JP2009089992A - Rice cooker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rice cooker capable of raising rice cooking performance and heat insulating performance by eliminating flux distribution change in induction heating, and saving energy by eliminating the enlargeness of an appliance. <P>SOLUTION: The rice cooker includes: a main body 10; the lid 20 of the main body 10; a pot 11 to be freely removably stored in the main body 10; a pot temperature detecting means 40; pot heating means 12, 17, 33 for heating the pot 11 by electromagnetic induction; and a control means 13 for controlling the pot heating means 12, 17, 33. A reflection layer 50 having an aluminum deposited membrane and constituted of a resin film is arranged on the inner side of the main body 10. Thus, since a heat insulating member is the reflection layer 50 having the aluminum deposited membrane and constituted of the resin film, an eddy current is not caused to flow during induction heating, thereby eliminating the flux distribution change and raising improvement in rice cooking performance and heat insulating performance. Besides, the appliance is not enlarged in the configuration, and then, the rice cooker for saving energy is provided. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an electromagnetic induction heating type rice cooker.

In recent years, energy-saving product development has been required with global warming. Therefore, in rice cookers, it is indispensable to reduce the amount of power consumed during rice cooking and heat retention, and those equipped with a member having a heat insulating effect are widely used to reduce the amount of power consumed. And what used the vacuum heat insulating material as a member with a heat insulation effect is known (for example, refer patent documents 1 and 2).
JP 2001-204622 A JP 2005-1114015 A

  However, in the conventional configuration, the rice cooker can reduce power consumption due to the heat insulating effect of the vacuum heat insulating material, but the vacuum heat insulating material is composed of a core material made of a heat insulator and a skin material that covers the core material, Metal foil is used for the outer skin material in order to suppress gas intrusion. Therefore, in the case of the electromagnetic induction heating method, when the magnetic field from the induction heating means passes through the metal foil, eddy current flows and the magnetic flux distribution in the metal foil changes greatly. In addition, when the distance between the metal foil and the pan surface varies, or when the thickness of the metal foil varies, there is a problem that the magnetic flux distribution in the metal foil changes more greatly, resulting in a decrease in rice cooking performance and heat retention performance. It was. Furthermore, the vacuum heat insulating material has a problem in that the arrangement of the vacuum heat insulating material in the main body leads to an increase in the size of the device.

  The present invention solves the conventional problem, and improves the rice cooking performance and heat retention performance by eliminating the magnetic flux distribution change during electromagnetic induction heating, and eliminates the increase in the size of the equipment, thereby reducing the energy-saving rice cooker. The purpose is to provide.

  In order to solve the conventional problems, the rice cooker of the present invention includes a main body having an upper surface opened, a lid that covers the upper surface opening of the main body so as to be opened and closed, and a pan that is detachably stored in the main body. A pan temperature detecting means that abuts when the pan is housed, a pan heating means for heating the pan by electromagnetic induction, and a control means for controlling the pan heating means. A reflective layer made of a resin film is provided.

  As a result, since the heat insulating member is a reflective layer composed of a resin film having an aluminum vapor deposition film, eddy current does not flow during electromagnetic induction heating, there is no change in magnetic flux distribution, and rice cooking performance and heat insulation performance are improved, A rice cooker with energy-saving properties can be provided without increasing the size of the device.

  The rice cooker of the present invention can improve rice cooking performance and heat retention performance, eliminate the increase in size of the device, and provide an energy-saving rice cooker.

  1st invention is the main body with which the upper surface opened, the lid | cover which covers the upper surface opening part of the said main body so that opening and closing is possible, the pan detachably accommodated in the said main body, and the pan temperature detection means contact | abutted at the time of the storage of the said pan And a pan heating means for heating the pan by electromagnetic induction, and a control means for controlling the pan heating means, and a reflective layer comprising an aluminum vapor deposition film and made of a resin film is disposed inside the main body. The rice cooker is installed. As a result, since the heat insulating member is a reflective layer composed of a resin film having an aluminum vapor deposition film, eddy current does not flow during electromagnetic induction heating, there is no change in magnetic flux distribution, and rice cooking performance and heat insulation performance are improved, A rice cooker with energy-saving properties can be provided without increasing the size of the device.

  In the second invention, in particular, in the first invention, since the reflective layer is integrated with the inner surface of the main body, the troublesome work of disposing the reflective layer on the main body is eliminated, and the left and right, upper and lower sides of the reflective layer, or Displacement such as the rotation direction can be prevented. For this reason, a reflective layer can be arrange | positioned stably and energy saving property can be improved.

