EP2268927A1

EP2268927A1 - Control arrangement for controlling a control valve

Info

Publication number: EP2268927A1
Application number: EP09732854A
Authority: EP
Inventors: Wolfgang Kauss
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2008-04-15
Filing date: 2009-04-08
Publication date: 2011-01-05
Also published as: JP2011517754A; DE102008018936A1; WO2009127349A1; KR20110030420A; US20110030816A1

Abstract

The invention relates to a control arrangement with a pilot aggregate (6) for controlling a control valve (2) comprising a first and a second control chamber (36, 38). The first control chamber (36) is provided for adjusting the control valve (2) in one direction and the second control chamber (38) for adjusting the control valve in the opposite direction. The control chambers (36, 38) are applied each with a pilot pressure of the pilot aggregate (6). Besides the pilot aggregate (5), the control arrangement further comprises a pilot valve (4) for applying a control chamber (36, 38) with an outlet pressure. The supply pressure of the pilot valve (4) is hereby the pilot pressure of the pilot aggregate (6) effective in one of the control chambers (36, 38) and the output pressure of the pilot valve (4) is effective in the other control chamber (36, 38), wherein the output pressure is equal or smaller than the pilot pressure.

Description

Control arrangement for controlling a directional control valve

The invention relates to a control arrangement for controlling a directional control valve according to the preamble of patent claim 1.

For large pressure medium flow rates, a pilot valve is often provided for the control of a directional control valve, which can be designed as a mechanical-hydraulic pilot control unit in mobile work equipment. Such a pilot unit is known for example from the data sheet RD 64 552 of the applicant. The pilot unit has a plurality of adjustable pressure reducing valves that are manually operated with a control lever. The amount of the pilot pressure is dependent on the position of the control lever, whereby a proportional-hydraulic control of the directional control valve is possible. Such a pilot unit is known in terms of its structural design, for example from DE 27 51 946 C2 or from DE 199 49 802 A1. Instead of or as an alternative to the mechanical hydraulic pilot control of the directional control valve, an electrohydraulic pilot control can be provided.

In DE 10 2005 005 928 a mechanical-hydraulic pilot control is combined with an electro-hydraulic pilot control of a directional control valve. In each case, the highest pilot control pressure set on the pilot control unit or on the electrically adjustable pilot control valve lies in a control chamber of the directional control valve. A disadvantage of this solution is that if there is a fault in the control electronics of the electrically adjustable pilot valve, this could adjust the directional control valve in an unpredictable manner, which leads to dangerous situations in the use of such a control arrangement.

In contrast, the invention is based on the object to provide a control arrangement that is simple and safe to use. The object is achieved by a control arrangement having the features of patent claim 1.

According to the invention, a control arrangement has a pilot control unit for controlling a directional control valve, which has a first and a second control chamber. The first control chamber is used for adjusting the directional control valve in one direction and the second control chamber for adjusting in the opposite direction, wherein one of the control chambers is acted upon by a pilot pressure of the pilot control unit. In addition to the pilot control unit, the control arrangement also has a pilot valve for pressurizing one of the control chambers with an outlet pressure. The supply pressure of the pilot valve is in this case the effective in the former of the control chambers pilot pressure of the pilot control unit and the output pressure of the pilot valve is effective in the other control chamber, wherein the output pressure is equal to or less than the pilot pressure.

This solution has the advantage that the pilot valve is opened only in response to the pilot pressure of the pilot unit, which, for example, in a malfunction of the pilot valve, the directional control valve can not be moved against the predetermined by the pilot unit direction. In this case, at most one equilibrium position of the directional valve is possible since the output pressure corresponds at most to the pilot pressure.

The pilot valve is advantageously an electromagnetic pressure reducing valve, whereby the output pressure acting in a control chamber is easily adjustable.

