EP3560885A1 - Industrial truck - Google Patents

Abstract

The invention relates to an industrial truck (1) with a trailer device (20) for transporting trailers and with a lifting device (9) for lifting loads, the lifting device (9) comprising a fork carriage (13) which is connected to a fork-shaped load suspension device (14 ) is provided, wherein the load-carrying means (14) has at least one load section (14a; 14b) which extends around a substantially horizontal first pivot axis (D1) on the fork carriage (13) between a folded-out position and a folded-in position by essentially 90 ° is pivotally arranged. The fork carriage (13) is arranged on a lifting carriage (11) so as to be pivotable about a substantially horizontal second pivot axis (D2). The lifting carriage (11) can be raised and lowered on the lifting device (9). An actuator (25) is provided, with which the fork carriage (13) can be pivoted about the second pivot axis (D2) relative to the lifting carriage (11) and with which the at least one load section (14a; 14b) of the load-carrying means (14) can be pivoted about the first pivot axis (D1) is pivotable relative to the fork carriage (13).

Description

The invention relates to a truck with a trailer hitch for transporting trailers and with a lifting device for lifting loads, wherein the lifting device comprises a fork carriage which is provided with a fork-shaped load-receiving means, wherein the load receiving means has at least one load portion which is a substantially horizontal first pivot axis is arranged on the fork carriage between an unfolded position and a folded position to pivot substantially 90 °.

The intra-company transport of goods and material flow, in particular the supply of material to production lines in production plants, is usually carried out by means of trailers on which the goods to be transported are transported, in particular by means of pallets within the production plant.

For pulling one or more of these trailers trained as a tractor forklifts are used, which are provided with a corresponding hitch to which one or more trailers can be attached. Such trucks should have compact dimensions to safely transport the trailer within a production plant on cramped transport routes can.

For loading and unloading of the trailers designed as a forklift trucks are used, which are provided with a lifting device, such as a mast, to which a fork carriage is arranged up and down movable. On the fork carriage, a load-receiving means, for example, one of two forks existing fork is arranged. Such trucks are to be provided for the safe transport of a load located on the forks with a tilting function for the lifting device, with the tips of the lifting device can be tilted up to a loss of load on the load-carrying means when driving on an irregular road to avoid. The tilting function of the load handler shall be designed for the maximum load in order to keep the load leaning for each load on the load handler Lifting device with the tips to achieve upward. In order to achieve the tilting function of the load-handling device, it is known, the lifting mast on which the fork carriage is arranged liftable and lowered, run tiltable or tiltable to arrange the fork carriage in the mast.

In order to implement the functions pulling trailers and loading and unloading the trailer with a single truck, which combines the function of a compact tractor with the function of a forklift, is from the generic DE 10 2008 036 411 A1 an industrial truck is known, which is provided with a towing device for towing trailers and in which the arranged on a fork carriage, which is arranged in a lifting mast liftable and lowered, arranged forked load-receiving means on and fold-load sections between an unfolded position (function of Truck as a forklift, for example, for loading and unloading the trailer) and a retracted position (function of the truck as a compact tractor for towing trailers) are arranged to substantially 90 ⁰ pivotally mounted on the fork carriage. As a result, a truck is provided in a simple manner, on the one hand has the function of a tractor, due to the folding load sections of the load-receiving device compact dimensions of the truck in the vehicle longitudinal direction when pulling one or more trailers are achieved, and on the other hand has the function of a forklift, with which the trailers can be loaded and unloaded.

The folding function of the load sections of the load receiving means between the unfolded and the folded position is only possible if there is no load on the load sections. The folding function is thus interpreted only on the load-free state.

That from the DE 10 2008 036 411 A1 Known truck is provided with no tilting function of the lifting device to allow tilting the downwardly unfolded lifting device with a load thereon for its safe transport.

The present invention has for its object to provide an industrial truck of the type mentioned, with low construction costs is provided with a folding function of the load sections and a tilting function of the unfolded load sections.

This object is achieved in that the fork carriage is pivotally mounted on a lifting carriage about a substantially horizontal second pivot axis, wherein the lifting of the lifting device is arranged raised and lowered, and an actuator is provided with which the fork carriage about the second pivot axis is pivotable relative to the lifting carriage and with which the at least one load portion of the load receiving means is pivotable about the first pivot axis relative to the fork carriage.

According to the invention, the fork carriage is pivotably arranged on the lifting carriage, which can be raised and lowered on the lifting device, about a substantially horizontal second pivoting axis. In this way, a tilting function of the load sections can be achieved in a simple manner, with which the tips of the downwardly folded load sections can be tilted upward to avoid loss of load on the load handling device when driving on an irregular roadway. According to the invention, furthermore, the load sections are arranged pivotable about a substantially horizontal first pivot axis on the fork carriage between an unfolded position and a folded-in position by substantially 90 °. In this way, the folding function of the load sections can be achieved in a simple manner to achieve compact dimensions of the truck for transporting trailers in the folded position of the load sections. According to the invention, only a single and thus a common actuator is provided for the folding function and the tilting function of the load sections, so that the two functions (folding function of the load sections and tilting functions of the load sections) can be implemented with low construction costs.

The truck according to the invention has the function of a tractor for pulling trailers with load sections folded upwards. With the load sections folded upwards, small dimensions of the truck in the vehicle longitudinal direction can be achieved in order to achieve agile maneuvering in narrow aisles. Preferably, the hitch to which the trailer are coupled, arranged on the fork carriage and thus on the rear of the vehicle. The truck according to the invention has with down unfolded load sections continue the function of a forklift for loading and unloading the trailer and for transporting loads on the unfolded load sections. With the tilting action of the fork carriage, and thus the tilting action of the load sections arranged on the fork carriage, it is possible to tilt the tips of the load sections upwards, so that a loss of the load on the load sections during travel, in particular at high speeds, over an irregular roadway can be safely avoided. In the truck according to the invention is usually the load during their transport in the rear of the truck, so that a driver of the truck does not see the load while driving the truck. With the tilting function of the fork carriage and thus the tilting action of arranged on the fork carriage load sections here the risk of loss of the load located on the unfolded load sections is reliably avoided.

