Induction heating type stove

Abstract

The induction heating type stove according to an embodiment of the present application can include a housing, a cover plate coupled to an upper end of the housing, an upper plate portion in which an object to be heated is disposed being provided at a top surface of the cover plate, a thin film coated to the upper plate portion, an opening portion being formed at a center of the thin film, a work coil portion provided inside the housing, including a first work coil and a second work coil, and at least one inverter driven such that a current flows in the first work coil and the second work coil, a current direction flowing through the first work coil and a current direction flowing through the second work coil can be the same or different according to the object to be heated.

Description

TECHNICAL FIELD

[0001] The present invention relates to an induction heating type cooktop. More specifically, the present invention relates to an induction heating type cooktop coated with a thin film. BACKGROUND

[0002] Various types of cooking apparatuses for heating food are used in homes or restaurants. In the past, gas stoves using gas as fuel have been widely used, but in recent years, devices using electricity instead of gas to heat a heated object, such as a cooking vessel, are being popularized.

[0003] The method of using electricity to heat a heated object is mainly divided into a resistance heating method and an induction heating method. The resistance method is a method of transferring heat generated when an electric current flows through a metal resistance wire or a non-metallic heating element such as silicon carbide to a heated object (for example, a cooking vessel) by radiation or conduction, thereby heating the heated object. In addition, the induction heating method is a method of generating eddy currents in a heated object composed of a metal component using a magnetic field generated around a coil when a high-frequency power of a predetermined size is applied to the coil, so that the heated object itself is heated.

[0004] In recent years, induction heating methods are mostly applied to cooktops.

[0005] However, in the case of applying an induction heating type cooktop, there is a limitation that only a magnetic body can be heated. That is, in the case where a non-magnetic body (for example, heat-resistant glass, ceramic, etc.) is disposed on the cooktop, there is a problem that the induction heating type cooktop cannot heat the heated object.

[0006] In order to improve the problems that such an induction heating type cooktop has, the present invention aims to use a thin film. Specifically, the cooktop of the present invention can include a thin film to which an eddy current is applied to heat a non-magnetic body. In addition, such a thin film can be formed to have a skin depth thicker than its thickness, whereby a magnetic field generated in a working coil passes through the thin film to apply an eddy current to a magnetic body, so that the magnetic body can also be heated.

[0007] On the other hand, an induction heating type cooktop can also be driven in a dual coil (for example, a combination of an inner coil and an outer coil) method. In the existing dual coil driving method, an inverter driving the inner coil and an inverter driving the outer coil are respectively provided to determine the output of the dual coil.

[0008] At this point, the signals from the separate inverters driving each coil must be perfectly synchronized to prevent the stove's output from fluctuating. Therefore, in existing coil-driven methods, additional circuitry for synchronizing inverter signals is required to control the output, which complicates the circuit configuration.

[0009] Furthermore, in existing dual-coil drive systems, an outer coil must be driven if a higher output is required. Therefore, there is a problem that the size of the object being heated must be sufficiently larger than the outer coil to generate a higher output. Summary of the Invention

[0010] The problem that the invention aims to solve

[0011] The purpose of this invention is to minimize the problem of reduced heating efficiency for both magnetic and non-magnetic materials in induction heating stoves capable of heating both magnetic and non-magnetic materials.

[0012] The purpose of this invention is to provide an apparatus in an induction heating stove capable of heating both magnetic and non-magnetic materials, which can improve the heating efficiency of magnetic and non-magnetic materials separately without needing to sense the type of object being heated.

[0013] Technical solutions to the problem

[0014] The induction heating stove of this invention can change the magnetic field concentration area by controlling the direction of the current flowing through each of a plurality of working coils driven by an inverter.

[0015] In the induction heating stove of this invention embodiment, when the direction of the current flowing through each of the plurality of working coils is controlled to be different, the magnetic field strength in the central region of the plurality of working coils can be made stronger than the magnetic field strength in the outer region.

[0016] In the induction heating stove of this invention embodiment, when the direction of the current flowing through each of the plurality of working coils is controlled to be the same, the magnetic field strength in the central region of the plurality of working coils can be made weaker than the magnetic field strength in the outer region.

[0017] The induction heating stove of this invention may further include a control unit, which controls the direction of the current flowing through each of a plurality of working coils by comparing the target power and the output power.

[0018] Invention Effects

[0019] According to the present invention, the magnetic field can be concentrated on the thin film or magnetic container by changing the magnetic field concentration area, thereby minimizing the reduction in heating efficiency for magnetic and non-magnetic materials respectively, thus having the advantage of improving heating performance.

[0020] According to the present invention, even without additional sensors for sensing whether the heated object is magnetic or non-magnetic, heating efficiency can be improved, thus offering the advantages of reduced manufacturing costs and simplified structure. Attached Figure Description

[0021] Figure 1 This is a diagram illustrating an embodiment of the induction heating stove of the present invention.

[0022] Figure 2 This is a cross-sectional view showing an induction heating stove and a heated object according to an embodiment of the present invention.

[0023] Figure 3 This is a cross-sectional view showing an induction heating stove and a heated object according to another embodiment of the present invention.

[0024] Figure 4 and Figure 5 This is a graph illustrating the relationship between film thickness and skin depth.

[0025] Figure 6 and Figure 7 It is a graph illustrating the impedance changes between the thin film and the heated object, depending on the type of object being heated.

[0026] Figure 8 and Figure 9 This is a diagram illustrating an embodiment of an induction heating stove of the present invention.

[0027] Figure 10a This is an example diagram showing the direction of current flowing through the first and second working coils of a stove according to an embodiment of the present invention.

[0028] Figure 10b It shows the current as follows Figure 10a This is an example diagram showing the magnetic field distribution around the working coil section when the flow occurs in the working coil section as shown.

[0029] Figure 10c It shows the current as follows Figure 10a An example diagram illustrating the coupling state of the magnetic field when the flow occurs in the working coil section as shown.

[0030] Figure 10d This is an example diagram showing the state of the thin film when the magnetic field concentration region is the outer region of the working coil.

[0031] Figure 11aThis is an example diagram showing the direction of current flowing through the first and second working coils of a stove according to an embodiment of the present invention.

[0032] Figure 11b It shows the current. Figure 11a This is an example diagram showing the magnetic field distribution around the working coil section when the flow is as shown in the diagram.

[0033] Figure 11c It shows the current as follows Figure 11a An example diagram illustrating the coupling state of the magnetic field when the flow occurs in the working coil section as shown.

[0034] Figure 12 This is a control block diagram illustrating the configuration of an induction heating stove according to an embodiment of the present invention.

[0035] Figure 13 This is a circuit diagram of an induction heating stove according to the first embodiment of the present invention.

[0036] Figure 14 This is a circuit diagram of an induction heating stove according to the second embodiment of the present invention.

[0037] Figure 15 This is a circuit diagram of an induction heating stove according to the third embodiment of the present invention.

[0038] Figure 16 This is a flowchart illustrating a method for operating an induction heating stove according to an embodiment of the present invention when the magnetic body takes priority.

[0039] Figure 17 This is a flowchart illustrating a method for operating an induction heating stove according to an embodiment of the present invention when a non-magnetic body is prioritized. Detailed Implementation

[0040] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to refer to the same or similar constituent elements.

[0041] The following will describe an embodiment of the induction heating stove of the present invention.

