| 摘要 |
<p>PROBLEM TO BE SOLVED: To improve an output efficiency by forming a cut at the joint part between the first and second iron cores to reduce the joint area between them. SOLUTION: Related to an ignition coil, a center iron-core (first iron core) 18 is provided inside a primary coil bobbin 12 while a winding iron-core (second iron-core) 19 is provided at the outer peripheral part of an insulating case 11. The winding iron-core 11 is stamped from a silicon steel plate of relatively thin into an endless form. Related to the winding iron-core 19, a plurality of slots 19a are provided at such parts as facing each other. The slots 19a are longer than the end surface of the center iron-core 18 while extending in parallel each other. These slots 19a are stamped at the same time when a band material 19' is stamped, and provided at such position as agree each other when wound endless.</p> |
