EP1067296B1 - Electrohydraulic lifting module - Google Patents

Electrohydraulic lifting module Download PDF

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Publication number
EP1067296B1
EP1067296B1 EP00112802A EP00112802A EP1067296B1 EP 1067296 B1 EP1067296 B1 EP 1067296B1 EP 00112802 A EP00112802 A EP 00112802A EP 00112802 A EP00112802 A EP 00112802A EP 1067296 B1 EP1067296 B1 EP 1067296B1
Authority
EP
European Patent Office
Prior art keywords
pressure
consumer
function
control
line
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
EP00112802A
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German (de)
French (fr)
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EP1067296A1 (en
Inventor
Martin Heusser
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.)
Hawe Hydraulik GmbH and Co KG
Original Assignee
Hawe Hydraulik GmbH and Co KG
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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
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B66—HOISTING; LIFTING; HAULING
    • B66F—HOISTING, LIFTING, HAULING OR PUSHING, NOT OTHERWISE PROVIDED FOR, e.g. DEVICES WHICH APPLY A LIFTING OR PUSHING FORCE DIRECTLY TO THE SURFACE OF A LOAD
    • B66F9/00—Devices for lifting or lowering bulky or heavy goods for loading or unloading purposes
    • B66F9/06—Devices for lifting or lowering bulky or heavy goods for loading or unloading purposes movable, with their loads, on wheels or the like, e.g. fork-lift trucks
    • B66F9/075—Constructional features or details
    • B66F9/20—Means for actuating or controlling masts, platforms, or forks
    • B66F9/22—Hydraulic devices or 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
    • F15B21/00—Common features of fluid actuator systems; Fluid-pressure actuator systems or details thereof, not covered by any other group of this subclass
    • F15B21/14—Energy-recuperation 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
    • F15B2211/20—Fluid pressure source, e.g. accumulator or variable axial piston pump
    • F15B2211/205—Systems with pumps
    • F15B2211/20507—Type of prime mover
    • F15B2211/20515—Electric motor
    • 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
    • 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
    • F15B2211/30535—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
    • F15B2211/40—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
    • F15B2211/405—Flow control characterised by the type of flow control means or valve
    • F15B2211/40515—Flow control characterised by the type of flow control means or valve with variable 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
    • F15B2211/405—Flow control characterised by the type of flow control means or valve
    • F15B2211/40576—Assemblies of multiple valves
    • F15B2211/40584—Assemblies of multiple valves the flow control means arranged in parallel with a check 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
    • F15B2211/415—Flow control characterised by the connections of the flow control means in the circuit
    • F15B2211/4159—Flow control characterised by the connections of the flow control means in the circuit being connected to a pressure source, an output member and a return line
    • 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
    • F15B2211/426—Flow 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
    • F15B2211/40—Flow control
    • F15B2211/45—Control of bleed-off flow, e.g. control of bypass flow to the return line
    • 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
    • F15B2211/46—Control of flow in the return line, i.e. meter-out 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
    • F15B2211/50—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
    • F15B2211/50563—Pressure control characterised by the type of pressure control means the pressure control means controlling a differential 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
    • F15B2211/515—Pressure control characterised by the connections of the pressure control means in the circuit
    • F15B2211/5151—Pressure control characterised by the connections of the pressure 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
    • F15B2211/50—Pressure control
    • F15B2211/515—Pressure control characterised by the connections of the pressure control means in the circuit
    • F15B2211/5153—Pressure control characterised by the connections of the pressure control means in the circuit being connected to an output member and a directional control valve
    • F15B2211/5154—Pressure control characterised by the connections of the pressure control means in the circuit being connected to an output member and a directional control valve being connected to multiple ports of 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
    • F15B2211/515—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
    • F15B2211/60—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
    • F15B2211/605—Load sensing circuits
    • F15B2211/6051—Load sensing circuits having valve means between output member and the load sensing circuit
    • F15B2211/6055—Load sensing circuits having valve means between output member and the load sensing circuit 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
    • F15B2211/70—Output members, e.g. hydraulic motors or cylinders or control therefor
    • F15B2211/71—Multiple output members, e.g. multiple hydraulic motors or cylinders
    • F15B2211/7142—Multiple output members, e.g. multiple hydraulic motors or cylinders the output members being arranged in multiple groups

