METHOD OF MOLDING BLANK FOR OBTAINING LARGE-SIZED SHELLS MADE OF COMPOUND MATERIAL AND MANDREL FOR ITS REALIZATION Russian patent published in 1995 - IPC

FIELD: metal working. SUBSTANCE: layer of the aluminium foil, sheets of the monoband aluminium-boron with the layer formation and another layer of the aluminium foil are successively stacked on the mandrel. The pattern cutting of the aluminium foil layer adjoining the mandrel is exercised with an allowance on edge for the bend. During the stacking of the monoband sheets the preliminary fastening of the sheet edge parallel to the mandrel generatrix is exercised towards the mandrel. Ensuring the sheet tension, the consequent, beginning with the fastened edge, pressing of the sheet along the mandrel generatrix is exercised in the circumferential direction to the preceding layer. After that, without relieving the pressure a free edge is preliminarily tied with the mandrel. In this case the monoband sheets are stacked overlapped shutting down the butt joints of the preceding sheets. After the placement of the foil outer layer the ends of the foil are glued between themselves. The preliminary fastening of the sheets is taken off. After relieving in succession the pressure in the circumferential direction the edges of the foil layer adjoining the mandrel are bent on the foil outer layer and are glued with it. The mandrel has technological shell 1 to accommodate blank 2 placed on carcass 3 made of upper 4 and lower 5 rings whose lateral surface contacts with the internal surface of the technological shell and is mounted for rotation on central tube 6 fastened on stand 7, tightened plates 8 placed outside the technological shell along its generatrix and threaded studs 9 to fit nuts 10 mounted on the lateral surface of lower ring 5 and one at a time-at the upper face end of each plate 8 perpendicular to the mandrel axis. In this case rings 4,5 are made so that their face ends overhang the edges of technological shell 1. On the upper face end of upper ring 4 notches 11 are made through which studs 9 are passed. Similar notches 12 are made on the lower face end of each plate 8 and studs 9 are passed through them. EFFECT: facilitated manufacture. 2 cl, 3 dwg