JP2003144310A - Rice cooker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve assembly work efficiency, to prevent the occurrence of nonuniformity in cooking, to prevent the induced heating of peripheral members and to reduce a body heater for warmth retention. SOLUTION: In a rice cooker 1 having an induction heating coil 13 for performing induction heating on a rice cooking pot 2 by arranging a protecting frame 9 composed of non-conductive materials inside a body 7 of a rice cooker body 6, housing the rice cooking pot 2 inside the protecting frame 9 and supplying a high-frequency current on the outer face of the protecting frame 9, the protecting frame 9 is arranged to be extended downward from a shoulder part 7b of the body 7, and the induction heating coil 13 is arranged over the range of a curved part 2c continued from an upper part corresponding to the side face 2b of the rice cooking pot 2 to the bottom face 2a of the rice cooking pot 2 except for an area corresponding to the bottom face 2a of the rice cooking pot 2.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art As shown in FIG. 3, a conventional induction heating type rice cooker 100 is rotatable on a rice cooker pot 101, a rice cooker main body 102 that houses the rice cooker pot 101, and the rice cooker main body 102. And a lid 110 attached to the.

The rice cooker body is a body 10 having a cylindrical shape with a bottom.
3, a protective frame 104 and an inner case 105 made of a non-conductive material for housing the rice cooking pot 101 are provided.
Further, between the body 103 and the protective frame 104, an induction heating coil 106, a rice pan temperature sensor 107, and a control board 108 on which a microcomputer is mounted are arranged. Further, a body heater 109 is arranged on the outer peripheral portion of the inner body 105.

The lid 110 has a radiator plate and a lid heater inside, and an inner lid on the lower surface facing the rice cooking pot 101.

The microcomputer mounted on the control board 108 supplies a high frequency current to the induction heating coil 106 to generate a high frequency magnetic field in the induction heating coil 106. As a result, the rice cooking pot 101 is induction-heated by this high-frequency magnetic field, and the rice in the rice cooking pot 101 is cooked.

[0006]

However, in the rice cooker 100, the induction heating coil 106 is provided in the rice cooker 1.
01 is arranged so as to be induction-heated from the side surface portion to the bottom surface portion. Since the region corresponding to the bottom portion is located in a substantially horizontal direction, the induction heating coil 106 needs to be wound in a spiral shape. Therefore, the induction heating coil 10
6 cannot be directly wound around the outer peripheral surface of the protective frame 104,
Since it is necessary to use a dedicated jig, there is a problem that the mounting work is complicated and the cost is high.

Further, in the rice cooker 100, the rice cooker 10
1 by the induction heating coil 106a located on the side surface and the induction heating coil 106b located on the bottom surface.
In 01, as illustrated, convections C1 and C2 are generated from both the side surface portion and the bottom surface portion. Then, these convections C1 and C2 may act to cancel each other out. As a result, the rice in the region R1 located at a predetermined distance from the bottom surface of the rice cooking pot 101 is cooked in a hard state. On the other hand, the rice in the region R2 attached to the bottom surface of the rice cooking pot 101 is likely to be charred due to the precipitation of bran flowing out from the rice. That is, there is a problem that uneven cooking occurs in the rice cooking pot 101.

Further, in the rice cooker 100, there is a problem that when the rice cooker 100 is placed on a stainless steel sink, it is heated by induction heating. Furthermore, in the rice cooker 100, in order to keep the upper part of the rice cooking pot 101 warm, the body heater 109 is required, which causes a problem of high cost.

In the rice cooker 100, the rice cooking pot 10
Since the lower half of 1 is induction-heated, the rice cooker has a protective frame 10
4 is arranged so as to be positioned at a predetermined distance from the No. 4 and is hooked on the opening portion of the body 103 communicating with the protective frame 104 to hang it down. Therefore, there is an inconvenience that the distance between the protective frame 104 and the rice cooker 101 is not stable due to an attachment error or a manufacturing error of the protective frame or the body 103, and the cooked state is slightly different for each rice cooker.

Further, since the rice cooking pot 101 is installed on the body 103, it is necessary to manufacture the body 103 with a resin that can withstand high temperatures, which causes a problem of high cost.
Furthermore, when cooking rice, there is a problem that the floating rice cooking pot 101 vibrates and a resonance sound is generated.

Therefore, in the present invention, the assembly workability is improved,
An object of the present invention is to provide a rice cooker capable of preventing uneven cooking, preventing induction heating of peripheral members, and reducing the number of body heaters for keeping heat.

