METHOD OF SHAPING THIN-SHEET LARGE-SIZE PRODUCTS AND PUNCH OF RAM PRESS FOR PERFORMING THE METHOD Russian patent published in 1995 - IPC

FIELD: metal pressure forming. SUBSTANCE: method of shaping thin-sheet large-size products comprises two stages. At first stage shaping is being provided with use of an elastic punch by 1/3 of a predetermined depth. Then an upper plate of the press is being slightly raised in order to inspect correctness of a shaping process beginning and to create an air cushion over a blank. Further the second stage is being performed. An upper plate of the hydraulic press with the elastic punch is being descended by a working effort. Before the raising of the upper plate of the hydraulic press compressed air is being fed through an opening in a center of the elastic punch, providing an increased pressure of the air cushion and a necessary deformation of a central portion of the blank. According to results of mathematic simulation of such method of forming blanks with use of the finite element method and to checking of the results, had been received upon realizing the method, a diameter d of a passage for supplying the compressed air, had been made in the central portion of the elastic punch, is to be calculated, when a next condition is satisfied; 0,8·h·H/D≅d≅1,5·h·H/D, where h maximum depth of the forming process, m; H a height of the elastic punch, m; D a diameter of the elastic punch, m. EFFECT: enlarged using range of the method. 2 cl, 2 dwg