机械5

汽车拨叉加工工艺分析及铣削夹具设计 摘要 夹具是零件加工的夹紧装置，是加工零件的一种必不可少的装置。随着零件的尺寸变化，越来越多的夹具被淘汰了，因此，设计一套专用夹具是十分有必要的。在设计专用夹具时要考虑工件的定位方案，工件的夹紧方案和设计夹紧机构，夹具的其他组成部分，夹具的结构形式等。 本课题的主要研究内容是汽车拨叉加工工艺分析及铣削夹具设计。汽车拨叉位于传动轴的端部。其主要作用是传递扭矩，使变速器获得换挡的动力。该零件属于特殊形状零件，但复杂程度一般。由于拨叉在工作时需要承受冲击载荷，因此要求其有一定的强度和刚度。 结合零件加工的重点和难点，从零件的结构分析入手，合理的进行定位基准选择、夹具的设计、各种刀具参数选择以及切削用量的选择等。在安排工艺过程时，根据加工要求不同，需要进行粗精加工。另外还确定了切削参数，加工工时，填写工艺过程卡片和工序卡片。设计了一套铣16mm槽的铣床专用夹具。 关键词：汽车拨叉、加工工艺、16mm槽、铣床、专用夹具 Abstract Jig is the clampi
ng device for parts processi
ng,which is a
n esse
ntial device for processi
ng parts. With the cha
nge of the size of parts, more a
nd more fixtures are elimi
nated. Therefore, it is
necessary to desig
n a set of special fixtures. Whe
n desig
ni
ng the special fixture,we should co
nsider the positio
ni
ng scheme of theworkpiece, the clampi
ng scheme of theworkpiece a
nd the desig
n of the clampi
ng mecha
nism, other parts of the fixture, the structure of the fixture a
nd so o
n. The mai
n co
nte
nt of this subject is the a
nalysis of the processi
ng tech
nology of the automobile fork a
nd the desig
n of the milli
ng fixture. The fork is located at the e
nd of the tra
nsmissio
n shaft. Its mai
n fu
nctio
n is to tra
nsfer torque so that the tra
nsmissio
n ca
n get the power of shifti
ng. This part belo
ngs to special shape parts, but the complexity is ge
neral. Because the fork is subjected to impact loadwhe
nworki
ng, it requires certai
n stre
ngth a
nd rigidity. Combi
ni
ngwith the key a
nd difficult poi
nts of parts processi
ng, starti
ng from the structural a
nalysis of parts, reaso
nable selectio
n of positio
ni
ng datum, fixture desig
n,various tool parameters selectio
n a
nd cutti
ng parameters selectio
n. Whe
n arra
ngi
ng the tech
nological process, rough fi
nishi
ng is required accordi
ng to differe
nt processi
ng requireme
nts. I
n additio
n, cutti
ng parameters, machi
ni
ng hours, process process cards a
nd process cardswere determi
ned. A special fixture for milli
ng 16mm groove is desig
ned. Keywords: Automobile fork, processi
ng tech
nology, 16mm slot, milli
ng machi
ne, special fixture 目录 摘要I Abstract II 第一章绪论1 1.1机床夹具的概念1 1.2机床夹具的作用及组成1 1.3机床夹具的分类1 1.4机床夹具的研究现状2 1.5选题目的及其意义2 第二章零件的分析4 2.1零件的作用4 2.2零件的组成表面、加工要求、形位公差分析4 2.2.1零件的组成表面4 2.2.2零件的加工要求5 2.2.3零件的形位公差5 第三章零件的工艺规程设计6 3.1确定零件的生产类型及毛坯的制造形式6 3.1.1确定零件的生产类型6 3.1.2确定毛坯的制造形式6 3.2基准的选择与确定7 3.3加工工艺路线的确定8 3.4加工机床及加工装备的选择8 3.5确定加工余量9 3.6计算切削用量、基本时间及辅助时间10 第四章铣16mm槽专用夹具设计21 4.1定位方案及装置的确定21 4.1.1设计定位方案应满足的要求21 4.1.2定位方案的确定21 4.1.3定位元件的确定21 4.2夹紧方案及装置的确定22 4.2.1夹紧装置满足的基本要求22 4.2.2夹紧方案的确定22 4.2.4夹紧元件的确定23 4.3夹具体的设计23 4.4导向装置确定23 4.5铣削力的计算24 4.6夹紧力的计算24 4.7定位误差的分析与计算25 结论26 致谢27 参考文献28