Folding arm type crane suspension arm

The utility model discloses a folding arm type crane jib. Relates to a lorry-mounted crane. Comprising a second telescopic arm, a third telescopic arm and a fourth telescopic arm, the third telescopic arm slides on the fourth telescopic arm in a reciprocating mode through a first linear driving mechanism arranged in the fourth telescopic arm. The second telescopic arm slides on the third telescopic arm in a reciprocating mode through a second linear driving mechanism arranged in the fourth telescopic arm. Specifically, a cylinder body of the first linear driving mechanism is hinged to the inner side wall of the fourth telescopic arm, and the piston rod end of the first linear driving mechanism is hinged to the inner side wall of the third telescopic arm. According to the utility model, an external arm head oil cylinder bracket component in the prior art is canceled, so that the suspension arm is better lightened, the self-weight moment is reduced in a full-extension state, and the actual lifting performance i