JP2018032551A - Induction heating cooker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an induction heating cooker capable of improving heat resistance of a heating section for induction heating an object to be heated and improving an electric power input to the heating section.SOLUTION: The induction heating cooker includes: a first heating unit and a second heating unit, disposed below a heating port of a top plate for induction heating an object to be heated; a first driving circuit for driving the first heating unit; and a second driving circuit which is provided separately from the first driving circuit and drives the second heating unit. At least one of the first heating unit and the second heating unit has an annular conductor formed in a ring shape of a flat conductive material.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an induction heating cooker for inductively heating an object to be heated by generating an eddy current.

  A conventional induction heating cooker includes an annular main heating coil, a plurality of sub heating coils, and an inverter circuit that supplies induction heating power to the main heating coil and the sub heating coil, respectively. The sub-heating coil has been proposed in which a bundle of about 30 thin wires of about 0.1 mm to 0.3 mm in a spiral shape is wound and wound while twisting a plurality of such bundles (for example, Patent Documents). 1).

JP 2012-79580 A

  In a conventional induction heating cooker, a heating coil is formed by bundling a thin conductive wire having a thickness of about 0.1 mm to 0.3 mm with an insulating film while twisting a plurality of the bundles. For this reason, it is necessary to make the temperature of the heating coil lower than the heat resistance temperature of the insulating film, and there is a problem that the electric power supplied to the heating coil cannot be increased.

  The present invention is made in order to solve the above-described problems, and can improve the heat resistance of a heating unit that induction-heats an object to be heated, and can improve the power supplied to the heating unit. An induction heating cooker is obtained.

  An induction heating cooker according to the present invention includes a top plate on which an object to be heated is placed, a heating port formed on the top plate and indicating a placement position of the object to be heated, and the heating port of the top plate. The first heating unit and the second heating unit that are disposed below the first heating unit and induction heating the object to be heated, the first driving circuit that drives the first heating unit, and the first driving circuit are provided separately from each other, A second drive circuit that drives the second heating unit, wherein at least one of the first heating unit and the second heating unit includes an annular conductor formed in a plate-like conductive material in an annular shape. is there.

  In the present invention, since at least one of the first heating unit and the second heating unit has an annular conductor in which a flat conductive material is formed in an annular shape, heat resistance can be improved, and electric power to be input Can be improved.

It is a disassembled perspective view which shows the induction heating cooking appliance which concerns on Embodiment 1. FIG. FIG. 3 is a plan view schematically showing first heating means of the induction heating cooker according to Embodiment 1. It is a perspective view which shows typically the 1st heating means of the induction heating cooking appliance which concerns on Embodiment 1. FIG. FIG. 3 is a block diagram showing a drive circuit for first heating means of the induction heating cooker according to Embodiment 1. It is a figure which shows the drive circuit of the induction heating cooking appliance which concerns on Embodiment 1. FIG. It is a figure which shows typically the outer periphery plate-shaped coil of the induction heating cooking appliance which concerns on Embodiment 1. FIG. It is a figure explaining operation | movement of the outer periphery plate-shaped coil of the induction heating cooking appliance which concerns on Embodiment 1. FIG. It is a perspective view explaining the cooling air sent to the 1st heating means of the induction heating cooking appliance which concerns on Embodiment 1. FIG. It is sectional drawing which shows the inner peripheral coil and annular conductor of the induction heating cooking appliance which concerns on Embodiment 1. FIG. FIG. 3 is a plan view schematically showing first heating means of the induction heating cooker according to Embodiment 1. It is a perspective view which shows typically the 1st heating means of the induction heating cooking appliance which concerns on Embodiment 1. FIG. It is a figure which shows the AA cross section of FIG. 11 typically. It is a perspective view which shows typically the 1st heating means of the induction heating cooking appliance which concerns on Embodiment 4. FIG. It is a top view which shows typically the 1st heating means of the induction heating cooking appliance which concerns on Embodiment 5. FIG. It is a top view which shows typically the 1st heating means of the induction heating cooking appliance which concerns on Embodiment 6. FIG.

Embodiment 1 FIG.
(Constitution)
1 is an exploded perspective view showing an induction heating cooker according to Embodiment 1. FIG.
As shown in FIG. 1, an induction heating cooker 100 has a top plate 4 on which an object to be heated 5 such as a pan is placed. FIG. 1 illustrates an example in which the object to be heated 5 is placed as a load. The top plate 4 includes a first heating port 1, a second heating port 2, and a third heating port 3 as heating ports for inductively heating the article to be heated 5, and corresponds to each heating port. The first heating means 11, the second heating means 12, and the third heating means 13 are provided, and the object to be heated 5 can be placed on the respective heating ports to perform induction heating. Is.
In the first embodiment, the first heating means 11 and the second heating means 12 are provided side by side on the front side of the main body, and the third heating means 13 is provided at substantially the center on the back side of the main body. .
In addition, arrangement | positioning of each heating port is not restricted to this. For example, three heating ports may be arranged side by side in a substantially straight line. Moreover, you may arrange | position so that the position of the depth direction of the center of the 1st heating means 11 and the center of the 2nd heating means 12 may differ.

  The top plate 4 is entirely made of a material that transmits infrared rays, such as heat-resistant tempered glass or crystallized glass, and a rubber packing or sealing material is interposed between the upper surface and the outer periphery of the upper surface of the induction heating cooker 100 main body. Fixed in a watertight state. The top plate 4 has a circular shape indicating a rough placement position of the pan corresponding to the heating range (heating port) of the first heating means 11, the second heating means 12, and the third heating means 13. The pan position indication is formed by applying paint or printing.

  On the front side of the top plate 4, the heating power (input power) and the cooking menu (when the heated object 5 is heated by the first heating means 11, the second heating means 12, and the third heating means 13) An operation unit 40a, an operation unit 40b, and an operation unit 40c (hereinafter may be collectively referred to as the operation unit 40) are provided as input devices for setting a water heating mode, a fried food mode, and the like. Further, in the vicinity of the operation unit 40, a display unit 41a, a display unit 41b, and a display unit 41c for displaying the operation state of the induction heating cooker 100, input / operation contents from the operation unit 40, and the like are provided.

Note that the operation units 40a to 40c and the display units 41a to 41c are not particularly limited, for example, when the operation units 40a and 41c are provided for each heating port, or when the operation unit 40 and the display unit 41 are provided collectively. Note that the operation units 40a to 40c include, for example, mechanical switches such as push switches and tact switches, touch switches that detect input operations based on changes in the capacitance of the electrodes, and the like. The display units 41a to 41c are configured by, for example, an LCD (Liquid Crystal Device) or an LED.
In the following description, a case where the display operation unit 43 in which the operation unit 40 and the display unit 41 are integrally configured is provided will be described. The display operation unit 43 is configured by, for example, a touch panel in which touch switches are arranged on the upper surface of the LCD.

