A turret tool rest includes a main shaft, a turret turning shaft, a turret, a joint base, a mill housing connection shaft, and an engagement member. The main shaft rotates a tool. A part of the main shaft is provided in the turret turning shaft. The turret turning shaft has a first coupling hole. The turret is connected to the turret turning shaft via which the turret is rotated. The joint base has a second coupling hole. The mill housing connection shaft is connected to the joint base. The mill housing connection shaft is provided between the main shaft and the turret turning shaft. Each of the mill housing connection shaft, the joint base, the part of the main shaft, and the turret turning shaft are disposed to rotate around a rotation axis of the turret. The engagement member moves in the first coupling hole and the second coupling hole.

A machine tool includes: a turret configured to hold a tool through a clamp mechanism; a workpiece main spindle device configured to rotatably hold a workpiece; a switching unit configured to change a clamp state of the clamp mechanism by using rotation torque of the workpiece main spindle device; and an in-machine robot configured to move the switching unit. The clamp mechanism includes a torque input hole to which rotation torque is applied to change the clamp state. The switching unit includes an input shaft coupled with the workpiece main spindle device, an output shaft coupled with the torque input hole of the clamp mechanism and configured to output torque to the torque input hole, and a transmission mechanism configured to transfer, to the output shaft, the rotation torque of the workpiece main spindle device input through the input shaft.

An automatic lathe includes a positioning block that positions a rod material, the rod material projecting from a main spindle contacting the positioning block, and a sensor that moves in a direction intersecting with a shaft center C direction of the main spindle to detect a cut off condition of the rod material. The positioning block includes a groove that allows movement of the sensor, and moves in the same direction as a movement direction of the sensor between a position that contacts the rod material and a position that has no contact with the rod material. The sensor moves along the path in the position that has no contact with the rod material.

An automatic lathe includes a positioning block that positions a rod material, the rod material projecting from a main spindle contacting the positioning block, and a sensor that moves in a direction intersecting with a shaft center C direction of the main spindle to detect a cut off condition of the rod material. The positioning block includes a groove that allows movement of the sensor, and moves in the same direction as a movement direction of the sensor between a position that contacts the rod material and a position that has no contact with the rod material. The sensor moves along the path in the position that has no contact with the rod material.

A machine tool includes a main spindle movably supported in an axial direction, and two gang tool posts disposed opposed to each other with an axis of the main spindle located therebetween. Each of the two gang tool posts is supported movably in X and Y directions that are perpendicular to the axial direction of the main spindle. Each of the two gang tool posts is provided with tools arranged parallel to each other in the Y direction. One of the two gang tool posts is movably disposed in a Z direction that is a same direction as the axial direction of the main spindle. Any one of the two gang tool posts is integrally provided with a turning tool base that turnably supports tools about a Y-axis along the Y direction.

A machine tool includes a main spindle movably supported in an axial direction, and two gang tool posts disposed opposed to each other with an axis of the main spindle located therebetween. Each of the two gang tool posts is supported movably in X and Y directions that are perpendicular to the axial direction of the main spindle. Each of the two gang tool posts is provided with tools arranged parallel to each other in the Y direction. One of the two gang tool posts is movably disposed in a Z direction that is a same direction as the axial direction of the main spindle. Any one of the two gang tool posts is integrally provided with a turning tool base that turnably supports tools about a Y-axis along the Y direction.

A horizontal lathe machine includes a work spindle unit disposed on a middle portion of a machine base and proximate to a front side of the machine base for holding a workpiece in an X-direction, and two tooling turret units located at two opposite sides of the spindle unit and driven to move in the X-direction by X-direction driving units. Each turret unit has a saddle movable on the machine base in the X-direction, and a turret driven by a turret driving member to rotate about a turret axis in a Y-direction that is perpendicular to the X-direction for facilitating a tool changing operation.

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 technology capable of improving machining performance of a lathe is provided. A first attaching position and a second attaching position are adjacent to each other in a tool unit attaching direction perpendicular to a spindle axis direction. A second tool unit attached to the second attaching position is of a shape avoiding an area that a spindle possibly occupies relatively with respect to a first tool unit working on the workpiece. When a rotary tool unit is attached to one of the first attaching position and the second attaching position, a machining point of the second tool unit working on the workpiece is deviated to the side of the spindle in the spindle axis direction from the rotational center of the rotary tool unit across the turret surface.

A technology capable of downsizing the lathe is provided. The lathe comprises a spindle which rotates a workpiece on a spindle axis, a turret head, and a tool unit switching driving unit. The turret head has a plurality of turret surfaces to which a tool unit is radially attached around an indexing axis. To at least part of the turret surfaces, the tool unit is attached in a plurality of attaching positions provided in an indexing axis direction along the indexing axis. The tool unit switching driving unit rotates the turret head on the indexing axis and moves the turret head in the indexing axis direction to switch the tool units for use to machine the workpiece.