The pilot unit may be a low-cost standard component and is connected for example via a pilot line with a control chamber of the directional control valve, via the pilot unit each one of the pilot control lines with a control oil supply line in control oil connection can be brought and the other pilot line is relieved to a tank. A supply line of the pilot valve is preferably connected to the highest-pressure pilot line of the pilot valve in control oil, wherein the highest pressure pilot line is connected to one of the control chambers of the directional control valve, and the other control chamber by adjusting the pilot valve to the supply line or with the pressure-reduced pilot line is connectable. The pilot valve can thus be supplied with in a simple arrangement with the pilot pressure of the pilot unit.

With a shuttle valve cascade is a simple picking up the higher of the pilot pressures of the pilot unit, which is provided as the supply pressure of the pilot valve and for acting on the other control chamber with the output pressure of the pilot valve allows. In this case, two output connections of the pilot control unit are advantageously each connected to one of the pilot control lines, which each lead to an input connection of two pilot changeover valves. Another input port of the pilot change-over valves is connected via connecting lines and a common output line to a working port of the pilot valve. Furthermore, in each case one output connection of the pilot changeover valves is in each case connected in each case via a control line to one of the control chambers of the directional control valve and via a respective supply line to an input connection of a supply changeover valve whose output connection is in communication with the pressure connection of the pilot control valve.

The pilot valve can, for the purpose of relieving pressure to a tank, be connected to a tank connection via a tank line to an outlet connection of an inverse shuttle valve, the input ports of the inverse shuttle valve each being connected to one of the pilot control lines via a low pressure line.

A consumer, for example in the form of a hydraulic cylinder can be connected in a known manner with a piston rod side annular space with a working line and with a bottom-side cylinder chamber with another working line of the directional control valve. Preferably, a microcontroller controls the pilot valve in response to the displacement of a piston of the hydraulic cylinder and / or a control oil pressure in the pressure-highest working line between the hydraulic cylinder and the directional control valve and / or a control oil pressure in the supply line to the pilot valve. This is advantageous because depending on the operating conditions of the control arrangement, the directional control valve is acted upon by a different output pressure of the pilot control valve controlled by a microcontroller and thus, for example, the adjustment speed of the valve slide of the directional control valve can be controlled. Furthermore, an EFM (Electronic Flow Matching) is possible.

In an advantageous embodiment, the control arrangement controls at least two consumers, each associated with a control arrangement, wherein the one of the consumer associated pilot valve is acted upon by a valve arrangement with the pilot pressure of the other consumer associated first pilot unit as the supply pressure. This makes it possible that a pilot unit controls two consumers.

In order for only the first pilot unit to be able to drive both loads, the valve arrangement has, for example, two connection changeover valves whose input connections are respectively connected to connection channels branching from the pilot control lines of the first pilot unit and to the pilot control lines of the second pilot unit and whose respective output connection to the input connection of the first pilot changeover valves and the input connection the inverse shuttle valve of the shuttle valve cascade associated with the pilot valve for the one consumer is connected.

In the control oil flow path between the first pilot control unit and the respective connection changeover valve, a lockable switching valve can be arranged in order to be able to regulate advantageously an activation of the other consumer with the first pilot control unit. The input ports of the connection changeover valves, which are connected to the first pilot control unit, can be acted upon via the switching valve with tank pressure or with the pilot pressure of the first pilot control unit.

The pilot valves are controlled by a common microcontroller and can therefore be flexibly controlled.

Advantageous developments of the invention are the subject of further subclaims.

In the following, preferred embodiments of the invention will be explained in more detail with reference to schematic drawings. Show it:

Fig. 1 is a circuit diagram of a control arrangement for driving a directional control valve according to a first embodiment;

Fig. 2 is a circuit diagram of the control arrangement according to a second embodiment; and

3 shows an enlarged detail A of the circuit diagram of the control arrangement from FIG. 2.

