Adjustable counterweight mechanism for tower crane

Abstract

The present application relates to the technical field of counterweight system of tower crane, and discloses a kind of adjustable counterweight mechanism for tower crane, including tower crane body, counterweight arm and hoist arm, steel frame is fixedly installed on counterweight arm, transfer trolley is installed in the inside of steel frame, one end of transfer trolley is installed with additional frame, multiple counterweight blocks one are embedded in transfer trolley, connecting shaft body is installed at both ends of transfer trolley, one end of steel frame is installed with hydraulic cylinder one, the output end of hydraulic cylinder one is fixedly connected with one of connecting shaft body, and weighting unit is also arranged on counterweight arm;This adjustable counterweight mechanism for tower crane, by setting transfer trolley carrying counterweight block one is limited to slide in steel frame, and the length of force arm is adjusted by using hydraulic cylinder one to drive transfer trolley to move, continuous adjustment of counterbalance moment is realized without increasing or decreasing the number of counterweight blocks, effectively solve the problem of excessive or insufficient counterweight in the traditional fixed counterweight block adjustment mode.

Description

Technical Field

[0001] This invention relates to the field of counterweight systems for tower cranes, specifically to an adjustable counterweight mechanism for tower cranes. Background Technology

[0002] In the construction industry, tower cranes are the core equipment for vertical transportation of heavy objects. Their counterweight system is a key component in ensuring the stability of the entire machine. It is mainly used to balance the overturning moment transmitted by the boom, preventing the tower crane from tilting forward or overturning during lifting operations. Existing tower crane counterweight mechanisms typically consist of three parts: the counterweight boom, the counterweight blocks, and the fixing device. The counterweight boom, as the mounting carrier of the counterweight system, is mostly a box-shaped steel structure or truss structure, with a length ranging from 8 meters to 25 meters depending on the tower crane model. It has a load-bearing platform at the end for installing the counterweight blocks. The counterweight blocks, as the core component for torque balance, are generally made of cast iron or concrete. For ease of transportation and installation, they are usually designed as standardized modules, with a single block weighing between 5 tons and 20 tons. The surface has lifting holes and positioning pin holes, which are stacked to form the total counterweight. The fixing device uses high-strength bolts, pins, or welding to rigidly fix the stacked counterweight blocks to the end of the counterweight boom, preventing displacement due to vibration during operation.

[0003] In the actual operation, the required total counterweight is determined by mechanical calculation based on the rated lifting capacity, maximum radius and tower height of the crane boom. Then, the counterweight blocks are combined according to the fixed weight of each block (e.g., a total counterweight of 15 tons requires 3 five-ton counterweight blocks). Finally, the counterweight blocks are locked in the preset position of the balance boom by the fixing device to generate a balancing torque that matches the load at the end of the crane boom.

[0004] In actual construction, tower cranes frequently need to handle complex working conditions with different lifting weights (such as from 3 tons of steel bars to 10 tons of formwork) and different ranges (such as from 15 meters of close-range hoisting to 40 meters of long-range operation). Fixed-weight counterweights can only be adjusted in steps by increasing or decreasing their quantity, but this is quite cumbersome. The counterweights need to be placed on or removed from the load-bearing platform using hooks. If the tower crane is in a state of excessive counterweight during long-term operation, it will aggravate the fatigue of the tower steel structure and increase the energy consumption of the drive mechanism. On the other hand, insufficient counterweight will lead to an increase in the forward tilting moment of the tower crane, causing the tower foundation to bear additional tension. Therefore, we propose an adjustable counterweight mechanism for tower cranes. Summary of the Invention

