DE10058032A1 - Hydraulic control arrangement - Google Patents

Abstract

A load independent flow distribution control arrangement for at least two hydraulic users is disclosed, with an adjuster pump, the setting of which is altered depending upon a user load pressure in a repeater line, each user being provided with a proportioning diaphragm with a serial pressure equaliser. Should a load pressure limit for a user be exceeded, the side of the completely pilot-open regulator piston in the pressure equaliser, acting in the closing direction and corresponding to said user, is fed the pressure of the next lowest load user, by means of the above valve arrangement.

Description

The invention relates to a hydraulic control arrangement for at least two hydraulic consumers according to the Preamble of claim 1.

Such a control arrangement - also load sensing Circuit called - is used among other things for the activation of mobile machines, such as excavators puts. The controls are hydraulically operated Aggregates of the working machine, for example a slewing gear, a traction drive, a bucket, a stick or one on an excavator boom-mounted gripper controlled.

In a control arrangement known from WO 95/32364 A1 Each of the hydraulic consumers is adjusted bare metering orifice with a downstream pressure compensator assigned, via which the pressure drop at the metering orifice is kept constant, so that the respective Ver Required amount of pressure medium flowing from the opening cross-section the metering orifice and not the load pressure of the consumer or depends on the pressure of the variable pump. If the ver variable displacement pump with maximum displacement and the pressure medium volume flow is not sufficient to the specified Maintain pressure drop across the orifice plates, the pressure carriages of all operated hydraulic ver need adjusted in the closing direction so that all pressure medium volume flows to the individual consumers around the same percentage can be reduced. With such a move against load-independent flow distribution (LUDV) then all targeted consumers with a percent speed reduced by the same amount.  

From WO 95/32364 A1 it is known to exceed a certain load pressure on a consumer Load pressure of the next, lower load hydraulic Consumer to the load sensing controller of the variable pump Report to. The load pressure is selected so that the supply the other hydraulic consumers is guaranteed. In the known solution, this is achieved in that the spring chamber of the pressure compensator of the lower load chers via a pressure relief valve arrangement with the Tank is connectable. When a certain one is exceeded Load pressure, the pressure relief valve opens a throttle rare connection to the tank, so that the pressure in the spring chamber the pressure compensator of the lower load consumer the value set on the pressure relief valve increases and the control piston is brought into its open position becomes.

The disadvantage of this control arrangement is that a Partial flow is discharged to the tank and thus cannot be used for consumer control. Another disadvantage is that the recirculation The pressure medium to the tank generates heat in the system and thus pump performance is destroyed.

To overcome this disadvantage is in the DE 198 31 595 A1 from the applicant a hydraulic circuit proposed with a control arrangement through which at exceed the limit load pressure of the control piston Pressure balance of the consumer with the highest load pressure in Closing direction is applied so that the inlet to this consumer is reduced, the function of hydraulic consumer is always guaranteed. By reducing the inflow to the consumer with the highest load pressure becomes the lower load accordingly with a higher pressure medium volume flow supplied so that their function is optimized.  

In this known solution, the maximum load pressure limited to a predetermined value that is chosen is that the variable pump is not in the power control area arrives so that the lower load consumers can continue to be supplied with pressure medium. problema However, the table remains that the highest load pressure in the system is specified by the limit load pressure, so that at unun operating conditions the lower load consumers no longer in the required manner with pressure medium are available.

In contrast, the invention is based on the object a control arrangement for at least two hydraulic Ver need to create, in which the pressure medium supply to the lower load consumers is improved.

This task is accomplished by a control arrangement with the Features of claim 1 solved.

