| 摘要 |
<p>In a combined control valve for controlling a pressure medium flow delivered by a hydraulic pump to a pressure medium circuit with an open centre and to at least one pressure medium circuit with a closed centre, a housing having an inlet port connected to the hydraulic pump, a first outlet port connected to the pressure medium circuit having an open centre, a second outlet port connected to a hydraulic accumulator and to the pressure medium circuit having a closed centre, a third outlet port connected to a make up reservoir, and auxiliary valve controlling a passage between the inlet port and the third outlet port in dependance on the pressure in the second outlet port, passage means connecting the inlet port to the second outlet port via a one-way valve. A normally closed control valve is subjected on the one hand to the pressure in the inlet port and on the other hand to the pressure in a control chamber, said control valve opening on a predetermined difference between such two pressures.</p> |
