Induction heating type cooktop

Abstract

The present invention includes: a housing; a cover plate, attached to the upper end of the housing, having an upper plate portion on its top surface for placing an object to be heated; a working coil disposed inside the housing; a heat insulation member disposed between the upper plate portion and the working coil; a first film disposed on the bottom surface of the upper plate portion and heated by induction from the working coil; and a second film disposed on the top surface of the upper plate portion and in contact with the object to be heated.

Description

Technical Field

[0001] This invention relates to induction heating stoves. Background Technology

[0002] Cooking appliances used in homes and restaurants in various ways to heat food. Gas stoves, which use gas as fuel, were widely used in the past, but in recent years, devices that use electricity to heat objects such as pots and pans have become increasingly popular.

[0003] The main methods of heating objects using electricity are resistance heating and induction heating. Resistance heating involves transferring heat generated when current flows through a non-metallic heating element such as a metal resistance wire or silicon carbide to the object being heated (e.g., a cooking container) via radiation or conduction. Induction heating, on the other hand, utilizes the magnetic field generated around a coil when a specified amount of high-frequency power is applied to it. This magnetic field induces eddy currents in the object being heated, which is made of metal, thus heating the object itself.

[0004] In recent years, induction heating has been widely used in cooktops.

[0005] However, induction heating cooktops have a limitation: they can only heat magnetic materials. That is, if a non-magnetic material (e.g., heat-resistant glass, ceramic, aluminum pots, etc.) is placed on the cooktop, the induction heating cooktop cannot heat that object.

[0006] To address the problems associated with induction heating cooktops, this invention aims to utilize a thin film. Specifically, the cooktop of this invention may include a thin film to which eddy currents are applied to heat a non-magnetic material. Furthermore, this thin film may be formed with a skin depth greater than its thickness, thereby allowing the magnetic field generated by the operating coil to pass through the film and apply eddy currents to a magnetic material, thus also heating the magnetic material.

[0007] On the other hand, when the object being heated is a non-magnetic metal (e.g., aluminum), the heating characteristics of the non-magnetic metal may be less efficient than those of other objects, both in terms of direct heating based on a working coil and indirect heating based on a thin film. Summary of the Invention

[0008] The problem that the invention aims to solve

[0009] The purpose of this invention is to minimize the problem of reduced heating efficiency of non-magnetic metals in induction heating cookers that heat both magnetic and non-magnetic materials.

[0010] Technical solutions to the problem

[0011] The stove of this invention includes a thin film of a strongly magnetic material that forms an open ring and is in contact with a non-magnetic object being heated, thereby being able to change the heating characteristics of the object being heated.

[0012] The stove in this embodiment of the invention has a dual thin-film structure, thus enabling heating of both magnetic and non-magnetic materials.

[0013] Invention Effects

[0014] According to the present invention, an advantage is that both magnetic and non-magnetic materials can be heated by the same heating source, and heating efficiency can be maximized even when the cooking container is a non-magnetic metal. Attached Figure Description

[0015] Figure 1 This is a diagram illustrating an embodiment of the induction heating stove of the present invention.

[0016] Figure 2 This is a cross-sectional view showing an induction heating stove and a heated object according to a first embodiment of the present invention.

[0017] Figure 3 This is a cross-sectional view showing an induction heating stove and a heated object according to a second embodiment of the present invention.

[0018] Figure 4 and Figure 5 This is a graph illustrating the relationship between the thickness of the first thin film and the skin depth.

[0019] Figure 6 This is a cross-sectional view showing an induction heating stove and a heated object according to a third embodiment of the present invention.

[0020] Figures 7 to 11 This is an illustrative diagram showing the shape of the second thin film according to an embodiment of the present invention.

[0021] Figure 12 This is an illustrative diagram showing the shape of the thin film according to the third embodiment of the present invention.

[0022] Figure 13 This is a graph showing the heating efficiency of the induction heating stove of the present invention. Detailed Implementation

[0023] 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.

[0024] The following will describe an embodiment of the induction heating stove of the present invention.

