| 摘要 |
PURPOSE:To releave a compression stress and reduce an iron loss by a method wherein a DC magnetic field is applied to a core to produce a positive magnetic distortion after a heat treatment or during the cooling process after the heat treatment and a liquid insulation material is applied to the core at that state and cured. CONSTITUTION:An exciting coil 3 is applied to a toroidal core 2 composed of a wound amorphous magnetic material thin strip 1. The toroidal core 2 is housed in an annealing furnace 4, in which an inert gas such as CO2 or N2, is enclosed to prevent oxidization, and subjected to a heat-treatment in a magnetic field. The heat treatment in the magnetic field is carried out by heating under the existence of the DC magnetic field produced by excitation of the toroidal core 2 by connecting the exciting coil 3 to an external DC source 5. After the toroidal core 2 is subjected to the heat treatment in the magnetic field at a prescribed temperature for a prescribed time, the core 2 is taken out of the annealing furnace 4. Then the exciting coil 3 is connected to the DC source 5 again to apply the DC field to the toroidal core 2 and at that state liquid epoxy resin of about 20-1,000 centipoise is applied to the core 2 by brushing 6 or impregnation and then cured. |
