BUFFER

摘要

PROBLEM TO BE SOLVED: To provide a buffer capable of preventing derailment during earthquake efficiently.SOLUTION: A buffer 1 of the invention for solving problems comprises; a cylinder 2; a piston 3 slidably inserted into the cylinder 2; a rod 4 inserted into the cylinder 2 and coupled to the piston 3; a rod side chamber 5 and a piston side chamber 6 defined by the piston 3 in the cylinder 2; a tank 7; an attenuation passage communicating the rod side chamber 5 and the tank 7 and having a normal time passage 8a and an emergency passage 8b arranged in parallel to the normal time passage 8a; and an attenuation valve V having a variable relief valve 20 and a normal close type opening/closing valve 21 disposed on a midway of the normal time passage 8a and a passive valve 22 and a normal open type opening/closing valve 23 disposed on a midway of the emergency passage 8b.