EP1472175B1 - Hoisting gear with device for determining the load - Google Patents

Abstract

The invention relates to a device for determining a load on a hoist of a crane for handling a container, including rope drum, drive motor as well as hoist transmission disposed between drive motor and rope drum and having a hoist transmission case which is swingably supported about an axis in parallel relationship to the rope drum axis and can be supported on its opposite end on at least one torque support, which a device for indirect determination of the load, suspended from the ropes, is assigned to. In order to create a device for determining a load on a hoist, whereby the load determination is protected from external mechanical influences and effected directly on the rope winch and which device is able to determine the entire load suspended from the ropes as well as also single loads and optionally center of gravity positions of the load, it is proposed that in a hoist with two twin rope drums which are arranged on the same axis and operated in synchronism and which have each a pair of load-carrying ropes which can be spooled and unspooled in a same direction, a load-carrying rope of each pair of load-carrying ropes is guided in a common first load-guiding plane, which extends substantially horizontal and is tangent to the twin rope drums, and routed about deflection rollers into the vertical, and the other two load-carrying ropes of each pair of load-carrying ropes are guided vertically in a common second load-guiding plane which is tangent to the twin rope drums.

Description

The invention relates to a hoist, in particular a hoist of a crane for container handling, with a device for load detection, with at least one cable drum, at least one drive motor and a arranged between the drive motor and cable drum hoist gear, which is arranged in a supported on one side of Hubwerksgetriebe Hubwerksgetriebegehäuse, said the Hubwerksgetriebegehäuse is pivotally mounted in the region of one of its front ends about an axis extending parallel to the cable drum axis and in the region of its other end face on at least one torque arm can be supported, which is associated with a measuring device for indirect detection of the load hanging on the ropes.

For automatically operated cranes, in particular cranes for container handling, the detection of the load picked up by the crane is of central importance. It serves the safety of the crane and the person entrusted with it so that e.g. in case of overload, the crane can be switched off, as a weighing device for determining the load and its load distribution in the ropes or for determining the center of gravity of the load itself, e.g. in unevenly loaded containers. Finally, the load detection also serves as an indicator for the statistical determination of the maintenance intervals in connection with the counted operating hours.

The load detection takes place in conventional systems in the rope or in the hoist device. The measurement of the axial force in the hoist gear, which is caused by the helical teeth of the spur gears, as a proportional size of the cable force is known, but it fails because of the inaccuracy of the load measurement. The disturbances from the thermal expansion and external temperature effects can only be compensated with considerable technical effort.

A known technique for load detection uses the mounting of the hoist gear on a torque arm. Here, the measured on the torque arm support force is proportional to the cable force and thus hanging on the ropes mass. The load detection works relatively easy when all of the Rope drums unwound ropes are guided tangentially in the same direction. If the ropes are unwound in different directions, then conventional load detection via the torque arm is not possible.

If several hoisting ropes are wound on a common drum, the measurement of the cable force can be made in each rope strand. Here, a measuring device is installed at the end of the rope, the sum of all measured rope forces then corresponds to the mass of the load. In this case, however, the measuring device must be supplied with external energy, preferably electrical, which must be transported by the crane to the rope end. The power lines and the measuring devices are located directly on the load handling device. This means that the power lines must be protected against external mechanical effects, which causes a considerable technical effort and thus high costs.

From US patent 6,144,307 a hoist with a load sensing device according to the preamble of claim 1 is known. The hoist has in the usual way a cable drum, which is mounted at both ends via supports on a mounting plate. At one end of the cable drum, the axis of the cable drum is extended beyond the support in the form of a drive shaft. On this drive shaft, a transmission is attached on the output side, which is connected on the drive side with a drive motor. The transmission is thus freely rotatable about the drive shaft of the cable drum. In the usual way, a restriction of this free rotation on the transmission housing a torque arm in the form of a lever is arranged, which is connected via a further arm of the mounting plate. Arranged in the arm is a load cell which measures the degree of rotation of the gearbox about the drive shaft when the hoist is under load. Based on the measured rotation then the load acting on the hoist load can be determined.

Object of the present invention is to provide a hoist with a device for load detection, in which the load detection, protected against external mechanical effects, takes place directly on the winch and which is capable of both the entire load hanging on the ropes as well as individual loads and possibly to detect the center of gravity of the load.

To solve the problem, the invention proposes that at a Hoist with a device for load detection, with two achsgleichen, synchronously driven double rope drums each with a coiled up and unwound load cable pair, each a load rope each load cable pair in a common first, substantially horizontally extending, the double rope drums tangential load guide level and around Deflection rollers is redirected to the vertical and the other two load cables of each load cable pair are guided vertically in a common second, the double rope drums tangential load guide plane.

