Induction heating conditioner

Abstract

To provide an induction heating cooker which can efficiently heat a heating object with the use of a plurality of heating coils.SOLUTION: An induction heating cooker comprises: a top plate; a coil unit disposed under the top plate; a controller which controls the heating of a heating object. The coil unit has a plurality of coil pieces disposed in a heating region where the heating object is heated. The heating region has a plurality of coil arrangement regions which are defined by: an outer circumferential line defining the outer circumference; and a plurality of boundary lines radially extending from the center. The plurality of coil pieces are disposed inside the plurality of coil arrangement regions. The controller controls the heating of the heating object while flowing currents to all of the plurality of coil pieces.SELECTED DRAWING: Figure 2

Description

[[Technical Field]]

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

[0002] Conventionally, induction heating cookers having a plurality of heating coils have been known. For example, Patent Document 1 describes an induction heating device that drives a relay when detecting that a load is placed on a top plate, supplies high-frequency current to a plurality of heating coils, and heats the load. [[Prior Art Documents]] [[Patent Documents]]

[0003] [[Patent Document 1]] Japanese Patent Application Laid-Open No. 2021-141082 [[Summary of the Invention]] [[Problem to be Solved by the Invention]]

[0004] In recent years, induction heating cookers have been required to efficiently heat an object to be heated using a plurality of heating coils.

[0005] An object of the present disclosure is to provide an induction heating cooker that can efficiently heat an object to be heated by a plurality of heating coils. [[Means for Solving the Problem]]

[0006] The induction heating cooker according to this disclosure comprises a top plate, a coil unit disposed below the top plate, and a controller that controls the heating of an object by the coil unit. The coil unit comprises a plurality of coil pieces arranged in a heating region for heating an object in a plan view. The heating region has a plurality of coil arrangement regions defined in a plan view by an outer peripheral line defining the outer periphery of the heating region and a plurality of boundary lines extending radially from the center of the heating region toward the outer periphery. The plurality of coil pieces are arranged within the plurality of coil arrangement regions in a plan view. The controller controls the heating of the object by supplying current to all of the plurality of coil pieces. [Effects of the Invention]

[0007] According to this disclosure, it is possible to provide an induction heating cooker that can efficiently heat an object to be heated using multiple heating coils. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic perspective view of an example of an induction heating cooker according to Embodiment 1 of the present disclosure. [Figure 2] This is a plan view of an example of a coil unit according to Embodiment 1 of the present disclosure. [Figure 3] Figure 2 is a schematic enlarged view of the coil pieces that make up the coil unit. [Figure 4] This is a block diagram of an example of the configuration of an induction cooker according to Embodiment 1 of the present disclosure. [Figure 5] This is a circuit diagram of an example of an induction heating cooker according to Embodiment 1 of the present disclosure. [Figure 6] This graph shows an example of a current waveform when the phase difference between the currents flowing through adjacent parts of two coil pieces is 0°. [Figure 7] This graph shows an example of a current waveform when the phase difference between the currents flowing in adjacent parts of two coil pieces is 180°. [Figure 8]This is a schematic diagram showing an example of a heating region controlled by the first heating mode in the induction heating cooker of Embodiment 1 according to the present disclosure. [Figure 9] This is an example distribution diagram of the temperature of an object heated using the first heating mode. [Figure 10] This is a schematic diagram showing another example of a heating region controlled by the second heating mode in the induction heating cooker of Embodiment 1 according to the present disclosure. [Figure 11] This is an example of a temperature distribution diagram of an object heated using the second heating mode. [Figure 12] This is an example of a temperature distribution diagram of an object heated using the third heating mode. [Figure 13] This is an example of a temperature distribution diagram of an object heated using the fourth heating mode. [Figure 14] This is an example distribution diagram of the temperature of an object heated using the fifth heating mode. [Figure 15A] This graph shows an example of the temperature change of an object when it is heated using a conventional induction cooker with a heating coil. [Figure 15B] This graph shows an example of the temperature change of an object when it is heated using the induction heating cooker of Embodiment 1 of this implementation. [Figure 16] This is a circuit diagram of another example of the induction heating cooker according to Embodiment 1 of the present disclosure. [Figure 17] This is a circuit diagram of yet another example of the induction heating cooker according to Embodiment 1 of the present disclosure. [Figure 18] This is a circuit diagram of yet another example of the induction heating cooker according to Embodiment 1 of the present disclosure. [Modes for carrying out the invention]

[0009] Hereinafter, embodiments according to 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 embodiments. Even in embodiments other than these, various modifications can be made according to the design as long as they do not depart from the technical idea of the present disclosure.

[0010] Conventionally, an induction heating cooker having a plurality of heating coils has a heating region, and the plurality of heating coils are disposed in the heating region. In this case, the conventional induction heating cooker controls heating within the heating region by switching whether to supply a high-frequency current to the heating coils or not, for example, by turning a relay on / off. In the conventional induction heating cooker, the intensity of heating within the heating region is locally changed or the overall heating power within the heating region is changed, for example, by stopping power supply to some of the heating coils.

[0011] As described above, in the conventional induction heating cooker, since there are heating coils that are not energized under heating control, it is difficult to perform heating at high output. In addition, the conventional induction heating cooker produces local changes in heating intensity within the heating region depending on whether power is supplied to the heating coils or not, so there are few modes of local change. Furthermore, since the intensity of heating within the heating region is switched depending on whether power is supplied to the heating coils or not, the conventional induction heating cooker has a low response speed for heating control. In addition, the conventional induction heating cooker cannot detect magnetic coupling between the non-energized heating coil and the object to be heated, so it cannot reflect the reaction from the object to be heated in heating control. Further, the conventional induction heating cooker cannot control local heating intensity in a region heated by a single heating coil. Still further, the conventional induction heating cooker cannot heat the portion of the object to be heated placed above the gap between a plurality of heating coils.

[0012] (Embodiment 1) FIG. 1 is a schematic perspective view of an example of an induction heating cooker 1 according to Embodiment 1 of the present disclosure. FIG. 2 is a plan view of an example of a coil unit 4 according to Embodiment 1 of the present disclosure. As shown in FIG. 1, the induction heating cooker 1 according to the present disclosure includes a top plate 2, a coil unit 4 disposed below the top plate 2, and a controller 5 that controls heating of a heating target object by the coil unit 4. As shown in FIG. 2, the coil unit 4 includes a plurality of coil pieces 10A to 10F disposed in a heating region S0 for heating a heating target object in plan view. The heating region S0 has a plurality of coil arrangement regions S1 to S6 defined in plan view by an outer peripheral line L10 defining an outer periphery of the heating region S0, and a plurality of boundary lines L1 to L6 extending radially from a center C1 of the heating region S0 toward the outer periphery. The plurality of coil pieces 10A to 10F are disposed in the plurality of coil arrangement regions (S1 to S6) in plan view. Each of the plurality of coil pieces has a coil wire disposed in plan view along two adjacent boundary lines among the plurality of boundary lines (L1 to L6), and the outer peripheral line L10 connecting the two adjacent boundary lines. The controller 5 controls heating of the heating target object while supplying current to all of the plurality of coil pieces 10A to 10F.

[0013] According to this configuration, the induction heating cooker 1 can efficiently heat a heating target object. Specifically, the heating region S0 is divided into a plurality of coil arrangement regions S1 to S6 by the plurality of boundary lines L1 to L6 and the outer peripheral line L10. In each of the plurality of coil arrangement regions S1 to S6, a coil wire 11 constituting the coil piece 10 is disposed along two adjacent boundary lines and the outer peripheral line L10 connecting the two adjacent boundary lines. Accordingly, the coil wire 11 of the coil piece 10 is disposed from the center C1 of the heating region S0 toward the outer periphery in plan view, so that the induction heating cooker 1 according to Embodiment 1 can reduce uneven heating. In addition, the gap between the plurality of coil pieces 10 can be reduced, and variation in the gap can be reduced.

[0014] Furthermore, according to the induction heating cooker 1 of this disclosure, the controller 5 controls the heating of the object to be heated while supplying current to all of the coil pieces 10A to 10F. Therefore, since the controller 5 energizes all of the coil pieces 10A to 10F, it is possible to avoid current concentration in one of the coil pieces 10A to 10F, and the object to be heated can be heated with overall high output. In addition, since all of the coil pieces 10A to 10F are constantly energized, the response speed is fast. Therefore, each coil piece 10A to 10F can respond quickly to instructions from the controller 5. Moreover, the controller 5 can control the response speed of each coil piece 10A to 10F by, for example, continuously and progressively changing the current parameter.

[0015] [Overall structure] The induction heating cooker 1 will be described using Figure 1. The XYZ coordinate system shown in the figure is included to aid in understanding the invention and is not intended to limit it. The X and Y axes represent the horizontal direction, and the Z axis represents the vertical direction.

[0016] As shown in Figure 1, the induction cooker 1 is a cooker that induces heating of a cooking container C containing a food to be cooked T. In this specification, the cooking container C is described as an example of a food to be heated. The food to be heated is not limited to the cooking container C, but can be any food that is to be induction heated.

[0017] The induction heating cooker 1 has a top plate 2 on which a cooking container C is placed, made of, for example, heat-resistant glass, and a housing 3 attached to the underside of the top plate 2. Inside the housing 3 are multiple coil units 4, a controller 5, and an input / output interface device 6. Each of the multiple coil units 4 is positioned below the top plate 2 and induces heating of the cooking container C placed on the opposite portion of the top plate 2. That is, each of the multiple coil units 4 functions as an induction heating coil unit. The controller 5 can control the multiple coil units 4. The user can operate the multiple coil units 4 by operating the input / output interface device 6, which is controlled by the controller 5.

[0018] [Coil Unit] The coil unit 4 will be described below using Figures 2 and 3.

[0019] As shown in Figure 2, the coil unit 4 comprises multiple coil pieces 10A to 10F. These multiple coil pieces 10A to 10F are components corresponding to the heating coils of conventional induction cookers. Hereafter, when it is not necessary to distinguish between the multiple coil pieces 10A to 10F, they will be collectively referred to as coil piece 10 or multiple coil pieces 10.

[0020] Multiple coil pieces 10 are arranged in a heating region S0 that heats an object to be heated in a plan view. In this specification, "plan view" means a view from the vertical direction, i.e., the Z-axis direction. The heating region S0 is a closed region having a center C1 in a plan view, and is the region in which the multiple coil pieces 10 are arranged. In Embodiment 1, the heating region S0 is formed in a circular shape in a plan view. Alternatively, the heating region S0 may be the region in which the cooking container C shown on the upper surface of the top plate 2 is placed.

[0021] The heating region S0 is not limited to being circular in plan view. For example, the heating region S0 may be rectangular, elliptical, or regular polygonal in plan view. If the heating region S0 is rectangular in plan view, the center C1 of the heating region S0 is the intersection of the diagonals. If the heating region S0 is elliptical in plan view, the center C1 of the heating region S0 is the intersection of the major axis and the minor axis. If the heating region S0 is a regular polygon in plan view, the center C1 of the heating region S0 is the center of the inscribed circle that is tangent to all the outer sides constituting the regular polygon.

