Shield device and induction heating type cooktop system including the same

Abstract

The present disclosure relates to a shield device and an induction heating type cooktop system including the same, wherein the shield device is intended to reduce electromagnetic waves exposed to the outside of the cooktop and may include a case placed on the top of the cooktop and a shield coil disposed inside the case.

Description

Technology Field

[0001] The present disclosure relates to a shielding device for reducing electromagnetic waves and an induction heating type cooktop system including the same. Background Technology

[0003] Various types of cooking appliances are used to heat food in homes and restaurants. Traditionally, gas ranges using gas as fuel have been widely used, but recently, devices that heat cooking vessels using electricity instead of gas are becoming more popular.

[0004] Methods of heating an object using electricity are broadly divided into resistance heating and induction heating. Resistance heating is a method of heating by transferring heat generated when an electric current is passed through a metal resistance wire or a non-metallic heating element, such as silicon carbide, to a cooking vessel through radiation or conduction. Induction heating, on the other hand, is a method of heating the cooking vessel itself by generating eddy currents in a cooking vessel made of metal components using a magnetic field generated around a coil when high-frequency power of a predetermined magnitude is applied to the coil.

[0005] On the other hand, with this type of induction heating method, a problem may arise where some of the magnetic field generated by the coil fails to reach the cooking vessel and is exposed to the outside. In particular, the issue of electromagnetic wave exposure can become more significant if the cooking vessel is small or the heating intensity is strong. The problem to be solved

[0007] The present disclosure aims to provide a shielding device for reducing electromagnetic wave exposure.

[0008] The present disclosure aims to provide an induction heating type cooktop system comprising a shielding device for reducing electromagnetic wave exposure and a cooktop.

[0009] The present disclosure aims to minimize the problem of electromagnetic waves generated in a working coil being exposed to the outside.

[0010] The present disclosure aims to provide a shield device for reducing electromagnetic waves generated from an induction heating cooktop as an accessory in the form of a pad.

[0011] The present disclosure aims to provide a shield device and an induction heating cooktop system that reduce electromagnetic waves generated by an induction heating cooktop while providing an additional function through energy storage. means of solving the problem

[0013] A shield device according to an embodiment of the present disclosure is used in an induction heating type cooktop equipped with a working coil, and may include a case placed on the upper part of the cooktop and a shield coil disposed inside the case.

[0014] The inner diameter of the shield coil can be larger than the outer diameter of the working coil.

[0015] The inner diameter of the shield coil can be larger than the diameter of the heating area of ​​the cooktop.

[0016] The case can be formed of silicone.

[0017] A guide can be formed in the case to guide the position of the shield device.

[0018] The shield device may further include an energy storage circuit having a shield capacitor connected to a shield coil.

[0019] The shield device may further include a timer that counts the cooking time of the cooktop using power stored in an energy storage circuit.

[0020] The shield device may further include a temperature sensor that detects the temperature of a cooking vessel heated by a cooktop using power stored in an energy storage circuit.

[0021] The temperature sensor can be placed on the inside of the shield coil.

[0022] The shield device may further include an output unit that outputs information related to the cooktop using power stored in an energy storage circuit.

[0023] The first thickness of the area where the energy storage circuit is placed in the case may be thicker than the second thickness of the area where the shield coil is placed.

[0024] A cooktop comprising a working coil according to an embodiment of the present disclosure and a top glass having a heating region through which a magnetic field generated from the working coil passes, and

[0025] In an induction heating type cooktop system including a shield device placed on a cooktop, the shield device may include a case placed on the top of the cooktop and a shield coil placed inside the case. Effects of the invention

[0027] According to an embodiment of the present disclosure, since electromagnetic waves exposed to the outside through a shielding device are minimized, there is an advantage in that the possibility of harm to the human body caused by the cooktop can be minimized.

[0028] According to an embodiment of the present disclosure, the problem of electromagnetic wave exposure can be reduced simply by placing it on the top glass of a cooktop, thus providing the advantage of providing a shield device that is easy to use.

[0029] According to an embodiment of the present disclosure, since a pad-shaped shield device is provided as an accessory, it can be used on existing cooktops and, since it is not fixed, the user can selectively use it on any cooktop, thus having the advantage of increased versatility.

[0030] According to an embodiment of the present disclosure, since the shield device can accumulate energy to provide additional functions, there is an advantage of increased utility.