The guidance of the four load ropes in two substantially transversely aligned planes is the prerequisite for the detection of the load on a hoist with four ropes, as used in particular for container handling. While two load ropes of each pair of load cables are wound off and wound up directly from the cable drum, the remaining two other load ropes are first guided substantially horizontally, in order then to deflect them around deflection rollers into the vertical. The Double rope drums are designed and equipped so that when driving the rope drums on the common gear each four ropes are wound up or unwound simultaneously and synchronously. Since the housing is pivotally hinged on one of its sides and supported on its other side on a torque arm with measuring device, can easily detect the forces representing the cable forces at the measuring device.

In order to determine an accurate detection of the rope forces of all ropes and thus the size of the hanging on the ropes load, it is proposed according to a further feature of the invention that the first and the second load guide plane intersect in a third plane, passing through the axis of rotation of the Double cable drums and the pivot axis of the hoist gear extends, which is provided on the side facing away from the pulleys and the torque arm side of the gear housing and that the torque arm is associated with a force transducer for detecting the total of the effective rope forces.

The proposal of the invention, a geometric dependence between the load guide levels and thus the load cables and the pivot axis of the gear housing is defined by the distances from the middle of the load rope to the axis of rotation for both guided in the load management levels ropes are the same size. Regardless of the individual cable forces in the cable strands, this arrangement causes a force transducer integrated in the torque arm to always record the total sum of the suspended load.

In another alternative of the present invention, it is provided that the pivot axis is provided on the side facing the pulleys and the torque arm side facing away from the transmission housing, that in the pulleys measuring axes for detecting the there vertically acting cable forces of the articulated load cables are arranged and that the cable forces of vertically guided other load cables in the load cell of the load cables adjacent torque arm can be detected.

In this solution, a separate detection of the rope forces at least in pairs possible. While the load cell in the torque arm detects the resulting from the directly vertically guided ropes effective forces, the rope forces of the other, initially guided approximately horizontally and then deflected ropes on Sensors are detected, which are located in the axes of the pulley. In this way, a more accurate statement about the load distribution in the cable strands can be made without the measuring devices, as in the above-described prior art, must be arranged in the vicinity of the lifting device.

In a further embodiment of the present invention, it is provided that the cable forces of the load cables guided vertically in the second load guidance level can be detected in the force transducers of two load strands adjacent spaced torque arms whose geometric arrangement with respect to the Hubwerksgetriebegehäuse and the distances to the load cables clearly can be determined, wherein the pivot axis of the Hubwerksgetriebegehäuses permits tilting movements.

This proposed solution makes it possible by the exact detection of the rope forces also an exact statement about the center of gravity of the load. The guided around the pulleys load ropes in the measuring axes of the pulleys allow accurate determination of the respective vertical acting cable force in each rope. For the load ropes, which are unwound directly from the double rope drum in the vertical load guidance plane, such a separate load detection is possible because two spaced torque arms are used with associated force sensors, which are articulated exactly geometrically determinable on Hubwerksgetriebegehäuse and the Hubwerksrahmen. The force transducers are preferably arranged symmetrically at a defined distance from one another on both sides of a vertical center plane through the transmission housing, their distance from the load rope to be measured being known. Due to the geometric conditions, the rope load to be determined can thus be easily detected in the force-measuring devices; if the loads involved in the two force-measuring devices are different, this is an indication of an eccentric center of gravity. Since the different rope loads can also be detected at the deflecting rollers, the center of gravity of the load can be determined mathematically via the geometric conditions and evaluated accordingly.
Because the distance of the cables from the force measuring devices or the torque supports during winding and unwinding of the rope changes, is provided according to a further feature of the invention that the variable data of the cable distances are electronically determined and monitored within the second load management level. This monitoring is known in principle and is used here to obtain clear measuring signals at each lifting height.

With the invention, a hoist with a device for load detection is proposed, which is performed directly on the side winds. As a result, the measuring device is largely protected from external influences of measurement; impressed accelerations, which occur with relative measurements with force transducers entrained on the load receiving means, do not arise. In the invention is always measured absolutely.

An embodiment of the invention is illustrated in the drawing and will be described below.

Fig. 1

die Ansicht einer Krananlage der Erfindung,

Fig. 2

eine Ausführung des erfindungsgemäßen Hubwerks zur Lasterfassung,

Fig. 3

eine vereinfachte schematische 3D-Darstellung des Hubwerkes nach Fig. 2,

Fig. 4

eine schematische 3D-Darstellung einer ersten Ausführungsvariante und

Fig. 5

eine schematische 3D-Darstellung einer zweiten Ausführungsvariante der Erfindung.

