公开(公告)号：US09705291B2

公开(公告)日：2017-07-11

申请号：US15072820

申请日：2016-03-17

Applicant: NGK SPARK PLUG CO., LTD.

Inventor： Yuichi Yamada ,  Takuya Kawade

IPC: F02B19/12 ,  H01T13/32 ,  H01T13/16 ,  H01T13/39

CPC classification number: H01T13/32 ,  H01T13/16 ,  H01T13/39

Abstract: An ignition plug having a ground electrode that includes a base material layer and an erosion-resistant layer having a thermal conductivity of 40 w/m·K or more. The erosion-resistant layer extends at least from the center-electrode-facing portion to a location closer to the fixed end than a front end of the center electrode and 0.2 mm≦thickness t1 of the erosion-resistant layer≦thickness T of the ground electrode 30−0.6 mm is satisfied.

公开(公告)号：US09948070B2

公开(公告)日：2018-04-17

申请号：US15546875

申请日：2016-01-29

Applicant: NGK SPARK PLUG CO., LTD.

Inventor： Takuya Kawade ,  Yuichi Yamada

IPC: H01T13/20 ,  H01T13/39 ,  H01T21/02 ,  H01T13/32 ,  C22C1/04

CPC classification number: H01T13/39 ,  C22C1/0466 ,  H01T13/06 ,  H01T13/32 ,  H01T21/02

Abstract: A spark plug includes an insulator, a metal shell surrounding the insulator, a center electrode disposed in the insulator, with a front end thereof exposed outside from the insulator, a ground electrode having a fixed end portion fixed to the metal shell and a free end portion located at a predetermined gap apart from the center electrode, and a coating part formed of noble metal or noble metal alloy so as to cover at least a region of an inner surface of the ground electrode from a first intersection to a second intersection, where the first intersection is an intersection at which an imaginary line extending from an outer circumference of the center electrode intersects the ground electrode; and the second intersection is an intersection at which an imaginary plane extending through a midpoint of the predetermined gap in parallel with the front end intersects the ground electrode.