| 摘要 |
PROBLEM TO BE SOLVED: To provide a machine tool capable of preventing reduction in processing accuracy by correcting a sag of a ram itself caused by extension and rotation of the ram.SOLUTION: The machine tool includes: a saddle 16 supported so as to be movable; a ram 17 for rotatably supporting a main shaft 18, capable of being extended in an axial direction of the main shaft 18, with respect to the saddle 16, and supported rotatably around a pivot A orthogonal to an axis of the main shaft 18; and tension bars 31a, 31b for correcting a sag of the ram 17 by pulling up a tip of the ram 17 upward. The tensile force of the tension bars 31a, 31b is controlled according to an extension amount &Dgr;Z and a rotational angle α of the ram. |
