Abstract: An ignition coil includes a coil main body portion, a conductive member, and a protective portion. The coil main body portion generates a high voltage. The conductive member electrically connects the coil main body portion and a terminal metal fitting of a spark plug. The conductive member is arranged inside the protective portion. The protective portion has an electrically insulating property. The conductive member includes an elastic portion that elastically deforms in a longitudinal direction of the conductive member, and a conductive terminal that is arranged on a distal end side of the elastic portion. The conductive terminal has a distal end surface that includes a concave surface or a convex surface that abuts on the terminal metal fitting of the spark plug. A contact portion between the concave surface or the convex surface and the terminal metal fitting of the spark plug has an annular shape.

Abstract: An ignition coil includes a coil main body portion, a conductive member, and a protective portion. The coil main body portion generates a high voltage. The conductive member electrically connects the coil main body portion and a terminal metal fitting of a spark plug. The conductive member is arranged inside the protective portion. The protective portion has an electrically insulating property. The conductive member includes an elastic portion that elastically deforms in a longitudinal direction of the conductive member, and a conductive terminal that is arranged on a distal end side of the elastic portion. The conductive terminal has a distal end surface that includes a concave surface or a convex surface that abuts on the terminal metal fitting of the spark plug. A contact portion between the concave surface or the convex surface and the terminal metal fitting of the spark plug has an annular shape.

Abstract: An ignition coil disposed and used in the neighborhood of a part made of a conductive material is provided with a first core made of a magnetic material, around which a primary coil and a secondary coil are wound; and a second core made of a magnetic material and having a cylindrical portion, in which the primary coil and the secondary coil and the first core are contained, and forms a closed magnetic path in conjunction with the first core.

Abstract: An ignition coil assembly for internal combustion engine has a voltage withstanding air gap of a predetermined shape and an insulating resin cover for covering the external iron core provided in addition to resin mold and partitioning wall in order to electrically insulate from the secondary coil the external iron core constituting a magnetic path together with the internal iron core.