| 摘要 |
<p>A piston (19) inserted into a cylindrical housing (2) is connected to a clamp rod (5). A lock chamber (20) is provided above the piston (19), and an annular valve chamber (41) is formed in a peripheral wall of a rod hole (18) into which the clamp rod (5) is inserted. At a last stage of swing ascending of the clamp rod (5), a shuttle member (42) fitted at the outside of a lower portion of the clamp rod (5) ascends and fits into the valve chamber (41) due to a differential pressure of a pressurized oil applied when the shuttle member (42) starts to fit into the valve chamber (41). Then, a flow rate of the pressurized oil to be discharged from the lock chamber (20) is controlled by a restriction gap between the shuttle member (42) and the clamp rod (5). At an early stage of swing descending of the clamp rod (5), a flow rate of the pressurized oil to be supplied to the lock chamber (20) is controlled by a restriction gap between the valve chamber (41) and the shuttle member (42).</p> |