Definitions

  • the invention relates to an electro-hydraulic lifting module of the type specified in the preamble of claim 1.
  • an important aspect is to use electrical energy sparingly or to use a load-related pressure potential of the hydraulic pressure medium to recover electrical energy.
  • Modern industrial trucks contain a speed-adjustable supply pump that is driven by an electric motor.
  • a load-related pressure potential of the pressure medium is used for energy recovery by the supply pump driving the electric motor as a generator.
  • the electrical energy obtained is returned to the battery.
  • industrial trucks such as reach trucks, for energy recovery e.g. the consumer of the main lifting function in question.
  • a reach truck for example, the so-called initial lifting cylinder, which should also be operable during the energy-saving mode of the supply pump.
  • an electrohydraulic lifting module known from EP 0 669 281 A for an industrial truck with a lifting mast
  • a single pump is provided which can lower a main consumer in a lowering line monitored by a pressure compensator and drive a generator.
  • a common control valve device is also provided for all consumers to operate a secondary function, which works with the pressure compensator as a two-way flow controller.
  • a pilot pressure-controlled bypass valve is provided between a return connection to the pump and the tank connected to the tank, switches to a position in which the lowering branch is connected directly to the tank.
  • the lowering branch is permanently connected to the suction side of the single pump for a regeneration operating mode of the pump upstream of the bypass valve.
  • the invention has for its object to provide an electro-hydraulic lifting module of the type mentioned with an efficient energy saving mode of the supply pump.
  • the entire pressure difference between the pressure level of the consumer of the main lifting function and the tank pressure level is used for energy recovery.
  • Only a single supply pump enables a relatively simple hydraulic control circuit with a special connection anyway for the functions of the necessary components and thus a structurally simple electrohydraulic lifting module, which is particularly useful for reach trucks.
  • the electric motor of the single supply pump is used in the energy-saving mode on the control side in such a way that it either supplies electricity as a generator or additionally consumes electricity.
  • the consumer pressure supply lines are connected to the outputs of a three-way proportional flow control device, and the control valve component for lifting the consumer of the main lifting function is arranged downstream of the three-way proportional flow control device and in the direct connection to the tank. As such, the control valve component controls the lifting process of the consumer of the main lifting function when the supply pump is driven.
  • the three-way proportional flow control device allocates the required amount to the consumer of the secondary function.
  • the first and second control pressures for the pressure balance of the flow control device are tapped from the pressure supply line for the consumer of the secondary function, so that here the pressure conditions in the direct connection to the tank, in which direct connection the control valve component for lifting the consumer of the main lifting function have no influence. This enables smooth transitions between the energy-saving mode and the supply mode to be controlled.
  • the proportional measuring orifice in the pressure supply line of this consumer sets exactly the required pressure difference as required, which is maintained by the pressure compensator for supplying the consumer of the secondary function.
  • the at least one consumer of the secondary function is controlled via a proportional control valve, a representative load pressure being tapped off as the first control pressure for the pressure compensator downstream of the proportional directional control valve. This saves a separate proportional measuring orifice. It is obvious that several consumers for secondary functions can each be controlled with a proportional control valve and the highest load pressure is then supplied to the pressure compensator as the first control pressure, expediently via shuttle valve devices.
  • the control valve component can be a simple 2/2 directional or directional control valve or, if appropriate, a 2/2 proportional control valve.
  • the speed control of the supply pump can be used for a clean ramp control of the consumer of the main lifting function.
  • a clean ramp function can be performed using the proportional directional control valve can be controlled without the supply pump having to make any significant contribution.
  • the crossing point at which the pressure supply line to the consumer of the main lifting function is connected can also be arranged in the control valve component (position: lifting) arranged in the direct connection to the tank.
  • the control valve component should then expediently be a structurally simple 3/2-way control valve in black / white construction (two switching positions: open to the tank or open to the consumer) or a 3/2-proportional control valve that controls a ramp function.
  • control valve component in the secondary line should be a 2/2-way proportional control valve.
  • a simple 2/2 black / white control valve can also suffice here, because if necessary the flow control device and / or the control valve component cooperate in the direct connection when lowering.
  • the system pressure is - as usual - secured by a pressure relief valve on the pressure side of the supply pump.
  • pressure protection is also expedient for the possibly lower pressure level of the consumer of the secondary function provided, namely by a second, provided between the pressure supply line to the consumer of the secondary function and the tank, then set lower pressure relief valve, or a pressure relief valve positioned in the control line for the first control pressure of the pressure compensator.
  • the second pressure relief valve is bypassed by a relief line containing a throttle for the first control pressure.
  • the throttle in the relief line is dimensioned so that even the first low pilot pressure is properly reported to the pressure compensator.
  • the consumer VH is, for example, the lifting cylinder, while the consumer VN e.g. is the so-called initial stroke cylinder.
  • a single supply pump P is provided which is driven by a speed-controllable electric motor M for lifting control. In addition to the supply mode for energy recovery (electrical energy) or energy saving, this supply pump P can also be operated in an energy-saving mode.
  • the supply pump P with pressure medium displaced from the consumer VH drives the electric motor M as a generator and generates energy, or the electric motor M only just absorbs the energy that is not present in the displaced pressure medium of the consumer VH for actuating the consumer VN. If the energy in the displaced pressure medium is sufficient for the secondary function, then electrical energy is recovered or, despite the secondary function, no electrical energy needs to be supplied.
  • a line 1 leads from the pressure side of the supply pump P to the input of a three-way proportional current control device SR, which can be adjusted by a proportional magnet m1p.
  • a direct connection 2 to the tank T is connected to a first oil side of the flow control device SR, while a pressure supply line 15 to the at least one consumer VN or its directional or directional control valve W is connected to the other oil side.
  • the system pressure is monitored by a pressure relief valve 3.
  • a pressure supply line 5 to the consumer VH is connected, in which a check valve 6 is arranged, which blocks in the backflow direction.
  • a control valve component 10 for lifting control of the consumer VH is arranged in the direct connection 2, which in the embodiment of FIG. 1 is designed as a 2/2 proportional directional control valve 30 and with a proportional magnet m3p for adjustment Is provided.
  • a return line 11 leads from the consumer VN to the tank T.
  • a second pressure relief valve 3a is provided in a control line 12.
  • the second pressure relief valve 3a is bypassed by a control line loop 13 in which a throttle point 14 is provided.
  • the second pressure relief valve 3a and the control line 12 are provided here as an expedient option.
  • the consumer VH for the main lifting function is monitored by a so-called lowering brake B, which is also responsible for limiting the maximum outflow quantity when lowering.
  • a lowering brake B which is also responsible for limiting the maximum outflow quantity when lowering.
  • a further control valve component 9 for lowering control is contained, namely a 2/2-way proportional control valve with a proportional magnet m2p.
  • the secondary line 8 leads between a check valve R blocking in the direction of the tank T and the supply pump P to the suction side of the supply pump 3.
  • Each directional control valve W (a simple directional or directional control valve in FIG. 1) of a consumer VN for the secondary function is connected to the pressure supply line 15 with a pressure line 16, and to the return line 11 with a return line 17th
  • the control valve component 10 is adjusted for lifting from the open position in the direction of the shut-off position when the supply pump P is driven (by means of of the proportional magnet m3p), so that 5 pressure builds up in the pressure supply line.
  • the flow control device SR directs the pressure and the quantity only to the crossing point 4.
  • the control valve component 9 remains in the shut-off position shown.
  • the lowering brake B is bypassed by the check valve that opens; the consumer VH extends in the lifting direction.
  • the control takes place depending on the energization of the proportional magnet m3p; if necessary, the speed of the electric motor M used to control a clean ramp function and set the desired speed. If an auxiliary function is controlled at the same time, then the pressure medium required for this is provided in the pressure supply line 15 by energizing the proportional magnet m1p, the speed of the electric motor M then also being increased if necessary.
  • control valve component 10 is again adjusted in the direction of the open position and, if no secondary function has to be controlled, the electric motor M is also switched off. If a secondary function is also to be controlled, this can be done by regulating the speed of the supply pump P and energizing the proportional solenoid m1p. Optionally, the control valve component 10 is also held in the shut-off position.
  • the flow control device SR only opens at the crossing point 4, the control valve component 10 is held in the open position, and becomes Control valve component 9 adjusted from the shut-off position shown in the direction of the through position, by means of the proportional magnet m2p. Since the check valve R then closes, the pressure medium displaced by the secondary line 8 is pressed by the supply pump P, which drives the electric motor M as a hydraulic motor as a generator for energy recovery. The pressure medium passing the supply pump P flows through the line 1, the flow control device SR and the direct connection 2 via the control valve component 10 to the tank T.
  • the proportional magnet m1p is energized accordingly in order to lead the required quantity into the pressure supply line 15, from which the consumer VN is then actuated via its directional or directional control valve W.
  • Pressure medium displaced from a consumer VN flows via the return line 17 and the return line 11 directly to the tank.
  • FIG. 2 differs from that of FIG. 1 in that the control valve component 10 for the lifting control is a simple 2/2-way control valve 31 with a simple switching magnet m3.
  • the speed control of the electric motor M is used.
  • the rest of the structure is the same. 1, the three-way proportional flow control device SR is shown in detail, namely with a pressure compensator D and a measuring orifice MB arranged downstream of the pressure compensator D in the pressure supply line 15 and adjustable by the proportional magnet m1p.
  • the pressure compensator D holding the pressure difference set on the measuring orifice MB is set by first and second control pressures and a control spring 20 and holds the set pressure difference even in the event of pressure fluctuations in line 1 and / or 15.
  • the first control pressure acts together with the control spring 20 in the opening direction the pressure compensator D from the line 1 to the pressure supply line 15.
  • the first control pressure comes from a control line 12a, which branches off from the control line 12 branching off from the pressure supply line 15 at the intersection 18 with the second pressure relief valve 3a.
  • the crossing point 18 is located downstream of the measuring orifice MB.
  • the second control pressure is tapped at a crossing point 21 upstream of the measuring orifice MB in the pressure supply line 15, transmitted via a control line 22 to the other side of the pressure compensator D and acts on it in the opening direction from the pressure line 1 to the direct connection 2 to the tank T. Since the first and second control pressures are tapped only in the circuit of the secondary function, the pressure conditions in lines 1, 2 or in the pressure supply line 5 to the consumer VH have no influence on the control intervention of the current control device SR.
  • the line loop 13 with the throttle point 14, which should be narrower than a throttle point 19 in the control line 12a, serves to relieve the control line 12a if the measuring orifice MB is adjusted into its shut-off position and no secondary function can be controlled.
  • FIG. 3 differs from the two aforementioned embodiments in that the control valve component 10 for lifting control contains the crossing point 4 'between the direct connection 2 and the pressure supply line 5 and for this purpose as a 3/2-way control valve 32 without a proportional function and is formed with a switching magnet m3.
  • the symbolism shows that it is a 3/2-way seat valve that replaces the check valve 6 with the seat valve function 6 '.
  • the directional and directional control valves W of the consumer VN for the secondary functions are simple directional control valves without a proportional function, each consumer VN being connected to the directional or directional control valve W via working lines 23, 24.
  • FIG. 4 corresponds functionally to the embodiment of FIG. 2 with the control valve component 10 designed as a simple 2/2-way control valve 31, which is adjustable by means of a switching magnet m3.
  • the measuring orifice required for the pressure compensator D is not contained in the pressure supply line 15, but the proportionally adjustable measuring orifice is formed by a directional or directional control valve WP for the consumer VN of the secondary function, which is a proportional control valve with the proportional solenoids m1p (and, if necessary, an inflow regulator, not shown).
  • the first control pressure for the pressure compensator D results in the working line 23, 24 that is acted upon, which is transmitted via the control line 12a and is tapped, for example, at a shuttle valve 25 between the working lines 23, 24.
  • the first control pressure is transferred from the shuttle valve 25 directly to the control line 12a via a control line 26.
  • their control lines 26, 28 are linked via at least one additional shuttle valve 27, which transmits the highest first control pressure into the control line 12a.
  • the second control pressure is tapped from the pressure supply line 15 via the control line 22.
  • control valve component 10 for the lifting control is a 3/2-way control valve of simple design with a switching magnet m3.
  • this is not a poppet valve, but a slide valve, which also contains the crossing point 4 'to the pressure supply line 5.
  • control valve component 9 (lowering) in the secondary line 8 could be a simple 2/2-way black / white directional control valve with a simple switching magnet (without proportional function).
  • control valve component 10 for lifting control is a 3/2-way proportional control valve 34 with at least one proportional magnet m3p in slide valve design and with a control function (indicated by the parallel lines).

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Description

Die Erfindung betrifft einen elektrohydraulischen Hubmodul der im Oberbegriff des Anspruchs 1 angegebenen Art.The invention relates to an electro-hydraulic lifting module of the type specified in the preamble of claim 1.

