A machine tool includes: a movable body that supports a tool; a feed drive unit that feed-drives the movable body; a numerical control unit that controls the feed drive by the feed drive unit to perform cutting by the tool; an acceleration sensor that is provided on the movable body and detects acceleration of the movable body; and a command unit that outputs a stop command to stop driving of the feed drive unit to the numerical control unit when the acceleration of the movable body exceeds a threshold value set in advance on the basis of an output of the acceleration sensor. The command unit sets the threshold value to a first threshold value in a cutting control state, and sets the threshold value to a second threshold value lower than the first threshold value in a feed control in a non-cutting control state.

A machine tool includes: a movable body that supports a tool; a feed drive unit that feed-drives the movable body; a numerical control unit that controls the feed drive by the feed drive unit to perform cutting by the tool; an acceleration sensor that is provided on the movable body and detects acceleration of the movable body; and a command unit that outputs a stop command to stop driving of the feed drive unit to the numerical control unit when the acceleration of the movable body exceeds a threshold value set in advance on the basis of an output of the acceleration sensor. The command unit sets the threshold value to a first threshold value in a cutting control state, and sets the threshold value to a second threshold value lower than the first threshold value in a feed control in a non-cutting control state.

A motor control device includes an acceleration detecting section configured to detect an acceleration of a control object, and an acceleration control section configured to control an acceleration of a motor driving the control object based on the detected acceleration, in which the acceleration control section includes a vibration component extraction filter configured to extract a vibration component generated between the motor and the control object, and the vibration component extraction filter changes a filter characteristic frequency according to at least one of a position and a mass of the control object.

A motor control device includes an acceleration detecting section configured to detect an acceleration of a control object, and an acceleration control section configured to control an acceleration of a motor driving the control object based on the detected acceleration, in which the acceleration control section includes a vibration component extraction filter configured to extract a vibration component generated between the motor and the control object, and the vibration component extraction filter changes a filter characteristic frequency according to at least one of a position and a mass of the control object.

A machining center for machining a center groove on a pulley and a flange formed at opposite ends of a crankshaft of a vehicle includes a measurement unit configured to measure a moment of the crankshaft when the crankshaft is loaded and actuated, a control unit configured to calculate an imbalance amount of the crankshaft and to derive center drill coordinates for removing the imbalance amount, a compensation unit mounted in a base frame and configured to compensate a position of the crankshaft by rotating first and second rotating elements based on the center drill coordinates inputted from the control unit when the crankshaft is transported and clamped by a clamping system, and a machining unit configured to machine the center groove in the pulley and the flange of the crankshaft.

A machining center for machining a center groove on a pulley and a flange formed at opposite ends of a crankshaft of a vehicle includes a measurement unit configured to measure a moment of the crankshaft when the crankshaft is loaded and actuated, a control unit configured to calculate an imbalance amount of the crankshaft and to derive center drill coordinates for removing the imbalance amount, a compensation unit mounted in a base frame and configured to compensate a position of the crankshaft by rotating first and second rotating elements based on the center drill coordinates inputted from the control unit when the crankshaft is transported and clamped by a clamping system, and a machining unit configured to machine the center groove in the pulley and the flange of the crankshaft.

A diagnostic system includes a tool to perform machining on a workpiece, a test piece to be subjected to test machining by the tool for abnormal detection, a sensor to generate sensor data representing a physical quantity generated in the test machining, and circuitry. The test piece is different from the workpiece. The circuitry controls the tool to perform the test machining in each cycle of machining on the workpiece and calculates a degree of abnormality from the sensor data of the test machining. The test machining is performed on the test piece under a test machining condition corresponding to a machining condition of the machining on the workpiece.

A diagnostic system includes a tool to perform machining on a workpiece, a test piece to be subjected to test machining by the tool for abnormal detection, a sensor to generate sensor data representing a physical quantity generated in the test machining, and circuitry. The test piece is different from the workpiece. The circuitry controls the tool to perform the test machining in each cycle of machining on the workpiece and calculates a degree of abnormality from the sensor data of the test machining. The test machining is performed on the test piece under a test machining condition corresponding to a machining condition of the machining on the workpiece.

A machine tool that visualizes the state of a ball screw in an easy-to-understand way includes a detector that detects at least one sensed value among vibrations, sound, and a current, heat, light, and power value applied to drive a ball screw during warming-up, a feature amount extractor that extracts a first feature amount and a second feature amount from the sensed value obtained by the detector, and a display that displays a point plotting the sensed value, and at least two boundaries laid out like contour lines to represent the possibility of generation of an anomaly in the ball screw, on a plane having a first axis defined by numerical values regarding the first feature amount and a second axis defined by numerical values regarding the second feature amount.

A machine tool that visualizes the state of a ball screw in an easy-to-understand way includes a detector that detects at least one sensed value among vibrations, sound, and a current, heat, light, and power value applied to drive a ball screw during warming-up, a feature amount extractor that extracts a first feature amount and a second feature amount from the sensed value obtained by the detector, and a display that displays a point plotting the sensed value, and at least two boundaries laid out like contour lines to represent the possibility of generation of an anomaly in the ball screw, on a plane having a first axis defined by numerical values regarding the first feature amount and a second axis defined by numerical values regarding the second feature amount.