[0025] 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 a first embodiment of the present invention. Figure 3 This is a cross-sectional view showing an induction heating stove and a heated object according to a second embodiment of the present invention.

[0026] First, refer to Figure 1 The induction heating stove 1 of this embodiment may include a housing 25, a cover plate 20, a working coil WC, and a first thin film TL-1.

[0027] A working coil WC can be provided in the housing 25.

[0028] For reference, in addition to the working coil WC, the housing 25 may be equipped with various devices related to the driving of the working coil (e.g., a power supply unit that provides AC power, a rectifier unit that rectifies the AC power from the power supply unit into DC power, an inverter unit that converts the DC power rectified by the rectifier unit into resonant current and provides it to the working coil through a switching operation, 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 specific descriptions of these are omitted.

[0029] The cover plate 20 can be combined with the upper end of the housing 25, and its top surface can have an upper plate portion 15 for placing the object to be heated (not shown).

[0030] Specifically, the cover 20 may include an upper plate portion 15 for placing heated objects such as cooking containers.

[0031] Here, for example, the upper plate 15 can be made of glass material (e.g., ceramic glass).

[0032] Additionally, an input interface (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 input interface may also be located in other positions besides the upper plate 15.

[0033] For reference, the input interface is a module used to input the user's desired heating intensity or the driving time of the induction heating cooker 1, and can be implemented in various ways such as physical buttons or touch panels. Additionally, for example, the input interface can be equipped with a power button, a lock button, a power level adjustment button (+, -), a timer adjustment button (+, -), a charging mode button, etc. Furthermore, the input interface can transmit the input received from the user to an input interface control module (not shown), and the input interface control module 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 working coil) based on the input received from the input interface control module (i.e., the user's input); details of this will be omitted.

[0034] On the other hand, the upper plate 15 can visually display, in the shape of a stove opening, whether the working coil WC is 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.

[0035] The working coil WC can be placed inside the housing 25 to heat the object being heated.

[0036] Specifically, the control of the working coil WC can be controlled by the aforementioned control module (not shown), and when the object to be heated is placed on the upper plate 15, it can be driven by the control module.

[0037] In addition, the working coil 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 first thin film TL-1, which will be described later.

[0038] In addition, the working coil WC can heat the object being heated by induction heating and can be configured to overlap with the first thin film TL-1 in the longitudinal direction (i.e., vertical or up-down direction).

[0039] For reference only. Figure 1 The example shown depicts a single working coil WC disposed in the housing 25, but is not limited to this. That is, more than one working coil may be disposed in the housing 25, but for ease of explanation, this embodiment of the invention will be described using a single working coil WC disposed in the housing 25 as an example.

[0040] To heat the non-magnetic parts of the object to be heated, a first thin film TL-1 can be disposed on the upper plate portion 15. The first thin film TL-1 can be inductively heated by a working coil WC. Furthermore, since the first thin film TL-1 is heated, the object to be heated can receive heat from the first thin film TL-1 by means of heat convection or heat conduction.

[0041] The first thin film TL-1 can be disposed on the top or bottom surface of the upper plate portion 15. For example, as Figure 2 As shown, the first thin film TL-1 can be disposed on the top surface of the upper plate portion 15, or as... Figure 3 As shown, the first thin film TL-1 can be disposed on the bottom surface of the upper plate portion 15.

[0042] The first thin film TL-1 can be configured to overlap with the working coil 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.

[0043] In addition, the first thin film TL-1 may have at least one of the properties of magnetic and non-magnetic (i.e., magnetic, non-magnetic, or both).

[0044] Furthermore, for example, the first thin film TL-1 can be made of a conductive material (e.g., silver (Ag)), and as shown, it can be disposed on the upper plate portion 15 in a shape consisting of a plurality of repeating rings with different diameters. The first thin film TL-1 can also be made of other materials that are not conductive. Furthermore, the first thin film TL-1 can also be formed in other shapes that are not consisting of a plurality of repeating rings with different diameters.

[0045] For reference only. Figure 1 The diagram shows a first thin film TL-1, but it is not limited to this. That is, if there are multiple stove openings, multiple thin films can be added, but for ease of explanation, the example of setting a first thin film TL-1 will be used.

