SPARK PLUG HAVING FIRING PAD

摘要

A spark plug has a shell, an insulator, a center electrode, a ground electrode, and a firing pad. The firing pad is made of a precious metal material and is attached to the ground electrode. The firing pad has a side surface at a peripheral edge that can be flush or nearly flush with a free end surface of the ground electrode. This construction can help improve ignitability and flame kernel growth of the spark plug during a sparking event, and can provide better thermal management at the attached ground electrode and firing pad.

主权项

1. A spark plug, comprising:
a shell having an axial bore; an insulator having an axial bore and being disposed at least partially within the axial bore of the shell; a center electrode disposed at least partially within the axial bore of the insulator; a ground electrode attached to the shell and composed of a nickel-based alloy material; and a firing pad attached to the ground electrode and composed of a platinum-based alloy material containing at least 25 wt.% of nickel, the firing pad having a protrusion projecting from a bottom side of the firing pad that concentrates current flow therethrough amid a resistance welding process, wherein the attachment between the firing pad and the ground electrode includes a resistance-welded weldment and lacks a laser-welded weldment, the protrusion facilitates the absence of a laser-welded weldment in the attachment between the firing pad and the nickel-based alloy material of the ground electrode.