Provided is a numerical controller capable of shortening cycle time while maintaining machining accuracy of a rigid tap. The numerical controller includes: a rigid tap control unit that executes a rigid tap by synchronizing rotational speed of a spindle with feedrate; a synchronization error monitoring unit that starts or terminates monitoring of a synchronization error between the rotational speed of the spindle and the feedrate at a point R set to a height equal to or higher than a top of a workpiece; and a workpiece top detection unit that detects a position of the workpiece top. The synchronization error monitoring unit starts monitoring the synchronization error at the position of the workpiece top instead of the point R.

A method of configuring a machine (201) for production of a thread, having a pitch (227), on a workpiece (310), the machine (201) comprising: a tool (220) having a thread (223) centred on a first axis (250) and comprising one or more thread-producing peaks (225) for producing the thread having the pitch (227); and a tool holder (210) holding the tool (220), the method comprising: determining a first distance (441), in a first direction (260) parallel to the first axis (250), from a reference position (412) of the tool holder (210) to a first thread-producing peak (226) on the tool (220) when said tool (220) is held in the tool holder (210); and setting a first configuration (401) of the machine (201) wherein the reference position (412) of the tool holder (210) has a displacement (440) parallel to the first axis (250) from a reference position (411) of the workpiece (310) depending only upon: the determined first distance (441); a translation (443) parallel to the first axis (250) to account for an angular offset (340) between the first thread-producing peak (226) and a desired thread start position (311) on the workpiece (310); and an integer multiple (444) of the pitch (227).

A machine learning device includes: a state information acquisition unit configured to cause the control device to execute a tapping program to acquire from the control device, state information including a torque command value with respect to the spindle motor, a drive state including deceleration, a ratio of a movement distance in acceleration and a movement distance in deceleration; an action information output unit configured to output action information including adjustment information of the ratio of the movement distance in acceleration and the movement distance in deceleration, to the control device; a reward output unit configured to output a reward value in reinforcement learning based on a torque command value in deceleration, and a target torque command value in deceleration; and a value function update unit configured to update an action value function based on the reward value, the state information, and the action information.

A controller for controlling a synchronized operation of spindle and feed axes. A spindle-axis control section includes an initial-motion control section for accelerating a spindle axis from a starting position; a maximum-acceleration detecting section for detecting a maximum acceleration of the spindle axis during acceleration; a residual rotation-amount detecting section for detecting a residual rotation amount of the spindle axis; a current-speed detecting section for detecting a current speed of the spindle axis; a decelerating-motion control section for decelerating the spindle axis to reach an intermediate speed, after the acceleration; a positioning-motion control section for decelerating the spindle axis to reach the target position after reaching the intermediate speed; and a torque-command limiting section for limiting a fluctuation of a torque command of the position control, instructed to the spindle axis, to a predetermined range over a period until a predetermined elapse condition is satisfied after reaching the intermediate speed.

Provided is a numerical controller capable of shortening cycle time while maintaining machining accuracy of a rigid tap. The numerical controller includes: a rigid tap control unit that executes a rigid tap by synchronizing rotational speed of a spindle with feedrate; a synchronization error monitoring unit that starts or terminates monitoring of a synchronization error between the rotational speed of the spindle and the feedrate at a point R set to a height equal to or higher than a top of a workpiece; and a workpiece top detection unit that detects a position of the workpiece top. The synchronization error monitoring unit starts monitoring the synchronization error at the position of the workpiece top instead of the point R.

A numerical control device comprising an acceleration/deceleration characteristic acquisition part which acquires predetermined acceleration/deceleration characteristic information showing a correspondence between a command speed and a maximum acceleration of a spindle, a rotation amount acquisition part which acquires predetermined rotation amount information showing the rotation amount of the spindle for a period from when feed operation of the spindle is started to when a tapping tool reaches a bottom of the hole of a workpiece, a machining time calculation part which calculates a correspondence between the command speed and a machining time required to reach the rotation amount, based on the acceleration/deceleration characteristic information and the rotation amount information, and a speed determination part which determines an optimum value of the command speed for minimizing the machining time, based on the correspondence calculated by the machining time calculation part.

A machine tool controller including a numerical control section, a spindle-axis control section and a feed-axis control section. The spindle-axis control section includes a section for making the spindle axis perform an accelerated rotation at maximum capacity from a process start position toward a target thread depth, with a maximum rotation speed set as a target value; a section for detecting a maximum acceleration during the accelerated rotation based on a rotational position; a section for detecting a residual rotation amount from a current position to the target thread depth, based on a total rotation amount and the rotational position; a section for detecting a current speed based on the rotational position; and a section for making the spindle axis perform a decelerated rotation at maximum capacity to reach the target thread depth after the accelerated rotation, based on the maximum acceleration, the residual rotation amount and the current speed.

The invention relates to methods for producing a thread with a predetermined thread pitch in a workpiece.