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.

Date of Patent:
Oct. 13, 2020

Filed:

Aug. 24, 2017
Applicant:

Nippon Steel Corporation, Tokyo, JP;

Inventors:

Junichi Okubo, Tokyo, JP;

Kenji Tamura, Tokyo, JP;

Kunihiro Yoshida, Tokyo, JP;

Samsoo Hwang, Tokyo, JP;

Ryusuke Nakano, Tokyo, JP;

Masao Hori, Tokyo, JP;

Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B21K 1/08 (2006.01);
U.S. Cl.
CPC ...
B21K 1/08 (2013.01);
Abstract

A production method includes a preforming process, a forming process and a finish forging process. In the preforming process, an intermediate preform is formed from a billet. In the forming process, while each of a plurality of rough journals of the intermediate preform is held and pressed vertically by a pair of holding dies, rough pins are decentered in directions perpendicular to the pressing direction by the holding dies and an axial direction of the intermediate preform, and the intermediate preform is pressed in the axial direction of the intermediate preform. In the finish forging process, a final preform is placed such that the directions in which the rough pins are decentered are parallel to a horizontal direction, and the thus placed final preform is pressed vertically by a pair of pressing dies. The production method reduces the risk of occurrence of seams on a forged crankshaft.


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