Active dynamic balance tower crane

Abstract

The utility model provides an active dynamic balance tower crane which comprises a tower body, a working arm and a balance arm, wherein the working arm and the balance arm are respectively arranged on two sides of the tower body; wherein a hoisting / walking trolley is arranged on the working arm, and a dynamic counterweight mechanism is arranged on the balance arm. Compared with a traditional static counterweight mode, the active dynamic balance tower crane has the advantages that the dynamic counterweight mechanism can avoid bending deformation of the tower body caused by unbalanced torque of the working arm and the balance arm in a non-working state; in the working state, the front-back shaking amplitude of the tower crane can be reduced, the safety performance of the tower crane is improved, the working environment of a tower crane driver is improved, and the fear of the driver is reduced. In addition, compared with a balancing weight in passive arc motion, the mechanism can actively adjust the balance moment to be equal to the working moment in real time according to the change of the working moment on the working arm, and as the working moment is actively balanced, the overturning moment to a foundation is minimum, the safety performance of the tower crane is improved, and the accident occurrence probability is reduced.

Description

Technical Field

[0001] This utility model relates to the field of tower crane technology, specifically to an active dynamic balancing tower crane. Background Technology

[0002] The working principle of tower cranes is based on torque balance and mechanical transmission. The torque balance of existing tower cranes uses static balance, which means that the torque during operation is balanced by counterweights at the end of the counterweight boom to ensure the normal operation and safety of the tower crane.

[0003] Because the torque generated by the counterweight is constant, the torques of the boom and counterweight boom are not equal in the non-working state of a tower crane. The overturning moment generated by this difference is resisted by the tower body bending moment. In the working state, as the boom torque changes, torque balance may occasionally occur, but in most cases, the torques are not balanced, and the difference between the two constantly changes with the boom torque. The overturning moment generated by this difference is resisted by the tower body bending moment. Since the overturning moment is constantly changing, the tower body bending moment is also constantly changing, which is the reason for the tower body swaying.

[0004] The existing technology, "Research on Automated Counterweight Control and Dynamic Characteristics Analysis of Tower Cranes," published in the journal *Mechanical and Electrical Engineering*, 2021, Vol. 1, pp. 108-112 (5 pages), describes a dynamic balance control method that achieves torque balance in tower cranes by adjusting the position of the counterweight in real time. This control method effectively reduces the swaying of tower cranes during operation, improving their safety and stability. Since the counterweight slides back and forth on the counterweight boom, a horizontal force (Newton's First Law of Motion) is inevitably generated when the counterweight moves from a stationary state to a moving state or vice versa. This horizontal force acts horizontally on the tower body (Newton's Third Law of Motion). Given that the counterweight mass is 6 to 10 tons, according to Newton's Second Law of Motion, F=ma, this horizontal force is relatively large. The additional bending moment generated at the top of the tower body under this horizontal force will make the tower less safe.

[0005] CN116443746A discloses a luffing jib tower crane where the counterweight's arc-shaped movement is achieved by a drive unit moving a moving rod, with the counterweight traction onto the counterweight boom via a rocker arm. In this method, the counterweight's movement is fixed, occurring passively in conjunction with the rotation of the boom and the movement of the drive unit, moving rod, and rocker arm—a passive arc-shaped movement rather than real-time adjustment based on the boom torque. Clearly, this method of counterweight movement has significant limitations. The counterweight's arc-shaped movement is passive, entirely dependent on the boom's rotation, and cannot be adjusted in real-time according to the boom torque. Utility Model Content

[0006] This invention proposes an active dynamic balancing tower crane, which solves the problem of unbalanced tower body torque and inability to adjust it in real time in the existing tower crane balancing technology.

[0007] The technical solution of this utility model is implemented as follows:

[0008] An active dynamic balancing tower crane includes a tower body and a working boom and a counterweight boom respectively arranged on both sides thereon; wherein the working boom is equipped with a lifting / traveling trolley, and the counterweight boom is equipped with a dynamic counterweight mechanism;

[0009] The dynamic counterweight mechanism includes a boom frame hinged below the counterweight arm or near the tower body, with a counterweight block hinged below the boom frame and movable pulley blocks on both sides of the counterweight block; it also includes fixed pulley blocks on both sides of the counterweight arm and a winch above the counterweight arm, with steel cables at the input and output ends of the winch passing over the fixed pulley blocks and connecting to the bottom of the counterweight arm respectively.

