Locked Tool - Deep-Drawing Process and Examples of Operations with Elastic Blank-Holders 950917
For the production of deep-drawn parts on single-acting presses, constructive tool variants are presented, by means of which the drawing result may be improved and the machine-related disadvantages may be compensated.
For the new tool principle with a “locked tool”, connectable adjustment elements produce a direct form closure connection between the drawing die and the blank-holder, thus replacing the function of the die cushion. Due to an active control of the blank-holding force, these so-called Damping-Locking elements make it possible to directly influence the deep-drawing process. By means of the hydraulic drawing cylinders, the blank-holding force may, locally along the perimeter of the part and during the drawing process, be adapted to the process conditions required.
The elastic blank-holder automatically adapts itself to the sheet thickness of the flange. In this way, the material flow is improved and the time-consuming incorporation of the correction picture is no more required, as locally increased pressures are avoided in a self-regulating manner.