A display device includes a position information acquisition part, a rotation information acquisition part, a first waveform generation part, a second waveform generation part, and a waveform display part, which displays plural second waveform data. The position information acquisition part acquires position information of a feed axis. The rotation information acquisition part acquires the rotation speed of a workpiece as rotation information of a spindle. The first waveform generation part generates first waveform data representing a change of the position information over time from time series position information of the feed axis. The second waveform generation part generates plural second waveform data by obtaining a time per rotation from the rotation speed, dividing the first waveform data into partial waveform data for time per rotation, and sequentially shifting each partial waveform data in the time axis direction so as to match a start point of the first waveform data.

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.

The invention provides a control apparatus for a machine tool, which can perform reciprocating vibration in consideration of a vibration frequency, increase flexibility in machining a workpiece, and perform vibration cutting by means of an external spindle or the like without rotating a spindle. The control apparatus and the machine tool include control means. The control means includes an imaginary spindle regarded as a spindle for rotating a workpiece W or a cutting tool. The control means sets the number of rotations of the imaginary spindle and the number of reciprocating vibrations in accordance with a vibration frequency attributable to a cycle during which an operation instruction can be issued.

To provide a machine tool and a control device for the machine tool that can smoothly cut a workpiece while segmenting chips by feeding a cutting tool in a feed direction while reciprocally vibrating the cutting tool along the feed direction on the basis of a condition set by a user. The machine tool (100) or the control device (C) includes the control section (C1) that determines a number of rotations of the relative rotation and a number of vibrations of the reciprocal vibration per rotation of the relative rotation when the workpiece (W) is machined in accordance with a vibration frequency dependent on a period in which an operating instruction can be executed.

To provide a machine tool and a control device for the machine tool that can smoothly cut a workpiece while segmenting chips by feeding a cutting tool in a feed direction while reciprocally vibrating the cutting tool along the feed direction on the basis of a condition set by a user. The machine tool (100) or the control device (C) includes: a setting unit (C1, C2) for utilizing a number of rotations of relative rotation of a workpiece (W) and the cutting tool, a number of reciprocal vibrations of the cutting tool per rotation of the relative rotation, and a vibration frequency dependent on a period in which the control device (C) can execute an operating instruction when the workpiece W is machined as parameters and for setting values of two of the parameters to a control section (C1); and a correcting unit (C1) for setting the remaining one of the parameters to a predetermined value and correcting the values of the two of the parameters set by the setting unit on the basis of the value of the remaining one of the parameters.

The purpose of the present invention is to both break down chips and suppress sympathetic vibration in a machine. This work machine control device superposes a swinging command for commanding relative swinging between a workpiece and a cutting tool onto a movement command for commanding relative movement between the workpiece and the cutting tool, thereby generating air cuts in chips from the workpiece to break down the chips. A position information acquisition unit of the work machine control device acquires position information related to the relative positions of the workpiece and the tool. A state assessment unit of the work machine control device assesses that a state of instability is in effect, under the condition that a positional deviation exceeds a threshold value, the positional deviation increasing with increases in the difference between actual relative positions that are based on the position information and command relative positions that are based on the movement command and the swinging command. A swinging switching unit of the work machine control device performs a switching process for switching a swinging condition in relative swinging, under the condition that it is assessed that the state of instability is in effect.