Automated MAG welding of bogies for railroad wagons

Bogies are an essential component of railroad car chassis. They allow the ideal distribution of weight and the maintenance of rail contact of all wheels in all driving situations. These safety-relevant parts require high precision and quality in MAG welding. For a customer in Romania who specializes in the production of such bogies, Lasaco was asked to implement the automation of the welding work with a modern production system.

Together with our cooperation partner Kuka, we designed a system for industrial robots that met the customer's requirements in all respects. With the welding robot, MAG welding is possible on two independent stations. For optimal positioning of all relevant components, each industrial robot was given 11 axes of motion. The smooth workflow is supported, among other things, by a state-of-the-art laser camera system that constantly scans the components and determines tolerances that affect the course of the weld seams. Production has now been running fully automatically for years thanks to the Kuka industrial robot.

Industrial robot from Kuka with two independent stations for MAG welding

Accurate positioning of the sometimes very heavy components is required for rapid production. Before MAG welding can begin, the parts must be brought into the so-called tub position. For this purpose, Lasaco, together with Kuka, designed the system with two independent stations and welding robots, each of which operates with eleven automatically controlled motion axes. This ensures the ideal positioning of the components for the welding robot during each processing step.

Compensation of component tolerances is the biggest challenge for the welding robot

Components such as bogies for railroads have comparatively large tolerances. We therefore had to enable the welding robot to automatically compensate for the component tolerances. This was made possible after coordination with the manufacturer Kuka through the installation of a laser camera from Mabotic, with which the industrial robots can precisely record the seam geometry before MAG welding. Based on this information, the software, which is also involved, calculates the optimal guidance of the weld track. All other process parameters are also adjusted by the software, ensuring that the welding robot always delivers consistent quality. The data processing takes only a few seconds. The robot controller then adopts the parameters for the calculated welding path and the Kuka robot can start MAG welding.

Fully automatic tool change of the industrial robot

The Kuka industrial robot is able to perform an automatic tool change. This makes it possible to switch quickly between using the welding torch and the camera system. The decisive advantage of this approach is the ability to perform the welding work without interruptions. This increases the productivity of the production line enormously.

High-quality welds thanks to cored wire

The weld seams for rail car bogies were to be implemented in a very high quality according to DB specifications. Already during the planning of the project, the experts from Lasaco were able to recommend a suitable welding process for this. MAG welding with Kuka industrial robots is optimized by the use of high-quality flux-cored wire in order to achieve the required quality in the weld seams.

Extreme operating conditions challenge the MAG welding robot from Lasaco and Kuka

The production of railroad cars and their components is an extremely demanding process for equipment and materials. The conditions prevailing in this industry require continuous use of the industrial robots six days a week in 24-hour operation. To ensure that the robot system can meet these requirements without any problems, regular maintenance intervals are essential. To facilitate this maintenance, Lasaco has carried out comprehensive training of the operating personnel on site at the customer's premises. This provides the customer with its own maintenance capacities, without which uninterrupted production of the bogies would hardly be possible.

The highlights of the MAG welding of components for rail cars project at a glance:

  • Continuous checking of the current seam geometry by means of a laser camera.

  • Fully automatic generation of the weld tracks with constant adjustment of the process parameters to compensate for component tolerances.

  • A total of 22 axes for component positioning controlled by the robots.

  • Automatic tool change between camera scanner and welding torch.

  • Automatic adaptation of parameters to the currently generated weld path.

  • Use of filler wire for high-quality welds according to DB specifications.

Project gallery: Take a look at our Kuka industrial robot in action during MAG welding of railroad bogies