EP3443182B1 - Electrohydraulic control circuit for a large manipulator - Google Patents

Description

The invention relates to an electrohydraulic control circuit with hydraulically actuated drive units, by means of which the mast segments of a manipulator, in particular a large manipulator for truck-mounted concrete pumps, can be adjusted with regard to their orientation, with an electrically controlled proportional valve assigned to one of the drive units, which is connected to hydraulic working lines of the respective drive unit for its control in the Normal operation is connected, with the respective proportional valve being connected to a pressure supply line, with an emergency valve being connected to the hydraulic working lines of the respective drive unit for its control in emergency operation for emergency operation.

The invention also relates to a manipulator, in particular a large manipulator for truck-mounted concrete pumps, with such a control circuit.

Such an electro-hydraulic control circuit is from WO 2014/165888 A1 known. This document does not disclose any possibility of simply and safely addressing the emergency valves in the event of a failure of the electronics or the hydraulics for normal operation, so that the manipulator cannot be controlled conveniently and intuitively via the emergency valves for salvage or repair. In addition, a common return line is disclosed for normal operation and emergency operation. In the event of a leak in this return line, emergency operation would not be possible. In addition, an emergency operation is also not possible if the Pressure supply unit, which is connected to the pressure supply line, fails. Another disadvantage of the control circuit disclosed is that a separate control oil circuit is provided for opening/closing the hydraulically pilot operated check valves and for supplying the hydraulically pilot-controlled proportional valve. As a result, an additional pressure supply line and tank line are required for this control oil circuit.

the DE 20 2007 008628 U1 discloses an emergency actuation valve, for example in the case of an excavator to drain the hydraulic oil from a chamber of a hydraulic cylinder in a targeted manner and to set down the excavator arm if the hydraulics or electronics fail. The emergency actuation valve arranged on the hydraulic cylinder is actuated via an energy transmission line by means of an energy accumulator or by a muscle-powered device.

the CN 201 924 601 U relates to decentralized hydraulics for the mast of a truck-mounted concrete pump.

the CN 104 863 366 A shows a hydraulic control block for the decentralized control of a concrete pump boom. The block contains a control valve that is hydraulically controlled by a central pilot valve.

In the EP 2 347 988 A1 a mast damping for the mast of a truck-mounted concrete pump is described. The individual boom cylinders are controlled conventionally, ie centrally. The activation of the first and second mast cylinder is superimposed for the vibration damping by decentralized valves, i.e. on the mast cylinders, which are supplied by a separate hydraulic pump.

Is described in U.S. 6,282,893 B1 a hydraulic cylinder in which the control valve, possibly also the hydraulic pump and the hydraulic tank, is integrated.

The object of the invention is to specify a control circuit and a manipulator that eliminates the disadvantages described and a safe Emergency operation and comfortable and intuitive operation if the regular control circuit components fail.

This object is achieved by an electrohydraulic control circuit according to claim 1 and by a manipulator according to claim 6.

According to the invention it is provided that in emergency operation the emergency valve is controlled via an emergency operating unit. This has the particular advantage that in the event of a failure or problems with the normal control system, which activates the proportional valves, the drive units can still be activated safely via the emergency valves, for example in order to salvage the articulated mast even if the mast hydraulic system for normal operation or the electrical control system fails be able. According to the invention, the emergency valve is actuated electrically via an emergency operating unit in emergency operation. This enables reliable control in emergency operation.

According to the invention, a power supply to the emergency operating unit is activated by means of a key switch in the emergency operating state. According to the invention, the emergency control unit has simple buttons and/or switches with which, on the one hand, the articulated joint or slewing gear of the articulated mast to be controlled is selected and, on the other hand, the direction of travel for the selected articulated joint or slewing gear or the respective

Drive unit is set. With this emergency control unit, a simple and less error-prone control for emergency operation is given, since the emergency control unit is electrically robust.

An advantageous embodiment provides that the proportional valve and the emergency valve are arranged directly on the associated drive unit to be controlled. The resulting relatively short hydraulic connecting lines lead to more sensitive control of the drive units. In the usual arrangement of the proportional valves for controlling the drive units of a large manipulator in a central control block arranged away from the drive units, the proportional valves are connected to the drive units via relatively long hydraulic lines. Because hose breaks or the like cannot be ruled out with this arrangement, the drive units usually have lowering brake valves which prevent the large manipulator from lowering in the event of damage. In machines according to the prior art, these lowering brake valves must first be pressed open by the hydraulic pressure before the drive unit can react. In connection with the long hydraulic lines or hoses, this leads to a greatly delayed response behavior of the drive units. When the proportional valve is arranged on or in the immediate vicinity of the drive unit, the hydraulic tubing between the proportional valve and the drive unit can be omitted and the lowering brake valves can be replaced by check valves with a comparatively faster control behavior, which further improves the reaction of the drive unit to control commands from the proportional valve.