A first heating unit 11, a second heating unit 12, and a third heating unit 13 are provided below the top plate 4 and inside the main body, and each heating unit is mounted on each heating port. The placed object 5 is induction-heated.
It should be noted that an electric heater (for example, a nichrome wire, a halogen heater, or a radiant heater) that heats at least one of the first heating means 11, the second heating means 12, and the third heating means 13 by, for example, radiation. You may comprise.

  The induction heating cooker 100 includes a drive circuit 50 for supplying high-frequency power to the coils of the first heating means 11, the second heating means 12, and the third heating means 13, and the drive circuit 50. A control unit 45 for controlling the operation of the whole cooking device is provided. In addition, the induction heating cooker 100 is provided with a blower 60 that blows cooling air into the main body.

  An intake port 46 and an exhaust port 47 are formed on the rear side of the induction heating cooker 100. The blower 60 provided inside the main body sucks air outside the main body from the intake port 46 and supplies cooling air into the main body. The cooling air supplied into the main body cools components inside the main body, and then is exhausted from the exhaust port 47 to the outside of the main body.

FIG. 2 is a plan view schematically showing first heating means of the induction heating cooker according to the first embodiment.
FIG. 3 is a perspective view schematically showing first heating means of the induction heating cooker according to the first embodiment.
2 and 3, the first heating means 11 includes an inner peripheral coil 11a disposed in the center of the heating port, an outer peripheral left plate coil 111b, an outer peripheral right plate disposed around the inner peripheral coil 11a. And the outer peripheral upper plate-like coil 111c and the outer peripheral lower plate-like coil 112c. The outer periphery of the first heating unit 11 has a substantially circular shape corresponding to the first heating port 1.

  The inner peripheral coil 11a is composed of an inner peripheral inner coil 111a and an inner peripheral outer coil 112a that are arranged substantially concentrically. The inner circumference inner coil 111a and the inner circumference outer coil 112a have a circular plane shape, and a conductive wire made of any metal (for example, copper, aluminum, etc.) coated with an insulating film is wound in the circumferential direction. It is configured. The inner circumference inner coil 111 a and the inner circumference outer coil 112 a are connected in series and driven and controlled by one drive circuit 50. Note that the inner circumference inner coil 111a and the inner circumference outer coil 112a may be connected in parallel, or may be driven using independent drive circuits (inverter circuits).

  As shown in FIG. 3, a plurality of magnetic bodies 80 made of a magnetic material such as ferrite are provided under the inner peripheral coil 11a. The plurality of magnetic bodies 80 are formed in a rod shape extending radially from the center of the inner peripheral coil 11a or in the radial direction of the inner peripheral coil 11a. By providing a plurality of magnetic bodies 80 under the inner peripheral coil 11a, the high-frequency magnetic flux is easily linked and the leakage magnetic flux is reduced.

  The outer peripheral left plate coil 111b includes an annular conductor 311b, a magnetic core 321b, and an outer peripheral left primary coil 331b. The outer right plate coil 112b includes an annular conductor 312b, a magnetic core 322b, and an outer right primary coil 332b. The outer peripheral upper plate coil 111c includes an annular conductor 311c, a magnetic core 321c, and an outer peripheral primary coil 331c. The outer peripheral lower plate coil 112c includes an annular conductor 312c, a magnetic core 322c, and an outer lower primary coil 332c.

Hereinafter, the outer periphery left plate coil 111b, the outer periphery right plate coil 112b, the outer periphery upper plate coil 111c, and the outer periphery lower plate coil 112c may be collectively referred to as the “outer periphery plate coil 300”.
Further, the four annular conductors 311b, 312b, 311c, and 312c may be collectively referred to as “annular conductor 310”.
The four magnetic cores 321b, 322b, 321c, and 322c may be collectively referred to as “magnetic core 320”.
Further, the outer left primary coil 331b, the outer right primary coil 332b, the outer upper primary coil 331c, and the lower outer primary coil 332c may be collectively referred to as a “primary coil 330”.

  The annular conductor 310 is disposed around the inner peripheral coil 11a so as to substantially follow the circular outer shape of the inner peripheral coil 11a. The annular conductor 310 is formed of a flat conductive material in an annular shape and constitutes an electrically closed circuit. The annular conductor 310 has, for example, a substantially 1/4 arc shape (square shape) planar shape. That is, the annular conductor 310 is configured to extend substantially along the circular planar shape of the inner peripheral coil 11a in a ¼ arc-shaped region adjacent to the inner peripheral coil 11a. The number of annular conductors 310 is not limited to four. Further, the shape of the annular conductor 310 is not limited to this, and for example, a configuration using a plurality of circular annular conductors 310 may be used.

Under the annular conductor 310, a magnetic body 70 made of a magnetic material such as ferrite is provided. The magnetic body 70 is formed in a flat plate shape, for example. One or more annular conductors 310 are provided. For example, as shown in FIG. 3, the magnetic body 70 is formed larger than the outer edge of the annular conductor 310.
Thus, by providing the magnetic body 70 under the annular conductor 310, the high-frequency magnetic flux is easily linked and the leakage magnetic flux is reduced. In addition, the outer end of the magnetic body 70 is disposed on the outer peripheral side with respect to the annular conductor 310. For this reason, the leakage magnetic flux to the outer peripheral side of the high frequency magnetic flux generated from the annular conductor 310 can be reduced, and the efficiency of induction heating can be improved.

  The primary coil 330 is configured by winding a conductive wire made of an arbitrary metal (for example, copper, aluminum, etc.) coated with an insulating film around the magnetic core 320. The outer peripheral left primary coil 331b and the outer peripheral right primary coil 332b are connected in series and controlled by one drive circuit 50. The outer periphery primary coil 331 c and the outer periphery lower primary coil 332 c are connected in series and driven and controlled by one drive circuit 50.

FIG. 4 is a block diagram showing a drive circuit of the first heating means of the induction heating cooker according to the first embodiment.
As shown in FIG. 4, the first heating unit 11 is driven and controlled by drive circuits 50a, 50b, and 50c. That is, the inner circumference inner coil 111a and the inner circumference outer coil 112a constituting the inner circumference coil 11a are driven and controlled by the drive circuit 50a. The outer left primary coil 331b and the outer right primary coil 332b are driven and controlled by the drive circuit 50b. The outer primary coil 331c and the lower primary coil 332c are driven and controlled by the drive circuit 50c.

