SPARK PLUG AND AN INTERNAL COMBUSTION ENGINE IGNITING SYSTEM USING THE SAME

摘要

A spark plug having a center electrode, a ground electrode, and an insulator. The ground electrode has a firing surface formed in a tip end side, and the firing surface is opposed to a side face of the center electrode. The insulator covers the outside of the center electrode and is placed such that a tip end portion is between the side face of the center electrode and the firing surface of the ground electrode. A discharge high voltage is applied across the center electrode and the ground electrode such that a polarity of the center electrode is positive and that of the ground electrode is negative. The high voltage causes a spark discharge to be generated between the firing surface of the ground electrode and a tip end portion of the center electrode.