SPARK PLUG RESISTORS, SPARK PLUGS AND PARTS THEREOF;
Where the owner name is not linked, that owner no longer owns the brand
Technical Examples
A spark plug according to the invention includes a metal shell that has a threaded portion with an outer diameter of 10 mm or less, or equal to 12 mm, an insulator, a center electrode, and a ground electrode. The spark plug has an improved structure in which an end portion of the insulator tapers toward an end thereof that protrudes from an end of the metal shell, and dimensional parameters, including a space G of the spark gap in the spark plug, a taper degree of the end portion of the insulator that is represented by an outer diameter difference (D?D0) in the end portion, and a size T0 of the air pocket formed in the spark plug, each have an effective range determined based on the experimental investigation results from the inventors. The structure ensures high insulation properties and high ignition capability of the spark plug.