【摘要】 设计一种全可变液压气门机构(fully hydraulic variable valve system,FHVVS),实现气门最大升程、开启持续角和配气相位的连续可变,通过进气门早关方式取代传统节气门来控制发动机的负荷。试验结果表明:与传统节气门汽油机相比,无节气门汽油机可以显著降低中小负荷工况下的平均泵气损失压力,大幅度降低泵气损失、提高机械效率。在小于等于50%负荷工况点,发动机转速为2000 r/min时无节气门汽油机的机械效率可以提高3. 6%～10. 2%,3000 r/min时机械效率可以提高2. 8%～7. 1%。更多还原

【Abstract】 Fully hydraulic variable valve system( FHVVS) is desighed to achieve continuous variation of the maximum valve lift,valve opening duration and valve timing. The gasoline engine with FHVVS can control engine load by means of the early intake valve closing( EIVC) strategy instead of traditional throttle.Expermental results show that the pumping mean effective pressure( PMEP) of unthrottled gasoline engine at low to medium load is greatly reduced and the mechanical efficiency is improved significantly compared with the throttled gasoline engine. The mechanical efficiency of unthrottled gasoline engine improves 3. 6% ～ 10. 2% under load conditions less than or equal to 50% at 2000 r/min engine speed and improves 2. 8% ～ 7. 1% at 3000 r/min.更多还原