编号
XXXXX职业技术学院
毕业论文
题 目
汽车连杆的加工工艺及夹具设计 学生姓名 学 号 系 部 专 业
XXXX XXXXXX 机电工程系 机械制造与自动化
XXXXXX XXX 副教授 XXX 副教授
二〇一三年十月
班 级 指导教师 顾问教师
摘要
摘 要
连杆是柴油机的主要传动件之一，本文主要论述了连杆的加工工艺及其夹具设计。连杆的尺寸精度、形状精度以及位置精度的要求都很高，而连杆的刚性比较差，容易产生变形，因此在安排工艺过程时，就需要把各主要表面的粗精加工工序分开。逐步减少加工余量、切削力及内应力的作用，并修正加工后的变形，就能最后达到零件的技术要求。
针对连杆的加工过程，本文还进行了专用夹具的设计。分别是：铣剖分面夹具设计和扩大头孔夹具。夹具体为铸造件，安装稳定，刚度好，但制造周期较长。
关键词: 连杆 变形 加工工艺 夹具设计
I
Abstract
Abstract
The connecting rod is one of the main driving medium of diesel engine, this text expounds mainly the machining technology and the design of clamping device of the connecting rod. The precision of size, the precision of profile and the precision of position , of the connecting rod is demanded highly , and the rigidity of the connecting rod is not enough, easy to deform, so arranging the craft course, need to separate the each main and superficial thick finish machining process. Reduce the function of processing the surplus , cutting force and internal stress progressively , revise the deformation after processing, can reach the specification requirement for the part finally .
In view of the connecting rod machining process, this article also has carried on the special fixture design. Respectively is: milling fixture design subdivision surface and expanding hole clamp head. Specific for casting parts, stable installation, good stiffness, but manufacturing cycle is longer than the other.
Keywords:Connecting rod Deformination Processing technology Design of clamping device
II
目 录
目 录
摘 要 ............................................................................................................................. I ABSTRACT .................................................................................................................. II 第一章 汽车连杆加工工艺设计 ................................................................................... 1 1.1连杆的结构特点分析 ........................................................................................... 1 1.2连杆的主要技术要求拟定 ................................................................................... 1 1.2.1 大、小头孔的尺寸精度、形状精度 ............................................................ 2 1.2.2 大、小头孔轴心线在两个互相垂直方向的平行度 .................................... 2 1.2.3 大、小头孔中心距 ........................................................................................ 2 1.2.4 连杆大头孔两端面对大头孔中心线的垂直度 ............................................ 3 1.2.5 大、小头孔两端面的技术要求 .................................................................... 3 1.2.6 螺栓孔的技术要求 ........................................................................................ 3 1.2.7 有关结合面的技术要求 ................................................................................ 3 1.3连杆的材料和毛坯选择 ....................................................................................... 3 1.4连杆的机械加工工艺过程设计 ........................................................................... 5 1.5连杆的机械加工工艺过程分析 ........................................................................... 7 1.5.1 工艺过程的安排 ............................................................................................ 7 1.5.2 定位基准的选择 ............................................................................................ 8 1.5.3 确定合理的夹紧方法 .................................................................................... 9 1.5.4 连杆两端面的加工 ........................................................................................ 9 1.5.5 连杆大、小头孔的加工 ................................................................................ 9 1.5.6 连杆螺栓孔的加工 ...................................................................................... 10 1.5.7 连杆体与连杆盖的铣开工序 ...................................................................... 10 1.5.8 大头侧面的加工 .......................................................................................... 10 1.6连杆加工工艺设计应考虑的问题 ..................................................................... 10 1.6.1 工序安排 .................................................................................................... 10 1.6.2 定位基准 .................................................................................................... 10 1.6.3 夹具使用 .................................................................................................... 11 1.7切削用量的选择原则 ......................................................................................... 11 1.7.1 粗加工时切削用量的选择原则 .................................................................. 11 1.7.2 精加工时切削用量的选择原则 .................................................................. 12 1.8确定各工序的加工余量、计算工序尺寸及公差 ............................................. 12 1.8.1 确定加工余量 .............................................................................................. 12 1.8.2 确定工序尺寸及其公差 .............................................................................. 13 1.9计算工艺尺寸链 ................................................................................................. 14 1.9.1 连杆盖的卡瓦槽的计算 .............................................................................. 14 1.9.2 连杆体的卡瓦槽的计算 .............................................................................. 15 1.10工时定额的计算 ............................................................................................... 15 1.10.1 铣连杆大小头平面 .................................................................................... 15 1.10.2 粗磨大小头平面 ........................................................................................ 16 1.10.3 加工小头孔 ................................................................................................ 16 1.10.4 铣大头两侧面 ............................................................................................ 17 1.10.5、扩大头孔 .................................................................................................. 17
III
汽车连杆的加工工艺及夹具设计
