问题柴油机的发展过去侧重于向提高输出功率的方向努力,现在则面临社会对降低噪声、减少排气和提高燃料经济性的额外要求。这些要求往往相矛盾,并常向活塞设计工作者提出一些困难的问题,同时活塞设计工作者也必须牢记提供长寿命部件的需求。从这些趋向来看,活塞顶是特别薄弱的,在运用及在各个研究阶段中,这一部位发生故障的柴油机数目越来越多。特别是在负荷迅速且规则变化的高速和中速柴 Problems Diesel engines, which have historically been focused on increasing output power, are now facing additional social demands to reduce noise, reduce emissions and increase fuel economy. These requirements are often contradictory and often pose some difficult problems for piston designers, and piston designers must also keep in mind the need to provide long-lived components. From these tendencies, the piston crown is particularly weak and there is an increasing number of diesel engines in use and at various stages of the breakdown. Especially in the rapid load and the rules of high-speed and medium-speed firewood