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WO2004042235A1 - Double-circuit hydraulic system - Google Patents

Double-circuit hydraulic system Download PDF

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Publication number
WO2004042235A1
WO2004042235A1 PCT/DE2003/003126 DE0303126W WO2004042235A1 WO 2004042235 A1 WO2004042235 A1 WO 2004042235A1 DE 0303126 W DE0303126 W DE 0303126W WO 2004042235 A1 WO2004042235 A1 WO 2004042235A1
Authority
WO
WIPO (PCT)
Prior art keywords
pressure
circuit
pump
load pressure
valve
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.)
Ceased
Application number
PCT/DE2003/003126
Other languages
German (de)
French (fr)
Inventor
Thomas Weickert
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.)
Bosch Rexroth AG
Original Assignee
Bosch Rexroth 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
Priority claimed from DE10255738A external-priority patent/DE10255738A1/en
Application filed by Bosch Rexroth AG filed Critical Bosch Rexroth AG
Priority to DE50308813T priority Critical patent/DE50308813D1/en
Priority to EP03753319A priority patent/EP1558849B1/en
Priority to AU2003271543A priority patent/AU2003271543A1/en
Priority to JP2004549050A priority patent/JP2006505750A/en
Publication of WO2004042235A1 publication Critical patent/WO2004042235A1/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

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
    • 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
    • F15B11/17—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors using two or more pumps
    • 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
    • F15B11/165—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors with sensing of servomotor demand or load for adjusting the pump output or bypass in response to demand
    • 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
    • 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
    • E02F9/2253—Controlling the travelling speed of vehicles, e.g. adjusting travelling speed according to implement loads, control of hydrostatic transmission
    • 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
    • E02F9/2278—Hydraulic circuits
    • E02F9/2285—Pilot-operated systems
    • 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
    • F15B2211/20576—Systems with pumps with multiple pumps
    • 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
    • F15B2211/30505—Non-return valves, i.e. check 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
    • F15B2211/30—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
    • F15B2211/30555—Inlet and outlet of the pressure compensating valve being connected to the 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
    • F15B2211/31—Directional control characterised by the positions of the valve element
    • F15B2211/3144—Directional control characterised by the positions of the valve element the positions being continuously variable, e.g. as realised by proportional 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
    • F15B2211/30—Directional control
    • F15B2211/315—Directional control characterised by the connections of the valve or valves in the circuit
    • F15B2211/3157—Directional control characterised by the connections of the valve or valves in the circuit being connected to a pressure source, an output member and a return line
    • F15B2211/31582—Directional control characterised by the connections of the valve or valves in the circuit being connected to a pressure source, an output member and a return line having multiple pressure sources and a single output member
    • 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
    • F15B2211/329—Directional control characterised by the type of actuation actuated by fluid 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
    • F15B2211/40—Flow control
    • F15B2211/405—Flow control characterised by the type of flow control means or valve
    • F15B2211/40507—Flow control characterised by the type of flow control means or valve with constant throttles or orifices
    • 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
    • F15B2211/40—Flow control
    • F15B2211/41—Flow control characterised by the positions of the valve element
    • F15B2211/413—Flow control characterised by the positions of the valve element the positions being continuously variable, e.g. as realised by proportional 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
    • F15B2211/40—Flow control
    • F15B2211/415—Flow control characterised by the connections of the flow control means in the circuit
    • F15B2211/41509—Flow control characterised by the connections of the flow control means in the circuit being connected to a pressure source and a 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
    • F15B2211/40—Flow control
    • F15B2211/42—Flow control characterised by the type of actuation
    • F15B2211/428—Flow control characterised by the type of actuation actuated by fluid 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
    • F15B2211/40—Flow control
    • F15B2211/465—Flow control with pressure compensation
    • 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
    • F15B2211/50—Pressure control
    • F15B2211/505—Pressure control characterised by the type of pressure control means
    • F15B2211/50509—Pressure control characterised by the type of pressure control means the pressure control means controlling a pressure upstream of the pressure control means
    • F15B2211/50518—Pressure control characterised by the type of pressure control means the pressure control means controlling a pressure upstream of the pressure control means using pressure relief 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
    • F15B2211/50—Pressure control
    • F15B2211/505—Pressure control characterised by the type of pressure control means
    • F15B2211/50509—Pressure control characterised by the type of pressure control means the pressure control means controlling a pressure upstream of the pressure control means
    • F15B2211/50518—Pressure control characterised by the type of pressure control means the pressure control means controlling a pressure upstream of the pressure control means using pressure relief valves
    • F15B2211/50527—Pressure control characterised by the type of pressure control means the pressure control means controlling a pressure upstream of the pressure control means using pressure relief valves using cross-pressure relief 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
    • F15B2211/50—Pressure control
    • F15B2211/505—Pressure control characterised by the type of pressure control means
    • F15B2211/50554—Pressure control characterised by the type of pressure control means the pressure control means controlling a pressure downstream of the pressure control means, e.g. pressure reducing 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
    • F15B2211/50—Pressure control
    • F15B2211/51—Pressure control characterised by the positions of the valve element
    • F15B2211/513—Pressure control characterised by the positions of the valve element the positions being continuously variable, e.g. as realised by proportional 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
    • F15B2211/50—Pressure control
    • F15B2211/515—Pressure control characterised by the connections of the pressure control means in the circuit
    • F15B2211/5158—Pressure control characterised by the connections of the pressure control means in the circuit being connected to a pressure source and an output member
    • 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
    • F15B2211/50—Pressure control
    • F15B2211/52—Pressure control characterised by the type of actuation
    • F15B2211/528—Pressure control characterised by the type of actuation actuated by fluid 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
    • F15B2211/50—Pressure control
    • F15B2211/575—Pilot pressure control
    • 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
    • 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
    • F15B2211/6052—Load sensing circuits having valve means between output member and the load sensing circuit using check 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
    • F15B2211/635—Circuits providing pilot pressure to pilot pressure-controlled fluid circuit elements
    • F15B2211/6355—Circuits providing pilot pressure to pilot pressure-controlled fluid circuit elements having valve means
    • 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
    • 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
    • F15B2211/80—Other types of control related to particular problems or conditions
    • F15B2211/88—Control measures for saving energy

