July 2008 Edition

hot markets review: oil, gas

Cutting premium threads

Automated oil coupling cell solves a barrel full of production problems

Oil couplings were being manufactured on manual lathes or NC machines in 1977 when P.S. Reddy, Okuma product specialist, began in the business. About a year later, CNC machines came on the scene for production, and premium threads or proprietary threading oil drill-pipe couplings also were developed then.

While the concept of oil coupling production hasn’t changed much, the need to produce better, faster, safer, and more accurate couplings has. Okuma and Partners in THINC have collaborated to create automated oil coupling cell solutions — unique to the industry — to help meet growing demands on the oil and energy business.

"The standard methods for coupling production have included a lot of manual loading and unloading of coupling material into older equipment with the operator constantly stopping the machine to remove chips, particularly during the threading process," Reddy says.

"Cutting over chips, breaking an insert, high scrap rates and operator injuries were issues customers told us they would like to resolve," he says. "No one had previously pursued this because of the time and money involved."

Enter Okuma and a group of collaborators.

“Cutting over chips, breaking an insert, high scrap rates and operator injuries were issues customers told us they would like to resolve. No one had previously pursued this because of the time and money involved.” — P.S. Reddy

Out went at least three machines and three operators from the conventional method for production. They weren’t needed with the new automated cell.

The new automated oil coupling cell features the four-axis Okuma Lathe Oil Country (LOC650), a two-axis Okuma V80R vertical turning lathe, and a Fanuc gantry robot.

For the 14.75 throughbore cell, the robot loads a double-length coupling blank weighing approximately 105 pounds into the LOC650 (zone 1). The lathe performs the ID and OD roughing and finishing and a cut-off operation to produce two 10" couplings before sending the processed couplings down a gravity-fed conveyor to the V80R lathe (zone 2) for threading, profiling, and finishing.

Coupling cycles

A complete 9 5/8" diameter premium coupling can be produced in approximately 11-12 minutes, 24 hours a day. If parts, tools or maintenance become necessary in one zone, the other zone can still continue production, avoiding an entire operation standstill.

"Besides the fact that the robot does all of the heavy lifting and there are no additional set-ups involved, we’ve tackled the chip evacuation issues that have also kept operators busy throughout the cutting process," Reddy says. "A lot of this wouldn’t be possible without the participation from so many of our collaborators at Partners in THINC."

Partners include many well-known names in the manufacturing industry including LNS Turbo, BigFix, Symantec, Trend Micro, Webex, Hexagon Metrology, ChipBlaster, ToolBoss, Kennametal, Sandvik, Marposs, Schunk, Iscar, Zoller, Caron Engineering, and Shell Lubricants.

The partners are able to capitalize on the open architecture (API) of the THINC-OSP control to interface/integrate with the lathes seamlessly. For example, the Fanuc robot is integrated through the THINC-OSP control through a robot D-interface instead of having to hardwire the unit.

As a result, it can connect directly through the Ethernet network and easily become the master for the load/unload cycle — confirming when parts are clamped/unclamped as well as responding properly when the machine is open or closed.

Another THINC-OSP integration is with Marposs gaging, set to check the thread and ID diameter once the part is complete. The interface provides feedback through the controller to offset tool geometry, making the ID smaller or larger based on tool wear or thermal growth.

Before there was an automated oil-coupling cell, operators were constantly removing chips from the chuck jaws and the part itself to avoid breaking inserts and tools and creating out-of-round parts. Now, with ChipBlaster, precisely placed coolant creates a constant flow that not only flushes the chips out and away from the chuck and part, but also helps cut shorter chips to avoid stringers and balls that impede the process.

On the V80R, the vertical spindle, modified adapter and gravity also help minimize chip build-up. With automation, it’s even more important to remove chips properly or the Schunk "oil country" chucks and Fanuc robot cannot grasp the part or parts properly. Chips can also damage tools causing gouging of the part.

Variations coming

"We had a lot of hurdles to overcome with the initial cell to combat the chip removal issues, but have been able to apply the knowledge to the current and future cell development with great success," says Jeff Estes, director of Partners in THINC. "We’ve already sold our first cell and are working on variations for other customers and potential customers."

After customers saw the new automated coupling cell demonstrations, interest developed for cells that would handle different sized-couplings and configurations to fit a variety of customer needs, particularly demands for 4"-7" API and premium couplings.

As a result, the newest automated oil-coupling cell to be created by Okuma and Partners in THINC has been modified to cut P110 seamless steel coupling on an Okuma 2SP-V60R vertical lathe and an Okuma LU45 horizontal lathe that is loaded/unloaded by a Fanuc 2000i robot.

The smaller cell also means fewer machines and operators needed to maintain production compared to conventional methods. Estes says Gosiger Automation came on board to assist in the development of new solutions, particularly the robot safety fence integration and the floor-mounted robot system.

"Gosiger Automation helped with some problem solving with the first cell, but have become very active with the new cell development," he explains. "The smaller coupling cell will be fully operational for demonstrations at IMTS 2008 at the Okuma booth. We’re very excited to have such a platform to showcase this advanced technology in conjunction with our Partners in THINC partners."

"What we’re creating here is not a done deal, but an ongoing process — one that we are constantly improving and customizing based on customer needs and applications," Estes adds.

Okuma and Partners in THINC

What do you think?
Will the information in this article increase efficiency or save time, money, or effort? Let us know by e-mail from our website at www.ToolingandProduction.com or e-mail the editor at dseeds@nelsonpub.com.