Induction heating cooker

Abstract

To provide an induction heating cooker capable of suppressing the generation of a beat sound while operating a plurality of heating coils.SOLUTION: An induction heating cooker comprises: a first coil; a second coil; a third coil that is arranged so as to be arranged to the first and second coils; a top plate; one inverter circuit that supplies a high-frequency current to each coil; a first relay unit that is connected to between the first coil and the inverter circuit; a second relay unit that is connected to between the second coil and the inverter circuit; and a control part. The control part is constructed so as to execute any one of a plurality of operation modes. The plurality of operation modes contains: a first operation mode that supplies the high-frequency current to the first and third coil from the inverter circuit; and a second operation mode that supplies the high-frequency current to the second and third coils from the inverter circuit.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present disclosure relates to an induction heating cooker. [Background technology]

[0002] Conventionally, induction heating cookers have been known that have multiple heating coils and allow a cooking vessel to be placed across the multiple heating coils. For example, Patent Document 1 discloses an induction heating cooker that, when it detects that a load is placed on a top plate, drives a relay and passes a high-frequency current through the heating coil on which the load is placed, out of the multiple heating coils, to heat the load. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2021-141082 A Summary of the Invention [Problem to be solved by the invention]

[0004] When multiple heating coils are used to heat one load, there is a problem in that a humming noise may be generated due to the operation of each heating coil.

[0005] An object of the present disclosure is to provide an induction heating cooker that operates multiple heating coils while suppressing the generation of humming noise. [Means for solving the problem]

[0006] An induction heating cooker according to one aspect of the present disclosure includes a first coil, a second coil different from the first coil, and a third coil different from the first coil and the second coil, the third coil being disposed between the first coil and the second coil so as to be adjacent to the first coil and the second coil, a top plate provided above the first coil, the second coil, and the third coil, an inverter circuit that supplies high-frequency current to each of the first coil, the second coil, and the third coil that can operate integrally, a first relay unit connected between the first coil and the inverter circuit, a second relay unit connected between the second coil and the inverter circuit, and an inverter circuit. and a control unit that controls the operation of the inverter circuit and the operations of the first relay unit and the second relay unit, the control unit being configured to execute one of a plurality of operation modes for operating at least one of the first coil, the second coil, and the third coil, the plurality of operation modes including a first operation mode in which a high-frequency current is supplied from the inverter circuit to the first coil and the third coil by turning on the first relay unit and turning off the second relay unit, and a second operation mode in which a high-frequency current is supplied from the inverter circuit to the second coil and the third coil by turning off the first relay unit and turning on the second relay unit. Effect of the Invention

[0007] According to the present disclosure, it is possible to provide an induction heating cooker that operates multiple heating coils while suppressing the generation of humming noise. [Brief description of the drawings]

[0008] [Figure 1] 1 is a schematic perspective view of an example of an induction heating cooker according to an embodiment of the present disclosure; FIG. [Diagram 2] FIG. 2 is a plan view of an example of a coil unit according to an embodiment of the present disclosure; [Diagram 3] FIG. 3 is a plan view showing an example of a heating region for the coil unit of FIG. [Figure 4] 4 is a schematic enlarged view of a coil piece constituting the coil unit of FIG. 2 and FIG. 3; [Diagram 5]FIG. 1 is a block diagram showing schematic electrical connections relating to a coil unit of an induction heating cooker according to an embodiment of the present disclosure; [Figure 6] FIG. 2 is a schematic circuit diagram showing an example of electrical connection between an inverter circuit and a coil unit of an induction heating cooker according to an embodiment of the present disclosure. [Figure 7] FIG. 2 is a schematic circuit diagram showing an example of electrical connection between an inverter circuit and a coil unit of an induction heating cooker according to an embodiment of the present disclosure. [Figure 8] FIG. 2 is a schematic circuit diagram showing an example of electrical connection between an inverter circuit and a coil unit of an induction heating cooker according to an embodiment of the present disclosure. [Figure 9] A circuit diagram showing the inverter circuit of FIG. [Figure 10] Schematic circuit diagram of an induction heating cooker according to a first modified example [Figure 11] Schematic circuit diagram of an induction heating cooker according to a second modification [Figure 12] Schematic circuit diagram of an induction heating cooker according to a third modification [Figure 13] Schematic circuit diagram of an induction heating cooker according to a fourth modification DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. However, the configuration described below is merely an example of the present disclosure, and the present disclosure is not limited to the following embodiment. The technology in the present disclosure is not limited to this, and various modifications, substitutions, additions, omissions, etc. are possible depending on the design, etc., even if it is other than these embodiments, as long as it does not deviate from the technical idea of ​​the present disclosure.

[0010] Although the present disclosure has been fully described in connection with the preferred embodiments with reference to the accompanying drawings, various changes and modifications will be apparent to those skilled in the art, and such changes and modifications should be understood to be included within the scope of the present disclosure as defined by the appended claims unless they depart therefrom.

[0011] Conventionally, there is known an induction heating cooker that has multiple heating coils and operates two or more of the multiple heating coils with multiple inverter circuits to heat one cooking vessel efficiently with the multiple heating coils. In general, the high-frequency current supplied to the heating coil in an induction heating cooker has a frequency higher than the human audible range. However, when high-frequency currents having different frequencies flow through the multiple heating coils and the difference in frequency is within the human audible range, a beat sound based on the difference in frequency may be recognized by a user as noise. Therefore, when multiple heating coils are operated using multiple inverter circuits, a beat sound may be generated due to the difference in frequency between the high-frequency currents flowing through each heating coil.

[0012] The induction heating cooker according to the present disclosure is configured to operate multiple heating coils, i.e., coil pieces, that heat a common cooking vessel using one inverter circuit. Since multiple coil pieces are operated using one inverter circuit, multiple frequencies whose frequency difference is within the human audible range are not supplied to the multiple coil pieces that heat a common cooking vessel. Therefore, the induction heating cooker according to the present disclosure can suppress the generation of humming noise caused by the difference in frequency of high-frequency currents flowing through the multiple coil pieces.

[0013] In the induction heating cooker according to the present disclosure, since a single inverter circuit operates multiple coil pieces, it is difficult for the controller to change the switching of whether to supply current to each coil piece for each coil piece depending on the operation of the inverter circuit. The coil unit of the induction heating cooker according to the present disclosure extends longer in the depth direction than in the left-right direction. A user of the induction heating cooker according to the present disclosure may place a cooking vessel in an area on the top plate that is heated by a part of the coil unit, for example, when the size of the cooking vessel is smaller than the coil unit of the induction heating cooker. In this case, if the controller supplies high-frequency current to the coil pieces other than the area where the cooking vessel is placed, an object to be heated that is not intended by the user may be heated. In addition, the efficiency of heating the cooking vessel may decrease.

[0014] Therefore, the induction heating cooker according to the present disclosure has a relay connected to at least a part of the path between each coil piece and the inverter circuit, the relay being capable of electrically opening the path. The induction heating cooker is configured so that the controller can control the coil pieces to which high-frequency current is supplied by switching the relay between open and closed. This allows the induction heating cooker to efficiently heat by switching the coil pieces to be operated while suppressing the generation of humming noise.

[0015] (Embodiment) [composition] FIG. 1 shows a schematic perspective view of an example of an induction heating cooker 1 according to an embodiment of the present disclosure. Note that the XYZ coordinate system shown in the figure is described to facilitate understanding of the invention and is not intended to limit the invention. The X-axis direction indicates the left-right direction. The Y-axis direction indicates the depth direction. The Z-axis direction indicates the vertical direction.

[0016] As shown in Fig. 1, the induction heating cooker 1 is a cooker that inductively heats a cooking container C that contains an object to be cooked T. The cooking container C is described as an example of an object to be inductively heated by the induction heating cooker 1. The object to be heated is not limited to the cooking container C, and may be any object that can be inductively heated.

[0017] The induction heating cooker 1 has a top plate 2 made of, for example, heat-resistant glass on which a cooking container C is placed, and a housing 3 attached to the bottom surface of the top plate 2. A plurality of coil units 4, 5, a controller 6, and an operation panel 7 are mounted inside the housing 3. The top plate 2 is disposed above the plurality of coil units 4, 5. Each of the plurality of coil units 4, 5 is disposed below the top plate 2, and induction heats the cooking container C placed on the portion of the top plate 2 that faces it. That is, each of the plurality of coil units 4, 5 functions as an induction heating coil unit.

[0018] Coil unit 4 will be described later. Coil unit 5 is a coil unit different from coil unit 4. Coil unit 5 may be composed of one coil, or may be composed of multiple coils.

[0019] The controller 6 is, for example, a computer, and includes an arithmetic circuit and a storage device. The controller 6 can control the multiple coil units 4 and 5. The controller 6 is an example of a control unit of the induction heating cooker 1 according to the present disclosure.

[0020] The arithmetic circuit controls the overall operation of the induction heating cooker 1. The arithmetic circuit may be either a circuit in which hardware resources and software work together to realize a predetermined function, or a circuit in which a dedicated hardware circuit is used to realize a predetermined function.

[0021] As an example of the former, the arithmetic circuit includes a general-purpose processor such as a CPU or MPU that executes a program to realize a predetermined process or function. The arithmetic circuit is configured to be able to communicate with a storage device. The arithmetic circuit reads out and executes an arithmetic program or the like stored in the storage device to realize various functions in the controller 6. As an example of the latter, the arithmetic circuit includes an FPGA or an ASIC. As can be understood from the above, the arithmetic circuit can be realized using a semiconductor integrated circuit such as a CPU, an MPU, a GPU, an FPGA, a DSP, or an ASIC.

[0022] The storage device is a storage medium that can store various information. The information includes programs and data. For example, the storage device stores an arithmetic program for implementing various functions according to the present embodiment. The storage device is implemented, for example, by a volatile or non-volatile semiconductor memory such as a DRAM, an SRAM, or a flash memory, an SSD, an HDD, or other storage devices, or an appropriate combination thereof. For example, the arithmetic circuit can execute a plurality of heating modes and a plurality of operation modes, which will be described later, using the programs or data stored in the storage device.

[0023] The operation panel 7 is electrically connected to the controller 6. The operation panel 7 is an example of an input / output interface device. A user can operate the operation panel 7 to operate the multiple coil units 4, 5 via the controller 6. In addition, the user can grasp the operating status of each of the coil units 4, 5 based on the information displayed on the operation panel 7.

[0024] [Coil unit] The coil unit 4 will be described below with reference to FIGS.

