| 摘要 |
PURPOSE:To avoid an abnormal increase of the resistance even though the piston speed is made higher by providing a flexible ring body with a penetrated hole between the oil area partition material and the disc valve. CONSTITUTION:When the piston speed is made higher during an extension stroke, the resistance is determined by the total area of the opening of the penetrated hole 4a of the ring body. The ring body is formed with metal plate, the spring constant of which is higher than that of the disc valve 7, so that the ring size is less than the total area of the opening, which is formed under the valve seat 3d, and is greater than the total area of the opening of the penetrated hole when the ring body is flexed. In this way, the outer circumference of the ring body is flexed downwards by oil pressure greater than a fixed value, and is separated from the valve seat of piston to avoid an unusual increase of the resistance. |
