Spark plug having a low noise level

摘要

A spark plug incorporating a winding type inductor has a low noise level from a low frequency range to a high frequency range. The spark plug comprises a ceramic insulator having a bore, a metal fitting surrounding the insulator, a center electrode, a terminal electrode and a noise-attenuation element arranged in the bore of the ceramic insulator and sealed to the center and terminal electrodes through glass, said noise-attenuation element consisting of an inductance component alone or a combination of an inductance component and a resistance component, and said inductance component being arranged extending to both sides of a sealed level for the noise-attenuation element formed by an end of the metal fitting which is connected to the insulator.