PURPOSE: To reduce number of parts, simplify structure, and make the maintenance of the drive system easy, in a numerically controlled turret lathe, by achieving common use of one drive system for both the turret shaft and the second main spindle.
CONSTITUTION: A turret lathe 1 includes a first clutch 5, a turret 6, a second clutch 8, a second spindle 9, and so forth. In machining a part with the lathe 1, upon the issuance of a turret instruction, the indexed state of the turret 6 is detected by a detector 7 and its output is fed back, and control is made such that the contents in an error registor 2 becomes zero with reference to the turret instruction, and indexing of the turret 6 is thus finished. Then, by a second spindle instruction by means of the M code, an auxiliary function code programmed in the NC apparatus, the clutch 5 is switched over to the clutch 8 and the main spindle 9 is thereby driven. Thus, it is attained to reduce the number of the parts, simplify the structure, and make easy the maintenance of the drive system.
FUJITA NAOKI
IWAGAYA TAKASHI