Definitions

  • the invention relates to a hydraulic two-circuit system for controlling consumers of a mobile device, in particular a caterpillar device according to the preamble of claim 1.
  • US Pat. No. 6,170,261 B1 discloses a hydraulic two-circuit system for a mobile device, for example a chain or caterpillar device.
  • the undercarriage has two chains, each of which can be controlled separately from one another via one of the hydraulic circuits.
  • a slewing gear and aggregates of the equipment such as the boom, the dipper stick and the bucket are also connected.
  • Each of the two hydraulic circuits is supplied with pressure medium by a variable displacement pump, which is controlled as a function of the highest load pressure of the consumers in the respective assigned circuit.
  • the invention is based on the object of creating a hydraulic two-circuit system which, with a simple structure, enables the energy losses to be minimized when the two circuits are connected together.
  • This task is performed by a hydraulic two-circuit
  • the hydraulic dual-circuit system has an interconnection valve arrangement with two valve devices, each of which prevents one in one of the circuits from interconnecting the two circuits higher load pressure with a low pressure medium requirement is reported in the other circuit with a lower load pressure and high pressure medium requirement.
  • the load pressure corresponding to the actual requirements is reported to the respectively assigned variable displacement pump, so that in the event that a high pressure is present in one of the circles with a low pressure medium requirement, the variable displacement pump is not started up and thus the energy losses compared to the solution mentioned at the outset are considerably minimized.
  • the solution according to the invention allows that in the event that a high pressure is present in one of the circuits with a high pressure medium requirement, this high load pressure is reported to the second circuit if a lower load pressure is present in it.
  • the interconnection valve arrangement has two pressure compensators, each of which is assigned to one of the circuits. These pressure compensators are each acted upon in the opening direction by the load pressure tapped in the respective circuit and in the closing direction by the respective pump pressure. Furthermore, non-return valves or the like are provided in load pressure lines connected to the pressure compensators, which, when the pressure compensator is open, prevent a higher circuit from which one is connected from being reported to the circuit assigned to it via the open pressure compensator. I.e. , The reporting of this higher load pressure in the other circuit is only possible if the pressure compensator assigned to the circuit with a higher load pressure opens.
  • the solution with two pressure compensators and two check valves is extremely simple, with only the pump pressures and the load pressures having to be tapped for control.
  • the pressure compensators are acted upon in addition to the load pressure in the opening direction or by the force of a spring, the spring force of which is smaller than the pump ⁇ p.
  • valve arrangements for controlling the consumers and the chassis of the mobile device for example the caterpillar device
  • the two pressure compensators and the associated check valves are combined in an intermediate plate , so that the Ali binding to the two circles is extremely easy.
  • the interconnection of the two circuits takes place automatically depending on the pressures applied to the pressure compensators (pump pressure, load pressure).
  • pressure compensators pump pressure, load pressure
  • the output connection of this directional valve connects, for example in a basic position, the spring space of the associated pressure compensator, which is acted upon by the load pressure, with the tank, so that this pressure compensator always remains in the closed position, and thus an interconnection of the two circuits via this pressure compensator is not possible.
  • the directional control valve is preferably designed as an electrically operated 4/3-way valve which can be switched arbitrarily by the operator into one of the three operating positions described above (automatic operation, locking of the circuits and interconnection of the circuits).
  • the hydraulic two-circuit system according to the invention can be used particularly advantageously in a caterpillar device in which the hydraulic motors for driving the two chains are each controlled via one of the circles.
  • Figure 1 shows an extract of a circuit diagram of a control block for controlling a caterpillar device; a detailed representation of the circuit diagram of Figure 2 and
  • FIG. 3 shows a directional control valve for actuating pressure compensators of the circuit diagram according to FIG. 2.
  • This excavator control system 1 is constructed as a two-circuit system with two hydraulic circuits 2, 4, each of which is supplied with pressure medium via a variable displacement pump, not shown.
  • the excavator provided with the control system shown in FIG. 1 has a chassis with two chains, the travel drives of which can be supplied with pressure medium independently of one another via the two circuits 2, 4.
  • other excavator consumers such as a slewing gear, a stick, a bucket or a boom, are controlled via the dual-circuit system.
  • the control block which realizes the excavator control according to FIG. 1 is of disc construction type, the two variable pumps, not shown, being connected to the control block at pressure connections P_ and P2.
  • This also has a tank connection T and work connections A] _, B] _ and A 3 , B 3 , to which the drive of the right or left chain is connected.
  • the other consumers of the excavator such as the drive of the slewing gear, the hydraulic cylinders for actuating the stick, the bucket or the boom are connected to further connections A 2 , B2 and A 4 , B 4 etc.
  • the control block shown also has two load pressure connections, hereinafter referred to as LS ⁇ and LS 2 , via which the load pressure acting in the respective circuit 2, 4 is tapped and fed to the flow control valve (not shown) of the variable displacement pump, which is therefore dependent on the latter highest load pressure is controlled.
  • the control of the aforementioned consumers takes place in each case via a proportionally adjustable directional valve 6, which is connected downstream of a pressure compensator 8.
  • the directional control valve 6 has a speed part which forms a variable measuring orifice and a directional part, the measuring orifice being connected upstream of the pressure compensator 8 and the directional part being arranged downstream of the pressure compensator 8.
  • Each pressure compensator 8 is in the closing direction acted upon by the load pressure and in the opening direction by the pressure downstream of the metering orifice of the directional valve 6.
  • the pressure compensator piston adjusts itself to a control position depending on the control pressures present, in which the pressure drop across the measuring orifice of the proportionally adjustable directional control valve 6 is kept constant, so that volume flow control independent of the load pressure is made possible.
  • Such LS controls are well known, so that a detailed description of the structure of the directional control valve 6 and the downstream pressure compensator 8 can be dispensed with.
  • the control of the directional control valve 6 takes place in each case via pilot valves 10, 12, via which a control pressure is applied to the front control surfaces of a slide of the directional control valve 6.
  • pilot valves are actuated, for example, depending on the actuating movement of a joystick.
  • each directional control valve 6 has two working connections, each of which is connected to the associated consumer connections A, B via a working line 18 or 20.
  • an outlet connection of the directional control valve 6 is connected to the tank connection T of the control block via a tank line 22.
  • pressure relief valves are also provided in the working lines, the pressure limiting valves limiting the pressure at the working connections 2, B 2 , B] _ and B 3 and A 4 (not shown) being designed with a suction function so that when the consumer runs ahead, pressure medium can be sucked in from the tank in order to avoid the.
  • a load pressure signaling line 28, 30 connected to the load pressure connection LS of the two circuits 2, 4 is connected to the common tank line 22 via an LS flow control valve 32 or 34.
  • the pressure compensators 8 are designed in such a way that, in their fully opened end position, they report the pressure present at their inlet (pressure downstream of the measuring orifice) into the load pressure line 28 or 30, so that the highest load pressure in the respective circuit 2 or 4 is always in this ,
  • the directional valves described above with the associated pressure compensator 8, the pilot valves 10, 12 and the pressure limiting valves 24, 25 can each be accommodated in a disk or in a common control block.
  • an interconnection valve arrangement 38 is provided in an intermediate disk 36, via which, under certain operating conditions, the pressure lines 14, 16 of the two hydraulic circuits 2, 4 can be connected together, so that the controlled consumers of both variable pumps be supplied together with pressure medium.
  • the interconnection valve arrangement 38 has two pressure scales 40, 42, which are each biased in the direction of their open position by a spring 44.
  • the spring force of the spring is designed so that it is slightly below the pump ⁇ p. If this is, for example, approximately 20 bar, the spring force of the spring 44 will be approximately between 10 and 19 bar.
  • the upper pressure compensator 40 in FIG. 2 is assigned to circuit 2 and the lower pressure compensator 42 to circuit 4.
  • the pressure (pump pressure) applied to the pressure line 14 is led to a control surface of the pressure compensator 40 which is effective in the closing direction and the highest load pressure which is present in the load pressure line 28 of the circuit 2 is tapped via a control line 46 and is guided to a control surface of the pressure compensator 40 which is effective in the opening direction.
  • the control line 46 opens into the spring space for the spring 44.
  • the pressure in the pressure line 16 of the second circuit 4 becomes a control surface of the pressure compensator 42 which is effective in the closing direction and the pressure in the
  • the two input connections P and LS of the pressure compensators 40, 42 are connected to the assigned pressure lines 14 and 16 and the load pressure signaling lines 28 and 30, respectively.
  • a check valve 50, 52 is provided upstream of the LS connection of the pressure compensators 40, 42, which enables a pressure medium flow from the load pressure signal line 14 or 16 to the assigned LS connection, but blocks in the opposite direction.
  • the two output connections A, B are connected to the load pressure measuring lines 28, 30 and the pressure lines 14, 16 of the respective other circuit 2, 4.
  • this interconnection valve arrangement is explained on the basis of two operating states of the excavator control. It is initially assumed that there is an operating state in which the consumer connected to the working connections A 2 , B 2 , for example the handle, requires a large amount of pressure medium and accordingly there is a comparatively low pump pressure in the hydraulic circuit 2.
  • the pressure compensator 42 assigned to the second circuit 4 ⁇ pp is held in its closed position by the high pump pressure, while the pressure compensator 40 assigned to the first circuit 2 is brought into a control position due to the drop in pump pressure, in which the connections P, LS are included the connections A, B are connected.
  • the variable displacement pump assigned to the second circuit 4 can deliver pressure medium to the stem (connections A 2 , B2) connected to the first circuit 2, so that the higher pressure medium requirement of this consumer is ensured.
  • the check valve 50 prevents the higher load pressure present in the load pressure reporting line 30 from being reported into the load pressure reporting line 28 of the first circuit 2, so that the pressure level in this circuit remains low and the energy losses described above do not occur.
  • the pressure compensator 50 throttles the pressure medium flow from the higher pressure level prevailing in the second circuit 4 to the pressure level required in the first circuit 2.
  • the pressure compensator 40 Due to the pressure drop in the first circuit 2 and the corresponding reduction in the pump pressure, the pressure compensator 40 is brought into its control position, so that the two circuits 2, 4 are connected to one another. By connecting these two circles, the pupa pressure in the second circle 4 also drops, so that the pressure compensator 42 assigned to this circuit also opens accordingly, so that the two circles 2, 4 are connected to one another via both pressure compensators 40, 42.
  • a kind of LUDV single-circuit system is set, which is operated in under-saturation - the crawler device goes straight ahead and the connected consumer (boom) is supplied with pressure medium.
  • the interconnection valve arrangement 38 works automatically and binds the two circles 2, 4 in the event of one or both circles being under-saturated. It may now be necessary for the operator to arbitrarily interconnect both circuits in order, for example, to ensure optimal supply to one of the consumers. However, it may also be necessary to lock the two circles against each other in order to prevent interconnection.
  • the control valve 54 shown in FIG. 3 is designed as a 4/3-way valve and has a pressure connection P, an LS connection LS and a tank connection T and a control connection S which is connected to the control line 46 or 48 leading to the spring chamber.
  • the LS connection is connected to the load pressure signaling line 28 or 30 of the respective circuit 2, 4.
  • the pressure connection P can be connected to the two pressure lines 14, 16 of the two hydraulic circuits 2, 4 via a shuttle valve 56. The higher of the two pump pressures is always led to the pressure port P via the shuttle valve 56.
  • the pressure port P and the LS port LS are shut off and the control line 46 (48) is connected to the tank port T. I.e. , the tank pressure acts in the spring chamber, so that the respective pressure compensator 40, 42 is biased in the closed position by the pump pressure acting in each case - the two pressure compensators 40, 44 are closed and the two circles 2, 4 are locked against one another.
  • a hydraulic dual-circuit brake system for controlling consumers of a mobile device for example a caterpillar device
  • the two hydraulic circuits can be interconnected via an interconnection valve arrangement, with a device, for example non-return valves, ensuring that when the circuits are interconnected, a higher load pressure with low pressure medium requirement in one of the circuits is not reported in the other circuit with a lower load pressure
  • the interconnection valve arrangement has two pressure compensators, each of which is acted upon by the pump pressure and the load pressure in the associated circuit and which are connected upstream of check valves.

