Patent ID: 9065256
Filing Date: 2015-06-23
Classification: H01T

Abstract:
1. A spark plug configured to be fitted in a combustion chamber of an internal combustion engine, comprising: a central electrode of cylindrical shape including a conductive material, which includes an upper end and a lower end configured to be arranged in the combustion chamber; an insulating material component substantially tubular in shape, made of an electrically insulating material that includes an upper part and a lower part, and which surrounds the central electrode over a portion of its length so that the lower end of the central electrode extends beyond the lower part of the insulating material component; a shell made of conductive material, substantially tubular in shape that includes an upper part and a lower part, the lower part of the shell comprising an upper end segment adjacent to the upper part of the shell and a lower end segment opposite to the upper end segment, and the shell surrounds the insulating material component over a portion of its length so that the lower part of the insulating material component extends beyond the lower part of the shell; wherein the insulating material component comprises an annular groove, on its outer periphery, spaced apart axially from a lower end of the lower part of the insulating material component, the insulating material component is covered with a layer of metalized material over its entire outer surface from its upper end up to an edge of the groove, and the lower end segment of the shell is arranged in the groove.