Flexible Fixturing Enhances Production Flow in Robotic Welding Environments
In traditional robotic welding environments, parts were held in place with dedicated
tooling sensors and custom fixtures (jigs). Although effective, custom fixtured
machinery can be expensive and limiting. Hard tooling does not allow for quick
part changeover, part-to-part variations, or enable efficient workcells that
can tackle multiple tasks. Traditional welding systems also required parts
be moved manually into the workcell for hand welding and inspection.
Contemporary welding manufacturing environments demand flexibility and
require frequent product changeovers whenever necessary. Constant pressure
exists in the manufacturing environment to provide higher quality parts faster
and in smaller runs to satisfy customers. In a welding system, this is done
with multiple industrial robots adapted with simple grippers that allow the
robot to manipulate the part from every angle, achieve 360° welds, and
better overall weld positioning. This flexible fixturing with
robotics is less expensive, improves product quality, and increases manufacturing
In the following example, the robot equipped with a simple gripper picks
up work pieces from random bins or trays. Flexible and low-cost robotic welding systems such
as these eliminate dedicated peripheral devices and labor for part feeding
and aligning. Lower cost, simple grippers are also used which eliminate the
need for part present sensors.
Automatic Workpiece Feeding for Welding Applications
||Flexible Fixturing Robot System
|Fork Truck Operator
||Chance of accident or injury.
||Fork Truck Operator or Automated Guided Vehicle
||Both cost effective and efficient.
|Workcell operator retrieves part
||Heavy, awkward parts; hard to handle part-to-part variation.
||Vision system locates part in bin or feeder.
||A variety of parts can be presented with no fixturing required.
|Operator welds the part.
||Inconsistent welds and weld process.
||Robot uses process data to weld the part.
||Consistent process and recipe management; matches repeatable high quality
welds. Easy and quick changeover achieved. Cost effective lower volumes possible.
||Possibility of human error.
||Vision system inspects the parts and the output.
||Accurate part output, improves part quality and better recipe management
(gas, wire type, etc.).
|Good/Bad Part Recording
||Time consuming and can be inaccurate.
||Network information is sent to the PC.
||Efficient data transfer and validation.
||No additional sensors required.
||Uses vision to reduce the number of geometric tooling required in order
to simplify the system.
Manual operations traditionally transferred workpieces into the workcell.
Now, a robot with FANUC Robotics' integrated iRVision can be used to find and pick the parts. iRVision
can be trained to locate different parts and sort them, or determine whether
or not they pass inspection before or after the weld. iRVision
tools can also be used in the actual workcell to adjust the off-line program
to the actual workpiece.
Shown below is a TripleARM system in which two M-20iA
robots together with an ARC Mate 100iC are controlled by a single controller to provide flexible programming and
improved capability. The M-20iA robots'
integrated through arm cables improve motion range and increase flexibility
for a variety of conditions. iRVision 3DL
allows loosely ordered parts to be picked from bins eliminating expensive
complex tooling. iRVision also provides
part identification and robot path guidance which increases process reliability.
In this example, the M-20iA robots pick
exhaust pipes from bins while coordinating the pipe assembly with an ARC Mate
robot. This seamless coordination allows production of a wider variety of
A TripleARM Robot Controlling Two M-20iA
Handling Robots with an ARC Mate 100iC
As discussed in Using
Robots to Go From CAD to Part, off-line programming tools can assist
in creating a cost-effective welding environment. Off-line programming uses
a 3D CAD model of the workpiece to set up and program the system before it
is tested on actual equipment. It simplifies and reduces costs for system
layout, performing interference checks and estimating cycle time while conserving
critical workcell resources such as equipment and manpower. The off-line programming
operator can specify the welding path by simply clicking the line on the CAD
model. A welding program is then easily generated with the designation of
torch angle, and travel angle after the verification of both the robot stroke
limits, and that there is no interference between robots and work pieces.
In the completely coordinated example below, the R-1000iA
robot loads and unloads a family of products. A two-axis positioner with a
simple tool holds the part in place. The DualARM ARC Mate 100iC
robot with iRVision locates the weld seam.
Finally, the R-1000iA cleans and polishes
A QuadARM robot can be used to control two R-2000iB
Handling robots with dual ARC Mate 100iCs
providing flexible programming and improved capability. An ARC Mate 100iC through arm welding dressout package provides
a wider motion range without the reliability of external weld torches. Through
arm cables provide off-line programming capability without touchup so a variety
of parts can be programmed off-line and there's no need to spend time to validate
on the actual cell. Due to its high payload capacity and excellent work envelope,
the R-2000iB robot provides flexible part
placement with excellent path control for coordinated motion. In the following
example, Dual R-2000iB robots with tool
changers dock various part fixtures while coordinating with an ARC Mate 120iC robot improving workcell flexibility.
R-2000iB/165F and ARCMate 120iC Welding Workcell
The following figure shows two QuadARM ARC Mate 100iC
robots with DualARM M-710iC Toploader robots providing flexible programming and improved capability. The ARC Mate 100iC robots with integrated through arm cables improve
motion range and increase flexibility for a variety of conditions. In this
system example, a variety of parts is picked from loose ordered racks all
while coordinating the assembly with QuadARM ARC Mate robots to produce high
QuadARM ARC Mate 100iC with DualARM
M-710iC Toploader Robots
Several successful flexible fixturing systems exist that are proven
to cut costs and improve production. For example ARCMate 100iB
robots, along with Dual Arm and R-2000iA
robots, have been used to weld after market mufflers. This system used several
key software features to create a labor savings and flexible model changeover
for the customer including Dual Drive simplified tooling and reduced integration
and programming costs. In addition, the customer realized an increase in production
and part throughput.
After-Market Muffler Welding
In another system in which no robots had been used previously, FANUC
Robotics' M-710iC robots are welding commercial
heating and cooling units. Using iRVision
for part ID to locate weld seams among various stainless steel models, the
customer was able to reduce labor costs and cycle time, while improving product
quality. Faster process times were realized versus traditional touch sensing
Robots are Being Used to Weld Industrial Heating/Cooling Units
ARCMate 100iC robots solved increased
labor cost issues and improved product quality for one industrial customer
welding transformers. iRVision was used
to locate and weld complex parts which also produced faster process times.
No orientation was required since iRVision
was used to locate the “flats” on each weld nut making welding
easier. iRVision was incorporated into
other applications within the same cell for an efficient and cost-effective
iRVision to Locate Weld Joints
In some cases, flexible manufacturing systems combine material handling,
spot welding and gas metal arc welding (GMAW) to incorporate an efficient
and proven weld and process technology. This is the case in which ARCMate
100iC robots, along with R-2000iA material handling and servo gun robots are assembling
a complex galvanized bumper assembly. Almost immediately, the customer realized
a labor savings with a system that handles frequent model changeovers at low
GMAW of Galvanized Bumper Assembly
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