EP3770428B1 - Hydraulic compressed medium supply assembly for a mobile working machine and method - Google Patents

Description

field of invention

The invention relates to a hydraulic pressure medium supply arrangement for an open hydraulic circuit, for example for mobile working machines, according to the preamble of claim 1.

Background of the Invention

A pressure and flow control system is known from the document RE 30630/04.13 from Rexroth. This is used for the electro-hydraulic control of a swivel angle, a pressure and an output of an axial piston variable displacement pump. The control system has an axial piston variable displacement pump with an electrically controlled proportional valve. This can be used to control an actuating piston. This is used to adjust a swash plate of the variable displacement pump. A displacement sensor is provided for the actuating piston, via which a pivoting angle of the swash plate can be determined on the basis of the displacement path of the actuating piston. As an alternative to the position sensor, a swivel angle of the swash plate can also be picked up on the swivel axis using a Hall sensor. The volume flow of the variable displacement pump can in turn be determined from the swivel angle of the swash plate. The variable displacement pump is driven by a motor. If the variable displacement pump is not driven and the actuating system is depressurized, then the variable displacement pump pivots to a maximum delivery volume by the spring force of a spring. On the other hand, when the variable displacement pump is in the driven state and the pilot valve is de-energized and the pump outlet is closed, the variable displacement pump pivots to a zero stroke pressure. Equilibrium between the pump pressure on the setting piston and the spring force of the spring occurs at around 4 to 8 bar. The basic setting is usually adopted with the control electronics de-energized. A controller for the pilot valve has a target pressure, a target swivel angle and optionally a target power value as input variables. An actual pressure on the outlet side of the variable displacement pump is detected by a pressure sensor. As explained above, an actual swivel angle is determined via the displacement pickup. The recorded actual values are processed digitally in an electronic unit and compared with the specified target values. A minimum value generator then ensures that only the controller assigned to the desired operating point is automatically active. An output signal from the minimum value generator is then a desired value for a proportional magnet on the pilot valve. To control the pilot valve, a displacement path of a valve spool of the pilot valve is detected by a displacement pickup and reported to the controller. In the document RE 30242/03.10 from Rexroth, external control electronics for the described adjustment of the axial piston adjustment machine are disclosed. Furthermore, an electro-hydraulic control system is disclosed in the document RD 92 088/08.04 from Rexroth.

From the EP 1 460 505 A2 an alternate regulation of a pressure and a flow rate is disclosed. Here, a pivotable hydraulic axial piston adjustment machine is provided, which is connected to another hydraulic machine via a drive shaft. Furthermore, a control circuit for a drive torque of the adjusting machine is provided. An actual drive torque and a setpoint drive torque are supplied to the control circuit, from which a manipulated variable for an actuating device of the adjusting machine is determined. The setpoint drive torque, in turn, is an output variable from a minimum value generator. This selects an output variable of a pressure control and a volume flow control. The volume flow of the hydraulic machine connected to the adjustment machine is provided as the actual volume flow. Furthermore, a high pressure of this hydraulic machine is provided as the actual pressure.

Furthermore, in the documents EP 2 851 565 B1 , U.S. 4,801,247 , U.S. 5,182,908 , EP 034 9092 B1 , US5267441 , US5967756 and US5170625 each disclosed a hydraulic machine with a swivel angle sensor and a pressure sensor. The pressure, the volume flow and the power can be controlled.

Disclosure of Invention

In contrast, the invention is based on the object of creating a hydraulic pressure medium supply arrangement that is simple and inexpensive in terms of device technology and yet reliably and dynamically regulates and/or limits essential control variables of an adjustable hydraulic machine and parameters. Furthermore, a simple method for the pressure medium supply arrangement should be provided.

The object with regard to the pressure medium supply arrangement is achieved according to the features of claim 1 and with regard to the method according to the features of claim 13.

Advantageous developments of the invention are the subject matter of the dependent claims.

According to the invention, a hydraulic pressure medium supply arrangement is provided for an open hydraulic circuit, in particular for a mobile work machine. The pressure medium supply arrangement can have a hydraulic machine and an adjustment mechanism. The adjustment mechanism is preferably used to adjust a delivery volume of the hydraulic machine. An actuating cylinder with an actuating piston is provided for this purpose. Furthermore, the adjustment mechanism has an electrically proportionally controllable pilot valve. This can be used to control an inflow and/or an outflow in a control chamber of the actuating cylinder that is delimited by the actuating piston, in order to apply pressure medium to the actuating piston for actuation. Furthermore, the pressure medium supply arrangement preferably has an electronic controller. More preferably, this has at least one setpoint outlet pressure of the hydraulic machine as an input variable. Alternatively or additionally, a setpoint delivery volume of the hydraulic machine can be provided as an input variable for the controller. It is conceivable to define the target variable(s) or alternatively to design them to be adjustable, so that they can be adapted as needed during operation, for example. A manipulated variable for the pilot valve is preferably provided as the output variable of the controller. Furthermore, the controller can have a first control loop for an actual outlet pressure of the hydraulic machine. This is preferably tapped off between a high-pressure connection of the hydraulic machine and a main control valve for consumers. Alternatively or additionally, the first control loop can be provided for an actual delivery volume of the hydraulic machine. If the hydraulic machine is an axial piston machine with an adjustable swivel cradle or swash plate for setting a delivery volume, the actual delivery volume can be recorded using a suitable means, for example a swivel angle sensor, such as a displacement sensor for the actuating piston. As an alternative to the position sensor, a swivel angle of the swash plate can also be picked up on the swivel axis using a Hall sensor. In other words, a measuring device for detecting the displacement position or the displacement volume is provided. It would also be conceivable to determine the swivel angle via a torque of the drive shaft and a pressure measurement. Preferably, the first control loop is subordinate to a second control loop, which can be provided for a delivery volume adjustment speed. An actual delivery volume adjustment speed, in particular as a derivation of the actual delivery volume, of the hydraulic machine is preferably provided as the input variable for the second control circuit. If the actual delivery volume adjustment speed is determined via the actual delivery volume, the recorded actual delivery volume can advantageously be used both for the first and for the second control circuit, which means that separate detection of the actual delivery volume adjustment speed is not necessary. An output variable of the second control loop is preferably the manipulated variable for the pilot valve. Advantageously, the second control loop, a control value from the first Be supplied control circuit in the form of a delivery volume adjustment speed. The manipulated variable from the first control loop can then be a target value for the second control loop.

