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. 20, 2016
Filed:
Jul. 31, 2013
Mitsubishi Heavy Industries, Ltd., Tokyo, JP;
Hyoji Yoshimura, Nagoya, JP;
FUJI HOLLOW VALVE INC., Shizuoka, JP;
YOSHIMURA COMPANY, Aichi, JP;
Abstract
Forming of a valve head portion () of a hollow engine valve (V) comprising a material particularly satisfactory in heat resistance is performed by cold forging. The material with excellent heat resistance is worked to form a valve head portion semifinished product () having a hollow hole (S) whose inner diameter (φ) is equal to the maximum inner diameter (φ) of a hollow hole (S) of a finished product of the valve head portion (), and having a diameter-increased section () whose maximum outer diameter (φ) is equal to the maximum outer diameter (φ) of a diameter-increased section () of the finished product. Parts of the valve head portion semifinished product other than a central part to a lower part of the diameter-increased section () are necked down by cold forging performed a plurality of times to obtain the finished product of the valve head portion ().