CRANE

Description

[0001] The present invention relates to a crane, for example in the form of a fast-erecting crane comprising a telescopic and / or luffing tower, with a crane control system for controlling crane movements by means of drive devices, wherein the crane control system has a monitoring device for monitoring stability and limiting crane movements when a load limit is reached.

[0002] Such a crane is shown, for example, in EP 3428112 A1, which discloses a crane according to the preamble of claim 1, wherein the wind force acting on the boom system is monitored for the erection process of the boom. Another crane of the aforementioned type is also shown in EP 1221426 A2.

[0003] In cranes such as construction cranes, for example mobile cranes or tower cranes, a crane control system or a monitoring device implemented within it is usually used to monitor whether the stability of the crane is ensured or whether the crane load reaches a critical load limit, so that the crane is in danger of falling over or is otherwise endangered, in order to switch off the corresponding drive devices of the crane in good time if necessary.

[0004] In particular, the lifting load and the reach of the lifting load can be monitored. This can be done, for example, by determining the tensile force acting on the hoist rope or the resulting torque induced at the hoist winch, and – with regard to the reach – by monitoring the position of a trolley or the length of trolley travel rope that has been unwound. Depending on the crane type, these parameters can also be determined in other ways. For example, with cranes that have a luffing jib, the reach can be determined via the luffing angle and, if applicable, the extended jib length. By determining the lifting load and its reach, a load moment acting on the crane can be calculated. This load moment can then be compared with a corresponding load limit in the form of a limiting moment to ensure the crane's stability.In principle, the aforementioned load moment can also be determined in other ways, for example by sensory detection of bending deformations of the tower, tensile stresses in the tower longitudinal chords or in a bracing system, or the load on support feet.

[0005] However, it is not only the load moment that can endanger stability, but also excessively high load loads themselves, which, if the trolley has moved very far inwards or the overhang is very small, are not critical with regard to the load moment, but can lead to structural failure.

[0006] If the monitoring device detects that a load is being lifted that is generally too heavy and / or that a specific lifting load is being moved too far outwards, so that the reach for this load becomes too large, the crane control can shut down the hoist drive and, if necessary, other drives such as the trolley drive or the luffing drive in order to ensure the stability of the crane, in particular to prevent any further crane movements that would endanger the stability even further.

[0007] The stability of a crane, however, does not depend solely on the aforementioned factors of lifting capacity and reach, but is also influenced by other variables, such as dynamic factors like movement speed and acceleration. To maximize the load-bearing capacity and stability reserves of a crane without compromising safety, it has been proposed to work with different load limits or to progressively restrict crane movements as the stability reserves decrease. For example, document EP 2 847 121 B1 describes a tower crane that operates with a total of three load limits in the form of so-called load-bearing curves. If a first load limit is reached or exceeded, all crane movements can still be performed, but only at reduced speed and acceleration.If a second load limit is exceeded, the crane drives can only be operated individually until a third load limit is reached, at which point individual operation of a drive is also switched off or only movements that increase stability are permitted.

[0008] Furthermore, consideration has already been given to taking the crane's configuration into account and, depending on the equipment fitted to the crane, providing or selecting different load limits, for example in the form of load curves. For instance, a reduced load limit could be selected if the crane is erected with reduced ballast, or a higher load curve could be provided if the crane is erected without an operator's cab. The different load limits could, for example, be stored in a programmable logic controller (PLC) so that they are activated depending on the configuration.

[0009] Based on this, the present invention aims to create an improved crane of the aforementioned type that avoids the disadvantages of the prior art and advantageously develops the latter further. In particular, a further increase in load capacity and / or performance should be achieved, and the highest possible load capacities and travel speeds should be permitted without compromising stability.

[0010] According to the invention, the aforementioned problem is solved by a crane according to claim 1. Preferred embodiments of the invention are the subject of the dependent claims.

[0011] It is therefore proposed that at least one load limit relevant for restricting crane movements be adjusted to the crane's wind resistance, which can vary depending on the crane's setup and / or operating condition. If the crane is in a more aerodynamic setup or operating condition, where strong winds have less of an impact on the crane and its stability, the load limit can be increased. Conversely, a lower load limit may be appropriate if the crane is in a setup and / or operating condition where it has higher wind resistance and is more susceptible to wind, or where the wind exerts a higher wind or tipping moment on the crane.

