摘要：焊接变位机也已成为制造业的一种不可缺少的设备，在焊接领域把它划为焊接辅助机。就型式系列和品种规格而言，已问世的约有十余个系列，百余个品种规格，正在形成一个新兴行业。  
本题目是设计前车架全方位焊接变位机。它要求具有两个自由度，实现前车架焊接过程中可绕相互垂直的轴回转360º，被焊工件的任一条焊缝都可以转到平焊或船焊位置，避免立焊和仰焊，从而保证焊接质量，改善工人劳动强度和工作环境，提高生产效率。34752
设计的具体过程是根据预定的载荷和要求进行L臂结构设计和机架结构设计。这两部分主要为焊接结构，首先进行受力分析，了解不同情况下受弯矩和扭矩的大小确定截面的大致形状和板厚。然后考虑工件的空间尺寸及空间回转运动等因素，防止转动部件在工作中发生碰撞。然后考虑结构的合理性，根据传动件的大小确定焊接结构的大小，为L臂安排配重，然后对整个结构进行强度校核。最后绘制相关的零件图、总装图。  
选用的方法主要是机械设计的相关知识，使用到的有材料力学、机械设计、UG等。  
毕业论文关键词： 焊接变、夹具设计、结构设计。
 5 tons loader front frame welding positioner overall design
Abstract：
  Welding positionerhas become an indispensable manufacturing equipment, which is zoned welding assistant engine in the welding area. Patterns and varieties of specifications on the series, has been developed, some over 10 series, more than 100 varieties of specifications, a newly emerging industries.  
The topic is design the front frame full displacement welding positioner.It requires a two degrees of freedom, realize the front frame welding process can turn around the perpendicular axis 360 º, the welding work pieces of any one of the welding line can turn to flat welding or ship welding position, avoid set up welding and welding, so as to ensure welding quality,improve the labor intensity and working environment,improve production efficiency.  
The specific design process is according to the predetermined load and requirements for L arm structure design and frame structure design. The two parts mainly for welding structure, first mechanics analysis, understanding the different cases by bending moment and the size of the torque, determine the general form of the section and thickness. Then consider the size and space turn sports factors, prevent rotating components work in a collision. Consider the rationality of the  structure, according to the size of the transmission parts to determine the size of welding structure, for L arm counterweight arrangement, and then for the whole structure strength check. Finally draw relevant parts graph, assembly drawing.  
The selection of the method is mainly related knowledge of mechanical design, using material mechanics, the mechanical design, UG.  
Keywords: welding ，positioner, fixture design, structure design.
 目录
1 绪论    1
1.1 焊接变位机概述    1
1.1.1 焊接变位机的定义    1
1.1.2 焊接变位机的分类    1
1.2 焊接变位机的功能    2
1.3 前车架焊接变位机设计技术指标    2
1.4 国际和国内焊接变位机的发展现状    3
1.4.1 国外焊接变位机的产品简介    4
1.4.2 国内焊接变位机的产品简介    5
2 L型焊接变位机总体设计    6
2.1 结构件焊接变位机的选型    6
2.2 常见几种变位机结构    6
2.2.1 双立柱单回转焊接变位机    6
2.2.2 U型双座式头尾双回转焊接变位机    7 5吨装载机前车架焊接变位机总体设计+CAD图纸:http://www.751com.cn/jixie/lunwen_32383.html