In the realm of truck-mounted crane operations, safety is of paramount importance throughout the driving process. Among the various safety aspects, the stability of truck-mounted cranes stands out as a crucial consideration. Ensuring the stability of these powerful machines is essential to prevent accidents and safeguard the well-being of operators and those in the vicinity. So, what exactly are the requirements for stability? Now, the author will provide a detailed introduction for car owners.
Requirements for lifting stability of truck-mounted cranes:
During the lifting operation of truck-mounted cranes, several factors can pose a threat to stability. Lifting overweight objects is a significant risk. When a crane attempts to lift an object that exceeds its rated capacity, it can strain the mechanical components and undermine the stability of the entire system. The excessive weight can put excessive stress on the boom, chassis, and other structural elements, increasing the likelihood of instability and potential overturning.
Operational errors can also lead to excessive inertial force. For example, if the operator suddenly accelerates or decelerates the boom during lifting, it can generate a powerful inertial force that can disrupt the balance of the crane. Similarly, improper handling of the controls or abrupt movements can cause the load to swing unpredictably, further destabilizing the crane.
Subsidence of the supporting surface is another concern. When the crane is set up on an unstable or soft ground, the weight of the crane and the load being lifted can cause the supporting surface to sink. This can result in an uneven distribution of weight and a loss of stability. In extreme cases, the subsidence can be so severe that the crane topples over.
Excessive wind force is yet another factor that can affect the stability of truck-mounted cranes. Strong winds can exert a significant lateral force on the boom and the entire crane structure. If the crane is not properly secured or if the wind speed exceeds the crane’s design limits, it can be pushed off balance and even overturn.
For wheeled and truck-mounted cranes, due to their structural conditions, regardless of whether outriggers are used or not during operation, the most dangerous unstable working condition is when the boom is in a position perpendicular to the side overturning line of the vehicle body. This configuration maximizes the leverage effect of the load and wind forces, making the crane more susceptible to tipping. Therefore, when considering the stability of the crane and conducting stability tests for entry and exit, the working condition with the boom on the front side is taken as the basis. Under this working condition, the crane must have a minimum guaranteed stability to ensure safe operation.
The lifting capacity of wheeled and truck-mounted cranes is not only determined by the stability of the whole machine but also controlled by the strength of the boom. The selection of the boom section is a critical aspect of crane design. It is calculated according to a certain working condition, which typically includes a specific boom length, amplitude, and corresponding lifting weight. The designers must ensure that the boom can withstand the forces exerted by the load without buckling or failing.
Once the boom section is determined, the lifting weight under different boom lengths and amplitudes is calculated based on the existing strength of the boom. This process results in the creation of a lifting weight-amplitude curve, known as the strength lifting characteristic. Different boom lengths yield a set of different curves, each representing the safe lifting capacity for a particular configuration.
Different types of truck-mounted cranes have different strength lifting characteristic curves. These curves are marked on the signboard in the cab to provide essential information for the operator. The driver must operate the crane in strict accordance with the requirements of the curve. Adhering to these guidelines ensures that the crane is not overloaded and that the boom is operated within its safe working limits.
Some cranes are equipped with alarm devices to further enhance safety. These alarms are designed to sound when the crane approaches or exceeds its safe lifting limits. They can detect factors such as excessive weight, improper boom angle, or high wind speed and alert the operator to take corrective action. By providing real-time feedback, these alarm devices help prevent the crane from being overloaded and reduce the risk of accidents.
As can be seen from the above, in order to ensure the lifting stability of the crane, the driver must strictly abide by safety operating procedures. This includes carefully assessing the load before lifting, ensuring that the crane is set up on a stable supporting surface, and operating the controls with precision and caution. It is strictly prohibited to use the crane overloaded or rotate heavy objects at high speed. Overloading the crane can lead to structural failure and instability, while rotating heavy objects at high speed can generate excessive centrifugal force, which can cause the crane to overturn.
For example, imagine a truck-mounted crane operator who ignores the safe lifting limits and attempts to lift a load that is too heavy. As the crane struggles to support the excessive weight, the boom may start to bend, and the chassis may become unstable. The added stress on the mechanical components can lead to a sudden failure, causing the crane to tip over and potentially causing serious damage and injury.
On the other hand, if an operator rotates a heavy load at high speed, the centrifugal force can push the crane off balance. The sudden shift in weight distribution can cause the outriggers to lift off the ground or the vehicle to skid, resulting in a dangerous situation.
To avoid such scenarios, operators must be thoroughly trained in the safe operation of truck-mounted cranes. They should understand the limitations of the equipment, be familiar with the strength lifting characteristic curves, and know how to respond to various potential hazards. Regular maintenance and inspection of the crane are also essential to ensure that all components are in good working condition and that safety features are functioning properly.
In conclusion, ensuring the lifting stability of truck-mounted cranes is a complex task that requires a combination of proper design, operator training, and strict adherence to safety procedures. By understanding and meeting the requirements for stability, operators can minimize the risk of accidents and ensure the safe and efficient operation of these powerful machines.