An advantageous embodiment provides that the emergency operating unit is connected, preferably wired, to the power supply and the emergency valve. This ensures that the manipulator can be safely controlled in emergency operation via simple, preferably electrical connections, for example without the availability of the usual wireless radio remote control for controlling the proportional valves for normal operation or an electronic mast control,

A particularly advantageous embodiment provides that the emergency operating unit is connected, preferably wired, to the power supply and the emergency valve via a movable cable. In this way the operator can move away from the machine with the emergency control unit in order to be able to see the position of the mast during the emergency control. This ensures safe control of the articulated mast even in emergency operation.

According to the invention, the power supply provides a constant voltage and the emergency valve is controlled with this constant voltage.

This ensures in a simple manner that, in emergency operation, the manipulator can be operated with a simple, not necessarily regulated, voltage supply in emergency operation. According to the invention it is provided that the emergency operation unit is activated for emergency operation with a key switch, so that an unintentional or unauthorized activation of emergency operation is not possible.

According to the invention, switches and/or buttons are arranged on the emergency operating unit, with which the emergency valve can be subjected to a constant voltage by actuating the switches and/or buttons in order to move the associated drive unit. This enables simple, robust control of the drive units even in emergency operation.

It is also advantageous that the proportional valve can be controlled with a stepping motor. As a result, a safe electro-hydraulic control circuit can be implemented, which ensures excellent response behavior of the mast segments. In addition, proportional valves that can be controlled with a stepper motor are significantly lighter and smaller than similarly powerful valves with proportional magnets, which enables a significant weight saving and a reduction in the required installation space. Since the proportional valve with a stepper motor is also not a hydraulically pilot-controlled valve, this embodiment of the invention eliminates the need for a separate control oil circuit, which reduces the number of hydraulic lines on the mast segments, which also results in a significant weight saving.

It is of particular advantage that the stepping motor of the proportional valve can be controlled via a BUS data connection. This allows a significant weight saving compared to a hydraulic pilot control of the valve. This is of particular interest, since it enables the constant desire for a larger range of large manipulators to be realized.

It is also advantageous that a local control device (ECU) is set up on the drive unit in order to receive BUS data signals and to control the stepping motor of the proportional valve. With such a local control device (ECU), the stepping motor can be controlled particularly precisely and quickly by precisely specifying the setting steps. Another advantage of the local control device is that information can be processed locally and therefore the The number of electrical lines on the articulated mast and the utilization of the CAN bus system can be reduced to a minimum. Advantageously, a voltage supply to the outputs of the local control device (ECU) is switched off when switching to emergency operation. This guarantees that the (safety-relevant) valves controlled by the local control device are placed in a safe state.

It is of particular advantage that several separate power supplies can lead to the local control device (ECU), with at least a first power supply supplying the local control device (ECU), more precisely the computing units of this, and at least a second power supply supplying the outputs on the local control device ( ECU) supplied. In this way, the outputs of the local control unit (ECU), which can be connected to safety-related valves, can be switched off independently of the computing units of the local control unit (ECU). This ensures that the system is in a safe state in the event of an error, with the computing units of the local control unit (ECU) still being able to process data, for example to enable queries from locally connected sensors and the transmission of the measured values to a central controller.

A particularly advantageous embodiment provides that when switching over to emergency operation, the first voltage supply is interrupted and/or the second voltage supply remains activated. The interruption of the first voltage supply leads to the control device (ECU) being switched off, so that errors caused by this are avoided. Activating the second power supply means that the drive units can still be controlled. However, it can also be advantageous not to interrupt the first voltage supply so that the sensors connected to the control device (ECU) continue to supply information and the control device (ECU) logs this.

It is particularly advantageous that the emergency valve is actuated automatically at periodic intervals. This can happen, for example, when the control circuit or the manipulator is put into operation and the mast for example, is still in an edition. With this automatic actuation of the valves, it can be ensured that they do not jam even if they are not used for a long time. For this actuation, the control device also has a control output for the emergency valve, which is preferably isolated from the second voltage supply via a diode circuit.

Also advantageous is an embodiment in which check valves upstream and/or downstream of the proportional valve are relieved in emergency operation. This prevents the non-return valves from opening, since, depending on the cross-section of the return lines used, back pressures that cannot be ignored can occur with larger hydraulic oil delivery volumes, especially when moving the articulated mast.

One embodiment of the invention provides that the proportional valve and/or a switching valve and/or at least one check valve switch to a safe state when the power supply fails, in particular when the power supplies fail. In this way it can be ensured that the manipulator does not move and remains in the current position if the power supply fails.

An embodiment of the invention provides that the emergency valve is connected to another return line, while the proportional valve is connected to another, regular return line. This allows the drive unit to be controlled via the emergency valve, even if the regular return line has a fault or is leaking. Returning the hydraulic oil to the tank via separate return lines makes the control circuit less error-prone.

