Nippon Steel & Sumitomo Metal Corporation

Seiichi Daimaru

Masaaki Mizumura

Toshiyuki Niwa

Masahiro Kubo

Takeshi Kawachi

Hiroshi Yoshida

Koichi Sato

Yasushi Yamamoto

Tohru Yoshida

Kaoru Kawasaki

Naoki Yoshinaga

Yasuharu Tanaka

Yasunobu Miyazaki

Yukihisa Kuriyama

Satoshi Shirakami

Atsushi Seto

Shunji Hiwatashi

Masayoshi Suehiro

Takashi Ariga

Hatsuhiko Oikawa

Nobutaka Shimizu

Tatsuya Sakiyama

Satoru Okayama

A roll forming apparatus for roll forming for producing from a sheet material a shaped steel which varies in cross-sectional shape in a longitudinal direction comprises a first rolling die which has an annular ridge part which varies in cross-sectional shape in a circumferential direction; a second rolling die which has an annular groove part which varies in cross-sectional shape in a circumferential direction; and a drive device for the first rolling die and the second rolling die. At least transition parts of the side surfaces of the annular ridge part of the first rolling die are provided with relief so that the gap with respect to the side surfaces of the annular groove part of the second rolling die becomes broader inward in the radial direction.

Method of producing shaped steel changing in cross-sectional shape in longitudinal direction and roll forming apparatus for same

A method of identification of a cause of occurrence of springback comprising a press forming analysis step of numerically analyzing forming conditions of press forming to obtain forming data of a press formed part, a processing step of processing at least one of a physical property value and physical property quantity data of part of the regions of said press formed part among forming data of said press formed part, and a springback value calculation step of calculating a springback value based on the results of said processing.

Method of identification of cause and/or location of cause of occurrence of springback

A roll forming device, for roll forming for the purpose of manufacturing shaped steel the cross-sectional shape of which varies in the longitudinal direction, is equipped with: first die rolls having an annular ridge part the cross-sectional shape of which varies in the circumferential direction; second die rolls having an annular groove part the cross-sectional shape of which varies in the circumferential direction; and a drive device for the first die rolls and the second die rolls. A gap is provided at the side surfaces of the annular ridge part of the first die rolls, across the entire circumference in the circumferential direction, such that the gap with respect to the side surfaces of the annual groove parts of the second die rolls widens inward in the radial direction.

Method for manufacturing shaped steel the cross-sectional shape of which changes in the longitudinal direction, and roll forming device

A front vehicle body structure for a vehicle body () having a vehicle interior compartment () and a front compartment () which is provided in front of the vehicle interior compartment (). The front vehicle body structure is provided with: strut towers () to which the upper edges of struts for the front wheels are mounted; front pillars () extending, at positions at the front of the vehicle interior compartment and on both sides in the width direction, from the roof of the vehicle interior compartment toward the upper edge of the rear of the front compartment; and reinforcement members () each having one end joined to the strut tower and the other end joined to the front pillar. Each of the reinforcement members is joined to the strut tower on both the inner side and outer side of a plane (S) with respect to the vehicle body, the plane (S) passing through the axis of the strut and extending in the front-rear direction of the vehicle body. As a result of the configuration, the front vehicle body structure can efficiently increase the torsional rigidity of the vehicle body of the automobile and in turn can efficiently reduce the weight of the vehicle body by a plate thickness reduction achieved using a high-tensile steel plate.

Front body structure

When forming a hat-shaped cross section member having, on its cross section perpendicular to its longitudinal direction, vertical wall portions on both sides, and flange portions on both sides connected to the respective vertical wall portions, and a top sheet portion connected to the vertical wall portions on both sides, and having a bent portion bent in the longitudinal direction with the flange portions positioned outside by using punches and dices, a dice shoulder radius of the dice for obtaining the shape of the hat-shaped cross section member is set to R, the hat-shaped cross section member is formed by the dice having a dice shoulder radius Rlarger than the dice shoulder radius R, and then the hat-shaped cross section member is formed by the dice having the dice shoulder radius R.

Forming method of metal member excellent in shape freezing property

A structure () for a front section of a vehicle body in a vehicle body () comprising a front chamber () disposed on the forward side of a vehicle interior () is provided with the following: a pair of front side members (), located within the front chamber, that extend in the longitudinal direction of the vehicle body; a pair of strut towers () disposed on either side in the width direction of the front chamber and within which front wheel suspensions are disposed; and reinforcement members () that link the top of each strut tower with the front side members that face the strut towers, and that extend between the strut towers and the front side members. This configuration allows a structure for a front section of a vehicle body to be provided that can efficiently improve the rigidity of the vehicle body of an automobile against torsion and against lateral bending, and that can efficiently reduce the weight of the vehicle body by means of thickness reduction using a high-strength steel plate.

Growing community of inventors

Tokyo, Japan

Seiichi Daimaru