JP2011060630A - Self-resonant coil for induction heating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a self-resonant coil for an induction heating device capable of sufficiently heating even though a distance between a heating coil and a pan is separated each other. <P>SOLUTION: The self-resonant coil for an induction heating device has a resonant coil 103 with an inductance component, and is installed on an object to be heated 106 heated with the induction heating device. Thus, sufficient heating can be achieved by making self-resonance with frequency of a magnetic field emitted from the heating coil 101 of the induction heating device even though the distance between the heating coil and the pan is separated. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an induction heating device used in general households, restaurants, factories, and the like, and more particularly to its self-resonant coil.

  In recent years, induction heating cookers typified by IH cooking heaters are widely used in homes. The conventional IH cooking heater must be used with the pan placed on the top plate. When the pan is removed from the top plate, the coupling with the heating coil is reduced and sufficient heating cannot be performed. In addition, when using a wok with a flat bottom, the coupling between the heating coil and the pan weakened, and sufficient heating could not be achieved. Until now, the structure which added the instrument which induces a magnetic field between a pan and a heating coil (for example, refer to patent documents 1 and 2), the structure which formed the shape of the heating coil according to the shape of the bottom of a pan (for example, patent) Reference 3) has been studied.

JP 2007-329020 A JP-A-11-162627 Japanese Patent Laid-Open No. 9-92453

  However, all of the conventional configurations have to be used with the distance between the heating coil and the pan always constant, and the pan cannot be used by shaking it away from the induction heating device. It was.

  In view of the above-described conventional problems, an object of the present invention is to provide a self-resonant coil for an induction heating device that can perform sufficient heating even when the heating coil and the pan are separated from each other.

  In order to solve the above problems, a self-resonant coil for an induction heating device according to the present invention includes a resonance coil having an inductance component, is attached to an object to be heated that is heated by the induction heating device, and is heated by the induction heating device. A self-resonant coil for an induction heating device, wherein the coil self-resonates at a frequency of a magnetic field generated by the coil.

  Thereby, even if the distance between the heating coil and the pan is increased, sufficient heating can be realized.

  The self-resonant coil for induction heating apparatus of the present invention can realize sufficient heating even if the distance between the heating coil and the pan is increased.

The figure which shows the structure of the self-resonance coil for induction heating apparatuses in Embodiment 1 of this invention. Sectional drawing which shows the structure of the self-resonance coil for induction heating apparatuses in Embodiment 1 of this invention The figure which shows the self-resonance coil for induction heating apparatuses with which the self-resonance coil 102 in Embodiment 1 of this invention was comprised by the coil for several resonances

  A first invention includes a resonance coil having an inductance component, is attached to an object to be heated by an induction heating device, and self-resonates at a frequency of a magnetic field generated by the heating coil of the induction heating device. This is a self-resonant coil for an induction heating device.

  With this configuration, high heating efficiency can be realized even if the distance between the heating coil and the object to be heated is large.

  The second invention is the self-resonant coil for the induction heating device according to the first invention, wherein the self-resonant coil is composed of a plurality of resonance coils each having a different resonance frequency, and the frequency of the magnetic field generated by the heating coil of the induction heating device. It is the self-resonant coil for induction heating apparatuses which controls a heating area | region by. With this configuration, the heating area of the object to be heated can be controlled.

  According to a third aspect of the present invention, in the self-resonant coil for the induction heating device according to the first aspect, the self-resonant coil is composed of a plurality of resonance coils each having a different resonance frequency, and the respective induction frequencies are close to each other. This is a self-resonant coil for a device. This configuration facilitates frequency control of power input to the heating coil.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a diagram showing a configuration of a self-resonant coil for an induction heating device according to the present invention. FIG. 2 is a cross-sectional view showing the configuration of the self-resonant coil for the induction heating device of the present invention.

  The heating coil 101 is connected to an inverter circuit that generates high-frequency power at both ends, generates a high-frequency magnetic field, induces a current in a self-resonant coil 102 described later via a top plate 105 made of an insulator, This is a heating coil for inductively heating the heated object 106.

  The self-resonant coil 102 includes a resonance coil 103 having an inductance component and a dielectric sheet 104 that is a sheet-like dielectric. The self-resonance coil 102 self-resonates at a specific frequency due to the inductance component and parasitic capacitance component of the resonance coil 103. Causes resonance. The self-resonant coil 102 is attached to the bottom surface of the object 106 to be heated. Self-resonant coil 102 is insulated from object to be heated 106 by dielectric sheet 104.

