1、 I 摘 要 曲轴是汽车发动机的重要零件。它的作用是把活塞的往复直线运动变成传动轴的旋转运动，将 作用在活塞的气体压力变成扭矩，用来驱动工作机械和发动机各辅助系统进行工作。曲轴在工作时 承受着不断变化的压力、 惯性力和它们的力矩作用， 因此要求曲轴具有强度高、 刚度大、 耐磨性好， 轴颈表面加工的尺寸精确，且润滑可靠。 本设计是根据被加工曲轴的技术要求，进行机械工艺规程的设计，然后运用夹具设计基本原理 和方法，拟定夹具设计方案，完成夹具结构设计。主要工作有：绘制产品零件图，了解零件结构特 点和技术要求；根据生产类型和所在企业生产条件，对零件进行结构分析及工艺分析；确定毛坯种 类及制造方法；拟定
2、零件机械加工工艺过程，确定各工序的加工余量与工序尺寸；机械加工工序卡 片；设计指定的专用夹具，绘制装配总图和主要零件图。 本次设计主要是为了提高曲轴零件的生产效率，以及加工精度。因此，制定工艺路线时严格按 照基准先行，先主后次，先粗后精，先面后孔的工艺设计准则。先加工出基准，再用精基准定位加 工其它工序。在夹具设计时，选择的是卧加两端加工的工序，加工时选择两个 V 形块支撑和轴向定 位块定位，用压板夹紧，并且在夹具上设置合适的行程距离方便产品换型。 通过本次设计我查阅了许多书籍和行业资料，了解到行业的发展进程和部分先进技术，扩展了 我的专业视野，为将来的学习生活都有着重要的影响。 关键词关键词
3、：机械制造，加工工艺，曲轴，夹具 II ABSTRACTABSTRACT Crankshaft is a very important parts of diesel engine. Ist action is change the to and fro straight-line motion of the piston into rotary motion,and change the gas pressure on the piston into torque, that is used to drive executive body and accessory system of th
4、e diesel engine. Crankshaft is withstanding the changing pressure, inertia force and the torque. So the crankshaft mast have high strength, high rigidity, high abrasion resistance and the surface of axle journal must have high precision with well lubricating. This design according to the required pr
5、ocessing crankshaft technology, design of mechanical process, and then using the basic principle and method of fixture design, fixture design scheme, completed the design of fixture structure. The main work is: drawing parts drawing, understand the structure feature of parts and technology; accordin
6、g to the production and the production conditions, analysis of structural analysis and process on parts; determine the blank type and manufacturing method; develop parts machining process, determine the machining allowance and process dimensions of each process; machining process card the specified; special fixture design, drawing assembly drawing and parts drawing. This design is mainly in order to improve the production efficiency and the crankshaft parts, machining precision. Therefore, the
