| 简介 |
PROBLEM TO BE SOLVED : To provide a spark plug including an earth electrode containing a high Ni content and Y and/or rare earth elements, and having high bonding strength between the earth electrode and a main metal fitting.
SOLUTION : A spark plug includes the elemental composition of the earth electrode containing Ni of 96% or more and the total of Y and/or rare metal elements of more than 0 mass% and 0.3 mass% or less, and satisfies the conditions that (1) when a straight line passing through a center of gravity G of the earth electrode in the tip face of the main metal fitting and perpendicular to an axis line X is set as a straight line L, a distance A in the axis line X direction from the tip of the main metal fitting to one end of the earth electrode is 0.1 mm or more in a cross section appeared when cutting the main metal fitting by a plane passing through the center of gravity G and perpendicular to the straight line L, (2) when a location deformed by welding an electrode material to an intermediate body of the metal fitting is set as a fusion part, a difference C between a distance B in the axis line X direction from the tip of the main metal fitting to the rear end of the fusion part and the distance A on an outer peripheral surface of the main metal fitting is 2 mm or less, and (C) the ratio of A to the difference C (A/C) is 0.2 or more.
COPYRIGHT : (C)2013, JPO&INPIT |
客服热线：
手机版
二维码
