Abstract: Provided is a shearing method which can produce a worked material having a sheared edge excellent in surface perpendicularity and surface properties with a good productivity while suppressing tool wear and damage. The method comprises a first shearing step of placing a first blank having first and second surfaces on a first die so that said second surface is arranged on said first die side, and shearing said first blank from said first surface toward said second surface in a sheet thickness direction of said first blank by a first punch arranged at said first surface side to obtain a first punched out material and first worked material; and a second shearing step of placing a second blank and (x) using said first punched out material as a second punch, (y) using said first worked material as a second die, or both thereof.

Abstract: Provided is a steel material shearing method that enables highly productive and low-cost production of a steel material with a sheared surface having excellent hydrogen embrittlement resistance, fatigue strength, and stretch flangeability. The shearing method comprises making a clearance between a die and a punch 5 to 80% of a sheet thickness of a workpiece, shearing the workpiece using the punch, and, by utilizing a punched material punched out by the punch, pressing an end face of the punched out material against the sheared surface of the worked material on the die to produce a steel sheet with a sheared edge having excellent hydrogen embrittlement resistance and fatigue strength.

Abstract: A shearing method of a plate-shaped workpiece for applying a shear force in a thickness direction of the plate-shaped workpiece includes: a step for starting applying the shear force on the workpiece with a clearance between action points in a surface direction orthogonal to the thickness direction of the workpiece; a step for applying the shear force after the start of applying the shear force until a fractured surface is created in the workpiece; and a step for increasing the clearance depending on a deformation of the workpiece in the thickness direction after starting applying the shear force until the fractured surface is created in the workpiece.

Abstract: The present invention provides a method for shear processing whereby a sheared surface having a small residual stress and excellent surface properties is formed and the service life of a punch is prolonged in a shear processing for shearing, by a shear line that crosses a weld zone, a workpiece with a large thickness of level difference of a weld zone and/or obtained by welding together a steel sheet having a strength of 1000 MPa or more and another steel sheet. The shearing for shear processing method according to the present invention is a method for shearing a workpiece having a weld zone using a punch and a die, the method characterized in that two protrusions are provided to a cutting edge of the punch, all or part of the weld zone of the workpiece is flanked from the two sides by the two protrusions, and the workpiece is sheared by a shear line that crosses the weld zone.

Abstract: In a manufacturing method of sheared components, the shearing including a process of fixing a workpiece to a die, and a process of punching the workpiece by bringing a punch and the die relatively close to each other, is performed a plurality of times, and when a shearing sequence is started, the shearing is performed by using a punch including a first cutting edge having a first tip end surface which opposes the workpiece, and a first retracting surface which retracts from the first tip end surface considering an approaching direction to the die as a standard; and a die including a second cutting edge having a second tip end surface which opposes the workpiece, and a second retracting surface which retracts from the second tip end surface considering an approaching direction to the punch as a standard.

Abstract: Provided is a shearing method which can produce a worked material having a sheared edge excellent in surface perpendicularity and surface properties with a good productivity while suppressing tool wear and damage. The method comprises a first shearing step of placing a first blank having first and second surfaces on a first die so that said second surface is arranged on said first die side, and shearing said first blank from said first surface toward said second surface in a sheet thickness direction of said first blank by a first punch arranged at said first surface side to obtain a first punched out material and first worked material; and a second shearing step of placing a second blank and (x) using said first punched out material as a second punch, (y) using said first worked material as a second die, or both thereof.

Abstract: Provided is a steel material shearing method that enables highly productive and low-cost production of a steel material with a sheared surface having excellent hydrogen embrittlement resistance, fatigue strength, and stretch flangeability. The shearing method comprises making a clearance between a die and a punch 5 to 80% of a sheet thickness of a workpiece, shearing the workpiece using the punch, and, by utilizing a punched material punched out by the punch, pressing an end face of the punched out material against the sheared surface of the worked material on the die to produce a steel sheet with a sheared edge having excellent hydrogen embrittlement resistance and fatigue strength.

Abstract: A cutting method using a stamping press according to the present disclosure is a method to cut a workpiece that is configured from a first metal sheet and a second metal sheet joined at a weld portion and that has a heat-affected zone around the weld portion, in which the workpiece is cut using a punch. The punch includes a flat portion and a projecting portion projected more toward the workpiece than a flat portion of the punch. The workpiece is positioned with respect to the punch at a position such that the projecting portion starts cutting at least at one out of the heat-affected zone or the weld portion before the flat portion cuts the workpiece. The workpiece is then cut by moving the punch and a die relative to each other in this state of positioning so as to shear across the weld portion on the workpiece.

Abstract: There is provided a hole widening method including a preparing process of preparing a forming tool which has a diameter-increasing portion increasing in diameter from a front end side toward a rear end side and a line-shaped projection formed to protrude outward from a surface of the diameter-increasing portion, and a workpiece in which a pilot hole is formed; and a hole widening process of successively widening the pilot hole by pushing the forming tool into the pilot hole such that the line-shaped projection of the forming tool comes into point contact with a part of a circumferential edge portion of the pilot hole in the workpiece two times or more, and forming a stretched flange.

Abstract: In a breaking prediction method of predicting a breaking portion of a component, which is obtained by forming a metal sheet, by using a finite element method, the breaking portion is easily and reliably extracted.

Abstract: In a manufacturing method of sheared components, the shearing including a process of fixing a workpiece to a die, and a process of punching the workpiece by bringing a punch and the die relatively close to each other, is performed a plurality of times, and when a shearing sequence is started, the shearing is performed by using a punch including a first cutting edge having a first tip end surface which opposes the workpiece, and a first retracting surface which retracts from the first tip end surface considering an approaching direction to the die as a standard; and a die including a second cutting edge having a second tip end surface which opposes the workpiece, and a second retracting surface which retracts from the second tip end surface considering an approaching direction to the punch as a standard.