Method and apparatus for forming a necked and flanged part on a hollow cylindrical body

摘要

A method and an apparatus for forming circumferentially extending necked and flanged parts at an end of a bilaterally open hollow cylindrical body. First and second axially aligned shafts carry axially displaceable first and second inner tools, respectively. Each inner tool has a circumferential body-shaping and a circumferential body-supporting surface. In a first axial position of the two inner tools the shaping surfaces together define a circumferential shaping groove situated inside the hollow body, and the body-supporting surfaces support the hollow body. In a second axial position the two inner tools are at a greater axial distance from one another than in the first position to allow introduction of a hollow body therebetween. A third shaft, carrying an outer tool having a circumferential shaping surface, extends parallel to the first and second shafts. A positioning arrangement is provided for aligning the circumferential shaping surface of the outer tool with the circumferential shaping groove and for radially moving the outer tool towards the two inner tools such that a circumferential portion of the hollow body is deformed and forced into the shaping groove causing the two inner tools to axially spread apart from one another.