Variable valve train for automotive petrol engine

U današnjem svijetu autoindustrije teži se ugradnji opreme koja osigurava bolje performanse motora (prvenstveno poboljšanje pogonskog momenta i snage koju motor razvija), a da ta oprema pri tome bude relativno jeftina, pouzdana i ponajviše kompaktna. Uz sve to, želja je smanjenje specifične potrošnje goriva koja je uvijek najveći dokaz isplativosti ugrađene instalacije i smanjenja emisije kojoj se uvijek teži. U ovom diplomskom radu prikazan je sustav varijabilnog pogona bregastih vratila usisa i ispuha koji se odnosi na fazni pomak. Izvedba Otto motora sa atmosferskim usisom na kojoj je navedeni sustav prikazan je slična izvedbi motora BMW M54B30, gdje su uspoređene performanse motora bez varijabilnog pogona s performansama motora s varijabilnim pogonom bregastih vratila. Za proračun i grafičku analizu navedenih izvedbi motora korišten je software Lotus Engine Simulation. Također, nakon usporedbe rezultata proračuna dan je osvrt na opravdanost ugradnje navedenog sustava koji je u današnjim automobilskim motorima sve češća pojava.In today's automotive industry it is tending to install the equipment which provides better performances (mainly meaning on improvent of torque and power that the engine develops), while being cheap, reliable and compact. It is also tendency to reduce the specific fuel consumption, which is always the best sign of profitability of built-in equipment, and also to reduce the emissions. In this final thesis it is shown the variable valve train which relates to cam phasing. The version of automotive petrol engine with atmosferic suction on which this variable valve train system is shown is similar to engine BMW M54B30. Performances of engine without cam phasing are compared with the performances of engine with cam phasing. For calculation and graphic analysis of this versions of engines is used software Lotus Engine Simulation. After comparison of the results it is given a review on the profitability of installation such of equipment which is in today's automotive engines becoming more often practice