T. Toyozawa, NIPPON STEEL CORPORATION, FUTTSU-CITY, Japan
The overhead traveling crane in the factory runs on the tracks over hundreds of meters in order to suspend various heavy loads. In general, these tracks are consisted of the rails of ten meter length each, connected by the joints with bolts and splice plates. This bolt joint can be constructed easily and rapidly, however it cannot prevent from occurring a joint gap. Each time the crane runs over a joint gap, the impact are generated to cause a dent on rail. The bigger a dent grows, the higher a impact is, and vice versa. Consequently, renewal of all rails are needed when this impact causes serious damage on the crane device. Therefore, the joint without a gap is required to prolong the lifetime of tracks. Though weld can be an example of the joint without a gap, it doesn’t become popular because of long construction time and necessity of skilled welder.In this paper, we introduced new kind of joint without a gap we developed; it doesn’t need long construction time and skilled welder. The contrivance of this new joint is only that splice plates are changed from usual steel into Fe-Mn-Si shape memory alloy transformed by tensile beforehand. These splice plates are shrank by heat up and a gap disappears from the joints.