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Fluid Mechanics (AREA)
  • Physics & Mathematics (AREA)
  • Structural Engineering (AREA)
  • Civil Engineering (AREA)
  • Mining & Mineral Resources (AREA)
  • Mechanical Engineering (AREA)
  • Fluid-Pressure Circuits (AREA)
  • Operation Control Of Excavators (AREA)
  • Braking Arrangements (AREA)
  • Regulating Braking Force (AREA)
  • Braking Systems And Boosters (AREA)

Abstract

The invention relates to a double-circuit hydraulic system for controlling consumers of mobile equipment such as track equipment. Two hydraulic circuits (2, 4) can be interconnected by means of a system provided with interconnection valves (38). According to said invention, a device such as non-return valve makes it possible to ensure that, a high pressure in the circuit supplying reduced quantity of a pressure fluid does not impact another circuit having a low pressure, the circuits (2, 4) being interconnected. In the preferred embodiment, the inventive system provided with interconnection valves comprises two manometers (40, 42) which are exposed to a pumped pressure and the load pressure of the corresponding circuit, the non-return valves being arranged upstream thereof.

Description

Beschreibung description

Hydraulisches ZweikreissystemHydraulic two-circuit system

Die Erfindung betrifft ein hydraulisches Zweikreissystem zur Ansteuerung von Verbrauchern eines mobilen Gerätes, insbesondere eines Raupengerätes gemäss dem Oberbegriff des Patentanspruchs 1.The invention relates to a hydraulic two-circuit system for controlling consumers of a mobile device, in particular a caterpillar device according to the preamble of claim 1.

In der US 6,170,261 Bl ist ein hydraulisches Zweikreissystem eines mobilen Gerätes, beispielsweise eines Ketten- oder Raupengeräts offenbart. Bei derartigen Raupengeräten hat das Fahrwerk zwei Ketten, die jeweils über einen der hydraulischen Kreise getrennt voneinander ansteuerbar sind. An die beiden hydraulischen Kreise des Kettengerätes sind des Weiteren noch ein Drehwerk sowie Aggregate der Ausrüstung, wie beispielsweise der Ausleger, der Löffelstiel und der Löffel angeschlossen. Jeder der beiden hydraulischen Kreise wird von einer verstellpumpe mit Druckmittel gespeist, die in Abhängigkeit vom jeweils höchsten Lastdruck der Verbraucher im jeweils zugeordneten Kreis angesteuert werden.US Pat. No. 6,170,261 B1 discloses a hydraulic two-circuit system for a mobile device, for example a chain or caterpillar device. In such caterpillar devices, the undercarriage has two chains, each of which can be controlled separately from one another via one of the hydraulic circuits. To the two hydraulic circuits of the chain device, a slewing gear and aggregates of the equipment, such as the boom, the dipper stick and the bucket are also connected. Each of the two hydraulic circuits is supplied with pressure medium by a variable displacement pump, which is controlled as a function of the highest load pressure of the consumers in the respective assigned circuit.

Für den Fall, dass neben den beiden Ketten noch zumindest ein Verbraucher der Ausrüstung betätigt werden soll, besteht die Möglichkeit, zur Vermeidung einer Druckmittelunterversorgung beide hydraulischen Kreise zusammenzuschalten. Bei der in der US 6,170,261 Bl offen- barten Lösung erfolgt diese Zusammenschaltung der beiden hydraulischen Kreise über ein Zusammenschaltventil, über das die mit den beiden Pumpen verbundenen Druckleitungen sowie die Lastdruckmeldeleitungen der beiden Kreise zusammengeschaltet werden. Die Ansteuerung des Zusammen- schaltventils erfolgt in Abhängigkeit von der Druckmittelzufuhr zum zusätzlichen Verbraucher. Zusätzlich kann der Bediener manuell eingreifen und die beiden Kreise zusammenschalten.In the event that at least one consumer of the equipment is to be actuated in addition to the two chains, there is the possibility of interconnecting the two hydraulic circuits in order to avoid a supply of pressure medium. In the solution disclosed in US Pat. No. 6,170,261 B1, this interconnection of the two hydraulic circuits takes place via an interconnection valve via which the pressure lines connected to the two pumps and the load pressure signaling lines of the two circuits are interconnected. The control valve is controlled depending on the pressure medium supply to the additional consumer. In addition can the operator intervenes manually and interconnect the two circles.

Nachteilig bei dieser Lösung ist, dass beispielsweise bei der Ansteuerung eines an den einen hydraulischen Kreis angeschlossenen Verbraucher mit hohem Druckmittel- bedarf und geringem Druck und bei Ansteuerung eines an den anderen Kreis angeschlossenen Verbrauchers mit geringem Mengenbedarf und hohem Druck beide Kreise über das Zusammenschaltventil verbunden werden, so dass der höhere Lastdruck des letztgenannten Kreises auch im erstgenannten Kreis anliegt. Aufgrund dieses höheren Lastdruckes wird die Pumpe- des ersten Kreises hochgefahren, so dass beide Kreise auf das höhere Druckniveau angehoben werden. Der Druck im erstgenannt hydraulischen Kreis muss dann entsprechend wieder auf das erforderliche Druckniveau heruntergeregelt werden, was erhebliche Energieverluste zur Folge hat. Ein weiterer Nachteil besteht darin, dass bei der Lösung gemäss der US 6,170,261 Bl ein erheblicher schaltungstechnischer Aufwand zum Abgreifen des Lastdrucks vom zusätzlichen Verbraucher und zur Ansteuerung des Zusammenschaltventils erforderlich ist.The disadvantage of this solution is that, for example, when controlling a consumer connected to the hydraulic circuit with a high pressure medium requirement and low pressure and when controlling a consumer connected to the other circuit with low volume requirement and high pressure, both circuits are connected via the interconnection valve , so that the higher load pressure of the latter circuit is also present in the first circuit. Due to this higher load pressure, the pump of the first circuit is started up, so that both circuits are raised to the higher pressure level. The pressure in the first-mentioned hydraulic circuit must then be reduced accordingly to the required pressure level, which results in considerable energy losses. Another disadvantage is that the solution according to US Pat. No. 6,170,261 B1 requires a considerable amount of circuitry for tapping the load pressure from the additional consumer and for controlling the interconnection valve.

Dem gegenüber liegt der Erfindung die Aufgabe zugrun- de, ein hydraulisches Zweikreissystem zu schaffen, das mit einfachem Aufbau eine Minimierung der Engergieverlu- ste im Falle des Zusammenschaltens beider Kreise ermöglicht .In contrast, the invention is based on the object of creating a hydraulic two-circuit system which, with a simple structure, enables the energy losses to be minimized when the two circuits are connected together.

Diese Aufgabe wird durch ein hydraulisches Zweikreis-This task is performed by a hydraulic two-circuit

System mit den Merkmalen des Patentanspruchs 1 gelöst.System with the features of claim 1 solved.

Erfindungsgemäß hat das hydraulische Zweikreissystem eine Zusammenschaltventilanordnung mit zwei Ventilein- richtungen, die jeweils verhindern, dass bei der Zusammenschaltung der beiden Kreise ein in einem der Kreise wirkender höherer Lastdruck bei geringem Druckmittelbedarf in den anderen Kreis mit niedrigerem Lastdruck- und hohem Druckmittelbedarf gemeldet wird. D. h. , in beiden Kreisen wird der den tatsächlichen Anforderungen entspre- chende Lastdruck zur jeweils zugeordneten Verstellpumpe gemeldet, so dass in dem Fall, in dem in einem der Kreise ein hoher Druck bei geringem Druckmittelbedarf anliegt, die Verstellpumpe nicht hochgefahren wird und somit die Energieverluste gegenüber der eingangs genannten Lösung erheblich minimiert sind. Die erfindungsgemässe Lösung lässt es jedoch zu, dass in dem Fall, in dem in einen der Kreise ein hoher Druck bei hohem Druckmittelbedarf anliegt, dieser hohe Lastdruck in den zweiten Kreis gemeldet wird, falls in diesem ein niedrigerer Lastdruck anliegt.According to the invention, the hydraulic dual-circuit system has an interconnection valve arrangement with two valve devices, each of which prevents one in one of the circuits from interconnecting the two circuits higher load pressure with a low pressure medium requirement is reported in the other circuit with a lower load pressure and high pressure medium requirement. I.e. , in both circles the load pressure corresponding to the actual requirements is reported to the respectively assigned variable displacement pump, so that in the event that a high pressure is present in one of the circles with a low pressure medium requirement, the variable displacement pump is not started up and thus the energy losses compared to the solution mentioned at the outset are considerably minimized. However, the solution according to the invention allows that in the event that a high pressure is present in one of the circuits with a high pressure medium requirement, this high load pressure is reported to the second circuit if a lower load pressure is present in it.