Figure 1 shows a circuit diagram of a control arrangement 1 for controlling a directional control valve 2 according to a first embodiment. The directional control valve 2 is adjustable via a pilot valve 4 controlled by a microcontroller 3 and / or via a pilot control unit 6, a consumer, in the form of a hydraulic cylinder 8, being connected to the directional control valve 2. Such a control arrangement 1 can be used for example in mobile hydraulics in backhoe loaders, mini or compact excavators.

In the pilot unit 6 is in principle adjustable pressure reducing valves that are operated by hand. A detailed description of this can be found for example in the documents mentioned in the introduction DE 27 51 946 C2 or DE 199 49 802 A1. The pilot unit 6 has an input port VE to which a control oil supply line 12 is connected, two output ports VA1, VA2 each connected to a pilot line 14, 16, and a tank port VT connected to a tank 18. With a lever 20 of the pilot unit 6, the control oil supply line 12 in control oil connection with the pilot line 14 or 16 can be brought, wherein the respective not connected to the control oil supply line 12 pilot line 14, 16 is connected to the tank 18 and wherein the height of the pilot pressure in the pilot line 14th or 16 is dependent on the position of the control lever 20, which reduces the supply pressure in the control oil supply line 12 to the required pilot pressure via the pressure reducing valves. When not actuated pilot unit, both pilot lines 14, 16 are relieved to the tank 18.

The pilot control lines 14, 16 each lead to a first input connection EVW1 of a pilot changeover valve 22, 24. The pilot control changeover valves 22, 24 have a further input connection EVW2 to which in each case a connection line 26, 28 is connected, which is connected in common to a working connection A. of the pilot valve 4 connected output line 30 open. At an output terminal AVW1 of the shuttle valves 22, 24 branches off in each case a control line 32, 34, which is in each case connected to a control chamber 36, 38 of the directional control valve 2. About the control chambers 36, 38, a valve spool of the directional control valve 2 can be acted upon by pilot pressure and thereby displaced.

The directional control valve 2 is a continuously adjustable 3-way valve which is adjustable from its illustrated basic position 0 via the valve spool in the direction of the positions a or b.

The pilot changeover valves 22, 24 have a further output connection AVW2, on which in each case a supply line 40, 42 produces a control oil connection to an input connection EW1, EW2 of a supply changeover valve 44, respectively. An output terminal EA1 of the service shuttle valve 44 is connected via a pressure line 46 to a pressure port P of the pilot valve 4, whereby this is supplied with a supply pressure, the pilot pressure the pilot control unit 6, ie the larger of the pilot pressures at the output terminals VA1, VA2 corresponds. Via the pilot control changeover valves 22, 24, their respective input connection EVW1, EVW2, to which the highest control oil pressure is applied, is connected to the two output connections AVW1, AVW2. The same applies to the change-over supply valve 44, and here too the input connection EW1, EW2, at which the highest control oil pressure is active, is turned on to the output connection EA1.

A control oil drain line 48 connects a pilot oil drain port T of the pilot valve 4 to an output port IA of an inverse shuttle valve 50. Two input ports IE1, IE2 of the inverse shuttle valve 50 are connected via low pressure lines 52, 54 to one of the pilot lines 14, 16 in pilot oil communication, respectively T of the pilot valve 4 with one of the pilot control line 14, 16 can be brought into connection. In this case, the control oil connection between the respective pressure-reduced low-pressure line 52, 54 and the outlet port IS is opened by the inverse shuttle valve 50.

The pilot valve 4 is an electro-hydraulic pressure reducing valve with three ports P, A, T, wherein the voltage applied to the working port A of the pilot valve 4 output pressure is fed back to a valve spool of the pilot valve 4 and acts against the force of an electromagnet 56. The valve spool of the pilot valve 4 is biased by the force of a spring 58 which also acts against the electromagnet 56 in the direction of a position in which the connection between the output line 30 and the control oil drain line 48 is turned on. When the electromagnet 56 is energized, the valve spool is displaced in a direction in which the output line 30 is connected to the pressure line 46.