It shows

Fig. 1

the view of a crane system of the invention,

Fig. 2

an embodiment of the lifting mechanism according to the invention for load detection,

Fig. 3

a simplified schematic 3D representation of the hoist according to Fig. 2,

Fig. 4

a schematic 3D representation of a first embodiment and

Fig. 5

a schematic 3D representation of a second embodiment of the invention.

FIG. 1 shows in a simplified representation the overall view of a crane installation in which the present invention can be used. The elevated bridge crane 1 consists of the bridge 2 and the cat 3. From the hoist 4 and the two double rope drums 4.1 and 4.2 each lead two, so a total of four cables 5.1 to 5.4 to the load-carrying means 6, which carries the load 7. The load is an ISO container in the illustrated embodiment.

In Fig. 2, the hoist 4 is shown enlarged on the cat 3 in a detailed view. The hoist 4 consists of the gear 8 with the gear housing, the drive motors 9, the two Doppef cable drums 4.1 and 4.2 and the two pulleys 10.1 and 10.2. The gear housing 8 is supported within the cat 3 on the two gear bearings 11.1 and 11.2 and the torque arm 12 from.

Visible, the load cables are 5.3 and 5.4 guided in a first horizontal load guide plane between the double cable drum 4.1 or 4.2 and the pulleys 10.1 and 10.2, while the load cables 5.1 and 5.2 directly from the load drums 4.1 and 4.2 vertically in a common vertical second load guide plane are guided. The pivot axis 13 of the gear housing 8 extends through the two gear bearings 11.1 and 11.2, it lies in a plane 14 which runs through the intersection of the two Seu management levels on the one hand and the axis of rotation of the cable drums 4.1 and 4.2. In the illustrated vertical and horizontal rope drain the dimensional distances from the center of the rope to the pivot axis 13 remain the same in these geometric conditions, i. y is equal to z.

In this illustrated arrangement of the hoist ensures that the built-in torque arm 12 load cell 15 detects the total sum of the load, regardless of the individual rope forces in the cable strands 5.1 to 5.4. However, in this arrangement, a statement about the center of gravity of the load 7 is not possible.

The solution described above is again shown geometrically simplified in FIG. 3 in a schematic 3D representation. Recognizable are the hoist 4, the two double rope drums 4.1 and 4.2 and the two pulleys 10.1 and 10.2. The gear housing 8 is supported within the cat 3 on the pivot axis 13 extending through the gear bearings 11.1 and 11.2 and the torque support 12. The pivot axis 13 lies in the dash-dotted lines indicated third level 14, which runs through the intersection of the two load guide levels and the axis of rotation of the cable drums 4.1 and 4.2. As described, the measure distances from the center of the rope to the axis of rotation 13 remain the same size, i. y is equal to z. In this case, y describes the distance from the load rope 5.1 to the pivot axis 13 and z the distance from the load rope 5.3 to the pivot axis 13. The same applies to the load cables 5.2 and 5.4 of the other double rope drum. The integrated in the torque arm 12, not shown in detail load cell 15 detected in this arrangement, the total sum of the load, regardless of the individual rope forces in the cable strands 5.1 to 5.4.

A further alternative of the invention is shown in Fig. 4, in a schematic 3D representation of the hoist 4 can be seen, of which the two double soap drums 4.1 and 4.2 and the pulleys 10.1 and 10.2 are shown. The transmission housing 8 is supported within the cat 3 on the two gear bearings 16.1 and 16.2 and on the torque arm 17. The rope forces in the load cables 5.3 and 5.4 are determined by the measuring axes 19.1 and 19.2 in the guide rollers 10.1 and 10.2, the integrated torque arm 17 load cell 18 records the sum of the load from the individual vertically acting rope forces in the cable strands 5.1 and 5.2. This solution thus enables a separate detection of the rope forces on both sides of the transmission, a statement about the center of gravity of the load 7 can not be made with this arrangement.

