A new robotic facility entered production in July 2004 at the Coventry factory of automotive supplier Unipart Eberspächer Exhaust Systems (UEES), to manufacture stainless steel exhausts for the Land Rover Discovery 3, due for launch this autumn, and for a future model of Range Rover. A total of 21 Motoman robots served by rotary positioners from the same supplier have been installed. Most are for arc welding, with two robots being deployed for in-process sub-assembly operations. Motoman advises that four interlinked cells make up the new production facility, which operates two shifts, five days a week producing three exhaust variants for the Discovery 3 and, later this year, three for the future Range Rover model. Two cells containing four robots each currently weld twin-skinned, fabricated manifolds for V6 and V8 petrol engines respectively for the Discovery 3; and a twin-robot cell welds all the downpipes. The fourth cell, with nine robots, produces inter-rears – the section from the end of the downpipes to the tailpipes, including silencers, of which four are required for each petrol engine. A further two Motoman robots carry out assembly of internals for the silencers. One technical innovation that has reduced both the capital investment and footprint of the inter-rear production cell was to configure two Motoman UP20 robots with a twin-wire feed system, normally used with identical wires to increase speed of deposition and allow thicker material to be welded. However, in this case two different types of stainless steel wire are used sequentially, one austenitic and the other ferritic, to accomplish different joining operations and avoid having to install additional robots. The same technique is used on a Motoman UP6 robot for cup welding on V6 manifolds.