An embodiment of the invention provides that the additional pressure supply line is connected to an emergency pressure supply unit, while the other pressure supply line is connected to another pressure supply unit. This allows the drive unit to be driven safely in emergency operation, even if the regular pressure supply unit fails. The use of a separate emergency pressure supply unit makes the control circuit more fault-tolerant.

An advantageous embodiment provides that the proportional valve and the emergency valve are arranged directly on the associated drive unit to be controlled. The resulting relatively short hydraulic connecting lines lead to more sensitive control of the drive units. In the usual arrangement of the proportional valves for controlling the drive units of a large manipulator in a central control block arranged away from the drive units, the proportional valves are connected to the drive units via relatively long hydraulic lines. Because hose ruptures or the like cannot be ruled out with this arrangement, lowering brake valves are usually arranged on the drive units, which prevent the large manipulator from lowering in the event of damage. In machines according to the prior art, these lowering brake valves must first be pressed open by the hydraulic pressure before the drive unit can react. In connection with the long hydraulic lines or hoses, this leads to a greatly delayed response behavior of the drive units. When the proportional valve is arranged on or in the immediate vicinity of the drive unit, the hydraulic tubing between the proportional valve and the drive unit can be omitted and the lowering brake valves can be replaced by check valves with a comparatively faster control behavior, which further improves the reaction of the drive unit to control commands from the proportional valve.

It is also advantageous that the proportional valve can be controlled with a stepping motor. As a result, a safe electro-hydraulic control circuit can be implemented, which ensures excellent response behavior of the mast segments. In addition, proportional valves that can be controlled with a stepper motor are significantly lighter and smaller than similarly powerful valves with proportional magnets, which enables a significant weight saving and a reduction in the required installation space. Furthermore, since the proportional valve with a stepper motor is not a hydraulically pilot-operated valve, there is no need for a dedicated valve in this embodiment of the invention Control oil circuit, which reduces the number of hydraulic lines on the mast segments, which also results in significant weight savings.

It is of particular advantage that the stepping motor of the proportional valve can be controlled via a BUS data connection. This allows a significant weight saving compared to a hydraulic pilot control of the valve. This is of particular interest, since it enables the constant desire for a larger range of large manipulators to be realized.

It is also advantageous that a local control device (ECU) can be set up on the drive unit in order to receive BUS data signals and to control the stepping motor of the proportional valve. With such a local control device (ECU), the stepping motor can be controlled particularly precisely and quickly by precisely specifying the setting steps. Another advantage of the local control device is that information can be processed locally and therefore the number of electrical lines on the articulated mast and the utilization of the CAN bus system can be reduced to a minimum.

A voltage supply to the outputs of the local control unit (ECU) is advantageously switched off when switching over to emergency operation. This guarantees that the (safety-relevant) valves controlled by the local control device are placed in a safe state.

It is of particular advantage that several separate power supplies can lead to the local control device (ECU), with at least a first power supply supplying the local control device (ECU), more precisely the computing units of this, and at least a second power supply supplying the outputs on the local control device ( ECU) supplied. In this way, the outputs of the local control unit (ECU), which can be connected to safety-related valves, can be switched off independently of the computing units of the local control unit (ECU). A safe state of the system can thus be guaranteed in the event of an error, with data still being able to be processed by the arithmetic units of the local control unit (ECU). For example, to enable the querying of locally connected sensors and the transmission of the measured values to a central control.

A particularly advantageous embodiment provides that when switching over to emergency operation, the first voltage supply is interrupted and/or the second voltage supply remains activated. The interruption of the first voltage supply leads to the control device (ECU) being switched off, so that errors caused by this are avoided. Activating the second power supply means that the drive units can still be controlled. However, it can also be advantageous not to interrupt the first voltage supply so that the sensors connected to the control device (ECU) continue to supply information and the control device (ECU) logs this.

Also advantageous is an embodiment in which check valves upstream and/or downstream of the proportional valve are relieved in emergency operation. This prevents the non-return valves from opening, since, depending on the cross-section of the return lines used, back pressures that cannot be ignored can occur with larger hydraulic oil delivery volumes, especially when moving the articulated mast.

An advantageous embodiment provides that the emergency pressure supply unit is set up in normal operation to supply pressure to another pressure receiver used in normal operation. This can be, for example, a water pump for a high-pressure cleaner, since this unit is usually not used in emergency operation and is therefore available for the drive in emergency operation. This multiple use, both in normal operation and in emergency operation, saves weight and reduces the number of components required.

Of particular advantage is an embodiment in which the emergency pressure supply unit is set up to supply pressure to an agitator during normal operation. In normal operation, the agitator is driven by a hydraulic motor and stirs the liquid concrete in the feed hopper of a concrete pump so that the concrete can be pumped through a concrete pump after it has been poured in Truck mixer not solidified in the hopper and the suction openings of the delivery cylinder can be better fed. For emergency operation of the manipulator, the emergency pressure supply unit is simply switched over.

