Patent ID: 8814769
Filing Date: 2014-08-26
Classification: B23B,B23Q,Y10T

Abstract:
1. A machine tool having a lathing function using a rotationally fixed tool and a milling function using a rotary tool, comprising: a rotatable spindle, a housing member supporting said spindle in a rotatable manner, a main clamp provided at said spindle for clamping a fixed-tool tool holder during fixing the fixed tool and for clamping a rotary-tool tool holder during fixing the rotary tool, an auxiliary clamp provided at said housing member for clamping the fixed-tool tool holder, together with said main clamp, during fixing the fixed tool, and an arm member including a first gripper and a second gripper capable of grasping the tool holders, for exchanging one of said tool holders that is loaded to said spindle and grasped at said first gripper for another one of said tool holders that is grasped at said second gripper, which exchanging occurs by rotating the arm member about a central axis arranged at a center position of the arm member between said first gripper and said second gripper, and by sliding the arm member in an axial direction of the central axis, said auxiliary clamp being arranged at a position not interfering with said arm member during the rotation and axial movement of the arm member during the exchanging of the tool holders, wherein when viewed in a direction of a rotation axis of said spindle, the auxiliary clamp is located outside of a rotation region constituted by the area over which said arm member rotates during the rotation of the arm member about the central axis during the exchanging of the tool holders; wherein said auxiliary clamp is spaced from the spindle rotation axis, and wherein said auxiliary clamp includes a releasable collet for clamping a pull stud of the fixed-tool tool holder, and includes a tapered face whose diameter varies along a retracting direction along which the fixed-tool tool holder is retracted in order to clamp the fixed-tool tool holder with the auxiliary clamp, wherein the tapered face is configured to be in surface-contact with a tapered face of the fixed-tool tool holder, which tapered face of the auxiliary clamp is spaced along the retracting direction from the collet when the pull stud is clamped by the collet.