According to the invention when a limit is exceeded load pressure on a consumer, for example one Gripper, a side of an effective in the closing direction this consumer associated control piston a metering orifice downstream pressure compensator with the highest load pressure of the other hydraulic consumers. That is, according to the invention when the Limit load pressure of the control pistons not with the maximum Load pressure, but with the lower highest load pressure of the other consumer. The one to a load Sensing and / or power controller of the variable pump acc The system pressure then corresponds to the highest load pressure other consumers, so that the variable pump due to the lower pressure levels more quantity for further, parallel Provides consumer movements. The one with before the load pressure exceeding the limit load pressure Beat consumers will continue to be addicted from the lower system pressure reported to the pump  Pressure medium supplied so that its function is guaranteed is.

In a preferred variant, the invention has Control arrangement a downstream of the orifice of the highest load pressure leading consumer Signal line, on the one hand via a pressure valve with a Tank and on the other hand via a check valve with the Load-sensing control of the variable load pump pressure line is connected. Branches from the load pressure line further a load pressure branch line from which the in Closing direction effective side of a control piston one of the Dosing orifice downstream pressure compensator with the pressure in the load pressure line is acted upon.

The pressure valve is designed so that it over limit load pressure, the connection to the tank controls so that the load-sensing pressure in the area of this Consumer is relieved to the tank - in the Lastmel The line can then not be the limit load pressure build up appropriate load pressure, but the pressure in the Load reporting line corresponds to the load pressure of the next one, lower load consumer. The effective in closing me side of the control piston of the pressure compensator is over the Load pressure branch line with this the lower load Ver appropriate system pressure.

In the flow path between the orifice and the Pressure valve is a nozzle for limiting the over the Flowing control oil quantity provided for the reporting line.

The pressure valve is preferably used as Druckabschaltven til executed so that the limit load pressure by the am Pressure cut-off valve adjustable switch-off pressure specified is. This pressure cut-off valve blocks the connection to Tank only when the load pressure on the assigned Consumer under a predetermined switching pressure difference  the cut-off pressure has dropped to a cut-in pressure. This ensures that the load pressure is on this consumer to a comparatively high value can be limited while the one reported to the variable pump Pressure in the load pressure reporting line by the highest Load pressure of other consumers is determined. In the Effective opening direction control side of the pressure relief valve is assigned via a control line with the load pressure of the neten consumer.

A pressure accumulator can be assigned to the consumer the one over which the load pressure on the consumer, for example the clamping pressure of a gripper on a largely constant value can be maintained, even if the goods seized still yields and any leaks are compensated for can. In this case, it is particularly advantageous if an unlockable locking block is assigned to the consumer and the memory in the area between consumer and barrier block is connected.

The nozzle for limiting the control oil flow is at a preferred embodiment in an inner bore of the control piston of the pressure compensator. This inner boh tion opens on the one hand in the end face of the control piston and on the other hand in a peripheral wall, in the circumferential a control edge is formed on the wall-side mouth region via which a connection to the reporting line is opened is noticeable. In principle, the pressure downstream of the Metering orifice also behind the pressure compensator via a check valve can be tapped, so that no hole in the rule piston is required.

The control arrangement preferably has a variable displacement pump with load-sensing controller, which has a maximum pressure and lei performance control is superimposed.  

Other advantageous developments of the invention are the subject of further subclaims.

The following is a preferred embodiment the invention with reference to schematic drawings tert.

Show it:

Figure 1 is a circuit diagram of the first Ausführungsbeispie les.

FIG. 2 shows the control arrangement from FIG. 1 with a proportional directional control valve with a pressure compensator;

Fig. 3 is a detailed view of the valve arrangement shown in Fig. 2 Darge.

In Fig. 1, a part of a circuit diagram of a control arrangement for controlling the hydraulic consumers of a mobile implement, for example an excavator, is shown. This has several consumers, for example a slewing gear, a stick, a travel drive, a boom, a support and a gripper, which are supplied with pressure medium by a variable displacement pump. In the illustration according to FIG. 1, only the pressure medium supply of a gripper is shown, which is actuated by a hydraulic cylinder 2.

The pressure medium supply of the hydraulic cylinder 2 takes place via a dash-dotted valve arrangement 4 , which is summarized with corresponding valve arrangements for supplying the other consumers to form a LUDV control block.

