In a method of machining a workpiece (60) having first and second gearings (61, 62), a reference tooth structure of the first gearing (61) is identified. The reference tooth structure is then measured with a reference measuring device (140) to determine a reference rotational angular position of the workpiece. Subsequently, the second gearing (62) is machined in such a way that the second gearing obtains a rotational angular position which is in a predetermined relationship to the determined reference rotational angular position.

A machining device threads a workpiece by relatively rotating the workpiece and a multi-blade tool and relatively moving them along a feed direction to perform cutting processes in the radial direction of the workpiece along the same cutting path in a predetermined spiral form. A controller performs a groove machining to form a threaded portion with vibration in the radial direction of the workpiece and a finish machining to form the threaded portion by bringing the multi-blade tool into contact with the grooved portion of the workpiece. The multi-blade tool has a first cutting blade and a second cutting blade arranged side by side along the feed direction. The controller sets amplitude of a vibration waveform to a value at which a cutting edge of the second cutting blade does not come into contact with the screw bottom surface of the workpiece in the finish machining.

Disclosed are threading device and threading method, including a turning step for threading a rotating workpiece with a predetermined cutting depth, by relatively moving a tool in the axial direction of the workpiece and then rounding-up the workpiece obliquely by relatively moving the tool in the axial direction and radially outward. The workpiece is subjected to the threading process by repeatedly carrying out the turning step while sequentially shifting the axial position for starting the rounding-up of the workpiece relative to an axial position where the rounding-up of the workpiece has been started in a previous turning step.

Provided are a control device and a control method for a machine tool which are capable of further reducing a command-waiting time. This control device for a machine tool which controls synchronized operation of a main shaft and a feed shaft comprises: a numerical value control unit; a main shaft control unit; a rotation detection unit. The numerical value control unit has a main shaft command output unit which, when a cutting operation and pulling-out operation are carried out from a machining start position to a target position an arbitrary number of times, acquires from the tapping program the rotation amount and the maximum rotation speed of the main shaft in the cutting operation and pulling-out operation and which supplies the rotation amount and the maximum rotation speed of the main shaft to the main shaft control unit as the main shaft command.

A turning thread automatic diagnosing method includes collecting a spindle actual speed and a feeding shaft actual speed of a lathe; based upon the spindle actual speed and the feeding shaft actual speed, continuously calculating thread errors to obtain a thread error curve; and analyzing an error cause according to the thread error curve. In addition, a turning thread automatic diagnosing system is disclosed, using the method. A data processing system and a storage medium are also disclosed. The technology of the embodiments can automatically identify the problem causing a thread error and provide a corresponding solution.

A machine tool according to the disclosure has a spindle rotatably holding a cylindrical workpiece, a turret holding a thread whirling tool having a cutter ring having a base on which a through hole is formed and a plurality of types of cutting tools disposed on the inner diameter side of the base and having different shapes, so as to rotatably holds the cutter ring, a controller controlling rotations and relative movements of the spindle and the turret, wherein the controller has the spindle hold a workpiece, disposes the workpiece in the through hole so that the workpiece penetrates the through hole, rotates at least one of the cutter ring and the workpiece, and switches movements of the thread whirling tool in an extending direction of the workpiece and a direction intersecting with the extending direction thereof based on a selected predetermined cutting tool.

A method and a device are provided for simplifying a flow-hole screw process, in which the difference between a process parameter and its smoothed value is employed as a criterion for changing said process parameter or another process parameter in order in particular to be able to determine the changeover point between hole forming and thread forming.

A method for machining and measuring workpieces includes: machining a workpiece by a gear cutting process, wherein a tooth flank of the workpiece is produced or machined; measuring an actual geometry of the tooth flank produced by the gear cutting process by a measuring process; determining a deviation of the actual geometry from a predetermined nominal geometry of the tooth flank; determining a corrected gear cutting process for at least partially reducing the deviation; and machining the workpiece and/or a further workpiece by the corrected gear cutting process. The determination of the corrected gear cutting process for at least partial reduction of the deviation has the specification that a distinction is made between first and second evaluation areas of the tooth flank, wherein first and second permissible deviations of the actual geometry from the nominal geometry is specified for the evaluation areas of the tooth flank, respectively.

The invention relates to a method for producing or machining, by cutting, an identical set of teeth on each of a plurality of workpieces, in particular at least 4 workpieces, of a workpiece batch on one or more gear-cutting machines (100) having a gear-cutting tool (S), which has a set of teeth having rake faces (5) and having an axis of rotation (B1), in rolling machining engagement, in which method, in the event that a deviation of a set of teeth from the tooth profile sought for said set of teeth is detected or expected, a countermeasure that counteracts said deviation is determined and the production/machining of additional workpieces of said workpiece batch is continued using the countermeasure, the countermeasure being, at least in part, a change in the position of the rake faces relative to the axis of rotation of the tool, which change is brought about by means of grinding performed on the gear-cutting machine or at a grinding machine (140) that belongs to the machine group of the gear-cutting machine.

A control device for a machine tool in which a tool used to machine a workpiece is mounted to a main spindle that is relatively movable with respect to the workpiece. The control device includes: a parameter preparing unit that stores a predetermined parameter regarding a control in advance; an evacuation unit that causes the tool to perform an evacuation operation from the workpiece; and a chip discharging unit that causes the tool to perform a chip discharging operation. The evacuation operation of the tool by the evacuation unit and the chip discharging operation by the chip discharging unit are performable at respective predetermined timings.