Design And Simulation Of The Electro-hydraulic Variable Valve Timing System

Traditional engine's cam valve timing through varied valve timingexperimentation, with considering other working condition and select one of themimmovable valve timing, which engine capability eclectic project. Because it'svalve timing is settled, and in which can not adjust during working condition.Therefore engine capability is difficult to be the best working condition undervaried machinery going. Owing to requirements of environmental protection andhuman beings' continual development. Low energy consumption and decreasepollution have been automotive engine's further direction. Engine is working underthe condition, which have both nicer motivity and low fuel consumption which tobe satisfied with the regulation of emission.Variable Valve Timing System can adjust one or several ones of parametervalve timing, valve opening duration and valve lift according to engine's workingcontinual condition, in order to better fuel consumption economical and bettermoment of wrest and characteristics of power, and enhance the stability of idlespeed, and reduce emission. The base of immovable configuration of cylinder headand reserving drive system of original machinery intake valve, the dissertation isabout project of Electro-Hydraulic variable valve timing, and then the device fix onthe engine at Shifeng195, which will replace the former exhaust valve drive device.Its main working content is bellow:1. Hydraulic pressure system design of Electro-Hydraulic variable valvetiming, and choose hydraulic pressure system parameter.2. Electro-Hydraulic variable valve timing actuator design.3. Control system hardware design.4. Control system software design.5. Experimental research is on actuator characteristics.6. Establish Electro-Hydraulic variable valve timing mathematic mold, andstimulant research is Matlab/simulink available.Draw a conclusion through analyzing actuator characteristics experimentalresearch:1. Reiteration of the actuator valve displacement profile is excellent,valve-opening position's maximal error is only 2 °CA.2. As varied engine speed, the actuator can open and close according toquondam one valve timing, opening speed and area of circulate section are obviousbetter than quondam engine.3. Changing drive pressure of hydraulic pressure system, and it can changevalve opening speed.4. The actuator can realize valve timing continual varied change.5. The actuator can realize valve lift continual varied change.Eventually the paper brings forward improving design for several deficienciesof Electro-Hydraulic variable valve timing.