  According to a third aspect of the invention, in particular, in the first or second aspect of the invention, the reflective layer is disposed on the inner side surface portion of the main body except the portion facing the bottom surface portion of the pan, so that it can be easily exposed to the outside air from the side surface of the main body. Heat can be suppressed and the rice can be stably and efficiently maintained at a predetermined temperature with a small number of reflective layers.

  According to a fourth aspect of the invention, in particular, in any one of the first to third aspects of the invention, the reflective layer is a resin laminate film together with the seal layer and the protective layer, so that the contact breakage when the reflective layer is disposed on the main body. In addition, it can prevent oxidation and corrosion when water etc. intrude into the main body by mistake, and can fully exhibit the original function of the reflective layer.

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

(Embodiment 1)
1 and 2 show a rice cooker according to Embodiment 1 of the present invention.

  As shown in FIG. 1, a substantially cylindrical main body 10 having an upper surface opened is provided with a lid 20 that covers the upper surface opening so as to be freely opened and closed. The pot storage portion 30 provided in the main body 10 includes a protective frame 32 and a body coil base 31. The pan 11 that is detachably stored in the pan storage portion 30 of the main body 10 is formed of a magnetic material such as copper, stainless steel, or iron, and has a gap with the pan storage portion 30 during storage. A pot heating means 12 for heating the pot 11 by electromagnetic induction is disposed at a portion of the protective frame 32 facing the bottom of the pot 11. The pot heating means 12 constitutes a pot bottom heating means together with the pot heating means 33 disposed outside the corner side surface of the protective frame 32. These pan heating means 12 and 33 are constituted by induction heating coils having a center substantially directly below the center of the bottom of the pan 11. Moreover, the part facing the pan 11 side part of the trunk | coil coil base 31 is comprised with the induction heating coil, and the pan heating means 17 which heats the pan 11 side part by electromagnetic induction is arrange | positioned.

  The control means 13 for controlling the pot heating means 12, 17, 33 has an input power control means 13a and a heating control means 13b, and a microcomputer (not shown) is mounted on the circuit board. The microcomputer controls the current for generating an alternating magnetic field in the pan heating means 12, 17, 33 by software.

  The pan temperature detection means 40 is configured to come into contact with the bottom of the pan when the pan 11 is stored in the pan storage unit 30.

  The pot 11 contains a cooked product 15 such as rice and water inside, and is heated by the pot heating means 12, 17, 33 to cook the cooked product 15.

  In addition, a reflective layer 50 is disposed on the inner side of the main body 10 along the inner side. As shown in FIG. 2, the reflection layer 50 is composed of a resin film 50b having an aluminum vapor deposition film 50a. The aluminum vapor-deposited film 50a is obtained by evaporating aluminum in a high vacuum state and vaporizing the vapor, and the vapor-deposited film thickness is a thin film of about 0.05 μm (generally a reflective layer of a vacuum heat insulating material, Alternatively, the aluminum foil used for the outer skin material has a foil thickness of about 6 μm). The specific resistance of aluminum is about 3 μΩ · cm, and the specific resistance per unit thickness of the foil and film is 5 μΩ in the case of an aluminum foil having a foil thickness of 6 μm, and the aluminum deposited film 50a having a deposited film thickness of 0.05 μm. In this case, it becomes 600 μΩ, and the aluminum deposited film 50a has a much higher resistance.

  In addition, when the magnetic field generated by the pan heating means passes through the conductor, a current flows through the conductor. At this time, the current flows concentrated on the periphery of the conductor is called a skin effect. The current decreases as it goes from the surface to the inside. The current value is 1 / e of the surface at a distance d from the surface, and this distance d is called the skin depth. Note that e is the base of the natural logarithm.

Here, the skin depth d [m] in the case of aluminum is obtained. The skin depth d is expressed by the following equation:
d = (2 / 2Πfμσ) ^1/2
f indicates frequency [Hz], here 30 kHz, μ indicates magnetic permeability [H / m], here 4Πe−7, σ indicates conductivity [S / m], and here is calculated as 40e6, d≈460 μm It becomes.

Moreover, the resistance value R [Ω] of aluminum in alternating current is expressed by the following equation:
R = L / dCσ
L is the length [m], d is the skin depth [m], C is the circumference of the conductor [m], σ is the conductivity [S / m], and a numerical value is substituted to calculate the foil thickness of 6 μm. In the case of an aluminum foil, the resistance value R [Ω] is about 9Ω, and the resistance value R [Ω] in the case of the aluminum deposition film 50a having a deposition film thickness of 0.05 μm is about 1088Ω. High resistance.

