Abstract: There is provided a holder main body which has a simple structure, allows automatic tool change, and has high suction efficiency of cutting chips to be capable of preventing internal deposition. There is provided a holder man body having a mounting hole in which a cutting tool is attachable and attached to a spindle of a machine tool, the holder main body including: a second suction hole which penetrates through the holder main body in an axial direction so as to be connected with a first suction hole penetrating in the axial direction through the cutting tool attached in the mounting hole; and a third suction hole connected with the second suction hole and capable of sucking air other than suction air coming from the first suction hole.

Abstract: To provide a machine tool including a workpiece inner surface machining tool which is not only capable of machining an inner surface of a workpiece into a spherical shape but also capable of machining a bearing surface which is a flat surface and machining the combination of a spherical surface and a flat surface. A machine tool 1 machines a surface to be machined m1 located on an inner surface of a workpiece 21 by a tool 20 having: a supporting member 22; a cutting tool 23 which is supported to be pivotable about a support shaft 19 located on a plane b? perpendicular to an axis a of the supporting member 22 and has a cutting edge 23a at one end; a drive shaft 24 pivoting the cutting tool 23 by moving in an axis a direction; and a link member 25.

Abstract: To provide a machine tool including a workpiece inner surface machining tool which is not only capable of machining an inner surface of a workpiece into a spherical shape but also capable of machining a bearing surface which is a flat surface and machining the combination of a spherical surface and a flat surface. A machine tool 1 machines a surface to be machined m1 located on an inner surface of a workpiece 21 by a tool 20 having: a supporting member 22; a cutting tool 23 which is supported to be pivotable about a support shaft 19 located on a plane b? perpendicular to an axis a of the supporting member 22 and has a cutting edge 23a at one end; a drive shaft 24 pivoting the cutting tool 23 by moving in an axis a direction; and a link member 25.

Abstract: There is provided a holder main body which has a simple structure, allows automatic tool change, and has high suction efficiency of cutting chips to be capable of preventing internal deposition. There is provided a holder man body having a mounting hole in which a cutting tool is attachable and attached to a spindle of a machine tool, the holder main body including: a second suction hole which penetrates through the holder main body in an axial direction so as to be connected with a first suction hole penetrating in the axial direction through the cutting tool attached in the mounting hole; and a third suction hole connected with the second suction hole and capable of sucking air other than suction air coming from the first suction hole.