BOLT FASTENING STRUCTURE

PROBLEM TO BE SOLVED: To provide a bolt fastening structure capable of being simplified and surely carrying out a detent function. SOLUTION: In this bolt fastening structure, a rail 1 is fastened to a floor board 2 with bolts 3 and nuts 4. Through holes 15 for inserting bolt shafts and heads are formed at the floor board 2 to which the bolt heads are fixed, and circumferences of the through holes 15 are cut corresponding to the shape of the bolt head, to form the recessed portions 16 capable of allowing the bolt heads to be rotated in the nut fastening direction or the nut unfastening direction on shaft centers of the bolt shafts with the symmetric shape on the shaft centers through the through holes 15. The recessed portions 16 formed by being cut corresponding to the shape of the bolt head are formed in a state of partially remaining the circumference of the through hole 15, and thus the recessed portions 16 can allow the bolt head to be rotated in the nut fastening direction or the nut unfastening direction at an angle of less than 180 degrees on the shaft center of the bolt shaft. COPYRIGHT: (C)2007,JPO&INPIT