JPH08266402A - Induction heating rice cooker - Google Patents

Abstract

PURPOSE: To eliminate heat shortages and then allow good rice cooking by joining a magnetic metallic material to the outside of a thick-walled part at the corner from the bottom wall to the side wall of the whole of a pan. CONSTITUTION: A pan body 1 is formed from a nonmagnetic material in a bottomed cylindrical form, a part rising from the bottom to the side wall is made thicker than the other parts, the inside perimeter is formed in a circular form, the outside perimeter is swollen out diagonally downward in a nearly trapezoidal form. A magnetic metallic material 2 is joined to the pan body 1 from the outside perimeter of the bottom wall 1a to the lower outside perimeter of the side wall 1b via the outside perimeter of the thickened wall part 1c. Thus, the thickened wall part makes it possible to increase the heat capacity of the corners, and the joining of the magnetic metallic material makes heat generation possible. The formation of a thickened wall part allows positioning near an induction coil and increases the magnetic flux density of the corers, activates heat generation at the corners, and resolves undermixing inside the pan body.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an induction heating rice cooker utilizing electromagnetic induction.

[0002]

2. Description of the Related Art An induction heating rice cooker using electromagnetic induction is known to have high heating efficiency. Conventionally, a non-magnetic material and F
e, one using a clad material with stainless steel, one in which a magnetic metal is sprayed on the outer surface of the bottom wall of an aluminum pot main body, and a magnetic metal plate is fixed, etc. are known.
However, although the former is high in cost and the latter is inexpensive, there is a problem that the heat quantity is still insufficient in the rising portion from the bottom wall to the side peripheral wall (hereinafter referred to as a corner portion).

As a countermeasure against this, in a conventional aluminum pot main body, there has been proposed a technique for increasing the heat capacity by increasing the wall thickness so that the outer peripheral surface of the corner portion bulges outward (actual exploitation). 62-11639). FIG.
It is a sectional view showing the above-mentioned conventional aluminum hook main body, and the hook main body 1 is formed in a bottomed cylindrical shape by using aluminum as a material, and the outer peripheral surface of the corner portion rising from the bottom wall to the side peripheral wall is the outside. It is thicker than the other parts so that it bulges out.

[0004]

By the way, in the conventional induction heating rice cooker having such a pot body, the heat capacity of the corner portion becomes large, and as a result, the temperature drop of the corner portion during heat retention is reduced, but In the initial stage of heating, the thickness is relatively lower than that of the other portions, and the external convection inside the heating process is small, and there is a problem that the stirring action by convection is insufficient.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide an induction heating rice cooker which eliminates heat shortage in a corner portion of a pot main body and enables good rice cooking. It is in.

[0006]

An induction heating rice cooker according to the present invention is formed of a non-magnetic material into a bottomed cylindrical shape, and a corner portion rising from a bottom wall to a side peripheral wall has an entire outer peripheral surface. In an induction heating rice cooker having a pot main body formed to have a thick wall that bulges outward along the circumference, a magnetic metal material is provided on the outer peripheral surface of the bottom wall of the pot main body, the outer peripheral surface of the thick portion and the outer peripheral surface of the side peripheral wall. The feature is that they are joined together.

[0007]

According to the present invention, by joining the magnetic metal material to the outside of the thick portion in the corner portion from the bottom wall to the side peripheral wall of the entire hook, the heat capacity of the corner portion due to the thick portion increases, It becomes possible to generate heat by joining magnetic metal materials, and because it is located close to this induction coil due to the formation of a thick portion, the magnetic flux density at the corner portion is further increased, and positive heating is also made at the corner portion. As a result, the lack of agitation inside the pot body can be eliminated.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to the drawings showing the embodiments. FIG. 1 is a partially enlarged sectional view of an induction heating rice cooker according to the present invention, in which 1 denotes a pot main body and 3 and 4 denote induction coils. The whole hook body 1 is made of a non-magnetic material such as aluminum and has a bottomed tubular shape. The inner peripheral surface is formed in an arc shape by making the rising portion from the bottom surface of the hook main body 1 to the side peripheral wall, that is, the corner portion thicker than the other, but the outer peripheral surface has a substantially trapezoidal cross section over the entire circumference. It bulges diagonally outward and downward.

A magnetic metal material 2 made of iron, stainless steel or the like is joined and formed from the outer peripheral surface of the bottom wall 1a of the hook main body 1 to the outer peripheral surface of the side peripheral wall 1b through the outer peripheral surface of the thick portion 1c. The magnetic metal material 2 is formed on the outer surface of the bottom wall of the aluminum pot main body 1 by thermal spraying, and after the preformed magnetic metal material 2 is housed in the mold, the molten aluminum solution is poured into the mold and applied with a die. It is formed by a method of pressing, so-called molten metal forging or the like.