Bei selbstfahrenden Flurförderfahrzeugen ist ein wichtiger Aspekt, mit der elektrischen Energie sparsam umzugehen bzw. ein lastbedingtes Druckpotential des hydraulischen Druckmittels zur Rückgewinnung elektrischer Energie zu nutzen. Moderne Flurförderfahrzeuge enthalten eine drehzahlregelbare Versorgungspumpe, die von einem Elektromotor angetrieben wird. Ein lastbedingtes Druckpotential des Druckmittels wird zur Energie-Rückgewinnung genutzt, indem die Versorgungspumpe den Elektromotor als Generator antreibt. Die gewonnene elektrische Energie wird in die Batterie zurückgeführt. Bei Flurförderfahrzeugen wie Schubmaststaplem kommt für die Energie-Rückgewinnung z.B. der Verbraucher der Haupthebefunktion in Frage. Allerdings enthält ein solches Flurförderfahrzeug häufig auch wenigstens einen Verbraucher für eine Nebenfunktion, ein Schubmaststapler beispielsweise den sogenannten Initialhubzylinder, der auch während des Energiespar-Modus der Versorgungspumpe betätigbar sein soll. Bei einem durch Vorbenutzung in der Praxis bekannten Hubmodul dieser Art ist eine zweite Versorgungspumpe für die Betätigung des Verbrauchers der Nebenfunktion vorgesehen. Diese zusätzliche Versorgungspumpe ist teuer. Um die Nebenfunktion steuern zu können, ist zudem der hydraulische Steuerkreis aufwendig. Dies ist ein Nachteil, der durch den Energie-Rückgewinn oder die Einsparung nicht aufgewogen wird.In the case of self-propelled industrial trucks, an important aspect is to use electrical energy sparingly or to use a load-related pressure potential of the hydraulic pressure medium to recover electrical energy. Modern industrial trucks contain a speed-adjustable supply pump that is driven by an electric motor. A load-related pressure potential of the pressure medium is used for energy recovery by the supply pump driving the electric motor as a generator. The electrical energy obtained is returned to the battery. In industrial trucks such as reach trucks, for energy recovery e.g. the consumer of the main lifting function in question. However, such an industrial truck often also contains at least one consumer for an auxiliary function, a reach truck, for example, the so-called initial lifting cylinder, which should also be operable during the energy-saving mode of the supply pump. In a lifting module of this type which is known in practice through prior use, a second supply pump is provided for actuating the consumer of the secondary function. This additional supply pump is expensive. In order to be able to control the secondary function, the hydraulic control circuit is also complex. This is a disadvantage that is not offset by energy recovery or savings.

Es ist zwar aus der Praxis eine weitere Lösung mit nur einer einzigen Versorgungspumpe bekannt, bei der jedoch im Energiespar-Modus der Pumpe keine gesteuerte Versorgung einer Nebenfunktion möglich ist. Diese Lösung ist zwar baulich wenig aufwendig und preisgünstiger als die Lösung mit zwei Pumpen, jedoch nachteilig, weil der Initialhubzylinder des Schubmaststaplers nicht ausfahrbar ist, wenn der Haupthebezylinder einfährt und die Pumpe Energie abgibt.A further solution with only a single supply pump is known from practice, but in which no controlled supply of an auxiliary function is possible in the pump's energy-saving mode. This solution is structurally little complex and inexpensive than the solution with two pumps, but disadvantageous because the initial lift cylinder of the reach truck cannot be extended when the main lifting cylinder retracts and the pump releases energy.

Bei einem aus EP 0 669 281 A bekannten elektrohydraulischen Hubmodul für ein Flurförderfahrzeug mit einem Hubmast ist eine einzige Pumpe vorgesehen, die im Senkbetrieb des Hauptverbrauchers in einem von einer Druckwaage überwachten Senkstrang einen Generator treiben kann. Zur Betätigung auch einer Nebenfunktion ist eine gemeinsamen Steuerventilvorrichtung für alle Verbraucher vorgesehen, die mit der Druckwaage als Zweiwege-Stromregler arbeitet.In an electrohydraulic lifting module known from EP 0 669 281 A for an industrial truck with a lifting mast, a single pump is provided which can lower a main consumer in a lowering line monitored by a pressure compensator and drive a generator. A common control valve device is also provided for all consumers to operate a secondary function, which works with the pressure compensator as a two-way flow controller.

In einem aus JP 0 22 15 700 A (JP 01034627) bekannten, elektrohydraulischen Hubmodul ist zwischen einem Rückführanschluss zur Pumpe und dem Tank ein pilotdruckgesteuertes Beipassventil vorgesehen, das abhängig vom steigenden Senkdruck gegen Federdruck aus einer Schaltstellung, in der ein Senkzweig über eine Senkbremse mit dem Tank verbunden ist, in eine Stellung schaltet, in der der Senkzweig direkt mit dem Tank verbunden ist. Der Senkzweig ist für einen Regenerationsbetriebsmodus der Pumpe stromauf des Beipassventils permanent an die Saugseite der einzigen Pumpe angeschlossen.In an electrohydraulic lifting module known from JP 0 22 15 700 A (JP 01034627), a pilot pressure-controlled bypass valve is provided between a return connection to the pump and the tank connected to the tank, switches to a position in which the lowering branch is connected directly to the tank. The lowering branch is permanently connected to the suction side of the single pump for a regeneration operating mode of the pump upstream of the bypass valve.

In einem Hubmodul gemäß GB 13 65 511 A werden bei Senkbetrieb des Hauptverbrauchers mit Energierückgewinnung keine Nebenverbraucher mit dem verdrängten Druckmittel versorgt.In a lifting module in accordance with GB 13 65 511 A, no secondary consumers are supplied with the displaced pressure medium when the main consumer is operating with energy recovery.

Weiterer Stand der Technik ist enthalten in EP 0 908 413 A und DE 92 18 483 U.Further prior art is contained in EP 0 908 413 A and DE 92 18 483 U.

Der Erfindung liegt die Aufgabe zugrunde, einen elektrohydraulischen Hubmodul der eingangs genannten Art mit einem effizienten Energiespar-Modus der Versorgungspumpe zu schaffen.The invention has for its object to provide an electro-hydraulic lifting module of the type mentioned with an efficient energy saving mode of the supply pump.

Die gestellte Aufgabe wird erfindungsgemäß mit den Merkmalen des Anspruchs 1 gelöst.The object is achieved according to the invention with the features of claim 1.

Im Energiespar-Modus ist bei unter Last einfahrendem Hauptverbraucher eine gesteuerte Betätigung des Verbrauchers der Nebenfunktion möglich, in dem aus dem Verbraucher für die Haupthebefunktion verdrängtes Druckmittel nochmals zum Arbeiten im Verbraucher der Nebenfunktion herangezogen wird. Dies erfolgt in einem Ausmaß, das bedarfsabhängig eine Energierückgewinnung, oder bei reduzierter Stromaufnahme des Elektromotors einen Spareffekt bedeutet. Denn es wird zumindest anteilig verdrängtes Druckmittel des Verbrauchers der Hauptfunktion eingesetzt, um den Druck bzw. die Menge für den Verbraucher der Nebenfunktion zu erzielen und auch um Energie zurückzugewinnen. Vom Hauptverbraucher beim Senken verdrängtes Druckmittel wird über den Nebenstrang in jedem Fall zuerst durch die Versorgungspumpe gedrückt, die bei ausreichendem Druckpotential Energie erzeugt. Reicht das Potential des verdrängten Druckmittels für die Nebenfunktion nicht aus, greift die Versorgungspumpe ergänzend ein. Ist kein Verbraucher einer Nebenfunktion zu betätigen, dann wird der gesamte Druckunterschied zwischen dem Druckniveau des Verbrauchers der Haupthebefunktion und dem Tankdruckniveau zur Energierückgewinnung eingesetzt. Nur eine einzige Versorgungspumpe ermöglicht einen relativ einfachen hydraulischen Steuerkreis mit einer speziellen Verschaltung ohnedies für die Funktionen erforderlicher Komponenten und somit einen baulich einfachen elektrohydraulischen Hubmodul, der insbesondere für Schubmaststapler zweckmäßig ist. Der Elektromotor der einzigen Versorgungspumpe wird in deren Energiespar-Modus steuerungsseitig so eingesetzt, dass er entweder als Generator Strom liefert oder ergänzend Strom aufnimmt. Dabei sind die Druckversorgungsleitungen der Verbraucher an die Ausgänge einer Dreiwege-Proportional-Stromregeleinrichtung angeschlossen, und wird die Steuerventilkomponente zum Heben des Verbrauchers der Haupthebefunktion stromab der Dreiwege-Proportional-Stromregeleinrichtung und in der Direktverbindung zum Tank angeordnet. An sich wird mit der Steuerventil-Komponente der Hebevorgang des Verbrauchers der Haupthebefunktion gesteuert, wenn die Versorgungspumpe angetrieben wird, Im Energiespar-Modus der Versorgungspumpe teilt die Dreiwege-Proportional-Stromregeleinrichtung dem Verbraucher der Nebenfunktion die benötigte Menge zu.In the energy-saving mode, when the main consumer retracts under load, controlled actuation of the consumer of the secondary function is possible, in which pressure medium displaced from the consumer for the main lifting function is used again to work in the consumer of the secondary function. This takes place to an extent which, depending on need, means energy recovery, or a saving effect when the electric motor consumes less power. This is because at least partially displaced pressure medium from the consumer of the main function is used to achieve the pressure or the quantity for the consumer of the secondary function and also to recover energy. Pressure medium displaced by the main consumer when lowering is in any case first pushed through the secondary line by the supply pump, which generates energy when there is sufficient pressure potential. If the potential of the displaced pressure medium is not sufficient for the secondary function, the supply pump intervenes. If no consumer of a secondary function is to be operated, then the entire pressure difference between the pressure level of the consumer of the main lifting function and the tank pressure level is used for energy recovery. Only a single supply pump enables a relatively simple hydraulic control circuit with a special connection anyway for the functions of the necessary components and thus a structurally simple electrohydraulic lifting module, which is particularly useful for reach trucks. The electric motor of the single supply pump is used in the energy-saving mode on the control side in such a way that it either supplies electricity as a generator or additionally consumes electricity. The consumer pressure supply lines are connected to the outputs of a three-way proportional flow control device, and the control valve component for lifting the consumer of the main lifting function is arranged downstream of the three-way proportional flow control device and in the direct connection to the tank. As such, the control valve component controls the lifting process of the consumer of the main lifting function when the supply pump is driven. In the energy-saving mode of the supply pump, the three-way proportional flow control device allocates the required amount to the consumer of the secondary function.

