JP4155248B2 - rice cooker - Google Patents

Description

  The present invention relates to an induction heating rice cooker used for home use and business use.

  In a conventional induction heating rice cooker, an inductor is configured by using a magnetic shield ring as a method for reducing a leakage magnetic field from a heating coil (see, for example, Patent Document 1) or by winding a coil near the outer periphery of the heating coil. A thing (for example, refer patent document 2) etc. are known.

  FIG. 8 shows the configuration of Patent Document 1, in which an electromagnetic shield ring 2 in which an aluminum plate, a lead wire, or the like is formed in an annular shape is disposed on the outer periphery of the heating coil 1. In the induction heating apparatus having this configuration, an induction current flows through the electromagnetic shield ring 2 by being induced by the high-frequency magnetic field generated in the heating coil 1, and further, the induction current causes a high-frequency magnetic field generated from the heating coil 1 to be generated in the electromagnetic shield ring 2. Produces a reverse high-frequency magnetic field. As a result, the high-frequency magnetic field generated from the electromagnetic shield ring 2 acts so as to cancel the high-frequency magnetic field generated at the outer periphery of the heating coil 1, so that the high-frequency leakage magnetic field of about 20 k to 100 kHz leaking from the heating coil 1 is reduced. .

9 and 10 show the configuration of Patent Document 2, in which an inductor 5 is configured by winding around the outer periphery of the heating coil 1, and the high-frequency magnetic field generated from the heating coil 1 and the inductor 5 are The high-frequency magnetic field components that are generated are arranged to cancel each other. As a specific circuit example, as shown in FIG. 10, a power supply unit 3 composed of a commercial power supply, an inverter 11 that converts the power of the power supply unit 3 into high-frequency power, and the power of the inverter 11 into a high-frequency magnetic field. The inverter 11 includes a heating coil 1 to be converted and a pan 15 that generates heat upon receiving a magnetic field from the heating coil 1. The inverter 11 includes a rectifier 4 that rectifies commercial power and an inductor that smoothes the output of the rectifier 4. 5 and a smoothing capacitor 6, a semiconductor switch 8 that controls power supply to the heating coil 1, and a resonance capacitor 7 that smoothes the switching operation of the semiconductor switch 8.
JP-A-57-115795 Japanese Patent Publication No. 63-7672

  However, in the configuration as shown in Patent Document 1, the high-frequency leakage magnetic field can be reduced by the effect of the electromagnetic shield ring 2, but the power source frequency generated from the heating coil 1 or a magnetic field having a frequency twice the power source (hereinafter referred to as the power source frequency). , The low frequency magnetic field) is hardly absorbed by the pan on the heating coil 1, and the electromagnetic shield ring 2 cannot sufficiently generate a reverse magnetic field, so that the low frequency magnetic field is not reduced and is emitted to the outside. .

  On the other hand, in the configuration shown in Patent Document 2, since the winding is operated as the inductor 5 (about several hundreds μH), the number of winding turns increases. At this time, the low-frequency magnetic field emitted from the winding becomes larger than the low-frequency magnetic field emitted from the heating coil 1, resulting in an increase in the low-frequency magnetic field emitted to the outside. Further, the conventional induction heating device aims to cancel the high-frequency magnetic field, and the winding for reducing the leakage magnetic field is limited to the vicinity of the heating coil 1 and has no freedom of arrangement, and is further arranged in the vicinity of the heating coil. The magnetic field distribution to the heated object such as the pan 15 changes, and particularly in the case of a rice cooker, there arises a problem that it greatly affects the rice cooking performance.

  This invention solves the said conventional subject, and it aims at providing the rice cooker which does not have a bad influence on rice cooking performance while reducing that a low frequency magnetic field is radiated | emitted from a heating coil.

In order to solve the conventional problems, a rice cooker of the present invention is connected to a pot, a heating coil for induction heating the pot, a lid located on the top surface of the pot and openable and closable, and a power supply unit. Rectifying means for rectifying commercial frequency power and converting it to power having a low frequency component twice the commercial frequency, a series connection circuit of an inductor and a smoothing capacitor connected in series with the rectifying means, An inverter for converting electric power having a low-frequency component into high-frequency electric power and supplying a high-frequency current in which the low-frequency component and the high-frequency component are superimposed on the heating coil, and the low-frequency component having the low-frequency component in the inverter the wiring of the series connection circuit in which a current flows, the generated from wiring the low-frequency magnetic field and the generated from the heating coil low frequency magnetic field coiled wires arranged such that the direction of canceling each other And having, in which a magnetic field generated from the coil-shaped wiring is disposed the coiled wires to the lid so as not to interfere with the magnetic field to be absorbed into the pot generated from the heating coil.

