Method and mobile crane

Abstract

The invention relates to a method for adjusting a first guy force in a first guy between a boom of a mobile crane and a superstructure of the mobile crane, wherein the first guy force is automatically adjusted by adjusting a second guy force in a second guy between the boom of the crane and a component of the crane.

Description

Technical Field

[0001] The present invention relates to a method for adjusting the first cable force in a first cable between the boom of a mobile crane and the upper structure of the mobile crane. Existing technology As is known in the prior art, mobile cranes have counterweights to balance the loads lifted by the mobile crane. Here, the counterweight can be formed or arranged on a movable counterweight vehicle. The counterweight can also be referred to as a herringbone counterweight.

[0002] For example, mobile cranes with counterweights or A-frame counterweights are disclosed in US 11,235,961 B2, EP 0 989 087 A1, JP 6260591 B, JP 7230895 B and EP 3 925 924 A4.

[0003] Furthermore, it is known that in the prior art, the counterweight vehicle of a mobile crane is connected to the auxiliary boom of the crane via a cable, wherein the auxiliary boom is connected to the upper structure of the crane via another cable.

[0004] Here, the cables are subjected to a corresponding tension force. This tension changes as the mobile crane moves. Significant changes in the tension force in the cables between the auxiliary boom and the superstructure can occur, especially when the superstructure rotates or when the mobile crane travels over uneven terrain.

[0005] In order to control the cable force in the cable, it is known from the prior art that the length of the cable between the auxiliary boom and the counterweight vehicle can be changed by a counterweight lifting cylinder located in the cable, thereby raising or lowering the counterweight vehicle or the counterweight arranged on the counterweight vehicle, and / or thereby changing the force of the counterweight vehicle being pulled into the auxiliary boom by the cable.

[0006] Here, the counterweight lifting cylinder is controlled manually by the operator using four operating elements on the dashboard of the mobile crane.

[0007] These four operating elements are Figure 2 As shown in the figure, Figure 2 An excerpt from the operating instructions for a mobile crane is shown. Similarly, from... Figure 2 The functional descriptions of these four operating elements are obtained from this.

[0008] When manipulating the operating elements to "raise the A-shaped counterweight" and "lower the A-shaped counterweight", both counterweight lifting cylinders are operated simultaneously. Summary of the Invention

[0009] In this context, the object of the present invention is to provide a method for improving the monitoring of cable forces in the cables of a mobile crane.

[0010] This objective is achieved by a method having the features described in independent claim 1. Advantageous improvements of the invention are the subject of the dependent claims.

[0011] Accordingly, according to the present invention, the first cable force is automatically adjusted by adjusting the second cable force in the second cable between the crane boom and the crane components.

[0012] Preferably, the method is a computer-implemented method.

[0013] Preferably, the component is a counterweight vehicle.

[0014] The counterweight vehicle can be implemented by attaching counterweights to a self-propelled modular transport vehicle (SPMT). The counterweight vehicle can move on its own.

[0015] Preferably, the adjustment of the first cable force and / or the adjustment of the second cable force are specified during the travel of the mobile crane, after the travel of the mobile crane, during the rotation of the superstructure, and / or after the rotation of the superstructure.

[0016] Preferably, one or more lifting elements, especially hydraulic cylinders, are arranged in the second cable, and the force of the second cable is adjusted by adjusting the length of one or more lifting elements.

[0017] Hydraulic cylinders can also be called counterweight lifting cylinders.

[0018] Preferably, the length of the second cable is changed only in very small amounts, for example, only on the order of centimeters or decimeters.

[0019] Additionally or alternatively, the first cable force can also be adjusted by controlling the first cable force, wherein the second cable force or the length of the second cable is manually adjusted by the operator.

[0020] In other words, preferably, the second cable force can be adjusted by adjusting or changing the length of one or more lifting elements and / or the length of the second cable.

[0021] Preferably, the automatic adjustment of the first cable force is initiated upon instruction from the operator of the mobile crane and / or after authorization from the control unit of the mobile crane.

