| 摘要 |
<p>In a high pressure hydraulic system wherein a source supplies pressurized fluid to a slave unit through a control valve operative to maintain the slave unit in a desired condition, leakage from the slave unit past the control valve when the source is inoperative is prevented by a control valve comprising two solenoid-operated valves, oppositely acting and arranged in series between the source and the slave unit, each valve being closed to prevent flow through the valve in a direction towards the other valve and opened to permit flow in both directions, under the control of a solenoid and the pressure differential acting across the valve. A seating portion on the valve located between the other valve and the slave unit is of elastomeric material to provide a leakproof seal when that valve is closed. In the construction shown the slave unit is an hydraulic suspension strut, and the system is adapted as a vehicular suspension levelling system, with the valves and the source being manipulated as required by an electronic control system.</p> |
