JP2006304932A - Rice cooker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rice cooker for which the generation of huge water bubbles in a steam container is reduced, the intrusion of water into a pot is eliminated and heating efficiency for steam generation is improved. <P>SOLUTION: The steam container 12 for housing water and generating steam is constituted of two or more different metal layers. Thus, the steam container 12 is heated evenly, a boiling source is not concentrated in the steam container 12, water bubble generating place are dispersed, the generation of huge water bubbles is reduced, the intrusion of water into the pot 2 is eliminated, a rice cooking performance is improved and the heating efficiency is improved further. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a rice cooker that uses steam to cook rice.

  Conventionally, a rice cooker that uses steam to cook rice to improve the taste of cooked rice is already known (see, for example, Patent Document 1).

This heats the water in a steam container with a container heating means, generates steam, supplies this steam to the cooking pot, and cooks rice.
JP 2003-144212 A

  However, in the conventional configuration, at least a part of a steam container made of metal is used to boil water, but the steam container for generating steam is composed only of a magnetic metal such as stainless steel. For this reason, it cannot be said that the heat conductivity of the steam container is ensured to a sufficient level, and when the water in the steam container is boiled, the heat generation level of the portion facing the container heating means is separated from the container heating means. Since the heat generation level of the part is different, the boiling source is concentrated at a predetermined place in the steam container, and water bubbles are continuously generated at the same place. If such a water bubble jumps, enters the pot and falls on the rice, only that part of the rice will be whitened, it will also be rice that contains too much moisture, it will look bad and it will be bad taste There was a problem. In addition, in order to suppress water bubbles, the container heating means is intentionally lowered to cope with it, the effect of steam generation is diminished, or the product is made larger and the capacity of the steam container is increased so that the product can be used easily. There was a problem that the damage was lost.

  The present invention solves the above-mentioned conventional problems, and reduces the generation of huge water bubbles by dispersing the generation locations of water bubbles without concentrating the boiling source in the steam container, An object of the present invention is to provide a rice cooker that can eliminate the intrusion of water into the water and can increase the heating level of the steam container.

  In order to solve the conventional problems, a rice cooker of the present invention includes a pan, a heating means for heating the pan, a lid for covering the pan, a steam container for storing water, and electromagnetic induction for the steam container. A container heating means for heating and generating steam; a steam path for supplying the steam generated in the steam container to the pan; and a control means for controlling the heating means and the container heating means. The induction heat generating part is constituted by two or more different metal layers.

  This prevents the boiling source from concentrating in the steam container, disperses the locations where water bubbles are generated, reduces the generation of huge water bubbles, and prevents strong water from entering the pot. The steam can be fed into the pan and the rice cooking performance can be improved.

  The rice cooker of the present invention can increase the amount of heating to increase steam momentum, eliminate the intrusion of water bubbles into the pot when steam is generated, and improve the effect of steam generation to improve rice cooking performance.

  The first invention is a pan, a heating means for heating the pan, a lid for covering the pan, a steam container for storing water, a container heating means for generating steam by electromagnetic induction heating the steam container, A steam path for supplying the steam generated in the steam container to the pan; and a control means for controlling the heating means and the container heating means, wherein the electromagnetic induction heating part of the steam container has two or more layers of different metals By comprising by a layer, the temperature distribution of a steam container can be made uniform and the heating state of a steam container can be stabilized, raising the efficiency of heat_generation | fever.

  According to a second aspect of the invention, in particular, in the first aspect of the invention, the metal layer of the vapor container is formed as a nonmagnetic metal by comprising a magnetic metal layer and a nonmagnetic metal layer thinner than the magnetic metal layer on the outer layer. While using an alloy metal such as aluminum, copper, titanium, or brass, the efficiency of heat generation can be increased.

  According to a third invention, in particular, in the first invention, the metal layer of the vapor container is constituted by a nonmagnetic metal layer and a nonmagnetic metal layer thinner than the inner layer on the outer layer, thereby reducing the thickness of the vapor container. However, it is possible to make the heating state of the steam container uniform and to quickly switch between generation and stop of steam, prevent discomfort when the lid is opened during steam generation, and improve rice cooking performance Become.

