Control arrangement for at least two hydraulic consumers and pressure differential valve for said control arrangement

A control arrangement for supplying pressure medium to at least two hydraulic consumers (14, 15, 16) comprising

• a variable-displacement pump (10) which is controlled according to required flow and a setting of which is variable as a function of highest load pressure of actuated said hydraulic consumers (14, 15, 16), by a pump controller (11),
• two displaceable meter-in variable restrictors (17, 18, 19), a first of which is arranged between a feed line (13), which leads from the variable-displacement pump (10), and a first hydraulic consumer (14, 15, 16), and a second of which is arranged between the feed line (13) and a second hydraulic consumer (14, 15, 16), and
• two pressure compensators (23, 24, 25) a first of which is connected downstream of the first meter-in variable restrictor (17, 18, 19) and a second of which is connected downstream of the second meter-in variable restrictor (17, 18, 19), and a control piston of which is actable on in an opening direction, on a front side, by pressure downstream of the associated meter-in variable restrictor (17, 18, 19), and wherein
• the control pistons of the pressure compensators (23, 24, 25) are actable on in a closing direction by a control pressure which is present in a rear control space (26), is derived from feed pressure prevailing in the feed line (13) with a valve device (45, 52) and changes with the feed pressure,wherein the valve device is a pressure differential valve (45, 52), an inlet (46) of which is connected to a feed line (13) and an outlet (47) of which is connected to r the rear control space (28) of the a pressure compensator (23, 24, 25).

A control arrangement for supplying pressure medium to at least two hydraulic consumers (14, 15, 16) comprising

• a variable-displacement pump (10) which is controlled according to required flow and a setting of which is variable as a function of highest load pressure of actuated said hydraulic consumers (14, 15, 16), by a pump controller (11),
• two displaceable meter-in variable restrictors (17, 18, 19), a first of which is arranged between a feed line (13), which leads from the variable-displacement pump (10), and a first hydraulic consumer (14, 15, 16), and a second of which is arranged between the feed line (13) and a second hydraulic consumer (14, 15. 16), and
• two pressure compensators (23, 24, 25), a first of which is connected downstream of the first meter-in variable restrictor (17, 18, 19), and a second of which is connected downstream of the second meter-in variable restrictor (17, 18, 19), and a control piston of which is actable on in an opening direction, on a front side, by pressure downstream of the associated meter-in variable restrictor (17, 18, 19), and wherein
• the control pistons of the pressure compensators (23, 24, 25) are actable on in a closing direction by a control pressure which is present in a rear control space (26), is derived from feed pressure prevailing in the feed line (13) with a valve device (45, 52) and changes with the feed pressure, wherein the rear control spaces (26) of the plurality of pressure compensators (23, 24) are directly connected to one another, so that a same control pressure prevails in the rear control spaces (26) of said pressure compensators (23, 24).

A control arrangement for supplying pressure medium to at least two hydraulic consumers (14, 15, 16) comprising

• a variable-displacement pump (10) which is controlled according to required flow and a setting of which is variable as a function of highest load pressure of actuated said hydraulic consumers (14, 15, 16), by a pump controller (11),
• two displaceable meter-in variable restrictors (17, 18, 19), a first of which is arranged between a feed line (13), which leads from the variable-displacement pump (10), and a first hydraulic consumer (14, 15, 16), and a second of which is arranged between the feed line (13) and a second hydraulic consumer (14, 15, 16), and
• two pressure compensators (23, 24, 25), a first of which is connected downstream of the first meter-in variable restrictor (17, 18, 19), and a second of which is connected downstream of the second meter-in variable restrictor (17, 18, 19), and a control piston of which is actable on in an opening direction, on a front side, by pressure downstream of the associated meter-in variable restrictor (17, 18, 19), and wherein
• the control pistons of the pressure compensators (23, 24, 25) are actable on in a closing direction by a control pressure which is present in a rear control space (26), is derived from feed pressure prevailing in the feed line (13) with a valve device (45, 52) and changes with the feed pressure, further comprising a load signaling line (37), to which the highest load pressure of the hydraulic consumers (14, 15, 16) actuated in each case is input via selection valves (36), and by a valve (51) which opens up fluid communication from the load signaling line (37) to the rear control space (26) of at least one pressure compensator (23, 24) when a difference between the feed pressure and the highest load pressure falls below a defined level.

