机械5

摘要 本设计是基于拨叉零件的加工工艺规程及一些工序的铣断夹具设计。拨叉零件的主要加工表面是外圆及孔系。一般来说，保证平面的加工精度要比保证孔系的加工精度容易。因此，本设计遵循先面后槽的原则。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系加工精度。主要加工工序安排是先以支承孔系定位加工出顶平面，在后续工序中除个别工序外均用顶平面和工艺孔定位加工其他孔系与平面。夹具选用专用夹具，夹紧方式多选用手动夹紧，夹紧可靠，机构可以不必自锁。因此生产效率较高。适用于大批量、流水线上加工。能够满足设计要求。 关键词拨叉类零件；工艺；夹具； Abstract This desig
n is based o
n the processi
ng procedure of the fork parts a
nd the desig
n of the cutti
ng fixture for some worki
ng procedures. The mai
n machi
ned surface of the fork part is the outer circle a
nd the hole system. Ge
nerally speaki
ng, it is easier to e
nsure the machi
ni
ng precisio
n of the pla
ne tha
n to e
nsure the machi
ni
ng precisio
n of the hole system. Therefore, this desig
n follows the pri
nciple of the first face a
nd the back groove. The processi
ng of holes a
nd pla
nes is clearly divided i
nto rough a
nd fi
nishi
ng stages to e
nsure the machi
ni
ng accuracy of the hole system. The mai
n process is that first the series of supporti
ng hole fix a
nd machi
ne the top pla
ne, i
n additio
n to the follow-up processes arei
ndividual processes with top surface a
nd hole positio
ni
ng processi
ng other series of hole a
nd pla
ne. The fixture is selected with special fixture, a
nd the clampi
ng way is mostly ma
nual clampi
ng, a
nd the clampi
ng is reliable, a
nd the mecha
nism ca
n
not lock itself. Therefore, the productio
n efficie
ncy is high. It is suitable for large batch a
nd assembly li
ne processi
ng. It ca
n meet the desig
n requireme
nts. Keywords diali
ng fork parts; process; fixture; 目录 摘要I Abstract II 第1章绪论1 1.1课题背景1 1.2夹具的发展史1 1.3小结2 第2章ca6140拨叉的加工工艺规程设计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确定生产类型4 2.3确定毛坯4 2.3.1确定毛坯种类4 2.3.2确定铸件加工余量及形状4 2.3.3绘制铸件零件图4 2.4工艺规程设计4 2.4.1选择定位基准4 2.4.2制定工艺路线5 2.4.3选择加工设备和工艺设备6 2.4.4机械加工余量、工序尺寸及公差的确定6 2.5确定切削用量及基本工时8 2.6本章小结21 第3章铣断铣床夹具设计22 3.1研究原始质料22 3.2定位基准的选择22 3.3切削力及夹紧分析计算23 3.4误差分析与计算24 3.5零、部件的设计与选用26 3.5.1定位销选用26 3.5.2夹紧装置的选用27 3.5.3定向键与对刀装置设计27 3.6夹具设计及操作的简要说明30 结论31 参考文献32 致谢33