[0012] According to the invention, it is proposed that the monitoring device includes a wind resistance detection device for detecting at least one variable wind resistance parameter that influences the wind resistance of the crane and is configured to change the load limit depending on the detected wind resistance parameter and / or to consider different load limits depending on said wind resistance parameter. This allows the crane's susceptibility to wind loads to be taken into account more precisely and the crane's stability to be better utilized without compromising it. If the detection device determines a lower wind resistance of the crane, the aforementioned load limit can be increased or a load limit with less restrictive movement can be selected.The aforementioned load limit can also be a limit for the permissible wind load, such that higher wind speeds may be permitted in a more aerodynamic setup and / or operating condition of the crane. Alternatively or additionally, the aforementioned load limit can also be a limit for the load moment and / or the lifting capacity, at which point crane movements or drive systems of the crane are restricted or switched off.

[0013] According to the invention, the aforementioned wind resistance detection device can determine the presence and / or position of a wind-relevant attachment, so that the monitoring device can change the load limit and / or take different load limits into account depending on the presence and / or position of one or more wind-catching components. Such wind-resistant attachments can be, in particular, large-area and / or closed-area, especially upright, attachments whose wind resistance is relatively high compared to the structural parts of the crane, which are often designed as trusses or beam profiles.

[0014] In particular, the wind resistance detection device can detect large-area, upright components with a poor drag coefficient (cw) or wind resistance coefficient, especially with regard to a potentially variable position on the crane structure.

[0015] In particular, the wind resistance detection device can include positioning means for determining the height and / or distance of the wind-sensitive component from a tipping axis of the crane, so that the monitoring device can adjust the aforementioned load limit depending on the determined height and / or the specific tipping axis distance. The tipping axis can be defined, for example, by the crane's outriggers or, more generally, by boundary points of a contact surface, or it can be estimated approximately. In principle, the monitoring device can be designed to lower the load limit the higher and / or the further away from the tipping axis the wind-sensitive component is located.The consideration of the height of a wind-relevant component is based on the idea that if the same component is positioned relatively low, it will have relatively little impact on the stability of the crane, since the lever arm for the wind force and thus the wind-induced tipping moment is relatively small, whereas the same component causes a significantly higher wind-induced tipping moment at the same wind speed if it is positioned higher.

[0016] In an advantageous further development of the invention, the wind resistance detection device can also include size determination means to determine the size of the cross-sectional area of ​​the component relevant for wind resistance when components of different sizes can be attached to the crane and / or arranged in different positions, as is the case, for example, with advertising boards or tarpaulins.

[0017] In particular, the wind resistance detection device can be configured to detect the presence and / or position of a control and / or personnel platform, for example, in the form of a crane operator's cabin. Depending on the detected control and / or personnel platform and / or the detected position of the cabin or control platform, the monitoring device can increase or decrease at least one load limit for restricting crane movements.

[0018] In particular, the crane may have a position-variable control and / or operator platform, for example in the form of a crane operator's cabin. The position detection devices can record the respective position of the control and / or operator platform, whereby the monitoring device can increase or decrease the specified load limit depending on the recorded position of the control and / or operator platform.

[0019] For example, the crane may have a height-adjustable operator's platform and / or personnel platform that can be moved up and down along a crane tower. Alternatively or additionally, an operator's platform and / or personnel platform may be provided that can be moved along a boom of the crane. The wind resistance detection device determines the position, in particular the height, of the operator's platform and / or personnel platform and transmits this information to the monitoring device, which then adjusts the load limit depending on the determined position. In particular, the load limit can be reduced the higher the operator's platform and / or personnel platform is positioned.

[0020] Alternatively or additionally, the wind resistance detection device can also include advertising surface detection elements to detect the presence and / or position of an advertising surface, which may be in the form of an advertising panel and / or a stretched advertising cloth or banner. Such advertising surfaces are often mounted on higher sections of crane towers or on a crane boom to ensure good visibility even from a distance. However, such high-mounted, often large-format advertising panels or surfaces significantly increase the wind resistance of the crane. Therefore, it is advisable to reduce the load limit when such large advertising surfaces are mounted at greater heights on the crane, while conversely, a higher or extended load limit can be applied when such relatively high-mounted large-format advertising banners are absent.