[0025] Fig. 2 is a plan view of an example of a coil unit 4 according to an embodiment of the present disclosure. Fig. 3 is a plan view showing an example of a heating region related to the coil unit 4. Fig. 4 is a schematic enlarged view of a coil piece 10A constituting the coil unit 4 of Figs. 2 and 3.

[0026] As shown in FIG. 2, the coil unit 4 has a front coil 4A, a rear coil 4B, and an overlapping coil 4C. The front coil 4A is an example of a first coil. The rear coil 4B is an example of a second coil different from the first coil. The overlapping coil 4C is an example of a third coil different from the first coil and the second coil. In a plan view, the overlapping coil 4C is disposed on the rear side in the depth direction (Y-axis direction) from the front coil 4A. In a plan view, the rear coil 4B is disposed on the rear side in the depth direction from the overlapping coil 4C. In this specification, "plan view" means a view from the vertical direction, i.e., the Z-axis direction. The overlapping coil 4C is disposed between the front coil 4A and the rear coil 4B so as to be adjacent to the front coil 4A and the rear coil 4B.

[0027] In this embodiment, the outer periphery of the area formed by the front coil 4A and the overlapping coil 4C has a circular shape in a plan view. This area corresponds to the first heating area S1 described later. The outer periphery of the area formed by the rear coil 4B and the overlapping coil 4C has a circular shape in a plan view. This area corresponds to the second heating area S2 described later. The area formed by the front coil 4A, the rear coil 4B, and the overlapping coil 4C corresponds to the third heating area S3 described later. The shapes of the first heating area S1 and the second heating area S2 may be various shapes including a triangle or a rectangle. Since the bottom surface of a pan is often circular, the heating efficiency of the pan can be further improved by having the first heating area S1 and the second heating area S2 have a circular shape as in the induction heating cooker 1 according to this embodiment. The pan is an example of a cooking vessel C. In this way, from the viewpoint of further improving the heating efficiency of the pan, the shapes of the first heating area S1 and the second heating area S2 may be other than a circle, for example, a polygon having hexagons or more sides.

[0028] The front coil 4A has a plurality of coil pieces 10A to 10D. In this embodiment, the front coil 4A has four coil pieces 10A to 10D. The four coil pieces 10A to 10D include a first coil piece 10A, a second coil piece 10B, a third coil piece 10C, and a fourth coil piece 10D. The first coil piece 10A is disposed adjacent to the second coil piece 10B and a sixth coil piece 10F described later. The second coil piece 10B is disposed adjacent to the first coil piece 10A and the third coil piece 10C. The third coil piece 10C is disposed adjacent to the second coil piece 10B and the fourth coil piece 10D. The fourth coil piece 10D is disposed adjacent to the third coil piece 10C and a fifth coil piece 10E described later.

[0029] The overlap coil 4C has a plurality of coil pieces 10E-10F. In the present embodiment, the overlap coil 4C has two coil pieces 10E-10F. The two coil pieces 10E-10F include a fifth coil piece 10E and a sixth coil piece 10F. The fifth coil piece 10E is disposed adjacent to the fourth coil piece 10D, the sixth coil piece 10F, and a tenth coil piece 10J described below. The sixth coil piece 10F is disposed adjacent to the first coil piece 10A, the fifth coil piece 10E, and a seventh coil piece 10G described below.

[0030] The rear coil 4B has a plurality of coil pieces 10G to 10J. In this embodiment, the rear coil 4B has four coil pieces 10G to 10J and is configured similarly to the front coil 4A. Specifically, the four coil pieces 10G to 10J include a seventh coil piece 10G, an eighth coil piece 10H, a ninth coil piece 10I, and a tenth coil piece 10J. The seventh coil piece 10G is disposed adjacent to the sixth coil piece 10F and the eighth coil piece 10H. The eighth coil piece 10H is disposed adjacent to the seventh coil piece 10G and the ninth coil piece 10I. The ninth coil piece 10I is disposed adjacent to the eighth coil piece 10H and the tenth coil piece 10J. The tenth coil piece 10J is disposed adjacent to the ninth coil piece 10I and the fifth coil piece 10E.

[0031] Thus, each of the coils 4A to 4C includes a plurality of coil pieces 10. Therefore, the front coil 4A, the rear coil 4B, and the overlapping coil 4C can also be referred to as the front coil piece group 4A, the rear coil piece group 4B, and the overlapping coil piece group 4C, respectively. Each of the coil pieces 10A to 10J is arranged so as to be adjacent to at least two of the coil pieces 10.

[0032] Hereinafter, when there is no need to distinguish between the multiple coil pieces 10A to 10J, they will be collectively referred to as coil piece 10 or multiple coil pieces 10.

[0033] As shown in FIG. 3, a first heating area S1, a second heating area S2, and a third heating area S3 are defined in a plan view. The first heating area S1 indicates an area heated by the front coil 4A and the overlapping coil 4C. The second heating area S2 indicates an area heated by the rear coil 4B and the overlapping coil 4C. The third heating area S3 indicates an area heated by the front coil 4A, the rear coil 4B, and the overlapping coil 4C. The front coil 4A and the overlapping coil 4C are arranged in the first heating area S1. The rear coil 4B and the overlapping coil 4C are arranged in the second heating area S2. The front coil 4A, the rear coil 4B, and the overlapping coil 4C are arranged in the third heating area S3.

[0034] The first heating area S1 is an area having a center C1 in a plan view, and is an area in which the multiple coil pieces 10A-10F are arranged. In the present embodiment, the first heating area S1 has a circular shape in a plan view. The first heating area S1 may be an area in which a cooking container C shown on the upper surface of the top plate 2 is arranged in a plan view. Alternatively, the first heating area S1 may be an area smaller than an area in which a cooking container C can be arranged in a plan view shown on the upper surface of the top plate 2.

[0035] In the first heating region S1, the coil pieces 10A to 10F are arranged adjacent to each other. Specifically, the coil pieces 10A to 10F are arranged radially in a plan view.

[0036] The first heating region S1 has multiple coil arrangement regions S11-S16. The multiple coil arrangement regions S11-S16 are arranged radially and adjacently around the center C1 of the first heating region S1 in a plan view. Specifically, the multiple coil arrangement regions S11-S16 are defined by multiple boundary lines L11-L16 that extend radially from the center C1 of the first heating region S1 toward the outer periphery in a plan view, and an outer periphery line L1 that defines the outer periphery of the first heating region S1.

[0037] The boundary lines L11-L16 are arranged radially at equal intervals around the center C1 of the first heating region S1 in plan view. The boundary lines L11-L16 are straight lines extending from the center C1 of the first heating region S1 toward the outer periphery in plan view. The angles between two adjacent boundary lines among the boundary lines L11-L16 are substantially the same. As a result, the coil arrangement regions S11-S16 have substantially the same shape and substantially the same dimensions in plan view. In this specification, "substantially" means within an error of 10%, and preferably within an error of 5%.

[0038] Each of the multiple coil arrangement regions S11 to S16 has a sector shape in plan view. In this specification, a "sector shape" is a shape defined by two straight lines (radii) extending from the center of a circle to the outer periphery in plan view, and an arc connecting the two straight lines.

[0039] In this embodiment, the boundary lines include six boundary lines L11 to L16, and the angle between two adjacent boundary lines is 60 degrees. As a result, the first heating region S1 is divided into six coil arrangement regions S11 to S16 that have approximately the same shape and approximately the same dimensions in a plan view.

[0040] The coil pieces 10A to 10F are arranged in the coil arrangement regions S11 to S16, respectively, in a plan view. As a result, the coil pieces 10A to 10F are arranged radially and adjacent to each other in the first heating region S1 in a plan view.

[0041] The second heating area S2 is an area having a center C2 in a plan view, and is an area in which the multiple coil pieces 10E-10J are arranged. In the present embodiment, the second heating area S2 has a circular shape in a plan view. The second heating area S2 may be an area in which a cooking container C shown on the upper surface of the top plate 2 is arranged in a plan view. Alternatively, the second heating area S2 may be an area smaller than an area in which a cooking container C can be arranged in a plan view shown on the upper surface of the top plate 2.

[0042] In the second heating region S2, the coil pieces 10E to 10J are arranged adjacent to each other. Specifically, the coil pieces 10E to 10J are arranged radially in a plan view.

[0043] The second heating region S2 has multiple coil arrangement regions S21 to S26. The multiple coil arrangement regions S21 to S26 are arranged radially and adjacently around the center C2 of the second heating region S2 in a plan view. Specifically, the multiple coil arrangement regions S21 to S26 are defined by multiple boundary lines L21 to L26 that extend radially from the center C2 of the second heating region S2 toward the outer periphery in a plan view, and an outer periphery line L2 that defines the outer periphery of the second heating region S2.

[0044] The boundary lines L21 to L26 are arranged radially at equal intervals around the center C2 of the second heating region S2 in a plan view. The boundary lines L21 to L26 are straight lines extending from the center C2 of the second heating region S2 toward the outer periphery in a plan view. The angles between two adjacent boundary lines among the boundary lines L21 to L26 are substantially the same. As a result, the coil arrangement regions S21 to S26 have substantially the same shape and dimensions in a plan view.

[0045] Each of the multiple coil arrangement regions S21 to S26 has a sector shape in plan view.

[0046] In the present embodiment, the multiple boundary lines in the second heating region S2 include six boundary lines L21 to L26, and the angle between two adjacent boundary lines is 60 degrees. This divides the second heating region S2 into six coil arrangement regions S21 to S26 that have approximately the same shape and approximately the same dimensions in a plan view.

[0047] In addition, in this embodiment, the two coil arrangement regions S21, S22 in the second heating region S2 overlap with the two coil arrangement regions S15, S16 in the first heating region S1.

[0048] The multiple coil pieces 10E-10J are arranged in multiple coil arrangement regions S21-S26, respectively, in a plan view. As a result, the multiple coil pieces 10E-10J are arranged radially and adjacent to each other in the second heating region S2 in a plan view.

[0049] The seventh to tenth coil pieces 10G-10J are arranged in the multiple coil arrangement regions S23-S26. The fifth and sixth coil pieces 10E-10F are arranged in the two coil arrangement regions S21, S22. That is, the fifth and sixth coil pieces 10E-10F are shared by the first heating region S1 and the second heating region S2.

[0050] The third heating region S3 is a region in which the multiple coil pieces 10A to 10J are arranged in a plan view, and is a region that is heated by the multiple coil pieces 10A to 10J. The third heating region S3 overlaps with the first heating region S1 and the second heating region S2 in a plan view.

