Welding quality, point by point

KUKA Roboter optimizes process reliability in spot welding

2005. szeptember 9.

Augsburg/Essen, September 2005 – At this year’s flagship fair “Schweissen & Schneiden” (Booth 130 in Hall 1) in Essen, Germany, KUKA Roboter, the Augsburg-based market leader and driving force for industrial innovation in the welding technology sector, is unveiling a new technology for the optimization of process reliability in spot welding: interchangeable, electric motor-driven weld guns with an integrated force sensor.

These interchangeable, electric motor-driven weld guns with integrated force sensors from Augsburg-based KUKA Roboter are the major innovation in spot welding at “Schweissen & Schneiden”. The KUKA KR C2 robot controller continuously regulates the exact force throughout the welding operation using a sensor integrated into the motor of the gun. The result is reproducibly high seam quality. Existing industry solutions have relied on expensive and sporadic quality control using special quality assurance systems. The special feature of the solution from KUKA Roboter is that the servo gun is operated as a robot external axis. This significantly reduces cycle times compared with solutions involving external controllers. This is because all gun motions are programmed and executed via the robot control panel in synchronization with the robot motion. Furthermore, the internal communication between the robot and the gun controller eliminates interface problems. The servo guns are controlled using the tried-and-tested KUKA axis servos in the robot control cabinet.

The force-controlled servo guns are programmed and operated using the KUKA. ServoGun_FC technology package. Customers receive the sensor system and KUKA robot controller as a complete system.

The challenge lies in new materials

Robotic spot welding is widely used in mass production, and not just in the automotive industry, where KUKA Roboter has been a recognized partner for many years. Other industries are increasingly turning to this technology, particularly in the fields of apparatus engineering, electronic systems and the manufacture of domestic appliances, such as washing machines and tumble driers. New materials, however, have significantly increased the demands placed on spot welding technology. The increasing use of high-strength steels is continuously reducing weld tolerances. This is precisely where KUKA Roboter comes in with its new solution, optimizing the process by means of high accuracy and reproducibility of the electrode force thanks to the integrated sensor system.

This approach from KUKA eliminates thermally-induced force fluctuations, and the weld force remains constant, even when the electrode tips have started to wear. Furthermore, force profiles can be defined, bringing the user a high degree of flexibility with respect to the material to be processed. An interesting “byproduct” is the possibility of obtaining weld point documentation based on the force signal generated during the process. This is highly useful in the age of the warranty obligation.

Turnkey spot welding system solutions from a single supplier

In addition to tried-and-tested spot welding robots, KUKA Roboter also offers complete systems for this sector. The customer no longer needs to look to a range of different manufacturers for the individual components required. KUKA Roboter provides complete, tested systems tailored to the customer’s specific requirements – all from a single supplier. In this way, the customer is spared lengthy negotiations and coordination with contacts from different companies. Another advantage for the customer is that a complete system from KUKA Roboter also comes with comprehensive customer support for the entire functional unit.

A powerful partner in all areas of welding

KUKA Roboter has been a powerful partner to the automotive industry for many years and is extremely familiar with the requirements of its customers. There are very few manufacturers who have not placed their confidence in KUKA robotic solutions in their worldwide production facilities. Additionally, KUKA robots can nowadays be found in all branches of industry. Customers benefit from the company’s expertise that has been acquired over many years, resulting in integrated solutions. KUKA Roboter offers robotic solutions and highly rationalized process technologies covering the entire welding process chain, from spot welding to laser welding and arc welding. These are complemented by so-called hub technologies based on the intelligent networking of standard controllers. Irrespective of the individual technologies involved, KUKA Roboter’s welding portfolio is characterized by an integrated system philosophy, a uniform look and feel, common application devices and consistent maintenance and upgrade concepts.

About KUKA Roboter GmbH

KUKA Roboter GmbH, Augsburg, is a member of the IWKA Aktiengesellschaft Group (Karlsruhe) and ranks among the world’s leading suppliers of industrial robots. Core competencies are the development, production and sale of industrial robots, controllers, software and linear units. The company is the market leader in Germany and Europe, and the number three in the world. The KUKA Robot Group employs about 2,000 people worldwide. Of these, 1,100 are employed in Germany, either at the KUKA Robot Group headquarters in Augsburg, or at various subsidiaries. In 2004, sales totaled 425 million euro. Over 20 subsidiaries provide a presence in the rest of Europe, the US and Asia.