JP4853153B2 - Induction heating device - Google Patents

Description

  The present invention relates to an induction heating apparatus that heats an object to be heated made of a conductive material by electromagnetic induction using an induction heating coil to which high-frequency power is supplied.

  A general induction heating apparatus has a configuration as shown in FIGS.

  The induction heating apparatus of FIG. 6 uses an induction heating coil 5a configured by winding a coil conductor into a cylindrical shape as shown in Patent Document 1. When such a cylindrical induction heating coil 5a is used, a rod-like object to be heated 1a made of a conductive material is inserted into the central hollow portion where the magnetic flux generated by the induction heating coil 5a is concentrated and heated. Therefore, very efficient heating can be performed.

  On the other hand, for example, an induction heating apparatus optimal for an electromagnetic cooker as shown in FIG. 7 is conductive on the upper surface of an induction heating coil 5b formed by winding a coil conductor in a flat plate shape. A heated object 1b such as a cooking pan made of a material is placed and induction heated by an induction heating coil 5b. In the case of the induction heating apparatus as shown in FIG. 7, since the magnetic flux generated by the induction heating coil 5b is distributed above and below the heating coil 5b, the heating efficiency tends to be lower than that in the conventional apparatus of FIG. Therefore, it is necessary to concentrate the magnetic flux in order to increase the heating efficiency. For this reason, in such an induction heating device, a plurality of magnetic bodies 4g made of rod-shaped or flat-plate-like ferrite are dispersedly arranged on the lower surface of the heating coil so as to suppress the dispersion below the magnetic flux.

Moreover, the induction heating apparatus optimal for an electromagnetic cooker as shown in FIG. 8 as shown in FIG. 8 as shown in Patent Document 3 has a magnetic body 4g arranged only on the lower surface of the heating coil 5b in FIG. A magnetic body 4h having a U-shaped cross section that surrounds the outer peripheral portion of the heating coil 5b. Thus, if the periphery of the heating coil 5b is also surrounded by a magnetic material, the dispersion of the magnetic flux generated by the heating coil 5b is further suppressed and the magnetic flux is concentrated on the heated object 1b such as a cooking pot. The heating efficiency can be further increased.
JP 2005-206906 A JP 2004-327056 A JP 2003-100429 A

  By the way, when an induction heating apparatus is used to heat a flat object to be heated, which is coupled to the center portion and is rotatably supported by the support column, the support column is inserted into the hollow portion at the center portion of the heating coil. Because the flat plate portion is positioned on the upper surface of the induction heating coil, the magnetic flux concentrates on the support column, and the support column that does not require heating is heated. For this reason, when induction heating a flat plate-like object to which a rod-like column is coupled at the center in this way, it becomes difficult to efficiently heat the flat plate-like object without heating the column. There's a problem.

  In order to solve such problems, an object of the present invention is to provide an induction heating apparatus that can avoid induction heating of a support and can efficiently heat a flat object to be heated. .

  In order to solve such a problem, the present invention provides an induction heating coil formed by winding a coil conductor in a cylindrical shape, and an object to be heated by electromagnetic induction placed on the upper surface of the induction heating coil. In an induction heating apparatus comprising a heated object and a conductive material support column that supports the object to be heated from the lower surface, and the support column is inserted into the hollow portion at the center of the induction heating coil, A magnetic material is disposed between the support post and the inner wall of the coil.

  And in this invention, the said magnetic body is placed between the inner wall of the said induction heating coil and the support | pillar, the vertical member placed in parallel with these, and the horizontal placed horizontally under the said induction heating coil. It is preferable that a gap be provided between the vertical member and the horizontal member of the magnetic body.

  According to the present invention, by arranging the magnetic body between the support column supporting the flat object to be heated inserted into the hollow portion of the central portion of the induction heating coil and the inner wall of the induction heating coil, Since the magnetic flux flowing in the magnetic material is concentrated and the magnetic flux flowing to the support is shielded, the support becomes difficult to be induction-heated, and the magnetic flux flows to the flat object to be heated placed on the induction heating coil. The amount is increased and the heating efficiency can be improved.

  Embodiments of the present invention will be described with reference to examples shown in the drawings.

  FIG. 1 is a perspective view including a longitudinal section showing Embodiment 1 of the present invention. In this figure, reference numeral 1 denotes a plate-shaped object to be heated made of a conductive metal, and the object to be heated 1 is rotatably supported by a metal support 2 coupled to the center of the lower surface. . An induction heating coil 3 is formed by winding a coil conductor into a cylindrical shape, and is excited by a high-frequency alternating current supplied from a high-frequency power source (not shown).

  In order to heat the object to be heated 1, the support column 2 is inserted into the hollow part 3 a at the center of the induction heating coil 3 and arranged so that the object to be heated 1 is positioned on the upper surface of the induction heating coil 3. And the magnetic body 4 which consists of ferrite etc. is arrange | positioned between the support | pillar 2 and the inner wall of the induction heating coil 3 in the hollow part 3a of the induction heating coil, and the magnetic flux generated by the induction heating coil 3 is coil hollow. In the portion 3a, the magnetic material is concentrated on 4 so as not to pass through the column 2 that supports the article 1 to be heated.

