| 摘要 |
<p>A hydraulic control system for controlling a hydraulic actuator (A) comprising a pump (P) for supplying fluid to the actuator and a directional valve (11) for controlling the flow of fluid to the actuator. The directional valve (11) includes a poppet piston (13) that provides a variable orifice (14). The position of the poppet piston (13), is controlled by a pilot flow controlled by a pilot valve (18) which may be controlled by a solenoid controller (5). The flow out of the pilot valve (18) is connected to the outlet of the directional valve (11). A pressure compensator (25) is provided between the inlet (10) to the directional valve (11) and the pilot valve (18) and maintains the pilot flow to the pilot valve constant. The pressure of fluid being applied to the actuator (A) by the directional valve (11) is also sensed and caused to produce a force opposing the opening force applied to the pilot valve (18) to result in a smooth and accurate control of the load. <IMAGE></p> |