  Furthermore, since the aluminum vapor deposition film 50a is discontinuous, when the magnetic field generated by the pan heating means 12, 17, 33 is transmitted through the reflection layer 50 during rice cooking or heat retention, eddy current does not flow through the reflection layer 50, and reflection occurs. There is no change in the magnetic flux distribution in the layer 50. Similarly, as shown in FIG. 1, the electromagnetic wave 80 generated from the magnetic field generated by the pan heating means 12, 17, and 33 leaks to the outside of the main body 10 and is regulated by the Radio Law. 80 is also very weak. Further, since the reflection layer 50 is disposed along the inner surface of the main body 10, the distance between the reflection layer 50 and the pan heating means 12, 17, 33 is secured, and the thickness of the aluminum vapor deposition film 50a varies. However, the influence on the magnetic flux distribution of the reflective layer 50 is minimal.

  Similarly, since the distance between the reflective layer 50 and the pan heating means 12, 17, 33 is ensured, the influence of the magnetic field generated by the pan heating means 12, 17, 33 on the reflective layer 50 is minimal. Moreover, since the reflective layer 50 reflects the radiant heat 70 from the pan 11 to the inside of the main body 10, heat dissipation to the outside of the main body 10 is suppressed. Therefore, since the amount of heat necessary for maintaining the rice at a predetermined temperature is prevented from being radiated to the outside of the main body 10, the heating capacity required for the pot heating means 12, 17, 33 to heat the pot 11. The temperature can be maintained with low power consumption.

  When the reflective layer 50 is not disposed on the inner surface of the main body 10, the average power consumption per hour is 18.8 Wh when the heat is kept for 12 hours, whereas the reflective layer 50 is disposed on the inner surface of the main body 10. When installed, the average power consumption per hour during the 12-hour heat retention is 18.3 Wh, and it has been confirmed that the power consumption can be reduced by about 2.7%. In addition, the descending speed until the rice reaches a predetermined temperature was approximately 0.40 ° C./min when the reflective layer 50 was not provided on the inner surface of the main body 10, but reflected on the inner surface of the main body 10. In the case where the layer 50 is disposed, it is confirmed that the temperature is about 0.37 ° C./min. The reflection layer 50 reflects the radiant heat 70 from the pan 11 to the inside of the main body 10, so It can be seen that heat dissipation is suppressed.

  Furthermore, since the heat insulating material is not disposed in the main body 10, the outer shape of the main body 10 can be made at least as much as the heat insulating material thickness. Moreover, since the aluminum vapor deposition film 50a can be formed by a versatile method, it is easy to manufacture and secures mass productivity.

  As described above, according to the rice cooker of the present embodiment, the heat insulation temperature is maintained with a small amount of power consumption by disposing the reflective layer including the aluminum vapor deposition film and the resin film inside the main body. In addition, it is possible to prevent a decrease in rice cooking performance and heat retention performance.

(Embodiment 2)
3 and 4 show a rice cooker according to Embodiment 2 of the present invention. Since the basic configuration is the same as that of the first embodiment, the same elements are denoted by the same reference numerals and the description thereof is omitted.

  As shown in FIG. 3, in the present embodiment, the reflective layer 50 is integrated along the inner surface of the main body 10.

  FIG. 4 shows a cross section thereof, and since the reflective layer 50 is integrated with the main body 10, when the main body 10 is attached or detached, for example, interference between the reflective layer 50 and the pan heating means 12, 17, 33 is avoided, Assemblability is improved.

  As described above, the complicated operation of integrating the reflective layer 50 with the main body 10 and separately arranging the reflective layer 50 on the main body 10 can be prevented. In other words, it is possible to prevent dislocations such as left and right, up and down, or the rotation direction, and to stably dispose the reflective layer 50. Moreover, since the distance from the pan 11 does not vary significantly by integrating the reflective layer 50 and the main body 10, the reflective layer 50 stably reflects the radiant heat 70 from the pan 11 to the inside of the main body 10. The rice can be stably maintained at a predetermined temperature, and the heat insulation temperature can be maintained with a small amount of power consumption. Moreover, since there is no change of magnetic flux distribution in the reflective layer 50 similarly to Embodiment 1, it is possible to prevent the rice cooking performance and the heat retention performance from deteriorating.

