作者曾研究了改善理论和实际热效率的方法,并对有关因素作了分析。结果表明,理论热效率得到大的改善主要靠提高最高燃烧压力P_(max)。 P_(max)增加,发动机零部件承受的负荷也将相应增大,尤其是燃烧室周围一些零部件,如同时承受热负荷和机械负荷的活塞、气缸盖,将比过去经受更高的温度和压力,这就必须更进一步提高强度。显然在设计阶段要预测可靠性和耐久性是非常困难的。但作者还是建立了一套籍助有限元分析和其它测量的有效评价方法。作者还阐明了活塞、气缸盖和连杆这些主要零部件的设计要点,并提出了一些设计方法。此外,还建立了一套评价方法和负荷循环规范,供耐久试验和鉴定考核用。 The authors have studied ways to improve both theoretical and practical thermal efficiency and have analyzed the relevant factors. The results show that the theoretical improvement of thermal efficiency is mainly by increasing the maximum combustion pressure P max. As P_ (max) increases, the load on engine components will also increase accordingly. In particular, some components around the combustion chamber, such as pistons and cylinder heads that withstand both thermal and mechanical loads, will experience higher temperatures and Pressure, which must be further increased strength. Obviously in the design stage to predict the reliability and durability is very difficult. However, the author has also established a set of effective evaluation methods that support finite element analysis and other measurements. The author also clarified the main points of the design of piston, cylinder head and connecting rod, and proposed some design methods. In addition, a set of evaluation methods and load cycle specifications have also been established for endurance testing and qualification testing.