WORKING-PIECE ROLLING DEVICE FOR LATHE

The present invention relates to a device for rotating a workpiece on a lathe capable of rotating a workpiece to cut an end portion of the workpiece by a cutting unit installed on a reciprocating stand. The device includes a frame; a spindle which is installed on the frame to be rotated and on which an insertion port where the workpiece can be inserted is formed on the center of rotation; a plurality of chuck members of which each one end portion is installed on the inner periphery of the insertion port and the other portions touches the outer periphery of the workpiece inserted into the insertion port; a pressing unit which presses the other end portions of the chuck members to a direction adjacent to a rotary shaft line of the spindle by an elastic force in order to fix the workpiece to the spindle; a driving unit which rotates the spindle; and an unlocking unit which locks the pressing unit to make the pressing member pressing the chuck member stop to unlock the fixated state of the workpiece to the spindle when exchanging the workplace. The device for rotating the workpiece on a lathe according to the present invention is provided to prevent defects caused by a fluid leakage by fixating the workpiece to the spindle by applying an elastic force to the chuck member without a separate oil pressure and to reduce time for installing and manufacturing with a simple structure.