The tilting function of the fork carrier and the load sections preferably consists in a pivoting movement of the fork carrier about the second pivot axis through an angle of 10 ° or less. The tilt function of the fork carriage and the load sections must be available for each load weight of a load transported on the load sections (from 0 kg up to the maximum load / payload of the truck).

The folding function of the load portions preferably consists of a pivoting movement of the load sections about the first pivot axis by approximately 90 ^0th Since the load sections in the folded-up position are located almost in a vertical position, the folding function of the load sections must be available only when there is no load on the load sections, as in the event that a load is on the load sections , the Einklappvorgang the load sections can not be ended up.

The combination of the two different functions of the load sections (folding function and tilting function of the load sections) is technically complex, since the two functions require different force levels. According to the invention, however, not two different actuators, namely a first actuator for the folding function and a second actuator for the tilting function required for the two functions of the load sections (folding function and tilting function of the load sections), but it is a single, common actuator for both Folding function as well as for the tilt function provided. This leads to advantages, since this results in a simple construction with low construction costs and a simple control, since only one actuator must be supplied with energy, which can be further reduce the construction cost.

According to a preferred embodiment of the invention, the actuator is formed by a linear drive which pivots in a first adjustment the fork carriage about the second pivot axis relative to the lifting and pivoted in a second adjustment the at least one load portion of the load receiving means about the first pivot axis relative to the fork carriage. With a linear drive, which pivots in the first adjustment the fork carriage about the second pivot axis relative to the lifting and thus the tilting function of the load sections allows and pivots in a second adjustment the at least one load section of the lifting device about the first pivot axis relative to the fork carriage and thus the folding function achieved the load section, the two function (tilting function and folding function) and the two different movements (fork carriage pivot for tilting function / load sections swing for folding function) can be achieved in a simple manner and with low construction costs.

According to a preferred embodiment of the invention, the actuator is formed by a hydraulic cylinder which is fastened with a cylinder housing on the lifting and has an extendable piston rod which pivots in a first stroke range the fork carriage about the second pivot axis relative to the lifting and in a second stroke range the pivoted at least one load portion of the load receiving means about the first pivot axis relative to the fork carriage. The two functions (tilting function and folding function) and the two different movements (fork carriage pivoting for tilting function / swiveling load sections for folding function) can thus be achieved in a simple manner and with low construction costs by a single hydraulic cylinder.

With particular advantage, at least one first contact body is arranged on the piston rod, which is in operative connection with a vertical contact surface of the lifting carriage, and arranged at least a second contact body, which is in operative connection with a relative to the vertical inclined contact surface of the fork carriage. With Such contact bodies, which are in operative connection with a vertical contact surface of the lifting carriage and with respect to the vertical inclined contact surface of the fork carriage, can be achieved in the first stroke easily pivotal movement of the fork carriage on the lifting carriage to the second pivot axis to the tilting function of Fork carrier and thus to achieve arranged on the fork carriage load sections.

The vertical contact surface of the lifting carriage preferably extends over the first stroke region and the second stroke region of the piston rod, and the inclined contact surface of the fork carrier extends over the first stroke region of the piston rod. This ensures that the fork carriage is pivoted only in the first stroke range and the piston rod can be supported on the vertical contact surface of the lifting carriage both in the first stroke and in the second stroke on the first contact body.

At least one third contact body is preferably arranged on the piston rod, which comes into operative connection in the second stroke region of the piston rod with an actuating device, with which the at least one load portion of the load receiving means is pivotable about the first pivot axis relative to the fork carriage. With such a contact body which comes into operative connection with the actuating device in the second stroke region, which pivots the load sections about the first pivot axis, a pivotal movement of the load sections on the fork carrier about the first pivot axis can be achieved in the second stroke region of the piston rod in a simple manner to achieve the folding function of the load sections.

According to an advantageous embodiment of the invention, the actuating device has a first actuating lever, which is articulated on the fork carrier and supported on the at least one load section of the load receiving means. With such an actuating lever which is actuated directly or indirectly by the piston rod, the load sections can be pivoted about the first pivot axis in a simple manner.

The actuating device can have only the first actuating lever which comes into operative connection directly with the piston rod in the second stroke region and is actuated directly by the piston rod.

According to an advantageous embodiment of the invention, the actuating device has a second actuating lever, which is articulated on the first actuating lever and which is provided with a receptacle for the third contact body. The first actuating lever is thus actuated indirectly by the piston rod. The use of a second actuating lever, which comes into operative connection with the piston rod in the second stroke region and which transmits the forces of the piston rod to the first actuating lever, makes it possible to fold in and out the load sections with small forces to be applied.

Preferably, a second contact body between two first contact bodies is arranged on the piston rod and two third contact body are provided, between which the two first contact body and the second contact body are arranged. On the piston rod thus a total of five contact bodies are arranged. This makes it possible to arrange the second contact body on the longitudinal axis of the piston rod and to arrange the two first contact body and the two third contact body symmetrically to the longitudinal axis of the piston rod, which has a favorable effect on the distribution of forces on the piston rod.

According to an advantageous embodiment of the invention, the contact bodies are designed as rollers rotatably mounted on the piston rod. As a result, during the tilting function and during the folding function, there is no sliding friction but rolling friction on the contact bodies, whereby wear and tear can be minimized.

According to a preferred embodiment of the invention, the first stroke range of the piston rod is greater than the second stroke range of the piston rod. This allows a favorable design of the required forces and the required energy for the tilting function and the folding function. For the folding function usually only low to medium pressures of the hydraulic cylinder are required because the folding function, which is 90 ⁰ , only without resting load, usually in the range 5% of the payload, must be performed. As is the tilting function of the fork carriage, which usually is only 3 ° -10 ° and must be available for the maximum load / payload, thus extending over a wide stroke range of the piston rod, the tilting function can also be implemented with low to medium pressures in the hydraulic cylinder.

With particular advantage, an end stop is provided according to an embodiment of the invention between the lifting carriage and the fork carriage, which limits the pivoting movement of the fork carriage relative to the lifting carriage. With such an end stop, the tilting action with raised tips of the load sections can be easily restricted to a desired value, for example 3 ° -5 °.

