Rear supporting leg device of bridge girder erection machine

The invention discloses a rear supporting leg device of the bridge girder erection machine. The device comprises a rear supporting leg cross beam, a bottom rotating supporting frame is fixed to the bottom face of the rear supporting leg cross beam, a rear supporting leg cross beam pulley block is installed on the rear supporting leg cross beam, and a rear supporting leg balancing base is fixedly connected to a top plate of the rear supporting leg cross beam pulley block through bolts. An inner sleeve body connecting seat is hinged to the rear supporting leg balancing base through a balancing shaft; rear supporting leg moving hanging wheels move along the bridge girder erection machine main beam, the friction force is small, the effect is good, the bottom rotating supporting frame can be adjusted to be located on the bottom face of the rear supporting leg cross beam according to needs, the bottom rotating supporting frame can be located over the two side wall portions of the box girder,and rear supporting leg