[0046] 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 component 35, shielding plate 45, support component 50, and cooling fan 55.

[0047] The heat insulation element 35 can be disposed between the upper plate 15 and the working coil WC.

[0048] Specifically, the heat insulation element 35 can be installed below the upper plate 15, and the working coil WC can be arranged below the heat insulation element 35.

[0049] This heat insulation element 35 can prevent the heat generated when the first thin film TL-1 or the heated object HO is heated by the driving of the working coil WC from being transferred to the working coil WC.

[0050] That is, if the first thin film TL-1 or the heated object HO is heated by electromagnetic induction of the working coil WC, the heat of the first thin film TL-1 or the heated object HO will be transferred to the upper plate 15, and the heat of the upper plate 15 will be transferred to the working coil WC again, which may damage the working coil WC.

[0051] As described above, the heat insulation element 35 blocks the heat transferred to the working coil WC, thereby preventing the working coil WC from being damaged by heat and thus preventing the heating performance of the working coil WC from decreasing.

[0052] For reference, although not a necessary component, a partition (not shown) may also be provided between the working coil WC and the heat insulation component 35.

[0053] Specifically, a partition (not shown) can be inserted between the working coil WC and the heat insulation member 35, so that the working coil WC and the heat insulation member 35 do not directly contact each other. Thus, the partition (not shown) can prevent the heat generated when the first thin film TL-1 or the heated object HO is heated by the driving of the working coil WC from being transferred to the working coil WC through the heat insulation member 35.

[0054] That is, the partition (not shown) can share part of the function of the heat insulation 35, thereby minimizing the thickness of the heat insulation 35, which in turn minimizes the gap between the heated object HO and the working coil WC.

[0055] Additionally, there may be a plurality of partitions (not shown), which can be arranged between the working coil WC and the heat insulation member 35 to be spaced apart from each other. Thus, air drawn into the interior of the housing 25 by the cooling fan 55 (described later) can be guided to the working coil WC by the partitions.

[0056] 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 WC, thereby improving the cooling efficiency of the working coil WC.

[0057] The shielding plate 45 can be installed on the bottom surface of the working coil WC to block the downward magnetic field generated when the working coil WC is driven.

[0058] Specifically, the shielding plate 45 can block the downward magnetic field generated when the working coil WC is driven, and can be supported upward by the support member 50.

[0059] 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.

[0060] Specifically, the support member 50 can indirectly support the heat insulation member 35 and the working coil WC upward by supporting the shielding plate 45 upward, so that the heat insulation member 35 can be closely attached to the upper plate 15.

[0061] As a result, the distance between the working coil WC and the heated object HO can be maintained constant.

[0062] 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 cooker 1.

[0063] A cooling fan 55 can be located inside the housing 25 to cool the working coil WC.

[0064] 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.

[0065] 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 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.

[0066] This enables effective cooling of the components inside the housing 25 (especially the working coil WC).

[0067] Furthermore, as described above, the air supplied by the cooling fan 55 to the outside of the housing 25 of the working coil WC can be guided to the working coil WC by the partition. As a result, the working coil 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).

[0068] 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 5 The characteristics and composition of the first thin film described above will be explained in more detail.

[0069] Figure 4 and Figure 5 This is a graph illustrating the relationship between the thickness of the first thin film and the skin depth.

[0070] The first thin film TL-1 can be made of a material with low relative permeability.

[0071] Specifically, because the first thin film TL-1 has a low relative permeability, its skin depth may 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 the first thin film TL-1, the deeper its skin depth.

[0072] Furthermore, the skin depth of the first thin film TL-1 can be greater than the thickness of the first thin film TL-1. That is, the first thin film TL-1 has a relatively thin thickness (e.g., 0.1 μm to 1,000 μm), while the skin depth of the first thin film TL-1 is greater than the thickness of the first thin film TL-1. Therefore, the magnetic field generated by the working coil WC passes through the first thin film TL-1 and is transmitted to the heated object HO, thereby inducing eddy currents in the heated object HO.