The inner induction coil 3 of the induction coils 3 and 4 is concentrically opposed to the bottom surface of the shuttle body 1, and the outer induction coil 4 is a trapezoidal thick portion 1 of the shuttle body 1.
It is located close to the outer peripheral surface of c. Particularly, by forming the thick portion 1c, the induction coil 4 and the magnetic metal material 2 are positioned closer to each other, the magnetic flux density around the thick portion 1c becomes larger, and the amount of heat generation also increases.

The height H of the magnetic metal material 2 on the side peripheral wall 1b of the pot main body 1 (the magnetic metal material 2 bonded to the outer peripheral surface of the bottom wall 1a)
15 mm). The reason why the height is set to 15 mm is that if it is formed to this height, the ratio of the clad material to the electric power at the bottom wall of the main body of the kettle becomes 98%, and in practice, the same efficiency as that of the clad material can be obtained.

FIG. 2 is a graph showing the relationship between the height of the magnetic metal material 2 on the side peripheral wall 1b of the shuttle body 1 and the eddy current density. The horizontal axis indicates the distance (mm) from the center of the shuttle body 1, and the vertical axis indicates the vertical axis. Is shown by taking the squared value of the eddy current density. In the graph, the broken line a has a height H: 2 mm, the broken line b has a height H: 5 mm, the dashed-dotted line a has a height H: 10 mm, and the dashed-dotted line b has a height H: 20.
mm, the solid line a indicates the height H: 30 mm, and the solid line b indicates the case of the pot main body made of the clad material.

As is apparent from this graph, if the height H of the magnetic metal material 2 on the side peripheral wall 1b of the kettle body 1 is 20 mm or more (shown by the one-dot chain line b), the eddy current is the same as that of the kettle body made of clad material. It can be seen that the density can be obtained. However, if the height of the magnetic metal material 2 is increased, the cost increases accordingly, so that it is possible to obtain 98% of the eddy current density of the bottom wall of the clad body made of clad material, which is a desirable efficiency range for the kettle body. The height of the magnetic metal material 2 may be set to 15 mm.

FIG. 3 is a graph showing the height H of the magnetic metal material 2 and the ratio of the square value of the eddy current density of the aluminum pot body to the square of the eddy current density of the pot body made of clad material. The horizontal axis represents the height (mm) of the magnetic metal material, and the vertical axis represents the ratio (%). As is apparent from this graph, if the height of the magnetic metal material 2 is 15 mm, the ratio (%) is about 98%.

In such an embodiment, the wall thickness of the corner portion which is the rising portion from the bottom wall to the side peripheral wall of the shuttle main body 1 is increased, and the thick wall portion 1c in a state of being bulged outward is provided. The bottom wall 1a, the thick wall portion 1c, and the side peripheral wall 1 are formed.
By forming the magnetic metal material 2 over a part of b, the heat capacity can be increased at the corner portion, heat can be generated, and external convection can be promoted, and the heat shortage at the corner portion can be easily eliminated. Becomes

[0016]

As described above, in the present invention, the outer peripheral surface of the thick portion is covered with the magnetic metal material, so that the heat capacity can be increased and the heat quantity can be increased by the heat generation in this corner portion. Insufficient heat at the beginning of heating can be reliably eliminated, and convection in the cooker main body during heating and cooking can be promoted to obtain a good cooked state.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an induction heating rice cooker according to the present invention.

FIG. 2 is a graph showing the relationship between the height of the magnetic metal material on the side peripheral wall of the hook main body and the eddy current density.

FIG. 3 shows the height of the magnetic metal material on the side peripheral wall of the hook main body,
It is a graph which shows the relationship with the eddy current density ratio with respect to the pot main body made of a clad material.

FIG. 4 is a vertical sectional view of a conventional induction heating rice cooker. 1 Kettle body 1a Bottom wall 1b Side peripheral wall 1c Thick part 2 Magnetic metal material

Claims (1)

[Claims] 1. A non-magnetic material is formed into a cylindrical shape with a bottom, and a corner portion rising from the bottom wall to the side peripheral wall is formed thick so that the outer peripheral surface thereof bulges outward over the entire circumference. An induction heating rice cooker having a pot main body, wherein a magnetic metal material is joined to the outer peripheral surface of the bottom wall, the outer peripheral surface of the thick wall portion and the outer peripheral surface of the side peripheral wall of the pot main body.