[0022] The heating region S0 has multiple coil arrangement regions S1 to S6. In a plan view, the multiple coil arrangement regions S1 to S6 are arranged radially and adjacent to each other with respect to the center C1 of the heating region S0. Specifically, in a plan view, the multiple coil arrangement regions S1 to S6 are defined by multiple boundary lines L1 to L6 that extend radially from the center C1 of the heating region S0 toward the outer periphery, and by an outer periphery line L10 that defines the outer periphery of the heating region S0. In a plan view, the multiple coil arrangement regions S1 to S6 are formed in a fan shape.

[0023] In Embodiment 1, the multiple boundary lines L1 to L6 are arranged radially at equal intervals with respect to the center C1 of the heating region S0 in a plan view. The multiple boundary lines L1 to L6 are straight lines extending from the center C1 of the heating region S0 toward the outer circumference in a plan view. The angles formed by two adjacent boundary lines L1 to L6 are approximately the same. As a result, in a plan view, the multiple coil arrangement regions S1 to S6 have approximately the same shape and approximately the same size. In this specification, "approximately" means an error of 10% or less, preferably an error of 5% or less.

[0024] In Embodiment 1, the multiple boundary lines consist of six boundary lines L1 to L6, and the angle between two adjacent boundary lines is 60 degrees. As a result, the heating region S0 is divided into six coil arrangement regions S1 to S6 that are substantially the same shape and size in a plan view.

[0025] Multiple coil pieces 10 are arranged within multiple coil arrangement regions S1 to S6 in a plan view. Specifically, one coil piece 10 is arranged within one coil arrangement region. As a result, the multiple coil pieces 10 are arranged radially and adjacent to each other within the heating region S0 in a plan view.

[0026] Each of the multiple coil pieces 10 has a coil wire 11 that is wound and arranged within each of the multiple coil arrangement regions S1 to S6. In a plan view, the coil wire 11 is arranged along two adjacent boundary lines L1 to L6 and an outer perimeter line L10 that connects the two adjacent boundary lines. Within the coil arrangement regions S1 to S6, the coil wire 11 is arranged along the lines L1 to L6 and L10 that define the coil arrangement regions S1 to S6, and is wound inward.

[0027] In Embodiment 1, the multiple coil pieces 10 have substantially the same shape and substantially the same size in a plan view.

[0028] Figure 3 is a schematic enlarged view of the coil piece 10 that constitutes the coil unit 4 in Figure 2. Figure 3 shows the coil piece 10A placed in the coil arrangement region S1. Coil arrangement regions S2 to S6 have the same configuration as coil arrangement region S1, so their explanation is omitted. Also, coil pieces 10B to 10F have the same configuration as coil piece 10A, so their explanation is omitted.

[0029] As shown in Figure 3, the coil piece 10A placed in the coil placement region S1 has a coil wire 11 that, in a plan view, is arranged along two adjacent boundary lines L1 and L2 and an outer peripheral line L10 connecting the two adjacent boundary lines L1 and L2. The coil wire 11 is made of a conductive material.

[0030] In a plan view, the coil wire 11 is arranged to circle around the coil arrangement region S1 along the boundary lines L1, L2 and the outer circumference line L10. In a plan view, the coil wire 11 is arranged in a frame shape. In Embodiment 1, since the coil arrangement region S1 is formed in a fan shape in a plan view, the outer shape of the coil wire 11 is formed in a fan shape in a plan view.

[0031] In Embodiment 1, the coil wire 11 has a first coil wire section 20, a second coil wire section 30, and a third coil wire section 40. The first coil wire section 20, the second coil wire section 30, and the third coil wire section 40 are integrally formed. The first coil wire section 20, the second coil wire section 30, and the third coil wire section 40 have approximately the same wire diameter. Each of the first coil wire section 20, the second coil wire section 30, and the third coil wire section 40 is a wire section in which multiple metal wires are twisted together and wound around multiple turns. For example, the wire section is made by twisting together about 20 copper wires with a diameter of 0.2 mm and winding them around about 60 turns. Note that the diameter of the metal wire is not limited to 0.2 mm and may be set as appropriate. For example, the diameter of the metal wire may be appropriately selected within the range of 0.01 mm to 0.5 mm. Also, the material of the metal wire is not limited to copper, but may be aluminum or a copper and aluminum clad material, for example. Furthermore, the number of wires bundled together (i.e., the so-called number of cores) is not limited to 20, but may be selected as appropriate. For example, the number of cores may be selected as appropriate within the range of 5 to 50. Also, the number of turns of the wire section is not limited to 10, but may be set as appropriate. For example, the number of turns may be selected as appropriate within the range of 5 to 20.

[0032] The first coil wire section 20 is arranged along two adjacent boundary lines L1 and L2 and the outer circumference line L10 in a plan view. The first coil wire section 20 is the outermost part of the coil wire 11 of the coil piece 10 in a plan view. The first coil wire section 20 is formed in a frame shape in a plan view. The outer shape of the first coil wire section 20 is formed in a fan shape in a plan view.

[0033] Specifically, the first coil wire section 20 has straight sections 21 and 22, a curved section 23, and connecting sections 24, 25, and 26. The straight section 21 is a substantially straight coil section arranged along the boundary line L1. The straight section 22 is a straight coil section arranged along the boundary line L2. The curved section 23 is a curved coil section arranged along the outer circumference line L10. The connecting section 24 is a coil section that connects one end of the straight section 21 and one end of the straight section 22 on the center C1 side of the heating region S0 in a plan view. The connecting section 25 is a coil section that connects the other end of the straight section 21 and one end of the curved section 23 on the outer circumference line L10 side of the heating region S0 in a plan view. The connecting section 26 is a coil section that connects the other end of the straight section 22 and the other end of the curved section 23 on the outer circumference line L10 side of the heating region S0 in a plan view. The connecting sections 24, 25, and 26 have, for example, a U-shaped curved form.

[0034] In this specification, "arranged along boundary lines L1, L2 or outer perimeter line L10" means, unless otherwise specified, that there are no other components interfering with boundary lines L1, L2 or outer perimeter line L10, and that the component extends in substantially the same direction as the boundary lines L1, L2 or outer perimeter line L10.

[0035] The second coil wire section 30 is positioned inside the first coil wire section 20 in a plan view. In Embodiment 1, the second coil wire section 30 is positioned along the inside of the first coil wire section 20 in a plan view. The second coil wire section 30 is formed in a frame shape along the inside of the first coil wire section 20 in a plan view. The outer shape of the second coil wire section 30 is formed in a fan shape in a plan view.

[0036] Specifically, the second coil wire section 30 has straight sections 31 and 32, a curved section 33, and connecting sections 34, 35, and 36. The straight section 31 is a straight coil portion arranged along the straight section 21 of the first coil wire section 20. The straight section 32 is a straight coil portion arranged along the straight section 22 of the first coil wire section 20. The curved section 33 is a curved coil portion arranged along the curved section 23 of the first coil wire section 20. The connecting section 34 is a coil portion that connects one end of the straight section 31 and one end of the straight section 32 on the center C1 side of the heating region S0 in a plan view. The connecting section 35 is a coil portion that connects the other end of the straight section 31 and one end of the curved section 33 on the outer circumference line L10 side of the heating region S0 in a plan view. The connecting section 36 is a coil portion that connects the other end of the straight section 32 and the other end of the curved section 33 on the outer circumference line L10 side of the heating region S0 in a plan view. The connecting parts 34, 35, and 36 have, for example, a U-shaped curved form.

[0037] The third coil wire section 40 is positioned inside the second coil wire section 30 in a plan view. In Embodiment 1, the third coil wire section 40 is positioned along the inside of the second coil wire section 30 in a plan view. The third coil wire section 40 is formed in a frame shape along the inside of the second coil wire section 30 in a plan view. The outer shape of the third coil wire section 40 is formed in a fan shape in a plan view.

[0038] Specifically, the third coil wire section 40 has straight sections 41 and 42, a curved section 43, and connecting sections 44, 45, and 46. The straight section 41 is a straight coil portion arranged along the straight section 31 of the second coil wire section 30. The straight section 42 is a straight coil portion arranged along the straight section 32 of the second coil wire section 30. The curved section 43 is a curved coil portion arranged along the curved section 33 of the second coil wire section 30. The connecting section 44 is a coil portion that connects one end of the straight section 41 and one end of the straight section 42 on the center C1 side of the heating region S0 in a plan view. The connecting section 45 is a coil portion that connects the other end of the straight section 41 and one end of the curved section 43 on the outer circumference line L10 side of the heating region S0 in a plan view. The connecting section 46 is a coil portion that connects the other end of the straight section 42 and the other end of the curved section 43 on the outer circumference line L10 side of the heating region S0 in a plan view. The connecting parts 44, 45, and 46 have, for example, a U-shaped curved form.

[0039] In Embodiment 1, the straight sections 21, 31, and 41 are arranged approximately parallel to each other. The straight sections 22, 32, and 42 are arranged approximately parallel to each other. The curved sections 23, 33, and 43 are arranged facing each other.

[0040] Figure 4 is a block diagram of an example of the configuration of an induction cooker 1 according to Embodiment 1 of the present disclosure. As shown in Figure 4, the induction cooker 1 comprises three coil units 4, a controller 5, and an input / output interface device 6.

[0041] [controller] Controller 5 is a control device that controls the operation of the induction cooker 1. Specifically, Controller 5 can control the operation of each coil unit 4. Controller 5 comprises an arithmetic circuit 7 and a memory device 8.

[0042] The arithmetic circuit 7 executes processing in the controller 5. The arithmetic circuit 7 includes a general-purpose processor such as a CPU or MPU that realizes predetermined functions by executing a program. The arithmetic circuit 7 is configured to communicate with the storage device 8 and realizes various processing in the controller 5 by calling and executing arithmetic programs etc. stored in the storage device 8. Processing in the controller 5 includes, for example, controlling the local intensity of heating by multiple coil pieces, outputting control signals to the inverter circuit 53 described later, or acquiring temperature information described later. The arithmetic circuit 7 is not limited to a configuration in which hardware resources and software cooperate to realize predetermined functions, but may also be a hardware circuit specifically designed to realize predetermined functions. That is, the arithmetic circuit 7 can be realized with various processors other than CPUs and MPUs, such as GPUs, FPGAs, DSPs, and ASICs. Such an arithmetic circuit 7 may be composed of, for example, a signal processing circuit which is a semiconductor integrated circuit.

[0043] The storage device 8 is a storage medium capable of storing various types of information. The storage device 8 can be implemented as, for example, memory such as DRAM, SRAM, or flash memory, an HDD, an SSD, or other storage devices, or a combination thereof as appropriate. The storage device 8 stores programs for implementing the various processes performed by the arithmetic circuit 7 as described above. The storage device 8 can also store information acquired by the controller 5 through multiple coil pieces 10, such as temperature information, which will be described later.

[0044] [Input / Output Interface Device] The input / output interface device 6 functions as an input device for receiving information from the user and an output device for outputting information to the user. The input / output interface device 6 may include an operation panel for the user to operate the induction cooker 1, buttons for the user to change the heat level, and a display and speaker for informing the user of the status of the induction cooker 1. For example, the user can change a predetermined sequence, which will be described later, by operating the input / output interface device 6.

