Patent attributes
The present invention relates to a bolt structure including: a base bolt having one side end portion inserted into holes formed at the time when a fixed structure and an object to be fixed are laid on top of each other; a core bolt adapted to be advanceably and retreatably screw-coupled to the base bolt; a nut fastened to the end portion of the base bolt protruding from the holes to maintain the state where the fixed structure and the object to be fixed are laid on top of each other; locking units adapted to selectively pressurize the external surface of the nut to prevent the escape of the base bolt; and a restraint unit adapted to be advanceably and retreatably screw-coupled to the base bolt and come into contact with the end portion of the core bolt to restrain the advancement and retreat of the core bolt.