DEVICE AND METHOD FOR PREVENTING A TOOL FROM BREAKING WHEN FINE BLANKING AND/OR FORMING A WORKPIECE

摘要

An exchangeable plate is suspended on a top plate and held in a lower end position without force by a hydraulic clamping means. In an upper end position, it is connected with force fit to, and re-detached from, the top plate as a function of a stripping operation of a scrap web from a V-ring pressure plate. The exchangeable plate is transferred from the lower into the upper end position by movement of a ram, and transferred from the upper into the lower end position by gravity. A sensing distance, adapted to the brake path of the drive system, is provided between the top plate and the exchangeable plate. A sensing device in the V-ring pressure plate outputs a signal to the computer for stopping the drive system and deactivating the hydraulic system. A sensor detects premature movement of a pressure plate in the exchangeable plate.

主权项

1. A device for preventing a tool from breaking during fine blanking or forming in a press that includes a ram and a fine blanking head, the ram being driven by a drive system and carrying out a stroke movement between top dead center and bottom dead center, the fine blanking head being disposed above the ram and having a main cylinder in which a V-ring piston located on a stroke axis is accommodated, the V-ring piston being associated with a plurality of V-ring pressure pins that are disposed coaxially to the stroke axis and axially guided in a top plate attached to the main cylinder and that are supported on a V-ring pressure plate, the V-ring pressure plate being associated with the top plate, and together with the V-ring piston and the V-ring pressure pin, forming an axially displaceable structure for a cutting, forming and stripping operation, wherein the fine blanking head is connected to a hydraulic system for generating pressures acting on the tool by way of valves that can be actuated by a computer, the device comprising:
an exchangeable plate suspended on the top plate; a sensing device disposed in the V-ring pressure plate; a sensor disposed in the top plate; hydraulic clamping means for holding the exchangeable plate; hydraulic guide means for guiding the exchangeable plate; wherein the exchangeable plate is held by the hydraulic clamping means, in a lower end position without force with respect to the top plate; wherein in an upper end position the exchangeable plate can be connected with force fit to and re-detached from the top plate as a function of a stripping operation of a scrap web from the V-ring pressure plate; wherein the exchangeable plate can be transferred from the lower into the upper end position by a movement of a ram and from the upper into the lower end position due to gravity; wherein a sensing distance that is adapted to the brake path of the drive system is provided between the top plate and the exchangeable plate, the sensing distance being associated with the sensing device, which is disposed in the V-ring pressure plate and which outputs a signal to the computer for stopping the drive system and for deactivating the hydraulic system via the sensor disposed in the top plate in the event of a premature movement of a pressure plate disposed in the exchangeable plate.