Currently, lightweighting is an important development trend in the automotive field, and OEMs need high-tech and cost-effective solutions to meet the market demand for both lightweighting and safety. Compared with traditional stamping, roll forming process has outstanding advantages such as high efficiency, material saving, environmental protection, low cost, etc. It is one of the manufacturing process methods for automotive parts.
Body-in-white, as an important part of automobile, accounts for about 40% of the total vehicle weight, so the optimization of body-in-white weight reduction has become an important part of lightweight design. At present, the international new car body-in-white development and design, widely used in advanced high-strength steel, which has a considerable portion of the components, such as front and rear bumpers, door beams, frame rails, roof bow-type frame, the body of the B-pillar and chassis and other components, are completed by the roll-forming manufacturing method. According to statistics, the automobile components manufactured by the roll forming process are about 10% of the vehicle weight.
As shown in Figure 1, the bumper plate is a part that reduces deformation in order to realize the ability to maintain the interior space of the driver's compartment after a car has been subjected to a lateral impact. The part is made of duplex high-strength hot-dip galvanized steel plate by roll forming and then laser welding, installed in the left and right front doors. The anti-collision plate requires laser welding after roll forming, the tolerance of section is ±0.1mm, the seams are required to be tightly fitted, and the straightness of the seams is ≤0.2mm.
Figure 1:Door impact plate
Online laser welding is also widely used in new energy high-strength steel battery trays. In new energy vehicles, the weight of the power battery system accounts for 18%-30% of the entire vehicle, while the case mass accounts for about 10%-20% of the total mass of the battery pack. Due to the current technical limitations of the battery itself, as the largest structural component of the power system battery pack tray is the engineers to study the first target of lightweight. Battery tray material is mainly high-strength steel or aluminum alloy, but the cost of aluminum alloy tray is 2-3 times the steel tray, from the material to the finished product of carbon emissions is 5 times the steel tray, so more and more manufacturers to develop advanced lightweight high-strength steel and thermoforming steel battery tray instead of aluminum alloy tray, and the use of roll-forming, thermoforming, laser welding and other advanced technologies, in order to improve the safety of the battery pack and the structure of the car body On the premise of improving the safety of the battery pack and body structure to reduce the height of the structure as much as possible, saving space and reducing the weight of the battery pack itself.
Figure 2 is a brand of battery tray box, using 1500Mpa and above ultra-high-strength steel complex closed-end truncated shape. It has a variety of ultra-high-strength steel roll-rolled battery pack technology solutions, including roll pressing, online laser welding integrated solutions. The solutions include innovative day-shaped cut-offs, eye-shaped cut-offs and complex deformed roll-rolled cut-offs for battery cases.
Figure 2: Battery tray lower case
Picture 3: Rolling line for structural parts of battery trays
Automotive high-strength steel components roll forming production line requires a variety of equipment and technology, including online laser welding equipment is the key equipment and technology in the closed roll forming production line. Daedalus laser is a well-known high-end laser equipment and intelligent manufacturing solutions provider, focusing on providing automotive lightweight laser solutions, which independently developed automotive high-strength steel online laser welding equipment is a high-performance, flexible, automated laser welding equipment. First, high performance: the equipment is equipped with advanced lasers, welding head, CNC system, weld inspection system, etc., with high quality welding beam, not easy to spatter, low heat impact, high weld strength and good metallurgical organization, no need to re-treatment of weld channel, low energy consumption, low pollution, etc.; Second, flexible: the equipment is equipped with a mobile ground rail, can be very convenient to meet the user to replace the roller equipment to cope with the demand for different product production; Third, high degree of automation: the welding head is fixed in the automotive lightweight steel online laser welding equipment is a high performance, flexible, automated laser welding equipment, High degree of automation: the welding head is fixed on the three-axis (XYZ) module, through the weld monitoring system to track the auxiliary patrol edge positioning, can quickly and real-time spot alignment of the weld position for accurate welding. In addition, the welding head control system is linked with the control of the pipe making line system, when the roll pressure line is activated, the welding system will also work synchronously, which is convenient for the operator to control.