This solution has the advantage of creating an electronically controllable hydraulic machine for open circuit mobile applications which has a simple pump adjustment mechanism without hydromechanical feedback. In contrast to the prior art, it is not necessary to detect a position of the actuating piston of the pilot valve, which means that corresponding means can be dispensed with, with the result that costs and the complexity of the device are reduced. The pressure medium supply arrangement is therefore designed to be extremely simple and inexpensive. By taking into account the actual delivery volume adjustment speed, the dynamics of the system are in turn taken into account when controlling the pilot valve. The manipulated variable of the pilot valve is therefore also dependent on the displacement volume adjustment speed, which leads to high control quality.

In a further embodiment of the invention, the first control circuit preferably has the actual outlet pressure of the hydraulic machine and/or the actual delivery volume of the hydraulic machine as input variables.

The first control loop of the controller can also be designed for an actual torque of the hydraulic machine. A target torque and an actual torque, for example, are then provided as input variables for the controller. Alternatively or additionally, it is conceivable that the first control loop of the controller is designed for an actual power including an actual speed of the hydraulic machine. It is also conceivable that the actual power or the actual torque can be determined from the actual speed via a characteristic curve in order to then regulate the actual power. A controller, in particular a P controller, can be provided for controlling the actual torque. Alternatively, it is conceivable to design the controller as a PI controller or as a PID controller.

In a further embodiment of the invention, the first control loop has a manipulated variable for the actual output pressure of the hydraulic machine and/or for the actual delivery volume of the hydraulic machine and/or for the actual torque of the hydraulic machine. The controller can then provide an overriding control that has a minimum value generator for the output manipulated variables of the first control loop. An output variable of the minimum value generator is then preferably the control value in the form of the delivery volume adjustment speed, which is supplied to the second control loop. The minimum value generator ensures that only the controller assigned to the desired operating point is automatically active. For example, the minimum value generator selects the smallest of the manipulated variables that are supplied and then feeds this to the subordinate second control circuit as the target delivery volume adjustment speed.

The first control loop preferably has a controller for the delivery volume or the swivel angle—from which the delivery volume can be determined—of the hydraulic machine. This is preferably a P controller, for example. Alternatively, this can be designed as a PI controller or as a PID controller. The controller can have a target swivel angle and an actual swivel angle or a target delivery volume or actual delivery volume as an input variable.

A filter, for example in the form of a PT1 element or a filter of a higher order, is preferably provided for the actual swivel angle. The signal can be calmed down in a simple manner by the filter.

The first control circuit preferably has a regulator for the actual outlet pressure of the hydraulic machine. The actual outlet pressure and the setpoint outlet pressure, which are recorded in particular by a pressure sensor, are supplied to this as input variables. A PID controller is preferably provided as the controller. Alternatively, a P controller or PI controller can be used. The target outlet pressure of the hydraulic machine is preferably adjustable. In particular, an actual load-sensing (LS) pressure of the consumers, which are supplied with pressure medium via the pressure medium supply arrangement, is recorded in order to determine the desired output pressure. In particular, the actual LS pressure is the highest actual load pressure of the consumers. The actual LS pressure is preferably fed to the controller or regulator for the actual outlet pressure as an input variable. In a load-sensing (LS) control, the highest load pressure of the variable displacement pump is to be reported and the variable displacement pump is to be regulated in such a way that the actual outlet pressure in the pump line is a specific pressure difference (delta_p) above the highest actual load pressure. Thus, it is advantageously provided that the regulator for the actual outlet pressure is additionally supplied with a setpoint differential pressure as an input variable. The target outlet pressure can then be calculated by adding the actual LS pressure and the target differential pressure and can be used by the controller as an input variable. The setpoint differential pressure can either be parameterized as a fixed value or can be flexibly adjusted and specified as a parameter.

In particular, it is also conceivable to record several actual LS pressures and to form a maximum value or to prioritize in the controller. This can be done by feedback to a main valve or to a main control valve if, for example, a delivery rate of the hydraulic machine (pump) is limited and the delivery rate guided through the main valve can thus be limited, which, for example, prioritizes a hydraulic steering in the event of a Undersupply is possible. In this case, the hydraulic machine (pump) is advantageously set to a minimum quantity in addition to the LS pressure control, in order to also ensure steerability in the event of a pressure sensor error. In other words, the LS pressure, on the basis of which the hydraulic machine is regulated, can be regarded as the leading variable. In addition, it is conceivable that a minimum amount is set as a function of the steering request, so that steering ability is retained even if there is incorrect information regarding the LS pressure.

An I component can be provided in a controller for the actual outlet pressure and/or for the actual delivery volume and/or for the actual torque, such as in a PID controller, which is explained above. It can then be provided, particularly when using the minimum value generator, that the controller or controller(s) that are not active and have an I component freeze the I component or, in particular, partially or completely reset it. If the controller is then active, the I component is used in the usual way and the controller can react immediately. As a result, the I component of the controller(s) is/are not raised during inactivity. This embodiment can be referred to as "anti-windup", which means that the freezing and the reset of the I component are combined.

One or more filters with a pressure-dependent filter coefficient can advantageously be provided for the regulator of the actual outlet pressure. The respective filter is, for example, a variable PT1 filter or a higher-order filter. The filter or a respective filter is preferably provided for the actual outlet pressure and/or for the actual LS pressure. The pressure-dependent filter is preferably designed in such a way that when the actual outlet pressure of the hydraulic machine increases, the filtering is reduced and, conversely, when the actual outlet pressure of the hydraulic machine decreases, the filtering is increased in order to influence the dynamics of the control.

Alternatively or additionally, one or more filters, in particular with pressure-dependent filter coefficients, can be used for the other controllers listed above and below, in particular for one or more input variables.

Alternatively or additionally, it is conceivable to provide an asymmetric filter for the controller of the actual outlet pressure and/or for one or more of the controllers listed above and below, in particular for the one or more input variable(s). This depends on the direction in which the swash plate is pivoted. This means that the filtering of the filter in the first pivoting direction is different compared to the filtering in the second pivoting direction.

