Development Of Valve Train Powered By Electronic Hydraulic System And Using In Engine

From the 21st century, the sources of energy has been increasingly tension and environmental protection has become increasingly outstanding with the developing of automotive industry, people put forward even more strict requirement to enhance economy of engine fuel consume and reduce harmful emissions, and low energy consume and low pollution have been engine's develop objects. Because the valve system is an important part of the engine and its performance has much effect on the Internal Combustion Engine performance, so variable valve timing technology is becoming import research subject.VVT changed the status of the traditional engine's valve timing unchanged, and it can offer the best valve timing for engine's all work conditions. VVT solves the inconsistency between the power and economy at different speeds or different load, and it also can improve harmful emissions in a certain extent. Because VVT system can realize the adjustment of the valve timing, valve lift, valve open period according to the respective operation conditions in all work extension, it has been paid much attention by people, and VVT has developed to practical stage as the fast development of electronics technology. Along with the mature of technology, full variable valve timing system which is used now can synthetically control valve timing, valve lift, so it will replace the throttle in the future.Homogeneous Charge Compression Ignition (HCCI) is of a new combustion mode. In this combustion, the engine has high thermo efficiency corresponded with Diesel engines, it also has low level of fuel consume and harmful emissions. So HCCI has been the hot topic in the engine business too. The author find the internal EGR which using the remains exhaust gas to heat up the fresh mixture to achieve HCCI is the best measure via contrasting all kinds of plans. VVT system can vary the valve timing to make a part of exhaust gas remain in the cylinder. HCCI has some difficulties in controlling ignition timing and combustion rate. VVT can solve these problems via varying the valve timing, valve lift, valve open period, accordingly it can make combustion course perfectly, and it also can enlarge the work range.First of all, the author carried through the performance calibration test on the engine which was altered from ZS1105. Through this experiment, the angle of spark-advance, fuel injection pulse width can be confirmed and exhaust data also can be known. This work offered controlling gist and contrasting standard for the performance experiments of full variable valve timing system powered by electronic hydraulic system and HCCI combustion.The author improved the machine of full variable valve timing system powered by electronic hydraulic based on the problems which were found in previous work. The problems of leak, flow deficiency and valve return after arriving the maximum lift have been solved. Then the performance experiment on the improved machine was carried through. The result showed that the system could work persistently, all phenomena of problems were vanished, and the opening rate and valve open period of vale exceed the level of original machine.By further testing and computing, the delayed crank angle of electromagnetic valve when the vale was opening and closing at different speed were ascertained. The author gave the trigger instruction ahead according to the delayed time. So the opening and closing of the valve can be controlled accurately in this way.At last, according to the data of computing, the author made the exhaust valve close early and intake valve open late by varying the valve timing to achieve internal EGR in cylinder when the speed of engine was 1000r/min. The HCCI combustion test was carried out in this way. So the author got the load range, the data of fuel consumption and exhaust gas of HCCI at 1000r/min.It can prove that internal EGR can make HCCI, and all advantages of HCCI can be validated in this experiment. This result can lay the foundation for the HCCI experiments with exhaust residual and exhaust re induction in all conditions, and it also offer the validate gist for computing.