[0022] Preferably, one or more measuring elements, particularly measuring plates, are arranged in the first cable, the measuring elements being designed and arranged for measuring the force of the first cable.

[0023] Preferably, the first cable force is adjusted to the theoretical value or theoretical range, and / or the theoretical value or theoretical range is preset by entering the measured value of the first cable force.

[0024] Preferably, during adjustment, the second cable force is maintained within a preset value range, particularly based on the first cable force.

[0025] Preferably, the first cable force and / or the second cable force are kept within a defined range.

[0026] Preferably, the adjustment of the first cable force is carried out in the control loop, wherein the measured value of the first cable force is taken as the actual value, the preset value or range of the first cable force is taken as the theoretical value or range of the theoretical value, and the adjustable value of the second cable force and / or the length of the second cable are taken as control variables.

[0027] Preferably, the boom is an auxiliary boom or an A-frame boom.

[0028] The present invention also relates to a mobile crane, particularly a crawler crane, having a boom, a superstructure and components, particularly a counterweight, wherein a first cable is provided between the boom and the superstructure, and a second cable is provided between the boom and the components, wherein the mobile crane has means designed for performing the method according to the present invention.

[0029] Preferably, no additional components are required to implement the invention in mobile cranes known in the prior art.

[0030] Preferably, the present invention improves the ease of operation of mobile cranes and provides added value in terms of operating speed.

[0031] Since the first cable force is continuously monitored and maintained by adjusting or adjusting the second cable force or adjusting the length of the counterweight lifting cylinder, it is preferable that the rotation and / or travel of the mobile crane is no longer interrupted to manually correct the length of the counterweight lifting cylinder.

[0032] Preferably, the usability of the mobile crane is improved because, in the method according to the invention, the limits of the first cable force and / or the hydraulic pressure in the tilting bracket of the main boom and / or the hydraulic pressure in the tilting bracket of the auxiliary boom are not accidentally exceeded. Exceeding these limits typically causes any travel or rotational movement of the mobile crane to stop. Therefore, when the method according to the invention is performed during the operation of the mobile crane, it preferably results in very few stop commands from the crane control device.

[0033] In this respect, it should be noted that the term "a" does not necessarily mean exactly one of the elements, although this is one possible implementation, but can also refer to multiple elements. Similarly, the use of the plural includes both the presence of a single mentioned element and, conversely, a plural of mentioned elements. Furthermore, all the features of the invention described herein can be claimed in any combination thereof or independently of each other. Attached Figure Description

[0034] Other advantages, features, and effects of the present invention will become apparent from the following description of preferred embodiments with reference to the accompanying drawings, in which identical or similar parts are indicated by the same reference numerals. Wherein: Figure 1 A schematic diagram of an embodiment of a mobile crane according to the present invention is shown.

[0035] Figure 2 A table is shown containing descriptions of the operating elements and functions of mobile cranes used in the prior art. Detailed Implementation

[0036] exist Figure 1 On the mobile crane shown in the form of a crawler crane, the load 7 is suspended from the main boom 8 by the lifting rope 20.

[0037] The main boom 8 is connected to the auxiliary boom 12 via the main boom cable 10 and can swing.

[0038] The auxiliary boom 12 is connected to the upper structure 21 via the first cable 14.

[0039] Additionally, the auxiliary boom 12 is also connected to the counterweight vehicle 3 via a second cable 16. A second cable force F2 is generated in the second cable 16, which... Figure 1 It is symbolically shown in the figure by an arrow with reference numeral 23.

[0040] The second cable 16 has two parallel counterweight lifting cylinders 4 as lifting elements. One of the counterweight lifting cylinders 4 is located on the left side, and the other is located on the right side. The length of the counterweight lifting cylinders 4 can be changed, thereby changing the length of the second cable 16.

[0041] The guide device 17 maintains a constant distance between the counterweight vehicle 3 and the crawler crane 1.

[0042] The second cable force F2 refers to the force applied under load 7. Figure 1 The right-hand rotation torque is introduced into the boom system and then absorbed by the weight of the counterweight vehicle 3.

[0043] The crawler crane 1 has a crane control device 18.

