Entwicklung von Werkzeugschäften für einen Betrieb im überkritischen Drehzahlbereich

High-speed milling (HSC milling) is the most used manufacturing technology for machining work pieces with deep cavities especially in die and mold-making. HSC milling encounters particular limitations wherein tools must be used with peculiar large slenderness ratio (?/? > 20). The large aspect ratios cause reduction in the first natural critical bending frequency. In addition, the centrifugal force generated by the unbalance increase proportionally to the square of the spindle rotational speed. And here the excited not damped resonancevibrations force to work at rotational speeds in the subcritical range. This means, that the maximum allowed operating rotational speed of shank tools is limited by their first natural critical bending frequency. Beside vibrations tool breakages are also not inevitable. These effects lead to that the over length shank tools conventionally cannot be used with HSC-capable rotational speeds. Thereby, the advantages of HSC machining and the available potential capacity of modern HSC spindles (e. g. spindle rotation speeds up to 80.000 min -1 ) stay unused. As part of the dissertation a method for the safe design of over length HSC-tool shanks (?/? > 20) were developed and tested. Thereby the aforementioned issues are feasible to handle. The constructed by the developed solution procedures over length HSCshank tools are able to pass through the first bending natural frequency thereafter to work in supercritical speeds. The speed limits of the usual market over length shank tools are thereby significantly (8-10 times) can be exceeded. The accomplished scientific work also opens up further possibilities for application of one-sided clamped spindles and shafts in supercritical speeds.