Damit der Regeleingriff der Dreiwege-Proportional-Stromregeleinrichtung im Energiespar-Modus der Versorgungspumpe exakt nach dem Bedarf des Verbrauchers für die Nebenfunktion erfolgt, werden die ersten und zweiten Steuerdrücke für die Druckwaage der Stromregeleinrichtung aus der Druckversorgungsleitung für den Verbraucher der Nebenfunktion abgegriffen, so dass hier die Druckverhältnisse in der Direktverbindung zum Tank, in welcher Direktverbindung sich die Steuerventil-Komponente zum Heben des Verbrauchers der Haupthebefunktion befindet, keinen Einfluss haben. Dadurch lassen sich ruckfreie Übergänge zwischen dem Energiesparmodus und dem Versorgungsmodus steuern.So that the control intervention of the three-way proportional current control device in the energy-saving mode of the supply pump exactly according to the needs of the consumer the secondary function takes place, the first and second control pressures for the pressure balance of the flow control device are tapped from the pressure supply line for the consumer of the secondary function, so that here the pressure conditions in the direct connection to the tank, in which direct connection the control valve component for lifting the consumer of the main lifting function have no influence. This enables smooth transitions between the energy-saving mode and the supply mode to be controlled.

Für diese vorerwähnte Funktion kommen zwei Verschaltungsprinzipien in Frage. Bei einem einfachen Richtungs- oder Wegesteuerventil für den Verbraucher der Nebenfunktion stellt in der Druckversorgungsleitung dieses Verbrauchers die Proportional-Messblende bedarfsabhängig exakt die jeweils erforderliche Druckdifferenz ein, die von der Druckwaage für die Versorgung des Verbrauchers der Nebenfunktion gehalten wird. Im zweiten Fall wird der wenigstens eine Verbraucher der Nebenfunktion über ein Proportional-Steuerventil gesteuert, wobei stromab des Proportional-Wegesteuerventils ein repräsentativer Lastdruck als der erste Steuerdruck für die Druckwaage abgegriffen wird. Dies spart eine eigene Proportional-Messblende ein. Es liegt auf der Hand, dass auch mehrere Verbraucher für Nebenfunktionen jeweils mit einem Proportionalsteuerventil gesteuert werden können und dann der jeweils höchste Lastdruck als der erste Steuerdruck der Druckwaage zugeführt wird, zweckmäßigerweise über Wechselventileinrichtungen.Two interconnection principles can be used for this function. In the case of a simple directional or directional control valve for the consumer of the secondary function, the proportional measuring orifice in the pressure supply line of this consumer sets exactly the required pressure difference as required, which is maintained by the pressure compensator for supplying the consumer of the secondary function. In the second case, the at least one consumer of the secondary function is controlled via a proportional control valve, a representative load pressure being tapped off as the first control pressure for the pressure compensator downstream of the proportional directional control valve. This saves a separate proportional measuring orifice. It is obvious that several consumers for secondary functions can each be controlled with a proportional control valve and the highest load pressure is then supplied to the pressure compensator as the first control pressure, expediently via shuttle valve devices.

Günstig ist es, die Druckversorgungsleitung zum Verbraucher der Haupthebefunktion von einem Kreuzungspunkt ausgehen zu lassen, der sich stromauf der Steuerventil-Komponente in der Direktverbindung zum Tank befindet. Das von der Dreiwege-Proportional-Stromregeleinrichtung zugeteilte Druckmittel nimmt dann den Weg zu diesem Verbraucher, wobei gegebenenfalls gleichzeitig auch der Verbraucher für die Nebenfunktion steuerbar bleibt. Die Steuerventil-Komponente kann ein einfaches 2/2-Richtungs- oder Wegesteuerventil oder, falls zweckmäßig, ein 2/2-Proportional-Steuerventil sein. Im erstgenannten Fall kann für eine saubere Rampensteuerung des Verbrauchers der Haupthebefunktion die Drehzahlregelung der Versorgungspumpe eingesetzt werden. Im zweiten Fall kann eine saubere Rampenfunktion über das Proportional-Wegesteuerventil gesteuert werden, ohne dass die Versorgungspumpe nennenswert beitragen müsste.It is expedient to let the pressure supply line to the consumer of the main lifting function start from a crossing point which is located upstream of the control valve component in the direct connection to the tank. The pressure medium allocated by the three-way proportional flow control device then takes the way to this consumer, the consumer optionally also remaining controllable for the secondary function. The control valve component can be a simple 2/2 directional or directional control valve or, if appropriate, a 2/2 proportional control valve. In the former case, the speed control of the supply pump can be used for a clean ramp control of the consumer of the main lifting function. In the second case, a clean ramp function can be performed using the proportional directional control valve can be controlled without the supply pump having to make any significant contribution.

Alternativ kann der Kreuzungspunkt, an dem die Druckversorgungsleitung zum Verbraucher der Haupthebefunktion angeschlossen ist, auch in der in der Direktver bindung zum Tank angeordneten Steuerventilkomponente (Stellung: Heben) angeordnet sein. Die Steuerventil-Komponente sollte dann zweckmäßig als baulich einfaches 3/2-Wegesteuerventil in Schwarz/Weiß-Bauweise (zwei Schaltstellungen: zum Tank offen oder zum Verbraucher offen) oder ein eine Rampenfunktion steuerndes 3/2-Proportional-Wegesteuerventil sein.Alternatively, the crossing point at which the pressure supply line to the consumer of the main lifting function is connected can also be arranged in the control valve component (position: lifting) arranged in the direct connection to the tank. The control valve component should then expediently be a structurally simple 3/2-way control valve in black / white construction (two switching positions: open to the tank or open to the consumer) or a 3/2-proportional control valve that controls a ramp function.

Da an solche Flurförderfahrzeuge und speziell die Haupthebefunktion hohe Sicherheitsanforderungen gestellt werden, ist es zweckmäßig, den Verbraucher der Haupthebefunktion durch ein Senkbremsventil abzusichern.Since high safety requirements are placed on such industrial trucks and especially the main lifting function, it is expedient to secure the consumer of the main lifting function by means of a lowering brake valve.

Um auch beim Verstellen des Verbrauchers der Haupthebefunktion in Senkrichtung eine saubere Rampenfunktion steuern zu können, sollte die Steuerventilkomponente in dem Nebenstrang ein 2/2-Proportional-Wegesteuerventil sein. Allerdings kann hier auch ein einfaches 2/2-Schwarz/Weiß-Steuerventil genügen, weil gegebenenfalls die Stromregeleinrichtung und/oder die Steuerventilkomponente in der Direktverbindung beim Senken mitwirken.In order to be able to control a clean ramp function even when adjusting the consumer of the main lifting function in the lowering direction, the control valve component in the secondary line should be a 2/2-way proportional control valve. However, a simple 2/2 black / white control valve can also suffice here, because if necessary the flow control device and / or the control valve component cooperate in the direct connection when lowering.

