摘要
为实现某发动机小型化、轻量化的目标,将自然吸气4缸汽油机改造成3缸汽油机,应用倒拖法分别进行发动机在节气门全闭和全开状态下的摩擦功对比试验。试验结果表明,节气门全闭时3缸汽油机的摩擦压力损失(pmm)值均比4缸汽油机大45%左右,节气门全开时则大30%左右。为了分析3缸发动机摩擦功变大的原因,应用理论和经验公式相结合的方法对汽油机的摩擦功进行估算,分析结果表明,改造后3缸机摩擦功增大的主要原因是存在进排气空挡致使泵气损失增大,其内部摩擦损失则变化很小。
To achieve the engine downsizing and lightweight, a 4-cylinder naturally aspirated gasoline engine was modified to a 3-cylinders naturally aspirated engine, and the p~ （Friction Mean Effective Pressure）comparison experiments with full close and full open throttle were carried out. The experiment result showed that the Prom Of the 3-cylinder gasoline engine was about 45% and 30~ larger than that of the 4-cylinder gasoline engine in full close and full open throttle respectively. In order to ana- lyze the reason, the Pm~ of gasoline engine was estimated with the theoretical and empirical formulas. The result showed that the main reason of Prom increase in the 3-cylinder gasoline engine was the resulting pumping loss increase by the intake/exhaust neutral, but the actual interior friction loss between them was almost the same.
出处
《车用发动机》
北大核心
2013年第2期10-13,共4页
Vehicle Engine
关键词
汽油机
摩擦功
对比试验
摩擦损失
泵气损失
gasoline engine
friction mean effective pressure
comparison experiment
friction loss
pumping loss