[0042] Figure 1 This is a diagram illustrating an embodiment of the induction heating stove of the present invention. Figure 2 This is a cross-sectional view showing an induction heating stove and a heated object according to an embodiment of the present invention. Figure 3 This is a cross-sectional view showing an induction heating stove and a heated object according to another embodiment of the present invention.

[0043] First, refer to Figure 1The induction heating stove 1 of this embodiment may include a shell 25, a cover plate 20, working coil parts WC1 and WC2 (i.e., the first working coil part and the second working coil part), and thin films TL1 and TL2 (i.e., the first thin film and the second thin film).

[0044] The housing 25 may be provided with working coil sections WC1 and WC2.

[0045] For reference, in addition to the working coil sections WC1 and WC2, various devices related to the driving of the working coil section may be provided in the housing 25 (e.g., a power supply section that provides AC power, a bridge diode and capacitor that rectifies the AC power from the power supply section into DC power, an inverter that converts the rectified DC power into resonant current and provides it to the working coil through a switching action, a control module that controls the operation of various devices in the induction heating stove 1, a relay or semiconductor switch that turns the working coil on or off, etc.), but these will be described in detail later.

[0046] The cover plate 20 can be combined with the upper end of the housing 25, and an upper plate portion 15 for placing the object to be heated (not shown) can be provided on its top surface.

[0047] Specifically, the cover 20 may include an upper plate portion 15 for placing heated objects such as cooking containers.

[0048] Here, for example, the upper plate 15 can be made of glass material (e.g., ceramic glass).

[0049] Additionally, an interface section (not shown) may be provided on the upper plate 15, which receives input from the user and transmits the corresponding input to the input interface control module (not shown). Of course, the interface section may also be provided in other locations besides the upper plate 15.

[0050] For reference, the interface section is a module for inputting the user's desired heating intensity or the driving time of the induction heating stove 1, and can be implemented in various ways such as physical buttons or a touch panel. Additionally, the interface section may include, for example, a power button, a lock button, a power level adjustment button (+, -), a timer adjustment button (+, -), and a charging mode button. Furthermore, the interface section can transmit input received from the user to an input interface control module (not shown), which in turn can transmit the input to the aforementioned control module (i.e., the inverter control module). Moreover, the aforementioned control module can control the operation of various devices (e.g., the operating coil) based on the input received from the input interface control module (i.e., the user's input); details of this will be omitted.

[0051] On the other hand, the upper plate 15 can visually display, in the shape of a stove opening, whether the working coils WC1 and WC2 are driven and the heating intensity (i.e., firepower). This stove opening shape can be displayed by an indicator light (not shown) consisting of a plurality of light-emitting elements (e.g., LEDs) disposed within the housing 25.

[0052] The working coils WC1 and WC2 can be installed inside the housing 25 to heat the object being heated.

[0053] Specifically, the working coil section WC can be controlled and driven by the aforementioned control module (not shown). When the object to be heated is placed on the upper plate section 15, it can be driven by the control module.

[0054] In addition, the working coil section WC can directly heat magnetic objects (i.e., magnetic bodies), while non-magnetic objects (i.e., non-magnetic bodies) can be indirectly heated through the thin film TL described later.

[0055] Furthermore, the working coil section WC can heat the object being heated by induction heating and can be configured to overlap with the thin film TL in the longitudinal direction (i.e., vertical or up-down direction).

[0056] For reference only. Figure 1 The example shown depicts two working coil portions WC1 and WC2 disposed in the housing 25, but it is not limited to this. That is, one or more working coil portions may be disposed in the housing 25, but for ease of explanation, in the embodiment of the present invention, two working coil portions WC1 and WC2 disposed in the housing 25 will be used as an example for explanation.

[0057] A thin film TL is coated onto the upper plate portion 15 to heat the non-magnetic parts of the object being heated. The thin film TL can be induction heated by the working coil portion WC.

[0058] The thin film TL can be coated on the top or bottom surface of the upper plate portion 15. For example, as... Figure 2 As shown, the thin film TL can be coated on the top surface of the upper plate 15, or as... Figure 3 As shown, the thin film TL can be coated on the bottom surface of the upper plate 15.

[0059] The thin film TL can be configured to overlap with the working coil section WC in the longitudinal direction (i.e., vertical or up-down direction). Therefore, the object to be heated can be heated regardless of its position or type.

[0060] In addition, thin film TL can have at least one of the properties of magnetic and non-magnetic (i.e., magnetic, non-magnetic, or both).

[0061] Furthermore, for example, the thin film TL can be made of a conductive material (e.g., aluminum), and as shown, can be coated on the upper plate portion 15 in a shape consisting of a plurality of repeating rings with different diameters, but is not limited thereto. That is, the thin film TL can also be made of other materials that are not conductive. In addition, the thin film TL can also be formed in other shapes that are not consisting of a plurality of repeating rings with different diameters.

[0062] For reference only. Figure 2 and Figure 3 The diagram shows a single thin film TL, but it is not limited to this. That is, multiple thin films can also be coated, but for the sake of illustration, we will use coating a single thin film TL as an example.

[0063] The thin film TL will be explained in more detail later.

[0064] Next, refer to Figure 2 and Figure 3 The induction heating stove 1 of this embodiment may further include at least some or all of the following: heat insulation material 35, shielding plate 45, support member 50, and cooling fan 55.

[0065] The heat insulation material 35 can be disposed between the upper plate portion 15 and the working coil portion WC.

[0066] Specifically, the heat insulation material 35 can be installed below the upper plate 15, and the working coil section WC can be arranged below it.

[0067] This heat insulation material 35 can block the heat generated when the thin film TL or the heated object HO is heated by the drive of the working coil section WC from being transferred to the working coil section WC.

[0068] That is, if the thin film TL or the heated object HO is heated by electromagnetic induction through the working coil section WC, the heat of the thin film TL or the heated object HO will be transferred to the upper plate section 15, and the heat of the upper plate section 15 will be transferred to the working coil section WC again, which may damage the working coil section WC.

[0069] As described above, the heat insulation material 35 blocks the heat transferred to the working coil section WC, thereby preventing the working coil section WC from being damaged by heat, and further preventing the heating performance of the working coil section WC from decreasing.

[0070] For reference, although not a necessary component, a partition (not shown) may be provided between the working coil section WC and the heat insulation material 35.

[0071] Specifically, a partition (not shown) can be inserted between the working coil section WC and the heat insulation material 35, so that the working coil section WC and the heat insulation material 35 do not directly contact each other. Thus, the partition (not shown) can prevent the heat generated when the working coil section WC is driven to heat the thin film TL or the heated object HO from being transferred to the working coil section WC through the heat insulation material 35.

[0072] That is, the partition (not shown) can share part of the function of the heat insulation material 35, thereby minimizing the thickness of the heat insulation material 35, which in turn minimizes the gap between the heated object HO and the working coil part WC.

[0073] Additionally, a plurality of partitions (not shown) may be provided, and the plurality of partitions may be arranged between the working coil section WC and the heat insulation material 35 to separate each other. Thus, air drawn into the interior of the housing 25 by the cooling fan 55 (described later) may be guided to the working coil section WC by the partitions.

[0074] That is, the baffle can guide the air flowing into the interior of the housing 25 through the cooling fan 55 to be properly delivered to the working coil section WC, thereby improving the cooling efficiency of the working coil section WC.

[0075] The shielding plate 45 can be installed on the bottom surface of the working coil section WC to block the downward magnetic field generated when the working coil section WC is driven.

[0076] Specifically, the shielding plate 45 can block the downward magnetic field generated when the working coil section WC is driven, and can be supported upward by the support member 50.

