EP1780171B1 - Lift truck with a support leg arrangement - Google Patents

Lift truck with a support leg arrangement Download PDF

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Publication number
EP1780171B1
EP1780171B1 EP06021245A EP06021245A EP1780171B1 EP 1780171 B1 EP1780171 B1 EP 1780171B1 EP 06021245 A EP06021245 A EP 06021245A EP 06021245 A EP06021245 A EP 06021245A EP 1780171 B1 EP1780171 B1 EP 1780171B1
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EP
European Patent Office
Prior art keywords
mast
lifting
hydraulic cylinders
path difference
pump
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EP06021245A
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German (de)
French (fr)
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EP1780171A2 (en
EP1780171A3 (en
Inventor
Jessica Finke
Paul Rickers
Henrik Schröder
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Jungheinrich AG
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Jungheinrich AG
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Classifications

    • 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
    • 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
    • B66F9/08—Masts; Guides; Chains

Definitions

  • the invention relates to a mast, in particular for a high-bay stacker according to claim 1.
  • Height-adjustable masts are e.g. known as part of industrial trucks with high-lift equipment in a variety of designs. With the help of masts to be transported loads are recorded and stored at different altitudes, the lifting load is moved substantially vertically.
  • Such a mast consists in principle of an outer frame in which moves directly a load-carrying means. Such a construction is relatively rare. In most cases, one or more driving masts move in the stationary mast. In a single and double telescopic mast, this is an inner mast. In a triple-telescopic mast, these are two, and in the quad telescopic mast, three inner masts.
  • the individual mast frames consist of two lateral support profiles, which are connected at the top and bottom by transverse struts.
  • the transmission of the bending load resulting from the lifting load is carried out between the nested mast frame normally via rollers, which are arranged at the top and bottom of the frame profiles.
  • the drive for the height adjustment is usually by means of hydraulic lifting cylinders and chains that produce a relative movement between the mast frame.
  • the construction of the mast frame is created so that the extended mast is rigid in its main load direction, so that it deforms as little as possible by the bending moment of a load at a higher altitude. Too much deformation leads to a shift of the center of gravity and thus to increase the force acting on the truck tipping moment. As a result, the stability of the vehicle is adversely affected.
  • the necessary bending stiffness is achieved by selecting lifting frame profiles with reasonably large moments of inertia.
  • a lateral bending In addition to the main bending load can also occur a lateral bending, which is caused by an eccentric center of gravity of the lifting load or by dynamic lateral mass forces. Due to the resulting lateral bending of the mast, the lateral Hublasthebelarm is increased and thus increases the lateral tilting moment.
  • the rigidity of the mast frame with respect to lateral bending is usually achieved by connecting the two lateral support profiles of the mast frame by massive transverse stiffeners (ladder-shaped). These transverse stiffeners obstruct the view through the mast frame and increase its weight.
  • Out EP 1 528 035 A2 It is known to monitor the inclination of a mast from a position sensor and to control the pressure in the hydraulic cylinders so that the inclination is compensated.
  • Out DD 30489 It has become known to control the amount of fluid to the lifting cylinders of a lifting mast load-dependent.
  • the invention has for its object to provide a mast, especially for a high-bay stacker, in which a lateral bending is prevented from the outset.
  • a control device for the two linear actuators is provided, with which a path difference of the stroke of the linear actuators is measured and the linear actuators are controlled so that the path difference remains zero.
  • the supply of equal volumes of pressure medium is ensured by a quantity divider are arranged between the hydraulic pressure source and the hydraulic cylinders, via which the hydraulic cylinders are each supplied with the same pressure medium volume.
  • Hydraulic flow dividers do not work well in practice, so that the same stroke on the hydraulic cylinders can not be guaranteed completely safe. Because the pressure medium is compressible to some extent, and in the piping system compliances of the pressure medium-carrying parts are present, such as in pipes and hoses. For practical applications, such flow divider can work satisfactorily.
  • Downstream of the flow divider are the lines to the hydraulic cylinders on one in the speed controllable pump are connected and the pump is driven at a path difference of the hydraulic cylinder or an inclination angle of the mast from a motor, wherein the direction of rotation of the motor is dependent on the sign of the path difference or the inclination angle.
  • the speed and conveying direction of the pump are predetermined by an electronic control, which measures the travel of each lifting cylinder or the inclination angle of the mast with a sensor device.
  • a throttle can be connected in parallel to the equalizing pump, which ensures that the pump is not operated at unacceptably low speeds.
  • a shut-off valve can be provided in series with the balance pump, which is opened only during operation of the balance pump. In case of failure of the balancing pump, this valve is closed, so that a pressure compensation and thus a loss of stabilizing effect is avoided. In the case of a path difference or an inclination angle from the lifting mast, the compensating pump is then activated in such a way that the path difference or the angle of inclination is minimized.
  • dynamic deformations such as e.g. When cornering the truck occur, to reduce within certain limits.
  • a controllable three / three-way valve with two input ports is located on the master cylinder, while an output port is connected to the tank.
  • the control device controls in accordance with the path difference or the inclination angle, the valve so that one of the two hydraulic cylinders is connected to the tank.
  • a possible difference in the stroke of the Hydraulic cylinder is compensated by allowing fluid to flow into the tank through the valve until the stroke of both cylinders is equal again.
  • each lifting cylinder is associated with a controllable lifting / lowering valve, which are located at the output of a hydraulic pump and the control device in accordance with the path difference or the inclination angle of one of the two lifting / lowering valves so controls that the path difference or the inclination angle becomes zero, respectively.
  • Fig. 1 schematically shown a mast, with a stationary mast frame 10, which can be attached to a high-bay forklift.
  • a stationary mast frame 10 which can be attached to a high-bay forklift.
  • two hydraulic cylinders 14, 16 are based, which are connected to an upper cross member 18 of a mast frame 20.
  • arrows 22 and 24 different lifting forces are to be indicated, which lead to a lateral bending moment 26. In the embodiments described below, a deflection is to be prevented despite a bending moment generated by the load.
  • Fig. 2 can be seen that the hydraulic cylinders 14, 16 are supplied via a so-called flow or flow divider 30 with pressure medium.
  • the flow divider ensures that both hydraulic cylinders 14, 16 regardless of their load in each case the same pressure medium volume is supplied, so that the hydraulic cylinders 14, 16 execute the same stroke paths.
  • Fig. 3 the hydraulic cylinders 14, 16 are connected via the flow divider 30 to a hydraulic pump.
  • a parallel connection 32 between the supply lines to the hydraulic cylinders 14, 16 is provided, in which a small controllable pump 34 is arranged, which is driven by an electric motor 36.
  • Parallel to the pump 34 is a throttle 38.
  • the circuit arrangement shown operates as follows.
  • the flow divider 30 should ensure that the hydraulic cylinders 14, 16 are each supplied with equal volumes. For various reasons, this is not always guaranteed.
  • a sensor device not shown measures the strokes of the hydraulic cylinders 14, 16. At a difference between the measured strokes, the electric motor 36 is driven and drives the pump 34 in one direction so that the measured path difference is made zero. Once the path difference is zero, the motor 36 is turned off. During this Operation, the valve 40 is opened, which is otherwise closed when the pump 34 is not operating, in order not to jeopardize the uniform supply of the hydraulic cylinders 14, 16 via the flow divider 30 in case of failure of the pump 34.
  • the throttle 38 ensures that the pump is not operated at impermissibly low speeds.
  • a fault of the flow divider 30 can be compensated by means of a three / three-way valve 42, the two inputs are respectively connected to the hydraulic cylinders 14, 16 and whose output is connected to a tank 44. With a stroke difference, the valve 42 is opened, so that one of the two hydraulic cylinders 14, 16 as long pressure fluid is discharged into the tank 44 until the stroke of both cylinders is equal again.
  • the required regulation corresponds to that according to Fig. 4 ,
  • each hydraulic cylinder 14, 16 is associated with a lifting and lowering valve 46, 48, which are driven by an electronic unit, not shown. With the help of a sensor, which is not shown, the stroke paths of the hydraulic cylinders 14, 16 are measured.
  • the control of the valves 46, 48 via the control device is such that the supply of pressure medium from a pump 50 is different until the Hubwegdifferenz has become zero again.

