| 摘要 |
PURPOSE:To enable to display a constantly appropriate damping force by a method wherein a check valve is provided at an upper part of a sheet pipe, and a defficiency of a hydraulic oil in an upper hydraulic chamber is compensated for by supplying the oil from an oil reserving chamber to eliminate a negative- pressure. CONSTITUTION:A check valve casing 33 is provided at the upper end of the sheet pipe 13 in an outer tube 11, and the check valve 34 having a pressing spring 36 inside the casing 33. Hydraulic chambers C, A are communicated to each other by an oil hole 32, an oil passage 37 and an oil hole 31 through the valve 34. When a piston 18 moves at high speed and the amount of the oil flowing into the chamber A is insufficient so that a negative-pressure tends to develop in the chamber A, the valve 34 is opened against the pressing spring 36, and the oil in the chamber C flows into the chamber A through the oil hole 32, the oil passages 35, 37 and the oil hole 31 to compensate for the defficiency of the oil. Accordingly, generation of a negative-pressure in the hydraulic chamber A can be prevented and the reduction in the damping force can be prevented. |