[0031] According to an embodiment of the present disclosure, since a position for maximizing the efficiency of the shield device is guided through a guide, there is an advantage of being able to minimize the exposure to electromagnetic waves. Brief explanation of the drawing

[0033] FIG. 1 is a perspective view showing a cooktop and a cooking vessel according to an embodiment of the present disclosure.6 FIG. 2 is a cross-sectional view of a cooktop and a cooking vessel according to an embodiment of the present disclosure. FIG. 3 is a diagram showing a circuit of a cooktop according to an embodiment of the present disclosure. FIG. 4 is a drawing showing the output characteristics of a cooktop according to an embodiment of the present disclosure. FIG. 5 is a drawing showing an induction heating type cooktop system according to an embodiment of the present disclosure. FIG. 6 is a graph showing the current flowing through the working coil and the shield coil, respectively, according to an embodiment of the present disclosure. FIG. 7 is a cross-sectional view of a cooktop and shield device according to an embodiment of the present disclosure. Figure 8 is a plan view showing only the working coil and shield coil separately from Figure 7. FIG. 9 is a cross-sectional view illustrating a shield device further comprising an energy storage circuit according to an embodiment of the present disclosure. FIG. 10 is a graph showing the voltage of a shield capacitor and the current flowing through the working coil and the shield coil, respectively, according to an embodiment of the present disclosure. FIG. 11 is a drawing showing in detail an energy storage circuit according to an embodiment of the present disclosure. FIG. 12 is a drawing showing the configuration of a shield device according to an embodiment of the present disclosure. Specific details for implementing the invention

[0034] Hereinafter, embodiments related to the present disclosure will be described in more detail with reference to the drawings. The suffixes "module" and "part" for components used in the following description are assigned or used interchangeably solely for the ease of drafting the specification and do not have distinct meanings or roles in themselves.

[0036] Hereinafter, an induction heating type cooktop and a method of operation thereof according to an embodiment of the present disclosure will be described. For convenience of explanation, the “induction heating type cooktop” will be referred to as the “cooktop.”

[0038] FIG. 1 is a perspective view showing a cooktop and a cooking vessel according to an embodiment of the present disclosure, and FIG. 2 is a cross-sectional view of a cooktop and a cooking vessel according to an embodiment of the present disclosure.

[0039] A cooking vessel (1) can be positioned on top of a cooktop (10), and the cooktop (10) can heat the cooking vessel (1) positioned on top.

[0040] First, explain how the cooktop (10) heats the cooking vessel (1).

[0041] As illustrated in FIG. 1, the cooktop (10) can generate a magnetic field (20) such that at least a portion of it passes through the cooking vessel (1). At this time, if the material of the cooking vessel (1) contains an electrical resistance component, the magnetic field (20) can induce an eddy current (30) in the cooking vessel (1). This eddy current (30) heats the cooking vessel (1) itself, and since this heat is transmitted through conduction or radiation to the interior of the cooking vessel (1), the contents of the cooking vessel (1) can be cooked.

[0042] Meanwhile, if the material of the cooking vessel (1) does not contain an electrical resistance component, eddy current (30) is not generated. Therefore, in this case, the cooktop (10) cannot heat the cooking vessel (1).

[0043] Accordingly, the cooking vessel (1) that can be heated by this cooktop (10) may be a metal vessel such as a stainless steel vessel or an enamel or cast iron vessel.

[0044] Next, the method by which the cooktop (10) generates a magnetic field (20) is explained.

[0045] As shown in FIG. 2, the cooktop (10) may include at least one of a top glass (11), a working coil (12), and a ferrite core (13).

[0046] The top glass (11) can support the cooking vessel (1). That is, the cooking vessel (1) can be placed on the upper surface of the top glass (11). A heating zone in which the cooking vessel (1) is heated can be formed in the top glass (11).

[0047] Also, the top glass (11) can be formed of reinforced glass made of ceramic material that is synthesized from various minerals. Accordingly, the top glass (11) can protect the cooktop (10) from external impacts, etc.

[0048] In addition, the top glass (11) can prevent foreign substances such as dust from entering the cooktop (10).

[0049] The working coil (12) may be located below the top glass (11). Current may or may not be supplied to the working coil (12) to generate a magnetic field (20). Specifically, current may or may not flow through the working coil (12) depending on the on / off state of the internal switching element of the cooktop (10).

[0050] When current flows through the working coil (12), a magnetic field (20) is generated, and this magnetic field (20) can generate an eddy current (30) by encountering an electrical resistance component contained in the cooking container (1). The eddy current heats the cooking container (1), and accordingly, the contents of the cooking container (1) can be cooked.

[0051] In addition, the heat output of the cooktop (10) can be adjusted according to the amount of current flowing through the working coil (12). As a specific example, the more current flowing through the working coil (12), the more magnetic field (20) is generated, and accordingly, the magnetic field passing through the cooking vessel (1) increases, so the heat output of the cooktop (10) can be increased.