  According to a fourth aspect of the present invention, the outer layer of the electromagnetic induction heating part of the steam container has a non-outer layer thickness of 0.1 to 2.0 times the thickness at which the same skin electrical resistance value as that of iron is obtained. Calculate the thickness necessary to obtain the same value as the iron skin electrical resistance value in consideration of the frequency band to be used for the magnetic metal layer, and a nonmagnetic metal that is 0.1 to 2 times the thickness By arranging the layers and obtaining efficient heat generation, it is possible to improve the heating efficiency of the container vapor and improve the rice cooking performance.

  According to a fifth aspect of the present invention, the metal layer of the steam container is constituted by a clad material in which two or more magnetic metal layers and a nonmagnetic metal layer having a higher thermal conductivity than the magnetic metal layer are combined in the inner layer. The heating state of the steam container is made more uniform, the boiling source is not concentrated in the steam container, and the generation location of water bubbles is dispersed to further reduce the generation of huge water bubbles. It becomes possible to reduce the invasion of rice and improve the rice cooking performance.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 shows a rice cooker according to Embodiment 1 of the present invention.

  As shown in FIG. 1, the rice cooker main body 1 includes a detachable pan 2 that contains rice and water therein, a lid 3 that covers the opening of the pan 2, and a pan 2 that is fixed to the pan 2 side of the lid 3. And the steam generating means 5 for generating steam, and the steam path 6 for guiding the generated steam to the pan 2.

  In the rice cooker main body 1, the heating means 7 including a heating coil for induction heating the pan 2 and the pan temperature urged to the pan 2 by a spring (not shown) for measuring the temperature of the pan 2. Detection means 8 is installed. The lid 3 is provided with a steam cylinder 9 for discharging excess steam in the pan 2 to the outside of the rice cooker body 1, and a lid heating means 10 comprising a heating coil for induction heating the inner lid 4. ing. The inner lid 4 is provided with a steam introduction hole 11 through which the steam generated by the steam generation means 5 is introduced into the pan 2.

  The steam generating means 5 includes a removable steam container 12 for storing water, and a container heating means 13 including a heating coil for induction heating the steam container 12. The steam container 12 has an inner surface made of ferritic stainless steel, and a 20 μm thick copper plating is applied to the outer surface.

  The container heating means 13 is disposed on the side of the steam container 12 so as to heat the side of the steam container 12, and is fixed to the container storage unit 14.

  As the non-magnetic metal constituting the outer surface of the steam container 12, an alloy metal such as aluminum, titanium, or brass may be used in addition to copper.

When performing electromagnetic induction heating, it is common to use a metal material having a high skin electric resistance value for the heat generating part of the steam container for electromagnetic induction heating. For example, in a typical ferritic stainless steel, 430 stainless steel, when a high frequency current of 25 kHz is passed through a heating coil, the skin electric resistance value is 23.3 × 10 ⁻⁴ Ω, and in iron, it is as high as 9.4 × 10 ⁻⁴ Ω. It can be said that it is suitable for electromagnetic induction heating. On the other hand, aluminum is as low as 0.48 × 10 ⁻⁴ Ω and copper is as low as 0.39 × 10 ^−4, and is usually not suitable for electromagnetic induction heating.

  Normally, when a magnetic field is applied to a nonmagnetic metal, a repulsive magnetic field is generated in the nonmagnetic metal, a repulsive current flows, the magnetic field cannot pass through the nonmagnetic metal, and no heat is generated by electromagnetic induction heating.

  However, as these non-magnetic metals are also made thinner, the skin electric resistance value eventually increases, and electromagnetic induction heating becomes possible. This is because if the non-magnetic metal is sufficiently thin, the resistance value of the skin is increased and the resistance magnetic field is less likely to be generated. The magnetic field passes through the non-magnetic metal, and the passed magnetic field induces eddy currents to induce resistance. This is because heating occurs.

  For this reason, in the case of the first embodiment, the copper on the outer surface is heated by electromagnetic induction, and since this copper is thin, the remaining magnetic field penetrating the copper heats the ferritic stainless steel on the inner surface and efficiently steams the steam container 12. Will be heated.

  The steam path 6 is fixed in the lid 3 and connects the steam container 12 of the steam generating means 5 and the pan 2 in communication. In addition, since the connecting portion between the steam path 6 and the steam container 12 is sealed with a sealing packing, and the connecting portion between the steam path 6 and the inner lid 4 is also sealed with the sealing packing, the steam container The steam generated in 12 does not leak, and is all charged into the pot 2 through the steam inlet hole 11.

