Bolt-nut fastening mechanism

Abstract

Clearance can be secured, the thrust of a bolt provided with a left-hand external screw thread is stabilized and the costs of component members are reduced in attaching a steering member to a body frame. A bolt-and-nut fastening mechanism includes a right-hand boltprovided with a metal-to-metal contact locking mechanismon a threaded part, a left-hand boltprovided with an internal screw threadwith which the bolt engages, and a fixing nutcapable of engaging with the left-hand screw threadof the left-hand boltor a memberprovided with an internal screw thread with which the left-hand screw threadof the left-hand boltengages. The locking mechanismof the boltthrusts the left-hand boltforward so that the gap between the top surfaceof the head of the left-hand bolt and an inner panelis narrowed, and the head of the left-hand boltcomes into contact with the inner panelto define a clearance between a body frame and the bracketof a steering member. The boltis screwed into the left-hand boltand the base surfaceof the bolt comes into contact with an outer panelto produce a fastening force. The fastening force is transmitted through the left-hand boltto attach the steering member. A welded nutmay be omitted and an internal screw threadwith which the left-hand bolt engages may be formed in the bracketof the steering member.