In the following, the control of the valve spool of the directional control valve 2 of the control arrangement 1 will be explained in more detail. To shift the valve spool of the directional control valve 2 in the direction of position a, the control lever 20 of the pilot control unit 6 is actuated such that a pilot pressure in the pilot control line 14 or 16 sets, the height of which depends on the position of the control lever 20. Through the control pressure in the pilot control line 14, the connection via the pilot change-over valve 22 to the control line 32 and the supply line 40 is opened. About the supply line 40, the change of supply valve 44 and the pressure line 46 is the supply pressure corresponding to the pilot pressure in the pilot line 14, at the input port P of the pilot valve 4 at. The pilot pressure is further acted upon by the pilot change-over valve 22 via the control line 32 and the control chamber 36 to the valve spool of the directional control valve 2. Via the pilot valve 4, an outlet pressure counter to the pilot pressure acts on the valve spool of the directional control valve 2, which is explained in more detail below.

To set the output pressure in the output line 30, the electromagnet 56 of the pilot valve 4 is energized, so that a certain effective current flows through its winding. The magnet exerts a force dependent on the current force on the valve spool of the pilot valve 4, which acts against the force of the spring 58 and against the output pressure in the output line 30. This output pressure increases until an equilibrium of forces exists on the valve spool. When this equilibrium of forces is reached, the valve spool of the pilot control valve 4 assumes a control position in which small movements in one or the other direction are sufficient to connect the working port A to the pressure port P and / or the control oil drain port T, which is connected via the control oil drainage port. line 48 is connected to the pilot line 16 via the inverse shuttle valve 50 and the low pressure line 54 and thus is on the pilot unit 6 in control oil connection with the tank 18. Depending on the current thus an output pressure in the output line 30, wherein this is acted upon via the connecting line 28, the pilot change valve 24, the control line 34 and the control chamber 38 to the valve spool of the directional control valve 2 and acts against the pilot pressure. At the valve spool of the directional control valve 2 thus sets a pressure difference between the pilot pressure and the output pressure. The pressure difference is maximum when the output pressure is zero, whereby the valve spool of the directional control valve 2 is displaced at maximum displacement in the direction of the position a of the directional control valve 2. If the output pressure is increased via the pilot valve 4, then the adjustment speed of the valve spool decreases. If the output pressure corresponds to the pilot pressure, the pressure difference is zero and thus minimal, whereby the valve spool of the directional control valve 2 is stopped. The displacement or control of the valve spool of the directional control valve 2 in the direction of the position b is carried out according to the above explained, wherein the pilot control line 16 is acted upon by the pilot control unit 6 with pilot pressure, while the pilot control line 14 is connected via the pilot unit 6 to the tank 18.

The directional control valve 2 has a working port WP, a tank port WT and two output ports WA1, WA2. The outlet port WA1 is connected to a bottom-side cylinder space 62 of the hydraulic cylinder 8 via a working channel 60, and the outlet port WA2 is connected to an annular space 66 of the hydraulic cylinder 8 via a working channel 64. For example, a pump for supplying pressure medium to the hydraulic cylinder 8 is connected to the pressure connection WP. A piston 68 of the hydraulic cylinder 8 is adjusted by the directional control valve 2 is moved to the positions a or b, wherein in the positions a of the cylinder chamber 62 or in the positions b of the annular space 64 is acted upon by the pressure at the pressure port WP.