  The control unit 45 includes a microcomputer or a DSP (digital signal processor). The control unit 45 controls the drive circuits 50a, 50b, and 50c based on the operation content from the display operation unit 43 and the like. In addition, the control unit 45 performs display on the display operation unit 43 according to the operation state.

  FIG. 5 is a diagram illustrating a drive circuit of the induction heating cooker according to the first embodiment. In addition, although the drive circuit 50 is provided for every heating means, the circuit structure may be the same and may be changed for every heating means. FIG. 5 shows a drive circuit 50a for driving the inner peripheral coil 11a.

  As shown in FIG. 5, the drive circuit 50a includes a DC power supply circuit 22, an inverter circuit 23, and a resonance capacitor 24a. The input current detection means 25a is composed of, for example, a current sensor, detects a current input from the AC power supply (commercial power supply) 21 to the DC power supply circuit 22, and outputs a voltage signal corresponding to the input current value to the control unit 45. .

  The DC power supply circuit 22 includes a diode bridge 22a, a reactor 22b, and a smoothing capacitor 22c, converts an AC voltage input from the AC power supply 21 into a DC voltage, and outputs the DC voltage to the inverter circuit 23.

  The inverter circuit 23 is a so-called half-bridge type inverter in which IGBTs 23a and 23b as switching elements are connected in series to the output of the DC power supply circuit 22, and diodes 23c and 23d are parallel to the IGBTs 23a and 23b as flywheel diodes, respectively. It is connected to the. The IGBT 23 a and the IGBT 23 b are driven on and off by a drive signal output from the control unit 45. The control unit 45 turns off the IGBT 23b while turning on the IGBT 23a, turns on the IGBT 23b while turning off the IGBT 23a, and outputs a drive signal that turns on and off alternately. Thus, the inverter circuit 23 converts the DC power output from the DC power supply circuit 22 into a high-frequency AC power of about 20 kHz to 100 kHz, and supplies the power to the resonance circuit including the inner peripheral coil 11a and the resonance capacitor 24a. .

  The resonant capacitor 24a is connected in series to the inner peripheral coil 11a, and this resonant circuit has a resonant frequency corresponding to the inductance of the inner peripheral coil 11a, the capacity of the resonant capacitor 24a, and the like. The inductance of the inner peripheral coil 11a changes according to the characteristics of the metal load when the object to be heated 5 (metal load) is magnetically coupled, and the resonance frequency of the resonance circuit changes according to the change in the inductance.

  With this configuration, a high-frequency current of about several tens of A flows through the inner peripheral coil 11a, and the object placed on the top plate 4 directly above the inner peripheral coil 11a by the high-frequency magnetic flux generated by the flowing high-frequency current. The heated object 5 is induction-heated. The IGBTs 23a and 23b, which are switching elements, are composed of, for example, a silicon-based semiconductor, but may be configured using a wide band gap semiconductor such as silicon carbide or a gallium nitride-based material.

  By using a wide band gap semiconductor for the switching element, the conduction loss of the switching element can be reduced, and the drive circuit has good heat resistance characteristics even when the switching frequency (driving frequency) is high (high speed). The heat dissipation fins of the circuit can be reduced in size, and the drive circuit can be reduced in size and cost.

  The coil current detection means 25b is connected to a resonance circuit composed of the inner peripheral coil 11a and the resonance capacitor 24a. The coil current detection means 25b is constituted by, for example, a current sensor, detects a current flowing through the inner peripheral coil 11a, and outputs a voltage signal corresponding to the coil current value to the control unit 45.

  Although the drive circuit 50a for driving the inner peripheral coil 11a has been described with reference to FIG. 5, the drive circuit 50b for driving the outer peripheral left primary coil 331b and the outer peripheral right primary coil 332b, the outer peripheral upper primary coil 331c, and the outer peripheral lower primary coil 332c. The same configuration can be applied to the driving circuit 50c to be driven. Note that the drive circuits 50 a, 50 b, and 50 c may be connected in parallel to the AC power supply 21.

The inverter circuit 23 of the drive circuits 50b and 50c corresponds to the “first drive circuit” of the present invention, and may include the DC power supply circuit 22 of the drive circuits 50b and 50c.
The inverter circuit 23 of the drive circuit 50a corresponds to the “second drive circuit” of the present invention, and may include the DC power supply circuit 22 of the drive circuit 50a.
The outer peripheral plate coil 300 corresponds to the “first heating unit” of the present invention.
The inner peripheral coil 11a corresponds to the “second heating unit” and the “heating coil” of the present invention.
The magnetic body 70 corresponds to the “first magnetic body” of the present invention.
The magnetic body 80 corresponds to the “second magnetic body” of the present invention.
The primary coil 330 corresponds to the “first coil” of the present invention.
The magnetic core 320 corresponds to the “core” of the present invention.

Here, details of the configuration of the outer peripheral plate coil 300 will be described with reference to FIG.
FIG. 6 is a diagram schematically showing an outer peripheral plate coil of the induction heating cooker according to the first embodiment. 6 shows a state in which the outer peripheral plate coil 300 shown in FIG. 3 is turned upside down. Further, in FIG. 6, for the purpose of explanation, the ratio of the shape and size of each part of the outer peripheral plate coil 300 is different from that in FIGS.

  The annular conductor 310 is formed of a conductive material such as a metal having a low electric resistance such as aluminum or copper. The annular conductor 310 is formed by, for example, processing a metal plate into an annular shape that forms a closed circuit that is electrically closed by cutting or pressing, and then bending the annular conductor 310 in the middle of the length direction in a perpendicular direction. It is formed in a letter shape. The annular conductor 310 has a horizontal portion 310a disposed on the lower surface of the top plate 4 and a vertical portion 310b extending substantially vertically from one end of the horizontal portion 310a. The annular conductor 310 is not provided with an insulating film.

  The primary coil 330 is configured by winding a conductive wire in a flat plate shape on the back surface of the vertical portion 310 b of the annular conductor 310. As shown in the drawing, a part of the coil bundle (straight line portion) of the primary coil 330 is disposed on the back surface of one vertical portion 310 b of the annular conductor 310. Further, another coil bundle (straight line portion) of the primary coil 330 is disposed on the back surface of the other vertical portion 310 b of the annular conductor 310.

  The magnetic core 320 is made of, for example, ferrite, and is arranged so as to constitute a magnetic circuit in which a high-frequency magnetic flux generated when a high-frequency current is passed through the primary coil 330 is linked to the annular conductor 310.

