Experimental Research on the Opening and Closing Characteristics of Intake Valve for Diesel Engine

The test bench of the electro-hydraulic late intake valve closing (EHLIVC) mechanism was built after the new EHLIVC mechanism was developed based on DK4A diesel engine. The effects of oil pressure and control pulse on the opening and closing characteristics of EHLIVC were investigated. Results indicate that the oil pressure has little influence on the closing action time of the additional lift, but it has obvious influence on the opening action time of the additional lift and the opening action time keep linearly decrease with the increase of the oil pressure. And the oil pressure has little effect on the opening delay of the additional, but it has significantly influence on the closing delay of the additional and the closing delay decreased with the increase of the oil pressure. When the oil pressure beyond 4.5MPa, the closing delay keep constant. In contrast, the control pulse has no effect on both the opening delay and closing delay. However, it has important impact on the opening duration of the additional lift and the opening duration time keep linearly increase trend with the increase of the control pulse.