Hydraulic threaded bolt clamping device and method for tightening large screws by means of said hydraulic threaded bolt clamping device

摘要

A hydraulic threaded bolt clamping device for tightening and releasing threaded bolts has a pressure medium supply connected to a pressure medium connector. A cylinder rests against a machine part that is to be clamped and a periodically pressure-loaded piston is guided seal-tightly in the cylinder and rests against a threaded bushing screwed onto the threaded bolt. A control device actuates the pressure medium supply for supplying pressure medium to the bolt clamping device. After a nominal value corresponding to a nominal prestressing force has been reached the pressure medium supply is switched off. The nominal screw prestressing force or a corresponding nominal pressure of the pressure medium supply is preset by an input device. A measuring device measures relative displacement of the threaded end of the bolt relative to the cylinder. An evaluation device determines residual actual screw prestress after pressure relief of the bolt clamping device.