(Heating operation)
Next, the heating operation of the induction heating cooker in the first embodiment will be described.

  FIG. 7 is a diagram for explaining the operation of the outer peripheral plate coil of the induction heating cooker according to the first embodiment. In FIG. 7, the illustration of the magnetic core 320 is omitted.

The display operation unit 43 gives an instruction to start cooking (fire power input) by the user. When an instruction to start cooking is given, the controller 45 performs a heating operation by controlling at least one of the drive circuits 50a, 50b, and 50c in accordance with the heating power to be induction-heated.
When the drive circuit 50a is driven, a high frequency current is supplied to the inner peripheral coil 11a, and a high frequency magnetic flux is generated from the inner peripheral coil 11a. Thereby, an eddy current flows through the heated object 5 placed above the inner peripheral coil 11a, and the heated object 5 is induction-heated by this eddy current.

When the drive circuits 50b and 50c are driven, a high frequency current is supplied from the drive circuits 50b and 50c to the primary coil 330 of the outer plate coil 300.
As shown in FIG. 7, when a high frequency current is supplied to the primary coil 330, a high frequency magnetic flux φ <b> 1 is generated around the primary coil 330. The high-frequency magnetic flux φ1 passes through the magnetic core 320 (ferrite) having a small magnetic resistance. Since the magnetic circuit composed of the magnetic core 320 is arranged so as to be linked to the annular conductor 310, the high-frequency magnetic flux φ 1 is linked to the annular conductor 310. As a result, as shown in FIG. 7, an induced current flows through the annular conductor 310 by electromagnetic induction.

  That is, the outer plate coil 300 has the same operating principle as a transformer. If the primary coil 330 is a primary winding of N turns, the annular conductor 310 becomes a secondary winding of 1 turns, and N: 1 Think of it as a transformer. Therefore, a current (N times the current) larger than the coil current flowing through the primary coil 330 flows through the annular conductor 310 at the same frequency as the coil current.

  When a high-frequency induced current flows through the annular conductor 310, a high-frequency magnetic flux φ2 is generated around the annular conductor 310 as shown in FIG. Since this high-frequency magnetic flux φ2 is linked to the heated object 5 disposed on the top surface of the horizontal portion 310a of the annular conductor 310 via the top plate 4, an eddy current flows through the heated object 5, and this eddy current causes The article 5 to be heated is induction heated.

In addition, the heating site | part of the to-be-heated material 5 can be arbitrarily controlled by driving the inner periphery coil 11a and the outer periphery plate-shaped coil 300 by the separate drive circuit 50. FIG. For example, when heating the small-diameter object to be heated 5 or when heating the center of the large-diameter object to be heated 5, only the drive circuit 50a can be driven to perform induction heating only by the inner peripheral coil 11a. . Moreover, you may drive any one of the drive circuit 50b or the drive circuit 50c according to the shape etc. of the to-be-heated material 5.
Note that the control unit 45 may make the maximum value of the power supplied to the outer peripheral plate coil 300 larger than the maximum value of the power supplied to the inner peripheral coil 11a.

  As described above, in the first embodiment, the outer peripheral plate coil 300 includes the annular conductor 310 in which the flat conductive material is formed in an annular shape. For this reason, the heat resistance of the outer peripheral plate coil 300 itself is determined by the heat resistance of the material of the outer peripheral plate coil 300 (for example, copper). Therefore, heat resistance can be greatly improved as compared with a conventional heating coil in which conductive wires with insulating coatings are wound in a bundle. By improving the heat resistance, a large current can flow through the outer plate coil 300, and the input power (input heating power) can be increased.

  For example, since the conventional heating coil is formed by twisting a plurality of copper wires to which an insulating film is applied, the heat resistance of the heating coil is determined by the material of the insulating film. Since a general induction heating cooker uses a copper wire provided with a 180 ° C. heat-resistant insulating film, it is necessary to use the heating coil at a temperature of 180 ° C. or less, and the input power can be increased. In addition, when the input power is increased, it can be energized only for a short time. On the other hand, the annular conductor 310 of the outer peripheral plate-like coil 300 in the first embodiment is configured by a metal plate (for example, a copper plate) formed by pressing or the like without an insulating film, and the heat resistance temperature of the metal plate is Since it is higher than the heat resistance temperature of the insulating film, the heat resistance can be improved as compared with the conventional heating coil.

  In the first embodiment, the outer peripheral plate coil 300 disposed on the outer peripheral side of the heating port has the annular conductor 310. For this reason, the input electric power (input thermal power) to the outer peripheral plate coil 300 can be increased. Therefore, it is possible to suppress a decrease in the temperature of the outer peripheral portion of the article 5 to be heated. Therefore, it is possible to increase the heating power of the outer peripheral portion of the article to be heated 5 and to obtain an induction heating cooker that can be cooked deliciously in a short time.

  For example, when fried food is cooked using a frying pan as the object to be heated 5, the heat at the bottom of the frying pan heated by induction heating escapes from the upper end of the frying pan outer periphery, the frying pan outer peripheral temperature is lowered, and the cooking performance May decrease and usability may deteriorate. By applying the outer plate coil 300 of the present embodiment, it is possible to increase the input power to the outer plate coil 300, so it is possible to suppress a decrease in the outer peripheral temperature of the frying pan, and to cook fried food The performance can be improved.

(Cooling air volume)
Next, the amount of cooling air blown to the inner peripheral coil 11a and the outer peripheral plate coil 300 will be described.

FIG. 8 is a perspective view for explaining cooling air blown to the first heating means of the induction heating cooker according to the first embodiment.
As described above, the induction heating cooker 100 is provided with the blower 60 that blows cooling air into the main body. The cooling air supplied into the main body by the blower 60 is blown to the inner peripheral coil 11a and the outer peripheral plate coil 300.
As shown in FIG. 8, a magnetic body 70 formed in a flat plate shape is provided under the annular conductor 310. The magnetic body 70 is formed larger than the outer edge of the annular conductor 310, for example. On the other hand, a plurality of magnetic bodies 80 are formed in a rod shape extending radially or radially below the inner peripheral coil 11a. That is, in a plan view, the ratio of the area of the magnetic body 80 to the area surrounded by the outer edge of the inner peripheral coil 11 a is larger than the ratio of the area of the magnetic body 70 to the area of the area surrounding the outer edge of the annular conductor 310. It is small.

