DENKIKIKYOTETSUSHINNOSHODONHOHO

摘要

PURPOSE:To assure a necessary annealing temp. and to relieve strain by maintaining the entire part of an iron core for electrical equipment at a specified temp. by high-frequency excitation and partially projecting a laser beam to the corner part of the iron core for electrical equipment and near said part. CONSTITUTION:High-frequency current is supplied by using a high frequency power supply 3 to a winding 2 for high-frequency excitation and the annular iron core 1 is excited by the high frequency and is heated up to the necessary temp. The laser beam is projected by using a CO2 laser to the corner part 1b which is the strained part of the annular iron core 1 and is focused 6 is spot there to heat the corner part. The beam is moved quickly over the entire part of the corner part 1b so that the entire part is heated up to the necessary annealing temp. The projection of the laser beam is stopped and the iron core is cooled at a specified rate when the necessary temp. is attained. The annealing state for relieving the strain of the iron core for electrical equipment is thereby executed inexpensively and quickly.