| 摘要 |
<p>The purpose of this invention is to provide a press brake for achieving accurate bending processing of a work by correcting an engagement positional relation between upper tool and lower die according to bending data. This press brake comprises an operation means for calculating a D value indicating a theoretical engagement positional relation between the upper tool and lower die corresponding to a target bending angle according to the bending data, a control means for controlling the engagement positional relation between the upper tool and lower die according to the theoretical D value to achieve actual bending processing of the work, an operation means for calculating a mean value of bending angles obtained by measuring plural positions of the work subjected to bending processing, an operation means for calculating a theoretical load for bending the work at the mean value of the bending angles and then calculating a theoretical mechanical deflection according to the theoretical load, a detecting means for detecting an actually applied pressure in left and right hydraulic cylinders at the time of actual bending processing of the work, an operation means for calculating an actual mechanical deflection according to the detected actually applied pressure, and an operation means for calculating the amount of correction for the D value according to a difference between the theoretical mechanical deflection and the actual mechanical deflection. A further purpose of this invention is to provide a bending apparatus intended to improve the bending accuracy for various bending conditions and reduce the frequency of corrections. A control unit for controlling a D value of a distance from the bottom of the die to the tip of the punch comprises an input means for inputting the material of a work, tensile strength, work thickness and the like, a work winding determination means for determining whether or not the work winds around the tip of the punch according to the input data, a spring-back amount operation means for obtaining the amount of spring back when it is determined that the work winds or does not wind around the tip of the punch, air bend/bottoming determination means for determining air bend or bottoming according to the amount of spring back and a magnitude of a target angle, a work nipping angle operation means for obtaining a work nipping angle when air bend is determined, a an operation means for pressure applied when the work is nipped, and an operation means for table moving position at angle in which the work is nipped. <IMAGE></p> |
