The Application Of Variable Valve Timing Technology On Gasoline Engine

As a high cost performance solution, Variable Valve Timing (VVT) is used widely in gasoline engine these years, in order to improve either peak power and low end torque, or part load fuel consumption, or be faced with the problem of minimizing vehicles environmental impact as the regulations becomes stricter. Along with the cost become lower and the more perfect application, the VVT technology is also widely used in economy vehicles especially recent years.This paper describes a research activity, concerning applying VVT system on an existed engine, which is a 1.3L DA471QA MPI engine from Dongan company. The main research activity include: focus on Continually Variable Valve Timing (CVVT). By collecting a lot of material used in this paper concerning VVT technology, which can be found inland or overseas, and studying some VVT engine sample, the layout of different VVT system is be studied, and make a design on applying VVT system. By using the AVL BOOST simulation software to calculate and analyze factors to effect engine performance, the engine performance which is improved by changing valve timing and intake manifold length is studied.The validation was performed on a demonstration engine which simulates VVT system in engine rig test. The engine peak power can reach up to 61.8 kw, improved 4% compared to MPI engine, engine low end torque is also improved obviously. The result has basically achieved the target which is peak power 62kw with keeping low end torque.This paper gave a basic VVT layout by studying to apply CVVT on an existed DOHC engine, meanwhile analyze theoretically, the research activity is well consulting worth as a base idea for the other engine applying VVT system.