FORTSCHALTEINRICHTUNG FUER DEN WERKZEUGHALTER EINER NUMERISCH GESTEUERTEN DREHBANK

摘要

An index control apparatus for the tool rest of an NC lathe for driving the tool rest to a desired indexed position on the basis of an NC machining command. In order to make the swivelling velocity of the tool rest adjustable as desired and to index the tool rest quickly and with a high accuracy, a servo motor is used as the driving source for swivelling the tool rest. The swivelling angle and the swivelling velocity of the tool rest are optimized in accordance with an index command and the current position of the tool rest, and quick indexing operation is enabled in respective of the indexed position. The output torque of the servo motor is limited at the time of clamping/unclamping the tool rest, thereby facilitating the clamping/unclamping operation.