Method for manufacturing press-formed product, and blank

Abstract

A method for manufacturing a press-formed product includes clamping a blank (10) between a support surface (140) of a first press die (100) and a support surface (340) of a third press die (300), and pressing a second press die (200) into the first press die (100) to draw the blank (10), wherein a ridge (130) of an edge of a press hole (123) of the first press die (100) has a curved region (131) that extends in a curved manner, and when a corner end portion (11) is defined, the corner end portion (11) of the blank (10) between an intersection point M and an intersection point N includes both line segments MO and NO, and a part of the corner end portion (11) is outside a region between the line segment MO and the line segment NO.

1 . A method for manufacturing a press-formed product, comprising:
 clamping a blank between a support surface of a first press die and a support surface of a third press die; and   pressing a second press die into the first press die to draw the blank,   wherein a ridge of an edge of a press hole of the first press die has a curved region that extends in a curved manner,   when seen in a direction perpendicular to the blank, and   when a first normal line passing through a first end portion of the curved region in an extension direction of the ridge is defined as a straight line L 1 , a second normal line passing through a second end portion of the curved region in the extension direction of the ridge is defined as a straight line L 2 , an intersection point between the straight line L 1  and an end portion of the blank is defined as an intersection point M, an intersection point between the straight line L 2  and an end portion of the blank is defined as an intersection point N, a straight line passing through the intersection point M and perpendicular to the straight line L 1  is defined as a straight line L 4 , a straight line passing through the intersection point N and perpendicular to the straight line L 2  is defined as a straight line L 3 , an intersection point between the straight lines L 3  and L 4  is defined as an intersection point O, a line segment connecting the intersection point M and the intersection point O is defined as a line segment MO, and a line segment connecting the intersection point N and the intersection point O is defined as a line segment NO, and   when the blank is clamped between the first press die and the third press die, a corner end portion of the blank between the intersection point M and the intersection point N includes both the line segment MO and the line segment NO, and a part of the corner end portion is outside a region between the line segment MO and the line segment NO.   
     
     
         2 . A blank,
 wherein in a square region included in a corner of a first rectangle, each side of which passes only through an edge and outside of the blank, with a length of one side being 40% of a short side of the first rectangle, the blank is in contact with both of two sides of a second rectangle that each side passes only through an edge and inside of the blank, and   in a rectangular region that passes through two contact points between two sides of the second rectangle and the blank and of which a corner overlaps the first rectangle, the blank is in contact with both of two sides of the first rectangle.   
     
     
         3 . The blank according to  claim 2 , wherein the blank is in contact with both of the two sides of the first rectangle within a range of 10% of the length of the short side of the first rectangle from the corner of the first rectangle.