In a further embodiment of the invention, an amplification factor (Kp), in particular for the controller for the actual outlet pressure, is provided which depends on the actual temperature of the pressure medium Hydraulic machine, in particular the pressure medium on the output side, and/or the actual speed of the hydraulic machine and/or the actual outlet pressure of the hydraulic machine and/or a predetermined pressure gradient or setpoint pressure gradient, in particular for the setpoint outlet pressure of the hydraulic machine. The amplification factor can thus be determined as a function of these variables. The amplification factor can then be multiplied by the control deviation, for example in the controller, with the control deviation being, for example, the setpoint differential pressure minus the actual differential pressure and the actual differential pressure being equal to the actual LS pressure minus the actual outlet pressure. It is preferably provided that the lower the actual temperature, the lower the amplification factor, since this can prevent or at least reduce oscillations of the hydraulic machine, preferably in the cold state of the hydraulic machine. Conversely, the greater the actual temperature, the greater the amplification factor. Alternatively or additionally, it can be provided that the lower the actual speed of the hydraulic machine, the greater the amplification factor, since the pressure build-up depends on the volume flow and thus on the speed of the hydraulic machine. Correspondingly, the reverse can also apply here that the greater the actual speed, the smaller the amplification factor. Alternatively or additionally, it can be provided that the greater the pressure gradient of the setpoint outlet pressure, the greater the amplification factor. This is advantageous because the greater the pressure gradient, the greater the requirement to swing out the hydraulic machine, and the hydraulic machine must therefore react more quickly than in the small-signal range. Conversely, it also applies here that the smaller the pressure gradient, the smaller the amplification factor. Alternatively or additionally, it can be provided that the greater the actual outlet pressure, the greater the amplification factor. This is advantageous because the system dynamics are higher with a larger actual outlet pressure. The hydraulic machine can thus be pivoted more quickly without becoming unstable. Conversely, the same relationship applies.

The amplification factor can advantageously be in the form of a control parameter that is dependent on the operating point. For example, the following can apply for pressure control and/or for torque control and/or for swivel angle control: the greater the actual outlet pressure, the greater the amplification factor can be, or the amplification factor is increased up to a predetermined actual outlet pressure and then with a further increase Actual outlet pressure lowered again. In other words, an amplification factor can also be provided in the controllers for the actual outlet pressure and/or for the actual torque, in particular for the actual variables. In particular, in other words, a pressure-dependent adjustment of the control loop gains can be provided. The control parameters can thus be adjusted during operation of the pressure medium supply arrangement. Advantageously, the control dynamics and/or control stability are adjusted as needed during operation.

In a further embodiment of the invention, it can be provided that a target pressure gradient is provided for the regulator of the actual outlet pressure. This is preferably adaptable and adjustable. The setpoint pressure gradient can then have an influence on the setpoint outlet pressure, for example. One influence is such, for example, that the higher the setpoint pressure gradient, the faster the hydraulic machine should swing out. The higher the setpoint pressure gradient, the faster the requirement grows than the actual gradient, which is why the hydraulic machine is pivoted faster in order to reach the setpoint pressure gradient. It is conceivable to use the setpoint pressure gradient as a limit for the setpoint outlet pressure or as a limit for the change in the setpoint outlet pressure.

In a further embodiment of the invention, the first control circuit preferably has a controller for the actual torque or the actual power based on the actual torque multiplied by the actual speed. An actual speed can be provided as an input variable, which is picked up from a drive shaft, in particular via a speed sensor, of the hydraulic machine. The actual torque or absorption torque of the hydraulic machine (pump) can then be calculated from the actual speed. The actual torque is calculated from the actual swivel angle multiplied by the actual outlet pressure divided by the hydromechanical efficiency. The hydromechanical efficiency is a function of the actual outlet pressure, the actual swivel angle and the actual speed and can be determined, for example, using a characteristic curve. Furthermore, a setpoint torque can be specified for the controller. The manipulated variable on the output side of the controller is preferably fed to the minimum value generator. The characteristic curve for determining the actual torque is dependent on the actual pressure and/or the actual swivel angle, for example. In other words, an instantaneous power can be calculated with the controller, especially if the actual speed is included.

In a further refinement of the invention, the actual variables for the first and second control circuits or part of the actual variables and one or more derivatives thereof are filtered in order to calm the signals. A PT1 element or a variable PT1 element is used here, for example, as already explained above.

In a further embodiment of the invention, it is conceivable to provide a delivery volume adjustment speed specification or a maximum delivery volume adjustment speed for the controller, which is supplied to the second control loop, in particular downstream of the minimum value generator. In particular, the delivery volume adjustment speed specification is fed to the controller via a control element. This preferably has the control value from the first control loop as an input variable, ie the control value output by the minimum value generator. The delivery volume adjustment speed specification can be provided as a further input variable be. The final set delivery volume adjustment speed for the second control circuit can then be provided as the output variable of the control element. In particular, the control value of the minimum value generator is limited via the additionally specified delivery volume adjustment speed specification, which can be adjusted, for example, in order to influence the control dynamics of the pressure medium supply arrangement. The default delivery volume adjustment speed can be, for example, a positive or negative maximum of the delivery volume adjustment speed. The higher the final setpoint delivery volume adjustment speed, the faster the hydraulic machine can swing out.

The control dynamics of the pressure medium supply arrangement can be influenced in a simple manner with the adjustable setpoint pressure gradient explained above and/or the adjustable delivery volume adjustment speed specification. The control force for the pilot valve can thus be dependent on the setpoint pressure gradient and/or on the delivery volume adjustment speed specification. These values can be variably adjusted during operation. The control dynamics can thus be adjusted as required during operation and can be dependent on the operating point or working point, for example. The pump dynamics can thus be limited and/or adjusted by the value(s). The swivel angle of the hydraulic machine and/or the delivery volume adjustment speed can then be regulated in such a way that the setpoint value or values are not exceeded. In other words, the dynamics of the pressure medium supply arrangement can be adjusted via software parameters with the adjustable variables (desired pressure gradient and/or the adjustable delivery volume adjustment speed specification), with which, for example, soft or hard machine behavior can be adjusted. The dynamics can also be changed for sub-functions. One sub-function can be matched to the target pressure gradient and the other sub-function to the delivery volume adjustment speed specification. By adapting the dynamics, a reduction in vibrations is also made possible. Furthermore, jerky movements can be avoided. It has been shown that the hydraulic pressure medium supply arrangement leads to an increase in efficiency, in particular due to less control oil consumption.

Another advantage of the hydraulic pressure medium supply arrangement is easier integration compared to hydromechanical controllers, since, for example, connecting lines or hoses to the hydromechanical controller of the variable displacement pump are omitted.

In a further embodiment of the invention, pilot control and/or auto-calibration of a neutral current can be provided for an actuator of the pilot valve. In other words, a pressure-dependent specification of a neutral signal value for the pilot valve can be present. The neutral signal value is, for example, the full control value for the Pilot valve in which the displacement volume adjustment speed is zero. The actual outlet pressure can be used for this. A neutral current can then be determined from this, in particular via a characteristic diagram. This is then preferably fed to the manipulated variable of the controller, in particular by addition. The controller can be relieved by the pilot control of the neutral current. In other words, the neutral current can be auto-calibrated. This may be necessary in order to keep the hydraulic machine in a stationary state as a function of an actual outlet pressure and/or a viscosity of the pressure medium and/or a spring variation and/or a magnetic variation of the pilot valve. In this way, it is possible to compensate for the hardware scatter via the auto-calibration of the neutral current.