The representation in Fig. 5 shows a further alternative of the invention, also here the hoist is designated 4. The two double rope drums carry the position numbers 4.1 and 4.2. The load cables 5.3 and 5.4 are guided over the pulleys 10.1 and 10.2, which are provided with measuring axes 19.1 and 19.2 as in the solution according to FIG. 4 and allow a separate detection of the rope forces in the cable strands 5.3 and 5.4. The gear housing 8 is supported within the cat 3 on the gearbox bearing 20 and the two torque arms 21.1 and 21.2. In the torque arms 21.1 and 21.2 integrated force transducer 22.1 and 22.2 are provided, which individually detect the vertically acting rope forces in the cable strands 5.1 and 5.2. For this the following data are known:
The constant measured values in the force transducers 22.1 and 22.2, the constant torque arm distance a, the geometry of the groove profile of the cable drum, the respective lifting height dependent dimensional distances x, which change during winding and unwinding of the cables. These variable data are transmitted and monitored electronically, as is known in the art.

The rope forces in the cable strands 5.3 and 5.4 were determined separately, so that now all the rope forces of each strand of rope 5.1 to 5.4 are known and evaluated. Due to the exact detection of these rope forces a statement about the position of the center of gravity of the load 7 is possible in this arrangement, the Hubwerkslagerung.

LIST OF REFERENCE NUMBERS

Overhead crane

1

bridge

2

cat

3

hoist

4

Double cable drum

4.1; 4.2

Last ropes

5.1 to 5.4

Load handling devices

6

load

7

gearbox

8th

drive motor

9

guide rollers

10.1; 10.2

transmission bearings

11.1; 11.2

torque arm

12

swivel axis

13

level

14

Load cell

15

transmission bearings

16.1; 16.2

torque arm

17

Load cell

18

measuring axes

19.1; 19.2

transmission bearings

20

torque arm

21.1; 21.2

Load cell

22.1; 22.2

Claims (5)

1. Hoisting gear (4), in particular hoisting gear of a crane for container handling, having a device for load detection, having at least one cable drum (4.1, 4.2), at least one drive motor (9), and a hoisting gear mechanism which is disposed between the drive motor (9) and the cable drum (4.1, 4.2) and is disposed in a hoisting gear mechanism housing (8) which is supported on one side on the hoisting gear frame, wherein the hoisting gear mechanism housing (8) is mounted in the region of an end-face end in such a way as to be pivotable about an axis extending in parallel with the cable drum axis and is able to be supported in the region of its other end-face end on at least one torque support (17) which is allocated a measuring device for indirect detection of the load suspended on the cables (5.1 to 5.4),
   characterised in that
   the hoisting gear (4) comprises two coaxial synchronously drivable double cable drums (4.1 and 4.2) each having a load cable pair (5.1 to 5.4) which can be wound and unwound in the same direction, in each case a load cable (5.3; 5.4) of each load cable pair (5.1; 5.3 and 5.2; 5.4) is guided in a common first substantially horizontally extending load guiding plane tangential to the double cable drums (4.1 and 4.2) and is diverted into the vertical direction around diverting rollers (10.1; 10.2), and the two other load cables (5.1; 5.2) of each load cable pair (5.1; 5.3 and 5.2; 5.4) are vertically guided in a common second load-guiding plane tangential to the double cable drums (4.1 and 4.2).
2. Hoisting gear as claimed in claim 1, characterised in that the first and second load guiding planes intersect in a third plane (14) which extends through the rotational axis of the double cable drums (4. 1 and 4.2) and the pivot axis (13) of the hoisting gear mechanism (8), which pivot axis is provided on the side of the mechanism housing (8) remote from the diverting rollers (10.1 and 10.2) and the torque support (12), and that the torque support (12) is allocated a force transducer (15) to detect the overall total of the active cable forces.
3. Hoisting gear as claimed in claim 1, characterised in that the pivot axis (13) is provided on the side of the mechanism housing (8) facing the diverting rollers (10.1 and 10.2) and remote from the torque support (17), that in the diverting rollers (10.1 and 10.2) measuring spindles (19.1; 19.2) are disposed for detecting the cable forces, acting vertically at that location, of the diverted load cables (5.3 and 5.4), and that the cable forces of the vertically guided other load cables (5.1 and 5.2) can be detected in the force transducer (18) of the torque support (17) which adjoins the load cables (5.1 and 5.2).
4. Hoisting gear as claimed in claim 1, characterised in that the cable forces of the load cables (5.1 and 5.2) which are vertically guided in the second load-guiding plane, can be detected in the force transducers (22.1 and 22.2) of two mutually spaced torque supports (21.1 and 21.2) which adjoin the load cables (5.1 and 5.2), the geometric arrangement of which torque supports in relation to the mechanism housing (8) and the distances (x) to the load cables (5.1 and 5.2) being clearly determinable, wherein the pivot axis of the mechanism housing (8) permits tilting movements.
5. Hoisting gear as claimed in claim 1, characterised in that the variable data of the cable spacings within the second load-guiding plane are electronically detected and monitored.

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