LIFTING GEAR

Abstract

The present invention relates to lifting gear, more particularly a crane, such as a rotary tower crane and/or mobile crane, having a supporting structure, a determination device for determining a load state and/or an operating state of the supporting structure, and a control unit for controlling actuators of the lifting gear depending on the determined load state and/or operating state, wherein the actuators are allocated to the supporting structure for the active bracing and/or deformation of the supporting structure in a variable manner during lifting gear operation, and the control unit is configured to temporarily and variably brace and/or deform the supporting structure by means of the actuators depending on the detected load state and/or operating state in order to relieve the load on supporting structure parts which are subject to high load.

Claims

1. A lifting gear comprising: a rotary tower crane and/or a mobile crane comprising: a supporting structure; a determination device for determining a load state and/or an operating state of the supporting structure; and a control unit for controlling actuators of the lifting gear in response to the determined load state and/or to the determined operating state, wherein the controlling actuators are allocated to the supporting structure for the active bracing and/or deformation of the supporting structure in a variable manner during lifting gear operation, and wherein the control unit is configured to temporarily and variably brace and/or deform the supporting structure with the actuators in response to the detected load state and/or to the detected load state operating state such that to relieve load on supporting structure parts that are subject to high load.

2. The lifting gear of claim 1, wherein the supporting structure comprises at least one boom, from which a load suspension is suspended, wherein the actuators are configured to variably brace and/or deform the boom during lifting gear operation.

3. The lifting gear of claim 2, wherein a tower is suspended from the at least one boom, and wherein the actuators are configured to variably brace and/or deform the tower during lifting gear operation.

4. The lifting gear of claim 3, wherein the actuators are configured to variably lengthen and/or shorten longitudinal chords of the boom and/or of the tower during operation.

5. The lifting gear of claim 1, wherein the determination device is configured to identify the supporting structure parts subjected to compression during lifting gear operation and/or supporting structure components subjected to tension during lifting gear operation, and wherein the control unit is configured to shorten the supporting structure parts subjected to tension during lifting gear operation and/or lengthen the supporting structure parts subjected to compression during lifting gear operation with the actuators.

6. The lifting gear of claim 1, wherein the determination device is configured to determine a wind load acting on the supporting structure, wherein the control unit is configured to shorten at least one supporting structure portion arranged on a windward side and/or to lengthen at least one supporting structure portion arranged on a leeward side, depending on the determined wind load.

7. The lifting gear of claim 6, wherein the wind load comprises a wind speed and a wind direction.

8. The lifting gear of claim 7, wherein the control unit with the actuators variably lengthens a leeward lower chord of a boom and/or leeward corner bars of a tower depending on the determined wind load and/or variably shortens a windward lower chord of the boom and/or windward corner bars of the tower and/or a windward tensioning element depending on the determined wind load.

9. The lifting gear of claim 8, wherein the determination device comprises at least one wind speed sensor and at least one wind direction sensor for determining the wind speed, and wherein the control unit is configured to temporarily manipulate the supporting structure with the actuators in a variable manner depending on a detected wind speed and a detected wind direction.

10. The lifting gear of claim 7, wherein the determination device comprises at least one wind speed sensor and at least one wind direction sensor for determining the wind speed, and wherein the control unit is configured to temporarily manipulate the supporting structure with the actuators in a variable manner depending on a detected wind speed and a detected wind direction.

11. The lifting gear of claim 1, wherein the determination device comprises a sensor system for detecting deformations and/or loads of a boom and/or a tower and/or a bracing for the boom and/or the tower, and wherein the control unit is configured to actively manipulate the supporting structure with the actuators depending on sensor signals of said sensor system during lifting gear operation.

12. The lifting gear of claim 1, wherein the determination device comprises a sensor system for determining at least one load and/or operating condition parameter from the following group of parameters: set-up condition, support geometry, ballasting, tower height, boom length, boom angle position, trolley position, maximum possible lifting load, maximum possible lifting speed, actual lifting load, actual lifting speed, lifting rope force and supporting structure deformations; and wherein the control unit is configured to actively manipulate the supporting structure during lifting gear operation with the actuators depending on the sensor signals of the sensor system.