[0052] The ferrite core (13) is a component for protecting the internal circuit of the cooktop (10). Specifically, the ferrite core (13) acts as a shield to block the effect of the magnetic field (20) generated from the working coil (12) or the electromagnetic field generated from the outside on the internal circuit of the cooktop (10).

[0053] To this end, the ferrite core (13) can be formed from a material with very high permeability. The ferrite core (13) serves to guide the magnetic field flowing into the interior of the cooktop (10) to flow through the ferrite core (13) without being radiated. The way the magnetic field (20) generated in the working coil (12) moves through the ferrite core (13) may be as shown in FIG. 2.

[0054] Meanwhile, the cooktop (10) may include additional components in addition to the top glass (11), working coil (12), and ferrite core (13) described above. For example, the cooktop (10) may further include an insulating material (not shown) located between the top glass (11) and the working coil (12). That is, the cooktop according to the present disclosure is not limited to the cooktop (10) shown in FIG. 2.

[0056] FIG. 3 is a diagram showing a circuit of a cooktop according to an embodiment of the present disclosure.

[0057] The circuit diagram of the cooktop (10) shown in FIG. 3 is merely illustrative for convenience of explanation, and therefore the present disclosure is not limited thereto.

[0058] Referring to FIG. 3, an induction heating type cooktop may include at least some or all of a power supply unit (110), a rectifier unit (120), a DC link capacitor (130), an inverter (140), a working coil (12), a resonant capacitor (160), and an SMPS (170).

[0059] The power supply unit (110) can receive external power. The power received by the power supply unit (110) from the outside may be AC ​​(Alternation Current) power.

[0060] The power supply unit (110) can supply alternating current voltage to the rectifier unit (120).

[0061] The rectifier (120) is an electrical device for converting alternating current into direct current. The rectifier (120) converts the alternating current voltage supplied through the power supply (110) into a direct current voltage. The rectifier (120) can supply the converted voltage to the DC terminals (121).

[0062] The output terminal of the rectifier (120) can be connected to the DC terminal (121). The DC terminal (121) output through the rectifier (120) can be called a DC link. The voltage measured at the DC terminal (121) is called the DC link voltage.

[0063] The DC link capacitor (130) serves as a buffer between the power supply unit (110) and the inverter (140). Specifically, the DC link capacitor (130) is used to maintain the DC link voltage converted through the rectifier unit (120) and supply it to the inverter (140).

[0064] The inverter (140) serves to switch the voltage applied to the working coil (12) so that a high-frequency current flows through the working coil (12). The inverter (140) may include a semiconductor switch, and the semiconductor switch may be an IGBT (Insulated Gate Bipolar Transistor) or a SiC device, but since this is merely an example, it is reasonable to assume that it is not limited thereto. The inverter (140) drives the semiconductor switch to cause a high-frequency current to flow through the working coil (12), and accordingly, a high-frequency magnetic field is formed in the working coil (12).

[0065] The working coil (12) may or may not have current flowing through it depending on whether the switching element is driven. When current flows through the working coil (12), a magnetic field is generated. The working coil (12) can generate a magnetic field as current flows to heat the cooking appliance.

[0066] One side of the working coil (12) is connected to the connection point of the switching element of the inverter (140), and the other side is connected to the resonant capacitor (160).

[0067] The switching element is driven by a driving unit (not shown), and the switching element is controlled by the switching time output from the driving unit, so that the switching elements operate alternately and apply a high-frequency voltage to the working coil (12). And, since the on / off time of the switching element applied by the driving unit (not shown) is controlled in a gradually compensated manner, the voltage supplied to the working coil (12) changes from a low voltage to a high voltage.

[0068] The resonant capacitor (160) may be a component to serve as a buffer. The resonant capacitor (160) controls the saturation voltage rise rate during the turn-off of the switching element, thereby affecting energy loss during the turn-off time.

[0069] A Switching Mode Power Supply (170) refers to a power supply that efficiently converts power according to switching operations. The SMPS (170) converts a DC input voltage into a square wave voltage and then obtains a controlled DC output voltage through a filter. The SMPS (170) can minimize unnecessary losses by controlling the flow of power using a switching processor.

[0070] In the case of a cooktop (10) configured with a circuit diagram as shown in FIG. 3, the resonance frequency is determined by the inductance value of the working coil (12) and the capacitance value of the resonance capacitor (160). Then, a resonance curve is formed around the determined resonance frequency, and the resonance curve can represent the output power of the cooktop (10) according to the frequency band.

[0072] Next, FIG. 4 is a drawing showing the output characteristics of a cooktop according to an embodiment of the present disclosure.