  With such a configuration, the cooling air blown to the outer peripheral plate-like coil 300 collides with the magnetic body 70 formed in a flat plate shape, flows toward the inner peripheral coil 11a, and a plurality of air flows from below the inner peripheral coil 11a. The flow passes between the magnetic bodies 80 and passes around the inner peripheral coil 11a. Therefore, the amount of cooling air supplied to the inner peripheral coil 11 a is larger than the amount of cooling air supplied to the annular conductor 310. Therefore, even if the air volume of the blower 60 is reduced, the air volume of the cooling air supplied to the inner peripheral coil 11a can be ensured. In addition, the blower 60 can be reduced in size and power consumption. Further, noise due to the operation of the blower 60 can be reduced.

  As described above, the outer peripheral plate-like coil 300 has a heat resistant temperature higher than that of the inner peripheral coil 11a, so that the amount of cooling air can be made smaller than that of the inner peripheral coil 11a. For this reason, the area of the magnetic body 70 provided under the annular conductor 310 can be increased. Therefore, the high-frequency magnetic flux generated from the annular conductor 310 is easily linked, the leakage magnetic flux is reduced, and the object to be heated 5 can be induction-heated efficiently.

  In the first embodiment, by providing the flat magnetic body 70 under the annular conductor 310, the amount of cooling air supplied to the inner peripheral coil 11a is reduced to the cooling supplied to the annular conductor 310. Although it was set as the structure which becomes larger than the wind volume of a wind, you may adjust an air volume not only by this but by arbitrary members. For example, an opening is provided in the support member that supports the inner peripheral coil 11a and the annular conductor 310, and an opening area in a range corresponding to the inner peripheral coil 11a is made larger than an opening area in a range corresponding to the annular conductor 310. Also good. Even in such a configuration, the air volume of the cooling air supplied to the inner peripheral coil 11 a can be made larger than the air volume of the cooling air supplied to the annular conductor 310.

(Modification 1)
FIG. 9 is a cross-sectional view showing an inner peripheral coil and an annular conductor of the induction heating cooker according to the first embodiment.
As shown in FIG. 9, the inner peripheral coil 11 a is arranged with a gap G between the inner peripheral coil 11 a and the lower surface of the top plate 4.
By providing the gap G in this way, the cooling air can be easily ventilated, and the temperature rise of the inner peripheral coil 11a can be suppressed. Moreover, it becomes difficult for the heat of the to-be-heated material 5 to be transmitted to the inner peripheral coil 11a via the top plate 4, and the temperature rise of the inner peripheral coil 11a can be suppressed.

The annular conductor 310 is disposed at a position closer to the top plate 4 than the inner peripheral coil 11a. For example, as shown in FIG. 9, the annular conductor 310 is disposed in contact with the lower surface of the top plate 4.
That is, since the annular conductor 310 has a high heat-resistant temperature, there is no need to provide a gap G for passing cooling air, and the distance between the annular conductor 310 and the object to be heated 5 can be shortened, and induction is efficiently performed. Heating can be performed.

(Modification 2)
In the above description, the magnetic body 70 formed in a flat plate shape is provided under the annular conductor 310, but the shape and number of the magnetic bodies 70 are not limited to this.

FIG. 10 is a plan view schematically showing first heating means of the induction heating cooker according to the first embodiment.
As shown in FIG. 10, a plurality of magnetic bodies 71 made of a magnetic material such as ferrite are provided under the annular conductor 310. The plurality of magnetic bodies 71 are formed in a rod shape. In plan view, the ratio of the area of the magnetic body 80 to the area surrounded by the outer edge of the inner peripheral coil 11 a is larger than the ratio of the area of the magnetic body 71 to the area surrounding the outer edge of the annular conductor 310. It is small.
Other configurations are the same as those in FIG. 3, and the same reference numerals are given to the same configurations.

  Even in such a configuration, the amount of cooling air passing between the plurality of magnetic bodies 80 from below the inner peripheral coil 11a is equal to that of cooling air passing between the plurality of magnetic bodies 71 from below the annular conductor 310. It becomes larger than the air volume. Therefore, even if the air volume of the blower 60 is reduced, the air volume of the cooling air supplied to the inner peripheral coil 11a can be ensured. In addition, the blower 60 can be reduced in size and power consumption. Further, noise due to the operation of the blower 60 can be reduced.

  The larger the proportion of the area of the magnetic body 71 that occupies the area surrounding the outer edge of the annular conductor 310, the more efficient induction heating can be achieved, and the cooling air passing through the annular conductor 310 can be reduced to reduce the internal temperature. The airflow to the circumferential coil 11a can be increased. For this reason, for example, the ratio of the area of the magnetic body 70 in the area surrounding the outer edge of the annular conductor 310 in a plan view is desirably 50% or more.

(Modification 3)
FIG. 11 is a perspective view schematically showing a first heating means of the induction heating cooker according to the first embodiment.
FIG. 12 is a diagram schematically showing an AA cross section of FIG. 11.
In FIG. 11 and FIG. 12, illustration of a part of the configuration is omitted.

  As shown in FIGS. 11 and 12, the magnetic body 70 formed in a flat plate shape has a groove 70 a in which the annular conductor 310 is disposed. The groove 70 a has a shape corresponding to the shape of the horizontal portion 310 a of the annular conductor 310. Further, the depth of the groove 70 a is substantially the same as the thickness of the horizontal portion 310 a of the annular conductor 310.

  With such a configuration, the magnetic body 70 is also disposed on the inner and outer side surfaces of the annular conductor 310, and the high-frequency magnetic flux generated from the annular conductor 310 is easily concentrated on the magnetic body 70, and the efficiency of induction heating is increased. Can be improved.

Embodiment 2. FIG.
In the second embodiment, a convection cooking mode in which induction heating by the inner peripheral coil 11a and induction heating by the outer peripheral plate coil 300 are alternately switched will be described.
In addition, the structure of the induction heating cooking appliance 100 in this Embodiment 2 is the same as that of the said Embodiment 1. FIG. Hereinafter, the difference from the first embodiment will be mainly described.

(Convection cooking mode)
When an instruction to start cooking in the convection cooking mode is given by the user, the control unit 45 alternately drives the drive circuit 50a and the drive circuits 50b and 50c at predetermined time intervals in accordance with the heating power to be induction-heated. Thereby, the induction heating by the inner peripheral coil 11a and the induction heating by the outer peripheral plate coil 300 are alternately switched every predetermined time.
In this way, by changing the heating of the inner peripheral portion and the outer peripheral portion of the heated object 5 at predetermined time intervals, convection is applied to the heated object inside the heated object 5 (pan) in stewed cooking. It can be generated, and it is possible to suppress boiling and scorching while soaking the taste.