Der Systemdruck wird - wie üblich - durch ein Druckbegrenzungsventil an der Druckseite der Versorgungspumpe abgesichert. Zweckmäßigerweise ist jedoch auch für das ggfs. niedrigere Druckniveau des Verbrauchers der Nebenfunktion eine Druckabsicherung vorgesehen, und zwar durch ein zweites entweder zwischen der Druckversorgungsleitung zum Verbraucher der Nebenfunktion und dem Tank vorgesehenes, dann niedriger eingestelltes, Druckbegrenzungsventil, oder ein in der Steuerleitung für den ersten Steuerdruck der Druckwaage positioniertes Druckbegrenzungsventil.The system pressure is - as usual - secured by a pressure relief valve on the pressure side of the supply pump. However, pressure protection is also expedient for the possibly lower pressure level of the consumer of the secondary function provided, namely by a second, provided between the pressure supply line to the consumer of the secondary function and the tank, then set lower pressure relief valve, or a pressure relief valve positioned in the control line for the first control pressure of the pressure compensator.

Um sicherzustellen, dass die Dreiwege-Proportional-Stromregeleinrichtung bei Nichtbetätigung des Verbrauchers der Nebenfunktion zuverlässig sperrt, wird das zweite Druckbegrenzungsventil durch eine eine Drossel enthaltende Entlastungsleitung für den ersten Steuerdruck umgangen. Die Drossel in der Entlastungsleitung ist so bemessen, dass auch niedriger erster Steuerdruck ordnungsgemäß der Druckwaage gemeldet wird.In order to ensure that the three-way proportional flow control device reliably blocks the secondary function when the consumer is not actuated, the second pressure relief valve is bypassed by a relief line containing a throttle for the first control pressure. The throttle in the relief line is dimensioned so that even the first low pilot pressure is properly reported to the pressure compensator.

Ausführungsformen des Erfindungsgegenstandes werden anhand der Zeichnung erläutert. Es zeigen:

Fig. 1
ein Blockdiagramm einer ersten Ausführungsform eines Hubmoduls in drucklosem Zustand,
Fig. 2
ein Blockdiagramm einer weiteren Ausführungsform, wobei in Fig. 2 die in Fig. 1 nur symbolisch dargestellte Dreiwege-Proponional-Stromregeleinrichtung im Detail angedeutet ist,
Fig. 3
ein Blockschaltbild einer weiteren Ausführungsform eines Hubmoduls,
Fig. 4
eins Blockdiagramm einer weiteren Ausführungsform eines Hubmoduls,
Fig. 5
einen Teil einer weiteren Ausführungsform, und
Fig. 6
einen Teil einer noch weiteren Ausführungsform eines solchen Hubmoduls.
Embodiments of the subject matter of the invention are explained with reference to the drawing. Show it:
Fig. 1
2 shows a block diagram of a first embodiment of a lifting module in the depressurized state,
Fig. 2
3 shows a block diagram of a further embodiment, the three-way proponional flow control device, which is only symbolically shown in FIG. 1, being indicated in detail in FIG. 2,
Fig. 3
2 shows a block diagram of a further embodiment of a lifting module,
Fig. 4
1 shows a block diagram of a further embodiment of a lifting module,
Fig. 5
part of a further embodiment, and
Fig. 6
a part of yet another embodiment of such a lifting module.

Ein elektrohydraulischer Hubmodul S in Fig. 1, beispielsweise für ein Flurförderfahrzeug wie einen nicht gezeigten Schubmaststapler, ermöglicht es, einen für eine Haupthebefunktion einer Last F verantwortlichen Verbraucher VH und wenigstens einen Verbraucher VN für eine Nebenfunktion gleichzeitig oder getrennt zu steuern. Der Verbraucher VH ist beispielsweise der Hubzylinder, während der Verbraucher VN z.B. der sogenannte Initialhubzylinder ist. Es ist eine einzige Versorgungspumpe P vorgesehen, die zur Hebesteuerung durch einen drehzahlregelbaren Elektromotor M angetrieben wird. Diese Versorgungspumpe P ist zusätzlich zum Versorgungsmodus zur Energierückgewinnung (elektrische Energie) oder Energie-Einsparung auch in einem Energiespar-Modus betreibbar. Dies bedeutet, dass die Versorgungspumpe P mit aus dem Verbraucher VH verdrängtem Druckmittel den Elektromotor M als Generator treibt und Energie erzeugt, oder der Elektromotor M nur gerade die Energie aufnimmt, die zum Betätigen des Verbrauchers VN im verdrängten Druckmittel des Verbrauchers VH nicht vorhanden ist. Reicht die Energie im verdrängten Druckmittel für die Nebenfunktion, dann wird elektrische Energie rückgewonnen oder braucht trotz der Nebenfunktion keine elektrische Energie zugeführt werden.An electrohydraulic lifting module S in FIG. 1, for example for an industrial truck such as a reach truck, not shown, makes it possible to control a consumer VH responsible for a main lifting function of a load F and at least one consumer VN for a secondary function simultaneously or separately. The consumer VH is, for example, the lifting cylinder, while the consumer VN e.g. is the so-called initial stroke cylinder. A single supply pump P is provided which is driven by a speed-controllable electric motor M for lifting control. In addition to the supply mode for energy recovery (electrical energy) or energy saving, this supply pump P can also be operated in an energy-saving mode. This means that the supply pump P with pressure medium displaced from the consumer VH drives the electric motor M as a generator and generates energy, or the electric motor M only just absorbs the energy that is not present in the displaced pressure medium of the consumer VH for actuating the consumer VN. If the energy in the displaced pressure medium is sufficient for the secondary function, then electrical energy is recovered or, despite the secondary function, no electrical energy needs to be supplied.

Im Hubmodul-Kernbereich HM (strichpunktiert hervorgehoben) führt eine Leitung 1 von der Druckseite der Versorgungspumpe P zum Eingang einer Dreiwege-Proportional-Stromregeleinrichtung SR, die durch einen Proportionalmagneten m1p verstellbar ist. An eine erste Abölseite der Stromregeleinrichtung SR ist eine Direktverbindung 2 zum Tank T angeschlossen, während an die andere Abölseite eine Druckversorgungsleitung 15 zu dem wenigstens einen Verbraucher VN bzw. dessen Richtungs- oder Wegesteuerventil W angeschlossen ist. Der Systemdruck wird durch ein Druckbegrenzungsventil 3 überwacht. An einem Kreuzungspunkt 4 in der Direktverbindung 2 ist eine Druckversorgungsleitung 5 zum Verbraucher VH angeschlossen, in der ein in Rückströmrichtung sperrendes Rückschlagventil 6 angeordnet ist. Zwischen dem Kreuzungspunkt 4 und dem Tank T ist in der Direktverbindung 2 eine Steuerventil-Komponente 10 zur Hebesteuerung des Verbrauchers VH angeordnet, die in der Ausführungsform der Fig. 1 als 2/2-Proportional-Wegesteuerventil 30 ausgebildet und mit einem Proportionalmagneten m3p zur Verstellung ausgestattet ist. Von dem Verbraucher VN führt eine Rücklaufleitung 11 zum Tank T. Zwischen der Druckversorgungsleitung 15 und der Rücklaufleitung 11 ist ein zweites Druckbegrenzungsventil 3a in einer Steuerleitung 12 vorgesehen. Das zweite Druckbegrenzungsventil 3a wird von einer Steuerleitungsschleife 13 umgangen, in der eine Drosselstelle 14 vorgesehen ist. Das zweite Druckbegrenzungsventil 3a und die Steuerleitung 12 sind hier als zweckmäßige Option vorgesehen.In the stroke module core area HM (dash-dotted lines), a line 1 leads from the pressure side of the supply pump P to the input of a three-way proportional current control device SR, which can be adjusted by a proportional magnet m1p. A direct connection 2 to the tank T is connected to a first oil side of the flow control device SR, while a pressure supply line 15 to the at least one consumer VN or its directional or directional control valve W is connected to the other oil side. The system pressure is monitored by a pressure relief valve 3. At a crossing point 4 in the direct connection 2, a pressure supply line 5 to the consumer VH is connected, in which a check valve 6 is arranged, which blocks in the backflow direction. Between the crossing point 4 and the tank T, a control valve component 10 for lifting control of the consumer VH is arranged in the direct connection 2, which in the embodiment of FIG. 1 is designed as a 2/2 proportional directional control valve 30 and with a proportional magnet m3p for adjustment Is provided. A return line 11 leads from the consumer VN to the tank T. Between the pressure supply line 15 and the return line 11, a second pressure relief valve 3a is provided in a control line 12. The second pressure relief valve 3a is bypassed by a control line loop 13 in which a throttle point 14 is provided. The second pressure relief valve 3a and the control line 12 are provided here as an expedient option.