[0051] The detailed configuration of the first coil piece 10A will be described with reference to FIG.

[0052] As shown in Fig. 4, the first coil piece 10A has a coil piece main body 11, an outer lead wire 12, and an inner lead wire 13. Thus, the first coil piece 10A has two ends. The two ends include a first end 14 corresponding to the inner lead wire 13 and a second end 15 corresponding to the outer lead wire 12. The first coil piece 10A has a coil wire that is wound a plurality of times. The coil wire has a first end 14 and a second end 15. The first end 14 and the second end 15 are connected to an inverter circuit 20, which will be described in detail later.

[0053] The coil piece body 11 is a portion formed by winding a coil wire. The coil piece body 11 has a frame shape in a plan view. In this embodiment, the coil piece body 11 has a fan shape in a plan view. The shape of the coil piece body 11 is not limited to a fan shape, and may have any shape, such as a triangle or a circle. When the shape of the coil piece body 11 is a fan shape, the shapes of the first heating region S1 and the second heating region S2 are circular, which matches the general shape of the bottom of a pot as described above, and the density of the coil pieces can be increased, allowing the pot to be heated efficiently.

[0054] The outer lead wire 12 is a lead wire that is led out from the outside of the coil piece body portion 11 .

[0055] The inner lead wire 13 is a lead wire that is led out from the inside of the coil piece body portion 11 .

[0056] In the present embodiment, the first coil piece 10A is formed of a single coil wire. The coil wire is an example of an electric wire. The coil wire is made of, for example, a conductive material.

[0057] In this embodiment, the second to tenth coil pieces 10B to 10J have the same configuration as the first coil piece 10A. Therefore, in the first to tenth coil pieces 10A to 10J, the lengths of the multiple outer lead wires 12 are equal. In addition, in the first to tenth coil pieces 10A to 10J, the lengths of the multiple inner lead wires 13 are equal. Note that the length of the outer lead wire 12 and the length of the inner lead wire 13 may be different or equal. In this way, the multiple coil pieces 10A to 10J are all composed of approximately the same coil pieces, which can reduce manufacturing costs. Also, the effects of electromagnetic noise can be reduced.

[0058] [Electrical connection configuration] FIG. 5 shows a schematic block diagram of electrical connections related to one of the coil units 4 of the induction heating cooker 1. As shown in FIG. 5, the induction heating cooker 1 has a power supply unit 8, one inverter circuit 20, a relay unit 30, and a coil unit 4. The inverter circuit 20 and the relay unit 30 are connected to a controller 6 and receive control signals from the controller 6. In the induction heating cooker 1 according to the present embodiment, the electrical connections related to the other of the coil unit 4 and the coil unit 5 may be configured in the same manner as described above. The power supply unit 8 may be shared by the coil units 4 and 5.

[0059] The power supply unit 8 is connected to a power supply such as a commercial AC power supply. When the power supply unit 8 is connected to a power supply, it converts the applied voltage of the power supply to a predetermined voltage and outputs it. The power supply unit 8 may have a rectifying and smoothing circuit including a diode bridge and a capacitor. The power supply unit 8 is connected to an inverter circuit 20 and applies the converted voltage to the inverter circuit 20 to supply power. The inverter circuit 20 can supply high-frequency current to each of the front coil 4A, the rear coil 4B, and the overlapping coil 4C that can operate integrally. In this specification, "integrally operable" means that the controller 6 can operate at least two of the front coil 4A, the rear coil 4B, and the overlapping coil 4C in combination to heat a common heating object. "Integratedly operable" may also mean that a magnetic field generated by a high-frequency current flowing through each coil piece 10 of each coil 4A to 4C can be generated while being influenced by a high-frequency current from an adjacent coil piece 10 and can act to heat a common heating object. In this embodiment, among the heating regions composed of multiple heating coils that can be operated by one inverter circuit 20, the second heating region S2 is the only heating region that is the same size as the first heating region S1. This allows the induction heating cooker 1 to provide the convenience of cooking while moving the pan from the first heating region S1 to the second heating region S2, or from the second heating region S2 to the first heating region S1, while specifying the heating region to some extent allows the coil unit 4 to be controlled taking into account the user's usage mode, thereby improving heating efficiency. Also, specifying the heating region to some extent prevents the user's operation from becoming complicated.

[0060] The inverter circuit 20 is connected to the power supply unit 8, the relay unit 30, and the coil unit 4. The inverter circuit 20 includes, for example, a plurality of switching elements and a plurality of capacitors. Each switching element includes, for example, an IGBT and a diode connected in anti-parallel to the IGBT. Each switching element of the inverter circuit 20 switches on / off based on a control signal received from the controller 6. The plurality of capacitors includes a resonant capacitor. The plurality of capacitors may include a snubber capacitor.

[0061] The relay unit 30 is connected to some of the multiple paths between the inverter circuit 20 and the coil unit 4. The details of the relay unit 30 will be described later.

[0062] As described above, the coil unit 4 has a plurality of coil pieces 10. The first end 14 of each coil piece 10 is connected to the inverter circuit 20. The second end 15 of each coil piece 10 is connected to the inverter circuit 20 via a path different from the path connecting the first end 14 and the inverter circuit 20.

[0063] The controller 6 controls the operation of the inverter circuit 20 to control the current flowing through the multiple coil pieces 10 of the coil unit 4. Specifically, the controller 6 controls the operation of the inverter circuit 20 so that a high-frequency current flows through the multiple coil pieces 10 when the coil unit 4 heats an object to be heated. The controller 6 controls the on / off of the switching elements of the inverter circuit 20 so that a high-frequency current flows through each coil piece 10 by current resonance, for example, via the coil pieces 10 and a resonant capacitor in the inverter circuit 20.

[0064] The induction heating cooker 1 according to the present embodiment is configured to supply high-frequency current to each coil piece 10 by current resonance to operate each coil piece 10, but is not limited thereto. The induction heating cooker 1 may be configured to operate each coil piece 10 by any method. For example, the induction heating cooker 1 may be configured to provide a resonance capacitor in parallel with each coil piece 10, and to supply high-frequency current to each coil piece 10 by voltage resonance through each coil piece 10 and each resonance capacitor to operate each coil piece 10.

[0065] [circuit] Fig. 6 is a schematic circuit diagram showing an example of electrical connection between the inverter circuit 20 and the coil unit 4 of the induction heating cooker 1 according to the present embodiment. The circuit diagram in Fig. 6 shows the electrical connection on the first end 14 side of each coil piece 10 of the coil unit 4.

[0066] 6, in the induction heating cooker 1, the inverter circuit 20 and each coil piece 10 are connected by a plurality of paths. A relay unit 30 is connected to some of the paths.

[0067] The relay unit 30 includes a front relay unit 31 and a rear relay unit 32. The front relay unit 31 is an example of a first relay unit. The rear relay unit 32 is an example of a second relay unit. The front relay unit 31 includes two relays 31A to 31B. The rear relay unit 32 includes two relays 32A to 32B. Each of the relays 31A to 31B and 32A to 32B is a switch whose opening and closing can be controlled by the controller 6. For example, each of the relays 31A to 31B and 32A to 32B may be a switch such as a mechanical relay, or may be a semiconductor switch such as a MOSFET or a solid-state relay (SSR). In this embodiment, the controller 6 controls each of the relays 31A to 31B so that the relays 31A to 31B of the front relay unit 31 have the same opening and closing state. The controller 6 also controls each of the relays 32A to 32B so that the relays 32A to 32B of the rear relay unit 32 have the same opening and closing state.

[0068] 6, the first ends 14 of the coil pieces 10A-10D of the front coil 4A are connected to the inverter circuit 20 via one of two paths. Specifically, a connection point 16A between the first end 14 of the first coil piece 10A and the first end 14 of the third coil piece 10C is connected to the inverter circuit 20 via a relay 31A. A connection point 16B between the first end 14 of the second coil piece 10B and the first end 14 of the fourth coil piece 10D is connected to the inverter circuit 20 via a relay 31B.

[0069] Each of the coil pieces 10G-10J of the rear coil 4B is configured similarly to each of the coil pieces 10A-10D of the front coil 4A. Specifically, a connection point 16C between a first end 14 of the seventh coil piece 10G and a first end 14 of the ninth coil piece 10I is connected to the inverter circuit 20 via a relay 32A. A connection point 16D between a first end 14 of the eighth coil piece 10H and a first end 14 of the tenth coil piece 10J is connected to the inverter circuit 20 via a relay 32B.

[0070] Each of the coil pieces 10E to 10F of the overlap coil 4C is connected to the inverter circuit 20 without passing through a relay unit 30.

[0071] Fig. 7 is a schematic circuit diagram showing an example of electrical connection between the inverter circuit 20 and the coil unit 4 of the induction heating cooker 1 according to the present embodiment. The circuit diagram of Fig. 7 shows electrical connection on the second end 15 side of each coil piece 10 of the coil unit 4.

[0072] 7, the circuit of the induction heating cooker 1 according to the present disclosure has a connection point 17 connected to an inverter circuit 20. In the induction heating cooker 1, the inverter circuit 20 and each coil piece 10 are connected via the connection point 17. Specifically, the second end 15 of each coil piece 10 is connected to the connection point 17.

[0073] As shown in FIGS. 6 and 7, the first end 14 and the second end 15 of each coil piece 10 are connected to an inverter circuit 20 via a predetermined path.

[0074] FIG. 8 is a schematic circuit diagram showing an example of electrical connection between the inverter circuit 20 and the coil unit 4 of the induction heating cooker 1 according to the present embodiment.

[0075] As shown in Fig. 8, the coil pieces 10A-10J are divided into a first group G1 and a second group G2. The first group G1 and the second group G2 each include a plurality of coil pieces 10 that are not adjacent to each other. That is, every other coil piece 10 among the coil pieces 10A-10J is included in the same group. The first group G1 includes the first coil piece 10A, the third coil piece 10C, the fifth coil piece 10E, the seventh coil piece 10G, and the ninth coil piece 10I. The second group G2 includes the second coil piece 10B, the fourth coil piece 10D, the sixth coil piece 10F, the eighth coil piece 10H, and the tenth coil piece 10J.

[0076] The coil pieces 10A, 10C, 10E, 10G, and 10I included in the first group G1 are connected in parallel to the inverter circuit 20. Therefore, the same voltage is applied to each of the coil pieces 10A, 10C, 10E, 10G, and 10I from the inverter circuit 20. The coil pieces 10B, 10D, 10F, 10H, and 10J included in the second group G2 are connected in parallel to the inverter circuit 20. The same voltage is applied to each of the coil pieces 10B, 10D, 10F, 10H, and 10J from the inverter circuit 20.

