JP2006051139A - Electromagnetic induction heating rice cooker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To retain the whole of a heating container evenly at high temperatures by maintaining the temperature on a side face of the heating container by reducing the heat radiation from the side face of the heating container, and to improve the rice boiling performance by preventing the unevenness of the boiled rice inside a rice boiling container in a large-sized rice cooker for business use using an induction heating coil. <P>SOLUTION: The rice cooker has the induction heating coil 3 and the rice boiling container 1 disposed inside a storage case 7. Joule heat is generated on the bottom of the rice boiling container 1 with magnetic force lines generated from the induction heating coil 3, and the rice boiling container 1 is heated with the generated joule heat. The rice cooker also has an outer container 6 made of a material which generates heat by the electromagnetic induction heating, disposed at a prescribed distance on an outer side face of the rice boiling container 1. The leaked magnetic force lines which are not inputted in the rice boiling container are collected in the outer container 6 to make the outer container generate heat. In this way, as the rice boiling container is secondarily heated from outside with the heat of the outer container 6, the heat radiation from the rice boiling container 1 is reduced. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a large electromagnetic induction heating rice cooker that cooks about 4 kg of rice in a commercial kitchen.

  In the electromagnetic induction heating rice cooker, there are methods shown in Patent Document 1 and Patent Document 2 as a method for uniformly heating the entire rice cooking container to cook rice with less uneven cooking.

  In the former Patent Document 1, an induction heating coil is disposed on the bottom and side surfaces of a rice cooking container to heat the rice cooking container from the bottom and side surfaces.

  Moreover, what is shown to the latter patent document 2 provides the container which inserts this rice cooking container in the outer side of a rice cooking container, and flows hot air between these containers.

  By the way, the electromagnetic induction heating rice cooker shown in Patent Document 1 and Patent Document 2 described above is used to cook a rice cooker having a maximum rice cooker amount of 1.8 L, which is used in general households, that is, about 1 kg of rice. It is a small rice cooker used.

  On the other hand, gas cookers that use combustion gas as a heat source are generally used in the case of commercial rice cookers that perform large-scale rice cookers of around 4 mm, but in recent years, induction is similar to the small rice cookers described above. Electromagnetic induction heating rice cookers using heating coils are also being used.

  After the flame from the burner hits the bottom of the rice cooking container, the gas rice cooker wraps the rice cooking container as a high-temperature combustion exhaust gas, and heat is further transferred from this high temperature exhaust gas to the rice cooking container. It is said that it is kept at a high temperature and can be cooked uniformly in any part of the rice cooking container to produce delicious rice.

  Compared with this, in the electromagnetic induction heating rice cooker using the induction heating coil, the surface of the rice cooking container facing the heating coil becomes high temperature, but the portion not facing the heating coil is at a high temperature like the gas rice cooker. Difficult to do.

  Then, as shown in patent document 3, while installing an induction heating coil and a rice cooking container in a storage case, a vapor | steam discharge port is provided in the back surface of the storage case of the same height as the lid | cover from which the water vapor of a rice cooking container comes out, and this steam The thing which also heated the upper part of the rice cooking container with the water vapor | steam discharged | emitted from a discharge port is proposed.

  In addition, as a method for improving the rice cooking performance, a method of winding an induction heating coil along the R portion on the outer periphery of the bottom surface of the rice cooking container has been commercialized.

JP 2003-290022 A

JP-A-8-182608 Japanese Patent Laid-Open No. 8-117099

  Although what is shown to patent document 1 is a small rice cooker used in a general household, since the induction heating coil is arrange | positioned at the bottom face and side surface of a rice cooking container, manufacturing cost increases.

  Moreover, since the side surface of a rice cooking container tends to be overheated conversely when there is little rice cooking amount, the control which prevents this is required and there exists a problem also difficult in terms of control.

  Moreover, although what is shown in patent document 2 is also a small rice cooker used in a general household, this thing needs to make the air path formed by the rice cooking container and the container which inserts this rice cooking container into a sealed structure. Therefore, there is a problem that the structure becomes large.

  Furthermore, in the commercial rice cooker using the induction heating coil shown in Patent Document 3, the lower part of the rice cooker is sufficiently heated, but the upper part of the side surface is still underheated, There was a problem that it was difficult to improve rice cooking performance due to variations in heating.

  In addition, even in the case where the induction heating coil is rolled up along the R portion of the bottom outer periphery of the rice cooker, the side temperature of the rice cooker does not reach the side temperature of the gas cooker. The current situation is inferior.

  This invention solves said subject in the large-sized rice cooker for business using the induction heating coil.

  In the first aspect of the present invention, in the rice cooker that provides the induction heating coil and the rice cooking container in the storage case, generates Joule heat by the magnetic lines generated by the induction heating coil on the bottom surface of the rice cooking container, and heats the rice cooking container. An outer container made of a material that generates heat by electromagnetic induction heating is provided on the outer side surface of the rice cooking container, and leakage magnetic lines that are not input to the rice cooking container are collected by the outer container, and the outer container is heated to cook rice. The container is secondarily heated from the outside to reduce the heat radiation from the rice cooking container.

  Moreover, in Claim 2, a heat insulating material is inserted between the outer container and the storage case.

  According to claim 1 of the present invention, the heat released from the rice cooking container can be reduced by conducting the heat generated by absorbing the leakage magnetic field near the coil at the lower end of the outer container to the entire outer container. The rice cooking container is maintained at a high temperature to obtain good rice cooking performance.