The valve arrangement 4 shown in FIG. 1 has a pressure connection P which is connected via a pressure line 6 to a variable displacement pump which can be adjusted by means of an LS regulator. The pressure medium flowing back from the hydraulic cylinder 2 can be returned to a tank via a tank connection T.

The highest load pressure of the above-mentioned consumers is fed via a load signaling line 8 to the LS regulator of the pump.

The control arrangement also has two Arbeitsan connections A, B, which are connected via working lines 10 and 12 to a cylinder space 14 and an annular space 16 of the hydraulic cylinder 2 . The working line 10 can be blocked by means of an unlockable locking block 18 without leakage oil, so that the gripper can be held in its closed position.

A storage line 20 leading to a reservoir 22 branches off between the blocking block 18 and the hydraulic cylinder 2 . Through this memory 22 , a yielding of the gripped goods and any leakage losses are compensated for, so that the gripper is reliably held in its closed position.

To actuate the valve arrangement 4 , two control connections a, b are also provided, via which the valve arrangement can be acted upon by a control pressure.

The valve arrangement according to the invention has a proportional directional valve 26 with a speed part and with a directional part 29 , the speed part being formed by an orifice 28 . The metering orifice 28 is followed by a pressure compensator 30 , the control piston 104 ( FIG. 3) in the closing direction of the force of a weak closing spring 32 and the control pressure in a load pressure branch line 34 can be acted on, which leads to a control connection d which leads to the load signaling line 8 connected is. The regulating piston of the pressure compensator 30 is acted upon by the pressure downstream of the measuring orifice 28 in the opening direction.

Depending on the position of the downstream of the pressure compensator 30 on the ordered directional part 29 of the directional control valve 26 , the outlet of the pressure compensator 30 is connected to a working channel 36 or 38 connected to the working connection A or the working connection B. Each working channel 36 , 38 is assigned a pressure-limiting valve 40 or 42 , which opens a connection to a tank channel 44 connected to the tank connection T when a maximum pressure is exceeded.

The directional control valve 26 is acted upon by two control lines 46 , 48 with the control pressures present at control connections a, b, so that the valve body is displaced from a spring-loaded basic position as a function of the applied control pressure difference.

Depending on the pressure in the load pressure branch line 34 and the force of the closing spring 32 on the one hand and the pressure downstream of the metering orifice 28 on the other hand, the control piston of the pressure compensator 30 is brought into a control position in which the pressure drop across the metering orifice 28 is kept constant regardless of the load pressure, so that the volume flow to the consumer is proportional to the opening cross section of the orifice 28 . That is, the control piston of the pressure compensator 30 closes until the pressure upstream of the pressure compensator 30 , apart from the weak closing spring, is equal to the load signaling pressure in the load signaling device 8 .

If the load pressure on the hydraulic cylinder 2 to the highest load pressure, the control piston of the pressure compensator 30 is moved against the force of the closing spring 32 and the load pressure in the load pressure signaling line 8 into an end position in which a signaling line 50 with the pressure between the metering orifice 28 and the input the pressure compensator 30 is acted upon.

This signal line 50 is on the one hand via a check valve 52 with the load signal line 8 and a Druckab switching valve 54 connected to the tank port T. The valve body of the pressure cut-off valve 54 is biased into a closed position via a control spring. In Publ voltage direction of the pressure in a control conduit 56 branched from the storage line 20, so that the pressure in the memory 22 or in the cylinder chamber 14 of the hydraulic cylinder 2 acts on the piston of the Druckabschaltventils 54 in the opening direction acts. The control spring of the pressure cut-off valve 54 is set so that it switches when a maximum limit load pressure is exceeded, for example caused by a pressure build-up when the gripper goes to a stop, so that the signaling line 50 is connected to the tank connection T. The pressure cut-off valve 54 blocks the connection to the tank connection T only when the pressure in the accumulator 22 or in the cylinder space 14 has dropped, for example, 100 bar below a cut-off value by a predetermined switching pressure difference. Since the function of such a pressure shut-off valve 54 is known from the prior art, reference may be made to the relevant literature, for example the publication: Der Hydrauliktrainer, Band 1 ; Mannesmann Rexroth GmbH; 2nd edition, 1991, pp. 230 ff.