  As a result, the magnetic field generated from the coiled wiring cancels each other with the low-frequency leakage magnetic field from the heating coil, thereby greatly reducing the leakage magnetic field and ensuring a sufficient distance between the coiled wiring and the heating coil. In addition, the magnetic field generated from the coiled wiring does not interfere with the magnetic field generated from the heating coil and absorbed by the pan, and there is no adverse effect on the rice cooking performance.

  The rice cooker of the present invention has little influence on the rice cooking performance and can reduce the low-frequency leakage magnetic field generated from the heating coil.

The first aspect of the invention relates to a pan, a heating coil for induction heating the pan, a lid positioned on the top of the pan and openable and closable, and connected to a power supply unit to rectify the power of the commercial frequency. Rectifying means for converting power having a low frequency component of twice the frequency, a series connection circuit of an inductor and a smoothing capacitor connected in series with the rectifying means, and power having the low frequency component into high frequency power An inverter for converting and supplying a high-frequency current in which the low-frequency component and the high-frequency component are superimposed on the heating coil, and wiring of the series connection circuit in the inverter through which the low-frequency current having the low-frequency component flows, The coil-shaped wiring has a coil-shaped wiring arranged so that the low-frequency magnetic field generated from the wiring and the low-frequency magnetic field generated from the heating coil cancel each other. By arranging the coiled wiring on the lid so that the magnetic field generated from the heating coil is not disturbed by the heating coil and absorbed by the pan, the magnetic field generated from the coiled wiring is The low-frequency magnetic field generated from the coil is greatly reduced by canceling each other and the distance between the coil-shaped wiring and the heating coil is sufficiently large, so the magnetic field generated from the coil-shaped wiring is generated from the heating coil. It does not interfere with the magnetic field absorbed by the pan and does not adversely affect rice cooking performance.

  In particular, according to the second invention, in the first invention, the coiled wiring is formed by winding a plurality of times in a circular shape, and the respective circular diameters of the coiled wiring are made substantially the same, so that Since the coiled wiring can be handled as one part, the workability when arranging the coiled wiring on the lid can be improved, and the shape of the coiled wiring is stable, Stable magnetic shielding performance can be obtained.

  In particular, in the first or second invention, the third invention is such that the diameter of the coiled wiring is larger than the inner diameter of the pan, so that the diameter of the coiled wiring is the diameter of the heating coil arranged in the vicinity of the pan. Since the diameter can be kept equal to or greater than that, the low-frequency leakage magnetic field emitted from the heating coil through the pan to the upper surface of the rice cooker can be canceled out.

  In a fourth aspect of the invention, in particular, in any one of the first to third aspects of the invention, the lid includes a back lid disposed facing the inside of the pan, and a lid heating means for heating the back lid. Since the coiled wiring is arranged on the outer periphery of the back cover so as not to hinder the attachment and detachment of the back cover, the coiled wiring does not disturb the user when removing the back cover. The low-frequency leakage magnetic field can be reduced while ensuring the rice cooking performance, and the handleability can be further improved.

  According to a fifth aspect of the invention, in particular, in any one of the first to fourth aspects of the invention, the lid is a back lid disposed facing the inside of the pan, a lid coil for inductively heating the back lid, and the lid coil. And a low-frequency magnetic field generated from the wiring, wherein the heating coil 1 is provided with an inverter that supplies a high-frequency current in which a low-frequency component and a high-frequency component are superimposed, and the low-frequency current having the low-frequency component flows in the inverter. And the low-frequency magnetic field generated by the lid heating coil wire cancel each other, so that the low-frequency magnetic field generated from the heating coil is canceled and low-frequency leakage occurs when the lid is induction-heated The magnetic field can be reduced.

  6th invention is equipped with the trunk | drum coil which inductively heats the side of a pan | pan on the side of a pan especially in 5th invention, and makes the winding direction of a lid | cover coil and a trunk | drum coil the same direction, By allowing the current to flow in the direction opposite to the winding direction of the coiled wiring, the low frequency magnetic field generated from the heating coil is canceled out, and the low frequency leakage magnetic field and the side of the pan that are generated when the lid is induction heated. A low-frequency leakage magnetic field generated when induction heating is performed can be reduced.

