| 摘要 |
PROBLEM TO BE SOLVED: To improve durability and to reduce a manufacturing cost by making the thickness of a magnetic metallic layer formed at least at the bottom part of a cooking tool to be heated large at the band of the high magnetic flux density of magnetic fluxes closer to a heating coil and gradually reducing the thickness of the other part. SOLUTION: The heat generating quantity of the magnetic metallic layer 3 is different corresponding to its thickness and material but in order to obtain a prescribed heat generating quantity, 0.5 to 1.0mm thermal spaying thickness is generally required in the case of iron. In addition, the density of the magnetic fluxes, namely current density, is maximized at the position P of the average diameter of the inner and outer diameter of the annular heating coil 6 on the center diameter of the heating coil 6. Thus, the thickness of the part of the layer 3 opposed to P where the average diameter of the heating coil 6 exists is maximized and this thickness is continuously reduced along with going in the directions of an outer periphery and an inner periphery from this part in the layer 3. Thereby the distribution of temperature is made uniform to make peeling difficult and to reduce the quantity of magnetic metallic material required for generating a prescribed quantity of power. |