[0077] The connection point 17 indicates a point between each coil piece 10. In this specification, this point is referred to as a midpoint. In this specification, "midpoint" means a point between at least two coil pieces 10. For example, the midpoint may indicate a point that can be a reference for the current flowing through multiple coil pieces 10. The midpoint may indicate a point where a coil piece 10 included in a first group G1 and a coil piece 10 included in a second group G2 are connected. The midpoint may indicate a point where the second ends 15 of each of multiple coil pieces 10 that are connected to each other are connected.

[0078] [Operation] Next, the operation of the induction heating cooker 1 according to the present disclosure will be described.

[0079] The induction heating cooker 1 according to the present disclosure can locally control the intensity of heating when heating an object placed on the top plate 2 on the coil unit 4. For example, the controller 6 of the induction heating cooker 1 can control the intensity of local heating by heating the object in one or more heating modes. A heating mode indicates a heating method that locally generates an area where heating is strong or weak. Therefore, when the controller 6 controls the object to be heated in a predetermined heating mode, a predetermined part of the object corresponding to the predetermined heating mode can be heated more strongly than other parts. The controller 6 can heat the object to be heated in one or more heating modes by changing the parameters of the current supplied to each coil piece 10 for each heating mode. The heating mode can be stored in a storage device together with the parameters of the current that realizes the heating mode, for example. The parameters include the amplitude, phase, and frequency of the current.

[0080] It is not necessary to use a predetermined heating mode for controlling the strength of localized heating by the controller 6. For example, current parameters that can heat a specific region strongly (or weakly) may be stored in a storage device, and when there are multiple regions that require strong heating, the controller 6 may control heating by combining the stored information.

[0081] The one or more heating modes include a first heating mode in which a portion of the heating object arranged in a region located between adjacent coil pieces 10 in the heating region and to which high-frequency current is supplied is heated more strongly than other portions. The one or more heating modes include a second heating mode in which a portion of the heating object arranged in a region located on the outer periphery of adjacent coil pieces 10 in the heating region is heated more strongly than other portions. The one or more heating modes may include other heating modes that can heat the heating object with a distribution different from the above.

[0082] In the induction heating cooker 1 according to the present embodiment, the controller 6 can obtain information on the temperature of the object to be heated. When the coil unit 4 heats the object to be heated, the magnetic field generated by each coil piece 10 affects the object to be heated, and a current is generated in the object to be heated, thereby heating the object to be heated. The magnetic field is affected by the object to be heated, and therefore the impedance of each coil piece 10 changes. In general, the impedance of the coil piece 10 changes depending on the presence or absence of the object to be heated placed in the range affected by the magnetic field generated by the coil piece 10, and the magnetism due to the material of the object. The impedance also changes depending on the temperature of the object to be heated, and therefore the controller 6 can obtain the change in the temperature of the object to be heated by obtaining the change in the characteristics of each coil piece 10, such as grasping the impedance of each coil piece 10. For example, the controller 6 can obtain the change in the temperature of the area of ​​the object to be heated that is heated by each coil piece 10, by obtaining the change in the characteristics of each coil piece 10. In other words, the controller 6 can use each coil piece 10 like a temperature sensor.

[0083] For example, the controller 6 can acquire changes in the characteristics of each coil piece 10 by providing a current sensor in the circuit to acquire the current flowing through each coil piece 10 and acquiring the change in the current value relative to the voltage value. The method of acquiring changes in the characteristics of each coil piece 10 is not limited to a current sensor, and for example, the controller 6 may acquire changes in the characteristics using a voltage sensor.

[0084] When the controller 6 acquires information on temperature from the multiple coil pieces 10, the controller 6 may store the information as temperature information in the storage device. The temperature information may be, for example, relative and qualitative information between the multiple coil pieces 10. The temperature information is not limited to this, and may be a numerical value. The controller 6 can detect, for example, a location where the temperature is relatively low based on information that associates the positions of the multiple coil pieces 10 with the temperature information acquired based on each of the multiple coil pieces 10. Therefore, the controller 6 can control the parameters of the current flowing through each of the multiple coil pieces 10 so as to strongly heat the location where the temperature is relatively low. In this way, the controller 6 can control the parameters of the current flowing through each of the multiple coil pieces 10 based on information that associates the positions of the multiple coil pieces 10 with the temperature information acquired based on each of the multiple coil pieces 10.

[0085] Moreover, the controller 6 can switch between a connected state in which each of the coil pieces 10A-10D, 10G-10J is electrically connected to the inverter circuit 20 and an open state in which they are not connected, by switching the front relay unit 31 and the rear relay unit 32 open and closed. The controller 6 is configured to be able to execute one of a plurality of operation modes in which at least one of the front coil 4A, the rear coil 4B, and the overlapping coil 4C is operated by switching between the connected state and the open state for each coil piece 10. The operation modes can be stored in a storage device.

[0086] The plurality of operation modes include a front drive mode and a rear drive mode. The front drive mode is an example of a first operation mode. The rear drive mode is an example of a second operation mode.

[0087] The front driving mode indicates an operation mode in which the front coil 4A and the overlapping coil 4C are operated and the rear coil 4B is not operated. The controller 6 first turns on the relays 31A and 31B of the front relay unit 31 and turns off the relays 32A and 32B of the rear relay unit 32. Then, the controller 6 operates the inverter circuit 20 to execute the front driving mode in which high-frequency current is supplied to the front coil 4A and the overlapping coil 4C.

[0088] The rear drive mode indicates an operation mode in which the rear coil 4B and the overlapping coil 4C are operated and the front coil 4A is not operated. The controller 6 first turns on the relays 32A and 32B of the rear relay unit 32 and turns off the relays 31A and 31B of the front relay unit 31. Then, the controller 6 operates the inverter circuit 20 to execute the rear drive mode in which high-frequency current is supplied to the rear coil 4B and the overlapping coil 4C.

[0089] For example, when heating an object to be heated placed in the first heating region S1, the user can operate the operation panel 7 to execute heating in the front driving mode. When the controller 6 receives an instruction to operate in the front driving mode, it executes the front driving mode and supplies a high-frequency current to the front coil 4A and the overlapping coil 4C. The induction heating cooker 1 can inductively heat the object to be heated placed in the first heating region S1 by the high-frequency current flowing through the front coil 4A and the overlapping coil 4C.

[0090] For example, when heating an object to be heated placed in the second heating region S2, the user can operate the operation panel 7 to execute heating in the rear driving mode. When the controller 6 receives an instruction to operate in the rear driving mode, it executes the rear driving mode and supplies high-frequency current to the rear coil 4B and the overlapping coil 4C. The induction heating cooker 1 can inductively heat the object to be heated placed in the second heating region S2 by the high-frequency current flowing through the rear coil 4B and the overlapping coil 4C.

[0091] As will be described in detail later, the controller 6 can detect whether or not a heating target is placed in the heating region by operating the coil unit 4. The controller 6 may determine the operation mode to be executed based on the detection result without receiving an instruction regarding the operation mode from the user.

[0092] The multiple operation modes may include a full drive mode. The full drive mode is an example of a third operation mode. The full drive mode indicates an operation mode in which the front coil 4A, the rear coil 4B, and the overlapping coil 4C are operated. The controller 6 first turns on the relays 31A to 31B, 32A to 32B. Then, the controller 6 operates the inverter circuit 20 to execute the full drive mode in which high-frequency current is supplied to the front coil 4A, the rear coil 4B, and the overlapping coil 4C.

[0093] For example, when heating an object to be heated placed in the third heating region S3, the user can operate the operation panel 7 to execute heating in the full driving mode. When the controller 6 receives an instruction to operate in the full driving mode, it executes the full driving mode and supplies high-frequency current to the front coil 4A, the rear coil 4B, and the overlapping coil 4C. The induction heating cooker 1 can induction heat the object to be heated placed in the third heating region S3 by the high-frequency current flowing through each of the coils 4A to 4C.

[0094] The number of coil pieces 10 connected to the inverter circuit 20 changes between the pre-driving mode and the full driving mode. When the number of connected coil pieces changes, the appropriate capacitance value for the resonant capacitor may change. Therefore, the induction heating cooker 1 according to the present disclosure is configured to be able to change the capacitance value of the resonant capacitor depending on the operation mode. For example, by configuring the circuit of the induction heating cooker 1 as shown in FIG. 9, the controller 6 can change the capacitance value of the resonant capacitor depending on the operation mode.

[0095] Fig. 9 shows a circuit diagram illustrating the inverter circuit 20 of the circuit diagram shown in Fig. 8 in more detail. As shown in Fig. 9, each coil piece 10 is connected to one or more capacitors in the inverter circuit 20. Specifically, each coil piece 10 in the first group G1 is connected to a first resonant capacitor 21. Also, each coil piece 10 in the first group G1 is connected to a second resonant capacitor 22 via a capacitor relay 23. Similarly, each coil piece 10 in the second group G2 is connected to the first resonant capacitor 21. Also, each coil piece 10 in the second group G2 is connected to the second resonant capacitor 22 via a capacitor relay 23.

[0096] The controller 6 is configured to be able to control the opening and closing of the capacitor relay 23 by outputting a control signal. For example, when executing the front drive mode, the controller 6 can turn off the capacitor relay 23 and operate the inverter circuit 20 so that the first resonant capacitor 21 is energized. For example, when executing the full drive mode, the controller 6 can turn on the capacitor relay 23 and operate the inverter circuit 20 so that the first resonant capacitor 21 and the second resonant capacitor 22 are energized.

[0097] The multiple operation modes may include a central driving mode. The central driving mode is an example of a fourth operation mode. The central driving mode indicates an operation mode in which the overlapping coil 4C is operated and the front coil 4A and the rear coil 4B are not operated. The controller 6 first turns off the relays 31A-31B, 32A-32B. Then, the controller 6 operates the inverter circuit 20 to execute the central driving mode in which a high-frequency current is supplied to the overlapping coil 4C. The induction heating cooker 1 can induction heat an object to be heated that is arranged in an area having the coil arrangement areas S15-S16 by the high-frequency current flowing through the overlapping coil 4C. The area corresponds to the area formed by the fifth coil piece 10E and the sixth coil piece 10F.

