摘要 |
PURPOSE:To remarkably enlarge the range able to be machined by a single tool, by mounting a blade tool in an alternative manner such that the tip is positioned either on the opposite side of the center of an outerspindle with respect to the center of an inner shaft, or on the center side thereof. CONSTITUTION:The spindle 6 of a variable tool diameter type spindle device 3 has a double structure consisting of an inner spindle 7 and an outer spindle 8. The inner spindle 7 is set rotatable with respect to the outer spindle 8 and is set eccentric to the axis of the spindle 8 by (e). At the tip end of the inner spindle 7, a tapered hole 9 for mounting a tool is provided in the position eccentric to the spindle axis by (e). The outer spindle 8 is supported in the spindle housing 10. The inner spindle 7 is rotated relatively to the outer spindle 8 by driving a servomotor 16, while by driving a rotation driving motor 23, the inner and outer spindles 7 and 8 are integrally rotated on the axis O of the outer spindle 8, and the rotation is indexed by a disc 27 and a detector 29. |