Ignition coil having air layers as insulators and manufacturing method therefor

摘要

An ignition coil has a case and a central core placed in the case. A secondary spool is wound with a secondary coil and placed outside the central core in the case. A cylindrical primary spool is wound with a primary coil and placed outside the secondary spool in the case. A resin insulator is filled in the case to maintain the insulation between each member. Air layer is partitioned in at least one of a gap between the central core and the secondary spool and a gap between the primary spool and the case.