EP0931758B1 - Lift truck with dampening device - Google Patents

Lift truck with dampening device Download PDF

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Publication number
EP0931758B1
EP0931758B1 EP99100741A EP99100741A EP0931758B1 EP 0931758 B1 EP0931758 B1 EP 0931758B1 EP 99100741 A EP99100741 A EP 99100741A EP 99100741 A EP99100741 A EP 99100741A EP 0931758 B1 EP0931758 B1 EP 0931758B1
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EP
European Patent Office
Prior art keywords
piston
damping
arrangement according
transport arrangement
load
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
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EP99100741A
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German (de)
French (fr)
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EP0931758A1 (en
Inventor
Eugen Prinz
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Still Wagner GmbH and Co KG
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Still Wagner GmbH and Co KG
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Publication of EP0931758A1 publication Critical patent/EP0931758A1/en
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    • BPERFORMING OPERATIONS; TRANSPORTING
    • B66HOISTING; LIFTING; HAULING
    • B66FHOISTING, 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
    • B66F9/00Devices for lifting or lowering bulky or heavy goods for loading or unloading purposes
    • B66F9/06Devices 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
    • B66F9/075Constructional features or details
    • B66F9/20Means for actuating or controlling masts, platforms, or forks
    • B66F9/22Hydraulic devices or systems
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B66HOISTING; LIFTING; HAULING
    • B66FHOISTING, 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
    • B66F9/00Devices for lifting or lowering bulky or heavy goods for loading or unloading purposes
    • B66F9/06Devices 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
    • B66F9/075Constructional features or details
    • B66F9/08Masts; Guides; Chains

