JPH11309066A - Rice cooker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent dew condensation by temperature drop and to reduce the sogginess of cooked rice by dew dripping by reducing the temperature drop of an inner pot upper side face where a temperature easily lowers at the time of steaming and at the time of heat insulation. SOLUTION: A flange part 12 extended in the outer peripheral direction is provided on a side face position below the upper end of an inner pot 1 formed of a metallic material and a thick part 11 formed in a shape thicker than the side face part of the inner pot 1 is provided from the upper end to the flange part 12. Then, the thick part 11 is constituted of an inner pot inner surface material 13 and an inner pot outer surface material 15, the inner pot inner surface material 13 and the inner pot outer surface material 15 are constituted so as not to be in contact by providing a clearance part 16 excluding a connection part 14 for connecting them at the inner pot upper end, the conduction route of heat is prolonged and heat is hardly discharged.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rice cooker and a technique relating to the shape of an inner pot.

[0002]

2. Description of the Related Art A conventional rice cooker inner pot is disclosed in Japanese Patent No. 2701.
As in Japanese Patent No. 645, a plate material is formed into a pot-like shape, and a flange portion obtained by folding the plate material is provided at the upper end thereof, and the inner pot is supported on the main body by the flange portion. Alternatively, instead of a plate material, the bottom portion is formed thicker by a molten metal forging method (casting), as in JP-A-7-184768.

[0003] In both prior art examples, as shown in FIG.
Of the inner pot 1 is provided at the upper end of the inner pan 1 for supporting the main body 2 on the main body 2.

[0004]

In such a conventional configuration, a flange portion is provided at the upper end of the inner pot, and the flange portion supports the inner pot on the rice cooker main body, and serves as a handle when a user attaches and detaches the inner pot. Although it is configured, it is easily cooled by the influence of the outside air because it is in contact with the main body and conducts heat to the main body, and even the one that is not in contact with the main body extends outward from the upper end of the inner pot. As a result, there is no problem during rice cooking when the inner pot is heated with high electric power and heat is supplied by steam generated in the inner pot, but the heating becomes weaker “steaming” and “warming”
In the above, since the heat is dissipated from the flange portion, the temperature above the inner side surface of the inner pot becomes lower than the rice temperature.

[0005] As a result, dew condensation occurs at a low temperature,
The resulting condensed water flowed down along the side of the inner pot, and had a problem of dripping on the rice and causing the rice to stick.

[0006]

According to the present invention, a flange portion extending in the outer peripheral direction is provided at a side position below the upper end of the inner pot, and the inner pot is provided between the upper end and the flange portion. A thick part formed thicker than the side part is provided.The thick part is composed of the inner pot inner surface material and the inner pot outer surface material, and the inner pot inner surface material and the inner pot outer material are joined at the upper end of the inner pot. It is configured such that there is no gap and there is no contact except for.

[0007]

According to the structure of the present invention, there is a gap between the flange portion and the inner surface material of the inner pot, so that heat is hardly transmitted. That is, since the heat conduction from the flange portion is transmitted through the thickness of the outer surface material of the inner pan, and is transmitted to the thickness of the inner surface material of the inner pan via the joint at the upper end of the inner pan, the conventional inner pan has a flange portion at the upper end. Compared with the inner pot, the heat transfer path is longer and the heat resistance can be configured to be larger. As a result, even if the heat is radiated from the flange portion, the temperature drop on the inner surface of the inner pan can be suppressed low, and the condensation and dripping due to the temperature drop can be reduced. Further, when the thickness of the joining portion is thinner than the thickness of the inner pan inner surface material and the inner pan outer surface material, or when the thickness of the inner pan outer surface material is smaller than the thickness of the inner pan inner surface material,
Heat of the inner pot inner surface material is less likely to be transmitted to the flange portion, which is more effective.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 is an overall sectional view of a rice cooker of the present invention, and FIG. 2 is an enlarged sectional view of an upper portion of an inner pot of the rice cooker. In the figure, 1 is an inner pot, 2 is a main body, 3 is a lid, 4 is a protective frame,
5 is an electromagnetic induction heating coil, 6 is a temperature sensor, 7 is a control unit, and 8 is a magnetic shield. Reference numeral 11 denotes a thick portion, 12 denotes a flange portion, 13 denotes an inner pot inner surface material, 14 denotes a joining portion, 15 denotes an inner pot outer surface material, 16 denotes a gap portion, and 17 denotes a magnetic metal material layer. Is formed.

