Witter Towbars installs ten ABB robotic welding cells

Witter Towbars, which is described as the UK's leading manufacturer of towbars, currently produces a complete range of towbars and towing-related accessories including cycle carriers, roof racks, and towing and non-towing steps. Following its last investment in 2005, Witter Towbars approached ABB for new welding cells to help improve plant efficiency and control, and provide full traceability of weld parameters by enabling monitoring of the weld data.

Working closely with Witter Towbars, ABB examined the key stages and requirements of the production line to determine what the robots would need to achieve and how. The answer was to provide Witter Towbars with ten welding cells, each featuring an ABB IRB1600 ID robot. The robot, which has an extremely slim arm, can combine multiple-axis movements and 360-degree rotations, which is excellent for performing the complex welds on round tubing needed in towbar manufacture.

Since being installed, the IRB1600 ID robots have helped the plant achieve a 20 per cent improvement in efficiency. The robots' ability to complete 360-degree welds has also reduced cycle times and improved both path accuracy and overall weld quality.

Furthermore, the installation is helping Witter Towbars to meet its own stringent requirements. The cells have been planned to accommodate the company's production line requirements, which limited the amount of floor space available for ABB's equipment. Using ABB's RobotStudio offline programming software, each cell has been virtually tested before being installed, which enabled the company to anticipate and resolve any potential problems in advance. There was also a requirement for improved fume extraction to improve workplace health and safety.

Factory automation

Speaking about the robot cells, Gary Nuttall, a Senior Manufacturing Engineer at Witter Towbars, explains: "Our history of investment in automation has helped to drastically reduce the number of manual welds carried out over the past five years. We still have a manual weld facility, but it is now only a fraction of what it was and is only used on specific, very old products that cannot be carried out using a robot.

"Our employees now form a multi-skilled workforce and have a much nicer plant to work in. The new cells contribute to an improved appearance at the plant as it is cleaner and quieter, producing a pleasant working environment for our employees. The new lines are an important development for the plant and the company as a whole, as they will be used for two of our new product lines: commercial roof racks and a new four-bike cycle carrier, ZX400."

Witter Towbars has made a significant investment in its modern manufacturing facility in North Wales, including laser cutting machines and the ABB robotic welding cells. Older models of ABB robots are currently being replaced and further developments for new automated production lines are under consideration.

Welding robots

ABB's IRB 1600ID robot is excellent for arc welding applications, as its dress pack is integrated inside the robot's upper arm. Containing all of the equipment necessary for arc welding, including the power supply, welding wire, shielding gas and pressurised air, the integrated dress pack is a key feature of the robot automation system that is now in place at the Witter Towbars plant.

An integrated welding cable follows the arm's movements, which ensures it does not get caught in any surrounding fixtures or workpieces. Nuttall credits the arm's manoeuvrability as a major selling point: "The older robots we have been using have a form of manipulator using eight index positions. With the new full manipulator, tubing that used to require a number of separate welds can be completed in a single 360-degree movement, helping to reduce our cycle times, improve path accuracy and enhance the quality of the weld."

For further information about the potential benefits of integrating robots into production processes, go to www.abb.co.uk/robotics.