[0077] The support member 50 can be disposed between the bottom surface of the shielding plate 45 and the lower plate of the housing 25 to support the shielding plate 45 upward.

[0078] Specifically, the support member 50 can indirectly support the heat insulation material 35 and the working coil part WC upward by supporting the shielding plate 45 upward, so that the heat insulation material 35 can be closely attached to the upper plate part 15.

[0079] As a result, the distance between the working coil section WC and the heated object HO can be maintained constant.

[0080] For reference, the support member 50 may include, for example, an elastic body (e.g., a spring) for supporting the shielding plate 45 upwards, but is not limited thereto. Furthermore, since the support member 50 is not an essential component, it can be omitted from the induction heating stove 1.

[0081] A cooling fan 55 can be installed inside the housing 25 to cool the working coil section WC.

[0082] Specifically, the cooling fan 55 can be driven by the aforementioned control module and can be installed on the side wall of the housing 25. Of course, the cooling fan 55 can also be installed in other locations besides the side wall of the housing 25, but in this embodiment of the invention, for ease of explanation, the example of the cooling fan 55 being installed on the side wall of the housing 25 will be used for illustration.

[0083] In addition, such as Figure 2 and Figure 3 As shown, the cooling fan 55 can draw in air from outside the housing 25 and deliver it to the working coil section WC, or it can draw in air (especially hot air) from inside the housing 25 and exhaust it to the outside of the housing 25.

[0084] This enables effective cooling of the components inside the housing 25 (especially the working coil section WC).

[0085] Furthermore, as described above, the air supplied by the cooling fan 55 to the outside of the housing 25 of the working coil section WC can be guided to the working coil section WC by the partition. As a result, the working coil section WC can be directly and effectively cooled, thereby improving the durability of the working coil WC (i.e., durability improvement based on preventing thermal damage).

[0086] As described above, an induction heating stove 1 according to an embodiment of the present invention may have the above-described features and configuration, and in the following description, reference will be made to... Figures 4 to 7 The characteristics and composition of the above-mentioned thin film will be explained in more detail.

[0087] Figure 4 and Figure 5 This is a graph illustrating the relationship between film thickness and skin depth. Figure 6 and Figure 7 It is a graph illustrating the impedance changes between the thin film and the heated object, depending on the type of object being heated.

[0088] Thin-film TL can be made from materials with low relative permeability.

[0089] Specifically, due to the low relative permeability of thin-film TL, the skin depth of thin-film TL can be relatively deep. Here, skin depth refers to the depth of current penetration from the material surface, and relative permeability can be inversely proportional to skin depth. Therefore, the lower the relative permeability of thin-film TL, the deeper the skin depth of thin-film TL.

[0090] Furthermore, the skin depth of the thin film TL can be greater than the thickness of the thin film TL. That is, the thin film TL has a relatively thin thickness (e.g., 0.1 μm to 1,000 μm), while the skin depth of the thin film TL is greater than the thickness of the thin film TL. Therefore, the magnetic field generated by the working coil section WC passes through the thin film TL and is transmitted to the heated object HO, thereby inducing eddy currents in the heated object HO.

[0091] That is, such as Figure 4 As shown, when the skin depth of the thin film TL is thinner than the thickness of the thin film TL, the magnetic field generated by the working coil WC may have difficulty reaching the heated object HO.

[0092] However, as Figure 5 As shown, when the skin depth of the thin film TL is deeper than the thickness of the thin film TL, the magnetic field generated by the working coil section WC can reach the heated object HO. That is, in the embodiment of the present invention, the skin depth of the thin film TL is deeper than the thickness of the thin film TL, so most of the magnetic field generated by the working coil section WC passes through the thin film TL and is transmitted to the heated object HO and consumed, thereby mainly heating the heated object HO.

[0093] On the other hand, since the thin film TL has a relatively thin thickness as described above, it can have a resistance value that can be heated by the working coil section WC.

[0094] Specifically, the thickness of the thin film TL can be inversely proportional to the resistance value (i.e., surface resistance value) of the thin film TL. That is, the thinner the thin film TL coated onto the upper plate portion 15, the greater the resistance value (i.e., surface resistance value) of the thin film TL. Therefore, the thin film TL can be coated onto the upper plate portion 15 more thinly, so that its characteristics can be changed to a load that can be heated.

[0095] For reference, for example, a thin film TL can have a thickness between 0.1 μm and 1,000 μm, but is not limited to this.

[0096] The thin film TL, which has the characteristics described above, exists for heating non-magnetic materials. Therefore, the impedance characteristics between the thin film TL and the heated object HO can be changed depending on whether the heated object HO disposed on the upper plate 15 is a magnetic or non-magnetic material.

[0097] First, the following explanation addresses the case where the heated object HO is a magnetic material.

[0098] When a magnetic object HO is placed on the upper plate 15 and the working coil WC is driven, as follows: Figure 6 As shown, the resistive component R1 and inductive component L1 of the magnetic heated object HO can form an equivalent circuit with the resistive component R2 and inductive component L2 of the thin film TL.

[0099] In this case, the impedance of the heated object HO with magnetism in the equivalent circuit (i.e., the impedance composed of R1 and L1) can be less than the impedance of the thin film TL (i.e., the impedance composed of R2 and L2).

[0100] Therefore, with the equivalent circuit described above formed, the magnitude of the eddy current I1 applied to the magnetic heated object HO can be greater than the magnitude of the eddy current I2 applied to the thin film TL. Thus, most of the eddy current generated by the working coil section WC can be applied to the heated object HO to heat it.

[0101] That is, when the object being heated HO is a magnetic body, most of the eddy current is applied to the object being heated HO due to the formation of the above-mentioned equivalent circuit, so the working coil section WC can directly heat the object being heated HO.

[0102] Of course, some eddy current is also applied to the thin film TL, causing the thin film TL to be slightly heated. Therefore, the object HO to be heated can be indirectly heated slightly by the thin film TL. In this case, the working coil section WC can be the main heating source, and the thin film TL can be the secondary heating source. However, the degree to which the object HO is indirectly heated by the thin film TL may be meaningless compared to the degree to which the object HO is directly heated by the working coil section WC.

[0103] Next, the case where the heated object is a non-magnetic body will be explained below.

[0104] When a non-magnetic heated object HO is placed on the upper plate 15 and the working coil WC is driven, the non-magnetic heated object HO may not have impedance, while the thin film TL may have impedance. That is, the resistive component R and the inductive component L may exist only in the thin film TL.

[0105] Therefore, when a non-magnetic heated object HO is placed on the upper plate 15 and the working coil WC is driven, as Figure 7 As shown, the resistive component R and the inductive component L of the thin film TL can form an equivalent circuit.

[0106] Therefore, the eddy current I can be applied only to the thin film TL, and the eddy current is not applied to the non-magnetic heated object HO. More specifically, the eddy current I generated by the working coil section WC can be applied only to the thin film TL, thereby heating the thin film TL.

[0107] That is, when the object to be heated HO is a non-magnetic body, as described above, the eddy current I is applied to the thin film TL to heat the thin film TL. Therefore, the non-magnetic object to be heated HO can be indirectly heated by the thin film TL heated by the working coil section WC. In this case, the thin film TL can be the main heating source.

[0108] In summary, regardless of whether the heated object HO is magnetic or non-magnetic, the heated object HO can be directly or indirectly heated by a heat source, which is referred to as the working coil section WC. That is, when the heated object HO is magnetic, the working coil section WC can directly heat the heated object HO; when the heated object HO is non-magnetic, the thin film TL heated by the working coil section WC can indirectly heat the heated object HO.