13. The lifting gear according to claim 1, wherein the determination device comprises an estimation device for estimating at least one set-up condition and/or operating condition parameter on the basis of an existing set-up condition and/or load and/or operating condition data, and wherein the control unit is configured to actively manipulate the supporting structure with the actuators depending on the at least one estimated set-up condition and/or operating condition parameter.

14. The lifting gear of claim 1, wherein the determination device comprises a prediction device configured to predict a future load state and/or operating state on the basis of stored data on past lifting gear operations including past listing gear load and operating state data, wherein the control unit is configured to actively manipulate the supporting structure depending on the predicted load state and/or operating state with the actuators.

15. The lifting gear of claim 1, wherein the determination device is configured to identify supporting structure parts with lower load capacity reserve and/or stability reserve and supporting structure parts with comparatively higher load capacity reserve and/or stability reserve, wherein the control unit is configured to actively brace and/or deform the supporting structure depending on the identified supporting structure parts with lower and/or comparatively higher load capacity reserve and/or stability reserve with the actuators so the load capacity reserves and/or stability reserves of the supporting structure parts are made uniform and/or supporting structure parts with lower load capacity reserve and/or stability reserve are relieved and/or supporting structure parts with comparatively higher load capacity reserve and/or stability reserve are loaded.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The present invention is explained in more detail below with reference to preferred embodiments and associated drawings. The drawings show:

[0033] FIG. 1: a side view of a lifting gear in the form of a rotary tower crane boom according to an advantageous embodiment of the invention, in which the actuator system for manipulating the supporting structure comprises various actuators for adjusting a bracing and the upper and lower chords of the crane boom, and this sensor system for detecting load and operating condition data comprises a plurality of sensors on the boom and the bracing,

[0034] FIG. 2: a rear view of a lifting gear in the form of a tower crane similar to FIG. 1, the crane being shown in a crosswind loading situation, and

[0035] FIG. 3: a side view of the lifting gear from FIG. 2, showing a raised position of the boom.

DETAILED DESCRIPTION

[0036] As shown in the figures, the lifting gear 1 may be designed in the form of a crane 2, wherein as an example there is shown a tower crane. The crane 2 can comprise a boom 3, which can be luffed up and down about a horizontal axis by a luffing mechanism, cf. FIG. 3. Independently thereof, the boom 3 can sit on a tower 4, which can be designed to be telescopic and/or foldable, more particularly if the crane is designed as a mobile fast-erecting crane. Said tower 4 may, for example, be seated on a rotatable superstructure 5, so that the boom 3 is rotatable together with the tower 4 about an upright axis of rotation by a slewing gear, but possibly also the boom 3 can be rotatable relative to the tower 4 about the upright axis if it is a top slewing gear. Said superstructure 5 may be seated on an undercarriage designed as a truck or on a crawler chassis or similar.

[0037] Said boom 3 and/or tower 4 may be designed as a hollow section and/or bar structure or a hybrid thereof. For example, the boom 3 and possibly also the tower 4 may comprise longitudinal chords 6, which may be interconnected by cross struts 7. In case of the boom 3, said longitudinal chords 6 are referred to as upper and lower chords, cf. FIG. 1.

[0038] A load suspension means 8 can run from the boom 3, for example in the form of a load hook, and the hollow point can be moved along the boom 3 by a trolley 10, cf. FIG. 1. The hoist rope 9 running off the trolley 10 can be retracted and released by a hoist drive for raising and lowering the load suspension means 8. Further drive devices not shown in more detail may be provided for the other crane movements, such as in particular a slewing gear drive for rotating the boom 3 about the upright axis, a trolley drive for adjusting the trolley 10, a luffing drive for luffing the boom 3 up and down, cf. FIG. 3, and possibly a telescoping drive for telescoping the boom and/or the tower in and out.

[0039] An electronic control unit 11 controls said drive devices and may cooperate with or include a monitoring device 12 to restrict or prevent crane movement if the stability of the crane is compromised. Such a monitoring device 12 can, for example, monitor the tilting moment acting on the crane 2, wherein for this purpose, for example, the outreach and the load picked up can be monitored, for example by sensory detection of the trolley position and sensory determination of the hoist rope force. However, possibly other or additional monitoring sensors can detect, for example, strains or reaction forces to perform stability monitoring.

[0040] As shown in the figures, the supporting structure 13 can include a bracing 14 that can brace the boom 3 and, if necessary, the tower 4. Such bracing 14 may include one or more bracing cables and/or bracing rods and/or bracing belts and/or bracing chains or, more generally, bracing tension means which may be supported by bracing supports 16 which may extend transversely to the longitudinal direction of said bracing tension means 15.