[0073] That is, such as Figure 4 As shown, when the skin depth of the first thin film TL-1 is thinner than the thickness of the first thin film TL-1, the magnetic field generated by the working coil WC may have difficulty reaching the heated object HO.

[0074] However, as Figure 5 As shown, when the skin depth of the first thin film TL-1 is deeper than the thickness of the first thin film TL-1, the magnetic field generated by the working coil WC can reach the heated object HO. That is, in the embodiment of the present invention, the skin depth of the first thin film TL-1 is deeper than the thickness of the first thin film TL-1, so most of the magnetic field generated by the working coil WC passes through the first thin film TL-1 and is transmitted to the heated object HO and consumed, thereby mainly heating the heated object HO.

[0075] On the other hand, since the first thin film TL-1 has a relatively thin thickness as described above, it can have a resistance value that can be heated by the working coil WC.

[0076] Specifically, the thickness of the first thin film TL-1 can be inversely proportional to the resistance value (i.e., surface resistance value) of the first thin film TL-1. That is, the thinner the first thin film TL-1 coated onto the upper plate portion 15, the greater the resistance value (i.e., surface resistance value) of the first thin film TL-1. Therefore, the first thin film TL-1 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.

[0077] For reference, for example, the first thin film TL-1 may have a thickness between 0.1 μm and 1,000 μm, but is not limited thereto.

[0078] Through the above embodiments, the induction heating stove 1 of the present invention includes a first thin film TL-1, so that the heated object HO can be heated regardless of whether the heated object HO has magnetic properties.

[0079] However, in the case where only the first thin film TL-1 is provided in the induction heating cooker 1, the heating performance may vary depending on the characteristics of the heated object HO disposed on the upper plate 15.

[0080] For example, the heating performance may differ depending on whether the heated object HO is a strongly magnetic metal (e.g., stainless steel 430), a non-magnetic non-metallic material (e.g., glass), or a non-magnetic metal (e.g., aluminum).

[0081] In particular, when the heated object HO is a non-magnetic metal (e.g., aluminum), the heating characteristics of non-magnetic metals may be less efficient than those of other objects, both in terms of direct heating based on the working coil WC and indirect heating based on the first thin film TL-1.

[0082] That is, the heating efficiency of the heated object HO may be the worst when the heated object HO is a non-magnetic metallic container (e.g., aluminum).

[0083] To address this problem, the induction heating cooker 1 of the present invention may further include a second thin film TL-2.

[0084] For reference, in this specification, a strongly magnetic body can refer to an object strongly magnetized in the direction of an external magnetic field, and a non-magnetic body can refer to an object weakly magnetized in the direction of an external magnetic field. Strongly magnetic bodies can be iron, cobalt, nickel, or alloys thereof, and non-magnetic bodies can be aluminum, copper, manganese, or alloys thereof, but these are merely examples.

[0085] Next, refer to Figure 6 The arrangement of the second thin film TL-2 of the present invention will be further described in detail.

[0086] Figure 6 This is a cross-sectional view showing an induction heating stove and a heated object according to a third embodiment of the present invention.

[0087] like Figure 6 As shown, the induction heating cooker 1 of the present invention may include: a first thin film TL-1 disposed on the bottom surface of the upper plate portion 15; and a second thin film TL-2 disposed on the top surface of the upper plate portion 15. The thickness of the second thin film TL-2 may be 1T (or 1mm), but this is only an example.

[0088] The first thin film TL-1 and the second thin film TL-2 can be configured to overlap in the longitudinal direction (i.e., the vertical direction or the up-down direction) across the upper plate portion 15. The working coil WC can be configured to overlap with the first thin film TL-1 and the second thin film TL-2 in the longitudinal direction (i.e., the vertical direction or the up-down direction).

[0089] The second thin film TL-2 can be disposed on the top surface of the upper plate portion 15 such that one side of it is in contact with the heated object HO. The second thin film TL-2 can be made of a strongly magnetic material (e.g., stainless steel 430).