  As described above, according to the rice cooker of the present embodiment, by keeping the reflective layer integrated with the inner surface of the main body, it is possible to maintain the heat insulation temperature with a small amount of power consumption and to prevent the rice cooking performance and the heat insulation performance from being deteriorated. The assembly of the main body is improved.

(Embodiment 3)
FIG. 5 shows a rice cooker according to Embodiment 3 of the present invention. Since the basic configuration is the same as that of the first and second embodiments, the same elements are denoted by the same reference numerals and the description thereof is omitted.

  As shown in the figure, in the present embodiment, the reflective layer 50 is integrally disposed on the inner side surface portion of the main body 10 except for the portion facing the bottom surface portion of the pan 11.

  Heat dissipation to the outside of the main body 10 is likely to occur on the inner side surface of the main body 10 except for the bottom surface portion of the pot 11 on the inner surface of the main body 10 that is generally easily exposed to outside air. Therefore, the reflective layer 50 is disposed only on the inner surface of the main body 10 except for the bottom surface of the pot 11 on the inner surface of the main body 10.

  As described above, according to the rice cooker of the present embodiment, by disposing the reflective layer on the inner side surface portion of the main body except for the portion facing the bottom surface portion of the pan, from the side surface of the main body that is easily exposed to the outside air to the outside. Heat can be suppressed, and rice can be stably and efficiently maintained at a predetermined temperature with a small number of reflective layers. In addition, the heat insulation temperature can be maintained with a small amount of power consumption, and the rice cooking performance and the heat insulation performance can be prevented from being lowered, so that the assembly of the main body is improved.

(Embodiment 4)
FIG. 6 shows a rice cooker according to Embodiment 4 of the present invention. Since the basic configurations of the first to third embodiments and the rice cooker are the same, description thereof is omitted.

  As shown in the figure, in the present embodiment, the reflective layer 50 is a resin laminate film 60 together with a seal layer 60a and a protective layer 60b.

  Since the layer structure of the resin laminate film 60 is general, the seal layer 60a is made of high-density polyethylene having a thickness of 50 μm, and the protective layer 60b is made of polyethylene terephthalate having a thickness of 12 μm, and can be laminated by a versatile construction method. Manufacturing is easy and mass productivity can be secured. In addition, when the shape holding force is inferior, such as bending or bending due to the internal stress of the reflective layer 50, the rice cooking performance or the heat insulation performance is reduced, and the power consumption for maintaining the heat insulation temperature is increased. It does not depend on the thickness of the protective layer 60b. Moreover, by comprising the resin laminate film 60, the flexibility of the reflective layer 50 is improved, and the reflective layer 50 can be freely disposed on the inner side surface of the main body 10.

  As described above, according to the rice cooker of the present embodiment, since the reflective layer is made of the resin laminate film together with the seal layer and the protective layer, the reflective layer can be disposed freely and is disposed on the main body. It is possible to prevent oxidation and corrosion when the contact breakage or water intrudes into the main body by mistake, and to fully exhibit the original function of the reflective layer.

  As described above, the rice cooker according to the present invention can improve rice cooking performance and heat retention performance, eliminate the increase in size of the device, and be energy saving. It can be applied to all rice cookers.

Sectional drawing of the rice cooker in Embodiment 1 of this invention. Partial enlarged sectional view showing the reflective layer Sectional drawing of the rice cooker in Embodiment 2 of this invention. Partial enlarged sectional view showing the reflective layer portion Sectional drawing of the rice cooker in Embodiment 3 of this invention. Partial expanded sectional view which shows the reflection layer part of the rice cooker in Embodiment 4 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Main body 11 Pan 12, 17, 33 Pan heating means 13 Control means 20 Lid 50 Reflective layer 50a Aluminum vapor deposition film 50b Resin film 60 Resin laminate film 60a Seal layer 60b Protective layer

Claims (4)

A main body having an upper surface opened; a lid that covers the upper surface opening of the main body so as to be freely opened and closed; a pan that is detachably stored in the main body; a pan temperature detecting means that is in contact with the pan when stored; A rice cooker comprising a pan heating means for heating by induction and a control means for controlling the pan heating means, and a reflective layer having an aluminum vapor deposition film and made of a resin film is disposed inside the main body. The rice cooker according to claim 1, wherein the reflective layer is integrated with the inner surface of the main body. The rice cooker according to claim 1 or 2, wherein the reflective layer is disposed on the inner side surface portion of the main body excluding a portion facing the bottom surface portion of the pan. The rice cooker according to any one of claims 1 to 3, wherein the reflective layer is a resin laminate film together with a seal layer and a protective layer.

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