Robots make light work of assembly

As part of its ongoing, multi million pound improvement programme, Magneti Marelli has restructured its production facility for automotive headlamp units. The original line employed labour intensive batch building, with a bad working environment that was uncomfortably hot and where workers were effectively isolated from their colleagues.

With an emphasis lean production more flexibility in labour utilisation, the company explored the robotic option, and saw it as an opportunity to automate the unpleasant repetitive operations, boost morale and promote team building.

ATM won the contract for the robotic systems and, over the last two years, has successfully provided automated production equipment on three lines: manufacture of clear lenses, with polycarbonate injection moulding taking the place of traditional glass prismatic lenses; manufacture of reflector mouldings from thermoset plastic, produced in a cell system; and manufacture of head lamp housings injection, moulded in polypropylene.

The first stage of the project was the automation of the production line for the headlamp reflector mouldings. Modern headlights do not use prismatic front lenses to direct the beam in the desired direction. This is now achieved through the shape of the moulded reflectors and the positions of the bulbs, meaning the mouldings are a precision component requiring extreme levels of consistent quality production.

ATM installed 11 AX2000 model robots with an automatic moulding unloader. The AX2000 is a pneumatically driven machine with movement through three axes. On the line, the robots have to contend with hot conditions and the presence of chemical fumes, and offer the necessary simplicity for frequent tool changes.

Sabir Hirji, ATM’s technical director, says: ‘The project presented us with a number of challenges. A variety of different machines were required, with differing complexities and the ability to perform a range of operations, with precision, in demanding environments.’

The project was completed with the installation of ATM machines into the production line for the headlamp housings. With these being made of thermoplastic, the machine had to use silicon grippers to cope with temperatures as high as 180 degrees C.