[0041] For example, bracing means 15 may be articulated to the boom 3 and extend across the back of the boom 3 to a tower top or, as shown in FIG. 1, to a bracing support 16, which may be articulated to the boom link or to the top end portion of the tower 4. The said bracing support 16 can be articulated by a further bracing tension means 15 on the superstructure 5, for example in the area of the ballast. However, it is understood that other guides of the bracing tension means are also possible, depending on the design of the lifting gear 1. For example, a spatial bracing system can also be provided which can brace the boom 3 not only in the upright longitudinal center plane but also transversely thereto, wherein such a spatial bracing system can be designed as a butterfly bracing system, for example, in which a V-shaped bracing block 16 can be provided via which two bracing tension means can be guided to the right and left of the boom 3, on which the bracing tension means 15 can have a common attachment point or also two spaced attachment points.

[0042] In order to be able to actively manipulate, more particularly variably brace and/or brace the supporting structure 13 online during lifting gear operation, provision is made for an actuator 17 which can comprise a number of actuators 18 which can be provided on various portions of the supporting structure 13.

[0043] For example, actuators 18 can be allocated to the upper and lower chords of the boom 3 by means of which the upper and lower chords can be shortened and/or lengthened.

[0044] For example, the actuators 18 allocated to the bracing 14 may include an actuator for shortening or lengthening the boom bracing tension means and an actuator for shortening and lengthening the neck bracing tension means.

[0045] Independently thereof, an actuator 18 can also be provided for shortening and/or lengthening a bracing support 16, cf. FIG. 1.

[0046] Said actuators 18 may in principle be designed in various ways, for example comprising pressure medium or hydraulic cylinder units, wherein provision can also be made for electric actuators such as spindle drives.

[0047] Said actuator 17 can be controlled and operated by the control unit 11 to variably manipulate the supporting structure 13 depending on the current load state and/or operating state of the crane 2.

[0048] For determining said load state and/or operating state of the crane 2, a determination device 19 is provided, which may comprise a sensor system 20 for detecting load state and/or operating condition parameters. In this regard, said sensor system 20 may include a plurality of sensors 21 that may be allocated to different portions or elements of the supporting structure 13 to detect their load and/or deformation and/or position and/or movement and/or acceleration.

[0049] The sensors 21 mentioned can in principle be designed in different ways, for example comprising strain gauges or inclination sensors on the steel structure or the profile structure of the supporting structure 13 and/or force measuring elements on the bracing means 15. For example, as FIG. 1 shows, sensors 21 can detect loads and/or deformations and/or inclinations of the upper and lower chords 6 of the boom 3. Additional sensors 21 can detect tensile forces in the bracing tension means 15 extending above the boom 3 and/or along the tower 4. Further sensors 21 can be allocated to the bracing supports 16 in order to detect forces and/or deformations and/or positions and/or movements prevailing there.

[0050] As FIG. 2 shows, further sensors 21 may be provided for detecting external influences such as wind load, wherein such sensors 21 may include, for example, wind speed gauges on one or different portions of the supporting structure 13. As FIG. 2 shows, for example, such a wind speed sensor may be provided at the tip of the boom 3 and the tip of a bracing support 16. Advantageously, such a wind sensor can also detect or determine the wind direction, more particularly whether the wind is coming across the boom 3 and at what angle.

[0051] As described above, the sensor system 20 can include various other sensors to detect other load state and/or operating condition parameters, for example, the set-up condition, the boom luffing position, the weight of the load supported by the load suspension means 8, the position of the trolley 10, or other variables relevant to the load and operating condition of the supporting structure 13.

[0052] For load and/or operating condition parameters that are difficult to measure, the determination device 19 may also include an estimation module that estimates the corresponding parameter based on the available system variables. Said estimation device may be implemented in the electronic control unit 11.

