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. 08, 2014
Filed:
Jul. 25, 2008
Yasuhito Tanaka, Kanagawa, JP;
Hisanaga Yokoyama, Kanagawa, JP;
Yasuhito Tanaka, Kanagawa, JP;
Hisanaga Yokoyama, Kanagawa, JP;
Nittan Valve Co., Ltd., Hadano-Shi, Kanagawa, JP;
Abstract
A forged exhaust poppet valve and a method of solution heat treating the same are provided. The forged exhaust poppet valve () includes a head portion () which has a seat portion () on the outer periphery thereof and is integral with a diametrically tapered neck portion () connected to a stem portion (). Using a radio-frequency heating apparatus, a solution heat treatment is given to a predetermined transitional region (A) of the neck portion and the stem portion that is exposed to exhaust air during a valve opening period such that the grain size in the region (A) does not exceed ASTM 10, thereby securing a necessary high-temperature creep strength in the region (A) and a necessary hardness (wear resistance) in the seat portion () and thereby rendering the exhaust poppet valve highly durable.