One embodiment of the invention provides that the proportional valve and/or a switching valve and/or at least one check valve switch to a safe state when the power supply fails, in particular when the power supplies fail. In this way it can be ensured that the manipulator does not move and remains in the current position if the power supply fails. It is particularly advantageous that the emergency valve is actuated automatically at periodic intervals. This can happen, for example, when the control circuit or the manipulator is put into operation and the mast is still on a support, for example. With this automatic actuation of the valves, it can be ensured that they do not jam even if they are not used for a long time. For this actuation, the control device also has a control output for the emergency valve, which is preferably isolated from the second voltage supply via a diode circuit.

It is also advantageous that, in order to close check valves, they are relieved via the additional return line. This allows the use of smaller cross-sections for the regular return line, since the check valves can be closed safely even with larger dynamic pressures. A smaller cross-section in the return line also offers potential for reducing the overall weight of the control circuit or the manipulator. The invention also relates to a manipulator, in particular a large manipulator for truck-mounted concrete pumps, with an articulated mast that can be folded out, which has a turntable that can be rotated about a vertical axis and a plurality of mast segments, with the mast segments being pivotable to a limited extent on articulated joints about bending axes relative to an adjacent mast segment or the turntable are wherein an electrohydraulic control circuit as above and below described, is provided. A manipulator with such a control circuit enables safe emergency operation if the regular control circuit components fail.

An advantageous embodiment of this manipulator provides that the proportional valve is arranged directly on an associated drive unit to be controlled, that is to say at the attachment location of the drive unit. Due to the particularly small size and the low weight of the proportional valve according to the invention, this is particularly suitable for a decentralized hydraulic control circuit. The proportional valve can be arranged on the drive unit to be controlled in such a way that the proportional valve, together with the drive unit on the mast segment of the articulated mast, changes its position relative to the turntable or the concrete pump. Thanks to the direct arrangement of the proportional valve on the associated drive unit to be controlled, the length of the working lines can be significantly reduced, which improves the response behavior of the manipulator and allows it to be moved more agilely and dynamically.

Figuren 1 und 2:

einen hydraulischen Steuerkreis gemäß der Erfindung;

Figur 3:

Schaltplan eines Steuerkreises für ein einzelnes Antriebsaggregat;

Figur 4:

erfindungsgemäßer Manipulator

Figur 5:

einen elektrohydraulischen Steuerkreis gemäß der Erfindung mit Notbedienungseinheit.

Further features, details and advantages of the invention result from the following description and from the drawings. An embodiment of the invention is shown purely schematically in the following drawings and is described in more detail below. Corresponding objects are provided with the same reference symbols in all figures. Show it:

Figures 1 and 2:

a hydraulic control circuit according to the invention;

Figure 3:

Circuit diagram of a control circuit for a single power unit;

Figure 4:

manipulator according to the invention

Figure 5:

an electro-hydraulic control circuit according to the invention with emergency control unit.