[0010] Furthermore, the fixed pulley assembly includes a fixed pulley A disposed on the side of the balance arm and a fixed pulley B disposed at the bottom of the balance arm near the fixed pulley A. Fixed shafts A and B, which are fixed to the balance arm, are respectively passed through the fixed pulleys A and B.

[0011] Furthermore, the movable pulley group includes an extension frame A and an extension frame B respectively disposed on the top sides of the counterweight block, and movable pulleys A and B are rotatably disposed on the extension frame A and the extension frame B respectively;

[0012] The steel cables at the input and output ends of the winch pass over fixed pulley A, movable pulley B, fixed pulley B and movable pulley A respectively, and are fixed to the bottom of the balance arm.

[0013] Furthermore, a driver's cab is provided above the tower body, and a level monitoring instrument is provided inside or above the driver's cab. The level monitoring instrument is electrically or wirelessly connected to the control box above the counterweight arm.

[0014] Furthermore, the upper and lower sides of the boom frame are each provided with hinge A and hinge B, which are fixed to the bottom of the balance arm and the top of the counterweight, respectively. The boom frame swings at the bottom of the balance arm and above the counterweight by hinge connection with hinge A and hinge B.

[0015] Furthermore, a hook for suspending the limiting counterweight is hinged on the side of the counterweight arm near the tower body. An electric actuator is hinged to one side of the hook and fixed to the bottom of the counterweight arm. The electric actuator is electrically or wirelessly connected to the control box.

[0016] The beneficial effects of the technical solution provided in this application are as follows:

[0017] 1. Compared to traditional static counterweight methods, this active dynamic balancing tower crane's dynamic counterweight mechanism avoids tower bending deformation caused by torque imbalance between the working boom and the counterweight boom in non-working states. In working states, it reduces the tower crane's forward and backward sway, improving safety performance, enhancing the operator's working environment, and reducing operator anxiety. Furthermore, compared to passively moving counterweights, this mechanism actively adjusts the counterweight boom's torque in real-time based on the working boom's torque, ensuring they are equal. Because it actively balances the working torque, it minimizes the overturning moment on the foundation, improving tower crane safety and reducing the probability of accidents.

[0018] 2. This active dynamic balancing tower crane, whether in working or non-working state, keeps the tower crane's center of gravity close to or near the center of the tower body, placing the tower body in (or close to) an axially compressed state. This eliminates or reduces the bending moment and sway amplitude of the tower body, thereby reducing metal fatigue and deformation, extending the service life of the tower crane, and thus saving costs. It also reduces the stress on the connecting bolts of the standard tower sections, improving the safety of the tower crane. Furthermore, it prevents the tower crane's center of gravity from deviating too far from the tower body, which could lead to instability and collapse. Safety performance is improved during the installation, dismantling, and jacking of the standard tower sections. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the active dynamic balancing tower crane of Embodiment 1 of this utility model;

[0021] Figure 2 This is a schematic diagram of the balance arm of this utility model;

[0022] Figure 3 This is an enlarged schematic diagram of the fixed pulley block of this utility model;

[0023] Figure 4 This is an enlarged schematic diagram of the movable pulley block of this utility model;

[0024] Figure 5 This is an enlarged schematic diagram of the hanger frame of this utility model;

[0025] Figure 6 This is a schematic diagram of the cross-section of the balance arm of this utility model;

[0026] Figure 7This is a schematic diagram of the active dynamic balancing tower crane of Embodiment 2 of this utility model.

