公开(公告)号：US10756517B1

公开(公告)日：2020-08-25

申请号：US16837154

申请日：2020-04-01

Applicant: NGK SPARK PLUG CO., LTD.

Inventor： Yusuke Kawamura ,  Shunsuke Tsuga

IPC: H01T13/06 ,  H01T13/20

Abstract: A spark plug that provides an increase in the combustion speed of an engine. The spark plug includes a center electrode, a ground electrode, an insulator, and a cover portion. In a cross-sectional area of a region surrounded by an inner wall surface of the cover portion in a cross section taken along a plane perpendicular to an axial line CX of the spark plug, the cover portion includes: a narrow portion positioned on the front end side with respect to the ground electrode in the direction of the axial line CX and narrowed such that the cross-sectional area is smallest; and a cover front portion positioned on the front end side of the narrow portion and having the cross-sectional area that is larger than the cross-sectional area of the narrow portion and that is largest at the front end of the cover front portion.