ATM robot cell secures production of seat belt mountings

The automotive industry is by far the largest user of robots within the UK and it is not uncommon for an assembly plant to have literally hundreds of robots deployed on welding, handling and assembly tasks. Robots are also a key part of the production systems in many of the 1st and 2nd Tier supplier plants, and at first glance it might appear that this market sector has too become saturated and that all technically and financially justifiable opportunities have been identified. However, with some innovative thinking, it is still possible to identify concepts for automation that will free up labour for re-deployment in other areas of production and still generate realistic financial payback. This has been the case at a Sunderland-based Tier 1 supplier to Nissan, where a previously manual welding and assembly process, requiring six operators over the three production shifts, has been automated using a single robot and a series of component feeding systems.

Components produced by the system are part of the seat belt mounting arrangement for the Nissan Qashqai, and each vehicle requires four such parts. The assembly comprises two small, formed plates and a threaded nut that needs to be held captive, in a repeatable position, between the two plates.

Three separate bowl feeder and linear units are used to present the parts to an escapement, where they are loaded in the correct position and orientation for welding. A Fanuc model 10iA, six axis robot, then picks up the components and moves to the spot welding station, manipulating the parts to complete the two spot welds required in a cycle time of just 8 seconds. Finished parts are then loaded to a box, presented on a conveyor system. The system has the capacity to hold four full boxes, one being filled and three empty boxes. This, in conjunction with the bulk hoppers used to present parts to the feeding systems provides 4 hours of continuous and unmanned running. The system also has an automatic tip dressing system which operates following a pre-determined number of cycles, ensuring high-quality welds at all times.

This system was built by ATM on two steel-fabricated plinths, for ease of transportation and subsequent installation on site. This concept allowed the system to be powered up and running within 2.5 hours of being sited. The system is now running on a three-shift basis to meet the demand for the new Qashqai, which is being produced at the rate of 4000 vehicles per week at Nissan's Sunderland plant.

For further information about robots from ATM, please visit www.atmautomation.com.