[0005] The purpose of this invention is to provide an adjustable counterweight mechanism for tower cranes to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: an adjustable counterweight mechanism for tower cranes, comprising a tower crane body, a counterweight boom, and a lifting boom. A steel frame is fixedly installed on the counterweight boom, and a transfer trolley is installed inside the steel frame. The transfer trolley slides within the steel frame and is limited in its movement. An additional frame is fixedly installed at one end of the transfer trolley. Multiple counterweight blocks are embedded in the transfer trolley. Connecting shafts are fixedly installed at both ends of the transfer trolley. A hydraulic cylinder is fixedly installed at one end of the steel frame. The output end of the hydraulic cylinder penetrates the inner wall of the end of the steel frame and is fixedly connected to one of the connecting shafts. The hydraulic cylinder drives the transfer trolley carrying the counterweight blocks to adjust its displacement along the steel frame. By changing the balance torque, it adapts to different working conditions of the lifting boom. Furthermore, a weight-adding unit is provided on the counterweight boom to increase the overall weight of the transfer trolley.

[0007] Preferably, multiple guide rails are fixedly installed on both sides of the transfer trolley, and a movable slider is symmetrically slidably connected on each guide rail. A spring mechanism connects the movable slider to the guide rail, and a roller is rotatably connected to the bottom of the movable slider. A movable part is symmetrically arranged between the connecting shafts, and the height of the movable slider is adjusted by controlling the roller. A steel shaft is fixedly installed on the movable slider, and a friction block is fixedly installed at the end of the steel shaft. Friction panels are symmetrically installed at the upper and lower positions of the steel frame, and the friction panels are located on the movement trajectory of the friction block.

[0008] Preferably, the moving part includes a connecting panel that contacts the roller, and the connecting panel has a plurality of trapezoidal grooves, each corresponding to a roller; when the roller contacts the connecting panel, the friction block is in close contact with the friction panel; when the roller contacts the trapezoidal groove, the friction block separates from the friction panel.

[0009] Preferably, a magnetic plate frame is slidably mounted on the connecting shaft, the connecting panel is fixedly connected to the magnetic plate frame, a constant force spring is connected between the magnetic plate frame and the end of the transfer trolley, and an electromagnetic mechanism is also fixedly mounted on one of the connecting shafts. When the electromagnetic mechanism is energized, it generates a repulsive force with the magnetic plate frame.

[0010] Preferably, a rotating panel is rotatably mounted on the steel shaft, a torsion spring sleeved on the steel shaft is connected between the rotating panel and the movable slider, and a snap-fit ​​shaft is rotatably mounted on the rotating panel, with a ball embedded at the end of the snap-fit ​​shaft.

[0011] Preferably, one side of the friction panel is provided with multiple snap-fit ​​blocks that are fixedly connected to the inner wall of the steel frame; when the roller contacts the connecting panel, the snap-fit ​​shaft is located between the snap-fit ​​blocks and is in contact with the snap-fit ​​blocks.

[0012] Preferably, the weighting unit includes a frame fixedly mounted on a balance arm, multiple rollers rotatably mounted inside the frame, a movable frame mounted on the frame, multiple counterweights II placed inside the movable frame, the counterweights II moving vertically within the movable frame, and a hydraulic cylinder II fixedly mounted on the frame, the output end of the hydraulic cylinder II being fixedly connected to the movable frame.

[0013] Preferably, a partition is fixedly installed inside the frame, and a cylinder is installed between the partition and the bottom inner wall of the frame. A bearing panel with rollers is provided on the partition, and the bearing panel is fixedly connected to the output end of the cylinder. The cylinder controls the bearing panel to rise to the top of the frame; the second hydraulic cylinder causes the movable frame to carry the second counterweight to the bearing panel; the cylinder controls the bearing panel to descend, causing the second counterweight to detach from the movable frame.

[0014] Preferably, L-shaped brackets are symmetrically installed on the frame, and magnetic shafts are slidably installed on the brackets. A plastic spring is connected between the end of the magnetic shaft and the bracket. An electromagnet is fixedly installed on the bracket. When the electromagnet is energized, a repulsive force is generated between it and the magnetic shaft. Guide shafts are symmetrically installed at one end of the movable frame. When the movable frame contacts the end of the frame, the electromagnet is de-energized, and the magnetic shaft is inserted into the guide shaft and fixed under the action of the plastic spring.

