Device for preventing unbalance loading of ladle crane
By installing weight sensors and a PLC system on the crane to automatically determine the status of the hook, the safety hazards caused by the driver's blind spot are solved, and safety and operational efficiency are improved.
Patent Information
- Application Number
- CN202520185804.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-06
- Publication Date
- 2026-01-27
- Estimated Expiration
- 2035-02-06
AI Technical Summary
Because the building obstructs the view of the gantry hook, the driver cannot see it directly and cannot confirm whether the hook is securely attached, posing a safety hazard of the ladle falling.
Employing weight sensors, dual-channel data transmitters, a PLC system, dual-channel weighing meters, and displays, the system automatically determines the hook status by measuring and comparing the weight difference between the two gantry hooks and will alarm or stop the lifting mechanism when there is an off-center load, ensuring safe lifting.
It improves the safety of crane operation, reduces equipment damage or personal injury caused by improper hook engagement, simplifies the operation process, and improves operation efficiency.
Smart Images
Figure CN223836975U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of crane eccentric loading. Background Technology
[0002] During casting crane hoisting operations, due to building obstructions, the operator may not be able to directly see the gantry hook and confirm that the hook's lugs are securely fastened. Confirmation relies primarily on ground-based command personnel. If the command personnel fail to confirm properly, the gantry hook may snag on the ladle's trunnions or trunnion retaining rings, potentially leading to a ladle falling after hoisting, with catastrophic consequences. Although a monitoring video system is installed in the operator's cab, the wireless transmission causes signal delays and buffering, necessitating ground-based command personnel for verification. A more direct and effective safety system is urgently needed. Utility Model Content
[0003] The technical problem to be solved by this utility model is: how to solve the problem that the gantry hook cannot be directly seen due to the obstruction of the building, and the gantry hook is caught on the trunnion of the ladle lifting lug or the trunnion retaining ring, causing the ladle to fall after lifting.
[0004] The technical solution adopted by this utility model is: a device for preventing uneven loading of a casting crane, including a weight sensor for measuring the weight of a ladle (8) installed at the connection between the two arms of the main trolley frame (6) and the gantry hook beam (5), a dual-channel data transmitter (7) installed on the main trolley frame (6) and connected to the weight sensor by electrical signal, a PLC system (2) installed in the crane electrical room, a dual-channel weighing meter (1) and a display installed in the crane cab, and two steel wire ropes on both sides of the gantry hook beam (5) are each connected to a hook for hanging the ladle. The weight sensor includes a left weight sensor (3) installed on the left arm of the gantry hook beam (5) and a right weight sensor (4) installed on the right arm of the gantry hook beam (5). The dual-channel data transmitter (7), the dual-channel weighing meter (1) and the display are all connected to the PLC system (2) by electrical signal.
[0005] The left weight sensor (3) on the left arm is a set of four left weight sensors, and the right weight sensor (4) is a set of four left weight sensors.
[0006] It also includes visual aids and gyroscope aids.
[0007] It also includes a left fixed pulley and a right fixed pulley, with the left weight sensor (3) installed below the left fixed pulley and the right weight sensor (4) installed below the right fixed pulley.
[0008] The main trolley frame is the platform for installing the hoisting mechanism and the main trolley traveling mechanism. The dual-channel data transmitter, hoisting drum, and hoisting fixed pulley are all installed on the main trolley frame.
[0009] When hoisting steel ladles, the hooks on both sides of the gantry hook plate are subjected to two similar forces, which are half the weight of the steel ladle. The wire ropes on both sides of the gantry hook beam are also subjected to the same force, and the fixed pulleys on both sides exert the same force on the weight sensor. At this time, the left and right weight sensor values displayed by the two channels AB of the weighing instrument are two similar weight values.
[0010] When the left ladle trunnion is properly hooked on the plate hook (hook) and the right trunnion is pressing against the plate hook, the right plate hook of the gantry hook will be subjected to a large force. This force is transmitted through the left and right wire ropes and fixed pulleys of the gantry hook beam to the weight sensor below the fixed pulley. The weight sensors on both sides transmit electrical signals to the dual-channel data transmitter and then through the cable to the dual-channel instrument in the driver's cab. The weights on both sides will be displayed separately. When the difference between the weight on the right and the weight on the left reaches the set value, the weighing instrument will output a fault signal. After the signal is transmitted to the PLC system, it will interrupt the control signal of the hoisting mechanism, and the hoisting mechanism will stop rising, thus achieving the purpose of protecting the safety of the hoisted object during lifting.
[0011] After the ladle is hoisted onto the lower hook of the gantry hook, the load cells on both sides transmit the weight to the dual-channel instrument, which displays the weight of the load hoisted by the two gantry hooks. A load deviation range can be set at this point. If the load on both gantry hooks is unevenly distributed, or if one side is under load while the other is not, and the deviation reaches the set value, the weighing instrument outputs a fault signal to the PLC, thereby disconnecting the lifting control circuit of the hoisting mechanism and issuing a corresponding alarm.
