| 摘要 |
PROBLEM TO BE SOLVED: To solve problem of a conventional spark-ignition internal combustion engine wherein when plasma is generated in the combustion chamber and an air-fuel mixture is ignited by a spark discharge between the plasma and an ignition plug, if spark discharge is made by applying a negative high voltage to the center electrode of the ignition plug, electrons tend to be diffused, and the density of the plasma is reduced.SOLUTION: In this spark-ignition internal combustion engine, the electric field generated in the combustion chamber is reacted with a spark discharge by an ignition plug to generate plasma for igniting an air-fuel mixture. The ignition plug 1 includes the center electrode 14 installed in a housing while being insulated and a grounding electrode 15 attached to the bottom end of the housing apart from the center electrode. The spark discharge is made by applying a positive high voltage with respect to the potential of the grounding electrode to the center electrode at each ignition timing. |