[0109] As described above, the induction heating stove 1 of this embodiment can heat both magnetic and non-magnetic materials. Therefore, regardless of the placement and type of the object to be heated (HO), it can be heated. Thus, users can place the object to be heated in any heating area on the upper plate 15 without needing to determine whether the object to be heated (HO) is magnetic or non-magnetic, thereby improving ease of use.

[0110] Furthermore, the induction heating stove 1 of this embodiment can directly or indirectly heat the object being heated using the same heat source, thus eliminating the need for an additional heating plate or radiant heater. This not only improves heating efficiency but also reduces material costs.

[0111] On the other hand, when the heated object HO is a magnetic material, in the equivalent circuit described above, most of the eddy currents are applied to the heated object HO, but some of the eddy currents are also applied to the thin film TL, thereby reducing the heating efficiency of the heated object HO, which is a magnetic material. Therefore, it is preferable to minimize the eddy currents applied to the thin film TL. That is, when the heated object HO is a magnetic material, it is preferable to maximize the magnetic field coupled to the heated object HO.

[0112] For the same reason, when the heated object HO is a non-magnetic body, it is also preferable to maximize the eddy current applied to the thin film TL.

[0113] Therefore, the induction heating stove 1 of the present invention can adjust the magnetic field concentration area by controlling the current direction of the working coil WC, thereby improving the heating efficiency regardless of whether the heated object HO is a magnetic or non-magnetic body.

[0114] Then, refer to Figures 8 to 9The present invention will describe a method for adjusting the magnetic field concentration area by controlling the current direction of the working coil section WC in an induction heating stove 1 according to an embodiment of the present invention.

[0115] Figure 8 and Figure 9 This is a diagram illustrating an embodiment of an induction heating stove of the present invention.

[0116] On the other hand, Figure 1 The diagram illustrates a case where an induction heating stove has two burner openings, allowing the object HO to be heated to be heated either by the drive of the first working coil section WC1 or by the drive of the second working coil section WC2. Figure 8 For ease of explanation, the description assumes there is only one burner opening. That is, the number of burners provided in the induction heating stove of the present invention can vary.

[0117] Reference Figure 8 An embodiment of the induction heating stove of the present invention may include a working coil section WC disposed below a thin film TL, and the working coil section WC may be composed of a plurality of working coils.

[0118] For example, a plurality of working coils WC-1 and WC-2 may include a first working coil WC-1 and a second working coil WC-2, but the number of working coils provided in a working coil section WC may be different. Hereinafter, it is assumed that a working coil section WC is composed of a first working coil WC-1 and a second working coil WC-2.

[0119] The first working coil WC-1 and the second working coil WC-2 constituting the working coil section WC can be arranged adjacent to each other. The adjacent arrangement of the first working coil WC-1 and the second working coil WC-2 can mean that they are arranged close enough that the magnetic field induced in one working coil (e.g., the first working coil WC-1) affects the magnetic field induced in the other working coil (e.g., the second working coil WC-2). Therefore, as... Figure 8 As shown, the first working coil WC-1 and the second working coil WC-2 can be configured to have a point contact.

[0120] A thin film TL that is perpendicularly overlapped with the working coil portion WC, which includes the first working coil WC-1 and the second working coil WC-2, can be coated on the top or bottom surface of the upper plate portion 15.

[0121] An opening TL-I may be formed at the center of the thin film TL. The opening TL-I may include a center TL-C of the opening of the thin film TL and a region extending from the center TL-C of the opening to a predetermined distance. The opening TL-I of the thin film is a portion not coated with the thin film TL, and it may be an area opened for sensing the temperature of the upper plate portion 15.

[0122] Furthermore, the opening TL-I of the thin film can be a region through which the magnetic field induced in the working coil section WC passes. That is, the opening TL-I of the thin film can perform the function of allowing the magnetic field to pass through, so that the magnetic field generated in the working coil section WC is coupled with the heated object HO.

[0123] The center TL-C of the opening may overlap with the center WC-C of the working coil portion in the vertical direction. The opening TL-I and the central region WC-I of the working coil portion may overlap at least partially in the vertical direction. The central region WC-I of the working coil portion may include the center WC-C of the working coil portion and a region extending from the center WC-C of the working coil portion to a predetermined distance. The accompanying drawings show that the diameters of the opening TL-I and the central region WC-I of the working coil portion are the same, but this is not a limitation.

[0124] With this configuration, when the magnetic field concentration area described later is the central region WC-I of the working coil section, the magnetic field passing through the opening TL-I can be coupled to the heated object HO more.

[0125] Furthermore, the peripheral region WC-O of the working coil section can be configured to perpendicularly overlap with at least a portion of the thin film TL. Therefore, when the magnetic field concentration region is the peripheral region WC-O of the working coil section, the magnetic field can couple more strongly to the thin film TL, thereby improving the heating efficiency of the heated object HO, which is a non-magnetic material.

[0126] According to one embodiment, the shapes of the first working coil WC-1 and the second working coil WC-2 can be as follows: Figure 8 The hollow circular shape is shown. That is, the first working coil WC-1 and the second working coil WC-2 can each be a hollow circle. According to another embodiment, as... Figure 9 As shown, the first working coil WC-1 and the second working coil WC-2 can each be semi-circular in shape. In this case, holes may not be formed in the first working coil WC-1 and the second working coil WC-2. That is, the shape of each working coil can have various forms. Therefore, the shape of the working coils does not limit the scope of the invention. In this specification, for ease of explanation, a hollow circular working coil portion WC is used for description.

[0127] like Figure 9As shown, the semi-circular first working coil WC-1 and second working coil WC-2 can be configured such that the working coil portion WC has a circular shape. In the circular working coil portion WC, the central region WC-I, which is the area extending from the exact center of the working coil portion WC to a predetermined distance, and the opening TL-I can overlap at least partially in the vertical direction. The peripheral region WC-O of the working coil portion and the thin film TL can also overlap at least partially in the vertical direction.

[0128] As described above, the current in the first working coil WC-1 and the second working coil WC-2 constituting the working coil section WC can be controlled to flow in the same direction or in different directions. The concentration region of the magnetic field can be changed according to the direction of the current flowing through the first working coil WC-1 and the second working coil WC-2, respectively. The magnetic field concentration region changed according to the direction of the current flowing through the first working coil WC-1 and the second working coil WC-2 will be described below.

[0129] First, refer to Figures 10a to 10b The magnetic field concentration region when the directions of the currents flowing through the first working coil WC-1 and the second working coil WC-2 are the same is explained.

[0130] Figure 10a This is an example diagram showing the direction of current flowing through the first and second working coils of a stove according to an embodiment of the present invention.

[0131] For example, such as Figure 10a As shown, if we assume that the current flowing through the first working coil WC-1 is in a clockwise direction, then the current flowing through the second working coil WC-2 can be in the same clockwise direction as the current flowing through the first working coil WC-1.

[0132] At this time, the magnetic field generated by the first working coil WC-1 and the magnetic field generated by the second working coil WC-2 can be formed in the same direction in the outer region WC-O of the working coil section. If the magnetic field generated by the first working coil WC-1 and the magnetic field generated by the second working coil WC-2 are formed in the same direction, then in the outer region WC-O of the working coil section, the magnetic fields generated by each working coil can be superimposed.