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  • Engineering & Computer Science (AREA)
  • Transportation (AREA)
  • Structural Engineering (AREA)
  • Civil Engineering (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Geology (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Forklifts And Lifting Vehicles (AREA)

Description

Die Erfindung bezieht sich auf einen Hubmast, insbesondere für einen Hochregalstapler nach dem Patentanspruch 1.The invention relates to a mast, in particular for a high-bay stacker according to claim 1.

Höhenverstellbare Hubgerüste sind z.B. als Bestandteil von Flurförderzeugen mit Hochhubeinrichtungen in den unterschiedlichsten Konstruktionsformen bekannt. Mit Hilfe der Hubgerüste sollen zu transportierende Lasten in unterschiedlichen Höhenlagen aufgenommen und abgelegt werden, wobei die Hublast im Wesentlichen vertikal bewegt wird.Height-adjustable masts are e.g. known as part of industrial trucks with high-lift equipment in a variety of designs. With the help of masts to be transported loads are recorded and stored at different altitudes, the lifting load is moved substantially vertically.

Ein derartiges Hubgerüst besteht im Prinzip aus einem äußeren Standrahmen, in dem sich unmittelbar ein Lastaufnahmemittel bewegt. Eine derartige Konstruktion ist relativ selten. In den meisten Fällen bewegen sich im Standmast ein oder mehrere Fahrmaste. Bei einem Einfach- und Zweifach-Teleskop-Hubgerüst ist das ein innerer Fahrmast. Bei einem Dreifach-Teleskop-Hubgerüst sind das zwei, und beim Vierfach-Teleskop-Hubgerüst drei innere Fahrmaste.Such a mast consists in principle of an outer frame in which moves directly a load-carrying means. Such a construction is relatively rare. In most cases, one or more driving masts move in the stationary mast. In a single and double telescopic mast, this is an inner mast. In a triple-telescopic mast, these are two, and in the quad telescopic mast, three inner masts.

