EP0515639B1 - Hydraulic system - Google Patents

Hydraulic system Download PDF

Info

Publication number
EP0515639B1
EP0515639B1 EP92901394A EP92901394A EP0515639B1 EP 0515639 B1 EP0515639 B1 EP 0515639B1 EP 92901394 A EP92901394 A EP 92901394A EP 92901394 A EP92901394 A EP 92901394A EP 0515639 B1 EP0515639 B1 EP 0515639B1
Authority
EP
European Patent Office
Prior art keywords
pump
pressure
consumer
hydraulic system
control
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP92901394A
Other languages
German (de)
French (fr)
Other versions
EP0515639A1 (en
Inventor
Otwin Eich
Franz-Peter Salz
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Oerlikon Barmag AG
Original Assignee
Barmag AG
Barmag Barmer Maschinenfabrik AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Barmag AG, Barmag Barmer Maschinenfabrik AG filed Critical Barmag AG
Publication of EP0515639A1 publication Critical patent/EP0515639A1/en
Application granted granted Critical
Publication of EP0515639B1 publication Critical patent/EP0515639B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B21/00—Common features of fluid actuator systems; Fluid-pressure actuator systems or details thereof, not covered by any other group of this subclass
    • F15B21/08—Servomotor systems incorporating electrically operated control means
    • F15B21/087—Control strategy, e.g. with block diagram
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
    • E02F9/20—Drives; Control devices
    • E02F9/22—Hydraulic or pneumatic drives
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
    • E02F9/20—Drives; Control devices
    • E02F9/22—Hydraulic or pneumatic drives
    • E02F9/2221—Control of flow rate; Load sensing arrangements
    • E02F9/2225—Control of flow rate; Load sensing arrangements using pressure-compensating valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B49/00—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00
    • F04B49/06—Control using electricity
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B49/00—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00
    • F04B49/08—Regulating by delivery pressure
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
    • F15B11/16—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors
    • F15B11/161—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors with sensing of servomotor demand or load
    • F15B11/163—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors with sensing of servomotor demand or load for sharing the pump output equally amongst users or groups of users, e.g. using anti-saturation, pressure compensation
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B2205/00—Fluid parameters
    • F04B2205/07—Pressure difference over the pump
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/20—Fluid pressure source, e.g. accumulator or variable axial piston pump
    • F15B2211/205—Systems with pumps
    • F15B2211/2053—Type of pump
    • F15B2211/20546—Type of pump variable capacity
    • F15B2211/20553—Type of pump variable capacity with pilot circuit, e.g. for controlling a swash plate
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/20—Fluid pressure source, e.g. accumulator or variable axial piston pump
    • F15B2211/25—Pressure control functions
    • F15B2211/253—Pressure margin control, e.g. pump pressure in relation to load pressure
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/30—Directional control
    • F15B2211/305—Directional control characterised by the type of valves
    • F15B2211/30525—Directional control valves, e.g. 4/3-directional control valve
    • F15B2211/3053—In combination with a pressure compensating valve
    • F15B2211/30535—In combination with a pressure compensating valve the pressure compensating valve is arranged between pressure source and directional control valve
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/30—Directional control
    • F15B2211/31—Directional control characterised by the positions of the valve element
    • F15B2211/3105—Neutral or centre positions
    • F15B2211/3111—Neutral or centre positions the pump port being closed in the centre position, e.g. so-called closed centre
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/30—Directional control
    • F15B2211/32—Directional control characterised by the type of actuation
    • F15B2211/327—Directional control characterised by the type of actuation electrically or electronically
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/60—Circuit components or control therefor
    • F15B2211/605—Load sensing circuits
    • F15B2211/6051—Load sensing circuits having valve means between output member and the load sensing circuit
    • F15B2211/6054—Load sensing circuits having valve means between output member and the load sensing circuit using shuttle valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/60—Circuit components or control therefor
    • F15B2211/63—Electronic controllers
    • F15B2211/6303—Electronic controllers using input signals
    • F15B2211/6306—Electronic controllers using input signals representing a pressure
    • F15B2211/6309—Electronic controllers using input signals representing a pressure the pressure being a pressure source supply pressure
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/60—Circuit components or control therefor
    • F15B2211/63—Electronic controllers
    • F15B2211/6303—Electronic controllers using input signals
    • F15B2211/6306—Electronic controllers using input signals representing a pressure
    • F15B2211/6313—Electronic controllers using input signals representing a pressure the pressure being a load pressure
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/60—Circuit components or control therefor
    • F15B2211/63—Electronic controllers
    • F15B2211/6303—Electronic controllers using input signals
    • F15B2211/6333—Electronic controllers using input signals representing a state of the pressure source, e.g. swash plate angle
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/60—Circuit components or control therefor
    • F15B2211/65—Methods of control of the load sensing pressure
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/60—Circuit components or control therefor
    • F15B2211/665—Methods of control using electronic components
    • F15B2211/6652—Control of the pressure source, e.g. control of the swash plate angle
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/70—Output members, e.g. hydraulic motors or cylinders or control therefor
    • F15B2211/71—Multiple output members, e.g. multiple hydraulic motors or cylinders

