A roller hemming device includes a backing metal, a guide roller, a bending roller, a pressing unit, and a swinging unit. The backing metal includes an abutment surface and a guide surface. The abutment surface is brought into abutment against a first panel member. The guide roller is moved in an extending direction of the guide surface with abutting against the guide surface. With being moved synchronously with the guide roller, the bending roller presses a bent peripheral edge portion of the first panel member via the backing metal such that the bent peripheral edge portion of the first panel member is pinched between the bending roller and the guide roller, and folds the bent peripheral edge portion of the first panel member back to a periphery edge portion of a second panel member. The pressing unit presses the bending roller toward the backing metal.

A method of forming a vehicle panel includes deforming a sheet metal workpiece between stamping tools to form a first and second edges that converge at a corner of the workpiece's main surface. The first edge is defined by a junction of the main surface and a first flange. The second edge is defined the main surface and a second flange. Forming the first and second edges includes deforming the workpiece so that the second flange has a first region bent to a first angle relative to the main surface and an unwinding region bent to an angle that unwinds from the first region as the second flange approaches the corner. The method includes deforming the workpiece between a second set of stamping tools that deform the first flange and the unwinding region of the second flange until the first and second flanges are bent greater than 90°.

Disclosed is an example of a method of manufacturing a pressed product including a substantially U-shaped main body and an undercut flange situated in the main body, in which an angle modification process can be eliminated. In the disclosed method, a third bent part, which is situated away from a first bent part towards a second bent part on a metallic sheet by a first length or more, is bent such that the first bent part is moved towards a first press direction and the undercut flange is moved towards a second press direction. The first press direction and the second press direction are opposite to each other. The first length is a length from a boundary between the undercut flange and a first plate portion to a tip of the undercut flange sized by projecting the undercut flange on an imaginary surface orthogonal to the first plate portion.

After an annular plate is blanked from a metal flat plate in a blanking step, an inner peripheral portion of the annular plate is deformed upward in a burring step. As a result, a hat-shaped intermediate product having an upstanding tubular portion and an annular plate portion is formed. After that, an outer peripheral portion of the annular plate portion is folded step by step toward an inner peripheral side of the annular plate portion. As a result, a folded portion composed of a first folded portion and a second folded portion is formed, whereby a connection portion having a second flange portion is formed.

A strength flanging method which improves the method of stretch flanging by press forming so as to disperse strain generated during a forming operation in a blank and in turn prevent the formation of cracks at the center of an arc part, which strength flanging method performs stretch flanging using a stretch flanging tool provided with a top surface part having a protruding part in a top view, straight wall parts, a main slanted wall part between the top surface part and the straight wall parts positioned forming an angle with the top surface part of more than 0° and less than 90° and with the straight wall parts of 10° or more and less than 90° and having two intersecting ridgelines at the straight wall part sides, a first sub slanted wall part sharing one ridgeline among the two ridgelines with the main slanted wall part and positioned forming angles with the top surface part and a straight wall part of more than 0° and less than 90°, and a second sub slanted wall part sharing the other ridgeline among the two ridgelines with the main slanted wall part and positioned forming angles with the top surface part and a straight wall part of more than 0° and less than 90°.

A method of forming a vehicle panel includes deforming a sheet metal workpiece between stamping tools to form a first and second edges that converge at a corner of the workpiece's main surface. The first edge is defined by a junction of the main surface and a first flange. The second edge is defined the main surface and a second flange. Forming the first and second edges includes deforming the workpiece so that the second flange has a first region bent to a first angle relative to the main surface and an unwinding region bent to an angle that unwinds from the first region as the second flange approaches the corner. The method includes deforming the workpiece between a second set of stamping tools that deform the first flange and the unwinding region of the second flange until the first and second flanges are bent greater than 90°.

A strength flanging method which improves the method of stretch flanging by press forming so as to disperse strain generated during a forming operation in a blank and in turn prevent the formation of cracks at the center of an arc part, which strength flanging method performs stretch flanging using a stretch flanging tool provided with a top surface part having a protruding part in a top view, straight wall parts, a main slanted wall part between the top surface part and the straight wall parts positioned forming an angle with the top surface part of more than 0° and less than 90° and with the straight wall parts of 10° or more and less than 90° and having two intersecting ridgelines at the straight wall part sides, a first sub slanted wall part sharing one ridgeline among the two ridgelines with the main slanted wall part and positioned forming angles with the top surface part and a straight wall part of more than 0° and less than 90°, and a second sub slanted wall part sharing the other ridgeline among the two ridgelines with the main slanted wall part and positioned forming angles with the top surface part and a straight wall part of more than 0° and less than 90°.

A roller hemming device includes a backing metal, a guide roller, a bending roller, a pressing unit, and a swinging unit. The backing metal includes an abutment surface and a guide surface. The abutment surface is brought into abutment against a first panel member. The guide roller is moved in an extending direction of the guide surface with abutting against the guide surface. With being moved synchronously with the guide roller, the bending roller presses a bent peripheral edge portion of the first panel member via the backing metal such that the bent peripheral edge portion of the first panel member is pinched between the bending roller and the guide roller, and folds the bent peripheral edge portion of the first panel member back to a periphery edge portion of a second panel member. The pressing unit presses the bending roller toward the backing metal.

A method of forming a vehicle panel includes deforming a sheet metal workpiece between stamping tools to form a first and second edges that converge at a corner of the workpiece's main surface. The first edge is defined by a junction of the main surface and a first flange. The second edge is defined the main surface and a second flange. Forming the first and second edges includes deforming the workpiece so that the second flange has a first region bent to a first angle relative to the main surface and an unwinding region bent to an angle that unwinds from the first region as the second flange approaches the corner. The method includes deforming the workpiece between a second set of stamping tools that deform the first flange and the unwinding region of the second flange until the first and second flanges are bent greater than 90.

After an annular plate is blanked from a metal flat plate in a blanking step, an inner peripheral portion of the annular plate is deformed upward in a burring step. As a result, a hat-shaped intermediate product having an upstanding tubular portion and an annular plate portion is formed. After that, an outer peripheral portion of the annular plate portion is folded step by step toward an inner peripheral side of the annular plate portion. As a result, a folded portion composed of a first folded portion and a second folded portion is formed, whereby a connection portion having a second flange portion is formed.