| 摘要 |
PURPOSE:To make damping characteristic arbitrarily settable in a very low speed region with the linear damping characteristic obtained for a piston speed by providing a high damping valve, having in series a plurality of valve seats in the first communication path, and urging a spool in the second communication path parallel to this first communication path in a reverse direction to the pressure receiving direction. CONSTITUTION:A cylinder 1 is divided into an upper part chamber A and a lower part chamber B by a piston 2, and the first seat surface and an extension side first-step damping valve 7 are provided in the lower end part of an extension side communication path 2c, while the second seat surface and a damping valve 8 are provided in the outside of the path 2c. In a spool hole 13a, a spool 19 is vertical direction slidably provided by partitioning a pressure receiving chamber D1 in an upper surface side of the spool hole, and an annular groove 19a for connecting upper and lower side communication holes 13d, 13e to communicate is formed with an extension side variable throttle 30 formed between the communication hole 13d and the annular groove 19a. Since the damping force characteristic in a low speed operation region is set by a low damping valve and that in a high speed operation region is set by a high damping valve, the damping force characteristic can be easily and arbitrarily set from the very low speed operational region to the high speed operational region. |