Definitions

  • the invention relates to a transport arrangement with an industrial truck, in particular Pallet stacker, and a load formed by a pallet or a lattice box, the air handling vehicle being an arbitrarily controllable lifting device for lifting and Lowering the load picked up by the lifting device, wherein the load is settable on a road surface by lowering the lifting device and wherein a damping device is provided to delay the lowering movement is ,.
  • the lifting device of industrial trucks of the type mentioned can be of a Operator can be controlled arbitrarily. Formed by pallets or lattice boxes Loads can be driven under with a load fork attached to the lifting device then be raised. When the load on the fork again to be parked on the road surface, the lifting device is on lowest position lowered In order to damage the load by a too fast To avoid touching down on the road surface, it is necessary to Lower the lowering speed of the lifting device in good time.
  • the lowering speed of the Operator can be specified continuously or multi-stage via an operating element.
  • the control element is usually a on a housing of the industrial truck arranged lever connected to a hydraulic valve provided.
  • lever has ergonomic disadvantages due to its size and location on.
  • this is Control element for the lifting device designed as an electrical switching element and arranged on a control drawbar of the industrial truck.
  • EP 0 622 331 A1 discloses a hydraulic lifting cylinder To provide the truck with a cushioning that is just before the End position of the lifting cylinder piston is effective, but not at the time the lowering movement at which the pallet comes into contact with the road surface To ensure that the load is placed gently on the road surface, thus also a sensitive one in the arrangement described in EP 0 622 331 A1 Control of lowering speed required by the operator.
  • the present invention is therefore based on the object of a generic To provide transport arrangement in which a sensitive setting of the Load on the road surface is easily possible.
  • the damping device is designed so that during the lowering movement of the lifting device, before the impact of the load on the road surface.
  • the Damping device Through the Damping device is the lowering speed of the lifting device before Impact of the load on the road surface automatically reduced A conscious Control of this process by the operator is therefore unnecessary. A Damage to a load due to a violent impact on the Road surface can be practically excluded.
  • the damping device lasts at most for the last 25th Centimeters of the lowering movement of the lifting device before lowering the load the road surface is effective. Results will be particularly useful reached when the damping device at most on the last 15 centimeters of the Lowering movement of the lifting device before placing the load on the Road surface is effective. Along the predominant section of the Lowering movement of the lifting device takes place with maximum Speed Only the last few centimeters before touching the Road surface is the lowering movement by means of the invention Damping device braked.
  • the lifting device has a hydraulic lifting cylinder and the Damping device is in operative connection with the hydraulic lifting cylinder, there is the advantage that no additional components for damping the Lowering movements are required.
  • the damping device is advantageously in the hydraulic Integrated lifting cylinder. There are special advantages if the Damping device as end position damping of the hydraulic lifting cylinder is executed.
  • the end position of the lifting cylinder corresponds to the lowest position the lifting device. Before reaching this lowest position, the Lowering movement braked by the end position damping of the lifting cylinder.
  • piston rod, the piston and the damping piston are hollow cylindrical are formed, there is the advantage that hydraulic fluid through the lifting cylinder through to other consumers.
  • damping device offers special Advantages if the industrial truck is designed as a pallet truck. At Pallet stackers on the one hand have the need to quickly lower a load enable, on the other hand, a gentle placement of the load on the To enable road surface.
  • An electrical one can expediently be used to control the lifting device Switching element can be provided.
  • the switching element is preferably on one Control drawbar of the truck arranged.
  • a pedestrian-controlled high-lift truck is shown in FIG. 1 as an industrial truck Industrial truck is in the area of a drive part 20 with at least one Drive wheel and with usually at least one caster on one Road surface on. The drive wheel and the caster are not in the figure shown.
  • the truck with two load rollers is located in the area of a load part 21 22 on the road surface, the load rollers on each wheel arm (Fig. 2, item 30) are attached directly or indirectly.
  • the wheel arms are shown in FIG a load fork 23 covered, which is shown in its lowest position.
  • the load fork 23 is raised and lowered on a mast 25 by means of a load carriage 24 attached movably.
  • the mast 25 has two not vertically movable Outer masts 25a and two slidable along the outer masts 25a, with rollers 26 guided inner masts 25b.
  • the load carriage 24 is in turn with rollers 27 in the profiles of the inner masts 25b guided vertically.
  • On the load carriage 24 are two lifting chains 27 (only the right lifting chain in the drawing can be seen) attached, which is mounted on the vertically movable inner masts 25b guide rollers 28 are guided and on a cross member 29 connected to the outer masts 25a are attached.
  • Two lifting cylinders (only the left lifting cylinder in the drawing is recognizable) are arranged on the sides of the mast 25, one not vertically movable cylinder housing 1 of the lifting cylinder on the outer mast 25a is attached and an extendable piston rod 10 on one with the vertically movable inner masts 25b connected cross member 31 attacks.
  • the load part of the truck is shown in a front view
  • Load fork 23 is shown in its lowest position above load fork 23 there is a load placed on the road surface 32, in this Embodiment a pallet 33.
  • the pallet 33 can be raised. If the load fork is lowered again, the Pallet 33 on the road surface 32, a short time later the fork reaches their lowest position shown, in which the piston rod 10 completely in the Cylinder body 1 is retracted before hitting the pallet 33 on the
  • a damping device becomes effective on the road surface, which brakes the lowering movement of the load fork 23.
  • the damping device described below can be used with industrial trucks or used without an initial lifting device.
  • an initial lifting device can the entire load part 21 relative to the drive part 20 by a few centimeters be raised, the vertical distance between the load rollers 22 to the Radarmen 30 is enlarged.
  • Figure 3 shows a damping device which in the lower portion of the hydraulic lifting cylinder is integrated within the cylinder housing 1 is an axial Slidable piston 4 is arranged, which is connected to the piston rod 10. in the Contrary to the figure representation, piston 4 and piston rod 10 can also be formed in one piece. Is between the piston 4 and the cylinder housing 1 an annular gap of small width is provided.
  • the piston 4 has a cylindrical Bore 8 in which a hollow cylindrical damping piston 11 is arranged.
  • the hollow cylindrical damping piston 11 has in its lower, the Area facing cylinder bottom 2 at least one opening 16; only the For the sake of clarity, only one opening 16 is shown in the figure.
  • the Hollow cylindrical damping piston 11 is in the cylindrical bore 8 of the piston 4th axially displaceable He is also by means of a spring 15 in the direction of Inlet and outlet opening 3 biased. Furthermore, the damping piston 15 a stop 13 through which the maximum relative displacement of the Damping piston 11 is limited relative to the piston 4.
  • the spring 15 supports at its upper end facing away from the cylinder base 2 on an annular Part 9 of the piston rod 10 from.
  • the piston 4 has one on its side facing the cylinder bottom 2 Pressure receiving surface 5, which is within the cylinder bore and in height the cylinder chamber 6 arranged in the inlet and outlet opening 3 determines or defines.
  • Another annular cylinder chamber 7 is through the inner surface of the Cylinder housing 1 and defined by the outer surface of the piston rod 10.
  • the remaining hydraulic medium in the cylinder chamber 6 can only do more through the opening 16 of the damping piston 11 into the cylindrical bore 14 and pass through this into the inlet and outlet opening 3. With a corresponding Dimensioning of the openings) 16, this transfer occurs from hydraulic medium the cylinder chamber 6 in the cylindrical space 14 such that the lowering movement in its last section is significantly delayed and a load without impact on the the road surface is set down.

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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 betrifft eine Transportanordnung mit einem Flurförderzeug, insbesondere Hochhubwagen, und einer von einer Palette oder einer Gitterbox gebildeten Last, wobei das Fluflörderzeug eine willkürlich steuerbare Hubvorrichtung zum Anheben und Absenken der mit der Hubvorrichtung aufgenommenen Last aufweist, wobei die Last durch Absenken der Hubvorrichtung auf einer Fahrbahnoberfläche absetzbar ist und wobei eine Dämpfungsvorrichtung zum Verzögern der Absenkbewegung vorgesehen ist,.The invention relates to a transport arrangement with an industrial truck, in particular Pallet stacker, and a load formed by a pallet or a lattice box, the air handling vehicle being an arbitrarily controllable lifting device for lifting and Lowering the load picked up by the lifting device, wherein the load is settable on a road surface by lowering the lifting device and wherein a damping device is provided to delay the lowering movement is ,.

