Final Automated Welding Presentation

8/13/2019 Final Automated Welding Presentation

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What is Automated Welding

Semiautomatic Operator manually loads the part into the welding fixture

Weld controller keeps the process, torch motion and stillness ofthe part to present parameters

When weld is completed the operator removes the completedassembly

Fully automatic welding, Machines load the work piece

Index the part or torch into position

Accomplish the weld

Monitors the quality of the joint

Unloads the finished product


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Why Not Automate?

Disadvantages- Higher initial setup costs

* less than $5000 for a manual setup

* About $30,000 for semiautomatic

* Up to $250,000 for fully automatic

- Flexibility of performance is exchanged for accurate, repeatable, andprecise welds.

- Placing all eggs in one basket

* Relying on 1 machine for an 8 person job

- Longer lead and delivery times for automated machinery


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Economics

Manual

Welding

Semi-Automatic

System

Automatic

System

Number of systems required for

equal output 8x 4x 1x

Individual system cost $5,000 $30,000 $190,000

Total equipment/system investment $40,000 $120,000 $190,000

Individual welder cost/year $48,000 - -

Individual operator cost/year - $30,000 $30,000

Labor cost/year for equal volume

of output. (one 8 hour shift) $384,000 $120,000 $30,000

Labor & equipment costs for a 12

month period with one 8 hour shift $424,000 $240,000 $220,000

Labor & equipment costs for a 12

month period with two 8 hour shifts $808,000 $360,000 $250,000


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Types of Automated Welding

TIG Welding

Common high quality process

Arc formed between tungsten electrodeand metal being welded

Gas fed through the torch to shield theelectrode and molten weld pool

Benefits Low distortion

Precise control of welding variables

Excellent quality welds


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MIG Welding Wire continuously fed

from a spool Benefits

All position capability Less operator skill

required Minimal post welding

cleaning required Problems

Undercutting Irregular wire feed Unstable arc

Difficult arc starting


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Ultrasonic Welding

Mechanical vibrations

Parts to be weldedsimultaneouslybonded

Static and dynamic

forces at same timecause fusion of parts

Can be used forplastic or metal


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Ultrasonic Welding

Advantages

Strength of bond Very fast and easily automated

Energy efficient

High productivity with low costs

Disadvantage

Maximum component length~250mm


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Laser Welding

Advantages- Capable of Deep penetration welds with minimum heat effective zones (minimizes thermal distortion and increases precision)

- Ability to weld dissimilar metals

- Fiber optics are utilized to transmit kilowatts of laser power

- Fiber optics carry the laser beam to the end of robotic welding arms

- High depth-to-width ratio of the produced welds


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Laser Welding

Advantages- High processing speed and the independence of

electrical conductivity of the welded materials.

- No filler material is required thus laser welds are lessbulky and more precise

- Fine grain structure

- The well defined laser beams are excellent tools for

welding thin materials, hermetic welds, or in close proximity to heat-sensitive components.

- Hard to reach areas can be laser welded if a line-of-site exists.


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Laser Welding

Disadvantages

- High investment costs

- Requires precise preparation

of the workpieces

- Weldability is restricted forsome materials


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New Technology

Remote Laser Welding

Fuzzy Logic Controls

High Speed Automated Welding


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Laser beam manipulated by mirrors

minimal tooling required no robot arm

makes process even faster uses small motor

less required maintenance acetone to clean mirrors every six shifts


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Stationary Laser - up to 3m away

Allows for more welds to be done at one

stationSaves on time and floor space

DaimlerChrysler Jeep Liberty rear door assembly

requires 54 welds all done at one laser stationsince April 2001. Replaced 4 conventional spot

welding stations.


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Speed 3kW CO2 diffusion cooled laser

resistance weld taking 3 sec. Can be done in 0.5sec.

5kW CO2 increases speed by 40%

Post Operations few or none = faster time to market

Flexibility change software for new part, not tooling

anything in line of sight


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Remote Laser Problems

Automotive industry requires coated sheet

metals

Fights corrosion

Coatings are uneven in thickness Excess coating vaporizes faster than metal and blows metal

away when not properly vented.

Europe is setting higher standards for uniform coating Uniform thickness restraints vs. amount per unit area


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The Future

Laser/Arc Welding Laser welding - highly precise but costly

$300,000 (50-60x cost of arc weldingsystem)

Arc Welding - inexpensive but inaccurate arc jump is unpredictable

Laser/Arc Welding Inexpensive low intensity laser (7W)

Creates path of ionized molecules Conventional arc welder - arc follows

path of least resistance

$35,000 - reduces cost of precisionwelding by 90%


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High Speed Automated WeldingProject, based at the Universityof Waterloo

Examining the GMAW process to identifystrategies allowing faster weldingwhile eliminating defects such asundercutting and humping which are

characteristic of high-speedautomated welding.


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New Model Developed

Actual arc length and electricalconditions are measured for various

welding conditions and compared tothe model

Special camera systemLaser Strobeused to observe arc length

Observations of how weld pool changesshape used to find how defects occurunder different welding conditions


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Fuzzy Logic: A superset of conventionallogic that has been extended tohandle the concept of partial truth

Gives the ability to use only 1 integrated logic ICinstead of 6 or more digital signal processorswith the same results at a drastically lower price


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Benefits Improved weld quality

Raised productivity

Decreased scrap-rates

Faster setup time Reduced operator skill

requirements

Lower cost (than normal

controllers) Data rate reduced by 700x, and

thus the serial signal can betransmitted over largedistances.


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Case Study - Laser Bellows

Bellows offer a flexibleseal for a variety parts

ie; Volume compensators,expansion joints, vacuum valveseals, manipulators,semiconductors

Material typically 0.003-0.008thick

Used by companies such asNASA, GE, Allied Chemical, Mobil


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Laser Bellows

Currently manually welded using arc (TIG)

Highly skilled operators are difficult to find

Demand varies making planning difficult

Labor intensive welding

Destructive testing is required to insure quality


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Laser Bellows

5 to 10 Times Quicker Quicker Changeovers

Vision Seam Tracking ( +/- 0.0002)

100% In Process Quality Check

Highly Concentrated Heat Source (Smaller HAZ) Thinner Material (Less Mechanical Resistance)

100 ipm (manual 15 ipm)


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Questions

Final Automated Welding Presentation

Documents

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