[0045] [circuit] Figure 5 is a circuit diagram of an example of an induction heating cooker 1 according to Embodiment 1 of the present disclosure. As described above, the induction heating cooker 1 comprises a plurality of coil pieces 10A to 10F that constitute a coil unit 4. The induction heating cooker 1 also includes a diode bridge 51, a smoothing capacitor 52, a plurality of inverter circuits 53A to 53F, and a plurality of resonant capacitors 54A to 54F, 55A to 55F as electronic components for realizing heating by the plurality of coil pieces 10A to 10F. The induction heating cooker 1 may have circuits with the same configuration for each of the plurality of coil units 4, or it may have circuits with different configurations. Hereinafter, when it is not necessary to distinguish between the plurality of inverter circuits 53A to 53F, they will be collectively referred to as inverter circuit 53 or plurality of inverter circuits 53. Hereinafter, when it is not necessary to distinguish between the plurality of resonant capacitors 54A to 54F, they will be collectively referred to as resonant capacitor 54 or plurality of resonant capacitors 54. Hereafter, when it is not necessary to distinguish between multiple resonant capacitors 55A to 55F, they will be collectively referred to as resonant capacitor 55 or multiple resonant capacitors 55.

[0046] The diode bridge 51 is connected to an AC power supply (for example, a 100V or 200V commercial AC power supply) 50, and fully rectifies the AC voltage input from the AC power supply to convert it into a pulsating DC voltage, which is then applied between the wirings 56a and 56b.

[0047] The smoothing capacitor 52 is connected between wirings 56a and 56b and smooths the voltage applied from the diode bridge 51.

[0048] Inverter circuit 53A has switching elements 57A and 58A connected in series between wiring 56a and 56b. Each switching element 57A and 58A has an IGBT and a diode connected in antiparallel to the IGBT. Each switching element 57A and 58A switches on / off based on a control signal received from controller 5. Inverter circuits 53B to 53F have switching elements 57B to 57F and switching elements 58B to 58F. Inverter circuits 53B to 53F have the same configuration as inverter circuit 53A, so their description is omitted. Each of the switching elements 57B to 57F and switching elements 58B to 58F has the same configuration as switching elements 57A and 58A, so their description is omitted.

[0049] The resonant capacitors 54A and 55A are connected in series between wiring 56a and 56b. Each of the resonant capacitors 54B to 54F and 55B to 55F is configured in the same way as resonant capacitors 54A and 55A.

[0050] Coil piece 10A has one end connected between switching elements 57A and 58A, and the other end connected between resonant capacitors 54A and 55A. Coil piece 10 is controlled so that a high-frequency current with predetermined parameters flows when the switching elements 57A and 58A are switched on or off. The other coil pieces 10B to 10F have the same configuration as coil piece 10A, so their description is omitted.

[0051] The controller 5 can control the operation of the inverter circuit 53 to control the current flowing through the multiple coil pieces 10 of the coil unit 4. Specifically, the controller 5 can control the operation of the inverter circuit 53 so that a high-frequency current always flows through the multiple coil pieces 10 when the object to be heated is heated by the coil unit 4. The controller 5 can switch heating modes by controlling the current flowing through each coil piece 10. In Embodiment 1 of this disclosure, the circuit of the coil unit 4 includes, but is not limited to, multiple inverter circuits 53, and may be configured so that the current flowing through the multiple coil pieces 10 is controlled by a single inverter circuit.

[0052] [Operation] Next, the operation of the induction heating cooker 1 of Embodiment 1 according to this disclosure will be described.

[0053] The induction cooker 1 of Embodiment 1 according to this disclosure can control the localized heating intensity when heating an object placed on the top plate 2 on the coil unit 4. For example, the controller 5 of the induction cooker 1 can control the localized heating intensity by heating the object using one or more heating modes. A heating mode indicates a heating method that locally creates areas of strong heating or weak heating. Therefore, when the controller 5 controls the object to be heated using a predetermined heating mode, a predetermined part of the object corresponding to that predetermined heating mode may be heated more strongly than other parts. The heating mode can be stored in the storage device 8, for example, along with the current parameters that realize that heating mode. Note that the controller 5 does not necessarily have to use predetermined heating modes to control the localized heating intensity. For example, the storage device 8 may store current parameters that can strongly (or weakly) heat a predetermined area, and if there are multiple areas that need to be heated strongly, the controller may combine the stored information to control the heating.

[0054] The following describes an example of how the controller 5 according to this embodiment 1 controls the localized intensity of heating on the object to be heated.

[0055] In the induction cooker 1, the multiple coil pieces 10 are arranged within multiple coil arrangement regions defined by an outer circumference line defining the outer perimeter of the heating region and multiple boundary lines extending radially from the center of the heating region toward the outer perimeter, as described above. For example, two adjacent coil pieces 10A and 10B are arranged within two adjacent coil arrangement regions S1 and S2, respectively. Coil arrangement regions S1 and S2 are defined by a shared boundary line L2. Therefore, a portion of coil piece 10A and a portion of coil piece 10B are arranged along the boundary line L2.

[0056] The controller 5 can control the currents flowing through coil pieces 10A and 10B such that the current flowing through the portion of coil piece 10A along the boundary line L2 and the current flowing through the portion of coil piece 10B along the boundary line L2 have a predetermined phase difference. The portion of coil piece 10A along the boundary line L2 corresponds to the straight portions 22, 32, and 42 of the coil wire 11 shown in Figure 3. The portion of coil piece 10B along the boundary line L2 corresponds to the straight portions 21, 31, and 41 of the coil wire 11 when coil piece 10A shown in Figure 3 is considered to be coil piece 10B.

[0057] For example, the controller 5 can control the current so that it has a phase difference of 0° as a predetermined phase difference, that is, so that it is in phase. By controlling the current in this way, the controller 5 can heat the portion of the object to be heated that is placed in the region corresponding to the adjacent parts of coil piece 10A and coil piece 10B more strongly than the other parts of the object to be heated. More specifically, the controller 5 can heat the portion of the object to be heated more strongly than the portion of the object placed in the region corresponding to the other parts of coil piece 10A and coil piece 10B.

[0058] The region corresponding to adjacent parts is, for example, the region located vertically above (in the Z direction in Figure 1) that part on the top plate 2. The region corresponding to other parts is, for example, the region located vertically above parts other than adjacent parts of coil pieces 10A and 10B (such as the central part or the outer periphery) on the top plate 2.

[0059] Figure 6 is a graph showing an example of current waveforms when the phase difference between the currents flowing to adjacent parts of two adjacent coil pieces is 0°. More specifically, Figure 6(a) is a graph showing the current waveform flowing along the boundary line L2 in coil piece 10A. Figure 6(b) is a graph showing the current waveform flowing along the boundary line L2 in coil piece 10B. Each current waveform shown in Figure 6 has the same frequency and amplitude, but is not limited to these. In the current waveforms shown in Figure 6, the case where the current flows clockwise in coil piece 10A and coil piece 10B is shown as the positive direction current. As shown in Figure 6, the controller 5 can control the current so that the phase difference between the currents flowing to adjacent parts is 0° by controlling the inverter circuit 53 so that the current flowing in coil piece 10A and the current flowing in coil piece 10B flow in opposite directions.

[0060] Furthermore, for example, the controller 5 can control the current to have a phase difference of 180° as a predetermined phase difference. By controlling the current in this way, the controller 5 can heat the portion of the object to be heated that is placed in the region corresponding to the outer periphery of coil piece 10A and coil piece 10B more strongly than other parts of the object to be heated. More specifically, the controller 5 can heat the portion of the object to be heated more strongly than the portion of the object placed in the region corresponding to the interior of coil piece 10A and coil piece 10B.

[0061] The region corresponding to the outer periphery is, for example, the region located vertically above (in the Z direction in Figure 1) the coil pieces 10A and 10B on the top plate 2. The region corresponding to the interior is, for example, the region located vertically above the interior of the coil pieces 10A and 10B on the top plate 2. The region corresponding to the interior may also be the region on the top plate 2 that is surrounded by the region corresponding to the outer periphery.

[0062] Figure 7 is a graph showing an example of current waveforms when the phase difference between the currents flowing to adjacent parts of two adjacent coil pieces is 180°. More specifically, Figure 7(a) is a graph showing the current waveform flowing along the boundary line L2 in coil piece 10A. Figure 7(b) is a graph showing the current waveform flowing along the boundary line L2 in coil piece 10B. Each current waveform shown in Figure 7 has the same frequency and amplitude, but is not limited to these. In the current waveforms shown in Figure 7, the case where the current flows clockwise in coil piece 10A and coil piece 10B is shown as the positive direction current. As shown in Figure 7, the controller 5 can control the current so that the phase difference between the currents flowing to adjacent parts is 180° by controlling the inverter circuit 53 so that the current flowing in coil piece 10A and the current flowing in coil piece 10B flow in the same direction.

[0063] The predetermined phase difference is not limited to 0° or 180°, but may be 30°, 45°, 60°, or 90°. Furthermore, the predetermined phase difference may be any other difference.

[0064] Furthermore, the controller 5 can control the local intensity of heating on the object to be heated by controlling the inverter circuit 53 so that there is a predetermined frequency difference between the currents flowing through two adjacent coil pieces. That is, the controller 5 can control the local intensity of heating on the object to be heated by controlling the inverter circuit 53 so that there is a predetermined frequency difference between the current flowing through coil piece 10A and the current flowing through coil piece 10B. The controller 5 can control the frequency difference between the current flowing through coil piece 10A and the current flowing through coil piece 10B, for example, to be 0, or to be an integer multiple of 1 or more of the frequency of the current flowing through one of the coil pieces 10. That is, the frequency difference can be an integer multiple of 0 or more of the frequency of the current flowing through one of the coil pieces 10. However, the frequency difference is not limited to these, and the controller 5 may control the inverter circuit 53 so that the frequency difference is not an integer multiple of 0 or more. For example, the controller 5 may control the frequency and phase of the current so that the peaks of the amplitudes of the currents flowing through each coil piece 10 match at least partially.

[0065] In this way, the controller 5 can control the local intensity of heating of the object to be heated by supplying a current having predetermined parameters to each coil piece 10. Therefore, by controlling the current, the controller 5 can heat the object to be heated placed on the top plate 2 in a predetermined heating mode. The parameters include the amplitude, phase, and frequency of the current. The controller 5 can control the parameters of the current flowing through each coil piece 10, for example, by controlling the on / off state of the inverter circuit 53. In Embodiment 1 of this disclosure, the predetermined heating mode includes, but is not limited to, the first heating mode to the fifth heating mode.

[0066] Figure 8 is a schematic diagram showing an example of a heating region controlled by the first heating mode in an induction heating cooker according to Embodiment 1 of the present disclosure. Figure 8 shows six coil pieces 10A to 10F as a coil unit 4. The multiple coil pieces 10A to 10F shown in Figure 8 correspond to the multiple coil pieces 10A to 10F shown in Figure 2. In Figure 8, for simplicity, the first coil wire section 20, the second coil wire section 30, and the third coil wire section 40 shown in Figure 3 are omitted, and the multiple coil pieces 10 are shown as a single coil wire. Note that the shape of the coil piece 10 is not limited to this, and for example, another coil wire may be arranged in the central part of each of the multiple coil pieces 10. In Figure 8, region S21 is a region in which the object to be heated can be heated strongly. Region S21 is located in the adjacent parts of two adjacent coil pieces.

[0067] The controller 5 can heat a portion of the object placed in the region corresponding to region S21 more strongly than other parts of the object by supplying a current with parameters, for example, shown in Table 1, to each coil piece 10. The parameters shown in Table 1 will henceforth be referred to as the first parameters. The portion of the object placed in the region corresponding to region S21 is, for example, the portion of the top plate 2 located vertically above region S21 (in the Z direction in Figure 1).

