Tool holder

摘要

In a tool holder, a tip run-out correction mechanism includes an annular stepped portion (41) formed on a cylindrical support portion (48) of a holder body (31); a ring member (42) rotatably fitted onto the annular stepped portion (41); an eccentric cam (43) disposed within the ring member (42), the eccentric cam (43) extending radially through the ring member (42) and being rotatable about a radially extending axis; and a pin (44) disposed within the ring member (42) to be movable along a direction parallel to the centre axis of a flange portion (33) of the holder body (31). One end of the pin (44) is in contact with the eccentric cam (43), and the other end of the pin (44) is in contact with a rear end face of a clamp sleeve (38) which clamps a tool (29) inserted into a chuck sleeve (34) of the holder body (31). The eccentric cam (43) is rotated so as to adjust a pressing force that the pin (44) applies to the rear end face of the clamp sleeve (38), thereby to elastically deform a base end portion (341) of the chuck sleeve (34) in a radial direction in such a manner that tip run-out of the tool approaches zero.