Electric forklifts are widely used in cargo handling and transportation in cargo yards, warehouses and ports due to their flexibility, low noise and no pollution. The DC contactor is an important component in the electrical system of electric forklifts. It is used to complete the operation, stop and speed regulation of the vehicle. Regardless of the environmental conditions of the use of electric forklifts, the common faults of its contactors are mostly non-engagement or poor contact of the dynamic and static contacts of the main contact: disconnection failure, contact burnout or welding capacity, etc. Based on the structure and action principle of the common clap contactor of electric forklifts, the reasons for its failure are analyzed.
The structure and principle of operation of electric forklift contactors. Contactors are generally composed of contact systems, electromagnetic systems, arc extinguishing devices, return springs, brackets, and fixing devices. The electromagnet core generates electromagnetic force. Because the electromagnetic force is greater than the mechanical reverse force of the return spring, the main contact bracket connected with the armature is driven. At the same time, during this process, the return spring is compressed, and the normally closed interlock contact is separated. After the excitation coil is de-energized, the electromagnet loses its excitation, and the residual magnetic force is less than the mechanical reverse force of the return spring, so that the armature is reset and the main contact is disconnected; at the same time, in this process, the normally closed interlock contact is engaged.
