The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 17, 2024
Filed:
Jun. 14, 2022
Niterra Co., Ltd., Aichi, JP;
Takeshi Sakuma, Aichi, JP;
Yuichi Yamada, Aichi, JP;
Haruki Yoshida, Aichi, JP;
Hiroki Shimada, Aichi, JP;
Takuto Koba, Aichi, JP;
NITERRA CO., LTD., Nagoya, JP;
Abstract
A spark plugof the present invention includes an insulatormade from an alumina-based sintered body and including: a leg portionprovided on a front end side; a middle trunk portionprovided on a rear end side of the leg portionand having a larger diameter than the leg portion; and a flange portionprovided on the rear end side of the middle trunk portionand having a larger diameter than the middle trunk portion. In the spark plug, in a state where a cut surfaceobtained by cutting the middle trunk portionin a direction perpendicular to an axial line AX direction at an arbitrary position in the axial line AX direction is mirror-polished, when 20 observation regions X each being 185 μm×250 μm are set so as not to overlap each other, and with respect to each of a plurality of pores included in the 20 observation regions X, a square value P[μm] of a length P [μm] of a circumference of the pore is obtained, an average value of the square values P[μm] of top 20 pores having the largest square values P[μm] is not greater than 2200 μm, and a proportion T [%] of a total area of all pores included in the 20 observation regions X relative to a total area (100%) of the 20 observation regions X is not greater than 5%.