EP3708528B1 - Working machine and method for operating same - Google Patents

Description

The invention relates to a work machine, in particular a construction machine, with a mast with a mast head, a support cable which is guided along the mast over the mast head, a cable winch with a rotatably mounted winch drum on which the support cable is attached for winding and unwinding, a working element , which is arranged for vertical movement on the support cable, and a control unit through which the cable winch for unwinding the support cable from the winch drum can be operated in an unwinding mode in which the working element on the support cable is lowered to a base, with a cable pressure device with at least one pressure element is provided, according to the preamble of claim 1. Such a work machine is from the DD 289 994 A5 known. The invention also relates to a method for operating such a work machine according to claim 12.

A generic working machine is based, for example, on the EP 3 144 260 B1 emerged. A support cable is guided over a mast head on a mast in order to raise and lower a lifting element as quickly as possible by means of a cable winch arrangement.

When a work element is lowered by means of such a work machine, it is usually provided that, before the work element hits the ground, it is attached to the cable drums by means of a corresponding braking device is braked. If the working element nevertheless hits a base surface, in particular a floor, at a relatively fast lowering speed, an undesired cable oscillation can develop on the supporting cable, which propagates over the mast head to a winch drum. This rope oscillation can cause rope windings on the winch drum to jump out of their intended position. If the winch drum continues to be operated, this can then lead to an unclean winding of the carrying rope on the winch drum with crossing rope areas.

Such a disordered rope winding on the winch drum can lead to damage to the winch drum and in particular to increased wear of the support rope. As a result, not only can the service life of the suspension cable be shortened considerably, but the maximum load capacity of the suspension cable can also be impaired overall.

It is known in principle to provide guide devices on a winch drum for the targeted guiding and introduction of the support cable to the winch drum. Due to the rope vibrations that occur, however, such guide devices can also be overloaded and damaged or skipped.

The invention is based on the object of specifying a work machine and a method for operating the work machine with which the negative effects of rope oscillation of the suspension rope can be counteracted.

According to the invention, the object is achieved on the one hand by a work machine with the features of claim 1 and on the other hand by a method with the features of claim 12. Preferred embodiments of the invention are given in the dependent claims.

The working machine according to the invention is characterized in that the pressure element to counteract a cable oscillation of the carrying cable when the working element strikes the base can be adjusted by a control unit by means of an actuating element into a pressure position in which the pressure element rests on the carrying cable with a pressure force.

The invention is based on the knowledge that in the event of an intended or unintentional impact of a working or lifting element on a support cable on a base or floor surface, a cable oscillation can be counteracted at least in some areas by applying a defined pressure force to the support cable by means of a cable pressure device . Thus, a position of the suspension cable can be fixed or tensioned at least in certain areas in such a way that this can counteract the spread of a cable oscillation. The working element can be a tool, a gripper, a load hook with a load or another load.

A preferred embodiment of the invention consists in that the pressure element can be adjusted by the control unit from a retracted position into the pressure position immediately before or when the working element hits the base area. In order to avoid unnecessary rope friction and thus frictional wear, the pressure element according to a preferred embodiment of the invention is only held briefly in the pressure position on the support cable. In this case, the support cable is brought into contact with a short period of time before an expected impact or when the working element strikes the base area. When the working element is lifted, the pressure can be released again.

Any processing mode can be specified by the control unit, for example a control program with a defined course of a processing speed. In the simplest case, the control unit can be designed in such a way that it is designed for free manual operation by an operator.

The effect and formation of a rope oscillation is greater, the faster the work element is lowered and the higher the speed of impact on a base. In particular, the use of a work machine according to the invention is advantageous if the processing mode is a free fall mode. The base area can be the floor, another area or also a liquid surface.

In the context of the invention, a free-fall mode can be understood to mean a processing mode in which the winch drum is essentially not braked or operated in a non-positive manner in a free-running lowering. Such a free fall mode can be particularly advantageous if, for example For soil compaction by dropping an impact weight, a particularly large impact impulse is desired.

A particularly good suppression of rope oscillation can be achieved according to a development of the invention in that the rope pressure device is arranged between the mast head and the winch drum, in particular near the winch drum. This reliably counteracts the spread of rope oscillation in the area of the winch drum and onto the rope winding.

For a particularly compact construction of the work machine according to the invention, it is preferred that a single pressure element is pressed against the support cable in the pressure position. In many cases, this enables a sufficient containment of rope oscillation to be achieved.