[0098] In the induction heating cooker 1 according to the present disclosure, the controller 6 can determine whether or not a cooking vessel C is placed on each coil piece 10. The controller 6 can also determine the material of the placed cooking vessel C. In general, the impedance of the coil piece 10 changes depending on the presence or absence of a heating object placed within an area affected by the magnetic field generated by the coil piece 10 and the magnetism caused by the material of the object. Therefore, the controller 6 can determine whether or not a cooking vessel C is placed and, if so, the material of the cooking vessel C by detecting the change in impedance of each of the coil pieces 10A to 10J.

[0099] For example, when the coil unit 4 is operated in the full drive mode, the controller 6 can switch between opening and closing of the relay units 31, 32 and determine whether or not a cooking container C is placed on the basis of a response including a change in impedance. When the controller 6 determines that the cooking container C is placed only in a portion of the third heating region S3, the controller 6 may operate the coil unit 4 so as to heat at least that portion of the third heating region S3.

[0100] Furthermore, the controller 6 can determine current parameters including frequency based on the determined material and operate the coil unit 4 with a current having the parameters. Therefore, the controller 6 can heat the cooking vessel C placed above the coil unit 4 with parameters suitable for the material of the cooking vessel C.

[0101] [effect] According to the induction heating cooker 1 according to the embodiment of the present disclosure, the following effects can be achieved.

[0102] The induction heating cooker 1 includes a first coil 4A, a second coil 4B, a third coil 4C, a top plate 2, one inverter circuit 20, a first relay unit 31, a second relay unit 32, and a control unit 6. The second coil 4B is a coil different from the first coil 4A. The third coil 4C is a coil different from the first coil 4A and the second coil 4B. The top plate 2 is provided above the first coil 4A, the second coil 4B, and the third coil 4C. The inverter circuit 20 supplies high-frequency current to each of the first coil 4A, the second coil 4B, and the third coil 4C, which can operate integrally. The first relay unit 31 is connected between the first coil 4A and the inverter circuit 20. The second relay unit 32 is connected between the second coil 4B and the inverter circuit 20. The controller 6 controls the operation of the inverter circuit 20 and the operations of the first relay unit 31 and the second relay unit 32. The controller 6 is configured to execute one of a plurality of operation modes for operating at least one of the first coil 4A, the second coil 4B, and the third coil 4C. The plurality of operation modes include a first operation mode and a second operation mode. In the first operation mode, the controller 6 turns on the first relay unit 31 and turns off the second relay unit 32 to supply high-frequency current from the inverter circuit 20 to the first coil 4A and the third coil 4C. In the second operation mode, the controller 6 turns off the first relay unit 31 and turns on the second relay unit 32 to supply high-frequency current from the inverter circuit 20 to the second coil 4B and the third coil 4C.

[0103] According to this configuration, in the induction heating cooker 1 using multiple coils, some of the coils can be used in an overlapping manner in multiple heating regions. For example, the induction heating cooker 1 according to this embodiment can use the overlapping coil 4C in an overlapping manner in the first heating region S1 and the second heating region S2 as shown in Fig. 3. Therefore, the induction heating cooker 1 can reduce the space of the coil unit 4.

[0104] In addition, in the induction heating cooker 1, since each coil piece 10 is operated by a common inverter circuit 20, the high-frequency current flowing through each coil piece 10 has the same frequency. When the induction heating cooker 1 heats an object to be heated using each coil 4A to 4C that operate integrally, multiple frequencies whose difference falls within the audible range of humans are not used. Therefore, the induction heating cooker 1 according to the present disclosure can suppress the generation of a humming sound caused by the difference in frequency of the high-frequency current flowing through each coil piece 10.

[0105] Furthermore, the induction heating cooker 1 can change the coil pieces 10 to be operated by controlling the relay units 31, 32 to use one of a number of operation modes. By providing the relay units 31, 32, the induction heating cooker 1 can achieve the above operation with only one inverter circuit 20, and therefore the number of inverter circuits 20, which are relatively expensive components, can be reduced, thereby reducing manufacturing costs. Furthermore, the induction heating cooker 1 can reduce the number of inverter circuits 20, thereby saving space. Furthermore, the induction heating cooker 1 can be controlled by the relay units 31, 32 so that current is not supplied to coil pieces 10 that do not need to be operated, thereby enabling efficient heating.

[0106] In addition, in the induction heating cooker 1, the multiple operation modes include a third operation mode in which high-frequency current is supplied from the inverter circuit 20 to the first coil 4A, the second coil 4B, and the third coil 4C by turning on the first relay unit 31 and the second relay unit 32. By controlling in this way, the induction heating cooker 1 can heat a wider area than when it is operated in the first operation mode or the second operation mode. Therefore, the induction heating cooker 1 can heat a large heating object such as an oval pot or a pot with a large diameter, and the user's applications can be expanded.

[0107] Furthermore, in the induction heating cooker 1, the inverter circuit 20 has a plurality of resonant capacitors 21, 22, and the resonant capacitors 21, 22 to which current is applied are at least partially different between the first operation mode and the third operation mode. With this configuration, the controller 6 can change the number of capacitors to be energized according to the number of coil pieces 10 to be operated. Therefore, the induction heating cooker 1 can use a circuit having an appropriate capacitance value according to the operation, and the loss of the inverter circuit 20 can be reduced.

[0108] Moreover, in the induction heating cooker 1, the inverter circuit 20 includes one or more capacitor relays 23 connected to at least some of the multiple resonant capacitors 21, 22. The control unit 6 controls the operation of the one or more capacitor relays 23. With this configuration, the induction heating cooker 1 can use a circuit having an appropriate capacitance value depending on the operation, and the loss of the inverter circuit 20 can be reduced.

[0109] Moreover, in the induction heating cooker 1, the multiple operation modes include a fourth operation mode in which high-frequency current is supplied from the inverter circuit 20 to the third coil 4C by turning off the first relay unit 31 and the second relay unit 32. By controlling in this way, the induction heating cooker 1 can operate only the third coil 4C arranged between the first coil 4A and the second coil 4B. The induction heating cooker 1 can heat a small cooking container C only in the part of the coil unit 4 where the third coil 4C is arranged, which can expand the range of uses for users.

[0110] Furthermore, in the induction heating cooker 1, the control unit 6 switches at least one of the first relay unit 31 and the second relay unit 32 between open and closed to determine the presence or absence of a cooking container C on the top plate 2 and the material of the cooking container C placed thereon. By controlling in this manner, the induction heating cooker 1 can detect the position where the cooking container C is placed on the top plate 2 and heat the heating area corresponding to that position. Also, the cooking container C can be heated using current parameters according to the material of the placed cooking container C. Therefore, the induction heating cooker 1 can improve cooking performance.

[0111] In addition, in the induction heating cooker 1, the outer periphery formed by the first coil 4A and the third coil 4C is circular in plan view. With this configuration, the induction heating cooker 1 can heat the cooking container C using a heating coil having a shape suitable for the shape of the cooking container C. Therefore, the induction heating cooker 1 can improve cooking performance.

[0112] Moreover, in the induction heating cooker 1, the first coil 4A has four coil pieces 10A to 10D. The induction heating cooker 1 can vary the distribution of the heat intensity of the heating object by the four coil pieces 10A to 10D by controlling the parameters of the current flowing through the coil pieces 10A to 10D. Therefore, when the induction heating cooker 1 heats the heating object using the first coil 4A, the induction heating cooker 1 can efficiently heat the heating object. Moreover, the induction heating cooker 1 can heat the heating object evenly and suppress uneven heating.

[0113] In the induction heating cooker 1, the first relay unit 31 includes two relays 31A and 31B. The four coil pieces include a first coil piece 10A, a second coil piece 10B, a third coil piece 10C, and a fourth coil piece 10D. The second coil piece 10B is arranged adjacent to the first coil piece 10A. The third coil piece 10C is arranged adjacent to the second coil piece 10B. The fourth coil piece 10D is arranged adjacent to the third coil piece 10C. One of the two relays 31A is connected between the first coil piece 10A and the third coil piece 10C and the inverter circuit 20. The other of the two relays 31B is connected between the second coil piece 10B and the fourth coil piece 10D and the inverter circuit 20. With this configuration, the induction heating cooker 1 can supply currents having different parameters to the two adjacent coil pieces 10. Therefore, when the induction heating cooker 1 uses the first coil 4A to heat an object to be heated, the heating can be controlled evenly and the object can be heated efficiently. Also, since the induction heating cooker 1 does not need to provide a relay for each coil piece 10, the number of parts used can be reduced, which reduces manufacturing costs and saves space.

[0114] In the induction heating cooker 1, the first coil 4A, the second coil 4B, and the third coil 4C each have a plurality of coil pieces 10A to 10J. Each of the plurality of coil pieces 10A to 10J has an electric wire wound a plurality of times, and the electric wire has a first end 14 and a second end 15 connected to the inverter circuit 20. The first end 14 of each of the plurality of coil pieces 10A to 10D of the first coil 4A is connected to the inverter circuit 20 via a first relay unit 31. The first end 14 of each of the plurality of coil pieces 10G to 10J of the second coil 4B is connected to the inverter circuit 20 via a second relay unit 32. The first end 14 of each of the plurality of coil pieces 10E to 10F of the third coil 4C is connected to the inverter circuit 20 without passing through the first relay unit 31 and the second relay unit 32. The second end 15 of each of the plurality of coil pieces 10A to 10J is connected to one connection point 17 connected to the inverter circuit 20.

[0115] According to this configuration, the induction heating cooker 1 does not need to connect the second end 15 of each coil piece 10 to the inverter circuit 20, and the number of parts can be reduced, leading to lower manufacturing costs. Also, since the second end 15 of each coil piece 10 is connected to one connection point 17, the induction heating cooker 1 can suppress the generation of electromagnetic noise and improve electromagnetic compatibility (EMC).

[0116] In addition, since the second ends 15 of the coil pieces 10 are all connected to the connection points 17, the control unit 6 can perform heating by each coil piece 10 without passing a current through the electric wire connecting the connection points 17 and the inverter circuit 20. Therefore, the induction heating cooker 1 can efficiently heat the object to be heated.

[0117] In the present embodiment, the coil arrangement regions S11 to S16 and S21 to S26 have substantially the same shape and size, but are not limited thereto. For example, the coil arrangement regions S11 to S16 and S21 to S26 may have different shapes and / or different sizes.

[0118] In the present embodiment, the coil pieces 10A to 10J have substantially the same shape and substantially the same size, but the present invention is not limited to this. For example, the coil pieces 10A to 10J may have different shapes and / or different sizes.

