Robot speeds up welding with automatic temperature control

A new temperature-sensing welding robot could improve the speed and consistency of welds between different metals, its creators claim.

The temperature sensor dramatically reduces the time taken to programme the welding robot, researchers say.

Researchers from University West in Trollhättan, Sweden, have developed a tool for friction stir welding (FSW) that automatically prevent the welding temperature from exceeding the metals’ melting point.

‘It’s thanks to this temperature controller that we’ve managed to raise both the quality and the productivity of the robot system,’ said researcher Jeroen De Backer in a statement.

‘The robot welds with higher precision and with the temperature controller it only takes a few hours to programme 3D joints. Manual programming of a similar component took up to a week.’

FSW uses a rotating non-consumable cylinder that is pressed into the material to be welded. The combination of frictional heat and the mechanical “stirring” creates a high-quality welding joint, without melting the material.

But if the temperature becomes too high and the metals melt, the welding tool sinks through the sheets. The temperature sensor allows the robot to automatically control the heat generated by controlling the force and tool rotation.

The researchers have used the new tool to weld advanced three-dimensional joints, which enables the welding of small and more complex components with curved surfaces.

De Backer said the technique could be of particular interest to hybrid and electric vehicle manufacturers.

‘Car manufacturers aim to reduce the weight of the electric vehicle and positioning of the heavy batteries is a key factor in this,’ he said. ‘The battery consists of different metals such as aluminium and copper.

‘Friction stir welding provides the possibility to join those materials and allows thereby integration of the battery in the vehicle chassis so that the battery becomes a part of the bearing structure.’

The project was a collaboration with Volvo Aero, SAAB Automobile and the welding equipment company ESAB.