Title:
SPARK PLUG
Document Type and Number:
Japanese Patent JP2016066448
Kind Code:
A
Abstract:
PROBLEM TO BE SOLVED: To reduce a possibility of destruction of an insulator by preventing durability of a connection from being reduced.SOLUTION: The insulator includes a first portion, a second portion and an intermediate part. The first portion accommodates a distal end of a terminal fitting and has a first inner diameter. The second portion is disposed closer to a rear end than the first portion and has a second inner diameter that is larger than the first inner diameter. The intermediate part is disposed between the first portion and the second portion. The terminal fitting includes a rough surface part including at least either one or more protrusions or one or more recesses on an outer peripheral surface. In a portion of the terminal fitting disposed within a through-hole, the Vickers hardness in a portion closer to the rear end than the rough surface part is equal to or higher than 200 Hv and equal to or lower than 320 Hv. A first ratio that is a ratio of an outer diameter of the rough surface part in the first portion with respect to the first inner diameter is 0.90 or more. A second ratio that is a ratio of the first inner diameter with respect to the second inner diameter is 0.80 or more and 0.98 or less.SELECTED DRAWING: Figure 1
Inventors:
KITA JUMPEI
YOSHIDA HARUKI
YOSHIDA HARUKI
Application Number:
JP2014193680A
Publication Date:
April 28, 2016
Filing Date:
September 24, 2014
Export Citation:
Assignee:
NGK SPARK PLUG CO
International Classes:
H01T13/34; F02P13/00
Domestic Patent References:
| JP2013206740A | 2013-10-07 | |||
| JP2013041753A | 2013-02-28 | |||
| JP2006100250A | 2006-04-13 | |||
| JP2013131375A | 2013-07-04 |
Attorney, Agent or Firm:
Fenghwa International Patent Office