钻扩铰连杆螺栓孔夹具设计说明书

课程设计说明书机床夹具设计钻、扩、铰连杆大头孔与连杆盖的螺栓孔夹具指导教师学院名称工程学院专业及班级机械设计制造及其自动化1班提交日期答辩日期月I【摘要】连杆是发动机的主要传动件之一，本文主要论述了连杆的加工工艺及其中一个加工环节的夹具设计。通过计算连杆的尺寸精度、形状精度以及位置精度，选择合适的夹具方案，设计出能保证加工精度的专用夹具。【关键词】连杆加工工艺夹具设计II目录1序言····································································12零件设计具体内容·························································12.1零件的作用·····························································12.2零件的工艺性分析······················································12.2.1大、小头孔的尺寸精度、形状精度······································12.2.2大、小头孔轴心线在两个方向的平行度···································22.2.3大、小头孔中心距·····················································22.2.4大头孔两端面对大头孔中心线的垂直度···································22.2.5大、小头孔两端面的技术要求···········································22.2.6螺栓孔的技术要求·····················································22.2.7有关结合面的技术要求·················································22.3零件工艺路线的制定·····················································32.4确定工序的加工余量、工序尺寸及公差·····································72.4.1大头孔端面加工余量···················································72.4.2大头孔外圆加工余量···················································72.4.3小头孔端面加工余量···················································82.4.4连杆体结合面加工余量·················································82.4.5螺栓座端面加工余量···················································82.4.6小头孔加工余量·······················································92.4.7大头孔加工余量·······················································92.4.8螺栓孔加工余量·······················································92.5确定切削用及基本工时··················································102.5.1粗铣大小头孔两端面··················································102.5.2粗磨大头孔两端面····················································102.5.3精磨大头孔两端面····················································112.5.4粗铣大头孔两侧面····················································112.5.5粗车大头孔外圆表面··················································112.5.6钻小头孔····························································122.5.7扩小头孔····························································12III2.5.8铰小头孔····························································122.5.9粗镗大头孔··························································132.5.10铣断杆盖···························································132.5.11粗铣连杆体结合面···················································132.5.12精铣连杆体结合面···················································142.5.13精磨连杆体结合面···················································142.5.14粗铣连杆体螺栓座端面···············································142.5.15半精铣连杆体螺栓座端面·············································142.5.16钻螺栓孔孔·························································152.5.17扩螺栓孔···························································152.5.18铰螺栓孔···························································152.5.19粗铣小头孔两端面···················································162.5.20半精镗大头孔·······················································162.5.21精镗大头孔·························································162.5.22粗铣通油槽·························································162.5.23粗铣轴瓦槽·························································173钻、扩、铰螺栓孔夹具设计·················································173.1问题的提出····························································173.2夹具结构方案的确定····················································173.2.1定位基准与定位元件的选择············································173.2.2刀具导向装置的确定··················································183.2.3夹紧机构的确定······················································183.2.4其它装置和夹具体确定················································203.3定位误差分析计算······················································203.4夹具操作介绍··························································213.5设计主要优缺点························································21参考文献··································································2211序言机床夹具设计是学习完机械制造工艺学后的实践设计。这是我们机制专业在毕业设计之前最后一次对所有所学的课程知识的综合性应用；也是一次深入的整合性复习；同时还是一次理论与实践联系起来的训练。因此，机床夹具设计对于我们机制专业是十分重要的。连杆是发动机的主要零件之一，它连接活塞和曲轴。连杆属于典型的“杂件”类零件，不但精度要求高，形状十分复杂，制造难度大，而且一次生产批量较大，直接影响发动机质量。本篇论文详细介绍了连杆的加工方法的拟定与确立，并对加工中对钻、扩、铰连杆大头孔与连杆盖的螺栓孔工序所采用的专业夹具进行设计。从工艺与专用夹具的方向进行了一定的探讨。希望能通过这次的课程设计对自己未来从事的工作进行一次适应性训练。从中锻炼自己分析问题、解决问题的能力，为以后的工作打下良好的基础。2零件设计具体内容2.1零件的作用连杆是汽车发动机中的主要传动部件之一，作用是把活塞和曲轴联结起来，使活塞的往复直线运动变位曲柄的回转运动，以输出动力。它把作用于活塞顶面的膨胀的压力传递给给曲轴，又受曲轴的驱动而带动活塞压缩气缸中的气体，因此它承受着急剧变化的动载荷。连杆由连杆体及连杆盖两部分组成。连杆体及连杆盖上的大头孔用螺栓和螺母与驱逐装在一起。为了减少磨损和便于维修，连杆的大头孔内装有薄壁金属轴瓦。连杆盖和连杆体大头之间有一组垫片。连杆小头用活塞销与活塞连接。大头孔内压入青铜衬套，减少磨损，便于更换和维修。连杆杆身一般采用从大头到小头逐步变小的工字型截面形状。为了保证发动机运转均衡，同一发动机中各连杆的质量不能相差太大，因此，在连杆部件的大、小头两端设置了去不平衡质量的凸块，以便在称量后切除不平衡。2.2零件的工艺性分析连杆上需进行机械加工的主要表面为：大、小头孔及其两端面，连杆体与连杆盖的结合面及连杆螺栓定位孔等。连杆体和连杆盖切开后加工的是结合面和螺栓孔，而且螺栓孔是同时加工的；而两端面加工是之前就加工好的。2.2.1大、小头孔的尺寸精度、形状精度2为了使大头孔与轴瓦及曲轴、小头孔与活塞销能密切配合，减少冲击的不良影响和便于传热。大头孔公差等级为IT7，表面粗糙度Ra应为0.8m；大头孔的椭圆度和锥度公差为mm012.0。小头孔公差等级为IT8，表面粗糙粗Ra应,0.8m；小头孔的椭圆度和锥度公差为mm014.0。2.2.2大、小头孔轴心线在两个方向的平行度两孔轴心线在连杆轴线方向的平行度误差会使活塞在气缸中倾斜，从而造成气缸壁磨损不均匀，同时使曲轴的连杆轴颈产生边缘磨损，所以两孔轴心线在连杆