公开(公告)号：US20180358784A1

公开(公告)日：2018-12-13

申请号：US16001451

申请日：2018-06-06

Applicant: NGK SPARK PLUG CO., LTD.

Inventor： Hironori UEGAKI ,  Shoma TSUMAGARI ,  Kazuhiro KUROSAWA ,  Katsuya TAKAOKA ,  Kuniharu TANAKA

IPC: H01T13/41 ,  H01T13/34

CPC classification number: H01T13/41 ,  H01T13/34

Abstract: A spark plug has an insulator, a rod-shaped electrode member disposed in an axial hole of the insulator, and a cylindrical magnetic member disposed on an outer circumference of the electrode member within the axial hole. The insulator includes a large inner diameter region, a middle inner diameter region located frontward of the large inner diameter region and having an inner diameter smaller than that of the large inner diameter region, and a small inner diameter region located frontward of the middle inner diameter region and having an inner diameter smaller than that of the middle inner diameter region. The electrode member is retained on a step portion of the insulator between the middle inner diameter region and the small inner diameter region. The magnetic member is positioned in the axial hole at a location within the large inner diameter region.