JPH11197007A - Induction heating rice cooker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accelerate water convection in a rice-cooking pot and reduce a dispersion of an amount of heat transferring to the rice by changing a shape of the rice-cooking pot. SOLUTION: A rice-cooking pot 5 is induction-heated by a high-frequency magnetic field generated by first and second induction-heating coils 7 and 8 connected to high-frequency inverters 6. A side of the rice-cooking pot 5 has a roughly conical shape widening upward, where an angle of inclination from a bottom outer periphery of the rice-cooking pot 5 is 84-88 degrees.

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 used in ordinary households.

[0002]

2. Description of the Related Art In an induction heating type rice cooker, a high frequency magnetic field is generated from an induction heating coil, and a rice cooker is heated by an eddy current caused by electromagnetic induction.

[0003] Hereinafter, a conventional induction heating type rice cooker will be described.
A description will be given based on FIG. In the figure, 1 is a rice cooker, 2 is a high-frequency inverter, 3 is connected to the high-frequency inverter 2, a first induction heating coil arranged inside the bottom of the rice cooker 1, 4 is also connected to the high-frequency inverter 2, This is a second induction heating coil disposed outside the bottom of the rice cooker 1. The side portion of the rice cooker 1 is formed in a vertical cylindrical shape.

As shown in this configuration, a high-frequency magnetic field is generated from the first and second induction heating coils 3 and 4 by a high-frequency current supplied by the high-frequency inverter 2, and an eddy current due to electromagnetic induction is generated. The rice cooker 1 is heated.

[0005]

In the above-mentioned conventional configuration, as shown in FIG. 5, the convection of water in the rice cooker 1 is mainly caused by the first induction heating coil 4 in the pre-cooking step. Of the rice cooker 1 and the convection rising at the side of the rice cooker 1 caused by the heating of the second induction heating coil 3. that time,
Since the heating by the second induction heating coil 4 is stronger than the heating by the first induction heating coil 3, the convection speed ascending the side of the rice cooker 1 is relatively high. As a result, the convection balance inside the rice cooker 1 is biased, so that the effect of stirring the rice by the two convections is reduced, the amount of heat transfer to the rice becomes uneven, and uneven cooking occurs, which causes a problem in the rice cooking performance. Met.

Therefore, the present invention solves the above-mentioned conventional problems. By improving the shape of a rice cooker, the convection balance of water inside the rice cooker is made uniform, and the variation in the amount of heat transfer to rice is reduced. It is another object of the present invention to provide an induction heating type rice cooker that can cook more delicious rice.

[0007]

Means for Solving the Problems In order to solve the above problems, an induction heating type rice cooker of the present invention has a rice cooker which is induction-heated by an induction heating coil, and the rice cooker is disposed at a bottom edge of the rice cooker. Has a substantially conical shape with an inclination angle of about 84 to 88 degrees.

[0008]

The invention according to claim 1 comprises a rice cooker which is induction-heated by a high-frequency magnetic field generated from an induction heating coil, wherein the rice cooker has a substantially conical flared side. The angle of inclination from the outer edge of the pot bottom is about 84-88.
By shifting the convection center that rises the side of the rice cooker to the outside, the convection that rises relatively in the center of the rice cooker is strengthened, and the convection balance of the water inside the rice cooker is evened. I can do it. Therefore, it is possible to provide an induction-heated rice cooker that can reduce the variation in the amount of heat transfer to rice and cook more delicious rice.

The invention according to claim 2 is characterized in that the center of the rice cooker is raised by raising the bottom center of the rice cooker into a generally conical convex shape and having a height of about 5 mm from the lowermost portion of the outer wall of the rice cooker. The rising convection can be strengthened, the convection balance inside the rice cooker can be more even, and the variation in the amount of heat transfer to rice can be reduced.

According to the third aspect of the present invention, in particular, by setting the thickness of the rice cooker pot to about 3.3 mm, a predetermined pot temperature distribution can be obtained, and the convection balance inside the rice cooker can be made even more uniform. The variation in the amount of heat transfer to the heat sink can be reduced.

