| 摘要 |
A hydroelastic deep-drawing apparatus in presses for drawing sheet-metal shapes has a ram, a punch, a plurality of short-stroke cylinders, a plurality of drawing pins, a sheet-holder plate supported by the apparatus in relation to the plurality of short-stroke cylinders, a drawing die, a platen having a grid division thereon with a plurality of intersecting points, a plurality of hydraulic short-stroke pistons having multipoint control, each of the short-stroke pistons cooperating with a corresponding one of said plurality of short-stroke cylinders; a common die-cushion plate wherein the drawing pins are 1) arranged according to the geometry of said drawing-die at respective intersecting points of said grid division, and 2) supported on the common die-cushion plate via the short-stroke piston; and a position regulated and synchronous running differential cylinder/piston system which supports the die-cushion plate at its four outer corners. The plurality of short-stroke cylinders can be connected to create hydraulic force action zones according to the geometry of the sheet-holder plate or a workpiece and during the downward travel of the ram, starting at a predetermined coupling point, the die-cushion plate and the sheet-holder plate execute in the direction of the downward travel, a preliminary stroke while simultaneously maintaining a safety spacing between the ram and the sheet-holder plate. Additionally, subsequent to the preliminary stroke, the sheet-holder plate is raised a counterstroke distance relative to the die-cushion plate such that the workpiece is clamped in place; and subsequent to this, the ram executes a drawing operation relative to the punch during the completion of the downward travel of the ram. Thus, the impact shock to the workpiece is minimized.
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