| 摘要 |
<p>A press brake is provided for bending a work accurately. An engagement position relationship between upper and lower molds is controlled based on a D value indicating a theoretical engagement position relationship between upper and lower molds which correspond to a target bending angle for actually bending a work, a theoretical machine deflection is calculated based on a theoretical load for performing bending to an average value for bending angles, an actual machine deflection is calculated based on an actual pressure by a hydraulic cylinder and a correction amount of the D value is calculated based on the difference between the theoretical machine deflection and the actual machine deflection. In addition, not only the bending angle accuracy relative to various bending conditions is to be improved but also the number of corrections is to be reduced. A device for calculating a distance D value comprises input means for enabling the input of work material, tensile strength, plate thickness and so forth, work winding judging means, spring back amount calculating means, an air bend, bottoming judging means, work holding angle calculating means, means for calculating a pressuring force when a work is held, and table travelling value calculating means.</p> |