Advantageously, the end stop is formed by an elastic element, which is connected to the fork carriage and cooperates with a stop surface of the lifting carriage. With a resilient element as an end stop, a smooth stopping of the pivoting movement of the fork carriage and thus the tilting function can be achieved. If the towing device is arranged on the fork carriage, with the elastic element also in trailer operation of the truck with one or more trailers attached a reduction of the hitch coming from the hitch and shocks when pulling the trailer during acceleration and deceleration can be achieved.

The elastic element is preferably formed as a sleeve, which is arranged on a fastening rod fastened to the fork carriage. As a result, the end stop can be implemented in a simple manner and with low construction costs.

The second actuating lever is preferably designed as a push rod.

If, according to an advantageous embodiment of the invention, the second actuating lever is provided on the receptacle for the third contact body with an insertion bevel for the third contact body, a guide for the third contact body can be achieved in a secure manner with the insertion bevels, so that the third contact body during the stroke the piston rod is passed into the receptacle for an optimum fit.

Advantageously, the second actuating lever is acted upon by a spring in an initial position. The spring makes it possible to hold the actuating lever securely in a defined starting position, if this does not cooperate with the third contact body, so as to ensure that the third contact body can meet when extending the piston rod into the receptacle on the second operating lever.

With particular advantage, a sensor device is provided, with which the pivotal movement of the at least one load section of the load-receiving means about the first pivot axis relative to the fork carriage can be detected. With such a sensor device, the folding function can be safely monitored and the folded position and the unfolded position of the load sections are detected in order to achieve high reliability of the truck.

Preferably, the at least one load portion of the load-receiving means is supported in the unfolded position on a support surface of the fork carriage. As a result, it is reliably prevented that the load sections can not pivot about the first pivot axis to below the unfolded position and it is achieved a secure and stable support of the load located on the unfolded load sections on the fork carriage.

According to an advantageous embodiment of the invention, the at least one load portion of the load receiving means in the retracted position with a stop on a vehicle body of the truck come into abutment. This prevents in a simple manner that the lifting can be raised when the load sections are in the folded-up position. As a result, a safe trailer operation can be achieved.

Preferably, the hitch is arranged on the fork carriage.

According to an advantageous embodiment of the invention, a hydraulic lifting cylinder is provided for raising and lowering the lifting carriage, which is associated with a pressure limiting valve for limiting a maximum load to be lifted. With such a pressure relief valve can be avoided in a simple way lifting a too heavy load.

According to an advantageous embodiment of the invention, the hydraulic cylinder is designed as a double-acting hydraulic cylinder, which is associated with a further pressure relief valve. With such another pressure relief valve, the tilting function and the folding function of the load sections can be easily secured and prevented from tilting too heavy a load with the tilting function and / or performing the folding function when there is a load on the load sections.

Figur 1

eine erfindungsgemäßes Flurförderzeug in einer perspektivischen Darstellung auf das Fahrzeugheck mit nach unten ausgeklappten Lastabschnitten,

Figur 2

das Flurförderzeug der Figur 1 mit nach oben eingeklappten Lastabschnitten,

Figur 3

einen Ausschnitt der Figur 1 mit durch die Neigefunktion waagerecht angeordneten Lastabschnitten,

Figur 4

die Figur 3 in einer Seitenansicht,

Figur 5

eine Darstellung gemäß der Figur 4 mit durch die Neigefunktion nach oben geneigten Lastabschnitten,

Figur 6

eine Darstellung gemäß der Figur 4 mit durch die Klappfunktion nach oben eingeklappten Lastabschnitten,

Figur 7

einen Schnitt der Figur 4 mit durch die Neigefunktion waagerecht angeordneten Lastabschnitten,

Figur 8

einen Schnitt der Figur 5 mit durch die Neigefunktion nach oben geneigten Lastabschnitten,

Figuren 9a bis 9c

Schnittdarstellungen gemäß den Figuren 7 und 8 mit einer Verdeutlichung des Aufbaus und Ablauf der Klappfunktion der Lastabschnitte,

Figur 10

eine Ansicht gemäß Pfeil A in der Figur 3,

Figur 11

einen als Hydraulikzylinder ausgebildeten Stellantrieb,

Figur 12

den Hydraulikzylinder der Figur 11 in verschiedenen Hubstellungen,

Figur 13

einen Ausschnitt der Figur 9b in einer perspektivischen Darstellung,

Figuren 14a-14c

Schnittdarstellungen gemäß der Linie B-B der Figur 10 mit unterschiedlichen Stellungen des Gabelträgers und der Lastabschnitte,

Figur 15

einen Ausschnitt der Figur 6 in einer vergrößerten Darstellung,

Figur 16

den zweiten Betätigungshebel in einer Seitenansicht,

Figur 17

einen Ausschnitt der Figur 3 mit einer Verdeutlichung des Aufbaus der Sensoreinrichtung,

Figur 18

einen Ausschnitt der Figur 2 mit einer Verdeutlichung des Aufbaus des Anschlags an dem Fahrzeugkörper des Flurförderzeugs und

Figur 19

den Schaltplan einer Hydraulikanlage des erfindungsgemäßen Flurförderzeugs.

Further advantages and details of the invention will be explained in more detail with reference to the embodiment shown in the schematic figures. This shows

FIG. 1

an inventive truck in a perspective view of the rear of the vehicle with downwardly unfolded load sections,

FIG. 2

the truck of the FIG. 1 with upwardly folded load sections,

FIG. 3

a section of the FIG. 1 with load sections arranged horizontally by the tilting function,

FIG. 4

the FIG. 3 in a side view,

FIG. 5

a representation according to the FIG. 4 with load sections inclined upwards by the tilting function,

FIG. 6

a representation according to the FIG. 4 with the folding sections folded upwards by the folding function,

FIG. 7

a cut of FIG. 4 with load sections arranged horizontally by the tilting function,

FIG. 8

a cut of FIG. 5 with load sections inclined upwards by the tilting function,

FIGS. 9a to 9c

Sectional views according to the FIGS. 7 and 8 with an explanation of the structure and sequence of the folding function of the load sections,

FIG. 10

a view according to arrow A in the FIG. 3 .

