为改善燃油消耗和降低排放,世界各国在汽油发动机和柴油发动机上都开发出不少新技术。 一、汽油发动机新技术 1.多气门技术 多气门结构是指发动机每缸具有2个以上的气门。目前,在国外汽油发动机上一般都采用每缸4气门(2个进气门和2个排气门)和5气门(3个进气门和2个排气门)。采用多气门结构可提高发动机充气效率,火花塞可 To improve fuel consumption and reduce emissions, many countries in the world have developed many new technologies on gasoline engines and diesel engines. First, the new gasoline engine technology 1. Multi-valve technology Multi-valve structure is the engine has more than two valves per cylinder. At present, four valves per cylinder (two intake valves and two exhaust valves) and five valves (three intake valves and two exhaust valves) are generally used on foreign gasoline engines. Multi-valve structure can improve the efficiency of the engine charge, spark plug can be