Abstract: An internal combustion engine ignition coil includes: a center core; a primary coil provided on an outer side of the center core; a secondary coil provided on an outer side of the primary coil; and a side core provided on an outer side of the primary coil and the secondary coil and formed by stacked electromagnetic steel sheets, the side core having one contact portion in contact with one end surface of the center core and another contact portion in contact with another end surface of the center core with a magnet therebetween. The side core is composed of a plurality of side core portions fitted to each other to be movable relative to each other in a longitudinal direction of the center core.

Abstract: An ignition coil includes a primary coil, a secondary coil, a center core, a side core, a core cover, a case, and an insulating resin. The core cover is formed in a form that covers an inner side face, one thickness direction end face, and an other thickness direction end face of the side core. Wall portions that divide a mass of the insulating resin into portions, or reduce an amount thereof, are provided in the core cover on an aperture portion side of the case, which is the one thickness direction end face side of the side core.

Abstract: An ignition coil includes a primary coil, a secondary coil, a center core, a side core, a core cover, a case, and an insulating resin. The core cover is formed in a form that covers an inner side face, one thickness direction end face, and an other thickness direction end face of the side core. Wall portions that divide a mass of the insulating resin into portions, or reduce an amount thereof, are provided in the core cover on an aperture portion side of the case, which is the one thickness direction end face side of the side core.

Abstract: An internal combustion engine ignition coil includes: a center core; a primary coil provided on an outer side of the center core; a secondary coil provided on an outer side of the primary coil; and a side core provided on an outer side of the primary coil and the secondary coil and formed by stacked electromagnetic steel sheets, the side core having one contact portion in contact with one end surface of the center core and another contact portion in contact with another end surface of the center core with a magnet therebetween. The side core is composed of a plurality of side core portions fitted to each other to be movable relative to each other in a longitudinal direction of the center core.