When the crane is lifting something, it should not go out of the boom. This is because when the crane is out of arm, the distance from the hook to the top of the boom will be lengthened, which will cause the center of gravity of the lifted object to shift upwards, resulting in the lifted object being unstable and prone to accidents such as overturning and collision. Therefore, the crane should keep the boom perpendicular to the ground when it is lifting a heavy object and should not be out of arm.
The skill of the crane out of the arm mainly lies in understanding the working principle of the telescopic mechanism and mastering the correct operation steps. At present, the boom of the crane mainly has two kinds of ways: rope row telescoping and single-cylinder pin telescoping. For single-cylinder pin-type boom, for example, 6-section boom, its telescoping is through the cylinder head of the telescopic mechanism to extend or retract the boom section by section.
In practice, it is necessary to first remove the cylinder displacement sensor, adjust the potentiometer therein, correct the zero point of the cylinder displacement sensor through the computer, and then manually extend the boom and datermine the actual values of the displacement sensor for the 46%, 92%, and 100% retracted percentage of each section of the boom in turn, and input them into the computer.
Finally either way, it is necessary to be clear about the relationship between the main boom elevation angle, horizontal distance across, and vertical distance across, and vertical distance across. During the jib operation, it should be ensured that the center of the suspended object is directly under the jib, and overloading is strictly prohibited. At the same time, attention should be paid to maintaining the safety distance between the boom and the building and other equipment to prevent collision accidents. Afterward, after completing the lifting arm operation, the boom should be locked to prevent accidental movement.
For example, at a construction site, a crane is lifting a steel plate weighing 10 tons. Due to the narrow space at the construction site, the crane driver decides to extend the boom first in order to lift the steel plate to the designated position. However, when he just extended the boom, the steel plate suddenly lost balance and tipped to one side. Fortunately, the workers around him reacted in time and quicklt evacuated the danger zone, avoiding a serious personal injury accident.
This case tells us that a crane should never have its arm out when it is hoisting a heavy object. Otherwise, once an accident occurs, the consequences will be unimaginable. Therefore, in actual work, we must strictly abide by the operating procedures to ensure the safety of crane operation.
