| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an ignition device for an internal combustion engine capable of lowering a charge potential of a dielectric body surface at a power supply side of an ignition plug, of suppressing generation of streamer discharge at the outside of a combustion chamber, and of achieving excellent durability and stable ignition.SOLUTION: An ignition plug 100 includes at least a shaft-like center electrode 10, a dielectric body 20, a housing 3, and a ground electrode 30, and comprises a discharge space 40 sectionalized between the center electrode 10 and the ground electrode 30 at the inside of a combustion chamber 81, a dielectric body head part 23, and a center electrode terminal part 12. Between a part where the dielectric body head part 23 is exposed from a cap part 62, and the housing 3, an insulating layer 50 is provided so as to be tightly bonded to a part or all of these surfaces over the whole periphery. The insulating layer 50 has a diameter larger than that at a part where the cap part 62 of the dielectric body head part 23 is attached.</p> |
