Showing papers on "Hydroforming published in 1991"
TL;DR: In this paper, a detailed numerical stress analysis is offered, featuring by an ad-hoc "finite difference" scheme, accounting for the blank/tool interfacial friction and the out-of-plane curvature of the product.
15 citations
Patent•
18 Jul 1991
TL;DR: In this paper, a method for hydroforming metallic pieces in a matrix, in which the leaktight closure of the ends of the piece and the pressurising of the liquid located therein are exerted simultaneously by the action of pushers (thrust devices) on the ends, is described.
Abstract: The subject of the invention is a method for hydroforming metallic pieces in a matrix, in which the leaktight closure of the ends of the piece and the pressurising of the liquid located therein are exerted simultaneously by the action of pushers (thrust devices) on the ends of the piece. The hydroforming machine according to the invention comprises, in a vessel 1, two thrust jacks (rams) 2, 3, the rods of which carry the pushers 16, 17, intended to enter into contact with the ends of a tube 21 contained in a die (matrix) consisting of two half-dies 4, 5. These two half-dies are held in place by the action of clamps (blocks) 9, 10.
8 citations
CERN1
TL;DR: In this paper, the advantages of the present solution are discussed from the technical and financial points of view, in particular optimisation of the forming and heat treatment sequence, together with the characteristics of the final products.
Abstract: Superconducting accelerating structures made of niobium coated copper cavities are now installed in various new particle accelerators. The standard manufacturing technique for the copper shells associates spinning and welding. But a parallel way, hydroforming of monolithic parts, leads to better dimensional and surface quality. Parts are obtained by plastic deformation of copper tubes up to 200%. Hydroforming is performed at room temperature with intermediate annealings in a vacuum oven. Pieces have been produced in a large range of dimensions: tube diameters from 60 to 300 mm and lengths up to 3 m. Manufacturing procedures, in particular optimisation of the forming and heat treatment sequence, are presented together with the characteristics of the final products. Comparisons are done with theoretical computations. The advantages of the present solution are discussed from the technical and financial points of view.