the figure 1 shows an electrohydraulic control circuit 1 according to the invention for controlling hydraulically operated drive units, wherein in figure 1 a total of five drive units 2, 2a, 2b, 2c, 2d for driving the mast segments 3, 3a, 3b, 3c, 3d ( 4 ) are shown. The drive units 2, 2a, 2b, 2c, 2d allow an adjustment of the mast segments 3, 3a, 3b, 3c, 3d ( 4 ) of the manipulator 4 ( 4 ) regarding their orientation. The drive units 2, 2a, 2b, 2c, 2d can be driven in normal operation by means of a first hydraulic pressure supply unit 5, with this operating state in figure 1 is shown. Here, the first pressure supply unit 5 supplies the drive units 2, 2a, 2b, 2c, 2d with hydraulic pressure via the pressure supply (P1) 24 in order to drive the drive units 2, 2a, 2b, 2c, 2d. The first pressure supply (P1) 24 is in figure 1 shown in phantom, while the first return (T1) 25 is shown in phantom. The hydraulic oil conveyed by the first pressure supply unit 5 is supplied to the individual mast segments 3, 3a, 3b, 3c, 3d ( 4 ) or the drive units 2, 2a, 2b, 2c, 2d arranged there. The first return (T1) 25 returns the hydraulic oil from the drive units 2, 2a, 2b, 2c, 2d to the tank 23, from where the hydraulic oil is available for renewed delivery through the hydraulic pump line 22. In addition to the first pressure supply unit 5 , the hydraulic pump train 22 includes further pressure supply units 6 , 8 . The second pressure supply unit 6 is connected to charge a hydraulic accumulator 7 in its first operating state. The third pressure supply unit 8, which is used as an emergency pressure supply unit 8, supplies an agitator 9 or its drive motor with hydraulic pressure during normal operation. The individual drive units 2, 2a, 2b, 2c, 2d have their own proportional valves 28 ( 3 ), which are arranged in parallel on the first pressure supply (P1) 24 and on the first return (T1) 25. Preferably, the proportional valve 28 ( 3 ) with a stepping motor 31 ( 3 ) controllable. With the proportional valve 28 ( 3 ) the associated drive unit 2, 2a, 2b, 2c, 2d, in particular the hydraulic cylinder, can be moved by the proportional valve 28 ( 3 ) the drive unit 2, 2a, 2b, 2c, 2d associated working lines 29, 30 ( 3 ) subjected to a pressure difference. For this purpose, the working lines 29, 30 ( 3 ) either with a first pressure supply (P1) 24 or a first return (T1) 25 through the proportional valve 28 ( 3 ) connected. In figure 1 An emergency stop circuit with an emergency stop valve 21 can also be seen, through which the hydraulic oil conveyed by the pressure supply units 5, 6 can simply flow back into the tank 23 in an emergency. The emergency stop valve 21 is switched, for example, when one of the emergency stop buttons 51 ( figure 5 ) is pressed. For its second operating state, the second pressure supply unit 6 has a downstream switchover 19, via which the hydraulic oil delivered can be switched over from the hydraulic accumulator 7 of a piston pump to the first pressure supply (P1) 24. With the switchover of the second pressure supply unit 6 to the first pressure supply (P1) 24, the delivery volume can be increased in such a way that the drive units 2, 2a, 2b, 2c, 2d the mast segments 3, 3a, 3b, 3c, 3d ( 4 ) Pivot such that the specified speeds of the individual drive units 2, 2a, 2b, 2c, 2d are reliably achieved even when several drive units are moved at the same time. In particular for quick erection and dismantling of the articulated mast 10 ( 3 ) it makes sense to switch on the second pressure supply unit 6 in order to move the manipulator 4 ( 4 ) to be able to pivot in the range of the maximum possible speed. The emergency pressure supply unit 8 also has a downstream switch 20, in which case the pumped hydraulic oil can be switched away from the agitator 9, as a possible pressure receiver in normal operation, towards the emergency circuit (P2, T2) 26, 27 in emergency operation. This emergency circuit 26, 27 enables the drive units 2, 2a, 2b, 2c, 2d to be moved if the regular pressure supply (P1, T1) 24, 25 fails. The drive units 2, 2a, 2b, 2c, 2d, in particular their hydraulic cylinders, can be proceeded in emergency operation in that the separate pressure supply (P2) 26 or the separate return (T2) 27 applies a pressure difference to the drive units 2, 2a, 2b, 2c, 2d. For this purpose, the working lines 29, 30 ( 3 ) optionally connected to the second pressure supply (P2) 26 or a second return (T2) 27 from the control valve 36 for emergency operation. In emergency operation, the drive units 2, 2a, 2b, 2c, 2d are supplied with pressure by the emergency pressure supply unit 8 via the separate pressure supply (P2) 26 and the separate return (T2) 27, so that if there is a leak in the pressure supply (P1) 24 or the return (T1) 25, but also if the first pressure supply unit 5 fails, it is still possible to control the drive units 2, 2a, 2b, 2c, 2d is. This ensures that if the regular pressure supply (P1, T1) 24, 25 fails, the articulated mast 10 ( 4 ) can still be moved, for example to remove articulated mast 10 ( 4 ) to retract and, if necessary, to pump out the residual concrete from the concrete pump and the delivery pipes.

In figure 2 the electrohydraulic control circuit 1 is off figure 1 shown in emergency mode. The emergency pressure supply unit 8 is switched on via the switchover 20 of the separate pressure supply (P2) 26, which is shown in dashed lines, and supplies the drive units 2, 2a, 2b, 2c, 2d with hydraulic pressure and thus drives the drive units 2, 2a, 2b, 2c, 2d on. The return of the hydraulic oil runs via the second return (T2) 27, which is shown in broken lines. In this state, a power supply is supplied to an emergency operation unit 56 ( figure 5 ) by means of a key switch 53 ( figure 5 ) via a switch 55 to be actuated electrically, for example ( figure 5 ) activated. The emergency control unit 56 is connected via the switch 55 to a simple voltage source, for example the manipulator's on-board battery 54, which supplies a constant voltage ( figure 5 ) and has simple buttons and/or switches with which, on the one hand, the articulated joint 13, 13a, 13b, 13c, 13d ( 4 ) or slewing gear 12 ( 4 ) of articulated mast 10 ( 4 ) is selected and on the other hand the direction of travel for the selected articulated joint 13, 13a, 13b, 13c, 13d ( 4 ) or slewing gear 12 ( 4 ) or the drive unit 2, 2a, 2b, 2c, 2d ( Figures 1 to 3 ) is specified. With this emergency operating unit 56 ( figure 5 ) is a simple and less error-prone control for emergency operation, since the emergency operation unit 56 ( figure 5 ) is electrically robust. From the emergency operation unit 56 ( figure 5 ) leads a cable bundle with twelve cores to the emergency valves. By pressing the button on the emergency operating unit 56 ( figure 5 ) the 24 V voltage supply of an on-board battery 54 ( figure 5 ) on the respective electromagnetic emergency valve 36 to be actuated for the selected articulated joint 13, 13a, 13b, 13c, 13d ( 4 ) or slewing gear 12 ( 4 ) placed. The emergency operating unit 56 ( figure 5 ) can be hardwired or wired or be connected to the electrical system via a plug connection, for example an option box. Preferably, the emergency operating unit 56 ( figure 5 ) via a long cable 57 ( Fig.5 ) is connected to the machine so that the user can use the emergency control unit 56 ( figure 5 ) from the manipulator and can follow the articulated mast movements without having to rely on the help of other people.

