1、 I 摘要摘要 连杆机构中两端分别与主动和从动构件铰接以传递运动和力的杆件。例如在 往复活塞式动力机械和压缩机中,用连杆来连接活塞与曲柄。连杆多为钢件,其 主体部分的截面多为圆形或工字形,两端有孔,孔内装有青铜衬套或滚针轴承, 供装入轴销而构成铰接。连杆是汽车发动机中的重要零件,它连接着活塞和曲 轴,其作用是将活塞的往复运动转变为曲轴的旋转运动,并把作用在活塞上的力 传给曲轴以输出功率。连杆在工作中,除承受燃烧室燃气产生的压力外,还要承 受纵向和横向的惯性力。因此,连杆在一个复杂的应力状态下工作。它既受交变 的拉压应力、又受弯曲应力。连杆的主要损坏形式是疲劳断裂和过量变形。通常 疲劳断裂的部位
2、是在连杆上的三个高应力区域。连杆的工作条件要求连杆具有较 高的强度和抗疲劳性能;又要求具有足够的钢性和韧性。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部分工序夹具设计。制定工艺路线时主 要考虑粗、精加工安排、加工方法选择、工序集中与分散、加工顺序等方面的要求。 接着确定加工余量、工序尺寸及切削用量,最后设计夹具。本论文介绍了确定加工连 杆的生产纲领及生产类型;确定连杆的毛坯材料及尺寸,确定毛坯加工余量;设计连 杆加工工艺;确定部分重要工序所用的工艺装备和设备;计算部分重要工序的切削用 量和基本时间;设计重要工序所用的夹具。连杆的尺寸精度、形状精度以及位置精度 的要求都很高
3、,而连杆的工作环境恶劣,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,才能最后达到零件的技术要求。 关键词关键词: 连杆;变形;工作环境;加工工艺;夹具设计 II Abstract At both ends of linkage with the active and passive components in order to convey movement and the hinged edge of the bar. For example, in reciprocating pist
4、on compressor and power machinery, to connect the piston with connecting rod and crank. Connecting rod for steel parts, the main part of the cross section for the round or shaped, both ends have a hole or holes with needle bearing bronze bushing for the pin into and constitute a hinged axis. Linkage
5、 is an important automotive engine parts, it is connected to the piston and the crankshaft, its role is to the reciprocating piston movement into rotary movement of the crankshaft, and the role of the force in the piston to the crankshaft to the output power. Link at work, in addition to gas produce
6、d by the combustion chamber under pressure, also have to face the vertical and horizontal inertia force. Therefore, the connecting rod in a complex work under the stress state. It is subject to alternating stress of tension and compression, but also by the bending stress. Link the main form of fatigue damage and excessive deformation. Usually the site of fatigue fracture in the connecting rod on the three regions of high stress. Requirements of the working conditions of connecting rod connecting