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Patent Searching and Data


Title:
SPARK PLUG
Document Type and Number:
WIPO Patent Application WO/2014/030273
Kind Code:
A1
Abstract:
The purpose of the present invention is to achieve superior resistance to contamination in a spark plug in which the main body hardware is reduced in diameter without increasing the length of a leg part. A spark plug (1) is provided with an insulator (2) and main body hardware (3) that has a threaded part (15) with a thread diameter of M12 or less and that is provided on the outer periphery of the insulator (2). The insulator (2) is provided with a latching part (14) that latches to a stepped part (21) of the main body hardware (3) via sheet packing (22), and a leg part (13) that forms a clearance (33) with the inside peripheral surface of the main body hardware (3). Letting L (mm) be the distance toward the tip end side from tip part (22E) of the sheet packing (22) and A (mm) be the size of the clearance (33), the position at which the size A is 0.5 mm or less is more to the back end side than the position that includes a position 2.0 mm from the tip part (22E) to the tip end side. In addition, in a range of 3.0 ≤ L ≤ 4.0, A ≥ L × 0.2 + 0.2 (mm) is satisfied.

Inventors:
KUKI, Hiroaki (C/O NGK SPARK PLUG CO. LTD, 14-18,Takatsuji-cho, Mizuho-ku, Nagoya-sh, Aichi 25, 〒4678525, JP)
UEDA, Tomoaki (C/O NGK SPARK PLUG CO. LTD, 14-18,Takatsuji-cho, Mizuho-ku, Nagoya-sh, Aichi 25, 〒4678525, JP)
YAMADA, Yuichi (C/O NGK SPARK PLUG CO. LTD, 2808 Oaza-Iwasaki, Komaki-sh, Aichi 10, 〒4858510, JP)
Application Number:
JP2013/002425
Publication Date:
February 27, 2014
Filing Date:
April 10, 2013
Export Citation:
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Assignee:
NGK SPARK PLUG CO., LTD. (14-18, Takatsuji-cho Mizuho-ku, Nagoya-sh, Aichi 25, 〒4678525, JP)
International Classes:
H01T13/20
Foreign References:
JP2007184299A2007-07-19
JPH10289777A1998-10-27
JPH10289777A1998-10-27
JP2006236906A2006-09-07
Other References:
See also references of EP 2889971A4
Attorney, Agent or Firm:
AOKI, Noboru et al. (C/O NGK SPARK PLUG CO. LTD, 2808 Oaza-Iwasaki, Komaki-sh, Aichi 10, 〒4858510, JP)
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