[0021] In a further development of the invention, the wind resistance detection device can also include alignment determination means that can determine or take into account the orientation of a wind-relevant component relative to an upright crane longitudinal center plane and / or with respect to a vertical. For example, large, upright advertising surfaces that extend essentially parallel to the crane longitudinal center plane, which runs vertically through the crane boom, and catch wind perpendicular to said crane longitudinal center plane, can be more critical with regard to wind resistance, since cranes are regularly very sensitive to transverse loads, or the ballast is hardly effective against such transverse loads. On the other hand, corresponding advertising surfaces or windbreak surfaces can be better tolerated by the crane if they are positioned perpendicular to the said crane longitudinal center plane or at a shallower angle to the vertical.

[0022] Therefore, the monitoring device can adjust the load limit depending on the specific orientation of the windbreak surface or the wind-relevant component relative to the vertical and / or relative to the upright crane longitudinal center plane.

[0023] The aforementioned wind resistance detection device can advantageously be designed to operate semi-automatically and / or fully automatically. In a semi-automatic configuration, for example, confirmation from the crane operator and / or technician can be requested, with such a request being automatically displayed, for instance, on a crane control display. Such a confirmation request could, for example, include the question "Crane cabin up or down?" if the crane cabin can only be positioned in two locations on the tower. Alternatively or additionally, for example, on a touchscreen display, a crane diagram could be shown along with a prompt such as "Please tap the position of the advertising panel!", whereupon the crane operator or technician can tap the mounting position of the advertising banner.Depending on the input signal following such a query, the monitoring device can then adjust the load limit, in particular increase or decrease it, depending on whether and at what position a wind-relevant component is located.

[0024] To enable even simpler operation and / or to detect possible adjustments during crane operation, the wind resistance detection device can also be designed to operate fully automatically and have sensors that can continuously or cyclically detect the position of a position-variable, wind-relevant component such as the crane operator's cabin or a control station, so that, depending on a signal from the wind resistance detection device, the monitoring device can continuously or cyclically adjust the load limit.

[0025] However, fully automatic detection can also consist of the fact that the attachment of a wind-relevant component, such as an advertising panel, to the crane tower or boom is automatically detected by a sensor and reported to the monitoring device, which then adjusts the load limit accordingly.

[0026] The invention is explained in more detail below with reference to a preferred embodiment and the accompanying drawings. The drawings show: Fig. 1 a schematic side view of a quick-erecting crane designed as a tower crane according to an advantageous embodiment of the invention, the crane operator's cabin of which is mounted on the tower of the crane in a height-adjustable manner, Fig. 2 a lifting capacity / reach diagram showing several load limits in the form of different limit load curves and the different load capacity ranges defined therein, in which the crane control provides different restrictions on crane movements in different operating modes.

[0027] How Figure 1As shown, the crane 1 can be designed as a tower crane and have a tower 2 that stands upright during operation and supports a cantilevered boom 3. The lower end of the tower 2 can be mounted on a slewing platform 4, which is rotatable about an upright axis and supported on a chassis 5, which can be designed as a truck or otherwise movable, but can also optionally form a rigid, non-movable support base.

[0028] A trolley 7 can be longitudinally mounted on the boom 3 and moved back and forth by means of a trolley cable 8. A lifting cable 6 with a load hook can run down the trolley 7.

[0029] The crane 1 comprises a control and / or personnel platform 9, which can be designed as a crane operator's cabin or lift cabin 10. The aforementioned control and / or personnel platform 9 is mounted in a height-adjustable manner. In particular, the aforementioned crane operator's cabin or lift cabin 10 can be mounted on the tower 2 in a longitudinally movable manner, for example by means of a cabin carriage that is guided on the tower profile, for example by its longitudinal chords.

[0030] As the Figure 1As shown, the control and / or operator platform 9 can be held by a suspension and moved to various height positions, which can engage the chassis, in particular the top of the crane operator or lift cabin 10. The cabin 10 can be moved up and down an outer side of the tower 2, for example by means of a roller guide or rail guide along the tower. If necessary, however, the cabin can also be located inside the tower profile, for example, if it is only used as an access aid to reach the boom or a control platform located at the top and the tower profile is sufficiently voluminous.

[0031] How Figure 1 Furthermore, it shows, for example, that an advertising surface 11 can be mounted on the boom 3, for example in the form of a large advertising panel, which stands upright parallel to the crane's longitudinal center plane, which is the drawing plane of the Figure 1 forms, can be arranged.

[0032] A control device 21, which may, for example, include a microprocessor, a program memory and other electronic components, controls the drive devices by which the aforementioned crane movements can be carried out, in particular the raising and lowering of the hoist rope 6, the movement of the trolley 7 over the trolley travel rope 8, optionally a rocking up and down of the boom 3, and the raising and lowering of the crane operator's lift cabin 10, and also the actuation of a slewing mechanism to rotate the crane 1 about an upright axis.

