Ignition coil for internal combustion engine

An ignition coil for an internal combustion engine comprising:

• a primary coil and a secondary coil magnetically coupled to each other;
• a second spool which the secondary coil is wound around;
• and
• a connection terminal connected to a high voltage side of the secondary coil and supported by a terminal support portion provided at the second spool,
• wherein
• the terminal support portion includes an insertion hole portion allowing the connection terminal to be inserted in an insertion direction as a coil radial direction;
• the connection terminal includes a protrusion protruding outside the connection terminal in a direction orthogonally crossing the insertion direction;
• the protrusion is engaged to the insertion hole portion from inward in the coil radial direction;
• the connection terminal formed by bending a metal wire material capable of being elastically deformed, in a U shape opened outwardly in the coil radial direction;
• and
• the protrusion is formed as a bending portion of a U-shaped connection terminal as and the protrusion of the connection terminal is the connection terminal formed in the U shape positioned in the insertion hole portion.