  The parasitic capacitance component is mainly generated between the lines of the resonance coil 103. As the dielectric constant of the dielectric sheet 104 increases, the parasitic capacitance component increases and the self-resonance frequency can be lowered. Further, a configuration in which a capacitor is connected to both ends of the resonance coil 103 without using the dielectric sheet 104 may be employed.

  The operation and action of the self-resonant coil for an induction heating device of the present invention configured as described above will be described.

  Electric power having the same frequency as the self-resonant frequency of the self-resonant coil 102 is input to the heating coil 101. The heating coil 101 generates a high-frequency magnetic field, and the self-resonant coil 102 receives this magnetic field and causes self-resonance. At this time, a high frequency current is induced in the self-resonant coil 102 to generate a high frequency magnetic field. The object to be heated 106 is induction-heated by receiving a high-frequency magnetic field generated by the self-resonant coil 102.

  In the case where the self-resonant coil 102 is not provided, when the distance between the heating coil 101 and the object 106 to be heated is increased, the coupling between the two is weakened, and the heating efficiency is greatly reduced. However, when the self-resonant coil 102 is attached in the vicinity of the object 106 to be heated, the self-resonant coil 102 generates a strong magnetic field in the self-resonant state, so that the heating coil 101 and the object 106 to be heated are separated from each other. The heating efficiency is not greatly reduced.

  FIG. 3 is a diagram showing a self-resonant coil for an induction heating apparatus in which the self-resonant coil 102 of the present invention is composed of a plurality of resonance coils. The resonance coil is an example in which the resonance coil includes three resonance coils, a first resonance coil 201, a second resonance coil 202, and a third resonance coil 203. Since the resonance coils have different sizes, the inductances are different. Therefore, the first resonance coil 201, the second resonance coil 202, and the third resonance coil 203 cause self-resonance at different resonance frequencies.

  Further, the self-resonance frequency may be adjusted by adjusting the mutual inductance generated between the respective resonance coils.

  In FIG. 3, the plurality of resonance coils are concentrically arranged, but the central axes do not have to be the same, and any arrangement may be employed.

  When the frequency of the electric power input to the heating coil 101 is changed, a current is induced only in the resonance coil whose frequency matches the self-resonance frequency. Since it is possible to select which coil of the plurality of resonance coils is made to pass current depending on the frequency of the electric power input to the heating coil 101, the heating region of the object to be heated 106 can be controlled. For example, when a current is passed through the third resonance coil 203, only the outer peripheral portion of the bottom surface of the article to be heated 106 can be heated.

  Further, when the Q value of the self-resonant coil 102 is high, the frequency bandwidth is narrowed, so the frequency of the electric power input to the heating coil 101 must be finely controlled. When the self-resonant coil 102 is composed of a plurality of resonance coils, and there are a plurality of self-resonant frequencies, and these frequencies are close to each other, the frequency bandwidth is widened, so the frequency control of the power input to the heating coil 101 is performed. It becomes easy.

  As described above, by attaching the self-resonant coil 102 that causes self-resonance at the frequency of the magnetic field generated by the heating coil 101 to the object 106 to be heated, even if the distance between the heating coil 101 and the object 106 to be heated is large, high heating efficiency Can be realized.

  The self-resonant coil for induction heating device of the present invention is not limited to induction heating devices used in general homes, restaurants, factories, etc., but for all devices using the principle of electromagnetic induction such as wireless tags and non-contact charging devices. Even applicable.

DESCRIPTION OF SYMBOLS 101 Heating coil 102 Self-resonant coil 103 Resonant coil 104 Dielectric sheet 105 Top plate 106 Heated object 201 First resonance coil 202 Second resonance coil 203 Third resonance coil

Claims (3)

A self-resonant for induction heating apparatus, comprising a resonance coil having an inductance component, attached to an object to be heated by an induction heating apparatus, and self-resonating at a frequency of a magnetic field generated by the heating coil of the induction heating apparatus Resonant coil. The self-resonant coil for an induction heating device according to claim 1, wherein the self-resonant coil is composed of a plurality of resonance coils each having a different resonance frequency, and the heating region is controlled by the frequency of a magnetic field generated by the heating coil of the induction heating device. The self-resonant coil for an induction heating device according to claim 1, wherein each of the self-resonant coils is composed of a plurality of resonance coils having different resonance frequencies.