Methods of machining a body to produce a chip wherein the body is formed of a material and in a state such that the material exhibits sinuous flow during a machining operation. The methods include providing a layer located on a surface of the body, and machining the body by causing engagement between a cutting tool and the body in a contact region below an area of the surface having the coating layer thereon and moving the cutting tool relative to the body to produce the chip having the layer thereon. The layer reduces sinuous flow in the material of the body.

Methods of machining a body to produce a chip wherein the body is formed of a material and in a state such that the material exhibits sinuous flow during a machining operation. The methods include providing a layer located on a surface of the body, and machining the body by causing engagement between a cutting tool and the body in a contact region below an area of the surface having the coating layer thereon and moving the cutting tool relative to the body to produce the chip having the layer thereon. The layer reduces sinuous flow in the material of the body.

A machine tool capable of facilitating the setting of the vibration cutting conditions. A control unit acquires a feed speed of a object to be fed without a vibration (Fa), a number of rotations of a spindle required for a single cycle of the vibration (K), and a returning amount (R) representing a distance of a returning feed per the single cycle of the vibration. According to the acquired parameters, the control unit decides at least one parameter among a cutting amount (D) representing a distance of a change in a position of the object per the single cycle of the vibration, a cutting feed speed (F) of the object, and a returning feed speed (B) of the object. The control unit controls the position of the object to be fed with the vibration at least according to the decided parameter.

A control device includes a control part which generates a torque command based on a resultant command, which is obtained by adding a position deviation, which is the difference between a position command and the actual position of a feed shaft, to an oscillation command to control the feed shaft, and an elastic deformation amount calculation part which calculates the elastic deformation amount of a structure composed of a tool or workpiece and the feeding mechanism therefor based on the torque command. An oscillation command generation part generates the above oscillation command based on the rotation speed of the workpiece, the position command of the feed shaft, and the above elastic deformation amount.

A control device includes a control part which generates a torque command based on a resultant command, which is obtained by adding a position deviation, which is the difference between a position command and the actual position of a feed shaft, to an oscillation command to control the feed shaft, and an elastic deformation amount calculation part which calculates the elastic deformation amount of a structure composed of a tool or workpiece and the feeding mechanism therefor based on the torque command. An oscillation command generation part generates the above oscillation command based on the rotation speed of the workpiece, the position command of the feed shaft, and the above elastic deformation amount.

A display device acquires and displays information on a machine tool that includes a spindle for relatively rotating workpiece and a cutting tool and feed axes for relatively feeding the workpiece and the cutting tool and that performs machining on the workpiece while making the cutting tool and the workpiece swing relatively, and includes: a first information display unit that displays first information indicating a position to which the cutting tool is relatively fed with respect to the workpiece; a second information display unit that displays second information indicating a relationship between the phase of the spindle and the positions of the feed axes; and a range selection unit that selects part of the first information as a selection range, and the second information display unit changes the display range of the second information such that the display range corresponds to the selection range selected by the range selection unit.

A control device includes a position command generation part, an oscillation command generation part, and a storage part for storing machining operation conditions and servo control conditions. The oscillation command generation part includes an estimation part which estimates an oscillation amplitude and an oscillation frequency of an oscillation command based on a rotation speed of a workpiece and a position command generated by the position command generation part, and a determination part which determines whether or not the estimated oscillation frequency is an optimum value based on the machining operation conditions and the servo control conditions.

A control device includes a position command generation part, an oscillation command generation part, and a storage part for storing machining operation conditions and servo control conditions. The oscillation command generation part includes an estimation part which estimates an oscillation amplitude and an oscillation frequency of an oscillation command based on a rotation speed of a workpiece and a position command generated by the position command generation part, and a determination part which determines whether or not the estimated oscillation frequency is an optimum value based on the machining operation conditions and the servo control conditions.

This invention provides a machine tool that, in addition to sequentially separating a chip generated from a workpiece in a reliable manner, improves the roundness of the finished workpiece and improves the visual appearance and roughness of a machined surface of the workpiece, and a control apparatus of the machine tool. A machine tool or a control apparatus thereof includes a vibration frequency setting unit for setting vibration frequency of the reciprocal vibration with respect to one relative rotation when machining a workpiece so that the intersections of paths of a cutting tool during forward movement and backward movement are dispersed on a circumferential surface of the workpiece.

This invention provides a machine tool that, in addition to sequentially separating a chip generated from a workpiece in a reliable manner, improves the roundness of the finished workpiece and improves the visual appearance and roughness of a machined surface of the workpiece, and a control apparatus of the machine tool. A machine tool or a control apparatus thereof includes a vibration frequency setting unit for setting vibration frequency of the reciprocal vibration with respect to one relative rotation when machining a workpiece so that the intersections of paths of a cutting tool during forward movement and backward movement are dispersed on a circumferential surface of the workpiece.