Bei einem konkreten Ausführungsbeispiel der Erfindung hat die Zusammenschaltventilanordnung zwei Druckwaagen, von denen jede einem der Kreise zugeordnet ist. Diese Druckwaagen werden jeweils in Öffnungsrichtung von dem im jeweiligen Kreis abgegriffenen Lastdruck und in Schliess- richtung vom jeweiligen Pumpendruck beaufschlagt sind. Des Weiteren sind in mit den Druckwaagen verbundenen Lastdruckleitungen Rückschlagventile oder dergleichen vorgesehen, die bei geöffneter Druckwaage verhindern, dass ein höherer, von dem einen zugeschalteten Kreis über die geöffnete Druckwaage in den dieser zugeordneten Kreis gemeldet wird. D. h. , die Meldung dieses höheren Lastdruckes in den anderen Kreis ist nur dann möglich, wenn die dem Kreis mit höherem Lastdruck zugeordnete Druckwaage öff et .In a specific embodiment of the invention, the interconnection valve arrangement has two pressure compensators, each of which is assigned to one of the circuits. These pressure compensators are each acted upon in the opening direction by the load pressure tapped in the respective circuit and in the closing direction by the respective pump pressure. Furthermore, non-return valves or the like are provided in load pressure lines connected to the pressure compensators, which, when the pressure compensator is open, prevent a higher circuit from which one is connected from being reported to the circuit assigned to it via the open pressure compensator. I.e. , The reporting of this higher load pressure in the other circuit is only possible if the pressure compensator assigned to the circuit with a higher load pressure opens.

Die Lösung mit zwei Druckwaagen und zwei Rückschlagventilen ist äusserst einfach aufgebaut, wobei zur An- Steuerung lediglich die Pumpendrücke und die Lastdrücke abgegriffen werden müssen. Bei dieser Variante wird es besonders bevorzugt, wenn die Druckwaagen zusätzlich zum Lastdruck in Öffnungsrichtung bzw. durch die Kraft einer Feder beaufschlagt wer- den, deren Federkraft kleiner als das Pumpen-Δp ist.The solution with two pressure compensators and two check valves is extremely simple, with only the pump pressures and the load pressures having to be tapped for control. In this variant, it is particularly preferred if the pressure compensators are acted upon in addition to the load pressure in the opening direction or by the force of a spring, the spring force of which is smaller than the pump Δp.

In dem Fall, in dem die Ventilanordnungen zur Ansteuerung der Verbraucher und des Fahrwerks des mobilen Geräts beispielsweise des Raupengeräts in einem Steuer- block in Plattenbauweise zusammengefügt werden, wird es bevorzugt, dass die beiden Druckwaagen und die zugeordneten Rückschlagventile in einer Zwischenplatte zusammenge- fasst sind, so dass die Alibindung an die beiden Kreise äusserst einfach ist.In the event that the valve arrangements for controlling the consumers and the chassis of the mobile device, for example the caterpillar device, are combined in a control block in plate construction, it is preferred that the two pressure compensators and the associated check valves are combined in an intermediate plate , so that the Ali binding to the two circles is extremely easy.

Bei der vorbeschriebenen Lösung erfolgt die Zusammenschaltung der beiden Kreise automatisch in Abhängigkeit von den an den Druckwaagen anliegenden Drücken (Pumpendruck, Lastdruck) . Für den Fall, dass willkürlich eingegriffen werden soll, wird mit einer vorteilhaften Weiterbildung der Erfindung vorgeschlagen, den auf der in Öffnungsrichtung wirksamen Steuerfläche der Druckwaage wirkenden Steuerdruck - beispielsweise den Lastdruck - über ein Wegeventil abzugreifen. Der Ausgangsanschluss dieses Wegeventils verbindet beispielsweise in einer Grundstellung den mit dem Lastdruck beaufschlagten Federraum der zugeordneten Druckwaage mit dem Tank, so dass diese Druckwaage stets in Schliessstellung verbleibt und somit eine Zusammenschaltung der beiden Kreise über diese Druckwaage nicht möglich ist. In einer weiteren Schalt- Stellung des Wegeventils kann an diesen Federraum der höhere der beiden Pumpendrücke angelegt werden. In dieser Schaltstellung ist die jeweilige Druckwaage stets geöffnet, und beide Kreise über diese Druckwaage verbunden. In der dritten Schaltposition liegt am Federraum der Last- druck an - die Zusammenschaltventilanordnung arbeitet dann im vorbeschriebenen Automatikmodus .In the solution described above, the interconnection of the two circuits takes place automatically depending on the pressures applied to the pressure compensators (pump pressure, load pressure). In the event that intervention is to be carried out arbitrarily, it is proposed with an advantageous development of the invention to tap the control pressure acting on the control surface of the pressure compensator acting in the opening direction - for example the load pressure - via a directional valve. The output connection of this directional valve connects, for example in a basic position, the spring space of the associated pressure compensator, which is acted upon by the load pressure, with the tank, so that this pressure compensator always remains in the closed position, and thus an interconnection of the two circuits via this pressure compensator is not possible. In a further switching position of the directional valve, the higher of the two pump pressures can be applied to this spring chamber. In this switch position, the respective pressure compensator is always open, and both circuits are connected via this pressure compensator. In the third switching position, the load pressure on - the interconnection valve arrangement then operates in the automatic mode described above.

Das Wegeventil wird vorzugsweise als elektrisch betä- tigtes 4/3-Wegeventil ausgeführt, das willkürlich durch den Bediener in eine der drei vorbeschriebenen Betriebs- Stellungen schaltbar ist (Automatischer Betrieb, Verriegeln der Kreise und Zusammenschalten der Kreise) .The directional control valve is preferably designed as an electrically operated 4/3-way valve which can be switched arbitrarily by the operator into one of the three operating positions described above (automatic operation, locking of the circuits and interconnection of the circuits).

Das erfindungsgemässe hydraulische ZweikreisSystem lässt sich besonders vorteilhaft bei einem Raupengerät einsetzen, bei dem die Hydromotoren zum Antrieb der beiden Ketten über jeweils einen der Kreise angesteuert werde .The hydraulic two-circuit system according to the invention can be used particularly advantageously in a caterpillar device in which the hydraulic motors for driving the two chains are each controlled via one of the circles.

Sonstige vorteilhafte Weiterbildungen der Erfindung sind Gegenstand weiterer Unteransprüche.Other advantageous developments of the invention are the subject of further dependent claims.

Im folgenden wird ein bevorzugstes Ausführungsbei- spiel der Erfindung anhand schematischer Zeichnungen näher erläutert. Es zeigen:A preferred embodiment of the invention is explained in more detail below with the aid of schematic drawings. Show it:

Figur 1 einen Auszug eines Schaltschemas eines Steuerblockes zur Ansteuerung eines Raupengerätes; eine Detaildarstellung des Schaltschemas aus Figur 2 undFigure 1 shows an extract of a circuit diagram of a control block for controlling a caterpillar device; a detailed representation of the circuit diagram of Figure 2 and

Figur 3 ein Wegeventil zur Ansteuerung von Druckwaagen des Schaltschemas gemäss Figur 2.3 shows a directional control valve for actuating pressure compensators of the circuit diagram according to FIG. 2.

Diese Baggersteuerung 1 ist als Zweikreissystem mit zwei hydraulischen Kreisen 2, 4 aufgebaut, die jeweils über eine nicht dargestellte Verstellpumpe mit Druckmittel versorgt werden. Der mit der in Figur 1 dargestellten Steuerung versehene Bagger hat ein Fahrwerk mit zwei Ketten, deren Fahrantriebe über die beiden Kreise 2, 4 unabhängig voneinander mit Druckmittel versorgbar sind. Neben dem Fahrantrieb werden über das Zweikreissystem noch weitere Verbraucher des Baggers, wie beispielsweise ein Drehwerk, ein Stiel, ein Löffel oder ein Ausleger angesteuert .This excavator control system 1 is constructed as a two-circuit system with two hydraulic circuits 2, 4, each of which is supplied with pressure medium via a variable displacement pump, not shown. The excavator provided with the control system shown in FIG. 1 has a chassis with two chains, the travel drives of which can be supplied with pressure medium independently of one another via the two circuits 2, 4. In addition to the traction drive, other excavator consumers, such as a slewing gear, a stick, a bucket or a boom, are controlled via the dual-circuit system.

