04-10-2014, 09:58 AM
Abstracts: While bending the sheet Metal in Press Brake machine due to deflection of upper beam or lower table, there is an error in bending angle in sheet metal component in its entire length. Press-brakes are machines for bending sheet-metal. These machines are generally built up out of a stationary lower beam and a vertically moving upper beam connected by a frame. Conventional press-brakes are driven using one hydraulic cylinder at each end of the moving upper beam. Because the work piece is made between these actuators, both beams are exposed to three-point bending. Deflection of the beams leads to unwanted variations in the bend-angle along the length of the work piece. To reduce this deflection, ANASUYA has introduced a hydraulic drive system for the upper beam. The actuators now create a distributed load rather than two local forces, reducing the deflection to 2% of the original situation. This report concentrates on improving the lower beam. After analyzing the behavior of the lower beam, it was replaced by an assembly of a sub frame with a new lower beam stacked on top. This allows the lower beam to be supported directly beneath the work piece, preventing part of the bending. By making the supports between the sub frame and the lower beam moveable, the lower beam can be optimally supported for every different work piece. Due to the difference in bending-shape between the sub frame and the lower beam, the supports need to allow rotation while transduction the maximum load of 200 ton. Several possible solutions are offered for the supports. Attention is also paid to improving the stiffness of the sub frame and lower beam and the positioning of the supports. The benefit gained from all suggested design-changes is quantified using simulations and shows great promise.