Definitions

  • the invention relates to a hydraulic system according to the preamble of the claim, known from US-A-4,712,376.
  • this hydraulic system the measurement of the current delivery rate is to be carried out by detecting the pump speed. From this, the positions of the control valves are then to be corrected by means of a computer with the aid of previously determined nominal values from an electronic memory.
  • Another hydraulic system is known from DE 26 51 325 C2.
  • a control valve is notified on the one hand of the pressure at the pump and on the other hand of the highest load pressure. If the pump can no longer deliver the volume flow required by the valves assigned to the individual consumers, the pressure difference between the pressure of the pump and the highest load pressure is reduced.
  • the control valve consequently reduces the supply to the control pressure transmitter, by means of which the valves assigned to the consumers are actuated. This limits the flow of the valves. However, this limitation only becomes effective if there is already an excessive demand.
  • the object of the invention is to design the hydraulic system so that it is not susceptible to vibration and that any weighting and adaptation of the individual consumer flows to the operating parameters of the pump is also possible.
  • the solution results from the characterizing part of claim 1.
  • the solution has the advantage that, in contrast to the previous hydraulic systems, the operating state of the pump is recorded directly. Fluctuations in the operating state can therefore be effectively compensated for.
  • the control signals of the valves are reduced.
  • By measuring the pump current it can always be determined whether the supply of the individual consumers is guaranteed. This prevents undersupply.
  • the reduction of consumer currents can take place proportionally. However, a reduction according to priorities is also possible if, for. B. an individual consumer should not reduce his speed in contrast to the others.
  • control circuit which is the subject of this invention, intervenes only in exceptional cases, namely when the pumpable pump flow is not sufficient for the consumer flows set on the respective valves, which in total result in the current flow rate.
  • the current flow rate is reduced by reducing the respective consumer flows supplied.
  • Standard measuring devices are available for measuring the current delivery rate of the pump.
  • the current delivery volume can be measured by connecting the valves to the valves assigned to the individual consumers in the pump line (total delivery line), ie before the branching off of the consumer lines lead, a throttle or orifice arranged and the pressure drop is measured at this orifice.
  • the current delivery rate based on the predetermined possible delivery rate - at a given speed - can also be determined by the configurations according to claims 2 and 3.
  • valves that are assigned to the consumers. Basically, it can be assumed that these valves are adjusted electromagnetically or hydraulically from the outside, that is, by hand or by external input parameters. According to this invention, however, an adjustment signal for reducing the actuation of the valve piston is superimposed on these input signals if it is determined in the hydraulic system by measuring the current delivery quantity that the pumpable pump flow is exceeded.
  • the predeterminable pumpable pump current does not necessarily correspond to the maximum pumpable pump current. Rather, a lower limit, e.g. B. 80% of the maximum conveyable pump flow. This ensures that the hydraulic system does not fall out of its control range due to an absolute overload of the pump.
  • the adaptation of the consumer flows to the specified pump flow that can be conveyed when the limit value is exceeded is basically achieved by reducing the sum of the consumer flows to the specified limit value. In the simplest case, this can be done by reducing all consumer flows by the same percentage. However, it is also possible to weight the control signals, by means of which the consumer currents are reduced, differently for each consumer. This allows individual consumers to be given priority over other consumers. It can e.g. B. ensure that such consumers, for safety reasons, always with a certain consumer current have to be loaded, e.g. B. hydraulic brakes have priority over other consumers. This will be discussed later.
  • the embodiment of the invention according to claim 2 takes advantage of the knowledge that the delivery rate is also determined by the deflection of the balance piston of a 3-way pressure balance, which is deflected by the pressure difference between the pump pressure and the highest load pressure.
  • the current delivery rate is measured by measuring the deflection of the piston of a 3-way pressure compensator, which serves to keep the pressure difference between the pump pressure and the highest consumer pressure constant in a superimposed control loop.
  • the claim 3 relates to a hydraulic circuit with a control pump.
  • the current delivery volume is adjusted by relative adjustment between the stator (stationary part of the pump) and the rotor (rotating part of the pump) (see, for example, DE 26 51 325 C2), namely - in the preferred case - depending the pressure difference between the highest consumer pressure and the pump pressure.
  • the control position of the control pump is also used to measure the current flow.
  • a constant pump is used as the feed pump, which delivers a flow rate that is constant over time.
  • the delivery rate is measured immediately. That could e.g. B. happen directly by means of a built-in throttle on which a pressure difference is determined.
  • this can also be done by a 3-way pressure differential balance built into the delivery line, the balance piston of which is given the pressure difference between the pump pressure and the highest load pressure, the part of the flow rate not required to maintain this pressure difference depending on the position of the balance piston a bypass to the tank is derived.
  • either the position of the piston of the pressure compensator or the oil flow in the bypass to the tank can be used as a measure of the delivery flow provided for all the consumers.
  • This signal representing the flow rate is in turn compared in a comparator with a maximum flow rate and the difference signal is used to adjust or limit the flow rate supplied to the individual consumers.
  • this signal can either be superimposed with the delivery rate or the torque and / or the delivery pressure of the pump.
  • the special meaning of the invention according to claim 1 in the embodiment according to claims 2 and 3 is that the pump current is regulated by adapting the consumer currents to a predetermined limit value (pump current that can be conveyed), but this regulation only functions when the specified limit is reached.
  • the control pump or pressure differential balance is included in a second control circuit as a measuring element. So several control loops are superimposed.
  • An internal control circuit uses the pressure difference delta p between the pump pressure and the highest load pressure as the control variable and the control position of the control pump or the pressure compensating piston as the control variable.
  • the pressure difference delta p is measured on a piston and specified by dimensioning the spring of the pressure differential balance.
  • the control position of the control pump or the differential pressure balance ie. H. the manipulated variable is specified.
  • the superimposed outer control loop uses the currently measured delivery rate, ie the position of the piston of the differential pressure compensator in the sense of claim 2 or the control position of the control pump in the sense of claim 3 in order to be used in an emergency, ie Exceeding the limit value representing the pump flow that can be pumped, by adjusting the consumer flows as a manipulated variable, to keep the control variable specified by the limit value constant, namely the current flow rate.
  • the adaptation of the consumer flows of the individual consumers to the predetermined, maximum pumpable pump flow can also be achieved by superimposing the measurement signal obtained from the measurement of the current delivery quantity (deflection of the balance piston according to claim 2, control position of the control pump according to claim 3) with the pump output corresponding to the pump torque ( Delivery volume x delivery pressure) and / or the delivery pressure.
  • This has the advantage that a desired weighting of the delivery rate, the delivery torque and the delivery pressure of the control pump can be predetermined when the valve position is adapted to the maximum pump flow.
  • the current delivery capacity determined from the respective control position of the pump and the delivery pressure of the pump by multiplication or the torque of the pump is compared with a target torque and the output signal obtained from the difference is superimposed according to a selectable function, such that only when one is exceeded Given the predetermined drive torque, the position and adjustability of the valves assigned to the individual consumers are influenced, but not below this limit value.
  • the position and adjustability of the valves assigned to the individual consumers can be influenced when a certain pressure is exceeded by superimposing the delivery pressure after a certain function, but not below this pressure or only with a certain percentage.
  • the maximum external load is also taken into account when influencing the valves assigned to the consumers, in particular directional valves.
  • a pressure compensator can also be arranged in front of each valve, the pressure difference between the delivery pressure and consumer pressure, which is determined by a spring, which is taken off behind the respective valve, by adjusting the spring force as a function of the control position or superimposed on the torque and / or superimposed on the delivery pressure the control pump is adapted.
  • a setpoint processing is expedient.
  • the setpoints are the manually or automatically specified control signals for the valves assigned to the consumers. These externally entered setpoints can be fed to the system via attenuators (ramps). This specifies the rates of change at which the consumer currents can change if the setpoints entered change suddenly. It is thereby achieved that the adjustment speed of the pump or pressure differential balance is sufficient in any case to follow the change in the consumer flows over time. There can therefore be no shortage of consumers for a short time. Furthermore, the consumer flows requested by the entered target values can be roughly adapted to the maximum flow rate that can be supplied by the pump.
  • the setpoints entered from outside are brought into dependence on the sum of the setpoints entered and, in addition, on the predetermined pump flow that can be conveyed.
  • this leads to a weighting of the individual consumers and ensures that B. for safety reasons - important consumers always have an adequate oil flow.
  • the setpoints are reduced in advance if the specified pump flow that can be conveyed is expected to be exceeded on the basis of the input setpoint signals.
  • a control pump 1 is adjusted hydraulically.
  • a hydraulic valve (spring-loaded pressure compensator) 2 which detects the pump flow, is used for hydraulic adjustment.
  • the pressure compensator 2 is given on the one hand pump pressure and on the other hand the highest consumer pressure together with a spring load by spring 15 via a cascade of shuttle valves 3.
  • the pump 1 loads several consumers 4 ', 4 ⁇ , 4 ′′′.
  • Each consumer 4 is first a pressure control valve (pressure compensator, differential pressure compensator) 5 ';5 ⁇ ; 5 ′′′ upstream.
  • Characterized a constant pressure difference is set on the individual control valve 6, so that a load-independent, the control proportional setting of the respective consumer 4 ';4 ⁇ ; 4 utiliseen supplied volume flow (consumer flow) is possible.
  • the consumer current is therefore only dependent on signals a and b, with which the individual control valves are activated. As long as these signals are constant remain, the consumer current remains constant. However, this only applies on the condition that the control pump can provide a pump current sufficient for all consumers.
  • the control pump 1 is adjusted by an actuator 7.
  • the adjusting member 7 is a cylinder in which a piston with piston rod 17 is movable.
  • the piston adjusts the position of the rotor within the control pump, which is only indicated here.
  • the piston 16 is loaded on one side by a spring 18 and by the control pressure in line 19 emitted by the pressure compensator 2. As already described, this control pressure is dependent on the pressure difference between the pump pressure in the pump line 20 and the highest consumer pressure , which is determined by the cascade of shuttle valves 3.
  • the piston 16 is acted upon by the pump pressure in the pump line 20 on its side facing away from the spring 18.
  • the spring 18 and the control pressure 19 act in the sense of increasing the delivery volume of the control pump.
  • the control pump 1 is therefore included in a control circuit and has the function of supplying the manipulated variable to keep the controlled variable constant: pressure difference between the highest consumer pressure and the pump pressure.
  • the adjustment path with which the control pump 1 is adjusted by means of the actuator 7 is measured.
  • This adjustment path alpha is measured and given to the control unit 21, which will be described later.
  • the control unit is given a signal that represents the measured pump pressure and is designated P in the following. It goes without saying that both the adjustment value alpha and the pressure P via suitable converters into a form suitable for the control unit, e.g. B. a voltage must be converted.
  • control unit 21 is provided on the one hand with the setpoint input devices 13 ', 13 ⁇ , 13 ′′′ and on the other hand with the setpoint output devices, in particular amplifiers 14', 14 ⁇ , 14 ′′′.
  • Each output device is connected with its output lines A and B to the consumer, which has the same numbering. In order not to disturb the clarity of the circuit diagram, these connecting lines are not drawn.
  • control unit 21 also has the inlets for the adjustment path alpha and the pressure P.
  • the control unit is used to adapt the entered target values to the measured pump current.
  • the same control unit is also used for the hydraulic system according to FIG. 2. A description of FIG. 2 is therefore given first.
  • Three consumers 4 ', 4 ⁇ , 4 ′′′ are fed by a constant hydraulic pump 1.
  • a volume flow control is carried out by means of a pressure differential balance 22.
  • the piston 23 of the pressure differential balance is loaded on one side by a spring 24 and the highest load pressure.
  • the highest load pressure is determined via a cascade of shuttle valves 3.
  • the piston 23 is loaded by the pump pressure.
  • the differential pressure balance is connected to the tank via a bypass channel. By adjusting the piston 23, a constant pressure difference is adjusted. This regulation remains effective until the sum of the consumer flows supplied to the consumers exceeds the maximum pump flow that can be pumped.
  • Each consumer 4 is first a pressure control valve (pressure compensator, differential pressure compensator) 5 ';5 ⁇ ; 5 ′′′ upstream.
  • Each pressure control valve 5 is on the one hand the pressure in front of the associated control valve 6 ', 6 ⁇ , 6 ′′′ (directional control valve) and on the other hand the consumer pressure of the respective consumer 4 abandoned. Characterized a constant pressure difference is set on the individual control valve 6, so that a load-independent, the control proportional setting of the respective consumer 4 ';4 ⁇ ; 4 utiliseen supplied volume flow (consumer flow) is possible.
  • the balance piston of the differential pressure balance has a piston rod 25.
  • the displacement of the piston 23 is measured.
  • the output signal is called alpha.
  • the pump pressure and the displacement of the piston alpha is given to the control unit 21, which has already been described above. Reference is made to this description.
  • the adjustment path alpha is entered into a module 11.
  • a limit value alpha max is specified for module 11. This limit value alpha max can be specified constantly if only the input of the adjustment path is connected to the control unit 21. If the pump pressure P is also connected, further processing follows, which will be discussed later.
  • the measured adjustment path and the limit value alpha max are weighted.
  • the output signal of the module 11 is given to another module 10.
  • This function block 10 produces a positive constant output signal equal to 1 as long as the limit value of the adjustment path alpha max is greater than the measured adjustment path alpha. If the adjustment path alpha exceeds the limit value, the output signal of the function block 10 becomes smaller than 1.
  • the output signal a des decreases Function block 10 or 30, as long as the adjustment range alpha exceeds the limit value and until equilibrium is reached between the two.
  • the output signal of the function block 10, in the following weighting block can be further influenced by connecting the pressure measuring line P to the control unit 21. For this purpose, the measured value of the adjustment path is given to a multiplier 8 together with the final pump pressure.
  • the output signal of the multiplier 8 represents the hydraulic torque of the pump 1.
  • This output signal is related in block 9 to the maximum possible output signal.
  • the output signal of the module 9 is given to a further module 10, by which weighting takes place. The weighting can take place with the pump pressure and / or with the current adjustment path of the control pump. For this purpose, the current adjustment path is again related to the maximum adjustment path via module 11.
  • the output signal of the multiplier 8 is given to the function block 9 via a comparison block 26.
  • the comparison block the current torque pump determined by multiplication is related to the limit value Mmax of the pump, which is constantly specified.
  • the function block 9 now processes the output signal of the comparison block 26 so that it emits an output signal equal to 1 if the current torque is less than the limit value of the torque, and that it emits a time-reducing output signal as long as the currently determined torque is greater than that Limit is.
  • the output signal decreases according to a time-dependent function starting from 1 until equilibrium is reached by reducing the torque.
  • the output signal of the function block 9 is now used to process the maximum travel alpha max, as has already been indicated.
  • a multiplication module 27 is used for this purpose.
  • the limit value of the adjustment path alpha max is predetermined from the outside of this multiplication module, and on the other hand the output signal of the function block 9, which is related to the current torque.
  • the output signal of the multiplication module 27 is in turn given to the comparator 11. This ensures that the delivery rate of the pump is reduced when the predetermined torque is exceeded.
  • a permanently entered limit value of the pump pressure is related to the currently measured pump pressure in a comparator 28 (comparison module).
  • the module 10 now also contains a function module 29 which is controlled by the output signal of the comparator 28 and additionally by a limit value which represents the maximum desired value.
  • These entered quantities are now processed in the function block 29 in such a way that the function block 29 gives an output signal B which is zero as long as the measured pump pressure is less than the limit value Pmax of the pressure and which is equal to the limit value Smax of the setpoints if the measured pump pressure exceeds the limit value Pmax of the pump pressure.
  • the weighting block 10 with its two output signals A of the function block 30 and B of the function block then controls comparators 12 ', 12 ⁇ , 12 ′′′, each one of the valves 6', 6 ⁇ , 6 ′′′ for the individual consumers 4 ', 4 ⁇ , 4 ′′′ are assigned.
  • Each of these comparison elements 12 can be given a different setpoint via the setpoint generator 13 ', 13 ⁇ , 13 13.
  • the output signals of the comparison elements 12 are then via amplifiers 14 ', 14 ⁇ , 14 ′′′ the respective control signals for the magnets a1, b1, a2, b2, a3, b3 of the respective valves 6', 6 ⁇ , 6 ′′′ or the input signals of the actuators , through which the individual directional control valves 6 are controlled, superimposed.
  • the individual consumer 4 ', 4 ⁇ , 4 ′′′ can be supplied Volume flow are reduced so far that the total amount that can be pumped by the pump 1 is not exceeded.
  • the simultaneous detection and direct input of the adjustment path or the swivel angle of the control pump 1 can simultaneously ensure in the weighting module 10 that an adaptation of the current delivery rate to the maximum possible delivery rate takes place simultaneously with the adjustment to the current torque of the pump 1.
  • the current pump pressure P or other operating parameters of the hydraulic system can also be included in the weighting.
  • the comparison elements 12 - as shown in FIG. 13 - are divided into a multiplication module 31 ', 31 ⁇ , 31 ⁇ and a limiting module 32', 32 ⁇ , 32 ′′′.
  • the output signal A of the function block 30 and the setpoint value S1, S2, S3 are given to the multiplication block.
  • the setpoint S set is related to the current displacement of the pressure compensator or the variable displacement pump if the sum of the consumer flows exceeds the limit value of the pump flow.
  • the setpoints are reduced accordingly.
  • the output signal of the multiplication modules 31 is given to the limitation module 32 together with the output signal B of the function module 29, which establishes the relationship to the measured pump pressure.
  • the output signal of the limitation module 32 is limited to the entered limit value Smax of the setpoint.
  • Smax the limit value of the setpoint.
  • a further evaluation of the limit value Smax can be carried out in the sense that either there is no limit at all or the limit value is reduced or increased. This allows priorities to be given to individual consumers. Other consumers can be shut down or treated subordinately if the setpoint values set would lead to the limit value of the pump current being exceeded.
  • a setpoint processing is now additionally shown, which can be used optionally.
  • a setpoint generator 33 can be arranged upstream of the control unit 21.
  • the setpoint generator has a first component 34 for each input setpoint, which is referred to below as a ramp.
  • This ramp means that an abruptly entered setpoint only changes over time. This has the effect that the signal processing and adaptation of the hydraulic system can follow in time even when the setpoint value is entered suddenly and there is no temporary undersupply of the consumers.
  • the output signals of the ramps 34 are then multiplied in multiplication modules 35 by input limit values G1 to G3. These limit values represent a certain percentage of the limit value of the pump current. This results in a weighting of the entered target values in the multiplication modules 35.
  • the output signals of the multiplication modules 35 are fed to a summing element 36 with the output signal P2, which represents the sum of the output signals of the multiplication modules.
  • the signal E2 is given to a function block 37 together with a signal E1.
  • the signal E1 represents the maximum predetermined pump current in a form that is comparable to the signal E2.
  • the two input signals E1 and E2 are connected in the function block 37.
  • the output signal A is equal to 1 as long as the specified limit value of the pump delivery flow is greater than the set and weighted sum of the setpoints.
  • the output signal is equal to the quotient of the limit value and the weighted sum if the weighted sum is greater than the limit value.
  • the output signal of the function block 37 is now given to the multiplication blocks 38 ', 38 38, 38 ′′′.
  • the respective setpoint S1, S2, S3 is multiplied after it has preferably first been passed over the ramps 34 ′, 34 ⁇ , 34 ′′′.
  • the output signal of the multiplication modules 38 represents the respective setpoint given to the control unit 21.
  • This setpoint processing ensures that the setpoint input ensures that the setpoint values do not lead to consumption that far exceeds the specified limit value of the pump current. However, this is only a rough precaution.
  • the inventive superimposition of the adaptation of the consumer flows to the measured pump current ensures that each consumer remains functional within the framework assigned to it.
  • the particular importance of the invention lies in the fact that on the one hand the pump torque is corrected, but that a torque control can be superimposed on this torque control by simultaneously also detecting the speed of the pump or its delivery rate.
  • a control system comes into operation with which the setpoint signals with which the valves 6 are controlled are adapted to the currently measured pump delivery rate, preferably to the weighting of the currently measured pump delivery rate with the maximum predetermined pump delivery rate become.