[0053] As the example of FIG. 1 illustrates, the control unit 11 can actively manipulate the supporting structure 13 by means of the actuators 18 depending on internal influences in order to increase or at least ensure the stability of the supporting structure 13. If, for example, a load is to be lifted by the load suspension means 8, the control unit 11 can proceed as follows:

[0054] Via the sensor system 20, all necessary or helpful parameters of the load state and/or an operating state are detected and possibly additional parameters are estimated by the aforementioned submission of estimates. In particular, the determination device 19 can determine the set-up condition of the crane via the aforementioned sensor system 20 and possibly the estimation device 22, in particular the support and/or guy geometry, the ballasting, the tower height, the boom length and/or other relevant set-up condition variables such as permissible maximum travel speeds. Alternatively, or additionally, the determination device 19 determines the angular position of the boom 3 and/or the positioning of the trolley 10 on the boom 3 and/or the resulting maximum lifting load and/or maximum lifting speed. The aforementioned information can already be known or made available to the control unit 11 before the intended crane movement. The actual lifting movement is only indicated on the control unit 11 by actuating an operating element, for example in the form of a joystick, wherein the lifting movement can also be part of an automatically controlled travel movement of the crane. If the lifting movement of the crane control system is known or indicated, the actual lifting load and speed can be determined by the sensor system 20, for example by a load measuring axis and a speedometer on the lifting mechanism. At the same time, other sensors that may be attached to the supporting structure of the crane 2, for example in the form of strain gauges and/or inclination sensors on the steel structure and/or force measuring elements on the bracing cables, can detect the responses to the mechanical effect(s) of the lifting movement.

[0055] The control unit 11 can check and process the above data for correctness or plausibility in the manner described at the beginning. Quantities that cannot be detected by sensors or are difficult to detect, such as the deformation of the boom tip, can be calculated and/or estimated with sufficient accuracy based on other information such as the length and angle of the boom 3 and the guy geometry.

[0056] In addition to mechanical stresses or loads, other serviceability criteria such as deformation of the supporting structure 13 can also be detected by sensors or determined in other ways by the determination device 19.

[0057] To counteract excessive loads and/or deformations, various actuator strategies can be applied by the control unit 11. For example, by actuating the corresponding actuators 18, the control unit 11 can shorten the length of components subjected to tension and/or lengthen components subjected to compression and/or use both strategy approaches in combination. For example, the bracing tension means 15 and/or the upper chord 60 of the boom 3 can be shortened by the corresponding actuators 18. Alternatively, or additionally, for example, the lower chords 6u of the boom 3 and/or a bracing support 16, which may be hinged in a central section of the boom 3, may be lengthened by the corresponding actuators 18.

[0058] By shortening the upper chord and/or lengthening the lower chords and/or lengthening the center support and/or shortening the bracing tension means, the deformation of the boom 3 can be actively manipulated, wherein the control unit 11 can variably adjust this active manipulation depending on the load state and/or operating state currently determined by the determination device 19 in each case.

[0059] As shown in FIGS. 2 and 3, the control unit 11 can also control or adjust the active manipulation of the supporting structure 13 depending on external influences such as crosswinds.

[0060] In the example of FIGS. 2 and 3, the sensor system 20 can measure directly via the aforementioned wind sensors 21 and direction. Alternatively, or additionally, mechanical effects of the wind such as stresses, strains, angular changes, slip or rotational forces can also be detected by the sensor system 21, wherein redundant wind detection can possibly be performed.

[0061] The detection of external influences such as the crosswind mentioned, for example, is advantageously carried out in addition to the detection or determining of the system variables explained for the example of FIG. 1.

[0062] For example, if we consider the crane 2 with a boom 3 standing steeply, as shown in FIGS. 2 and 3, both the tower 4 and the boom 3 are deformed in the wind direction. In order to counteract such deformation, the control unit 11 can control the actuators 15 depending on the parameters characterizing the wind load, more particularly to shorten the length of components subjected to tensile loads, for example parts of the bracing 14 and/or the lower chord 6u of the boom 3 facing the wind and/or the corner bars or longitudinal chords 6 of the tower 4 facing the wind. Alternatively, or additionally, the control unit 11 may also cause components subjected to compression to be lengthened by corresponding actuation of the actuators 18, for example parts of the bracing 14, a lower chord of the boom 3 facing away from the wind and/or corner bars of the tower 4 facing away from the wind.

[0063] As shown more particularly in FIG. 2, for example, a neck bracing facing the wind can be shortened by a corresponding actuator 18. Alternatively, or additionally, the lower chord 6u facing away from the wind can be lengthened by actuating the actuator 18 allocated to the lower chord 6u.