  The magnetic body 4 may be integrally formed in a cylindrical shape, or may be divided into a plurality of bar-shaped segments 4a as shown in FIG. You may make it do. In addition, the shape of the rod-shaped segment 4a is not limited to the illustrated shape, and may be a rectangular parallelepiped shape.

  When heating the article 1 to be heated, high frequency AC power is supplied to the induction heating coil 3 from a power source (not shown), and the coil 3 generates a high frequency magnetic field. As shown by the dotted line in FIG. 1, the magnetic flux formed by this high frequency magnetic field passes through the magnetic circuit of the hollow part 3a of the coil 3, the object to be heated 1, the outer periphery of the coil 3, and the magnetic circuit of the magnetic body 4, and the electromagnetic Due to the induction action, the object to be heated 1 is heated by the eddy current generated in the object to be heated 1 of the conductive material. At this time, since the magnetic body 4 inserted between the pillars 2 coupled to the article 1 to be heated serves as a magnetic shield, almost no magnetic flux flows, and the pillars 2 are made of conductive metal. Even if it is done, it is hardly heated. Since the magnetic flux generated by the induction heating coil 3 is converged by the magnetic body 4 and flows to the heated object 1 in a concentrated manner, the heated object 1 is efficiently heated.

  FIG. 3 shows a second embodiment of the present invention. In the second embodiment, a magnetic body 4 made of ferrite or the like inserted between the induction heating coil 3 and the column 2 that supports the object to be heated 1 is inserted into the coil hollow portion 3 a and extends in parallel with the column 2. In addition to the vertical member 4b, a horizontal member 4c disposed horizontally on the lower surface of the coil 3 is provided, which is different from the first embodiment.

  As described above, when the magnetic member 4 is provided with the horizontal member 4b extending horizontally on the lower surface side of the coil 3, the magnetic flux diffused downward of the induction heating coil 3 is converged by the magnetic member horizontal member 4b. As a result, since the amount of magnetic flux passing through the article to be heated 1 can be increased, the heating efficiency of the article to be heated 1 can be increased as compared with that in the first embodiment.

  The magnetic body 4 may be integrally configured as a cylindrical body with a hook, but as shown in FIG. 4, a plurality of segmented segments 4d having an L-shaped cross section are arranged side by side on the circumference. You can also.

  And the vertical member 4b part and the horizontal member 4c part of the magnetic body 4 are not comprised integrally as shown in FIG. 5, but are divided | segmented and comprised so that the suitable space | gap g may be provided between both members. To. If the integrated structure is adopted, the magnetic flux is concentrated at the corner portion where the vertical member 4b and the horizontal member 4c are combined, so that the magnetic flux density is increased and the magnetic flux saturation phenomenon occurs. Since the magnetic resistance at the corner increases and the concentration of the magnetic flux is suppressed, it is possible to suppress the occurrence of the magnetic flux saturation phenomenon.

It is a perspective view containing the longitudinal cross-section which shows the structure of the induction heating apparatus of Example 1 of this invention. It is the top view which looked at the induction heating apparatus of FIG. 1 from the downward direction. It is a perspective view containing the longitudinal cross-section which shows the structure of the induction heating apparatus of Example 2 of this invention. It is a perspective view including the longitudinal cross-section which shows the modification of the magnetic body 4 in Example 2 of this invention. It is a perspective view including the longitudinal cross-section which shows the other modification of the magnetic body 4 in Example 2 of this invention. It is a perspective view which shows schematic structure of the conventional induction heating apparatus. It is a longitudinal cross-sectional view which shows schematic structure of the other conventional induction heating apparatus. Furthermore, it is a longitudinal cross-sectional view which shows schematic structure of the other conventional induction heating apparatus.

Explanation of symbols

1: Flat object to be heated 2: Support column for supporting object to be heated 3: Induction heating coil 4: Magnetic material

Claims (3)

  An induction heating coil configured by winding a coil conductor in a cylindrical shape, an object to be heated that is placed on the upper surface of the induction heating coil and heated by electromagnetic induction by the heating coil, and the object to be heated is supported from the lower surface. In an induction heating apparatus comprising a conductive material support post and the support post inserted through the hollow portion at the center of the induction heating coil, a magnetic material is provided between the support post in the hollow portion of the induction heating coil and the coil inner wall. An induction heating device characterized by being arranged.   The magnetic body is composed of a vertical member placed in parallel between the inner wall and the support of the induction heating coil, and a horizontal member placed horizontally below the induction heating coil. The induction heating apparatus according to claim 1, wherein The induction heating apparatus according to claim 2, wherein a gap is provided between the vertical member and the horizontal member of the magnetic body.

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