1 引言 一般而言,装用于中、重型商用汽车的柴油发动机,其生命周期要比轿车发动机的长,并且产量也比后者的低很多。因此,用于其加工和装配的生产设备的投资需要较长的时间才能收回成本。基于这些原因的考虑,商用车柴油机全新的换代产品并不多见和常见。但是,这并不意味着这类发动机不需要经常的改进和一步发展。正好相反, 1 Introduction Generally speaking, diesel engines used in medium- and heavy-duty commercial vehicles have a longer life cycle than a car engine and have a much lower output than the latter. As a result, investment in manufacturing equipment for its processing and assembly takes longer to recover. Based on these considerations, the new generation of commercial diesel engine replacement products are rare and common. However, this does not mean that such engines do not require constant improvement and further development. exactly the opposite,