Taha Presentation

8/7/2019 Taha Presentation

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Weft InsertionWeft Insertion

MethodMethod

ElectroMagnetic Force

AHA BIN YAHYA - -6 NTU 096 ANA ATIF NASEEM - -6 NTU 048

HOAIB IQBAL - -6 NTU 095



IntroductionA brief Background





Projectile MachineO Common projectile is

O 1/4th of shuttle size

O 1/10th

of shuttle massO Due to no weft yarn pirn

O Require very less energy

O Provided by a torsion bar

O Energy stored in itO Released in a sudden



Projectile MachineO Energy efficient than other

mechanismO But still not very muchO Due to a large number of

mechanical parts involved

O Electromagnetically operated pickingmechanism developed

O Projectile made of permanentmagnetO Loses it properties after some

timeO Attracts iron particles

ONot commercialized



Projectile & e.m.f.O Projectile can be picked either by

O Stroke methodO

Damages projectileO Produces noise

O Requires more partsO Energy losses

O Non-stroke method

O Less energyO Less noise



Projectile & e.m.f.O Non-stroke method

O Metallic Conductor ProjectileO

F=LIBO Required DC in projectile during

flightO Permanent contact, not

possible

O Permanent Magnet ProjectileO Attracted / repelled by em field

O Loses its characteristics

O Attracts tiny iron particles



Projectile & e.m.f.O FerroMagnetic Projectile

O Electromagnetic field promotesthe properties of the material

upto 2000 timesO Attracted towards point with

strongest magnetic field insidesolenoid

O Acts as SHM

: %Note 95 of emf is usually used to produce circular motions while only

% .5 is used to produce linear motion



Aim of investigationOf the research paper



O To produce weft insertion device

O Suitable for modern weavingmachines

O Simple in construction

O Low manufacturing cost

O Reliable in working

O Electromagnetic weft insertion



Assumed targetsO Maximum acceleration of 7k-11km/s-2

O 0.007 seconds acceleration time

O 6-7 cm distance during accelerationO Space required for weft insertion

systemO Determines

O Yarn waste

O Picking speedO 20-25 m/sec final speed

O Depends onO Loom width, rpm and picking

power



Design & constructionOf electromagnetic weft insertion system



Electrical PartsO Solenoid

O A coil of dia 1mm and resistance1.3Ω is turned into solenoid of length 150mm and 1020 coils.

O It has inductance of 1.9mH and4.4mH without and withprojectile respectively.

O 2 layers (also 4, 6, 8, 10, 12 and14)

O Optical Sensor

O Switch



6 0 m m

2 0 m m

5 0 m m

5 0 m m

1 5 0 m m

S ID E

V IE W

T O P

V IE W



Electrical PartsO Control circuit

O Consists of O

IC of NANDO Driver

O IGBT by Siemens



Mechanical PartsO Aluminum Rail (during flying)

O Guides projectile

O Keeps it in straight trackO Simple Brake

O Rubber

O Placed inside metallic U-shapedslot

O Stops projectile without vibration ordamage



Experimental &

Discussion



Parameters Studied

O Distance of projectile from solenoid

O Capacitor voltageO Coil number of layers

O Projectile length



Projectile DistanceO The current should turn off quickly as

soon as it reaches its maximum

O Shape of current-time fed is

importantO Projectile from center of shed and

before generation of emf plays animportant role in controlling

current-time fed.



,

C

u r r

e n

t

A

,Tim e m s

-Turn o ff tim e



Capacitor Voltage &

Energy Analysis





Capacitor Voltage &

Energy AnalysisO 30-60 V gives max speedO 60+V decreases speed

O Optimum is 20-30V asO It uses lesser energy as compared

to speed attainedO

:Note The amount of electrical energy%consumed is about 3 of Sulzer Ruti.loom



Layers in coil



Layers in coilO Optimum results were obtained

when two layers were used

O More layers increased the timeconstant and inductance

O The current took more time to turnoff thus inducing negative

accelerationO This keeps projectile in center of

shed



Projectile Length



Projectile LengthO Different projectiles of length 15-

80mm were tested

OA speedometer measured time takenby front and back of projectile to

pass through and with the length of projectile known, the speed wascalculated

O With the help of mass, the KE wasalso calculated



Summary & Conclusion



Summary & ConclusionO Maximum current in solenoid

O Material should be

O Sintered powderO High magnetic permeability

O High specific electrical resistance

O Current opening/closing frequency

should be maximumO Time of circuit should be minimum



Summary & ConclusionO projectile speed depends on coils,

and not on layersO Projectile should be 75-125% of

solenoid lengthO Increase in voltage increases speed

but decreases efficiencyO IR sensors should be used

O High speed, small size, cheap highperformance (not affected byemf)



Summary & Conclusion

O Speed of 20-30 m/s-2 could not be

achievedO Method of Electromagnetic weft

insertion was chosen rightly

O It requires further research

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