The electromagnet 56 of the pilot valve 4 is controlled via an electrical line 70 by the microcontroller 3, so that the control arrangement according to the EFM principle (electronic flow matching) is operable. In the EFM principle, valve elements are controlled electrically or electrohydraulically as a function of characteristic curves stored in the microcontroller 3. The input of the setpoints is done via a joystick operated by an operator to control the equipment (eg boom, bucket) of an implement with regard to speed and position. The control by the microcontroller 3 is dependent on several input variables. An input variable is the supply pressure of the pilot valve 4, which is tapped by a pressure measuring line 72 at an output terminal EA2 of the supply change valve 44 and converted via a pressure transducer 74 into an electrical signal 11, which is forwarded via the signal line 76 to the microcontroller 3. A further input variable for the microcontroller 10 is the control pressure of the hydraulic cylinder 8. This is picked off via an output connection AM of a measuring exchange valve 78 whose input connections EM1 and EM2 are each connected via a measuring line 80, 82 to the control channels 60, 64. The tapped control pressure is transmitted via the outlet connection AM of the measuring exchange valve 78 via a pressure led to another pressure transducer 86, which converts the measured pressure into an electrical signal 12, which is guided via a signal line 88 to the microcontroller 3. Another input variable for the microcontroller 3 is the displacement of the piston 68 from the hydraulic cylinder 8, which is converted via a position transducer 92 and a distance transducer 94 into an electrical signal 13 and passes via the signal line 96 to the microcontroller 3. It is quite conceivable that the microcontroller 3 is still supplied with other input variables and thus to enable an EFM control, which is indicated by the dashed lines 97 in FIG.

FIG. 2 shows a circuit diagram of a control arrangement 1 for controlling two consumers via two directional control valves 2, 98 according to a second exemplary embodiment. In principle, the control arrangement 1 of the first embodiment of FIG. 1 is present twice in FIG. 2, wherein the pilot control valves 4, 100 are controlled via a common microcontroller 3. The first directional control valve 2, on the left in FIG. 2, is adjusted via the first pilot control unit 6 and the first pilot valve 4 and the second directional control valve 98 is adjusted via the second pilot control unit 102 and the second pilot valve 100 as in the first exemplary embodiment in FIG. By the control arrangement 1 in Figure 2, the second directional control valve 98 is additionally adjustable with the pilot pressure of the first pilot control unit 6, which is explained in more detail below together with Figure 3.

FIG. 3 shows an enlarged detail A of the control arrangement 1 from FIG. 2. Connection channels 104, 106, see FIGS. 2 and 3, each branch from the pilot control lines 14, 16 connected to the first pilot control unit 6 and are in each case connected to the pressure connection SP of a lockable switching valve 108, 110 connected. This switching valve 108, 110 is an electrically adjustable 2-way valve which is normally in a spring-biased position 0, as shown in Figure 2, and energized in a working position a can be brought. To a working port SA of the switching valves 108, 110, in each case a connecting line 112, 114 is connected, each of which is in control oil connection to an input port VE1 of a connecting shuttle valve 116, 118. A further input connection VE2 of the connection changeover valves 116, 118 is in each case provided with a first, to the pilot control unit 102 via output connections VA1, VA2 connected pilot line section 120, 122 in conjunction. The output connection VA of the respective connection changeover valves 116, 118 is connected to a further pilot line section 124, 126 in control oil connection, like the pilot control lines 14, 16 in the first exemplary embodiment in FIG. 1 with the input connections IE1, IE2 of an inverse shuttle valve 128 and with the input connections EVW1, EVW2 a pilot change-over valve 130, 132 is connected. The switching valve 108, 110 is connected to a tank 18 via the tank port ST.

In the spring-biased basic position 0 of the switching valves 108, 110, which are adjusted via the microcontroller 3, in each case the connection between the connecting lines 112, 114 and the tank 18 and in the working positions a is the connection between the connecting channels 104, 106 and the connecting lines 112 , 114 opened. The directional control valves 2, 98 are each actuated via the corresponding pilot control unit 6, 102 and the pilot valves 4, 100, as described in the first embodiment in Figure 1.