In order to reduce the cable wear and also a friction on the pressure element, it is advantageous according to one embodiment of the invention that the at least one pressure element is provided with a roller in which the support cable comes to rest.

In principle, the pressure element can press freely on the suspension cable. A particularly expedient variant of the invention can be seen in the fact that the pressure element presses the support cable against the winch drum in the pressure position. The pressure element can be rod-shaped or preferably plate-shaped, the plate being adapted to the curvature of the winch drum. The pressure element can extend essentially over the axial length of the winch drum, so that the wound rope is reliably pressed against the winch drum even in the event of stronger rope oscillation.

A further advantageous embodiment of the invention results from the fact that two pressure elements are provided opposite one another, that the support cable is passed between the two pressure elements and that both pressure elements are pressed against the support cable in the pressure position. The two pressure elements can be arranged directly opposite one another or with a certain offset in a longitudinal direction of the support cable. In this way, a double pressure force is exerted, so to speak, on the supporting rope, so that the spread of the rope oscillation is counteracted particularly well.

In principle, the cable pressure device can be controlled by the control unit via a predetermined program which presses the pressure element against the supporting cable at certain times. The control unit can preferably be designed in such a way that when the cable drum is stopped or braked, the pressure element is placed against the support cable with the predetermined pressure force. A particularly expedient variant of the working machine according to the invention is that a determination device is provided which is designed to determine a position of the working element on the support cable and / or a state of the support cable, in particular a tension state of the support cable, that the determination device is in connection with the control unit and that depending on the determined position and / or the state of the suspension cable, the cable pressure device can be actuated by the control unit. An actuation preferably takes place when the working element strikes a floor.

The determination device can, for example, determine a length of the support cable, for example as a function of the number of revolutions of the winch drum. Furthermore, another condition of the suspension cable, in particular a tension condition of the suspension cable, can also be detected by the determination device. For example, a force measuring device can be provided on a pulley on the mast head, with which a tensile force on the support cable can be determined. For example, if the tensile force falls below a certain value or if it drops quickly, this can be recognized by the control unit as an occurrence of rope oscillation. The determination device can also comprise a camera which optically detects a cable oscillation.

By means of such a determination device, the occurrence of a cable oscillation can thus be detected particularly reliably and the cable pressure device can be actuated as required. The pressure element is adjusted, in particular, via an actuating element, in particular an actuating cylinder, particularly preferably a hydraulic cylinder.

In particular when the cable pressure device is arranged close to the winch, it can be advantageous that the mast is adjustable in its position, in particular relative to the angular position relative to the vertical, and that the cable pressure device is adjustable depending on the position of the mast. Especially when the mast is used as a cantilever mast is designed, which can be adjusted in a larger angular range, an adjustable mounting of the cable pressure device is expedient. In this way, a desired distance between the pressure element and the support cable can always be ensured, even if the position of the support cable changes due to a position adjustment of the mast. The adjustment device provided for this can be operated manually or preferably by means of at least one actuator. This can comprise an adjusting cylinder, preferably a hydraulic cylinder. The actuator can be operated by the operator or, in particular, by a control based on the position adjustment of the mast.

In principle, the working machine according to the invention can be designed as desired, in particular as a crane or a construction machine. According to one embodiment of the invention, it is particularly advantageous that the work machine is designed as a crawler crane, with an impact weight for soil compaction being attached to the support rope as a work element. A crawler crane is often referred to as a rope excavator, this being essentially a movable crane with a crawler chassis. A boom mast is adjustably mounted on a preferably rotatable superstructure on the crawler chassis, which is used in particular on construction sites for lifting work. In particular, an impact weight is provided as the working element, which is repeatedly raised for soil compaction and preferably dropped in a free-fall mode from a predetermined height onto a soil to be compacted. In this way, a simple but at the same time very effective method for soil compaction can be carried out.

In the method according to the invention for operating a work machine, in particular a construction machine, it is provided according to the invention that a support cable is guided along a mast over a mast head, the support cable being attached to a rotatably mounted winch drum of a cable winch for winding and unwinding and a working element is arranged on the support cable, which is moved vertically by the support cable, with the support cable being unwound from the winch drum of the cable winch by means of a control unit in a processing mode in which the working element is lowered to a base area, with at least one by means of an actuator Pressure element of a cable pressure device from the control unit to the support cable with a pressure force in a pressure position the support cable is pressed when the working element strikes the base, a cable oscillation of the support cable being counteracted.