[0027] In the diagram: 10 Tower body, 20 boom, 30 counterweight boom, 31 hook, 32 electric actuator, 40 control box, 50 lifting / traveling trolley, 70 operator's cab, 80 level monitoring instrument;

[0028] 60 Dynamic counterweight mechanism, 61 boom frame, 611 hinge A, 612 hinge B, 62 counterweight block, 63 winch, 64 fixed pulley block, 641 fixed pulley A, 642 fixed pulley B, 643 fixed shaft A, 644 fixed shaft B, 65 movable pulley block, 651 extension frame A, 652 extension frame B, 653 movable pulley A, 654 movable pulley B, 66 steel cable. Detailed Implementation

[0029] The technical solution of this utility model will be clearly and completely described below with reference to its embodiments. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0030] Example 1

[0031] Reference Figure 1-6An active dynamic balancing tower crane includes a tower body 10 and a working boom 20 and a counterweight boom 30 respectively arranged on both sides thereon. The working boom 20 is equipped with a lifting / traveling trolley 50, and the counterweight boom 30 is equipped with a dynamic counterweight mechanism 60. The dynamic counterweight mechanism 60 includes a boom frame 61 hinged below the counterweight boom 30 or near the tower body 10, a counterweight block 62 hinged below the boom frame 61, and movable pulley blocks 65 on both sides of the counterweight block 62. It also includes fixed pulley blocks 64 arranged on both sides of the counterweight boom 30 and a winch 63 arranged above the counterweight boom 30. The steel cables 66 at the input and output ends of the winch 63 pass over the fixed pulley blocks 64 and are connected to the bottom of the counterweight boom 30. When the lifting / traveling trolley 50 on the working boom 20 lifts a load or the load position changes, the control system adjusts the length of the steel cable 66 of the winch 63 in real time based on the vertical status information of the tower body 10 fed back by sensors. The steel cable 66 passes over the fixed pulley block 64 and connects to the bottom of the counterweight boom 30. Its winding and unwinding motion drives the counterweight block 62 to move along the arc path of the boom frame 61. Simultaneously, the coordinated work of the movable pulley block 65 and the fixed pulley block 64 ensures the smooth movement of the counterweight block 62, further improving the stability and safety of the tower crane and enabling it to maintain good balance under various working conditions. By setting a dynamic counterweight mechanism 60 on the counterweight boom 30, including the boom frame 61, counterweight block 62, movable pulley block 65, fixed pulley block 64, and winch 63, real-time precise adjustment and dynamic balance of the counterweight block 62 are achieved. This design not only effectively solves the problem of bending deformation of the tower body 10 caused by the torque imbalance between the working boom 20 and the counterweight boom 30 in the non-working state under traditional static counterweight methods, but also overcomes the defects of existing dynamic counterweight methods, such as the large inertia and insufficient adjustment precision of the counterweight block 62, significantly improving the stability and safety of the tower crane.

[0032] In some embodiments, the fixed pulley assembly 64 includes a fixed pulley A641 disposed on the side of the balance arm 30 and a fixed pulley B642 disposed at the bottom of the balance arm 30 near the fixed pulley A641. Fixed shafts A643 and B644, respectively fixed to the balance arm 30, are respectively passed through the fixed pulleys A641 and B642. The movable pulley assembly 65 includes extension frames A651 and B652 respectively disposed on the top sides of the counterweight block 62. Movable pulleys A653 and B654 are rotatably disposed on the extension frames A651 and B652 respectively. The steel cables 66 at the input and output ends of the winch 63 pass over the fixed pulleys A641, B654, B642, and A653 respectively, and are fixed to the bottom of the balance arm 30.

[0033] When the winch 63 is operating, the steel cables 66 at its input and output ends perform winding and unwinding actions respectively. For example, when it is necessary to move the counterweight 62 to the left, the steel cable 66 at the input end of the winch 63 tightens, while the steel cable 66 at the output end loosens. The steel cable 66 at the input end passes over the fixed pulley A641 and the movable pulley B654; when tightened, it moves the counterweight 62 to the left. At the same time, the steel cable 66 at the output end passes over the fixed pulley B642 and the movable pulley A653; when loosened, it does not obstruct the movement of the counterweight 62. Conversely, when it is necessary to move the counterweight 62 to the right, the steel cable 66 at the output end of the winch 63 tightens, while the steel cable 66 at the input end loosens, moving the counterweight 62 to the right. This design allows the winch 63 to precisely control the direction and position of the counterweight 62. Through the coordinated operation of the movable pulley block 65 and the fixed pulley block 64, the tension is distributed across multiple steel cables 66, thereby reducing the tension on the counterweight block 62 from a single steel cable 66 and decreasing the load on the winch 63. Specifically, each movable pulley can reduce the tension by half, so two movable pulleys can further reduce the tension. This precise counterweight block 62 movement mechanism allows the tower crane to adjust the position of the counterweight block 62 in real time according to changes in the load on the boom 20, achieving dynamic balance, reducing swaying of the tower crane during operation, and improving its stability and safety.