  In a seventh aspect of the invention, in particular, in any one of the first to sixth aspects of the invention, the coiled wiring is sandwiched by the resin constituting the lid and disposed on the back surface of the lid, thereby removing the back lid. In the state where the coiled wiring does not interfere with the user, the low-frequency leakage magnetic field can be reduced while ensuring the rice cooking performance.

  In addition to reducing the low-frequency leakage magnetic field with the coil-shaped wiring, the eighth invention is particularly suitable for any one of the first to seventh inventions by arranging an electromagnetic shield ring in the vicinity of the heating coil. The high-frequency leakage magnetic field can also be reduced by the cancellation effect of the high-frequency magnetic field by the electromagnetic shield ring.

  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.

  In FIG. 1, a power supply unit 3 including a commercial power supply is connected to an inverter 11, and the inverter 11 is connected to a heating coil 1 to supply a high-frequency current including a commercial frequency component to the heating coil 1. The heating coil 1 is disposed on the bottom surface and the bottom side surface of the pan 15 so as to be magnetically coupled to the pan 15 and induction-heats the pan 15. Under the heating coil 1, a magnetic-shielding ferrite 13 made of a magnetic material such as ferrite that enhances magnetic coupling with the pan 15 is disposed. The inverter 11 includes a rectifier 4 connected to the power supply unit 3, a series connection of an inductor 5 and a smoothing capacitor 6 connected in series with the rectifier 4, and a resonant capacitor 7 connected in parallel to the smoothing capacitor 6. The semiconductor switch 8 is connected in series, and the heating coil 1 and the resonant capacitor 7 are connected in parallel. The coil-shaped wiring 12 from the inductor 5 has a current component of the same frequency as the commercial frequency component flowing in the heating coil 1 and is wound a plurality of times in a coil shape so that current flows in the opposite direction to the heating coil 1. Is formed. And the coil-shaped wiring 12 is arrange | positioned so that the leakage magnetic field resulting from the commercial frequency component radiated | emitted from the heating coil 1 may be negated in the lid | cover 17 which is located in the upper surface of the pan 15, and can be opened and closed. .

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

  FIG. 2 shows a current path in each section of the inverter 11, and shows an input current I3, a current I5 flowing through the inductor 5 and the coiled wiring 12, and a current I1 flowing through the heating coil 1, respectively. The power supply unit 3 is composed of a commercial power source or the like, and supplies commercial frequency power to the inverter 11. Therefore, the input current I3 is a current having a commercial frequency component. In the inverter 11, the commercial power is rectified by the rectifying means 4 and converted into power having a frequency component twice that of the commercial power supply, and further converted into high-frequency power of about 20 k to 100 kHz using the semiconductor switch 8. This high frequency power is supplied to the heating coil 1 and supplied from the heating coil 1 to the pan 15 in the form of a high frequency magnetic field. In the pan 15, an eddy current is generated in the surface layer portion by the supplied high-frequency magnetic field, and as a result, heat is generated. Therefore, the current I5 flowing through the inductor 5 and the coil-shaped wiring 12 flows twice as much as the commercial frequency, and when the semiconductor switch 8 becomes conductive in the heating coil 1, the power source unit 3 → rectifying means A low frequency current having a component twice the commercial frequency generated in the loop of 4 → heating coil 1 → semiconductor switch 8 and a current I1 in which a high frequency component flowing in the heating coil 1 is superimposed according to the frequency of the semiconductor switch 8 flow. Therefore, the low frequency magnetic field generated from the heating coil 1 can be canceled by arranging the heating coil 1 and the coiled wiring 12 so that the low frequency magnetic fields cancel each other.

  On the other hand, since the coil-shaped wiring 12 is disposed on the lid 17, a sufficient distance from the heating coil 1 and the magnetic shield ferrite 13 can be secured, so that a cancellation magnetic field generated from the coil-shaped wiring 12 is generated from the heating coil 1. The distribution of the magnetic field for inductively heating the saucer 15 is not disturbed, and the distribution of the magnetic field converged by the magnetic-shielding ferrite 13 is not greatly disturbed. Therefore, since the rice cooking performance does not change significantly, it is possible to reduce the low-frequency leakage magnetic field while maintaining the conventional rice cooking performance.

  Further, a plurality of coiled wirings 12 are formed in a circular shape, and the diameter of each wiring 12 is made substantially the same diameter so that the coiled wiring 12 wound in advance can be handled as one component. The workability at the time of arranging the coil-shaped wiring 12 in 17 can be improved, and since the shape of the coil-shaped wiring 12 is stabilized, a stable magnetic shielding performance can be obtained.

