Ignition coil apparatus for internal combustion engine

摘要

An ignition coil apparatus for an internal combustion engine can be produced at low cost with a simple structure, and can be inserted into a bent plug hole without impairing insertability thereof. The apparatus is provided with a high voltage tower (2b) that holds a high voltage terminal (8) in its interior, and a cylindrical plug boot (10) that has electrical insulation and flexibility and is attached at its one end to the high voltage tower (2b). The plug boot 10 is installed on a main body of the internal combustion engine by being inserted into the bent plug hole. The plug boot (10) has a thin wall part (10a) of a thin thickness formed at a location facing in opposition to a bent portion of the plug hole.