发动机全可变液压气门机构进气性能的研究

Study on Intake Performance of SI Engine with Fully Variable Valve Hydraulic Actuation System

在全可变液压气门机构中,通过设置在配气凸轮与进气门之间的液压气门驱动机构驱使进气门开启,用泄油控制机构释放液压系统中的油压使进气门关闭。通过模拟计算分析了该液压气门机构中气门运动规律的主要特征,计算结果表明这种液压气门机构可通过改变泄油初始相位角实现进气门最大升程和进气迟闭角的连续可变。新研制了具有全可变液压气门机构的发动机样机,并试验测量了样机的进气性能。试验结果表明,这种全可变液压气门机构能够控制发动机气缸内的进气量。这对于降低发动机泵气损失、研制无节气门汽油机是十分必要的。

In the fully variable hydraulic valve actuation system, the intake valve is opened by the hy- draulic valve actuator which is set between the camshaft and the intake valve, and it is closed by the re- liever which could relieve the oil pressure of the hydraulic system. Main characteristics of valve movement are simulated. The calculation results show that the hydraulic valve actuation system can realize continu- ously variable valve lift and the early intake valve closing by changing the time of relieving oil pressure. A prototype engine with fully variable hydraulic valve mechanism was developed, and its intake performance was measured. Experimental results show that the intake efficiency of the prototype engine is controlled by the fully variable hydraulic valve mechanism. This is necessity to decrease the pumping loss and develop an un-throttled SI engine.