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:
Jun. 07, 2016
Filed:
Nov. 29, 2012
Ngk Spark Plug Co., Ltd., Nagoya-shi, Aichi, JP;
Katsuya Takaoka, Ichinomiya, JP;
Hirokazu Kurono, Nagoya, JP;
Toshitaka Honda, Nagoya, JP;
Syuuichiro Wakizoe, Kounan, JP;
Mitsushiro Kondo, Kounan, JP;
NGK SPARK PLUG CO., LTD., Nagoya-shi, Aichi, JP;
Abstract
A spark plug exhibiting excellent withstand voltage characteristics and mechanical strength at high temperature, which are comparable to those at ambient temperature. The spark plug having an insulator formed of an alumina-based sintered material containing: an Al component, an Si component, a Group 2 element component, and a rare earth element component. The amounts of such components satisfy a condition (1): 0.25≦oxide-reduced amount (mass %) of the Si component ≦1.25, and a condition (2): 1.35≦[(oxide-reduced amount of the Si component)/((oxide-reduced amount of the Group 2 element component)/(oxide-reduced amount of the rare earth element component))]≦7.5. The alumina-based sintered material includes alumina grains, and a glass phase including a crystal phase that satisfies a condition (3) that the crystal phase includes at least one of an aluminate crystal phase and a silicate crystal phase, each having a grain size of 20 to 350 nm.