Die einzelnen Mastrahmen bestehen aus zwei seitlichen Tragprofilen, die oben und unten durch Querstreben verbunden sind. Die Übertragung des aus der Hublast resultierenden Biegemoments erfolgt zwischen den ineinander verschachtelten Mastrahmen normalerweise über Laufrollen, die am oberen und unteren Ende der Rahmenprofile angeordnet sind. Der Antrieb für die Höhenverstellung erfolgt zumeist mittels hydraulischer Hubzylinder und Ketten, die eine Relativbewegung zwischen den einzelnen Mastrahmen erzeugen.The individual mast frames consist of two lateral support profiles, which are connected at the top and bottom by transverse struts. The transmission of the bending load resulting from the lifting load is carried out between the nested mast frame normally via rollers, which are arranged at the top and bottom of the frame profiles. The drive for the height adjustment is usually by means of hydraulic lifting cylinders and chains that produce a relative movement between the mast frame.

Die Konstruktion der Mastrahmen ist so geschaffen, dass das ausgefahrene Hubgerüst in seiner Hauptbelastungsrichtung biegesteif ist, damit es sich durch das Biegemoment einer in größerer Höhe befindlichen Last möglichst wenig verformt. Eine zu große Verformung führt zu einer Verschiebung des Lastschwerpunkts und damit zur Vergrößerung des auf das Flurförderzeug wirkende Kippmoments. Dadurch wird die Standsicherheit des Fahrzeugs negativ beeinflußt. Die notwendige Biegesteifigkeit wird durch die Auswahl von Hubrahmenprofilen mit angemessen großen Flächenträgheitsmomenten erreicht.The construction of the mast frame is created so that the extended mast is rigid in its main load direction, so that it deforms as little as possible by the bending moment of a load at a higher altitude. Too much deformation leads to a shift of the center of gravity and thus to increase the force acting on the truck tipping moment. As a result, the stability of the vehicle is adversely affected. The necessary bending stiffness is achieved by selecting lifting frame profiles with reasonably large moments of inertia.

Neben der Hauptbiegebelastung kann auch eine seitliche Biegung auftreten, die durch eine exzentrische Schwerpunktlage der Hublast oder durch dynamische seitliche Massenkräfte hervorgerufen wird. Durch die resultierende seitliche Verbiegung des Hubmastes wird der seitliche Hublasthebelarm vergrößert und damit auch das seitliche Kippmoment erhöht. Die Steifigkeit der Hubmastrahmen gegenüber seitlicher Verbiegung wird üblicherweise dadurch erreicht, dass die beiden seitlichen Tragprofile des Hubmastrahmens durch massive Querversteifungen (leiterförmig) verbunden werden. Diese Querversteifungen behindern die Sicht durch den Hubmastrahmen und vergrößern sein Gewicht.In addition to the main bending load can also occur a lateral bending, which is caused by an eccentric center of gravity of the lifting load or by dynamic lateral mass forces. Due to the resulting lateral bending of the mast, the lateral Hublasthebelarm is increased and thus increases the lateral tilting moment. The rigidity of the mast frame with respect to lateral bending is usually achieved by connecting the two lateral support profiles of the mast frame by massive transverse stiffeners (ladder-shaped). These transverse stiffeners obstruct the view through the mast frame and increase its weight.

Aus DE 4 038 730 ist eine Vorrichtung bekannt geworden, welche die aus der Verformung des Mastes durch das Lastmoment resultierende Verlagerung des Lastschwerpunktes durch Neigen des Mastes kompensiert. Eine seitliche Verbiegung wird nicht beeinflußt.Out DE 4 038 730 a device has become known which compensates for the displacement of the load center resulting from the deformation of the mast by the load moment by tilting the mast. A lateral bending is not affected.

Aus DE 101 33 585 A1 ist eine Vorrichtung zur Kompensation von Biegungen in der Hauptbiegerichtung beschrieben.Out DE 101 33 585 A1 a device for compensation of bends in the main bending direction is described.

In DE 3 016 156 und DE 3 101 953 sind Hubgerüste beschrieben, bei denen Längs- und Seitenverformungen durch Gegenmomente kompensiert werden, die über Zugmittel auf das Hubgerüst aufgebracht werden. Die Hubgerüste müssen hierzu mit aufwendigen Zusatzmechanismen ausgerüstet werden.In DE 3 016 156 and DE 3 101 953 masts are described in which longitudinal and lateral deformations are compensated by counter-moments, which are applied via traction means on the mast. The masts have to be equipped with elaborate additional mechanisms.

Aus DE 103 49 123 A1 ist ein Hubwerk bekannt geworden, bei dem zwei seitlich angeordnete Hubzylinder eines konventionellen Hubmastes mit unterschiedlichem Hydraulikdruck beaufschlagbar sind oder durch dynamisches Verändern der Drücke mittels einer zusätzlichen Pumpe zwischen den Zylindern.Out DE 103 49 123 A1 a hoist has become known in which two laterally arranged lifting cylinder of a conventional mast with different hydraulic pressure can be acted upon or by dynamically changing the pressures by means of an additional pump between the cylinders.