Die Hubvorrichtung von Flurförderzeugen der genannten Art kann von einer Bedienperson willkürlich gesteuert werden. Von Paletten oder Gitterboxen gebildete Lasten können mit einer an der Hubvorrichtung befestigten Lastgabel unterfahren und anschließend angehoben werden. Wenn die auf der Lastgabel befindliche Last wieder auf der Fahrbahnoberfläche abgestellt werden soll, wird die Hubvorrichtung auf ihre niedrigste Position abgesenkt Um eine Beschädigung der Last durch ein zu schnelles Aufsetzen auf der Fahrbahnoberfläche zu vermeiden, ist es erforderlich, die Absenkgeschwindigkeit der Hubvorrichtung rechtzeitig zu verringern.The lifting device of industrial trucks of the type mentioned can be of a Operator can be controlled arbitrarily. Formed by pallets or lattice boxes Loads can be driven under with a load fork attached to the lifting device then be raised. When the load on the fork again to be parked on the road surface, the lifting device is on lowest position lowered In order to damage the load by a too fast To avoid touching down on the road surface, it is necessary to Lower the lowering speed of the lifting device in good time.

Bei Geräten des Standes der Technik kann die Absenkgeschwindigkeit von der Bedienperson über ein Bedienelement stufenlos oder mehrstufig vorgegeben werden. Als Bedienelement ist hierzu üblicherweise ein an einem Gehäuse des Flurförderzeugs angeordneter, mit einem Hydraulikventil verbundener Hebel vorgesehen. Ein solcher Hebel weist jedoch aufgrund seiner Größe und seiner Lage ergonomische Nachteile auf. In einer anderen, ergonomisch günstigeren Ausführungsform ist das Bedienelement für die Hubvorrichtung als elektrisches Schaltelement ausgeführt und an einer Steuerdeichsel des Flurförderzeugs angeordnet Bei dieser Lösung besteht das Problem, daß ein feinfühliges Steuern der Senkgeschwindigkeit aufgrund der kurzen Schaltwege des elektrischen Schaltelements nur sehr schwer möglich ist Bei allen genannten Geräten des Standes der Technik besteht das Problem, daß ein sanftes Absetzen der Last auf der Fahrbahnoberfläche von der Bedienperson ein großes Maß an Übung, Konzentration und Feinfühligkeit erfordert.In devices of the prior art, the lowering speed of the Operator can be specified continuously or multi-stage via an operating element. For this purpose, the control element is usually a on a housing of the industrial truck arranged lever connected to a hydraulic valve provided. Such a However, lever has ergonomic disadvantages due to its size and location on. In another, more ergonomically advantageous embodiment, this is Control element for the lifting device designed as an electrical switching element and arranged on a control drawbar of the industrial truck This solution exists the problem that a sensitive control of the lowering speed due to the Short switching distances of the electrical switching element is very difficult to achieve All the above-mentioned devices of the prior art have the problem that a the operator gently deposits the load on the road surface requires a great deal of practice, concentration and sensitivity.

Aus der EP 0 622 331 A1 ist es bekannt, einen hydraulischen Hubzylinder eines Flurförderzeugs mit einer Endlagendämpfung zu versehen, die kurz vor der Endstellung des Hubzylinderkolbens wirksam wird, jedoch noch nicht zu dem Zeitpunkt der Absenkbewegung, zu dem die Palette mit der Fahrbahnoberfläche in Kontakt tritt Um ein sanftes Aufsetzen der Last auf der Fahrbahnoberfläche zu gewährleisten, ist also auch bei der in der EP 0 622 331 A1 beschriebenen Anordnung ein feinfühliges Steuern der Senkgeschwindigkeit durch die Bedienperson erforderlich. EP 0 622 331 A1 discloses a hydraulic lifting cylinder To provide the truck with a cushioning that is just before the End position of the lifting cylinder piston is effective, but not at the time the lowering movement at which the pallet comes into contact with the road surface To ensure that the load is placed gently on the road surface, thus also a sensitive one in the arrangement described in EP 0 622 331 A1 Control of lowering speed required by the operator.

Der vorliegenden Erfindung liegt daher die Aufgabe zugrunde, eine gattungsgemäße Transportanordnung zur Verfügung zu stellen, bei dem ein feinfühliges Absetzen der Last auf der Fahrbahnoberfläche auf einfache Weise möglich ist.The present invention is therefore based on the object of a generic To provide transport arrangement in which a sensitive setting of the Load on the road surface is easily possible.

Diese Aufgabe wird erfindungsgemäß dadurch gelöst, daß die Dämpfungsvorrichtung derart ausgeführt ist, daß sie während der Absenkbewegung der Hubvorrichtung, vor dem Auftreffen der Last auf der Fahrbahnoberfläche, wirksam wird. Durch die Dämpfungsvorrichtung wird die Absenkgeschwindigkeit der Hubvorrichtung vor dem Auftreffen der Last auf der Fahrbahnoberfläche automatisch verringert Eine bewußte Steuerung dieses Vorgangs durch die Bedienperson wird somit überflüssig. Eine Beschädigung einer aufgenommenen Last infolge eines heftigen Aufsetzens auf der Fahrbahnoberfläche kann praktisch ausgeschlossen werden.This object is achieved in that the damping device is designed so that during the lowering movement of the lifting device, before the impact of the load on the road surface. Through the Damping device is the lowering speed of the lifting device before Impact of the load on the road surface automatically reduced A conscious Control of this process by the operator is therefore unnecessary. A Damage to a load due to a violent impact on the Road surface can be practically excluded.