In the area between the outlet of the pressure compensator 30 and the directional part of the directional control valve 26 , two load holding valves 51 , 53 are provided, via which a backflow of the pressure medium from the working channels 36 , 38 to the pressure compensator 30 can be changed.

If the load pressure of the hydraulic cylinder 2 is the highest load pressure, the control piston of the pressure compensator 30 is in its fully open position. The load pressure on the hydraulic cylinder 2 is then reported via the signaling line 50 and the check valve 52 in the load pressure reporting line 8 , so that the variable pump is controlled as a function of the load pressure on the hydraulic cylinder 2 . When the limit load pressure is reached, the pressure cut-off valve 54 relieves the message line 50 . The variable displacement pump then goes back to the stand-by pressure or is controlled by the highest load pressure of other actuated consumers.

Figs. 2 and 3 show a section through a valve disc, with the valve assembly 4 of Fig. 1 is realized.

The valve disc has a housing 58 , in the valve bore 60, a valve spool 62 of the proportional Wegeven valve 26 is guided. By axial displacement of the valve slide 62 , the orifice 28 forming the speed part of the directional control valve can be adjusted. Downstream of the metering orifice 28 , the pressure balance 30 is inserted into the housing 58 as a built-in valve, from which the Druckmit tel then leads back to the directional part 29 of the directional control valve 26 and from there to one of the working connections A or B. In the housing 58 , the two load holding valves 51 , 53 and the two Druckbe limit valves 40 , 42 are also included.

The valve spool 62 is centered by means of two control springs 64 , 66 which are arranged in two control housings 68 which are attached to the housing 58 at the side. The spring spaces 70 , 72 delimited by these can be acted upon by a control pressure for the axial displacement of the valve slide 62 via the control connections a, b.

In the housing 58 of the valve segment, the two working connections A, B, the central pressure connection P and at least one tank connection T and further control connections are also formed. The two working connections A, B are connected via the working lines 10 and 12 and the blocking block 18 to the hydraulic cylinder 2 . The load pressure present in the load reporting line 8 is reported via the load pressure branch line 34 into the spring chamber 74 of the pressure compensator 30 .

When the pressure compensator 30 is fully open, the mel line 50 is opened so that the load pressure on the hydraulic cylinder 2 is reported via the check valve 52 in the load reporting line 8 . The signal line 50 is led to the input of the pressure cut-off valve 54 , which is acted upon in the closing direction by the force of a control spring and in the opening direction by the pressure in the accumulator 22 .

In the hinted line in Fig. 2 variant of the hydraulic accumulator 22 is connected via the opening between the locking block 18 and the hydraulic cylinder 2 SpeI cherleitung 20 to the working line 10 .

A dashed line indicates a variant in which the control side of the valve 54 and, for the sake of simplicity, the memory 22 are connected to the working line 10 via a line 20 'between the working connection A and the blocking block 18 . In this variant, there is no leakage from consumer 2 via valve 54 to the tank.

However, a valve 54 must now be used, which does not completely relieve the signal line 50 of pressure, but rather limits the pressure in the signal line to such a value that the hydraulic accumulator 22 remains charged.

For example, the valve 54 can be a proportional throttle 54 ', as shown in dashed lines in FIG. 2.

According to the enlarged representation in FIG. 3, the valve slide 62 has two end-side ring collars 76 , 78 which are arranged in the transition region to the spring spaces 70 , 72 . Two tank collars 80 , 82 , two control collars 84 , 86 lying between them are provided adjacent to the collars 78 , 76 and a central annular web 88 .

