Abstract: A press brake has upper dies and lower dies so as to be capable of attaching and detaching with an upper die exchange apparatus and a lower die exchange apparatus to a machine body of the press brake. And, the upper die and the lower die comprise the combination of divisional die chips. The storing of dies is performed with those die chips. And, the face width of the upper die chips is determined and combined according to size of a workpiece to be processed from the upper die chips.

Abstract: A press brake has upper dies and lower dies so as to be capable of attaching and detaching with an upper die exchange apparatus and a lower die exchange apparatus to a machine body of the press brake. And, the upper die and the lower die comprise the combination of divisional die chips. The storing of dies is performed with those die chips. And, the face width of the upper die chips is determined and combined according to size of a workpiece to be processed from the upper die chips.

Abstract: A press brake having a lower die disposed in a horizontal position and an upper die movable in up and down directions out of and into workpiece shaping relationship with lower die for shaping a workpiece, at least one workpiece measuring portion provided on the lower die, at least one workpiece measuring device at the workpiece measuring portion, the workpiece measuring device having probes movable in up and down directions for contacting the shaped portion of the workpiece which is in the lower die, a workpiece contacting portion on each of said probes for contacting said workpiece as the probes are moved upwardly in said lower die, and a displacement detecting device connected to the workpiece measuring device for detecting relative displacement in the up and down directions between the probes as the probes respectively engage the workpiece.

Abstract: The bending of a workpiece between a lower and an upper die is measured by way of a workpiece measuring device having a workpiece measuring portion. A depth chasing quantity in a predetermined position of the workpiece is obtained by a folding form operating portion on the basis of the measured folding angle. And, crowning quantity is obtained by a crowning correction operating portion. Moreover, a depth correction value is obtained by a depth correction operating portion and a balance correction value of right and left is obtained by a balance correction operating portion. Then, bending is performed on a workpiece on the basis of the obtained correction values.