L. Schuler Gmbh

Schuler Pressen Gmbh & Co.

L. Schuler Pressen Gmbh

Schuler Pressen Gmbh + Co. Kg

Siegfried Baur

Rudi Brandstetter

Gerhard Roos

Michael Jung

Heinz Horn

Hartmut Dexling

A drawing apparatus in a press or similar forming system has a blank holder which can be acted upon by one or optionally several pressure cylinders. Blocking devices are provided which act, in one case, directly upon a pressure cheek supporting the blank holder and, in another case, indirectly upon the pressure cheek by way of an articulated train or transmission train. Thereby, an unintentional lifting or lowering of the blank holder is prevented when the press is inoperative.

Drawing apparatus with blocking devices, detents and the like

A drawing device for a press is provided with a drawing slide, with a sheet holder having a sheet held therein, and with a pressure cheek which is arranged under the sheet holder and is connected with a piston rod which can be displaced in parallel to the drawing direction. The piston rod is operatively connected with a preacceleration piston of a preacceleration cylinder. The drawing cylinders are applied to the pressure cheek by way of drawing rods, in which case the drawing cylinders have drawing pistons with first and second piston spaces. The first piston space directed to the drawing rod is pressure controlled during the drawing operation for the sheet forming. In the event of a press stoppage during a sheet forming, a control valve device can be activated so that, for maintaining the pressure existing in the first piston space at the start of the press stoppage during the time of the press stoppage, pressure medium can be charged into the first piston space by way of a pressure medium generator.

Drawing device for a press with control device for maintaining pressure

A drawing mechanism for a press has a drawing slide and a plate holder with a plate held therein. A holding force, which acts against the drawing direction, can be applied to the plate by way of a piston rod which can be displaced in parallel to the drawing direction. A control accelerates the plate holder in the drawing direction before the drawing slide is placed on the plate holder because the plate holder is rapidly acceleratable independently of the drawing slide. A pre-acceleration cylinder is fixed to the press and has a pre-acceleration piston which is operatively connected with the piston rod. The pre-acceleration cylinder has first and second effective surfaces of different sizes which act in opposite directions, and a first and a second pressure chamber.

Drawing mechanism for a press

A run-up control for the pressure cheek in a drawing apparatus achieves stoppage times during the run-up phase by having a pressure cylinder with first and second pressure spaces as well as a control piston which is fixed in its position in the control cylinder when the second pressure space is acted upon with pressure. The control piston is fixed in its position by a piston rod, a fixed stop and an adjustable stop. The first pressure space is in a continuous flow connection with a mash pressure space which is reduced when the pressure cheek runs up so that the volume of the second pressure space determines the point in time of the stoppage time in the run-up phase of the pressure cheek.

Run-up control for the pressure cheek in a drawing apparatus

A control arrangement for regulating the speed of a pressure cylinder increases the controllable flow volume through a proportional-action (control) valve, while avoiding a larger valve or two valves of the same type that must be connected in parallel. A control valve is used which has at least two flow paths connected in parallel. At least one controllable valve is connected in series with a first of the flow paths for the blocking or release of the delivery pipe. The connected first flow path and the controllable valve are connected in parallel to the second flow path.

Control arrangement for regulating the speed of a pressure cylinder

A press having a drawing apparatus has a sheet metal part that is drawn in the drawing stage. This sheet metal part is to be taken over by a transfer device in a stage of the upward movement of the drawing apparatus that is as early as possible in order to utilize the long time period of the upward movement of the slide for the transfer movement. After the drawing, passing through the lower dead center of the slide movement and the drawing apparatus movement, the sheet metal holder is temporarily stopped in a removal position and is therefore temporarily prevented from continuing to move upward.

Press with a drawing apparatus

A drawing apparatus pressure pins acting upon the metal sheet holder in the bottom part of the tool are selected, has additional pressure cylinders fastened in the pressure cheek between the actual drawing apparatus acting upon a pressure cheek and the pressure pins. These additional pressure cylinders are individually controllable via valves from a pressure pipe. As a result, a precise influence is made on the drawing conditions of various sheet metal parts and their ejector movement from the bottom part of the tool.

Drawing apparatus in the bedplate of a press

A drawing apparatus in drawing stages of a press, having a pressure cheek divided into segments, to the corner areas of which pressure cylinders are applied. The pressure cylinders are fixed to the press. Their piston rods, by way of pressure rods, act upon a liftable and lowerable console. At least one locking cylinder which is fixed to the frame is provided which, by way of a lift bridge, is applied to the console and, corresponding to the pressure which acts upon it, prevents an upward movement of the console and thus of the pressure cheek. The point in time of the stop stage in the upward-moving stage can be determined by the valve control of the pressure in the locking cylinders.

Drawing apparatus in drawing stages of presses

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.

A sliding table, used for the exchange of tool or die sets of a press is moved into and out of the press on rails. The driving motion is caused by an adjusting mechanism in the sliding table. An underfloor power containing channel extends parallel to the moving direction of the sliding table and is used for containing at least one power supply line taken along by the sliding table. The underfloor power containing channel is closed in an upward direction by a covering, consisting of individual cover members, flexibly connected with one another and with its own drive which causes pre-stressing of the cover members prior to movement of the sliding table.

Growing community of inventors

Goppingen, Germany

Siegfried Baur