車床撥叉的加工工藝及夾具設(shè)計(jì)831006

機(jī)械論文編號(hào):JX038  論文字?jǐn)?shù):21644,頁數(shù):55   附CAD圖，文獻(xiàn)綜述

目   錄

摘 要………………………………………………………………………………………Ⅰ
ABSTRACT…………………………………………………………………………………… Ⅱ

1 緒論……………………………………………………………………………………………1
2 撥叉A的分析…………………………………………………………………………………2
 2.1零件的作用…………………………………………………………………………………2
 2.2撥叉A的工藝分析……………………………………………………………………………2
 2.3撥叉A的工藝要求……………………………………………………………………………2
   2.3.1加工要求……………………………………………………………………………2
   2.3.2平面的加工…………………………………………………………………………3
   2.3.3大頭孔的加工…………………………………………………………………………3
   2.3.4 小頭孔的加工……………………………………………………………………3
 2.4本章小結(jié)……………………………………………………………………………………3
3 工藝規(guī)程設(shè)計(jì)…………………………………………………………………………………5
 3.1確定毛坯的尺寸形式…………………………………………………………………………5
 3.2加工工藝過程…………………………………………………………………………………5
 3.3定位基準(zhǔn)的選…………………………………………………………………………………5
   3.3.1粗基準(zhǔn)的選擇……………………………………………………………………………5
   3.3.2 精基準(zhǔn)的選擇………………………………………………………………………6
 3.4工藝路線的擬訂………………………………………………………………………………6
   3.4.1確定工序的原則…………………………………………………………………………6
   3.4.2工序的特點(diǎn)………………………………………………………………………7
   3.4.3加工精度的劃分…………………………………………………………………………8
   3.4.4制定工藝路線…………………………………………………………………………8
 3.5本章小結(jié)…………………………………………………………………………………10
4 工序參數(shù)選擇、計(jì)算………………………………………………………………………11
 4.1毛坯的確定……………………………………………………………………………11
   4.1.1毛坯的工藝要求………………………………………………………………………11
4.1.2 毛坯形狀、尺寸要求……………………………………………………………………11
4.2 撥叉A偏差的計(jì)算…………………………………………………………………………12
4.2.1  撥叉平面的偏差及加工余量計(jì)算……………………………………………………12
4.2.2  大小頭孔的偏差及加工余量計(jì)算……………………………………………………13
   4.2.3銑槽的偏差及加工余量計(jì)算…………………………………………………14
 4.3確定切削用量及基本工時(shí)……………………………………………………………14
   4.3.1粗、精加工小頭孔端面……………………………………………………………14
   4.3.2加工孔到要求尺寸………………………………………………………………16
   4.3.3粗、精銑叉口兩側(cè)面………………………………………………………………20
   4.3.4粗、精鏜孔…………………………………………………………………………22
   4.3.5粗、精銑下平面……………………………………………………………………23
   4.3.6 粗、精銑槽……………………………………………………………………25
   4.3.7粗銑斜平面…………………………………………………………………………26
   4.3.8銑斷……………………………………………………………………………………26
 4.4時(shí)間定額計(jì)算及生產(chǎn)要求…………………………………………………………………26
   4.4.1粗、精加工小頭孔端面………………………………………………………………27
   4.4.2加工孔到要求尺寸………………………………………………………………27
   4.4.3粗、精銑叉口兩側(cè)面………………………………………………………………27
   4.4.4粗、精鏜孔…………………………………………………………………………28
   4.4.5粗、精銑下平面……………………………………………………………………28
   4.4.6粗、精銑槽………………………………………………………………………29
   4.4.7粗銑斜平面…………………………………………………………………………30
   4.4.8銑斷………………………………………………………………………………30
 4.5本章小結(jié)……………………………………………………………………………30
5 鏜孔夾具設(shè)計(jì)………………………………………………………………………………31
 5.1鏜孔夾具設(shè)計(jì)…………………………………………………………………………31
 5.1問題的提出……………………………………………………………………………31
 5.2定位基準(zhǔn)的選擇…………………………………………………………………………31
 5.3夾具方案的確定…………………………………………………………………………32
 5.4誤差分析與計(jì)算…………………………………………………………………………33
 5.5 切削力及夾緊力的計(jì)算…………………………………………………………………35 
5.6 鏜床夾具分析………………………………………………………………………………37
5.7 本章小結(jié)……………………………………………………………………………………38
6銑側(cè)面夾具設(shè)計(jì)……………………………………………………………………39
 6.1定位基準(zhǔn)的選擇…………………………………………………………………………39
 6.2 夾具方案的確定…………………………………………………………………………40
 6.3 定位誤差的分析及計(jì)算…………………………………………………………………40
 6.4切削力及夾緊力的計(jì)算…………………………………………………………………41
 6.5定向鍵與對刀裝置的選擇………………………………………………………………42
6.6 本章小結(jié)…………………………………………………………………………………44
7銑槽夾具設(shè)計(jì)……………………………………………………………………………45
 7.1定位基準(zhǔn)的選擇…………………………………………………………………………45
 7.2制定夾具設(shè)計(jì)方案………………………………………………………………………45
 7.3定位元件的選擇…………………………………………………………………………47
 7.4定位誤差分析…………………………………………………………………………48
 7.5銑削力與夾緊力計(jì)算……………………………………………………………………49
 7.6定向鍵與對刀裝置的選擇………………………………………………………………50
 7.7本章小結(jié)…………………………………………………………………………………52
8 結(jié)論 …………………………………………………………………………………………53
參考文獻(xiàn)………………………………………………………………………………………54
致謝……………………………………………………………………………………………55

摘  要

本設(shè)計(jì)是車床撥叉零件的加工工藝及專用夾具設(shè)計(jì)。從零件的結(jié)構(gòu)外型分析，它的外型復(fù)雜，且不易加工，因此該零件選用是鑄造件。它的主要加工面是孔、撥叉叉口兩端面和槽，在加工中由于面的加工精度要比孔的加工精度容易保證。因此，在設(shè)計(jì)中采用先面后孔的原則，并將孔與平面的加工劃分為粗加工和精加工階段，以保證加工精度。在本設(shè)計(jì)中，先以一個(gè)面加工出一個(gè)基準(zhǔn)面，然后，再以該基準(zhǔn)面加工相應(yīng)的孔。在后面的工序中，均以該孔為定位基準(zhǔn)，加工撥叉叉口兩端面、孔、底平面、槽和斜平面，在整個(gè)加工過程中，分別采用了銑床、鉆床和鏜床。并設(shè)計(jì)了銑側(cè)面、鏜孔和銑槽等的專用夾具，并對它們的定位都采用了一面兩銷定位。由于該零件的尺寸不大，所需的夾緊力不大。因此，夾緊方式都采用手動(dòng)夾緊，它的夾緊簡單，機(jī)構(gòu)的設(shè)計(jì)更為方便，滿足夾緊要求。

關(guān)鍵詞  撥叉零件，加工工藝，專用夾具，定位， 夾緊

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 Parts, Processing, Special Fixture, Positioning, Clamping