[0044] The first cable force F1 generated by the load 7 in the first cable 14 (which in) Figure 1 (Symbolic shown in the figure by an arrow marked with reference numeral 6) The force is measured by means of two tension measuring plates 5, each with two measuring units, and processed by a crane control device 18.

[0045] With a constant load 7, the first cable force F1 can be changed by altering the main boom angle (which is within the range of load 7). Figure 1 (symbolically shown in the figure with the reference numeral 11), changing the angle of the auxiliary boom (which is in...) Figure 1 (The length of the second cable 16 is symbolically shown in the figure with an arc arrow marked 15), or by means of a counterweight lifting cylinder 4.

[0046] In the crane control device 18, an automatic counterweight control program is provided as a control program in a programmed manner. This automatic counterweight control program contains instructions that, when executed, perform the method according to the invention on the mobile crane.

[0047] The automatic counterweight control program can be executed in the crane control device 18. The automatic counterweight control program assists the operator of the crawler crane 1 when the crawler crane 1 travels by means of the crawler chassis 2 and when the upper structure 21 of the crawler crane 1 rotates by means of the slewing mechanism 19. The counterweight vehicle 3 is connected to the slewing mechanism 9.

[0048] The automatic counterweight control program generates control commands, which are used to automatically track the counterweight lifting cylinder 4 or change its length as needed.

[0049] The automatic counterweight control program is an auxiliary program used to assist the rotation and travel of the crawler crane 1. If the operator of the crawler crane 1 selects this automatic counterweight control program, the crane control device 18 activates this function under specific conditions. For example, one condition is that the crawler crane 1 is in operation, that is, the crawler crane is ready to lift the load 7. Another condition is that the crane control device 18 has not triggered a movement stop command that limits the load.

[0050] After selecting the automatic counterweight control program (e.g., by means of operating buttons), the automatic counterweight control program stores the first cable force F1 currently provided by the crane control device 18. Subsequently, the automatic counterweight control program enters the first cable force F1.

[0051] The first cable force F1 consists of multiple components that work together to keep the entire boom system, including the main boom 8 and the auxiliary boom 12, stable and safe. This means that the entire boom system will not tilt forward toward the load 7, nor backward toward the counterweight vehicle 3.

[0052] The retraction of the counterweight lifting cylinder 4 shortens the length of the second cable 16. This is because the second cable provides a greater force to counteract the impact. Figure 1 The right-hand torque of the load 7 causes the second cable force F2 to increase and the first cable force F1 to decrease.

[0053] The counterweight lifting cylinder 4 moves out, which makes the length of the second cable 16 longer, the cable force F2 smaller, and the first cable force F1 larger.

[0054] Preferably, in the method according to the invention, the first cable force F1 is changed by changing the length of the second cable 16 and the resulting change in the second cable force F2.

[0055] The first cable force F1 and the second cable force F2 together form Figure 1 The left-handed torque in the middle, which cancels out the left-handed torque. Figure 1 The right-hand torque originating from load 7. Preferably, the first cable force F1 is kept within a specific range. If the first cable force F1 is too large, there is a risk that the entire crawler crane 1 will tip forward toward the ground through its tipping edge. A large first cable force F1 will also act as a torque on the slewing mechanism 19. Therefore, the slewing mechanism 19 is not subjected to pressure, but rather to a torque superimposed on that pressure. If the first cable force F1 is too small, there is a risk that the entire boom system will tip backward, and the tilting supports 9 and 13 will need to hold their respective booms in position.

[0056] The second cable force F2 should also be kept within the defined limits. A larger second cable force F2 will reduce the torque load on the slewing mechanism 19, but will increase the pressure transmitted in the slewing mechanism 19 in the process.

[0057] Preferably, the crane control device 18 does not preset a preset range for the second cable force F2. The entire counterweight vehicle 3 or the counterweight arranged on the configuration vehicle 3 can be fully raised, generating the maximum second cable force F2; or the counterweight vehicle 3 or the counterweight arranged on the configuration vehicle 3 can be fully lowered, generating the minimum second cable force F2. Preferably, the second cable force F2 cannot be controlled or adjusted independently because the second cable force F2 directly affects the first cable force F1. Therefore, preferably, the limited limit of the second cable force F2 is preset indirectly through the limit of the first cable force F1 or through the first cable force F1.