  The microcomputer as the control means 15 controls the operations of the heating means 7, the lid heating means 10 and the container heating means 13, and is fixed to the rice cooker body 1.

  About the rice cooker comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  First, predetermined rice and water are set in the pan 2, and the rice cooking process is started. In the rice cooking process, the rice is absorbed in water, the pan 2 is heated by the heating means 7, the inner lid 4 is heated by the lid heating means 10, and the entire pan 2 is uniformly heated at a stretch. A boiling process in which the water in the pan 2 is boiled, and a steaming process in which steam is supplied while suppressing the heating by the heating means 7 and the lid heating means 10 with almost no water in the pot 2. Cook rice by gelatinizing rice. The control means 15 controls the heating means 7 optimally according to the temperature of the pot 2 by the pot temperature detecting means 8, and cooks rice according to a predetermined rice cooking sequence. Several courses are prepared for the cooking sequence depending on the type of rice. When the rice cooking process is completed, the process automatically shifts to the heat retaining process so that the temperature of the cooked rice does not decrease, and the user can always obtain warm rice.

  In the case of generating steam, the control means 15 operates the container heating means 13 to heat the steam container 12 and generate steam. The generated steam passes through the steam path 6, is further heated by the inner lid 4, and is supplied to the pan 2 through the steam introduction hole 11.

  In the soaking process and the cooking process during cooking, the rice and water in the pan 2 can be rapidly and uniformly heated by introducing steam. Gelatinization progresses by supplying heat energy and moisture to the rice during the entire rice cooking process, but by adding steam to the rice in the steaming process, further heat energy can be obtained without causing the rice to burn or dry. And water can be given to further promote gelatinization. Further, since steam condenses and concentrates heat on the portion where the temperature is 100 ° C. or lower, it can be heated without unevenness, and the rice having a sufficiently high temperature is not heated excessively. As a result, good-tasting rice can be obtained.

  Moreover, also in a heat retention process, by drying the steam, the rice can be prevented from being dried, and further, the cooked rice can be uniformly reheated to heat the rice to an appropriate temperature.

  As described above, in the present embodiment, by forming the magnetic metal layer and the non-magnetic metal layer thinner than the inner layer on the outer layer, high heat generation efficiency can be obtained while freely setting the material of the outer layer. .

(Embodiment 2)
Next, a second embodiment will be described. The parts other than those described below and the operation during rice cooking / warming are the same as those in the first embodiment.

  As shown in FIG. 1, the rice cooker in this Embodiment comprises the steam container 12 with a metal material with high thermal conductivity. The metal having high thermal conductivity is a non-magnetic metal and there are various types. Here, the aluminum material will be described.

  Even with aluminum alone, it is possible to cause the steam container 12 to generate heat by setting the frequency for energizing the container heating means 13, but the outer surface of aluminum is plated with copper of 20 μm thickness in order to increase the heat generation efficiency. As described in the first embodiment, the copper plating layer generates heat efficiently, and this heat is transmitted to the entire steam container 12 by aluminum.

  At this time, when the steam container 12 is heated by the container heating means 13 in order to inject the steam, if the heat generated in the steam container 12 is not uniform, the boiling and the place where the steam container 12 boils intensively does not easily occur. A place occurs. Even in the case of generating steam, the control means 15 operates the container heating means 13 discontinuously in order to maintain an appropriate steam injection timing, but the steam heating container 12 faces the heating coil of the container heating means 13. Since heat is concentrated on the part, bubbles are generated only at this part, and the bubbles are rapidly increased to the surface of the water, and large splashes are splashed up.

  In this way, when splashed splashes are large and frequently occur, the splashes enter the steam path 6, continue to the steam path 6 as water droplets, enter the inner lid 4, and lower the temperature of the inner lid 4. And the rice and water cannot be heated uniformly. In addition, if the water drops enter the pan 2 from the steam introduction hole 11 in the steaming process or the heat insulation process, the water drops come into contact with the rice immediately below the steam introduction hole 11, depriving the heat of the rice, resulting in an uneven heating state. In particular, the rice directly under the steam inlet 11 may be whitened or swollen, and the taste of the rice may be deteriorated.

