NUMERICALLY CONTROLLED MACHINE TOOL

摘要

A numerically controlled machine tool comprises a work holding unit for holding a workpiece, and a tool capable of being moved along the Z-axis into a central bore formed in the workpiece. The tool has a shank and a cutting chip attached to the shank so as to project laterally from the shank. A driving mechanism controlled by a control unit moves the tool along a substantially circular path in an X-Y plane so that the cutting chip moves in a direction substantially coinciding with a tangent to the internal surface of the central bore of the workpiece at the point of contact of the cutting chip with the internal surface of the central bore.