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mining & Mineral Resources (AREA)
  • Civil Engineering (AREA)
  • Structural Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Fluid-Pressure Circuits (AREA)
  • Control Of Positive-Displacement Pumps (AREA)

Abstract

The invention concerns a hydraulic system in which several consumers (4) are powered by a common pump, the consumers (4) being controlled by control valves (6). If the hydraulic-fluid flows called for exceed the maximum flow which can be produced, a correction comes into action with which the reference-value signals by means of which the valves (6) are controlled are adjusted to the currently measured pumping rate, and preferably to the currently measured pumping rate weighted with the maximum prescribed pumping rate.

Description

Die Erfindung betrifft ein Hydrauliksystem nach dem Oberbegriff des Anspruchs, bekannt aus der US-A-4,712,376. Bei diesem Hydrauliksystem soll die Messung der aktuellen Fördermenge durch Erfassen der Pumpendrehzahl erfolgen. Daraus sollen dann die Stellungen der Steuerventile mittels eines Rechners unter Zuhilfenahme vorher ermittelter Nennwerte aus einem elektronischen Speicher korrigiert werden. Ein weiteres Hydrauliksystem ist bekannt durch die DE 26 51 325 C2.The invention relates to a hydraulic system according to the preamble of the claim, known from US-A-4,712,376. With this hydraulic system, the measurement of the current delivery rate is to be carried out by detecting the pump speed. From this, the positions of the control valves are then to be corrected by means of a computer with the aid of previously determined nominal values from an electronic memory. Another hydraulic system is known from DE 26 51 325 C2.

Dabei wird einem Regelventil einerseits der an der Pumpe anstehende Druck und andererseits der höchste Lastdruck gemeldet. Kann die Pumpe den von den Ventilen, welche den einzelnen Verbrauchern zugeordnet sind, geforderten Volumenstrom nicht mehr fördern, so reduziert sich die Druckdifferenz zwischen dem Druck der Pumpe und dem höchsten Lastdruck. Folglich reduziert das Regelventil die Versorgung der Steuerdruckgeber, durch welche die den Verbrauchern zugeordneten Ventile angesteuert werden. Dadurch werden die Ventile in ihrem Durchfluß begrenzt. Diese Begrenzung wird jedoch erst bei schon vorhandenem Überbedarf wirksam.A control valve is notified on the one hand of the pressure at the pump and on the other hand of the highest load pressure. If the pump can no longer deliver the volume flow required by the valves assigned to the individual consumers, the pressure difference between the pressure of the pump and the highest load pressure is reduced. The control valve consequently reduces the supply to the control pressure transmitter, by means of which the valves assigned to the consumers are actuated. This limits the flow of the valves. However, this limitation only becomes effective if there is already an excessive demand.

Bei dem durch das Patent 35 46 336 bekannten System werden die elektrischen Stellsignale der angesteuerten Wegeventile addiert. Der Volumenstrom, welcher der Summe der Stellsignale entspricht, wird mit dem maximal möglichen Pumpenstrom verglichen. Wenn die Summe der Stellsignale den möglichen Pumpenstrom überschreitet, werden die Stellsignale reduziert. Bei diesem System müssen alle Stellsignale erfaßt werden. Außerdem muß die Abhängigkeit der Ventildurchflüsse von den Stellsignalen mittels eines Rechners richtig berücksichtigt werden.In the system known from patent 35 46 336, the electrical control signals of the controlled directional valves are added. The volume flow, which corresponds to the sum of the control signals, is compared with the maximum possible pump flow. If the total of the control signals exceeds the possible pump current, the control signals are reduced. With this system, all control signals must be recorded. In addition, the dependence of the valve flows on the control signals must be properly taken into account by means of a computer.

Aufgabe der Erfindung ist es, das Hydrauliksystem so auszugestalten, daß es nicht schwingungsanfällig ist und daß im übrigen eine beliebige Gewichtung und Anpassung der einzelnen Verbraucherströme an die Betriebsparameter der Pumpe möglich ist.The object of the invention is to design the hydraulic system so that it is not susceptible to vibration and that any weighting and adaptation of the individual consumer flows to the operating parameters of the pump is also possible.

Die Lösung ergibt sich aus dem Kennzeichen des Anspruchs 1. Die Lösung hat den Vorteil, daß im Gegensatz zu den bisherigen Hydrauliksystemen der Betriebszustand der Pumpe unmittelbar erfaßt wird. Daher können Schwankungen des Betriebszustandes wirksam ausgeregelt werden.The solution results from the characterizing part of claim 1. The solution has the advantage that, in contrast to the previous hydraulic systems, the operating state of the pump is recorded directly. Fluctuations in the operating state can therefore be effectively compensated for.

Steigt die Summe der Verbraucherströme, die durch entsprechende Einstellung der den Verbrauchern zugeordneten Ventile gefordert wird, über die von der Pumpe maximal lieferbare Fördermenge an, so werden die Ansteuersignale der Ventile reduziert. Durch Messung des Pumpenstromes kann stets aktuell ermittelt werden, ob die Versorgung der einzelnen Verbraucher gewährleistet ist. Eine Unterversorgung wird dadurch vermieden. Die Reduzierung der Verbraucherströme kann verhältnisgleich erfolgen. Es ist jedoch auch eine Reduzierung nach Prioritäten möglich, wenn z. B. ein einzelner Verbraucher seine Geschwindigkeit im Gegensatz zu den anderen nicht reduzieren soll.If the sum of the consumer flows, which is required by appropriate setting of the valves assigned to the consumers, rises above the maximum delivery volume that can be delivered by the pump, the control signals of the valves are reduced. By measuring the pump current, it can always be determined whether the supply of the individual consumers is guaranteed. This prevents undersupply. The reduction of consumer currents can take place proportionally. However, a reduction according to priorities is also possible if, for. B. an individual consumer should not reduce his speed in contrast to the others.

Dabei erfolgt jedoch ein Eingriff des Regelkreises, der Gegenstand dieser Erfindung ist, nur in Ausnahmefällen, und zwar dann, wenn der förderbare Pumpenstrom nicht ausreicht für die an den jeweiligen Ventilen eingestellten Verbraucherströme, die in ihrer Summe die aktuelle Fördermenge ergeben. In diesem Falle wird die aktuelle Fördermenge durch Reduzierung der jeweils zugeführten Verbraucherströme vermindert.However, the control circuit, which is the subject of this invention, intervenes only in exceptional cases, namely when the pumpable pump flow is not sufficient for the consumer flows set on the respective valves, which in total result in the current flow rate. In this case, the current flow rate is reduced by reducing the respective consumer flows supplied.

Zur Messung der aktuellen Fördermenge der Pumpe stehen übliche Meßgeräte bereit. Insbesondere kann die aktuelle Fördermenge dadurch gemessen werden, daß in die Pumpenleitung (Gesamtförderleitung), also vor der Abzweigung der Verbraucherleitungen, welche zu den den einzelnen Verbrauchern zugeordneten Ventilen führen, eine Drossel oder Blende angeordnet und der Druckabfall an dieser Blende gemessen wird. Die aktuelle Fördermenge, bezogen auf die vorgegebene mögliche Fördermenge - bei vorgegebener Drehzahl - kann aber auch durch die Ausgestaltungen nach Anspruch 2 und 3 bestimmt werden.Standard measuring devices are available for measuring the current delivery rate of the pump. In particular, the current delivery volume can be measured by connecting the valves to the valves assigned to the individual consumers in the pump line (total delivery line), ie before the branching off of the consumer lines lead, a throttle or orifice arranged and the pressure drop is measured at this orifice. The current delivery rate, based on the predetermined possible delivery rate - at a given speed - can also be determined by the configurations according to claims 2 and 3.

Die Anpassung der Verbraucherströme an den förderbaren Pumpenstrom geschieht durch die Verstellung der Ventile, die den Verbrauchern jeweils zugeordnet sind. Grundsätzlich ist davon auszugehen, daß diese Ventile von außen, also von Hand oder durch fremde Eingabeparameter elektromagnetisch oder hydraulisch verstellt werden. Nach dieser Erfindung wird diesen Eingabesignalen jedoch ein Verstellsignal zur Verminderung der Aussteuerung des Ventilkolbens überlagert, wenn in dem Hydrauliksystem durch Messung der aktuellen Fördermenge festgestellt wird, daß der förderbare Pumpenstrom überschritten wird.The adaptation of the consumer flows to the pump flow that can be conveyed takes place by adjusting the valves that are assigned to the consumers. Basically, it can be assumed that these valves are adjusted electromagnetically or hydraulically from the outside, that is, by hand or by external input parameters. According to this invention, however, an adjustment signal for reducing the actuation of the valve piston is superimposed on these input signals if it is determined in the hydraulic system by measuring the current delivery quantity that the pumpable pump flow is exceeded.

Der vorgebbare förderbare Pumpenstrom entspricht nicht notwendigerweise dem maximalen förderbaren Pumpenstrom. Vielmehr wird ein geringerer Grenzwert, z. B. 80 % des maximal förderbaren Pumpenstromes vorgegeben. Dadurch wird erreicht, daß das Hydrauliksystem durch absolute Überlastung der Pumpe nicht aus seinem Regelbereich herausfällt.The predeterminable pumpable pump current does not necessarily correspond to the maximum pumpable pump current. Rather, a lower limit, e.g. B. 80% of the maximum conveyable pump flow. This ensures that the hydraulic system does not fall out of its control range due to an absolute overload of the pump.

Die Anpassung der Verbraucherströme an den vorgegebenen förderbaren Pumpenstrom bei Überschreitung des Grenzwertes geschieht grundsätzlich dadurch, daß die Summe der Verbraucherströme bis auf den vorgegebenen Grenzwert vermindert wird. Dies kann im einfachsten Falle dadurch geschehen, daß sämtliche Verbraucherströme um den gleichen Prozentsatz vermindert werden. Es ist jedoch auch möglich, die Ansteuersignale, durch welche die Verbraucherströme reduziert werden, für jeden Verbraucher unterschiedlich zu gewichten. Dadurch kann einzelnen Verbrauchern ein Vorrang vor anderen Verbrauchern eingeräumt werden. Es kann z. B. gewährleistet werden, daß solche Verbraucher, die aus Sicherheitsgründen immer mit einem bestimmten Verbraucherstrom beschickt werden müssen, z. B. hydraulische Bremsen, Vorrang haben vor anderen Verbrauchern. Hierauf wird an späterer Stelle noch eingegangen.The adaptation of the consumer flows to the specified pump flow that can be conveyed when the limit value is exceeded is basically achieved by reducing the sum of the consumer flows to the specified limit value. In the simplest case, this can be done by reducing all consumer flows by the same percentage. However, it is also possible to weight the control signals, by means of which the consumer currents are reduced, differently for each consumer. This allows individual consumers to be given priority over other consumers. It can e.g. B. ensure that such consumers, for safety reasons, always with a certain consumer current have to be loaded, e.g. B. hydraulic brakes have priority over other consumers. This will be discussed later.

Die Ausgestaltung der Erfindung nach Anspruch 2 macht sich die Erkenntnis zunutze, daß die Fördermenge auch durch die Auslenkung des Waagekolbens einer 3-Wege-Druckwaage bestimmt wird, der durch die Druckdifferenz zwischen dem Pumpendruck und dem höchsten Lastdruck ausgelenkt wird. Nach dieser Lösung erfolgt die Messung der aktuellen Fördermenge durch Messung der Auslenkung des Kolbens einer 3-Wege-Druckwaage, die in einem überlagerten Regelkreis der Konstanthaltung der Druckdifferenz zwischen dem Pumpendruck und dem höchsten Verbraucherdruck dient.The embodiment of the invention according to claim 2 takes advantage of the knowledge that the delivery rate is also determined by the deflection of the balance piston of a 3-way pressure balance, which is deflected by the pressure difference between the pump pressure and the highest load pressure. According to this solution, the current delivery rate is measured by measuring the deflection of the piston of a 3-way pressure compensator, which serves to keep the pressure difference between the pump pressure and the highest consumer pressure constant in a superimposed control loop.

