Model And Performance Studies Of Fully Flexible Electro-hydraulic Valve Actuators On Diesel Engine

Traditional driver system of engine valve used to control the intake valves and exhaust valves by mechanical cam. But for the cam profile is fixed, as is to say its valve lift, valve timing and other valve motion parameters are all fixed, which can’t be adjusted during the engine running process. Usually they can only ensure optimization performance of the engine in a specific working condition. To change the engine valve timing and valve lift plays an important role on increasing thermal efficiency and decreasing harmful emissions. At present,by changing the cam profile or changing the cam phrase angle, the variable valve mechanism for applying can only be optimized in certain working conditions, without meeting the real-time process controlling requirements. Therefore the valve actuation system has these deficiencies which makes engine performance can’t achieve optimization in every working conditions.This paper designs a fully flexible electro-hydraulic valve actuator. Based on the optimal pneumatic theory inside of the cylinder, this paper calculates the maximum air charger at different working speed for 4102 engine, get the optimal valve motion parameters at each case,and analysis the influence of valve motion parameters on engine performance. Based on the result above to matching design valve motion mechanisms on Engine CY4102BG. The designed fully flexible electro-hydraulic valve actuator keeps the valve and the spring of the original engine and cancels the camshaft, push rod, rocker arm of the original engine.The valve actuation mechanism fixed in the cylinder head replace the original one in the Engine CY4102BG This designed fully flexible electro-hydraulic valve actuator can control valve phrase, valve lift ,valve timing and some other valve motion parameters, which improves the performance of the engine very well. Meanwhile this specially designed buffer orifige can control the valve seating speed effectively which decreases vibration and noise during the valve moving down towards process. The internal feedback system forms a self-locking in its entire unit, with simple external controlling movement apartment to get more accurate and efficient outcome.Based on AMEsim simulation environment, this study builds a mechanic electric hydraulic model for the fully flexible electro-hydraulic valve actuator, which can do simulation analysis for the driving performance of the fully variable air charger, Simulation results show that the designed fully flexible electro-hydraulic valve actuator completely meet the requirements of the valve fully variable. At last, this study finishes electro hydraulic valve actuator, completes the design of actuation controller and then depending on the experiment platform of the 4102 engine, sets single cylinder intake driving test device for doing single cylinder driving research, the results show that the valve actuator driven by the control signal is given, can effectively achieve the valve motion parameters fully variable and assistance for the valve motion performance experiment of diesel engine.