FIG. 11

a trained as a hydraulic cylinder actuator,

FIG. 12

the hydraulic cylinder of FIG. 11 in different lifting positions,

FIG. 13

a section of the FIG. 9b in a perspective view,

Figures 14a-14c

Sectional views along the line BB of FIG. 10 with different positions of the fork carriage and the load sections,

FIG. 15

a section of the FIG. 6 in an enlarged view,

FIG. 16

the second operating lever in a side view,

FIG. 17

a section of the FIG. 3 with a clarification of the structure of the sensor device,

FIG. 18

a section of the FIG. 2 with an explanation of the construction of the stop on the vehicle body of the truck and

FIG. 19

the circuit diagram of a hydraulic system of the truck according to the invention.

In the Figures 1 and 2 an inventive truck 1 is shown in a perspective view, which can be used as a tractor and as a counterbalance forklift.

The truck 1, seen in the vehicle longitudinal direction on a front-side drive part 2, in which at least one not-shown steerable drive wheel is arranged. The industrial truck 1 according to the invention has an electric drive system and comprises a disposed in the drive part 2 and not shown, with the drive wheel in operative connection electric traction drive motor and steering motor. In the drive part 2 or adjacent to the drive part 2, a battery compartment 3 is arranged, in which a power supply device of the electric drive system can be arranged, for example a battery pack.

Subsequent to the drive part 2 and the battery compartment 3, the truck 1 a driver's workplace 4, which is formed by a standing platform 5. Adjacent to the driver's seat 4, a rear-side frame portion 6 is formed, which is provided with load rollers 7.

For operating the truck 1, a handlebar-like operating arrangement 8 is provided, which is arranged on the upper side of the drive part 2.

At the rear frame portion 6 or adjacent to the rear frame portion 6, the truck 1 according to the invention is provided with a lifting device 9. The lifting device 9 is designed as a mast with a fixed, non-tiltable stand mast 10, the two spaced in the vehicle transverse direction and vertically arranged stand mast sections 10 a, 10 b, which are attached, for example, to the rear frame portion 6. In the stationary mast sections 10a, 10b, a lifting 11 is arranged by means not shown guide rollers up and down movable. For lifting and lowering of the lifting carriage 11, a lifting drive 12, for example designed as a lifting cylinder 12a, is provided which is connected to the lifting carriage 11 by means of a lifting means, for example a lifting chain.

On the lifting carriage 11, a fork carriage 13 of the lifting device 9 is arranged. The fork carriage 13 is provided with a fork-shaped load-receiving means 14, which is formed in the illustrated embodiment of two laterally spaced in the vehicle transverse direction load sections 14a, 14b. The two Load sections 14a, 14b are disposed about a substantially horizontal, in the vehicle transverse direction arranged first pivot axis D1 on the fork carriage 13 between a downwardly unfolded position (Fig. FIG. 1 ) and an upwardly folded position ( FIG. 2 ) arranged pivotable about 90 °.

On the carriage 13, a hitch 20 is further provided for the transport of trailers. The hitch 20 in this case has a plurality of vertically spaced flange plates in which a coupling pin can be arranged. The towing device 20 can be manually operated or be designed as an automatic coupling device which can be actuated by means of a corresponding actuator from the driver's seat.

In the FIG. 1 in which the load sections 14a, 14b are folded down, the truck 1 has the function of a forklift, with which loads can be handled and transported on the load sections 14a, 14b. In the function as a forklift, a tilting function for the load sections 14a, 14b is desired, with which the load sections 14a, 14b can be tilted with the tips up to a loss of load on the load sections 14a, 14b while driving, in particular with high speeds to avoid over an irregular roadway. In the truck 1 according to the invention is usually located on the load sections 14a, 14b load during their transport in the rear of the truck 1, so that a looking forward in the direction of the handlebar 10, located in the driver's workplace 4 driver of the truck 1 the located in his back load while driving with the truck 1 does not see. With the tilting function of arranged on the fork carriage 13 load sections 14a, 14b in this case the risk of loss of the load on the unfolded load sections 14a, 14b load is reliably avoided.

In the FIG. 2 , in which the load sections 14a, 14b are folded upwards, the truck 1 has the function of a compact in the vehicle longitudinal direction tractor to which the trailer hitch 20 trailer can be attached and pulled.

In the truck 1 according to the invention, arranged on the lifting carriage 11 fork carriage 13 has a tilting function, with which the tips of the load sections 14a, 14b can be tilted upwards (reclining). In addition, the load sections 14a, 14b are provided with the folding function and can between the folded down position ( FIG. 1 ) and the folded-up position ( FIG. 2 ) folded in and unfolded.

The structure of the lifting carriage 11 with the fork carriage 13 and the load sections 14a, 14b with the tilting function and the folding function will be described below with reference to FIG FIGS. 3 to 18 described in more detail.

The fork carriage 13 is pivotally mounted on the lifting carriage 11 about a substantially horizontal, arranged in the vehicle transverse direction second pivot axis D2. The second pivot axis D2 is arranged in the upper region of the lifting carriage 11 and of the fork carrier 13.

An actuator 25 is provided, with which the fork carriage 13 is pivotable about the second pivot axis D2 relative to the lifting carriage 11 and with which the at least one load section 14a, 14b of the load receiving means 14 about the first pivot axis D1 relative to the fork carriage 13 is pivotable.

The actuator 25 is formed by a designed as a hydraulic cylinder 26 linear drive, which - as from the FIGS. 7 to 10 is visible - is attached to the cylinder 11 with a cylinder housing 26a and which has an extendable piston rod 26b, which - like the FIG. 12 is clarified - pivoted in a first stroke range H1 the fork carriage 13 about the second pivot axis D2 relative to the lifting carriage 11 and in a subsequent to the first stroke H1 second stroke H2 the at least one load section 14a, 14b of the load receiving means 14 about the first pivot axis D1 relative to Fork carriage 13 pivots.

For actuating the fork carrier 13 and the load sections 14a, 14b, a plurality of contact bodies are arranged on the piston rod 26b, as in FIG FIG. 11 is shown in more detail.

At least one first contact body 30a, 30b is arranged on the piston rod 26b, which is in operative connection with a vertical abutment surface 31a, 31b of the lifting carriage 11, and at least one second contact body 32 is arranged, which with a relative to the vertical V inclined contact surface 33 of the fork carriage 13 is in operative connection. The inclined contact surface 33 is followed by a contact surface 36 of the fork carrier 13. The contact surface 33 is thus inclined relative to the contact surface 31a, 31b. The abutment surface 31a, 31b is arranged on a front side of the lifting carriage 11 facing the fork carrier 13, and the inclined abutment surface 33 and the adjoining abutment surface 36 are arranged on a rear side of the fork carrier 13 facing the lifting carriage 11.

