Excavator bucket rod inner rib plate preassembling and positioning tool and assembling method

The invention relates to the field of engineering machinery, in particular to an excavator bucket rod inner rib plate preassembling positioning tool which comprises a top plate located on the upper portion, a positioning plate used for being matched with an inner rib plate is arranged below the top plate, and a reinforcing plate used for fixedly connecting the positioning plate with the top plate is arranged between the positioning plate and the top plate. The side portion of the reinforcing plate is provided with an arc edge used for being matched with the rear axle seat. The assembling method comprises the following steps that (1) the rear axle seat is installed on the positioning tool; (2) a reinforcing plate is attached to the outer wall of the barrel; (3) the inner rib plate is placed on the positioning tool; (4) the tops of the inner rib plates abut against the barrel; the method comprises the steps of (1) welding an inner rib plate and a barrel, (2) welding the inner rib plate and the barrel, (3) separ