The sheet sample which has to be formed, is clamped between two gripping jaws located on opposite ends, the forming die is fixed on to a die platform which can be moved hydraulically in a vertical direction. The forces necessary for the forming are transferred through the form die to the sheet sample.

SVSHPL offers a diverse selection of versatile sheet stretch forming presses, with a variety of options.  Our machine  designs are available in custom configurations with tonnage ratings from 160 to 3000 tons.  Our presses are custom engineered to meet specific requirements with regard to jaw width, distance between jaws, strokes, forming tonnage, and valuable options.

The options most commonly requested on presses manufactured today are: traversing gantry bulldozer, auxiliary die tables, auxiliary extrusion jaws, auxiliary curving jaws (for very tight radius fuselage sheets),  SCADA programmable curving jaws, Edge Compensation System, and 

The SCADA  programmable curving jaws eliminate the long, tedious, manual setup that has been the past industry standard on sheet jaws.  There is no longer a need for the operator to have to physically adjust the manually locked adjusting screws on each curving arm of the jaw assemblies.  The operator programs the desired radius from the operator console and the jaws automatically curve to the selected curvature.

PROCEDURE

Stretch forming is a metal forming process in which a piece of sheet metal is stretched and bent simultaneously over a die in order to form large contoured parts. Stretch forming is performed on a stretch forming machine, in which a piece of sheet metal is securely gripped along its edges by gripping jaws. The gripping jaws are each attached to a carriage that is pulled and rotated by hydraulic force to stretch the sheet. The tooling used in this process is a stretch form block, called a form die, which is a solid contoured piece against which the sheet metal will be pressed. The most common stretch presses are oriented vertically, in which the form die rests on a die platform that can be raised into the sheet by a hydraulic cylinder. As the form die is driven into the sheet, which is gripped tightly at its edges, the tensile forces increase and the sheet plastically deforms into a new shape.