[0033] The aforementioned crane control 21 can provide, in a manner known per se, corresponding operating levers or other input means for a crane operator so that he can control the various axes of movement of the crane.

[0034] The control device 21 further comprises a monitoring device 22, which, by means of suitable sensors, can monitor the crane loads acting on the crane, in particular the lifting load picked up by the load hook and the reach that the load hook or the trolley 7 has with respect to the crane's base. This reach can be determined, in particular, by the position of the trolley 7 on the boom 3 and, if applicable, by the luffing angle of the boom 3 relative to the horizontal.

[0035] In the aforementioned monitoring device 22, several load limits LM1, LM2 and LM3 and optionally also LM4 can be implemented, as shown here. Fig. 2 The monitoring device 22 compares the current load state with the specified load limits, whereby the control device 21 enables or restricts the operation of the aforementioned drive devices depending on the load capacity range in which the crane is currently located.

[0036] For example, as long as the crane is in load capacity range 1 below the limit load curve LM1, see: Figure 2 Several drive units can be operated simultaneously at relatively high or maximum drive speeds and accelerations. If crane 1 reaches the specified load limit LM1 by lifting a correspondingly heavy load or by increasing its reach, the crane can indeed move beyond this load limit LM1 into load capacity range II, but only by switching the control device 21 accordingly and reducing the speed and acceleration of the drives. This switching process can be triggered manually by the crane operator or automatically by a corresponding switching device when the limit is exceeded.

[0037] If the crane operation reaches the aforementioned second load limit LM2, this limit can also be exceeded, although then only individual operation of the drive units is possible. The corresponding switching process can be carried out manually or automatically. For example, in load range III, either only the hoist drive or only the trolley drive can be operated.

[0038] However, it goes without saying that the crane control does not necessarily have to be the one in Fig. 2 The three different load limits shown, LM1, LM2, and LM3, must be observed. If necessary, it is also possible to work with only one or two load limits.

[0039] The control device 21 and the monitoring device 22 also take into account, in particular, the wind resistance of the crane 1 depending on its setup or operating state. For example, the position of the crane operator's lift cabin 10 can influence the wind resistance or the wind moment caused by wind striking the cabin 10. The higher the crane operator's lift cabin 10 is moved along the tower 2, the greater the tipping moment caused by wind striking the cabin 10.

[0040] A wind resistance detection device 20, which can be implemented as a software module in the control device 21, can include position determination means 19 that can automatically detect or determine the height position of the aforementioned crane operator lift cabin 10.

[0041] For example, the aforementioned positioning means 19 can include sensors 23 that can determine the distance of the crane operator's lift cabin 10 from the boom 3 or from the upper end section of the tower 2. The height position can also be determined, for example, by sensors associated with the drive for height adjustment.

[0042] Alternatively or in addition to the height setting of the crane operator's lift cabin 10, the wind resistance detection device 20 can also have detection means 24 that can detect the presence of the advertising area 11 on the crane boom 3.

[0043] If such an advertising panel 11 is present, the wind resistance of the crane is significantly greater than if such an advertising surface 11 is not present.

[0044] The monitoring device 22 can take into account the height position of the crane operator's lift cabin 10 and / or the presence of the advertising space 11 in order to shift or adjust the load limits LM1, LM2 and / or LM3, as indicated by the arrow 11 in Fig. 2 This is indicated. For example, if the crane operator's cabin 10 is lowered, for instance to ground level in the area of ​​the undercarriage 5, the monitoring device 22 can increase or extend the aforementioned load limits LM1, LM2, and LM3 to allow for larger loads and / or outreaches. Conversely, the load limits can be shifted in the opposite direction (opposite arrow 11) if the cabin 10 is raised or an advertising banner 11 is attached to the boom.

[0045] Alternatively or in addition to such a shift in the aforementioned load limits, the monitoring device 22 may also take into account an additional load limit LM4, for example, instead of the load limit LM3, for instance, if the aforementioned driver's cab 10 is operated in a ground-level position and / or the advertising space 11 is not present, resulting in lower wind resistance. The aforementioned load curve LM4 may then be higher than the curve LM3, which in this case is not taken into account. Conversely, such a load limit LM4 may also be set below the load limit LM3, for example, if an additional advertising banner is attached to the boom.