[0133] Conversely, in the central region WC-I of the working coil section, the magnetic field generated by the first working coil WC-1 and the magnetic field generated by the second working coil WC-2 can form in different directions. If the magnetic field generated by the first working coil WC-1 and the magnetic field generated by the second working coil WC-2 form in different directions, then in the central region WC-I of the working coil section, the magnetic fields generated by each working coil can cancel each other out.

[0134] Therefore, when the direction of the current flowing through the first working coil WC-1 is the same as the direction of the current flowing through the second working coil WC-2, the magnetic field strength in the central region WC-I of the working coil may be weaker than the magnetic field strength in the outer region WC-O of the working coil.

[0135] Figure 10b It shows the current as follows Figure 10a This is an example diagram showing the magnetic field distribution around the working coil section when the flow occurs in the working coil section as shown.

[0136] like Figure 10b As shown, if the currents flowing through the first working coil WC-1 and the second working coil WC-2 are in the same direction, the magnetic field is concentrated in the outer region WC-O of the working coil section. Furthermore, it can be seen that the magnetic field in the central region WC-I of the working coil section is relatively weak.

[0137] Next, refer to Figures 10c to 10d This describes a method for an induction heating stove 1 to heat an object HO, which is a non-magnetic body.

[0138] Figure 10c It shows the current as follows Figure 10a An example diagram illustrating the coupling state of the magnetic field when the flow occurs in the working coil section as shown.

[0139] When viewed from the side, the induction heating stove 1 of this embodiment of the invention shows that the first working coil WC-1 may be located on one side of the working coil section WC, and the second working coil WC-2 may be located on the other side of the working coil section WC. The central region WC-I of the working coil section, including the contact point WC-C of the first working coil WC-1 and the second working coil WC-2, is located at the center of the working coil section WC. The peripheral region WC-O of the working coil section may include the remaining areas of the first working coil WC-1 and the second working coil WC-2 that are not located in the central region WC-I of the working coil section.

[0140] The arrows shown in the attached diagram represent the magnetic fields generated by the first working coil WC-1 and the second working coil WC-2, respectively. That is, it can be confirmed that if the currents flowing through the first working coil WC-1 and the second working coil WC-2 are in the same direction, the magnetic field is concentrated in the peripheral region WC-O of the working coil section. In other words, if the currents flowing through the first working coil WC-1 and the second working coil WC-2 are in the same direction, the magnetic field concentration region can be formed in the peripheral region WC-O of the working coil section.

[0141] The magnetic field induced in the working coil section WC can couple to the thin film TL, which is perpendicularly overlapped with the peripheral region WC-O of the working coil section, and heat the thin film TL. The heated thin film TL can heat the heated object HO.

[0142] Figure 10d This is an example diagram showing the state of the thin film when the magnetic field concentration region is the outer region of the working coil.

[0143] like Figure 10d As shown, the eddy current (EC) flowing through the thin film TL can heat the thin film TL. At this time, the eddy current EC will not flow through the opening TL-I formed in the center.

[0144] As described above, when the currents flowing through the first working coil WC-1 and the second working coil WC-2 are in the same direction, the magnetic field concentrated in the peripheral region WC-O of the working coil section has a higher probability of coupling with the thin film, thus maximizing the eddy current EC flowing through the thin film TL. Therefore, the situation where the currents flowing through the first working coil WC-1 and the second working coil WC-2 are in the same direction may be suitable for heating the object HO, which is a non-magnetic body.

[0145] Next, refer to Figures 11a to 11b The magnetic field concentration region when the directions of the current flowing through the first working coil WC-1 and the second working coil WC-2 are different is explained.

[0146] Figure 11a This is an example diagram showing the direction of current flowing through the first and second working coils of a stove according to an embodiment of the present invention.

[0147] For example, such as Figure 11a As shown, if we assume that the current flowing through the first working coil WC-1 is in a clockwise direction, then the current flowing through the second working coil WC-2 can be in a counterclockwise direction, which is different from the direction of the current flowing through the first working coil WC-1.

[0148] At this time, the magnetic field generated by the first working coil WC-1 and the magnetic field generated by the second working coil WC-2 can be formed in the same direction in the central region WC-I of the working coil section. If the magnetic field generated by the first working coil WC-1 and the magnetic field generated by the second working coil WC-2 are formed in the same direction, then in the central region WC-I of the working coil section, the magnetic fields generated by each working coil can be superimposed.

[0149] Conversely, in the outer region WC-O of the working coil section, the magnetic field generated by the first working coil WC-1 and the magnetic field generated by the second working coil WC-2 can form in different directions. If the magnetic field generated by the first working coil WC-1 and the magnetic field generated by the second working coil WC-2 form in different directions, then in the outer region WC-O of the working coil section, the magnetic fields generated by each working coil can cancel each other out.

[0150] Therefore, when the direction of the current flowing through the first working coil WC-1 is different from the direction of the current flowing through the second working coil WC-2, the magnetic field strength in the central region WC-I of the working coil may be stronger than the magnetic field strength in the outer region WC-O of the working coil.

[0151] Figure 11b It shows the current as follows Figure 11a This is an example diagram showing the magnetic field distribution around the working coil section when the flow occurs in the working coil section as shown.

[0152] like Figure 11b As shown, it can be seen that if the directions of the currents flowing through the first working coil WC-1 and the second working coil WC-2 are different, the magnetic field is concentrated in the central region WC-I of the working coil section. Furthermore, it can be seen that the magnetic field in the outer region WC-O of the working coil section is relatively weak.

[0153] Next, refer to Figure 11c This describes a method for heating an object HO, which is a magnetic material, using an induction heating stove 1.

[0154] Figure 11c It shows the current as follows Figure 11a An example diagram illustrating the coupling state of the magnetic field when the flow occurs in the working coil section as shown.

[0155] When viewed from the side, the induction heating stove 1 of this embodiment of the invention shows that the first working coil WC-1 may be located on one side of the working coil section WC, and the second working coil WC-2 may be located on the other side of the working coil section WC. The central region WC-I of the working coil section, including the contact point WC-C of the first working coil WC-1 and the second working coil WC-2, is located at the center of the working coil section WC. The peripheral region WC-O of the working coil section may include the remaining areas of the first working coil WC-1 and the second working coil WC-2 that are not located in the central region WC-I of the working coil section.

[0156] The arrows shown in the attached diagram represent the magnetic fields generated by the first working coil WC-1 and the second working coil WC-2, respectively. That is, it can be confirmed that if the directions of the currents flowing through the first working coil WC-1 and the second working coil WC-2 are different, the magnetic field is concentrated in the central region WC-I of the working coil section. In other words, if the directions of the currents flowing through the first working coil WC-1 and the second working coil WC-2 are different, the magnetic field concentration region can be formed in the central region WC-I of the working coil section.

[0157] The magnetic field induced in the working coil section WC can pass through the opening TL-I of the thin film that is perpendicularly overlapped with the central region WC-I of the working coil section, thereby generating eddy currents in the heated object HO and heating the heated object HO.

[0158] As described above, when the directions of the currents flowing through the first working coil WC-1 and the second working coil WC-2 are different, the probability of the magnetic field concentrated in the central region WC-I of the working coil section coupling with the heated object HO is higher, thus minimizing the eddy current EC flowing through the thin film TL. Therefore, the situation where the directions of the currents flowing through the first working coil WC-1 and the second working coil WC-2 are different may be suitable for heating the heated object HO, which is a magnetic material.