For adjusting the second directional control valve 98 via the first pilot control unit 6, the switching valve 108, 110, which is in communication with the pilot-pressure-pilot line 14, 16, opened in the working position a, for example by control of the microcontroller 3. It will be in the following Explanation assumed that the pilot control line 16 is acted upon by the pilot control unit 6 with pilot pressure, whereby the switching valve 108 is switched in the direction of the working positions a. The pilot pressure is forwarded via the connection channel 104 and the switching valve 108 to the connection line 112, which is connected to the connection change-over valve. This closes the connection to the pilot control line section 120 and opens a control oil connection to the second pilot line section 124. The pilot pressure is then applied via the pilot change valve 130 on the one hand via the control line 134 to the valve spool of the directional control valve 98 and the other via the supply line 136, the supply shuttle valve 138 and the pressure line 140 forwarded to the pilot valve 100 as a supply pressure. Via the pilot valve 100 can, as in the first embodiment of Figure 1, the valve spool of the directional control valve 98 against the Pilot pressure can be applied to an output pressure. The pilot pressure of the pilot unit 6 also serves as in the first embodiment in Figure 1 for controlling the directional control valve second

In order to move the valve spool of the directional control valve 98 through the pilot unit 6 in the opposite direction, the pilot pressure in the pilot line 14 is forwarded accordingly, as in the switching valve 108 described above, via the switching valve 110 to the directional control valve 98 and the pilot valve 100.

The actuation of the directional control valve 98 with the first pilot pressure of the first pilot control unit 6 is interrupted if the switching valve 108, 110 is closed, which is controllable in dependence on certain parameters via the microcontroller 3, or the second pilot control unit 106 is actuated and the second pilot pressure higher as the first one is. In this case, the input connection VE1 of the connection changeover valve 116, 118 is closed and the connection between the first pilot control line section 120, 122 and the second pilot control line section 124, 126 is established.

In the exemplary embodiments described above in FIGS. 1 and 2, a control arrangement 1 is shown, in which the directional control valves 2, 98 are hydraulically adjusted via the pilot control units 6, 106. This adjustment can be influenced by the electrohydraulic pilot control valves 4, 100 via the microcontroller 3 (EFM). If the electro-hydraulic control disturbed or faulty, the output pressure of the pilot valves 4, 100 corresponds to the valve spool of the directional control valves 2, 98 acts at most the pilot pressure, whereby the pressure difference is zero and the valve spool are kept in balance. As a result, the control arrangement 1 is extremely safe, since even with an electronic fault, the valve spool of the directional control valves 2, 98 can not be brought into a position other than that of the pilot control units 6, 106.

Disclosed is a control arrangement with a pilot control unit for controlling a directional control valve, which has a first and a second control chamber. The first control chamber is used to adjust the directional valve in one direction and the second control chamber for adjusting in the opposite direction, wherein the control chambers are each acted upon by a pilot pressure of the pilot control unit. In addition to the pilot control unit, the control arrangement also has a pilot valve for charging a control chamber with an outlet pressure. The supply pressure of the pilot valve here is effective in one of the control chambers pilot pressure of the pilot unit and the output pressure of the pilot valve is effective in the other control chamber, wherein the output pressure is equal to or less than the pilot pressure.

Claims

- 15 claims

1. Control arrangement for controlling a directional control valve (2), with a first control chamber (36), which can be acted upon for adjusting the directional control valve (2) in one direction via a pilot control unit (6) with a pilot pressure, and a second control chamber (38), which is acted upon for adjusting in the opposite direction via the pilot control unit (6) with a pilot pressure, and with a pilot valve (4) for acting on a control chamber (36, 38) with an outlet pressure, characterized in that the supply pressure of the pilot valve (4) in one of the control chambers (36, 38) effective pilot pressure of the pilot unit (6) and in the other control chamber (36, 38) of the output pressure of the pilot valve (4) is effective, which is equal to or smaller than the pilot pressure.

2. Control arrangement according to claim 1, wherein the pilot valve (4) is an electromagnetic pressure reducing valve.

3. Control arrangement according to claim 2, wherein the pilot control unit (6) via a respective pilot line (14, 16) with a control chamber (36, 38) of the directional control valve (2) is connected and via the pilot control unit (6) each one of the pilot control lines ( 14, 16) can be brought into control oil connection with a control oil feed line (12) and the respective other pilot control line (14, 16) can be relieved to a tank (18).

