US 12,308,620 B2
Spark plug
Takaaki Kikai, Nagoya (JP); and Satoshi Noguchi, Nagoya (JP)
Assigned to NITERRA CO., LTD., Nagoya (JP)
Filed by Niterra Co., Ltd., Nagoya (JP)
Filed on Dec. 18, 2023, as Appl. No. 18/543,334.
Claims priority of application No. 2023-004342 (JP), filed on Jan. 16, 2023.
Prior Publication US 2024/0243557 A1, Jul. 18, 2024
Int. Cl. H01T 13/54 (2006.01); H01T 13/32 (2006.01)
CPC H01T 13/54 (2013.01) [H01T 13/32 (2013.01)] 4 Claims
OG exemplary drawing
 
1. A spark plug comprising:
a center electrode;
a metal shell in which the center electrode is insulated and held, the metal shell including a cylindrical portion having an outer circumference provided with an external thread, the metal shell further including a hole penetrating the cylindrical portion in a radial direction; and
a ground electrode protruding from the metal shell toward the center electrode and connected, in the hole, to the cylindrical portion via a melt portion, wherein, in a cross section including a center line of the hole and the melt portion, the melt portion has a part in contact with the cylindrical portion, and the part is present on an outer side in the radial direction relative to the ground electrode,
wherein at least a portion of the melt portion is located radially outward from an outermost radial portion of the ground electrode.