In such a convection cooking mode, the control unit 45 may make the maximum value of the power supplied to the inner peripheral coil 11 a larger than the maximum value of the power supplied to the outer peripheral plate coil 300.
For example, when the upper limit power at one heating port is 3000 W, the drive circuits 50 b and 50 c are controlled so that the total power supplied to the outer plate coil 300 is 3000 W or less, and the power supplied to the inner coil 11 a. The drive circuit 50a may be controlled so that the power becomes 2000 W or less.
In other words, the drive circuit 50a is controlled so that the inner peripheral coil 11a is equal to or lower than the upper limit power determined by the heat resistance of the insulating film of the conductive wire, and the outer plate coil 300 has one heating port according to the standard or circuit design. The drive circuits 50b and 50c are controlled so as to be less than or equal to the upper limit power that can be input.

  Note that the drive circuit 50a, the drive circuit 50b, and the drive circuit 50c may be driven in an arbitrary order every predetermined time. In this case, the control unit 45 controls the drive circuit 50b so that the total power supplied to the outer peripheral left plate coil 111b and the outer right plate coil 112b is equal to or lower than the rated power (for example, 3000 W), and the outer upper plate The drive circuit 50c is controlled so that the total power supplied to the coil 111c and the outer peripheral lower plate coil 112c is equal to or less than the rated power (for example, 3000 W).

As described above, in the second embodiment, in the convection cooking mode in which the induction heating by the outer peripheral coil coil 300 and the induction heating by the inner peripheral coil 11a are alternately switched, the electric power supplied to the outer peripheral coil coil 300 is The electric power supplied to the peripheral coil 11a is made larger.
For this reason, the input electric power to the outer peripheral plate coil 300 can be increased. For example, when stewed cooking is performed using a large pan as the article to be heated 5, if the input power to the outer peripheral plate coil 300 is reduced, the outer peripheral portion having a large heating portion (area) cannot be sufficiently heated, Convection boiling by switching the input power between the outer peripheral plate coil 300 and the inner peripheral coil 11a may be insufficient. In the second embodiment, it is possible to sufficiently heat the outer peripheral portion having a large heating portion (area) of the article to be heated 5, and to further enhance the convection stew. It is possible to obtain an easy-to-use induction heating cooker that can be soaked.

Embodiment 3 FIG.
In the third embodiment, an operation for making the frequency of the high-frequency current supplied to the outer peripheral plate coil 300 higher than the frequency of the high-frequency current supplied to the inner peripheral coil 11a will be described.
In addition, the structure of the induction heating cooking appliance 100 in this Embodiment 3 is the same as that of the said Embodiment 1. FIG. Hereinafter, the difference from Embodiment 1 or 2 will be mainly described.

Generally, among the objects to be heated 5 for induction heating cookers, there is one in which a magnetic metal is sprayed or pasted on the central part of a non-magnetic metal. For example, there are many pasting frying pans in which a magnetic metal such as stainless steel is attached to the center of the bottom of a non-magnetic aluminum frying pan, and thermal spray frying pans in which a magnetic material such as iron is coated on the bottom of the frying pan. .
When such a dissimilar metal object to be heated 5 is placed on the heating port, if the driving frequency of the inner peripheral coil 11a and the outer peripheral plate coil 300 is set to the same or approximate frequency, the central portion (inner peripheral portion) ) And the outer peripheral portion cannot be heated together, and only the inner peripheral portion is heated or only the outer peripheral portion is heated.

Hereinafter, the operation of induction heating the object to be heated 5 of a different metal will be described.
When the user performs an operation of cooking the object to be heated 5 of a different metal, the control unit 45 drives the drive circuits 50a, 50b, and 50c, respectively. The control part 45 makes the frequency of the high frequency current supplied to the outer peripheral plate-shaped coil 300 higher than the frequency of the high frequency current supplied to the inner peripheral coil 11a. For example, the drive frequency of the drive circuits 50 b and 50 c is set to 60 kHz, and a high frequency current of 60 kHz is supplied to the outer plate coil 300. Further, the drive frequency of the drive circuit 50a is set to 22 kHz, and a high frequency current of 22 kHz is supplied to the inner peripheral coil 11a.

  Here, the drive frequency of the drive circuits 50b and 50c is set higher than the drive frequency of the drive circuit 50a by an audible frequency (20 kHz) or more. Due to the difference between the driving frequencies of the two adjacent coils, an abnormal sound (beat sound) may be generated from the heated object 5 such as a pan. In the third embodiment, since the difference in drive frequency is set higher than the audible frequency, abnormal noise is not heard and the occurrence of abnormal noise can be suppressed.

Note that the on-duty ratio in each drive circuit 50 may be varied according to the heating power to be induction-heated.
In addition, load determining means for determining the material of the object to be heated 5 is provided, it is determined whether or not the object to be heated 5 placed on the heating port is a material of a dissimilar metal. The above operation may be performed.

As described above, in the third embodiment, the frequency of the high frequency current supplied to the outer peripheral plate coil 300 is set higher than the frequency of the high frequency current supplied to the inner peripheral coil 11a.
For this reason, both the inner peripheral part and the outer peripheral part of the to-be-heated object 5 of a different metal can be induction-heated. Therefore, even when fried food cooking using a pasting frying pan or a thermal spray frying pan is performed, an easy-to-use induction heating cooker that ensures cooking performance can be obtained. Of course, if the material of the frying pan bottom is one type (uniform), the same effect can be obtained by making the driving frequencies of the inner peripheral coil 11a and the outer peripheral plate coil 300 the same.

  In particular, when the frequency of the high-frequency current supplied to the outer plate coil 300 is increased, a wide band gap semiconductor such as a gallium nitride material is used for the switching elements of the drive circuits 50b and 50c that drive the outer plate coil 300. The loss of the switching element in the high frequency drive can be suppressed, and a further effect can be obtained.

Embodiment 4 FIG.
FIG. 13 is a perspective view schematically showing first heating means of the induction heating cooker according to the fourth embodiment.
As shown in FIG. 13, the outer peripheral plate-like coil 300 according to the fourth embodiment is composed of one annular conductor 310d that is not divided, a magnetic core 320d, and a primary coil 330d.
The annular conductor 310d has a circular shape whose diameter is larger than that of the inner peripheral coil 11a, and is arranged concentrically with respect to the inner peripheral coil 11a. That is, the inner peripheral coil 11a is disposed at the center of the heating port, and the annular conductor 310d is disposed on the outer peripheral side of the inner peripheral coil 11a.
The primary coil 330d is configured by winding a conductive wire made of an arbitrary metal (for example, copper, aluminum, etc.) coated with an insulating film around the magnetic core 320d.
The magnetic core 320d is made of, for example, ferrite, and is arranged so as to constitute a magnetic circuit in which a high-frequency magnetic flux generated when a high-frequency current is passed through the primary coil 330d is linked to the annular conductor 310d.

