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:
Jan. 19, 2016
Filed:
Oct. 02, 2013
Ngk Spark Plug Co., Ltd., Nagoya-shi, Aichi, JP;
Osamu Yoshimoto, Aichi-ken, JP;
NGK SPARK PLUG CO., LTD., Aichi, JP;
Abstract
A spark plug is provided with: a central electrode; a ground electrode forming a spark discharge gap with the center electrode; and a chip welded to at least one of the electrodes. The chip has a thermal expansion coefficient smaller than a thermal expansion coefficient of the electrode to which the chip is welded, and the difference between the content A (mass %) of a noble metal component in the chip and the content B (mass %) of a noble metal component in the electrode (A−B) is 50 mass % or more. In an intermediate layer between the chip and the electrode, holes are present. When the length of a boundary between the chip and the intermediate layer is L (mm), and the length of the holes in a direction along the boundary of the chip and the intermediate layer is N (mm), 0.1≦N/L≦0.4.