Laser Welding Technology

Laser welding is a more advanced welding technology in industrial production. Since the 1980s, with the maturity of kilowatt-class laser technology, 300mw laser pointer welding has been gradually promoted. Laser welding technology is widely used in high precision manufacturing. In the industry, laser welding has become a reliable safety of automotive products another generation of nouns.

Laser welding is a high-energy laser beam with high energy density as a high-efficiency precision welding method, compared with the traditional spot welding has many advantages, can greatly enhance the performance of all aspects of the car: welding quality is better, high power laser welding with heat Fused welding wire filling the gap technology, welding the body after the overall bonding sheet metal material, welding surface smooth one, the overall quality of welding is extremely good. Ordinary spot welding Although the welding cost is low, but after the welding there is welding, welding wear, sealing the pores of the potential welding defects. Welding speed, laser welding welding speed of 5 to 6 m / min; spot welding speed of an average of 1/3 seconds. To the roof of the car, for example, the roof to be spot welding of about 100 solder joints. It would take 5 minutes to spot welding alone. Replaced by laser welding, a single laser welding head welding 4 m long area, time-consuming only 0.8 minutes.

After welding the sealing effect is good, laser welding welding method for the line welding, welding the body sheet metal area, the overall welding, to completely sealed, the perfect solution to the body can not leak, leak sealing requirements. Spot welding for the non-continuous welding, the inevitable distance between the solder joints, the gap between the solder joints may exist in the gap, in order to meet the body can not leak, leak sealing requirements must be assisted to seal to achieve. Laser welding parts of the higher strength, through the tensile test test can be found, a solder joint need to apply the force of about 3500 cattle, 200mw laser pointer welding to form the same length of the weld strength is 1.5 times the spot strength.

Laser welding needs to design the welding side is short, can effectively reduce the weight of the body: laser welding design of the lap edge is zero fit, the design only need to consider the sheet metal itself stamping process can be suitable; spot welding Side design should take into account the space of solder joints. According to the different thickness of the plate is generally about 16 mm, the extension of the material side means that the weight of the body heavier. Welding appearance more beautiful: laser welding to form the final appearance, smooth and neat lines, the overall texture. Spot welding to form the appearance of uneven, with solder pit, edges, burrs and other inherent defects, usually need to increase the decorative strip to block.

As a high-tech welding technology, burning laser welding is generally preferred to use in the appearance of the body area, because the body appearance of the area of ​​high quality requirements of the region. Welding of these areas if the use of spot welding, welding space is limited, the process layout will be very complex, will result in poor welding quality, can not achieve the desired appearance of the design quality effect. For example, the roof area and the back door area, the welding area is very narrow, while the design of the body sealing requirements; side area is because the welding area is not only narrow and the shape is very complex; door area is because the welding area is narrow and smooth, Welding space is empty, suitable for laser welding instead of spot welding to enhance the sealing effect of the door seal. Through the wide range of laser welding applications can not only prompt the car aesthetics, improve production efficiency, but also can effectively enhance the vehicle stiffness, thereby enhancing the safety of the car.

Currently, a laser source is used to melt the wire filler weld technology, requiring a zero gap between the interface to form a gap for 30mw laser pointer welding. To the car roof design, for example, laser welding focus on the top cover to strengthen the plate and the roof of the special connection, while taking into account the quality of the roof stamping process requirements, in addition to consider the roof and body lap design , The impact of the overall size deviation on the design structure after the completion of the body welding. Through a large number of experimental verification and field analysis, we believe that the overall side of the roof lap flange angle and evenness to be controlled at 0.3mm to meet the laser welding quality requirements.