| 摘要 |
PURPOSE:To change a tool radius with respect to the axial center of an outer main spindle, by forming a main spindle in double construction of inner and outer main spindles further eccentrically arranging the inner and the outer main spindles so as to change the relative position of a tool in the direction of rotation of these inner and outer main spindles. CONSTITUTION:An inner main spindle 7, which supports a tool T securing a plural number of edge tools T1, T2...Tn in the peripheral direction forming an angle, is rotated with respect to an outer main spindle 8, and the plural edge tools, whose radial distance from the axial center of the outer main spindle 8 to the edge tool is successively changed in accordance with this rotation, are used for machining holes of the same diameter. In this way, a frequency of using each edge tool is reduced, thus a number of replacement times of the tool can be decreased. |
