High efficiency, extended life spark plug having shaped firing tips
AssigneeGeneral Motors Corporation
InventorsRandolph Kwok-Kin Chiu, Keith Allen Penney, Donald Robert Van Uum, William Thomas Phillips, Jr.
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Abstract
A spark plug is provided which is suitable for use in a spark ignition system for an internal combustion engine. The spark plug is equipped with a specially configured firing tip on each of its electrodes for the purpose of minimizing the demand voltage of the spark plug, as well as extending the life of the spark plug by maximizing the time over which the demand voltage will remain within an acceptable level. For this purpose, the firing tips are configured such that their firing surfaces include at least three edges and three corners which serve as arc initiation sites of a relatively low resistance arc path between the electrodes.
Claims6
A spark plug for igniting a fuel mixture within a combustion chamber of an internal combustion engine, the spark plug comprising:
- a pair of electrodes which define a spark gap across which an electric spark is generated for igniting said fuel mixture;
- and
- a pair of firing tips affixed to said pair of electrodes such that said firing tips are coaxially aligned, said pair of firing tips being formed from a noble metal alloy, each of said pair of firing tips having a firing surface with a shape comprising at least three edges and at least three corners which form a convex polygon and serve as potential arc initiation sites for said electric spark across said spark gap;
- whereby said at least three edges and said at least three corners of said pair of firing tips serve to minimize the sparking voltage for the spark plug.
Dependencies are inferred from the claim text.