Der Anspruch 3 betrifft eine hydraulische Schaltung mit einer Regelpumpe. Bei einer solchen Regelpumpe wird das momentane Fördervolumen durch Relativverstellung zwischen Stator (ortsfester Teil der Pumpe) und Rotor (drehender Teil der Pumpe) (vgl. z. B. DE 26 51 325 C2) verstellt, und zwar - im bevorzugten Falle - in Abhängigkeit von der Druckdifferenz zwischen dem höchsten Verbraucherdruck und dem Pumpendruck. Hier wird zusätzlich die Regelstellung der Regelpumpe zur Messung des aktuellen Förderstroms benutzt.The claim 3 relates to a hydraulic circuit with a control pump. In such a control pump, the current delivery volume is adjusted by relative adjustment between the stator (stationary part of the pump) and the rotor (rotating part of the pump) (see, for example, DE 26 51 325 C2), namely - in the preferred case - depending the pressure difference between the highest consumer pressure and the pump pressure. Here, the control position of the control pump is also used to measure the current flow.

Bei der Lösung nach Anspruch 2 wird eine Konstantpumpe als Förderpumpe eingesetzt, die einen zeitlich konstanten Förderstrom liefert. In diesem Falle wird die Fördermenge unmittelbar gemessen. Das könnte z. B. direkt mittels einer eingebauten Drossel geschehen, an der eine Druckdifferenz ermittelt wird. Dies kann aber auch durch eine in die Förderleitung eingebaute 3-Wege-Druckdifferenzwaage geschehen, deren Waagekolben die Druckdifferenz zwischen dem Pumpendruck und dem höchsten Lastdruck aufgegeben wird, wobei der zur Aufrechterhaltung dieser Druckdifferenz nicht erforderliche Teil des Förderstromes in Abhängigkeit von der Stellung des Waagekolbens über einen Bypass zum Tank abgeleitet wird. Hierbei kann entweder die Stellung des Kolbens der Druckwaage oder der Ölfluß im Bypass zum Tank als Maß für den für die Gesamtheit der Verbraucher bereitgestellten Förderstrom benutzt werden. Dieses den Förderstrom repräsentierende Signal wird wiederum in einem Vergleichsglied mit einem maximalen Förderstrom verglichen und das Differenzsignal wird zur Verstellung oder Begrenzung des den einzelnen Verbrauchern zugeführten Förderstroms benutzt. Dabei kann dieses Signal - wie bereits zuvor beschrieben - entweder mit der Förderleistung bzw. dem Drehmoment und/oder dem Förderdruck der Pumpe überlagert werden.In the solution according to claim 2, a constant pump is used as the feed pump, which delivers a flow rate that is constant over time. In this case, the delivery rate is measured immediately. That could e.g. B. happen directly by means of a built-in throttle on which a pressure difference is determined. However, this can also be done by a 3-way pressure differential balance built into the delivery line, the balance piston of which is given the pressure difference between the pump pressure and the highest load pressure, the part of the flow rate not required to maintain this pressure difference depending on the position of the balance piston a bypass to the tank is derived. In this case, either the position of the piston of the pressure compensator or the oil flow in the bypass to the tank can be used as a measure of the delivery flow provided for all the consumers. This signal representing the flow rate is in turn compared in a comparator with a maximum flow rate and the difference signal is used to adjust or limit the flow rate supplied to the individual consumers. As already described, this signal can either be superimposed with the delivery rate or the torque and / or the delivery pressure of the pump.

Die besondere Bedeutung der Erfindung nach Anspruch 1 in der Ausgestaltung nach den Ansprüchen 2 und 3 besteht darin, daß eine Regelung des Pumpenstromes durch Anpassung der Verbraucherströme an einen vorgegebenen Grenzwert (förderbaren Pumpenstrom) erfolgt, daß diese Regelung aber nur dann in Funktion tritt, wenn der vorgegebene Grenzwert erreicht wird. Im Gegensatz zu der üblichen Funktion der sog. Regelpumpe bzw. Druckdifferenzwaage, die in Wirklichkeit eine Steuerfunktion innerhalb eines ersten Regelkreises ist, ist hier die Regelpumpe bzw. Druckdifferenzwaage in einen zweiten Regelkreis als Meßglied eingeschlossen. Es werden also mehrere Regelkreise überlagert. Ein innerer Regelkreis benutzt die Druckdifferenz delta p zwischen dem Pumpendruck und dem höchsten Lastdruck als Regelgröße und die Regelstellung der Regelpumpe bzw. des Druckwaagekolbens als Stellgröße. Dabei wird die Druckdifferenz delta p an einem Kolben gemessen und durch Dimensionierung der Feder der Druckdifferenzwaage vorgegeben. Durch die Stellung des Kolbens wird die Regelstellung der Regelpumpe bzw. der Druckdifferenzwaage, d. h. die Stellgröße vorgegeben.The special meaning of the invention according to claim 1 in the embodiment according to claims 2 and 3 is that the pump current is regulated by adapting the consumer currents to a predetermined limit value (pump current that can be conveyed), but this regulation only functions when the specified limit is reached. In contrast to the usual function of the so-called control pump or pressure differential balance, which is actually a control function within a first control circuit, the control pump or pressure differential balance is included in a second control circuit as a measuring element. So several control loops are superimposed. An internal control circuit uses the pressure difference delta p between the pump pressure and the highest load pressure as the control variable and the control position of the control pump or the pressure compensating piston as the control variable. The pressure difference delta p is measured on a piston and specified by dimensioning the spring of the pressure differential balance. The control position of the control pump or the differential pressure balance, ie. H. the manipulated variable is specified.

Der überlagerte äußere Regelkreis benutzt die aktuell gemessene Fördermenge, d. h. im Sinne des Anspruchs 2 die Stellung des Kolbens der Druckdifferenzwaage oder im Sinne des Anspruchs 3 die Regelstellung der Regelpumpe, um im Notfall, d. h. bei Überschreiten des den förderbaren Pumpenstrom repräsentierenden Grenzwerts, durch Anpassung der Verbraucherströme als Stellgröße die durch den Grenzwert vorgegebene Regelgröße, nämlich die aktuelle Fördermenge konstant zu halten.The superimposed outer control loop uses the currently measured delivery rate, ie the position of the piston of the differential pressure compensator in the sense of claim 2 or the control position of the control pump in the sense of claim 3 in order to be used in an emergency, ie Exceeding the limit value representing the pump flow that can be pumped, by adjusting the consumer flows as a manipulated variable, to keep the control variable specified by the limit value constant, namely the current flow rate.

Zusätzlich kann die Anpassung der Verbraucherströme der einzelnen Verbraucher an den vorgegebenen, maximal förderbaren Pumpenstrom auch durch Überlagerung des aus der Messung der aktuellen Fördermenge (Auslenkung des Waagekolbens gemäß Anspruch 2, Regelstellung der Regelpumpe gemäß Anspruch 3) gewonnenen Meßsignals mit der Pumpenleistung entsprechend dem Pumpenmoment (Fördervolumen x Förderdruck) und/oder dem Förderdruck erfolgen. Das hat den Vorteil, daß eine gewünschte Gewichtung der Fördermenge, des Fördermoments und des Förderdrucks der Regelpumpe bei der Anpassung der Ventilstellung an den maximalen Pumpenstrom vorgebbar ist. Dabei wird die aktuell aus der jeweiligen Regelstellung der Pumpe und dem Förderdruck der Pumpe durch Multiplikation ermittelte Förderleistung bzw. das Drehmoment der Pumpe mit einem Solldrehmoment verglichen und das aus der Differenz gewonnene Ausgangssignal nach einer wählbaren Funktion überlagert, etwa derart, daß nur bei Überschreiten eines vorgegebenen Antriebsmoments eine Beeinflussung der Stellung und Stellbarkeit der den einzelnen Verbrauchern zugeordneten Ventile erfolgt, unterhalb dieses Grenzwerts dagegen nicht. Ebenso kann durch Überlagerung des Förderdruckes nach einer bestimmten Funktion die Stellung und Stellbarkeit der den einzelnen Verbrauchern zugeordneten Ventile bei Überschreitung eines bestimmten Druckes beeinflußt werden, unterhalb dieses Druckes jedoch nicht oder nur mit einem bestimmten Prozentsatz. Dadurch wird auch die maximale äußere Last bei der Beeinflussung der den Verbrauchern zugeordneten Ventile, insbesondere Wegeventile berücksichtigt.In addition, the adaptation of the consumer flows of the individual consumers to the predetermined, maximum pumpable pump flow can also be achieved by superimposing the measurement signal obtained from the measurement of the current delivery quantity (deflection of the balance piston according to claim 2, control position of the control pump according to claim 3) with the pump output corresponding to the pump torque ( Delivery volume x delivery pressure) and / or the delivery pressure. This has the advantage that a desired weighting of the delivery rate, the delivery torque and the delivery pressure of the control pump can be predetermined when the valve position is adapted to the maximum pump flow. The current delivery capacity determined from the respective control position of the pump and the delivery pressure of the pump by multiplication or the torque of the pump is compared with a target torque and the output signal obtained from the difference is superimposed according to a selectable function, such that only when one is exceeded Given the predetermined drive torque, the position and adjustability of the valves assigned to the individual consumers are influenced, but not below this limit value. Likewise, the position and adjustability of the valves assigned to the individual consumers can be influenced when a certain pressure is exceeded by superimposing the delivery pressure after a certain function, but not below this pressure or only with a certain percentage. As a result, the maximum external load is also taken into account when influencing the valves assigned to the consumers, in particular directional valves.

Die Beeinflussung des jedem Verbraucher und der Gesamtheit der Verbraucher zugeführten Pumpenstroms erfolgt z. B. elektrisch oder hydraulisch dadurch, daß die den einzelnen Verbrauchern zugeordneten Ventile in Abhängigkeit von der Regelstellung oder überlagert dem Drehmoment und/oder überlagert dem Förderdruck der Regelpumpe beeinflußt wird. Alternativ kann jedoch auch vor jedem Ventil eine Druckwaage angeordnet sein, deren durch eine Feder vorgegebene Druckdifferenz zwischen Förderdruck und Verbraucherdruck, der hinter dem jeweiligen Ventil abgenommen wird, durch Verstellung der Federkraft in Abhängigkeit von der Regelstellung oder überlagert dem Drehmoment und/oder überlagert dem Förderdruck der Regelpumpe angepaßt wird.The influencing of the pump current supplied to each consumer and the total of the consumers takes place, for. B. electrically or hydraulically in that the individual consumers assigned valves depending on the control position or superimposed on the torque and / or superimposed on the delivery pressure of the control pump. As an alternative, however, a pressure compensator can also be arranged in front of each valve, the pressure difference between the delivery pressure and consumer pressure, which is determined by a spring, which is taken off behind the respective valve, by adjusting the spring force as a function of the control position or superimposed on the torque and / or superimposed on the delivery pressure the control pump is adapted.