  A plurality of rod-like magnetic bodies 71 made of a magnetic material such as ferrite are provided under the annular conductor 310d. In addition, the shape of the magnetic body 71 is not limited to this, A flat ferrite may be sufficient.

  Other configurations and heating operations are the same as those in any of the first to third embodiments.

As described above, in the fourth embodiment, the resistance and inductance of the outer peripheral plate coil 300 can be increased by configuring the outer peripheral plate coil 300 with one annular conductor 310d without dividing the outer peripheral plate coil 300. . Since the power conversion efficiency of the outer peripheral coil is improved by increasing the inductance, the high-frequency current flowing through the primary coil 330 can be reduced, and the induction heating cooker 100 with less conversion loss can be obtained.
In addition, since the high frequency current is supplied to the outer peripheral plate coil 300 and the inner peripheral coil 11a by separate drive circuits 50, the same effect can be obtained even when a frying pan or a large pan is used for the object to be heated 5. it can.

Embodiment 5. FIG.
FIG. 14 is a plan view schematically showing first heating means of the induction heating cooker according to the fifth embodiment.
In FIG. 14, the first heating means 11 includes an inner peripheral plate-like coil 12a (first heating portion) arranged at the center, and outer peripheral coils 12b and 12c (first ones) arranged around the inner peripheral plate-like coil 12a. 2 heating parts). The outer periphery of the first heating unit 11 has a substantially circular shape corresponding to the first heating port 1.

  Similar to the first embodiment, the inner peripheral plate-like coil 12a includes an annular conductor 310, a magnetic core 320 (not shown), and a primary coil 330 (not shown).

  A plurality of rod-like magnetic bodies (not shown) made of a magnetic material such as ferrite are provided under the annular conductor 310d. The shape of the magnetic material is not limited to this, and a flat ferrite may be used. For example, it is desirable that the ratio of the area of the magnetic body in the area surrounding the outer edge of the annular conductor 310 is 50% or more in plan view.

  The outer peripheral coil 12b includes an outer peripheral left coil 121b and an outer peripheral right coil 122b. The outer peripheral coil 12c includes an outer peripheral upper coil 121c and an outer peripheral lower coil 122c. The outer peripheral left coil 121b and the outer peripheral right coil 122b are connected in series and are driven and controlled by one drive circuit 50. Further, the outer periphery upper coil 121c and the outer periphery lower coil 122c are connected in series and driven and controlled by one drive circuit 50.

The outer peripheral left coil 121b, the outer peripheral right coil 122b, the outer peripheral upper coil 121c, and the outer peripheral lower coil 122c (hereinafter also referred to as “outer peripheral coil”) are arranged so as to substantially conform to the circular outer shape of the inner peripheral plate coil 12a. It arrange | positions around the plate-shaped coil 12a.
The four outer coils have a substantially ¼ arc shape (banana shape or pepper shape) planar shape, and conductive wires made of any metal (for example, copper, aluminum, etc.) coated with an insulating film are connected to the outer coil. It is configured by winding along a quarter arc shape. That is, the outer peripheral coil is configured to extend substantially along the circular planar shape of the inner peripheral plate-like coil 12a in a ¼ arc-shaped region adjacent to the inner peripheral plate-like coil 12a. Note that the number of outer peripheral coils is not limited to four. Further, the shape of the outer peripheral coil is not limited to this. For example, a configuration using a plurality of circular outer peripheral coils may be used.

  The first heating unit 11 in the fifth embodiment is driven and controlled by the drive circuits 50a, 50b, and 50c. That is, the primary coil 330 constituting the inner peripheral plate-like coil 12a is driven and controlled by the drive circuit 50a. Further, the outer left coil 121b and the outer right coil 122b constituting the outer coil 12b are driven and controlled by the drive circuit 50b. The outer peripheral upper coil 121c and the outer peripheral lower coil 122c constituting the outer peripheral coil 12c are driven and controlled by the drive circuit 50c.

  Other configurations are the same as those in the first embodiment. Further, the heating operation is the same as in any of the first to third embodiments.

  Even in such a configuration, the same effects as in the first embodiment can be obtained. Further, in the fifth embodiment, the inner peripheral plate coil 12a disposed at the center of the heating port has the annular conductor 310. For this reason, the input electric power (input thermal power) to the inner peripheral plate coil 12a can be increased. For this reason, for example, the small-diameter object to be heated 5 can be induction-heated with high heating power, and an induction heating cooker capable of cooking deliciously in a short time can be obtained.

Embodiment 6 FIG.
FIG. 15 is a plan view schematically showing first heating means of the induction heating cooker according to the sixth embodiment.
In FIG. 15, the first heating means 11 includes an inner peripheral plate-like coil 12a (first heating portion) arranged at the center, an outer peripheral left plate-like coil 111b arranged around the inner peripheral coil 11a, an outer periphery The right plate-shaped coil 112b, the outer peripheral upper plate-shaped coil 111c, and the outer peripheral lower plate-shaped coil 112c (second heating unit) are configured.

The inner peripheral plate-like coil 12a has the same configuration as that of the fifth embodiment.
The outer left plate coil 111b, the outer right plate coil 112b, the outer upper plate coil 111c, and the lower outer plate coil 112c have the same configuration as in the first embodiment.
Other configurations are the same as those in the first embodiment. Further, the heating operation is the same as in any of the first to third embodiments.

  With this configuration, the heat resistance of the inner peripheral plate-like coil 12a, the outer peripheral left-plate-like coil 111b, the outer peripheral right-plate-like coil 112b, the outer peripheral upper plate-like coil 111c, and the outer peripheral lower plate-like coil 112c is greatly improved. Can be improved.