Aus EP 1 528 035 A2 ist bekannt, die Neigung eines Mastes von einem Positionsgeber zu überwachen und den Druck in den Hydraulikzylindern so zu steuern, daß die Neigung kompensiert wird. Aus DD 30489 ist bekannt geworden, die Strömungsmittelmenge zu den Hubzylindern eines Hubmastes lastabhängig zu steuern.Out EP 1 528 035 A2 It is known to monitor the inclination of a mast from a position sensor and to control the pressure in the hydraulic cylinders so that the inclination is compensated. Out DD 30489 It has become known to control the amount of fluid to the lifting cylinders of a lifting mast load-dependent.

Aus DE-A-10321487 ist ein Flurförderaeug bekannt geworden, bei dem das Hubgerüst verschiebbar auf dem Chassis angeordnet ist. Die Verschiebung erfolgt mit Hilfe von zwei parallelen Schiebezylindern, wobei einer im Bodenbereich und einer oberen Bereich des Fahrzeugs angeordnet ist. Die Versorgung der beiden Hydraulikzylinder erfolgt über einen Stromteiler. Auf diese Weise kann das Hubgerüst horizontal verfahren werden. Durch unterschiedliche Ansteuerung der Hubzylinder lässt sich das Hubgerüst auch neigen.Out DE-A-10321487 is known a floor conveyor, in which the mast is slidably mounted on the chassis. The displacement takes place with the aid of two parallel sliding cylinders, one of which is arranged in the floor area and an upper area of the vehicle. The supply of the two hydraulic cylinders via a flow divider. In this way, the mast can be moved horizontally. By different control of the lifting cylinder, the mast can also tilt.

Aus US-A-4,395,189 ist ein Flurförderzeug bekannt geworden, bei dem zwei Hubgerüste nebeneinander angeordnet sind. Die Hubgerüste haben jeweils einen ausfahrbaren Mastschuss, wobei jeder Mastschuss durch einen Hubzylinder betätigt wird. Die beiden Hubzylinder werden über Stromteiler mit Hydraulikmedium versorgt.Out US-A-4,395,189 an industrial truck has become known in which two masts are arranged side by side. The masts each have an extendable mast shot, each mast shot is actuated by a lifting cylinder. The two lifting cylinders are supplied with hydraulic medium via flow dividers.

Der Erfindung liegt die Aufgabe zugrunde, einen Hubmast, insbesondere für einen Hochregalstapler, zu schaffen, bei dem eine seitliche Verbiegung von vornherein verhindert wird.The invention has for its object to provide a mast, especially for a high-bay stacker, in which a lateral bending is prevented from the outset.

Diese Aufgabe wird durch die Merkmale des Patentanspruchs 1 gelöst.This object is solved by the features of patent claim 1.

Bei der Erfindung nach Patentanspruch 1 ist eine Regelvorrichtung für die beiden Hubantriebe vorgesehen, mit der eine Wegdifferenz der Hubwege der Hubantriebe gemessen wird und die Hubantriebe so gesteuert werden, dass die Wegdifferenz Null bleibt.In the invention according to claim 1, a control device for the two linear actuators is provided, with which a path difference of the stroke of the linear actuators is measured and the linear actuators are controlled so that the path difference remains zero.

Bei der Erfindung nach Anspruch 4 ist die Zufuhr gleicher Druckmittel-Volumina gewährleistet, indem zwischen der Hydraulikdruckquelle und den Hydraulikzylindern ein Mengenteiler angeordnet werden, über den die Hydraulikzylinder jeweils mit gleichen Druckmittelvolumen versorgt werden. Hydraulische Stromteiler arbeiten in der Praxis nicht ideal, sodass der gleiche Hubweg an den hydraulischen Zylindern nicht vollständig sicher gewährleistet werden kann. Denn das Druckmittel ist in gewissem Maße kompressibel, und im Leitungssystem sind Nachgiebigkeiten der druckmittel führenden Teile vorhanden, etwa in Rohren und Schläuchen. Für praktische Anwendungen können derartige Mengenteiler zufriedenstellend arbeiten.In the invention according to claim 4, the supply of equal volumes of pressure medium is ensured by a quantity divider are arranged between the hydraulic pressure source and the hydraulic cylinders, via which the hydraulic cylinders are each supplied with the same pressure medium volume. Hydraulic flow dividers do not work well in practice, so that the same stroke on the hydraulic cylinders can not be guaranteed completely safe. Because the pressure medium is compressible to some extent, and in the piping system compliances of the pressure medium-carrying parts are present, such as in pipes and hoses. For practical applications, such flow divider can work satisfactorily.