The vertical contact surface 31a, 31b of the lifting carriage 11 extends over the first stroke region H1 and the second stroke region H2 and thus over the entire stroke of the piston rod 26b. The inclined contact surface 33 of the fork carrier 13 extends only over the first stroke range H1 of the piston rod 26b.

At least one third contact body 34a, 34b is arranged on the piston rod 26b, which comes into operative connection with an actuating device 40 in the second stroke region H2 of the piston rod 26, with which the at least one load section 14a, 14b of the load-receiving means 14 about the first pivot axis D1 relative to the fork carriage 13 is pivotable.

In the illustrated embodiment, on the piston rod 26 b - as shown in FIG. 11 can be seen - a total of five contact bodies 30a, 30b, 32, 34a, 34b arranged. The second contact body 32 is arranged on the longitudinal axis LA of the hydraulic cylinder 26. The second contact body 32 is mounted between two first contact bodies 30 a, 30 b, which are arranged on both outer sides of the contact body 32. Furthermore, two third contact bodies 34a, 34b are provided, between which the two first contact bodies 30a, 30b are arranged. The contact body 34a is disposed on the outside of the contact body 30a and the contact body 34b is disposed on the outside of the contact body 30b.

The contact bodies 30a, 30b, 32, 34a, 34b are designed as rollers rotatably mounted on the piston rod 26b. For rotatable mounting of trained as rollers Contact body 30a, 30b, 32, 34a, 34b, a fork-shaped holder 35 is disposed on the piston rod 26b, in which the rollers are rotatably mounted.

The trained as rollers first contact body 30a, 30b are only with the vertical contact surface 31a, 31b of the lifting carriage 11 in contact. The first contact bodies 30a, 30b designed as rollers extend on the contact surface 31a, 31b in the first stroke region H1 and the second stroke region H2. The designed as a roller second contact body 32 is only with the inclined contact surface 33 and the adjoining the inclined contact surface 33 bearing surface 36 of the fork carriage 13 in contact. The trained as a roller second contact body 32 runs in the first stroke range H1 on the inclined abutment surface 33 and in the second stroke range on the contact surface 36. The formed as rollers third contact body 34a, 34b reach only with the actuator 40 into contact to in the second Lifting range H2 to pivot the load portions 14a, 14b about the first pivot axis D1.

The actuator 40 has - as in the FIGS. 3 to 10 and 13 is shown in more detail - a first operating lever 41 which is articulated on the fork carriage 13 at a hinge axis G1. The first actuating lever 41 is further supported on the at least one load section 14a, 14b of the load receiving means 14. The two load sections 14a, 14b are connected by means of a transverse strut 14c (FIG. FIG. 10 ), on which the operating lever 41 is supported. For this purpose, a contact body 120 mounted rotatably about a second articulation axis G2 on the first actuation lever 41 can be provided on the first actuation lever 14 and designed as a roller. The contact body 120 is supported, for example, on the transverse strut 14c and rolls on this during pivoting of the load sections 14a, 14b of the load receiving means 14 about the first pivot axis D1. The actuating lever 41 of the actuating device 40 is thus in contact with the transverse strut 14c in the region of the second hinge axis G2 by means of the contact body 120 designed as a roller. When folding up and down of the load sections 14a, 14b of the load receiving means 14 about the first pivot axis D1, the contact point between the operating lever 41 and the transverse strut 14c changes, for which the formed as a roller contact body 120 rolls along the transverse strut 14c.

The actuator 40 has a pair of second operating levers 42a, 42b which are articulated on the first operating lever 41 about a hinge axis G3.

The operating lever 42a is - as from the FIGS. 15 and 16 is more apparent - provided with a receptacle 43a for the third contact body 34a. Accordingly, the operating lever 42b is provided with a receptacle 43b for the third contact body 34b.

The first actuating lever 41 thus actuates the two load sections 14a, 14b by means of the contact body 120 designed as a roller, and the second actuating levers 42a, 42b are provided in order to transmit the forces from the piston rod 26b of the hydraulic cylinder 26 to the first actuating lever 41. The second operating lever 42a, 42b is formed as a push rod which transfers only compressive forces F from the contact body 34a, 34b to the first operating lever 41, as in FIG FIG. 15 is illustrated.

On the receptacle 43a, 43b, the second actuating lever 42a, 42b is provided with an insertion bevel 44, which forms a guide to guide the third contact body 34a, 34b in the first stroke region H1, at the end of the first stroke H1 a perfect fit of the contact body 34a, 34b in the receptacle 43a, 43b to achieve.

The second actuating lever 42a, 42b is in each case by a spring 45 (FIG. FIG. 15 ) is acted upon in a starting position, in the FIG. 7 and 10 is shown. The spring 45 is fastened with a first end to the actuating lever 42a or 42b and with a second end to the fork carriage 13. In the illustrated embodiment, the spring 45 is formed as a tension spring.

Between the lifting carriage 11 and the fork carriage 13, an end stop 50 is provided which limits the pivoting movement of the fork carriage 13 relative to the lifting carriage 11 and thus the tilting movement of the tilting function. The structure of the end stop 50 is based on the Figures 10 . 13, 14a-14c described in more detail.

The end stop 50 is formed by an elastic element 51, which is connected to the fork carriage 13 and cooperates with a stop surface 52 of the lifting carriage 11.

The elastic element 51 is formed in the illustrated embodiment as a sleeve 51a, for example rubber sleeve, which is arranged longitudinally displaceably on a fastening rod 53 fastened to the fork carriage 13. The attachment rod 53 extends through a hole in the lifting carriage 11 onto the rear side of the lifting carriage 11 opposite the fork carrier 13, on which the stop surface 52 is formed. The elastic element 51 is arranged between the abutment surface 52 on the lifting slide 11 and a holder 54 arranged on the fastening rod 53. The holder 54 is formed in the illustrated embodiment by a nut screwed onto the mounting rod 53 and a washer, which is arranged between the element 51 and the nut.