Der die Baggersteuerung gemäss Figur 1 realisierende Steuerblock ist in Scheibenbaueise ausgeführt, wobei die beiden nicht dargestellten Verstellpumpen an Druckanschlüsse P_ und P2 an den Steuerblock angeschlossen sind. Dieser hat des Weiteren noch einen Tankanschluss T sowie Arbeitsanschlüsse A]_, B]_ sowie A3, B3 , an die der Antrieb der rechten bzw. linken Kette angeschlossen ist. An weitere Anschlüsse A2, B2 und A4, B4 etc. werden die weiteren Verbraucher des Baggers, wie beispielsweise der Antrieb des Drehwerks, die Hydrozylinder zur Betätigung des Stiels, des Löffels oder des Auslegers angeschlossen. Beim dargestellten Ausführungsbeispiel sei angenommen, dass an die Anschlüsse A2, B2 der Ausleger und an den Anschluss A4, B4 der Löffel angeschlossen sind.The control block which realizes the excavator control according to FIG. 1 is of disc construction type, the two variable pumps, not shown, being connected to the control block at pressure connections P_ and P2. This also has a tank connection T and work connections A] _, B] _ and A 3 , B 3 , to which the drive of the right or left chain is connected. The other consumers of the excavator, such as the drive of the slewing gear, the hydraulic cylinders for actuating the stick, the bucket or the boom are connected to further connections A 2 , B2 and A 4 , B 4 etc. In the exemplary embodiment shown, it is assumed that the boom is connected to the connections A2, B 2 and the bucket to the connections A 4 , B 4 .

Der dargestellte Steuerblock hat des Weiteren zwei Lastdruckanschlüsse, im folgenden LS^ und LS2 genannt, über die der im jeweiligen Kreis 2, 4 wirkende Lastdruck abgegriffen und zum Förderstromregelventil (nicht darge- stellt) der Verstellpumpe geführt wird, die somit in Abhängigkeit von diesem höchsten Lastdruck angesteuert wird.The control block shown also has two load pressure connections, hereinafter referred to as LS ^ and LS 2 , via which the load pressure acting in the respective circuit 2, 4 is tapped and fed to the flow control valve (not shown) of the variable displacement pump, which is therefore dependent on the latter highest load pressure is controlled.

Die Ansteuerung der vorgenannten Verbraucher erfolgt jeweils über ein proportional verstellbares Wegeventil 6, dem jeweils eine Druckwaage 8 nachgeschaltet ist. Das Wegeventil 6 hat einen eine veränderliche Messblende ausbildenden Geschwindigkeitsteil und einen Richtungs- teil, wobei die Messblende der Druckwaage 8 vorgeschaltet ist und der Richtungsteil stromabwärts der Druckwaage 8 angeordnet ist. Jede Druckwaage 8 ist in Schliessrichtung vom Lastdruck und in Öffnungsrichtung von dem Druck stromabwärts der Messblende des Wegeventils 6 beaufschlagt. Der Druckwaagenkolben stellt sich in Abhängigkeit von den anliegenden Steuerdrücken in eine Regelposi- tion ein, in der der Druckabfall über der Messblende des proportional verstellbaren Wegeventils 6 kontant gehalten wird, so dass eine lastdruckunabhängige Volumenstromsteuerung ermöglicht wird. Derartige LS-Steuerungen sind hinlänglich bekannt, so dass auf eine ausführliche Be- Schreibung des Aufbaus des Wegeventils 6 und der nachgeschalteten Druckwaage 8 verzichtet werden kann. Die Ansteuerung des Wegeventils 6 erfolgt jeweils über Pilot- ventile 10, 12, über die ein Steuerdruck an die stirnseitigen Steuerflächen eines Schiebers des Wegeventils 6 angelegt wird. Diese Pilotventile werden beispielsweise in Abhängigkeit von der Stellbewegung eines Joysticks betätigt .The control of the aforementioned consumers takes place in each case via a proportionally adjustable directional valve 6, which is connected downstream of a pressure compensator 8. The directional control valve 6 has a speed part which forms a variable measuring orifice and a directional part, the measuring orifice being connected upstream of the pressure compensator 8 and the directional part being arranged downstream of the pressure compensator 8. Each pressure compensator 8 is in the closing direction acted upon by the load pressure and in the opening direction by the pressure downstream of the metering orifice of the directional valve 6. The pressure compensator piston adjusts itself to a control position depending on the control pressures present, in which the pressure drop across the measuring orifice of the proportionally adjustable directional control valve 6 is kept constant, so that volume flow control independent of the load pressure is made possible. Such LS controls are well known, so that a detailed description of the structure of the directional control valve 6 and the downstream pressure compensator 8 can be dispensed with. The control of the directional control valve 6 takes place in each case via pilot valves 10, 12, via which a control pressure is applied to the front control surfaces of a slide of the directional control valve 6. These pilot valves are actuated, for example, depending on the actuating movement of a joystick.

Die Anschlüsse der Wegeventile 6 sind über eine Druckleitung 14, 16 mit dem Druckanschluss P]_ bzw. P2 verbunden. Des Weiteren hat jedes Wegeventil zwei Arbeitsanschlüsse, die jeweils über eine Arbeitsleitung 18 bzw. 20 mit den zugeordneten Verbraucheranschlüssen A, B verbunden sind. Zur Rückführung des Druckmittels vom Verbraucher ist ein Ausgangsanschluss des Wegeventils 6 über eine Tankleitung 22 mit dem Tankanschluss T des Steuerblocks verbunden.The connections of the directional control valves 6 are connected via a pressure line 14, 16 to the pressure connection P] _ or P2. Furthermore, each directional control valve has two working connections, each of which is connected to the associated consumer connections A, B via a working line 18 or 20. To return the pressure medium from the consumer, an outlet connection of the directional control valve 6 is connected to the tank connection T of the control block via a tank line 22.

In den Arbeitsleitungen sind zur Begrenzung des maxi- malen, zum Verbraucher geführten Druckes jeweils noch Druckbegrenzungsventile vorgesehen, wobei die den Druck an den Arbeitsanschlüssen 2, B2, B]_ und B3 sowie A4 (nicht dargestellt) begrenzenden Druckbegrenzungsventile mit Nachsaugfunktion ausgeführt sind, so dass bei einem Voreilen des Verbrauchers Druckmittel aus dem Tank nachgesaugt werden kann um Kavitätserscheinungen zu vermei- den. Eine jeweils an den Lastdruckanschluss LS der beiden Kreise 2, 4 angeschlossene Lastdruckmeldeleitung 28, 30 ist über ein LS-Stromregelventil 32 bzw. 34 mit der gemeinsamen Tankleitung 22 verbunden.To limit the maximum pressure supplied to the consumer, pressure relief valves are also provided in the working lines, the pressure limiting valves limiting the pressure at the working connections 2, B 2 , B] _ and B 3 and A 4 (not shown) being designed with a suction function so that when the consumer runs ahead, pressure medium can be sucked in from the tank in order to avoid the. A load pressure signaling line 28, 30 connected to the load pressure connection LS of the two circuits 2, 4 is connected to the common tank line 22 via an LS flow control valve 32 or 34.

Die Druckwaagen 8 sind so ausgeführt, dass sie in ihrer voll aufgesteuerten Endposition den an ihrem Eingang anliegenden Druck (Druck stromabwärts der Messblende) in die Lastdruckleitung 28 bzw. 30 melden, so dass in dieser stets der höchste Lastdruck im jeweiligen Kreis 2 oder 4 liegt .The pressure compensators 8 are designed in such a way that, in their fully opened end position, they report the pressure present at their inlet (pressure downstream of the measuring orifice) into the load pressure line 28 or 30, so that the highest load pressure in the respective circuit 2 or 4 is always in this ,

Die vorbeschriebenen Wegeventile mit der zugeordneten Druckwaage 8, den Pilotventilen 10, 12 sowie den Druckbe- grenzungsventilen 24, 25 können jeweils in einer Scheibe oder in einem gemeinsamen Steuerblock aufgenommen sein. Zur Verbindung der beiden hydraulischen Kreise 2, 4 ist in einer Zwischenscheibe 36 eine Zusammenschaltventilanordnung 38 vorgesehen, über die bei bestimmten Betriebs- zuständen die Druckleitungen 14, 16 der beiden hydraulischen Kreise 2, 4 zusammengeschaltet werden können, so dass die angesteuerten Verbraucher von beiden Verstellpumpen gemeinsam mit Druckmittel versorgt werden.The directional valves described above with the associated pressure compensator 8, the pilot valves 10, 12 and the pressure limiting valves 24, 25 can each be accommodated in a disk or in a common control block. To connect the two hydraulic circuits 2, 4, an interconnection valve arrangement 38 is provided in an intermediate disk 36, via which, under certain operating conditions, the pressure lines 14, 16 of the two hydraulic circuits 2, 4 can be connected together, so that the controlled consumers of both variable pumps be supplied together with pressure medium.

Der Aufbau der Zusammenschaltventilanordnung wird anhand der vergrösserten Darstellung gemäss Figur 2 erläutert.The structure of the interconnection valve arrangement is explained on the basis of the enlarged illustration according to FIG. 2.