[0015] Preferably, one end of the snap-fit ​​block has a triangular shape.

[0016] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention sets up a transfer trolley carrying a counterweight that slides within a steel frame and uses a hydraulic cylinder to drive the transfer trolley to move and adjust the lever arm length. This allows for continuous adjustment of the balance torque without adding or removing counterweights, effectively solving the problem of excessive or insufficient counterweights in the traditional fixed counterweight adjustment method. 2. This invention sets up a weight-adding unit on the balance arm, uses a movable frame to carry the counterweight block two on the frame, and drives the movable frame through the hydraulic cylinder two to transfer the counterweight block two to the mounting frame of the transfer trolley, thereby realizing flexible supplementation of the overall weight of the transfer trolley and can cope with extreme working conditions where the balance requirement cannot be met by simply moving the position of the transfer trolley. 3. This invention provides multiple mechanical locking mechanisms by setting guide rails, movable sliders, rollers, and moving parts on both sides of the transfer trolley, in conjunction with the friction block at the end of the steel shaft and the friction panel on the steel frame, as well as the interaction between the locking shaft and the locking block. This effectively avoids the safety hazard of the transfer trolley shifting under severe weather conditions such as strong winds. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the balance arm in this invention; Figure 3 This is a schematic diagram of the internal structure of the steel frame in this invention; Figure 4 This is a schematic diagram of the transfer trolley in this invention; Figure 5 This is a schematic diagram of the structure of the moving part in this invention; Figure 6 This is a schematic diagram of the movable slider in this invention; Figure 7 This is a schematic diagram of the moving slider and guide rail in this invention; Figure 8 This is a schematic diagram of the structure of the snap-fit ​​shaft and snap-fit ​​block in this invention; Figure 9 This is a schematic diagram of the structure of the weighting unit and the transfer trolley in this invention; Figure 10 This is a schematic diagram of the internal structure of the frame added in this invention; Figure 11 This is a schematic diagram of the weighting unit in this invention.