Abströmseitig vom Mengenteiler sind die Leitungen zu den Hydraulikzylindern über eine in der Drehzahl regelbare Pumpe verbunden sind und die Pumpe ist bei einer Wegdifferenz der Hydraulikzylinder oder einem Neigungswinkel des Hubmastes von einem Motor angetrieben wird, wobei die Drehrichtung des Motors vom Vorzeichen der Wegdifferenz bzw. des Neigungswinkels abhängig ist. Die Drehzahl und Förderrichtung der Pumpe werden von einer elektronischen Steuerung vorgegeben, die mit einer Sensoreinrichtung den Weg jedes Hubzylinders bzw. den Neigungswinkel des Mastes mißt. Nach einer Ausgestaltung der Erfindung kann parallel zur Ausgleichspumpe eine Drossel geschaltet werden, die gewährleistet, dass die Pumpe nicht mit unzulässig niedrigen Drehzahlen betrieben wird.Downstream of the flow divider are the lines to the hydraulic cylinders on one in the speed controllable pump are connected and the pump is driven at a path difference of the hydraulic cylinder or an inclination angle of the mast from a motor, wherein the direction of rotation of the motor is dependent on the sign of the path difference or the inclination angle. The speed and conveying direction of the pump are predetermined by an electronic control, which measures the travel of each lifting cylinder or the inclination angle of the mast with a sensor device. According to one embodiment of the invention, a throttle can be connected in parallel to the equalizing pump, which ensures that the pump is not operated at unacceptably low speeds.

Nach einer weiteren Ausgestaltung der Erfindung kann in Reihe mit der Ausgleichspumpe ein Abschaltventil vorgesehen werden, das nur bei Betrieb der Ausgleichspumpe geöffnet wird. Bei Ausfall der Ausgleichspumpe wird dieses Ventil geschlossen, sodass ein Druckausgleich und damit ein Verlust der stabilisierenden Wirkung vermieden wird. Bei einer Wegdifferenz bzw. einem Neigungswinkel vom Hubmast wird die Ausgleichspumpe dann so angesteuert, dass die Wegdifferenz bzw. der Neigungswinkel minimiert wird. Mit Hilfe einer derartigen Anordnung ist es auch möglich, dynamische Verformungen, wie sie z.B. bei Kurvenfahrten des Flurförderzeugs auftreten, in gewissen Grenzen zu reduzieren.According to a further embodiment of the invention, a shut-off valve can be provided in series with the balance pump, which is opened only during operation of the balance pump. In case of failure of the balancing pump, this valve is closed, so that a pressure compensation and thus a loss of stabilizing effect is avoided. In the case of a path difference or an inclination angle from the lifting mast, the compensating pump is then activated in such a way that the path difference or the angle of inclination is minimized. By means of such an arrangement, it is also possible to use dynamic deformations such as e.g. When cornering the truck occur, to reduce within certain limits.

Nach einer weiteren Ausgestaltung der Erfindung ist vorgesehen, dass parallel zum Mengenteiler ein steuerbares Drei/Dreiwege-Ventil mit zwei Eingangsanschlüssen an dem Hauptzylinder liegt, während ein Ausgangsanschluß an den Tank angeschlossen ist. Die Regelvorrichtung steuert nach Maßgabe der Wegdifferenz bzw. des Neigungswinkels das Ventil so an, dass einer der beiden Hydraulikzylinder mit dem Tank verbunden wird. Ein eventueller Unterschied im Hubweg der Hydraulikzylinder wird dadurch ausgeglichen, dass über das Ventil so lange Fluid in den Tank gelassen wird, bis der Hubweg beider Zylinder wieder gleich ist.According to a further embodiment of the invention it is provided that parallel to the flow divider a controllable three / three-way valve with two input ports is located on the master cylinder, while an output port is connected to the tank. The control device controls in accordance with the path difference or the inclination angle, the valve so that one of the two hydraulic cylinders is connected to the tank. A possible difference in the stroke of the Hydraulic cylinder is compensated by allowing fluid to flow into the tank through the valve until the stroke of both cylinders is equal again.

Eine andere Ausgestaltung der Erfindung sieht schließlich vor, dass jedem Hubzylinder ein steuerbares Hub-/Senkventil zugeordnet ist, die am Ausgang einer Hydraulikpumpe liegen und die Regelvorrichtung nach Maßgabe der Wegdifferenz oder des Neigungswinkels eines der beiden Hub-/Senkventile so ansteuert, dass die Wegdifferenz oder der Neigungswinkel jeweils zu null wird.Another embodiment of the invention finally provides that each lifting cylinder is associated with a controllable lifting / lowering valve, which are located at the output of a hydraulic pump and the control device in accordance with the path difference or the inclination angle of one of the two lifting / lowering valves so controls that the path difference or the inclination angle becomes zero, respectively.

Die Erfindung wird nachfolgend anhand von Zeichnungen näher erläutert:

Fig. 1
zeigt einen Hubmast, wie er mit einer erfindungsgemäßen Vorrichtung ausgestattet werden kann.
Fig. 2
zeigt eine erste Ausführungsform nach der Erfindung.
Fig. 3
zeigt eine zweite Ausführungsform nach der Erfindung.
Fig. 4
zeigt eine dritte Ausführungsform nach der Erfindung.
Fig. 5
zeigt eine vierte Ausführungsform nach der Erfindung.
The invention is explained in more detail below with reference to drawings:
Fig. 1
shows a mast, as it can be equipped with a device according to the invention.
Fig. 2
shows a first embodiment of the invention.
Fig. 3
shows a second embodiment of the invention.
Fig. 4
shows a third embodiment of the invention.
Fig. 5
shows a fourth embodiment of the invention.