[0068] [Table 1]

[0069] In Table 1, the relationship between the parameters of the current flowing to adjacent parts represents the relationship between the parameters of the current flowing to adjacent parts in two adjacent coil pieces (for example, coil piece 10A and coil piece 10B). This relationship is the same in Tables 2 to 6 described later. As shown in Table 1, in the first parameter, the currents flowing to adjacent parts have equivalent amplitude. In the first parameter, the currents flowing to adjacent parts have the same phase (i.e., a phase difference of 0°). In the first parameter, the currents flowing to adjacent parts have the same frequency. The controller 5 can heat the object to be heated in the first heating mode by controlling the current so that the first parameter shown in Table 1 is met for all pairs of adjacent coil pieces.

[0070] Figure 9 is a distribution diagram of an example of the temperature of an object heated by the first heating mode. Figure 9 shows the object viewed from diagonally above. Figures 11 to 14, which will be described later, also show the object viewed from diagonally above, similar to Figure 9. In Figure 9, region S22 is the region of the object that is hotter (i.e., the region that is strongly heated). As shown in Figure 9, the central part of the object is hotter than the surrounding part of the central part. Therefore, it can be seen that the central part of the object is heated more strongly than the surrounding part of the central part. Specifically, the region that is strongly heated by the first heating mode corresponds to the adjacent parts of two adjacent coil pieces, as shown in Figure 8.

[0071] Figure 10 is a schematic diagram showing an example of a heating region controlled by the second heating mode in an induction heating cooker according to Embodiment 1 of the present disclosure. Figure 10 shows six coil pieces 10A to 10F as a coil unit 4. In Figure 10, region S 23 This is a region where the object to be heated can be heated strongly. Region S23 is located on the outer circumference of the multiple coil pieces 10 (i.e., the outer circumference of the coil unit 4).

[0072] The controller 5 can heat a portion of the object placed in the region corresponding to region S23 more strongly than other parts of the object by supplying a current with parameters, for example, shown in Table 2, to each coil piece 10. The parameters shown in Table 2 will henceforth be referred to as the second parameter. The portion of the object placed in the region corresponding to region S23 is, for example, the portion of the top plate 2 located vertically above region S23 (in the Z direction in Figure 1).

[0073] [Table 2]

[0074] As shown in Table 2, in the second parameter, the currents flowing to adjacent parts have equivalent amplitudes. In the second parameter, the currents flowing to adjacent parts have opposite phases (i.e., a phase difference of 180°). In the second parameter, the currents flowing to adjacent parts have the same frequency. The controller 5 can heat the object to be heated in the second heating mode by controlling the current so that the second parameter shown in Table 2 is met for all pairs of adjacent coil pieces.

[0075] Figure 11 is a distribution diagram of an example of the temperature of an object when it is heated using the second heating mode. In Figure 11, region S24 is a region of the object with a high temperature (i.e., a region that is strongly heated). As shown in Figure 11, the central part of the object is at a lower temperature than the surrounding part. Therefore, it can be seen that the surrounding part of the object is heated more strongly than the central part. Specifically, the region that is strongly heated by the second heating mode corresponds to the outer circumference of the multiple coil pieces 10, as shown in Figure 10.

[0076] Furthermore, the controller 5 can heat the object to be heated in heating modes other than the first and second heating modes. For example, the controller 5 can heat the object to be heated in the third heating mode by supplying a current having the parameters shown in Table 3 to each coil piece 10. The parameters shown in Table 3 will henceforth be referred to as the third parameters.

[0077] [Table 3]

[0078] As shown in Table 3, in the third parameter, the currents flowing through adjacent parts have different amplitudes. In the third parameter, the currents flowing through adjacent parts have the same phase (i.e., a phase difference of 0°). In the third parameter, the currents flowing through adjacent parts have the same frequency. The controller 5 can heat the object to be heated in the third heating mode by controlling the current so that the third parameter shown in Table 3 is met for all pairs of adjacent coil pieces.

[0079] In the third heating mode, the controller 5 controls the current so that coil pieces with large current amplitudes and coil pieces with small current amplitudes are arranged alternately. Therefore, in the third heating mode, the amplitude of the current flowing through each coil piece 10 has one of two values. However, as will be described later, the controller 5 may control the current so that the type of current amplitude is a value selected from three or more values ​​in order to control heating in other heating modes.

[0080] Figure 12 is a distribution diagram of an example of the temperature of an object when it is heated by the third heating mode. In Figure 12, region S25 is a region where the temperature of the object is high (i.e., a region that is strongly heated). As shown in Figure 12, a part of the central portion of the object is hotter than the surrounding portion of the central portion. For example, in the coil unit 4 shown in Figure 8, coil pieces 10B, 10D and 10 FIf the amplitude of the current flowing through is greater than the amplitude of the current flowing through coil pieces 10A, 10C, and 10E, the object to be heated can be heated in this manner. The controller 5 can change the intensity of heating to the object to be heated and the area that is heated strongly by changing the amplitude of the current flowing through each coil piece 10.

[0081] Furthermore, for example, the controller 5 can heat the object to be heated in the fourth heating mode by supplying a current having the parameters shown in Table 4 to each coil piece 10. The parameters shown in Table 4 will henceforth be referred to as the fourth parameters.

[0082] [Table 4]

[0083] As shown in Table 4, in the fourth parameter, the currents flowing to adjacent parts have different amplitudes. In the fourth parameter, the currents flowing to adjacent parts have opposite phases (i.e., a phase difference of 180°). In the fourth parameter, the currents flowing to adjacent parts have different frequencies. The controller 5 can heat the object to be heated in the fourth heating mode by controlling the current so that the fourth parameter is as shown in Table 4 for all pairs of adjacent coil pieces.

[0084] In the fourth heating mode, the controller 5 controls the current so that coil pieces with large current amplitudes and coil pieces with small current amplitudes are arranged alternately. Therefore, in the fourth heating mode, the amplitude of the current flowing through each coil piece 10 has one of two values. However, as will be described later, the controller 5 may control the current so that the type of current amplitude is a value selected from three or more values ​​in order to control heating in other heating modes.

[0085] In the fourth heating mode, the controller 5 controls the current flowing through each coil piece 10 so that the difference in the frequency of the currents flowing through two adjacent coil pieces becomes a predetermined frequency difference. For example, the controller 5 may control the current flowing through one of two adjacent coil pieces so that the frequency of the current flowing through that one is twice the frequency of the current flowing through the other (i.e., a frequency difference of 1). The predetermined frequency difference is not limited to 1, but may be an integer multiple of 0 or more, as described above.

[0086] Figure 13 is a distribution diagram of an example of the temperature of an object heated using the fourth heating mode. In Figure 13, region S26 is the region of the object with a high temperature (i.e., the region that is strongly heated). As shown in Figure 13, the central part of the object is at a lower temperature than the surrounding part of the central part. Also, a part of the surrounding part is at a higher temperature than the rest of the surrounding part. Therefore, it can be seen that a part of the surrounding part of the object is heated more strongly than the central part and the rest of the surrounding part.

[0087] Furthermore, for example, the controller 5 can heat the object to be heated in the fifth heating mode by supplying a current having the parameters shown in Table 5 to each coil piece 10. The parameters shown in Table 5 will henceforth be referred to as the fifth parameters.

[0088] [Table 5]

[0089] As shown in Table 5, in the fifth parameter, the currents flowing to adjacent parts have equivalent amplitudes. In the fifth parameter, the currents flowing to adjacent parts have different phases. Specifically, in the fifth parameter, the currents flowing to adjacent parts have equivalent phase differences for all pairs of adjacent coil pieces. Equivalent phase differences are, for example, 60°, but are not limited to this. In the fifth parameter, the currents flowing to adjacent parts have the same frequency. The controller 5 can heat the object to be heated in the fifth heating mode by controlling the current so that the fifth parameter is as shown in Table 5 for all pairs of adjacent coil pieces.

[0090] Figure 14 is a distribution diagram of an example of the temperature of an object when it is heated using the fifth heating mode. In Figure 14, region S27 is the region where the temperature of the object is high (i.e., the region that is strongly heated). As shown in Figure 14, the central part of the object is wider and is hotter than the surrounding part of the central part. Therefore, it can be seen that the central part of the object is wider and is more strongly heated than the surrounding part of the central part. It can also be seen that heating is performed over a wider area compared to the first heating mode. Specifically, the region that is strongly heated by the fifth heating mode corresponds to the region above the coil unit 4 in the vertical direction.

[0091] The controller 5 does not limit the heating control to the first to fifth heating modes described above. The controller 5 can control heating in heating modes other than those described above by controlling the parameters of the current flowing to adjacent parts of two adjacent coil pieces so that the relationship is different from that of the first to fifth parameters. For example, the controller 5 can control the current flowing to each coil piece 10 to have the parameters shown in Table 6. The parameters shown in Table 6 will henceforth be referred to as the sixth parameter.

[0092] [Table 6]

[0093] As shown in Table 6, in the sixth parameter, the currents flowing to adjacent parts have different amplitudes. In the sixth parameter, the currents flowing to adjacent parts have the same phase (i.e., a phase difference of 0°). In the sixth parameter, the currents flowing to adjacent parts have different frequencies. The amplitude of the current in the sixth parameter is not equivalent to that of the first parameter. Due to this difference, the controller 5 can change the intensity of heating in adjacent parts by controlling the current flowing to each coil piece 10 to have the sixth parameter.

[0094] For example, the controller 5 can reduce the amplitude of the current flowing through a predetermined coil piece, thereby making the heating intensity of the region heated by that predetermined coil piece weaker compared to the heating intensity of the region heated by other coil pieces. The region heated by the predetermined coil piece includes the region heated by the adjacent parts between the predetermined coil piece and the coil piece adjacent to it.

[0095] In the heating mode described above, the controller 5 changes the intensity of heating using two types of current amplitudes, but is not limited to this. For example, the controller 5 may change the intensity of heating using three types of current amplitudes.

[0096] In this way, the controller 5 can locally control the intensity of heating of the object heated by the coil unit 4 by controlling at least one of the amplitude, phase, or frequency of the current flowing to adjacent parts.

[0097] In the induction heating cooker 1 according to Embodiment 1 of the present disclosure, the controller 5 can control the heating of the object to be heated using one or more heating modes from a plurality of heating modes that have different local distributions of heating intensity for the object to be heated. For example, the controller 5 may control the heating of the object to be heated using a first heating mode, or it may control the heating of the object to be heated using a second heating mode.

[0098] The controller 5 can control the heating of an object by switching between two or more heating modes from a plurality of heating modes. The controller 5 may, for example, alternately switch using two types of current parameters corresponding to two heating modes, or it may switch between the two types of current parameters to change alternately, continuously or in steps.

[0099] Controller 5 may have sequences that combine multiple heating modes. By having multiple sequences with different combinations of heating modes, Controller 5 can control heating with multiple appropriate heating modes depending on what is being cooked by heating the object to be heated.

[0100] Controller 5 may have a first sequence that combines at least a first heating mode and a second heating mode. Controller 5 may set the first sequence as the initial value when controlling heating. The first sequence is a sequence that can increase the heat output among multiple heating mode combinations. Therefore, if the user does not select another sequence, Controller 5 can control heating using the heating mode that can heat most efficiently. Controller 5 may also have a second sequence in which the combination of heating modes is different from the first sequence. If the user selects the second sequence, Controller 5 controls heating using the heating modes included in the second sequence.

