| 摘要 |
PROBLEM TO BE SOLVED: To improve damper characteristics of a hydraulic damper for performing a contraction operation from the most extended state.SOLUTION: A hydraulic damper 1 filled with compressive hydraulic oil (silicon oil) includes: a rod 12 to which a load is input from one end side; a piston 15 connected to the other end side of the rod 12; a head 16 that the rod 12 passes through; and a cylinder tube 11 forming an oil chamber 112 filled with the hydraulic oil between the rod 12 and the head 16. The piston 15 includes: an outer circumferential surface 115 facing the cylinder tube 11; a back surface abutted on the head 16 to regulate the movement of the rod 12; and an oil lead space 100 where a working pressure of the oil chamber 112 acts by an oil lead groove opened over the outer circumferential surface 115 and the back surface. The change of a pressure receiving area of the piston which receives the working pressure of the oil chamber 112 between the most extended state in which stroke is zero and a contraction operation state in which the stroke is not zero is suppressed, and force needed for starting the movement of the rod is suppressed. |
