MEASURING DEVICE FOR LOAD MEASUREMENT IN A HOIST

Abstract

A measuring device for load sensing in a lifting-cable-based hoist, in particular a crane, having at least one pulley for deflecting the lifting cable of the hoist, a fastening means in the form of a cable loop, at the end of which the pulley is mounted so as to be rotatable about its roller axis, and at least one measuring element for sensing a force applied to the pulley.

Claims

1. A measuring device for load measurement in a hoist rope-based lifting device or a crane, the measuring device having at least one deflection pulley for deflecting the hoist rope of the lifting device, a fastening means at whose end the deflection pulley is supported rotatably about its pulley axis, and at least one measuring element for detecting a force applied to the deflection pulley.

2. The measuring device in accordance with claim 1, wherein the fastening means is a loop body, a rope loop, or a plastic rope loop.

3. The measuring device in accordance with claim 1, wherein the measuring element comprises hanging scales and/or a plug gauge and/or a measuring ring.

4. The measuring device in accordance with claim 1, wherein the measuring element is connected to the fastening means, the fastening means comprising a loop body, by means of at least one connection means, the at least one connection means comprising a rocker arm.

5. The measuring device in accordance with claim 1, wherein the measuring device comprises at least one positional sensor, the at least one positional sensor comprising an angle transmitter.

6. The measuring device in accordance with claim 1, wherein the measuring device comprises at least one communication module adapted for transmitting measurement data to a reception unit, wherein the at least one communication module is adapted for wired and/or wireless communication.

7. A lifting device having at least one measuring device in accordance with claim 1, the at least one measuring device comprising a first measuring device.

8. The lifting device in accordance with claim 7, wherein the first measuring device is suspended at at least one pulley of the lifting device by means of the fastening means, the fastening means comprising a loop body, and wherein the hoist rope of the lifting device is deflected by means of the at least one deflection pulley of the first measuring device.

9. The lifting device in accordance with claim 8, wherein the first measuring device is suspended by means of the loop body at at least one deflection pulley of a pulley head of a boom system, with a centrally disposed deflection pulley serving to suspend the first measuring device in the pulley head.

10. The lifting device in accordance with claim 9, wherein a second measurement device is provided at the lifting device.

11. The lifting device in accordance with claim 10, wherein the second measuring device is fastened in a region of the hoist rope different from the first measuring device, and wherein one of the measuring devices is particularly preferably arranged at a start of a multiple reeving of the pulley head, while another measuring device is installed at an end of the multiple reeving.

12. The lifting device in accordance with claim 10, wherein the lifting device comprises at least two hoist ropes, and wherein at least one measuring device in accordance with claim 1 is provided per hoist rope.

13. The lifting device in accordance with claim 7, wherein the first measuring device communicates with a machine control of the lifting device via wired communication and/or is supplied with electrical energy by a line via an energy source of the lifting device.

14. The lifting device in accordance with claim 7, wherein the first measuring device is arranged at a hook block.

15. The lifting device in accordance with claim 7, wherein the first measuring device communicates with a machine control of the lifting device, and wherein the machine control is adapted to calculate a weight of a load taken up using forces measured by means of the first measuring device and taking into account the number of rope lines with multiple reeving.

16. A method of load measurement comprising: providing a measuring device for load measurement in a hoist rope-based lifting device, the measuring device having at least one deflection pulley, a fastening means at whose end the deflection pulley is supported rotatably about its pulley axis, and at least one measuring element; deflecting the hoist rope of the lifting device using the at least one deflection pulley; and detecting a force applied to the deflection pulley using the at least one measuring element.

17. The method of claim 16, wherein the fastening means is a loop body, a rope loop, or a plastic rope loop, and wherein the measuring element comprises hanging scales and/or a plug gauge and/or a measuring ring.

18. The method of claim 16, wherein the measuring element is connected to the fastening means, the fastening means comprising a loop body, by means of at least one connection means, the at least one connection means comprising a rocker arm.

19. The method of claim 16, wherein the measuring device comprises at least one positional sensor, the at least one positional sensor comprising an angle transmitter.

20. The method of claim 16, wherein the measuring device comprises at least one communication module, and the method further comprises transmitting measurement data to a reception unit using the at least one communication module, wherein the at least one communication module is adapted for wired and/or wireless communication.

Description

[0034] Further advantages and properties of the invention will be explained in more detail in the following with reference to an embodiment shown in more detail in the drawings. There are shown:

[0035] FIG. 1: a schematic representation of the force distribution in the individual rope lines during the lifting or lowering process.

[0036] FIG. 2: a perspective side view of the measuring device in accordance with the invention;

[0037] FIG. 3: a detailed representation of the pulley head without a fly boom of a crane in accordance with the invention with a measuring device installed;

[0038] FIG. 4: a sketched representation of the rope extent of the crane in accordance with the invention with a measuring device installed;

[0039] FIG. 5: an enlarged representation of the boom tip without a fly boom of a crane in accordance with the invention with a measuring device installed; and

[0040] FIG. 6: a further embodiment of the crane in accordance with the invention with two representations of a lifting hook, at the left without diagonal pull and at the right with diagonal pull.