[0034] In the above scheme, fixed pulleys A641 and B642 are installed on the sides and bottom of the counterweight arm 30, and fixed to the counterweight arm 30 by fixed shafts A643 and B644 respectively. Meanwhile, extension frames A651 and B652 are installed on both sides of the top of the counterweight block 62, with movable pulleys A653 and B654 rotatably mounted on them, forming a complex pulley system. This design not only effectively changes the direction of force on the steel cable 66, reducing frictional loss during traction, but also reduces the tension of a single steel cable 66 on the counterweight block 62 through the coordinated work of the movable pulley group 65 and the fixed pulley group 64, ensuring the accuracy and stability of the counterweight block 62's movement, and further improving the dynamic balance performance of the tower crane.

[0035] In some embodiments, a driver's cab 70 is provided above the tower body 10, and a level monitoring device 80 is provided inside or above the driver's cab 70. The level monitoring device 80 is electrically or wirelessly connected to the control box 40 above the counterweight arm 30.

[0036] A level monitoring device 80 is installed on the tower body. The level monitoring device 80 constantly monitors the verticality of the tower body. The level monitoring device 80, in conjunction with the control box 40, controls the operation of the winch 63 on the counterweight boom 30. When the lifting / traveling trolley 50 on the boom 20 moves to the far end to increase the working torque, the boom 20 tilts downward, and the tower body 10 will inevitably bend to one side of the boom 20. After the level monitoring device 80 detects that the tower body has changed its verticality, it transmits a signal and controls the start of the winch motor of the counterweight boom 30 through the control box 40. This pulls the counterweight pendulum of the counterweight boom 30 to move towards the tail end of the counterweight boom 30 to balance the working torque and make the tower body 10 vertical. The trolley of the boom 20 moves towards the tower body 10 to reduce the working torque. When the boom 20 rises, the tower body 10 will inevitably bend towards the side of the counterweight boom 30. After the level monitor 80 detects that the tower body has changed its vertical state, it controls the start of the winch of the counterweight boom 30 to pull the counterweight boom 30 towards the tower body 10 to balance the working torque and make the tower body 10 vertical. The operator's cab of the tower crane is located at the top of the tower body 10. The level monitor 80 can be placed inside the crane operator's cab 70 or on the top of the tower. Since the tower body 10 must be vertical during the installation of the tower crane and cannot exceed the deviation value, the level monitor 80 only needs to monitor the vertical state of the tower body 10. Specific monitoring schemes include, but are not limited to, methods such as changing the horizontal state to cause the hammer to swing relative to the ground, changing the horizontal state to cause an object to roll, or changing the horizontal state to cause mercury to roll in a glass tube. When all data of the crane are normal and under normal working conditions, the torque difference generated by the working boom 20 and the counterweight boom 30 and the non-vertical state of the tower body 10 are both necessary and sufficient conditions. Once the level monitor 80 detects that the tower body 10 is in a non-vertical state and exceeds the deviation value, it immediately sends a signal to the control box 40. The control box 40 makes the motor rotate forward or reverse by connecting or disconnecting the hoist 63 circuit of the counterweight boom 30, so that the counterweight swings back and forth on the counterweight boom 30, thereby changing the counterweight torque of the counterweight boom 30 and making the tower body 10 return to the vertical state.

