| 摘要 |
<p>A pressure-compensating directional control valve, particularly for actuating hydraulic actuators, of the type that comprises at least one modular valve body (2), which is affected by at least one through receptacle (3) for at least one shuttle (4) which can slide bidirectionally, by at least one driving fluid delivery port (14) connected to a pump, by at least one discharge port (15) for the fluid, by at least one first output-opening (16) and by a second output opening (17), which are connected respectively to the first chamber and to the second chamber of a hydraulic actuator, the shuttle (4) being controlled by remote operation means and being adapted to selectively connect the delivery port (14) to the first output opening (16) and the discharge port (15) to the second output opening (17) and vice versa, in the valve body (2) there being further at least one bridge (22) for the selective communication, by way of the shuttle (4), of the delivery port (14) with the first chamber or with the second chamber of the actuator, so as to actuate the actuator in one direction or the other; the valve further comprises at least one unidirectional hydrostat (23), which is connected to the bridge (22) by means of a supply duct (24) and is adapted to draw selectively a pressure signal of the load (LS) of the actuator, the signal (LS) being designed to adjust selectively the delivery pressure of the pump so as to keep substantially constant the pressure drop between the delivery port (14) and the actuator in any load condition.</p> |
