Balance weight mechanism capable of automatically disassembling and assembling axle housing

The invention provides an automatic disassembly and assembly axle housing counterweight mechanism which comprises a counterweight structure and a disassembly and assembly workbench, the counterweight structure comprises a detachable counterweight plate, the counterweight plate can be locked with or loosened from an axle housing under the condition of external force, and a lockable single tooth pin structure is designed in the counterweight structure. A disc spring is additionally arranged in the connecting rod pressing mechanism, so that the locking shaft can store elastic force to eliminate a gap between two teeth of the locking tooth pin, and the counterweight structure is tightly connected with a bridge opening; in order to adapt to bridge ports of different workpieces, a counterweight plate library is designed, when production changing is needed, a truss manipulator claws a current counterweight plate away, a needed counterweight plate is grabbed from the counterweight plate library and placed on a disass