To boost fuel efficiency more diesel engines are popping up, as well as improved four-cylinder engines.
为了提高燃料效率，更多的柴油发动机和改良的四缸发动机应运而生。
2
This paper introduces the process of repairing hydraulic cylinder by using boring and rolling combined working technology, working quantity is steady and production efficiency is high in this method.
介绍了用镗滚压复合加工技术修复液压缸筒的过程，此法修复缸筒质量稳定，生产效率高。
3
Cylinder rigid wake model has been adopted and the approximate treat in high efficiency. The results carried out for examples shows good agreement with experiments value.