新型发动机连续可变气门装置原理及分析

The principle and analysis of a new continuously variable valve train for SI engine

为了适应发动机不同工况对进气系统的要求,提出一种新型连续可变气门装置的原理及实现方法。新装置以液压作为驱动进气门运动的动力,其特色在于采用可控转角的调相凸轮调控进气门的相位、采用可控升程的气门升程调节器调控进气门的升程,据此实现发动机配气相位及气门升程的连续无级可变。对一台采纳新型配气机构的摩托车发动机进行了数学建模及仿真分析,结果表明:发动机进气迟闭角(IVC)的调节范围可达16～44℃A,进气早开角(IVO)的调节范围可达8～14℃A,进气门升程h调节范围可达0～7.825 mm,由此将配气机构的最佳适应范围拓宽至常用工况区域,从而有利于改善摩托车在中小负荷和中低转速区的性能,并为研制无节气门汽油机奠定了设计基础。

The principle and realization of a new continuously variable valve train is proposed to meet the requirement of air intake of SI engine（spark-ignition engine） at various operation loads.The intake valve is driven by hydraulic actuation,where a phase-modulated camshaft and an adjustable valve lift controller are used for controlling its timing angle and lift,respectively.Hence the valve timing and lift are infinitely variable within the working range.A mathematical model of the train for motorcycle engine was built for simulation.The results showed that the range of adjustable intake valve closing（IVC） and intake valve opening（IVO） were 16~44 ℃ A and 8~14 ℃ A,respectively,and for the valve lift,0~7.825 mm.The optimized engine operation range was hereby expanded and the engine performance at mid and low load/speed can be improved.This study results can also be further applied for the design of throttle-free motorcycle engine.