公开(公告)号：US09948069B2

公开(公告)日：2018-04-17

申请号：US15102310

申请日：2014-12-16

Applicant: NGK SPARK PLUG CO., LTD.

Inventor： Masayuki Segawa ,  Daisuke Sumoyama

IPC: H01T13/39 ,  H01T13/20 ,  H01T13/50

CPC classification number: H01T13/39 ,  H01T13/20 ,  H01T13/50

Abstract: A spark plug wherein least one of a center electrode and a ground electrode includes a shaft portion and an electrode tip joined to one surface of the shaft portion. The shaft portion includes a first core formed of a material containing copper and a first outer layer that is formed of a material having higher corrosion resistance than the first core and covers at least part of the first core. The electrode tip includes a second outer layer that is formed of a material containing a noble metal and forms the outer surface of the electrode tip and a second core that is formed of a material having a higher thermal conductivity than the second outer layer and is at least partially covered with the second outer layer.