JP2009245675A - Induction heating cooker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an induction heating cooker high in reliability by obtaining a heating coil in which fixation between the heating coil and a coil base is sure, and which is superior in insulating characteristics, and is superior in heating efficiency. <P>SOLUTION: At the outer periphery of aggregate wires 8 constituted by twisting strands of a conductor covered by an insulating layer or conductive wires in which the wires are bundled, an insulating layer 9 constituted of PFA of tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer which is fluororesin of a high melting point is installed, and an adhesive layer 10 constituted of PPS of a polyphenylene sulfide resin of a high melting point is installed at its outer periphery. Furthermore, the heating coil 3 is constituted of a coil conductive wire 7 in which a welding layer 11 constituted of FEP of tetrafluoroethylene-hexafluoropropylene copolymer, or ETFE of tetrafluoroethylene-ethylene copolymer which is fluororesin of a low melting point is installed at part of the outer periphery of the adhesive layer 10. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an induction heating cooker that heats an object to be heated such as a pan on a top plate using induction heating by a heating coil as a heat source in a kitchen or the like of a general household, and particularly relates to a heating coil.

  The heating coil of a conventional induction heating cooker has a bundle of litz wires formed by bundling together a plurality of conductor wires coated with an insulating layer such as enameled wire, and twisting this set wire together. A plurality of steps are wound around the circumference and formed into a disk shape.

  A resin coil base that holds this heating coil by bonding or screwing via a resin component is disposed below the top plate, and high frequency power is supplied to the heating coil to be heated and placed on the top plate. Inductive heating of copper and aluminum pans as well as iron, which is a product.

  When induction heating an iron pan, high frequency power of 20 to 40 kHz is supplied to the heating coil. However, when heating a copper or aluminum pan or the like, the heating coil has a frequency of 40 to 100 kHz higher than the above frequency. Supply high frequency power.

  When such a high-frequency power is supplied to the heating coil, the current density in the cross-sectional area of the conductor flows only to the outer periphery of the conductor due to the so-called skin effect, and the effective resistance value rises. The diameter is narrowed and many are bundled and twisted together.

  A plurality of conductor wires covered with an insulating layer are bundled to form an assembly wire, and the assembly wire is twisted to form a coil conductor, which is wound in a plurality of stages on a substantially identical circumference to form a disk. In a heating coil that is molded and configured to heat not only iron but also copper or aluminum pans, a part of or the entire outer periphery of the coil conductor wire is a fluororesin tetrafluoroethylene par It constitutes a PFA insulator of a fluoroalkyl vinyl ether copolymer, and on the outside thereof, a fluororesin having a low melting point is ETFE of tetrafluoroethylene / ethylene copolymer or FEP of tetrafluoroethylene / hexafluoropropylene copolymer. After forming the insulator in multiple stages on the same circumference and forming it into a disk shape, heat it to the outermost side of the coil conductor There has been proposed one that melts and solidifies ETFE or FEP, which is a fluororesin having a low melting point, and fixes the insulators adjacent to the coil conductors to stabilize the shape of the heating coil (see, for example, Patent Document 1). ).

JP 2004-47482 A

  However, a heating coil obtained by winding a coil conductor provided with an insulator made of two types of resin, fluororesin PFA and fluororesin ETFE or FEP, having different melting points on the outer periphery of the coil conductor in the above-described prior art, is a coil conductor. Because the fluororesin on the outer periphery of the material is non-adhesive, it is impossible to bond the heating coil to the coil base with an adhesive. It was necessary to use a fixing method such as screwing. Therefore, the number of parts increases and the fixing work is troublesome, which is expensive.

  Also, if the heating coil and the coil base are not completely fixed due to variations in work when the heating coil is held on the coil base, the positional relationship between the heating coil and the object to be heated will vary and the heating efficiency will deteriorate. Or the heating coil vibrates and generates abnormal noise.

