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:
Apr. 20, 2004
Filed:
Sep. 17, 2001
Naomichi Miyashita, Aichi, JP;
Yoshihiro Matsubara, Mie, JP;
Wataru Matsutani, Aichi, JP;
Masayuki Segawa, Aichi, JP;
Hiroaki Kuki, Aichi, JP;
Mamoru Musasa, Aichi, JP;
NGK Spark Plug Co., Ltd., Aichi, JP;
Abstract
A spark plug having a center electrode formed from an electrode base material , which is made of an Ni alloy containing an alloy component (e.g., Cr) capable of forming an oxide semiconductor having a resistivity of negative temperature coefficient. Thus, a corrosion suppression layer originating from the components of the electrode base material is formed on the surface of a tip end portion of the insulator so that corrosion (channeling) of the surface of the tip end portion of the insulator due to creeping spark discharge can be effectively suppressed. In addition, when the constituent metal of the electrode base material has a coefficient of thermal conductivity of 17 to 30 W/m·K, the heat transfer performance of the electrode is enhanced, so that durability against electrode consumption can be greatly improved.