| 摘要 |
PROBLEM TO BE SOLVED: To suppress a collision of a piston rod to a stopper rubber at a stroke end, and to reduce the impact at the time of the collision. SOLUTION: A hydraulic shock absorber is fitted with a piston 17 united with a piston rod 18 in a cylinder 14. Extending side/contracting side high pressure relief valves 27, 23 are provided on a guide seal 19 and a base valve 16, and extending side/contracting side sub low pressure relief valves 44, 45 are provided on the piston 17, and extending side/contracting side main low pressure relief valves 37, 36 are provided on annular members 33, 32. Usually, low damping force is generated by the main low pressure relief valves 37, 36. When stroke is enlarged, the piston 17 blocks annular grooves 28, 29, so that the extending side/contracting side high pressure relief valves 27, 23 generate high damping force to suppress a collision to a stopper rubber. At a stroke end, the extending side/contracting side sub low pressure relief valves 44, 45 of the piston 17 generates low damping force through the grooves 48, 49 to reduce the impact to the stopper rubber at the time of the collision. |
