A control device for a machine tool and a machine tool, for which settings of the number of vibrations per rotation become easy, is provided. The control device of the machine tool controls a relative rotation between a workpiece and a cutting tool and a relative reciprocal movement between the workpiece and the cutting tool in a feed direction to perform vibration cutting to the workpiece. The control device includes a control section for controlling a spindle headstock, a first tool post, and a second tool post, the workpiece W being installed on the spindle headstock, the first tool post being provided to be reciprocally movable along the feed direction with respect to the spindle headstock and installed with a first cutting tool for cutting the workpiece, and the second tool post being provided to be reciprocally movable along the feed direction with respect to the spindle headstock independently of the first tool post and installed with a second cutting tool for cutting the workpiece.

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.

A control device for a machine tool and a machine tool, for which settings of the number of vibrations per rotation become easy, is provided. The control device of the machine tool controls a relative rotation between a workpiece and a cutting tool and a relative reciprocal movement between the workpiece and the cutting tool in a feed direction to perform vibration cutting to the workpiece. The control device includes a control section for controlling a spindle headstock, a first tool post, and a second tool post, the workpiece W being installed on the spindle headstock, the first tool post being provided to be reciprocally movable along the feed direction with respect to the spindle headstock and installed with a first cutting tool for cutting the workpiece, and the second tool post being provided to be reciprocally movable along the feed direction with respect to the spindle headstock independently of the first tool post and installed with a second cutting tool for cutting the workpiece.

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.

A controller performs high-accuracy oscillation control in which an axis driven by a motor is rocked in accordance with the rotation of a spindle motor for driving a main spindle. This controller determines a reference speed of rocking motion based on a reference speed set in advance, a reference main spindle rotational speed of the spindle motor, and an actual main spindle rotational speed, and calculates a rocking motion speed for each control period based on the determined reference speed of the rocking motion. The calculated rocking motion speed for each control period is added to a command outputted by the controller for controlling the position of the motor for each control period.

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.

A controller performs high-accuracy oscillation control in which an axis driven by a motor is rocked in accordance with the rotation of a spindle motor for driving a main spindle. This controller determines a reference speed of rocking motion based on a reference speed set in advance, a reference main spindle rotational speed of the spindle motor, and an actual main spindle rotational speed, and calculates a rocking motion speed for each control period based on the determined reference speed of the rocking motion. The calculated rocking motion speed for each control period is added to a command outputted by the controller for controlling the position of the motor for each control period.

The present invention provides a technique for reducing the workload of a machine tool user selecting one specific shaft to swing. Provided is a device 1 for controlling a machine tool that performs swinging cutting by causing only one specific shaft to swing, said device 1 for controlling a machine tool comprising: a swarf shredding determination unit 14 for determining, on the basis of tool data with which a tool shape can be recognized or relative positional relationship data pertaining to a workpiece and the tool, and movement data for causing the workpiece and the tool to move relative to each other, whether it is possible to shred swarf when performing swinging cutting by swinging only one specific shaft among a plurality of feed shafts; a swinging shaft selection unit 15 for selecting, on the basis of the result of determination by the swarf shredding determination unit 14, one specific shaft as a swinging shaft; and a swinging movement control unit 16 for controlling, on the basis of processing conditions, the one specific shaft selected by the swinging shaft selection unit 15 so as to cause the one specific shaft to swing.