[0073] First, the Q factor (quality factor) may be a value indicating the sharpness of resonance in a resonant circuit. Thus, in the case of a cooktop (10), the Q factor is determined by the inductance value of the working coil (12) included in the cooktop (10) and the capacitance value of the resonant capacitor (160). The resonance curve differs depending on the Q factor. Therefore, the cooktop (10) has different output characteristics depending on the inductance value of the working coil (12) and the capacitance value of the resonant capacitor (160).

[0074] Figure 4 shows an example of a resonance curve according to the Q factor. Generally, the larger the Q factor, the sharper the shape of the curve, and the smaller the Q factor, the broader the shape of the curve.

[0075] The horizontal axis of a resonance curve represents frequency, and the vertical axis represents output power. The frequency at which maximum power is output on the resonance curve is called the resonance frequency (f0).

[0076] Generally, the cooktop (10) uses a frequency in the right region relative to the resonant frequency (f0) of the resonance curve. Also, the cooktop (1) may have a minimum operating frequency and a maximum operating frequency that can be operated pre-set.

[0077] For example, the cooktop (10) operates from a maximum operating frequency (fmax) to a minimum operating frequency (f min It can operate at a frequency corresponding to the range of ). That is, the operating frequency range of the cooktop (10) is the maximum operating frequency (f max From ) to minimum operating frequency (f min It can be up to ).

[0078] For example, the maximum operating frequency (f max ) may be the maximum switching frequency of the IGBT. The maximum switching frequency of the IGBT may refer to the maximum frequency at which it can be driven, taking into account the voltage withstand capability and capacitance of the IGBT switching device. For example, the maximum operating frequency (f max ) can be 75kHz.

[0079] Minimum operating frequency (f) min ) can be about 20 kHz. In this case, since the cooktop (10) does not operate at an audible frequency (about 16 Hz to 20 kHz), it has the effect of reducing the noise of the cooktop (10).

[0080] Meanwhile, the aforementioned maximum operating frequency (f max The setting values ​​of ) and the minimum operating frequency (fmin) are merely exemplary and are not limited thereto.

[0081] When such a cooktop (10) receives a heating command, it can determine the operating frequency according to the heat level set in the heating command. Specifically, the cooktop (10) can adjust the output power by lowering the operating frequency as the set heat level is higher and increasing the operating frequency as the set heat level is lower. That is, when the cooktop (10) receives a heating command, it can implement a heating mode that operates in any one of the operating frequency ranges according to the set heat level.

[0083] Meanwhile, some of the magnetic field generated by the working coil (12) may be exposed to the outside. In particular, if the size of the cooking container (1) is smaller than the working coil (12) or if the cooking container (1) and the working coil (12) are not aligned, more magnetic field may be exposed, which can worsen electromagnetic wave problems. Additionally, as the heat level increases, the problem of electromagnetic wave exposure may increase.

[0084] Accordingly, an induction heating type cooktop system according to an embodiment of the present disclosure may include a cooktop (10) and a shield device (300) placed on the cooktop (10).

[0085] The cooktop (10) includes a working coil (12) and a top glass (11), and a heating area (H, see FIG. 7) through which a magnetic field generated from the working coil (12) passes may be formed in the top glass (11). A shield device (300) may be used in the cooktop (10) and may include a shield coil (312, see FIG. 5) that generates a magnetic field that cancels out the magnetic field generated from the working coil (12).

[0086] FIG. 5 is a drawing showing an induction heating type cooktop system according to an embodiment of the present disclosure.

[0087] As illustrated in FIG. 5, an induction heating type cooktop system according to an embodiment of the present disclosure may include a cooktop (10) and a shield device (300) placed on the cooktop (10). The cooktop (10) may include a case (10a) that protects elements such as a working coil (12). The upper part of the case (10a) may be a top plate glass (11).

[0088] The shield device (300) may include a case (300a) placed on top of the cooktop (10) and a shield coil (312) placed inside the case (300a).

[0089] The shield coil (312) can be formed from a PCB, FPCB, copper wire, Litz-wire, or Stamp coil, etc.

[0090] The case (300a) can be formed of silicon.

[0091] The cooking vessel (1) may be heated by placing it directly on the cooktop (10), or, as shown in FIG. 5, if a shield device (300) is placed on the cooktop (10), the cooking vessel (1) may be heated by placing it on the shield device (300).

[0092] When current flows through the working coil (12), a first magnetic field (20) is generated, and the first magnetic field (20) can generate eddy currents in the cooking vessel (1) to heat the cooking vessel (1). Meanwhile, at least some of the first magnetic field (20) generated from the working coil (12) may not pass through the cooking vessel (1) and may be exposed to the outside of the cooktop (10).