Der Verbraucher VH für die Haupthebefunktion ist durch eine sogenannte Senkbremse B überwacht, die auch für eine Begrenzung der maximalen Abströmmenge beim Senken verantwortlich ist. An einem Kreuzungspunkt 7 der Druckversorgungsleitung 5 zweigt ein Nebenstrang 8 ab, in dem eine weitere Steuerventil-Komponente 9 für die Senksteuerung enthalten ist, und zwar ein 2/2-Proportional-Wegesteuerventil mit einem Proportionalmagneten m2p. Der Nebenstrang 8 führt zwischen einem in Richtung zum Tank T sperrenden Rückschlagventil R und der Versorgungspumpe P zur Saugseite der Versorgungspumpe 3.The consumer VH for the main lifting function is monitored by a so-called lowering brake B, which is also responsible for limiting the maximum outflow quantity when lowering. At a crossing point 7 of the pressure supply line 5 branches off a secondary line 8, in which a further control valve component 9 for lowering control is contained, namely a 2/2-way proportional control valve with a proportional magnet m2p. The secondary line 8 leads between a check valve R blocking in the direction of the tank T and the supply pump P to the suction side of the supply pump 3.

Jedes Wegesteuerventil W (in Fig. 1 ein einfaches Wege- oder Richtungssteuerventil) eines Verbrauchers VN für die Nebenfunktion ist an die Druckversorgungsleitung 15 mit einer Druckleitung 16 angeschlossen, und an die Rücklaufleitung 11 mit einer Rückleitung 17.Each directional control valve W (a simple directional or directional control valve in FIG. 1) of a consumer VN for the secondary function is connected to the pressure supply line 15 with a pressure line 16, and to the return line 11 with a return line 17th

Funktion:Function:

Ist in der in Fig. 1 gezeigten Grundstellung der Verbraucher VH gegen die Last F zu heben, ohne einen Verbraucher VN zu betätigen, dann wird bei angetriebener Versorgungspumpe P die Steuerventil-Komponente 10 für das Heben aus der Durchgangsstellung in Richtung zur Absperrstellung verstellt (mittels des Proportionalmagneten m3p), so dass sich in der Druckversorgungsleitung 5 Druck aufbaut. Die Stromregeleinrichtung SR leitet den Druck und die Menge nur zum Kreuzungspunkt 4. Die Steuerventil-Komponente 9 verharrt in der gezeigten Absperrstellung. Die Senkbremse B wird durch das sich öffnende Rückschlagventil umgangen; der Verbraucher VH fährt in Heberichtung aus. Die Steuerung erfolgt in Abhängigkeit von der Bestromung des Proportionalmagneten m3p; gegebenenfalls wird auch die Drehzahl des Elektromotors M benutzt, um eine saubere Rampenfunktion zu steuern und die gewünschte Geschwindigkeit einzustellen. Wird gleichzeitig eine Nebenfunktion gesteuert, dann wird das dafür erforderliche Druckmittel in der Druckversorgungsleitung 15 durch Bestromen des Proportionalmagneten m1p bereitgestellt, wobei dann gegebenenfalls auch die Drehzahl des Elektromotors M erhöht wird.If, in the basic position shown in FIG. 1, the consumer VH is to be lifted against the load F without actuating a consumer VN, then the control valve component 10 is adjusted for lifting from the open position in the direction of the shut-off position when the supply pump P is driven (by means of of the proportional magnet m3p), so that 5 pressure builds up in the pressure supply line. The flow control device SR directs the pressure and the quantity only to the crossing point 4. The control valve component 9 remains in the shut-off position shown. The lowering brake B is bypassed by the check valve that opens; the consumer VH extends in the lifting direction. The control takes place depending on the energization of the proportional magnet m3p; if necessary, the speed of the electric motor M used to control a clean ramp function and set the desired speed. If an auxiliary function is controlled at the same time, then the pressure medium required for this is provided in the pressure supply line 15 by energizing the proportional magnet m1p, the speed of the electric motor M then also being increased if necessary.

Ist die Last F anzuhalten, dann wird die Steuerventil-Komponente 10 wieder in Richtung auf die Offenstellung verstellt und, falls keine Nebenfunktion gesteuert werden muss, auch der Elektromotor M abgeschaltet. Ist weiterhin eine Nebenfunktion zu steuern, so kann dies durch die Drehzahlregelung der Versorgungspumpe P und die Bestromung des Proportionalmagneten m1p erfolgen. Gegebenenfalls wird dabei auch die Steuerventil-Komponente 10 in der Absperrstellung gehalten.If the load F is to be stopped, then the control valve component 10 is again adjusted in the direction of the open position and, if no secondary function has to be controlled, the electric motor M is also switched off. If a secondary function is also to be controlled, this can be done by regulating the speed of the supply pump P and energizing the proportional solenoid m1p. Optionally, the control valve component 10 is also held in the shut-off position.

Ist der Verbraucher VH unter der Last F zu senken, und zwar ohne gleichzeitig eine Nebenfunktion zu steuern, dann bleibt der Elektromotor M abgeschaltet, öffnet die Stromregeleinrichtung SR nur zum Kreuzungspunkt 4, wird die Steuerventil-Komponente 10 in der Durchgangsstellung gehalten, und wird die Steuerventil-Komponente 9 aus der gezeigten Absperrstellung in Richtung auf die Durchgangsstellung verstellt, und zwar mittels des Proportionalmagneten m2p. Da das Rückschlagventil R dann sperrt, wird das durch den Nebenstrang 8 verdrängte Druckmittel durch die Versorgungspumpe P gedrückt, die als Hydraulikmotor den Elektromotor M als Generator zur Energie-Rückgewinnung antreibt. Das die Versorgungspumpe P passierende Druckmittel strömt durch die Leitung 1, die Stromregeleinrichtung SR und die Direktverbindung 2 über die Steuerventil-Komponente 10 zum Tank T.If the consumer VH is to be reduced under the load F, and without simultaneously controlling an auxiliary function, then the electric motor M remains switched off, the flow control device SR only opens at the crossing point 4, the control valve component 10 is held in the open position, and becomes Control valve component 9 adjusted from the shut-off position shown in the direction of the through position, by means of the proportional magnet m2p. Since the check valve R then closes, the pressure medium displaced by the secondary line 8 is pressed by the supply pump P, which drives the electric motor M as a hydraulic motor as a generator for energy recovery. The pressure medium passing the supply pump P flows through the line 1, the flow control device SR and the direct connection 2 via the control valve component 10 to the tank T.

Ist während dieses Energierückgewinnungs-Modus der Versorgungspumpe P auch eine Nebenfunktion zu steuern, dann wird der Proportionalmagnet m1p entsprechend bestromt, um die erforderliche Menge in die Druckversorgungsleitung 15 zu führen, aus der dann der Verbraucher VN über sein Wege- oder Richtungssteuerventil W betätigt wird. Aus einem Verbraucher VN verdrängtes Druckmittel strömt über die Rückleitung 17 und die Rücklaufleitung 11 direkt zum Tank. Bei dieser Steuerung der Nebenfunktion ist es nicht erforderlich, die Versorgungspumpe P anzutreiben, solange das Druckpotential im verdrängten Druckmittel ausreichend ist. Ist dies nicht der Fall, dann greift die Versorgungspumpe P ergänzend ein.If an auxiliary function is also to be controlled during this energy recovery mode of the supply pump P, then the proportional magnet m1p is energized accordingly in order to lead the required quantity into the pressure supply line 15, from which the consumer VN is then actuated via its directional or directional control valve W. Pressure medium displaced from a consumer VN flows via the return line 17 and the return line 11 directly to the tank. With this control of the secondary function, it is not necessary to drive the supply pump P as long the pressure potential in the displaced pressure medium is sufficient. If this is not the case, then the supply pump P intervenes.

