Automatic folding and unfolding mechanism of folding arm of crane and folding and unfolding method of mechanism

The present invention discloses an automatic closing mechanism for development and closing the folding arm crane development method, development of the automatic closing mechanism comprises a connection assembly, the boom assembly, the carriage assembly and closing assembly development, by which the bracket assembly to the connecting assembly It is connected to the boom assembly, which is connected via the receiving assembly development coupling assembly, respectively, of the crane and the assembly of the carrier assembly. The connector assembly comprises a pin member and a lug plate member, the pin member comprises a first pin, second pin and third pin, the boom assembly comprising a first arm, a second arm, and a third joint arm, the first arm and the second arm is articulated by the first pin, the second arm and the third arm is articulated by the second pin, the first arm of the lower chord through the third hinge pin relative to the tower. The present invention enables the operation of the folding arm to close development flexible and comfortable, have a smaller transport size, to facilitate rapid transport of the crane, the installation and removal of the confined space.