Furthermore, a sensor device 70 is provided, with which the pivotal movement of the at least one load section 14a, 14b of the load-receiving means 14 about the first pivot axis D1 relative to the fork carriage 13 can be detected. The sensor device 70 is in the illustrated embodiment - as from the Figures 10 and 14 it can be seen more clearly - from a sensor 71 arranged on the fork carriage 13, for example a non-contact inductive sensor, and measuring elements 72 arranged on the load section 14a, for example finger-like expansions which, when the load section 14a is pivoted about the first pivot axis D1 into the measuring field of FIG Move sensor 71. The sensor device 70 is in communication with an electronic control device of the industrial truck 1.

The at least one load section 14a, 14b of the load receiving means 14 is supported in the downwardly unfolded position on a support surface 75 of the fork carrier 13 ( FIG. 18 ). For this purpose, the load sections 14a, 14b are each provided with a stop 76, which rests against the support surface 75 of the fork carrier 13 in the downwardly unfolded position and thus prevent further downward pivoting of the load sections 14a, 14b downwards. If, in the downwardly unfolded position, there is a load on the load sections 14a, 14b, the weight of the load is supported via the stop 76 and the support surface 75 on the fork carriage 13.

At least one of the two load sections 14a, 14b of the load receiving means 14 can come into abutment in the folded-up position with a stop 80 on a vehicle body of the truck 1 in Appendix. For this purpose, the load sections 14a, 14b are each provided with a projection 81 which, in the folded-up position of the load sections 14a, 14b, can come into contact with the stop 80. When abutment of the projection 81 on the stop 80, an unintentional lifting of the lifting carriage 11 in the stationary mast 10 can be avoided, for example, when pulling a towed device attached to the hitch 20 trailer.

In the Figures 3-5 . 7 . 8th and 9a the configuration of the floor conveyor 1 according to the invention is shown as a counterbalance forklift. The load sections 14a, 14b are located in the folded down with the folding function position. In the FIGS. 3, 4 and 7 are the load sections 14a, 14b in a horizontal position by the tilting position with a minimum tilt angle of beispielswiese 0 °. The piston rod 26b of the hydraulic cylinder 26 is fully retracted. In the Figures 5 . 8th and 9a are the load sections 14a, 14b in a tilted by the tilting position position with raised peaks with a maximum tilt angle of beispielswiese 3 ⁰ -5 ⁰ (recline). The piston rod 26b of the hydraulic cylinder 26 is extended to the end of the first stroke range H1.

In the FIGS. 6 and 9c the configuration of the floor conveyor 1 according to the invention is shown as a tractor. The load sections 14a, 14b are in the folded-up with the folding function position. The piston rod 26b of the hydraulic cylinder 26 is extended to the end of the second stroke range H2.

In the truck 1 according to the invention, the lifting carriage 11 in the stationary mast 10 by means of the lifting drive 12 can be raised and lowered. On the lifting carriage 11, the fork carrier 13 is pivotably arranged about the second axis of rotation D 2, in order with the hydraulic cylinder 26, the tilting function of the downwardly unfolded load sections 14 a, 14 b for a secure transport on the Load sections 14a, 14b located in the configuration of the truck 1 to allow as a counterbalance forklift. The rotational movement of the fork carrier 13 about the second pivot axis D2 forms the tilting function and the tilting movement of the load sections 14a, 14b. The load sections 14a, 14b are arranged foldable about the first pivot axis D1 on the fork carriage 13 in order to achieve with the hydraulic cylinder 26, the folding function of the load sections 14a, 14b, with downwardly unfolded load sections 14a, 14b, the configuration of the truck. 1 as a counterbalance forklift and with folded up load sections 14a, 14b to achieve the configuration of the truck 1 as a tractor. The load sections 14a, 14b are in the downwardly unfolded position with the stop 76 on the support surface 75 of the fork carrier 13 and can not pivot further down about the first pivot axis D1.

Is based on the FIGS. 3, 4 and 7 When the piston rod 26b of the hydraulic cylinder 26 is extended downward, the contact bodies 30a, 30b arranged on the piston rod 26b move downwards on the abutment surfaces 31a, 31b of the lifting carriage 11 and the contact body 32 arranged on the piston rod 26b runs on the inclined abutment surface 33 of the fork carrier 13 downward. This causes pivoting of the fork carrier 13 about the second pivot axis D2 relative to the lifting carriage 11 and the tilting function of the load sections 14a, 14b is achieved. The inclined contact surface 33 of the fork carrier 13 extends over the first stroke region H1 of the lifting cylinder 26, so that only the tilting function of the load sections 14a, 14b with the rotational movement of the fork carrier 13 relative to the lifting carriage 11 is achieved in the first stroke region H1 of the hydraulic cylinder 26.

During the extension movement of the piston rod 26b in the first stroke region H1 of the hydraulic cylinder 26, the insertion bevels 44 on the actuating lever 42a, 42b guide the contact bodies 34a, 34b arranged on the piston rod 26b into the receptacles 43a, 43b of the actuating levers 42a, 42b, so that at the end of the first stroke range H1, the contact bodies 34a, 34b run into the receptacles 43a, 43b of the actuating lever 42a, 42b.

The Figures 5 . 8th and 9a show the position at the end of the first stroke range H1 of the piston rod 26b, in which the load portions 14a, 14b are tilted with the tilting function maximum upwards.

Is based on the Figures 5 . 8th and 9a the piston rod 26b of the hydraulic cylinder 26 is further extended downwards into the stroke region H2, the contact bodies 30a, 30b arranged on the piston rod 26b run downwards on the abutment surfaces 31a, 31b of the lifting carriage 11 and the contact body 32 arranged on the piston rod 26b runs against the abutment surface 36 of the fork carriage 13 down. The contact surface 36 is arranged parallel to the contact surface 31a, 31b, so that the extension movement of the piston rod 36b in the second stroke region H2 does not lead to any further pivoting of the fork carrier 13 about the second pivot axis D2 relative to the lifting slide 11. Is based on the Figures 5 . 8th and 9a When the piston rod 26b of the hydraulic cylinder 26 is further extended downward into the stroke range H2, the contact bodies 34a, 34b arranged in the receptacle 43a, 43b of the second actuating levers 42a, 42b actuate the first actuating lever 41 on the piston rod 26b, so that the load portions 14a, 14b about the first pivot axis D1 on the fork carriage 13 are pivoted upward and folded ( FIG. 9b ). At the end of the second stroke region H2, the load sections 14a, 14b are completely folded upwards (FIG. FIGS. 6 , and 9c ). In the second stroke region H2 of the hydraulic cylinder 26, the contact bodies 34a, 34b with the actuating levers 42a, 42b, which transmit the extension movement of the piston rod 26b of the hydraulic cylinder 26 to the load sections 14a, 14b, thus only the folding function of the load sections 14a, 14b achieved with the rotational movement of the load sections 14a, 14b relative to the fork carrier 13.