Die Ausführungsform der Fig. 2 unterscheidet sich von der der Fig. 1 dadurch, dass die Steuerventil-Komponente 10 für die Hebesteuerung ein einfaches 2/2-Wegesteuerventil 31 mit einem einfachen Schaltmagneten m3 ist. Um dennoch eine saubere Hebesteuerung des Verbrauchers VH (zweckmäßige Rampenfunktion) zu erzielen, wird die Drehzahlregelung des Elektromotors M genutzt. Der weitere Aufbau ist gleich. Unterschiedlich zur Darstellung in Fig. 1 ist die Dreiwege-Proportional-Stromregeleinrichtung SR detailliert dargestellt, und zwar mit einer Druckwaage D und einer der Druckwaage D in der Druckversorgungsleitung 15 nachgeordneten, durch den Proportionalmagneten m1p verstellbaren Messblende MB. Die die an der Messblende MB eingestellte Druckdifferenz haltende Druckwaage D wird von ersten und zweiten Steuerdrücken und einer Regelfeder 20 eingestellt und hält die eingestellte Druckdifferenz auch bei Druckschwankungen in der Leitung 1 und/oder 15. Der erste Steuerdruck wirkt zusammen mit der Regelfeder 20 in Öffnungsrichtung der Druckwaage D von der Leitung 1 zur Druckversorgungsleitung 15. Der erste Steuerdruck stammt aus einer Steuerleitung 12a, die von der am Kreuzungspunkt 18 von der Druckversorgungsleitung 15 abzweigenden Steuerleitung 12 mit dem zweiten Druckbegrenzungsventil 3a abzweigt. Der Kreuzungspunkt 18 befindet sich stromab der Messblende MB. Der zweite Steuerdruck wird an einem Kreuzungspunkt 21 stromauf der Messblende MB in der Druckversorgungsleitung 15 abgegriffen, über eine Steuerleitung 22 an die andere Seite der Druckwaage D übertragen und beaufschlagt diese in Öffnungsrichtung von der Druckleitung 1 zur Direktverbindung 2 zum Tank T. Da die ersten und zweiten Steuerdrücke nur im Kreis der Nebenfunktion abgegriffen werden, haben die Druckverhältnisse in den Leitungen 1, 2 oder in der Druckversorgungsleitung 5 zum Verbraucher VH keinen Einfluss auf den Regeleingriff der Stromregeleinrichtung SR. Die Leitungsschleife 13 mit der Drosselstelle 14, die enger sein sollte, als eine Drosselstelle 19 in der Steuerleitung 12a, dient zum Entlasten der Steuerleitung 12a, falls die Messblende MB in ihre Absperrstellung verstellt wird und keine Nebenfunktion zu steuern ist.The embodiment of FIG. 2 differs from that of FIG. 1 in that the control valve component 10 for the lifting control is a simple 2/2-way control valve 31 with a simple switching magnet m3. In order to achieve a clean lifting control of the consumer VH (expedient ramp function), the speed control of the electric motor M is used. The rest of the structure is the same. 1, the three-way proportional flow control device SR is shown in detail, namely with a pressure compensator D and a measuring orifice MB arranged downstream of the pressure compensator D in the pressure supply line 15 and adjustable by the proportional magnet m1p. The pressure compensator D holding the pressure difference set on the measuring orifice MB is set by first and second control pressures and a control spring 20 and holds the set pressure difference even in the event of pressure fluctuations in line 1 and / or 15. The first control pressure acts together with the control spring 20 in the opening direction the pressure compensator D from the line 1 to the pressure supply line 15. The first control pressure comes from a control line 12a, which branches off from the control line 12 branching off from the pressure supply line 15 at the intersection 18 with the second pressure relief valve 3a. The crossing point 18 is located downstream of the measuring orifice MB. The second control pressure is tapped at a crossing point 21 upstream of the measuring orifice MB in the pressure supply line 15, transmitted via a control line 22 to the other side of the pressure compensator D and acts on it in the opening direction from the pressure line 1 to the direct connection 2 to the tank T. Since the first and second control pressures are tapped only in the circuit of the secondary function, the pressure conditions in lines 1, 2 or in the pressure supply line 5 to the consumer VH have no influence on the control intervention of the current control device SR. The line loop 13 with the throttle point 14, which should be narrower than a throttle point 19 in the control line 12a, serves to relieve the control line 12a if the measuring orifice MB is adjusted into its shut-off position and no secondary function can be controlled.

Die Ausführungsform der Fig. 3 unterscheidet sich von den beiden vorgenannten Ausführungsformen dadurch, dass die Steuerventil-Komponente 10 zur Hebesteuerung den Kreuzungspunkt 4' zwischen der Direktverbindung 2 und der Druckversorgungsleitung 5 enthält und zu diesem Zweck als 3/2-Wegesteuerventil 32 ohne Proportionalfunktion und mit einem Schaltmagneten m3 ausgebildet ist. Durch die Symbolik ist gezeigt, dass es sich um ein 3/2-Wegesitzventil handelt, das das Rückschlagventil 6 durch die Sitzventilfunktion 6' ersetzt.The embodiment of FIG. 3 differs from the two aforementioned embodiments in that the control valve component 10 for lifting control contains the crossing point 4 'between the direct connection 2 and the pressure supply line 5 and for this purpose as a 3/2-way control valve 32 without a proportional function and is formed with a switching magnet m3. The symbolism shows that it is a 3/2-way seat valve that replaces the check valve 6 with the seat valve function 6 '.

Auch die Wege- und Richtungssteuerventile W der Verbraucher VN für die Nebenfunktionen sind einfache Wegesteuerventile ohne Proportionalfunktion, wobei jeder Verbraucher VN über Arbeitsleitungen 23, 24 an das Wege- oder Richtungssteuerventil W angeschlossen ist.The directional and directional control valves W of the consumer VN for the secondary functions are simple directional control valves without a proportional function, each consumer VN being connected to the directional or directional control valve W via working lines 23, 24.

Die Ausführungsform von Fig. 4 entspricht funktionell der Ausführungsform der Fig. 2 mit der als einfaches 2/2-Wegesteuerventil 31 ausgebildeten Steuerventil-Komponente 10, die mittels eines Schaltmagneten m3 verstellbar ist. Im Unterschied zur Stromregeleinrichtung SR der Fig. 2 ist die für die Druckwaage D erforderliche Messblende nicht in der Druckversorgungsleitung 15 enthalten, sondern wird die proportional verstellbare Messblende durch ein Wege- oder Richtungssteuerventil WP für den Verbraucher VN der Nebenfunktion gebildet, das ein Proportional-Steuerventil mit den Proportionalmagneten m1p (und ggfs. einem nicht gezeigten Zulaufregler) ist. Dank des Proportionalwegesteuerventils WP ergibt sich in der jeweils beaufschlagten Arbeitsleitung 23, 24 der erste Steuerdruck für die Druckwaage D, der über die Steuerleitung 12a übertragen und beispielsweise an einem Wechselventil 25 zwischen den Arbeitsleitungen 23, 24 abgegriffen wird. Für den Fall, dass nur ein Verbraucher VN für eine Nebenfunktion vorgesehen ist, wird der erste Steuerdruck vom Wechselventil 25 über eine Steuerleitung 26 direkt an die Steuerleitung 12a übertragen. Sind mehrere Verbraucher VN für Nebenfunktionen vorgesehen, dann sind deren Steuerleitungen 26, 28 über wenigstens ein weiteres Wechselventil 27 verknüpft, das den jeweils höchsten ersten Steuerdruck in die Steuerleitung 12a überträgt. Der zweite Steuerdruck wird wie in Fig. 2 über die Steuerleitung 22 aus der Druckversorgungsleitung 15 abgegriffen.The function of FIG. 4 corresponds functionally to the embodiment of FIG. 2 with the control valve component 10 designed as a simple 2/2-way control valve 31, which is adjustable by means of a switching magnet m3. In contrast to the current control device SR of FIG. 2, the measuring orifice required for the pressure compensator D is not contained in the pressure supply line 15, but the proportionally adjustable measuring orifice is formed by a directional or directional control valve WP for the consumer VN of the secondary function, which is a proportional control valve with the proportional solenoids m1p (and, if necessary, an inflow regulator, not shown). Thanks to the proportional directional control valve WP, the first control pressure for the pressure compensator D results in the working line 23, 24 that is acted upon, which is transmitted via the control line 12a and is tapped, for example, at a shuttle valve 25 between the working lines 23, 24. In the event that only one consumer VN is provided for a secondary function, the first control pressure is transferred from the shuttle valve 25 directly to the control line 12a via a control line 26. If several consumers VN are provided for secondary functions, their control lines 26, 28 are linked via at least one additional shuttle valve 27, which transmits the highest first control pressure into the control line 12a. As in FIG. 2, the second control pressure is tapped from the pressure supply line 15 via the control line 22.

