L. Schuler Gmbh

Gerhard Roos

Siegfried Baur

Rudi Brandstetter

Wolfgang Michael

Hartmut Dexling

A drawing installation for a press which has to produce the holding force for the counter-holding during the drawing. The drawing ram displaces the sheet metal part and the sheet metal holder against the holding force to be produced by the drawing installation and must additionally overcome the inertia forces which occur as a result of the acceleration of the parts of the drawing installation at the beginning of the deformation of the sheet metal part. In order to avoid the forces which occur thereby impact-like, the piston rod transmitting the holding force is pre-accelerated in the drawing direction prior to the contact of the drawing ram on the sheet metal holder. The piston rod has an operating surface adapted to be acted upon in the drawing direction. The pressure space coordinated to the operating surface is adapted to be connected with a pressure quantity space of a pre-acceleration cylinder and with a reservoir by way of a follow-up control. The control with respect to time of the pre-acceleration cylinder and of the refill from the reservoir takes place in dependence on the movement of the drawing ram, controlled by the press. The drawing installation is utilizable in presses with mechanically driven drawing ram and a sheet metal holder holding the sheet metal part.

Drawing installation for a press

A drawing installation for a press which must produce the holding force during the drawing operation. The drawing ram displaces the sheet metal part and the sheet metal holder against the holding force and additionally must overcome at the beginning of the sheet metal deformation the inertia forces of the accelerated parts of the drawing installation. In order to avoid the forces which occur thereby in an impact-like manner, the piston rods transmitting the holding force and the ejector piston rods are pre-accelerated prior to the drawing ram. The piston rods each include an operating surface adapted to be acted upon in the drawing direction. The pressure spaces coordinated thereto are connected with a pressure quantity space each of a pre-acceleration cylinder and by way of a refill control with a pressure source. The control of the pre-acceleration cylinder and of the refill from the pressure source takes place in dependence on the movement of the drawing ram. The drawing installation can be used in presses with mechanically driven drawing rams and sheet metal holders retaining the sheet metal part whereby the functions of holding and ejection are carried out by separate pressure cylinders.

Drawing mechanism for a press

A drawing apparatus, by means of which the different individual functions such as control of the sheet metal holder pressure, control of the sheet metal holder upward movement, control of the ejector movement and of the end position abutment are adjustable, respectively, controllable independently of one another. In a drawing apparatus with pressure cylinders (8) for the sheet metal retention during the drawing and with pressure cylinders (9) for the ejection of the workpieces, with a pressure cheek (1) guided in the press table and movable and supported by the pressure cylinders (8, 9) and with a follower control installation (48) acting in the lower dead-center position on a pressure cylinder (8) effecting the sheet metal retention during the drawing operation, the pressure cylinders (8, 9) are thereby held fixed at the press; the piston rods (6) of the pressure cylinders (8, 9) effecting the sheet metal retention are adapted to be placed in the direction (14) of the sheet metal retaining pressure against the pressure cheek (1) and one follower control installation (48, 49) is coordinated to each pressure cylinder (8) effecting the sheet metal retention and to each pressure cylinder (9) effecting the ejection; with the use of several pressure cylinders (9) for the ejections, one follower control installation each is connected thereto, possibly one follower control installation common to all such pressure cylinders may be used.

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Ebersbach-Bunwangen, Germany

Gerhard Roos