Zweckmäßig ist es, wenn die Dämpfungsvorrichtung höchstens auf den letzten 25 Zentimetern der Absenkbewegung der Hubvorrichtung vor dem Absetzen der Last auf der Fahrbahnoberfläche wirksam ist. Besonders zweckmäßige Ergebnisse werden erreicht, wenn die Dämpfungsvorrichtung höchstens auf den letzten 15 Zentimetern der Absenkbewegung der Hubvorrichtung vor dem Absetzen der Last auf der Fahrbahnoberfläche wirksam ist. Entlang des überwiegenden Abschnitts der Absenkbewegung der Hubvorrichtung erfolgt das Absenken mit maximaler Geschwindigkeit Erst auf den letzten Zentimetern vor dem Berühren der Fahrbahnoberfläche wird die Absenkbewegung mittels der erfindungsgemäßen Dämpfungsvorrichtung abgebremst.It is expedient if the damping device lasts at most for the last 25th Centimeters of the lowering movement of the lifting device before lowering the load the road surface is effective. Results will be particularly useful reached when the damping device at most on the last 15 centimeters of the Lowering movement of the lifting device before placing the load on the Road surface is effective. Along the predominant section of the Lowering movement of the lifting device takes place with maximum Speed Only the last few centimeters before touching the Road surface is the lowering movement by means of the invention Damping device braked.

Wenn die Hubvorrichtung einen hydraulischen Hubzylinder aufweist und die Dämpfungsvorrichtung mit dem hydraulischen Hubzylinder in Wirkverbindung steht, ergibt sich der Vorteil, daß keine zusätzlichen Bauteile zum Dämpfen der Absenkbewegung erforderlich sind.If the lifting device has a hydraulic lifting cylinder and the Damping device is in operative connection with the hydraulic lifting cylinder, there is the advantage that no additional components for damping the Lowering movements are required.

Vorteilhafterweise ist hierbei die Dämpfungsvorrichtung in dem hydraulischen Hubzylinder integriert. Besondere Vorteile ergeben sich, wenn die Dämpfungsvorrichtung als Endlagendämpfung des hydraulischen Hubzylinders ausgeführt ist. Die Endlage des Hubzylinders entspricht hierbei der tiefsten Position der Hubvorrichtung. Vor dem Erreichen dieser tiefsten Position wird die Absenkbewegung von der Endlagendämpfung des Hubzylinders abgebremst.The damping device is advantageously in the hydraulic Integrated lifting cylinder. There are special advantages if the Damping device as end position damping of the hydraulic lifting cylinder is executed. The end position of the lifting cylinder corresponds to the lowest position the lifting device. Before reaching this lowest position, the Lowering movement braked by the end position damping of the lifting cylinder.

Vorteilhafterweise weist der Hubzylinder die folgenden Merkmale auf:

  • ein Zylindergehäuse, in dem ein mit einer Kolbenstange verbundener Kolben axial verschiebbar angeordnet ist,
  • einen hohlzylindrischen Dämpfungskolben, der in seinem einem Zylinderboden zugewandten Bereich wenigstens eine Öffnung aufweist, in der zylindrischen Bohrung des Kolbens axial verschiebbar angeordnet ist, mittels einer Feder in Richtung einer in dem Zylinderboden vorgesehenen Ein- und Auslaßöffnung für ein Hydraulikmedium vorgespannt ist und wenigstens einen Anschlag aufweist, der die maximale Relativverschiebung des Dämpfungskolbens gegenüber dem Kolben begrenzt
The lifting cylinder advantageously has the following features:
  • a cylinder housing in which a piston connected to a piston rod is arranged so as to be axially displaceable,
  • a hollow cylindrical damping piston which has at least one opening in its area facing a cylinder bottom, is axially displaceably arranged in the cylindrical bore of the piston, is biased by a spring in the direction of an inlet and outlet opening for a hydraulic medium provided in the cylinder bottom, and at least one stop has, which limits the maximum relative displacement of the damping piston relative to the piston

Wenn sich der Kolben und die Kolbenstange auf eine Position in der Nähe der Ein- und Auslaßöffnung zubewegen oder von dieser Position wegbewegen, der Dämpfungskolben auf dem Ventilsitz bereits bzw. noch aufsitzt, dann ist die Zylinderkammer nur über die Öffnung des Dämpfungskolbens mit der Ein- und Auslaßöffnung verbunden ist Eine derartige Endlagendämpfung ist für einen Hydraulikzylinder für allgemeine Anwendungen bereits aus der DE 297 07 639 U1 bekannt.When the piston and piston rod are in a position close to the inlet and Move or move the exhaust port away from that position Damping piston already or still sits on the valve seat, then that is Cylinder chamber only through the opening of the damping piston with the inlet and Outlet opening is connected Such a cushioning is for one Hydraulic cylinders for general applications already from DE 297 07 639 U1 known.