The method can in particular be carried out with a work machine, which has been described above. The advantages described above can be achieved with the method. In principle, the method can be used wherever rapid and, in particular, repetitive lowering of a work element on a suspension cable is desired.

A preferred variant of the method of the invention consists in that an impact weight is provided as the working element and that the impact weight is repeatedly dropped onto the ground in a free-fall mode to compact the ground. In this way, a simple and effective soil compaction can be carried out with a safe cable guide.

The invention is further described below with reference to preferred exemplary embodiments, which are shown schematically in the drawings.

Fig. 1

eine Seitenansicht einer erfindungsgemäßen Arbeitsmaschine, welche als ein Raupenkran ausgebildet ist;

Fig. 2

eine vergrößerte perspektivische Detailansicht einer erfindungsgemäßen Seilandruckeinrichtung in Rückzugsposition;

Fig. 3

eine perspektivische Detailansicht der Seilandruckeinrichtung von Fig. 2 in Andruckposition;

Fig. 4

eine perspektivische Detailansicht einer zweiten Ausführungsform einer erfindungsgemäßen Seilandruckeinrichtung;

Fig. 5

eine perspektivische Detailansicht einer dritten Ausführungsform einer erfindungsgemäßen Seilandruckeinrichtung;

Fig. 6

eine perspektivische Detailansicht einer vierten Ausführungsform einer erfindungsgemäßen Seilandruckeinrichtung;

Fig. 7

eine perspektivische Detailansicht einer fünften Ausführungsform einer erfindungsgemäßen Seilandruckeinrichtung; und

Fig. 8

eine perspektivische Detailansicht einer sechsten Ausführungsform einer erfindungsgemäßen Seilandruckeinrichtung.

In the drawings show:

Fig. 1

a side view of a work machine according to the invention, which is designed as a crawler crane;

Fig. 2

an enlarged perspective detailed view of a cable pressure device according to the invention in the retracted position;

Fig. 3

a perspective detailed view of the cable pressure device of Fig. 2 in pressure position;

Fig. 4

a perspective detailed view of a second embodiment of a cable pressure device according to the invention;

Fig. 5

a perspective detailed view of a third embodiment of a cable pressure device according to the invention;

Fig. 6

a perspective detailed view of a fourth embodiment of a cable pressure device according to the invention;

Fig. 7

a perspective detailed view of a fifth embodiment of a cable pressure device according to the invention; and

Fig. 8

a perspective detailed view of a sixth embodiment of a cable pressure device according to the invention.

A working machine 10 of the invention designed as a crawler crane Fig. 1 has a mobile carrier device 12. The carrier device 12 comprises a crawler track 14 on which a superstructure 15 is rotatably mounted. A mast 16, which is also referred to as a cantilever arm, is mounted on the upper carriage 15 so as to be pivotable about a horizontal pivot axis. To pivot the mast 16, a holding beam 26, a support beam 28 and an adjusting cable mechanism 27 are provided on the upper carriage 15 in a manner known in principle.

At least one support cable 20, on which a working element 30 is suspended, which in the illustrated embodiment is designed as an impact weight 32 for soil compaction, is guided from the upper carriage 15 via a mast head 18 of the mast 16. In the exemplary embodiment, the support cable 20 is adjustably driven via a double winch arrangement in the upper carriage 15, as is basically known from the prior art. In order to avoid cable oscillation, a cable pressure device 40 is arranged on each of the two sections of the support cable 20, one of which is attached to the holding beam 26, also called A beam, and the other to the mast 16. The ends of the support cable 20 are each attached to a cable winch in the upper carriage 15, so that a double cable winch arrangement is provided for fast lifting processes.

In the Figures 2 and 3 a first embodiment of a cable pressure device 40 according to the invention is shown in more detail, which is adjustably mounted on the holding carrier 26. The cable pressure device 40 has a first pressure element 42a, which is mounted as a rotatable roller 44 on a base support 46. Furthermore, a second pressure element 42b, which is also designed as a roller 44, is provided, which is rotatably mounted on two lateral rockers 48. The two rockers 48 are pivotably mounted on the base support 46 and are each connected to it via a linear actuating member 50, which is designed as a hydraulic cylinder.

In Fig. 2 the cable pressure device 40 is shown in a state in which the support cable 20 extends without contact or at most with a slight contact between the two pressure elements 42a, 42b down to a cable winch 22 with a winch drum 24 rotatably mounted in the upper carriage. By winding and unwinding the support cable 20 on or from the winch drum 24, the working element 30 can be raised or lowered on the support cable 20. The cable winch 22 has a winch drive in a basically known manner, which is actuated via a control unit (not shown).

