| 摘要 |
<p>The present invention relates to a machine tool (11) for machining a large-sized workpiece (89) such as aircraft parts mounted on a workpiece mounting table (99), by moving a spindle having a tool mounted thereon in directions along the x-axis, the Y-axis and the Z-axis. The machine tool (11) can provide a highly efficient, high-speed and highly precise machining for a large-sized workpiece (89) and solve a problem of a compact installation area. In order to solve this problem, according to the present invention, a workpiece support structure (15) is disposed in opposed relation to a spindle support structure (13) which a spindle head (73) movable in the directions along the X-axis, the Y-axis and the Z-axis. The workpiece mounting table (99) of the workpiece support structure (15) is provided with pallet securing means on two opposed pallet mounting surfaces thereof and is supported to allow for rotational indexing about a horizontal axis extending in the direction along the X-axis. The workpiece (89) is machined by setting one of the pallet mounting surfaces in a horizontal state to mount a pallet (105) thereon and then by positioning the pallet (105) in a vertical state by rotational indexing means. <IMAGE></p> |