Für besondere Einsatzzwecke des erfindungsgemäßen Hydrauliksystems ist eine Sollwert-Aufbereitung zweckmäßig. Die Sollwerte sind die von Hand oder automatisch vorgegebenen Ansteuersignale für die den Verbrauchern zugeordneten Ventile. Diese von außen eingegebenen Sollwerte können über Dämpfungsglieder dem System zugeführt werden (Rampen). Dadurch werden die Änderungsgeschwindigkeiten vorgegeben, mit welchen sich die Verbraucherströme bei sprunghafter Änderung der eingegebenen Sollwerte ändern können. Dadurch wird erreicht, daß die Verstellgeschwindigkeit der Pumpe bzw. Druckdifferenzwaage in jedem Falle ausreicht, um der zeitlichen Änderung der Verbraucherströme zu folgen. Es kann daher auch kurzzeitig nicht zu einer Unterversorgung der Verbraucher kommen. Ferner können die durch die eingegebenen Sollwerte angeforderten Verbraucherströme grob an die von der Pumpe maximal lieferbare Durchflußmenge angepaßt werden. Hierzu werden die von außen eingegebenen Sollwerte in Abhängigkeit gebracht von der Summe der eingegebenen Sollwerte und zusätzlich von dem vorgegebenen förderbaren Pumpenstrom. Dadurch wird zum einen eine Gewichtung der einzelnen Verbraucher erreicht und gewährleistet, daß für die - z. B. aus Sicherheitsgründen - wichtigeren Verbraucher stets ein ausreichender Ölstrom bereitsteht. Es erfolgt zum anderen bereits vorab eine Reduzierung der Sollwerte, wenn eine Überschreitung des vorgegebenen förderbaren Pumpenstroms aufgrund der eingegebenen Sollwertsignale zu erwarten ist.For special applications of the hydraulic system according to the invention, a setpoint processing is expedient. The setpoints are the manually or automatically specified control signals for the valves assigned to the consumers. These externally entered setpoints can be fed to the system via attenuators (ramps). This specifies the rates of change at which the consumer currents can change if the setpoints entered change suddenly. It is thereby achieved that the adjustment speed of the pump or pressure differential balance is sufficient in any case to follow the change in the consumer flows over time. There can therefore be no shortage of consumers for a short time. Furthermore, the consumer flows requested by the entered target values can be roughly adapted to the maximum flow rate that can be supplied by the pump. For this purpose, the setpoints entered from outside are brought into dependence on the sum of the setpoints entered and, in addition, on the predetermined pump flow that can be conveyed. On the one hand, this leads to a weighting of the individual consumers and ensures that B. for safety reasons - important consumers always have an adequate oil flow. On the other hand, the setpoints are reduced in advance if the specified pump flow that can be conveyed is expected to be exceeded on the basis of the input setpoint signals.

Im folgenden werden Ausführungsbeispiele der Erfindung anhand der nachfolgend beschriebenen Schaltpläne dargestellt.In the following, exemplary embodiments of the invention are illustrated using the circuit diagrams described below.

Es zeigen:

Fig. 1
einen Schaltplan für ein Hydrauliksystem mit Regelpumpe;
Fig. 2
einen Schaltplan zur Darstellung des Hydrauliksystems, bei dem zur Messung der Fördermenge eine Druckdifferenzwaage benutzt wird;
Fig. 3
einen Schaltplan mit Einzelheiten nach den Figuren 1 bzw. 2;
Fig. 4
einen Schaltplan für die Sollwert-Aufbereitung.
Show it:
Fig. 1
a circuit diagram for a hydraulic system with control pump;
Fig. 2
a circuit diagram to illustrate the hydraulic system in which a differential pressure balance is used to measure the flow rate;
Fig. 3
a circuit diagram with details according to Figures 1 and 2;
Fig. 4
a circuit diagram for the setpoint processing.

Zu Fig. 1:
Eine Regelpumpe 1 wird hydraulisch verstellt. Zur hydraulischen Verstellung dient ein Regelventil (federbelastete Druckwaage) 2, die den Pumpenstrom erfaßt. Zur Erfassung des Pumpenstroms wird der Druckwaage 2 einerseits Pumpendruck und andererseits der höchste Verbraucherdruck gemeinsam mit einer Federbelastung durch Feder 15 über eine Kaskade von Wechselventilen 3 aufgegeben. Durch die Pumpe 1 werden mehrere Verbraucher 4′, 4˝, 4‴ beschickt. Jedem Verbraucher 4 ist zunächst ein Druckregelventil (Druckwaage, Druckdifferenzwaage) 5′; 5˝; 5‴ vorgeschaltet. Jedem der Druckregelventile 5 wird einerseits der Druck vor dem zugeordneten Steuerventil 6′; 6˝; 6‴ (Wegeventil) und andererseits der Verbraucherdruck des jeweiligen Verbrauchers 4 aufgegeben. Dadurch wird an dem einzelnen Steuerventil 6 eine konstante Druckdifferenz eingestellt, so daß in weiten Bereichen eine lastunabhängige, der Ansteuerung proportionale Einstellung des dem jeweiligen Verbraucher 4′; 4˝; 4‴ zugeführten Volumenstroms (Verbraucherstrom) möglich ist.1:
A control pump 1 is adjusted hydraulically. A hydraulic valve (spring-loaded pressure compensator) 2, which detects the pump flow, is used for hydraulic adjustment. To detect the pump flow, the pressure compensator 2 is given on the one hand pump pressure and on the other hand the highest consumer pressure together with a spring load by spring 15 via a cascade of shuttle valves 3. The pump 1 loads several consumers 4 ', 4˝, 4 ‴. Each consumer 4 is first a pressure control valve (pressure compensator, differential pressure compensator) 5 ';5˝; 5 ‴ upstream. Each of the pressure control valves 5, on the one hand, the pressure upstream of the associated control valve 6 ';6˝; 6 ‴ (directional valve) and on the other hand the consumer pressure of the respective consumer 4 abandoned. Characterized a constant pressure difference is set on the individual control valve 6, so that a load-independent, the control proportional setting of the respective consumer 4 ';4˝; 4 geführten supplied volume flow (consumer flow) is possible.

Der Verbraucherstrom ist also in weiten Bereichen nur von den Signalen a bzw. b abhängig, mit denen die einzelnen Steuerventile angesteuert werden. Solange diese Signale konstant bleiben, bleibt auch der Verbraucherstrom konstant eingeregelt. Dies gilt allerdings nur unter der Voraussetzung, daß die Regelpumpe einen für sämtliche Verbraucher ausreichenden Pumpenstrom bereitstellen kann.In a wide range, the consumer current is therefore only dependent on signals a and b, with which the individual control valves are activated. As long as these signals are constant remain, the consumer current remains constant. However, this only applies on the condition that the control pump can provide a pump current sufficient for all consumers.

Die Regelpumpe 1, deren grundsätzlicher Aufbau bereits zuvor beschrieben wurde, wird durch ein Stellglied 7 verstellt. Bei dem Verstellglied 7 handelt es sich um einen Zylinder, in dem ein Kolben mit Kolbenstange 17 beweglich ist. Der Kolben verstellt die Position des Rotors innerhalb der Regelpumpe, was hier nur angedeutet wird. Der Kolben 16 wird auf einer Seite belastet durch eine Feder 18 und von durch den von der Druckwaage 2 abgegebenen Steuerdruck in Leitung 19. Dieser Steuerdruck ist - wie bereits zuvor geschildert - abhängig von der Druckdifferenz zwischen dem Pumpendruck in der Pumpenleitung 20 und dem höchsten Verbraucherdruck, der durch die Kaskade von Wechselventilen 3 ermittelt wird. Der Kolben 16 wird auf seiner von der Feder 18 abgewandten Seite mit dem Pumpendruck in Pumpenleitung 20 beaufschlagt. Die Feder 18 und der Steuerdruck 19 wirken im Sinne einer Vergrößerung des Fördervolumens der Regelpumpe.The control pump 1, the basic structure of which has already been described above, is adjusted by an actuator 7. The adjusting member 7 is a cylinder in which a piston with piston rod 17 is movable. The piston adjusts the position of the rotor within the control pump, which is only indicated here. The piston 16 is loaded on one side by a spring 18 and by the control pressure in line 19 emitted by the pressure compensator 2. As already described, this control pressure is dependent on the pressure difference between the pump pressure in the pump line 20 and the highest consumer pressure , which is determined by the cascade of shuttle valves 3. The piston 16 is acted upon by the pump pressure in the pump line 20 on its side facing away from the spring 18. The spring 18 and the control pressure 19 act in the sense of increasing the delivery volume of the control pump.

Die Regelpumpe 1 ist also in einen Regelkreis eingeschlossen und hat die Funktion, die Stellgröße zu liefern zur Konstanthaltung der Regelgröße: Druckdifferenz zwischen dem höchsten Verbraucherdruck und dem Pumpendruck.The control pump 1 is therefore included in a control circuit and has the function of supplying the manipulated variable to keep the controlled variable constant: pressure difference between the highest consumer pressure and the pump pressure.

Der Verstellweg, mit dem die Regelpumpe 1 mittels des Stellgliedes 7 verstellt wird, wird gemessen. Dieser Verstellweg alpha wird gemessen und dem Steuergerät 21 aufgegeben, das später beschrieben wird. Ferner wird dem Steuergerät ein Signal aufgegeben, das den gemessenen Pumpendruck repräsentiert und im folgenden mit P bezeichnet wird. Es ist selbstverständlich, daß sowohl der Verstellwert alpha als auch der Druck P über geeignete Wandler in eine für das Steuergerät geeignete Form, z. B. eine Spannung umgewandelt werden müssen.The adjustment path with which the control pump 1 is adjusted by means of the actuator 7 is measured. This adjustment path alpha is measured and given to the control unit 21, which will be described later. Furthermore, the control unit is given a signal that represents the measured pump pressure and is designated P in the following. It goes without saying that both the adjustment value alpha and the pressure P via suitable converters into a form suitable for the control unit, e.g. B. a voltage must be converted.

Es sei erwähnt, daß das Steuergerät 21 zum einen mit den Sollwert-Eingabegeräten 13′, 13˝, 13‴ und zum anderen mit den Sollwert-Ausgabegeräten, insbesondere Verstärkern 14′, 14˝, 14‴ versehen ist. Jedes Ausgabegerät ist mit seinen Ausgabeleitungen A und B mit dem Verbraucher verbunden, der die gleiche Numerierung aufweist. Um die Übersichtlichkeit des Schaltplanes nicht zu stören, sind diese Verbindungsleitungen nicht gezeichnet.It should be mentioned that the control unit 21 is provided on the one hand with the setpoint input devices 13 ', 13˝, 13 ‴ and on the other hand with the setpoint output devices, in particular amplifiers 14', 14˝, 14 ‴. Each output device is connected with its output lines A and B to the consumer, which has the same numbering. In order not to disturb the clarity of the circuit diagram, these connecting lines are not drawn.

Wie bereits erwähnt, besitzt das Steuergerät 21 ferner die Einlässe für den Verstellweg alpha und den Druck P. Das Steuergerät dient zur Anpassung der eingegebenen Sollwerte an den gemessenen Pumpenstrom.As already mentioned, the control unit 21 also has the inlets for the adjustment path alpha and the pressure P. The control unit is used to adapt the entered target values to the measured pump current.

Dasselbe Steuergerät wird auch für das Hydrauliksystem nach Fig. 2 verwandt. Daher erfolgt zunächst eine Beschreibung der Fig. 2.The same control unit is also used for the hydraulic system according to FIG. 2. A description of FIG. 2 is therefore given first.

Zu Fig. 2:
Drei Verbraucher 4′, 4˝, 4‴ werden durch eine konstante Hydraulikpumpe 1 gespeist. Dabei erfolgt eine Volumenstromregelung mittels einer Druckdifferenzwaage 22. Der Kolben 23 der Druckdifferenzwaage wird auf einer Seite durch eine Feder 24 sowie den höchsten Lastdruck belastet. Der höchste Lastdruck wird über eine Kaskade von Wechselventilen 3 ermittelt. Auf der anderen Seite wird der Kolben 23 durch den Pumpendruck belastet. Die Druckdifferenzwaage ist über einen Bypass-Kanal mit dem Tank verbunden. Durch Verstellung des Kolbens 23 wird eine konstante Druckdifferenz eingeregelt. Diese Regelung bleibt solange wirksam, bis die Summe der den Verbrauchern zugeführten Verbraucherströme den maximal förderbaren Pumpenstrom übersteigt.
Jedem Verbraucher 4 ist zunächst ein Druckregelventil (Druckwaage, Druckdifferenzwaage) 5′; 5˝; 5‴ vorgeschaltet. Jedem Druckregelventil 5 wird einerseits der Druck vor dem zugeordneten Steuerventil 6′, 6˝, 6‴ (Wegeventil) und andererseits der Verbraucherdruck des jeweiligen Verbrauchers 4 aufgegeben. Dadurch wird an dem einzelnen Steuerventil 6 eine konstante Druckdifferenz eingestellt, so daß in weiten Bereichen eine lastunabhängige, der Ansteuerung proportionale Einstellung des dem jeweiligen Verbraucher 4′; 4˝; 4‴ zugeführten Volumenstroms (Verbraucherstrom) möglich ist.2:
Three consumers 4 ', 4˝, 4 ‴ are fed by a constant hydraulic pump 1. A volume flow control is carried out by means of a pressure differential balance 22. The piston 23 of the pressure differential balance is loaded on one side by a spring 24 and the highest load pressure. The highest load pressure is determined via a cascade of shuttle valves 3. On the other hand, the piston 23 is loaded by the pump pressure. The differential pressure balance is connected to the tank via a bypass channel. By adjusting the piston 23, a constant pressure difference is adjusted. This regulation remains effective until the sum of the consumer flows supplied to the consumers exceeds the maximum pump flow that can be pumped.
Each consumer 4 is first a pressure control valve (pressure compensator, differential pressure compensator) 5 ';5˝; 5 ‴ upstream. Each pressure control valve 5 is on the one hand the pressure in front of the associated control valve 6 ', 6˝, 6 ‴ (directional control valve) and on the other hand the consumer pressure of the respective consumer 4 abandoned. Characterized a constant pressure difference is set on the individual control valve 6, so that a load-independent, the control proportional setting of the respective consumer 4 ';4˝; 4 geführten supplied volume flow (consumer flow) is possible.