[0018] In the diagram: 1. Tower crane body; 2. Counterbalance boom; 3. Lifting boom; 4. Steel frame; 41. Friction panel; 42. Clip-on block; 5. Transfer trolley; 51. Additional frame; 52. Counterweight block one; 53. Connecting shaft; 54. Guide rail; 55. Moving slider; 56. Spring mechanism; 57. Roller; 58. Steel shaft; 59. Friction block; 50. Magnetic plate frame; 501. Constant force spring; 502. Electromagnetic mechanism; 503. Rotating panel; 504, Torsion spring; 505, Snap-fit ​​shaft; 506, Partition; 507, Cylinder; 508, Bearing panel; 6, Hydraulic cylinder one; 7, Weighting unit; 71, Frame; 72, Movable frame; 73, Counterweight two; 74, Hydraulic cylinder two; 75, Bracket; 76, Magnetic shaft; 77, Plastic spring; 78, Electromagnet; 79, Guide shaft; 8, Moving part; 81, Connecting panel; 82, Trapezoidal groove. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Please see Figure 1-11This invention provides a technical solution: an adjustable counterweight mechanism for tower cranes. This invention addresses the technical problems in the background art by making corresponding improvements. During operation, the counterweight weight can be flexibly adjusted according to the lifting weight. The mechanism includes a tower crane body 1, a counterweight boom 2 and a lifting boom 3 mounted on the tower crane body 1. A steel frame 4 is fixedly mounted on the counterweight boom 2, located at the end of the counterweight boom 2 furthest from the tower crane body 1. A transfer trolley 5 is installed inside the steel frame 4, with an additional frame 51 fixedly mounted at one end of the transfer trolley 5. The transfer trolley 5 can slide within the steel frame 4 with limited movement. Connecting shafts 53 are fixedly mounted at both ends of the transfer trolley 5, and a hydraulic cylinder 6 is fixedly mounted at one end of the steel frame 4. The output end passes through the inner wall of the end of the steel frame 4 and is fixedly connected to one of the connecting shafts 53; the transfer trolley 5 carrying the counterweight 52 can be driven by the hydraulic cylinder 6 to adjust the displacement along the steel frame 4, and the balance torque can be changed to adapt to the different working conditions of the lifting arm 3; the balance arm 2 is also equipped with a weighting unit 7, which can increase the overall weight of the transfer trolley 5. The weighting unit 7 includes a frame 71, a movable frame 72 and multiple counterweights 73 placed in the movable frame 72. Multiple counterweights 52 are embedded on the transfer trolley 5. Positioning pins are installed on both sides of the counterweights 52 and the counterweights 73. Positioning pin grooves corresponding to the positioning pins are provided on the frame 51 and the transfer trolley 5. As a further limitation of the present invention, the weighting unit 7 also includes a second hydraulic cylinder 74 fixedly installed at the end of the frame 71. The output end of the second hydraulic cylinder 74 is fixedly connected to the movable frame 72. The frame 71 is fixedly installed on the balance arm 2. A roller shaft is rotatably connected to the inner wall of the frame 71. Figure 9 Appendix Figure 10 and attached Figure 11 As shown, counterweight 73 is in contact with the roller on frame 71. It should be noted that the weight of counterweight 73 is less than the weight of counterweight 52. The movable frame 72 is mounted on frame 71, and the bottom of the movable frame 72 is in contact with the roller on frame 71. The movable frame 72 is then driven by hydraulic cylinder 74 to move and adjust the counterweight 73 on frame 71. A partition 506 is fixedly installed inside the added frame 51. A cylinder 507 is installed between the partition 506 and the bottom of the added frame 51. A bearing panel 508 with rollers is set above the partition 506. The bearing panel 508 is slidably connected to the added frame 51. The bearing panel 508 is fixedly connected to the output end of the cylinder 507. The cylinder 507 controls the bearing panel 508 to rise to the top of the added frame 51. The second hydraulic cylinder 74 drives the movable frame 72 to move the counterweight 73 onto the bearing panel 508. The cylinder 507 controls the bearing panel 508 to descend, so that the counterweight 73 falls from the movable frame 72 under the action of gravity. The internal detachment mechanism is as follows: The frame 71 is symmetrically equipped with L-shaped brackets 75, on which magnetic shafts 76 are slidably mounted. A plastic spring 77 connects the end of the magnetic shaft 76 to the bracket 75. An electromagnet 78 is fixedly mounted on the bracket 75. When the electromagnet 78 is energized, a repulsive force is generated between it and the magnetic shaft 76. A guide shaft 79 is symmetrically mounted on one end of the movable frame 72, and a through hole (not shown in the figure) is opened on the guide shaft 79. When the movable frame 72 contacts the end of the frame 71, the electromagnet 78 is de-energized, and the magnetic shaft 76, under the action of the plastic spring 77, is inserted into the through hole of the guide shaft 79 for fixation. Figure 11 As shown, one end of the magnetic shaft 76 is close to the guide shaft 79, and the other end of the magnetic shaft 76 passes through the bracket 75 and extends to one side of the electromagnet 78.

