Design Of Welding Fixture For Car Aluminum Alloy Bumper

In recent years,Car production and ownership is increasing.The car is convenient for people to travel,meanwhile,three major problems such as shortage of energy sources,safety,depravation of environment are produced by it.Therefore,low fuel consumption,low emissions and high safety performance are the problems that the global automobile industries must face and solve.Lightweight is a very effective way to solve these problems,Aluminum alloy is an ideal material for lightweight.It is very important to study the properties of aluminum alloy and increase its application in automobile industry.With the advantages of low density,high strength and superior corrosion resistance,aluminum alloy's have been applied in many fields,such as aviation and aerospace,machinery manufacturing,shipbuilding,civil engineering and chemical industries.And the scope of application is expanding.However,in industrial production,the welding of aluminum alloy is always a difficult problem because of its very strong oxidation ability,big thermal conductivity and special heat capacity,large welding hot cracking tendency,welding blowholes and other defects.In the car industry,the aluminum alloy components are generally thin-walled parts,which make the difficulty coefficient of welding fixture design increased.Therefore,the research of aluminum alloy welding fixture design has become the most urgent task of promoting its widely use in engineering material.In the paper,according to the properties of aluminum alloy and the problems existing in its welding,taking the welding of car alloy bumper as an example,the design of the welding fixture has been completed with the using the MIG welding.First of all,based on the computer aided design software-UG,the welding fixture has been designed,and the application of computer and the development trend in the future have been analyzed briefly.Second,based on the aluminum alloy bumper,the scheme design of welding fixture and specific fixed clamping have been completed.Third,the design of other parts of the fixture has been completed,the interference and clamping forces have been checked and calculated.Finally,the feasibility of the scheme has been verified based on real experimental fixture.In this paper,the finite element analysis software is used for static linear analys of the clamping force and the reliability of the typical parts of the fixture.The results are as follows:Before welding,The clamping mechanism has the function of positioning and clamping,and the exiting static load have little effect on structure strain and stress of the bumper,the function and feasibility of the fixture structure have been verified.In welding,the clamping mechanism has the more or less function of correcting the thermal deformation of the structure,besides,the obvious phenomenon of stress concentration isn't generated.