[0037] The aforementioned level monitoring instrument 80 can employ various monitoring methods, with the following specific features: The level monitoring instrument 80 is a precision plumb bob device. In this device, the plumb bob is positioned between two plates at a slight distance. In a horizontal state, the plumb bob does not contact either plate. The plumb bob device is located inside the operator's cab 70. When the tower body 10 tilts, the end plates of the plumb bob also tilt, but the plumb bob remains vertically downward. When the plumb bob contacts one of the plates, a weak circuit is activated, which is then converted into an electrical signal. Alternatively, the level monitoring instrument 80 may contain a tilt sensing device. This device includes a smooth sphere or cylinder, placed on a tilt-sensitive platform within the operator's cab. When the tower body 10 tilts, the sphere or cylinder rolls on the platform due to gravity. A pressure sensor or displacement sensor is located below the platform to detect changes in the position of the sphere or cylinder and convert them into an electrical signal. Alternatively, the level monitoring instrument 80 may be a closed glass tube containing a suitable amount of mercury. When the tower body 10 tilts, the mercury rolls within the glass tube due to gravity. Electrodes are located at both ends of the glass tube. By detecting the contact between mercury and the electrodes as it rolls within the glass tube, the direction and degree of tilt of the tower 10 can be determined. The electrical signals obtained from these monitoring methods are transmitted to the control box 40 above the balance arm 30 via electrical connections (such as cables) or wireless connections (such as Bluetooth or Wi-Fi). The control box 40 has a built-in signal processing module and control logic module to analyze and process the monitoring signals. When the tilt of the tower 10 exceeds a set deviation value, the control box 40 connects or disconnects the circuit of the winch 63 of the balance arm 30, causing the motor to rotate forward or backward.

[0038] In some embodiments, the boom frame 61 has hinge seats A611 and B612 fixed to the bottom of the counterweight arm 30 and the top of the counterweight block 62 on its upper and lower sides, respectively. The boom frame 61 swings at the bottom of the counterweight arm 30 and above the counterweight block 62 through hinge connections with hinge seats A611 and B612. The boom frame 61 forms a hinged structure with the bottom of the counterweight arm 30 and the top of the counterweight block 62 through the hinge seats A611 and B612 on its upper and lower sides. When the winch 63 is working, the winding and unwinding action of the steel cable 66 will cause the counterweight block 62 to move along the arc-shaped path of the boom frame 61. Due to the hinged relationship between the boom frame 61, the counterweight arm 30, and the counterweight block 62, the movement of the counterweight block 62 is more stable and precise. Specifically, when the position of the counterweight 62 needs to be adjusted to balance the torque of the boom 20, the winch 63 pulls the counterweight 62 via the steel cable 66, causing it to move along an arc-shaped path on the boom frame 61. The swinging of the boom frame 61 allows the counterweight 62 to adjust its position within a certain range, thereby changing the torque generated by the counterweight 62 to match the load torque on the boom 20. This design ensures that the tower crane maintains good balance under various working conditions, reduces the swaying of the tower body 10, and improves the stability and safety of the tower crane.

[0039] In some embodiments, a hook 31 for suspending and limiting the counterweight 62 is hinged to the side of the counterweight boom 30 near the tower body 10. An electric actuator 32, hinged to the bottom of the counterweight boom 30, is connected to one side of the hook 31. The electric actuator 32 is electrically connected (e.g., by cable) or wirelessly connected (e.g., via Bluetooth, Wi-Fi) to the control box 40. When the tower crane stops working or when the counterweight 62 needs to be retracted, the position of the counterweight 62 is first adjusted by the winch 63, moving it to the side closer to the tower body 10. Then, the control box 40 controls the electric actuator 32 to push or pull the hook 31, causing the hook 31 to be mounted on the boom frame 61, thereby limiting the position of the counterweight 62 and preventing it from swaying or shifting due to external factors such as wind when not in operation. When the tower crane needs to be put back into operation, the electric actuator 32 reverses its movement, releasing the hook 31, and the counterweight 62 can then move freely on the boom frame 61, ready for dynamic balance adjustment.

