ACCURACY REQUIREMENTS OF FINEBLANKING PRESSES.

Fineblanking presses are triple-acting special machines which have to be adapted to the conditions of fineblanking. In order to attain high stroke rates in spite of relatively low blanking speeds the drive systems are designed so that the idle movements are performed in minimal time. High-speed presses with mechanical ram drive are used for small stampings. Larger components require hydraulic presses with which the accumulator drive has proved to be particularly effective. The eight-point ram guide which is supported on the rigid symmetrically constructed press frame ensures components of extereme accuracy and also prolongs tool life. This article sets out to deal mainly with the mechanical and hydraulic drive units, with the accuracy requirements of the press, with the methods of prevention of tool fracture and in a brief survey with the ancillary units linked directly with the press.