[0011] The invention according to claim 4 is that the rice cooker is intermittently heated according to the number of cooked rice in the early stage of the pre-cooking step, so that the rice is sufficiently stirred by the effect of the rice cooker side inclination. When the heating is stopped, the rice is placed in a stable state using the heat capacity of the rice cooker or the like, thereby preventing the gelatinization of rice due to excessive heating and keeping the rice inside the rice cooker at a predetermined temperature. Therefore, it is possible to provide an induction-heated rice cooker that can reduce the variation in the amount of heat transfer to rice and cook more delicious rice.

[0012]

(Embodiment 1) Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. In FIG. 1, 5
Is a rice cooker, 6 is a high-frequency inverter, 7 is connected to the high-frequency inverter 6, a first induction heating coil disposed inside the bottom of the rice cooker 5, and 8 is also connected to the high-frequency inverter 6, (5) A second induction heating coil disposed outside the bottom. The side portion of the rice cooker 5 is formed in a substantially conical shape spreading upward.

A high-frequency magnetic field is generated from the first and second induction heating coils 7 and 8 by a high-frequency current supplied by the high-frequency inverter 6, and the rice cooker 5 is heated by an eddy current due to electromagnetic induction. You. As shown in FIG. 2, particularly during the pre-cooking step, inside the rice cooker 5,
A convection rising in the center of the rice cooker 5 and a convection rising in the side of the rice cooker 5 are generated. The convection center rising on the side of the pot 5 moves outward. As a result, the convection that rises relatively in the center of the rice cooker 5 is relatively strengthened, and the two convection balances are equalized, and the rice stirring effect is promoted. Therefore, variation in the amount of heat transfer to rice can be reduced. According to experiments by the inventors, it has been found that the angle of inclination of the side of the rice cooker 5 from the bottom outer edge of the rice cooker 5 of about 84 to 88 degrees is effective.

(Embodiment 2) Next, a second embodiment of the present invention will be described with reference to the drawings. In FIG.
9 is a rice cooker, 10 is a high-frequency inverter, 11 is connected to the high-frequency inverter 10, a first induction heating coil arranged inside the bottom of the rice cooker 9, 12 is also connected to the high-frequency inverter 10, It is composed of a second induction heating coil arranged outside the bottom of the pan 9. The side of the rice cooker 9 is formed in a substantially conical shape spreading upward, and in addition, the center of the bottom of the rice cooker 9 is raised to form a substantially conical convex shape.

In this embodiment having the above configuration,
By raising the center of the bottom of the rice cooker 9 in addition to the inclination of the side of the rice cooker 9, the convection upward in the center of the rice cooker 9 is enhanced. For this reason, the two convection balances become more even, and the stirring effect of rice is promoted. Therefore,
Variations in heat transfer to rice can be reduced.
According to experiments by the inventors, it has been found that the height of the bottom of the rice cooker 9 is approximately 5 mm from the lowermost portion of the outer wall of the rice cooker 9 to be effective. In addition, when raising the bottom center of the rice cooker 9 further, the same effect can be obtained by making the side part inclination of the rice cooker 9 closer to 90 degrees.

(Embodiment 3) Next, a third embodiment of the present invention will be described with reference to the drawings. In FIG.
13 is a rice cooker, 14 is a high-frequency inverter, 15 is connected to the high-frequency inverter 14, a first induction heating coil disposed inside the bottom of the rice cooker 13, 16 is also connected to the high-frequency inverter 14, It comprises a second induction heating coil disposed outside the bottom of the pan 13. The side portion of the rice cooker 13 is formed in a generally conical shape spreading upward, and in addition, the thickness of the rice cooker 13 is
It has a predetermined thickness in accordance with the side inclination.

In the present embodiment configured as described above, a predetermined pot temperature distribution can be obtained by the heat capacity of the pot.
The convection balance inside the rice cooker can be further equalized, and the variation in heat transfer to rice can be reduced. According to experiments by the inventors, the thickness of the rice cooker 13 was about 3.3.
mm has been found to be effective. When the thickness of the rice cooker 13 is further reduced, the same effect can be obtained by increasing the inclination of the side of the rice cooker 13.

(Embodiment 4) Next, a fourth embodiment of the present invention will be described with reference to the drawings. In FIG.
17 is a rice cooker, 18 is a high-frequency inverter, 19 is a first induction heating coil connected to the high-frequency inverter 18 and located inside the bottom of the rice cooker 17, 20 is also connected to the high-frequency inverter 18, The second induction heating coil 21 disposed outside the bottom of the pan 17 is constituted by control means connected to the high-frequency inverter 18. The side portion of the rice cooker 17 is formed in a substantially conical shape spreading upward.