[0021] The tower crane body 1 needs to calculate and determine the required total counterweight based on the rated lifting capacity, maximum radius, and tower height of the boom 3. However, in actual operation, the tower crane frequently needs to handle complex working conditions such as different lifting capacities and radii. Adjusting the number of counterweight blocks according to the weight of the lifted load is cumbersome (it requires placing the counterweight blocks on or removing them from the load-bearing platform using the hook). This often results in excessive or insufficient counterweight, which, over time, will affect the structural strength of the tower crane body 1. Therefore, in this invention, the following operation can be performed: During normal lifting operation, the displacement adjustment of the transfer trolley 5 within the steel frame 4 is controlled according to the rated lifting capacity and maximum radius of the boom 3. The hydraulic cylinder 6 applies force to one of the connecting shafts 53, causing the transfer trolley 5 to move within the steel frame 4. For ease of understanding, the following example is provided: Adjustment when the lifting weight increases: Assuming the original balance state is "15-ton counterweight × 5-meter lever arm = 75-ton-meter torque", when the lifting weight increases from 8 tons to 10 tons, the working radius remains unchanged, and the overturning moment increases from 8 tons × 9.375 meters = 75-ton-meter to 10 tons × 9.375 meters = 93.75-ton-meter. If the counterweight weight remains unchanged at 15 tons, the transfer trolley 5 only needs to be moved away from the tower crane body 1 by 6.25 meters, 15 tons × 6.25 meters = 93.75-ton-meter, and the torque balance can be achieved by extending the lever arm. Adjustment when the lifting capacity increases: When the lifting capacity remains unchanged, such as 8 tons, but the lifting capacity increases from 30 meters to 37.5 meters, the overturning moment increases from 8 tons × 30 meters = 240 tons·m to 8 tons × 37.5 meters = 300 tons·m. If the counterweight weight is still 15 tons, simply move the transfer trolley 5 from the original 16-meter lever arm (15 tons × 16 meters = 240 tons·m) to a 20-meter lever arm (15 tons × 20 meters = 300 tons·m). By increasing the lever arm from 16 meters to 20 meters, the counterweight moment can be increased from 240 tons·m to 300 tons·m, thus balancing the new overturning moment without the need for additional counterweights.

[0022] When the lifting weight is reduced, such as from 10 tons to 5 tons, or the amplitude is reduced, if the original combination of 15 tons counterweight + 6.25 meters lever arm (93.75 ton-meters) is still used, the balancing moment will far exceed the overturning moment (5 tons × 9.375 meters = 46.875 ton-meters), resulting in "excessive counterweight". In this case, the transfer trolley 5 is moved to the fulcrum (i.e., tower crane body 1) at a distance of 3.125 meters. At this time, the counterweight moment is 15 tons × 3.125 meters = 46.875 ton-meters. The balancing moment can be reduced by shortening the lever arm, thus avoiding excessive load on the 2nd end of the balance arm, which would lead to fatigue of the tower structure and increased drive energy consumption. Similarly, when the amplitude is reduced, the transfer trolley 5 only needs to be moved to the fulcrum (i.e., tower crane body 1).

[0023] Therefore, in practical applications, torque balance adjustment can be achieved by moving the position of the transfer trolley 5. However, in specific operations, because the tower crane body 1 needs to frequently handle complex working conditions with different lifting weights and amplitudes, it is easy for the transfer trolley 5 to move to the furthest point away from the tower crane body 1, and even when the number of counterweight blocks 52 is increased to the maximum, there is still a situation of insufficient counterweight. At this time, counterweight blocks 73 are added to the mounting frame 51 to deal with this sudden situation. Before lifting, i.e., the boom 3 is not lifting any heavy objects, hydraulic cylinder 6 controls the transfer trolley 5 to move towards the end of the tower crane body 1 (the transfer trolley 5 contacts the steel frame 4). Then, cylinder 507 controls the bearing panel 508 to rise to the top. When the bearing panel 508 rises to the top, the rollers on the bearing panel 508 and the rollers on the frame 71 are on the same plane. At this time, the bearing panel 508 is on the movement trajectory of the counterweight 73. Then, hydraulic cylinder 74 drives the movable frame 72 to move on the frame 71, that is, the movable frame 72 carries the counterweight 73 to the bearing panel 508. Cylinder 507 controls the bearing panel 508 to descend, so that... Counterweight 73 detaches from the movable frame 72. It should be noted that since multiple counterweights 73 are placed inside the movable frame 72, the appropriate number of counterweights 73 can be selected according to actual needs. For example, if two counterweights 73 are needed, hydraulic cylinder 74 controls the movable frame 72 to move with two counterweights 73 onto the bearing panel 508. Then, cylinder 507 controls the bearing panel 508 to descend. Under the action of gravity, counterweights 73 descend with the bearing panel 508 until the bearing panel 508 contacts the partition 506. At this time, counterweights 73 completely detach from the movable frame 72, and the positioning pin enters the positioning pin groove of the added frame 51.

