Finished component in 37 seconds, ABB robots way

By Niraj M Wanikar, Chief Editor, CNCTimes.com, 2015-03-17 10:58:36

From a sheet metal blank to a finished component in just 37 seconds – made possible by the new ABB robots in the Wolfsburg factory of German automotive supplier KWD Automobiltechnik GmbH.

Installed in eight welding cells, these robots produce wheel housings, sills and A-pillars for a German car manufacturer. The roll-up door of the welding cell opens almost silently. A KWD employee places several sheet metal blanks into the fixture of a turntable along with another part that has already had adhesive robotically applied in a previous step.

The employee then closes the door, activating the welding process. A turntable inside the welding cell positions the blanks in front of two ABB IRB 6640 industrial robots which make several spot welds, firmly joining the blanks together. Another IRB 6640 removes the joined part and positions it under a stationary welding gun which makes further spot welds. Finally, the component is moved underneath a scriber for marking.

This entire process takes only seconds until the finished wheel housing is ready to be removed from the cell.

Welding car parts at high speeds, KWD Automobiltechnik GmbH, Germany

Fast and compact

In addition to wheel housings, the automotive supplier KWD Automobiltechnik GmbH produces A-pillars and sills for a new model of a well-known German car manufacturer. Realizing they needed a new solution to meet the demands of their customer, KWD had rather stringent requirements for cycle times between parts.

“The necessary parts could not be produced with our existing equipment. This project earned ABB an ‘A plus’,” says Mr Guido Wittenberg, who is responsible for the technical planning at KWD.

Explains KWD production manager Mr Randy Koch, describing why the company invested in eight new automated welding cells, “The process from loading the blanks to the finished component, for instance, could not take longer than 37 seconds at each station.” Thanks to intensive simulations carried out in advance, ABB engineers were able to guarantee this cycle time.

Mr Wittenberg, who is responsible for the technical planning at KWD, adds, “On an average, the other suppliers’ concepts were 10% slower than our specification. In addition, space is restricted in our production halls and the space-saving design of the ABB robotic cells came in very handy for us.”

A total of 20 ABB IRB 6640 robots, and one ABB IRB 2600 robot, are now working in the four new plants. Safety features such as access control, enclosures, light barriers and roll-up doors were also supplied and installed by ABB. As the system supplier, ABB was responsible for the planning, design, manufacture, delivery, assembly and commissioning of the plants.

Millimeter accuracy with ABB software

“As an automotive supplier we have to stick to very tight tolerances,” says Koch, highlighting the precision of the machines.

The IRB 6640 robots have no trouble meeting the strict requirements for handling and welding processes. The powerful IRC5 robot controller allows them to work with sub-millimeter precision, meaning the welds are on exactly the same spot, on every part, every time.

In addition, the controller monitors the robots’ internal loads, reducing the risk of overload situations and extending the lifetime of the robots. “With regard to service and maintenance cost, this was a very important argument for us,” stresses Wittenberg.

Six weeks to the first component

Given that ABB represents the third robot manufacturer to have a presence in the factory, the operating personnel were particularly skeptical at first.

“For our colleagues this meant an increased initial training effort and an adaptation phase,” explains Wittenberg. However, by providing comprehensive theoretical and practical training, ABB ensured a short transition. “The short implementation time was impressive,” says Koch. “From delivery of the equipment to production of the first component it took only six weeks.”

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