Alternatively, it is also conceivable to use the emergency operating unit 56 ( figure 5 ) from a switching device attached to the machine with a radio receiver, which can be operated via another simple separate radio remote control or the radio remote control 15 ( 4 and 5) is controlled.

the figure 3 shows a schematic representation of an electrohydraulic control circuit 1 for controlling a hydraulically actuated drive unit 2, by means of which a mast segment 3, 3a, 3b, 3c, 3d ( 4 ) of a manipulator, in particular a large manipulator for truck-mounted concrete pumps, is adjustable in terms of its orientation, with an electrically controlled proportional valve 28, which is connected to the hydraulic working lines 29, 30 of the drive unit 2 to control it. For a better overview, only a detail of the control circuit 1 is off figure 1 and 2 shown, which controls a drive unit 2. The proportional valve 28 can be controlled with a stepping motor 31, the proportional valve 28 containing a valve piston and a return spring. The valve piston on the proportional valve 28 is actuated via a toothed rack by means of the stepping motor 31. A monitoring unit for monitoring the adjustment steps carried out by the stepping motor 31 is provided on the stepping motor 31. In order to be able to understand the position in which the proportional valve 28 is located, a memory is also provided for storing the adjustment steps of the stepper motor 31 that have been carried out. The actuation by means of the stepper motor 31 enables a very precise adjustment of the proportional valve 28 independently of the flow forces that occur, which particularly accurate control of the drive unit 2 allows. In figure 3 the electrically controlled proportional valve 28 can also be seen, with which the drive unit 2, in particular the hydraulic cylinder, can be moved by Proportional valve 28 acts on the working lines 29, 30 assigned to the drive unit 2 with a pressure difference. For this purpose, the working lines 29, 30 are optionally connected to a first pressure supply (P1) 24 or a first return (T1) 25 through the proportional valve 28. The proportional valve 28 is controlled via an associated stepping motor 31 by a local electronic control device ECU (electronic control unit), which is set up to receive BUS data signals and to control the stepping motor of the proportional valve. The local electronic control unit (ECU) monitors the state of the local system via sensors connected to it (e.g. the pressure sensors 32a, 32b), enables the implementation of complex algorithms, offers an interface for external communication, in particular to a central control unit 52 via a bus system ( preferably CAN) to connect. The sensors can be connected either analogously or via another local BUS system (in particular CAN). The local processing of the sensor data has the advantage that the electrical connection lines to a central control unit 52 ( 4 u. 5) and the utilization of the BUS system, which the local control device (ECU) with the central control unit 52 ( 4 u. 5) connects, to be or will be reduced. Several power supplies are provided to supply the local control unit (ECU) with energy, with a first power supply (U1) supplying the local control unit (ECU) and at least one second power supply (U2) supplying the outputs on the local control unit (ECU). In the event of an emergency stop triggered by an emergency stop button 51 ( attached to the machine figure 5 ) or by detection of a fatal error by the local control unit (ECU) or the central control unit 52 ( 4 u. 5), the following steps are carried out: the hydraulic oil flow is controlled via the emergency stop valve 21 ( 1 and 2) to tank 23 ( 1 u. 2) diverted, in addition, all hydraulic supplies for the operation of the concrete pump are switched off or to tank 23 ( 1 and 2) redirected. Furthermore, the second power supply (U2) is switched off, so that the outputs of the local control unit (ECU) are de-energized, and all valves switch to a safe state, so that no mast movement can take place. In this case of error, the key switch 53 ( figure 5 ) can be switched to emergency mode so that the Emergency control unit 56 ( figure 5 ) via a switch 55 ( figure 5 ) from an on-board battery 54 ( figure 5 ) are supplied with voltage. In addition, emergency operation can be activated if one of the drive units 2, 2a, 2b, 2c, 2d or the slewing gear 12 ( 4 ) cannot be moved in normal operation due to a malfunction. Here, too, the key switch 53 ( figure 5 ) switched to emergency operation, which also means that the second power supply (U2) is switched off, so that the outputs of the local control unit (ECU) are de-energized.

