METHOD AND PRESS-FORMING APPARATUS FOR MANUFACTURING STRUCTURAL MEMBER FOR AUTOMOTIVE BODY

摘要

To reduce the generation of cracking in the edge of the ridge flange (7a, 7b) and wrinkling near the base of the ridge flange and can suppress an increase in the pad load, while press forming the structural member (1) that is made of a high-tensile steel sheet or a thick steel sheet and that has a substantially gutter-shaped cross section and an outward continuous flange in an end of the structural member.;A method for manufacturing the structural member (1), the method including: a first step in which the pad (15, 15A, 15B, 15C, 21) presses the forming material (16) against the punch (13) to raise a portion corresponding to a flange to be formed in ends of at least the gutter bottom (2) and the ridge (3a, 3b) in a direction opposite to the pressing direction, the pad (15, 15A, 15B, 15C, 21) bends an end of a portion to be formed into the ridge (3a, 3b) in the pressing direction and restrains at least a part of the end, and the punch (13) and the die (14) carry out press forming to form an intermediate product while a region other than an end in a portion to be formed into the gutter bottom (2) remains unrestrained.

主权项

1. A method for manufacturing a structural member for an automotive body, the structural member being formed by pressing a forming material made of a steel sheet by using a press-forming apparatus having a punch, a die, and a pad facing the punch, the structural member extending in a predetermined direction, having a substantially gutter-shaped cross section intersecting the predetermined direction, and including
a gutter bottom, a ridge continuing to the gutter bottom, a vertical wall continuing to the ridge, and an outward continuous flange being continuously formed along at least one end in the predetermined direction, the one end at least including a part of the ridge, a part of the gutter bottom, and a part of the vertical wall, the method comprising: a first step in which
the pad presses the forming material against the punch to raise a portion corresponding to a flange to be formed in ends of at least the gutter bottom and the ridge in a direction opposite to the pressing direction, andthe punch and the die carry out press forming to form an intermediate product, while the pad bends an end of a portion to be formed into the ridge in the pressing direction and restrains at least a part of the end, and a region other than an end in a portion to be formed into the gutter bottom remains unrestrained; and a second step in which
the intermediate product is further pressed to form the structural member for the automotive body.