[0024] Since the tower crane body 1 is located at a high altitude, it is easily affected by wind in windy weather, which may cause safety accidents. The transfer trolley 5 and the mobile frame 72 are fixedly connected to hydraulic cylinder 6 and hydraulic cylinder 74 respectively. However, relying solely on the connection between hydraulic cylinder 6 and hydraulic cylinder 74 will still pose certain safety hazards. Based on this, this application provides a locking and fixing structure. When the movable frame 72 is in contact with the frame 71, the guide shaft 79 on the movable frame 72 is fixed by the magnetic shaft 76 to prevent the movable frame 72 from shifting. When the movable frame 72 needs to move, a counterweight 73 is placed inside the mounting frame 51. The electromagnet 78 is energized, and a repulsive force is generated between it and the magnetic shaft 76, causing the magnetic shaft 76 to press against the plastic spring 77. The magnetic shaft 76 then exits from the through hole of the guide shaft 79 (not shown in the figure), releasing the locking and fixing. When the movable frame 72 resets and re-contacts the frame 71, the electromagnet 78 is de-energized, and the magnetic shaft 76 is reinserted into the through hole of the guide shaft 79 under the rebound action of the plastic spring 77, completing the locking and fixing.

[0025] Specifically, to prevent the transfer trolley 5 from shifting in windy weather, this application has fixedly installed multiple guide rails 54 on both sides of the transfer trolley 5. Each guide rail 54 has a symmetrically slidable slider 55, with a spring mechanism 56 connecting the slider 55 to the guide rail 54. A roller 57 is rotatably mounted on the bottom of the slider 55. A moving part 8, which controls the height adjustment of the slider 55 via the roller 57, is also symmetrically arranged between the connecting shafts 53. A steel shaft 58 is fixedly mounted on the slider 55, and a friction block 59 is fixedly mounted on the end of the steel shaft 58. Friction panels 41 are also symmetrically mounted on the steel frame 4, and the friction panels 41 are located on the movement trajectory of the friction blocks 59. The moving part 8 includes a connecting panel 81 that contacts the roller 57. The connecting panel 81 has multiple trapezoidal grooves 82, each corresponding to a roller 57. When the roller 57 contacts the connecting panel 81, the friction block 59 is in close contact with the friction panel 41. When the trapezoidal groove 82 contacts, the friction block 59 separates from the friction panel 41; a magnetic plate frame 50 is rotatably mounted on the connecting shaft 53, and the connecting panel 81 is fixedly connected to the magnetic plate frame 50. A constant force spring 501 is connected between the magnetic plate frame 50 and the side of the transfer trolley 5. An electromagnetic mechanism 502 is also fixedly mounted on one of the connecting shafts 53. When the electromagnetic mechanism 502 is energized, it generates a repulsive force with the magnetic plate frame 50. A rotating panel 503 is also rotatably mounted on the steel shaft 58. A torsion spring 504 sleeved on a steel shaft 58 is connected between the panel 503 and the movable slider 55. A snap-fit ​​shaft 505 is rotatably mounted on the rotating panel 503. A ball is embedded at the end of the snap-fit ​​shaft 505. A plurality of snap-fit ​​blocks 42 fixedly connected to the inner wall of the steel frame 4 are provided on one side of the friction panel 41. When the roller 57 contacts the connecting panel 81, the snap-fit ​​shaft 505 is located between the snap-fit ​​blocks 42 and is in contact with the snap-fit ​​blocks 42. One end of the snap-fit ​​block 42 is triangular.