[0119] In the present embodiment, an example has been described in which the boundary lines L11-L16 are straight lines extending from the center C1 of the first heating region S1 toward the periphery in a plan view, but the present invention is not limited thereto. Also, an example has been described in which the boundary lines L21-L26 are straight lines extending from the center C2 of the second heating region S2 toward the periphery in a plan view, but the present invention is not limited thereto. For example, the boundary lines L11-L16 may be curved lines extending from the center C1 of the first heating region S1 toward the periphery in a plan view.

[0120] In the present embodiment, the longitudinal direction of the coil unit 4 is arranged in the depth direction of the induction heating cooker 1, and the front coil 4A, overlapping coil 4C, and rear coil 4B obtained by dividing the coil unit 4 are arranged in the depth direction, but the present invention is not limited to this. For example, the longitudinal direction of the coil unit 4 may be arranged in the left-right direction of the induction heating cooker 1, and each coil obtained by dividing the coil unit 4 may be arranged in the left-right direction.

[0121] In the present embodiment, an example has been described in which the first heating region S1 and the second heating region S2 each have six coil arrangement regions S11-S16, S21-S26, but the present invention is not limited thereto. In addition, an example has been described in which the number of the coil pieces 10 included in the coil unit 4 is ten, but the present invention is not limited thereto. For example, the first heating region S1 and the second heating region S2 may each have four coil arrangement regions. In addition, the number of the coil pieces 10 included in the coil unit 4 may be seven. Specifically, for example, the induction heating cooker 1 may be configured such that the front coil 4A and the rear coil 4B each have three coil pieces 10, and the overlapping coil 4C has one coil piece.

[0122] (Variation 1) FIG. 10 is a schematic circuit diagram of the induction heating cooker 1 of the first modification. Specifically, the circuit diagram of FIG. 10 shows the electrical connection of the second end 15 side of the coil unit 4 in the first modification. The induction heating cooker 1 of the first modification includes a plurality of center point relays 33A to 33H. The controller 6 is configured to be able to control the operation of each center point relay 33. Hereinafter, when there is no need to distinguish between the plurality of center point relays 33A to 33H, they will be collectively referred to as the center point relay 33 or the plurality of center point relays 33. The center point relay 33 is an example of an opening relay. The controller 6 can disconnect the connection between the second end 15 of the coil piece 10 and the inverter circuit 20 by turning off, that is, opening, the center point relay 33.

[0123] As shown in Fig. 10, the second end 15 of each of the coil pieces 10A to 10J may be independently connected to the inverter circuit 20 via a midpoint relay 33. That is, the second end 15 of each coil piece 10 may be connected to the inverter circuit 20 via a midpoint relay 33 without being electrically connected to the second end 15 of the other coil pieces 10. For example, the second end 15 of the first coil piece 10A may be connected to the inverter circuit 20 via a midpoint relay 33A. The second end 15 of the second coil piece 10B may be connected to the inverter circuit 20 via a midpoint relay 33B. The other coil pieces 10C to 10D and 10G to 10J may be configured in a similar manner.

[0124] In the induction heating cooker 1 of the first modification, the controller 6 turns on the midpoint relay 33 connected to the coil piece 10 to be operated among the coil unit 4, and turns off the other midpoint relays 33. In the case of the circuit shown in Fig. 7, the second end 15 of each of the coil pieces 10A to 10J is connected to a connection point 17 connected to the inverter circuit 20. Therefore, even if the controller 6 controls the first relay unit 31 or the second relay unit 32 to be turned off so that a certain coil piece 10 does not operate, the potential of the coil piece 10 may fluctuate via the connection point 17. Such a change in potential may become electromagnetic noise.

[0125] In the induction heating cooker 1 of the first modification, by turning off the midpoint relay 33 of the coil piece 10, the second end 15 of the coil piece 10 can be electrically disconnected from the inverter circuit 20 or the second end 15 of the other coil piece 10. Therefore, the induction heating cooker 1 of the first modification can suppress the generation of noise and improve EMC.

[0126] In this manner, the induction heating cooker 1 of the first modification includes a plurality of opening relays 33A-33H each connected to the inverter circuit 20. The first coil 4A, the second coil 4B, and the third coil 4C each have a plurality of coil pieces 10A-10J. Each of the plurality of coil pieces 10A-10J has an electric wire wound a plurality of times. The electric wire has a first end 14 and a second end 15 connected to the inverter circuit 20. The first end 14 of each of the plurality of coil pieces 10A-10D of the first coil 4A is connected to the inverter circuit 20 via the first relay unit 31. The first end 14 of each of the plurality of coil pieces 10G-10J of the second coil 4B is connected to the inverter circuit 20 via the second relay unit 32. The first end 14 of each of the plurality of coil pieces 10E-10F of the third coil 4C is connected to the inverter circuit 20 without passing through the first relay unit 31 and the second relay unit 32. The second ends 15 of the coil pieces 10A to 10D and 10G to 10J of the first coil 4A and the second coil 4B are connected to an inverter circuit 20 via any one of a plurality of opening relays 33A to 33H.

[0127] According to such a configuration, the induction heating cooker 1 can suppress the generation of noise and improve EMC. Moreover, by further including a plurality of opening relays 33, the induction heating cooker 1 can realize an operation that improves EMC with only one inverter circuit 20. Therefore, the induction heating cooker 1 can reduce the number of inverter circuits, which are relatively expensive parts, and therefore can reduce manufacturing costs. Moreover, the induction heating cooker 1 can reduce the number of inverter circuits 20, and therefore can save space in the coil unit 4.

[0128] (Variation 2) Fig. 11 is a schematic circuit diagram of the induction heating cooker 1 of the modified example 2. Specifically, the circuit diagram of Fig. 11 shows electrical connections on the second end 15 side of the coil unit 4 in the modified example 2. The induction heating cooker 1 of the modified example 2 includes a plurality of center point relays 34A-34D. The controller 6 is configured to be able to control the operation of each of the center point relays 34A-34D. Hereinafter, when there is no need to distinguish between the plurality of center point relays 34A-34D, they will be collectively referred to as the center point relay 34 or the plurality of center point relays 34. The center point relay 34 is an example of an opening relay.

[0129] 11, the second end 15 of each coil piece 10 may be connected to the second end 15 of another coil piece 10, and connection points 18A-18D between the second ends 15 may be connected to the inverter circuit 20 via a midpoint relay 34. Hereinafter, when there is no need to distinguish between the connection points 18A-18D, they will be collectively referred to as a connection point 18 or a plurality of connection points 18. Each connection point 18 may indicate a midpoint between the second ends 15 of the plurality of coil pieces 10 that are connected to each other.

[0130] In the circuit of the second modification, the second end 15 of the first coil piece 10A and the second end 15 of the third coil piece 10C are connected to the inverter circuit 20 via the same midpoint relay 34A. Specifically, the second end 15 of the first coil piece 10A and the second end 15 of the third coil piece 10C are connected to a connection point 18A, and the connection point 18A is connected to the inverter circuit 20 via the midpoint relay 34A. The second end 15 of the second coil piece 10B and the second end 15 of the fourth coil piece 10D are similarly connected to a connection point 18B and connected to the inverter circuit 20 via the same midpoint relay 34B. The second end 15 of the seventh coil piece 10G and the second end 15 of the ninth coil piece 10I are similarly connected to a connection point 18C and connected to the inverter circuit 20 via the same midpoint relay 34C. The second end 15 of the eighth coil piece 10H and the second end 15 of the tenth coil piece 10J are similarly connected to the connection point 18D, and are connected to the inverter circuit 20 via the same midpoint relay 34D.

[0131] As in the first modification, in the induction heating cooker 1 of the second modification, the controller 6 turns on the midpoint relay 34 connected to the coil piece 10 to be operated of the coil unit 4, and turns off the other midpoint relays 34. Therefore, as in the first modification, the induction heating cooker 1 of the second modification can suppress the generation of noise and improve EMC.

[0132] In this way, the induction heating cooker 1 of the second modification further includes two opening relays 34A, 34B each connected to the inverter circuit. Each of the four coil pieces 10A to 10D has an electric wire wound multiple times. The electric wire has a first end 14 and a second end 15 connected to the inverter circuit 20. The first end 14 of each of the first coil piece 10A and the third coil piece 10C is connected to one of the two relays 31A. The first end 14 of each of the second coil piece 10B and the fourth coil piece 10D is connected to the other of the two relays 31B. The second end 15 of each of the first coil piece 10A and the third coil piece 10C is connected to the inverter circuit 20 via one of the two opening relays 34A. The second end 15 of each of the second coil piece 10B and the fourth coil piece 10D is connected to the inverter circuit 20 via the other of the two opening relays 34B.

[0133] According to such a configuration, the induction heating cooker 1 can suppress the generation of noise and improve EMC. Moreover, by further including a plurality of opening relays 34, the induction heating cooker 1 can realize an operation that improves EMC with only one inverter circuit 20. Therefore, the induction heating cooker 1 can reduce the number of inverter circuits, which are relatively expensive parts, and therefore can reduce manufacturing costs. Moreover, the induction heating cooker 1 can reduce the number of inverter circuits 20, and therefore can save space in the coil unit 4. Moreover, the induction heating cooker 1 of the modified example 2 can reduce the number of center point relays 34 compared to the induction heating cooker 1 of the modified example 1, and therefore can reduce the number of parts and manufacturing costs.

[0134] (Variation 3) Fig. 12 is a schematic circuit diagram of the induction heating cooker 1 of the modified example 3. Specifically, the circuit diagram of Fig. 12 shows electrical connections on the second end 15 side of the coil unit 4 in the modified example 3. The induction heating cooker 1 of the modified example 3 includes a plurality of center point relays 35A to 35B. The controller 6 is configured to be able to control the operation of each of the center point relays 35A to 35B. Hereinafter, when there is no need to distinguish between the plurality of center point relays 35A to 35B, they will be collectively referred to as the center point relay 35 or the plurality of center point relays 35. The center point relay 35 is an example of an opening relay.

[0135] 12, the second end 15 of each coil piece 10 may be connected to the second ends 15 of multiple other coil pieces 10, and connection points 19A, 19B between the second ends 15 may be connected to the inverter circuit 20 via a midpoint relay 35. Hereinafter, when there is no need to distinguish between the connection points 19A to 19B, they will be collectively referred to as a connection point 19 or multiple connection points 19. Each connection point 19 may indicate a midpoint between the second ends 15 of the multiple coil pieces 10 that are connected to each other.