  DESCRIPTION OF SYMBOLS 1 1st heating port, 2nd heating port, 3rd heating port, 4 Top plate, 5 To-be-heated object, 11 1st heating means, 11a Inner peripheral coil, 12 2nd heating means, 12a Inner peripheral plate coil, 12b outer peripheral coil, 12c outer peripheral coil, 13 third heating means, 21 AC power supply, 22 DC power supply circuit, 22a diode bridge, 22b reactor, 22c smoothing capacitor, 23 inverter circuit, 23a, 23b IGBT, 23c, 23d diode, 24a resonance capacitor, 25a input current detection means, 25b coil current detection means, 40 operation unit, 40a-40c operation unit, 41 display unit, 41a-41c display unit, 43 display operation unit, 45 control unit, 46 intake port, 47 exhaust port, 50 drive circuit, 50a drive circuit, 50b drive circuit, 50c drive cycle Road, 60 Blower, 70 Magnetic body, 70a Groove, 71 Magnetic body, 80 Magnetic body, 100 Induction cooking device, 111a Inner inner coil, 111b Outer left plate coil, 111c Outer upper plate coil, 112a Inner outer Coil, 112b outer right plate coil, 112c outer lower plate coil, 121b outer left coil, 121c outer upper coil, 122b outer right coil, 122c outer lower coil, 300 outer plate coil, 310 annular conductor, 310a horizontal portion 310b vertical portion, 310d annular conductor, 311b annular conductor, 311c annular conductor, 312b annular conductor, 312c annular conductor, 320 magnetic core, 320d magnetic core, 321b magnetic core, 321c magnetic core, 322b magnetic core, 322c Magnetic core, 330 Primary coil, 330d Primary coil, 331b outer periphery left primary coil, 331c outer periphery upper primary coil, 332b outer periphery right primary coil, 332c outer periphery lower primary coil.

Claims (21)

A top plate on which the object to be heated is placed;
A heating port formed on the top plate and indicating a placement position of the object to be heated;
A first heating unit and a second heating unit, which are arranged below the heating port of the top plate and induction-heat the object to be heated;
A first drive circuit for driving the first heating unit;
A second drive circuit that is provided separately from the first drive circuit and drives the second heating unit;
With
At least one of the first heating unit and the second heating unit is
An induction heating cooker having an annular conductor in which a flat conductive material is formed in an annular shape. The first heating unit includes
The annular conductor;
A first coil that generates a first high-frequency magnetic flux when supplied with a first high-frequency current from the first drive circuit;
A core formed of a magnetic material and constituting a magnetic circuit in which the first high-frequency magnetic flux is linked to the annular conductor,
The induction heating cooker according to claim 1, wherein the second heating unit is configured by a heating coil formed by winding a conducting wire. A fan for blowing air to the heating coil and the annular conductor;
The induction heating cooker according to claim 2, wherein an air volume supplied to the heating coil is larger than an air volume supplied to the annular conductor. A first magnetic body formed of a magnetic material and disposed below the annular conductor;
A second magnetic body formed of a magnetic material and disposed below the heating coil;
With
In plan view,
The ratio of the area of the second magnetic body in the area of the range surrounded by the outer edge of the heating coil is as follows:
The induction heating cooker according to claim 2 or 3, wherein the induction heating cooker is smaller than a ratio of an area of the first magnetic body to an area of a range surrounding an outer edge of the annular conductor. The first magnetic body is
One or more are provided for one annular conductor;
In plan view,
The induction heating cooker according to claim 4, wherein a ratio of an area of the first magnetic body to an area in a range surrounding an outer edge of the annular conductor is 50% or more. The induction heating cooker according to claim 4 or 5, wherein the first magnetic body is configured by a flat ferrite. The induction heating cooker according to any one of claims 4 to 6, wherein the first magnetic body has a groove in which the annular conductor is disposed. The induction heating cooker according to any one of claims 4 to 7, wherein the first magnetic body has an outer peripheral end portion of the heating port disposed closer to the outer peripheral side than the annular conductor. The induction heating cooker according to any one of claims 2 to 8, wherein the annular conductor is disposed closer to the top plate than the heating coil. The induction heating cooker according to any one of claims 2 to 9, wherein the annular conductor is in contact with the top plate. The induction heating cooker according to any one of claims 2 to 10, wherein the annular conductor and the heating coil have different diameters and are arranged concentrically. The heating coil is disposed in the center of the heating port,
The induction heating cooker according to claim 11, wherein the annular conductor is disposed on an outer peripheral side of the heating coil. The annular conductor is disposed in the center of the heating port,
The induction heating cooker according to claim 11, wherein the heating coil is disposed on an outer peripheral side of the heating coil. A plurality of the annular conductors are provided for one heating port,
The heating coil is disposed in the center of the heating port,
The induction heating cooker according to any one of claims 2 to 10, wherein the plurality of annular conductors are arranged around the heating coil. A controller for controlling the first drive circuit and the second drive circuit;
The controller is
The induction heating cooker according to any one of claims 2 to 14, wherein a maximum value of electric power supplied to the first heating unit is made larger than a maximum value of electric power supplied to the second heating unit. The controller is
In the cooking mode in which the induction heating by the first heating unit and the induction heating by the second heating unit are alternately switched,
The induction heating cooker according to claim 15, wherein the power supplied to the first heating unit is made larger than the power supplied to the second heating unit. The controller is
Controlling the first drive circuit so that the power supplied to the first heating unit is 3000 W or less;
The induction heating cooker according to claim 15 or 16, wherein the second drive circuit is controlled so that electric power supplied to the second heating unit is 2000 W or less. The controller is
The induction heating cooker according to any one of claims 15 to 17, wherein a frequency of the high-frequency current supplied to the first heating unit is set higher than a frequency of the high-frequency current supplied to the second heating unit. Each of the first heating unit and the second heating unit includes the annular conductor,
The first heating unit includes
A first coil that generates a first high-frequency magnetic flux when supplied with a first high-frequency current from the first drive circuit;
A first core that is formed of a magnetic material and forms a magnetic circuit in which the first high-frequency magnetic flux is linked to the annular conductor;
The second heating unit includes
A second coil that generates a second high-frequency magnetic flux when supplied with a second high-frequency current from the second drive circuit;
The induction heating cooker according to claim 1, further comprising: a second core that is formed of a magnetic material and forms a magnetic circuit in which the second high-frequency magnetic flux is linked to the annular conductor. A first magnetic body formed of a magnetic material and disposed below the first heating unit;
The first magnetic body is
One or more are provided for one annular conductor;
In plan view,
The induction heating cooker according to claim 19, wherein a ratio of an area of the first magnetic body occupying an area surrounding an outer edge of the annular conductor is 50% or more. A second magnetic body formed of a magnetic material and disposed below the second heating unit;
The second magnetic body is
One or more are provided for one annular conductor;
In plan view,
The induction heating cooker according to claim 19 or 20, wherein a ratio of an area of the second magnetic body occupying an area in a range surrounding an outer edge of the annular conductor is 50% or more.

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