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摘要

PURPOSE:To make it possible to rapidly carry short sized workpieces to which the primary machining is applied on one end side of the main spindle of a machine tool, by carrying the workpieces to the other end side through the interior of the main spindle, then applying the secondary machining to said workpieces being holded by means of a chuck. CONSTITUTION:A main spindle 2 rotatably provided on the spindle stock 1 of a machine tool is formed into hollow structure and on both ends of the main spindle 2, chucks C1, C2 are mounted. Short sized workpieces, to which the primary machining is applied at the chuck C1 on the end of the main spindle 2 and the chuck C2 on the opposed side thereof, are carried to the interior of the chuck C1 through the hollow of the main spindle 2 and holded by the chuck C1 so that the secondary machining is applied thereto. Further, the machine tool is provided with tool heads T1, T2 movably mounted on the respective end parts of the main spindle 2. Therefore, workpieces are moved in the interior of the main spindle 2 and the fastening of the chucks C1, C2 are only performed, thereby the secondary machining can be immediately applied thereto.