Limiting mechanism for tower crane

Abstract

The utility model relates to the technical field of cranes, and discloses a limiting mechanism for a tower crane, which comprises a beam frame, the outer wall of the beam frame is in sliding connection with a moving trolley, a steel cable is arranged in the moving trolley, the bottom of the steel cable is fixedly connected with a lifting hook, the outer wall of the steel cable is fixedly connected with a cross, and the cross is fixedly connected with the lifting hook. A limiting assembly is arranged below the moving trolley. The limiting assembly comprises a first pressure relay and a switch. In the utility model, the cross ascends along with the steel cable and pushes the sliding frame to extrude the pressure relay I, so that a power supply of the moving trolley can be quickly cut off, the trolley is forcibly stopped from running, a lifting hook or goods is effectively prevented from colliding with a crane structure, the equipment damage risk caused by collision is greatly reduced, and the safe running of the crane is ensured; meanwhile, the personnel safety and the operation order of a construction site are guaranteed, and the stability and the reliability of operation of the tower crane are remarkably improved.

Description

Technical Field

[0001] This utility model relates to the field of crane technology, and in particular to a limiting mechanism for tower cranes. Background Technology

[0002] In the modern construction industry, tower cranes, as indispensable large-scale mechanical equipment, undertake heavy material handling tasks. With the continuous expansion of construction projects and the increasing complexity of construction, more stringent requirements are placed on the operational precision, safety, and stability of tower cranes. Among these, the limit mechanism, as a key component ensuring the safe operation of the tower crane, directly affects the smoothness of the entire construction process and the safety of personnel and equipment. Developing an efficient and reliable limit mechanism for tower cranes has become an important direction for technological innovation in construction machinery.

[0003] Traditional tower crane limit technology relies heavily on relatively simple mechanical contact limit switches. These switches are typically installed on critical parts of the crane, such as the rails and boom. When a hoisted component moves to a preset position, it mechanically contacts the limit switch, triggering a circuit to cut off the power supply and thus limiting the movement. The underlying principle is based on simple circuit on / off control, using mechanical collision to alter the circuit state and restrict the position of moving parts. While this technology can constrain the crane's range of motion to some extent, it has gradually revealed numerous limitations in complex construction environments.

[0004] In existing technologies, when the hook and cable accidentally approach the moving trolley due to cargo swing or operator error, traditional limit mechanisms cannot respond quickly and accurately. Due to the limited trigger sensitivity of their mechanical contact limit switches and the slow circuit response speed, they often fail to cut off the power supply to the moving trolley in time, making it highly susceptible to collisions between the hook or cargo and the crane structure. Such collisions not only cause serious damage to critical structural components of the crane, significantly increasing equipment maintenance costs and downtime, but also pose a significant threat to personnel safety at the construction site, severely disrupting operational order and making it difficult to effectively guarantee the stability and reliability of tower crane operations. Utility Model Content

[0005] To overcome the above shortcomings, this utility model provides a limiting mechanism for tower cranes, which aims to improve the problem that traditional limiting mechanisms are difficult to respond quickly and accurately, causing the hook or cargo to easily collide with the crane structure.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a limiting mechanism for a tower crane, comprising a beam frame, a movable trolley slidably connected to the outer wall of the beam frame, a steel cable disposed inside the movable trolley, a hook fixedly connected to the bottom of the steel cable, a cross fixedly connected to the outer wall of the steel cable, and a limiting component disposed below the movable trolley;

[0007] The limiting assembly includes a pressure relay and a switch. The outer wall of the pressure relay is fixedly connected to the lower part of the moving trolley. A switch is provided below the pressure relay. A sliding frame is fixedly connected to the lower surface of the switch. A sliding shaft is fixedly connected to the middle part of the sliding frame. A second pressure relay is fixedly connected inside the cross.

[0008] Furthermore, a telescopic rod is fixedly connected to the lower surface of the sliding frame, a spring is sleeved on the outer wall of the telescopic rod, and an alarm component is installed inside the cross.

[0009] Furthermore, the alarm assembly includes a buzzer and an alarm light, with the buzzer disposed inside the cross and the alarm light fixedly connected to the top corner of the cross.

[0010] Furthermore, the bottom of the telescopic rod is fixedly connected to the upper surface of the cross, and the telescopic rod is used to guide the sliding frame and the spring.

[0011] Furthermore, one end of the spring is fixedly connected to the upper surface of the cross, and the other end of the spring is fixedly connected to the lower surface of the sliding frame.

[0012] Furthermore, the outer wall of the slide shaft is slidably connected to the inside of the cross, and the bottom of the slide shaft is slidably connected to the inside of the pressure relay.

[0013] Furthermore, the switch is attached to the pressure relay.