Der Waagekolben der Druckdifferenzwaage besitzt eine Kolbenstange 25. Der Verstellweg des Kolbens 23 wird gemessen. Das Ausgangssignal wird mit alpha bezeichnet. Der Pumpendruck und der Verstellweg des Kolbens alpha wird dem Steuergerät 21 aufgegeben, was bereits zuvor beschrieben worden ist. Auf diese Beschreibung wird Bezug genommen.The balance piston of the differential pressure balance has a piston rod 25. The displacement of the piston 23 is measured. The output signal is called alpha. The pump pressure and the displacement of the piston alpha is given to the control unit 21, which has already been described above. Reference is made to this description.

Anhand von Fig. 3 und unter Bezugnahme auf die insoweit gleichen Figuren 1 und 2 wird im folgenden die Verarbeitung der eingegebenen Sollwerte in Steuergerät 21 zu Stellgrößen für die Wegeventile 6 beschrieben.3 and with reference to FIGS. 1 and 2, which are the same in this respect, the processing of the input desired values in control unit 21 into control variables for the directional control valves 6 is described below.

In dem Steuergerät 21 wird der Verstellweg alpha einem Baustein 11 eingegeben. Gleichzeitig wird dem Baustein 11 ein Grenzwert alpha max vorgegeben. Dieser Grenzwert alpha max kann konstant vorgegeben werden, wenn nur die Eingabe des Verstellweges am Steuergerät 21 angeschlossen ist. Wenn auch der Pumpendruck P angeschlossen ist, folgt eine weitere Verarbeitung, auf die später noch eingegangen wird.In the control unit 21, the adjustment path alpha is entered into a module 11. At the same time, a limit value alpha max is specified for module 11. This limit value alpha max can be specified constantly if only the input of the adjustment path is connected to the control unit 21. If the pump pressure P is also connected, further processing follows, which will be discussed later.

In dem Baustein 11 erfolgt eine Gewichtung des gemessenen Verstellweges und des Grenzwertes alpha max. Das Ausgangssignal des Bausteines 11 wird einem weiteren Baustein 10 aufgegeben. Dieser Funktionsbaustein 10 ergibt ein positives konstantes Ausgangssignal gleich 1, solange der Grenzwert des Verstellweges alpha max größer ist als der gemessene Verstellweg alpha. Wenn der Verstellweg alpha den Grenzwert überschreitet, wird das Ausgangssignal des Funktionsbausteines 10 kleiner als 1. Von 1 ausgehend verkleinert sich das Ausgangssignal a des Funktionsbausteins 10 bzw. 30, solange der Verstellweg alpha den Grenzwert überschreitet und bis zwischen beiden Gleichgewicht eintritt. Das Ausgangssignal des Funktionsbausteines 10, im folgenden Gewichtungsbaustein, kann durch Anschluß der Druckmeßleitung P an das Steuergerät 21 weiter beeinflußt werden. Hierzu wird der Meßwert des Verstellweges gemeinsam mit dem Pumpenddruck einem Multipliziergerät 8 aufgegeben. Das Ausgangssignal des Multipliziergeräts 8 repräsentiert das hydraulische Drehmoment der Pumpe 1. Dieses Ausgangssignal wird im Baustein 9 zu dem maximal möglichen Ausgangssignal in Beziehung gesetzt. Das Ausgangssignal des Bausteins 9 wird einem weiteren Baustein 10 aufgegeben, durch den eine Gewichtung erfolgt. Die Gewichtung kann mit dem Pumpendruck und/oder mit dem aktuellen Verstellweg der Regelpumpe erfolgen. Über den Baustein 11 wird dazu auch der aktuelle Verstellweg wieder zu dem maximalen Verstellweg in Beziehung gesetzt.In block 11, the measured adjustment path and the limit value alpha max are weighted. The output signal of the module 11 is given to another module 10. This function block 10 produces a positive constant output signal equal to 1 as long as the limit value of the adjustment path alpha max is greater than the measured adjustment path alpha. If the adjustment path alpha exceeds the limit value, the output signal of the function block 10 becomes smaller than 1. Starting from 1, the output signal a des decreases Function block 10 or 30, as long as the adjustment range alpha exceeds the limit value and until equilibrium is reached between the two. The output signal of the function block 10, in the following weighting block, can be further influenced by connecting the pressure measuring line P to the control unit 21. For this purpose, the measured value of the adjustment path is given to a multiplier 8 together with the final pump pressure. The output signal of the multiplier 8 represents the hydraulic torque of the pump 1. This output signal is related in block 9 to the maximum possible output signal. The output signal of the module 9 is given to a further module 10, by which weighting takes place. The weighting can take place with the pump pressure and / or with the current adjustment path of the control pump. For this purpose, the current adjustment path is again related to the maximum adjustment path via module 11.

Dabei wird - wie Fig. 3 zeigt - das Ausgangssignal des Multipliziergerätes 8 über ein Vergleichsbaustein 26 dem Funktionsbaustein 9 aufgegeben. In dem Vergleichsbaustein wird das durch Multiplikation ermittelte aktuelle Drehmoment Pumpe in Beziehung gesetzt zu dem Grenzwert Mmax der Pumpe, der konstant vorgegeben wird. Der Funktionsbaustein 9 verarbeitet nun das Ausgangssignal des Vergleichsbausteins 26 so, daß er ein Ausgangssignal gleich 1 abgibt, wenn das aktuelle Drehmoment kleiner als der Grenzwert des Drehmomentes ist, und daß er ein sich zeitlich verkleinerndes Ausgangssignal abgibt, solange das aktuell ermittelte Drehmoment größer als der Grenzwert ist. Das Ausgangssignal verkleinert sich nach einer zeitabhängigen Funktion von 1 ausgehend, bis durch Herabsetzung des Drehmomentes Gleichgewicht eintritt. Das Ausgangssignal des Funktionsbausteines 9 wird nun zur Aufarbeitung des maximalen Stellweges alpha max benutzt, wie dies bereits zuvor angedeutet worden ist. Dazu dient ein Multiplikationsbaustein 27. Diesem Multiplikationsbaustein wird einerseits der Grenzwert des Verstellweges alpha max von außen fest vorgegeben, zum anderen das Ausgangssignal des Funktionsbausteines 9, das in Beziehung steht zum aktuellen Drehmoment. Das Ausgangssignal des Multiplikationsbausteines 27 wird wiederum dem Komparator 11 vorgegeben. Hierdurch wird erreicht, daß bei Überschreitung des vorgegebenen Drehmomentes die Fördermenge der Pumpe verkleinert wird.3, the output signal of the multiplier 8 is given to the function block 9 via a comparison block 26. In the comparison block, the current torque pump determined by multiplication is related to the limit value Mmax of the pump, which is constantly specified. The function block 9 now processes the output signal of the comparison block 26 so that it emits an output signal equal to 1 if the current torque is less than the limit value of the torque, and that it emits a time-reducing output signal as long as the currently determined torque is greater than that Limit is. The output signal decreases according to a time-dependent function starting from 1 until equilibrium is reached by reducing the torque. The output signal of the function block 9 is now used to process the maximum travel alpha max, as has already been indicated. A multiplication module 27 is used for this purpose. On the one hand, the limit value of the adjustment path alpha max is predetermined from the outside of this multiplication module, and on the other hand the output signal of the function block 9, which is related to the current torque. The output signal of the multiplication module 27 is in turn given to the comparator 11. This ensures that the delivery rate of the pump is reduced when the predetermined torque is exceeded.

Um auch den Pumpendruck zu berücksichtigen, wird in einem Komparator 28 (Vergleichsbaustein) ein fest eingegebener Grenzwert des Pumpendrucks zu dem aktuell gemessenen Pumpendruck in Beziehung gesetzt. Der Baustein 10 enthält nun auch einen Funktionsbaustein 29, der durch das Ausgangssignal des Komparators 28 und zusätzlich durch einen Grenzwert angesteuert wird, der den maximalen Sollwert repräsentiert. Diese eingegebenen Größen werden nun in dem Funktionsbaustein 29 derart verarbeitet, daß der Funktionsbaustein 29 ein Ausgangssignal B gibt, das gleich Null ist, solange der gemessene Pumpendruck kleiner als der Grenzwert Pmax des Druckes ist, und das gleich dem Grenzwert Smax der Sollwerte ist, wenn der gemessene Pumpendruck den Grenzwert Pmax des Pumpendrucks übersteigt.In order to also take into account the pump pressure, a permanently entered limit value of the pump pressure is related to the currently measured pump pressure in a comparator 28 (comparison module). The module 10 now also contains a function module 29 which is controlled by the output signal of the comparator 28 and additionally by a limit value which represents the maximum desired value. These entered quantities are now processed in the function block 29 in such a way that the function block 29 gives an output signal B which is zero as long as the measured pump pressure is less than the limit value Pmax of the pressure and which is equal to the limit value Smax of the setpoints if the measured pump pressure exceeds the limit value Pmax of the pump pressure.

Der Gewichtungsbaustein 10 mit seinen beiden Ausgangssignalen A des Funktionsbausteines 30 und B des Funktionsbausteines steuert sodann Vergleichsglieder 12′, 12˝, 12‴ an, die jeweils einem der Ventile 6′, 6˝, 6‴ für die einzelnen Verbraucher 4′, 4˝, 4‴ zugeordnet sind. Jedem dieser Vergleichsglieder 12 kann über die Sollwertgeber 13′, 13˝, 13‴ ein unterschiedlicher Sollwert aufgegeben werden. Die Ausgangssignale der Vergleichsglieder 12 werden sodann über Verstärker 14′, 14˝, 14‴ den jeweiligen Stellsignalen für die Magnete a1, b1, a2, b2, a3, b3 der jeweiligen Ventile 6′, 6˝, 6‴ oder den Eingangssignalen der Stellgeber, durch die die einzelnen Wegeventile 6 angesteuert werden, überlagert. Dadurch kann nach einer voreingestellten Funktion und einem voreingestellten Sollwert der dem einzelnen Verbraucher 4′, 4˝, 4‴ zugeführte Volumenstrom so weit herabgenommen werden, daß die von der Pumpe 1 förderbare Gesamtmenge nicht überschritten wird. Durch die gleichzeitige Erfassung und direkte Eingabe des Verstellweges bzw. des Schwenkwinkels der Regelpumpe 1 kann im Gewichtungsbaustein 10 gleichzeitig sichergestellt werden, daß auch eine Anpassung der aktuellen Fördermenge an die maximal mögliche Fördermenge gleichzeitig mit der Anpassung an das aktuelle Drehmoment der Pumpe 1 erfolgt. Ebenso können in die Gewichtung der aktuelle Pumpendruck P oder sonstige Betriebsparameter des Hydrauliksystems mit eingehen.The weighting block 10 with its two output signals A of the function block 30 and B of the function block then controls comparators 12 ', 12˝, 12 ‴, each one of the valves 6', 6˝, 6 ‴ for the individual consumers 4 ', 4˝ , 4 ‴ are assigned. Each of these comparison elements 12 can be given a different setpoint via the setpoint generator 13 ', 13˝, 13 13. The output signals of the comparison elements 12 are then via amplifiers 14 ', 14˝, 14 ‴ the respective control signals for the magnets a1, b1, a2, b2, a3, b3 of the respective valves 6', 6˝, 6 ‴ or the input signals of the actuators , through which the individual directional control valves 6 are controlled, superimposed. As a result, according to a preset function and a preset setpoint, the individual consumer 4 ', 4˝, 4 ‴ can be supplied Volume flow are reduced so far that the total amount that can be pumped by the pump 1 is not exceeded. The simultaneous detection and direct input of the adjustment path or the swivel angle of the control pump 1 can simultaneously ensure in the weighting module 10 that an adaptation of the current delivery rate to the maximum possible delivery rate takes place simultaneously with the adjustment to the current torque of the pump 1. The current pump pressure P or other operating parameters of the hydraulic system can also be included in the weighting.

