公开(公告)号：US20190296526A1

公开(公告)日：2019-09-26

申请号：US16353294

申请日：2019-03-14

Applicant: NGK SPARK PLUG CO., LTD.

Inventor： Takaaki KIKAI ,  Daisuke SUMOYAMA ,  Takuto NAKADA

IPC: H01T13/39 ,  H01T21/02 ,  C22C5/04 ,  C22F1/14

Abstract: A spark plug comprising: a first electrode including a tip containing Ir as a main material, and a base member to which the tip is joined; and a second electrode opposed to the tip with a spark gap therebetween. The number of crystal grains appearing in a range of 0.25 mm2 on an arbitrary cross-section of the tip in a first direction connecting the tip and the second electrode within the spark gap, is not less than 20. When a length of each of the crystal grains in the first direction is denoted by Y, and a length of each of the crystal grains in a second direction perpendicular to the first direction is denoted by X, 5 μm≤X≤100 μm and Y/X≥1.5 are satisfied.

公开(公告)号：US20180019581A1

公开(公告)日：2018-01-18

申请号：US15646559

申请日：2017-07-11

Applicant: NGK SPARK PLUG CO., LTD.

Inventor： Daisuke SUMOYAMA ,  Takuto NAKADA ,  Tsutomu SHIBATA ,  Takaaki KIKAI

IPC: H01T13/39 ,  H01T13/10 ,  H01T13/32 ,  H01T13/38

CPC classification number: H01T13/39 ,  H01T13/10 ,  H01T13/20 ,  H01T13/32 ,  H01T13/38

Abstract: At least one of a center electrode and a ground electrode of a spark plug includes an electrode body, an electrode tip, and a welded portion formed between the electrode body and the electrode tip. The electrode tip includes a cover layer that covers at least a side surface of a tip body, and the cover layer is formed of IrAl. On a section formed by cutting the electrode tip near a boundary with the welded portion, an area of the tip body is represented by Sa. An area of a projection on the section of a non-contact portion of an opposite surface of the tip body not in contact with the welded portion is represented by Sb. In this case, Sa−Sb corresponds to 35% or more of Sa.