A machine tool includes a spindle capable of holding a workpiece and rotatable on a spindle axis and a tool post on which a tool is attachable to machine the workpiece held by the spindle. The tool post includes a first turnable holder turnable on a first turning axis perpendicular to the spindle axis. The first turnable holder has a first tool unit mounting part where a rotary tool is attachable. The tool post further includes a second turnable holder turnable on a second turning axis perpendicular to the spindle axis and different from the first turning axis. The second turnable holder has a second whirling tool mounting part where a thread whirling tool is attachable.

The present disclosure relates to a long boring bar device of a machine tool and, more particularly, to a long boring bar device of a machine tool, wherein a boring bar is detachably fastened to a holder, and a head tool is detachably fastened to the boring bar to automatically exchange a head tool through an automatic tool changer, thereby reducing non-processing time and improving productivity of the machine tool.

A tool-changing device which is used on machine tools (18). Here, provision is made to carry out positioning of a tool holder (2) in the working position (6) of the tool holder with the aid of the locking element (7) of the drive device (4) of the tool-changing device (1). An adjusting movement (22) of the locking element (7) into the locking position (9) of the locking element on the tool holder (2) that is required for the use of the tool (3) is used to position the tool holder (2) in the working position (6) thereof, by the adjusting movement (2) of the locking element (7) being converted into a positioning movement (21) of the tool holders (2).

A tool-changing device which is used on machine tools (18). Here, provision is made to carry out positioning of a tool holder (2) in the working position (6) of the tool holder with the aid of the locking element (7) of the drive device (4) of the tool-changing device (1). An adjusting movement (22) of the locking element (7) into the locking position (9) of the locking element on the tool holder (2) that is required for the use of the tool (3) is used to position the tool holder (2) in the working position (6) thereof, by the adjusting movement (2) of the locking element (7) being converted into a positioning movement (21) of the tool holders (2).

A cutting tool rest (31) includes a clamping mechanism part (131) and a first piston (61). First piston (61) includes a first facing section (63) and a second facing section (64), and clamping mechanism part (131) includes a lever (135). First piston (61) reciprocates between a first position at which lever (135) and first facing section (63) are in contact with each other to operate clamping mechanism part (131) in a clamped state and a second position at which lever (135) and second facing section (64) are in contact with each other to operate clamping mechanism part (131) in an unclamped state. Cutting tool rest (31) includes a second piston (71) that moves first piston (61) to a third position between the first position and the second position. When first piston (61) is located at the third position, lever (135) is separated from first facing section (63) and second facing section (64).

A machine tool includes a spindle capable of holding a workpiece and rotatable on a spindle axis and a tool post on which a tool is attachable to machine the workpiece held by the spindle. The tool post includes a first turnable holder turnable on a first turning axis perpendicular to the spindle axis. The first turnable holder has a first tool unit mounting part where a rotary tool is attachable. The tool post further includes a second turnable holder turnable on a second turning axis perpendicular to the spindle axis and different from the first turning axis. The second turnable holder has a second whirling tool mounting part where a thread whirling tool is attachable.