4缸连杆发动机正文c.doc

摘 要 连杆是运动的主要关键件之一，它工作的稳定性、可靠性对机的整机 ABSTRACT The connecting rod is one of important part in diesel engine，the stability and reliability of it are very important to machine quality of diesel engine，the light quality and high precision of connecting rod，is helpful to reduce energy consumption and the noise of diesel engine． The connecting rod is one of the main driving medium of diesel engine, this text expounds mainly the machining technology and the design of clamping device of the connecting rod。The paper analyzed how to reasonable choice benchmark of processing；and how to determine the direction and point of clamping force；and how to reasonably choose various spots processing way and the technical process of connecting rod；and to give the definite method of various processes machining allowance；and to important analyses the primary cause of influence connecting rod working accuracy．The precision of size, the precision of profile and the precision of position , of the connecting rod is demanded highly , and the rigidity of the connecting rod is not enough, easy to deform, so arranging the craft course, need to separate the each main and superficial thick finish machining process. Reduce the function of processing the surplus, cutting force and internal stress progressively, can reach the specification requirement for the part finally. Keywords：Connecting rod; Processing technology；Deformation; Design of clamping device目 录 1 绪论 1 2 发动机工作原理 1 3 发动机连杆工艺设计 3 3.1 发动机连杆结构特点分析 3 3.2 连杆的主要工艺技术要求 4 3.3 连杆的材料及毛坯 5 3.4 发动机连杆的机械加工概况 6 3.5 发动机连杆加工工艺规程设计 7 3.6 连杆加工工艺设计分析 11 3.7 切削用量的选择原则 12 3.8 确定各工序的加工余量、计算工序尺寸及公差 14 3.9 工时定额的计算 16 3.10 发动机连杆检测 29 4 铣剖分面夹具设计 31 4.1 设计分析 31 4.2 夹具体设计 31 4.3 切削力及夹紧力的计算 32 4.4 定位误差分析 33 5 总结 35 参 考 文 献 37 致 谢 38 1 绪论 汽车整体技术发展日新月异,而作为汽车的心脏—发动机技术的进步显得更受关注。连杆作为发动机重要的传动部件，它的制造技术的发展显得尤为重要。 在加工工艺方面国内外连杆生产方式大致有：锻造、铸造、粉末冶金等，传统锻造有将连杆体和盖分开锻造、连杆体和盖整体锻造两种。60年代中期粉末热锻技术开始发展起来，从80年代以来粉末冶金注射成型（PIM）(或用机械方法或用激光束制造预裂纹) 断裂,使大端连杆盖从连杆体移去。国内汽车厂及设备制造厂一汽- 大众、上海大众