IGNITION COIL FOR INTERNAL COMBUSTION ENGINES

摘要

PROBLEM TO BE SOLVED: To suppress cracks of an ignition coil due to thermal stresses in internal combustion engines. SOLUTION: A center core 110 is composed of thin strips 110a. A resin layer 154 near one strip 110a, having the maximum width W among the strips, has a thickness t1 greater than a thickness t2 of a resin layer 154 at other parts. This prevents the resin layer 154 and secondary spools 131 continuing thereto from cracking.