[0090] If the second thin film TL-2 of the strongly magnetic material comes into contact with the heated object HO, which is a metallic non-magnetic material, the heating characteristics of the heated object HO can be changed. For example, by having the second thin film TL-2 of the strongly magnetic material come into contact with the heated object HO, the heating characteristics of the heated object HO can be changed, thereby increasing the amount of magnetic field induced in the heated object HO.

[0091] Therefore, the working coil WC of the present invention can perform induction heating on the heated object HO, which is a non-magnetic metal in contact with the second thin film TL-2.

[0092] However, when the second thin film TL-2 is formed as a strongly magnetic body, depending on the shape and thickness of the second thin film TL-2, the induced magnetic field that needs to be transmitted to the heated object HO is transmitted to the second thin film TL-2, thereby heating the second thin film TL-2. Therefore, it may reduce the heating efficiency of the heated object HO.

[0093] Therefore, the induction heating cooker 1 of the present invention may include a second thin film TL-2 having a shape that minimizes its own heating. Next, referring to... Figures 7 to 11 Various embodiments illustrating the possible shapes that the second thin film TL-2 of the present invention may have are described.

[0094] Figures 7 to 11 This is an illustrative diagram showing the shape of the second thin film according to an embodiment of the present invention.

[0095] Reference Figure 7 The second thin film TL-2 can be shaped to include at least one circular open ring L1, L2. The circular open rings L1, L2 can be circular shapes with a hollow center and a break on one side. The circular open rings L1 and L2 can be concentric circles with the same center but different diameters. In addition, the circular open rings L1 and L2 with different diameters can be connected to each other.

[0096] The second thin film TL-2 may exclude the central region TL-I of the second thin film TL-2. The central region TL-I of the second thin film TL-2 may refer to the exact center TL-C of the second thin film TL-2 and the area extending from the center TL-C of the second thin film TL-2 to a specified distance, and may refer to the area that overlaps vertically with the central region of the working coil WC. The central region of the working coil WC may refer to the exact center WC-C of the working coil WC (refer to...). Figure 12 ) and from the center WC-C of the working coil WC (refer to Figure 12 (to the area at the specified distance).

[0097] When the second thin film TL-2 is configured including its central region TL-I, it overlaps with the central region of the working coil WC, thereby increasing the induced magnetic field associated with the second thin film TL-2. If the induced magnetic field associated with the second thin film TL-2 increases, the degree of heating of the second thin film TL-2 increases, and the heating efficiency of the heated object HO decreases. Therefore, the second thin film TL-2 of the present invention may not include the central region TL-I.

[0098] In addition, the open circular loops L1 and L2, which are disconnected on one side of the second thin film TL-2, can prevent the current flowing along the second thin film TL-2 from flowing in a closed loop by using the induced magnetic field to induce eddy currents in the second thin film TL-2.

[0099] That is, the second thin film TL-2 of the present invention has an open-loop shape with a hollow center, which can minimize the situation of induction heating by the working coil WC.

[0100] In addition, the second thin film TL-2 forms at least one hollow space, namely a slit 71, which can minimize the flow of eddy currents and prevent the second thin film TL-2 from deforming due to heat.

[0101] Next, refer to Figure 8 The second film TL-2 of the present invention may also include a protrusion 73 on one side. The protrusion 73 of the second film TL-2 can serve as a handle so that the user can easily hold the second film TL-2.

[0102] Next, refer to Figure 9 The second thin film TL-2 of the present invention may include a plurality of circular open rings L1 and L2 with one side broken, and the broken portion of each open ring may face opposite directions. That is, the first open ring L1 may be configured to be broken on one side at the 12 o'clock position, and the second open ring L2 may be configured to be broken on one side at the 6 o'clock position.

[0103] Based on the same principle, refer to Figure 10The second thin film TL-2 of the present invention may include: a first open ring L1 of a first diameter, with one side disconnected in the 6 o'clock direction; a second open ring L2 of a second diameter, with one side disconnected in the 12 o'clock direction; and a third open ring L3 of a third diameter, with one side disconnected in the 6 o'clock direction.

