밸브타이밍 변화에 대한 스파크점화 엔진의 운전 및 배출가스 특성

Abstract

Variable valve timing (VVT) is the effective ways to improve peak power and part load fuel consumption of SI engines. VVT system is a relatively simple, low cost and easy application, therefore it is very attractive to be adopted in the newly manufactured engine. The objective of this work was to investigate the effects of intake and exhaust valve timings on engine operating parameters and exhaust emissions using a 4-cylinder in-line gasoline-fueled engine with VVT. Various Intake and exhaust valve timing data were measured and analyzed. Their correlations with each valve timing effect were also investigated in low and middle engine speed and load. The experimental results indicate that the pumping work, NOx emissions were reduced, while improvements in fuel economy and performance were achieved.