Method for Documented Tightening and Re-Tightening of a Screw Connection

摘要

In a tightening method for a screw connection of a bolt and a nut by using a tensioning device, a rotary drive, and a process control unit with documentation module, the nut is tightened with the rotary drive by a tightening moment required for the nut to bear against a support. The screw connection is elongated by exerting axial tension on a threaded end of the bolt protruding from the nut. The nut is further tightened while maintaining elongation, and a rotation angle covered during further tightening is detected by a rotation angle sensor. Lengthening of the bolt is calculated from the rotation angle and thread geometry of the screw connection. A longitudinal force in the threaded bolt is calculated from lengthening of the bolt, bolt diameter and bolt length. The calculated longitudinal force and an identifier identifying the screw connection are stored in the documentation module.