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VIBRATION FEEDING OF VIBRATION FEEDING OF SMALL PARTSSMALL PARTS

PreparePrepare byby: : Miha PipanMiha PipanMarko MalnaričMarko MalnaričMarko Marko JanževičJanževič

AbstractAbstractVibratory feeding of small parts with length 0.5 mm to 5 mm?Vibratory feeding of small parts with length 0.5 mm to 5 mm?Can it be done?Can it be done?

Small parts are usually manipulated by gripingSmall parts are usually manipulated by griping(micro assembly)!(micro assembly)!

Vibratory feeding is suited for parts with minimum length 6 Vibratory feeding is suited for parts with minimum length 6 mm and width 3.6 mm. mm and width 3.6 mm.

What are the main problems with vibratory feeding of smaller What are the main problems with vibratory feeding of smaller parts?parts?

How can they be solved?How can they be solved?

VibratoryVibratory feedersfeeders

•Vibratory feeders are the most versatile type of machine for feeding and orienting pars•Main parts: -vibrating unit

-track-bowl

•Are weary expensive •The tooling is made for eachpart separately

ProblemsProblems withwith smallsmall partsparts

The main problems are the:Adhesive forces; because of them the parts stick to the bowl, to the other parts and track

AdhesiveAdhesive forcesforcesThis forces are present every where but they don’t have This forces are present every where but they don’t have a big influence until we are working with small parts. For a big influence until we are working with small parts. For vibratory feeding vibratory feeding ofof smallsmall partsparts three main forces accrue:three main forces accrue:

Surface tension forceSurface tension force Van Van DerDer Walls forcesWalls forces

Electrostatic attractionElectrostatic attraction

Adhesive forces and dynamics of part Adhesive forces and dynamics of part vibrationvibration

BBececaause of adhesive forces a large acceleration isuse of adhesive forces a large acceleration isrequiredrequired a>a>g+xg+x where x is the acceleration related to where x is the acceleration related to adhesive forcesadhesive forces

Where A is amplitude and w is frequency of the tooling plate. G is the gravitational force and m is the mass of the part. Adhesive force Fadh can be calculated from:

From second Newton law we calculate the requirement for a part come loose in the presence of adhesive forces

PPiezoelectricallyiezoelectrically driven driven vibratory parts feeder vibratory parts feeder

Typical Typical piezoelectric vibration generator piezoelectric vibration generator having piezoelectric elements attached to having piezoelectric elements attached to

opposite sides of a resilient plate for opposite sides of a resilient plate for generating slight vibratory motion. generating slight vibratory motion.

Vibratory parts feeder incorporating such Vibratory parts feeder incorporating such piezoelectric vibration generator for piezoelectric vibration generator for

feeding small parts in a predetermined feeding small parts in a predetermined supplying direction.supplying direction.

ComponentsComponents

PiezoelectricallyPiezoelectrically driven driven vibratory parts feeders vibratory parts feeders includeinclude::a basea basea vibratorya vibratory conveyor conveyor ttable able parts feeder bowlparts feeder bowlfour piezoelectric four piezoelectric vibration generatorvibration generatorss

Piezoelectric vibration generator Piezoelectric vibration generator

a pair of resilient a pair of resilient plate joined plate joined together at their together at their one endsone endstwo piezoelectric two piezoelectric elements attached elements attached to a front and a to a front and a rear surface of rear surface of resilient plateresilient plate

Advantageous Advantageous

large vibratory impulses can be imported large vibratory impulses can be imported to the vibratory conveyor table to the vibratory conveyor table the current vibratory parts feeder is the current vibratory parts feeder is relatively large in height relatively large in height the amplitude extend linearly between the the amplitude extend linearly between the base and the vibratory conveyor table. base and the vibratory conveyor table. easily adjustment of the amplitude and easily adjustment of the amplitude and direction of vibrations direction of vibrations impulseimpulse

THE OPTION OF FLEXIBLE FEEDERSTHE OPTION OF FLEXIBLE FEEDERS

One One ofof themthem is FPF 2000!is FPF 2000!FPF 2000 is FPF 2000 is flexibleflexible feederfeeder forfor smallsmall partsparts

It It consistsconsists ofof programmableprogrammable mehanicalmehanicalgaugesgauges, a , a visionvision senzorsenzorflexibleflexible manipulator manipulator suchsuch as a as a programmableprogrammable robot to robot to activelyactively orientorient partsparts

It It cancan feedfeed andand orientorient bulkbulk packedpacked smallsmallcomponentscomponents directlydirectly intointo assemblyassembly lineslines

It It cancan bebe reconfIguredreconfIgured automaticallyautomatically to to feedfeed differentdifferent partspartsthroughtthrought softwaresoftware controlcontrol

HOW THE FPF 2000 WORKSHOW THE FPF 2000 WORKS

FPF 2000FPF 2000 Part Part sihouettessihouettes as as seenseenbyby machinemachine visionvision systemsystem

PART CHANGEOVERPART CHANGEOVER

Is Is accomplishedaccomplished byby simplysimply loadingloading a a softwaresoftware parameter file parameter file forfor thethenextnext part part typetype

TheThe useruser placesplaces thethe part in front part in front ofof thethe cameracamera andand choosechoose a a pickpickpointpoint andand followsfollows a a machinemachine visionvision

Operator Operator setssets thethe heightheight andand widthwidth mehanicalmehanical gauginggauging devicesdevicesstepperstepper motorsmotors to to bringbring thethe partsparts intointo roughrough alignmentalignment on on thetheconveyerconveyer

TheThe systemsystem subtractssubtracts thethe part part outlineoutline fromfrom thethe backgroundbackground imageimage

It It thenthen generatesgenerates a a seriesseries ofof additionaladditional templatestemplates, , electronicallyelectronicallyrotatingrotating thethe partsparts imageimage in in smallsmall incrementsincrements overover 360360ºº ofof rotationrotation

CCHARACTERISTIC OF PFP 2000HARACTERISTIC OF PFP 2000

TheThe systemsystem indentifiesindentifies andand locateslocates partsparts betweenbetween 0,05 0,05 mm mm andand 12 mm 12 mm approximatelyapproximately 350 350 msekmsekThisThis feederfeeder cancan bebe modifiedmodified to to handlehandle largerlarger or or heavierheavierpartspartsPartsParts needneed to to havehave at at leastleast one one nonnon--rollingrolling stablestableconfigurationconfiguration

PartsParts sizesize limitatonslimitatons is is betweenbetween 0,5 mm to 5 mm0,5 mm to 5 mm

PFP 2000 PFP 2000 costcost 55.000$ (55.000$ (lessless thethe robot)robot)