机械5

摘要 随着机床加工精度的提高，为了降低定位误差，提高加工精度，对夹具的制造精度要求相应提高。为了适应不同行业的需要和经济性，夹具有不同的型号，以及不同档次的精度标准供选择。夹具的通用性直接影响其经济性，采用模块、组合式的夹具系统只有夹具系统的可重组性、可重构性及可扩展性功能强，应用范围广，通用性好，夹具利用率高，元件的功能强，使得夹具的通用性好，元件少而精，配套的费用低，经济使用才有推广的价值。 本设计是结合目前实际生产中，通用夹具不能满足生产要求，而专门设计的一种铣床夹具，主要包括夹具的定位方案，夹紧方案，夹具体与定位键的设计及加工精度等方面的分析。 该夹具具有良好的加工精度，针对性强，主要用于拨叉铣40×28上平面零件工序的加工。本夹具具有夹紧力装置，具备现代机床夹具所要求的高效化和精密化的特点，可以有效的减少工件加工的基本时间和辅助时间，大大提高了劳动生产力，有效地减轻了工人的劳动强度。 关键词：拨叉；机床夹具；定位；工序；夹紧力 Abstract With the improveme
nt of machi
ni
ng accuracy of machi
ne tools, i
n order to reduce the positio
ni
ng error a
nd improve the machi
ni
ng accuracy, the ma
nufacturi
ng accuracy of fixture is required to be improved accordi
ngly. I
n order to meet the
needs a
nd eco
nomy of differe
nt i
ndustries, clamps have differe
nt models a
nd differe
nt grades of accuracy sta
ndards for selectio
n. The ge
nerality of fixture directly affects its eco
nomy. O
nly the modular a
nd combi
ned fixture system has stro
ng fu
nctio
n of reco
nfigurability, reco
nfigurability a
nd expa
nsibility, wide applicatio
n ra
nge, good ge
nerality, high utilizatio
n rate of fixture a
nd stro
ng fu
nctio
n of compo
ne
nts, which makes the fixture have good ge
nerality, few a
nd precise compo
ne
nts, low cost of supporti
ng, a
nd eco
nomic use has the value of promotio
n. This desig
n is a ki
nd of milli
ng machi
ne fixture specially desig
ned i
n combi
natio
n with the curre
nt actual productio
n, which ca
n
not meet the productio
n requireme
nts of the ge
neral fixture. It mai
nly i
ncludes the positio
ni
ng scheme, clampi
ng scheme, clamp specific a
nd positio
ni
ng key desig
n a
nd processi
ng accuracy a
nalysis of the fixture. The fixture has good machi
ni
ng accuracy a
nd stro
ng perti
ne
nce. It is mai
nly used for the machi
ni
ng of shift fork milli
ng 40 × 28 upper pla
ne parts. The fixture has a clampi
ng force device, which has the characteristics of high efficie
ncy a
nd precisio
n required by moder
n machi
ne tool fixture. It ca
n effectively reduce the basic time a
nd auxiliary time of workpiece processi
ng, greatly improve the labor productivity a
nd effectively reduce the labor i
nte
nsity of workers. Key words: shift fork; machi
ne tool fixture; positio
ni
ng; process; clampi
ng force 目录 摘要1 Abstract 2 第1章绪论1 第2章零件的分析2 2.1零件的分析2 2.1.1零件的作用2 2.1.2零件的工艺分析2 2.2工艺规程设计2 2.3制定工艺路线。 3 2.4机械加工余量。 4 2.5确定切削用量及基本工时。 5 第3章铣40×28上平面夹具设计13 3.1.夹具结构设计14 3.1.1定位机构14 3.1.2夹紧机构15 3.2机床夹具的总体形式16 3.2.1确定夹具体： 17 3.2.2确定联接体： 17 3.2.3夹具体的总体设计图: 17 3.3绘制夹具零件图18 3.4绘制夹具装配图18 3.5误差分析21 3.5.1定位误差21 3.5.2产生定位误差的原因22 3.6定位误差的计算22 结论24 致谢25 参考文献26