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MOTOMAN ROBOTICS (UK) LTD |
Press Release
LINKED ROBOTIC CELLS AUTOMATE BENDING AND WELDING OF LIGHTS continued
A robot was chosen to manipulate the component rather than a servo-powered positioner. A series of grippers is needed to accept different components from the press brake cell or from the manual loading gate, or both, depending on the product. Two end effectors have been designed and installed on the UP130 by Bauromat, one for long components and the other for smaller, square parts.
It would not have been feasible to position components for welding using traditional manipulation techniques, as some products need to be held at unusual angles to the weld torch to achieve the correct attitude for laying down a neat weld pool that does not require extensive dressing afterwards.
Furthermore, positioning accuracy is crucial as it is only too easy to blow a hole in thin sheet material with the weld torch, and it was felt that twin-opposed robots could better provide the required degree of accuracy and control. Already a wealth of data and experience has been gained, and the cell continues to be used both for research and as a production tool.
The need to retain two methods of loading the welding cell was driven by the disparity between the press brake cycles and the welding times, the latter being considerably shorter at between 0.5 and 1.5 minutes. In practice, for most of the day shift a mix of jobs is manually loaded for welding, including some components that cannot be folded by the automated press brake anyway. The turret punch press operator also runs the robot welder, so there is no additional labour cost involved.
During the ghost shift and at appropriate times during the manned evening shift, the press brake robot passes the folded part directly to the handling robot in the welding cell. Currently, when the cells work in tandem, the welding system is idle for a proportion of the time waiting for components to arrive from the press brake. However, the intention is to introduce grinding or linishing after welding to dress the components and balance the cycles, using the UP130 to present the weld seams to a static, abrasive machining station.
Weld cycle programming is currently by teach-in, but this too will be taken off-line in the near future. Sixty to seventy product variants, mainly long, thin fittings but also end caps, are produced in the cell in batches of 200 to 6,000-off, although this will reduce as in-house jig design and manufacture progresses.
Mr Johnson summarised: “For anyone thinking of automating production processes, it is noteworthy that articulated arm robots are very reliable these days. The Motoman equipment has not failed once in either cell since their installation.
“Another, often-overlooked factor is that this type of automation is visually appealing and has proved to be a useful sales tool when customers visit us. Rightly or wrongly, people do not expect a part that comes out of a robot cell to be inaccurate.
“Perhaps most importantly, the modern trend is towards manufacturing more product variants of greater complexity in smaller batches; certainly this is our experience. Automated CNC cells are the best way to handle such production economically.”
For More Information Contact:
Motoman Robotics (UK) Ltd
Johnson Park, Wildmere Road, Banbury, Oxon OX16 3JU
Tel: 01295 272755
FAX: 01295 267127
E-mail:
information@motoman.co.uk