[0026] As described above, when the hydraulic cylinder 6 drives the transfer trolley 5 to adjust its displacement within the steel frame 4, the electromagnetic mechanism 502 is energized, generating a repulsive force between itself and the magnetic plate frame 50. The magnetic plate frame 50 compresses the constant force spring 501, and the connecting panel 81 and its trapezoidal groove 82 move synchronously with it. The spring mechanism 56, in a compressed state, causes the moving slider 55 to move on the guide rail 54. Finally, the roller 57 on the moving slider 55 enters the trapezoidal groove 82 and comes into contact with it, thereby causing the friction block 59 to... The friction panel 41 is separated, and the locking shaft 505 disengages from the locking blocks 42, thus releasing the restriction on the transfer trolley 5. At this time, the transfer trolley 5 can move. When the transfer trolley 5 stops moving, the electromagnetic mechanism 502 is de-energized, and the constant force spring 501, which is in a compressed state, applies a force to the magnetic plate frame 50, causing the magnetic plate frame 50 to reset, that is, to move towards the electromagnetic mechanism 502. The magnetic plate frame 50 drives the connecting panel 81 to reset, and the roller 57 no longer contacts the trapezoidal groove 82 and the connecting panel 81. Contact; the movable slider 55 is reset under the action of the spring mechanism 56. During the reset process, the movable slider 55 presses against the spring mechanism 56. During the movement of the movable slider 55, the steel shaft 58 on the movable slider 55 drives the friction block 59 to make close contact with the friction panel 41. The rotating panel 503 on the steel shaft 58 moves synchronously, and the locking shaft 505 on the rotating panel 503 moves between the locking block 42. If the position where the transfer trolley 5 stops causes the locking shaft 505 to contact the end of the locking block 42, then... Because one end of the locking block 42 has a triangular (i.e., the side wall is inclined) inclined structure, the locking shaft 505 is adjusted in angle under the action of the inclined surface of the locking block 42. The rotating panel 503 is adjusted in angle, and the torsion spring 504 is in a deformation and storage state until the locking shaft 505 enters between the locking blocks 42. At this time, if the transfer trolley 5 is subjected to a force and moves, the friction panel 41 generates resistance to the movement of the friction block 59, and the locking block 42 hinders the movement of the locking shaft 505, thereby positioning the transfer trolley 5.

[0027] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0028] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An adjustable counterweight mechanism for a tower crane, comprising a tower crane body (1), a counterweight boom (2), and a lifting boom (3), characterized in that: A steel frame (4) is fixedly installed on the balance arm (2). A transfer trolley (5) is installed inside the steel frame (4). The transfer trolley (5) slides within the steel frame (4). An additional frame (51) is also fixedly installed at one end of the transfer trolley (5). Multiple counterweights (52) are embedded in the transfer trolley (5). A connecting shaft (53) is fixedly installed at both ends of the transfer trolley (5). A hydraulic cylinder (6) is fixedly installed at one end of the steel frame (4). The output end of the hydraulic cylinder (6) passes through the inner wall of the end of the steel frame (4) and is fixedly connected to one of the connecting shafts (53). The hydraulic cylinder (6) drives the transfer trolley (5) to carry the counterweights (52) and adjust its displacement along the steel frame (4). By changing the balance torque, it adapts to the different working conditions of the lifting arm (3). A weight-adding unit (7) is also provided on the balance arm (2). The weight-adding unit (7) increases the overall weight of the transfer trolley (5).

2. The adjustable counterweight mechanism for tower cranes according to claim 1, characterized in that: Multiple guide rails (54) are fixedly installed on both sides of the transfer trolley (5). Each guide rail (54) has a symmetrically slidably connected movable slider (55). A spring mechanism (56) is connected between the movable slider (55) and the guide rail (54). A roller (57) is rotatably connected to the bottom of the movable slider (55). A movable part (8) is symmetrically arranged between the connecting shafts (53) to control the height adjustment of the movable slider (55) through the roller (57). A steel shaft (58) is fixedly installed on the movable slider (55). A friction block (59) is fixedly installed at the end of the steel shaft (58). Friction panels (41) are symmetrically installed at the upper and lower positions of the steel frame (4). The friction panels (41) are located on the movement trajectory of the friction block (59).

