| 摘要 |
PURPOSE:To maintain durability and prevent the increase of length by providing a damping valve at the downstream end of a valve seat member, and changing the initial load of the damping valve by the sliding motion of the pressure chamber of the valve seat member at the time of being supplied with first-order lag oil pressure. CONSTITUTION:At the expansion stroke time, operating oil in an expanding side oil chamber A flows into a valve case member 6 through the expanding side port 3a of a piston 3 and a communicating hole 6b, reaches the pressure receiving face side of an expanding side damping valve 4 through the port 7a of a valve seat member 7 and flows out into a pressing side oil chamber while bending the outer peripheral end of the valve 4 with oil pressure so as to generate the specified damping force at the valve 4. In the case of oscillation frequency in a cylinder 1 at this time being in a low oscillation frequency region, the operating oil passes through an orifice 12a upstream of a pressure chamber R, and first-order lag oil pressure is generated in the pressure chamber R. An O-ring 9 thereby recedes, and a pressing member 11 series- connected to the O-ring 9 slides to bend the outer peripheral end of the valve 4, thus changing the expanding side damping force generated at the valve 4 into the high damping force tendency. Machining for lowering the strength of a piston rod is thereby dispensed with while preventing the increase of length. |
