The present invention discloses a method for coreless spinning of a large-ratio multi-variable-diameter hollow shaft, belonging to the field of spinning. The present invention includes following steps: S1: clamping a blank in a lower die unit, driving the workpiece to rotate, causing a rough spinning wheel and a fine spinning wheel to be in contact with the workpiece for staggered spinning, and performing curved reciprocating feed spinning via point contact to form a roughly-spun blank; S2: shifting the rough spinning wheel and the fine spinning wheel, causing shaping spinning wheels to be in contact with the workpiece for shaping spinning, and subjecting the shaping spinning wheels to linear contact shaping and fine spinning only in a radial direction, to obtain a finely spun blank. The present invention solves the problems of high machining difficulty and poor molding quality of hollow shafts in the prior art.

The present invention discloses a method for coreless spinning of a large-ratio multi-variable-diameter hollow shaft, belonging to the field of spinning. The present invention includes following steps: S1: clamping a blank in a lower die unit, driving the workpiece to rotate, causing a rough spinning wheel and a fine spinning wheel to be in contact with the workpiece for staggered spinning, and performing curved reciprocating feed spinning via point contact to form a roughly-spun blank; S2: shifting the rough spinning wheel and the fine spinning wheel, causing shaping spinning wheels to be in contact with the workpiece for shaping spinning, and subjecting the shaping spinning wheels to linear contact shaping and fine spinning only in a radial direction, to obtain a finely spun blank. The present invention solves the problems of high machining difficulty and poor molding quality of hollow shafts in the prior art.

Provided is a wheel spinning die wherein the plurality of identical slide blocks are connected end to end to form a circular ring, and the slide blocks are inserted into an annular groove between the side wall of a circular groove at the upper end of the lower die and the central connecting block; during spinning, each arc flange is clamped at the joint of an outer wheel lip and a rim under a spoke; and during die releasing, the slide blocks can move up and down together with the vertical movement of a wheel blank, so that the problem of releasing of a reverse draft die at the joint of the cold spinning wheel rim and the outer wheel lip can be solved, wheel damage caused by die releasing can be eliminated, and the yield and production efficiency of wheels are improved.

Provided is a wheel spinning die wherein the plurality of identical slide blocks are connected end to end to form a circular ring, and the slide blocks are inserted into an annular groove between the side wall of a circular groove at the upper end of the lower die and the central connecting block; during spinning, each arc flange is clamped at the joint of an outer wheel lip and a rim under a spoke; and during die releasing, the slide blocks can move up and down together with the vertical movement of a wheel blank, so that the problem of releasing of a reverse draft die at the joint of the cold spinning wheel rim and the outer wheel lip can be solved, wheel damage caused by die releasing can be eliminated, and the yield and production efficiency of wheels are improved.

A process for manufacturing a light-alloy hybrid wheel, implements the following separate operation phases: making a flange with an internal profile capable of constituting a tire bead seat; making a rim with, on one side, an outer profile capable of constituting a tire bead seat and, on the other side, a circular flank for assembly with a part of the flange; and assembling the flange with the rim, at the seat of said flange and the circular flank of the rim. The rim is made according to the following consecutive operations: an operation of manufacturing a circular flank; then an operation of expanding said circular flank to the size of the final rim in a single step; then an operation of cold or hot flospinning of said circular flank so as to obtain the rim in the final shape and profile thereof, comprising a shoulder only on the side that will not be welded to the flange.

A process for manufacturing a light-alloy hybrid wheel, implements the following separate operation phases: making a flange with an internal profile capable of constituting a tire bead seat; making a rim with, on one side, an outer profile capable of constituting a tire bead seat and, on the other side, a circular flank for assembly with a part of the flange; and assembling the flange with the rim, at the seat of said flange and the circular flank of the rim. The rim is made according to the following consecutive operations: an operation of manufacturing a circular flank; then an operation of expanding said circular flank to the size of the final rim in a single step; then an operation of cold or hot flospinning of said circular flank so as to obtain the rim in the final shape and profile thereof, comprising a shoulder only on the side that will not be welded to the flange.

A method for producing a screw foundation for securing elements in the ground, provides a cylindrical tube as an initial form and a conical front portion tapering to an insertion tip is then molded on to the cylindrical tube using a non-cutting process, the front portion being provided at least in some regions with a thread-like contour for screwing into the ground. An inner contour for a screwing tool is formed integrally in a rear end of the tube by flow forming, and the front portion and the thread-like contour are formed exclusively by flow forming.

A method for producing a screw foundation for securing elements in the ground, provides a cylindrical tube as an initial form and a conical front portion tapering to an insertion tip is then molded on to the cylindrical tube using a non-cutting process, the front portion being provided at least in some regions with a thread-like contour for screwing into the ground. An inner contour for a screwing tool is formed integrally in a rear end of the tube by flow forming, and the front portion and the thread-like contour are formed exclusively by flow forming.

A method for manufacturing a rotationally symmetrical shaped article, which has a cylindrical, concentric hub axially closed on one side, in a shaping process is performed such that at least one pressure roll is in contact with a rotating, closed, planar circular blank sheet and presses the material of the blank radially from the outside inward against a projecting part that runs upright on the circular blank such that the thickness of the circular blank decreases and the hub including a blind hole is formed.

A method for manufacturing a rotationally symmetrical shaped article, which has a cylindrical, concentric hub axially closed on one side, in a shaping process is performed such that at least one pressure roll is in contact with a rotating, closed, planar circular blank sheet and presses the material of the blank radially from the outside inward against a projecting part that runs upright on the circular blank such that the thickness of the circular blank decreases and the hub including a blind hole is formed.