In Fig. 1 ist schematisch ein Hubmast gezeigt, mit einem Standmastrahmen 10, der etwa an einem Hochregalstapler angebracht werden kann. An einer unteren Querstrebe 12 des Standmastrahmens stützen sich zwei Hydraulikzylinder 14, 16 ab, die mit einer oberen Querstrebe 18 eines Fahrmastrahmens 20 verbunden sind. Durch die Pfeile 22 und 24 sollen unterschiedliche Hubkräfte angedeutet werden, die zu einem seitlichen Biegemoment 26 führen. In den nachstehend beschriebenen Ausführungsformen soll eine Verbiegung trotz eines von der Last erzeugten Biegemoments verhindert werden.In Fig. 1 schematically shown a mast, with a stationary mast frame 10, which can be attached to a high-bay forklift. At a lower cross member 12 of the stationary mast frame, two hydraulic cylinders 14, 16 are based, which are connected to an upper cross member 18 of a mast frame 20. By arrows 22 and 24 different lifting forces are to be indicated, which lead to a lateral bending moment 26. In the embodiments described below, a deflection is to be prevented despite a bending moment generated by the load.

In Fig. 2 ist zu erkennen, dass die Hydraulikzylinder 14, 16 über einen sogenannten Strom- oder Mengenteiler 30 mit Druckmittel versorgt werden. Der Mengenteiler sorgt dafür, dass beiden Hydraulikzylindern 14, 16 unabhängig von deren Belastung jeweils gleiches Druckmittelvolumen zugeführt wird, sodass die Hydraulikzylinder 14, 16 gleiche Hubwege ausführen.In Fig. 2 can be seen that the hydraulic cylinders 14, 16 are supplied via a so-called flow or flow divider 30 with pressure medium. The flow divider ensures that both hydraulic cylinders 14, 16 regardless of their load in each case the same pressure medium volume is supplied, so that the hydraulic cylinders 14, 16 execute the same stroke paths.

In Fig. 3 sind die Hyraulikzylinder 14, 16 über den Stromteiler 30 mit einer Hydraulikpumpe verbunden. Außerdem ist eine Parallelverbindung 32 zwischen den Zuleitungen zu den Hydraulikzylindern 14, 16 vorgesehen, in der eine kleine regelbare Pumpe 34 angeordnet ist, die von einem Elektromotor 36 angetrieben wird. Parallel zur Pumpe 34 liegt eine Drossel 38. Außerdem befindet sich in der Querverbindung ein Schaltventil 40. Die gezeigte Schaltungsanordnung arbeitet wie folgt.In Fig. 3 the hydraulic cylinders 14, 16 are connected via the flow divider 30 to a hydraulic pump. In addition, a parallel connection 32 between the supply lines to the hydraulic cylinders 14, 16 is provided, in which a small controllable pump 34 is arranged, which is driven by an electric motor 36. Parallel to the pump 34 is a throttle 38. In addition, there is a switching valve 40 in the cross-connection. The circuit arrangement shown operates as follows.

An sich soll der Stromteiler 30 dafür sorgen, dass den Hydraulikzylindern 14, 16 jeweils gleiche Volumina zugeführt werden. Aus verschiedenen Gründen ist dies aber nicht immer gewährleistet. Eine nicht gezeigte Sensorvorrichtung mißt die Hubwege der Hydraulikzylinder 14, 16. Bei einer Differenz zwischen den gemessenen Hubwegen wird der Elektromotor 36 angesteuert und treibt die Pumpe 34 in einer Richtung so an, dass die gemessene Wegdifferenz zu null gemacht wird. Sobald die Wegdifferenz null ist, wird der Motor 36 ausgeschaltet. Während dieses Vorgangs ist das Ventil 40 geöffnet, das ansonsten bei Nichtbetrieb der Pumpe 34 geschlossen ist, um bei einem Ausfall der Pumpe 34 nicht die gleichmäßige Versorgung der Hydraulikzylinder 14, 16 über den Stromteiler 30 zu gefährden. Die Drossel 38 gewährleistet, dass die Pumpe nicht mit unzulässig niedrigen Drehzahlen betrieben wird.In itself, the flow divider 30 should ensure that the hydraulic cylinders 14, 16 are each supplied with equal volumes. For various reasons, this is not always guaranteed. A sensor device not shown measures the strokes of the hydraulic cylinders 14, 16. At a difference between the measured strokes, the electric motor 36 is driven and drives the pump 34 in one direction so that the measured path difference is made zero. Once the path difference is zero, the motor 36 is turned off. During this Operation, the valve 40 is opened, which is otherwise closed when the pump 34 is not operating, in order not to jeopardize the uniform supply of the hydraulic cylinders 14, 16 via the flow divider 30 in case of failure of the pump 34. The throttle 38 ensures that the pump is not operated at impermissibly low speeds.