[0101] In the induction heating cooker 1 according to Embodiment 1 of this disclosure, the controller 5 can acquire information regarding 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 within the object to be heated, causing the object to be heated. Since the magnetic field is affected by the object to be heated, the impedance of each coil piece 10 changes. Generally, the impedance of the coil piece 10 changes depending on the presence or absence of the object to be heated placed within the range affected by the magnetic field generated by the coil piece 10, and the magnetism due to the material of the object. Since the impedance also changes with the temperature of the object to be heated, the controller 5 can acquire the change in the temperature of the object to be heated by acquiring the change in the characteristics of each coil piece 10, such as by understanding the impedance of each coil piece 10. For example, by acquiring the change in the characteristics of each coil piece 10, the controller 5 can acquire the change in the temperature of the region of the object to be heated that is heated by each coil piece 10. In other words, the controller 5 can use each coil piece 10 as a temperature sensor.

[0102] The controller 5 can acquire changes in the characteristics of each coil piece 10 by, for example, equipping the circuit with a current sensor that acquires the current flowing through each coil piece 10 and acquiring the change in the current value in relation to the voltage value. The method for acquiring changes in the characteristics of each coil piece 10 is not limited to a current sensor; for example, the controller 5 may acquire changes in characteristics using a voltage sensor.

[0103] When the controller 5 obtains temperature information from the multiple coil pieces 10, it can store this information as temperature information in the storage device 8. The temperature information may be, for example, relative and qualitative information between the multiple coil pieces 10A to 10F. The temperature information is not limited to this and may also be numerical. Based on information that associates the positions of the multiple coil pieces 10 with the temperature information obtained based on each of the multiple coil pieces 10, the controller 5 can, for example, detect areas with relatively low temperatures. Therefore, the controller 5 can control the parameters of the current flowing through each of the multiple coil pieces 10 so as to strongly heat the areas with relatively low temperatures. In this way, the controller 5 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 obtained based on each of the multiple coil pieces 10.

[0104] For example, the controller 5 may change the amplitude of the current flowing through one or more coil pieces 10 based on this information. By changing the amplitude of the current, the controller 5 can control the intensity of heating in the area heated by the coil piece 10. The controller 5 may also change the phase of the current flowing through any two adjacent coil pieces based on this information. By changing the phase of the current, the controller 5 can control the location of the area that is strongly heated by the two adjacent coil pieces.

[0105] Furthermore, the controller 5 can determine whether or not an object to be heated is placed on the top plate 2 located vertically above each coil piece 10 by passing current through multiple coil pieces 10 and acquiring changes in the characteristics of the multiple coil pieces 10. For example, when the controller 5 determines that an object to be heated is placed on the top plate 2, it controls the parameters of the current flowing through each of the multiple coil pieces 10 to control the heating area by one or more coil pieces 10 corresponding to the placed position. In this way, the controller 5 can control the current to efficiently heat the area where the object to be heated is placed.

[0106] In the induction heating cooker 1 according to this disclosure, the controller 5 controls the coil unit 4 to energize all of the coil pieces 10 when heating an object to be heated. Therefore, even if the user moves the object to be heated while it is being heated, the controller 5 can determine whether or not the object to be heated is placed on each coil piece 10, and can quickly change the heating area according to the determination result.

[0107] The objects to be heated using induction cookers include cooking containers such as pots or frying pans that contain the objects to be cooked. Such containers may be made of magnetic materials, such as iron, but are not limited to this, and may be made of multiple materials. These multiple materials may include non-magnetic materials, such as aluminum, in addition to magnetic materials. When a container is made of multiple materials, for example, the central part of the bottom may be made of a magnetic material, and the surrounding part (i.e., the outer perimeter) may be made of a non-magnetic material. In such a container, where the outer perimeter is made of a non-magnetic material, if the central part and the surrounding part are heated with the same intensity, the temperature rise in the surrounding part will be smaller than that of the central part because the heating efficiency is lower.

[0108] As described above, according to the induction heating cooker 1 of Embodiment 1 of this disclosure, the controller 5 can control the local intensity of heating. Therefore, when a container whose outer circumference is made of a non-magnetic material is placed on the top plate, the controller 5 can efficiently heat the container by controlling the current to strongly heat the area corresponding to the non-magnetic material. The controller 5 can determine whether or not a container made of a non-magnetic material is placed on the top plate, for example, based on the change in impedance of each coil piece 10A to 10F. For example, the controller 5 can heat the outer circumference of a container placed on the top plate more strongly than other parts of the container by controlling it to heat in the second heating mode, at least temporarily. That is, the controller 5 controls the current flowing in adjacent parts of two adjacent coil pieces to be 180° ° By controlling the current in a different way, the container can be heated efficiently.

[0109] Figure 15A is a graph showing an example of temperature change of an object when it is heated using a conventional induction cooker with a heating coil. In Figure 15A, the vertical axis represents temperature (°C), and the horizontal axis represents time (seconds). Regarding the temperature change shown in Figure 15A, the object being heated is a cooking container, a pot, and as the temperature of the pot rises, the oil, which is the food being cooked, contained within the container is heated. Specifically, the graph in Figure 15A shows an example of temperature change when approximately 500g of oil is heated to approximately 200°C using a conventional induction cooker. The graph in Figure 15A shows temperature changes at multiple locations on the object being heated. In Figure 15A, line A represents the temperature of the central part of the pot in the radial direction. Line B represents the temperature of the area surrounding the central part of the pot. That is, line A represents the temperature of the inside of the pot in the radial direction (hereafter referred to as the inner pot temperature), and line B represents the temperature of the outside of the pot in the radial direction (hereafter referred to as the outer pot temperature). Line C represents the oil temperature measured at the radial center of the pan. Line D represents the oil temperature measured at the peripheral part of the pan around the said central part. In other words, line C represents the temperature of the radially inner part of the oil contained in the pan (hereafter referred to as the outer oil temperature), and line D represents the temperature of the radially outer part of the oil contained in the pan (hereafter referred to as the outer oil temperature). Line E represents the temperature measured by infrared radiation using a radiation thermometer.

[0110] In Figure 15A, the controller of a conventional induction cooker starts heating at around 0 seconds. Once heating begins, the temperatures rise as shown in Figure 15A. Conventional induction cookers have a heating coil located in the central part of the heating area. Therefore, the object being heated is heated strongly in the central part, and the area around the central part is heated weaker compared to the central part.

[0111] Therefore, as shown in Figure 15A, when heating an object using a conventional induction cooker, the temperature of the inner pot rises significantly more than the temperature of the outer pot. In the example shown in Figure 15A, after 100 seconds from the start of heating, there is a difference of approximately 50°C between the inner and outer pot temperatures. Because there is a temperature difference between the inner and outer pot temperatures, a temperature difference also occurs between the inner and outer oil temperatures. In the example shown in Figure 15A, after 100 seconds from the start of heating, there is a difference of approximately 15°C. Consequently, with conventional induction cookers, the time required for the outer oil temperature to rise to 200°C is longer than the time required for the inner oil temperature to rise to 200°C.

[0112] Furthermore, induction cookers control the temperature of the object being heated so that it does not exceed a predetermined temperature (e.g., 300°C). If the heating output is increased, the inner pot temperature may reach the predetermined temperature before the outer oil temperature rises to 200°C. Increasing the heating output increases the temperature difference between the inner and outer pots, thus increasing the likelihood that the inner pot temperature will reach the predetermined temperature before the oil temperature rises to 200°C. Therefore, when heating with a conventional induction cooker, the heating time cannot be shortened beyond a certain time even if the output is simply increased.

[0113] In contrast, the induction cooker of Embodiment 1 of this disclosure can control the localized intensity of heating on the object to be heated, thus shortening the heating time compared to conventional induction cookers. Figure 15B is a graph showing an example of the temperature change of an object to be heated when it is heated using the induction cooker of Embodiment 1 of this disclosure. In Figure 15B, the vertical axis represents temperature (°C), and the horizontal axis represents time (seconds). Regarding the temperature change shown in Figure 15B, the object to be heated is a pot, which is a cooking container, and as the temperature of the pot rises, the oil, which is the food to be cooked, contained in the container is heated. Specifically, the graph in Figure 15B shows an example of the temperature change when approximately 500g of oil is heated to approximately 200°C using the induction cooker 1 of Embodiment 1 of this disclosure. The graph in Figure 15B shows the temperature change at multiple locations on the object to be heated. Lines A to E in Figure 15B represent the same temperatures as lines A to E in Figure 15A.

[0114] In Figure 15B, the controller 5 of the induction cooker 1 starts heating at approximately 0 seconds. Once heating begins, the temperatures rise as shown in Figure 15B. As described above, the induction cooker 1 is equipped with multiple heating coils (i.e., multiple coil pieces 10) arranged radially from the center of the heating region. Also, as described above, the controller 5 of the induction cooker 1 can control the local intensity of heating by controlling the parameters of the current flowing through the multiple coil pieces 10. In the example shown in Figure 15B, the controller 5 heats the object to be heated by switching between the first heating mode and the second heating mode (i.e., in the first sequence).

[0115] In the example shown in Figure 15B, first, the controller 5 controls heating in the first heating mode during period t1. Therefore, during period t1, the temperature of the inner pot rises significantly higher than the temperature of the outer pot. During period t2, the controller 5 controls heating in the second heating mode. Therefore, during period t2, the temperature of the outer pot rises significantly higher than the temperature of the inner pot. As can be seen from Figure 15B, the controller 5 then switches between the first heating mode and the second heating mode alternately, locally heating the central and peripheral parts of the object being heated. As a result, the difference between the inner and outer pot temperatures is smaller compared to the example shown in Figure 15A. Consequently, the difference between the inner oil temperature and the outer oil temperature is also smaller.

[0116] Thus, compared to conventional induction cookers, induction cooker 1 can heat the object to be heated more evenly, thus enabling more efficient heating of the object. For example, in the example shown in Figure 15B, the controller 5 can control the object to be heated to heat the entire object by heating the central part of the object in the first heating mode and the surrounding area of ​​the central part of the object in the second heating mode. Furthermore, because the central part and its surrounding area of ​​the object to be heated are heated in a balanced manner, the temperature does not rise only in certain areas, as is the case with conventional induction cookers. Therefore, the heating output from the coil unit 4 can be increased, and according to the induction cooker 1 of Embodiment 1, the heating time can be shortened compared to conventional induction cookers. In the example shown in Figure 15A, the internal oil temperature exceeds 200°C approximately 350 seconds after heating, and in the example shown in Figure 15B, the internal oil temperature exceeds 200°C approximately 220 seconds after heating, indicating that the heating time has been shortened.

[0117] [effect] The induction heating cooker 1 according to Embodiment 1 can achieve the following effects.

[0118] The induction cooker 1 according to Embodiment 1 of the present disclosure comprises a top plate 2, a coil unit 4 disposed below the top plate 2, and a controller 5 that controls the heating of an object by the coil unit 4. The coil unit 4 comprises a plurality of coil pieces 10A to 10F arranged in a heating region S0 that heats an object in a plan view. In a plan view, the heating region S0 has a plurality of coil arrangement regions S1 to S6 defined by an outer peripheral line L10 that defines the outer periphery of the heating region S0, and a plurality of boundary lines L1 to L6 that extend radially from the center C1 of the heating region S0 toward the outer periphery. The plurality of coil pieces 10A to 10F are arranged within the plurality of coil arrangement regions (S1 to S6) in a plan view. In a plan view, the plurality of coil pieces have coil wires arranged along two adjacent boundary lines (L1 to L6) and an outer peripheral line L10 connecting the two adjacent boundary lines. Controller 5 controls the heating of the object to be heated by supplying current to all of the coil pieces 10A to 10F.

