NUMERICAL CONTROL APPARATUS

摘要

The disclosed numerical control apparatus can process- workpiece at high speed and high precision, while suppress- ing tool abrasion, by maintaining the optimum cutting conditions determined by combination of the spindle revolution number and the tool feed speed. In the numeri- cal control apparatus (10), the spindle revolution number control sections (17, 18) changes the revolution number of the spindle according to the tool feed speed obtained by the feed speed deciding sections (11 to 15) on the basis of the tool movement form commanded by a processing program. Further, in the case of the numerical control apparatus (20), the spindle revolution number is changed by the spindle revolution number control sections (23 to 25) on the basis of the change in the contact position between the tool and the workpiece to be cut in the tool axial movement direction. Further, in the case of the numerical control apparatus (30), the spindle revolution number is changed by the spindle revolution number control sections (37 and 38) on the basis of the tool feed speed including tool axial movement direction data obtained by the feed speed deciding sections (31 to 35) on the basis of the tool movement form.