The control means 21 controls the high-frequency current supplied from the high-frequency inverter 18 according to information such as the pot temperature and the number of cooked rice. The high frequency inverter 18
A high-frequency magnetic field is generated from the first and second induction heating coils 19 and 20 by the high-frequency current supplied from the heating device, and the rice cooker 17 is heated by an eddy current due to electromagnetic induction. At this time, in the early stage of the pre-cooking step, the rice cooker 17 is intermittently heated according to the temperature of the cooker, the number of cooked rice, and the like, and a predetermined power is supplied. Thereafter, the heating of the rice cooker 17 is stopped until the cooking process is started.

In this embodiment configured as described above,
When the rice cooker 17 is heated, the rice can be sufficiently agitated by the effect of the inclination of the side of the rice cooker 17 to equalize the convection balance inside the rice cooker 17. Further, when the heating of the rice cooker 17 is stopped, the rice cooker 17 is placed in a stable state using the heat capacity of the rice cooker 17 or the like, thereby preventing the gelatinization of rice due to excessive heating and maintaining the inside of the rice cooker 17 at a predetermined temperature. Can be kept.

[0021]

As described above, the first aspect of the present invention provides
The side of the cooking pot has a generally conical shape that expands upward, and the angle of inclination from the outer edge of the bottom of the cooking pot is approximately 84 to 88 degrees, which equalizes the convection balance inside the cooking pot and promotes the rice stirring effect by convection. Can be done. Therefore, it is possible to provide an induction-heated rice cooker that can reduce the variation in the amount of heat transfer to rice and cook more delicious rice.

According to a second aspect of the present invention, the bottom center of the rice cooker is raised to have a substantially conical convex shape, and its height is about 5 m.
m, the convection balance inside the rice cooker can be further equalized. Therefore, it is possible to provide an induction rice cooker that can reduce the variation in the amount of heat transfer to rice and cook more delicious rice.

Further, in the invention according to claim 3, the thickness of the rice cooker pot is set to about 3.3 mm, and a predetermined pot temperature distribution can be obtained. Therefore, variation in the amount of heat transfer to rice can be reduced.

[0024] Further, in the invention according to claim 4, the rice cooker is intermittently heated according to the number of cooked rice in the early stage of the pre-cooking process, and thereafter, the heating of the rice cooker is stopped until the cooking process is started. It is possible to prevent the rice from being gelatinized due to excessive heating, maintain the inside of the rice cooker at a predetermined temperature, and reduce the variation in the amount of heat transferred to the rice.

[Brief description of the drawings]

FIG. 1 is a block diagram of an induction heating rice cooker according to a first embodiment of the present invention.

FIG. 2 is a block diagram of an induction heating rice cooker according to a second embodiment of the present invention.

FIG. 3 is a block diagram of an induction heating rice cooker according to a third embodiment of the present invention.

FIG. 4 is a block diagram of an induction heating rice cooker according to a fourth embodiment of the present invention.

FIG. 5 is a block diagram of a conventional induction heating rice cooker.

[Explanation of symbols]

1, 5, 9, 13, 17 Rice cooker 2, 6, 10, 14, 18 High frequency inverter 3, 4, 7, 8, 11, 12, 15, 16, 19, 20
Induction heating coil 21 Control means

Continued on the front page (72) Inventor Toshihiro Sasaki 1006 Kazuma Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd.

Claims (4)

[Claims] 1. An induction heating type rice cooker having a rice cooker induction-heated by an induction heating coil, wherein the rice cooker has a substantially conical shape having an inclination angle of about 84 to 88 degrees from a bottom outer edge. vessel. 2. The induction heating rice cooker according to claim 1, wherein the bottom of the rice cooker has a substantially conical convex shape in which the bottom center is raised about 5 mm from the lowermost part of the outer wall. 3. The induction heating type rice cooker according to claim 1, wherein the rice cooker has a thickness of about 3.3 mm. 4. The induction heating rice cooker according to claim 1, wherein in the pre-cooking step, the rice cooker is intermittently heated in accordance with the total number of cooked rice only at the initial stage, and thereafter the heating is stopped.