Ingition coil for internal combustion engine

• Main Authors: Kawai, Kazuhide, Sano, Masafuyu, Abe, Shigeya, Inagaki, Masahiro, Kasai, Hajime, Nakashima, Hidetoshi, Wada, Jyunichi, Tsunenaga, Koji, Osuka, Kazutoyo, Aoyama, Masahiko, Tauchi, Takashi, Buma, Kaneo, Sato, Yoshitaka, Akimoto, Katsunori
• Format: Patent
• Language: English
• Published: 28.11.2002

In a stick coil, there is disclosed an ignition coil for an internal combustion engine which can prevent a crack (a collar leak) from being generated due to a thermal stress. In this ignition coil, the structure is made such that a size (L) of a portion which is in parallel to an axial direction of a primary spool ( 121 ) in a projection portion ( 121 b ) is larger than a size (T) of a portion which is in parallel to an orthogonal direction to the axial direction of the primary spool ( 121 ). Accordingly, a frontal projected area of the projection portion ( 121 b ) as seen from a flowing direction of a resin becomes small, a resin flow is hard to get out of order at a time when the resin flows through a portion corresponding to the projection portion ( 121 b ) at the forming time, and a convoluted void and a weld are hard to be generated. Accordingly, since it is possible to prevent a mechanical strength in a root portion of the projection portion ( 121 b ) from being reduced, it is possible to previously prevent a crack from being generated in the root portion of the projection portion (the collar portion) ( 121 b ) due to a thermal stress so as to reduce an insulating property.