When adjusting the mast 16 and thus adjusting the support beam 26, a position of the cable pressure device 40 with the base beam 46 can be adjusted relative to the holding beam 26 via an adjusting device 52 and a changing position of the carrying cable 20 can be adjusted. For this purpose, the adjusting device 52 has an adjusting cylinder 54, which can also be operated hydraulically.

In Fig. 3 the state of the cable pressure device 40 is shown in a pressure position in which the two actuating members 50 are retracted so that the second pressure element 42b is moved relative to the first pressure element 42a. In this state, the second pressure element 42b presses against the support cable 20. In the illustrated embodiment, the support cable 20 also presses against the first pressure element 42a. Thus, the support cable 20 is, so to speak, clamped between the two pressure elements 42, 42b, but due to the use of rotatable rollers 44 a longitudinal movement of the cable 20 is still possible. However, a movement transverse to the longitudinal direction of the cable 20 in this pressure position is effectively prevented by the two pressure elements 42a, 42b.

If, for example, when executing a method according to the invention, the working element 30 designed as an impact weight 32, for example in a free fall mode with unbraked rotation of the winch drum 24, is lowered from an upper drop position onto a ground in order to exert an impact impulse for soil compaction on the ground, then the suspension rope 20 form a rope oscillation. This cable oscillation of the carrying cable 20 can propagate beyond the mast head 18 to the winch drum 24. Correct winding of the carrying cable 20 on the winch drum 24 can be impaired in this case. To prevent this from happening, will when the working element 30 hits the ground or a short period of time beforehand, the cable pressure device 40 is actuated. The time of impact can be recorded or specified. The pressure elements 42a, 42b are moved from the retracted position according to FIG Fig. 2 in the pressure position according to Fig. 3 procedure. At this pressure position according to Fig. 3 An oscillation of the suspension cable 20, which is largely determined by a cable movement transverse to the normal longitudinal direction of the suspension cable 20, can be prevented or reduced or suppressed to a considerable extent.

According to Fig. 4 a modified embodiment of the cable pressure device 40 according to the invention is shown. This is essentially the same as the cable pressure device 40 according to FIGS Figures 2 and 3 educated. However, the two pressure elements 42a, 42b are not designed as a roller, but as arcuate plates. Fig. 4 shows the state of the cable pressure device 40 with the pressure elements 42a, 42b in a retracted position accordingly Fig. 2 .

A third embodiment of the cable pressure device 40 according to the invention is shown in FIG Fig. 5 shown. In this embodiment, the two pressure elements 42a, 42b are also designed as rotatable rollers 44, but these have a fixed position relative to one another on the base support 46. Fig. 5 shows the retracted position in which the support cable 20 is passed largely unhindered through the two pressure elements 42a, 42b. To apply a pressure force, an actuating member 50 is provided, which is preferably designed as a hydraulic cylinder. By means of the actuating member 50, the base carrier 46 with the two pressure elements 42a, 42b is adjusted relative to the holding carrier 26, in particular pivoted about a pivot joint 56. As a result, at least one of the two pressure elements 42a, 42b presses against the support cable 20, which is deflected from its normal, unhindered passage position. This application of a pressure force to the support cable 20 transversely to its longitudinal direction can likewise at least significantly counteract the spreading of an undesired cable oscillation of the support cable 20 onto the winch drum 24.

Another embodiment of a cable pressure device 40 according to the invention is shown in FIG Fig. 6 shown, this cable pressure device 40 largely corresponding to the first embodiment according to FIGS Figures 2 and 3 is trained. In contrast to In the first embodiment, however, this cable pressure device 40 is not attached to the holding beam 26, but rather directly to the superstructure 15 of the work machine 10, close to the winch drum 24. Fig. 6 shows the cable pressure device 40 in the pressure position.

Another embodiment of a cable pressure device 40 according to the invention is shown in FIG Fig. 7 shown. The cable pressure device 40 has a single pressure element 42 which is rotatably mounted as a roller 44 on a base support 46. The base support 46 itself is mounted pivotably about a pivot joint 56, a pivot axis of the pivot joint 56 being oriented approximately parallel to an axis of rotation of the winch drum 24. In order to press the pressure element 42 against the support cable 20, an actuating member 50 designed as a pressure cylinder is provided. In the exemplary embodiment shown, the actuating member 50 presses the support cable 20 directly against the winch drum 24 in the pressing position.