[0040] Example 2

[0041] like Figure 7 As shown, unlike Embodiment 1, the boom 61 in the dynamic counterweight mechanism 60 is hinged to the side near the tower body 10. This design optimizes the movement path and adjustment range of the counterweight 62. This allows the counterweight 62 to move in an arc within the area near the tower body 10, facilitating more precise torque balance adjustment without increasing the overall structural dimensions. Specifically, because the boom 61 is positioned close to the tower body 10, the movement range of the counterweight 62 is concentrated near the tower body 10, allowing for a larger torque adjustment effect within a smaller movement range. The formula for calculating torque M is M = F × L, where F is the force and L is the lever arm (the distance from the point of application of the force to the fulcrum). When the counterweight 62 is positioned close to the tower body 10, although the lever arm L is short, a large torque change can be achieved within a small movement range through arc-shaped movement. This is because arc-shaped movement allows the counterweight 62 to produce a large displacement in the direction perpendicular to the lever arm, thereby achieving a large torque adjustment within a short straight-line distance. In actual operation of tower cranes, the load on the boom 20 changes frequently, requiring rapid adjustment of the counterweight 62 to maintain balance. The boom frame 61 is positioned close to the tower body 10, concentrating the movement range of the counterweight 62 near the tower body 10, reducing the travel distance and increasing adjustment speed. In practical applications, this means the tower crane can respond to load changes more quickly, reduce swaying, and improve operational efficiency.

[0042] Additionally, it should be noted that the counterweight 62 can be made into a standard, universal cast iron small part, such as a 50KG piece, which can be added and configured according to different tower crane models. It can be reused, avoiding the need to cast a one-time reinforced concrete counterweight for each tower crane, eliminating the trouble of disposing of reinforced concrete counterweights later, avoiding the generation of construction waste, being environmentally friendly, and saving the overall social cost.

[0043] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. An active dynamic balancing tower crane, characterized in that, It includes a tower body (10) and a working arm (20) and a counterweight arm (30) respectively set on both sides; wherein the working arm (20) is equipped with a lifting / traveling trolley (50) and the counterweight arm (30) is equipped with a dynamic counterweight mechanism (60); The dynamic counterweight mechanism (60) includes a boom frame (61) hinged below the balance arm (30) or near the tower body (10), a counterweight block (62) hinged below the boom frame (61), and movable pulley groups (65) on both sides of the counterweight block (62); it also includes fixed pulley groups (64) on both sides of the balance arm (30) and a winch (63) above the balance arm (30), and the steel cables (66) at the input and output ends of the winch (63) pass around the fixed pulley groups (64) and the fixed pulley groups (64) respectively and are connected to the bottom of the balance arm (30).

2. The active dynamic balancing tower crane as described in claim 1, characterized in that, The fixed pulley assembly (64) includes a fixed pulley A (641) disposed on the side of the balance arm (30) and a fixed pulley B (642) disposed at the bottom of the balance arm (30) near the fixed pulley A (641). Fixed shafts A (643) and B (644) fixed to the balance arm (30) are respectively provided through the fixed pulley A (641) and the fixed pulley B (642).

3. The active dynamic balancing tower crane as described in claim 2, characterized in that, The movable pulley assembly (65) includes an extension frame A (651) and an extension frame B (652) respectively disposed on the top two sides of the counterweight block (62), and movable pulleys A (653) and B (654) are respectively rotatably disposed on the extension frame A (651) and the extension frame B (652). The steel cables (66) at the input and output ends of the winch (63) pass over the fixed pulley A (641), the movable pulley B (654), the fixed pulley B (642) and the movable pulley A (653) respectively, and are fixed to the bottom of the balance arm (30).

4. The active dynamic balancing tower crane as described in claim 1, characterized in that, A driver's cab (70) is provided above the tower body (10). A level monitoring instrument (80) is provided inside or above the driver's cab (70). The level monitoring instrument (80) is electrically or wirelessly connected to the control box (40) above the balance arm (30).

5. The active dynamic balancing tower crane as described in claim 1, characterized in that, The upper and lower sides of the boom frame (61) are each provided with hinge A (611) and hinge B (612) fixed to the bottom of the balance arm (30) and the top of the counterweight (62). The boom frame (61) swings at the bottom of the balance arm (30) and above the counterweight (62) respectively through the hinge relationship with hinge A (611) and hinge B (612).

6. The active dynamic balancing tower crane as described in claim 1, characterized in that, A hook (31) for suspending a limiting counterweight (62) is hinged on one side of the counterweight arm (30) near the tower body (10), and an electric push rod (32) is hinged to one side of the hook (31) and fixed to the bottom of the counterweight arm (30).

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