July 2008 Edition
hot markets review: oil, gas
Cutting premium threads
Automated oil coupling cell solves a barrel full of production problems
Couplings in this photo are going to be threaded. A complete 9 5/8" diameter
premium coupling can be produced in approximately 11-12 minutes.
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
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.
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.
Waiting for its turn, this coupling will soon be threaded.
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
An inspector checks the threading on the oil couplings.
"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.