The valve bore 60 is connected to the tank channel 44 ( not shown in FIG. 3) and thus to the tank connection T via two channels 90 and 92 formed in the region of the collars 76 , 80 and 78 , 82 , respectively. The two Druckbegrenzungsventi le 40, 42 are inserted through the side opening into receiving bores in the housing 58 so that a connection between the passage 92 or 90 on the one hand and the tion in the Ventilboh 60 opening into working channel 36 and 34 on the other hand to produce.

On the housing 58 , two connecting channels 94 , 96 are also formed, via which the valve bore 60 in the area of the two control collars 84 , 86 is connected to an approximately central receiving bore 98 for the pressure compensator 30 . This receiving bore 98 opens into a medium pressure chamber 100 of the valve bore 60 . The two load holding valves 51 and 53 are inserted into the connecting channel 94 , 96 .

The pressure compensator 30 has a bushing 102 which is inserted into the receiving bore 98 and in which the control piston 104 is guided. This is biased via the closing spring 32 in the closed position. As mentioned with reference to FIG. 2 erläu tert, the spring chamber 74 of the pressure compensator 30 ver to the load signaling line 8 connected by means of the load pressure branch line 34.

The socket 102 has in the area of the two connecting channels 94 , 96 radial openings 106 , so that a connection between the central pressure chamber 100 and the connecting channels 94 or 96 is opened in the event of an axial displacement of the control piston 104 .

In the illustration according to FIG. 3 above the radial openings 106, the signal line 50 opens into the inner bore of the sleeve 102. The control piston 104 has an angular bore 108 , in the basic position shown in FIG. 3 position on the one hand in the end face of the control piston 104 and on the other hand in the circumferential area between the radial openings 106 and the mouth area of the message line 50 mün det. In this angular bore 108 , an aperture 110 is inserted. As will be explained in more detail below, the pressure in front of the pressure compensator can be tapped via the angular bore 108 and reported in the signaling line 50 . In principle, this pressure could also be tapped via a check valve in the area between the two load holding valves 51 , 53 from the connecting channel 94 or 96 . The applicant reserves the right to make its own claim to this tap option.

For a better understanding, the operating states of the LUDV control arrangement shown in FIGS . 1 to 3 are explained below.

First of all, it is assumed that the highest load pressure is not applied to the hydraulic cylinder 2 of the gripper, but to one of the other consumers, for example the boom, the arm or the slewing gear. As is customary in LUDV systems, this highest load pressure is present in the load pressure signaling line 8 , so that a pump pressure is set via the load-sensing controller (not shown) of the variable pump, which is a predetermined amount higher than the load pressure in the load signaling line 8 . This highest load pressure of the system is reported via the external load pressure branch line 34 bypassing the check valve 52 into the spring chamber of the pressure compensator 30 .

When the gripper is actuated, the valve slide 62 of the directional control valve 26 is shifted to the left (view according to FIG. 3), for example by applying a control pressure difference to the control connections a, b, so that the connection from the pressure connection P to the pressure chamber 100 is opened via the ring web 88 . This opening cross section corresponds to the effective diameter of the metering orifice 28 . The control piston 104 is shifted into a control position in which the pressure acting on its front end face is essentially as large as the load pressure acting on its rear side in the closing direction. In this Regelpo position, the mouth area of the signal line 50 is still blocked by the scope of the control piston 104 . In the event of an axial displacement of the valve slide 62 to the left ( FIG. 3), the load holding valve 53 is opened by the pressure downstream of the pressure compensator 30 , so that the pressure medium is directed via the directional part of the directional control valve 26 , that is to say via the connection between the connecting channel, which is opened by the control collar 86 94 and the working channel 36 , to the Ar beitsanschluß A and from there to the cylinder chamber 14 . The hydraulic cylinder 2 is extended and the gripper is closed. The displaced from the annulus 16 pressure medium flows via the working connection B, the working channel 34 and be controlled from the tank collar 80 connection between the working duct 34 and the duct 90 back to the tank T.