Die Zusammenschaltventilanordnung 38 hat zwei Druck- waagen 40, 42, die jeweils über eine Feder 44 in Richtung ihrer ÖffnungsStellung vorgespannt sind. Die Federkraft der Feder ist so ausgelegt, dass sie etwas unterhalb des Pumpen-Δp liegt. Liegt dieses beispielsweise bei etwa 20 bar, so wird die Federkraft der Feder 44 etwa zwischen 10 und 19 bar liegen. Die in Figur 2 obere Druckwaage 40 ist dem Kreis 2 und die untere Druckwaage 42 dem Kreis 4 zugeordnet. Der an der Druckleitung 14 anliegende Druck (Pumpendruck) wird zu einer in Schliessrichtύng wirksamen Steuerfläche der Druckwaage 40 geführt und der in der Lastdruckleitung 28 des Kreises 2 anliegende höchste Lastdruck über eine Steuerleitung 46 abgegriffen und zu einer in Öffnungsrichtung wirksamen Steuerfläche der Druckwaage 40 geführt. Bei dem dargestellten Ausführungsbeispiel mündet die Steuerleitung 46 in den Federraum für die Feder 44 ein.The interconnection valve arrangement 38 has two pressure scales 40, 42, which are each biased in the direction of their open position by a spring 44. The spring force of the spring is designed so that it is slightly below the pump Δp. If this is, for example, approximately 20 bar, the spring force of the spring 44 will be approximately between 10 and 19 bar. The upper pressure compensator 40 in FIG. 2 is assigned to circuit 2 and the lower pressure compensator 42 to circuit 4. The pressure (pump pressure) applied to the pressure line 14 is led to a control surface of the pressure compensator 40 which is effective in the closing direction and the highest load pressure which is present in the load pressure line 28 of the circuit 2 is tapped via a control line 46 and is guided to a control surface of the pressure compensator 40 which is effective in the opening direction. In the illustrated embodiment, the control line 46 opens into the spring space for the spring 44.

Entsprechend wird der Druck in der Druckleitung 16 des zweiten Kreises 4 zu einer in Schliessrichtung wirk- samen Steuerfläche der Druckwaage 42 und der Druck in derAccordingly, the pressure in the pressure line 16 of the second circuit 4 becomes a control surface of the pressure compensator 42 which is effective in the closing direction and the pressure in the

Lastdruckmeldeleitung 30 über eine weitere SteuerleitungLoad pressure reporting line 30 via a further control line

48 in den Federraum der Druckwaage 42 geführt.48 guided into the spring chamber of the pressure compensator 42.

Die beiden Eingangsanschlüsse P und LS der Druckwaa- gen 40, 42 sind mit den zugeordneten Druckleitungen 14 bzw. 16 und den Lastdruckmeldeleitungen 28 bzw. 30 verbunden. Stromaufwärts des LS-Anschlusses der Druckwaagen 40, 42 ist jeweils ein Rückschlagventil 50, 52 vorgesehen, das eine Druckmittelströmung von der Lastdruckmelde- leitung 14 bzw. 16 zum zugeordneten LS-Anschluss ermöglicht, in Gegenrichtung jedoch absperrt.The two input connections P and LS of the pressure compensators 40, 42 are connected to the assigned pressure lines 14 and 16 and the load pressure signaling lines 28 and 30, respectively. A check valve 50, 52 is provided upstream of the LS connection of the pressure compensators 40, 42, which enables a pressure medium flow from the load pressure signal line 14 or 16 to the assigned LS connection, but blocks in the opposite direction.

Die beiden Ausgangsanschlüsse A, B sind mit den Last- druckmeIdeleitungen 28, 30 bzw. den Druckleitungen 14, 16 des jeweils anderen Kreises 2, 4 verbunden.The two output connections A, B are connected to the load pressure measuring lines 28, 30 and the pressure lines 14, 16 of the respective other circuit 2, 4.

Die Funktion dieser Zusammenschaltventilanordnung wird anhand zweier Betriebszustände der Baggersteuerung erläutert . Es sei zunächst angenommen, dass ein Betriebszustand vorliegt, bei dem der an die Arbeitsanschlüsse A2, B2 angeschlossene Verbraucher, beispielsweise der Stiel viel Druckmittel benötigt und entsprechend ein vergleichsweise geringer Pumpendruck im hydraulischen Kreis 2 anliegt. Der an die Arbeitsanschlüsse A4, B4 des zweiten Kreises 4 angeschlossene Verbraucher, beispielsweise der Ausleger soll dagegen nur eine geringe Druckmittelmenge bei einem vergleichsweise hohen Pumpendruck benötigen. Bei diesem Betriebszustand wird die dem zweiten Kreis 4 Δpp zugeordnete Druckwaage 42 durch den hohen Pumpendruck in ihrer Schließstellung gehalten, während die dem ersten Kreis 2 zugeordnete Druckwaage 40 aufgrund des abgefallenen Pumpendruckes in eine Regelposition gebracht wird, in der' die Anschlüsse P, LS mit den Anschlüssen A, B verbunden sind. Dadurch kann die den zweiten Kreis 4 zugeordnete Verstellpumpe Druckmittel zu dem an den ersten Kreis 2 angeschlossenen Stiel (Anschlüsse A2 , B2) fördern, so dass der höhere Druckmittelbedarf dieses Verbrauchers gesichert ist. Das Rückschlagventil 50 verhindert dabei, dass der höhere, in der Lastdruckmeldeleitung 30 anliegende Lastdruck in die Lastdruckmeldeleitung 28 des ersten Kreises 2 gemeldet wird, so dass das Druckniveau in diesem Kreis gering bleibt und die eingangs beschrie- benen Energieverluste nicht auftreten. In ihrer Regelposition drosselt die Druckwaage 50 die Druckmittelströmung von dem höheren, im zweiten Kreis 4 herrschenden Druckniveau auf das im ersten Kreis 2 benötigte Druckniveau ab.The function of this interconnection valve arrangement is explained on the basis of two operating states of the excavator control. It is initially assumed that there is an operating state in which the consumer connected to the working connections A 2 , B 2 , for example the handle, requires a large amount of pressure medium and accordingly there is a comparatively low pump pressure in the hydraulic circuit 2. The consumer connected to the working connections A 4 , B 4 of the second circuit 4, for example the boom, on the other hand, should only require a small amount of pressure medium at a comparatively high pump pressure. In this operating state, the pressure compensator 42 assigned to the second circuit 4 Δpp is held in its closed position by the high pump pressure, while the pressure compensator 40 assigned to the first circuit 2 is brought into a control position due to the drop in pump pressure, in which the connections P, LS are included the connections A, B are connected. As a result, the variable displacement pump assigned to the second circuit 4 can deliver pressure medium to the stem (connections A 2 , B2) connected to the first circuit 2, so that the higher pressure medium requirement of this consumer is ensured. The check valve 50 prevents the higher load pressure present in the load pressure reporting line 30 from being reported into the load pressure reporting line 28 of the first circuit 2, so that the pressure level in this circuit remains low and the energy losses described above do not occur. In its control position, the pressure compensator 50 throttles the pressure medium flow from the higher pressure level prevailing in the second circuit 4 to the pressure level required in the first circuit 2.

Es sei nun angenommen, dass sich das Raupengerät inIt is now assumed that the caterpillar device is in

Geradeausfahrt befindet und dabei beide Ketten mit der vollen Druckmittelmenge versorgt werden. Beide Verstellpumpen sind vollständig hochgefahren und die Druckwaagen werden in Schliessrichtung mit dem maximalen Pumpendruck beaufschlagt und sind somit geschlossen und beide Kreise 2 , 4 voneinander getrennt . Wird nun ein weiterer Verbrau- eher, beispielsweise der Ausleger (Anschlüsse A2, B2) zugeschaltet, so sinkt aufgrund des Druckmittelbedarfs dieses Verbrauchers der Druck im ersten Kreis 2 ab. Ohne Zusammenschaltventilanordnung 38 würde dann die linke Kette (Anschluss A]_, B]_) nicht hinreichend mit Druckmittel versorgt, so dass das Raupengerät eine Kurve fährt. Dies wird durch die Zusammenschaltvorrichtung 30 jedoch in folgender Weise verhindert .Straight ahead and both chains are supplied with the full amount of pressure medium. Both variable pumps are fully started up and the pressure compensators are pressurized with the maximum pump pressure in the closing direction and are therefore closed and both circuits 2, 4 are separated from each other. If another consumer rather, for example the boom (connections A 2 , B2) is switched on, the pressure in the first circuit 2 drops due to the pressure medium requirement of this consumer. Without the interconnection valve arrangement 38, the left chain (connection A ] _, B] _) would then not be supplied with sufficient pressure medium, so that the caterpillar drive turns. This is prevented by the interconnection device 30 in the following manner.

