Bottom up robot

NKK is developing a welding robot that can weld on a ship`s bottom shell plate from underneath the bottom of the ship while in dry dock. The company says it has devised a way to prevent the welding metal from dripping by using a copper shoe under the welding pool, making it possible to weld from the outside of the shell. Consequently, automation of the welding process is possible, says NKK.

The robot inserts two welding torches horizontally, one above the other, into the gap between the two plates to be welded and weaves them sideways to fill the gap. The torches are fitted with laser sensors, which allow the robot to monitor the gap width and welding direction. The torches are mounted, together with the power source and control equipment, on a four-wheeled carriage fixed to the end of an extendible boom, which is raised to bring the machine against the shell plate.

NKK plans to conduct further tests to improve the accuracy of welding control and hopes to launch the system this year.

Contact: Tomohiko Sato
Fax: +81 3 3214 8400.