机械5

拖拉机Ⅱ—Ⅲ档拨叉零件的加工工艺及夹具设计 摘要 本次设计内容涉及了机械制造工艺及机床夹具设计、金属切削机床、公差配合与测量等多方面的知识。 拨叉铣宽7拨叉脚的夹具设计是包括零件加工的工艺设计、工序设计以及专用夹具的设计三部分。在工艺设计中要首先对零件进行分析，了解零件的工艺再设计出毛坯的结构，并选择好零件的加工基准，设计出零件的工艺路线；接着对零件各个工步的工序进行尺寸计算，关键是决定出各个工序的工艺装备及切削用量；然后进行专用夹具的设计，选择设计出夹具的各个组成部件，如定位元件、夹紧元件、引导元件、夹具体与机床的连接部件以及其它部件；计算出夹具定位时产生的定位误差，分析夹具结构的合理性与不足之处，并在以后设计中注意改进。 关键词：工艺、工序、切削用量、夹紧、定位、误差。 Fork Tech
nologya
nd Fixture Desig
n of the TractorⅡ-Ⅲgear shifti
ng fork Abstract The desig
n co
nte
nt i
nvolves the mecha
nical ma
nufacturi
ng process a
nd fixture desig
n,metal cutti
ng machi
ne,tolera
nce a
nd measureme
nt a
nd other aspects of k
nowledge. The fixture desig
n of fork milli
ngwidth 7 fork foot i
ncludes three parts: process desig
n,process desig
n a
nd special fixture desig
n.I
n the process desig
n,we should first a
nalyze the parts,u
ndersta
nd the process of the parts,the
n desig
n the structure of the bla
nk,select the processi
ng be
nchmark of the parts,a
nd desig
n the process route of the parts; the
n calculate the size of each step of the parts,the keyis to determi
ne the process equipme
nt a
nd cutti
ng parameters of each process; the
n desig
n the special fixture,a
nd select the fixture The compo
ne
nts of the fixture,such as positio
ni
ng eleme
nt,clampi
ng eleme
nt,guidi
ng eleme
nt,co
n
necti
ng part betwee
n the fixture a
nd the machi
ne tool a
nd other compo
ne
nts,are a
nalyzed,a
nd the positio
ni
ng error of the fixture is calculated,a
nd the ratio
nalitya
nd shortcomi
ngs of the fixture structure are a
nalyzed,a
nd the improveme
nt should be paid atte
ntio
n to i
n the future desig
n. Keywords: process,process,cutti
ng parameters,clampi
ng,positio
ni
ng,error. 目录 摘要1 Abstract 2 序言4 第一章零件的分析5 1.1零件的作用5 1.2零件的工艺分析5 第二章工艺规程设计6 2.1确定毛坯的制造形式6 2.2基面的选择的选择7 2.3制定工艺路线8 2.4机械加工余量、工序尺寸及毛坯尺寸的确定9 2.5确定切削用量及基本工时10 第三章铣拨叉脚的两个端面的夹具设计17 3.1问题的提出17 3.2定位基准的选择17 3.3切削力及夹紧力计算17 3.4定位误差分析19 3.5定向键与对刀装置设计20 3.6夹具设计及操作简要说明21 总结25 致谢26 参考文献27