A setpoint torque gradient is advantageously provided for the controller of the actual torque. This can be designed to be adaptable and adjustable, for example. The setpoint torque gradient can have an influence on the setpoint torque, for example. In this case, the setpoint torque gradient is preferably provided as a limit for the setpoint torque or for limiting the change in the setpoint torque. It is also conceivable to regulate the setpoint torque gradient as a specification. In this case, a target torque can be formed based on the target torque gradient. A provided filter or pre-filter can then set a target dynamic.

In a further embodiment, a superordinate machine control can be provided in addition to the control or pump control. This is, for example, the actual outlet pressure and/or the actual swivel angle and/or the actual torque and/or the actual delivery volume and/or the actual delivery volume adjustment speed and/or the gradient of the actual outlet pressure and/or the Maximum torque and / or the gradient of the torque change supplied.

In a further embodiment of the invention, it can be provided that a valve slide of the pilot valve is controlled in such a way that it executes an axial oscillating movement at times or continuously, in particular during operation of the pressure medium supply arrangement. The oscillating movement preferably takes place in such a way that the current switching position of the valve slide is practically not influenced. In other words, a pressure-dependent adjustment and optimization of the hysteresis-reducing measure (dither) takes place with the aim of optimizing the hysteresis of the pilot valve and not influencing the control dynamics through counter-compensation through the dither, especially if the controller output works in phase opposition or in phase with the dither.

In other words, a method is disclosed that is provided for controlling a displacement and/or a torque and/or a pressure of a hydrostatic machine.

• Erfassen eines vorgegebenen Soll-Drehmoments,
• Erfassen eines vorgegebenen Soll-Hubvolumens,
• Erfassen eines vorgegebenen Soll-Drucks,
• Erfassen eines Ist-Hubvolumens oder eingestelltem Hubvolumens,
• Erfassen eines Ist-Drucks oder eingestelltem Drucks,
• Ermittlung des Ist-Drehmoments oder des eingestellten Drehmoments an der Triebwelle der Maschine.

This can have an adjusting device for adjusting its stroke volume. The method preferably has the following steps:

• detecting a specified target torque,
• detecting a predetermined target stroke volume,
• detecting a specified target pressure,
• Detection of an actual stroke volume or a set stroke volume,
• detecting an actual pressure or set pressure,
• Determination of the actual torque or the set torque on the drive shaft of the machine.

As a further step, a volume flow can be regulated into or out of the actuating device by means of a control valve for setting the stroke volume on the basis of a force difference between a control force and a force acting on the control valve in the opposite direction. The force acting on the control valve in the opposite direction to the control force can be a spring force. Furthermore, the control force may be an electric force of a solenoid valve. The machine is adjusted as a function of the detected displacement and/or pressure and/or target displacement and/or target pressure and/or target torque. The swept volume is preferably set in such a way that the smallest swept volume that leads to the achievement of one of the target values is always set.

The hydraulic machine is preferably de-energized at zero lift or at maximum lift, depending on the fail-operation application.

As explained in the introduction, the volume flow of the hydraulic machine or variable displacement pump can be determined from the swivel angle of the swash plate. If the variable displacement pump is not driven and the actuating system is pressureless, then the variable displacement pump pivots to a maximum delivery volume, for example, by the spring force of a spring. On the other hand, when the variable displacement pump is in the driven state and the pilot valve is de-energized and the pump outlet is closed, the variable displacement pump pivots to a zero stroke pressure. A balance between the pump pressure on the positioning piston and the spring force of the spring plus the pump pressure on the counter-piston occurs at around 4 to 8 bar. The basic setting is usually adopted with the control electronics de-energized. Conversely, it would also be conceivable that when the pilot valve is de-energized, the variable displacement pump is pivoted to the maximum delivery volume in order to ensure that a consumer, such as a steering system, is supplied with pressure medium. A pressure-limiting valve is then preferably provided in order to limit the actual outlet pressure of the hydraulic machine. This can be done, for example, in that the valve behavior of the pilot valve is inverted. For example, when the pilot valve is de-energized, the actuating cylinder connection can be connected to the tank connection.

Brief description of the drawings

• Fig. 1 in einer schematischen Darstellung eine hydraulische Druckmittelversorgungsanordnung gemäß einem ersten Ausführungsbeispiel,
• Fig. 2 in einer schematischen Darstellung eine Steuerung für die Druckmittelversorgungsanordnung aus Fig. 1,
• Fig. 3 in einer schematischen Darstellung eine Steuerung für die Druckmittelversorgungsanordnung aus Fig. 1 gemäß einem weiteren Ausführungsbeispiel,
• Fig. 4 und Fig. 5 jeweils in einer schematischen Darstellung eine Ermittlung von Verstärkungsfaktoren eines Reglers gemäß einem Ausführungsbeispiel,
• Fig. 6a und 6b eine Raupenbagger und in einer schematischen Darstellung eine Druckmittelversorgungsanordnung für einen Raupenbagger,
• Fig. 7a und 7b einen Teleskoplader und in einer schematischen Darstellung eine Druckmittelversorgungsanordnung für einen Teleskoplader,
• Fig. 8a und 8b einen Kompaktbagger und in einer schematischen Darstellung eine Druckmittelversorgungsanordnung für einen Kompaktbagger und
• Fig. 9a und 9b ein Kühler-Lüfter-System und in einer schematischen Darstellung eine Druckmittelversorgungsanordnung für ein Kühler-Lüfter-System.

Preferred exemplary embodiments of the invention are explained in more detail below using schematic drawings. Show it:

• 1 in a schematic representation of a hydraulic pressure medium supply arrangement according to a first embodiment,
• 2 in a schematic representation of a controller for the pressure medium supply arrangement 1 ,
• 3 in a schematic representation of a controller for the pressure medium supply arrangement 1 according to another embodiment,
• 4 and 5 in each case in a schematic representation a determination of gain factors of a controller according to an embodiment,
• Figures 6a and 6b a crawler excavator and, in a schematic representation, a pressure medium supply arrangement for a crawler excavator,
• Figure 7a and 7b a telescopic loader and in a schematic representation a pressure medium supply arrangement for a telescopic loader,
• Figure 8a and 8b a compact excavator and, in a schematic representation, a pressure medium supply arrangement for a compact excavator and
• Figures 9a and 9b a cooler-fan system and, in a schematic representation, a pressure medium supply arrangement for a cooler-fan system.

