| 摘要 |
PURPOSE:To keep the operating oil pressure constant regardless of a stroke position by mounting a plurality of short and long strip of grooves on the inner surface of a cylinder in such a manner that working oil flows laminary. CONSTITUTION:A plurality of long and short grooves 1b are extended from the end portion 1a of the inner surface of a cylinder 1 on a chamber AC side. The grooves 1b are inclined at the same angle relative to the axial direction of the cylinder, and the shape of its section is, for example, triangle. A compressive force causes the working oil in the cylinder 1 to first pass through all the grooves and flow into the chamber AC. As a piston 2 advances into the cylinder 1, each end of the grooves 1b in the cylinder is successively closed by the piston 2. Therefore, during operations, the working oil pressure can be kep constant at any position of the piston 2. |