A similar embodiment is shown in FIG Fig. 8 shown, wherein in this cable pressure device 40 according to the invention, a curved plate is provided as the pressure element 42. This is also mounted on a base support 46, which is pressed directly against the winch drum 24 by an actuating member 50 so that the support cable is clamped between the winch drum 24 and the pressure element 42.

Claims (13)

1. Work machine, in particular a construction machine, comprising

   - a mast (16) having a mast head (18),

   - a support cable (20) which is guided along the mast (16), over the mast head (18),

   - a cable winch (22) comprising a rotatably mounted winding drum (24) to which the support cable (20) is attached for winding up and unwinding,

   - a work element (30) which is arranged on the support cable (20) for vertical movement, and

   - a control unit, by means of which the cable winch (22) can be operated in an unwinding mode, for unwinding the support cable (20) from the winding drum (24), in which the work element (30) is lowered, on the support cable (20), as far as a base surface,

   - wherein a cable contact pressure means (40) with at least one contact pressure element (42) is provided,

   characterized in that
   the contact pressure element can be adjusted into a contact pressure position by the control unit, by means of an actuating member (50), in order to counteract a cable oscillation of the support cable (20) when the base surface is struck, in which contact pressure position the contact pressure element (42) rests on the support cable (20) at a contact pressure force.
2. Work machine according to claim 1,
   characterized in that
   the contact pressure element (42) can be adjusted, by the control unit, from a retracted position into the contact pressure position either directly before, or while, the work element (30) strikes the base surface.
3. Work machine according to claim 1 or claim 2,
   characterized in that
   the unwinding mode is a freefall mode.
4. Work machine according to any of claims 1 to 3,
   characterized in that
   the cable contact pressure means (40) is arranged between the mast head (18) and the winding drum (24), in particular close to the winding drum (24).
5. Work machine according to any of claims 1 to 4,
   characterized in that
   a single contact pressure element (42) is pressed against the support cable (20) in the contact pressure position.
6. Work machine according to any of claims 1 to 5,
   characterized in that
   the at least one contact pressure element (42) is provided with a roller (44), on which the support cable comes to rest.
7. Work machine according to any of claims 1 to 6,
   characterized in that
   the contact pressure element (42) presses the support cable (20) against the winding drum (24) in the contact pressure position.
8. Work machine according to any of claims 1 to 6,
   characterized in that

   two contact pressure elements (42a, 42b) are provided opposite one another,

   in that the support cable (20) is guided through between the two contact pressure elements (42a, 42b), and

   in that both contact pressure elements (42a, 42b) are pressed against the support cable (20) in the contact pressure position.
9. Work machine according to any of claims 1 to 8,
   characterized in that

   a determination means is provided, which is designed for determining a position of the work element (30) on the support cable (20) and/or a state of the support cable (20), in particular a tension state of the support cable (20),

   in that the determination means is connected to the control unit, and

   in that the cable contact pressure means (40) can be actuated by the control unit depending on of the determined position and/or the state of the support cable (20).
10. Work machine according to any of claims 1 to 9,
    characterized in that

    the position of the mast (16), in particular the angular position thereof relative to the vertical, is adjustable, and

    in that the cable contact pressure means (40) is adjustable depending on the position of the mast (16).
11. Work machine according to any of claims 1 to 10,
    characterized in that
    said machine is designed as a crawler crane, wherein an impact device (32) for soil compaction is suspended on the support cable (20) as the work element (30).
12. Method for operating a work machine (10) according to any of claims 1 to 11, in particular a construction machine,

    in which a support cable (20) is guided along a mast (16), over a mast head (18), wherein the support cable (20) is attached to a rotatably mounted winding drum (24) of a cable winch (22) for winding up and unwinding, and a work element (30) is arranged on the support cable (20), which work element is moved vertically by the support cable (20), wherein a control unit unwinds the support cable (20) from the winding drum (24) of the cable winch (22) in an unwinding mode, in which the work element (30) on the support cable (20) is lowered as far as the base surface,

    wherein by means of an actuator (50) at least one contact pressure element (42) is pressed onto the support cable (20), in a contact pressure position, by the control unit, with a contact pressure, when the work element (30) strikes the base surface, wherein a cable oscillation of the support cable (20) is counteracted.
13. Method according to claim 12,
    characterized in that

    an impact weight (32) is provided as the work element (30), and

    the impact weight (32) is repeatedly dropped onto the ground, in a freefall mode, in order to compact the soil.

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