[0012]

In order to solve the above problems, in the rice cooker of the present invention, a protective frame made of a non-conductive material is arranged in the body of the rice cooker body, and the rice is cooked inside the protective frame. In a rice cooker accommodating a pan and an induction heating coil for inductively heating the rice cooker by energizing a high frequency current on the outer surface of the protector frame, the protector frame is directed downward from the shoulder of the body. The induction heating coil is arranged so as to extend in the range of a curved portion continuous from the upper portion corresponding to the side surface portion of the rice cooking pot to the bottom portion of the rice cooking pot, except for the area corresponding to the bottom portion of the rice cooking pot. It is arranged.

According to the rice cooker having the above-mentioned structure, the induction heating coil is not arranged in the portion corresponding to the bottom surface of the rice cooker. Therefore, the induction heating coil is only a portion that is spirally wound around the outer periphery of the protective frame, and there is no portion that is spirally wound. As a result, the induction heating coil can be directly wound around the protective frame and disposed without using a dedicated jig.

Further, since there is almost no convection from the bottom surface, there is no action to cancel the convection from the side surface.
It is possible to suppress uneven cooking. Further, even if the rice cooker is placed on the stainless steel sink, the stand is not heated by induction. Furthermore, since the induction heating coil is arranged from the upper part of the side surface of the rice cooker,
There is no need for an inner cylinder or a cylinder heater dedicated to heat retention. Therefore, the number of parts can be reduced and the assembling workability can be improved.

In the rice cooker, it is preferable that the rice cooking pot is placed on the bottom surface of the protective frame. With this configuration, the distance between the induction heating coil and the rice cooker can be stabilized, and the cooked state of each rice cooker can be stabilized. Further, since the rice cooker does not contact the body, it can be manufactured with an inexpensive heat-resistant resin. Further, it is possible to prevent the rice cooker from vibrating and generating resonance noise.

The bottom surface of the protective frame is preferably made of metal. By doing so, the installation strength can be improved, the stability can be improved, and the rice cooker can be reliably placed.

Specifically, the protective frame includes a protective frame main body made of a non-conductive resin whose lower end is opened, and a magnetic shield member which closes the opening of the protective frame main body and covers the side surface to block the passage of magnetism. It is preferable that With this configuration, it is possible to reliably prevent the electromagnetic waves emitted from the induction heating coil from leaking.

In the rice cooking pot, an outer surface material made of a metal having a low thermal conductivity is joined to an outer surface of a base material made of a metal having a high thermal conductivity. It is preferable to have a vacuum double structure in which a vacuum space is formed between the outer surface material. With this configuration, it is possible to prevent the heat in the rice cooker from being radiated from the bottom surface of the rice cooker that is heated only by heat conduction. In addition, since the heat from the side surface is evenly transferred, it is possible to ensure a uniform cooked state and reliably prevent burning. Furthermore, even if the rice cooker itself is placed on the sink, it is possible to prevent the sink from becoming hot.

Further, it is preferable that the bottom portion of the rice cooking pot is raised in an arc shape. With this configuration, convection from the side surface can be swirled to more reliably prevent the uneven cooking.

The induction heating coil preferably has a coarse upper part and a finely wound lower part. By doing so, it is possible to ensure a uniform cooked state without uneven cooking and to ensure reliable heat retention.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an induction heating type rice cooker 1 according to an embodiment of the present invention. This rice cooker 1 includes a rice cooker 2 and a rice cooker body 6 that accommodates the rice cooker 2 and performs induction heating.
And a lid 1 rotatably attached to the rice cooker body 6
9 and 9.

In the rice cooker 2, as shown in FIG. 2, an outer surface member 4 made of a thin plate made of stainless steel or the like having low heat conductivity is joined to an outer surface of a base material 3 made of aluminum or the like having high heat conductivity. It was done. A space 5 which is evacuated between the pan base material 3 and the outer surface material 4 is formed on the bottom surface 2a of the rice cooking pot 2 to have a vacuum double structure. Further, the bottom surface portion 2a of the rice cooking pot 2 is formed in a shape protruding upward in an arc shape and is continuous with the side surface portion 2b and a curved portion 2c which is a part of a contact circle.

In the rice cooking pot 2, for example, in the disc-shaped pot base material 3 and the outer surface material 4, spacers having the same diameter as the diameter of the central portion forming the space 5 are arranged. Then, the position excluding the spacer is pressure-bonded and joined in a vacuum chamber or the like, and then vacuum drawing is performed to perform drawing processing.

