Automated robot cell reduces weld time and improves quality of Caterpillar's sub-assemblies

Citation

(1998), "Automated robot cell reduces weld time and improves quality of Caterpillar's sub-assemblies", Industrial Robot, Vol. 25 No. 6. https://doi.org/10.1108/ir.1998.04925faf.005

Automated robot cell reduces weld time and improves quality of Caterpillar's sub-assemblies

Automated robot cell reduces weld time and improves quality of Caterpillar's sub-assemblies

Quality sub-assemblies for Caterpillar, the world's largest manufacturer of construction and mining machinery, are now being welded in less time, to higher, repeatable weld quality thanks to a CE-marked automated welding cell from Panasonic (see Plate 4).

Panasonic's single-robot, twin workstation welding cell is installed at Tamworth-based sub-contract manufacturer, Darwell Fabrications. and has completely automated the welding of the sub-assemblies for Caterpillar's Compact Wheel Loaders. The cell significantly reduces manufacturing time and cost as it allows the whole assembly to be fully welded in a single cycle without the need for manual welding and tacking.

Originally announced in April this year, Panasonic's modular, (CE-marked robot-based welding cells for manufacturers in the construction and agricultural equipment industries are modular systems that can accommodate components up to 3m in length and over 1,000kg in weight and can be supplied with the company's Spin Arc sensor for accurate, high-speed welding of larger component piece parts. Darwell's cell, which was constructed off-site and delivered as a single unit, is based around two workstations and a single Panasonic Pana Robo welding robot. Caterpillar's components are assembled in the cell by welding and pretacking brackets at the first workstation before transferring the kit of parts to the second workstation where they are welded to the larger, main plate components.

Plate 4 Automated robot cell for Caterpillar sub-assemblies

The new welding cell has been supplied complete with guarding and electric controls and is mounted onto a single, steel-fabricated plinth measuring 2.5 x 4.5m. A Pana Robo VR-008A welding robot is centrally mounted between the twin workstations, each of which incorporates a 1,000kg Panasonic Panadice manipulator and tailstock providing 2.5m between faceplates. The welding robot is interfaced to a Panasonic RF350 II inverter power source and is fitted with the Panasonic Spin Arc Sensor welding torch which provides the high-speed tracking necessary for a wide variety of joint configurations and weld sizes including lap joints stitch welding and multi-pass welds. The Spin Arc Sensor guarantees consistent, repeatable welding quality by ensuring the correct weld line positioning for both the tacking and welding of the sub-assembly components and the high-speed higher deposition welding of the final assembly.

Both of the cell's workstations are protected by a two-part lathe-type guard capable of opening to 2.5m to allow component loading manually or by crane in the case of heavier items and tooling plates. Flash protection screens are automatically positioned on the opening of the guard doors to ensure operator protection during loading.