Research On Electronics-Hydraulic Driving Of Variable Valve System

Accompanying with the gradually stricting of emission control regulations and the increasingly scarce of the world's energy, efficient, economical and environment protection become predominant direction of the I.C. engine technique's development .And the rapidly developing of the computer's software and hardware technic, it makes the electronic technique be widely used on the supervision system of engine .The electrical controlled injection fuel technique, STC(sequential turbocharging compression) technique and variable turbo nozzle technique etc. are successfully applied on engine, these consumedly improved its performance .But the traditional I.C. engine's disadvantage working together with the fixed constant valve phase is increasingly outstand, throwing off camshaft and its accessorial parts, fulfilling valve opening timing, opening continuance time and valve lift's variable. This type whole variable valve technique is more present its importance.Electronics-hydraulic driving variable valve system ,as a promising camless valve train ,depending on it can completely eliminate the cam-crank shaft mechanical linkage, allowing for a wide continuously variable valve timing, opening continuance time and valve lift .Through the use of variable valve timing(VVT), engine operation can be optimized in fuel economy, performance and emissions .Abroad, vast researches have been made in the area of electronics—hydraulic pressure driving variable valve system at structure design and control strategies ,but still being continuing due to some problems to deal with. It is far away from production.This paper based on the cultural heritage of the design and development experience from domestic to international at the variable valve system, combined my school's research result of the electronic control valve system,model analysis, simulating design and experiment research are combined together in research process .Aiming to 200 type diesel engines valve system, developed a set of single function, spring restoration, electronics-hydraulic driving variable valve system, and experience be done on the test-bed of the diesel engine electronics—hydraulic driving control system ,which is researched and manufactured by ourself. And according to work movement condition characteristics of 200 type diesel engine, analysing this variable valve system's controllable, obtaining some results. But some problems also be discovered, for example, corresponding to different rotate speed, controlling of valve lap over angle.Because the proper respond characteristic of electricity- liquid drive valve system, makes the open speed of inlet valve and close speed of exhaust valve are more difficult to solve from the aspect of the common rail pressure and timing control, so I did some improvement at system design towards originally system, but be limited by time, I can stay to do further research and developments for future only.