1、 摘要 I 摘 要 发动机作为汽车的心脏，其制造质量直接影响着汽车的使用性能。缸体作发动机各机构及各系统的装配基础零件，其制造精度对发动机的整体性能有着重要的影响。要提高发动机的使用性能，就必须控制发动机制造过程中关键零件的加工精度与加工质量。 随着我国经济的发展，国内对汽车的需求迅速增长，如何提高汽车产品零部件的生产效率和加工质量，对汽车行业的发展至关重要。发动机缸体是汽车五大部件之一，其生产效率和加工质量直接关系到汽车的生产效率和性能。发动机缸体传统的提高生产效率和加工质量的途径是尽量缩短辅助时间和采用刚性生产线， 这种途径在今天已经越来越不适应生产的发展。因此，在汽车行业中，如何提高发动
2、机缸体生产效率和加工质量是一项重要的研究课题。 本论文主要针对发动机下缸体及加工工艺 OP10 进行了研究，对本工序设计工艺方案进行了分析， 发动机缸体属于箱体类零件，结构复杂，加工易变形，因此加工精度要求高， 以缸体缸孔壁、曲轴孔等毛坯基准点为定位基准， 对缸体进行精确定位。 由于缸体各个结合面面积较大，且有较高的位置精度和粗糙度的要求；缸体的加工部位多、加工要求较高、工艺路线长、工件输送较难处理、使生产管理上较繁杂，对缸体进行加工时 采用卧式加工中心进行加工，采用卧式数控加工中心不仅能够改善加工质量而且能够极大提高加工效率。论文主要对 OP10工序加工中心加工时刀具进行了合理选择，夹具进行
3、了设计并对夹紧力进行了计算。 关键词 发动机缸体；定位基准；加工精度；加工中心 Abstract II Abstract The quality of the engines manufacturing influenced the performance of the car, as the engine is the heart of the motor vehicles. The accuracy of the manufacturing of the engine block has an important relationship with the overall performa
4、nce, because the engine block is the fundamental part in the system of the engine. We have to control the machining accuracy and machining quality. With the development of our economy and rapidly growing demand for cars in China, how to improve the production efficiency and processing quality of aut
5、o parts, is crucial to the development of automobile industry. Engine cylinder block is one of the five major parts, and its production efficiency and processing quality are directly related to production efficiency and performance of the car. The traditional method to improve production efficiency
6、and processing quality is trying to shorten the auxiliary time and adopt the way of a rigid line, which is already out of date in the current production. Therefore, how to improve the efficiency of engine cylinder block production and processing quality is an important research, and the WD615 engine
7、 used in heavy vehicles, including all kinds of engineering machinery, buses, power generation equipment, ships and other ideal power of engine, its cylinder processing design has greater significance. In this paper, we focus on the first step of the process and made research on the process. The eng
8、ine block belongs to the block pieces, which is complicated in structure and easy to be deformed. We could adopt crankshaft bore as the positioning datum to ensure the accuracy. As the junction surface has a big area and a high demand of the accuracy and roughness, including high amount of the machi
9、ning parts and high demand of the machining and the long routine of the processing, we have to adopt Horizontal machining center to improve the machining quality and efficiency. The task of the paper is mainly about the reasonable choice on the machining tools and calculation on the fixtures. Keyword: Engine cylinder Positioning reference Machining accuracy Machining center