  However, in the present embodiment, since the steam container 12 has a structure excellent in heat conduction, the generated heat is quickly transmitted to the entire steam container 12, realizing a uniform boiling state, and large splashes are not splashed up. It becomes difficult to enter the steam path 6. In addition, heat efficiency is increased because waste of heat conduction is reduced.

  Furthermore, since the heat vessel has a good thermal conductivity, there is no functional problem even if the vapor vessel 12 itself is thinned, so that the heat capacity of the vapor vessel 12 can be reduced. At this time, when the steam container 12 is heated, heat is efficiently transmitted to the entire steam container 12, and the steam container 12 stops heating the internal water (hot water) at the moment when the heating is stopped. Even if the lid 3 is opened, if the heating is stopped upon detecting that the lid is opened, the momentum of steam generation stops immediately, so that the steam is not expelled toward the user.

  In addition, although the problem by splash can be overcome by arrange | positioning the vapor | steam path | route 6 ensuring the height more than fixed from the vapor | steam container 12, the height of the whole rice cooker becomes high and installation property by a user is sufficient. Such a measure cannot be adopted.

  As described above, in the present embodiment, by forming the nonmagnetic metal layer and the nonmagnetic metal layer thinner than the inner layer in the outer layer, a uniform boiling state is realized, and the water in the steam container 12 has boiled. At the same time, large splashes penetrate into the steam path 6 and prevent water droplets from entering the pan 2 to improve the rice cooking performance, reduce the heat capacity of the steam container 12 and quickly generate / stop steam, While improving the effect of generating steam, it can be used comfortably by preventing unnecessary generation of steam. In addition, it is possible to control the steam that is fine without generating steam more than necessary.

  In addition, although the steam container 12 was demonstrated with the structure by aluminum and copper plating, the same effect can be acquired also with another nonmagnetic metal. Further, the inner surface and the outer surface are not limited to the plating process as long as they are thermally coupled.

  Further, even if another metal layer overlaps the inner surface, the same effect can be obtained.

(Embodiment 3)
Next, a second embodiment will be described. The parts other than those described below and the operation during rice cooking / warming are the same as those in the first embodiment.

  As shown in FIG. 1, the rice cooker in this Embodiment is using the clad material which comprised the steam container 12 for the outer surface with the ferrite-type stainless steel, and the inner surface with aluminum. At this time, in the steam container 12, the stainless steel layer on the outer surface generates heat, and the heat is diffused by the aluminum layer on the inner surface. Therefore, the inside of the steam container 12 can achieve a uniform boiling state, and it is possible to improve the rice cooking performance by preventing water droplets from entering the pot 2 without splashing large splashes.

  In addition, the thickness of each metal layer can be set arbitrarily. Further, it may be composed of several metal layers on the inner surface side.

  As described above, the rice cooker according to the present invention eliminates the intrusion of water bubbles into the pot when steam is generated and can improve the rice cooking performance, so that it can be optimally cooked regardless of household or business use. .

Sectional drawing of the rice cooker in Embodiment 1 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rice cooker body 2 Pan 3 Lid 4 Inner lid 5 Steam generating means 6 Steam path 7 Heating means 12 Steam container 13 Container heating means 15 Control means

Claims (5)

A pot, heating means for heating the pot, a lid for covering the pot, a steam container for storing water, a container heating means for electromagnetically heating the steam container to generate steam, and generated in the steam container A rice cooker comprising a steam path for supplying steam to the pan, and a control means for controlling the heating means and the container heating means, wherein the electromagnetic induction heating part of the steam container is composed of two or more different metal layers vessel. The rice cooker according to claim 1, wherein the metal layer of the steam container is composed of a magnetic metal layer and a nonmagnetic metal layer thinner than the magnetic metal layer on the outer layer. The rice cooker according to claim 1, wherein the metal layer of the steam container is composed of a nonmagnetic metal layer and a nonmagnetic metal layer thinner than the inner layer on the outer layer. 4. The rice cooker according to claim 2, wherein the outer layer of the electromagnetic induction heating part of the steam container is 0.1 to 2.0 times the thickness at which the same skin electrical resistance value as that of iron is obtained. . The metal layer of the steam container is a rice cooker composed of a clad material in which a magnetic metal layer and an inner layer thereof are combined with two or more nonmagnetic metal layers having higher thermal conductivity than the magnetic metal layer.

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