[0104] As another embodiment, refer to Figure 11 The second thin film TL-2 of the present invention may include at least one closed loop L1, L3 and at least one open loop L2, L4. The second thin film TL-2 includes: a closed loop L1 with a first diameter; an open loop L2 with a second diameter having a diameter larger than the first diameter; a closed loop L3 with a third diameter having a diameter larger than the second diameter; and an open loop L4 with a fourth diameter having a diameter larger than the third diameter, wherein the loops may be connected.

[0105] In addition, the second diameter open ring L2 may include a plurality of open ring portions L2-1, L2-2, L2-3, L2-4, L2-5, and the fourth diameter open ring L4 may include a plurality of open ring portions L4-1, L4-2, L4-3, L4-4, L4-5, L4-6.

[0106] That is, the second thin film TL-2 has a shape that optimizes the heating characteristics of the heated object HO, which is a non-magnetic metallic material, and can have a shape that combines open-loop and closed-loop structures. In addition, the open loop is composed of a plurality of open-loop parts, which can minimize magnetic field induction.

[0107] Figure 12 This is a diagram showing an induction heating stove of the present invention with a second thin film provided on the upper plate.

[0108] Figure 12 Examples Figure 7 The shape of the second thin film TL-2 shown is exemplary and therefore not limited thereto.

[0109] like Figure 12 As shown, the center TL-C of the second thin film TL-2 of the present invention can be placed in the vertical direction of the center WC-C of the working coil WC, and the second thin film TL-2 can be disposed on the top surface of the upper plate portion 15.

[0110] The second thin film TL-2 can be separated from the upper plate portion 15. Therefore, the second thin film TL-2 can be disposed on the upper plate portion 15 only when the heated object HO is a non-magnetic metallic body.

[0111] Next, refer to Figure 13 This describes the heating efficiency of the material of the heated object HO in the induction heating stove 1 based on the present invention.

[0112] Figure 13 This is a graph showing the heating efficiency of the induction heating stove of the present invention.

[0113] exist Figure 13 In the figure, the first bar chart 1301 represents the heating efficiency when the heated object HO is a strong magnetic metal, the second bar chart 1303 represents the heating efficiency when the heated object HO is a first non-magnetic metal, the third bar chart 1305 represents the heating efficiency when the heated object HO is a non-magnetic metal, and the fourth bar chart 1307 represents the heating efficiency when the heated object HO is a second non-magnetic metal.

[0114] Furthermore, looking at the graph from the left side, IH (1311) represents the heating efficiency of the existing induction heating cooker 1 without the first thin film TL-1 and the second thin film TL-2, based on the characteristics of the heated object HO. IH+first thin film (1313) represents the heating efficiency of the induction heating cooker 1 of the present invention with the first thin film TL-1 provided, based on the characteristics of the heated object HO. IH+first thin film+second thin film (1315) represents the heating efficiency of the induction heating cooker 1 of the present invention with the first thin film TL-1 provided on the bottom surface of the upper plate portion 15 and the second thin film TL-2 provided on the top surface, based on the characteristics of the heated object HO. IH+sensor (1317) represents the heating efficiency of the existing induction heating cooker 1 with a plate formed of a metal strong magnetic body with a different shape than the second thin film TL-2 of the present invention provided on the top surface of the upper plate portion 15, based on the characteristics of the heated object HO. A plate formed from a metallic strong magnetic body of a different shape than the second thin film TL-2 of the present invention can refer to a circular plate including the central region of the working coil WC, i.e., a centrally filled plate.

[0115] Reference Figure 13 It can be seen that in the existing induction heating cooker IH (1311), if the heated object HO is a strongly magnetic metal, the output is 3 [kW]; if the heated object HO is a first type of non-magnetic metal, the output is 1.25 [kW]; and if the heated object HO is a non-metallic, non-magnetic material or a second type of non-magnetic metal, there is no output. That is, it can be seen that in the existing induction heating cooker IH, the heating efficiency is high only in the case of a strongly magnetic metal, and low in the case of a first type of non-magnetic metal. Non-metallic, non-magnetic, and second type of non-magnetic metal containers will not be heated.