Like from the Figures 14a-14c it can be seen, the position of the Figure 14a of the FIG. 7 corresponds to the position of FIG. 14b of the FIG. 8 corresponds and the position of FIG. 14c of the FIG. 9c corresponds, at the end of the first stroke range H1 arranged on the actuating rod 53 elastic element 51 in abutment against the stop surface 52 and limits the tilting function of the fork carriage 13 and thus the load sections 14a, 14b to the desired value, for example, 3 ° to 5 °. The elastic element 51 in this case leads to a gentle stop of the tilting movement of the fork carrier 13 (FIG. FIG. 14b ). Since upwardly folded load sections 14a, 14b (FIG. FIG. 14c ) of the fork carriage 13 in the same position as in the FIG. 14b is and thus the elastic member 51 is in abutment against the stop surface 52 can be reduced with the elastic member 51 further in pulling a trailer attached to the hitch 20 vibration and shock from the hitch 20 in the train operation of a trailer during acceleration and Slowing down.

With the trained as rollers contact bodies 30a, 30b, 32, 34a, 34b, a sliding friction is avoided both during the tilting function and during the folding function and achieved a rolling friction, whereby wear is minimized. With the trained as a roller contact bodies 120 is further avoided during the folding function of the load sections 14a, 14b, a sliding friction in the contact point between the actuating lever 41 and cross member 14c and achieved a rolling friction, whereby wear is minimized. Furthermore, the actuating levers 41, 42a, 42b are preferably mounted accordingly in order to achieve low friction and low wear.

The first stroke range H1, in which the tilting function of the load sections 14a, 14b is achieved, which must be available for the maximum load / payload on the load sections 14a, 14b and which leads to an inclination of the load of, for example, 5 °, preferably extends over a stroke range of 0% to about 70% of the stroke of the piston rod 26b of the hydraulic cylinder 26. The second stroke range H2, in which the folding function of the load sections 14a, 14b is achieved by 90 °, the only for unloaded load sections 14a, 14b available The moving mass of the load sections 14a, 14b to be folded in is usually about 5% of the payload, preferably extends over a stroke range of about 70% to 100% of the stroke of the piston rod 26b of the hydraulic cylinder 26. The first stroke range H1 of Piston rod 26b is thus preferably larger than the second stroke region H2 of the piston rod 26b.

The ratio between piston stroke of the piston rod 26b, moving mass, required tilting movement and folding movement of the load sections 14a, 14b can thus be optimized so that low pressures of the hydraulic cylinder 26 for the tilt function without load, average pressures of the hydraulic cylinder 26 for the folding function and high pressures of Hydraulic cylinder 26 for the tilting function with load are required. With a pressure of the hydraulic cylinder 26 hedging Pressure limiting valve or a pressure sensor of the hydraulic cylinder 26 detected pressure sensor can therefore be detected and avoided in a simple manner incorrect operation, for example, the tilting function with an unacceptably high load on the load sections 14a, 14b avoided or prevented the folding function with a load on the load sections 14a, 14b become.

In the FIG. 19 the circuit diagram of a hydraulic system of the truck 1 according to the invention is shown.

A hydraulic pump 100 conveys into a delivery line 101. The lifting cylinder 12a is designed as a single-acting hydraulic cylinder, which is connected by means of a line 102 to the delivery line 101. In the line 102, a valve 103 is arranged, with which the lifting and lowering operation of the lifting cylinder 12 a can be controlled. From the delivery line 101 branches off to a container 105 guided drain line 106, in which a drain valve 104 is arranged.

To the delivery line 101, a pressure limiting valve 107 is connected, which limits the maximum delivery pressure in the delivery line 101 and serves to limit a to be lifted with the lifting cylinder 12a maximum load. With the pressure relief valve 107 thus raising an unacceptably high load can be prevented with the lifting cylinder 12a.

The hydraulic cylinder 26 for the tilting function and the folding function is designed as a double-acting hydraulic cylinder. For the control of the retraction movement and the extension movement of the piston rod 26 b, a directional control valve 110 is provided which is connected to the delivery line 101. Connected to the directional control valve 110 is a line 111a which is connected to the pressure chamber of the hydraulic cylinder 26 acting in the direction of the extension movement of the piston rod 26b and a line 111b connected to the pressure chamber of the hydraulic cylinder 26 acting in the direction of retraction of the piston rod 26b is. To the line 111a, another pressure limiting valve 112 is connected, which limits the maximum operating pressure in the line 111a. With the pressure limiting valve 112, the tilting function with an unduly high load on the load sections 14a, 14b and / or the folding function with a load on the load sections 14a, 14b can be prevented.

In the line 111a, a check valve 113 is further arranged, which can be controlled by the pressure in the line 111b in an open position. To bypass the check valve 113, a bypass line 114 is provided, in which a in the direction of the pressure chamber of the hydraulic cylinder 26 opening check valve 115 is arranged. With the check valve 113, an undesired movement and an undesired acceleration of the piston rod 26b due to external forces can be avoided.

The invention is not limited to the illustrated embodiment.

Instead of the actuating lever 41, 42 a, 42 b, the actuator may have only a single operating lever.

Instead of the embodiment of the actuator as a hydraulic cylinder 26, the actuator may be formed as an electric linear drive.

The tilting function can also be a tendency of the fork tips of the load sections 14a, 14b relative to the representation of FIG. 4 down and thus include a forward tilt of the load sections 14a, 14b.