Durch den Druckabfall im ersten Kreis 2 und der entsprechenden Absenkung des Pumpendruckes wird die Druckwaage 40 in ihre Regelposition gebracht, so dass die beiden Kreise 2, 4 miteinander verbunden sind. Durch die Verbindung dieser beiden Kreise sinkt auch der Pupen- druck im zweiten Kreis 4 ab, so dass entsprechend auch die diesem Kreis zugeordnete Druckwaage 42 öffnet, so dass die beiden Kreise 2, 4 über beide Druckwaagen 40, 42 miteinander verbunden sind. D. h. , es stellt sich eine Art LUDV-Einkreissyste ein, das in UnterSättigung be- trieben wird - die Geradeausfahrt des Raupengeräts bleibt erhalten und der zugeschaltete Verbraucher (Ausleger) wird mit Druckmittel versorgt .Due to the pressure drop in the first circuit 2 and the corresponding reduction in the pump pressure, the pressure compensator 40 is brought into its control position, so that the two circuits 2, 4 are connected to one another. By connecting these two circles, the pupa pressure in the second circle 4 also drops, so that the pressure compensator 42 assigned to this circuit also opens accordingly, so that the two circles 2, 4 are connected to one another via both pressure compensators 40, 42. I.e. , a kind of LUDV single-circuit system is set, which is operated in under-saturation - the crawler device goes straight ahead and the connected consumer (boom) is supplied with pressure medium.

Bei dem vorbeschriebenen Ausführungsbeispiel arbeitet die Zusammenschaltventilanordnung 38 automatisch und bindet die beiden Kreise 2, 4 im Falle einer Untersättigung eines oder beider Kreise. Es kann nun erforderlich sein, dass beide Kreise willkürlich vom Bediener zusammengeschaltet werden, um beispielsweise eine optimale Versorgung eines der Verbraucher zu gewährleisten. Es kann aber auch genauso erforderlich sein, die beiden Kreise gegeneinander zu verriegeln, um ein Zusammenschalten zu verhindern.In the exemplary embodiment described above, the interconnection valve arrangement 38 works automatically and binds the two circles 2, 4 in the event of one or both circles being under-saturated. It may now be necessary for the operator to arbitrarily interconnect both circuits in order, for example, to ensure optimal supply to one of the consumers. However, it may also be necessary to lock the two circles against each other in order to prevent interconnection.

Diese Varianten lassen sich auf vergleichsweise einfache Weise dadurch realisieren, dass die beiden Steuer- leitungen 46, 48 nicht direkt zu der in Öffnungsrichtung wirkenden Steuerfläche der Druckwaagen 40, 42 (Federraum) geführt sind sondern jeweils über ein Steuerventil 54, wie es in Figur 3 dargestellt ist.These variants can be realized in a comparatively simple way by the fact that the two control Lines 46, 48 are not led directly to the control surface of the pressure compensators 40, 42 (spring chamber) acting in the opening direction, but in each case via a control valve 54, as shown in FIG. 3.

Das in Figur 3 dargestellte Steuerventil 54 ist als 4/3-Wegeventil ausgeführt und hat einen Druckanschluss P, einen LS-Anschluss LS sowie einen Tankanschluss T und einen Steueranschluss S der mit der zum Federraum führen- den Steuerleitung 46 bzw. 48 verbunden ist. Der LS-Anschluss ist an die Lastdruckmeldeleitung 28 bzw. 30 des jeweiligen Kreises 2, 4 angeschlossen. Der Druckanschluss P ist über ein Wechselventil 56 mit den beiden Druckleitungen 14, 16 der beiden hydraulischen Kreise 2, 4 ver- bindbar. Über das Wechselventil 56 wird stets der höhere der beiden Pumpendrücke zum Druckanschluss P geführt. In der dargestellten Grundstellung (0) des Steuerventils 54 sind der Druckanschluss P und LS-Anschluss LS abgesperrt, und die Steuerleitung 46 (48) mit dem Tankanschluss T verbunden. D. h. , im Federraum wirkt der Tankdruck, so dass die jeweilige Druckwaage 40, 42 durch den jeweils wirkenden Pumpendruck in Schliesstellung vorgespannt ist - die beiden Druckwaagen 40, 44 sind geschlossen und die beiden Kreise 2, 4 gegeneinander verriegelt.The control valve 54 shown in FIG. 3 is designed as a 4/3-way valve and has a pressure connection P, an LS connection LS and a tank connection T and a control connection S which is connected to the control line 46 or 48 leading to the spring chamber. The LS connection is connected to the load pressure signaling line 28 or 30 of the respective circuit 2, 4. The pressure connection P can be connected to the two pressure lines 14, 16 of the two hydraulic circuits 2, 4 via a shuttle valve 56. The higher of the two pump pressures is always led to the pressure port P via the shuttle valve 56. In the basic position (0) of the control valve 54 shown, the pressure port P and the LS port LS are shut off and the control line 46 (48) is connected to the tank port T. I.e. , the tank pressure acts in the spring chamber, so that the respective pressure compensator 40, 42 is biased in the closed position by the pump pressure acting in each case - the two pressure compensators 40, 44 are closed and the two circles 2, 4 are locked against one another.

Beim Umschalten des elektrisch betätigten Steuerventils 54 in die Schaltstellung (a) wird der im jeweiligen Kreis 2, 4 anliegende Lastdruck in die Steuerleitung 46 (48) durchgeschaltet - die Zusammenschaltventilanordnung 38 arbeitet in der gleichen Weise, wie sie anhand der Figuren 1 und 2 erläutert wurde .When the electrically operated control valve 54 is switched to the switching position (a), the load pressure present in the respective circuit 2, 4 is switched through to the control line 46 (48) - the interconnection valve arrangement 38 works in the same way as explained with reference to FIGS. 1 and 2 has been .

Beim Umschalten des Steuerventils 54 in die mit (b) gekennzeichnete Stellung wird der Druckanschluss P mit dem Steueranschluss s verbunden, so dass im Federraum der höhere der beiden Pumpendrücke wirksam ist und die zuge- ordnete Druckwaage 40 (42) durch die Kraft der Feder 44 in der Öffnungsstellung gehalten wird. D. h. , das System wird dann als Einkreissystem betrieben, bei dem die Verbraucher durch beide Pumpen' mit Druckmittel versorgt werden.When the control valve 54 is switched to the position marked with (b), the pressure port P is connected to the control port s, so that the higher of the two pump pressures is effective in the spring chamber and the associated ordered pressure compensator 40 (42) is held in the open position by the force of the spring 44. I.e. The system is then operated as a single-circuit system in which the consumers are supplied with pressure medium by both pumps.

Offenbart ist ein hydraulisches Zweikreisbremssystem zur Ansteuerung von Verbrauchern eines mobilen Gerätes , beispielsweise eines Raupengerätes. Die beiden hydrauli- sehen Kreise können über eine Zusammenschaltventilanordnung zusammengeschaltet werden, wobei über eine Einrichtung, beispielsweise Rückschlagventile, sichergestellt ist, dass bei einer Zusammenschaltung der Kreise ein höherer Lastdruck bei geringem Druckmittelbedarf in einem der Kreise nicht in dem anderen Kreis mit niedrigerem Lastdruck gemeldet wird. Bei einer bevorzugten Variante hat die Zusammenschaltventilanordnung zwei Druckwaagen, die jeweils vom Pumpendruck und vom Lastdruck im zugeordneten Kreis beaufschlagt sind und denen Rückschlagventile vorgeschaltet sind. A hydraulic dual-circuit brake system for controlling consumers of a mobile device, for example a caterpillar device, is disclosed. The two hydraulic circuits can be interconnected via an interconnection valve arrangement, with a device, for example non-return valves, ensuring that when the circuits are interconnected, a higher load pressure with low pressure medium requirement in one of the circuits is not reported in the other circuit with a lower load pressure , In a preferred variant, the interconnection valve arrangement has two pressure compensators, each of which is acted upon by the pump pressure and the load pressure in the associated circuit and which are connected upstream of check valves.

BezugszeichenlisteLIST OF REFERENCE NUMBERS

Baggersteuerung erster Kreis zweiter Kreis Wegeventil Druckwaage Pilotventil Pilotventil Druckleitung Druckleitung Arbeitsleistung Arbeitsleistung Tankleitung Druckbegrenzungsventile Druckbegrenzungsventile Lastdruckmeldeleitung Lastdruckmeldeleitung LS-Stromregelventil LS-Stromregelventil Zwischenseheibe Zusammenschaltventilanordnung Druckwaage Druckwaage Feder Steuerleitung Steuerleitung Rückschlagventil Rückschlagventil Steuerventil Wechselventil Excavator control first circuit second circuit directional control valve pressure balance pilot valve pilot valve pressure line pressure line work performance work performance tank line pressure relief valve pressure relief valve load pressure signaling line load pressure signaling line LS flow control valve LS flow control valve intermediate disk interlocking valve arrangement pressure balance pressure compensator spring control line control line check valve check valve check valve control valve shuttle valve