Furthermore, by making the diameter of the coil-shaped wiring 12 formed in a circular shape larger than the inner diameter of the pan 15, the diameter of the coil-shaped wiring 12 is equivalent to the diameter of the heating coil 1 disposed in the vicinity of the pan 15. The above diameter can be maintained, and in particular, a low-frequency leakage magnetic field that passes through the pan 15 from the heating coil 1 and is radiated to the upper surface of the rice cooker can be reduced. In a rice cooker, since the low frequency leakage magnetic field is large in the upper surface direction of the rice cooker, it is effective to adopt a configuration that cancels out the low frequency leakage magnetic field in this direction.

  As described above, in the present embodiment, the coil in the vicinity of the heating coil 1 so that the current flows in the opposite direction to the heating coil 1 with the same frequency component as the low frequency component of the current flowing in the heating coil 1 in the inverter 11. The coil-shaped wiring 12 arranged in a shape cancels each other with the low-frequency magnetic field from the heating coil 1 by the low-frequency magnetic field generated from the coil-shaped wiring 12, and the low-frequency leakage magnetic field is greatly reduced. Since the coil-shaped wiring 12 is arranged on the lid 17 so that the coil-shaped wiring 12 and the heating coil 1 can be sufficiently separated from each other, a magnetic field generated from the coil-shaped wiring 12 is generated from the heating coil 1 and absorbed into the pan 15. This does not interfere with the generated magnetic field, so there is no adverse effect on rice cooking performance.

(Embodiment 2)
FIG. 3 shows the configuration of the rice cooker in Embodiment 2 of the present invention.

  In the present embodiment, the difference from the first embodiment is that a lid 17 is provided with a metallic back lid 18 facing the inside of the pan 15 and a lid heating means 19 for heating the back lid 18. In addition, the coil-shaped wiring 12 is disposed on the outer periphery of the back cover 18.

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

  The back lid 18 of the lid 17 is larger than the inner diameter of the pan 15 in order to maintain the airtightness of the pan 15 and is disposed in close contact with the upper frame of the pan 15. Further, the lid 18 is provided with lid heating means 19 for heating the lid 18 in order to heat the water droplets attached to the lid 18 and the surface of the rice during cooking. Therefore, a metal such as aluminum or stainless steel is used for the back cover 18 so as to improve heat transfer, and the surface temperature rises to around 100 ° C. Further, it is desired that the back cover 18 is directly exposed to steam during cooking, and is easily soiled by oneba generated during rice cooking, and can be removed from the cover 17 and cleaned. Therefore, by arranging the coil-like wiring 12 disposed on the lid 17 on the outer periphery of the back cover 18, it does not hinder the attachment or detachment of the back cover 18, and does not come into contact with the back cover 18. It is not necessary to use a high heat-resistant wire for the wiring 12 and the diameter of the coiled wiring 12 can be increased, so that the leakage magnetic field can be reduced.

  As described above, in the present embodiment, the lid 17 is disposed so as to face the inside of the pan 15, the lid heating means 19 that heats the back lid 18, and the coiled wiring 12. Since the coiled wiring 12 does not interfere with the user when removing the back cover 18 by disposing the coiled wiring 12 on the outer periphery of the back cover 18, a low-frequency leakage magnetic field is It can be reduced while ensuring the rice cooking performance, and the handleability can be further improved.

(Embodiment 3)
FIG. 4 shows the configuration of the rice cooker according to Embodiment 3 of the present invention.

  The present embodiment is different from the second embodiment in that a lid coil 20 for induction heating the back lid 18 is provided, and a current flows in the winding direction of the lid coil 20 in a direction opposite to the coil-shaped wiring 12. It is that it was arranged.

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

The lid 17 is provided with a back lid 18 that is larger than the inner diameter of the pan 15 and is placed in close contact with the upper frame of the pan 15 in order to maintain the airtightness of the pan 15. In addition, it is effective to heat the back cover 18 in order to heat the water droplets attached to the back cover 18 and the surface of the rice during cooking. At this time, the temperature of the back cover 18 can be rapidly increased by performing induction heating on the back cover 17 using magnetic stainless steel or the like. At this time, a lid coil 20 for heating the back cover 18 and an inverter 11 for supplying high-frequency power to the lid coil 20 are necessary, and the inverter 11 can be shared with the inverter 11 for supplying high-frequency power to the heating coil 1. Desirably, it can be realized by switching the coil by a semiconductor switch or a relay. At this time, since the heating coil 1 and the coiled wiring 12 are arranged so that currents flow in opposite directions, the low-frequency magnetic field generated from the heating coil 1 can be reduced. It is possible to reduce the low-frequency magnetic field generated from the lid coil 20 by winding the winding direction in the direction in which current flows in the direction opposite to that of the coiled wiring 12, that is, in the same direction as the heating coil 1.

