Title:
SPARK PLUG
Document Type and Number:
WIPO Patent Application WO/2023/135957
Kind Code:
A1
Abstract:
Provided is a spark plug (10) with which it is possible to reduce the occurrence of flexural buckling in a shaft portion. This spark plug comprises: an insulator (11) which has an axial hole (14) penetrating along the axis from the front end (12) to the back end (13); a center electrode (15) which is disposed on the front end-side of the axial hole; a metal terminal (20) which is disposed on the back end-side of the axial hole; and a connection portion (18) which electrically connects the center electrode and the metal terminal in the axial hole. The metal terminal comprises a head portion (21) disposed on the back end of the insulator, and a shaft portion (23) contiguous with the front end (22) of the head portion and disposed in the axial hole. The shaft portion is thinner than the head portion, and at least the front end (24) of the shaft portion is in contact with the connection portion. The metal terminal contains at least 97 wt% of Fe and 0.20-0.28 wt% of C, and the length of the shaft portion along the axis is at most 60 mm.
Inventors:
TANAKA KAZUKI (JP)
KOIKE KAZUKI (JP)
NAKAGAWA TOMOKI (JP)
SAKAI TAKAO (JP)
KOIKE KAZUKI (JP)
NAKAGAWA TOMOKI (JP)
SAKAI TAKAO (JP)
Application Number:
PCT/JP2022/043690
Publication Date:
July 20, 2023
Filing Date:
November 28, 2022
Export Citation:
Assignee:
NITERRA CO LTD (JP)
International Classes:
H01T13/39
Foreign References:
| JPH10144448A | 1998-05-29 | |||
| JP2000215963A | 2000-08-04 | |||
| JP2017183163A | 2017-10-05 | |||
| JPS63148585A | 1988-06-21 | |||
| JP2002222686A | 2002-08-09 | |||
| JP2006156110A | 2006-06-15 | |||
| JPH05315050A | 1993-11-26 |
Attorney, Agent or Firm:
PATENT FIRM SHINMEI CENTURY (JP)
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