Claims

Patentansprüche claims 1. Hydraulisches Zweikreissystem zur Ansteuerung von Verbrauchern eines mobilen Gerätes, insbesondere eines Raupengerätes, wobei jedem hydraulischen Kreis1. Hydraulic two-circuit system for controlling consumers of a mobile device, in particular a caterpillar device, each hydraulic circuit (2, 4) eine Verstellpumpe zugeordnet ist, über die die zugeordneten Verbraucher mit Druckmittel versorgbar sind und wobei die beiden Kreise (2, 4) über eine Zusammenschaltventilanordnung (38) derart miteinander verbindbar sind, dass die Verstellpumpe des einen Kreises (2, 4) Druckmittel in den anderen Kreis (4, 2) fördert, so dass dieser Kreis (4, 2) über beide Verstellpumpen mit Druckmittel versorgbar ist, und wobei die Verstellpumpen jeweils in Abhängigkeit vom Lastdruck im zugeordneten Kreis (2, 4) angesteuert sind, dadurch gekennzeichnet, dass die Zusammenschaltventilanordnung (38) zwei Ventileinrichtungen (40, 42; 50, 52) hat, von denen jede einem der Kreise (2, 4) zugeordnet ist und über die in Abhängigkeit vom Lastdruck und vom Pumpendruck im zugeordneten Kreis (2, 4) die Verbindung zum anderen Kreis (4, 2) aufsteuerbar ist, wobei die Verbindung der den Lastdruck führenden Leitungsabschnitte derart gestaltet ist, dass der Lastdruck vom anderen Kreis (4, 2) nicht in dan zugeordneten Kreis (2, 4) gemeldet werden kann.(2, 4) is assigned to a variable displacement pump, via which the assigned consumers can be supplied with pressure medium, and the two circuits (2, 4) can be connected to one another via an interconnection valve arrangement (38) such that the variable displacement pump of one circuit (2, 4 ) Promotes pressure medium in the other circuit (4, 2) so that this circuit (4, 2) can be supplied with pressure medium via both variable displacement pumps, and the variable displacement pumps are each controlled as a function of the load pressure in the assigned circuit (2, 4), characterized in that the interconnection valve arrangement (38) has two valve devices (40, 42; 50, 52), each of which is assigned to one of the circuits (2, 4) and via which, depending on the load pressure and the pump pressure in the assigned circuit (2 , 4) the connection to the other circuit (4, 2) can be controlled, the connection of the line sections carrying the load pressure being designed in such a way that the load pressure from the other circuit (4, 2) is not in dan z associated circle (2, 4) can be reported. 2. Zweikreissystem nach Patentanspruch 1, wobei die Zusammenschaltventilanordnung (38) zwei Druckwaagen2. Two-circuit system according to claim 1, wherein the interconnection valve arrangement (38) two pressure compensators (40, 42) hat, von denen eine Druckwaage (40) von dem in einen der Kreise (2) wirkenden Pumpendruck in Schliessrichtung und dem Lastdruck in Öffnungsrichtung und die andere Druckwaage (42) entsprechend vom Pumpendruck und vom Lastdruck im anderen Kreis (4) beaufschlagt ist, und über die Druck- und LS-Leitun- gen (14, 16; 28, 30) der beiden Kreise (2, 4) verbindbar sind, wobei in den LS-Leitungen (28, 30) Rückschlagventile (50, 52) vorgesehen sind, die eine Steuerölströmung vom Kreis > (2, 4) mit dem höheren Lastdruck in den Kreis (4, 2) mit dem niedrigeren Lastdruck verhindern.(40, 42), one of which has a pressure compensator (40) of the pump pressure acting in one of the circles (2) in the closing direction and the load pressure in the opening direction and the other pressure compensator (42) accordingly of the pump pressure and the load pressure in the other circuit (4 ) is acted upon, and via the pressure and LS lines gen (14, 16; 28, 30) of the two circuits (2, 4) can be connected, check valves (50, 52) are provided in the LS lines (28, 30), which control oil flow from the circuit> (2, 4) with the higher load pressure in the circuit (4, 2) with the lower load pressure. 3. Zweikreissystem nach Patentanspruch 1 oder 2, wobei die Druckwaagen (40, 42) jeweils eine in Öffnungs- richtung wirksame Feder (44) haben, deren Federkraft kleiner als der Druckabfall an der Pumpe ist .3. Two-circuit system according to claim 1 or 2, wherein the pressure compensators (40, 42) each have a spring (44) effective in the opening direction, the spring force of which is less than the pressure drop at the pump. 4. Zweikreissystem nach einem der vorhergehenden Patentansprüche, wobei die Zusammenschaltventilanord- nung (38) in einer Zwischenplatte (36) eines Ventil- blocks aufgenommen ist .4. Two-circuit system according to one of the preceding claims, wherein the interconnection valve arrangement (38) is received in an intermediate plate (36) of a valve block. 5. Zweikreissystem nach einem der vorhergehenden Patentansprüche, mit einer Verriegelungseinrichtung (54) zum Verriegeln der Zusammenschaltventilanordnung, so dass Wahlweise ein Zwei- oder Einkreissystem einstellbar ist.5. Two-circuit system according to one of the preceding claims, with a locking device (54) for locking the interconnection valve arrangement, so that either a two-circuit or single-circuit system is adjustable. 6. ZweikreisSystem nach Patentanspruch 2 und 6, wobei die Verriegelungseinrichtung jeweils ein einer Druckwaage (40, 42) zugeordnetes Steuerventil (54) hat, über das ein Federraum der Druckwaage (40, 42) wahlweise mit dem Lastdruck im zugehörigen Kreis (2, 4), mit dem Tankdruck oder mit dem höheren der Pu pen- drücke beaufschlagbar ist.6. Two-circuit system according to claim 2 and 6, wherein the locking device each has a pressure compensator (40, 42) assigned control valve (54), via which a spring chamber of the pressure compensator (40, 42) optionally with the load pressure in the associated circuit (2, 4 ), with which the tank pressure or the higher of the pump pressures can be applied. 7. Zweikreissystem nach Patentanspruch (6), wobei das Steuerventil (54) ein elektrisch betätigtes 4/3 -Wegeventil ist. Zweikreissystem nach einem der vorhergehenden Patentansprüche, wobei die Verbraucher Fahrwerksan- triebe für zwei Ketten eines Raupengeräts sowie weitere Agregate der Ausrüstung des Raupengeräts wie beispielsweise Löffel, Stiel, Ausleger sowie ein Drehwerk sind. 7. Two-circuit system according to claim (6), wherein the control valve (54) is an electrically operated 4/3 way valve. Two-circuit system according to one of the preceding claims, wherein the consumers are undercarriage drives for two chains of a caterpillar device and further units for the equipment of the caterpillar device, such as, for example, a spoon, stick, boom and a slewing gear.
PCT/DE2003/003126 2002-11-07 2003-09-19 Double-circuit hydraulic system Ceased WO2004042235A1 (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
DE50308813T DE50308813D1 (en) 2002-11-07 2003-09-19 HYDRAULIC TWO-WHEEL BRAKING SYSTEM
EP03753319A EP1558849B1 (en) 2002-11-07 2003-09-19 Double-circuit hydraulic system
AU2003271543A AU2003271543A1 (en) 2002-11-07 2003-09-19 Double-circuit hydraulic system
JP2004549050A JP2006505750A (en) 2002-11-07 2003-09-19 Hydraulic dual circuit system

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
DE10252241 2002-11-07
DE10252241.3 2002-11-07
DE10255738A DE10255738A1 (en) 2002-11-07 2002-11-28 Double-circuit hydraulic system for controlling consumers of mobile equipment such as track equipment comprises two circuits interconnected by an interconnecting valve arrangement having two valve devices
DE10255738.1 2002-11-28

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WO2004042235A1 true WO2004042235A1 (en) 2004-05-21

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JP (1) JP2006505750A (en)
KR (1) KR101011992B1 (en)
AT (1) ATE380942T1 (en)
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ITTO20100190A1 (en) * 2010-03-12 2011-09-13 Cnh Italia Spa HYDRAULIC SYSTEM

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US9790964B2 (en) 2014-09-25 2017-10-17 Cnh Industrial America Llc Hydraulic system
US9708796B2 (en) 2014-09-25 2017-07-18 Cnh Industrial America Llc Hydraulic valve
AT516181B1 (en) 2014-10-08 2016-03-15 Weber Hydraulik Gmbh hydraulic power unit
FR3064469B1 (en) 2017-03-30 2020-10-09 Capsum COLORED PARTICLES WITH HIGH PIGMENT CONTENT
JP6836487B2 (en) * 2017-09-21 2021-03-03 Ｋｙｂ株式会社 Control valve

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ITTO20100190A1 (en) * 2010-03-12 2011-09-13 Cnh Italia Spa HYDRAULIC SYSTEM
EP2365226A1 (en) * 2010-03-12 2011-09-14 CNH Italia S.p.A. Hydraulic system

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EP1558849B1 (en) 2007-12-12
AU2003271543A1 (en) 2004-06-07
KR101011992B1 (en) 2011-01-31
KR20050059333A (en) 2005-06-17
EP1558849A1 (en) 2005-08-03
JP2006505750A (en) 2006-02-16
DE50308813D1 (en) 2008-01-24
ATE380942T1 (en) 2007-12-15

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