A spindle abnormity detection device includes a first sensor configured to measure oscillation of a spindle of a machine tool, a second sensor configured to measure radial runout of an axis of a tool unit attached to the spindle, and a computer configured to perform abnormity determination of the spindle based on an oscillation comparison result and a runout comparison result, the oscillation comparison result being obtained by comparing a detection result obtained by the first sensor with an oscillation standard of the spindle, the runout comparison result being obtained by comparing a detection result obtained by the second sensor with a runout standard of the tool unit.

An abnormality diagnostic device for a feed axis mechanism diagnoses an abnormality occurrence and an abnormal portion of the feed axis mechanism. The feed axis mechanism transmits a rotation of a motor to a ball screw coupled by a coupling to rotate the ball screw. The abnormality diagnostic device includes a resonance frequency measuring unit and a diagnosis unit. The resonance frequency measuring unit measures a resonance frequency at a plurality of stroke positions within a stroke range of the feed axis mechanism. The diagnosis unit identifies the abnormal portion based on a relationship between the stroke positions and change amounts relative to a standard value of the measured respective resonance frequencies.

An abnormality diagnostic device for a feed axis mechanism diagnoses an abnormality occurrence and an abnormal portion of the feed axis mechanism. The feed axis mechanism transmits a rotation of a motor to a ball screw coupled by a coupling to rotate the ball screw. The abnormality diagnostic device includes a resonance frequency measuring unit and a diagnosis unit. The resonance frequency measuring unit measures a resonance frequency at a plurality of stroke positions within a stroke range of the feed axis mechanism. The diagnosis unit identifies the abnormal portion based on a relationship between the stroke positions and change amounts relative to a standard value of the measured respective resonance frequencies.

A method for determining a vibration amplitude of a tool, includes the steps of: generating a light beam of a light barrier with a transmitter for generating the light beam and a receiver for detecting a light intensity of the light beam; generating a receiver signal on the basis of a light intensity of the light beam that is detected by the receiver of the light barrier; positioning a tool tip of the tool in the light beam; causing the tool to vibrate; determining the vibration amplitude of the tool from a modulation of the receiver signal brought about by the vibration of the tool.

A method for determining a vibration amplitude of a tool, includes the steps of: generating a light beam of a light barrier with a transmitter for generating the light beam and a receiver for detecting a light intensity of the light beam; generating a receiver signal on the basis of a light intensity of the light beam that is detected by the receiver of the light barrier; positioning a tool tip of the tool in the light beam; causing the tool to vibrate; determining the vibration amplitude of the tool from a modulation of the receiver signal brought about by the vibration of the tool.

A machine tool includes a turning position adjustment unit configured to control a turning drive unit so that, when a tool is transferred between a spindle and a grip, if an amount of sway of the tool is greater than or equal to a threshold value, a turret is turned and the amount of sway of the tool becomes less than the threshold value, and an origin point correcting unit configured to correct an origin point in accordance with a turning position of the turret acquired by a turning position acquisition unit, when the turret is turned by the turning drive unit so that the amount of sway of the tool becomes less than the threshold value.

A machine tool includes a turning position adjustment unit configured to control a turning drive unit so that, when a tool is transferred between a spindle and a grip, if an amount of sway of the tool is greater than or equal to a threshold value, a turret is turned and the amount of sway of the tool becomes less than the threshold value, and an origin point correcting unit configured to correct an origin point in accordance with a turning position of the turret acquired by a turning position acquisition unit, when the turret is turned by the turning drive unit so that the amount of sway of the tool becomes less than the threshold value.

An abnormality detection device of a machine tool includes a plurality of vibration sensors mounted on a body of the machine tool at a plurality of positions; and a determination portion that determines an operation condition of the machine tool based on vibration information detected by the vibration sensors. The abnormality detection device detects abnormality of the machine tool according to determination information of the determination portion. The determination portion specifies a predetermined item whose machining accuracy lowers based on the mounted position of the vibration sensor that has detected abnormal vibration.

A spindle vibration measuring system which measures vibration of a spindle in a machining device that performs a cutting or abrading process on a workpiece. The machining device has a workpiece holder that holds the workpiece, the spindle that holds a tool, and a moving mechanism that relatively moves the workpiece holder and the spindle. The spindle vibration measuring system acquires positional variation data or vibration data of the moving mechanism when the spindle rotates, and a result related to vibration of the spindle to output or store based on the positional variation data or the vibration data.

A spindle vibration measuring system which measures vibration of a spindle in a machining device that performs a cutting or abrading process on a workpiece. The machining device has a workpiece holder that holds the workpiece, the spindle that holds a tool, and a moving mechanism that relatively moves the workpiece holder and the spindle. The spindle vibration measuring system acquires positional variation data or vibration data of the moving mechanism when the spindle rotates, and a result related to vibration of the spindle to output or store based on the positional variation data or the vibration data.