In the operating state in which the highest system load pressure is applied to the hydraulic cylinder 2 , the control piston 104 is moved against the force of the closing spring 32 and the prevailing in the Lastmel deleitung 8 lower load pressure in its end position, so that the connection between the angle bore 108 and the Message line 50 is opened. The highest load pressure prevailing on the lower end face of the control piston 104 is then reported via the signaling device 50 and the check valve 52 into the load reporting line 8 and the pump pressure is increased accordingly. The consumers are then controlled according to the well-known LUDV principle.

It is now assumed that the system pressure, that is to say the load pressure at the hydraulic cylinder 2, continues to rise and reaches the limit load pressure set at the pressure cut-off valve 54 . This means that the gripper pressure can be limited to a predetermined value, for example 300 bar, by adjusting the pressure cut-off valve 54 accordingly. When the limit load pressure is reached, the accumulator charging valve 54 (?) Is brought into the open position by the limit load pressure reported in the storage channel 56 , so that the message line 50 is connected to the tank T. The pressure in the message line 50 is then completely relieved of the open switching stage from to the tank T, so that the gripper section can no longer cause pressure build-up in the system. With the gripper closed, the system does not cut the pressure. After the signal line 50 is relieved of pressure, the load pressure in the load signal line 8 drops to the next higher consumer load pressure of a consumer operated in parallel, so that the pump pressure is reduced accordingly. The check valve 52 in the signaling line 50 prevents this reduced load pressure in the load signaling line 8 from being reduced to the tank. This highest load pressure of the consumers controlled in parallel to the gripper is reported via the load pressure branch 34 in the spring chamber 74 of the pressure compensator 30 . Because the gripper has moved to the stop, no pressure medium flows via the metering orifice 28 , so that 100 pump pressure is present in the pressure chamber. The pressure compensator 30 is therefore completely open. In this operating state, the resulting power loss is limited only to the amount of control oil flowing out through the aperture 110 in the angular bore 108 toward the tank T. If no parallel consumer is actuated, the pump pressure drops to the stand-by pressure.

In the exemplary embodiment shown in FIG. 2, the set gripper pressure is held by the leakage-oil-free shut-off via the locking block 18 , any leakage or the yielding of the gripped object being compensated for by the memory 22 .

If the load pressure on the gripper falls to the lower value set on the pressure cut-off valve 54 , the connection to the tank T is closed, so that the load pressure in the signaling line 50 rises and is reported via the check valve 52 into the load signaling line 8 . The system is back in normal LUDV mode.

The use of a pressure shut-off valve 54 has the advantage that the pressure at the gripper can be kept at a comparatively high level, for example 300 bar, the pressure shut-off valve only switching back at a lower level, for example 200 bar, so that the pump is not useless on the high one Pressure level but is controlled depending on the next lower load pressure.

In simpler applications, the use of a hydraulic accumulator 22 and / or the use of a blocking block 18 can be dispensed with. In this case, the switching pressure for the pressure cut-off valve is tapped directly from the working line 10 .

Instead of the pressure cut-off valve 54 , a pressure-limiting valve controlled by the pressure in the signaling line 50 or a similar suitable valve arrangement for limiting the limit load pressure can also be used in simple applications.

A LUDV control arrangement for at least is disclosed two hydraulic consumers, with a variable displacement pump, their setting depending on one in a load signaling line applied consumer load pressure changeable is, with each consumer a metering orifice with nachge switched pressure compensator is assigned. If exceed a limit load pressure at a consumer is determined by means of a valve assembly according to the invention in closing direction effective side of this consumer assigned  fully controlled control piston of the pressure compensator with the load pressure of the next lower load consumer applied.  