When the rice cooking pot 2 is for 5 cups having an opening diameter of about 19 cm, the radius r1 of the curved portion 2c is preferably in the range of about 1 cm to 4 cm. The radius r1 of the curved portion 2c is about 1 cm to 4c.
When it is in the range of m, the radius r2 of the raised bottom portion 2a is preferably in the range of about 5 cm to 10 cm. On the other hand, when the diameter of the opening of the rice cooker 2 is about 22 cm for 10 cups, the radius r1 of the curved portion 2c is about 2 cm to 5 cm.
It is preferably in the range of cm. And the curved portion 2c
When the radius r1 of R is in the range of about 2 cm to 5 cm, the radius r2 of the raised bottom portion 2a is preferably in the range of about 6 cm to 12 cm.

That is, it is preferable that the curved portion 2c of the rice cooking pot 2 has a radius r1 of about 15% of the diameter of the opening. Further, it is preferable that the bottom surface 2a that is raised in an arc shape has a radius r2 that is approximately 40% of the radius r1 of the curved portion 2c. By doing so, the convection C1 generated from the side surface portion 2b can be swirled to prevent uneven cooking of rice in the rice cooking pot 2.

The rice cooker body 6 is provided with an exterior body composed of a body 7 and a bottom body 8 for closing the bottom of the body 7. Inside the exterior body, a protective frame 9 for accommodating the rice cooking pot 2 is provided.
An induction heating coil 13, a ferrite core 14, a rice cooking pot temperature sensor 15, a control board 16 on which a microcomputer is mounted, and a fan 17 as a cooling unit are provided.

The body 7 is a resin case having a substantially elliptic cylinder shape having an opening at the top and bottom, and a protective frame 9 is integrally attached to the body 7, a lid 19 is rotatably attached to the upper end opening, and the lower end opening is the bottom. It is closed by the body 8. The body 7 and the bottom body 8 are formed of a heat resistant resin that can withstand a temperature of about 120 ° C.

The protective frame 9 is composed of a protective frame body 10 and a magnetic shield member 11. The protective frame body 10 and the magnetic shield member 11 are sequentially arranged with the body 7 turned upside down. These are fixed to the body 7 by screwing
It is sandwiched and fixed between the bottom body 8 and the bottom body 8.

The protective frame body 10 has a cylindrical shape with an opening at the top and bottom and conforms to the shape of the side surface portion 2b of the rice cooking pot 2.
It is formed of a resin that can withstand a temperature of 50 ° C. and has non-conductivity. At the upper end of the protective frame body 10, a step portion 10a that engages with a rib 7a provided at the opening of the shoulder portion 7b of the body 7 is provided, and is arranged so as to extend downward from the body 7. In addition, a through hole 10b is provided in the lower portion of the protective frame body 10 to allow the detection portion of the rice cooking pot temperature sensor 15 to pass therethrough. This through hole 10b
Is formed so that the pan base material 3 and the outer surface material 4 forming the rice cooking pan 2 are located in the curved portion 2c in close contact with each other.

The magnetic shield member 11 is the protective frame body 10
It closes the lower end opening and is made of metal such as aluminum that blocks the passage of magnetism. A mounting portion 12 for mounting the rice cooking pot 2 is provided on the magnetic shield 11 so as to protrude in an annular shape. The mounting portion 12 has a protruding amount such that a predetermined gap S is formed between the upper surface of the shoulder portion 7b of the body 7 and the lower surface of the flange 2d of the rice cooking pot 2.
The outer peripheral portion of the magnetic shield 11 extends upward and is formed in a substantially U shape so as to cover the side surface of the protective frame body 10.

The induction heating coil 13 is used to electromagnetically heat the outer surface member 4 of the rice cooker 2 through the protective frame body 10 when a high frequency current is applied thereto. It is positioned between and. The induction heating coil 13 is arranged in the range from the upper portion corresponding to the side surface portion 2b to the curved portion 2c except for the region corresponding to the bottom surface portion 2a of the rice cooking pot 2. The induction heating coil 13 has a portion corresponding to the upper portion of the protective frame main body 10 rough and a lower portion finely wound so as to ensure a uniform cooked state without unevenness of cooking, and instead of a body heater dedicated to heat retention. The induction heating coil 13 is configured to maintain heat. In addition, the induction heating coil 13 may have one continuous winding from the upper portion to the lower portion, or a plurality of windings having two or more windings may be provided. It is preferable that the lower part and the lower part are separately controllable independently.

