A cutting tool for turning includes a cutting insert having a cutting edge, a holder for holding the cutting insert, a wireless communication unit for transmitting information based on a measurement result of a sensor attached to the cutting tool, an acceleration sensor installed in the holder, and a control unit for performing first control for controlling activation of the wireless communication unit based on the measurement result of the acceleration sensor.

A machine tool includes: a hollow spindle including a hollow portion along an axial direction; a plurality of chuck claws openably mounted at a distal end portion of the hollow spindle, and configured to hold a workpiece; an operation rod inserted into the hollow portion of the hollow spindle in a movable manner, and configured to close the plurality of chuck claws with movement of the operation rod toward one side in the axial direction and open the plurality of chuck claws with movement of the operation rod toward the other side in the axial direction; and a measuring apparatus configured to measure an opening dimension of the plurality of chuck claws based on a movement amount of the operation rod.

A workpiece holding device includes: a chuck including a chuck body, and a plurality of chuck claws openably supported on the chuck body and configured to hold a workpiece; an operation rod configured to drive the plurality of chuck claws for opening and closing with movement of the operation rod; and a measuring apparatus configured to measure an opening dimension of the plurality of chuck claws based on a movement amount of the operation rod.

A machine tool includes: a hollow spindle including a hollow portion along an axial direction; a plurality of chuck claws openably mounted at a distal end portion of the hollow spindle, and configured to hold a workpiece; an operation rod inserted into the hollow portion of the hollow spindle in a movable manner, and configured to close the plurality of chuck claws with movement of the operation rod toward one side in the axial direction and open the plurality of chuck claws with movement of the operation rod toward the other side in the axial direction; and a measuring apparatus configured to measure an opening dimension of the plurality of chuck claws based on a movement amount of the operation rod.

A workpiece holding device includes: a chuck including a chuck body, and a plurality of chuck claws openably supported on the chuck body and configured to hold a workpiece; an operation rod configured to drive the plurality of chuck claws for opening and closing with movement of the operation rod; and a measuring apparatus configured to measure an opening dimension of the plurality of chuck claws based on a movement amount of the operation rod.

To provide a monitoring device, a machine tool, and a monitoring system capable of collecting data efficiently required for examining an alarm. A monitoring device is connected to multiple machine tools through a network. The monitoring device comprises: a monitoring unit that monitors the occurrence of an alarm in the machine tools; an acquisition unit that acquires a set of measurement target data items responsive to an alarm from a database on the occurrence of the alarm; and a collection unit that sets the set of measurement target data items in the multiple machine tools, and collects data measured by following the setting.

To provide a monitoring device, a machine tool, and a monitoring system capable of collecting data efficiently required for examining an alarm. A monitoring device is connected to multiple machine tools through a network. The monitoring device comprises: a monitoring unit that monitors the occurrence of an alarm in the machine tools; an acquisition unit that acquires a set of measurement target data items responsive to an alarm from a database on the occurrence of the alarm; and a collection unit that sets the set of measurement target data items in the multiple machine tools, and collects data measured by following the setting.

A cutting tool for turning includes a cutting insert having a cutting edge, a holder for holding the cutting insert, a wireless communication unit for transmitting information based on a measurement result of a sensor attached to the cutting tool, an acceleration sensor installed in the holder, and a control unit for performing first control for controlling activation of the wireless communication unit based on the measurement result of the acceleration sensor.