| 摘要 |
A method for forming a part of deformed cross section with non-rotation symmetry on an end portion of a cylindrical workpiece. The method includes steps of performing a first relative motion of a roller against the workpiece toward its one open end, and performing a second relative motion of the roller against at least a part of outer peripheral surface of the end portion of the workpiece toward the inside thereof, while the roller is rotated relative to the workpiece by one rotation, in such a state as being held to be in contact with the end portion, in a plane which is perpendicular to the moving direction of the first relative motion, and which includes a position where the roller contacts the outer peripheral surface of the end portion, and performing a rotational motion of the roller relatively rotating around the workpiece, while performing the second relative motion, with the roller being held to be in contact with the outer peripheral surface of the end portion. The first relative motion is performed up to a position exceeding the one open end, while repeating the second relative motion and the rotational motion. |