[0041] The measuring device 100 in accordance with the invention can be seen in detail from FIG. 2. It comprises a deflection pulley 101 that is adapted to deflect the hoist rope 4 of the crane in place of a deflection pulley attached in the pulley head 102 of the crane in accordance with the invention (FIG. 3). It is thereby possible to use the measuring device at any position in the reeving.

[0042] The schematic rope extent of the hoist rope 4 with an installed measuring device 100 can be easily recognized in FIG. 4, for example. The hoist rope 4 here extends from the hoist winch to the boom tip where it is led over the boom head top sheave 2 to the pulley head 102. A multiple reeving of the hoist rope 4 is present between the pulley head 102 and the hook block and provides four respective deflection pulleys at the pulley head 102 and in the region of the hook block. In the embodiment of FIG. 4 shown, the penultimate deflection pulley of the pulley head 102 is, for example, taken out of the rope extent and instead serves as a suspension means for the measuring device 100 in accordance with the invention. The hoist rope 4 instead extends over the integrated deflection pulley 101 of the measuring device 100 back to the hook block. Detailed representations of the boom tip can be seen from FIGS. 3 and 5.

[0043] The fastening of the measuring device 100 to the deflection pulley of the pulley head 102 is achieved by a rope loop 104 that is placed around the deflection pulley of the pulley head 102. The rope loop is preferably formed by a plastic rope. The two loop ends are connected to the measuring device 100 via a rocker arm 106. It is ensured by the flexible suspension of the measuring device 100 by means of the rope loop 104 that the measuring device is automatically aligned in the direction of the load taken up.

[0044] The deflection pulley 101 and the associated pulley support are connected to the rocker arm 106 via a measuring element 105 so that the force applied by the hoist rope 4 to the deflection pulley 101 can be detected by the measuring element 105. It can, for example, be designed as hanging scales, a plug gauge or as a measuring ring. In the embodiment of Figure shown, a plug gauge is specifically used.

[0045] To eliminate the above-named problem of the degree of action, a second measuring device, that is likewise introduced into the pulley head 102, can be used in addition to the measuring device 100 shown in FIGS. 3-5. It is meaningful in such a case to integrate one measuring device 100 as far to the front as possible in the reeving and to integrate a further measuring device 100 as far to the back as possible in the reeving. The second measuring device could also be designed in the form of a conventional measuring device, for example by a simple load cell or a plug gauge in the region of the rope anchor point 9.

[0046] The transmission of the measurement data takes place via a wired connection to the crane control. The energy supply of the measuring device 100 also takes place from a central energy source of the crane via supply lines. The at least one measuring device 100 delivers its data to the crane control. Optionally, an additional convention tension load cell delivers its data to the crane control. The crane control then calculates the weight of the load using the known number of rope lines between the pulley head 102 and the hook block 103 and the measured forces. In the simplest case, a linear relationship can be assumed.

[0047] FIG. 5 shows an embodiment of the crane with two lifting hooks and two winches (2-hook operation). Only one hoist rope 4 that is located at the pivot point of the horizontal luffable boom at the crane tower top is drawn in the representation. It may occur due to the parallel operation of a plurality of hoist ropes that the lifting hook is moved from a perpendicularly aligned location into a pivoted position relative thereto. It is, however, necessary in this connection that that the specific alignment of the lifting hook is considered in the calculation of the load taken up. It is sensible in this case if an angle transmitter 110 is additionally integrated in the measuring device 100. The deflection of the load with respect to the perpendicular can thus be determined and likewise transmitted to the crane control. The torque applied to the crane can hereby be detected and corrected by means of these data. The advantages of the measuring device 100 in accordance with the invention or of the crane in accordance with the invention can be summarized briefly again in the following.

[0048] The solution in accordance with the invention in the form of the measuring device 100 enables a particularly simple retrofitting of existing cranes or lifting devices since they can be particularly simply attached to existing rope pulleys of the crane or of the lifting device. In the invention, the measurement of the hook load takes place via the pull of the rope of the hoist rope 4. Due to the line number only one measuring element 105 is required for relatively low forces and a scaling takes place automatically over the reeving. The solution in accordance with the invention can be advantageously used in an operation with two hoist ropes and two winches. A respective measuring device 100 is here present in both hoist rope lines. The force in each of the hoist ropes is thus known and it is possible for the control to maintain the force as approximately the same in both hoist ropes by correcting the winch drive. An improper tilt of the bottom hook block is thus prevented.

[0049] A further advantage of the invention comprises the number of rope deflections remaining the same on an integration of the measuring device 100, whereby the hoist rope 4 is not subject to any greater wear. A signal transmission over a longer distance, for example by means of radio, is also not necessary since the measuring device 100 is always attached to the boom head 102, even if the rope anchor point Is at the bottom hook block. Due to the relatively low forces, standard measuring elements 105 can be used, whereby the measuring unit is very inexpensive. The total weight, including the bottom hook block 103 and any additional weights, suspended at the pulley head 10 can be detected by the measuring device 100.