| 摘要 |
PROBLEM TO BE SOLVED: To generate a larger flame kernel in a spark-ignition type internal combustion engine employing an active ignition method.SOLUTION: In a spark plug 12 for a spark-ignition type internal combustion engine, an electric field generated in a combustion chamber via an antenna 121 faced inside a combustion chamber of a cylinder, and spark discharge generated between a center electrode 121 and a ground electrode 122 of the spark plug 12 are interacted, so as to generate plasma in the combustion chamber and ignite air-fuel mixture. During discharging spark, the center electrode 121 has a high potential to the ground electrode 122. The ground electrode 122 is designed so that a projection area of the ground electrode 122 is larger than the projection area of the center electrode 121 when seen in an axial line direction L in which the center electrode 121 and the ground electrode 122 are opposed to each other. |