[0119] With this configuration, the induction cooker 1 can efficiently heat the object to be heated. Specifically, the heating region S0 is divided into multiple coil arrangement regions S1 to S6 by multiple boundary lines L1 to L6 and an outer circumference line L10. In each of the multiple coil arrangement regions S1 to S6, the coil wires 11 that make up the coil piece 10 are arranged along two adjacent boundary lines and the outer circumference line L10 that connects the two adjacent boundary lines. As a result, in a plan view, the coil wires 11 of the coil piece 10 are arranged from the center C1 of the heating region S0 toward the outer circumference, so that the induction cooker 1 of Embodiment 1 can reduce uneven heating. In addition, the gaps between the multiple coil pieces 10 can be made smaller and the variation in the gaps can be reduced. In Embodiment 1, the outer shape of the coil piece 10 in a plan view is fan-shaped to match the outer shape of each of the coil arrangement regions S1 to S6, which further reduces uneven heating, but the outer shape of the coil piece 10 may be other than fan-shaped. For example, the outer shape of the coil piece 10 in plan view may be elliptical or comma-shaped.

[0120] Furthermore, according to the induction heating cooker 1 of Embodiment 1 of this disclosure, the controller 5 controls the heating of the object to be heated while supplying current to all of the coil pieces 10A to 10F. Therefore, since the controller 5 energizes all of the coil pieces 10A to 10F, it is possible to avoid current concentration in one of the coil pieces 10A to 10F, and overall, the object to be heated can be heated with high output. In addition, since all of the coil pieces 10A to 10F are constantly energized, the response speed is fast. Therefore, each coil piece 10A to 10F can respond quickly to instructions from the controller 5. Furthermore, the controller 5 can control the response speed of each coil piece 10A to 10F by, for example, progressively changing the current parameter.

[0121] Furthermore, in the induction cooker 1, the controller 5 controls the local intensity of heating on the object to be heated by controlling at least some of the parameters of the current flowing through each of the multiple coil pieces 10A to 10F. The parameters include the amplitude, phase, and frequency of the current. In this way, the controller 5 of the induction cooker 1 can control the local intensity of heating on the object to be heated placed on the coil unit 4 by controlling at least some of the parameters of the current flowing through each of the multiple coil pieces 10A to 10F. Therefore, the induction cooker 1 can efficiently heat the object to be heated.

[0122] Furthermore, in the induction cooker 1, the controller 5 controls the heating of the object to be heated using one or more heating modes from a plurality of heating modes, each of which has a different local distribution of heating intensity. By controlling in this way, the controller 5 can control the local intensity of heating on the object to be heated, which is placed on or around the coil unit 4, using heating modes with predetermined local distributions of heating intensity. Therefore, the induction cooker 1 can efficiently heat the object to be heated.

[0123] Furthermore, in the induction cooker 1, the controller 5 controls the heating of the object to be heated by switching between two or more heating modes from among multiple heating modes. By controlling in this way, the controller 5 can control the heating of the object using multiple heating modes. Therefore, the induction cooker 1 can efficiently heat the object to be heated.

[0124] Furthermore, in the induction cooker 1, the controller 5 has multiple predetermined sequences that combine two or more heating modes, and each of the multiple predetermined sequences has a different combination of heating modes. With this configuration, the controller 5 can control heating using multiple appropriate heating modes depending on the food being cooked, for example, by allowing the user to select one of the multiple predetermined sequences. Therefore, the induction cooker 1 can efficiently heat the food being cooked.

[0125] Furthermore, in the induction cooker 1, the multiple heating modes include a first heating mode, in which the controller 5 controls the current flowing through each of the multiple coil pieces 10A to 10F, so that the object to be heated in the area corresponding to the adjacent parts of two adjacent coil pieces 10A to 10F is heated more strongly than the object to be heated in the area corresponding to the parts along the outer circumference line L10 of the two adjacent coil pieces. By heating the object to be heated in the first heating mode, the controller 5 can heat the part of the object to be heated located on the central part of the coil unit 4 more strongly than the part of the object to be heated located on the peripheral part of the central part of the coil unit 4. Therefore, the induction cooker 1 can efficiently heat the object to be heated when strongly heating the part of the object to be heated located on the central part of the coil unit 4.

[0126] Furthermore, in the induction cooker 1, the multiple heating modes include a second heating mode, in which the controller 5 controls the current flowing through each of the multiple coil pieces 10A to 10F, causing the object to be heated in the area corresponding to the part along the outer circumference line L10 of the multiple coil pieces 10A to 10F to be heated more strongly than the object to be heated in the area corresponding to the center of at least one of the coil pieces 10A to 10F. By heating the object to be heated using the second heating mode, the controller 5 can heat the part of the object to be heated that is on the periphery of the central part of the coil unit 4 more strongly than the part of the object to be heated that is above the center of at least one of the coil pieces 10A to 10F. Therefore, the induction cooker 1 can efficiently heat the object to be heated when strongly heating the part of the object to be heated that is on the periphery of the central part of the coil unit 4.

[0127] Furthermore, in the induction cooker 1, the controller 5 has a first sequence that combines at least a first heating mode and a second heating mode, and a second sequence in which the combination of heating modes is different from that of the first sequence. When the user selects the second sequence, the controller 5 controls the heating of the object to be heated using the second sequence. By controlling it in this way, the controller 5 heats the object to be heated using the first sequence if the user does not select the second sequence, and heats the object to be heated using the second sequence if the user selects the second sequence. Since the heat output of the first sequence is higher than that of the second sequence, the induction cooker 1 can heat the object to be heated using the sequence with higher heat output, except when the user selects the second sequence.

[0128] Furthermore, in the induction cooker 1, the controller 5 controls the current parameters flowing through each of the coil pieces 10A to 10F based on information that associates the positions of the multiple coil pieces 10A to 10F with the temperature information acquired based on each of the multiple coil pieces 10A to 10F. By controlling in this way, the controller 5 can identify areas with low temperatures within the object to be heated based on the temperature information, and control the current parameters flowing through the coil pieces associated with the low-temperature areas so that these areas can be heated more strongly. Therefore, the induction cooker 1 can efficiently heat the object to be heated.

[0129] Furthermore, in the induction cooker 1, the controller 5 controls the phase of the current flowing through two adjacent coil pieces based on information that associates the positions of the multiple coil pieces 10A to 10F with the temperature information acquired based on each of the multiple coil pieces 10A to 10F. By controlling in this way, the controller 5 can identify areas with low temperatures within the object to be heated based on the temperature information, and control the phase of the current flowing through two adjacent coil pieces associated with the low-temperature areas so that these areas can be heated more strongly. Therefore, the induction cooker 1 can efficiently heat the object to be heated.

[0130] Furthermore, in the induction cooker 1, the controller 5 controls the current parameters flowing through each of the coil pieces 10A to 10F based on the area on the top plate 2 where the object to be heated is placed. By controlling in this way, when the controller 5 acquires the area on the top plate 2 where the object to be heated is placed, it can control the current parameters to heat that area strongly. Therefore, the induction cooker 1 can efficiently heat the object to be heated.

[0131] Furthermore, in the induction cooker 1, the plurality of coil pieces 10A to 10F each have a first coil piece and a second coil piece positioned in each of two adjacent coil arrangement regions S1 to S6. Parts of the first coil piece and parts of the second coil piece are positioned along predetermined boundary lines L1 to L6. The controller 5 controls the current flowing through each of the plurality of coil pieces 10A to 10F such that the current flowing through the portion of the first coil piece along the predetermined boundary line and the current flowing through the portion of the second coil piece along the predetermined boundary line have a predetermined phase difference, a predetermined frequency difference, or both. By controlling in this way, the controller 5 of the induction cooker 1 can control the local intensity of heating for objects placed on or around the coil unit 4. In particular, the controller 5 can control the local intensity of heating for parts of objects placed on or around the first and second coil pieces. Therefore, the induction cooker 1 can efficiently heat objects.

[0132] Furthermore, in the induction cooker 1, the predetermined phase difference is, for example, 0°, 30°, 45°, 60°, 90°, or 180°. By controlling in this way, the controller 5 can control the local intensity of heating on parts of the object to be heated that are placed on the first coil piece and the second coil piece, or on their outer circumference. Therefore, the induction cooker 1 can efficiently heat the object to be heated.

[0133] Furthermore, in the induction cooker 1, the predetermined frequency difference is, for example, an integer multiple of zero or more of the frequency of the current flowing through the first coil piece or the second coil piece. By controlling in this way, the controller 5 can control the localized intensity of heating on the first coil piece and the second coil piece, or on their outer circumference, for parts of the object to be heated. Therefore, the induction cooker 1 can efficiently heat the object to be heated.

[0134] Furthermore, in the induction cooker 1, the controller 5 controls the current flowing through each of the multiple coil pieces 10A to 10F, which are arranged in each of two adjacent coil arrangement regions S1 to S6, such that the current flowing through each portion along the boundary line between the two adjacent coil pieces, among the multiple boundary lines L1 to L6, has a predetermined phase difference, a predetermined frequency difference, or both. By controlling in this way, the controller 5 of the induction cooker 1 can control the local intensity of heating for the object to be heated, which is placed on or around the coil unit 4. Therefore, the induction cooker 1 can efficiently heat the object to be heated.

[0135] Furthermore, in the induction cooker 1, the predetermined phase difference is, for example, 0°, 30°, 45°, 60°, 90°, or 180°. By controlling in this way, the controller 5 can control the local intensity of heating for objects placed on or around the coil unit 4. Therefore, the induction cooker 1 can efficiently heat objects.

[0136] Furthermore, in the induction cooker 1, the predetermined frequency difference is, for example, an integer multiple of zero or more of the frequency of the current flowing through one of two adjacent coil pieces. By controlling in this way, the controller 5 can control the local intensity of heating for objects placed on or around the coil unit 4. Therefore, the induction cooker 1 can efficiently heat objects.

[0137] Furthermore, in the induction cooker 1, when a heating object whose outer periphery is made of a non-magnetic material is placed on the top plate 2, the controller 5 controls the parameters of the current flowing through each of the multiple coil pieces 10A to 10F so that a predetermined phase difference of 180° is achieved. With this configuration, the controller 5 can, for example, control the heating to heat the peripheral portion more strongly than the central portion when a pot, whose central portion is made of a magnetic material and whose peripheral portion is made of a non-magnetic material, is placed on the top plate as the heating object. Therefore, the induction cooker 1 can efficiently heat the heating object.

[0138] In Embodiment 1, an example was described in which there are six coil arrangement regions S1 to S6, but the invention is not limited to this. Similarly, an example was described in which there are six coil pieces 10, but the invention is not limited to this. The number of coil arrangement regions may be between three and eight. The number of coil pieces 10 may be between three and eight. With such a configuration, it is possible to improve the heating efficiency of the induction cooker while reducing manufacturing costs.

[0139] In Embodiment 1, an example was described in which the multiple coil placement areas S1 to S6 have substantially the same shape and size, but the invention is not limited to this. For example, the multiple coil placement areas S1 to S6 may have different shapes and / or different sizes.