[0159] On the other hand, the induction heating stove 1 of the present invention can improve heating efficiency by controlling the concentrated area of ​​the magnetic field, without the need to set up a container identification sensor for identifying whether the heated object HO is a magnetic or non-magnetic object.

[0160] Next, refer to Figures 12 to 14 This invention describes a method for controlling the magnetic field concentration area in an induction heating stove 1 according to an embodiment of the present invention.

[0161] Figure 12 This is a control block diagram illustrating the configuration of an induction heating stove according to an embodiment of the present invention.

[0162] Reference Figure 12 The induction heating stove 1 may include an input interface control module 40, an inverter 60, a control unit 70, and a switch unit SW.

[0163] The input interface control module 40 can receive input information such as heating intensity or driving time from the interface section (not shown) and transmit it to the control unit 70. The input information received by the control unit 70 through the input interface control module 40 may include information about the target power.

[0164] Inverter 60 can supply resonant current to the working coil section WC through switching operation. The switching operation of inverter 60 can be executed by the switching operation control signal of control unit 70.

[0165] According to an embodiment, inverter 60 may include a first inverter 61 that drives the first operating coil WC-1 (see reference). Figure 14 , Figure 15 ) and the second inverter 62 (refer to) that drives the second working coil WC-2 Figure 14 , Figure 15 ).

[0166] The control unit 70 can control the first inverter 61 to change the direction of the current flowing through the first working coil WC-1, and can control the second inverter 62 to change the direction of the current flowing through the second working coil WC-2.

[0167] According to an embodiment, the switch SW can be driven to control the direction of the current flowing through the first working coil WC-1 and the second working coil WC-2, respectively. The method for controlling the current direction of the working coils by driving the switch SW will be described later. Figure 15 Please provide a detailed explanation.

[0168] That is, the control unit 70 can control the switching unit SW, or control the first inverter 61 and the second inverter 62, according to the circuit configuration described later, to change the current direction. This will be achieved through... Figures 13 to 15 Detailed explanation.

[0169] The control unit 70 can control the direction of the current flowing through the first working coil WC-1 and the direction of the current flowing through the second working coil WC-2 by comparing the target power and the output power.

[0170] In addition, the control unit 70 can control the overall operation of the induction heating stove 1.

[0171] Figure 12 The induction heating stove 1 shown is only one embodiment of the present invention. Therefore, some of the constituent elements shown may be integrated, added or omitted according to the specifications of the actual induction heating stove 1.

[0172] In the induction heating stove 1 of this embodiment of the invention, the control circuit for controlling the direction of the current flowing through the first working coil WC-1 and the second working coil WC-2 can be configured in various ways.

[0173] The control circuit can be configured to provide a switching section SW in an inverter 60, or to provide an inverter 60 in each coil, or to provide a separate bridge diode BD in each coil, so as to control the direction of the current flowing through the first working coil WC-1 and the second working coil WC-2 to be the same or different.

[0174] Next, refer to Figures 13 to 15 The method of controlling the direction of the current flowing through the working coil section WC by the control unit 70 is explained through the circuit diagram.

[0175] Figure 13 This is a circuit diagram of an induction heating stove according to the first embodiment of the present invention.

[0176] The control circuit may include a power supply unit V that provides AC power, a bridge diode BD that rectifies the AC power from the power supply unit into DC power, a DC link capacitor C1 that smooths the rectified DC power, an inverter 60 that converts the rectified DC power into a resonant current through a switching action and provides it to the working coil unit WC, the working coil unit WC that generates a magnetic field due to the resonant current, a switching unit SW that controls the current direction of the working coil unit WC, and a resonant capacitor C2.

[0177] The power supply unit V, bridge diode BD, and DC link capacitor C1 can perform the function of rectifying AC power into DC power and smoothing the rectified DC power before providing it to the inverter 60.

[0178] Inverter 60 can convert rectified DC power into resonant current through switching operations, and can be composed of at least two switching elements 60-1 and 60-2. Switching elements 60-1 and 60-2 can be high-frequency semiconductor devices. For example, switching elements may include IGBTs (Insulated Gate Bipolar Transistors), BJTs (Bipolar Junction Transistors), MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors), etc. Since the driving method of inverter 60 is a well-known technology, a detailed description thereof will be omitted.

[0179] One end of the first working coil WC-1 can be connected between the first switching element 60-1 and the second switching element 60-2, and the other end of the first working coil WC-1 can be connected to the first switch SW1. One end of the second working coil WC-2 can be connected to the first switch SW1, and the other end can be connected to the second switch SW2.

[0180] One end of the second switch SW2 can be connected to the second working coil WC-2, and the other end can be connected to the resonant capacitor C2.

[0181] The first switch SW1 and the second switch SW2 can simultaneously contact the first point or the second point through the control signal of the control unit 70.

[0182] For example, if the first switch SW1 and the second switch SW2 are connected to the first point, the current flowing through the first working coil WC-1 in a clockwise direction will flow through the second working coil WC-2 in a counterclockwise direction along the first point connected to the first working coil WC-1 and then move along the first point connected to the second switch SW2.

[0183] That is, if the first switch SW1 and the second switch SW2 are simultaneously in contact with the first point, the current flowing through the first working coil WC-1 and the second working coil WC-2 can be in opposite directions.

[0184] As another example, if the first switch SW1 and the second switch SW2 are connected to the second point at the same time, the current flowing out after passing through the first working coil WC-1 in a clockwise direction will flow through the second working coil WC-2 in a clockwise direction along the second point connected to the first working coil WC-1 and then move along the second point connected to the second switch SW2.

[0185] That is, if the first switch SW1 and the second switch SW2 are simultaneously in contact with the second point, the current flowing through the first working coil WC-1 and the second working coil WC-2 can be in the same direction.

[0186] One end of the second switch SW2 can be connected to the second working coil WC-2 by contacting the first point or the second point, and the other end of the second switch SW2 can be connected between the first resonant capacitor C2-1 and the second resonant capacitor C2-2.

[0187] With this control circuit configuration, the induction heating stove 1 of this embodiment of the invention can control the current direction of the working coil section WC using an inverter 60 and a switching unit SW. According to this embodiment, no additional circuit for synchronizing the inverter signal is required, thus offering the advantage of simplified structure.

[0188] Figure 14 This is a circuit diagram of an induction heating stove according to the second embodiment of the present invention.

[0189] According to the second embodiment, the inverter 60 may include a first inverter 61 and a second inverter 62.

[0190] One end of the first working coil WC-1 can be connected between the first switching element 61-1 and the second switching element 61-2 of the first inverter 61, and the other end of the first working coil WC-1 can be connected between the first resonant capacitor C2-a1 and the second resonant capacitor C2-a2.

[0191] One end of the second working coil WC-2 can be connected between the first switching element 62-1 and the second switching element 62-2 of the second inverter 62, and the other end of the second working coil WC-2 can be connected between the third resonant capacitor C2-b1 and the fourth resonant capacitor C2-b2.

[0192] That is, the control unit 70 can control the first inverter 61 connected to the first working coil WC-1 and the second inverter 62 connected to the second working coil WC-2 respectively, so as to control the direction of the current flowing through the first working coil WC-1 and the second working coil WC-2 to be the same or different. In addition, the control unit 70 can control the magnetic field region of the working coil WC more precisely than when using a single inverter. For example, it can control the first inverter 61 or the second inverter 62 so that the current flowing through the first working coil WC-1 or the second working coil WC-2 becomes 0.

