Pipe cutting machine with a controlled floating cutting mandrel, and cutting method

Pipe cutting machine with a pipe (3), from which a pipe section (3a) is to be cut to size, a stationary cutting die (1), a movable cutting die (2) which can be moved relative to the stationary cutting die (1), and a cutting mandrel (13) which is introduced into the pipe (3) and which comprises a stationary mandrel (14) and a mandrel (16) that can be moved relative to the stationary mandrel (14), wherein the cutting mandrel (13) is arranged in a cutting position in a floating manner,

• characterised in that the cutting mandrel (13) is arranged in the pipe (3) in a floating manner, and
• a magnetic coupling (6) is provided with a coupling stator (7) arranged outside of the pipe (3) and a coupling rotor (21) arranged on the stationary mandrel (14), and a movement of a magnetic field of the magnetic coupling (6) in a longitudinal direction (L) can be controlled using control values, and
• a position sensor (8) has a sensor stator (12), which is connected to a frame in a fixed position, and a sensor rotor (19), which is connected to the stationary mandrel (14) in a fixed position, said position sensor being used to measure deviations of the cutting mandrel (13) from the cutting position, and a control unit converts deviation measurement values into the control values, by means of which the cutting mandrel (13) can be returned to the cutting position.