[0140] Embodiment 1 describes an example in which the multiple coil pieces 10 are substantially the same shape and size, but is not limited to this. For example, the multiple coil pieces 10 may have different shapes and / or different sizes.

[0141] Furthermore, in Embodiment 1, the thicknesses of the first coil wire section 20, the second coil wire section 30, and the third coil wire section 40 were all the same, but at least one of the thicknesses may be different from the others. The thicker the coil wire section, the more turns can be added, and the greater the heating energy can be. Therefore, in areas where it is necessary to increase thermal efficiency, increasing the thickness of the coil wire section can increase the heating efficiency of the entire heating area S0. It is also possible to increase the heating energy by increasing the width of the coil wire section, but widening the width of the coil wire section makes it difficult to bend it sharply along the shape of the coil arrangement area S1 to S6. Therefore, increasing the thickness of the coil wire section rather than its width makes manufacturing easier.

[0142] In Embodiment 1, an example was described in which the multiple boundary lines L1 to L6 are straight lines extending from the center C1 of the heating region S0 toward the outer circumference in a plan view, but the embodiment is not limited to this. For example, the multiple boundary lines L1 to L6 may be curves extending from the center C1 of the heating region S0 toward the outer circumference in a plan view.

[0143] In Embodiment 1, an example was described in which the coil wire 11 has a first coil wire portion 20, a second coil wire portion 30, and a third coil wire portion 40, but the invention is not limited thereto. For example, the coil wire 11 may consist of only the first coil wire portion 20, without including the second coil wire portion 30 and the third coil wire portion 40. The coil wire 11 may also consist of only the first coil wire portion 20 and the second coil wire portion 30, without including the third coil wire portion 40. Furthermore, in Embodiment 1, the external shapes of the second coil wire portion 30 and the third coil wire portion 40 are fan-shaped in plan view, but for example, the external shape of at least one of the second coil wire portion 30 and the third coil wire portion 40 may be round or other shapes in plan view.

[0144] In Embodiment 1, an example was described in which the first coil wire portion 20, the second coil wire portion 30, and the third coil wire portion 40 are formed as a single unit, but the invention is not limited to this. For example, the first coil wire portion 20, the second coil wire portion 30, and the third coil wire portion 40 may be formed from separate members.

[0145] Embodiment 1 described an example in which the coil unit 4 is applied to an induction cooker 1, but it is not limited to this. The coil unit 4 may also be applied to devices other than the induction cooker 1.

[0146] (modified version) The embodiments of this disclosure are not limited to those described above. The embodiments can be modified in various ways depending on the design, etc., as long as the objectives of this disclosure can be achieved. Modifications of Embodiment 1 are described below. The modifications described below can be combined and applied as appropriate.

[0147] In one variant example, the circuit of the induction cooker 1 may be configured as shown in Figure 16. Figure 16 is a circuit diagram of another example of the induction cooker 1 of Embodiment 1 according to the present disclosure. In the circuit shown in Figure 16, the position of the resonant capacitor 54 is changed compared to the circuit shown in Figure 5. Specifically, the resonant capacitor 54 is located on the wiring 56a side of the switching element 57. Furthermore, resonant capacitors 59A to 59F are connected in parallel to the coil pieces 10A to 10F. With this configuration, the controller 5 can make the switching frequencies of the multiple inverter circuits 53 common regardless of the frequency of the coil piece 10, thereby suppressing the generation of hum.

[0148] In one variant example, the circuit of the induction cooker 1 may be configured as shown in Figure 17. Figure 17 is a circuit diagram of yet another example of the induction cooker 1 of Embodiment 1 according to the present disclosure. The circuit shown in Figure 17 has an increased number of diode bridges 51 compared to the circuit shown in Figure 5. Also, the number of coil pieces 10 located downstream of the diode bridges 51 has been changed. With this configuration, the diode bridges 51 for supplying power to the multiple coil pieces 10 are separated, so the controller 5 can easily detect the power.

[0149] In one variant example, the circuit of the induction cooker 1 may be configured as shown in Figure 18. Figure 18 is a circuit diagram of yet another example of the induction cooker 1 of Embodiment 1 according to the present disclosure. In the circuit shown in Figure 18, two coil pieces 10 are configured in parallel with respect to the circuit shown in Figure 5. With this configuration, the number of parts can be reduced, and therefore costs can be reduced.

[0150] Thus, the circuit of the induction heating cooker 1 according to Embodiment 1 of this disclosure is not limited to the circuit shown in Figure 5, and various circuits can be used.

[0151] (Summary of characteristics) As is clear from the above description, this disclosure includes the following embodiments. In the following, reference numerals are enclosed in parentheses solely to indicate their correspondence with the embodiments.

[0152] (Aspect 1) The induction cooker (1) comprises a top plate (2), a coil unit (4) positioned below the top plate (2), and a controller (5) that controls the heating of an object by the coil unit (4). The coil unit (4) comprises a plurality of coil pieces (10A~10F) positioned in a heating region (S0) that heats an object in a plan view. The heating region (S0) has a plurality of coil arrangement regions (S1~S6) defined in a plan view by an outer peripheral line (L10) that defines the outer periphery of the heating region (S0) and a plurality of boundary lines (L1~L6) that extend radially from the center of the heating region (S0) toward the outer periphery. The plurality of coil pieces (10A~10F) are positioned within the plurality of coil arrangement regions (S1~S6) in a plan view. The controller (5) controls the heating of the object by supplying current to all of the plurality of coil pieces (10A~10F).

[0153] With this configuration, the controller (5) controls the heating of the object to be heated while constantly supplying current to all of the coil pieces (10A to 10F). Therefore, because the controller (5) energizes all of the coil pieces (10A to 10F), it is possible to avoid current concentration in one of the coil pieces (10A to 10F), and overall, the object to be heated can be heated with high output. In addition, since all of the coil pieces (10A to 10F) are constantly energized, the response speed is fast. Therefore, each coil piece (10A to 10F) can respond quickly to instructions from the controller (5). Therefore, the induction cooker (1) can efficiently heat the object to be heated.

[0154] (Aspect 2) In the induction heating cooker (1) of Embodiment 1, Each of the multiple coil pieces (10A to 10F) may have a coil wire (11) that, in a plan view, is arranged along two adjacent boundary lines (L1 to L6) and an outer perimeter line (L10) connecting the two adjacent boundary lines. With this configuration, uneven heating can be reduced, allowing the induction cooker (1) to efficiently heat the object to be heated.

[0155] (Aspect 3) In the induction heating cooker (1) of Aspect 1 or Aspect 2, the controller (5) controls the local intensity of heating to the object to be heated by controlling at least a portion of the parameters of the current flowing through each of the plurality of coil pieces (10A to 10F), and the parameters may include the amplitude, phase, and frequency of the current. In this way, the controller (5) can control the local intensity of heating to the object to be heated placed on the coil unit (4) by controlling at least a portion of the parameters of the current flowing through each of the plurality of coil pieces (10A to 10F). Therefore, the induction heating cooker (1) can efficiently heat the object to be heated.

[0156] (Aspect 4) In the induction cooker (1) of aspect 3, the controller (5) may control the heating of the object to be heated using one or more heating modes from a plurality of heating modes, each having a different local distribution of heating intensity for the object to be heated. By controlling in this way, the controller (5) can control the local intensity of heating for the object to be heated, which is placed on or around the coil unit (4), using heating modes having a predetermined local distribution of heating intensity. Therefore, the induction cooker (1) can efficiently heat the object to be heated.

[0157] (Aspect 5) In the induction cooker (1) of aspect 4, the controller (5) may control the heating of the object to be heated by switching between two or more heating modes from among a plurality of heating modes. By controlling in this way, the controller (5) can control the heating of the object to be heated using multiple heating modes. Therefore, the induction cooker (1) can efficiently heat the object to be heated.

[0158] (Aspect 6) In the induction heating cooker (1) of Aspect 4 or Aspect 5, the controller (5) has a plurality of predetermined sequences that combine two or more heating modes, and each of the plurality of predetermined sequences may have a different combination of heating modes. With this configuration, the controller (5) can control heating using an appropriate plurality of heating modes according to the food being heated, for example, by the user selecting one of the plurality of predetermined sequences. Therefore, the induction heating cooker (1) can efficiently heat the food being heated.

[0159] (Aspect 7) In an induction cooker (1) according to any of aspects 4 to 6, the heating modes include a first heating mode, in which the controller (5) controls the current flowing through each of the multiple coil pieces (10A to 10F) to heat the object to be heated in a region corresponding to adjacent parts of two adjacent coil pieces (10A to 10F) more strongly than the object to be heated in a region corresponding to parts along the outer circumference lines (L10) of the two adjacent coil pieces. By heating the object to be heated with the first heating mode, the controller (5) can heat the portion of the object to be heated located on the central part of the coil unit (4) more strongly than the portion of the object to be heated located on the peripheral part of the central part of the coil unit (4). Therefore, when the induction cooker (1) strongly heats the portion of the object to be heated located on the central part of the coil unit (4), it can efficiently heat the object to be heated.

[0160] (Aspect 8) In the induction cooker (1) of Aspect 7, the multiple heating modes include a second heating mode, in which the controller (5) controls the current flowing through each of the multiple coil pieces (10A~10F) to heat the object to be heated in a region corresponding to the part along the outer circumference line (L10) of the multiple coil pieces (10A~10F) more strongly than the object to be heated in a region corresponding to the center of at least one of the multiple coil pieces (10A~10F). By heating the object to be heated with the second heating mode, the controller (5) can heat the part of the object to be heated that is on the peripheral part of the central part of the coil unit (4) more strongly than the part of the object to be heated that is above the center of at least one of the multiple coil pieces (10A~10F). Therefore, when the induction cooker (1) strongly heats the part of the object to be heated that is on the peripheral part of the central part of the coil unit (4), it can efficiently heat the object to be heated.

[0161] (Aspect 9) In the induction cooker (1) of Aspect 8, the controller (5) has a first sequence which combines at least a first heating mode and a second heating mode, and a second sequence which has a different combination of heating modes than the first sequence, and if the user selects the second sequence, the controller (5) may control the heating of the object to be heated in the second sequence. By controlling in this way, the controller (5) heats the object to be heated in the first sequence if the user does not select the second sequence, and heats the object to be heated in the second sequence if the user selects the second sequence. Since the heat output of the first sequence is higher than that of the second sequence, the induction cooker (1) can heat the object to be heated in the sequence with higher heat output, except when the user selects the second sequence.

[0162] (Aspect 10) In an induction cooker (1) according to any of aspects 3 to 9, the controller (5) may control the parameters of the current flowing through each of the coil pieces (10A to 10F) based on information relating the positions of the coil pieces (10A to 10F) to the temperature information obtained based on each of the coil pieces (10A to 10F). By controlling in this way, the controller (5) can identify areas with low temperatures within the object to be heated based on the temperature information and control the parameters of the current flowing through the coil pieces associated with the low-temperature areas so that these areas can be heated more strongly. Therefore, the induction cooker (1) can efficiently heat the object to be heated.

[0163] (Aspect 11) In the induction cooker (1) of aspect 10, the controller (5) may control the phase of the current flowing through two adjacent coil pieces based on information. By controlling in this way, the controller (5) can identify areas with low temperatures within the object to be heated based on temperature information and control the phase of the current flowing through two adjacent coil pieces associated with the low-temperature areas so that these areas can be heated more strongly. Therefore, the induction cooker (1) can efficiently heat the object to be heated.

