Hydraulic bolt tensioning device and method for tightening large bolts by means of a hydraulic bolt tensioning device

US8302509B2 · kind B2 · utility

Inventors

• Frank Hohmann · Warstein, DE
• Jörg Hohmann · Meschede, DE

Key dates

• Filing date: Aug 30, 2010
• Grant date: Nov 6, 2012
• Expiry date: Jun 14, 2031

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F16B31/043
• WIPO field: Machine tools
• WIPO sector: Mechanical engineering

Abstract

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.