Comparison of deep hole drilling processes on universal and dedicated drilling machines

Globoko vrtanje pravimo vrtanju z visokim razmerjem dolžine in premera izvrtine. Pri globokem vrtanju z vijačnimi svedri nastajajo težave s tolerancami in centričnostjo izvrtin. Z napredkom tehnologije lahko dosegamo velike globine izvrtin pri manjših premerih, v krajših časih. Namenski stroji omogočajo boljšo kakovost in bolj centrične izvrtine. Slabost namenskih strojev je visoka cena. Z izračunom stroška strojne ure smo ugotovili, da je strošek strojne ure pri namenskem stroju 30 % višji, kot pri univerzalnem stroju. Sklepamo, da bi bili rezultati bolj reprezentativni, če bi obravnavali kos z več kot eno izvrtino.Deep drilling is drilling of bores with high depth to diameter ratio. Deep drilling with twist drills is problematic because of excentric bores. The advancement of technology has made it possible to achieve large depths of bores at smaller diameters and in shorter times. Dedicated machines make it possible to drill more centric bores with higher quality. Downside of dedicated machines is high cost. We calculated machine hour rate and found out, dedicated machine hour rate is 30% higher. We conclude, the results would be more representative, if we dealt with piece with more than one bore