[0093] Meanwhile, when an electromotive force is generated in the shield coil (312) as current flows through the working coil (12), a voltage is generated in a direction to cancel it out according to Lenz's law. That is, as current flows through the working coil (12), an electromotive force is induced in the shield coil (312), and a voltage can be generated in a direction to cancel it out. Therefore, the shield coil (312) generates voltage even without being connected to a separate battery or power source, and the second magnetic field (320) generated by this voltage can cancel out the first magnetic field (20) generated in the working coil (12).

[0094] In this way, as the first magnetic field (20) exposed to the outside of the cooktop (10) is offset by the second magnetic field (320) generated from the shield coil (312), the problem of human exposure to electromagnetic waves can be reduced.

[0095] FIG. 6 is a graph showing the current flowing through the working coil and the shield coil, respectively, according to an embodiment of the present disclosure.

[0096] The first current (I1) shown in FIG. 6 may represent the current flowing through the working coil (12). The working coil (12) is supplied with current by an inverter (140) switch, and in the example of FIG. 6, the first current (I1) may be approximately 43A.

[0097] Meanwhile, as described above, a current is induced in the shield coil (312) in a direction that cancels out the first magnetic field (20) generated in the working coil (12), and thus a second current (I2) with a phase difference of 180 degrees from the first current (I1) can be induced. The second current (I2) may be approximately 17A.

[0098] In this way, when a second magnetic field (320) is generated as a second current (I2) is induced in the shield coil (312), the first magnetic field (20) can be canceled out, thereby reducing the magnetic field exposed outside the cooktop (10).

[0099] Table 1 below shows the results of measuring the magnetic field strength at distances of 0.0, 10.0, 20.0, 30.0, 40.0, and 50.0 [mm] from the cooktop (10) when the cooktop (10) is operating alone.

[0100] Distance from cooktop [mm] 0.0 10.0 20.0 30.0 40.0 50.0 Magnetic field measurement [uT] 8.68 6.80 5.31 3.99 3.29 2.54

[0101] Meanwhile, [Table 2] below shows the results of measuring the magnetic field strength at distances of 0.0, 10.0, 20.0, 30.0, 40.0, and 50.0 [mm] from the cooktop (10) when the cooktop (10) is operating with the shield device (300) placed on top of it.

[0102] Distance from cooktop [mm] 0.0 10.0 20.0 30.0 40.0 50.0 Magnetic field measurement [uT] 2.79 2.10 1.60 1.45 0.98 0.86

[0103] By comparing [Table 1] and [Table 2], it can be seen that when the shield device (300) is used compared to when the cooktop (10) is operated alone, there is a magnetic field reduction effect at a rate of 67.86, 69.12, 69.87, 63.66, 70.21, and 66.14%, respectively, when the distance from the cooktop (10) is 0.0, 10.0, 20.0, 30.0, 40.0, and 50.0 [mm].

[0105] Next, with reference to FIGS. 7 and 8, the working coil and shield coil of a cooktop system according to an embodiment of the present disclosure will be described in more detail.

[0106] FIG. 7 is a cross-sectional view of a cooktop and shield device according to an embodiment of the present disclosure, and FIG. 8 is a plan view showing only the working coil and the shield coil separately in FIG. 7.

[0107] In particular, for convenience of explanation, only the cooktop (10) and the working coil (12) placed inside the cooktop (10), and the shield device (300) and the shield coil (312) placed inside the shield device (300) are shown in FIG. 7.

[0108] Both the working coil (12) and the shield coil (312) can be wound in a circular shape. Accordingly, the inner diameter of the shield coil (312) may refer to the diameter of the innermost coil, and the outer diameter of the working coil (12) may refer to the diameter of the outermost coil.

[0109] Referring to FIG. 7, the inner diameter (L1) of the shield coil (312) may be greater than or equal to the outer diameter (L2) of the working coil (12). That is, the inner diameter (L1) of the shield coil (312) may be greater than or equal to the outer diameter (L2) of the working coil (12). That is, the working coil (12) may be placed inside the shield coil (312).

[0110] If the shield coil (312) is placed inside the working coil (12), at least some of the first magnetic field (20) generated from the working coil (12) must pass through the cooking vessel (1), but it encounters and cancels out the second magnetic field (320) generated from the shield coil (312) first, and thus a problem may occur in which the heating efficiency is reduced.

[0111] However, as shown in FIG. 7, when a working coil (12) is placed inside a shield coil (312), most of the first magnetic field (20) generated by the working coil (12) can pass through a cooking vessel (1) located in a heating area (H). And, if the cooking vessel (1) is smaller than the heating area (H) or is placed outside the heating area (H), the first magnetic field (20) exposed to the outside can be offset by the second magnetic field (320) generated by the shield coil (312).

[0112] Meanwhile, the heating area (H) may represent an area through which the first magnetic field (20) generated from the working coil (12) passes.