Other values can also be selected for the stroke ranges H1 and H2; for example, the first stroke range H1 in which the tilting function is achieved can extend over a stroke range from 0% to approximately 50% of the stroke of the piston rod 26b of the hydraulic cylinder 26 and second stroke range H2, in which the folding function is achieved, over a stroke range of about 50% to 100% of the stroke of the piston rod 26b of the hydraulic cylinder 26 extend.

Claims (23)

Truck (1) with a hitch (20) for transporting trailers and with a lifting device (9) for lifting loads, wherein the lifting device (9) comprises a fork carriage (13) provided with a fork-shaped load-receiving means (14), wherein the load receiving means (14) at least one load section (14a; 14b) about a substantially horizontal first pivot axis (D1) is arranged on the fork carrier (13) pivotable between an extended position and a retracted position by substantially 90 ^0, characterized in that the fork carriage (13) on a lifting carriage (11) about a substantially horizontal second pivot axis (D2) is pivotally mounted, wherein the lifting carriage (11) on the lifting device (9) is arranged raised and lowered, and an actuator (25) is provided, with which the fork carriage (13) about the second pivot axis (D2) relative to the lifting carriage (11) is pivotable and with the least s a load section (14a; 14b) of the load-receiving means (14) about the first pivot axis (D1) relative to the fork carriage (13) is pivotable. Truck according to claim 1, characterized in that the actuator (25) is formed by a linear drive which pivots the fork carrier (13) about the second pivot axis (D2) relative to the lifting carriage (D1) in a first adjustment and in a second adjustment at least one load portion (8a; 8b) of the load receiving means (14) pivoted about the first pivot axis (D1) relative to the fork carriage (13). Truck according to claim 1 or 2, characterized in that the actuator (25) by a hydraulic cylinder (26) is formed, which is fixed with a cylinder housing (26 a) on the lifting carriage (11) and an extendable piston rod (26 b), the pivoted in a first stroke range (H1) the fork carriage (13) about the second pivot axis (D2) relative to the lifting carriage (11) and in a second stroke region (H2) the at least one load section (14a, 14b) of the load receiving means (14) around the first pivot axis (D1) relative to the fork carriage (13) pivoted. Truck according to claim 3, characterized in that on the piston rod (26b) at least one first contact body (30a, 30b) is arranged, which is in operative connection with a vertical contact surface (31a, 31b) of the lifting carriage (11), and at least one second Contact body (32) is arranged, which is operatively connected to a relative to the vertical inclined contact surface (33) of the fork carrier (13). Industrial truck according to claim 4, characterized in that the vertical contact surface (31a; 31b) of the lifting carriage (11) extends over the first stroke region (H1) and the second stroke region (H2) of the piston rod (26b) and the inclined abutment surface (33 ) of the fork carrier (13) extends over the first stroke region (H1) of the piston rod (26b). Truck according to one of claims 3 to 5, characterized in that on the piston rod (26b) at least a third contact body (34a, 34b) is arranged in the second stroke region (H2) of the piston rod (26b) with an actuating device (40) in Active connection reaches, with which the at least one load portion (14a, 14b) of the load receiving means (14) about the first pivot axis (D1) relative to the fork carriage (13) is pivotable. Truck according to claim 6, characterized in that the actuating device (40) has a first actuating lever (41) which articulates on the fork carriage (13) and on the at least one load portion (14a, 14b) of the load receiving means (14) is supported. Industrial truck according to Claim 7, characterized in that the actuating device (40) has a second actuating lever (42a, 42b) which is articulated on the first actuating lever (41) and which is provided with a receptacle (43a, 43b) for the third contact body (34a 34b). Truck according to one of claims 4 to 8, characterized in that on the piston rod (26a) a second contact body (32) between two first contact bodies (30a, 30b) is arranged and two third contact bodies (34a, 34b) are provided, between which the two first contact bodies (30a, 30b) and the second contact body (32) are arranged. Truck according to one of claims 4 to 9, characterized in that the contact bodies (30a, 30b, 32, 34a, 34b) as on the piston rod (26b) rotatably arranged rollers are formed. Truck according to one of claims 3 to 10, characterized in that the first stroke range (H1) of the piston rod (26b) is greater than the second stroke range (H2) of the piston rod (26b). Truck according to one of claims 1 to 11, characterized in that between the lifting carriage (11) and the fork carriage (13) an end stop (50) is provided which limits the pivoting movement of the fork carrier (13) relative to the lifting carriage (11). Truck according to claim 12, characterized in that the end stop (50) by an elastic element (51) is formed, which is connected to the fork carriage (13) and cooperates with a stop surface (52) of the lifting carriage (11). Industrial truck according to claim 13, characterized in that the elastic element (51) is designed as a sleeve (51a) which is arranged on a fastening bar (53) fastened to the fork carriage (13). Truck according to one of claims 8 to 14, characterized in that the second actuating lever (42a, 42b) is designed as a push rod. Industrial truck according to one of claims 8 to 15, characterized in that the second actuating lever (42a, 42b) on the receptacle (43a, 43b) for the third contact body (34a, 34b) with an insertion bevel (44) for the third contact body (34a 34b). Truck according to one of claims 8 to 16, characterized in that the second actuating lever (42a, 42b) is acted upon by a spring (45) in an initial position. Truck according to one of claims 1 to 17, characterized in that a sensor device (70) is provided, with which the pivotal movement of the at least one load section (14a, 14b) of the load receiving means (14) about the first pivot axis (D1) relative to the fork carriage ( 13) is detectable. Truck according to one of claims 1 to 18, characterized in that the at least one load portion (14a, 14b) of the load-receiving means (14) in the unfolded position on a support surface (75) of the fork carrier (13) is supported. Truck according to one of claims 1 to 19, characterized in that the at least one load portion (14a, 14b) of the load receiving means (14) in the retracted position with a stop (80) on a vehicle body of the truck (1) can come into abutment. Truck according to one of claims 1 to 20, characterized in that the towing device (20) on the fork carriage (13) is arranged. Truck according to one of claims 1 to 21, characterized in that for raising and lowering of the lifting carriage (11), a hydraulic lifting cylinder (12a) is provided, which is associated with a pressure limiting valve (107) for limiting a maximum load to be lifted. Truck according to one of claims 3 to 22, characterized in that the hydraulic cylinder (26) is designed as a double-acting hydraulic cylinder, which is associated with a further pressure relief valve (112).

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