Ignition plug

Abstract

Abstract PURPOSE:To lower discharge voltage and reduce dispersion by specifying the diameter of a central electrode at a position of more than a specified distance from the tip end surface of the central electrode and forming it in steps or a taper. CONSTITUTION:The diameter d2 of a central electrode 1 at a position of a distance of at least 1.5mm from the tip end surface 2a of the central electrode is set to be within the range of 1.0-1.5 times the diameter d1 of the tip end to be formed in steps or a taper. This makes it possible to lower discharge voltage of an ignition plug including a platinum tip 2 at least on the discharge surface of the central electrode 1, and stable spark discharge characteristics can be kept for use for a long period. Especially in urban running conditions at 40-60km/h, flame-out of the ignition plug is prevented and stable ignitionability can be obtained.

Inventors

• 👤 Takashi Suzuki

Bibliographic Details