10-fold increase in productivity achieved with ABB robots
Innovative product design, combined with a flexible automation initiative spearheaded by ABB welding robots, has helped IT and electronic enclosure manufacturer, Rittal, maintain the competitive edge across its UK operations. On some operations the use of ABB welding robots has resulted in a 10-fold increase in productivity.
Based near Plymouth, the UK manufacturing arm of Rittal CSM Limited, part of the global Friedhelm Loh Group, supplies the IT server/data-communications market, providing a range of state-of-the-art enclosure systems for some of the world’s most prestigious manufacturers such as Dell and Compaq.
Rittal has integrated robot-based automation across its welding cells at regular time intervals and now employs ABB six-axis robots in a wide range of applications. These include MIG, TIG, spot, stud and plasma welding, as well as linishing operations.
Two fully automated paint plants, and various CNC-based machine tool operations including power pressing, roll forming, piercing and folding, complement the robots.
“The decision to automate was initially driven by a requirement for improved throughput at lower cost,” says Technical Director Stephen Hobbs.
“Robot manufacturers who were already customers of Rittal were invited to tender for the development of an initial cell. A short list was drawn up, and, against stiff competition, ABB was finally selected because they satisfied our requirements in a number of critical areas.”
“We selected ABB because it had a strong application-led background upon which Rittal could lean on; they said they could respond within four hours to a service request - an important and impressive claim when one considers the geographical location of our site; ABB’s robot technology is very sound; and last, but not least, it was important to us that our investment was safeguarded by using an industry leader with very extensive resources, and in this area, obviously ABB measured up.”
An ABB robot-based MIG welding cell manufacturing wall-mounted enclosures was introduced to a somewhat sceptical workforce in 1993 and immediately achieved increased output compared with previous manual welding operations. An added bonus was that it was possible to reassign personnel to more productive, less physically arduous duties.
Mr Hobbs adds: “A further benefit of using robotic welding was the high quality of the weld. The ABB robot is configured with some innovative tooling, which can access confined spaces more efficiently than by manual welding techniques, producing a cleaner, neater weld. This improved the aesthetics of the product and reduced the requirement to grind the weld.”
As the benefits of the original MIG cell became apparent, the system was extended with the addition of a further MIG welding robot, and ABB robot-based cells have been progressively added over the past eight years. In addition to MIG, TIG and plasma welding operations, a robotic stud welder and a robot ‘linishing’ system have also been installed.
Mr Hobbs comments: “As our investment has evolved, the earlier requirement of lowering costs and increasing productivity have changed. Funding for the robotic stud welding operation was justified because it was compact and more accurate than manual stud welding methods, while the robotic linishing system was introduced to enhance health and safety by removing certain manual operations.”
Rittal’s current complement of ABB robots comprises a MIG welding cell (two robots), TIG welding cell (one robot), linishing cell (one robot), three MIG frame welding cells (two robots to each cell), a further MIG frame welding cell (one robot), ‘VR’ spot welding cell (one robot), one stud weld cell (one robot) and one ‘TS8’ plasma/MIG cell (four robots). A further robot is used for training purposes.
Rittal employs a manufacturing strategy in which products are assembled in stages at progressive build levels or ‘platforms’. Basic sub-assemblies are fabricated on the initial build platform; the main structure and framework follow on the next platform, and chassis and stiffeners are added on the final platform. All the ABB robots are specially configured to operate on a specific build platform.
The most recent automation acquisition is the plant’s ‘TS8’ cell, which incorporates four ABB welding robots, fabricating one of Rittal’s flagship products, the TS8 enclosure system. ABB simultaneously supplied identical systems to both the UK and for Rittal’s USA manufacturing plant at Springfield, Ohio.
The TS8 cell typifies the Rittal concept of successfully integrating innovative product design and flexible automated manufacturing, to produce a versatile and elegant enclosure system that is leading-edge and extremely competitive on price.
The efficiency of the TS8 design - achieved through CAD/finite element calculations – uses fewer parts and less material than comparable products, and is complemented by the strength and rigidity of the product’s welded joint structure, which is fabricated using plasma arc and MIG robot welding techniques. An added bonus is that the weld seams are of such high quality that no post-welding dressing operations are required.
The ongoing investment in CNC and robot-based automation is resulting in the delineation between specific manufacturing processes become less distinct, as metal folding and welding cycles become single, continuous operations. Thus the possible acquisition of ‘press tending’ and ‘material handling’ robots in the near future could produce the plant’s first completely automated manufacturing line for some of Rittal’s products.
Working 24 hours a day, five days a week, the reliability of Rittal’s ABB robots is described by Mr Hobbs as ‘very good’ and expansion of robot-based technology within the plant is being actively discussed. Rittal is also considering using two ABB IndustrialIT software packages to increase productivity. ABB’s RobotStudio off-line editing program, and WebWare are just two future possibilities.
WebWareTM is a comprehensive software platform enabling local and remote monitoring of plant-wide production data, statistics and diagnostic information using a standard Internet browser. Using WebWareTM, Stephen Hobbs will be able to view live manufacturing data from Rittal’s USA and other plants around the world and, if necessary, use the information to ‘fine-tune’ the Plymouth operation to obtain optimum efficiency and output. Equally, other plants will be able to benefit from sharing the knowledge of the Plymouth plant.
Priority at the moment, however, is a major retooling programme with innovative tool design to fully realise the flexibility of ABB robots and delivering payback on investment in terms of even higher levels of productivity and manufacturing efficiency.
Eight years on and Rittal’s flexible automation initiative appears to be an unqualified success. Stephen Hobbs sums up: “On MIG welding alone, our productivity has risen 10-fold, so undoubtedly robot-based automation, coupled to our innovative product design and development, has given us major cost savings and competitive advantages in the market place.”