机械5

摘要 本设计是CA6140杠杆零件的加工工艺规程及一些工序的专用夹具设计。CA6140杠杆零件的主要加工表面是平面及孔。一般来说，保证平面的加工精度要比保证孔的加工精度容易。因此，本设计遵循先面后孔的原则。并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孔的加工精度。基准的选择以杠杆外圆面作为粗基准，以孔及其下表面作为精基准。先将底面加工出来，然后作为定位基准，在以底面作为精基准加工孔。整个加工过程选用组合机床。在夹具方面选用专用夹具。考虑到零件的结构尺寸简单，夹紧方式多采用手动夹紧，夹紧简单，机构设计简单，且能满足设计要求。 关键词杠杆零件，加工工艺，夹具，定位，夹紧 ABSTRACT This paper is to desig
n the craft processes of maki
ng the CA6140 lever spare parts a
nd some specialized to
ngs i
n the process. The CA6140 lever spare part primarily processes the surface a
nd bores. Ge
nerally speaki
ng, to guara
ntee the accuracy of the flat surface process is easier tha
n that of the bore. Therefore, this desig
n follows the pri
nciple that surface first a
nd the
n the bore, a
nd defi
nitely divides the process of flat surface a
nd bore i
nto coarse processes a
nd precise processes to guara
ntee the bore processes. The basic choice is to co
nsider 45 outside circle as rough basis a
nd to co
nsider 25 bore a
nd its
next surface as precise basis. The bottom is first processed out to be fixed positio
n basis, a
nd process the bore usi
ng the bottom as the precise basis. The whole processes choose the machi
ne bed. I
n the aspects of to
ngs choosi
ng, specialized to
ngs are used. I
n co
nsideratio
n of the simple co
nstructio
n size of the spare parts, clippi
ng by ha
nds is adopted. It is simple, a
nd the orga
nizatio
n desig
n is simple, a
nd ca
n satisfy the desig
n request. Key Words Lever spare parts, craft proces , to
ngs, fixed positio
n, tight clip 目录 摘要I ABSTRACT II 1绪论1 1.1课题背景及发展趋势1 1.2夹具的基本结构及夹具设计的内容1 2杠杆加工工艺规程设计3 2.1零件的分析3 2.1.1零件的作用3 2.1.2零件的工艺分析3 2.2杠杆加工的主要问题和工艺过程设计所应采取的相应措施4 2.2.1确定毛坯的制造形式4 2.2.2基面的选择4 2.2.3确定工艺路线4 2.2.4机械加工余量、工序尺寸及毛坯尺寸的确定6 2.2.5确定切削用量6 2.2.6确定基本工时18 2.3小结23 3钻Φ25孔专用夹具设计24 3.1问题的提出24 3.2定位基准的选择24 3.3切削力的计算与夹紧力分析24 3.4夹紧元件及动力装置确定25 3.5钻套、衬套、钻模板及夹具体设计26 3.6夹具精度分析28 3.7夹具设计及操作的简要说明28 4总结29 参考文献30 致谢31