[0012] This invention aims to improve crane operation safety and reduce potential accident risks by addressing blind spots for drivers and hook confirmation issues. It ensures the hook is securely engaged with the trunnion during each lift, preventing equipment damage or personal injury due to improper hook engagement. Automatic hook status confirmation simplifies operator tasks, reduces human error, and improves operational efficiency. Attached Figure Description
[0013] Figure 1 This is a schematic diagram of the overall structure of this utility model;
[0014] Among them, 1. Dual-channel weighing meter, 2. PLC system, 3. Left weight sensor, 4. Right weight sensor, 5. Gantry hook beam, 6. Overhead crane main trolley frame, 7. Dual-channel data transmitter, 8. Steel ladle. Detailed Implementation
[0015] The crane driver cannot directly see the gantry hook and cannot effectively confirm the situation of the double ears of the hook hanging on the ladle. It mainly relies on the ground signalman to direct and confirm. Once the signalman fails to confirm properly, the gantry hook may be hung on the trunnion or the trunnion retaining ring of the ladle, and there is a great potential hazard of the ladle falling after lifting. Therefore, the main purpose of this invention is to prevent the safety risks caused by the signalman's failure to confirm, and to judge whether the hook is safely hung through hardware.
[0016] There has been a situation where the gantry hook was hung on the trunnion of the hot metal ladle due to the signalman's failure to confirm clearly. Fortunately, the crane driver discovered the problem in time during the lifting and lowered it smoothly, avoiding a major accident.
[0017] Currently, the main methods to prevent eccentric lifting are visual assistance and gyroscope assistance. Since the liquid crane electronic scale sensors can be divided into the east and west sides to measure the weight separately, this provides the possibility to solve the problem of eccentric load. Through on-site measurement and testing, the test data was finally obtained and put into use. Taking the 320t crane as an example, its electronic scale system mainly consists of sensors, data transmitters, electronic scale instruments, and large displays. Among them, 8 weight sensors are respectively installed under the fixed pulleys on the east and west sides. The sensor signals on the east and west sides are respectively connected to the plc, and the data is transmitted to the dual-channel electronic scale instrument. The two channels can display the weight and calibration separately, and the total weight is displayed on the large display without affecting the reading.
[0018] When one side of the plate hook tip is hung on the trunnion of the ladle and the other side is properly hung, the steel rope on the side of the top hook tip will be under stress first until the other side is firmly hooked and then they will be stressed simultaneously. The weight deviation value between the two sides of the steel ropes is W1.
[0019] When one side of the plate hook jaw is hung on the trunnion retaining ring of the ladle and the other side is properly hung, the steel rope on the side of the retaining ring will be under stress first until the other side is firmly hooked and then they will be stressed simultaneously. The weight deviation value between the two sides of the steel ropes is W2.
[0020] Due to the unevenness of the ground steel rail, the deviation of the steel rope after replacing the steel rope, and the dropping of one side of the gantry hook jaw, these situations will also cause the steel ropes on both sides to lift the ladle in sequence. At this time, the maximum weight deviation value between the two sides of the steel ropes is W3.
[0021] Due to the signalman's failure to confirm, the two sides of the gantry hook tips顶住 the trunnion to lift the ladle. At this time, the maximum weight deviation value between the two sides of the steel ropes is W4.
[0022] In the above two cases, by setting a minimum deviation value W for the electronic scale, it is necessary to make W3 < W < W1 and satisfy W3 < W < W2 to trigger the eccentric load alarm and prevent continued lifting.
[0023] Due to height discrepancies in the ground steel rail track or variations in the length of the gantry hook ropes, the hooks on both sides may become caught on the trunnions or trunnions of the molten iron ladle, resulting in unequal tension on the two hooks. By modifying the electronic scale, the weight of the gantry hooks on both sides is recorded and compared. When the weight deviation exceeds the normal load range, the power supply to the lifting circuit is cut off, thus eliminating the risk. Tests showed that during normal molten iron ladle lifting, the weight deviation of the hooks on both sides is 3-8t; the deviation on one side of the hook tip is 0-22t (not off the ground); the deviation on one side of the trunnion retaining ring is 0-65t (not off the ground); and the deviation when both sides are caught on the hook tip is 21t (off the ground). Considering these factors, the deviation alarm value was set at 10t, which satisfies normal lifting requirements while addressing the safety hazards caused by these abnormal situations. Over the past year, through repeated testing and adjustments, reliable off-center load data has been obtained. Tests have verified that the situation of the overhead crane catching on the ladle trunnions or retaining rings during lifting can be avoided, achieving the purpose of the modification.
Claims
1. A device for preventing uneven loading on a casting crane, characterized in that: The system includes a weight sensor for measuring the weight of the ladle (8) installed at the connection between the two arms of the main trolley frame (6) and the gantry hook beam (5), a dual-channel data transmitter (7) installed on the main trolley frame (6) and connected to the weight sensor by electrical signal, a PLC system (2) installed in the overhead crane electrical room, a dual-channel weighing meter (1) and a display installed in the overhead crane cab, and two wire ropes on both sides of the gantry hook beam (5) are each connected to a hook for hanging the ladle. The weight sensor includes a left weight sensor (3) installed on the left arm of the gantry hook beam (5) and a right weight sensor (4) installed on the right arm of the gantry hook beam (5). The dual-channel data transmitter (7), the dual-channel weighing meter (1) and the display are all connected to the PLC system (2) by electrical signal.
2. The device for preventing uneven loading on a casting crane according to claim 1, characterized in that: The left weight sensor (3) on the left arm is a set of four left weight sensors, and the right weight sensor (4) is a set of four left weight sensors.
3. The device for preventing uneven loading on a casting crane according to claim 1, characterized in that: It also includes visual aids and gyroscope aids.
4. The device for preventing uneven loading on a casting crane according to claim 1, characterized in that: It also includes a left fixed pulley and a right fixed pulley, with the left weight sensor (3) installed below the left fixed pulley and the right weight sensor (4) installed below the right fixed pulley.