[0164] (Aspect 12) In an induction cooker (1) according to any of aspects 3 to 11, the controller (5) may control the current parameters flowing through each of the multiple coil pieces (10A to 10F) based on the area on the top plate (2) where the object to be heated is placed. By controlling in this way, when the controller (5) acquires the area on the top plate (2) where the object to be heated is placed, it can control the current parameters to strongly heat that area. Therefore, the induction cooker (1) can efficiently heat the object to be heated.

[0165] (Aspect 13) In the induction cooker (1) according to any of aspects 3 to 12, the number of coil arrangement regions (S1 to S6) may be 3 to 8. By configuring it in this way, it is possible to improve the heating efficiency of the induction cooker (1) while reducing manufacturing costs.

[0166] (Aspect 14) In an induction heating cooker (1) according to any of aspects 3 to 13, the plurality of coil pieces (10A to 10F) have a first coil piece and a second coil piece that are arranged in each of two adjacent coil arrangement regions (S1 to S6) among the plurality of coil arrangement regions, and a part of the first coil piece and a part of the second coil piece are arranged along a predetermined boundary line among the plurality of boundary lines (L1 to L6), and the controller (5) may control the current flowing through each of the plurality of coil pieces (10A to 10F) such that the current flowing through the part of the first coil piece along the predetermined boundary line and the current flowing through the part of the second coil piece along the predetermined boundary line have a predetermined phase difference, a predetermined frequency difference, or both. By controlling in this way, the controller (5) of the induction heating cooker (1) can control the local intensity of heating for an object to be heated that is placed on or around the coil unit (4). In particular, the controller (5) can control the localized intensity of heating on the first coil piece and the second coil piece, or on their outer circumference, for parts of the object to be heated. Therefore, the induction cooker (1) can efficiently heat the object to be heated.

[0167] (Aspect 15) In the induction cooker (1) of aspect 14, the predetermined phase difference may be 0°, 30°, 45°, 60°, 90°, or 180°. By controlling in this way, the controller (5) can control the local intensity of heating on the portion of the object to be heated that is placed on the first coil piece and the second coil piece, or on their outer circumference. Therefore, the induction cooker (1) can efficiently heat the object to be heated.

[0168] (Aspect 16) In the induction cooker (1) of aspect 14 or aspect 15, the predetermined frequency difference may be an integer multiple of zero or more the frequency of the current flowing through the first coil piece or the second coil piece. By controlling in this way, the controller (5) can control the local intensity of heating on the portion of the object to be heated that is placed on or around the first and second coil pieces. Therefore, the induction cooker (1) can efficiently heat the object to be heated.

[0169] (Aspect 17) In an induction cooker (1) according to any of aspects 3 to 13, the controller (5) may control the current flowing through each of the multiple coil pieces (10A to 10F) in each pair of adjacent coil pieces (10A to 10F) arranged in each of two adjacent coil arrangement regions (S1 to S6) among the multiple coil arrangement regions, such that the current flowing through each portion along the boundary line between the two adjacent coil pieces among the multiple boundary lines (L1 to L6) has a predetermined phase difference, a predetermined frequency difference, or both. By controlling in this way, the controller (5) can control the local intensity of heating for an object placed on or around the coil unit (4). Therefore, the induction cooker (1) can efficiently heat the object.

[0170] (Aspect 18) In the induction cooker (1) of aspect 17, the predetermined phase difference may be 0°, 30°, 45°, 60°, 90°, or 180°. By controlling in this way, the controller 5 can control the local intensity of heating for the object to be heated, which is placed on or around the coil unit 4. Therefore, the induction cooker 1 can efficiently heat the object to be heated.

[0171] (Aspect 19) In the induction cooker (1) of Aspect 17 or Aspect 18, the predetermined frequency difference may be an integer multiple of zero or more the frequency of the current flowing through one of the two adjacent coil pieces. By controlling in this way, the controller (5) can control the local intensity of heating for the object to be heated, which is placed on or around the coil unit (4). Therefore, the induction cooker (1) can efficiently heat the object to be heated.

[0172] (Aspect 20) In an induction cooker (1) according to any of aspects 17 to 19, the controller (5) may control the parameters of the current flowing through each of the multiple coil pieces (10A to 10F) so that a predetermined phase difference of 180° is achieved when an object to be heated, whose outer periphery is made of a non-magnetic material, is placed on the top plate (2). With this configuration, the controller 5 can, for example, control the heating so that the peripheral part is heated more strongly than the central part when a pot, whose central part is made of a magnetic material and whose peripheral part is made of a non-magnetic material, is placed on the top plate as an object to be heated. Therefore, the induction cooker 1 can efficiently heat the object to be heated.

[0173] The systems described in this disclosure are realized through the cooperation of hardware resources, such as a processor and memory, and software resources (computer programs). [Industrial applicability]

[0174] According to this disclosure, an induction heating cooker can be provided that can efficiently heat an object using multiple heating coils, and therefore can be suitably used in this type of industrial field. [Explanation of Symbols]

[0175] 1 induction cooker 2 Top Plate 3 cabinets 4 Coil Units 5 Controllers 6 Input / Output Interface Device 7 Arithmetic circuit 8 Storage device 10, 10A~10F coil piece 11 Coil wire 53, 53A~53F Inverter Circuit L1~L6 Boundary Lines L10 Outer Line S0 heating area S1~S6 Coil placement area

Claims

1. Top plate and A coil unit positioned below the top plate, A controller that controls the heating of the object to be heated by the coil unit, Equipped with, The coil unit comprises a plurality of coil pieces arranged in a heating region that heats the object to be heated in a plan view, The heating region has, in a plan view, a plurality of coil arrangement regions defined by an outer peripheral line defining the outer periphery of the heating region and a plurality of boundary lines extending radially from the center of the heating region toward the outer periphery. The plurality of coil pieces are arranged within the plurality of coil arrangement regions in a plan view. The controller controls the heating of the object to be heated while supplying current to all of the plurality of coil pieces. The controller controls the local intensity of heating on the object to be heated by controlling at least some of the parameters of the current flowing through each of the plurality of coil pieces, the parameters including the amplitude, phase and frequency of the current, Controlling at least a portion of the parameters includes controlling at least a portion of the parameters such that the currents flowing through adjacent portions of adjacent coils among the plurality of coil pieces have different phases, different frequencies, or both. Induction heating cooker.

2. The induction heating cooker according to claim 1, wherein each of the plurality of coil pieces has a coil wire that, in a plan view, is arranged along two adjacent boundary lines among the plurality of boundary lines and an outer perimeter line connecting the two adjacent boundary lines.

3. The induction cooker according to claim 1, wherein the controller controls the heating of the object to be heated using one or more heating modes from a plurality of heating modes having different local distributions of heating intensity for the object to be heated.

4. The induction cooker according to claim 3, wherein the controller controls the heating of the object to be heated by switching between two or more heating modes from the plurality of heating modes.

5. The induction cooker according to claim 4, wherein the controller has a plurality of predetermined sequences that combine two or more of the plurality of heating modes, and each of the plurality of predetermined sequences has a different combination of the plurality of heating modes.

6. The plurality of heating modes include a first heating mode, The induction cooker according to claim 3, wherein the first heating mode causes the controller to control the current flowing through each of the plurality of coil pieces so that the object to be heated in the region corresponding to adjacent parts of two adjacent coil pieces is heated more strongly than the object to be heated in the region corresponding to the parts along the outer circumference lines of each of the two adjacent coil pieces.

7. The aforementioned plurality of heating modes include a second heating mode, The induction cooker according to claim 3, wherein the second heating mode causes the controller to control the current flowing through each of the plurality of coil pieces, thereby heating the object to be heated in the region corresponding to the portion along the outer circumference line of the plurality of coil pieces more strongly than the object to be heated in the region corresponding to the center of at least one of the plurality of coil pieces.

8. The plurality of heating modes include a second heating mode, The second heating mode causes the controller to control the current flowing through each of the plurality of coil pieces so that the object to be heated in the region corresponding to the portion along the outer circumference line of the plurality of coil pieces is heated more strongly than the object to be heated in the region corresponding to the center of at least one of the plurality of coil pieces. The induction cooker according to claim 6, wherein the controller has a first sequence which combines at least the first heating mode and the second heating mode, and a second sequence which has a combination of heating modes different from the first sequence, and when the user selects the second sequence, the heating of the object to be heated is controlled in the second sequence.

9. The induction heating cooker according to claim 1, wherein the controller controls the parameter of the current flowing through each of the plurality of coil pieces based on information relating the positions of the plurality of coil pieces and temperature information obtained based on each of the plurality of coil pieces.

10. The induction heating cooker according to claim 9, wherein the controller controls the phase of the current flowing through two adjacent coil pieces based on the information.

11. The induction cooker according to claim 1, wherein the controller controls the parameter of the current flowing through each of the plurality of coil pieces based on the area on the top plate where the object to be heated is placed.

12. The induction heating cooker according to claim 1, wherein the number of the plurality of coil arrangement regions is three or more and eight or less.

13. The plurality of coil pieces include a first coil piece and a second coil piece, which are arranged in each of two adjacent coil arrangement regions among the plurality of coil arrangement regions. A portion of the first coil piece and a portion of the second coil piece are arranged along a predetermined boundary line among the plurality of boundary lines. The induction heating cooker according to any one of claims 1 to 12, wherein the controller controls the current flowing through each of the plurality of coil pieces such that the current flowing through the portion of the first coil piece along the predetermined boundary line and the current flowing through the portion of the second coil piece along the predetermined boundary line have different phases, different frequencies, or both.

14. The induction heating cooker according to claim 13, wherein the current flowing through the portion of the first coil piece along the predetermined boundary line and the current flowing through the portion of the second coil piece along the predetermined boundary line have a phase difference of 30°, 45°, 60°, 90°, or 180°.

15. The induction heating cooker according to claim 13, wherein the current flowing through the portion of the first coil piece along the predetermined boundary line and the current flowing through the portion of the second coil piece along the predetermined boundary line have a frequency difference of one or more integer multiples of the frequency of the current flowing through the first coil piece or the second coil piece.

16. The induction heating cooker according to any one of claims 1 to 12, wherein the controller controls the current flowing through each of the plurality of coil pieces such that, in each pair of adjacent coil pieces among the plurality of coil pieces arranged in each of two adjacent coil arrangement regions among the plurality of coil arrangement regions, the current flowing through each portion along the boundary line between the two adjacent coil pieces among the plurality of boundary lines has different phases or different frequencies or both.

17. The induction heating cooker according to claim 16, wherein the current flowing through each portion along the boundary line between the two adjacent coil pieces has a phase difference of 30°, 45°, 60°, 90°, or 180°.

18. The induction heating cooker according to claim 16, wherein the current flowing through each portion along the boundary line between the two adjacent coil pieces has a frequency difference of one or more integer multiples of the frequency of the current flowing through one of the two adjacent coil pieces.

19. The induction cooker according to claim 16, wherein the controller controls the parameters of the current flowing through each of the plurality of coil pieces such that when an object to be heated, whose outer periphery is made of a non-magnetic material, is placed on the top plate, the current flowing through each portion along the boundary line between two adjacent coil pieces has a phase difference of 180°.

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