[0193] With this control circuit configuration, the induction heating stove 1 of the present invention precisely controls the direction of the current flowing through the first working coil WC-1 and the direction of the current flowing through the second working coil WC-2, thereby having the advantage of being able to control the magnetic field concentration area in various ways.

[0194] Figure 15 This is a circuit diagram of an induction heating stove according to the third embodiment of the present invention.

[0195] The induction heating stove 1 of the third embodiment can be configured to be driven by a plurality of inverters having individual bridge diodes BD.

[0196] Reference Figure 15 The control circuit of the first working coil WC-1 can be configured to include a first power supply V1, a first bridge diode BD1, a first DC link capacitor C1-1, a first inverter 61, a first resonant capacitor C2-a1, and a second resonant capacitor C2-a2.

[0197] The control circuit for the second working coil WC-2 can be configured to include a second power supply V2, a second bridge diode BD2, a second DC link capacitor C1-2, a second inverter 62, a third resonant capacitor C2-b1, and a fourth resonant capacitor C2-b2.

[0198] That is, the control circuit of the first working coil WC-1 and the control circuit of the second working coil WC-2 can be constructed separately.

[0199] according to Figure 15 The control circuit is configured such that the AC power supplied from the first power supply V1 and the second power supply V2 can be rectified into DC power by the first bridge diode BD1 and the second bridge diode BD2 respectively, and then separate resonant currents can be provided to the first working coil WC-1 and the second working coil WC-2 by the switching action of the first inverter 61 and the second inverter 62.

[0200] As described in the above embodiments, the control unit 70 can control the first inverter 61 connected to the first working coil WC-1 and the second inverter 62 connected to the second working coil WC-2 respectively, so as to control the direction of the current flowing through the first working coil WC-1 and the second working coil WC-2 to be the same or different.

[0201] The control circuit of the third embodiment can increase the input voltage applied to the working coil section WC by having a separate bridge diode BD. Therefore, it has the advantage of being able to increase the output of the working coil section WC.

[0202] On the other hand, the induction heating stove 1 of the present invention can operate with either a magnetic body or a non-magnetic body set as the priority.

[0203] According to one embodiment, the induction heating stove 1 can prioritize cases where the heated object HO is a magnetic body.

[0204] Reference Figure 16 This describes the operation method of the induction heating stove 1 in this embodiment of the invention when the case where the heated object HO is a magnetic body is set as the priority.

[0205] Figure 16 This is a flowchart illustrating a method for operating an induction heating stove according to an embodiment of the present invention when a magnetic material is given priority.

[0206] The control unit 70 can receive the target power via the control module 40 through the input interface (S10). The target power can be the power that needs to be output from the power supply unit V of the drive coil unit WC. The target power can vary depending on the heating intensity desired by the user, etc.

[0207] The control unit 70 can control the current flowing through the first working coil WC-1 and the second working coil WC-2 in different directions (S12).

[0208] In the formation of such Figure 13 In the circuit shown, the control unit 70 can control the switch unit SW so that the first direction of the current flowing through the first working coil WC-1 and the second direction of the current flowing through the second working coil WC-2 are different. In the configuration as shown... Figure 14 or Figure 15 In the circuit shown, the control unit 70 can control the first inverter 61 and the second inverter 62 such that the first direction of the current flowing through the first working coil WC-1 and the second direction of the current flowing through the second working coil WC-2 are different.

[0209] As described above, regarding the mode in which the current flows through the first working coil WC-1 and the second working coil WC-2 have different directions, since the magnetic field concentration area is the central region WC-I of the working coil section, it can refer to the mode suitable for the heated object HO to be a magnetic body.

[0210] The control unit can determine whether the target power and the output power are consistent in different current direction modes (S13). The output power is the value obtained by multiplying the voltage and current in the power supply section V that drives the working coil section WC. The control unit 70 can sense the output power of the power supply section V and determine whether it is consistent with the target power.

[0211] The fact that the target power and output power are the same under different current directions means that the heated object HO is being properly heated with the target output.

[0212] Therefore, if the target power and the output power are the same, the control unit 70 can maintain the output in the current mode (S14). That is, the control unit 70 can continue to maintain a mode where the first direction of the current flowing through the first working coil WC-1 and the second direction of the current flowing through the second working coil WC-2 are different.

[0213] If the target power and the output power are inconsistent even when the applied voltage is increased or decreased, the control unit 70 can control the output power to a mode in which the current flowing through the first working coil WC-1 and the second working coil WC-2 are in the same direction (S15).

[0214] Even if the output power is controlled by increasing or decreasing the applied voltage, the discrepancy between the target power and the output power may indicate that the heated object HO is not being properly heated to the target output. That is, the heated object HO is not heated when the magnetic field concentration region is the central region WC-I of the working coil. This suggests that the magnetic field passing through the central region WC-I of the working coil is not coupled to the heated object HO, which may mean that the heated object HO is a non-magnetic body. Therefore, it may mean that the magnetic field concentration region needs to be changed to the outer region WC-O of the working coil.

[0215] This is because, under different current directions, the magnetic field concentration area is the central region WC-I of the working coil section. Therefore, the strength of the magnetic field coupled with the thin film TL is relatively weak. As a result, when the heated object HO is a non-magnetic body, the target power and the output power may not be consistent.

[0216] Therefore, if the target power and output power are inconsistent when the current flowing through the first working coil WC-1 and the second working coil WC-2 are in different directions, the control unit 70 can control the current flowing through the first working coil WC-1 and the second working coil WC-2 to be in the same direction.

[0217] After the control unit 70 controls the current direction of the first working coil WC-1 and the second working coil WC-2 to the mode in which the current direction of the first working coil WC-1 and the second working coil WC-2 is the same, it can determine whether the target power and the output power are consistent (S16).

[0218] While the control unit 70 controls the direction of the current flowing through the first working coil WC-1 and the second working coil WC-2 to be the same, if the target power and the output power are consistent, the output can be maintained in the current mode (S17).

[0219] In a mode where the target power and output power are the same, it can mean that the object being heated, HO, is being properly heated with the target output. Therefore, the control unit 70 can continue to maintain output in a mode where the first direction of the current flowing through the first working coil WC-1 and the second direction of the current flowing through the second working coil WC-2 are the same.

[0220] If the target power and the output power are inconsistent, the control unit 70 can control the output in the current mode (S18).

[0221] In a mode where the current direction is the same, the discrepancy between the target power and the output power may mean that the object being heated, HO, is not being heated with the target output.

[0222] Therefore, the control unit 70 can control the output by increasing or decreasing the applied voltage while maintaining the current direction of each coil until the target power is reached.

[0223] On the other hand, according to one embodiment, the induction heating stove 1 can prioritize the case where the heated object HO is a non-magnetic body.

[0224] Reference Figure 17 This describes the operation method of the induction heating stove 1 in this embodiment of the invention when the case where the heated object HO is a non-magnetic body is set as the priority.

[0225] Figure 17 This is a flowchart illustrating a method for operating an induction heating stove according to an embodiment of the present invention when non-magnetic materials are given priority.

[0226] The control unit 70 can receive the target power via the control module 40 through the input interface (S20).

[0227] The control unit 70 can be controlled to a mode in which the current flowing through the first working coil WC-1 and the second working coil WC-2 has the same direction (S22). The control unit 70 can control the switch unit SW or the first inverter 61 and the second inverter 62 so that the first direction of the current flowing through the first working coil WC-1 and the second direction of the current flowing through the second working coil WC-2 are the same.

