| 摘要 |
A spark plug for a spark-ignited internal combustion engine includes a generally tubular ceramic insulator. A conductive shell surrounds at least a portion of the ceramic insulator and includes at least one ground electrode. A center electrode is disposed in the ceramic insulator. The center electrode has an upper terminal end and a lower sparking end in opposing relation to the ground electrode, with a spark gap defining the space therebetween. The ground electrode extends from an anchored end adjacent the shell to a distal end adjacent the spark gap. The ground electrode includes a ledge formed on its distal end having at least one inset planar surface and an inset back wall. A high-performance metallic sparking tip is attached to the distal end of the ground electrode. The sparking tip has a base end disposed in surface-to-surface contact with the inset planar surface of the ledge. A particular advantage of the invention is achieved by the inset planar surface completely covering the base end of the sparking tip and extending outwardly therefrom to provide an exposed peripheral interface whereby optional attachment methods, such as welds may be applied, if desired, about at least a portion of the exposed periphery of the base end. In addition, portions of the sparking tip may abut the inset back wall, upper surface of center electrode or both enabling attachment of the sparking tip to the points where it abuts these surfaces.
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