Title:
SPARK PLUG
Document Type and Number:
WIPO Patent Application WO/2020/196245
Kind Code:
A1
Abstract:
This spark plug is better able to suppress insulator-penetrating discharge and is realized without diametrically enlarging the main metal fitting. In the spark plug, a center electrode (50) includes a major-diameter section (52) where the outer diameter is the largest in the center electrode (50). The major-diameter section (52) is locked against a rear-end directed face (22A) of the interior of an axial bore (20) of an insulator (10). The main metal fitting (30) includes, on the rear end side from the center electrode (50), an expanded-diameter section (36) the inner diameter of which expands towards the rear end side. The insulator (10) includes, as a portion thereof, a first section (70) in a region (AR) from the rear end of the rear-end directed face (22A) to the leading end of the expanded-diameter section (36). The first section (70) is thickest in the aforesaid region (AR), and is situated at least around the perimeter of the major-diameter section (52).
Inventors:
TANAHASHI YUSUKE (JP)
NISHIO NAOKI (JP)
KAWASHIMA YUSUKE (JP)
NISHIO NAOKI (JP)
KAWASHIMA YUSUKE (JP)
Application Number:
PCT/JP2020/012264
Publication Date:
October 01, 2020
Filing Date:
March 19, 2020
Export Citation:
Assignee:
NGK SPARK PLUG CO (JP)
International Classes:
H01T13/20; H01T13/34; H01T13/36
Foreign References:
| JP2013524446A | 2013-06-17 | |||
| JPH0227683A | 1990-01-30 | |||
| JP2019003721A | 2019-01-10 |
Attorney, Agent or Firm:
GRANDOM PATENT LAW FIRM (JP)
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