Ignition device having an electrode with a platinum firing tip and method of construction

摘要

An ignition device for an internal combustion engine and method of construction therefore includes a housing with an insulator secured therein. A center electrode is mounted within the insulator. A ground electrode extends from the housing with a portion of the ground electrode defining a spark gap across from the center electrode. At least a selected one of the center electrode or ground electrode has a platinum or platinum-based alloy firing tip. A resistance weld joint bonds the firing tip to the selected electrode and defines a lower surface of the firing tip that is embedded a first distance beneath an outer surface of the selected electrode. A continuous bead of overlapping laser weld pools is formed over an outer periphery of the firing tip. The overlapping weld pools extend a second distance beneath the outer surface of the selected electrode, with the second distance being greater than the first distance.