The temperature sensor 15 for the rice cooker pan penetrates the through hole of the protective frame body 10 so as to contact the outer surface of the curved portion 2c of the rice cooker pan 2 to detect the temperature of the rice cooker pan 2. It is detected and output to the microcomputer.

The control board 16 controls the load parts such as the induction heating coil 13 according to the stored program, and executes the rice cooking control desired by the user. The control board 16 is attached to the body 7 by a board holder 18 together with a cooling fan 17.

The lid 19 is a well-known one in which an inner lid for sealing the upper end opening of the rice cooking pot 2 is provided on the bottom surface of an exterior body composed of an upper plate and a lower plate.

As described above, in the rice cooker 1 of this embodiment,
The induction heating coil 13 is not arranged in a portion corresponding to the bottom surface portion 2a of the rice cooking pot 2. That is, the induction heating coil 13 is only arranged so as to be spirally wound around the outer periphery of the protective frame main body 10 having a substantially cylindrical shape, and the spiral wound portion corresponding to the area of the bottom surface portion 2a is Absent.

Therefore, when the rice cooker 1 is manufactured, the induction heating coil 13 can be directly wound around the protective frame main body 10 without using a dedicated jig. Moreover, since the induction heating coil 13 is disposed from a position corresponding to the upper portion of the side surface portion 2b of the rice cooking pot 2,
Inner case 105 shown in a conventional example and case heater 10 dedicated to heat retention
9 is unnecessary. Therefore, the number of parts can be reduced and the assembling workability can be improved.

In this embodiment, the rice cooker 2 is placed on the bottom surface of the protective frame 9 composed of the protective frame body 10 and the magnetic shield 11, and the upper surface of the shoulder portion 7b and the lower surface of the flange 2d of the rice cooker 2 are placed. A predetermined gap S is provided between the two. Therefore, it is possible to prevent an error in the distance between the induction heating coil 13 and the rice cooker 2 for each rice cooker due to a manufacturing error or an assembly error of each component, and to stabilize the distance. As a result, the cooked state of each rice cooker can be stabilized, and the magnetic shielding member 11 to be placed is made of metal,
Installation strength and stability can be improved. Furthermore, since the rice cooker 2 does not contact the body 7, the body 7
Can be manufactured with an inexpensive heat-resistant resin, and the cost can be reduced.

In the rice cooker 1 having the above structure, when a high frequency current is applied to the induction heating coil 13, the outer surface material 4 located on the side surface portion 2b and the curved portion 2c of the rice cooking pot 2 is induction-heated via the protective frame body 10. The region corresponding to the bottom surface portion 2a where the induction heating coil 13 is not disposed is not heated.

Therefore, since the induction heating coil 13 is not arranged at the bottom of the rice cooker 1, even if the rice cooker is installed on the stainless steel sink, the induction cooker does not heat the table. Absent. The protective frame 9 includes a protective frame body 10 and a magnetic shield member 11, and the magnetic shield member 11 is
Since it is configured to cover the side surface of the protective frame body 10, that is, the induction heating coil 13, it is possible to reliably prevent the electromagnetic waves emitted from the induction heating coil 13 from leaking out. Furthermore, since the rice cooker 2 is placed on the magnetic shield 11,
It is possible to prevent the rice cooking pot 2 from vibrating and generating resonance noise.

On the other hand, in the rice cooking pot 2, heat generated by induction heating is transferred to the pot base material 3 having high thermal conductivity, and the rice is cooked by heating the rice through the water contained therein. Also,
The generated heat is transferred to the bottom surface portion 2a by the pot base material 3 having high thermal conductivity. However, it is difficult for heat to be transferred to the portion of the outer surface member 4 having a low thermal conductivity on the bottom surface portion 2a.

Therefore, in the rice cooker 2, almost no convection C2 is generated from the bottom surface 2a, and convection C1 is generated from the side surface 2b.
Often occurs. Therefore, these convections C1 and C2
Do not have the effect of canceling each other out. as a result,
As illustrated, the convection C1 from the side surface portion 2b flows in a spiral shape, and it is possible to suppress the occurrence of uneven cooking in the entire area of the rice cooking pot 2. Moreover, in this embodiment, since the bottom surface 2a of the rice cooking pot 2 is raised in an arc shape, the convection C1 from the side surface 2b can be surely swirled.