Wenn die Kolbenstange, der Kolben und der Dämpfungskolben hohlzylindrisch ausgebildet sind, ergibt sich der Vorteil, daß Hydraulikfluid durch den Hubzylinder hindurch zu weiteren Verbrauchern geleitet werden kann.If the piston rod, the piston and the damping piston are hollow cylindrical are formed, there is the advantage that hydraulic fluid through the lifting cylinder through to other consumers.

Die Verwendung einer erfindungsgemäßen Dämpfungseinrichtung bietet besondere Vorteile, wenn das Flurförderzeug als Hochhubwagen ausgeführt ist. Bei Hochhubwagen besteht einerseits das Bedürfnis, ein schnelles Absenken einer Last zu ermöglichen, andererseits jedoch ein sanftes Aufsetzen der Last auf der Fahrbahnoberfläche zu ermöglichen.The use of a damping device according to the invention offers special Advantages if the industrial truck is designed as a pallet truck. At Pallet stackers on the one hand have the need to quickly lower a load enable, on the other hand, a gentle placement of the load on the To enable road surface.

Zweckmäßigerweise kann zur Steuerung der Hubvorrichtung ein elektrisches Schaltelement vorgesehen sein. Das Schaltelement ist vorzugsweise an einer Steuerdeichsel des Flurförderzeugs angeordnet. An electrical one can expediently be used to control the lifting device Switching element can be provided. The switching element is preferably on one Control drawbar of the truck arranged.

Weitere Vorteile und Einzelheiten der Erfindung werden anhand des in den schematischen Figuren dargestellten Ausführungsbeispiels näher erläutert. Dabei zeigt

Figur 1
ein zur Erfindung gehörendes Flurförderzeug,
Figur 2
den Lastteil des Flurförderzeugs mit einer Palette,
Figur 3
den unteren Abschnitt eines hydraulischen Hubzylinders.
Further advantages and details of the invention are explained in more detail with reference to the embodiment shown in the schematic figures. It shows
Figure 1
an industrial truck belonging to the invention,
Figure 2
the load part of the truck with a pallet,
Figure 3
the lower section of a hydraulic jack.

Als Flurförderzeug ist in Figur 1 ein deichselgeführter Hochhubwagen dargestellt Das Flurförderzeug steht im Bereich eines Antriebsteils 20 mit mindestens einem Antriebsrad und mit in der Regel mindestens einer Schwenkrolle auf einer Fahrbahnoberfläche auf. Das Antriebsrad und die Schwenkrolle sind in der Figur nicht dargestellt. Im Bereich eines Lastteils 21 steht das Flurförderzeug mit zwei Lastrollen 22 auf der Fahrbahnoberfläche auf, wobei die Lastrollen an jeweils einem Radarm (Fig. 2, Pos. 30) direkt oder indirekt befestigt sind. Die Radarme sind in der Figur 1 durch eine Lastgabel 23 verdeckt, die in ihrer untersten Position dargestellt ist.A pedestrian-controlled high-lift truck is shown in FIG. 1 as an industrial truck Industrial truck is in the area of a drive part 20 with at least one Drive wheel and with usually at least one caster on one Road surface on. The drive wheel and the caster are not in the figure shown. The truck with two load rollers is located in the area of a load part 21 22 on the road surface, the load rollers on each wheel arm (Fig. 2, item 30) are attached directly or indirectly. The wheel arms are shown in FIG a load fork 23 covered, which is shown in its lowest position.

Die Lastgabel 23 ist mittels eines Lastschlittens 24 an einem Hubgerüst 25 auf- und abbewegbar befestigt. Das Hubgerüst 25 weist zwei nicht höhenbewegliche Außenmasten 25a und zwei entlang der Außenmasten 25a verschiebbare, mit Rollen 26 geführte Innenmasten 25b auf. Der Lastschlitten 24 wiederum ist mit Rollen 27 in den Profilen der Innenmasten 25b höhenbeweglich geführt. An dem Lastschlitten 24 sind zwei Hubketten 27 (nur die in der Zeichnung rechte Hubkette ist erkennbar) befestigt, die über an den höhenbeweglichen Innenmasten 25b gelagerte Umlenkrollen 28 geführt sind und an einem mit den Außenmasten 25a verbundenen Querträger 29 befestigt sind. Zwei Hubzylinder (nur der in der Zeichnung linke Hubzylinder ist erkennbar) sind an den Seiten des Hubgerüsts 25 angeordnet, wobei ein nicht höhenbewegliches Zylindergehäuse 1 des Hubzylinders an dem Außenmast 25a befestigt ist und eine ausfahrbare Kolbenstange 10 an einem mit den höhenbeweglichen Innenmasten 25b verbundenen Querträger 31 angreift. The load fork 23 is raised and lowered on a mast 25 by means of a load carriage 24 attached movably. The mast 25 has two not vertically movable Outer masts 25a and two slidable along the outer masts 25a, with rollers 26 guided inner masts 25b. The load carriage 24 is in turn with rollers 27 in the profiles of the inner masts 25b guided vertically. On the load carriage 24 are two lifting chains 27 (only the right lifting chain in the drawing can be seen) attached, which is mounted on the vertically movable inner masts 25b guide rollers 28 are guided and on a cross member 29 connected to the outer masts 25a are attached. Two lifting cylinders (only the left lifting cylinder in the drawing is recognizable) are arranged on the sides of the mast 25, one not vertically movable cylinder housing 1 of the lifting cylinder on the outer mast 25a is attached and an extendable piston rod 10 on one with the vertically movable inner masts 25b connected cross member 31 attacks.

