SPARK PLUG WITH A RING/OPEN-RING SHAPED GROUND ELECTRODE

摘要

Spark plug for an internal combustion engine having a metal shell (20) enclosing a ceramic insulator (16) containing a conductive centre electrode (18) having a bottom end (58) exiting from the insulator. The bottom end of the centre electrode is spaced apart from a ground electrode (12) attached to the metal shell by at least one support member or mounting post (38). The ground electrode is ring/open-ring shaped and its interior diameter ranges from equal to the exterior diameter of the centre electrode to a multiple of the size of the interior diameter of the centre electrode.