Title:
SPARK PLUG
Document Type and Number:
WIPO Patent Application WO/2023/281957
Kind Code:
A1
Abstract:
The objective of the present invention is to suppress deterioration of airtightness while suppressing damage to an engine head. A spark plug comprising: an insulator formed with a shaft hole extending in the axial direction; a center electrode disposed in the shaft hole and having a tip portion protruding toward the distal end side of the shaft hole; a cylindrical main fitting that holds the insulator on the inner peripheral side and has a threaded portion formed on the outer peripheral surface; and a ground electrode having one end fixed in a through hole provided in the main fitting and having the other end forming a discharge gap with the tip of the center electrode, wherein the threaded portion includes a first threaded portion located on the rear end side in the axial direction with respect to the through hole and a second threaded portion located on the distal end side in the axial direction with respect to the through hole, and the effective diameter of the first threaded portion is larger than the effective diameter of the second threaded portion.
Inventors:
IMAI SUSUMU (JP)
GOZAWA TATSUYA (JP)
GOZAWA TATSUYA (JP)
Application Number:
PCT/JP2022/022752
Publication Date:
January 12, 2023
Filing Date:
June 06, 2022
Export Citation:
Assignee:
NGK SPARK PLUG CO (JP)
International Classes:
H01T13/20; H01T13/32
Domestic Patent References:
| WO2019242930A1 | 2019-12-26 |
Foreign References:
| JP2006236769A | 2006-09-07 | |||
| JPH0237485U | 1990-03-12 | |||
| JP2020170587A | 2020-10-15 | |||
| US20190376441A1 | 2019-12-12 | |||
| JP2019046660A | 2019-03-22 |
Attorney, Agent or Firm:
NOMURA Kazuhiro (JP)
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