Robotic flexible laser cutting

The application of robotic flexible laser cutting in the automotive industry is becoming increasingly common. This is inextricably linked to the development of laser technology and the refinement of robotic precision trajectory control technology.

Robotic flexible laser cutting has a variety of ways. It can be made into a single robot cutting platform and can be combined into a flexible processing line. The workpieces involved are mainly two different types of components: one is a 3D body structure and cover formed by extrusion or drawing of metal parts, including thermoformed parts, and the other is a tubular metal structural part. Including exhaust pipe, cross beams and so on. The traditional production method of the cover part is through the punching of the open mold, and then the punching die and trimming die and the like; the thermoformed part and the tubular part are completed by an expensive five-axis laser cutting machine tool. Because of the high cost of equipment, only some joint venture brand car manufacturers have the ability to purchase imported five-axis machine tools.

In the new situation, the needs of car users are becoming more diversified and personalized, and more and more new models are emerging. Most cars are gradually shrinking, because some auto manufacturers cannot predict and guarantee the sales volume and stable output of a certain model in the future, so they have begun to try low-cost robotic laser cutting equipment or production lines. This trend began with the automotive spare parts market and continues to expand and popularize in areas such as construction machinery, passenger cars, agricultural vehicles, and electric vehicles.

Laser cutting robot suitable for the automotive industry

The automotive industry uses a lot of industrial robots, but there are very few applications in the field of laser cutting. The problems exist on three levels. First, robotic applications in the automotive industry are mainly focused on spot welding, arc welding, spraying, and transportation, etc., which require low precision, but laser cutting often requires high positional accuracy, and there are high requirements for the accuracy of small trajectories such as small rounds; On the one hand, depending on the efficiency of the robot, the control speed of the joint movement of each axis of the robot is relatively slow, and at the same time, the weight of the robot arm is too large to be suitable for high-speed movement. The third aspect is the rigidity of the robot, the robot with poor rigidity is severely shaken, and the tracking performance of the robot is poor. Moreover, the robot is deformed badly, and it is impossible to accurately achieve the precise position of the workpiece in the digital model. Therefore, it is understandable that robots popular in the traditional automotive industry are questioned by customers in terms of laser cutting.

Stäubli, a company with centuries-old experiences in precision machinery and high-speed motion control, has the broadest design field in the automotive industry. In response to the needs of the automotive industry, Stäubli has implemented the RX160L flip-chip gantry structure robotic cutting system solution for lasers. The system has made breakthroughs in the following areas:

Large size robot wide format. With the RX160L robot, the 2.05?m sphere work area, the cutting table width can reach 3?m, more than the width of the expensive five-axis machine table width, the general automotive parts size in the RX160L flipping robot work area, some large Workpieces can also be implemented on mobile platforms.

The arm is light and rigid. Stäubli maintains rigidity by using cast-in-tube tubular structures; it uses aero-transformed cast aluminum with less distortion and lighter weight. The RX160L robot arm weighs only 250?kg, while the European robot with the same arm has to exceed 400?kg, which is very unsuitable for robotic flexible laser cutting.

The difference in mechanical accuracy of the robot. In addition to rigid differences in mechanical accuracy of robots, the most important difference is the mechanical transmission error, and the mechanical transmission error is mainly reflected in the reducer. The unique patented deceleration system JCS used by Stäubli has successfully applied over 100 years of experience in precision machinery to robots. This is the reason why Stäubli can receive customer approval on small hole cutting.

Successfully transplanted 5-axis machine tool technology to robots

Off-line programming techniques and automatic generation of fixtures are among the key technologies that have been promoted in the machine tool industry. The development and successful application of these technologies in the robotics field have enabled the robotic flexible laser cutting solutions to seamlessly link with the automotive industry.

The traditional robot programming method is online teaching programming, which takes time and labor, especially for automobile covers or fittings. The complicated space curves need to be cut, and the teaching cannot meet the design requirements.

Stäubli uses the ROBOTMASTER software for offline programming of the ST?UBLI RX160L robot. ROBOTMASTER robot offline software can virtualize the real cutting environment, including robots, laser cutting tools, workpieces and fixtures. The software can quickly set up and optimize the best robot cutting gestures. If the system appears to interfere or is out of range, the software will intelligently prompt.

Off-line software can also automate vivid precision fixtures. British PEPS offline software is a robotic laser cutting offline programming software specially developed for the world's most sophisticated robot ST?UBLI. It can provide automatic generation of fixture fixtures. The user can select fixtures according to the three-dimensional model of the workpiece and can fine-tune it.

Many integrators choose ordinary robots that are not suitable for laser cutting. The efficiency is low and the effect is poor, which affects the perception of users in the automotive industry in this field and negates the robot program. Stäubli believes that excellent integrators will use high-precision robots and integrate them into sophisticated system structures. According to different user products, basic models evolve into different robotic flexible cutting solutions that can use stand-alone or dual-machine or Combining multiple machines and platforms.

Cutting efficiency is determined by program and experience

The integration ability of integrators determines the final cutting effect and efficiency. The German JENOPTIK is Stäubli's laser application integrator, using a custom-made TX90 laser-cutting robot custom-made by Stäubli, custom light cutting heads and exclusive BIM (Beam-In-Motion) technology. The device's small hole positioning accuracy can reach ± ​​50μm, linear speed> 12μm/min. If the output of the product is relatively high, JENOPTIK can provide dual-machine equipment or multi-robot solutions.

Some local laser cutting system integrators with strong technical capabilities are also constantly raising awareness of robot laser cutting and continuously improving their integration capabilities. Shenzhen Dazu Laser chose Stäubli's robotic laser cutting solutions for the automotive industry. The system consists of two mobile working platforms. The robot switches between the workpieces on two platforms, and the non-working mobile platform pushes. Come out and feed. The customer of this system is a passenger car manufacturer. The demolition equipment manager is very satisfied with this. Not only is the cutting effect good, but also the efficiency is high. The duplex platform will not waste the feeding time. At present, this customer has already purchased nearly 10 sets of history. Tauber robotic equipment. And they plan to redesign a press line to replace a die press line with a robotic flexible production line. This involves the transfer of materials in the process through robots. The robot usage of this line may be up to several dozen. The use of robots not only saves costs, but also increases the level of automation. The entire process does not require manual intervention.

It is still a certain time before various domestic depots will accept the robotic flexible laser cutting method. Integrators need to further improve the robot's integration capability, improve system accuracy and speed, and in particular the safety and stability of the system, so that users in the automotive industry can gradually start batch production. Using robotic flexible laser cutting solutions.