Durch Ausfahren der Kolbenstange 10 können die Innenmasten 25b mit den Umlenkrollen 28 nach oben bewegt werden, wodurch der Lastschlitten 24 mit der Lastgabel 23 nach oben gezogen wird.By extending the piston rod 10, the inner masts 25b with the Deflection rollers 28 are moved upward, whereby the load carriage 24 with the Load fork 23 is pulled up.

In Figur 2 ist der Lastteil des Flurförderzeugs in frontaler Ansicht dargestellt Die Lastgabel 23 ist in ihrer tiefsten Position dargestellt Oberhalb der Lastgabel 23 befindet sich eine auf der Fahrbahnoberfläche 32 abgestellte Last, in diesem Ausführungsbeispiel eine Palette 33. Durch Anheben der Lastgabel 23 kann die Palette 33 angehoben werden. Wenn die Lastgabel wieder abgesenkt wird, setzt zunächst die Palette 33 auf der Fahrbahnoberfläche 32 auf, kurze Zeit später erreicht die Lastgabel ihre dargestellte tiefste Position, in der die Kolbenstange 10 vollständig in den Zylinderkörper 1 eingefahren ist Vor dem Auftreffen der Palette 33 auf der Fahrbahnoberfläche wird erfindungsgemäß eine Dämpfungsvorrichtung wirksam, welche die Absenkbewegung der Lastgabel 23 abbremst.In Figure 2, the load part of the truck is shown in a front view Load fork 23 is shown in its lowest position above load fork 23 there is a load placed on the road surface 32, in this Embodiment a pallet 33. By lifting the load fork 23, the pallet 33 can be raised. If the load fork is lowered again, the Pallet 33 on the road surface 32, a short time later the fork reaches their lowest position shown, in which the piston rod 10 completely in the Cylinder body 1 is retracted before hitting the pallet 33 on the According to the invention, a damping device becomes effective on the road surface, which brakes the lowering movement of the load fork 23.

Die nachfolgend beschriebene Dämpfungsvorrichtung kann bei Flurförderzeugen mit oder ohne Initialhubvorrichtung eingesetzt werden. Mittels einer Initialhubvorrichtung kann der gesamte Lastteil 21 relativ zum Antriebsteil 20 um einige Zentimeter angehoben werden, wobei hierzu der vertikale Abstand der Lastrollen 22 zu den Radarmen 30 vergrößert wird.The damping device described below can be used with industrial trucks or used without an initial lifting device. Using an initial lifting device can the entire load part 21 relative to the drive part 20 by a few centimeters be raised, the vertical distance between the load rollers 22 to the Radarmen 30 is enlarged.

Figur 3 zeigt eine Dämpfungsvorrichtung, die in den unteren Abschnitt des hydraulischen Hubzylinders integriert ist Innerhalb des Zylindergehäuses 1 ist ein axial verschiebbarer Kolben 4 angeordnet, der mit der Kolbenstange 10 verbunden ist. Im Gegensatz zu der Figurendarstellung können Kolben 4 und Kolbenstange 10 auch einstückig ausgebildet sein. Zwischen dem Kolben 4 und dem Zylindergehäuse 1 ist ein Ringspalt von geringer Breite vorgesehen. Der Kolben 4 weist eine zylindrische Bohrung 8 auf, in der ein hohlzylindrischer Dämpfungskolben 11 angeordnet ist.Figure 3 shows a damping device which in the lower portion of the hydraulic lifting cylinder is integrated within the cylinder housing 1 is an axial Slidable piston 4 is arranged, which is connected to the piston rod 10. in the Contrary to the figure representation, piston 4 and piston rod 10 can also be formed in one piece. Is between the piston 4 and the cylinder housing 1 an annular gap of small width is provided. The piston 4 has a cylindrical Bore 8 in which a hollow cylindrical damping piston 11 is arranged.

