| 摘要 |
<p>A hydraulic circuit 22 has a first node 68 and a second node 74. A first control valve 60 creates a first path between the first node 68 and a pump supply line 54 in a first position, and a second path between the first node 68 and a tank return line 58 in a second position. A second control valve 84 has a first port 82 coupled to the second node 74 and a second port 83 connected to a first chamber 34. A pilot operated check-valve 100 controls a path connected to a valve port 101. In a deactivated state, fluid can flow through the path only from the valve port toward a second chamber 32. In an activated state fluid can flow through the path in both directions. Pressure at the first node 68 exceeding a predefined threshold activates the pilot operated check-valve 100. A pressure control device 70 manages pressure at the valve port 101 selectively to pressure derived from the first node 68 or pressure in the tank return line 58.</p> |
