Abstract: There is provided a machining center capable of simplifying a driving force transmitting mechanism and restraining occurrence of noise and vibration. A machining center having a turret head 20 with a plurality of tools on a turret base 5 includes one tool drive motor for each tool, the tool drive motor rotary driving the corresponding tool independently.

Abstract: There is provided a machining center capable of simplifying a driving force transmitting mechanism and restraining occurrence of noise and vibration. A machining center having a turret head 20 with a plurality of tools on a turret base 5 includes one tool drive motor for each tool, the tool drive motor rotary driving the corresponding tool independently.

Abstract: An alignment apparatus 2 has a rotation angle position detector 35 comprising relatively rotatable first and second members 36 and 37. The first member 36 is secured on a first base 10 on a rotary table 83, and the second member 37 is secured to the lower face of a second base 41. A first movable body 43 is disposed on the second base 41 to be movable along a first axis, and a second movable body 45 is disposed on the first movable body 43 to be movable along a second axis. When the rotary table 83 is rotated while the second movable body 45 is restrained, the first movable body 43 is moved along the first and second axes. The misalignment amount between the rotary table 83 and the rotation angle position detector 35 is calculated from the movement position of the first movable body 43.

Abstract: This invention provides a tool clamping/unclamping device which allows a tool to be replaced simply and securely by another one in short time, and which prevents a lock nut from being loosened, from yielding a difference in phase, and from dropping off with respect to a main shaft. The tool clamping/unclamping device comprises a tool urging means for holding a tool holding member in its clamped state, a nut positioning means for adjusting the lock nut in its phase in rotation angle position with respect to the main shaft, a nut drop-off preventing means for regulating the amount of rotation angle of the nut, a nut loosening detection means for detecting the position of the nut in the direction of the main shaft, and/or a locking mechanism for engaging a steel ball urged by a spring with a lock hole to thereby lock the lock nut in the direction of rotation.