throughout the cooking pot 7, and the temperature of all parts of the cooking pot 7 is increased so as to uniformly heat foodstuff to be cooked.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an induction heating cooker which heats a cooking pot with magnetic flux flowing through an induction coil and flowing through a magnetic material.

[0002]

2. Description of the Related Art Generally, a pan used in an induction cooker uses a material for conducting heat to the entire pan and a magnetic material for generating a magnetic flux. As a result, a thick aluminum ( It is formed of a so-called clad steel, which is a two-layer pot in which stainless steel (magnetic material) is bonded to the outside with thermal conductivity inside. (Refer to Japanese Utility Model Publication No. 2-27518) Two sets of induction coils are provided corresponding to the bottom and sides of the two-layer pan, and the stainless steel itself is provided by the magnetic flux flowing through the stainless steel by passing a current through the induction coils. Heats up
This heat is conducted to the whole pan by aluminum so that the food to be cooked is cooked.

The reason for providing the above-mentioned two sets of induction coils is that, in general, stainless steel has poor heat conduction as compared with aluminum. The temperature of the side part (especially the upper part of the pan) is lower than that of the bottom part of the pan, and the temperature distribution becomes non-uniform, which causes a problem of uneven cooking in the case of a rice cooker.
For this reason, an induction coil dedicated to the bottom is provided at the bottom, and an induction coil dedicated to the side is provided at the side so as to make the temperature of the entire two-layer pan uniform.

[0004]

However, since the above-mentioned two-layer pan uses stainless steel having a large specific gravity, the weight of the pan as a whole is increased, which is about 1. It became eight times the weight, and adding rice and water to it further increased the weight and made it troublesome to handle.

Further, as described above, since the two sets of induction coils are provided, not only the cost is increased, but also the power consumption is increased and the electric circuit is complicated.

In the present invention, when the cooking pot itself generates heat by the induction coil, the temperature of the entire cooking pot is uniformly raised in a short time.

[0007]

DISCLOSURE OF THE INVENTION The present invention is directed to a cooking pot in which magnetic powder and carbon powder are mixed and fired, a frame for accommodating the cooking pot, and the cooking pot provided on the inner bottom portion of the frame. And an induction coil having a ring-shaped flat surface on which the cooking pot is placed, the cooking pot is placed on the induction coil, the induction coil is energized, and the cooking pot is heated by the magnetic flux flowing through the magnetic powder. To do.

Further, the cooking pot has a bottom wall and a rising wall continuous with the bottom wall, and the magnetic powder is mixed in the entire bottom wall of the cooking pot and near the lower part of the rising wall. .

The diameter of the flat portion of the induction coil and the diameter of the rising wall of the cooking pot are made substantially equal to each other, and when the cooking pot is placed on the induction coil, the rising wall is directly above the flat portion. It is located in.

Further, the width dimension of the flat portion of the induction coil is set to be approximately the same as the thickness dimension of the rising wall of the cooking pot, or the width dimension of the flat portion is set large.

[0011]

According to the present invention, a cooking pot prepared by mixing and firing magnetic powder and carbon powder is placed on an induction coil, and the induction coil is energized to heat the cooking pot by the magnetic flux flowing through the magnetic powder. Therefore, when the induction coil is energized, magnetic flux flows through the magnetic powder in the cooking pot to heat the entire cooking pot, and this heat is conducted to the entire cooking pot in a short time by the carbon powder. Generates heat evenly.

Further, since the magnetic powder is mixed in the whole bottom wall of the cooking pot and near the lower part of the rising wall, the amount of the magnetic powder which causes a weight increase is minimized and the rising wall is increased. Even if the magnetic powder is not mixed with the upper part of the powder, the upper part of the rising wall can be heated uniformly due to the thermal conductivity of the carbon powder.

When the cooking pot is placed on the induction coil, the rising wall is located immediately above the plane portion, so that the distance between the induction coil and the rising wall is the shortest and the loss of magnetic flux is small. The cooking pot becomes less and heats up efficiently.

Further, since the width dimension of the flat portion of the induction coil is set to be approximately the same as the thickness dimension of the rising wall of the cooking pot or the width dimension of the flat portion is set large, the magnetic flux is the rising wall of the cooking pot. Mainly flows to both the bottom and is heated.