[0113] The inner diameter (L1) of the shield coil (312) may be greater than or equal to the diameter (L3) of the heating area (H) of the cooktop (10). That is, the inner diameter (L1) of the shield coil (312) may be larger than or equal to the diameter (L3) of the heating area (H).

[0114] Accordingly, the second magnetic field (320) generated from the shield coil (312) passes through the heating area (H) but does not pass through the cooking container (1) and meets the exposed first magnetic field (20), which can be canceled out.

[0115] The working coil (12) and the shield coil (312) may not overlap in the vertical direction.

[0116] As described above, when the inner diameter (L1) of the shield coil (312) is greater than or equal to the outer diameter (L2) of the working coil (12) or the inner diameter (L1) of the shield coil (312) is greater than or equal to the diameter (L3) of the heating area (H), the first magnetic field (20) is concentrated into the cooking vessel (1), and at the same time, only the first magnetic field (20) that is exposed and cannot pass through the cooking vessel (1) is offset by the second magnetic field (320), thereby having the advantage of minimizing the reduction in heating efficiency and minimizing the problem of magnetic field exposure.

[0118] According to an embodiment, as illustrated in FIG. 8, a shield capacitor (351) may be further connected to the shield coil (312). Specifically, according to an embodiment, the shield device (300) may further include an energy storage circuit having a shield capacitor (351) connected to the shield coil (312).

[0119] FIG. 9 is a cross-sectional view illustrating a shield device further comprising an energy storage circuit according to an embodiment of the present disclosure.

[0120] According to an embodiment, the shield device (300) may further include an energy storage circuit (341), and the energy storage circuit (341) may include a shield capacitor (351) for storing energy. The energy storage circuit (341) will be described in detail in FIG. 8.

[0121] The first thickness (t1) of the area where the energy storage circuit (341) is placed in the case (300a) may be thicker than the second thickness (t2) of the area where the shield coil (312) is placed.

[0122] This results in a gap (L4, see FIG. 7) between the working coil (12) and the shield coil (312), and the gap (L4) increases as the case (300a) of the shield device (300) becomes thicker. Meanwhile, as the gap (L4) increases, the heating efficiency of the working coil (12) may decrease, so it is desirable to minimize the gap (L4). Therefore, in order to minimize the decrease in the heating efficiency of the working coil (12), it is desirable to minimize the second thickness (t2). However, the energy storage circuit (341) includes at least one component for energy storage, so the thickness may be increased by the component, and accordingly, the energy storage circuit (341) is spaced apart from the shield coil (312), and the first thickness (t1) of the area where the energy storage circuit (341) is placed may differ from the second thickness (t2).

[0123] For example, the thickness of the shield coil (312) is 210 mm and can be wound 7 turns, but this is merely an example. When the thickness of the shield coil (312) is 210 mm, the gap (L4) can be 8 mm.

[0124] And, the energy storage circuit (341) can be formed in the shield device (300) so as to be positioned so as not to overlap vertically with the heating area (H).

[0125] FIG. 10 is a graph showing the voltage of a shield capacitor and the current flowing through the working coil and the shield coil, respectively, according to an embodiment of the present disclosure.

[0126] The voltage (V) shown in FIG. 10 is the voltage of the shield capacitor (351), the first current (I1) may represent the current flowing through the working coil (12), and the second current (I2) may represent the current flowing through the shield coil (312).

[0127] When the first current (I1) flows through the working coil (12), a second current (I2) with a phase opposite to that of the first current (I1) is induced in the shield coil (312), and as the current flows through the shield coil (312), the energy insulated at both ends of the shield capacitor (351) connected to the shield coil (312) is charged and discharged, and the voltage (e.g., a 60Hz sine wave) can be rectified to accumulate energy.

[0128] Accordingly, according to an embodiment, the shield device (300) according to an embodiment of the present disclosure may include an energy storage circuit.

[0129] FIG. 11 is a drawing showing in detail an energy storage circuit according to an embodiment of the present disclosure.

[0130] Referring to FIG. 11, the shield device (300) may include at least some or all of a shield coil (312), an energy storage circuit (341), a temperature sensor (331), a timer (361), a control unit (370), and an output unit (380).

[0131] The energy storage circuit (341) may include at least some or all of a shield capacitor (351), a rectifier (353), a DC link capacitor (357), and a DC / DC converter (355).

[0132] Energy can be stored in the shield capacitor (351). Insulated energy can be charged and discharged as current flows through the shield coil (312) across the shield capacitor (351). The energy stored in the shield capacitor (251) can be supplied to other components after being rectified and converted to a predetermined size. The energy stored in the shield capacitor (251) can be an energy source for other components.

