With the VAG Diagnostic Tools rapid development of automobile technology , automobile manufacturing companies in the structural design of the car, manufacturing technology, materials selection and other aspects of a lot of research , hoping to develop a safe, reliable, energy-saving environmental protection, new cars. Under normal circumstances , the body dating from major fuel consumption of 70% , so the most important issue is how to reduce vehicle fuel consumption make the car lighter . First make the car lighter to start from lightweight materials , so not only can reduce body weight and increase the quality of equipment , reducing engine load , but also can significantly reduce the force suffered chassis components , making the car ‘s handling, even better economy . And there is ” light metal ,” said the aluminum metal , because its light weight , wear resistance, corrosion resistance , good elasticity, high stiffness and strength , excellent impact resistance , and good molding and high reproducibility , became the automobile light quantify the material of choice. Aluminum body cars because of low energy , safe, comfortable and strong load capacity relative advantages and favored.
First, the structural characteristics of the aluminum body
The use of aluminum in cars on show increasing in recent years . Partial or total use of aluminum has many models , such as BMW , Audi, Volvo, Land Rover , Jaguar , etc. Aluminum body aluminum alloy used basically by increasing or decreasing the ratio of alloying elements and the use of appropriate heat treatment , etc., to reach the desired performance . Currently , an aluminum alloy for automotive body sheet are Al-Cu (2000 series ), Al-Mg (5000 series) and Al-Mg-Si (6000 series ) three kinds . 6000 series aluminum due to its plasticity , high strength , becoming the first choice of many car manufacturers new body materials . For the different parts of the body, a different member of the aluminum alloy composition used , the type and heat treatment process is not the same . As the skeleton of the vehicle bumper , the bumper reinforcement beam and side beams , aluminum is used should have sufficient toughness and mild , in the event of a collision can have good absorption properties . Use of aluminum vehicle driveline components , not only has sufficient strength and toughness , and also has good thermal conductivity . Facts have proved that cars use aluminum indeed made good social and economic benefits.
When all aluminum body construction , according to their functional requirements of the body can be divided into castings , stampings, die castings , aluminum castings are manufactured to be able to carry large loads of parts , significantly reducing the weight but also has a high strength. The plate member has a complex geometry , typically by way of a vacuum die casting , so that they have high strength. Meanwhile , they also have good ductility , good weldability and high plasticity , to ensure they have a high level of security at the time of the collision .
Of course , there are some car use aluminum shortage . In the production of aluminum car body welding aluminum body welding increased by 60 % compared with conventional steel body energy , and once traffic accidents , higher maintenance costs aluminum body . Due to the low melting point of aluminum , poor repair , maintenance technicians need to use special tools and special aluminum body repair process method to repair.
Second, the aluminum body repair hardware requirements
1 , aluminum body dedicated gas protection welder and appearance repair machine
Because of the low melting point of aluminum , deformation, low current welding requirements , it must use a dedicated gas shielded welding aluminum body . Shape repair machines can not be like a normal repair machines to click stretched shape , can only use a dedicated machine repair welding aluminum body shape meson nails, nail stretcher using meson stretch .
2 , special aluminum body repair tools , powerful rivet gun
With traditional car accident repair is different, repair aluminum body is mostly riveting repair method , which must have a strong rivet gun . And aluminum body BMW SRS computer must be dedicated , can not be mixed with steel body repair tools . Because the repairs finished steel body , would have on the iron tools , if the aluminum body to repair , iron is embedded aluminum surface , causing corrosion of aluminum .
3 , dust explosion-proof vacuum system
In polished aluminum body process, will produce a lot of aluminum , aluminum is not only harmful, but explosive , so there must be explosion-proof dust vacuum system in a timely manner to absorb aluminum .
4 , an independent space for maintenance
Because aluminum body repair process demanding ensure quality automotive repair and maintenance of safe operation, to avoid contamination of aluminum for the workshop and explosions , to set up a separate aluminum body repairman bit . In addition, the aluminum body of the maintenance staff to conduct professional training , master repair aluminum body repair techniques, how to locate the drawing, welding , riveting , bonding , etc.
Third, the maintenance operation precautions
1, the localized stretching of the aluminum sheet is not good, easy to crack . If the hood inner panel because the shape is more complex , in the manufacture of the body in order to improve its tensile deformation properties of high strength aluminum alloy , elongation rate has exceeded 30 percent , so far as possible to ensure that maintenance is not mutated shape to avoid cracks.
2, the dimensional accuracy is not easy to grasp, difficult to control the rebound . To the extent possible in the maintenance of low-temperature heating method to release stress , it does not produce a solid rebound and other secondary deformation.
3 , because the ratio of aluminum to produce the bumps of soft steel , dust attached to the collision , and various other reasons make the maintenance of the part surface , scratches and other defects , so to clean the mold cleaning apparatus , the environment of dust , the air take appropriate measures to pollution , etc., to ensure that the parts intact.