[0228] As described above, regarding the mode in which the current flowing through the first working coil WC-1 and the second working coil WC-2 is in the same direction, since its magnetic field concentration area is the outer region WC-O of the working coil section, it can refer to a mode suitable for the heated object HO to be a non-magnetic body.

[0229] The control unit can determine whether the target power and the output power are consistent in the mode where the current direction is the same (S23).

[0230] In a mode where the current direction is the same, the target power and the output power being the same can mean that the heated object HO is being properly heated with the target output.

[0231] Therefore, if the target power and the output power are the same, the control unit 70 can maintain the output in the current mode (S24). That is, the control unit 70 can continue to maintain the mode in which the first direction of the current flowing through the first working coil WC-1 and the second direction of the current flowing through the second working coil WC-2 are the same.

[0232] If the target power and the output power are inconsistent even when the applied voltage is increased or decreased, the control unit 70 can control the output power to a mode in which the current flowing in the first working coil WC-1 and the second working coil WC-2 have different directions (S25).

[0233] Even if the output power is controlled by increasing or decreasing the applied voltage, the discrepancy between the target power and the output power may indicate that the heated object HO is not being properly heated to the target output. Specifically, the heated object HO is not heated when the magnetic field concentration region is the outer region WC-O of the working coil section. This suggests that the thin film TL hinders the coupling between the magnetic field and the heated object HO, which may imply that the heated object HO is magnetic. Therefore, it may be necessary to change the magnetic field concentration region to the central region WC-I of the working coil section.

[0234] This is because, under the same current direction mode, the magnetic field concentration area is the outer region WC-O of the working coil. Therefore, the magnetic field coupled with the thin film TL is stronger, so when the heated object HO is a magnetic body, the target power and the output power may not be consistent.

[0235] Therefore, if the target power and output power are inconsistent when the current flowing through the first working coil WC-1 and the second working coil WC-2 are in the same direction, the control unit 70 can control the current flowing through the first working coil WC-1 and the second working coil WC-2 to be in different directions.

[0236] After the control unit 70 controls the mode from the mode in which the current flowing through the first working coil WC-1 and the second working coil WC-2 is in the same direction to the mode in which the current flowing through the first working coil WC-1 and the second working coil WC-2 is in different directions, it can determine whether the target power and the output power are consistent (S26).

[0237] During the period when the direction of the current flowing through the first working coil WC-1 and the second working coil WC-2 is controlled to be different, if the target power and the output power are consistent, the control unit 70 can maintain the output in the current mode (S27).

[0238] The fact that the target power and output power are the same in different current direction modes means that the heated object HO is being appropriately heated with the target output. Therefore, the control unit 70 can continue to maintain output in different modes where the first direction of the current flowing through the first working coil WC-1 and the second direction of the current flowing through the second working coil WC-2 are different.

[0239] If the target power and the output power are inconsistent, the control unit 70 can control the output in the current mode (S28).

[0240] The discrepancy between target power and output power in modes with different current directions may mean that the heated object HO is not being heated with the target output.

[0241] Therefore, the control unit 70 can control the output by increasing or decreasing the applied pressure while maintaining the current direction of each coil until the target power is reached.

[0242] When the case where the object to be heated HO is a magnetic body is set as preferred, the control unit 70 can control the output according to the flowcharts S10 to S18. When the case where the object to be heated HO is a non-magnetic body is set as preferred, the control unit 70 can control the output according to the flowcharts S20 to S28.

[0243] The above description is merely an exemplary illustration of the technical concept of the present invention. Those skilled in the art to which this invention pertains can make various modifications and variations without departing from the essential characteristics of the present invention.

[0244] Therefore, the embodiments disclosed in this invention are used to explain rather than limit the technical concept of the invention, and the scope of the technical concept of the invention is not limited by these embodiments.

[0245] The scope of protection of this invention shall be interpreted by the appended claims, and all desired technical ideas within its equivalent scope shall be understood to be included within the scope of the claims of this invention.

Claims

1. An induction heating stove, in, include: case; A cover plate is attached to the upper end of the housing, and an upper plate portion for placing the object to be heated is provided on the top surface of the cover plate; A thin film is coated onto the upper plate portion, and the film is inductively heated when the object being heated is a non-magnetic body, and an opening is formed in the center of the film; The working coil section, disposed inside the housing, includes a first working coil and a second working coil; and At least one inverter is driven such that current flows in the first working coil and the second working coil. The direction of the current flowing through the first working coil and the direction of the current flowing through the second working coil may be the same or different depending on the object being heated. The first working coil and the second working coil are arranged adjacent to each other. The first working coil and the second working coil are disposed below the thin film. At least a portion of the opening overlaps with the central region of the working coil portion in the vertical direction.

2. The induction heating stove according to claim 1, wherein, The opening of the thin film is configured such that its center overlaps vertically with the contact point of the first working coil and the second working coil.

3. The induction heating stove according to claim 1, wherein, When the direction of the current flowing through the first working coil and the direction of the current flowing through the second working coil are different, the magnetic field generated by the first working coil and the magnetic field generated by the second working coil are formed in the same direction in the central region of the working coil section.

4. The induction heating stove according to claim 1, wherein, When the direction of the current flowing through the first working coil is different from the direction of the current flowing through the second working coil, the magnetic field strength in the central region of the working coil is stronger than the magnetic field strength in the peripheral region of the working coil.

5. The induction heating stove according to claim 1, wherein, When the direction of the current flowing through the first working coil is the same as the direction of the current flowing through the second working coil, the magnetic field generated by the first working coil and the magnetic field generated by the second working coil are formed in the same direction in the peripheral region of the working coil section.

6. The induction heating stove according to claim 1, wherein, When the direction of the current flowing through the first working coil is the same as the direction of the current flowing through the second working coil, the magnetic field strength in the central region of the working coil is weaker than the magnetic field strength in the peripheral region of the working coil.

7. The induction heating stove according to claim 1, wherein, It also includes a control unit that controls the first direction of the current flowing through the first working coil and the second direction of the current flowing through the second working coil by comparing the target power and the output power.

8. The induction heating stove according to claim 7, wherein, After controlling the first direction and the second direction to be different, the control unit controls the first direction and the second direction to be the same or different based on whether the target power and the output power are consistent.

9. The induction heating stove according to claim 8, wherein, If the target power and the output power are inconsistent after the control unit controls the first direction and the second direction to be different, then the control unit controls the first direction and the second direction to be the same.

10. The induction heating stove according to claim 7, wherein, After controlling the first direction and the second direction to be the same, the control unit controls the first direction and the second direction to be the same or different based on whether the target power and the output power are consistent.

11. The induction heating stove according to claim 10, wherein, If the target power and the output power are inconsistent after the control unit controls the first direction and the second direction to be the same, then the control unit controls the first direction and the second direction to be different.

12. The induction heating stove according to claim 1, wherein, It also includes a switching unit for controlling the direction of the current flowing through the first working coil and the second working coil, respectively.

13. The induction heating stove according to claim 12, wherein, It also includes a control unit that controls the switching unit by comparing the target power and the output power, such that the first direction of the current flowing through the first working coil and the second direction of the current flowing through the second working coil are the same or different.

14. The induction heating stove according to claim 7, wherein, The inverter includes a first inverter that drives the first working coil and a second inverter that drives the second working coil. The control unit controls the direction of the current flowing through the first working coil via the first inverter, and controls the direction of the current flowing through the second working coil via the second inverter.

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