机械5

摘要 本次设计是车床变速箱中拔叉零件的加工工艺规程及一些工序的专用夹具设计。此拔叉零件的结构较为复杂，其加工的地方主要是孔和平面。本设计先加工孔后加工面。将孔与平面的加工明确划分成粗加工和精加工阶段以保证它们的加工精度。基准选择以拔叉Φ32外圆作为粗基准，来加工中间的通孔，然后以此加工过的孔作为精基准。主要加工工序安排是先以中心孔定位加工出顶平面和右侧平面以及下面的大孔的两平面，再以中心孔定位加工出下端的大孔。加工时是用镗床镗孔。最后以这两个孔为基准，分别加工右侧的槽和顶面的螺纹底孔。整个加工过程选用了钻床、铣床和镗床。工件在机床上定位夹紧选用专用夹具，夹紧方式为手动夹紧，夹紧可靠，操作方便。因此生产效率较高，适用于大批量、流水线上加工。能够满足设计要求。 关键词：加工工艺定位夹紧专用夹具 Abstract This desig
n is a lathe gearbox fork parts i
n machi
ni
ng process pla
n
ni
ng a
nd some special fixture desig
n process. This fork parts of the structure is relatively complex, the mai
n processi
ng place is a hole a
nd pla
ne. This desig
n first after hole machi
ni
ng surface. The hole a
nd the pla
ne processi
ng clearly divided i
nto rough machi
ni
ng a
nd fi
nish machi
ni
ng stage to e
nsure the machi
ni
ng accuracy of them. Be
nchmark choose to forkΦ 32 cyli
ndrical as crude be
nchmark, to processi
ng i
n the middle of the hole, a
nd the
n processed hole as fi
ne be
nchmark. Mai
n machi
ni
ng process arra
ngeme
nt is first to ce
nter hole positio
n ChuDi
ng pla
ne a
nd pla
ne o
n the right side a
nd the big hole u
nder two pla
ne, agai
nwith ce
nter hole positio
ni
ng processi
ng out of the bottom hole. Is usedwhe
n processi
ng bori
ng bori
ng. Fi
nally based o
n the two holes, o
ne tap processi
ng o
n the right side of the ta
nk a
nd the top surface. Keywords：processi
ng tech
nology positio
ni
ng clampi
ng special fixture 目录 1序言1 2零件的分析1 2.1零件的作用1 2.2零件的工艺分析2 2.3审查拨叉的工艺性3 2.4确定拨叉生产类型4 2.4.1中批量生产4 2.4.2中批量生产采用流水线工艺特点4 3工艺规程设计5 3.1确定毛坯的制造形式5 3.2基面的选择5 3.3制定工艺路线5 3.4机械加工余量、工序尺寸及毛皮尺寸的确定6 3.5确立切削用量及基本工时8 4夹具设计13 4.1问题的提出13 4.2夹具设计13 4.2.1定位基准的选择13 4.2.2切削力和夹紧力计算14 4.2.3定位误差分析15 4.2.4.夹具设计及操作的简要说明16 5小结16 参考文献18