According to 1 a hydraulic pressure medium supply arrangement 1 is shown, which has a hydraulic machine in the form of an axial piston machine 2 . This has a pivoting cradle for adjusting a delivery volume. The axial piston machine 2 can be used both as a pump and as a motor. The axial piston machine 2 is driven via a drive unit 4, which can be, for example, an internal combustion engine, such as a diesel unit, or an electric motor. The axial piston machine 2 is connected to the drive unit 4 via a drive shaft 6 . A rotational speed 8 of the drive shaft 6 can be picked up via means that are not shown, for example via a rotational speed sensor, and can be fed to a controller of the pressure medium supply arrangement 1 . An adjusting mechanism 12 is provided for the axial piston machine 2 . This has a pilot valve 14. Its valve slide can be controlled electrically proportionally via an actuator 16. For this will a control variable 18 is supplied to the actuator 16 by a controller 20 . The valve slide of the pilot valve 14 is acted upon by a spring force of a valve spring 22 in the direction of a basic position. The spring force acts against the actuator force of the actuator 16.

The axial piston machine 2 is connected on the output side to a pressure line 24, which in turn is connected to a main control valve 26 or valve block. This can be used to control the pressure medium supply between the axial piston machine 2 and one or more consumers. A control line 28 branches off from the pressure line 24 and is connected to a pressure port P of the pilot valve 14 . The control line 28 is formed in a housing of the axial piston machine 2, for example. Furthermore, the pilot valve 14 has a tank connection T, which is connected to a tank via a tank line 30 . In addition, the pilot valve 14 has a working connection A, which is connected to a control chamber 32 of an actuating cylinder 34 . The control chamber 32 is delimited by an actuating piston 36 of the actuating cylinder. A swash plate of the axial piston machine 2 can then be adjusted via the actuating piston 36 . A displacement path of the actuating piston 36 is detected by a displacement sensor 38 . Alternatively or additionally, a pivoting angle of the pivoting cradle of the axial piston machine 2 is picked up by a rotary, magnetic sensor from a pivoting axis of the pivoting cradle. The actual delivery volume or the actual displacement volume of the axial piston machine 2 can then be determined via the recorded path. The actual delivery volume 40 is then reported to the controller 20 . In the basic position of the valve slide of the pilot valve 14, the pressure port P is connected to the working port A and the tank port T is shut off. When the valve slide is acted upon by the actuator force of the actuator 16, the valve slide is moved from its basic position in the direction of switch positions in which the pressure port P is blocked and the working port A is connected to the tank port T. Thus, in the basic position of the valve slide of the pilot valve 14 , the actuating piston 36 is acted upon by pressure medium from the pressure line 24 . Furthermore, a cylinder 42 is provided in the adjusting mechanism 12 . This has an actuating piston 44 which acts on the swash plate of the axial piston machine 2 . The actuating piston 44 delimits a control chamber 46 which is connected to the pressure line 24 . The actuating piston 44 is acted upon by the pressure medium of the control chamber 46 and by the spring force of a spring 48 in such a way that it loads the swash plate in the direction of increasing the delivery volume.

Furthermore, a pressure sensor 50 is provided, via which the pressure in the pressure line 24 is tapped and reported to the controller 20 , the pressure being an actual outlet pressure 52 . A pressure sensor 54 is also provided, which detects the highest actual load pressure (actual LS pressure) 56 which is transmitted to the controller 20 .

A controller 57 is connected to the controller 20 via a CAN interface 58 in order in particular to transmit the actual speed to the controller 20 . It is also conceivable to feed the actual speed 8 directly to the controller 20 .

When the pressure medium supply arrangement 1 is used, the position of the swash plate of the axial piston machine 2 is controlled via the pilot valve 14 and the actuating piston 36 . A volume flow delivered by the axial piston machine 2 is proportional to the position of the swash plate. The adjusting piston 44 or counter-piston, which is pretensioned by the spring 48, is constantly subjected to the actual outlet pressure or pump pressure. When the axial piston machine 2 is not rotating and the adjusting mechanism 12 is unpressurized, the swash plate is held in a +100 percent position by the spring 48 . When the axial piston machine 2 is driven and the actuator 16 of the pilot valve 14 is de-energized, the swash plate pivots to a zero stroke pressure, since the actuating piston 36 is acted upon by pressure medium from the pressure line 24 . Equilibrium between an actual outlet pressure at the actuating piston 36 and the spring force of the spring 48 occurs at a predetermined pressure or pressure range, for example between 8 and 12 bar. This zero stroke operation is assumed, for example, when the electronics or controller 20 are de-energized. The pilot valve 14 is controlled via the controller 20, which is, for example, preferably digital electronics, alternatively analog electronics. The controller 20 processes the required control signals, which is explained in more detail below.

2 shows a schematic of how the controller 20 works. It has a first control circuit 60 and a second control circuit 62. The first control circuit 60 has a controller 64 for a pivoting angle of the swash plate of the axial piston machine 2 1 , a regulator 66 for the outlet pressure of the axial piston machine 2 and a regulator 68 for a torque of the axial piston machine 2 . The controller 64 has a setpoint delivery volume 70 and the actual delivery volume 40 as input variables. A manipulated variable 72 is provided as the output variable. The controller 66 has a setpoint outlet pressure 74 and the actual outlet pressure 52 as input variables. A manipulated variable 75 is provided as the output variable. The controller 68 has an actual torque 76 or a setpoint torque as input variables. The actual torque is provided as a further input variable, which in turn can be determined, for example, using a characteristic diagram via the actual speed 8 . A manipulated variable 78 is provided as the output variable for the controller 68 . In the case of the respective controller 64 to 68, the input variables are each supplied to a control element in the form of a PID controller.

The manipulated variables 72, 75 and 78 are supplied to a minimum value generator 80. This ensures that only the controller 72, 75 or 78 is active. In this case, either the output pressure, the torque or the delivery volume is then precisely adjusted, with the other two variables being below a specified setpoint. An output signal of the minimum value generator 80 is then a setpoint in the form of a delivery volume adjustment speed or setpoint delivery volume adjustment speed 82. This is then an input variable for the second subordinate control circuit 62. Another input variable of the second control circuit 62 is the derivation of the actual delivery volume 40 , which is then an actual delivery volume adjustment speed 84 . The input variables 82 and 84 for the second control circuit 62 are then fed to a control element in the form of a PID element 86 . This then outputs the manipulated variable 18 for the pilot valve 14 1 out of.

