Spark plug cap and spark plug fitting method

摘要

A spark plug cap for facilitating the fitting/detaching operation of a spark plug with a built-in pressure sensor, and a method of easily fitting the spark plug with a built-in pressure sensor are provided. The spark plug cap is provided with a cylindrical part of glass-containing PBT, a grommet provided with a cable passing groove, and an ignition coil unit provided with a high voltage terminal. The cylindrical part includes a first engagement part engageable with a spark plug fastening tool on one end, a second engagement part of a metal material engageable with a hexagonal part of the spark plug with a built-in pressure sensor on the other hand, and a groove-shaped clamp part on the outer side surface. By engaging the hexagonal part with the second engagement part to attach the cylindrical part to the spark plug, holding a sensor output cable by the clamp part, and fitting and fastening the spark plug fastening tool in the first engagement part, the spark plug is fitted into an internal combustion engine.