Patent ID: 8015902

Claim:
A machine tool which machines a surface to be machined located on an inner surface of a workpiece gripped by a spindle headstock, the machine tool comprising: the spindle headstock gripping the workpiece; a movable base disposed coaxially with said spindle headstock to be movable in an axial direction; and a tool post disposed between said movable base and said spindle headstock to be movable in the axial direction, wherein said tool post supports a tool having: a supporting member; a cutting tool which is supported to be pivotable about a pivot axis located on a plane perpendicular to an axis of the supporting member and has a cutting edge at one end; and a driving member pivoting the cutting tool by moving in the axial direction, wherein the axial-direction movement of the driving member is enabled by said movable base, and wherein, when the surface to be machined of the workpiece is machined, an axial position of said movable base and an axial position of said tool post are controlled so as to cause a machining point by the cutting edge to move along a desired machining line.