[0014] This utility model has the following beneficial effects:

[0015] 1. In this utility model, when the hook and steel cable approach the moving trolley due to cargo swing or operational error, the cross bar rises with the steel cable, pushing the sliding frame to squeeze the pressure relay. Once the pressure relay is triggered, it can quickly cut off the power supply to the moving trolley, forcibly stopping the trolley's operation. This effectively avoids collisions between the hook or cargo and the crane structure, greatly reducing the risk of equipment damage caused by collisions, ensuring the safe operation of the crane, and protecting the safety of personnel and work order at the construction site. It also significantly improves the stability and reliability of tower crane operation.

[0016] 2. In this utility model, when the impact force continues to increase, the sliding shaft presses down to trigger the pressure relay two inside the cross, activating the alarm. At the same time, the buzzer and alarm light are triggered, using audible and visual signals to alert the operator for emergency intervention. This can promptly notify the operator when the danger escalates, preventing the accident from spreading. It forms a double protection with the limit stop. During the limit process, the spring supports the sliding frame via the telescopic rod and absorbs the impact energy, preventing rigid collision damage to the components. The spring reset function allows the limit component to automatically return to standby mode, ensuring continuous operation safety and further improving the overall safety and working efficiency of the tower crane. Attached Figure Description

[0017] Figure 1 This is a three-dimensional structural diagram of a limiting mechanism for a tower crane proposed in this utility model;

[0018] Figure 2 This is a schematic diagram of the lower structure of the moving trolley of a limiting mechanism for a tower crane proposed in this utility model.

[0019] Figure 3 This is a schematic diagram of the internal structure of the cross-shaped limiting mechanism for a tower crane proposed in this utility model.

[0020] Legend:

[0021] 1. Beam frame; 2. Moving trolley; 3. Steel cable; 4. Cross beam; 5. Hook; 6. Pressure relay one; 7. Sliding frame; 8. Switch; 9. Sliding shaft; 10. Pressure relay two; 11. Telescopic rod; 12. Spring; 13. Buzzer; 14. Warning light. Detailed Implementation

[0022] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0023] Reference Figure 1 - Figure 3This utility model provides an embodiment of a limiting mechanism for a tower crane, including a beam frame 1. A movable trolley 2 is slidably connected to the outer wall of the beam frame 1. A steel cable 3 is installed inside the movable trolley 2, connecting a hook 5 to other components of the crane. The hook 5 moves by its own lifting and lowering to lift goods. At the same time, when it approaches the movable trolley 2, it drives the cross 4 to rise and trigger the limiting mechanism. The bottom of the steel cable 3 is fixedly connected to the hook 5 for lifting goods and is the component that directly carries the goods. The outer wall of the steel cable 3 is fixedly connected to the cross 4. Under the push of the cross 4, the power supply is cut off by the pressure relay 6 squeezed by the switch 8 and the sliding shaft 9. A limiting component is provided below the movable trolley 2.

[0024] The limiting component includes a pressure relay 6 and a switch 8, which cooperate with the sliding frame 7 and the sliding shaft 9 to transmit the compressive force and trigger the pressure relay 6. The outer wall of the pressure relay 6 is fixedly connected to the lower part of the moving trolley 2. The switch 8 is located below the pressure relay 6. The sliding frame 7 is fixedly connected to the lower surface of the switch 8. The sliding shaft 9 is fixedly connected to the middle part of the sliding frame 7 to transmit the compressive force of the sliding frame 7 and trigger the pressure relay 6. When the impact force continues to increase, it further presses down to trigger the pressure relay 10 inside the cross 4. The pressure relay 10 is fixedly connected inside the cross 4.

[0025] Specifically, during construction, if the hook 5 and steel cable 3 approach the moving trolley 2 due to cargo swing or operational error, the mechanical linkage will be activated. The steel cable 3 will drive the cross beam 4 to rise, and the cross beam 4 will push the sliding frame 7. The sliding frame 7 will press the pressure relay 6 with the help of the switch 8 and the sliding shaft 9. The pressure relay 6 is extremely sensitive. After being pressed, it will quickly cut off the power supply to the moving trolley 2, causing the drive motor to stop and forcing the trolley to stop running, thus preventing the hook 5 or cargo from colliding with the crane structure. If the impact force continues to increase, the sliding shaft 9 will press down further, triggering the pressure relay 10 inside the cross beam 4, which will activate the alarm, forming a dual protection mechanism to ensure the safe operation of the crane.

[0026] Reference Figure 1 - Figure 3A telescopic rod 11 is fixedly connected to the lower surface of the sliding frame 7. A spring 12 is sleeved on the outer wall of the telescopic rod 11. During the limiting process, the telescopic rod 11 provides support, absorbs the energy generated by the impact of the cross 4 on the sliding frame 7, and compresses and deforms it, preventing the pressure relay 6 and switch 8 from being damaged by rigid collision. An alarm component is installed inside the cross 4. As the steel cable 3 rises, it pushes the sliding frame 7. When the impact force continues to increase, its internal structure cooperates with the sliding shaft 9 to trigger the pressure relay 10. It is a key transmission component for triggering the limiting and alarm mechanisms. The alarm component includes a buzzer 1. 3. The alarm light 14 and the buzzer 13 are installed inside the cross 4. The alarm light 14 is fixedly connected to the top corner of the cross 4. The bottom of the telescopic rod 11 is fixedly connected to the upper surface of the cross 4. The telescopic rod 11 is used to guide the sliding frame 7 and the spring 12. One end of the spring 12 is fixedly connected to the upper surface of the cross 4, and the other end of the spring 12 is fixedly connected to the lower surface of the sliding frame 7. The outer wall of the sliding shaft 9 is slidably connected to the inside of the cross 4. The bottom of the sliding shaft 9 is slidably connected to the inside of the pressure relay 10. The switch 8 is in contact with the pressure relay 6.