[0046] As mentioned, the monitoring device 22 can also take into account the presence of the advertising space 11. If this is present, for example, the following can be detected: Fig. 2The load limits LM1 and / or LM2 and / or LM3 and / or LM4 shown can be shifted downwards or inwards to impose restrictions on crane movements even at lower loads and / or outreaches. However, if the advertising surface 11 is not present and the detection device 24 therefore indicates that no such advertising surface 11 is present, the monitoring device 22 can apply the aforementioned load limits or only one of these load limits. Figure 2 increase or shift the position so that higher load capacities and / or projections can be driven.

[0047] Alternatively or in addition to shifting the aforementioned load limits LM1, LM2 and LM3 or applying an alternative load limit LM4, the monitoring device 22 can also adjust a load limit in the form of a maximum permissible wind speed for crane operation, in particular increase or decrease it, depending on the signal provided by the wind resistance detection device 20. For example, if the aforementioned advertising surface 11 is mounted on the boom 3 and the crane operator's cabin 11 is also located at the top of the tower, the permissible maximum wind speed can be reduced.

Claims

1. Crane, in particular a fast-erecting crane convertible in the form of a slewing tower crane, with a crane controller (21) for controlling crane movements, wherein the crane controller (21) has a monitoring device (22) for monitoring stability and limiting crane movements when a load limit (LM1, LM2, LM3, LM4) is reached, wherein the monitoring device (22) has a wind resistance detection unit (20) for detecting at least one variable wind-resistance parameter which influences the wind resistance of the crane and / or the wind torque exerted by a given wind on the crane (1), and is configured to modify said load limit (LM1, LM2, LM3, LM4) as a function of the detected wind-resistance parameter and / or to take into account different load limits as a function of the detected wind-resistance parameter, characterized in that the wind resistance detection unit (20) comprises accessory mounting surface detection means for detecting accessory mounting surfaces that can be mounted on the crane structure and / or for detecting the position of such accessory mounting surfaces, wherein the monitoring device (22) is configured to adjust the load limit and / or to select different load limits as a function of a signal from the accessory mounting surface detection means.

2. Crane according to the preceding claim, wherein the wind resistance detection unit (20) comprises position determination means (19) for determining the position of a position-variable component relevant to wind resistance on the crane structure, and the monitoring device (22) is configured to adjust the load limits and / or to select different load limits as a function of the determined position of the component relevant to wind resistance.

3. Crane according to the preceding claim, wherein the position determination means (19) comprises height determination means for determining the height of the component relevant to wind and / or the distance of the component relevant to wind from a tilt axis of the crane, the monitoring device (22) being configured to adjust the load limit and / or to select different load limits as a function of the determined height and / or the determined distance relative to the tilt axis.

4. Crane according to the preceding claim, wherein the monitoring device (22) is configured to lower the load limit and / or to select a lower load limit as the height and / or the distance relative to the tilt axis increases.

5. Crane according to any one of the preceding claims, wherein a position-variable, in particular height-adjustable, control and / or operator station (9) is provided and the position determination means, in particular height determination means, are configured for determining the position, in particular the height, of the control and / or operator station (9), wherein the monitoring device (22) is configured for adjusting the load limit and / or for selecting different load limits as a function of the determined position, in particular the height, of the control and / or operator station (9).

6. Crane according to any one of the preceding claims, wherein the accessory mounting surface detection means are configured to detect vertical advertising surfaces (11) and / or their position on the crane structure.

7. Crane according to any one of the preceding claims, wherein the accessory mounting surface detection means are configured to determine an inclination of the accessory mounting surface with respect to a vertical and / or with respect to a vertical longitudinal central plane of the crane, wherein the monitoring device (22) is configured to modify the load limit and / or to select different load limits as a function of the determined orientation.

8. Crane according to any one of the preceding claims, wherein the load limit to be adapted by the monitoring device (22) comprises a load capacity curve which specifies load-capacity limit values as a function of the outreach and / or a load-moment limit and / or a load-capacity limit.

9. Crane according to any one of the preceding claims, wherein the load limit to be adapted by the monitoring device (22) comprises a limit for the maximum permissible wind speed.

10. Crane according to any one of the preceding claims, wherein the monitoring device (22) is configured to operate at least semi-automatically, preferably fully automatically, and to effect the adjustment of the load limit at least semi-automatically, preferably fully automatically, as a function of a signal from the wind resistance detection unit (20)