Study On Valuable Valve Actuation System For Internal Combustion Engine

With the rapid increase of internal combustion engine possession, continually rise in oil prices, the increasingly serious atmospheric pollution, wide attention was paid to how to effectively improve the efficiency and reduce the emissions of internal combustion engine. Variable valve technology can optimize the gas exchanging process of internal combustion engine in different rotating speed, and reduce its fuel consumption and emissions.According to mechanical structure and working principle, many different kinds of variable valve actuation systems at home and abroad in recent years were classified and compared. Electro-hydraulic variable valve systems were the most potential, but because their existing problems of these systems, whose typical supply device was common rail, made it much difficult to take into practice. According to the existing problems of the current variable valve actuation systems, this thesis designed a new cam-type oil-supplied electro-hydraulic valve actuation system. According to making full use of internal combustion engine cylinder number and ignition order, this thesis designed an unique supply mode, a connection mode and an actuation mode. Through the reasonable design of the opposite cam-plunger type oil-supplied device, interface selector, electro-hydraulic valve and valve actuator with throttle and damping hole, the system realized fully flexible variable valve events, simplified the structure, reduced the cost and expanded the scope of application of this system. Through the use of MATLAB/Simulink software, this thesis modeled and simulated working process of the electro-hydraulic valve actuation system. The simulation results presented that this system had superior performance in flexibility of variable valve events, suitability with high speed of internal combustion engine, valve seat cushion control, and so on. At present, the system had entered the preliminary experimental research stage.