[0027] Specifically, during the limiting process, spring 12 and telescopic rod 11 work together. When cross 4 impacts sliding frame 7, spring 12 is supported by telescopic rod 11, absorbs impact energy and is compressed and deformed, preventing pressure relay 6 and switch 8 from being damaged by rigid collision. After pressure relay 10 is triggered, buzzer 13 and alarm light 14 are activated at the same time to warn the operator to intervene with sound and light signals. Telescopic rod 11 ensures that sliding frame 7 moves vertically and prevents off-center loading and jamming. After the impact force is released, spring 12 resets, driving the limiting component to return to standby, ensuring continuous and safe operation of the tower crane.

[0028] Working principle: When the hook 5 and steel cable 3 approach the moving trolley 2 due to the swing of the goods or operational errors, the cross 4 rises with the steel cable 3, pushing the sliding frame 7 to press the pressure relay 6 through the switch 8 and the sliding shaft 9. After the pressure relay 6 is triggered, the power supply of the moving trolley 2 is immediately cut off, forcibly stopping the trolley's operation and preventing the hook 5 or the goods from colliding with the crane structure. If the impact force continues to increase, the sliding shaft 9 further presses down to trigger the pressure relay 10 inside the cross 4, directly activating the alarm and forming a double protection.

[0029] Furthermore, during the limiting process, the spring 12, guided by the telescopic rod 11, supports the sliding frame 7 and absorbs the impact energy of the cross 4, preventing rigid collisions from damaging the pressure relay 6 or the switch 8. At the same time, the buzzer 13 and the alarm light 14 are triggered by the pressure relay 10, alerting the operator to intervene urgently through audible and visual signals. The telescopic rod 11 ensures that the sliding frame 7 moves vertically, preventing uneven loads from causing the mechanism to jam. The reset function of the spring 12 allows the limiting component to automatically return to standby mode after the pressure is released, ensuring safe continuous operation.

[0030] Finally, it should be noted that the above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. 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. A tower crane with a position limiting mechanism comprising a beam frame (1), characterized in that: The outer wall of the beam frame (1) is slidably connected with a moving trolley (2), the inside of the moving trolley (2) is provided with a steel cable (3), the bottom of the steel cable (3) is fixedly connected with a lifting hook (5), the outer wall of the steel cable (3) is fixedly connected with a cross (4), the lower portion of the moving trolley (2) is provided with a limiting assembly; The limiting assembly comprises a pressure relay one (6) and a switch (8), the outer wall of the pressure relay one (6) is fixedly connected below the moving trolley (2), the lower portion of the pressure relay one (6) is provided with a switch (8), the lower surface of the switch (8) is fixedly connected with a sliding frame (7), the middle portion of the sliding frame (7) is fixedly connected with a sliding shaft (9), the inside of the cross (4) is fixedly connected with a pressure relay two (10).

2. A tower crane position limiting mechanism according to claim 1, characterised in that: The lower surface of the sliding frame (7) is fixedly connected with a telescopic rod (11), the outer wall of the telescopic rod (11) is sleeved with a spring (12), the inside of the cross (4) is provided with an alarm assembly.

3. A tower crane position limiting mechanism according to claim 2, characterised in that: The alarm assembly comprises a buzzer (13) and an alarm lamp (14), the buzzer (13) is arranged in the inside of the cross (4), and the alarm lamp (14) is fixedly connected at the top corner of the cross (4).

4. A tower crane position limiting mechanism according to claim 3, wherein: The bottom of the telescopic rod (11) is fixedly connected to the upper surface of the cross (4), and the telescopic rod (11) is used for guiding the sliding frame (7) and the spring (12).

5. The position limiting mechanism for a tower crane according to claim 3, characterized in that: One end of the spring (12) is fixedly connected to the upper surface of the cross (4), and the other end of the spring (12) is fixedly connected to the lower surface of the sliding frame (7).

6. The position limiting mechanism for a tower crane according to claim 1, characterized in that: The outer wall of the sliding shaft (9) is slidably connected in the inside of the cross (4), and the bottom of the sliding shaft (9) is slidably connected in the inside of the pressure relay two (10).

7. The position limiting mechanism for a tower crane according to claim 1, characterized in that: The switch (8) is attached to the pressure relay one (6).

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