Hydraulic Bolt Tensioning Device and Method for Tightening Large Bolts by Means of a Hydraulic Bolt Tensioning Device

摘要

A hydraulic bolt tensioning device has a cylinder supported on a machine part that is to be clamped by threaded bolt and nut. An exchangeable bushing has a first end screwed onto a free threaded end of the threaded bolt that projects past the nut. A tensioning piston is seal-tightly guided in the cylinder and supported on a second end of the exchangeable bushing. A pressure medium is supplied into an annular space between cylinder and piston. A control device is provided for setting a nominal pressure of the pressure medium corresponding to a nominal pretension of the threaded bolt. A yield limit detection device detects whether a yield limit of the threaded bolt is reached during tensioning. A controller acts on a pressure relief device for pressure relief of the bolt tensioning device when reaching, or shortly after reaching, the yield limit of the threaded bolt.