In normal operation, depending on the position of the proportional valve 28, a supply pressure assigned to the pressure supply (P1) 24 is switched to a working line 29 or 30 of the assigned drive assembly 2. The check valves 33, 33a perform a load holding function when the control circuit 1 is in an inactive state or safe state. The check valve 38 also has a safety function, in particular it prevents the check valves 33, 33a from being pressed open in the event of a jammed valve piston outside of the central position in the proportional valve 28. The check valves 33, 33a and 38 are preferably designed as hydraulically pilot-operated check valves which are actuated indirectly by means of an electrically controllable switching valve 37 are opened. In addition, pressure sensors 32, 32a, 32b are provided which measure the supply pressure in the active state of the control circuit 1 and the pressures which act on the drive unit 2. In the illustrated embodiment, the electrohydraulic control circuit 1 also includes a hydraulic emergency circuit connected in parallel with the proportional valve 28 for emergency operation. This emergency circuit enables the drive unit 2 to be moved if the components assigned to the proportional valve 28 (upstream or downstream) fail. Each proportional valve 28 for controlling a drive assembly 2, 2a, 2b, 2c, 2d is assigned its own emergency circuit. The emergency circuit includes a control valve 36 for controlling the direction of travel of the drive assembly 2 in emergency operation and two mutually coupled valves 35, 35a, which are designed as hydraulically pilot operated check valves or lowering brake valves 35, 35a in a classic configuration. With the downstream adjustable flow control valves 34, 34a, the speed of travel can be adjusted in emergency operation. The drive unit 2, in particular the hydraulic cylinder, can be used in emergency mode be moved in that the control valve 36 for emergency operation applies a pressure difference to the working lines 29, 30 assigned to the drive unit 2. For this purpose, the working lines 29, 30 are optionally connected to a second pressure supply (P2) 26 or a second return (T2) 27 from the control valve 36. In emergency operation, the drive unit 2 is preferably supplied with pressure via the separate pressure supply (P2) 26 and the separate return (T2) 27, so that if there is a leak in the pressure supply (P1) 24 or the return (T1) 25, control of the drive unit 2 is possible. In this way it can be ensured that in the event of a failure of the regular mast control including the proportional valve 28, the articulated mast 10 ( 4 ) can still be moved, for example to remove articulated mast 10 ( 4 ) to retract and, if necessary, to pump out the residual concrete from the concrete pump and the delivery pipes. For this purpose, the local electronic control unit (ECU) monitors the state and the behavior of the control circuit 1 by means of the available sensors. As soon as the local electronic control unit (ECU) detects an error, it automatically switches the control circuit 1 to a safe state. For this purpose, the proportional valve 28 and, via the switching valve 37, the non-return valves 33, 33a, 38 are preferably switched to a safe state, in particular also when the power supply fails. The local electronic control unit (ECU) can be activated via a BUS system, which transmits control commands and setpoint values, which are preferably transmitted via a user interface, such as via the remote control device 15 ( 4 ), specified by a user and sent to the central control unit 52 ( 4 u. 5) are transmitted which, under certain circumstances, are processed and passed on to the local electronic control units (ECU).

In figure 4 a manipulator 4 according to the invention, in particular a large manipulator for truck-mounted concrete pumps, is shown schematically, with a folding mast 10 which has a turntable 12 rotatable about a vertical axis 11 and a plurality of mast segments 3, 3a, 3b, 3c, 3d. The mast segments 3, 3a, 3b, 3c, 3d, five in total in the exemplary embodiment, are on articulated joints 13, 13a, 13b, 13c, 13d, each about bending axes relative to an adjacent mast segment 3, 3a, 3b, 3c, 3d or the turntable 12 pivotable. For this purpose, on the mast segments 3, 3a, 3b, 3c, 3d in the Articulated joints 13, 13a, 13b, 13c, 13d each have a drive unit 2, 2a, 2b, 2c, 2d ( Figures 1 to 3 ) arranged. To control the drive units 2, 2a, 2b, 2c, 2d ( Figures 1 to 3 ) A central control unit 52 is provided, which converts a travel command, which specifies a desired direction of movement and travel speed of the mast tip 14 of the articulated mast 10 or an end hose attached thereto, into control signals for the drive units 2, 2a, 2b, 2c, 2d ( Figures 1 to 3 ) implemented. With the control lever 16 on the remote control device 15, which can be adjusted in several directions, a corresponding driving command can be generated. For this purpose, the control lever 16 is moved in an adjustment direction, and the central control unit 52 receives the generated driving command. The central control unit 52 then converts the driving command into control signals for the drive units 2, 2a, 2b, 2c, 2d ( Figures 1 to 3 ) around. These control signals are received by the local control unit (ECU) and converted into switching signals for the respective proportional valve 28 ( 3 ) or its stepping motor 31 ( 3 ) converted. The desired travel speed is also specified with the travel command. In order to be able to achieve higher travel speeds, the central control unit 52 switches to drive the drive units 2, 2a, 2b, 2c, 2d ( Figures 1 to 3 ) the additional pressure supply unit 6 ( 1 and 2) the first pressure supply unit 5 ( 1 and 2) to, this is preferably done automatically. The control unit can be switched between several operating states, with the automatic activation of the additional pressure supply unit 6 ( 1 and 2) preferably only occurs in a specific operating state. The user selects this special operating state, in particular when folding and unfolding the articulated mast 10, in order to select the maximum possible or permissible speeds for the drive units 2, 2a, 2b, 2c, 2d ( 1 u. 2) to be able to make optimal use of it and thus to save time when erecting the mast.