Statt einer Messung der Wegdifferenz der Hubwege der Hydraulikzylinder 14, 16 kann auch der Neigungswinkel gemessen werden, der mit Hilfe der beschriebenen Maßnahme bei einem Wert ungleich null wieder minimiert oder zu null gemacht wird.Instead of measuring the path difference of the stroke paths of the hydraulic cylinders 14, 16, it is also possible to measure the angle of inclination which, with the aid of the described measure, is again minimized or made zero at a value not equal to zero.

Bei der Ausführungsform nach Fig. 4 kann ein Fehler des Stromteilers 30 mit Hilfe eines Drei/Dreiwegeventils 42 ausgeglichen werden, dessen beide Eingänge jeweils mit den Hydraulikzylindern 14, 16 verbunden sind und dessen Ausgang mit einem Tank 44 verbunden ist. Bei einer Hubwegdifferenz wird das Ventil 42 geöffnet, sodass aus einem der beiden Hydraulikzylinder 14, 16 so lange Druckmittel in den Tank 44 abgelassen wird, bis der Hubweg beider Zylinder wieder gleich ist. Die hierzu erforderliche Regelung entspricht derjenigen nach Fig. 4.In the embodiment according to Fig. 4 a fault of the flow divider 30 can be compensated by means of a three / three-way valve 42, the two inputs are respectively connected to the hydraulic cylinders 14, 16 and whose output is connected to a tank 44. With a stroke difference, the valve 42 is opened, so that one of the two hydraulic cylinders 14, 16 as long pressure fluid is discharged into the tank 44 until the stroke of both cylinders is equal again. The required regulation corresponds to that according to Fig. 4 ,

Bei der Ausführungsform nach Fig. 5 ist jedem Hydraulikzylinder 14, 16 ein Hub- und Senkventil 46, 48 zugeordnet, die von einer nicht dargestellten Elektronik angesteuert werden. Mit Hilfe einer Sensorik, die nicht dargestellt ist, werden die Hubwege der Hydraulikzylinder 14, 16 gemessen. Die Ansteuerung der Ventile 46, 48 über die Regelvorrichtung ist derart, dass die Zufuhr von Druckmittel von einer Pumpe 50 so lange unterschiedlich ist, bis die Hubwegdifferenz wieder zu null geworden ist.In the embodiment according to Fig. 5 each hydraulic cylinder 14, 16 is associated with a lifting and lowering valve 46, 48, which are driven by an electronic unit, not shown. With the help of a sensor, which is not shown, the stroke paths of the hydraulic cylinders 14, 16 are measured. The control of the valves 46, 48 via the control device is such that the supply of pressure medium from a pump 50 is different until the Hubwegdifferenz has become zero again.

Claims (8)

  1. A lifting mast, in particular for a high-bay stacker lift truck, having a fixed mast and at least one extendable mast section with two parallel lift drives arranged laterally on the mast for extending the mast section from the fixed mast and a control for the lift drives, characterized in that a regulating device is provided for the two lift drives for measuring a path difference in the lifting paths of the lift drives and the lift drives are controlled such that the path difference remains zero.
  2. The lifting mast according to claim 1, characterized in that the lift drives have two motors, each driving a spindle drive, and the path difference is determined by measuring the angle of rotation of the spindle drives.
  3. The lifting mast according to claim 1, characterized in that the lift drives are disposed on hydraulic cylinders (14, 16) connectable to a hydraulic source and the supply of displaced volume to the hydraulic cylinders (14, 16) is controlled such that the lifting paths of the hydraulic cylinders (14, 16) are equal.
  4. A lifting mast, in particular for a high-bay stacker lift truck, having a fixed mast and at least one extendable mast section with two parallel hydraulic cylinders arranged laterally for extending the mast section from the fixed mast and a control for the hydraulic cylinders, characterized in that a volume or flow divider (30) is disposed between the hydraulic pressure sources and the hydraulic cylinders (14, 16), by means of which the hydraulic cylinders (14, 16) are supplied with the same volume of pressurizing medium and that the lines to the hydraulic cylinders (14, 16) are connected on the outflow side of a volume or flow divider (30) via a pump (34) regulated in its rotational speed and the pump (34) is driven by a motor (36) upon a path difference of the hydraulic cylinders (14, 16) or an angle of inclination of the lifting mast, wherein the rotational direction of the motor (36) is a prognostic function of the path difference, the angle of inclination respectively.
  5. The lifting mast according to claim 4, characterized in that a restrictor (38) is connected in parallel to the pump (34).
  6. The lifting mast according to claim 4 or 5, characterized in that a control valve (40) is disposed in the connecting line between the lines, which is normally closed, although opened when pump (34) is in operation.
  7. The lifting mast according to claim 3 or 4, characterized in that a controllable triple/three-way valve with two input connections to the hydraulic cylinders (14, 16) is disposed parallel to the volume or flow divider (30), while an output connection connects to the tank (44) and the regulating device controls the valve (42) based on the path difference or angle of inclination such that one of the two hydraulic cylinders (14, 16) is connected to the tank (44).
  8. The lifting mast according to claim 3, characterized in that each hydraulic cylinder (14, 16) is assigned a controllable lifting/lowering valve (46, 48) disposed at the outlet of a hydraulic pump (50) and the regulating device controls one of the two lifting/lowering valves (46, 48) based on the path difference such that the path difference will be zero.
EP06021245A 2005-10-22 2006-10-10 Lift truck with a support leg arrangement Expired - Fee Related EP1780171B1 (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE102005050733A DE102005050733A1 (en) 2005-10-22 2005-10-22 Lifting mast for shelf stacking truck has fixed mast with movable mast controlled by measuring mast deflection and regulating side mounted drives

