| 摘要 |
PURPOSE:To obtain desired high cut action from a low piston speed region to a high piston speed region by providing a pressure receiving part displaced to a side where a contraction area is reduced with fluid pressure in a demarcated chamber received in a variable restrictor for cutting between the demarcated chamber and a pressure receiving chamber. CONSTITUTION:Since fluid pressure on an upper part fluid chamber A side becomes high with an increase in speed of the operation of a piston 2, even when the vibration frequency of fluid pressure on the upper part fluid chamber A side has a fixed value or more, the flow possible quantity of fluid per unit area in an extension side variable restrictor b1 increases, and this acts so as to increase the transmission quantity of the fluid pressure on an extension side pressure receiving chamber D1 side. Meantime the rise of the fluid pressure, on the upper part fluid chamber A side and acting on the upper surface of a valve part 14c, causes the downward bending of the middle part to reduce an interval h2 to the upper end opening edge part of a middle hole 16a in an extension side sheet plate 16, and resulting in the reversely proportional reduction of the opening area of the extension side variable restrictor b1, consequently the increase part of flow possible quantity per unit area, based on the rise of fluid pressure, is offset with the reduction part of the opening area. |