Hierzu sind die Vergleichsglieder 12 - wie Fig. 13 zeigt - aufgegliedert in einen Multiplikationsbaustein 31′, 31˝, 31‴ sowie in einen Begrenzungsbaustein 32′, 32˝, 32‴. Dem Multiplikationsbaustein wird das Ausgangssignal A des Funktionsbausteines 30 sowie der eingestellte Sollwert S1, S2, S3 jeweils vorgegeben. Dadurch wird der eingestellte Sollwert S in Beziehung gesetzt zu dem aktuellen Verstellweg der Druckwaage bzw. der Verstellpumpe, wenn die Summe der Verbraucherströme den Grenzwert des Pumpenstromes übersteigt. Die Sollwerte werden entsprechend vermindert. Das Ausgangssignal der Multiplikationsbausteine 31 wird dem Begrenzungsbaustein 32 vorgegeben gemeinsam mit dem Ausgangssignal B des Funktionsbausteines 29, der die Beziehung zu dem gemessenen Pumpendruck herstellt. Bei Überschreitung des vorgegebenen Grenzwertes des Pumpendruckes wird das Ausgangssignal des Begrenzungsbausteines 32 begrenzt auf den eingegebenen Grenzwert Smax des Sollwerts. In jedem der Bausteine 32′, 32˝, 32‴ kann eine weitere Bewertung des zugeführten Grenzwertes Smax erfolgen in dem Sinne, daß entweder gar keine Begrenzung erfolgt oder eine Herabsetzung oder eine Vergrößerung des Grenzwertes. Hierdurch können einzelnen Verbrauchern Prioritäten eingeräumt werden. Andere Verbraucher können stillgesetzt oder nachrangig behandelt werden, wenn die eingestellten Sollwertvorgaben zu einer Überschreitung des Grenzwertes des Pumpenstromes führen würden.For this purpose, the comparison elements 12 - as shown in FIG. 13 - are divided into a multiplication module 31 ', 31˝, 31 ˝ and a limiting module 32', 32˝, 32 ‴. The output signal A of the function block 30 and the setpoint value S1, S2, S3 are given to the multiplication block. As a result, the setpoint S set is related to the current displacement of the pressure compensator or the variable displacement pump if the sum of the consumer flows exceeds the limit value of the pump flow. The setpoints are reduced accordingly. The output signal of the multiplication modules 31 is given to the limitation module 32 together with the output signal B of the function module 29, which establishes the relationship to the measured pump pressure. If the predetermined limit value of the pump pressure is exceeded, the output signal of the limitation module 32 is limited to the entered limit value Smax of the setpoint. In each of the modules 32 ', 32˝, 32 ‴, a further evaluation of the limit value Smax can be carried out in the sense that either there is no limit at all or the limit value is reduced or increased. This allows priorities to be given to individual consumers. Other consumers can be shut down or treated subordinately if the setpoint values set would lead to the limit value of the pump current being exceeded.

In Fig. 4 ist nun zusätzlich noch eine Sollwertaufbereitung gezeigt, die wahlweise eingesetzt werden kann. Hierzu kann dem Steuergerät 21 ein Sollwertgeber 33 vorgeordnet werden. Der Sollwertgeber weist einen ersten Baustein 34 für jeden eingegebenen Sollwert auf, der im folgenden als Rampe bezeichnet wird. Diese Rampe bewirkt, daß ein sprunghaft eingegebener Sollwert sich nur zeitlich abhängig ändert. Dadurch wird bewirkt, daß auch bei sprunghafter Sollwerteingabe die Signalverarbeitung und Anpassung des Hydrauliksystems zeitlich folgen kann und es nicht zu einer zeitweiligen Unterversorgung der Verbraucher kommt. Die Ausgangssignale der Rampen 34 werden sodann in Multiplikationsbausteinen 35 mit eingegebenen Grenzwerten G1 bis G3 multipliziert. Diese Grenzwerte repräsentieren einen bestimmten Prozentsatz des Grenzwertes des Pumpenstromes. Hierdurch erfolgt in den Multiplikationsbausteinen 35 eine Gewichtung der eingegebenen Sollwerte. Die Ausgangssignale der Multiplikationsbausteine 35 werden einem Summierglied 36 aufgegeben mit dem Ausgangssignal P2, das die Summe der Ausgangssignale der Multiplikationsbausteine repräsentiert.In Fig. 4, a setpoint processing is now additionally shown, which can be used optionally. For this purpose, a setpoint generator 33 can be arranged upstream of the control unit 21. The setpoint generator has a first component 34 for each input setpoint, which is referred to below as a ramp. This ramp means that an abruptly entered setpoint only changes over time. This has the effect that the signal processing and adaptation of the hydraulic system can follow in time even when the setpoint value is entered suddenly and there is no temporary undersupply of the consumers. The output signals of the ramps 34 are then multiplied in multiplication modules 35 by input limit values G1 to G3. These limit values represent a certain percentage of the limit value of the pump current. This results in a weighting of the entered target values in the multiplication modules 35. The output signals of the multiplication modules 35 are fed to a summing element 36 with the output signal P2, which represents the sum of the output signals of the multiplication modules.

Das Signal E2 wird einem Funktionsbaustein 37 aufgegeben gemeinsam mit einem Signal E1. Das Signal E1 repräsentiert den maximal vorgegebenen Pumpenstrom in einer Form, die dem Signal E2 vergleichbar ist. Im Funktionsbaustein 37 werden die beiden Eingangssignale E1 und E2 in Verbindung gesetzt. Das Ausgangssignal A ist gleich 1, solange der vorgegebene Grenzwert des Pumpenförderstroms größer als die eingestellte und gewichtete Summe der Sollwerte ist. Das Ausgangssignal ist gleich dem Quotienten aus Grenzwert und gewichteter Summe, wenn die gewichtete Summe größer ist als der Grenzwert.The signal E2 is given to a function block 37 together with a signal E1. The signal E1 represents the maximum predetermined pump current in a form that is comparable to the signal E2. The two input signals E1 and E2 are connected in the function block 37. The output signal A is equal to 1 as long as the specified limit value of the pump delivery flow is greater than the set and weighted sum of the setpoints. The output signal is equal to the quotient of the limit value and the weighted sum if the weighted sum is greater than the limit value.

Das Ausgangssignal des Funktionsbausteines 37 wird nun den Multiplikationsbausteinen 38′, 38˝, 38‴ aufgegeben. In jedem der Multiplikationsbausteine 38 wird der jeweilige Sollwert S1, S2, S3, nachdem er vorzugsweise zunächst über die Rampen 34′, 34˝, 34‴ geführt worden ist, multipliziert. Das Ausgangssignal der Multiplikationsbausteine 38 stellt den dem Steuergerät 21 vorgegebenen jeweiligen Sollwert dar. Durch diese Sollwertaufbereitung wird bereits bei der Sollwertaufgabe Vorsorge getragen, daß die eingestellten Sollwerte nicht zu einem Verbrauch führen, der den vorgegebenen Grenzwert des Pumpenstroms bei weitem übersteigt. Es handelt sich dabei jedoch nur um eine grobe Vorsorge. Die erfindungsgemäße Überlagerung der Anpassung der Verbraucherströme an den gemessenen Pumpenstrom gewährleistet, daß jeder Verbraucher in dem ihm zugewiesenen Rahmen funktionsfähig bleibt.The output signal of the function block 37 is now given to the multiplication blocks 38 ', 38 38, 38 ‴. In each of the multiplication modules 38, the respective setpoint S1, S2, S3 is multiplied after it has preferably first been passed over the ramps 34 ′, 34˝, 34 ‴. The The output signal of the multiplication modules 38 represents the respective setpoint given to the control unit 21. This setpoint processing ensures that the setpoint input ensures that the setpoint values do not lead to consumption that far exceeds the specified limit value of the pump current. However, this is only a rough precaution. The inventive superimposition of the adaptation of the consumer flows to the measured pump current ensures that each consumer remains functional within the framework assigned to it.

Die besondere Bedeutung der Erfindung liegt dabei darin, daß einerseits das Pumpendrehmoment ausgeregelt wird, daß dieser Momentenregelung aber eine Leistungsregelung überlagert werden kann, indem gleichzeitig auch noch die Drehzahl der Pumpe oder ihre Fördermenge erfaßt wird.The particular importance of the invention lies in the fact that on the one hand the pump torque is corrected, but that a torque control can be superimposed on this torque control by simultaneously also detecting the speed of the pump or its delivery rate.

In einem Hydrauliksystem werden mehrere Verbraucher 4 von einer gemeinsamen Pumpe gespeist. Dabei werden die Verbraucher 4 durch Steuerventile 6 gesteuert. Wenn die abgerufenen Ölströme die maximal förderbare Fördermenge überschreiten, tritt eine Regelung in Funktion, mit der die Sollwertsignale, mit welchen die Ventile 6 angesteuert werden, an den aktuell gemessenen Pumpenförderstrom, vorzugsweise an die Gewichtung des aktuell gemessenen Pumpenförderstroms mit dem maximal vorgegebenen Pumpenförderstrom, angepaßt werden.In a hydraulic system, several consumers 4 are fed by a common pump. The consumers 4 are controlled by control valves 6. If the oil flows retrieved exceed the maximum delivery rate, a control system comes into operation with which the setpoint signals with which the valves 6 are controlled are adapted to the currently measured pump delivery rate, preferably to the weighting of the currently measured pump delivery rate with the maximum predetermined pump delivery rate become.

BEZUGSZEICHENAUFSTELLUNGREFERENCE SIGN LISTING

11
Regelpumpe, PumpeControl pump, pump
22nd
Druckwaage, RegelventilPressure compensator, control valve
33rd
WechselventilShuttle valve
44th
Verbraucherconsumer
55
Druckregelventil, Druckwaage, DruckdifferenzwaagePressure control valve, pressure balance, pressure differential balance
66
Steuerventil, WegeventilControl valve, directional valve
77
StellgliedActuator
88th
MultipliziergerätMultiplier
99
Komparator (M/Mmax)Comparator (M / M max )
1010th
Baustein für GewichtungBuilding block for weighting
1111
Komparator (α/αgrenz)Comparator (α / α limit )
1212th
Komparator (Ist-/Sollwert)Comparator (actual / target value)
1313
SollwertgeberSetpoint generator
1414
Verstärkeramplifier
aa
Signal für StellmagnetSignal for control magnet
bb
Signal für StellmagnetSignal for control magnet
PP
PummpendruckPumping pressure
UU
elektrische Spannungelectrical voltage
1515
Federfeather
1616
Kolbenpiston
1717th
KolbenstangePiston rod
1818th
Federfeather
1919th
SteuerdruckControl pressure
2020th
PumpenleitungPump line
2121
SteuergerätControl unit
2222
Druckdifferenzwaage, DruckwaageDifferential pressure balance, pressure balance
2323
Kolbenpiston
2424th
Federfeather
2525th
KolbenstangePiston rod
2626
VergleichsbausteinComparison module
2727
MultiplikationsbausteinMultiplication module
2828
KomparatorComparator
2929
FunktionsbausteinFunction block
3030th
FunktionsbausteinFunction block
31′31 ′
))
31˝31˝
) Multiplikationsbaustein) Multiplication module
31‴31 ‴
))
32′32 ′
))
32˝32˝
) Begrenzungsbaustein) Limiting block
32‴32 ‴
))
3333
SollwertgeberSetpoint generator

Claims (8)

