ASTRACT
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 , Arrange technology process, the main surface coarse, finishing process, the former, half in balancing arrangement in the middle, finish machining precision arrangement in behind. This is due to the rough machining processes, thus cutting allowance of cutting force, clamping force inevitable large deformation, processed easily. After finishing separate coarse, moldings, deformation of finishing in half, Half of machining deformation of finishing in. This fixture design for drill connecting bolt hole special jig design.
Keyword: Processing technology；Limits.but；Dimension chain；Fixture design
目 录
第1章 绪 论 ...................................................... 1
1.1 设计任务 ..................................................... 1 1.2 加工工艺规程设计的目的和意义 ................................. 1 1.3 连杆加工的发展趋势 ........................................... 1
第2章 汽车连杆加工工艺规程设计 ................................. 3
2.1 连杆的结构特点 ............................................... 3 2.2 连杆的主要技术要求 ........................................... 3 2.2.1 大、小头孔的尺寸精度、形状精度 .............................. 3
2.2.2 大、小头孔轴心线在两个互相垂直方向的平行度 .............. 3 2.2.3 大、小头孔中心距 ........................................ 4 2.2.4 连杆大头孔两端面对大头孔中心线的垂直度 .................. 4 2.2.5 大、小头孔两端面的技术要求 .............................. 4 2.2.6 螺栓孔的技术要求 ........................................ 4 2.2.7 有关结合面的技术要求 .................................... 4 2.3 连杆的材料和毛坯 ............................................. 5 2.4 连杆的机械加工工艺过程 ....................................... 6 2.5 连杆的机械加工工艺过程分析 ................................... 8
2.5.1 工艺过程的安排 .......................................... 8 2.5.2 定位基准的选择 .......................................... 8 2.5.3 确定合理的夹紧方法 ...................................... 9 2.5.4 连杆两端面的加工 ....................................... 10 2.5.5 连杆大、小头孔的加工 ................................... 10 2.5.6 连杆螺栓孔的加工 ....................................... 10 2.5.7 连杆体与连杆盖的铣开工序 ............................... 11 2.5.8 大头侧面的加工 ......................................... 11 2.6 连杆加工工艺设计应考虑的问题 ................................ 11
2.6.1 工序安排 ............................................... 11 2.6.2 定位基准 ............................................... 11 2.6.3 夹具使用 ............................................... 11
2.7 切削用量的选择原则 .......................................... 12
2.7.1 粗加工时切削用量的选择原则 ............................ 12 2.7.2 精加工时切削用量的选择原则 ............................ 13 2.8 确定各工序的加工余量、计算工序尺寸及公差 .................... 13
2.8.1 确定加工余量 .......................................... 13 2.9 计算工艺尺寸链 .............................................. 14
2.9.2 连杆体的卡瓦槽的计算 .................................. 14 2.10 工时定额的计算 ............................................. 15
2.10.1 铣连杆大小头平面 ...................................... 15 2.10.2 粗磨大小头平面 ........................................ 16 2.10.3 加工小头孔 ............................................ 16 2.10.4 铣大头两侧面 .......................................... 17 2.10.5 扩大头孔 .............................................. 18 2.10.6 铣开连杆体和盖 ........................................ 18 2.10.7 加工连杆体 ............................................ 19 2.10.8 铣、磨连杆盖结合面 .................................... 19 2.10.9 铣、钻、镗（连杆总成体） .............................. 20 2.10.10 粗镗大头孔 ........................................... 22 2.10.11 大头孔两端倒角 ....................................... 22 2.10.12 精磨大小头两平面（先标记朝上） ....................... 22 2.10.13钻小头油孔 ............................................ 23 2.10.14 半精镗大头孔及精镗小头孔 ............................. 23 2.10.15 精镗大头孔 ........................................... 24 2.10.16 小头孔两端倒角 ....................................... 24 2.10.17 镗小头孔衬套 ......................................... 24 2.10.18 珩磨大头孔 ........................................... 25 2.11连杆加工工艺卡片及供需卡片填写 .............................. 25
第3章 钻螺栓孔夹具设计 ......................................... 26
3.1 钻螺栓孔夹具设计 ............................................ 26
3.1.1 问题的指出 ............................................. 26 3.1.2 夹具设计 ............................................... 26
(1) 定位基准的选择 .......................................... 26 (2) 夹紧方案 ................................................ 26 (3) 夹具体设计 .............................................. 26 (4) 定位误差分析 ............................................ 27 3.2 夹具体结构设计图 ............................................ 27
结束语 ............................................................. 29 参考文献 ........................................................... 30 致 谢 .............................................................. 31