[0136] In the circuit of the third modification, the second ends 15 of the first coil piece 10A to the fourth coil piece 10D are connected to the inverter circuit 20 via the same midpoint relay 35A. Specifically, the second ends 15 of the first coil piece 10A to the fourth coil piece 10D are connected to a connection point 19A, and the connection point 19A is connected to the inverter circuit 20 via the midpoint relay 35A. The second ends 15 of the seventh coil piece 10G to the tenth coil piece 10J are similarly connected to a connection point 19B, and connected to the inverter circuit 20 via the same midpoint relay 35B.

[0137] As in the first and second modifications, in the induction heating cooker 1 of the third modification, the controller 6 turns on the midpoint relay 34 connected to the coil piece 10 to be operated of the coil unit 4, and turns off the other midpoint relays 34. Therefore, as in the first and second modifications, the induction heating cooker 1 of the third modification can suppress the generation of noise and improve EMC.

[0138] In this manner, the induction heating cooker 1 of the third modification further includes an opening relay 35A connected to the inverter circuit 20. Each of the four coil pieces 10A to 10D has an electric wire wound multiple times. The electric wire has a first end 14 and a second end 15 connected to the inverter circuit 20. The first end 14 of each of the first coil piece 10A and the third coil piece 10C is connected to one of the two relays 31A. The first end 14 of each of the second coil piece 10B and the fourth coil piece 10D is connected to the other of the two relays 31B. The second end 15 of each of the four coil pieces 10A to 10D is connected to one connection point 19A connected to the inverter circuit 20 via the opening relay 35A.

[0139] According to such a configuration, the induction heating cooker 1 can suppress the generation of noise and improve EMC. Moreover, by further including the opening relay 35, the induction heating cooker 1 can realize an operation that improves EMC with only one inverter circuit 20. Therefore, the induction heating cooker 1 can reduce the number of inverter circuits 20, which are relatively expensive parts, and therefore can reduce manufacturing costs. Moreover, the induction heating cooker 1 can reduce the number of inverter circuits 20, and therefore can save space in the coil unit 4. Moreover, the induction heating cooker 1 of the modified example 2 can reduce the number of center point relays 35 compared to the induction heating cooker 1 of the modified example 2, and therefore can reduce the number of parts and manufacturing costs.

[0140] (Variation 4) Fig. 13 is a schematic circuit diagram of the induction heating cooker 1 of the modified example 4. Specifically, the circuit diagram of Fig. 13 shows electrical connections on the first end 14 side of the coil unit 4 in the modified example 4. The relay unit 30 of the induction heating cooker 1 of the modified example 4 further has a duplicate relay unit 36. The duplicate relay unit 36 ​​is an example of a third relay unit. The duplicate relay unit 36 ​​includes a first duplicate relay 36A and a second duplicate relay 36B. The controller 6 is configured to be able to control the operation of the duplicate relay unit 36.

[0141] 13, the overlap coil 4C may be connected to the inverter circuit 20 via a overlap relay unit 36. Specifically, the first end 14 of the fifth coil piece 10E may be connected to the inverter circuit 20 via a first overlap relay 36A. The first end 14 of the sixth coil piece 10F may be connected to the inverter circuit 20 via a second overlap relay 36B.

[0142] In the induction heating cooker 1 of the fourth modified example, the multiple operation modes may include a rear coil driving mode. The rear coil driving mode is an example of a fifth operation mode. The rear coil driving mode indicates an operation mode in which the rear coil 4B is operated and the front coil and the overlapping coil 4C are not operated. The controller 6 first turns on the relays 32A and 32B of the rear relay unit 32 and turns off the relays 31A, 31B, 36A, and 36B of the front relay unit 31 and the overlapping relay unit. Then, the controller 6 operates the inverter circuit 20 to execute the rear coil driving mode in which a high-frequency current is supplied to the rear coil 4B. The multiple operation modes may include a front coil driving mode in which only the front coil 4A is operated.

[0143] For example, when heating an object to be heated that is arranged in a rear coil heating area having a plurality of coil arrangement areas S23 to S26, the user can operate the operation panel 7 to perform heating in the rear coil driving mode. The rear coil heating area corresponds to the rear coil 4B, i.e., the area constituted by the seventh coil piece 10G to the tenth coil piece 10J. When the controller 6 receives an instruction to operate in the rear coil driving mode, it executes the rear coil driving mode and supplies a high-frequency current to the rear coil 4B. The induction heating cooker 1 can induction heat an object to be heated that is arranged in the rear coil heating area by the high-frequency current flowing through the rear coil 4B.

[0144] The induction heating cooker 1 of the fourth modification can heat a plurality of cooking containers C placed above the coil unit 4 by combining a plurality of operation modes. The controller 6 can heat, for example, one of the plurality of cooking containers C placed in the first heating region S1 and the other of the plurality of cooking containers C placed in the rear coil heating region. Specifically, the controller 6 executes the front driving mode to heat one of the plurality of cooking containers C, and after a certain period of time has elapsed, switches to the rear coil driving mode to heat the other of the plurality of cooking containers C. In this way, the controller 6 can efficiently heat the plurality of cooking containers C placed above the coil unit 4 by alternately switching between the front driving mode and the rear coil driving mode.

[0145] Thus, in the induction heating cooker 1 of the fourth modification, the multiple operation modes include a fifth operation mode in which high-frequency current is supplied only to the second coil 4B from the inverter circuit 20. The control unit 6 operates by alternately switching between the first operation mode and the fifth operation mode. This allows the induction heating cooker 1 to heat multiple cooking containers C with one coil unit 4, expanding the range of uses for users.

[0146] The induction heating cooker 1 further includes a third relay unit 36 ​​connected between the third coil 4C and the inverter circuit 20. The control unit 6 executes the fifth operation mode by turning off the first relay unit 31 and the third relay unit 36 ​​and turning on the second relay unit 32. The induction heating cooker 1 can efficiently heat a plurality of cooking containers C arranged above the coil unit by providing the relay unit 36 ​​between the third coil 4C and the inverter circuit 20. The induction heating cooker 1 can reduce the number of inverter circuits 20, which are relatively expensive parts, and therefore can reduce manufacturing costs. Furthermore, the induction heating cooker 1 can reduce the number of inverter circuits 20, and therefore can save space in the coil unit 4.

[0147] The induction heating cooker 1 may be provided with a midpoint relay between the second end 15 of the fifth coil piece 10E and the inverter circuit 20, and between the second end 15 of the fifth coil piece 10F and the inverter circuit 20. For example, in the circuit of the modified example 1 shown in FIG. 10, the induction heating cooker 1 may be provided with a midpoint relay 33I between the second end 15 of the fifth coil piece 10E and the inverter circuit 20. And, the induction heating cooker 1 may be provided with a midpoint relay 33J between the second end 15 of the sixth coil piece 10F and the inverter circuit 20. Similar modifications can be applied to the circuits of the modified examples 2 and 3 shown in FIG. 11 and FIG. 12.

[0148] Note that the induction heating cooker 1 of the fourth modification example heats the multiple cooking vessels C with only one inverter circuit 20 by including the relay units 31, 32, and 36, but is not limited to this. For example, the induction heating cooker 1 may be configured to include multiple inverter circuits 20 connected to the coils 4A to 4C, respectively, and the controller 6 controls the operation of each inverter circuit 20. By configuring in this way, the induction heating cooker 1 can heat the multiple cooking vessels C without including the multiple relay units 31, 32, and 36.

[0149] (Summary of aspects) As is apparent from the above description, the present disclosure includes the following aspects. In the following, reference symbols are given in parentheses only to clearly indicate the correspondence with the embodiments.

[0150] (Aspect 1) The induction heating cooker (1) according to the present disclosure is A first coil (4A); a second coil (4B) different from the first coil; a third coil (4C) different from the first coil and the second coil, the third coil being disposed between the first coil and the second coil so as to be adjacent to the first coil and the second coil; a top plate (2) provided above the first coil, the second coil, and the third coil; an inverter circuit (20) that supplies high-frequency current to each of the first coil, the second coil, and the third coil that can operate integrally; a first relay unit (31) connected between the first coil and the inverter circuit; a second relay unit (32) connected between the second coil and the inverter circuit; a control unit (6) that controls an operation of the inverter circuit, and an operation of the first relay unit and the second relay unit; Equipped with the control unit is configured to execute one of a plurality of operation modes for operating at least one of the first coil, the second coil, and the third coil; The plurality of operation modes include: a first operation mode in which the first relay unit is turned on and the second relay unit is turned off to supply high-frequency current from the inverter circuit to the first coil and the third coil; a second operation mode in which the first relay unit is turned off and the second relay unit is turned on to supply high-frequency current from the inverter circuit to the second coil and the third coil; Includes.

[0151] (Aspect 2) In the induction heating cooker (1) of aspect 1, the multiple operating modes may include a third operating mode in which high-frequency current is supplied from the inverter circuit (20) to the first coil (4A), the second coil (4B), and the third coil (4C) by turning on the first relay unit (31) and the second relay unit (32).

[0152] (Aspect 3) In the induction heating cooker (1) of aspect 2, the inverter circuit (20) has a plurality of resonant capacitors (21, 22), and the resonant capacitors to which current is applied are at least partially different between the first operation mode and the third operation mode.

[0153] (Aspect 4) In the induction heating cooker (1) of aspect 3, the inverter circuit (20) includes one or more capacitor relays (23) connected to at least some of the plurality of resonant capacitors (21, 22), The control unit (6) may control the operation of the one or more capacitor relays (23).

[0154] (Aspect 5) In the induction heating cooker (1) of any one of Aspects 1 to 4, the plurality of operating modes may include a fourth operating mode in which high-frequency current is supplied from the inverter circuit to the third coil by turning off the first relay unit and the second relay unit.

[0155] (Aspect 6) In the induction heating cooker (1) of any of aspects 1 to 5, the control unit (6) may switch at least one of the first relay unit (31) and the second relay unit (32) open or closed to determine the presence or absence of a cooking container (C) on the top plate (2) and the material of the cooking container placed on it.

[0156] (Aspect 7) In the induction heating cooker (1) of any one of Aspects 1 to 6, the plurality of operation modes includes a fifth operation mode in which a high-frequency current is supplied from the inverter circuit (20) only to the second coil (4B); The control unit (6) may be configured to alternate between the first operation mode and the fifth operation mode.

[0157] (Aspect 8) The induction heating cooker (1) of aspect 7, further comprising a third relay unit (36) connected between the third coil (4C) and the inverter circuit (20), The control unit (6) may execute the fifth operation mode by turning off the first relay unit (31) and the third relay unit and turning on the second relay unit (32).