  1. Hydraulic system,
    in which a plurality of consumers (4) are supplied by a common pump (1) each via a control valve (6),
    the consumer flows supplied to the individual consumers (4) being controllable by the associated control valves (6) in such a way that the actual delivery quantity of the pump (1) supplied to all of the consumers (4) is adaptable to the preset pump flow which may be delivered in that the actual delivery quantity of the pump (1) (the pump flow) is measured and upon exceeding a preset limit value (GP) is utilized for adaptation of the consumer flows, characterized in that the actual delivery quantity is determined by means of pressure balance (2, 22), which is connected to the pump line (20) and which is acted upon on the one hand by the pump pressure and on the spring side by the highest load pressure.
  2. Hydraulic system according to claim 1,
    characterized in that
    a 3-way pressure balance (22) is provided for regulating the pressure difference between the pump pressure and the highest load pressure
    and that, for measuring the actual delivery quantity, either the throughflow in the bypass of the pressure balance (22) or the piston movement of the pressure balance (22) is measured.
  3. Hydraulic system according to claim 1,
    characterized in that
    the pump (1) is a variable capacity pump,
    and that in addition the regulating position of the variable capacity pump is measured.
  4. Hydraulic system according to claim 3,
    characterized in that
    the regulating position of the variable capacity pump (1) is controllable as a function of the pressure difference between the pump pressure and the highest measured load pressure.
  5. Hydraulic system according to one of the preceding claims,
    characterized in that
    the product of the actual delivery quantity and the pump pressure is additionally utilized for adaptation of the consumer flows.
  6. Hydraulic system according to one of the preceding claims,
    characterized in that
    the pump pressure is additionally utilized for adaptation of the consumer flows.
  7. Hydraulic system according to one of the preceding claims,
    characterized in that
    the setpoint value signal, by means of which each of the control valves (6) may be triggered for adjustment of the consumer flow, is reduced as a function of the preset pump flow which may be delivered as well as of the sum of the adjusted setpoint value signals.
  8. Hydraulic system according to claim 7,
    characterized in that
    prior to the summing of the setpoint value signals, each setpoint value signal is multiplied by a limit value (GV) which is preset for the respective consumer.
EP92901394A 1990-12-15 1991-12-14 Hydraulic system Expired - Lifetime EP0515639B1 (en)

Applications Claiming Priority (5)

Application Number Priority Date Filing Date Title
DE4040177 1990-12-15
DE4040177 1990-12-15
DE4124792 1991-07-26
DE4124792 1991-07-26
PCT/DE1991/000976 WO1992010685A1 (en) 1990-12-15 1991-12-14 Hydraulic system

Publications (2)

Publication Number Publication Date
EP0515639A1 EP0515639A1 (en) 1992-12-02
EP0515639B1 true EP0515639B1 (en) 1995-03-08

Family

ID=25899382

Family Applications (1)

Application Number Title Priority Date Filing Date
EP92901394A Expired - Lifetime EP0515639B1 (en) 1990-12-15 1991-12-14 Hydraulic system

Country Status (6)

Country Link
US (1) US5394696A (en)
EP (1) EP0515639B1 (en)
JP (1) JPH05504820A (en)
DE (1) DE59104897D1 (en)
DK (1) DK0515639T3 (en)
WO (1) WO1992010685A1 (en)

Families Citing this family (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AT402280B (en) * 1995-08-01 1997-03-25 Hoerbiger Gmbh HYDRAULIC ACTUATING ARRANGEMENT FOR A VEHICLE TAIL
EP0786600A1 (en) * 1996-01-26 1997-07-30 José Maria Las Navas Garcia Multiple activation hydraulic system
JP3750841B2 (en) * 1998-11-12 2006-03-01 新キャタピラー三菱株式会社 Hydraulic control device for work machine
US6286299B1 (en) * 1999-04-26 2001-09-11 General Electric Co. Gas turbine combined lift/hydraulic system
DE10308289B4 (en) * 2003-02-26 2010-11-25 Bosch Rexroth Aktiengesellschaft LS-way valve block
JP2004347040A (en) * 2003-05-22 2004-12-09 Kobelco Contstruction Machinery Ltd Controller of working vehicle
EP2250379B1 (en) * 2008-03-10 2013-03-20 Parker-Hannifin Corporation Hydraulic system having multiple actuators and an associated control method
DE102009028816A1 (en) * 2009-08-21 2011-02-24 Deere & Company, Moline Hydraulic arrangement
DE102011075857A1 (en) * 2011-05-16 2012-11-22 Siemens Aktiengesellschaft Method, management device and natural gas storage system for the automated management of multiple flow devices
US9371898B2 (en) 2012-12-21 2016-06-21 Cnh Industrial America Llc Control system for a machine with a dual path electronically controlled hydrostatic transmission
JP6656913B2 (en) * 2015-12-24 2020-03-04 株式会社クボタ Working machine hydraulic system
US10718100B2 (en) * 2016-11-21 2020-07-21 Van-Tech Corporation Electro-hydraulic feed delivery system
DE102018212077A1 (en) * 2018-07-19 2020-01-23 Deere & Company Method for operating a hydraulic consumer on an electrically actuated control valve

Family Cites Families (26)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3987622A (en) * 1976-02-02 1976-10-26 Caterpillar Tractor Co. Load controlled fluid system having parallel work elements
US4103489A (en) * 1977-04-15 1978-08-01 Deere & Company Total power fluid system
US4165613A (en) * 1978-03-27 1979-08-28 Koehring Company Control apparatus for a plurality of simultaneously actuatable fluid motors
JPS56139316A (en) * 1980-01-07 1981-10-30 Komatsu Ltd Power loss reduction controller for oil-pressure type construction machine
US4537364A (en) * 1982-12-15 1985-08-27 Sundstrand Corporation Constant tension cable reel drive
US4723478A (en) * 1983-02-04 1988-02-09 The Cessna Aircraft Company Series self-leveling valve
DE3321483A1 (en) * 1983-06-14 1984-12-20 Linde Ag, 6200 Wiesbaden HYDRAULIC DEVICE WITH ONE PUMP AND AT LEAST TWO OF THESE INACTED CONSUMERS OF HYDRAULIC ENERGY
US4554992A (en) * 1983-09-09 1985-11-26 Fmc Corporation Hydraulically operated four wheel sweeper
IT1234937B (en) * 1985-02-14 1992-06-02 Cinotto Hydraulic ANTI-SATURATION SYSTEM FOR HYDRAULIC CONTROL CIRCUITS WITH PUMPS AND PRESSURE-CONTROLLED DISTRIBUTORS FOR WORKING PARTS OF EARTH-MOVING MACHINES
DE3535771A1 (en) * 1985-10-07 1987-04-09 Linde Ag HYDROSTATIC DRIVE WITH SEVERAL CONSUMERS
DE3644736C2 (en) * 1985-12-30 1996-01-11 Rexroth Mannesmann Gmbh Control arrangement for at least two hydraulic consumers fed by at least one pump
DE3546336A1 (en) * 1985-12-30 1987-07-02 Rexroth Mannesmann Gmbh CONTROL ARRANGEMENT FOR AT LEAST TWO HYDRAULIC CONSUMERS SUPPLIED BY AT LEAST ONE PUMP
DE3623066A1 (en) * 1986-07-09 1988-01-28 Rexroth Mannesmann Gmbh CIRCUIT ARRANGEMENT FOR THE SPEED CONTROL OF A HYDROSTATIC MACHINE CONNECTED TO A PIPE WITH IMPRESSED PRESSURE
US4712376A (en) * 1986-10-22 1987-12-15 Caterpillar Inc. Proportional valve control apparatus for fluid systems
JPH0830482B2 (en) * 1986-12-30 1996-03-27 マンネズマン・レツクスロス・ゲー・エム・ベー・ハー Control device for at least two hydraulic loads fed by at least one pump
DE3702000A1 (en) * 1987-01-23 1988-08-04 Hydromatik Gmbh CONTROL DEVICE FOR A HYDROSTATIC TRANSMISSION FOR AT LEAST TWO CONSUMERS
US4922787A (en) * 1987-06-26 1990-05-08 Kanzaki Kokyukoki Mfg. Co. Ltd. HST (hydrostatic transmission) housing axle driving apparatus
IN171213B (en) * 1988-01-27 1992-08-15 Hitachi Construction Machinery
US5134853A (en) * 1988-05-10 1992-08-04 Hitachi Construction Machinery Co., Ltd. Hydraulic drive system for construction machines
EP0379595B1 (en) * 1988-07-08 1993-09-29 Hitachi Construction Machinery Co., Ltd. Hydraulic driving apparatus
SE8803181D0 (en) * 1988-09-09 1988-09-09 Atlas Copco Ab HYDRAULIC DRIVING SYSTEM WITH A PRIORITY FUNCTION FOR HYDRAULIC MOTORS
US4936095A (en) * 1988-10-28 1990-06-26 Eaton Corporation Hydrostatic transmission system and power limiter control therefor
US5048293A (en) * 1988-12-29 1991-09-17 Hitachi Construction Machinery Co., Ltd. Pump controlling apparatus for construction machine
EP0440802B1 (en) * 1989-07-27 1995-10-18 Hitachi Construction Machinery Co., Ltd. Device for controlling hydraulic pump
FR2650635A1 (en) * 1989-08-07 1991-02-08 Rexroth Sigma Method for operating at least one variable output pump in an electrohydraulic plant, and electrohydraulic plant implementing this method
US5167121A (en) * 1991-06-25 1992-12-01 University Of British Columbia Proportional hydraulic control

Also Published As

Publication number Publication date
JPH05504820A (en) 1993-07-22
DE59104897D1 (en) 1995-04-13
US5394696A (en) 1995-03-07
EP0515639A1 (en) 1992-12-02
WO1992010685A1 (en) 1992-06-25
DK0515639T3 (en) 1995-05-22

Similar Documents

Publication Publication Date Title
EP0515608B1 (en) Hydraulic system
EP1664551B1 (en) Control system and method for supplying pressure means to at least two hydraulic consumers
DE4127342C2 (en) Hydraulic system with a pump
EP0515639B1 (en) Hydraulic system
DE3044515A1 (en) ADJUSTMENT DEVICE FOR HYDRAULIC PUMP WITH ADJUSTABLE FLOW RATE
DE19681386C2 (en) Control circuit of a mobile crusher
EP0626297B1 (en) Adjusting method for a brake value on a target value
DE4108915C2 (en) Hydraulic device for supplying pressure medium to a privileged primary load circuit
DE202011052170U1 (en) Coolant system for machine tools
DE3441185A1 (en) Drive system
EP3495056A1 (en) Improved control of water conservancy of a cooling section
EP0275969B1 (en) Control device for a hydrostatic transmission for at least two users
EP3816455A1 (en) Hydraulic control arrangement for supplying compressed media of at least two hydraulic consumers
DE10308289B4 (en) LS-way valve block
DE3528096C2 (en)
DE112004002768B4 (en) Hydraulic control system
DE60033097T2 (en) Hydraulic drive unit
DE3609399C2 (en)
EP1954949B1 (en) Hydraulic control device
EP3135924B1 (en) Hydraulic device
EP1934487A1 (en) Hydraulic control device
WO2016096565A1 (en) Circuit for actuating a rotating consumer
EP3895820A1 (en) Operation of a cooling device with minimum working pressure
DE4307827A1 (en) Hydraulic power supply system - with variable delivery provided by variable displacement pump that is adjusted to meet demands determined by commands to load devices
EP0334030B1 (en) Regulating device for a pressure regulation circuit

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 19920801

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): DE DK FR GB IT SE

17Q First examination report despatched

Effective date: 19940217

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE DK FR GB IT SE

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRE;WARNING: LAPSES OF ITALIAN PATENTS WITH EFFECTIVE DATE BEFORE 2007 MAY HAVE OCCURRED AT ANY TIME BEFORE 2007. THE CORRECT EFFECTIVE DATE MAY BE DIFFERENT FROM THE ONE RECORDED.SCRIBED TIME-LIMIT

Effective date: 19950308

Ref country code: GB

Effective date: 19950308

Ref country code: FR

Effective date: 19950308

REF Corresponds to:

Ref document number: 59104897

Country of ref document: DE

Date of ref document: 19950413

REG Reference to a national code

Ref country code: DK

Ref legal event code: T3

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SE

Effective date: 19950608

EN Fr: translation not filed
GBV Gb: ep patent (uk) treated as always having been void in accordance with gb section 77(7)/1977 [no translation filed]

Effective date: 19950308

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DK

Payment date: 19951020

Year of fee payment: 5

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 19951221

Year of fee payment: 5

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DK

Effective date: 19961214

REG Reference to a national code

Ref country code: DK

Ref legal event code: EBP

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Effective date: 19970902