  Moreover, since the whole rice cooking container is kept at high temperature by this, it will be cooked uniformly in any part in a rice cooking container similarly to a gas rice cooker, and delicious rice can be made.

  Further, according to claim 2, since the heat insulating material is inserted between the outer container and the storage case, the heat radiation from the outer container can be reduced, thereby keeping the outer container and the rice cooking container at a high temperature and improving the heat efficiency. Improvement can be achieved and the temperature of the storage case can be maintained at a low temperature.

  Next, an embodiment of the present invention will be described with reference to the accompanying drawings.

  In FIG. 1, 1 is a rice cooking container, which is formed by spraying a magnetic metal material on the outside of a magnetic metal material or high thermal conductivity aluminum. Reference numeral 2 denotes a lid that covers the upper opening of the rice cooking container 1. Reference numeral 3 denotes an induction heating coil, which is disposed below the rice cooking container 1. A resin coil base 4 supports the induction heating coil 3.

  A top plate 5 is mounted between the rice cooking container 1 and the heating coil 3 for insulation and waterproofing.

  Reference numeral 6 denotes an outer container made of a magnetic metal material such as iron or SUS430, and is installed on the outer side surface of the rice cooking container 1 at a predetermined distance so as to cover the outer side surface of the rice cooking container 1.

  Reference numeral 7 denotes a storage case constituting the outer shell of the device. 8 is a heat insulating material, for example, made of glass wool, and is inserted between the outer container 6 and the storage case 7.

  Reference numeral 9 denotes a temperature sensor that is in close contact with the outer bottom surface of the rice cooking container 1 and detects the temperature of the bottom surface.

  Reference numeral 10 denotes a control circuit, which generates an output signal based on a signal from the temperature sensor 9.

  An inverter circuit 11 is a circuit that supplies a high-frequency current to the heating coil 3 based on a signal from the control circuit 10. A power supply circuit 12 supplies power to the inverter circuit 11 and the control circuit 10.

  Reference numeral 13 denotes a power source. Reference numeral 14 denotes an operation panel on which switches for operating the device are mounted.

  Next, the operation of the present invention will be described with reference to the drawings.

  An appropriate amount of washed rice and water is put into the rice cooking container 1, and the lid 2 is put on, and then a switch (not shown) of the operation panel 14 is turned on to cause a high-frequency current from the inverter circuit 11 to the induction heating coil 3. The magnetic field lines are generated around this, and an eddy current is generated in the bottom surface of the rice cooking container 1, and the bottom surface of the rice cooking container 1 generates heat. And this heat heats the water and rice in the rice-cooking container 1, and also boils, and rice cooking advances.

  On the other hand, since all the magnetic lines generated in 3 parts of the induction heating coil cannot be absorbed by the bottom surface of the rice cooking container 1, some of them fly to the metal part around the rice cooking container 1 as leakage magnetic lines. At this time, in the present invention, since the outer container 6 made of a magnetic metal material is disposed at a predetermined distance on the outer side surface of the rice cooking container 1, the leakage magnetic field lines are collected in the outer container 6. Generates heat by the same action as that of the bottom surface of the rice cooking container 1 at the lower part.

  Since the outer container 6 is made of a metal material, when heat is generated in the lower part and the temperature of the outer container 6 becomes high, the heat is transferred to the upper part by heat conduction and the entire temperature rises.

  In addition, in the present invention, since the heat insulating material 8 is inserted between the storage case 7 and the outer container 6 and the heat radiation from the outer container 6 to the storage case 7 is small, the temperature of the outer container 6 is kept high. Is done.

  Therefore, the heat radiation from the side surface of the rice cooking container 1 is extremely reduced, and the rice cooking container 1 is maintained uniformly at a high temperature as a whole, and good rice cooking performance is obtained. This is the same effect as a gas rice cooker in which a high-temperature combustion gas flow envelops the entire rice cooking container and keeps the entire temperature high and uniform.

  Furthermore, in the present invention, when a magnetic metal material such as SUS430 and an aluminum material with good thermal conductivity, for example, a clad material with SUS304 attached thereto, are used for the outer container 6 with the aluminum material with good thermal conductivity. Since the temperature difference between the upper and lower sides is reduced and the temperature can be made uniform in a short time, it can contribute to the improvement of rice cooking performance.

It is a schematic sectional explanatory drawing which shows one Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rice cooking container 2 Lid 3 Induction heating coil 6 Outer container 7 Storage case 8 Heat insulating material 9 Temperature sensor 10 Control circuit 11 Inverter circuit 12 Power supply circuit

Claims (2)

An induction heating coil (3) and a rice cooking container (1) are provided in the storage case (7), and Joule heat is generated on the bottom surface of the rice cooking container (1) by the lines of magnetic force generated by the induction heating coil (3). In the rice cooker for heating (1), an outer container (6) made of a material that generates heat by electromagnetic induction heating while maintaining a predetermined distance is provided on the outer side surface of the rice cooking container (1), and the rice cooking container (1) The leakage magnetic field lines that are not input to the outer container (6) are collected in the outer container (6), the outer container (6) is heated, and the rice cooking container (1) is secondarily heated from the outside to reduce heat radiation from the rice cooking container (1). An electromagnetic induction heating rice cooker characterized by having been made. An electromagnetic induction heating rice cooker, wherein a heat insulating material (8) is inserted between the outer container (6) and the storage case (7).

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