[0116] The first metallic nonmagnetic body can refer to a nonmagnetic body that is more strongly magnetized by the induced magnetic field compared to the second metallic nonmagnetic body.

[0117] Furthermore, in the embodiment (IH + first thin film) 1313 where a first thin film TL-1 is added to the induction heating stove 1, if the heated object HO is a strong magnetic metal 1301, the output is 3 [kW]; if the heated object HO is a first non-magnetic metal 1303, the output is 2.4 [kW]; if the heated object HO is a non-magnetic non-metallic material 1305, the output is 2 [kW]; and if the heated object HO is a second non-magnetic metal 1307, the output is 1 [kW]. That is, if the first thin film TL-1 is provided in the induction heating stove 1, the heating efficiency is the same as in the prior art when the object is a strong magnetic metal 1301; the heating efficiency is high when the object is a first non-magnetic metal 1303; and the non-magnetic non-magnetic non-metallic materials 1305 and 1307 can be heated. However, when the object is a second non-magnetic metal 1307, the heating efficiency may be lower compared to other containers.

[0118] On the other hand, it can be seen that in the embodiment (IH + first film TL-1 + second film TL-2) 1315 in which the induction heating stove 1 is further provided with the first film TL-1 and the second film TL-2, the output is 3 [kW] when the heated object HO is a strong magnetic metal 1301, and the output is also 3 [kW] when the heated object HO is a first non-magnetic metal 1303. The output of the non-magnetic metal 1305 and the second non-magnetic metal 1307 is 2 [kW]. That is, it can be seen that if the first film TL-1 and the second film TL-2 are provided in the induction heating stove 1, the heating efficiency increases when the heated object HO is a non-magnetic metal 1303 or 1307, compared with the case where only the first film TL-1 is provided.

[0119] Furthermore, it is known that in the embodiment (IH + sensor) 1317 of the induction heating cooker 1, the heating efficiency of all types of heated objects HO decreases. This may mean that, since the sensor is a circular plate of a strongly magnetic body with a centrally filled portion, the heating efficiency decreases in all heated containers.

[0120] Therefore, through Figure 13 It is known that the heating efficiency of the first non-magnetic metal (e.g., stainless steel 304) and the second non-magnetic metal (e.g., aluminum) is increased by adjusting the material, shape, thickness and arrangement of the second thin film TL-2 of the present invention.

[0121] As described above, the induction heating stove 1 of this embodiment can heat both magnetic and non-magnetic objects. 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.

[0122] In addition, the induction heating stove 1 of this embodiment can directly or indirectly heat the object being heated using the same heat source, thereby not only improving heating efficiency but also reducing material costs.

[0123] 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.

[0124] 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.

[0125] 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 type cooktop, wherein, Comprising: a housing; a cover plate coupled to an upper end of the housing, having an upper plate portion on which a heated object is disposed; a work coil disposed inside the housing; a heat insulating member disposed between the upper plate portion and the work coil; a first film disposed on a bottom surface of the upper plate portion, heated by the work coil; and a second film disposed on a top surface of the upper plate portion, in contact with the heated object; the first film is formed in a ring shape; the second film includes at least one circular split ring, the circular split ring has a circular shape with a center void and one side broken off; the second film is made of a ferromagnetic material.

2. The induction heating type cooktop according to claim 1, wherein the second film includes a plurality of the circular split rings, the centers of the plurality of the circular split rings are the same as each other.

3. The induction heating type cooktop according to claim 2, wherein the plurality of the circular split rings are connected to each other.

4. The induction heating type cooktop according to claim 1, wherein the first film and the second film are disposed to overlap in a vertical direction with the upper plate portion interposed therebetween.

5. The induction heating type cooktop according to claim 4, wherein the first film and the second film are disposed to overlap in a vertical direction with the work coil.

6. The induction heating type cooktop according to claim 1, wherein the second film is separable from the upper plate portion.

7. The induction heating type cooktop according to claim 1, wherein the work coil inductively heats a metal non-magnetic heated object in contact with the second film.

8. The induction heating type cooktop according to claim 7, wherein the first film heats the metal non-magnetic heated object by thermal convection or thermal conduction.

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