The inner pot 1 is detachably housed in a main body 2, and a lid 3 is attached to the main body 2 so as to be openable and closable.
The openings of the inner pot 1 and the main body 2 are closed. A protection frame 4 is provided inside the main body 2, and an electromagnetic induction heating coil 5 is provided at the bottom of the protection frame 4. A temperature sensor 6 is provided at the center of the bottom of the protection frame 4 and contacts the bottom of the inner pan 1.

A control section 7 for generating a high-frequency magnetic field in the electromagnetic induction heating coil 5 is provided in the main body 2, and a temperature sensor 6 is also connected to the control section 7 so as to generate electric power determined based on temperature information. The energization of the electromagnetic induction heating coil 5 is controlled. A magnetic shield 8 is provided on the lower surface of the electromagnetic induction heating coil 5.
Is provided so that the high-frequency magnetic field generated from the electromagnetic induction heating coil 5 does not leak to the lower side.

The inner pot 1 is formed in a pot shape from an aluminum plate material of a high heat conductive material, and a thick portion 11 is provided at an upper end portion. Is provided. Thick part 1
Reference numeral 1 denotes an inner pan inner surface material 13 which is folded back at a joint portion 14 at the upper end of the inner pan to form an inner pan outer surface material 15 which constitutes an inner pan outer surface. The unit 12 is configured. The inner pot inner surface material 13 and the inner pot outer surface material 15 are opposed to each other without being provided with a gap portion 16 except that they are connected by a connecting portion 14.

At the bottom of the inner pot 1, there is provided a magnetic metal material layer 17 which generates heat by receiving a high-frequency magnetic field of the electromagnetic induction heating coil 5, and this heat is transmitted to the inner pot 1 to cook rice.

When a user puts rice and an appropriate amount of water into the inner pot 1 and operates a rice cooker switch (not shown), rice cooker is started. In rice cooking, a high frequency current is supplied to the electromagnetic induction heating coil 5 by the operation of the control unit 7, and a high frequency magnetic field generated from the electromagnetic induction heating coil 5 acts on the magnetic metal material layer 17 of the inner pot 1. The eddy current generated by the magnetic field generates heat as Joule heat, which is transmitted to the bottom of the inner pot 1 and heats rice and water in the inner pot 1.

When the inside of the inner pan 1 boils and the rice absorbs water and the water in the inner pan 1 runs out, the temperature of the bottom of the inner pan 1 rises rapidly, and the control unit 7 The energization of the electromagnetic induction heating coil 5 is stopped. Thereafter, the process proceeds to the steaming step.

Steaming is a process for converting rice into α-starch, and it is important to keep the temperature high. Heating is performed by the electromagnetic induction heating coil 5 to maintain the temperature, but only weak heating can be performed so that the rice is not scorched. At this time, the upper part of the inner pot 1 is far from the electromagnetic induction heating coil 5 and the temperature tends to decrease.
In addition, since the inner pan 1 is held by the main body, heat is easily transmitted to the main body, and the temperature of the flange 12 which is easily affected by the outside air is large and the temperature is easily lowered. The upper part was easy to cool down. As a result, dew was formed, and the dew flowed along the inner surface of the inner pot, causing a problem of sticking the rice.

In the present invention, the gap 16 is provided between the inner pot outer material 15 and the inner pot inner material 13 near the flange 12, so that even if the flange 12 cools down, the inner pot inner material is immediately turned on. 13 is hard to cool. That is, since heat is transmitted from the flange portion 12 to the thickness of the inner pot outer surface material 15, the connecting portion 14, and the inner pot inner surface material 13, the heat conduction distance is long, and the heat resistance is larger than that of the inner pot of the conventional rice cooker. As a result, it is difficult to cool the upper portion of the inner surface of the inner pot, it is possible to prevent dew condensation and dew, and it is possible to prevent rice from sticking.