[0133] The rectifier (353) can rectify the energy stored in the shield capacitor (251). The rectifier (353) can convert the power stored in the shield capacitor (251) into direct current power.

[0134] The DC link capacitor (357) can act as a buffer between the shield capacitor (251) and the DC / DC converter (355). The DC link capacitor (357) can maintain a constant voltage supplied from the shield capacitor (251) to the DC / DC converter (355).

[0135] The DC / DC converter (355) can step up or step down the voltage supplied by the rectifier (353). The DC / DC converter (355) can output voltages with adjusted magnitudes to suit each component.

[0136] The energy storage circuit (341) can supply power to components within the cooktop (10), such as a temperature sensor (331), a timer (361), a control unit (370), or an output unit (380). Accordingly, the shield device (300) has the advantage of not requiring a separate battery.

[0137] Meanwhile, according to the embodiment, the shield device (300) may include a battery instead of an energy storage circuit (341), and in this case, the shield device (300) may operate independently regardless of whether the cooktop (10) is operating.

[0138] At least one of the components provided in the cooktop (10), such as the temperature sensor (331), timer (361), control unit (370), or output unit (380), can be operated by receiving power from the energy storage circuit (341). That is, at least one of the components provided in the cooktop (10), such as the temperature sensor (331), timer (361), control unit (370), or output unit (380), can be driven using the stored energy as current is induced in the shield coil (312).

[0139] The temperature sensor (331) can detect the temperature of the cooking vessel (1). The temperature sensor (331) can detect the temperature of the cooking vessel heated by the cooktop (10) using power stored in the energy storage circuit (341).

[0140] The temperature sensor (331) may be placed inside the shield coil (312). According to one embodiment, as shown in the example illustrated in FIG. 9, the temperature sensor (331) may be provided in the center of the shield device (300).

[0141] When a shield device (300) is placed on the upper part of the cooktop (10), the temperature sensor equipped in the cooktop (10) may have reduced accuracy in detecting the temperature of the cooking container (1), so the temperature sensor (331) of the shield device (300) can detect the temperature of the cooking container (1).

[0142] The timer (361) can count the cooking time. That is, the timer (361) can count the cooking time of the cooktop (10) using the power stored in the energy storage circuit (341).

[0143] Alternatively, the timer (361) can determine whether the set time has been reached. That is, the timer (361) can count the set time using the power stored in the energy storage circuit (341) and determine whether the set time has been reached.

[0144] The control unit (370) can control the temperature sensor (331), energy storage circuit (341), timer (361), output unit (380), etc.

[0145] The control unit (370) can output information to the output unit (380) based on the output of the temperature sensor (331) and the timer (361). For example, the control unit (370) can control the output unit (380) to display the temperature of the cooking container (1) detected by the temperature sensor (331). The control unit (370) can control the output unit (380) to display the cooking time counted by the timer (361). The control unit (370) can control the output unit (380) to output a visual or auditory notification when it detects that the time set by the timer (361) has been reached.

[0146] The output unit (380) can output information related to the cooktop (10) using power stored in the energy storage circuit (341).

[0147] The output unit (380) may include at least one of a display that visually displays information or a speaker that audibly outputs information.

[0148] Additionally, although not shown in FIG. 11, the shield device (300) may further include an input section (399, FIG. 12).

[0149] That is, the configuration and input section (399) of FIG. 11 are merely exemplary, and the shield device (300) may include other components depending on the embodiment.

[0150] FIG. 12 is a drawing showing the configuration of a shield device according to an embodiment of the present disclosure.

[0151] The shield coil (312) and shield capacitor (351) are placed inside the case (300a), and the temperature sensor (331), output section (380), guide (391)(392) and input section (399) may have at least a portion exposed outside the case (300a). Although all of the above-described components are illustrated in FIG. 12, this is merely for convenience of explanation and is not limited thereto.

[0152] The shield coil (312) may be larger than the heating area. The shield coil (312) may be located outside the heating area.

[0153] A temperature sensor (331) can be placed at the center of the shield coil (312).

[0154] A shield capacitor (351) may be connected to the shield coil (312). The shield capacitor (351) may supply power to the temperature sensor (331), the output section (380), or the input section (399).

[0155] The output unit (380) can display information. According to the embodiment, the output unit (380) may include two or more. For example, the output unit (380) may include a first output unit (382) that displays information output from the temperature sensor (331) and a second output unit (384) that displays information output from the timer (361).

[0156] The input unit (399) can receive the time for the timer (361) to count.

[0157] A guide (391)(392) for guiding the position of the shield device (300) may be formed in the case (300a). The guide (391)(392) may guide the position where the shield device (300) is to be placed.

