| 摘要 |
<p>PURPOSE:To make quick annealing with good heating efficiency possible without generating deterioration and exfoliation in the insulating films among the layers of the iron cores for electric motors by annealing said iron cores by the use of induction heating of specific frequencies. CONSTITUTION:In the stage of annealing iron cores for electric motors by induction heating, the frequencies thereof are set at 1.4-1.8kHz, whereby the iron cores are annealed in a short time with good heating efficiency and the effect of economizing energy for the annealing is improved. The heating of the insulating films among the layers which are applied on the front and rear surfaces of each sheet of the iron cores up to the temp. at which the films deteriorate or exfoliate by the heating of the above-mentioned method is obviated. If the quantity of the electric power to be supplied in 1kg mass of the iron cores in the induction heating at the above-mentioned frequencies is set at 4.5-7.0KW, the heating efficiency is considerably improved, the considerable reduction in the heating time is made possible and the deformation of the iron cores is kept within a practicably usable range.</p> |