LIST OF REFERENCE NUMBERS

2

hydraulic cylinders

4

valve assembly

6

pressure line

8th

Load-sensing line

10

working line

12

working line

14

cylinder space

16

annulus

18

locking block

20

storage line

22

hydraulic accumulator

26

Proportional directional valve

28

metering diaphragm

29

direction part

30

pressure compensator

32

closing spring

34

Load pressure branch line

36

working channel

38

working channel

40

Pressure relief valve

42

Pressure relief valve

44

tank channel

46

control line

48

control line

50

reporting line

51

Load-holding valve

52

check valve

53

Load-holding valve

54

Pressure cut

56

control channel

58

casing

60

valve bore

62

valve slide

64

control spring

66

control spring

68

control housing

70

spring chamber

72

spring chamber

74

Spring chamber (DW)

76

collar

78

collar

80

tank Bund

82

tank Bund

84

control collar

86

control collar

88

ring land

90

channel

92

channel

94

connecting channel

96

connecting channel

98

location hole

100

pressure chamber

102

Rifle

104

control piston

106

Radial opening

108

angle hole

110

cover

Claims (10)

1. Hydraulic control arrangement for at least two hy draulic consumers ( 2 ), with a variable displacement pump whose setting can be changed as a function of a load pressure in a load signaling line ( 8 ), with each consumer ( 2 ) having a metering orifice ( 28 ) with a downstream pressure balance ( 30 ) is assigned, the control piston ( 104 ) of which can be acted upon in the closing direction by the load pressure in the load signaling line ( 8 ) and in the opening direction by the pressure downstream of the associated metering orifice ( 28 ), the load pressure of the assigned consumer ( 30 ) being fully activated 2 ) is reported via a signaling line in the load signaling line ( 8 ), and with a valve arrangement via which the effective pressure difference can be changed via a control piston assigned to a first of the two consumers when a limit load pressure is exceeded, characterized in that when the limit load pressure is exceeded to a consumer ( 2nd ) by means of the valve arrangement ( 4 ), the pressure in the signaling device ( 50 ) can be lowered and the effective side in the closing direction of the first consumer ( 2 ) associated control piston ( 104 ) can be acted upon with the highest load pressure of the other consumers. 2. Control arrangement according to claim 1, wherein the Mel deleitung ( 50 ) on the one hand via a preferably Druckge controlled valve ( 54 ) with a tank (T) and on the other hand via a check valve ( 32 ) with the load signaling line ( 8 ) and wherein a load pressure branch line ( 34 ) branching off from the load signaling line ( 8 ), the side of the control piston ( 104 ) acting in the closing direction can be acted upon by the pressure in the load signaling line ( 8 ). 3. Control arrangement according to claim 2, wherein in the message line ( 50 ) between the check valve ( 52 ) and metering orifice ( 28 ), an aperture ( 110 ) is provided. 4. Control arrangement according to claim 2 or 3, wherein the Vventil is a pressure cut-off valve ( 54 ) or a Druckbe limiting valve. 5. Control arrangement according to claim 4, wherein an effective in the opening direction control side of the valve ( 54 ) via a control line ( 20 , 56 ) with the load pressure of the assigned consumer ( 2 ) is applied. 6. Control arrangement according to one of the preceding claims, wherein the first hydraulic consumer ( 2 ) is preceded by a locking block ( 18 ). 7. Control arrangement according to one of the preceding claims, wherein a hydraulic accumulator ( 22 ) is arranged on the fluid path between the directional valve ( 26 ) and the first consumer ( 2 ). 8. Control arrangement according to claim 6 or 7, wherein the control line ( 24 ) branches off from a working line ( 10 ) between the blocking block ( 18 ) and the first consumer ( 2 ). 9. Control arrangement according to one of claims 3 to 8, wherein the diaphragm ( 110 ) in an inner bore of the control piston ( 104 ) is arranged, which opens on the one hand in an end face and on the other hand in a circumferential wall of the control piston ( 104 ), with the peripheral wall side A connection to the message line ( 50 ) can be opened towards the mouth area. 10. Control arrangement according to one of the preceding patent claims, the variable displacement pump using a load sensing Regulator is adjustable, which has a maximum pressure and lei performance control is superimposed.