US 12,214,407 B2
Press brake
Hideki Okada, Kobe (JP); Wataru Hirabayashi, Kobe (JP); Kristof Tyvaert, Gullegem (BE); and Alexander Cornelus, Gullegem (BE)
Assigned to KAWASAKI JOKOGYO KABUSXIXI KAISMA, Kobe (JP); and LVD COMPANY NV, Gullegem (BE)
Filed by Kawasaki Jukogyo Kabushiki Kaisha, Kobe (JP); and LVD Company nv, Gullegem (BE)
Filed on Dec. 28, 2021, as Appl. No. 17/563,078.
Application 17/563,078 is a continuation of application No. PCT/JP2020/025398, filed on Jun. 26, 2020.
Claims priority of application No. 2019-122091 (JP), filed on Jun. 28, 2019.
Prior Publication US 2022/0118496 A1, Apr. 21, 2022
Int. Cl. B21D 5/02 (2006.01); B30B 15/02 (2006.01); B30B 15/14 (2006.01); B30B 15/26 (2006.01)
CPC B21D 5/0272 (2013.01) [B21D 5/02 (2013.01); B30B 15/02 (2013.01); B30B 15/14 (2013.01); B30B 15/26 (2013.01)] 8 Claims
OG exemplary drawing
 
1. A press brake that performs bending with respect to a workpiece by a die and a punch, the press brake comprising:
the die that supports a rear surface of the workpiece;
a punch that is arranged so as to be opposed to the die and moves in an upper-lower direction relative to the die to press a front surface of the workpiece;
a crowning structure that has an upper piece and a lower piece that interlock together, the upper piece and the lower piece span across the die in a die longitudinal direction, and the crowning structure changes a crowning amount that is an amount of upward projection of a middle portion of the die relative to both end portions of the die in the die longitudinal direction;
a bending amount measuring sensor that measures a middle bending amount and end bending amounts, the middle bending amount being a bending amount of a width direction middle portion of the workpiece, the end bending amounts being bending amounts of width direction end portions of the workpiece;
a conveyor to convey the workpiece in a longitudinal conveying direction, wherein the longitudinal conveying direction and the die longitudinal direction of the die are within a horizontal plane and are orthogonal to each other; and
processing circuitry, wherein:
the processing circuitry is configured to acquire from the bending amount measuring sensor the middle bending amount and the end bending amounts of the workpiece that has been subjected to the bending by the die and the punch; and
the processing circuitry is configured to control the crowning structure to correct the crowning amount in accordance with a difference between a shortage of the middle bending amount from a target bending amount and a shortage of each end bending amount from the target bending amount and drives the crowning structure; and
the processing circuitry is configured to control the conveyor to control the workpiece to be conveyed to a bending position, drive the crowing structure based on the corrected crowning amount, and control the punch to press the workpiece in order to perform the bending again.