[0158] (Aspect 9) In the induction heating cooker (1) of any one of Aspects 1 to 8, an outer periphery formed by the first coil (4A) and the third coil (4C) may be circular in plan view.

[0159] (Aspect 10) In the induction heating cooker (1) of any one of Aspects 1 to 9, the first coil (4A) may have four coil pieces (10A to 10D).

[0160] (Aspect 11) In the induction heating cooker (1) of aspect 10, the first relay unit (31) includes two relays (31A, 31B), The four coil pieces are: A first coil piece (10A), a second coil piece (10B) disposed adjacent to the first coil piece; a third coil piece (10C) disposed adjacent to the second coil piece; a fourth coil piece (10D) arranged adjacent to the third coil piece; Including, one of the two relays (31A) is connected between the first coil piece and the third coil piece and the inverter circuit (20); The other of the two relays (31B) may be connected between the second coil piece and the fourth coil piece and the inverter circuit.

[0161] (Aspect 12) The induction heating cooker (1) of aspect 11 further includes two opening relays (33A, 33B) each connected to the inverter circuit (20), Each of the four coil pieces (10A to 10D) has an electric wire wound a plurality of times, the electric wire having a first end (14) and a second end (15) connected to the inverter circuit, the first ends of the first coil piece (10A) and the third coil piece (10C) are connected to one of the two relays (31A); the first ends of the second coil piece (10B) and the fourth coil piece (10D) are connected to the other of the two relays (31B); a second end of each of the first coil piece and the third coil piece is connected to the inverter circuit via one of the two opening relays (33A); A second end of each of the second coil piece and the fourth coil piece may be connected to the inverter circuit via the other of the two opening relays (33B).

[0162] (Aspect 13) The induction heating cooker (1) of aspect 11, further comprising an opening relay (35A) connected to the inverter circuit (20), Each of the four coil pieces (10A to 10D) has an electric wire wound a plurality of times, the electric wire having a first end (14) and a second end (15) connected to the inverter circuit, the first ends of the first coil piece (10A) and the third coil piece (10C) are connected to one of the two relays (31A); the first ends of the second coil piece (10B) and the fourth coil piece (10D) are connected to the other of the two relays (31B); The second ends of the four coil pieces may be connected to one connection point connected to the inverter circuit via the opening relay.

[0163] (Aspect 14) In the induction heating cooker (1) of any one of Aspects 1 to 9, the first coil (4A), the second coil (4B), and the third coil (4C) each have a plurality of coil pieces (10A to 10J), Each of the coil pieces has an electric wire wound a plurality of times, the electric wire having a first end (14) and a second end (15) connected to the inverter circuit; the first ends of the coil pieces (10A to 10D) of the first coil are connected to the inverter circuit (20) via the first relay unit (31); the first ends of the coil pieces (10G to 10J) of the second coil are connected to the inverter circuit via the second relay unit (32); the first ends of the coil pieces (10E to 10F) of the third coil are connected to the inverter circuit without passing through the first relay unit and the second relay unit, The second end of each of the plurality of coil pieces may be connected to a single connection point (17) that is connected to the inverter circuit.

[0164] (Aspect 15) The induction heating cooker (1) of any one of aspects 1 to 9 further comprises a plurality of opening relays (33A to 33H) each connected to the inverter circuit (20), each of the first coil (4A), the second coil (4B), and the third coil (4C) has a plurality of coil pieces (10A to 10J); Each of the coil pieces has an electric wire wound a plurality of times, the electric wire having a first end (14) and a second end (15) connected to the inverter circuit (20); the first ends of the coil pieces (10A to 10D) of the first coil are connected to the inverter circuit via the first relay unit (31); the first ends of the coil pieces (10G to 10J) of the second coil are connected to the inverter circuit via the second relay unit (32); the first ends of the coil pieces (10E to 10F) of the third coil are connected to the inverter circuit without passing through the first relay unit and the second relay unit, The second ends of the coil pieces of the first coil and the second coil may be connected to the inverter circuit via any one of the opening relays.

[0165] In this specification, the terms "first", "second", etc. are used for descriptive purposes only and should not be understood as expressing or implying the relative importance or ranking of technical features. Features qualified as "first" and "second" expressly or imply the inclusion of one or more of that feature.

[0166] The induction heating cooker described in the present disclosure is realized by cooperation between hardware resources, such as a processor and a memory, and software (computer program). [Industrial Applicability]

[0167] According to the present disclosure, an induction heating cooker that operates multiple heating coils while suppressing the generation of humming noise can be provided, and thus can be suitably used in this type of industrial field. [Explanation of symbols]

[0168] 1 induction cooker 2 Top plate 4 Coil unit 4A Front Coil 4B Back coil 4C Duplicate coil 6 Controller 10,10A~10J coil piece 14 1st end 15 2nd end 17 Connection points 20 Inverter circuit 30 Relay Unit 31 Front relay unit 32 Oku Relay Unit 33, 33A~33H Center point relay 34, 34A~34D Center point relay 35, 35A~35B Center relay 36 Duplicate Relay Unit

Claims

1. A first coil; a second coil different from the first coil; a third coil different from the first coil and the second coil, the third coil being disposed between the first coil and the second coil so as to be adjacent to the first coil and the second coil; and a top plate provided above the first coil, the second coil, and the third coil; an inverter circuit that supplies high-frequency current to each of the first coil, the second coil, and the third coil that can operate integrally; a first relay unit connected between the first coil and the inverter circuit; a second relay unit connected between the second coil and the inverter circuit; a control unit that controls an operation of the inverter circuit, and an operation of the first relay unit and the second relay unit; Equipped with the control unit is configured to execute any one of a plurality of operation modes in which at least one of the first coil, the second coil, and the third coil is operated; The plurality of operation modes include: a first operation mode in which the first relay unit is turned on and the second relay unit is turned off to supply a high-frequency current from the inverter circuit to the first coil and the third coil; a second operation mode in which the first relay unit is turned off and the second relay unit is turned on to supply high-frequency current from the inverter circuit to the second coil and the third coil; Including, Induction heating cooker.

2. 2. The induction heating cooker according to claim 1, wherein the plurality of operating modes include a third operating mode in which high-frequency current is supplied from the inverter circuit to the first coil, the second coil, and the third coil by turning on the first relay unit and the second relay unit.

3. 3. The induction heating cooker according to claim 2, wherein the inverter circuit includes a plurality of resonant capacitors, and the resonant capacitors to which current is applied are at least partially different between the first operation mode and the third operation mode.

4. the inverter circuit includes one or more capacitor relays connected to at least some of the plurality of resonant capacitors; The control unit controls the operation of the one or more capacitor relays.

4. The induction heating cooker according to claim 3.

5. 2. The induction heating cooker according to claim 1, wherein the plurality of operation modes include a fourth operation mode in which a high-frequency current is supplied from the inverter circuit to the third coil by turning off the first relay unit and the second relay unit.

6. The induction heating cooker of claim 1, wherein the control unit switches at least one of the first relay unit and the second relay unit between open and closed states to determine the presence or absence of a cooking container on the top plate and the material of the cooking container placed on it.

7. the plurality of operation modes includes a fifth operation mode in which a high-frequency current is supplied from the inverter circuit only to the second coil, The control unit alternately switches between the first operation mode and the fifth operation mode.

2. The induction heating cooker according to claim 1.

8. a third relay unit connected between the third coil and the inverter circuit, The control unit executes the fifth operation mode by turning off the first relay unit and the third relay unit and turning on the second relay unit.

8. The induction heating cooker according to claim 7.

9. The induction heating cooker according to claim 1 , wherein an outer periphery formed by the first coil and the third coil has a circular shape in a plan view.

10. The induction heating cooker according to claim 1 , wherein the first coil has four coil pieces.

11. The first relay unit includes two relays; The four coil pieces are: A first coil piece; a second coil piece disposed adjacent to the first coil piece; a third coil piece disposed adjacent to the second coil piece; a fourth coil piece disposed adjacent to the third coil piece; Including, one of the two relays is connected between the first coil piece and the third coil piece and the inverter circuit; the other of the two relays is connected between the second coil piece and the fourth coil piece and the inverter circuit; The induction heating cooker according to claim 10.

12. Further comprising two opening relays each connected to the inverter circuit; Each of the four coil pieces has an electric wire wound a plurality of times, the electric wire having a first end and a second end connected to the inverter circuit, the first ends of the first coil piece and the third coil piece are connected to one of the two relays; the first ends of the second coil piece and the fourth coil piece are connected to the other of the two relays; a second end of each of the first coil piece and the third coil piece is connected to the inverter circuit via one of the two opening relays; a second end of each of the second coil piece and the fourth coil piece is connected to the inverter circuit via the other of the two opening relays; The induction heating cooker according to claim 11.

13. Further comprising an opening relay connected to the inverter circuit, Each of the four coil pieces has an electric wire wound a plurality of times, the electric wire having a first end and a second end connected to the inverter circuit, the first ends of the first coil piece and the third coil piece are connected to one of the two relays; the first ends of the second coil piece and the fourth coil piece are connected to the other of the two relays; the second ends of the four coil pieces are connected to one connection point connected to the inverter circuit via the opening relay; The induction heating cooker according to claim 11.

14. each of the first coil, the second coil, and the third coil has a plurality of coil pieces; Each of the coil pieces has an electric wire wound a plurality of times, the electric wire having a first end and a second end connected to the inverter circuit, the first ends of the coil pieces of the first coil are connected to the inverter circuit via the first relay unit; the first ends of the coil pieces of the second coil are connected to the inverter circuit via the second relay unit; the first ends of the coil pieces of the third coil are connected to the inverter circuit without passing through the first relay unit and the second relay unit; the second ends of the coil pieces are connected to one connection point connected to the inverter circuit; The induction heating cooker according to any one of claims 1 to 9.

15. a plurality of opening relays each connected to the inverter circuit; each of the first coil, the second coil, and the third coil has a plurality of coil pieces; Each of the coil pieces has an electric wire wound a plurality of times, the electric wire having a first end and a second end connected to the inverter circuit, the first ends of the coil pieces of the first coil are connected to the inverter circuit via the first relay unit; the first ends of the coil pieces of the second coil are connected to the inverter circuit via the second relay unit; the first ends of the coil pieces of the third coil are connected to the inverter circuit without passing through the first relay unit and the second relay unit; a second end of each of the plurality of coil pieces of the first coil and the second coil is connected to the inverter circuit via any one of the plurality of opening relays; The induction heating cooker according to any one of claims 1 to 9.

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