Vol.2, No 1, 2004 pp. 95 -108
UDC 621.777
DETERMINATION OF THE WORKING PRESSURE FOR
HOLLOW AL-PROFILES EXTRUSION IN HALF-SUNK BRIDGE TOOLS
Tomislav R. Marinković1, Velibor J. Marinković2
1Company ''Nissal a.d.'', Niš, Serbia and Montenegro
2Faculty of Mechanical Engineering, Niš, Serbia and Montenegro
E-mail: velmar@masfak.ni.ac.yu
Abstract.The working pressure, that is, the extrusion force represents the most important parameter for the choice of the machine (press), tool design and determination of energy expenditure (work of deformation). A complex formula for calculating the working pressure for Al-profile extrusion is derived in the paper, namely, the formula that ensures, if computer-aided, an analysis of the effects of all the process factors (geometric, tribological, reological and technological). The derived formula adequately takes into consideration the effects of the mentioned factors, in the quantitative and qualitative sense, as confirmed by an experiment realized under the production conditions. Regarding the applied calculation methodology, the derived formula in its original form can also be used for calculating the working pressure for extrusion of hollow profiles of other materials (titan, titan alloys and the like) if it is the same technology of profile making.
Key Words: Extrusion Working Pressure, Hollow Profiles, Al-alloys, Bridge Tools.
ODREĐIVANJE RADNOG PRITISKA PROCESA ISTISKIVANJA
ŠUPLJIH AL-PROFILA U ALATU SA POLUUTOPLJENIM MOSTOM
Radni pritisak, odnosno sila istiskivanja predstavlja najvažniji parametar za izbor mašine (prese), projektovanje alata i određivanje utrošene energije (deformacionog rada). U radu je izvedena kompleksna formula za proračun radnog pritiska istiskivanja šupljih Al-profila, koja uz pomoć računara omogućava analizu uticaja svih faktora procesa (geometrijskih, triboloških, reoloških, tehnoloških). Izvedena formula adekvatno uzima u obzir uticaje pomenutih faktora, u kvantitativnom i kvalitativnom smislu, što je potvrđeno eksperimentom, koji je realizovan u proizvodnim uslovima. S obzirom na primenjenu metodologiju proračuna, izvedena formula u izvornom obliku  se može upotrebiti i za proračun radnog pritiska istiskivanja šupljih profila od drugih materijala ( titana, titanovih legura i dr), ukoliko se radi o istovetnoj tehnologiji izrade profila.
Ključne reči: radni pritisak istiskivanja, šuplji profili, Al-legure, mostni alati.