  As described above, in the present embodiment, induction heating using the cover coil 20 is used as a heating means for heating the back cover 18, and the winding direction of the cover coil 20 is opposite to the coil-shaped wiring 12. By allowing the current to flow, the low-frequency magnetic field generated from the heating coil 1 can be canceled and the low-frequency leakage magnetic field generated from the lid coil 20 can also be reduced.

(Embodiment 4)
FIG. 5 shows the configuration of the rice cooker according to Embodiment 4 of the present invention.

  In the present embodiment, the difference from the third embodiment is that the upper portion of the side surface of the pan 15 is provided with the body coil 21 for induction heating the side surface of the pan, and the winding direction of the lid coil 20 and the body coil 21 is the same direction. That is, the current flows so that the winding direction of the cover coil 20 and the body coil 21 is opposite to that of the coil-shaped wiring 12.

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

  It is known that when the upper part of the pan 15 is heated, moisture on the surface of the rice is reduced and stickiness of the rice is suppressed, and the taste is improved. Therefore, the upper side of the pan 15 can be heated with high efficiency by winding the body coil 21 in the vicinity of the upper end of the pan 15 and induction heating the pan 15. At this time, since the heating of the back cover 18 by the cover coil 20 produces the same effect, the number of switching circuits of the inverter 11 can be reduced by connecting the two in series to form a coil. Here, since the heating coil 1 and the coiled wiring 12 are arranged so that currents flow in opposite directions, the low-frequency magnetic field generated from the heating coil 1 can be reduced. It is possible to reduce the low frequency magnetic field generated from the body coil 21 by winding the winding direction in a direction in which a current opposite to the coiled wiring 12 flows, that is, in the same direction as the heating coil 1.

  As described above, in the present embodiment, the body coil 21 that heats the side surface of the pan 15 is provided, and the winding direction of the lid coil 20 and the body coil 21 flows in the opposite direction to the coil-shaped wiring 12. Thus, the low-frequency magnetic field generated from the heating coil 1 can be canceled and the low-frequency leakage magnetic field generated from the lid coil 20 can be reduced.

(Embodiment 5)
FIG. 6 shows the configuration of the rice cooker in the fifth embodiment of the present invention.

  In the present embodiment, the difference from the first embodiment is that the coil-shaped wiring 12 is sandwiched by a plurality of resin parts constituting the lid 17 and arranged on the back surface of the lid 17 so as not to be exposed on the surface of the lid 17. It is.

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

  It is desirable not to obstruct the opening and closing of the lid 17 and the attachment and detachment of the back lid 18, and it is desirable that there is no wiring on the pan-side surface portion of the lid 17 due to steam during cooking. Moreover, it is not desirable from the viewpoint of safety that the wiring is exposed on the surface of the housing. Therefore, the lid 17 is made of a plurality of resin parts, and the coil-shaped wiring 12 is sandwiched in the resin, so that the wiring can be prevented from appearing on the surface. Further, when the lid 17 is formed, the same effect can be obtained by integrally forming the coiled wiring 12.

  As described above, in the present embodiment, the lid 17 is made of resin, and the coil-shaped wiring 12 is sandwiched in the resin so that the wiring does not appear on the surface. When removing 18, the low-frequency leakage magnetic field can be reduced while ensuring the rice cooking performance in such a manner that the coiled wiring does not interfere with the user.

(Embodiment 6)
FIG. 7 shows the structure of the rice cooker in Embodiment 6 of this invention.

  The present embodiment is different from the first embodiment in that an electromagnetic shield ring 2 is arranged in the vicinity of the heating coil 1.