Publications (3)

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EP1780171A2 EP1780171A2 (en) 2007-05-02
EP1780171A3 EP1780171A3 (en) 2007-06-06
EP1780171B1 true EP1780171B1 (en) 2013-02-20

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EP06021245A Expired - Fee Related EP1780171B1 (en) 2005-10-22 2006-10-10 Lift truck with a support leg arrangement

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US (1) US20070089934A1 (en)
EP (1) EP1780171B1 (en)
CN (1) CN1994855B (en)
DE (1) DE102005050733A1 (en)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102007042878A1 (en) 2007-09-08 2009-03-12 Jungheinrich Aktiengesellschaft Hochhubflurförderzeug
EP2465812B1 (en) * 2010-12-16 2013-11-06 BT Products AB Industrial truck comprising an extendable mast
CN103288008A (en) * 2012-02-26 2013-09-11 吴涛慧 Loading and unloading vehicle with long roll shaft
CN104595480B (en) * 2015-01-05 2018-06-08 安徽维麦重工股份有限公司 A kind of internal combustion hydraulic fork lift is driven safety-restraint system
DE102017121818A1 (en) 2017-09-20 2019-03-21 Jungheinrich Ag Industrial truck, hydraulic system for an industrial truck and method for operating a hydraulic system

Family Cites Families (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DD30489A (en) *
US3782503A (en) * 1972-12-14 1974-01-01 Anderson Clayton & Co Mast stabilizer for lift trucks
WO1981003014A1 (en) * 1980-04-14 1981-10-29 Towmotor Corp Load lifting carriage and mast assembly
US4337959A (en) * 1980-06-05 1982-07-06 International Harvester Co. Self-leveling and height control hydraulic system
US4335894A (en) * 1980-06-05 1982-06-22 International Harvester Co. Implement level lift system with rephasing valves
US4395189A (en) * 1981-02-02 1983-07-26 Munten Gerard H Dual mast lift truck for unbalanced loads and the like
IT1187790B (en) * 1985-06-24 1987-12-23 Corghi Elettromecc Spa HYDRAULIC CONTROL SYSTEM FOR LIFT BRIDGES OF VEHICLES IN GENERAL
US4782920A (en) * 1987-02-04 1988-11-08 Cascade Corporation Load-lifting mast especially adapted for use with automatically-guided vehicles
SE469485B (en) * 1991-11-29 1993-07-12 Jan Lindholm PROCEDURE AND FLOW CONTROL VALVE STREAM FOR FLOW BALANCE
NL9200589A (en) * 1992-03-30 1993-10-18 Meijer Sjoerd HYDRAULIC DEVICE WITH SIMILAR AUGERS.
US5335499A (en) * 1992-09-24 1994-08-09 Viking Engineering & Development, Incorporated Multiple hydraulic actuators with series/parallel operation
FR2749630B1 (en) * 1996-06-07 1998-10-09 Lohr Ind DEVICE FOR MANEUVERING A CARRIER STRUCTURE FROM A TORQUE OF SCREWS EACH CARRYING A TRANSLATION NUT
CN2291407Y (en) * 1996-11-22 1998-09-16 刘水章 Double hydraulic motor driving device for electric balanced heavy-duty fork-lift truck
EP0866027B1 (en) * 1997-03-21 2004-05-26 Kabushiki Kaisha Toyota Jidoshokki Hydraulic control apparatus for industrial vehicles
JPH11171492A (en) * 1997-12-15 1999-06-29 Toyota Autom Loom Works Ltd Industrial vehicular data setting device and industrial vehicle
US6189432B1 (en) * 1999-03-12 2001-02-20 Hunter Engineering Company Automotive lift hydraulic fluid control circuit
GB2387372B (en) * 2002-04-10 2005-06-29 Lansing Linde Ltd Industrial truck
DE10321487A1 (en) * 2003-05-13 2004-12-02 Still Wagner Gmbh & Co. Kg Thrust mast stacker for placing loads into and out of shelves, has actuators that define position of multi-lift in longitudinal direction and inclination of multi-lift relative to slope axis
DE10342436B3 (en) * 2003-09-11 2005-03-17 Jungheinrich Ag Pump unit for manual fork lift truck has three-stage control valve with three no-return valves and switching valve
DE10349123A1 (en) * 2003-10-22 2005-05-19 Still Wagner Gmbh & Co Kg Hoist, especially for a high rack forklift

Also Published As

Publication number Publication date
US20070089934A1 (en) 2007-04-26
EP1780171A2 (en) 2007-05-02
CN1994855A (en) 2007-07-11
DE102005050733A1 (en) 2007-04-26
CN1994855B (en) 2013-11-13
EP1780171A3 (en) 2007-06-06

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