Method for producing a thread on at least one end of at least one metal tube and thread-cutting facility

A thread-cutting facility for producing threads at ends of metal tubes, comprising:

• a CNC machine tool (2) for machining a metal tube (3) to be provided with threads;
• a control device for implementing control commands to the machine tool (2);
• a device for optical measurement of the cut thread;
• a closed-loop control unit for deriving control commands from measurement data generated by the device for optical measurement,
• wherein the device for the optical measurement is coupled to the control device, and
• wherein the device for the optical measurement includes
• a measurement head with two opposing legs,
• each of the two opposing legs comprising a U-shaped frame arranged around the metal tube, with
• a camera and
• a light source positioned opposite the camera
• being arranged in each of the two opposing legs to form a respective measuring section across each U-shaped frame,
• wherein the measuring head is linearly movable, by a recirculating ball screw or a lantern pinion, relative to a carrier and pivotable about at least one axis, and
• wherein a first of the two legs of the measuring head is stationary relative to the measuring head and a second of the two legs is adjustable relative to the first of the two legs.

A thread-cutting facility for producing threads at ends of metal tubes, comprising:

• a CNC machine tool (2) for machining a metal tube (3) to be provided with threads;
• a control device for implementing control commands to the machine tool (2);
• a device for optical measurement of the cut thread;
• a closed-loop control unit for deriving control commands from measurement data generated by the device for optical measurement,
• wherein the device for the optical measurement is coupled to the control device, and
• wherein the device for the optical measurement includes
• a measurement head with two opposing legs,
• each of the two opposing legs comprising a U-shaped frame arranged around the metal tube, with
• a camera and
• a light source positioned opposite the camera
• being arranged in each of the two opposing legs to form a respective measuring section across each U-shaped frame, and
• wherein the measurement data used for deriving the control commands is obtained two or more cycles after machining the metal tube in the CNC machine tool.