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

  The coil-shaped wiring 12 disposed on the lid 17 reduces the low-frequency leakage magnetic field generated from the heating coil 1, while the leakage magnetic field canceling effect of the coil-shaped wiring 12 is 20 k to 50 kHz which is the drive frequency of the inverter 11. Less effective for high frequency magnetic fields. Therefore, by disposing the electromagnetic shield ring 2 in the vicinity of the heating coil 1, a canceling magnetic field is generated in the electromagnetic shield ring 2 to reduce a high-frequency leakage magnetic field. This is because a high-frequency induced current is generated in the electromagnetic shield ring 2 by the high-frequency magnetic field generated from the heating coil 1, and a high-frequency magnetic field is generated by the induced current, and this high-frequency magnetic field is opposite to the magnetic field generated from the heating coil 1. Because it becomes. In the present embodiment, since the coil-shaped wiring 12 is provided on the lid 17, there is no restriction on attachment to the electromagnetic shield ring 2. The electromagnetic shield ring 2 is preferably a non-magnetic metal such as aluminum that generates little heat against a high-frequency magnetic field.

  As described above, in the present embodiment, by arranging the electromagnetic shield ring 2 in the vicinity of the heating coil 1, in addition to the low-frequency leakage magnetic field reduction by the coiled wiring 12, the shield ring 2 causes a high-frequency leakage magnetic field. Can be reduced.

  The rice cooker of the present invention can reduce the low-frequency leakage magnetic field generated from the heating coil with little influence on the rice cooking performance, and can be applied to induction heating rice cookers used for home use and business use. .

The block diagram which shows the rice cooker in Embodiment 1 of this invention. The figure which shows the operation waveform of the rice cooker The block diagram which shows the rice cooker in Embodiment 2 of this invention. The block diagram which shows the rice cooker in Embodiment 3 of this invention. The block diagram which shows the rice cooker in Embodiment 4 of this invention. The block diagram which shows the rice cooker in Embodiment 5 of this invention. The block diagram which shows the rice cooker in Embodiment 6 of this invention. Configuration diagram showing a conventional induction heating device Configuration diagram showing another conventional induction heating device Circuit diagram of the induction heating device

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Heating coil 2 Electromagnetic shield ring 3 Power supply part 5 Inductor 11 Inverter 12 Coiled wiring 15 Pan 17 Lid 18 Back lid 19 Lid heating means 20 Lid coil 21 Trunk coil

Claims (8)

A pan, a heating coil for induction heating the pan, a lid that is located on the top of the pan and has a configuration that can be opened and closed, and is connected to a power supply unit to rectify the power of the commercial frequency and lower the frequency twice the commercial frequency. Rectifying means for converting power having frequency components, a series connection circuit of an inductor and a smoothing capacitor connected in series with the rectifying means, and converting the power having the low frequency components to high frequency power to the heating coil. An inverter that supplies a high-frequency current in which the low-frequency component and the high-frequency component are superimposed, and a wiring of the series connection circuit in the inverter through which the low-frequency current having the low-frequency component flows flows from the wiring. A coil-shaped wiring arranged so that a low-frequency magnetic field generated by the heating coil and a low-frequency magnetic field generated by the heating coil cancel each other, and a magnetic field generated from the coil-shaped wiring There cooker arranging the coiled wire to the lid so as not to interfere with the magnetic field to be absorbed into the pot generated from the heating coil. The rice cooker according to claim 1, wherein the coiled wiring is formed by winding a plurality of times in a circular shape, and each of the coiled wirings has a substantially same diameter. The rice cooker according to claim 1 or 2, wherein the diameter of the coiled wiring is larger than the inner diameter of the pan. The lid includes a back cover disposed facing the inside of the pan, and a lid heating means for heating the back cover, and the coiled wiring is arranged so as not to interfere with the attachment / detachment of the back cover. The rice cooker of any one of Claims 1-3 arrange | positioned in the outer periphery of a lid | cover. The lid includes a back cover disposed facing the inside of the pan, a cover coil for inductively heating the back cover, and an inverter for supplying a high frequency current in which a low frequency component and a high frequency component are superimposed on the cover coil and the heating coil 1. And the wiring in the inverter through which the low-frequency current having the low-frequency component flows is arranged so that the low-frequency magnetic field generated from the wiring and the low-frequency magnetic field generated from the lid heating coil wire cancel each other. The rice cooker of any one of Claims 1-4 installed. The side of the pan is provided with a body coil for induction heating of the side of the pan, and the winding direction of the lid coil and the body coil is the same direction, and the winding direction of the lid coil and the body coil is opposite to the coiled wiring. The rice cooker according to claim 5, wherein the gas flows. The rice cooker according to any one of claims 1 to 6, wherein the coil-shaped wiring is sandwiched between resins constituting the lid and disposed on the back surface of the lid. The rice cooker according to any one of claims 1 to 7, wherein an electromagnetic shield ring is disposed in the vicinity of the heating coil.

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