STOPPER

摘要

PROBLEM TO BE SOLVED: To provide a stopper capable of effectively preventing derailment in an earthquake.SOLUTION: A stopper S includes: a cylinder 1; a rod 2 freely inserted into the cylinder 1; a piston 3 connected to the rod 2 and freely slidably inserted into the cylinder 1 to form an extension side chamber R1 and a pressure side chamber R2 to be filled with fluid in the cylinder 1; a pressure side passage 4 communicating the pressure side chamber R2 with the extension side chamber R1; an extension side passage 5 communicating the extension side chamber R1 with the pressure side chamber R2 and allowing only fluid flow directing from the extension side chamber R1 to the pressure side chamber R2; and a relief valve 6 allowing only fluid flow directing from the pressure side chamber R2 to the extension side chamber R1 in the pressure side passage 4 and reducing a valve opening pressure by displacement from an ultimate extension position of the piston 3 to the cylinder 1 to a direction of compressing the pressure side chamber R2.