  SUMMARY OF THE INVENTION The present invention solves the above-described conventional problems, and the reliability between the heating coil and the coil base is stable and reliable by obtaining a heating coil with excellent insulation and excellent heating efficiency. An object of the present invention is to provide a high induction heating cooker.

  The present invention has been made to solve the above problems, and in an induction heating cooker that heats an object to be heated by supplying high-frequency power to a heating coil held by a coil base, the heating coil is insulated. A PFA of a tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer, which is a fluororesin having a high melting point, on the outer periphery of an assembly wire formed by twisting together a conductor wire coated with a layer or a conductive wire bundled with the wire An insulating layer is provided, an adhesive layer made of polyphenylene sulfide resin PPS having a high melting point is further provided on the outer periphery thereof, and a fluororesin having a low melting point is provided on a part of the outer periphery thereof. Consists of FEP of hexafluoropropylene copolymer or ETFE of tetrafluoroethylene / ethylene copolymer A welding layer is provided, the coil conductor is wound and then heated, and the welding layers of adjacent coil conductors are melted and solidified to stabilize the shape of the heating coil, and the adhesive layer and the coil base The space is adhered and held with an adhesive.

  The induction heating cooker according to the present invention is configured as described above, so that the heating coil and the coil base are securely fixed, and a stable heating coil with excellent insulation and excellent heating efficiency is obtained. Can do.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1 is a longitudinal sectional view of an essential part of an induction heating cooker showing an embodiment of the present invention, FIG. 2 is a perspective view showing the structure of a heating coil and a coil base, and FIG. 3 is a sectional view of a coil conductor. 4 is a perspective view of the coil conductor, and FIG. 5 is a sectional view of the heating coil and the coil base.

  In the figure, a heating coil 3 wound in a disk shape by winding a plurality of stages on substantially the same circumference is held by a coil base 4 made of PPS of polyphenylene sulfide resin which is an insulator, and the top plate 2 It is provided below.

  A heated object 1 such as a pan placed on the top plate 2 is induction-heated by supplying high-frequency power to the heating coil 3 with an inverter circuit (not shown).

  The heating coil 3 is mounted so as to be fitted inside the rib 5 provided in the central portion and the outermost peripheral portion of the coil base 4.

  A magnetic body 6 such as ferrite is provided on the lower side of the coil base 4 so that the magnetic flux generated from the heating coil 3 spreads below the coil base 4 and erroneously heats nearby metals and electronic components. This prevents the electronic components from being affected by noise caused by magnetic lines of force.

  The coil base 4 on which the heating coil 3 is mounted is urged in the direction of the top plate 2 by a plurality of springs (not shown), and the heating coil 3 is configured to be substantially parallel to the top plate 2.

  The coil conductor 7 that constitutes the heating coil 3 is formed by bundling a plurality of conductor wires having a diameter of, for example, 0.05 mm, which are insulated and coated with enamel or the like, and twisting the bundled conductors to form an assembly wire 8. An insulating layer 9 made of PFA (melting point: 310 ° C.) of tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer, which is a fluororesin having a high melting point and excellent insulating properties, is provided on the outer periphery of the assembly line 8 by extrusion molding. Further, an adhesive layer 10 made of polyphenylene sulfide resin PPS (melting point: 280 ° C.) having a high melting point is provided on the outside of the insulating layer 9 by extrusion molding. Further, a fluororesin having a low melting point is provided on the outside of the adhesive layer 10. FEP (melting point: 270 ° C.) of tetrafluoroethylene / hexafluoropropylene copolymer or tetrafluoroethylene / ethylene As shown in FIG. 4, a tape-like welded layer 11 composed of a copolymer ETFE (melting point: 260 ° C.) having a thickness of about 0.01 mm and a width of about 3 mm is formed in the length direction of the coil conductor 7. It is wound in a spiral shape with a certain gap at a winding pitch of 15 mm.