According to 3 Another embodiment for the controller 20 is shown in FIG 1 shown. This has a controller 88 for the delivery volume of the axial piston machine 2, see also 1 . Furthermore, a controller 90 for the outlet pressure of the axial piston machine 2 and a controller 92 for the torque of the axial piston machine 2 are provided. This is part of a first control circuit 94. Furthermore, a second control circuit 96, which is subordinate to the first control circuit, is provided for the delivery volume adjustment speed of the axial piston machine 2.

The controller 88 has a control element 98 in the form of a P element. Target delivery volume 70 and actual delivery volume 40 are provided as input variables. The actual delivery volume 40 is supplied with the control element 98 via a filter in the form of a PT1 filter. The manipulated variable 72 is provided as an output variable on the output side of the controller 88 and is supplied to the minimum value generator 80 .

The controller 90 has the actual outlet pressure 52, the actual LS pressure 56, a setpoint pressure difference 100 and a setpoint pressure gradient 102 as input variables. The actual LS pressure 56 and the setpoint pressure difference 100 are combined via a summing element 104 to form a setpoint outlet pressure. The target outlet pressure is then fed to a control element 106 in the form of an inverted PT1 element, which estimates a probable signal course. The target outlet pressure is then fed to a control element 108, which has the target pressure gradient 102 as a further input variable. Target pressure gradient 102 then specifies the maximum possible gradient that should be provided. The target output pressure is then influenced by the specified target pressure gradient 102 via the control element 108 in such a way that the dynamics of the pressure medium supply arrangement 1 are adjusted with the target pressure gradient 102 1 is controllable. For example, the influence can be such that the higher the setpoint pressure gradient 102, the faster the swash plate of the axial piston machine 2 can be adjusted. Conversely, the smaller the setpoint pressure gradient, the slower the swash plate of the axial piston machine 2 is adjusted. After the control element 108 is then the Target output pressure supplied to a control element 110 in the form of a PID element. Actual outlet pressure 52 is then provided as a further input variable for control element 110 . The output variable of the control element 110 is the manipulated variable 75 which is fed to the minimum value generator 80 .

The actual LS pressure 56 from the regulator 90 is fed before the summer 104 to a filter 112 which is a variable PT1 filter. The same applies to the actual outlet pressure, which is also fed to a filter 114 in the form of a variable PT1 filter before the control element 110 . The filters 112 and 114 have variable, in particular pressure-dependent, filter coefficients, which is explained in more detail above.

The controller 92 has the actual speed 8, the actual delivery volume 40, the actual outlet pressure 52 and a target torque 116 as input variables. The input variables are supplied to a control element 118 in the form of a P element. The manipulated variable 78 , which is fed to the minimum value generator 80 , is provided as the output variable for the control element 118 . After the control element 118, a control element 120 is provided for the manipulated variable 78, which, like the control element 106, is an inverted PT1 filter. Furthermore, the actual speed, the actual delivery volume 40 and the actual outlet pressure 8 are fed to a control element 122 before being fed to the control element 118 . This is used to calculate an actual torque 124 based on the actual speed 8, the actual delivery volume 40 and the actual outlet pressure 8. The calculation is carried out using a map of the control element 122. The map is dependent on the actual outlet pressure 52 , which is supplied to the control element 122. Furthermore, the control element 122 is supplied with the actual delivery volume 40 . The characteristics map can then depend on the actual delivery volume 40 as an alternative or in addition. In other words, actual torque 124 is formed from actual speed 8 and from actual outlet pressure 52 and/or from actual delivery volume 40 . The actual torque 124 is then fed to a filter 126 in the form of a PT1 element before it reaches the control element 118 .

Furthermore, the actual delivery volume 40 is fed to a filter 99 in the form of a PT1 element before it is fed to the control element 98 .

The minimum value generator 80 uses the manipulated variables 72, 75 and 78 to form the desired delivery volume adjustment speed 82. This is fed to a control element 128. With this, the dynamics of the pressure medium supply arrangement 1 can be influenced. For this purpose, a delivery volume adjustment speed specification 130 is provided as a further input variable for the control element 128, which is adjustable. For example, with the delivery volume adjustment speed specification 130, the setpoint delivery volume adjustment speed 82 output from the minimum value generator 80 can be limited and/or influenced in such a way that the higher the size 130 is, the faster the swash plate of the axial piston machine 2 can be pivoted and vice versa. Thus, the dynamics of the pressure medium supply arrangement 1 can be influenced by adjusting the delivery volume adjustment speed specification 130 and/or by adjusting the target pressure gradient 102 . For example, this allows the pressure medium supply arrangement 1 to be adapted to different work machines and/or to different conditions of use and/or to different purposes in a simple and cost-effective manner.

Downstream of the control element 128, the final target delivery volume adjustment speed 132 is fed to the second control loop 96 as an input variable. This has a control element 134 in the form of a PI element. Actual delivery volume adjustment speed 84 is provided as a further input variable for control element 134 . This is based on the actual delivery volume 40 which is derived in a control element 136 . The derivation, ie the actual delivery volume adjustment speed, is then fed to a filter 138 in the form of a PT1 filter. A control element 140 in the form of an inverted PT1 filter is then provided before the actual variable 84 is fed to the control element 134 . The control element 134 of the second control loop 96 indicates the manipulated variable 18 for the pilot valve 14 as the output variable 1 on. This is fed to a summing element 142 . A pre-control value 144 is provided as a further input variable for summing element 142 . This is an output variable of a control element 150, which has the actual output pressure 52 as an input variable. The pilot control value 144 is then determined on the basis of the actual outlet pressure 52 . The summing element 142 then links the manipulated variable 18 and the pilot value 144, with which a neutral current of the pilot valve is pilot-controlled. A pressure-dependent specification of a neutral signal value for the pilot valve 14 thus takes place 1 . This has the advantage that the controller 20 is relieved of this control task. A final manipulated variable 146 for the pilot valve 14 is then provided as the output variable of the summing element 142 .

It is conceivable that the summing element 142 has an in 3 not shown control element is downstream, which has the manipulated variable 146 as an input variable. A low-frequency signal is superimposed on this by the control element, so that the valve slide of the pilot valve 14 is constantly in axial oscillating movement, in order to prevent the valve slide from getting stuck. The final manipulated variable for the pilot valve 14 is then provided as the output variable of the control element. The superimposition of the low-frequency signal can be referred to as "dithering". The purpose of the dither is to reduce the hysteresis of the pilot valve 14 by maintaining a small movement of the valve spool. This movement must not be too large in order to avoid effects on the system (e.g. pilot valve 14 vibrates too violently so that the swivel angle or pressure also sees this vibration). The dither (frequency and amplitude) is optimized in such a way that the hysteresis is minimal and the system is not is stimulated. The smaller the frequency and the larger the amplitude, the easier it is to keep the valve slide moving. However, a low frequency leads to a long period of the superimposed "sine signal". This creates the problem that this period can run in the opposite direction to the desired signal. You get a delayed reaction if the superimposed dither runs in the opposite direction to the target signal, which can be disadvantageous in pump control. However, there is the possibility that at higher pressures the dither frequency can be increased and/or the amplitude reduced, since better lubrication takes place due to the pressure and the hysteresis of the pilot valve 14 decreases. This also reduces the influence of anti-phase dither and increases the control dynamics.