Reference List

1

control circuit

2 2a, 2b, 2c, 2d

drive units

3 3a, 3b, 3c, 3d

mast sections

4

manipulator

5

First pressure supply unit

6

Second pressure supply unit

7

hydraulic accumulator

8th

emergency pressure supply unit

9

agitator

10

articulated mast

11

vertical axis

12

turntable

13 13a, 13b, 13c, 13d

articulated joints

14

masthead

15

remote control device

16

control lever

17

steering

18

main valve

19

Shift A

20

Switch B

21

emergency stop valve

22

hydraulic pump train

23

tank

24

Pressure supply (normal operation)

25

return (normal operation)

26

Pressure supply (emergency operation)

27

return (emergency operation)

28

proportional valve

29

Working line A

30

Working line B

31

stepper motor

32 32a, 32b

pressure sensors

33 33a

load-holding/blocking valves

34 34a

adjustable flow control valves

35 35a

Lowering brake (check) valves

36

Control valve (emergency operation)

37

switching valve

38

check valve

51

Emergency stop button

52

Central control

53

key switch

54

board battery

55

Emergency operation switch

56

emergency control panel,

57

cable

ECU

control device

U1

first power supply

U2

second power supply

Claims (6)

1. Electrohydraulic control circuit (1) with hydraulically operated drive units (2, 2a, 2b, 2c, 2d) by means of which boom segments (3, 3a, 3b, 3c, 3d) of a manipulator (4), in particular a large manipulator for truck-mounted concrete pumps, with a fold-out articulated boom (10), which has a turntable (12) rotatable about a vertical axis and a plurality of boom segments (3, 3a, 3b, 3c, 3d), wherein the boom segments (3, 3a, 3b, 3c, 3d) are pivotable to a limited extent on articulated joints (13, 13a, 13b, 13c, 13d) respectively about articulated axes relative to an adjacent boom segment (3, 3a, 3b, 3c, 3d) or the turntable (12) by means of a drive unit in each case, are adjustable in respect of their orientation, each with an electrically controlled proportional valve (28) associated with one of the drive units, which valve is connected to hydraulic operating lines (29, 30) of the respective drive unit (2, 2a, 2b, 2c, 2d) for controlling it in normal operation, wherein the respective proportional valve (28) is connected to a pressure supply line (24) and to a return line (25), wherein an emergency valve (36) is connected for emergency operation to the hydraulic operating lines (29, 30) of the respective drive unit (2, 2a, 2b, 2c, 2d) for controlling it in emergency operation,
   characterised in that
   in emergency operation the emergency valve (36) is electrically controlled via an emergency operating unit (56), wherein the emergency operating unit (56) for emergency operation is activated by a key switch (53), wherein a voltage supply (54) with constant voltage to the emergency operating unit (56) is activated by means of the key switch (53), wherein switches and/or buttons are arranged on the emergency operating unit (56), wherein the emergency valve (36) can be acted upon by actuation of at least one of the switches and/or buttons with the constant voltage in order to move the associated drive unit (2, 2a, 2b, 2c, 2d), wherein the articulated joint (13, 13a, 13b, 13c, 13d) to be controlled or the turntable (12) of the articulated boom (10) is selected using the keys and/or buttons on the one hand and on the other hand the direction of travel for the selected articulated joint (13, 13a, 13b, 13c, 13d) or the turntable (12) and the respective drive unit (2, 2a, 2b, 2c, 2d) is determined.
2. Control circuit (1) according to claim 1, characterised in that the emergency operating unit (56) is connected to the voltage supply (54) and the emergency valve (36).
3. Control circuit (1) according to claim 2, characterised in that the emergency operating unit (56) is connected via a flexible cable (57) to the voltage supply (54) and the emergency valve (36).
4. Control circuit (1) according to any one of the previous claims, characterised in that the respective proportional valve (28) is controllable by a stepper motor (31), wherein the stepper motor (31) of the proportional valve (28) is controllable via a BUS data connection.
5. Control circuit (1) according to claim 4, characterised in that a control device (ECU) is arranged on the respective drive unit (2, 2a, 2b, 2c, 2d) to receive BUS data signals and to control the stepper motor (31) of the proportional valve (28).
6. Manipulator (4), in particular large manipulator for truck-mounted concrete pumps, with a fold-out articulated boom (10), which has a turntable (12) rotatable about a vertical axis (11) and a plurality of boom segments (3, 3a, 3b, 3c, 3d), wherein the boom segments (3, 3a, 3b, 3c, 3d) are pivotable to a limited extent on articulated joints (13, 13a, 13b, 13c, 13d) respectively about articulated axes relative to an adjacent boom segment (3, 3a, 3b, 3c, 3d) or the turntable (12), characterised by an electrohydraulic control circuit (1) according to any one of the previous claims.

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