[0158] According to one embodiment, the guide (391)(392) includes a first guide (391) and a second guide (392), and the first guide (391) and the second guide (392) may be positioned at the vertices of the shield device (300) so as to face each other diagonally. However, these positions are merely exemplary.

[0159] The guide (391)(392) can be formed so that the center of the shield coil (312) aligns vertically with the center of the working coil (12), and in this case, the electromagnetic wave reduction efficiency can be maximized.

[0160] Although two guides (391) and (392) are shown in FIG. 12, they are merely exemplary and are not limited thereto.

[0161] According to one embodiment, a ferromagnetic material such as iron may be disposed on the top glass (11) of the cooktop (10). That is, a guide (391)(392) containing a magnet is formed in one area of ​​the shield device (300), and a ferromagnetic material may be disposed on the top glass (11) of the cooktop (10) at a position that overlaps vertically with the guide (391)(392) when the shield device (300) is optimally disposed.

[0162] Accordingly, when using the shield device (300), the user can easily position the shield device (300) by finding a location around the top glass (11) of the cooktop (10) where the shield device (300) is attracted by magnetism. Accordingly, there is an advantage that the user can easily find the optimal location for reducing electromagnetic waves of the shield device (300).

[0163] Meanwhile, the shield device (300) according to the embodiment of the present disclosure can be used on any cooktop (10) regardless of the guide (391)(392). Also, the shield device (300) can be arbitrarily used on at least one burner provided in the cooktop (10).

[0164] In addition, according to the embodiment of the present disclosure, since a shield coil does not need to be separately provided inside the cooktop (10), there is no need for increased manufacturing costs or volume of the cooktop (10), and there is an advantage that it can be applied to a pre-manufactured cooktop (10).

[0166] The above description is merely an illustrative explanation of the technical concept of the present disclosure, and those skilled in the art to which the present disclosure pertains will be able to make various modifications and variations within the scope of the essential characteristics of the present disclosure without departing from its nature.

[0167] Accordingly, the embodiments disclosed in this disclosure are intended to explain, not limit, the technical concept of this disclosure, and the scope of the technical concept of this disclosure is not limited by these embodiments.

[0168] The scope of protection of the present disclosure shall be interpreted by the claims below, and all technical ideas within the equivalent scope shall be interpreted as being included within the scope of rights of the present disclosure.

Claims

Claim 1 A shield device used in an induction heating type cooktop comprising a cooktop case having a working coil provided therein, the shield device case placed on the upper part of the cooktop case; and a shield device comprising a shield coil disposed inside the shield device case. Claim 2 A shield device according to claim 1, wherein the inner diameter of the shield coil is larger than the outer diameter of the working coil. Claim 3 A shield device according to claim 1, wherein the inner diameter of the shield coil is larger than the diameter of the heating area of ​​the cooktop. Claim 4 In claim 1, the shield device case is a shield device formed of silicone. Claim 5 A shield device according to claim 1, wherein the shield device case has a guide formed therein for guiding the position of the shield device. Claim 6 A shield device according to claim 1, further comprising an energy storage circuit having a shield capacitor connected to the shield coil. Claim 7 A shield device according to claim 6, further comprising a timer that counts the cooking time of the cooktop using power stored in the energy storage circuit. Claim 8 A shield device according to claim 6, further comprising a temperature sensor that detects the temperature of a cooking vessel heated by the cooktop using power stored in the energy storage circuit. Claim 9 In claim 8, the temperature sensor is a shield device disposed inside the shield coil. Claim 10 A shield device according to claim 6, further comprising an output unit that outputs information related to the cooktop using power stored in the energy storage circuit. Claim 11 In claim 6, the shield device wherein the first thickness of the area where the energy storage circuit is disposed in the shield device case is thicker than the second thickness of the area where the shield coil is disposed. Claim 12 An induction heating type cooktop system comprising: a cooktop case having a top plate glass having a heating area formed therein through which a magnetic field generated from the working coil passes, wherein a working coil is provided inside; and a shield device placed on the cooktop, wherein the shield device comprises: a shield device case placed on the upper part of the cooktop case; and a shield coil disposed inside the shield device case. Claim 13 A cooktop system of an induction heating method according to claim 12, wherein the inner diameter of the shield coil is larger than the outer diameter of the working coil. Claim 14 A cooktop system of the induction heating method according to claim 12, wherein the inner diameter of the shield coil is larger than the diameter of the heating area of ​​the cooktop. Claim 15 An induction heating type cooktop system according to claim 12, wherein the shield device case has a guide formed therein to guide the position of the shield device. Claim 16 The induction heating type cooktop system according to claim 12, wherein the shield device further comprises an energy storage circuit having a shield capacitor connected to the shield coil.

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