METHOD AND MEDIUM SIZED SEMI-TORUS

The invention relates to a method and a working device for manufacturing a medium sized semi-torus made of stainless steel sheet by using the explosion plastic deformation in a mould of concrete steel submerged in a water tank. The claimed method for manufacturing the semi-torus (16) with a thickness g, the diameter of the flange D1, the average diameter DM, the radius of section Rst and the height Hst is the following: the semifinished sheet metal (17) is fixed between the active plate (6) and the holding plate (7), the pocket (4) under the semifinished plate (17) is sealed by applying a putty on the inner outline (d) and outer outline (D) of the plate, the mould (18) is descended into the water tank (10) where the plate (15) on which there was mounted the explosive block (14) is attached at a distance h above the semifinished sheet (17), the electric wires of the blasting cap for initiating the explosion connected "in short-circuit" are pulled out of the tank (10), the pocket (4) is vacuumed through the pipe (12) by a vacuum pump (13) until a pressure ranging between 0.1...0.2 bar is reached, when the vacuum pump (13) is stopped and the tank (10) is filled with water up to the level H, the detonation of the explosive (14) arranged in annular shape is initiated, the water is discharged from the tank (10), the mould (18) is pulled out of the tank and the semi-torus (16) is removed from the mould (18). The claimed device comprises a mould made of concrete (1) reinforced with metal bars (2), cast in a housing (3) with a working pocket (4) lined with a composite layer (5) of epoxy resin reinforced with glass fibres, an active plate (6) made of steel, a plate (7) also made of steel in which the semifinished product (8) is fixed by some bolts (9), a tank (10) with water (11), a pipe (12) connected to a vacuum pump (13) and an explosive charge (14) fixed on some wooden supports (15) at a distance h to the semifinished sheet (17) and a distance H to the water surface. Invenţia se referă la o metodă şi la un dispozitiv de lucru pentru obţinerea unui semitor de dimensiuni medii, fabricat din tablă de oţel inoxidabil, utilizând deformarea plastică prin explozie într-o matriţă din beton armat, imersată într-un bazin cu apă. Metodă de obţinere conform invenţiei a semitorului (16) cu grosimea g, diametrul flanşei D1, diametrul mediu DM, raza secţiunii Rst şi înălţimea Hst este următoarea: tabla (17) semifabricat este fixată între placa (6) activă şi placa (7) de reţine