LOCK NUT, AND LOCKINGLY TIGHTENING STRUCTURE USING THE LOCK NUT

摘要

One set of lock nuts (10) used in combination with a bolt (50) capable of being easily and surely locked with a simple structure and a lockingly tightening structure using the nuts, the nuts characterized in that a fitting recessed part (25) of circular shape in plane view is provided in one nut (20) around a screw hole (23) allowing the bolt (50) to be screwed thereinto, a fitting projected part (35) to be fitted to the fitting recessed part (25) is provided on the other nut (30) around a screw hole (33) allowing the bolt (50) to be screwed thereinto, and a fitting axis (41) as the center axis of a fitting part (45) formed by fitting the fitting recessed part (25) onto the fitting projected part (35) and screw holes (40) and (40) as the center axes of the screw holes in one and the other nuts are provided at positions eccentrically by a same amount from the fitting axis (41).