IRON CORE OF IGNITION COIL

摘要

PURPOSE:To abolish a bracket used to fix a shift of a split body and to realize a small-sized and lightweight iron core by providing the following: an excitation part where a primary coil and a secondary coil are wound on its outer periphery; a closed magnetic circuit formation part which is installed collectively to be ring-shaped; and a permanent magnet which repels a flux produced by the excitation part. CONSTITUTION:A closed magnetic circuit formation part 520 is installed to be ring-shaped and collectively; accordingly, even when a force is exerted to the outward direction from the inside of the closed magnetic circuit formation part 520, the closed magnetic circuit formation part 520 is hard to deform even without any reinforcement. An excitation part 510 where a primary coil 310 and a secondary coil 320 have been wound on its outer periphery and a permanent magnet 530 which repels a flux produced by the excitation part 510 are housed at the inside; an electric current is supplied to the primary coil 310; a strong repulsive force is generated between the permanent magnet 530 and the excitation part 510 and between the permanent magnet 530 and the closed magnetic circuit formation part 520 (at each air gap). In this case, even when the closed magnetic circuit formation part 520 is not reinforced at all, the air gap is not widened or is hardly widened. By this setup a bracket for reinforcement use can be abolished; a small-sized and lightweight iron core can be realized.