The invention discloses a radial-reverse combination
extrusion forming mold of a thin-wall cylindrical piece with an outer boss. The mold comprises an upper mold
assembly, a lower mold
assembly, a male mold, a female mold, a mandrel, a core support, an
extrusion ring, an ejection block and a movable block, wherein the male mold is mounted on the upper mold
assembly, the core support is mounted atthe bottom of the mandrel, the mandrel drives the core support to slide and stretch out and draw back of the male mold, and the
extrusion ring sleeves the part stretching out of the core support; thefemale mold is mounted on the lower mold assembly, a cavity and a movable block groove are arranged in the female mold, the core support and the cavity are located on the same central shaft, after themovable block groove allows the movable block to be placed and is filled with the movable block, the shape of the cavity is a full cylinder shape, the ejection block is arranged in the cavity, the height of the ejection block is smaller than the height of the cavity, the upper part of the movable block protrudes out of the ejection block, the side surface forms an inwards-concaved boss cavity, and the outer
diameter of the extrusion ring is the same as the
diameter of the female mold cavity. The radial-reverse combination extrusion forming mold of the thin-wall cylindrical piece with the outer boss can directly form the thin-wall cylindrical piece with any position, size and number of bosses at one step, and the mechanical performance of the thin-wall cylindrical piece is greatly improved.