Abstract
It is known that the center pin of a car body strikes strongly against the lateral displacement stopper of the bogie when the vehicle vibrates widely in the case of earthquake motion with a predominant frequency of over 1.4 Hz. During such movement, and due to considerably large wheel/rail lateral force and bogie rolling, etc., there is a risk of the wheel jumping to a height above the wheel flange, which in turn may result in derailment. It is thought that larger gap between the lateral displacement stopper and the center pin will improve running safety by buffering the strong impact against the lateral displacement stopper and because of a better vibration-damping effect of the lateral damper. Running safety effectively improves using a specially designed anti-seismic lateral damper which can provide large damping forces during a major earthquake. Accordingly, in this research, for the purpose of improving running safety in the case of an earthquake, a crushable lateral displacement stopper was developed with the same nominal gap from the center pin as currently used devices, in the normal condition, but which can expand in the case of a strong impact due to a large earthquake, in order to ensure vehicle running stability and quality. The crushable stopper is designed to be used together with a specially designed anti-seismic lateral damper. RTRI developed a mechanical crushable stopper with a mechanical fuse for the movement mechanism in order to expand gap in abnormal conditions, in such an earthquake. The seat of the lateral displacement stopper rubber gets displaced in the same direction as the expanding gap, if a fixed load (a setting load of a movement) acts on the stopper.
