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Portable Robot Automates Pipe Welding
by Jeffrey Noruk
A major supplier of oil well drill pipe developed a new design which will be the most efficient in the industry. To accomplish this the pipe had to incorporate unique features like full expandability and an integrated sand screen. This design challenged the normal manufacturing methods used in the past. The 40 feet length of the pipe presented challenges in the area of fixturing, weld consistency and excessive distortion. The manufacturing tolerances stacked up to exceed the ability of the original welding equipment to compensate for it. After making several prototypes, the customer decided that a change was needed and selected a Servo Robot portable fully programmable robot with integrated laser sensing known as Mobitrac.
Description of Process or Solution
The Mobitrac allowed the original setup to be greatly simplified by reducing the time to line up the weld joint to the fixed carriage that the robot rides on. Now only two points need to be programmed and from there the laser vision sensor takes over and follows the weld joint within the repeatibility required to make defect free welds. It is able to not only handle the inherent joint variability but also it can compensate for the real time distortion which occurs due to the length of the tube and the inability of the fixturing to control the distortion.
The success was easy to measure because prior to the installation of this equipment , this pipe was not weldable in any type of efficient manner. The setup time was excessively long and the ability of the welder to adjust the welding torch along the full 40 feet was not feasible, which meant defects were sure to occur. The welding speed was increased which improved productivity while at the same time insuring the weld quality met the welding standard. The original retrofit was so successful, that now a second system is being purchased to work in a subassembly operation where the joint is even more sensitive and the material thinner. This capability to produce the newly designed pipe in a fast and high quality fashion will allow this manufacturer to gain more market share in the industry.
Manufacturing Tolerances: Yes
ANSI/RIA R15.06-1992: Yes
Total Robots Installed: 2
Key Peripherals Installed: Laser Vision Sensor
Date Installed: November 2002
Shifts Per Day: 2