Further, since the bottom surface 2a of the rice cooking pot 2 has a vacuum double structure, it is possible to prevent the internal heat from being radiated from the bottom surface 2a which is heated only by heat conduction. Furthermore, since the heat from the side surface portion 2b is evenly transferred, it is possible to ensure a uniform cooked state and to reliably prevent burning. Furthermore, since the outer surface material 4 located on the outer surface side of the bottom surface portion 2a is made of a metal material having low thermal conductivity, even if rice cooking is completed and the rice cooking pot 2 is taken out and placed on the sink, It is possible to prevent the sink from becoming hot.

Since the temperature sensor 15 for the rice cooker for detecting the temperature of the rice cooker 2 is brought into contact with the outer surface of the curved portion 2c not having the double structure, the temperature sensor 15 for the rice cooker 2 is surely in the rice cooker 2. The temperature of can be detected.

[0044]

As is apparent from the above description, in the rice cooker of the present invention, the induction heating coil is not arranged in the area corresponding to the bottom portion of the rice cooking pot. Therefore, the induction heating coil to be provided need only have a spirally wound portion, and need not have a substantially spirally wound portion. As a result, the outer peripheral surface of the protective frame can be directly wound, and a jig dedicated for winding can be eliminated. Moreover, since the induction heating coil is wound from the upper part of the protective frame, a body heater dedicated to heat retention is unnecessary. Therefore, it is possible to improve the assembling workability and reduce the cost.

Further, during rice cooking, it is possible to almost eliminate convection from the bottom surface during induction heating in the rice cooking pot, so that it is possible to reliably prevent uneven cooking and charring on the bottom surface. Furthermore, even if the rice cooker is placed on a stainless steel sink, it can be reliably prevented from being heated by induction heating.

Further, since the rice cooker is placed on the lower surface of the protective frame, it is possible to stabilize the distance from the induction heating coil, the housed state of the rice cooker, and the cooked state of each rice cooker. Furthermore, since the heat of the rice cooker is not directly applied to the body forming the exterior body of the rice cooker body, it can be manufactured with an inexpensive heat-resistant resin, and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a rice cooker according to an embodiment of the present invention.

FIG. 2 is a partially enlarged sectional view of FIG.

FIG. 3 is a cross-sectional view showing a conventional rice cooker.

[Explanation of symbols]

1 ... rice cooker, 2 ... rice cooker pot, 2a ... bottom part, 2b ... side face part, 2c ... curved part, 3 ... pot base material, 4 ... outer surface material, 5 ... space, 6 ... rice cooker body, 7 ... body, 9 ... Protective frame, 10 ... Protective frame main body, 11 ... Magnetic-shield member, 12 ... Mounting part, 13 ... Induction heating coil, 19 ... Lid body.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masami Fukushima             Elephant 1-20-5 Tenma, Kita-ku, Osaka City, Osaka Prefecture             In Mahobin Co., Ltd. F term (reference) 3K051 AA08 AD25 AD35 AD40 CD42                 4B055 AA03 AA09 BA28 BA29 BA66                       BA69 CA02 CA04 CA05 CA15                       CB02 CB05 CB18

Claims (7)

[Claims] 1. A protective frame made of a non-conductive material is provided in the body of the rice cooker body, a rice cooker is accommodated inside the protective frame, and a high-frequency current is applied to the outer surface of the protective frame. In the rice cooker in which an induction heating coil for induction heating the rice cooking pot is arranged, the protection frame is arranged so as to extend downward from the shoulder portion of the body, and the induction heating coil is arranged in the rice cooking pot. A rice cooker characterized by being arranged in a range of a curved portion continuous from an upper portion corresponding to a side portion of a rice cooking pot to a bottom portion of the rice cooking pot, except for a region corresponding to the bottom portion. 2. The rice cooker according to claim 1, wherein the rice cooking pot is placed on the bottom surface of the protection frame. 3. The rice cooker according to claim 1, wherein the bottom surface of the protection frame is made of metal. 4. The protective frame includes a protective frame body made of a non-conductive resin having a lower end opened, and a magnetic shield member that closes an opening of the protective frame body and covers a side surface to block passage of magnetism. The rice cooker according to claim 3. 5. The rice cooking pot comprises a pan base material made of a metal having a high thermal conductivity and an outer surface material made of a metal having a low thermal conductivity joined to the outer surface of the pan base material. The rice cooker according to any one of claims 1 to 4, wherein the rice cooker has a vacuum double structure in which a vacuum space is formed between the rice cooker and the outer surface material. 6. The rice cooker according to claim 1, wherein a bottom portion of the rice cooking pot is raised in an arc shape.
Rice cooker described in paragraph. 7. The rice cooker according to claim 1, wherein the induction heating coil has a coarse upper part and a finely wound lower part.