Press with cutting shock dampening
AssigneeSchuler Pressen GmbH
InventorJuergen Fahrenbach
Life of this patent
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Abstract
To increase the cutting quality and to improve the operation of a press, in particular in punching high-strength martensitic materials or when punching thick sheet metal, a sheet metal holding device is provided for securely clamping the respective workpiece during the punching operation. The clamping force is increased to 40% or more of the ram force. The force exerted by the sheet metal holding device during the penetration of the workpiece can be further increased. The increase in the clamping force preferably takes place in a controlled manner as a function of the press angle.
Claims12
A punch press for punching a workpiece, comprising a press frame having a press bed for holding a lower die and a movably-mounted ram operatively connected to a drive device and carrying an upper die,
- a controllable supporting device configured to generate a variable force that is effective between the ram and the press bed, and
- a control unit which includes a reversing hydraulic valve and which is operatively associated with the supporting device to detect via a sensor device a measured ram position or a press angle that has a unique correlation with a ram position and that influences a supporting force exerted by the supporting device and acting between the ram and the workpiece as a function of the press angle or the measured ram position such that the supporting force is increased from a lower value to a higher value to allow a reversing operation of the hydraulic valve at a predetermined press angle just prior to a press angle at which a counterforce exerted by the workpiece during punching ceases.
Dependencies are inferred from the claim text.