4 shows a working-point-dependent control parameter for controller 20. This is, for example, an amplification factor Kp of controller 90 for the output pressure of axial piston machine 2. Amplification factor Kp is supplied to controller 20 via control element 110, for example. According to 4 the amplification factor Kp can be calculated via a control element 152 as a function of a temperature 154 of a pressure medium of the pressure medium supply arrangement 1. The temperature is picked up, for example, via a sensor from the pressure medium in the pressure line 24 . The amplification factor Kp is then determined, for example, using a characteristic diagram. Alternatively or additionally, the amplification factor can depend on the actual speed 8 via a control element 156 . Here, the amplification factor Kp is also determined using a characteristic diagram. Alternatively or additionally, a control element 158 is provided, via which the amplification factor Kp can be determined via the actual outlet pressure 52, it also being possible for this to take place via a characteristic diagram. Furthermore, as an alternative or in addition, the amplification factor Kp can be determined via a control element 160 based on the target pressure gradient 102 . The setpoint pressure gradient 102 can be derived from the setpoint outlet pressure 74 via a control element 162 . If the amplification factor Kp is determined via a number of control elements 152, 156, 158, 160, it can be linked via a respective output-side control element 164 and then finally output as the output variable of the control element 164.

According to figure 5 can alternatively or in addition to the in 4 The amplification factor Kp can be determined via the actual outlet pressure 52 using the control elements 152, 156, 158, 160 shown. A control element 166 is provided for this purpose, in which the amplification factor Kp is then determined based on the actual outlet pressure 52 via a characteristic diagram. In this case, the greater the actual outlet pressure, the greater the gain factor Kp. The amplification factor Kp can also be used for the controller 88 and/or 92 as an alternative or in addition to the controller 90 .

It is also conceivable that the transit times of at least one signal or a part of the signals or all signals of the control loops 94 and 96 be adjusted over time 3 is provided, wherein in particular a phase position of the signal or signals is adjustable. This can be done via the control element 106 and/or 120, for example.

In control element 150, pilot control value 144 can be determined, preferably on a model basis, taking into account flow forces in pilot valve 14 and/or a magnet characteristic of actuator 16 and/or a control edge characteristic of the valve slide of pilot valve 14 and/or a spring stiffness of valve spring 22.

According to Figure 6a a crawler excavator is shown according to Figure 6b a pressure medium supply arrangement, see 1 , having. This has the axial piston machine 2, which is driven by the drive unit 4 in the form of a diesel engine. The pressure medium supply to hydraulic cylinders 168 and 170, to hydraulic machines 172, 174 for moving the crawler excavator and to a hydraulic auxiliary drive 176 is controlled via the main control valve 26. In this case, the crawler excavator has various input means 178 for an operator, which are connected to a CAN bus 180 . Furthermore, pressure sensors 182 , 184 are connected to the CAN bus 180 . These pick up the actual outlet pressure of the axial piston machine 2 . A safety valve is provided on the input side of each of the hydraulic cylinders 168, 170, which protect the hydraulic cylinders 168, 170 in the event of a rupture of an inlet line. As explained above, required input variables are detected and, in particular, pilot valve 14 is controlled via controller 20 . In addition, the main control valve 26 is controlled as a function of the signals from the input means 178 detected via the CAN bus 180 .

Figure 7a shows a telehandler with one of the pressure medium supply arrangement according to FIG Figure 7b . This has two axial piston machines 2 and 186, which are driven by the drive unit 4 in the form of a diesel unit via a common drive shaft. Pilot valves of the axial piston machine 2, 186 are controlled via the controller 20 as explained above. The axial piston machine 186 serves to supply pressure medium to a wheel brake 188, a steering system 190 and a pilot oil supply 192. The pilot oil supply 192 is provided for the main control valve 26 or the main control valve block. The supply of pressure medium to hydraulic cylinders 168, 170, 194, 196 is controlled via this. Furthermore, a hydraulic machine 198 used and the hydraulic auxiliary motor 176 are controlled via the main control valve 26 . According to the embodiment in Figures 6a and 6b input means 178 are also provided here, which are connected to the controller 20, for example, by the CAN bus 180. Furthermore, a communication device 200 is provided in order to communicate wirelessly, for example via radio or WiFi, with a server and/or with a computer. For example, input variables for the controller 20 can then be adjusted via the communication device 200 and/or software can be expanded or updated. In addition, it is possible to send data via the communication device 200 that contain information about a state of the pressure medium supply arrangement 1 .

According to Figure 8a is a compact excavator with a pressure medium supply arrangement according to Figure 8b shown. Here, the axial piston machine 2 can be seen, which is driven by the drive unit 4 in the form of a diesel unit. Furthermore, the controller 20 is shown, which is connected, for example, to a pressure sensor 202 that picks up the actual outlet pressure of the axial piston machine 2 . In addition, the controller 20 is connected to a pressure sensor 204 which picks up the highest load pressure via the main control valve 26 or the main control block. Furthermore, the controller 20 is connected to the controller 20 with a displacement pickup 206 for the pivoting angle of the swash plate of the axial piston machine 2 . In addition, the pilot valve 14 is connected to the controller 20 . Five hydraulic cylinders 208 are connected to the main control valve 26 . Furthermore, the hydraulic machines 172, 174 and the hydraulic auxiliary motor 176 are connected. Optionally, the pilot oil supply 192 can be provided. Input means 178 can control the main control valve 26 hydraulically, for example, or can be connected to the pressure medium supply arrangement via the CAN bus 180 .

According to Figures 9a and 9b is the possibility of using the pressure medium supply arrangement 1 1 shown for a fan system. According to Figure 9a the axial piston machine 2 is provided, which is driven by the drive unit 4, for example in the form of a diesel unit. The actual outlet pressure of the axial piston machine 2 is picked up via the pressure sensor 50 . A fan motor in the form of a hydraulic machine 210 is driven via the axial piston machine 2 . This in turn drives vanes 212 to create airflow. The coolant of a cooling circuit is then cooled via the air flow. The pilot valve 14 can be controlled via the controller 20 . One or more temperatures picked up by sensors can be supplied to the controller 20 for example via the CAN bus 180 . The temperature can be, for example, a temperature of the coolant in a coolant line 214 and/or a temperature of the drive unit 4 and/or a temperature of the pressure medium. It is also conceivable to supply further input variables to the controller 20, as explained above.