  The tape-like welding layer 11 made of fluororesin FEP or ETFE is wound around the outer periphery of the adhesive layer 10. However, the fluororesin FEP or ETFE is made around a part of the outer periphery of the adhesive layer 10. It is good also as a structure which provides the made welding layer.

  When the heating coil 3 is manufactured, the coil conductor 7 is wound in a plurality of stages on the substantially same circumference, formed into a disk shape, and then heated to form a fluororesin FEP or ETFE having a low melting point. The tape-like weld layer 11 is melted and solidified, and the weld layers 11 of the adjacent coil conductors 7 are fixed to stabilize the shape of the heating coil.

  At this time, the insulating layer 9 made of fluororesin PFA having a high melting point inside the welded layer 10 is not deformed, and stable and highly reliable insulation can be obtained.

  The heating coil 3 having a stabilized shape is fitted between the rib 5 at the center of the coil base 4 and the rib 5 at the outermost periphery of the coil base 4 as shown in FIG. The adhesive layer 10 and the coil base 4 are fixed and held by bonding with an adhesive 12 such as a silicon adhesive. In addition, since PPS of polyphenylene sulfide resin has adhesiveness, it can be bonded by the adhesive 12.

  Thus, although the thing which comprised the insulator of the fluororesin on the outer periphery of the coil conducting wire 7 is a thing excellent in heat resistance and an insulation characteristic, since a fluororesin has non-adhesiveness, it is a coil as it is If it is intended to be mounted on the base 4, it is impossible to bond with an adhesive, and if a fixing method using screws is used with resin parts or the like, the work is cumbersome and expensive, but the adhesive layer 10 made of PPS By adopting a configuration in which the coil bases 4 are bonded with the adhesive 12, the heating coil 3 can be fixed to the coil base 4 with a simple configuration, and the cost can be reduced.

  Further, since the adhesive layer 10 provided on the coil conductor 7 is provided by extrusion molding on the outside of the insulating layer 9, the adhesive layer 10 and the coil base 4 are bonded with an adhesive 12 after being formed into the heating coil 3. In this case, since the coil base 4 and the coil conductor 7 are firmly fixed, when the high frequency power is supplied to the heating coil 3 for heating, the heating coil 3 does not vibrate and no abnormal noise is generated.

It is a principal part longitudinal cross-sectional view of the induction heating cooking appliance which shows one Example of this invention. It is a perspective view which similarly shows the structure of a heating coil and a coil base. Similarly it is sectional drawing of a coil conducting wire. It is a perspective view of a coil conducting wire similarly. It is sectional drawing of a heating coil and a coil base similarly.

Explanation of symbols

1 Heated object 3 Heating coil 4 Coil base 7 Coil conductor 8 Assembly wire 9 Insulating layer 10 Adhesive layer 11 Welding layer 12 Adhesive

Claims (2)

In an induction heating cooker that heats an object to be heated by supplying high-frequency power to a heating coil held by a coil base,
The heating coil is made of tetrafluoroethylene / perfluoroalkyl vinyl ether which is a fluororesin having a high melting point on the outer periphery of an assembly wire formed by twisting a conductor wire coated with an insulating layer or a conductive wire bundled with the wire. An insulating layer made of a copolymer PFA is provided, and an adhesive layer made of polyphenylene sulfide resin PPS having a high melting point is further provided on the outer periphery thereof. Further, a fluorine resin having a low melting point is provided on a part of the outer periphery. It is composed of a coil conductor provided with a welding layer composed of FEP of tetrafluoroethylene / hexafluoropropylene copolymer or ETFE of tetrafluoroethylene / ethylene copolymer, and after winding the coil conductor, The shape of the heating coil is obtained by melting and solidifying the welded layers of the coil conductors adjacent to each other by heating. With stabilized, the induction heating cooker where the structure is held by bonding with an adhesive between said adhesive layer and the coil base.   The induction heating cooker of Claim 1 WHEREIN: The said welding layer is comprised with a tape, and it was set as the structure wound around the outer periphery of the said contact bonding layer in a spiral shape.

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