Ignition coil

An ignition coil comprising:

• a primary coil and a secondary coil which are magnetically coupled with each other;
• a center core which is disposed inside inner peripheries of the primary coil and the secondary coil, the center core having a first surface and a second surface aligned with the first surface in an axial direction of the primary and the secondary coils;
• a first core member which includes a first core-facing portion and a first core side portion, the first core-facing portion faces the first surface of the center core, the first core side portion extending from the first core-facing portion in a first axial direction defined to be opposite a second axial direction along the axial direction of the primary and secondary coils, the first core member being arranged outside outer peripheries of the primary coil and the secondary coil;
• and
• a second core member which includes a second core-facing portion and a second core side portion, the second core-facing portion facing the second surface of the center core, the second core side portion extending from the second core-facing portion in the second axial direction and being located on an opposite side of the center core to the first core side portion in an orthogonal direction perpendicular to the axial direction of the primary and secondary coils, the second core member being arranged outside the outer peripheries of the primary coil and the secondary coil, wherein
• the first core-facing portion has an end surface which faces away from the first core side portion in the orthogonal direction, the end surface of the first core-facing portion facing in contact with a portion of the second core side portion to create a first contact region,
• the second core-facing portion has an end surface which faces away from the second core side portion in the orthogonal direction, the end surface of the second core-facing portion facing in contact with a portion of the first core side portion to create a second contact region, and
• each of the first contact region and the second contact region is shaped to approach in the second axial direction close to the first core side portion facing the second core side portion in the orthogonal direction.