4. Control arrangement according to claim 2 or 3, wherein a supply line (40, 42) of the pilot valve (4) with the highest pressure pilot line (14, 16) of the pilot control unit (6) is in control oil connection, wherein the highest pressure pilot line (14, 16) one of the control chambers (36, 38) of the directional control valve (2) is connected, and the other control chamber (36, 38) by adjusting the pilot valve (4) with the supply line (40, 42) or with the pressure-reduced pilot control line (14, 16) is connectable.

5. Control arrangement according to one of the preceding claims, with a shuttle valve cascade for tapping the higher of the pilot pressure of the pre- - 16 - control unit (6) as a supply pressure of the pilot valve (4) and for acting on the other control chamber (36, 38) with the output pressure of the pilot valve (4) is provided.

6. Control arrangement according to one of claims 3 to 5, wherein two output terminals (VA1, VA2) of the pilot unit (6) are each connected to one of the pilot control lines (14, 16), each to an input terminal (EVW1) of two pilot changeover valves ( 22, 24), wherein another input terminal (EVW2) of the Vorsteuerwechselventile (22, 24) respectively via connecting lines (26, 28) and a common output line (30) to a working port (A) of the pilot valve (4) is connected, two output connections (AVW 1, AVW2), the pilot changeover valves (22, 24) on the one hand via a control line (32, 34) to one of the control chambers (36, 38) of the directional control valve (2) and on the other hand via each supply line ( 40, 42) are each connected to an input connection (EW1, EW2) of a supply changeover valve (44) whose output connection is in communication with the pressure connection (P) of the pilot control valve (4).

7. Control arrangement according to one of claims 3 to 6, wherein the pilot valve (4) with a tank connection (T) via a control oil drain line (48) to an output terminal (IA) of an inverse shuttle valve (50) is connected, the input terminals (IE1, IE2 ) in each case via a low pressure line (52, 54) to one of the pilot control lines (14, 1 are included.

8. Control arrangement according to one of the preceding claims, wherein a hydraulic cylinder (8) having a piston rod side annular space (64) with a working line (62) and with a bottom-side cylinder chamber (62) with another working line (60) of the directional control valve (2) is connected ,

9. Control arrangement according to claim 8, wherein a microcontroller (10) controls the pilot valve (4) as a function of the displacement path of a piston (68) of the hydraulic cylinder (8) and / or a control oil pressure in the highest-pressure working line. - 17 - (60, 62) between the hydraulic cylinder (8) and the directional control valve (2) and / or a control oil pressure in the pressure line (40, 42) to the pilot valve (4) controls.

10. Control arrangement for controlling at least two consumers, each associated with a control arrangement according to one of the preceding claims, wherein the one of the consumer associated pilot valve (98) via a valve arrangement with the pilot pressure of the other consumer associated first pilot unit (6) acts as a supply pressure is.

11. Control arrangement according to claim 10, wherein the valve arrangement has two connection changeover valves (116, 118) whose input connections (VE1, VE2) each have connection channels (104, 106) branching from the pilot control lines (14, 16) of the first pilot control unit and with pilot control sections ( 120, 122) of the second pilot unit (108) and their respective output port (VA) to the input port (EVW1) of the pilot changeover valves (116, 118) and the input port (IE1, IE2) of the inverse shuttle valve (128) of the shuttle valve cascade connected to the pilot control valve (100) for the one consumer.

12. Control arrangement according to claim 11, wherein in the control oil flow path between the first pilot control unit (6) and the respective connection changeover valve (116, 118) a lockable switching valve (108, 110) is arranged.

13. Control arrangement according to claim 12, wherein the input terminals of the connection changeover valves (116, 118) which are connected to the first pilot control unit (6) via the switching valve (108, 110) with the tank pressure or with the pilot pressure of the first pilot control unit (6). can be acted upon.

14. Control arrangement according to one of claims 10 to 13, wherein the pilot valves (4, 100) are controlled by a common microcontroller (10).