Abstract: In adjusting phase for work (W), the operation of mounting/dismounting a reference tool on a spindle (6) is dispensed with and so is a storage space for the reference tool, and besides, it is arranged that the thrust on the work (W) does not directly act on the spindle (6) at the time of this phase adjustment. In a machine tool in which a spindle housing (7) supporting the specifically directed spindle (6) for rotation alone is supported for parallel motion in orthogonal three-axis directions (XYZ) by a numerical control mechanism (4), in determining the phase for the work (W) is feed-rotated around a specific axis (S), it is arranged that with a reference block (9) fixed to the spindle housing (7), the work (W) is feed-rotated around the specific axis (S) to abut the phase reference section (W1) of the work against the reference block (9), so as to find the amount of feed-rotation of the work at the time of this abutment.

Abstract: A multi-shaft spindle head, wherein a plurality of spindles (11) having tools at the tips thereof are disposed in the same direction, the rear ends of cutting fluid feed passages (21a) formed as the inner holes of cutting fluid feed tubes (21) installed in a non-rotating state at the rotating center parts of the spindles (11) are allowed to communicate with a common closed chamber (8) formed at the rear parts of the spindles (11), and atomized cutting fluid fed into the common closed chamber (8) is jetted from the tips of the openings at the rear end of the cutting fluid feed passages (21a).

Abstract: A tool holder of a machine tool, wherein a holder rear end part is fixed to the front end part of the spindle of the machine tool, a tool receiving surface part (8d) for receiving the rear end face of a shaft-like tool (11) fixed to a holder front end part so that a closed space in contact with the rear end face can be formed and mist cutting fluid passages (8f, 9c) for leading mist cutting fluid fed from the front end part of the spindle to the closed space (12) are formed in a holder body at a center of rotation, and exhaust passages are formed for opening a part of the tool receiving surface part in contact with the closed space (12) to the atmosphere, whereby even when the shaft-like tool (11) is small in diameter and the amount of the mist cutting fluid flowing out to the atmosphere through a passage hole (11a) in the shaft-like tool is small, the liquefied cutting fluid can be prevented from being accumulated in the mist cutting fluid passages by maintaining the flow velocity of the mist cutting fluid i

Abstract: In adjusting phase for work (W), the operation of mounting/dismounting a reference tool on a spindle (6) is dispensed with and so is a storage space for the reference tool, and besides, it is arranged that the thrust on the work (W) does not directly act on the spindle (6) at the time of this phase adjustment. In a machine tool in which a spindle housing (7) supporting the specifically directed spindle (6) for rotation alone is supported for parallel motion in orthogonal three-axis directions (XYZ) by a numerical control mechanism (4), in determining the phase for the work (W) is feed-rotated around a specific axis (S), it is arranged that with a reference block (9) fixed to the spindle housing (7), the work (W) is feed-rotated around the specific axis (S) to abut the phase reference section (W1) of the work against the reference block (9), so as to find the amount of feed-rotation of the work at the time of this abutment.

Abstract: A multi-shaft spindle head, wherein a plurality of spindles (11) having tools at the tips thereof are disposed in the same direction, the rear ends of cutting fluid feed passages (21a) formed as the inner holes of cutting fluid feed tubes (21) installed in a non-rotating state at the rotating center parts of the spindles (11) are allowed to communicate with a common closed chamber (8) formed at the rear parts of the spindles (11), and atomized cutting fluid fed into the common closed chamber (8) is jetted from the tips of the openings at the rear end of the cutting fluid feed passages (21a).

Abstract: A tool holder of a machine tool, wherein a holder rear end part is fixed to the front end part of the spindle of the machine tool, a tool receiving surface part 8d for receiving the rear end face of a shaft-like tool 11 fixed to a holder front end part so that a closed space in contact with the rear end face can be formed and mist cutting fluid passages 8f, 9c for leading mist cutting fluid fed from the front end part of the spindle to the closed space 12 are formed in a holder body at a center of rotation, and exhaust passages are formed for opening a part of the tool receiving surface part in contact with the closed space 12 to the atmosphere, whereby even when the shaft-like tool 11 is small in diameter and the amount of the mist cutting fluid flowing out to the atmosphere through a passage hole 11a in the shaft-like tool is small, the liquefied cutting fluid can be prevented from being accumulated in the mist cutting fluid passages by maintaining the flow velocity of the mist cutting fluid in the mist cut