Method and apparatus for machining roll surface

A roll surface machining apparatus for forming a three-dimensional pattern of protrusions or recesses in the surface of a roll, said apparatus comprising:

• a bed;
• a headstock, mounted on the bed, having a main spindle for rotating a roll as a workpiece while holding one end of the roll by means of a chuck and an indexing axis (C-axis) for indexing the roll in the circumferential direction;
• a tail stock, mounted on the bed and disposed opposite the headstock, for rotatably supporting the other end of the roll;
• a carriage including a saddle mounted on the bed movably in the longitudinal direction (Z-axis direction) of the roll, and a table mounted on the saddle movably in a direction (X-axis direction) perpendicular to the longitudinal direction of the roll;
• a tool post mounted on the table and having a plurality of cutting tools attached thereto;
• and
• a NC control unit for rotating the roll at a predetermined speed and moving the cutting tool and the roll relative to each other at a predetermined speed in the axial direction of the roll by means of C-Z axis interpolation based on the predetermined ratio of the roll rotating speed and relative moving speed of the cutting tool.