Hydraulic type screw thread bolt tightening device and method for tightening large-diameter screw using hydraulic pressure screw bolt tightening device

摘要

PROBLEM TO BE SOLVED: To provide a hydraulic thread bolt fastening device capable of preventing the breakage of a thread bolt and fastening and removing a highly loaded screw, and a method for controlling a pressure load of the hydraulic thread bolt fastening device.;SOLUTION: The hydraulic thread bolt fastening device includes a device (10) for detecting that the thread bolt reaches a yield point during the fastening of the thread bolt, and control devices (7, 11) for pressure-releasing the thread bolt fastening device (1) when reaching the yield point of the thread bolt to be fastened or immediately after the reaching.;COPYRIGHT: (C)2011,JPO&INPIT