Container self loading and unloading transport vehicles are mainly used for loading, unloading, and transporting containers, which is their basic function and has no significant difference from other types of container transport vehicles. However, its operating conditions can be divided according to different modes, mainly including self loading and unloading conditions, stacking conditions, and vehicle to vehicle conditions.
(1)In the self loading and unloading condition, the vehicle first stabilizes the entire vehicle by extending the support device, and then drives the driving cylinder of the lifting device to move the lifting head according to the predetermined trajectory. In this way, the container connected to the lifting head through a short chain can achieve position conversion from the ground to the transport vehicle chassis. The limitations of this working condition are relatively few. As long as it is ensured that the container does not interfere with the chassis or working devices of the transport vehicle during loading and unloading, the safety and smoothness of the loading and unloading process can be guaranteed. Therefore, self loading and unloading conditions are considered a relatively simple and basic operating mode
(2) Vehicle to vehicle operating conditions
Vehicle to vehicle operation refers to the direct transfer of containers between different vehicles by container self loading and unloading transport vehicles. Compared with self loading and unloading conditions, this condition puts higher demands on the working range of the vehicle, and the outermost point of its operating trajectory needs to be designed higher and farther. Therefore, this operating condition poses more stringent challenges to the structural design of the working device. When transferring containers between two vehicles, the support space will be affected, and the legs need to be able to cross the car chassis and directly support on the car chassis or other specific support methods, which also requires specially designed support devices to support.
(3) Stacking conditions
Under stacking conditions, the container self loading and unloading transport vehicle needs to stack the containers on its own vehicle above the existing containers on the ground. This working condition places extremely high demands on the vehicle's operating range and stability. Usually, most container self loading and unloading transport vehicles can complete the stacking of two layers of containers, that is, stacking the on-board containers on top of the ground containers. However, transport vehicles capable of stacking three layers of containers are very rare, and generally require reducing the loading weight of the containers to accommodate the increase in stacking layers.
During the stacking process, the crane arm needs to provide a huge lifting torque to ensure that the container can be safely and smoothly stacked. At the same time, the trajectory planning of the entire loading and unloading process is also crucial, ensuring that the container's trajectory is both reasonable and safe. In addition, the stability of container self loading and unloading transport vehicles also faces great challenges under stacking conditions.
In summary, the stacking condition imposes strict requirements on both the lifting and supporting devices in the working equipment. To achieve this working condition, specific technical design and vehicle configuration are required, so only a few specific types of container self loading and unloading transport vehicles have this function.
