拨叉零件的加工工艺及专用夹具设计.doc

攀枝花学院本科毕业设计（论文） 拨叉加工工艺及夹具设计 学生姓名： 学生学号： 0 院 （系）： 机 械 工 程 学 院 年级专业： 10级机制五班 指导教师： 副教授 二〇一四年五月 摘 要 本设计是拨叉零件的加工工艺及专用夹具设计。从零件的结构外型分析，它的外型复杂，且不易加工，因此该零件选用是铸造件。它的主要加工面是孔、拨叉叉口两端面、内部两侧面、螺纹孔和槽，在加工中由于面的加工精度要比孔的加工精度容易保证。因此，在设计中采用先面后孔的原则，并将槽、孔与平面的加工划分为粗加工和精加工阶段，以保证加工精度。在本设计中，先加工工件的右端面，以其作为一个基准面，再以该平面为基准，对定位孔加工。在后面的工序中，均以该孔和面为定位基准，加工拨叉叉口左端面、两侧面、底平面、槽和螺纹孔。在整个加工过程中，其采用了铣床、钻床、攻丝机。该设计中，我设计了铣拨叉叉口两侧面和加工螺纹孔的专用夹具，并对它们的定位均采用一面两销定位。由于该零件的尺寸不大，所需的夹紧力不大。因此，夹紧方式都采用手动夹紧，它的夹紧简单，机构的设计更为方便，满足夹紧要求。 关键词 拨叉零件，加工工艺，专用夹具，定位， 夹紧 全套图纸，加  ABSTRACT This design is a lather plectrum parts processing and special fixture designs. Parts from the appearance of the structure, its appearance complex and difficult process, so the selection of parts is casting.The parts are cast parts. In the processing, it is easier to ensure the processing accuracy of plane than the hole. So the parts’ main planes are hole, two blades of the Plectrum and groove. Therefore, in the design, it adopts the principle of plane first and hole second and divides the hole and plane’s working into extensive and intensive processing stages so as to ensure the accuracy. In this design, firstly, it uses the plane to work a datum; secondly, it uses the datum to work according hole. And in the latter process of working, it also takes hole as the poisoning base and works the two bales of Plectrum, hole, bottom plane, groove and inclined plane. In the entire machining process, it uses separately the milling machine, driller and boring machine. And the design aspect of milling, boring and milling ducts special fixture. They also have adopted the positioning of a two marketing positioning. According to the requirement, it designs the special fixture. For the size of parts is not very big, it doesn’t require strong clamping force. Therefore, methods of clamping are manual clamping; that is because it is simple and the design is more convenient to meet the requirements of clamping. Keywords Plectrum