[0058] The directions of action of the first cable force F1 and the second cable force F2 should also be considered in defining the lever arms. The lever arm of the second cable force F2 is more advantageous than that of the first cable force F1.

[0059] If, after the first cable force F1 is entered, the tracked crane 1 with the counterweight vehicle 3 travels across uneven terrain by means of the tracked chassis 2, or rotates by means of the slewing mechanism 19, the automatic counterweight control program calculates whether to extend or retract the counterweight lifting cylinder 4—that is, whether to extend or shorten the cable 16—by comparing the stored first cable force F1 with the current first cable force F1, in order to maintain the current first cable force F1 constant or within a range. If a result is determined, the counterweight lifting cylinder 4 is manipulated in the corresponding direction. This calculation is performed continuously to always maintain the previously entered first cable force F1. This is achieved using a known PI controller.

[0060] right Figure 1 The tensioner in cable 14 shown does not intervene.

[0061] In the absence of automatic counterweight control, in order to maintain the first tension force F1 within the desired range, the operator can adjust the tension force during rotation or travel by... Figure 2 The four operating elements on the dashboard in the crane cab shown are used to manually adjust the length of the second cable 16 by means of the counterweight lifting cylinder 4. The left and right counterweight lifting cylinders 4 can be extended or retracted using the four operating elements on the dashboard.

[0062] If the operator does not continuously adjust the counterweight lifting cylinder 4 manually, it will affect the second cable force F2 when driving over uneven ground, and in turn affect the first cable force F1.

[0063] The length of the second cable 16 translates into changes in the angles of the main boom 11 and the auxiliary boom 15. This effect is mitigated or kept within a small range by using the main boom tilt bracket 9 and the auxiliary boom tilt bracket 13.

[0064] The tilting supports 9 and 13 consist of hydraulic cylinders mounted on the main boom 11 and auxiliary boom 12 of the crawler crane 1. These hydraulic cylinders extend or retract according to the introduced force to stabilize the crawler crane 1.

[0065] If the counterweight vehicle 3 drives into the recess 22, the entire boom system, including the main boom 8 and the auxiliary boom 12, will be pulled backward, resulting in a force transfer between the second cable force F2 and the first cable force F1. This transfer is possible because the guide device 17 keeps the distance between the counterweight vehicle 3 and the crawler crane 1 constant.

[0066] This transfer directly affects the first cable force F1, and also affects the main boom tilting support 9 and the auxiliary boom tilting support 13.

[0067] Preferably, the first cable force F1 is within a defined range between the minimum and maximum force. The limit value is determined by a load capacity table and monitored by the crane control device 18. If the limit value is exceeded, the travel motion or rotation will stop.

[0068] The tilting supports 9 and 13 are compressed due to this unexpected force transfer, the oil in the tilting supports is compressed, and the oil pressure increases. In this situation, the oil pressure in the tilting supports 9 and 13 may exceed the maximum permissible oil pressure, causing the travel motion or rotation to stop. The oil pressure is measured and monitored. However, for the automatic counterweight control program or the method according to the invention, the oil pressure is not a regulating or control variable. The oil pressure is a result of control by the automatic counterweight control program.

[0069] After the automatic counterweight control program is activated, it is responsible for adjusting the counterweight lifting cylinder 4.

[0070] The first cable force F1 remains constant or within a certain range, allowing the operator to focus more on rotational or traveling motion. The minimum and maximum force limits of the first cable force F1 will not be reached, and the crawler crane 1 will not enter a traveling or rotating stop state.

[0071] Similarly, the oil pressure in the main boom tilt support 9 and the auxiliary boom tilt support 13 remains constant or within a small range because only a small force transfer occurs at the boom system due to ground unevenness.

[0072] from Figure 2 Four operating elements can be seen for manually controlling the first cable force F1 or manually adjusting the second cable force F2. These operating elements are implemented as buttons.

