METHOD FOR MANUFACTURING FORGED CRANKSHAFT - NIPPON STEEL & SUMITOMO METAL CORP

Title:

METHOD FOR MANUFACTURING FORGED CRANKSHAFT

Document Type and Number:

WIPO Patent Application WO/2016/152933

Kind Code:

A1

Abstract:

A method for manufacturing a forged crankshaft includes a first preparatory forming step, a second preparatory forming step, and a final preparatory forming step. In the first preparatory forming step, an article to be processed is reduced by a pair of first molds. Thus, while forming flat parts (23a) by reducing the cross-sectional area of locations forming pin parts and locations forming journal parts, a location (PA2) forming a pin part disposed at a second position (L2) is given eccentricity. In the second preparatory forming step, the initial preform (23) obtained in the first preparatory forming step is reduced by a second mold. Thus, a location (PA1) forming a pin part disposed at a first position (L1) is given eccentricity, and a location (PA3) forming a pin part disposed at a third position (L3) is given eccentricity on the opposite side from the location (PA1) forming the pin part disposed at the first position. As a result, the locations forming the pin parts can be given eccentricity and narrowed down in the preform, thereby improving material yield.

Inventors:

OKUBO JUNICHI (JP)
TAMURA KENJI (JP)
YOSHIDA KUNIHIRO (JP)
HWANG SAMSOO (JP)
NAKANO RYUSUKE (JP)
HORI MASAO (JP)

Application Number:

PCT/JP2016/059254

Publication Date:

September 29, 2016

Filing Date:

March 23, 2016

Export Citation:

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Assignee:

NIPPON STEEL & SUMITOMO METAL CORP (JP)

International Classes:

B21K1/08

Domestic Patent References:

WO2014091730A1

2014-06-19

Foreign References:

JPH0748786B2	1995-05-24
JPS55161541A	1980-12-16
JP2001105087A	2001-04-17
US2911705A	1959-11-10
JPS62244545A	1987-10-24

Other References: