| 摘要 |
Disclosed is a hydraulic system for utility vehicles, in particular agricultural tractors, for supplying primary and auxiliary pressure medium consumers ( 7, 12, 13 ) with different system pressures, which exceed the load pressure by a pre-determined control pressure differential. In order to produce a first control pressure differential for operating a primary pressure medium consumer, its load pressure is used directly for building up the system pressure and in order to produce a second, higher control pressure differential for operating an auxiliary pressure medium consumer ( 12,13 ), its load pressure is converted in an amplifying device ( 34 ) to an increased pressure, which is used for building up a higher system pressure. In order to obtain rapid response of an actuated auxiliary pressure medium consumer, it is proposed that the amplifying device ( 34 ) consists of a pressure reducing valve ( 35 ), which is permanently adjusted to a pre-determined reduced pressure and has a first pressure inlet ( 38 ), a second inlet ( 39 ), an outlet ( 40 ) and a control piston ( 42 ), whereby a line ( 5 ) conducting the system pressure is connected to the pressure inlet ( 38 ), a load reporting line ( 33 a) conducting the load pressure of the auxiliary pressure medium consumer ( 12, 13 ) is connected to the second inlet ( 39 ) and a load reporting line ( 41 ) subjecting the pressure control valve ( 14 ) to increased load pressure is connected to the outlet ( 40 ) and the control piston ( 42 ) is subjected on its one side to the force of a permanently adjusted spring ( 43 ), which determines the pre-determined reduced pressure as well as the load pressure of the auxiliary pressure medium consumer ( 12, 13 ) prevailing at the inlet ( 39 ), and on its other side to the pressure at the outlet ( 40 ).
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