[0073] As an alternative or addition to the method according to the invention, the operator of the crawler crane 1 can... Figure 2 The four operating elements are used to control the counterweight lifting cylinder 4.

[0074] Manipulate and maintain Figure 2 When the first operating element is activated from the top, the counterweight lifting cylinder 4 is shortened, thereby lifting the counterweight carriage 3 or the counterweight arranged on the counterweight carriage, and the second cable force F2 increases. Releasing the operating element interrupts the lifting.

[0075] Manipulate and maintain Figure 2 When the second operating element is activated from the top, the counterweight lifting cylinder 4 extends, thereby lowering the counterweight cart 3 or the counterweight arranged on the counterweight cart, and the second cable force F2 decreases. Releasing the operating element interrupts the lowering.

[0076] Manipulate and maintain Figure 2When the third operating element from the top is activated, the left counterweight lifting cylinder 4 is locked. Releasing this operating element releases the left counterweight lifting cylinder 4.

[0077] Manipulate and maintain Figure 2 When the fourth operating element from the top is activated, the right-side counterweight lifting cylinder 4 is locked. Releasing this operating element releases the right-side counterweight lifting cylinder 4.

[0078] List of reference numerals 1. Tracked crane 2 Tracked Chassis 3 counterweight vehicles 4 counterweight lifting cylinders 5 Tension Measuring Plates 6 First cable force F1 7 load 8 main booms 9 Main boom tilting support 10 main boom cables 11 Main boom angle 12 auxiliary booms 13 Auxiliary boom tilting support 14 First cable 15 Auxiliary boom angle 16 Second cable 17 Guiding Device 18 Crane Control Device 19 Rotary Mechanism 20 lifting ropes 21. Superstructure 22 Depression 23 Second cable force F2

Claims

1. A method for adjusting a first cable force in a first cable between the boom of a mobile crane and the upper structure of the mobile crane, characterized in that, The first cable force is automatically adjusted by adjusting the second cable force in the second cable between the boom of the mobile crane and the components of the mobile crane.

2. The method according to claim 1, characterized in that, The component in question is a counterweight vehicle.

3. The method according to claim 1 or 2, characterized in that, The first cable force and / or the second cable force are adjusted during the travel of the mobile crane, after the travel of the mobile crane, during the rotation of the superstructure, and / or after the rotation of the superstructure.

4. The method according to any one of the preceding claims, characterized in that, One or more lifting elements, particularly hydraulic cylinders, are arranged in the second cable, and the force of the second cable is adjusted by adjusting the length of the one or more lifting elements.

5. The method according to any one of the preceding claims, characterized in that, The automatic adjustment of the first cable force is initiated upon instruction from the operator of the mobile crane and / or upon authorization from the control unit of the mobile crane.

6. The method according to any one of the preceding claims, characterized in that, One or more measuring elements, particularly measuring plates, are arranged in the first cable, the measuring elements being designed and arranged to measure the force of the first cable.

7. The method according to any one of the preceding claims, characterized in that, Adjust the first cable force to the theoretical value or theoretical range, and / or preset the theoretical value or theoretical range by entering the measured value of the first cable force.

8. The method according to any one of the preceding claims, characterized in that, During adjustment, the second cable force is maintained within a preset value range, especially based on the first cable force.

9. The method according to any one of the preceding claims, characterized in that, The adjustment of the first cable force is performed in a control loop, wherein the measured value of the first cable force is taken as the actual value, the preset value or range of the first cable force is taken as the theoretical value or theoretical range, and the adjustable value of the second cable force and / or the length of the second cable are taken as control variables.

10. The method according to any one of the preceding claims, characterized in that, The boom is an auxiliary boom or an A-frame boom.

11. A mobile crane, particularly a crawler crane, comprising a boom, a superstructure and components, particularly a counterweight vehicle, wherein, A first cable is provided between the boom and the upper structure, and a second cable is provided between the boom and the component, wherein the mobile crane has means designed for performing the method according to any one of the preceding claims.

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