Der hohlzylindrische Dämpfungskolben 11 besitzt in seinem unteren, dem Zylinderboden 2 zugewandten Bereich wenigstens eine Öffnung 16; lediglich der Übersichtlichkeit halber ist in der Figur nur eine Öffnung 16 dargestellt. Der hohlzylindrische Dämpfungskolben 11 ist in der zylindrischen Bohrung 8 des Kolbens 4 axial verschiebbar angeordnet Er ist ferner mittels einer Feder 15 in Richtung der Ein- und Auslaßöffnung 3 vorgespannt. Desweiteren weist der Dämpfungskolben 15 einen Anschlag 13 auf, durch den die maximale Relativerschiebung des Dämpfungskolbens 11 gegenüber dem Kolben 4 begrenzt wird. Die Feder 15 stützt sich an ihrem oberen, dem Zylinderboden 2 abgewandten Ende an einem ringförmigen Teil 9 der Kolbenstange 10 ab.The hollow cylindrical damping piston 11 has in its lower, the Area facing cylinder bottom 2 at least one opening 16; only the For the sake of clarity, only one opening 16 is shown in the figure. The Hollow cylindrical damping piston 11 is in the cylindrical bore 8 of the piston 4th axially displaceable He is also by means of a spring 15 in the direction of Inlet and outlet opening 3 biased. Furthermore, the damping piston 15 a stop 13 through which the maximum relative displacement of the Damping piston 11 is limited relative to the piston 4. The spring 15 supports at its upper end facing away from the cylinder base 2 on an annular Part 9 of the piston rod 10 from.

Der Kolben 4 weist auf seiner, dem Zylinderboden 2 zugewandten Seite eine Druckaufnahmefläche 5 auf, die eine innerhalb der Zylinderbohrung und in der Höhe der Ein- und Auslaßöffnung 3 angeordnete Zylinderkammer 6 bestimmt bzw. definiert. Eine weitere ringförmige Zylinderkammer 7 wird durch die Innenfläche des Zylindergehäuses 1 sowie durch die Außenfläche der Kolbenstange 10 definiert.The piston 4 has one on its side facing the cylinder bottom 2 Pressure receiving surface 5, which is within the cylinder bore and in height the cylinder chamber 6 arranged in the inlet and outlet opening 3 determines or defines. Another annular cylinder chamber 7 is through the inner surface of the Cylinder housing 1 and defined by the outer surface of the piston rod 10.

Wird der Kolben 4 über die Kolbenstange 10 nach unten, in Richtung des Zylinderbodens 2 bewegt, so trifft zunächst die Unterseite des Dämpfungskolbens 11 auf den Ventilsitz 17. Dieser ist am innersten Ende der Bohrung der Ein- und Auslaßöffnung 3 in dem Zylinderboden 2 ausgebildet Während sich Kolbenstange 10 und Kolben 4 im Gegensatz zu dem bereits ruhenden Dämpfungskolben 11 weiterhin abwärts bewegen, verkleinert sich die Zylinderkammer 6 stetig. Das in der Zylinderkammer 6 befindliche Hydraulikmedium strömt teilweise durch den Ringspalt zwischen dem Kolben 4 und dem Zylindergehäuse 1 in die Zylinderkammer 7.If the piston 4 down over the piston rod 10, in the direction of Cylinder bottom 2 moves, so first hits the bottom of the damping piston 11 on the valve seat 17. This is the inlet and outlet at the innermost end of the bore Outlet opening 3 is formed in the cylinder base 2 while the piston rod 10 and piston 4 in contrast to the damping piston 11, which is already at rest move downward, the cylinder chamber 6 decreases steadily. That in the Hydraulic medium located in the cylinder chamber 6 partially flows through the annular gap between the piston 4 and the cylinder housing 1 into the cylinder chamber 7.

Das restliche in der Zylinderkammer 6 befindliche Hydraulikmedium kann nur mehr durch die Öffnung 16 des Dämpfungskolbens 11 in die zylindrische Bohrung 14 und über diese in die Ein- und Auslaßöffnung 3 gelangen. Bei einer entsprechenden Dimensionierung der Öffnungen) 16 erfolgt dieser Übertritt von Hydraulikmedium aus der Zylinderkammer 6 in den zylindrischen Raum 14 derart, daß die Absenkbewegung in ihrem letzten Abschnitt deutlich verzögert wird und eine Last ohne Stoß auf der auf der Fahrbahnoberfläche abgesetzt wird.The remaining hydraulic medium in the cylinder chamber 6 can only do more through the opening 16 of the damping piston 11 into the cylindrical bore 14 and pass through this into the inlet and outlet opening 3. With a corresponding Dimensioning of the openings) 16, this transfer occurs from hydraulic medium the cylinder chamber 6 in the cylindrical space 14 such that the lowering movement in its last section is significantly delayed and a load without impact on the the road surface is set down.

Claims (12)