When the steaming is completed, the process proceeds to the step of keeping the temperature of the rice at a constant level. However, the problem of the dripping is remarkable because the heating is further weakened and the time is longer than the steaming. In addition, the effect of the present invention is more remarkable than steaming, so that the rice can be prevented from sticking or deteriorating, and the rice can be kept warm for a long time in a good rice condition.

Further, in this embodiment, if the thickness of the joining portion is made smaller than the thickness of the inner pot inner surface material and the inner pot outer surface material (FIG. 3), the inner pot inner surface material (the inner pot upper end inner face) is changed from the inner pot upper inner pot. The amount of heat escaping to the flange via the outer surface material is reduced, which is more effective.

Even if the thickness of the outer surface material of the inner pot is reduced (FIG. 4), the heat dissipation to the flange portion is similarly reduced, which is effective.

[0020]

As described above, according to the present invention, a flange portion extending in the outer peripheral direction is provided at a side position below the upper end of the inner pot, and a portion between the upper end and the flange portion is formed thicker than the side portion of the inner pot. The thick part is composed of the inner pot inner surface material and the inner pot outer surface material, and the inner pot inner surface material and the inner pot outer surface material have a gap except for the joining part joined at the upper end of the inner pot. Since it is configured so that it does not touch the inner pot, the heat transmission path from the flange portion to the inner surface of the inner pot is long, and the thermal resistance can be increased. As a result, even if the heat is radiated from the flange portion, the temperature drop on the inner surface of the inner pan can be suppressed low, and the condensation and dripping due to the temperature drop can be reduced.

In the present embodiment, the flange portion, the inner pot outer surface material, and the inner pot inner surface material are formed by bending an integral plate-like material. However, the flange portion and the inner pot outer surface material are formed separately, and the joint portion is formed. The same effect can be obtained even in the manufacturing method of joining, and also in the manufacturing method of solidifying the melted material in the inner pot-shaped mold by the molten metal forging method, etc. A similar effect can be obtained.

Further, in this embodiment, the flange portion and the main body are in contact with each other, but the flange portion is partially in contact with the main body, or the flange portion is supported by the main body through another component, and the flange portion does not directly touch the main body. In this case, the effect of the present invention can be obtained because the flange portion extends outside the main body in the outer peripheral direction and is easily cooled.

[Brief description of the drawings]

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

FIG. 2 is an enlarged sectional view of an upper portion of an inner pot of the rice cooker according to the present invention.

FIG. 3 is an enlarged cross-sectional view of the rice cooker in a case where a thickness of an inner pot connecting portion is reduced.

FIG. 4 is an enlarged cross-sectional view when the thickness of an outer surface material of an inner pot of the rice cooker is reduced.

FIG. 5 is an enlarged sectional view of a main part of a conventional rice cooker.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Inner pan 2 Main body 11 Thick part 12 Flange part 13 Inner pan inner surface material 14 Joining part 15 Inner pan outer surface material 16 Gap

Claims (3)

[Claims] 1. A rice cooker in which an inner pan is detachably housed in a main body, and the main body has a heating section for heating the inner pan, wherein the inner pan (1) has a flange extending in an outer peripheral direction at a side position below an upper end. Part (12), and a flange part (12) from the upper end.
A thick portion (11) formed thicker than a side portion of the inner pot (1) is provided between the inner pots (1), and the thick portion (11) is formed of an inner pot inner surface material (1).
3) and an inner pan outer surface material (15), and the inner pan inner surface material (13) and the inner pan outer surface material (15) have a gap portion (16) except for a joint portion (14) joined at the upper end of the inner pan. A rice cooker characterized in that it is configured so as not to be in contact with. 2. The rice cooker according to claim 1, wherein the thickness of the joining portion (14) is smaller than the thickness of the inner pot inner surface material (13) and the inner pot outer surface material (15). 3. The rice cooker according to claim 1, wherein the thickness of the inner pot outer material (15) is smaller than the thickness of the inner pot inner material (13).