[0015]

Embodiments of the present invention will be described with reference to the drawings.
1 is a sectional view of an induction heating cooker according to the present invention, and FIG. 2 is a sectional view of a cooking pot. (1) is a cooker body consisting of an outer case (2) and a frame (3) provided inside the outer case, and (4) is a support plate provided on the inner bottom of the cooker body (1). , (5) are induction coils having a ring-shaped flat portion (6) fixed to the upper part of the support plate (4), and the width dimension (W1) of the flat portion (6) will be described later. It is set to be larger than the thickness dimension (W2) of the rising wall (11). (7) is a cooking pot in which magnetic powder (8) with increased density mixed with iron (8) and carbon powder (9) with good thermal conductivity are mixed, compressed and baked at a high temperature of 1000 ° C or more. And has a bottom wall (10) and a rising wall (11) connected to the bottom wall, and the carbon powder (9) ... is spread over the entire bottom wall (10) and the rising wall (11). The magnetic powders (8) are mixed in the bottom wall (10) as a whole and in the vicinity of the lower part of the rising wall (11) with increasing density.

The cooking pan (7) is formed by molding the bottom wall (10).
There is a car near the part that becomes the bottom and the lower part of the rising wall (11).
Binder powder (9) and magnetic powder (8) are mixed with a binder (not shown), and only carbon powder (9) is placed on the upper part of the rising wall (11) and fired.
This molded product has a relatively large thickness in order to maintain its shape (pot shape).

A flange (13) is provided on the periphery of the upper opening (12) of the cooking pot (7). The thermal conductivity (λ) of the carbon powder (9) ...
Although it is 0.16 (KcaL / mh ° C.), the density is increased by compressing and firing at a high temperature, and the thermal conductivity is several times higher.

Further, the specific weight (γ) of the carbon powder (9) is 1,540 (Kg / m ³ ), and the specific weight of aluminum is relatively high in heat conductivity and is lightweight. (Γ)
= Lighter than 2,710 (Kg / m ³ ). For example, as described above, when the weight of the molded product of the present invention when compressed and sintered at a high temperature is 1, aluminum has the same size as the molded product of the present invention, 1.45, and iron has 4. 23, copper is 4.82, which is extremely lightweight.

The outer peripheral edge of (14) is the cooking pot (7).
With the pan lid placed on the flange (13), carbon powder is mixed and baked in the same manner as the cooking pan (7). (15) is a temperature sensor that contacts the outer surface of the bottom wall of the cooking pot (7) provided at the center of the induction coil (5) in the shape of a ring, and detects the completion of cooking (rice cooking) and keeping the cooking pot ( 7) Detect the temperature and control circuit (not shown)
To enter.

Reference numeral (16) is a lid body for covering the cooker body (1), which is formed by an outer lid (17) and an inner lid (18),
A ventilation hole (19) communicating with the inside and outside is provided in part.
(20) is a vapor sensor provided in the vent hole (19).

Next, the operation will be described. First, after putting a predetermined amount of rice and water in the cooking pot (7), the pot lid (1)
4) is placed on the flange (13) of the cooking pot (7) to cover the top of the cooking pot.

Thereafter, when the cooking pot (7) is housed in the frame (3) and placed on the induction coil (5),
An induction coil (5) is located directly below the rising wall (11) of the cooking pot. Magnetic flux flowing through the magnetic powder (8) of the bottom wall (10) of the cooking pot (7) and the magnetic powder of the rising wall (11) of the cooking pot (7) by energizing the induction coil (5) ( The cooking pot generates heat due to the magnetic flux flowing through 8). As a result, the heat generated by the bottom wall (10) and the rising wall (11) is transferred to the upper side of the cooking pot in a short time due to the thermal conductivity of the carbon powder (9) and the temperature rises. In the comparison of the experimental results using the aluminum cooking pot, the molded product of the present invention reached a predetermined temperature in each part of the cooking pot about 72% earlier than the aluminum cooking pot.

The pot lid (1) is passed from the flange (13) of the cooking pot (7) which has become hot due to the thermal conductivity of the carbon.
Heat is conducted to 4), and the pot lid also rises to almost the same temperature as the cooking pot (7) to heat the rice and water in the cooking pot from above.

