Denso Corporation

Yoshiki Morita

Tetsuya Miwa

Hiromi Hiramatsu

Hirofumi Suzuki

Atsushi Iwami

Toshiya Nakamura

An ignition device for an internal combustion engine has a spark plug, an ignition coil, a housing and a mounting portion. The spark plug is for discharging a current to ignite an air-fuel mixture in a combustion chamber of the internal combustion engine. The ignition coil is for supplying the current to the spark plug. The housing encloses the spark plug and the ignition coil therein. The housing has a mounting portion to be disposed in a mounting hole provided in a cylinder head of the internal combustion engine. The mounting portion includes a screw portion a non-screw portion. The screw portion is to be screw-fastened to the mounting hole. The non-screw portion is not to be screw-fastened to the mounting hole.

Ignition device for internal combustion engine

In a spark plug, an annular seal packing is arranged in a gap defined between an insulator and a fitting. Electrically insulating oil is filled in an oil-retaining section of the gap that is located on the distal side of the packing. The oil-retaining section of the gap is the continuous section having a width ranging from 0.05 mm to 0.3 mm and an axial length of 2 mm or more from the packing. The filled insulating oil is retained within the oil-retaining section of the gap by its surface tension while it is in a liquid state.

Spark plug having insulating oil

A lead-free glaze that can be fired at a low temperature, a spark plug for which it is used, and a spark plug production method are provided. The lead-free glaze is for coating onto ceramic materials. This lead-free glaze contains 16-49 wt % of SiO , 15-35 wt % of B O , 0-10 wt % of Al O and 0-10 wt % of ZnO. A spark plug is provided that comprises coating the lead-free glaze onto the surface of an insulator and firing.

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Kariya, Japan

Yoshiki Morita