A rotatable buffer turret apparatus on which plural pairs of punches and dies to be set on a turret of a turret punch press are set, includes an upper buffer turret on which punch attachment holes in which the punches can be set are arranged circularly, and a lower buffer turret on which die attachment holes that is associated with the punch attachment holes and in which the dies can be set are arranged circularly. The upper and lower buffer turrets are rotatably attached to a single rotary shaft. A diameter of the lower buffer turret is made larger than a diameter of the upper buffer turret. The die attachment holes are formed in a circular die attachment area having a diameter larger than the diameter of the upper buffer turret. According to the apparatus, a tool exchange manually operated by an operator can be done easily and efficiently.

A rotatable buffer turret apparatus on which plural pairs of punches and dies to be set on a turret of a turret punch press are set, includes an upper buffer turret on which punch attachment holes in which the punches can be set are arranged circularly, and a lower buffer turret on which die attachment holes that is associated with the punch attachment holes and in which the dies can be set are arranged circularly. The upper and lower buffer turrets are rotatably attached to a single rotary shaft. A diameter of the lower buffer turret is made larger than a diameter of the upper buffer turret. The die attachment holes are formed in a circular die attachment area having a diameter larger than the diameter of the upper buffer turret. According to the apparatus, a tool exchange manually operated by an operator can be done easily and efficiently.

A numerical control apparatus controls a machine tool including an X axis for moving a turret to which a plurality of tools are attached, a H axis for rotating the turret, and a C axis for rotating a work and not including a Y axis orthogonal to the X axis. The numerical control apparatus includes a unit configured to independently rotate the H axis according to an independent rotation command for the H axis and perform tool replacement during an imaginary Y-axis control mode, the imaginary Y-axis control mode being a mode for converting an X-Y axes movement command in a machining program into a command in an X-H-C coordinate system and for driving the X axis, the H axis, and the C axis in association with one another according to the converted command.