Ngk Spark Plug Company, Limited

Niterra Co., Ltd.

Kengo Hattori

Osamu Yoshimoto

Daisuke Sumoyama

Tomoo Tanaka

Kazuki Ito

Takaaki Kikai

Hiroaki Izawa

Kaito Nakamura

A spark plug which is reduced in consumption of a discharge member, thereby having a longer service life. This spark plug is provided with: a first electrode that comprises a discharge member; and a second electrode that faces the discharge member, with a spark gap lying therebetween. The discharge member is mainly composed of Ru, while containing 0.5% by mass to 30% by mass of Ni or Co.

Spark plug

A noble metal tip for a spark plug according to the present invention contains iridium (Ir) in an amount of 50 mass % or more and aluminum (Al) in an amount of 0.1 mass % or more and 5 mass % or less, and further contains rhodium (Rh), wherein a metallographic structure comprised of fiber-like elements R is observed, and the fiber-like elements R of the metallographic structure have an average aspect ratio of 150 or more and have an average length of 25 μm or less in a minor axis direction.

Noble metal tip for spark plug, electrode for spark plug, and spark plug

A spark plug having a center electrode that includes a columnar noble metal tip at one end thereof, and a ground electrode that forms a spark gap between the ground electrode and a circular discharge surface of the tip. In the tip, a mass % of Pt is largest and a content percentage of Ni is more than or equal to 0 mass % and less than or equal to 40 mass %. In each of both a cross-section of the tip parallel to the discharge surface and a cross-section of the tip perpendicular to the discharge surface, particles each having an aspect ratio of more than or equal to 1 and less than or equal to 10 occupy more than or equal to 70% of observed particles in an area extending from an outline of the cross-section by a distance of 10% of a diameter of the discharge surface.

Growing community of inventors

Nagoya, Japan

Kengo Hattori