Precision bending press for relatively short pieces of sheet metal

A bending press for sheet metal, comprising:

• a reaction structure comprising a single pair of lateral uprights connected to one another by a connecting beam;
• at least one fixed tool-holder beam and at least one movable tool holder beam, said tool-holder beams attached to said lateral uprights and disposed in a general common plane, said movable tool holder beam movable towards said fixed tool-holder beam in order to follow a working path in said plane, one of which tool-holder beams carries a die and the other of which carries a forming punch, and in which the movable tool-holder beam includes n segments, n being greater than or equal to 2, which under a working load can deform substantially independently from each other;
• a plurality of actuators of a number equal to at least n+1 connected to, and for controlling the movement of, the movable tool-holder beam, the actuators being connected to the connecting beam of the reaction structure and said structure being stressed by the overall working load generated by the actuators;
• an auxiliary structure which is not affected appreciably by deformations of the reaction structure caused by the working load;
• a plurality of position transducers associated with respective actuators for generating signals which indicate the distance between the punch and the die and including means for sending said signals to a control processor and each transducer including a first part attached to the movable tool-holder beam and a second part attached to the auxiliary structure;
• and
• a control processor which receives signals from the position transducers and controls the actuators in such a manner that they impart identical displacements and displacement speeds to the beam;
• wherein each actuator applies a working load between the connecting beam and the movable tool-holder beam.