When operating a truck-mounted crane, it is important to pay attention to the relationship between the center of gravity and the lifting operation. The center of gravity is the resultant force of the weight of the object divided into many tiny volumes. The center of gravity has a significant relationship with the lifting operation of truck-mounted cranes. It is clearly stipulated in the lifting construction specifications that the line of action of the hook and the center of gravity of the load should be on the same vertical line. The position of the center of gravity of an object is one of the important technical data mastered for lifting operations.
The relationship between the center of gravity and the lifting operation of the truck-mounted crane is as follows:
The positional relationship of the center of gravity refers to the degree of levelness of the heavy object after it is lifted off the ground. In general lifting operations, the distances from the hook to each binding point are equal. At this point, it is required that the center of gravity of the object be at the positions of each binding point. If the binding point is not appropriate and the center of gravity deviates from its position, the heavy object will tilt after being lifted. In lifting operations, when objects are hoisted at an Angle, it is often not conducive to the installation and positioning of equipment, nor is it beneficial to the construction.
2. The center of gravity determines the load distribution of the force-bearing binding rope. When hoisting equipment, assemblies or reinforced concrete components with irregular shapes, due to the different vertical distances from the center of gravity to each strand of the binding rope, the forces acting on each strand of the binding rope are also different.
3. The position of the center of gravity and the force balance during the lifting of the heavy object determine the binding method of the heavy object. When the center of gravity is lower than the binding point, the binding of heavy objects is generally easier to reach balance. When the center of gravity of a heavy object is higher than the binding point, the binding method for lifting the heavy object is often more appropriate. For equipment with a center of gravity higher than the binding point, if the binding method adopted is inappropriate, the heavy object is prone to lose balance after being lifted, which may cause an accident.
4. The center of gravity during equipment transportation within the site is related to the binding method, transportation method and stability of the transportation process of heavy objects. The height of the center of gravity during equipment transportation within the site refers to the ratio of the height of the support surface of the heavy object to the contact width of the equipment on the support surface. When operating equipment with a relatively high center of gravity, lifting construction personnel should pay full attention. Although they are not heavy, their center of gravity is very high. When being towed within the site, accidents of them being pulled over occur from time to time. Therefore, equipment with a relatively high center of gravity also poses a risk of overturning during transportation operations.
5. When the equipment is turned over, the center of gravity is related to the change in the force on the binding rope. The position of the center of gravity of an object within the object is fixed and has nothing to do with the position of the object in space. During the process of turning a heavy object over, the center of gravity changes along with the flipping of the object, and the forces acting on each binding point also change accordingly. When performing heavy object lifting and turning operations, the force on each binding rope changes when the heavy object is flipped to different angles. Generally, the binding rope should be selected based on the load when the force is greater.
6. In lifting operations, measures should be taken to keep the object in a balanced state. The center of gravity of flow refers to the change in the center of gravity of a container holding liquid or bulk materials during lifting due to the flow of the liquid or bulk materials. When a truck-mounted crane is lifting such objects, measures should be taken to ensure that the objects are always in a state of force equilibrium and can automatically return to a balanced state in case of temporary instability.
