Title:
SPARK PLUG
Document Type and Number:
WIPO Patent Application WO/2022/168371
Kind Code:
A1
Abstract:
Provided is a spark plug with which pre-ignition of fuel gas that has flowed into an auxiliary chamber can be reduced. The spark plug is provided with: an insulator (11); a central electrode (14) disposed in the insulator; a main metal fitting (20) in which a shelf portion (23) for locking the insulator is provided; a grounding electrode (30) between the central electrode and which a spark gap (32) is provided; and a cap (40) joined to the main metal fitting by way of a melted portion (41). The cap forms an auxiliary chamber (42), and includes an injection port (45) penetrating from an inner surface (43) to an outer surface (44). There is a gap (47) extending from the auxiliary chamber to the melted portion, between a first surface (26) connecting an inner peripheral surface of the main metal fitting and an outer peripheral surface of the main metal fitting on a tip end side of the shelf portion, and a second surface (46) of the cap, connecting an inner surface and an outer surface thereof, and the gap includes an opening portion (48) which opens into the auxiliary chamber in a radial direction.
Inventors:
GOZAWA TATSUYA (JP)
NAKAGAWA RITSUKA (JP)
NAKAGAWA RITSUKA (JP)
Application Number:
PCT/JP2021/037591
Publication Date:
August 11, 2022
Filing Date:
October 11, 2021
Export Citation:
Assignee:
NGK SPARK PLUG CO (JP)
International Classes:
H01T13/54
Foreign References:
| JP2012199236A | 2012-10-18 | |||
| JP2020149924A | 2020-09-17 | |||
| US20200185888A1 | 2020-06-11 | |||
| JP2016062664A | 2016-04-25 |
Attorney, Agent or Firm:
PATENT FIRM SHINMEI CENTURY (JP)
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