3. The adjustable counterweight mechanism for tower cranes according to claim 2, characterized in that: The moving part (8) includes a connecting panel (81) that contacts the roller (57). The connecting panel (81) has a plurality of trapezoidal grooves (82) that correspond one-to-one with the roller (57). When the roller (57) contacts the connecting panel (81), the friction block (59) is in close contact with the friction panel (41). When the roller (57) contacts the trapezoidal groove (82), the friction block (59) separates from the friction panel (41).

4. The adjustable counterweight mechanism for tower cranes according to claim 3, characterized in that: A magnetic plate frame (50) is slidably mounted on the connecting shaft (53). The connecting panel (81) is fixedly connected to the magnetic plate frame (50). A constant force spring (501) is connected between the magnetic plate frame (50) and the end of the transfer trolley (5). An electromagnetic mechanism (502) is also fixedly mounted on one of the connecting shafts (53). When the electromagnetic mechanism (502) is energized, it generates a repulsive force with the magnetic plate frame (50).

5. The adjustable counterweight mechanism for tower cranes according to claim 3, characterized in that: A rotating panel (503) is rotatably mounted on the steel shaft (58). A torsion spring (504) sleeved on the steel shaft (58) is connected between the rotating panel (503) and the movable slider (55). A snap-fit ​​shaft (505) is rotatably mounted on the rotating panel (503), and a ball is embedded at the end of the snap-fit ​​shaft (505).

6. The adjustable counterweight mechanism for tower cranes according to claim 5, characterized in that: A plurality of snap-fit ​​blocks (42) are provided on one side of the friction panel (41) and are fixedly connected to the inner wall of the steel frame (4); when the roller (57) contacts the connecting panel (81), the snap-fit ​​shaft (505) is located between the snap-fit ​​blocks (42) and is in contact with the snap-fit ​​blocks (42).

7. An adjustable counterweight mechanism for tower cranes according to any one of claims 1-6, characterized in that: The weighting unit (7) includes a frame (71) fixedly mounted on the balance arm (2). Multiple rollers are rotatably mounted inside the frame (71). A movable frame (72) is provided on the frame (71). Multiple counterweights (73) are placed inside the movable frame (72). The counterweights (73) move vertically within the movable frame (72). A hydraulic cylinder (74) is also fixedly mounted on the frame (71). The output end of the hydraulic cylinder (74) is fixedly connected to the movable frame (72).

8. The adjustable counterweight mechanism for tower cranes according to claim 7, characterized in that: A partition (506) is fixedly installed inside the frame (51). A cylinder (507) is installed between the partition (506) and the bottom inner wall of the frame (51). A bearing panel (508) with rollers is provided on the partition (506). The bearing panel (508) is fixedly connected to the output end of the cylinder (507). The cylinder (507) controls the bearing panel (508) to rise to the top of the frame (51). The second hydraulic cylinder (74) causes the movable frame (72) to carry the second counterweight (73) to the bearing panel (508). The cylinder (507) controls the bearing panel (508) to fall, so that the second counterweight (73) is disengaged from the inside of the movable frame (72).

9. An adjustable counterweight mechanism for tower cranes according to claim 8, characterized in that: The frame (71) is also symmetrically equipped with L-shaped brackets (75), and a magnetic shaft (76) is slidably mounted on the bracket (75). A plastic spring (77) is connected between the end of the magnetic shaft (76) and the bracket (75). An electromagnet (78) is fixedly mounted on the bracket (75). When the electromagnet (78) is energized, a repulsive force is generated between it and the magnetic shaft (76). A guide shaft (79) is symmetrically mounted on one end of the movable frame (72). When the movable frame (72) contacts the end of the frame (71), the electromagnet (78) is de-energized, and the magnetic shaft (76) is inserted into the guide shaft (79) under the action of the plastic spring (77) to fix it.

10. An adjustable counterweight mechanism for a tower crane according to claim 6, characterized in that: One end of the snap-fit ​​block (42) has a triangular structure.

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