Claims (15)

1. Hydraulic pressurizing medium supply assembly for an open hydraulic circuit, having a hydro machine (2), having an adjusting mechanism (12) which has an actuating cylinder (34) having a set piston (36) for adjusting a delivery volume of the hydro machine (2) and which has a pilot valve (14) which is electrically actuatable in a proportional manner, wherein an inflow to and/or an outflow from a control chamber (32) of the actuating cylinder (34) that is limited by the set piston (36) is able to be controlled via the pilot valve (14) in order for the set piston (36) for actuation to be impinged with pressurizing medium, and wherein an electronic control (20) which as input variables has at least a nominal outlet pressure (74) of the hydro machine (2) and/or a nominal delivery volume or a nominal swivel angle (70) of the hydro machine (2), and which as an output variable has a control variable for the pilot valve (14) is provided, wherein the control (20) has a first closed-loop control circuit (60) for an actual outlet pressure (52) of the hydro machine (2) and/or for an actual delivery volume or an actual swivel angle (40) of the hydro machine (2), characterized in that the control (20) so as to underlie the first closed-loop control circuit (60) has a second closed-loop control circuit (62) for a delivery-volume adjustment rate or a swivel-angle adjustment rate of the hydro machine (2), said second closed-loop control circuit as an input variable having an actual delivery-volume adjustment rate or an actual swivel-angle adjustment rate (84) of the hydro machine, and as an output variable having the control variable (18) for the pilot valve (14), wherein the second closed-loop control circuit (62) is supplied a control value (82) from the first closed-loop control circuit (60) in the form of a nominal delivery-volume adjustment rate or a nominal swivel-angle adjustment rate (82).
2. Pressurizing medium supply assembly according to Claim 1, wherein the first closed-loop control circuit (60) of the control (20) is configured for an actual torque (8) of the hydro machine (2), and wherein a nominal torque (76) and the actual torque (8) are provided as input variables for the control (20).
3. Pressurizing medium supply assembly according to Claim 1 or 2, wherein the first closed-loop control circuit (60) emits in each case one control variable for the actual outlet pressure (52) of the hydro machine (2) and/or for the actual delivery volume or the actual swivel angle (40) of the hydro machine (2) and/or for the actual torque (8) of the hydro machine (2), wherein the control (20) has an alternating control which has a minimum value generator (80) for the emitted control variables (72, 75, 78).
4. Pressurizing medium supply assembly according to Claim 3, wherein the first closed-loop control circuit (60) for the actual outlet pressure (52) of the hydro machine (2) and/or for the actual delivery volume or the actual swivel angle (40) of the hydro machine (2) and/or for the actual torque (8) of the hydro machine (2) has a controller (110) with an I-proportion, wherein the I-proportion in the case of an inactive controller (110) having the I-proportion or inactive controllers (110) having the I-proportion is frozen or partially or completely reduced.
5. Pressurizing medium supply assembly according to one of Claims 1 to 4, wherein a nominal pressure gradient (102) is provided as an input variable for controlling the actual outlet pressure (52) in the first closed-loop control circuit (60).
6. Pressurizing medium supply assembly according to Claim 5, wherein the nominal pressure gradient (102) is adjustable for adapting the control dynamics of the pressurizing medium supply assembly.
7. Pressurizing medium supply assembly according to Claim 5 or 6, wherein the nominal pressure gradient (102) is used for limiting the variation of the nominal outlet pressure.
8. Pressurizing medium supply assembly according to one of the preceding claims, wherein a delivery-volume adjustment rate target or a swivel-angle adjustment rate target (130) is provided as an input variable for the control (20), said input variable being adjustable for adapting the control dynamics of the pressurizing medium supply assembly.
9. Pressurizing medium supply assembly according to Claim 8, wherein the delivery-volume adjustment rate target or the swivel-angle adjustment rate (130) is supplied to a control element (128) which as a further input variable has the control value of the first closed-loop control circuit (60) in the form of the nominal delivery-volume adjustment rate or the nominal swivel-angle adjustment rate (82), and wherein the control element (128) as an output variable emits a final nominal delivery-volume adjustment rate (132) for the second closed-loop control circuit (96), said output variable being limited by the delivery-volume adjustment rate target (130).
10. Pressurizing medium supply assembly according to one of the preceding claims, wherein the highest actual load pressure (56) of consumers (168, 170) which are supplied by the pressurizing medium supply assembly is detected as the actual load sensing (LS) pressure (56) and is supplied as an input variable to the control (20), and wherein a nominal pressure differential (100) is provided as an input variable for the control (20), wherein a nominal pressure for the control (20) which is provided as an input variable for the first closed-loop control circuit (60) is determined from the actual LS pressure (56) and the nominal pressure differential (100), and/or wherein actual LS pressures (56) of part of the consumers (168, 170) or of all consumers (168, 170) are detected by way of corresponding means, and wherein generating a maximum value or prioritizing the actual LS pressures (56) takes place in the control (20).
11. Pressurizing medium supply assembly according to one of the preceding claims, wherein a filter (99, 112, 114, 126, 138) is provided for at least one input variable, or for part of the input variables, or for all input variables of the control (20).
12. Pressurizing medium supply assembly according to one of the preceding claims, wherein a, or a respective, amplification factor (Kp) for the first closed-loop control circuit (60) is provided for controlling the actual outlet pressure (52) of the hydro machine (2) and/or for controlling the actual delivery volume (40) of the hydro machine (2) and/or controlling the actual torque (8) of the hydro machine (2), wherein the amplification factor (Kp) is a function of an actual temperature (154) and/or of the actual rotating speed (8) of the hydro machine (2) and/or of the actual outlet pressure (52) of the hydro machine (2) and/or of the nominal pressure gradient (102) of the hydro machine (2).
13. Pressurizing medium supply assembly according to one of the preceding claims, wherein a neutral current of the pilot valve (14) is pre-controlled.
14. Pressurizing medium supply assembly according to one of the preceding claims, wherein a valve slide of the pilot valve (14) is actuated in such a manner that said valve slide temporarily or continually carries out an axial oscillating movement, wherein the frequency and the amplitude of the oscillating movement is able to be controlled as a function of the actual outlet pressure.
15. Method having a hydraulic pressurizing medium supply assembly according to one of the preceding claims, wherein the pilot valve (14) is controlled by way of the first closed-loop control circuit (60) and the second closed-loop control circuit (62).

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