A control arrangement for supplying pressure medium to at least two hydraulic consumers (14, 15, 16) comprising

• a variable-displacement pump (10) which is controlled according to required flow and a setting of which is variable as a function of highest load pressure of actuated said hydraulic consumers (14, 15, 16), by a pump controller (11).
• two displaceable meter-in variable restrictors (17, 18, 19), a first of which is arranged between a feed line (13), which leads from the variable-displacement pump (10), and a first hydraulic consumer (14, 15, 16), and a second of which is arranged between the feed line (13) and a second hydraulic consumer (14, 15, 16), and
• two pressure compensators (23, 24, 25), a first of which is connected downstream of the first meter-in variable restrictor (17, 18, 19), and a second of which is connected downstream of the second meter-in-variable restrictor (17, 18, 19), and a control piston of which is actable on in an opening direction, on a front side, by pressure downstream of the associated meter-in variable restrictor (17, 18, 19), and wherein
• the control pistons of the pressure compensators (23, 24, 25) are actable on in a closing direction by a control pressure which is present in a rear control space (26), is derived from feed pressure prevailing in the feed line (13) with a valve device (45, 52) and changes with the feed pressure.
• a the control pressure for the rear control space (26) of the first pressure compensator (23, 24) is derived from the pump pressure by a first said valve device (45), and
• the control pressure for the rear control space (26) of another pressure compensator (25) is derived from the pump pressure by a second said valve device (52), and
• a priority valve (55), by which, in order to maintain a desired pressure difference across the meter-in variable restrictor (19) arranged upstream of said another pressure compensator (25), and therefore a sufficient a supply of pressure medium to a corresponding prioritized hydraulic consumer (16), in event of delivery quantity of the variable-displacement pump (10) not meeting demand (undersaturation), the control pressure in the rear control space (26) of the first pressure compensator (23, 24) is raisable to above the control pressure in case of saturation.

A control arrangement for supplying pressure medium to at least two hydraulic consumers (14, 15, 16) comprising

• a variable-displacement pump (10) which is controlled according to required flow and a setting of which is variable as a function of highest load pressure of actuated said hydraulic consumers (14, 15, 16), by a pump controller (11),
• two displaceable meter-in variable restrictors (17, 18, 19), a first of which is arranged between a feed line (13), which leads from the variable-displacement pump (10), and a first hydraulic consumer (14, 15, 16), and a second of which is arranged between the feed line (13) and a second hydraulic consumer (14, 15, 16), and
• two pressure compensators (23, 24, 25), a first of which is connected downstream of the first meter-in variable restrictor (17, 18, 19), and a second of which is connected downstream of the second meter-in variable restrictor (17, 18, 19), and a control piston of which is actable on in an opening direction, on a front side, by pressure downstream of the associated meter-in variable restrictor (17, 18, 19), and wherein
• the control pistons of the pressure compensators (23, 24, 25) are actable on in a closing direction by a control pressure which is present in a rear control space (26), is derived from feed pressure prevailing in the feed line (13) with a valve device (45, 52) and changes with the feed pressure, further comprising:
• a) a valve housing (70) having a valve bore (71), into which an inlet channel (46) and, at an axial distance therefrom, an outlet channel (47) open radially;
• <b) a piston slide (48), for controlling an opening cross section at the inlet channel (46) and which on a first end side is acted on by pressure prevailing in the inlet channel (46) and on its second end side is acted on by pressure prevailing in the outlet channel (47), is axially displaceable in the valve bore (71);
• c) a compression spring (49), which acts on the piston slide (48) so as to reduce the opening cross section, is accommodated in a spring space (75) situated between one end side of the piston slide (48) and a closure (72) of the valve bore (71);
• d) the outlet channel (47) opens freely into the spring space (75);
• and wherein
• e) the piston slide (48) is a hollow piston with bores (78), via which an annular space (80), which is formed between the piston slide (48) and the valve housing (70) and which has an encircling control edge for controlling the opening cross section at the inlet channel (46), is in fluid communication with the spring space (75), and having two sealing sections, which are in each case guided in a sealed manner in the valve bore (71) and of which one sealing section provides a seal between the inlet channel (46) and the spring space (75) and the other sealing section provides a seal between the fluid path (80, 82, 81, 83) passing through the piston slide (48) and the first end side of the piston slide (48).