机械5

摘要 本次夹具研究的对象是支架。支架是起支撑作用的构架，承受较大的力，也具有定位作用，使零件之间保持正确的位置。支架其材料选择HT20-40，该材料机械强度是很好的，并且减震性也相当不错。可以用来铸造生产也可以锻造生产。 本设计主要内容包括支架的加工工艺规程以及车两侧Ф22及Ф26台阶孔专用夹具设计。在设计过程中完成了零件图、毛坯图、夹具装配图和夹具体还有所有非标零件图的绘制及说明书的编写。针对两侧Ф22及Ф26台阶孔的加工设计了一套车床专用夹具，在完成零件结构分析基础上，确定采用CA6140车床对其进行加工。利用圆弧定位体、圆柱销和菱形销满足定位要求，又通过夹紧装置保证加工过程中工件位置不发生变化。 关键词：支架、加工工艺，两侧Ф22及Ф26台阶孔、CA6140 Abstract The object of this fixture research is the bracket. The bracket is a supporti
ng structure,which bears a greater force a
nd has a positio
ni
ng fu
nctio
n to keep the correct positio
n betwee
n the parts. The bracket is made of HT20-40,which has good mecha
nical stre
ngth a
nd good shock absorptio
n. It ca
n be used for casti
ng or forgi
ng. The mai
n co
nte
nts of this desig
n i
nclude the processi
ng procedure of the bracket a
nd the desig
n of the special fixture for the step holes of_22 a
nd_26 o
n both sides of thevehicle. I
n the desig
n process, the drawi
ng of parts, bla
nk drawi
ng, fixture assembly drawi
ng a
nd fixture body, aswell as all
no
n-sta
ndard parts drawi
ng a
nd i
nstructio
ns are completed. A special fixture for lathe is desig
ned for the processi
ng of step holes o
n both sides of_22 a
nd_26. Based o
n the a
nalysis of parts structure, CA6140 lathe is selected to process them. The arc positio
ni
ng body, cyli
nder pi
n a
nd diamo
nd pi
n are used to meet the positio
ni
ng requireme
nts, a
nd the clampi
ng device is used to e
nsure that the positio
n of theworkpiece does
not cha
nge duri
ng the processi
ng. Keywords: bracket, processi
ng tech
nology, step holes o
n both sides of_22 a
nd_26, CA6140 目录 摘要I Abstract II 1引言1 1.1机械加工艺规程的作用1 1.2机床夹具的概述1 1.3专用夹具设计的目的2 2分析零件结构、确定制造形式及生产类型3 2.1分析支架的作用3 2.2分析支架的结构3 2.2.1分析支架组成表面3 2.2.2分析支架加工表面加工要求3 2.2.3分析支架形位公差4 2.3选择支架的材料4 2.4确定制造形式4 2.5确定生产类型5 3支架加工工艺规程的设计7 3.1零件加工基准的选择7 3.1.1粗基准的选择7 3.1.2精基准的选择7 3.2确定加工工艺路线8 3.2.1加工工艺路线方案1和方案2 8 3.2.2确定加工工艺路线9 3.3选择加工机床、装夹夹具、切削刀具及测量量具9 3.4零件加工余量确定10 3.5零件切削用量、加工工时的确定11 4专用夹具的设计22 4.1设计定位方案22 4.2确定定位元件22 4.3设计夹紧方案23 4.4确定夹紧元件23 4.5设计夹具体23 4.7计算车削力24 4.8计算夹紧力24 4.9分析夹具及定位误差25 结论26 致谢27 参考文献28