An object is to provide a numerical control system of a machine tool which can check a parameter that needs to be adjusted for each of a spindle and a motor. A numerical control system of a machine tool includes a parameter check function unit for checking a drive control parameter of a spindle, and the parameter check function unit includes: an acceleration/deceleration time measurement unit which measures an acceleration/deceleration time that elapses after the spindle receives an acceleration command and/or a deceleration command until the completion of acceleration and/or the completion of deceleration; an acceleration/deceleration time specified value storage unit which stores a specified value of the acceleration/deceleration time that is previously determined for each specification of the machine tool; and a determination unit which compares the acceleration/deceleration time measured with the acceleration/deceleration time measurement unit and the specified value stored in the acceleration/deceleration time specified value storage unit so as to determine whether or not the drive control parameter of the spindle is proper.

A control apparatus of a machine tool including a feed axis, which is driven by a feed axis motor, includes a load torque estimation unit configured to estimate a load torque acting on a spindle motor, based on a torque command to the spindle motor which drives a spindle axis of the machine tool, and a speed of the spindle motor; and a speed control unit configured to control a speed of a feed axis motor such that the load torque estimated by the load torque estimation unit follows a prescribed load torque target value.

The present disclosure is directed toward a diagnostic method for a spindle arm of a machine. The method includes rotating the spindle arm of the machine at a first rotational speed, and acquiring, from an accelerometer, data indicative of a vibrational response of the spindle arm operating at the first rotational speed. The accelerometer is disposed along the spindle arm. The method further includes converting the vibrational response to a frequency based response to obtain a first frequency response, determining whether an amplitude of the first frequency response exceeds a diagnostic threshold, and performing a designated correction on the machine in response to the frequency response exceeding the diagnostic threshold.

A numerical controller decelerates a spindle feed rate in a bite portion to a bite velocity lower than a commanded feed rate when drilling is carried out and then, after passage through a velocity recovery point where a measured spindle load is made substantially constant, accelerates the spindle feed rate from the bite velocity to the commanded feed rate.

A drilling machine performs a feed operation while rotating a spindle, suspends the feed operation of the spindle for a predetermined dwell time at a predetermined hole bottom position, and then performs drilling by retreating the spindle. A controller for controlling the drilling machine calculates the dwell time based on a prescribed rotation amount in response to specification of the prescribed rotation amount (dwell rotation amount) at the hole bottom position.

Provided is a carbon fiber reinforced plastic machining method using CAM which includes the step (S10) of determining machining grade in accordance with a machining target and the step (S20) of determining machining grade in accordance with a machining process, in which the machining grade is a processing condition which is determined in accordance with the rotational speed and the feeding speed of a spindle as a machining tool.

A machine tool includes: a display; a tool configured to machine a workpiece; a spindle configured to rotate the tool or the workpiece; a sensor configured to detect a vibration frequency of the spindle or the tool; and a processor configured to control the machine tool. The processor is configured to: detect a chatter vibration in the spindle or the tool based on the vibration frequency; based on a frequency of the chatter vibration, a rotation speed of the spindle, and the number of cutting edges of the tool, calculate an order corresponding to the number of vibrations of the tool during a period of time until a current rotation angle of a first cutting edge of the tool reaches a current rotation angle of a second cutting edge of the tool; and present order information on the display, the order information indicating a magnitude of the calculated order.

Provided is a machine tool and a method for controlling the machine tool capable of precisely determine a success or a failure of a cut-off. An NC lathe performs a cut-off of a workpiece gripped by a first spindle and a second spindle and then performs a separation movement of the second spindle in a direction separating from the first spindle. The NC lathe includes a movement controlling unit adapted to perform a stop control of the first spindle at a command position of the first spindle during the separation movement of the second spindle and a cut-off success or failure determining unit adapted to monitor a positional deviation of the first spindle during the separation movement of the second spindle to determine a success or a failure of the cut-off, the positional deviation being a difference between the command position and an actual position of the first spindle.

A numerical controller includes: a vibration amplitude specifying unit for specifying an amplitude of a vibration component generated by a blade of a tool being brought into contact with a workpiece at a predetermined cycle, due to rotation of a spindle out of a spindle load; a gain calculating unit for calculating a gain of PID control such that an output of the feed speed is uninfluenced by the amplitude, based on the amplitude of the vibration component specified by the vibration amplitude specifying unit; and a speed control unit for outputting a feed speed of the spindle controlled by the PID control, by using the gain calculated by the gain calculating unit.

A numerical controller includes: a spindle load detection unit that detects time-series data on a load on a spindle when a workpiece is machined; a machining time setting unit that sets a machining time taken in machining the workpiece; a spindle load calculation unit that, based on the time-series data, calculates a load on the spindle applied when the workpiece is machined in the machining time set by the machining time setting unit and when a feed rate of the spindle is controlled so that the load on the spindle is a constant load; and a spindle load output unit that outputs data indicating the load on the spindle calculated by the spindle load calculation unit.