公开(公告)号：US20180138665A1

公开(公告)日：2018-05-17

申请号：US15813386

申请日：2017-11-15

Applicant: DENSO CORPORATION

Inventor： Hiroya ISHIGURO ,  Tomoaki YONEKURA

IPC: H01T13/20 ,  H01T13/36 ,  H01T13/12

CPC classification number: H01T13/20 ,  H01T13/08 ,  H01T13/12 ,  H01T13/36

Abstract: A spark plug includes a main fitting having a first, second, and third portions adjacent to each other. The spark plug further includes an insulator having a first opposing portion with a predetermined portion opposed to the first portion with a first interval, a second opposing portion with a second portion opposing the second portion with a second interval, and a third opposed portion opposed to the third portion. A connecting portion between the second opposing portion is supported by a support portion, and a value obtained by dividing the first interval by a length from the support portion to a rear end portion of the predetermined portion is configured to be smaller than a value obtained by dividing the second interval by a length from the support portion to a rear end portion of the second opposed portion.