Abstract: An apparatus for identification of a cause of occurrence of springback having a press forming analyzer for numerically analyzing forming conditions of press forming to obtain forming data of a press formed part, a springback analyzer for numerically analyzing said forming data to calculate a springback value, and a processor for 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 making said springback analyzer calculate the springback value based on the results of said processing.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A front vehicle body structure for a vehicle body (1) having a vehicle interior compartment (2) and a front compartment (3) which is provided in front of the vehicle interior compartment (2). The front vehicle body structure is provided with: strut towers (16) to which the upper edges of struts for the front wheels are mounted; front pillars (20) 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 (25, 70) 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.

Abstract: 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 R0, the hat-shaped cross section member is formed by the dice having a dice shoulder radius R1 larger than the dice shoulder radius R0, and then the hat-shaped cross section member is formed by the dice having the dice shoulder radius R0.

Abstract: 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.

Abstract: A structure (10) for a front section of a vehicle body in a vehicle body (1) comprising a front chamber (3) disposed on the forward side of a vehicle interior (2) is provided with the following: a pair of front side members (11), located within the front chamber, that extend in the longitudinal direction of the vehicle body; a pair of strut towers (16) disposed on either side in the width direction of the front chamber and within which front wheel suspensions are disposed; and reinforcement members (20) 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.

Abstract: A structure (10) for a front section of a vehicle body in a vehicle body (1) comprising a front chamber (3) disposed on the forward side of a vehicle interior (2) is provided with the following: a pair of front side members (11), located within the front chamber, that extend in the longitudinal direction of the vehicle body; a pair of strut towers (16) disposed on either side in the width direction of the front chamber and within which front wheel suspensions are disposed; and reinforcement members (20) 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.

Abstract: A front vehicle body structure for a vehicle body (1) having a vehicle interior compartment (2) and a front compartment (3) which is provided in front of the vehicle interior compartment (2). The front vehicle body structure is provided with: strut towers (16) to which the upper edges of struts for the front wheels are mounted; front pillars (20) 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 (25, 70) 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.

Abstract: When forming a hat-shaped cross section member having, on its cross section perpendicular to its longitudinal direction, vertical wall portions (1b and 1b) on both sides, flange portions (1a and 1a) on both sides connected to the respective vertical wall portions (1b and 1b), and a top sheet portion (1c) connected to the vertical wall portions (1b and 1b) on both sides, and having a bent portion (2) bent in the longitudinal direction with the flange portions (1a and 1a) positioned outside by using punches (5) and dices (4), a dice shoulder radius of the dice (4) for obtaining the final shape of the hat-shaped cross section member is set to R0, the hat-shaped cross section member is formed by the dice (4) having a dice shoulder radius R1 larger than the dice shoulder radius R0, and then the hat-shaped cross section member is formed by the dice (4) having the dice shoulder radius R0.

Abstract: 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.