PUNCHING METHOD, METHOD FOR MANUFACTURING PRESS-FORMED ARTICLE, PUNCHING DIE, AND PRESS-FORMED ARTICLE

摘要

Disclosed are a punching method, a method for manufacturing a press-formed article, a punching die, and a press-formed article, by which the press-formed article having an inferior angle section in which two surfaces that are mutually adjacent form an inferior angle can be formed by punching with high accuracy.A punching die (100) for forming splines (14) on a core metal plate (11) constituting a friction plate body (10) is configured of a first shearing blade section (102) in a cylindrical shape and a second shearing blade section (103) formed in a gear shape. Meanwhile, in cases when the splines (14) are formed in the inner peripheral section of the core metal plate (11), tooth crests (14c) in the splines (14) are first formed by strongly pressing the first shearing blade section (102) of the punching die (100) to the core metal plate (11). Bottom lands (14a) and side surfaces (14b) in the splines (14) are then formed by strongly pressing the second shearing blade section (103) of the punching die (100) to the tooth crests (14c) formed in the inner peripheral section of the core metal plate (11).