| 摘要 |
A tool holder (I0) includes: a collet chuck main body (11) having a tapered hole (18) formed in its tip end portion so as to be tapered toward an axial real' end; a tapered collet (21) having a tool insertion hole (23) that extends in an axial direction, a main tapered surface (22) that fits in the tapered hole (18), and a tip end tapered surface (27) positioned on an axial tip end side of the main tapered surface (22), and tapered toward an axial tip end; a cylindrical lock nut (31) having internal threads (32) that are screwed on external threads (17) formed on an outer periphery of the tip end portion of the collet chuck main body (11), for reducing a diameter of the tool insertion hole (23) by pressing the tapered collet (21) into the tapered hole (18); a tip end tapered member (41) having a tapered abutting surface (42) that fits on the tip end tapered surface (27), the tip end tapered member (41) being pressed toward the axial real' end by the lock nut (31); and a plain bearing (51) positioned in a plane perpendicular to a direction in which the tip end tapered member (41) is pressed by the lock nut (31), the plain bearing being inserted between the lock nut (31) and the tip end tapered member (41). |