Thus, when the water in the cooking pot (7) runs out and the temperature rises abruptly, the temperature sensor (15) which detects this temperature rise inputs the signal to the control circuit and outputs the signal to the induction coil (5). Stop energizing. After that, when the temperature in the cooking pot (7) decreases to the heat retention temperature (about 70 degrees), the induction coil (5) is energized to heat the cooking pot (7) again. In this case, Since the induction coil (5) has a large amount of heat due to the thickness of the cooking pot (7) and a small amount of heat is dissipated, heat can be generated with a small amount of electricity and the entire cooking pot (7) and the pot. The temperature of the lid (14) can be raised almost at the same time to keep the entire surface warm.

In this embodiment, the width dimension of the flat portion of the induction coil is set to be larger than the thickness dimension of the rising wall of the cooking pot. The width dimension and the thickness dimension of the rising wall may be substantially the same. In this case, since the accommodation amount is small, even if the width dimension of the flat portion is as small as the thickness dimension of the rising wall, both the bottom wall and the side wall of the cooking pot can generate heat.

[0026]

INDUSTRIAL APPLICABILITY As described above, the present invention provides a magnetic powder and a card.
Since a cooking pot in which Bonn powder is mixed and fired is placed on an induction coil and the coil is energized to heat the cooking pot by magnetic flux flowing through the magnetic powder, cooking is performed when the induction coil is energized. Magnetic flux flows through the magnetic powder in the pan to heat the entire cooking pan, and this heat is conducted to the entire cooking pan in a short time by the carbon powder, raising the temperature of each part of the cooking pan and increasing the temperature of the entire cooking target. Heat evenly. Therefore, there is no drawback that the food to be cooked located above the inside of the cooking pot is insufficiently heated. Also, the cooking pot is very lightweight and easy to clean and transport.

Further, since the magnetic powder is mixed in the entire bottom wall of the cooking pot and near the lower part of the rising wall, the amount of the magnetic powder which causes a weight increase is minimized and the rising wall is increased. Even if the magnetic powder is not mixed with the upper part of the powder, the upper part of the rising wall can be heated uniformly due to the thermal conductivity of the carbon powder. That is, since the use of magnetic powder having a lower thermal conductivity than that of carbon powder on the upper portion of the side wall of the cooking pot is avoided, the temperature of the upper portion of the side wall rises in a short time.

When the cooking pot is placed on the induction coil, the rising wall is located immediately above the flat surface portion, so that the distance between the induction coil and the rising wall becomes the shortest, and the rising wall and the bottom wall together. The rising wall can be actively heated.

Further, since the width dimension of the flat portion of the induction coil is set to be approximately the same as the thickness dimension of the rising wall of the cooking pot or the width dimension of the flat portion is set large, the magnetic flux is the rising wall of the cooking pot. Flows mainly through both bottom walls and is heated.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an induction heating cooker of the present invention.

FIG. 2 is a sectional view of the cooking pot.

[Explanation of symbols]

 1 Cooker main body 3 Frame 5 Induction coil 6 Plane part 7 Cooking pot 8 Magnetic powder 9 Carbon powder 10 Bottom wall 11 Rising wall W1 Width dimension W2 Thickness dimension

Claims (4)

[Claims] 1. A cooking pot in which magnetic powder and carbon powder are mixed and fired, a frame for accommodating the cooking pot, and a ring-shaped flat surface provided on the inner bottom of the frame for placing the cooking pot. And an induction coil having a portion, wherein the cooking pot is placed on the induction coil, the induction coil is energized, and the magnetic flux flowing through the magnetic powder heats the cooking pot. Cooking device. 2. The cooking pot has a bottom wall and a rising wall connected to the bottom wall, and the magnetic powder is mixed in the entire bottom wall of the cooking pot and near the lower part of the rising wall. The induction heating cooker according to claim 1. 3. The diameter of the flat portion of the induction coil and the diameter of the rising wall of the cooking pot are substantially equal to each other, and when the cooking pot is placed on the induction coil, the rising wall is directly above the flat portion. The induction heating cooker according to claim 1, wherein 4. The induction according to claim 1, wherein the width dimension of the flat portion of the induction coil is set to be substantially the same as the thickness dimension of the rising wall of the cooking pot or the width dimension of the flat portion is set large. Heating cooker.