In Fig. 5 ist wie in Fig. 3 die Steuerventil-Komponente 10 für die Hebesteuerung ein 3/2-Wegesteuerventil einfacher Bauart mit einem Schaltmagneten m3. Allerdings handelt es sich dabei nicht um ein Sitzventil, sondern um ein Schieberventil, in dem auch der Kreuzungspunkt 4' zur Druckversorgungsleitung 5 enthalten ist.In FIG. 5, as in FIG. 3, the control valve component 10 for the lifting control is a 3/2-way control valve of simple design with a switching magnet m3. However, this is not a poppet valve, but a slide valve, which also contains the crossing point 4 'to the pressure supply line 5.

In allen Ausführungsformen könnte die Steuerventilkomponente 9 (Senken) im Nebenstrang 8 ein einfaches 2/2-Schwarz/Weiß-Richtungssteuerventil mit einem einfachen Schaltmagneten (ohne Proportionalfunktion) sein.In all embodiments, the control valve component 9 (lowering) in the secondary line 8 could be a simple 2/2-way black / white directional control valve with a simple switching magnet (without proportional function).

Beim Senken des Verbrauchers VH kann Energie rückgewonnen werden, falls das Druckpotential auch für die Betätigung des Verbrauchers VN reicht. Ist dies nicht der Fall, wird dennoch Energie gespart, weil die Versorgungspumpe P nur ergänzend eingreift. Trotz der Energieeinsparung oder -Rückgewinnung ist jedoch die ordnungsgemäße Betätigung des Verbrauchers VN der einzigen Versorgungspumpe P sichergestellt.When the consumer VH is lowered, energy can be recovered if the pressure potential is also sufficient to actuate the consumer VN. If this is not the case, energy is nevertheless saved because the supply pump P only intervenes. Despite the energy saving or recovery, however, the proper actuation of the consumer VN of the single supply pump P is ensured.

In Fig. 6 ist die Steuerventil-Komponente 10 zur Hebesteuerung ein 3/2-Proportional-Wegesteuerventil 34 mit wenigstens einem Proportionalmagneten m3p in Schieberbauweise und mit einer Regelfunktion (durch die parallelen Linien angedeutet).6, the control valve component 10 for lifting control is a 3/2-way proportional control valve 34 with at least one proportional magnet m3p in slide valve design and with a control function (indicated by the parallel lines).

Claims (10)

  1. Electrohydraulic lifting module (S), in particular for a floor-level conveying vehicle, such as a forklift reach truck, with a single supply pump (P) which is drivable by means of an electric motor (M) and can be operated in a supply mode and in an energy-saving mode and on which are selectively connectable pressure supply lines (5, 15) with at least one consumer (VH) of a main raising function and of at least one consumer (VN) of a secondary function, with a secondary line (8), blocked in the return-flow direction to the tank, from the consumer (VH) of the main raising function via the supply pump (P) to a direct connection (2) to the tank, the consumer (VN) of the secondary function also being actuable in the energy-saving mode of the supply pump (P), characterized in that, in the energy-saving mode of the supply pump (P), the consumer (VN) of the secondary function can be actuated, at least in proportion, by means of pressure medium displaced out of the consumer (VH) of the main raising function with pressure via the secondary line (8) and by means of the supply pump (P), via a three-way proportional flow-regulating device (SR) which is provided on the pressure side of the supply pump, and to which the pressure supply lines (5, 15) of all the consumers (VH, VN) and the direct connection (2) to the tank (T) are connected on the outflow side, and in that, for the raising control of the main raising function, a control-valve component (10) is provided which monitors the direct connection (2) to the tank and which is arranged downstream of the three-way proportional flow-regulating device (SR) in the direction of flow in the secondary line.
  2. Lifting module according to Claim 1, characterized in that the three-way proportional flow-regulating device (SR) has a pressure balance (D) and a proportional measuring diaphragm (MB), in that the pressure balance is acted upon in the opening direction to the pressure supply line (15) of the consumer (VN) of the secondary function by a regulating spring (20) and by a first control pressure downstream of the proportional measuring diaphragm (MB) and in the opening direction to the pressure supply line (5) of the consumer (VH) of the main raising function by a second control pressure upstream of the proportional measuring diaphragm (MB).
  3. Lifting module according to Claim 2, characterized in that the proportional measuring diaphragm (MB) is arranged in the pressure supply line (15) of the consumer (VN) of the secondary function, a simple direction control valve (W) being provided for the said consumer.
  4. Lifting module according to Claim 2, characterized in that a proportional path control valve (WP) is provided for the consumer (VN) of the secondary function, and in that, as the first control pressure for the pressure balance (D), the load pressure of the consumer (VN) downstream of the proportional path control valve (WP) is picked up.
  5. Lifting module according to Claim 1, characterized in that the control-valve component (10) of the consumer (VH) of the main raising function is a 2/2-way black/white direction control valve (31) provided, downstream of an intersection point (4), in the direct connection (2) to the tank or is a 2/2-way proportional direction control valve (30), from which the pressure supply line (5) to the consumer (VH) of the main raising function leads.
  6. Lifting module according to Claim 1, characterized in that the control-valve component (10) of the consumer (VH) of the main raising function is a 3/2-way black/white direction control valve (33) provided in the direct connection (2) to the tank or a 3/2-way proportional direction control valve (34) containing an intersection point (4'), from which the pressure supply line (5) to the consumer (VH) of the main raising function leads.
  7. Lifting module according to Claim 1, characterized in that the consumer (VH) of the main raising function is safeguarded by a lowering braking valve (B) limiting the maximum descending speed under load.
  8. Lifting module according to at least one of the preceding claims, characterized in that a 2/2-way proportional direction control valve (9) or a 2/2-way black/white direction control valve is provided for the lowering control of the consumer (VN) in the secondary line (8).
  9. Lifting module according to Claim 1, characterized in that, in addition to a pressure-limiting valve (3) coordinated with the pressure level of the main raising function of the consumer (VH) and located downstream of the three-way proportional flow-regulating device (SR), a second pressure-limiting valve (3a) is provided, which is coordinated with the, if appropriate, lower pressure level of the consumer (VN) for the secondary function and which is arranged between the pressure supply line (15) of the consumer (VN) for the secondary function and the tank (T) or in a control line (12, 12a) for picking up the first control pressure.
  10. Lifting module according to Claim 9, characterized in that the second pressure-limiting valve (3a) is bypassed to the tank (T) by means of a relief line (13) for the first control pressure, the said relief line containing a throttle point (14).
EP00112802A 1999-07-06 2000-06-16 Electrohydraulic lifting module Expired - Lifetime EP1067296B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE29911686U DE29911686U1 (en) 1999-07-06 1999-07-06 Electro-hydraulic lifting module
DE29911686U 1999-07-06

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EP1067296A1 EP1067296A1 (en) 2001-01-10
EP1067296B1 true EP1067296B1 (en) 2004-12-29

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EP00112802A Expired - Lifetime EP1067296B1 (en) 1999-07-06 2000-06-16 Electrohydraulic lifting module

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DE (2) DE29911686U1 (en)

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DE10010670C2 (en) * 2000-03-04 2003-11-06 Jungheinrich Ag Hydraulic lifting device for battery-operated industrial trucks
DE10224730B4 (en) * 2001-06-29 2012-09-27 Linde Material Handling Gmbh Hydraulic control device
DE102004011913B4 (en) 2004-03-11 2005-12-29 Jungheinrich Ag Hydraulic lifting device for battery-operated industrial trucks
DE102006003414B3 (en) * 2006-01-24 2007-08-02 Sauer-Danfoss Gmbh & Co Ohg Hydraulic circuit arrangement
DE102007010697A1 (en) * 2007-03-06 2008-09-11 Jungheinrich Aktiengesellschaft Truck
EP2058270B1 (en) 2007-11-06 2010-05-26 HAWE Hydraulik SE Electrohydraulic lifting device
ES2345907T3 (en) 2007-11-21 2010-10-05 Hawe Hydraulik Se ELECTRO HYDRAULIC ELEVATOR MODULE.
EP3171039A1 (en) * 2015-11-18 2017-05-24 HAWE Hydraulik SE Hydraulic lifting module having a lifting and lowering function
DE102018112835A1 (en) 2018-05-29 2019-12-05 Fsp Fluid Systems Partner Holding Ag Hydraulic system, hydraulic unit, vehicle, procedures and use
GB2575480A (en) * 2018-07-11 2020-01-15 Parker Hannifin Emea Sarl A control valve assembly for a load handling vehicle

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DE4402653C2 (en) 1994-01-29 1997-01-30 Jungheinrich Ag Hydraulic lifting device for battery-powered industrial trucks
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DE50009076D1 (en) 2005-02-03
DE29911686U1 (en) 1999-09-16
EP1067296A1 (en) 2001-01-10

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