机械5

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。夹具利用率高，经济性好，对功能组件的使用和数量少。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。 此次设计是对汽车变速箱齿轮加工工艺及夹具设计，其零件为锻件，在看懂零件图的同时对零件的结构和工艺进行分析，明确粗基准和精基准的选择，确定零件的加工余量与毛坯的尺寸、从而确定零件的加工工艺过程、计算各工序的切削用量及工时。绘制零件图及毛坯图，填写加工工艺卡及工序卡。 本次设计滚齿加工齿轮齿形专用夹具，在减少停机时间的同时，还提高生产效率。设计内容包括定位方案以及夹紧方案的确定，定位元件和夹紧元件的选择，设计与机床连接零件—夹具体等。本次设计的夹具结构简易、紧凑，操作起来也比较方便灵活。更重要的是它在提高生产效率方面所起的作用尤为突出，体现了这次设计的主旨。 关键词：汽车变速箱、齿轮、加工工艺、滚齿、专用夹具 Abstract The clamp is a clampi
ng device for the machi
ni
ng of parts a
nd is a
n i
ndispe
nsable device for machi
ni
ng parts. The fixture has high utilizatio
n rate, good eco
nomy, a
nd low use a
nd qua
ntity of fu
nctio
nal compo
ne
nts. As the size of the part cha
nges, more a
nd more fixtures are elimi
nated, so it is
necessary to desig
n a special fixture. Whe
n desig
ni
ng a special fixture, 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 compo
ne
nts of the fixture, a
nd the structural form of the fixture should be co
nsidered. This desig
n is for the gear processi
ng tech
nology a
nd fixture desig
n of the automobile gearbox. The parts are forgi
ngs. The structure a
nd process of the parts are a
nalyzedwhile the parts drawi
ng is u
nderstood. The selectio
n of the rough refere
nce a
nd the fi
ne refere
nce is determi
ned, a
nd the machi
ni
ng allowa
nce of the parts is determi
ned. The amou
nt a
nd the size of the bla
nk, to determi
ne the machi
ni
ng process of the part, calculate the cutti
ng amou
nt a
ndworki
ng hours of each process. Draw the part drawi
ng a
nd bla
nk drawi
ng, fill i
n the processi
ng card a
nd process card. This desig
n of the hobbi
ng machi
ne gear tooth profile special fixture,while reduci
ng dow
ntime, but also improve productio
n efficie
ncy. The desig
n i
ncludes the positio
ni
ng scheme a
nd the determi
natio
n of the clampi
ng scheme, the selectio
n of the positio
ni
ng a
nd clampi
ng compo
ne
nts, the desig
n a
nd the machi
ne co
n
nectio
n parts- the clamp specific. The fixture structure of this desig
n is simple a
nd compact, a
nd the operatio
n is also co
nve
nie
nt a
nd flexible. More importa
ntly, its role i
n improvi
ng productio
n efficie
ncy is particularly promi
ne
nt, reflecti
ng the mai
n purpose of this desig
n. Keywords: automobile gearbox, gear, machi
ni
ng process, hobbi
ng, special fixture 目录 摘要I Abstract II 第一章绪论1 1.1本课题研究的意义1 1.2生产过程与工艺过程的概述1 1.3机械加工工艺过程的组成2 1.4提高机械加工生产率的途径3 1.5机床夹具的概述4 第二章零件的分析6 2.1零件作用的分析6 2.2零件材料的分析7 2.3零件组成表面的分析8 2.4零件加工要求的分析8 2.5零件形位公差的分析8 第三章零件加工工艺规程的设计9 3.1确定零件的生产类型9 3.2确定零件的制造形式9 3.3确定零件的加工基准11 3.4选择和确定加工工艺路线11 3.4.1表面加工方案的选择11 3.4.2选择加工工艺路线12 3.4.3确定加工工艺路线13 3.5确定机床加工的工艺装备14 3.6确定零件的加工余量14 3.7选择切削用量及计算加工工时15 第四章专用夹具的设计26 4.1设计定位方案26 4.2确定定位元件26 4.3设计夹紧方案27 4.4选择夹紧元件28 4.5设计夹具体28 4.6计算切削力29 4.7计算夹紧力29 4.8分析定位误差30 结论31 致谢32 参考文献33