  1. Transport arrangement with an industrial truck, in particular a high lift truck, and a load formed by a pallet (33) or a cage pallet, the industrial truck having a lifting device which can be controlled arbitrarily for lifting and loading the load picked up by the lifting device, it being possible for the load to be set down on a roadway surface (32) by lowering the lifting device, and a damping device being provided to retard the lowering movement, characterized in that the damping device is designed in such a way that, during the lowering movement of the lifting device, it becomes effective before the load meets the roadway surface (32).
  2. Transport arrangement according to Claim 1, characterized in that the damping device is effective at most over the last 25 centimetres of the lowering movement of the lifting device before the load is set down on the roadway surface (32).
  3. Transport arrangement according to Claim 1 or 2, characterized in that the damping device is effective at most over the last 15 centimetres of the lowering movement of the lifting device before the load is set down on the roadway surface (32).
  4. Transport arrangement according to one of Claims 1 to 3, characterized in that the lifting device has at least on hydraulic lifting cylinder, and the damping device is operatively connected to the hydraulic lifting cylinder.
  5. Transport arrangement according to Claim 4, characterized in that the damping device is integrated in the hydraulic lifting cylinder.
  6. Transport arrangement according to Claim 4 or 5, characterized in that the damping device is designed as an end-position damping means of the hydraulic lifting cylinder.
  7. Transport arrangement according to Claim 6, characterized in that the lifting cylinder has the following features:
    a cylinder housing (1), in which a piston (4) connected to a piston rod (10) is arranged such that it can be displaced axially,
    a hollow cylindrical damping piston (11) which, in its region facing a bottom of the cylinder (2), has at least one opening (16), is arranged such that it can be displaced axially in the cylindrical bore (8) of the piston (4), is biased by means of a spring (15) in the direction of an inlet and outlet opening (3) for a hydraulic medium provided in the bottom of the cylinder (2), and has at least one stop (13) which limits the maximum relative displacement of the damping piston (11) with respect to the piston (4).
  8. Transport arrangement according to Claim 7, characterized in that if the piston (4) and the piston rod (10) move towards a position in the vicinity of the inlet and outlet opening (3) or move away from this position, the damping piston (11) is already seated or still seated on the valve seat (17), and the cylinder chamber (6) is connected to the inlet and outlet opening (3) only via the opening (16) in the damping piston (11).
  9. Transport arrangement according to Claim 8, characterized in that the piston rod (10), the piston (4) and the damping piston (11) are hollow cylindrical.
  10. Transport arrangement according to one of Claims 1 to 9, characterized in that the industrial truck is designed as a high lift truck.
  11. Transport arrangement according to one of Claims 1 to 10, characterized in that in order to control the lifting device, an electrical switching element is provided.
  12. Transport arrangement according to one of Claims 1 to 11, characterized in that in order to control the lifting device, a switching element arranged on a control tiller of the industrial truck is provided.
EP99100741A 1998-01-21 1999-01-15 Lift truck with dampening device Expired - Lifetime EP0931758B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE19802119A DE19802119A1 (en) 1998-01-21 1998-01-21 Industrial truck with a lifting device
DE19802119 1998-01-21

Publications (2)

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EP0931758A1 EP0931758A1 (en) 1999-07-28
EP0931758B1 true EP0931758B1 (en) 2001-06-13

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EP99100741A Expired - Lifetime EP0931758B1 (en) 1998-01-21 1999-01-15 Lift truck with dampening device

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EP (1) EP0931758B1 (en)
DE (2) DE19802119A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1988297A2 (en) 2007-05-04 2008-11-05 Jungheinrich Aktiengesellschaft Hydraulic cylinder with adjustable end position dampening

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE10340957A1 (en) * 2003-09-05 2005-04-07 Jungheinrich Aktiengesellschaft Damping arrangement for the mast of a truck
DE102004039211A1 (en) * 2004-08-12 2006-02-23 Still Gmbh Mast and hydraulic cylinder with a compensation device
US8731785B2 (en) 2011-03-18 2014-05-20 The Raymond Corporation Dynamic stability control systems and methods for industrial lift trucks
US9403667B2 (en) * 2011-03-18 2016-08-02 The Raymond Corporation Dynamic vibration control systems and methods for industrial lift trucks
US8763990B2 (en) 2012-03-20 2014-07-01 The Raymond Corporation Turn stability systems and methods for lift trucks
US9302893B2 (en) 2013-02-07 2016-04-05 The Raymond Corporation Vibration control systems and methods for industrial lift trucks
ES2787948B2 (en) * 2020-03-11 2021-03-30 Carreras Grupo Logistico S A MACHINE FOR THE SEMI-AUTOMATIC PREPARATION OF FULL LAYERS IN FLEXIBLE ENVIRONMENTS OF HIGH CONSUMPTION WAREHOUSES

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Publication number Priority date Publication date Assignee Title
US4706781A (en) * 1985-02-28 1987-11-17 Kabushiki Kaisha Toyoda Jidoshokki Seisakusho Fluid-operated cylinder with cushioning flow rate control valve means
IT1272114B (en) * 1993-03-19 1997-06-11 Fiat Om Carrelli Elevatori Spa FORK LIFTING UNITS IN FORKLIFTS
DE29707639U1 (en) * 1997-04-28 1997-08-21 Still GmbH, 22113 Hamburg Hydraulic cylinder with shock protection

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1988297A2 (en) 2007-05-04 2008-11-05 Jungheinrich Aktiengesellschaft Hydraulic cylinder with adjustable end position dampening
DE102007021052A1 (en) 2007-05-04 2008-11-06 Jungheinrich Ag Hydraulic cylinder with variable end position damping

Also Published As

Publication number Publication date
EP0931758A1 (en) 1999-07-28
DE59900113D1 (en) 2001-07-19
DE19802119A1 (en) 1999-07-22

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