IGNITION COIL IN INTERNAL COMBUSTION ENGINE

PROBLEM TO BE SOLVED: To provide an ignition coil with stable electrical insulation, without damaging a part filled with an insulating material by absorbing the dislocation of a primary coil, at least in an axial direction. SOLUTION: A housing 60 is constituted in a way such that an upper end part 61a of a cylindrical lower case 61 is fitted to an opening of a cylindrical lower end part 62b of an upper case 62. A winding of the primary coil 12 turned into a cylindrical shape is fitted to the lower case 61. The inner face of the primary coil 12 is covered with an insulating film 40 with exfoliation characteristics to an insulating material. An inner core 10 and a secondary core 22 are stored with each given small space from the insulating film 40. The primary coil 12 is held with a given small space between the upper case 62 and the lower case 61. The all the hollow space including the small space between the insulating film 40 and the secondary coil 22 is filled with an insulating material. In addition, a flexible material B2 may be preferably provided at an upper end of the primary coil 12.