| 摘要 |
PROBLEM TO BE SOLVED: To provide a spark plug for an internal combustion engine, suitable for an internal combustion engine provided in an automobile or the like.SOLUTION: An spark plug 1 for an internal combustion engine comprises a cylindrical external conductor 10, a cylindrical dielectric 20 and a center electrode 30. The cylindrical dielectric 20 is held inside the external conductor 10 and includes a dielectric tip portion 21 that is exposed from the tip of the external conductor 10. The center electrode 30 is held inside the cylindrical dielectric 20 and includes an electrode tip portion 31 that is exposed from the tip of the cylindrical dielectric 20. The spark plug 1 is configured in such a way that a high-frequency voltage is applied to the center electrode 30 and a discharge S2 is formed from the electrode tip portion 31 toward the tip side Y1 in the plug axis direction Y. Between the electrode tip portion 31 and the dielectric tip portion 21, a space 50 separating the electrode tip portion 31 and the dielectric tip portion 21 is formed in such a way that before the discharge S2, partial discharge S1 is generated between the tip portions when the high frequency voltage is applied to the center electrode 30.SELECTED DRAWING: Figure 3 |
