Bab 27A Pengantar Proses Penyambungan.pdf

PengantarPengantar

ProsesProses PenyambunganPenyambungan

Ir. Tri Prakosa , M. Eng.Ir. Tri Prakosa , M. Eng.

ProsesProses ManufakturManufaktur II, II, FebruariFebruari 2011 2011

ProsesProses PenyambunganPenyambungan padapada MobilMobil

2

PengelasanPengelasan padapada bodybody mobilmobil

Types of Vehicle ConstructionTypes of Vehicle Construction

�Body-Over-Frame Construction

– A typical truck frame

Chapter 4

– A typical truck frame with sub-frame components.

Types of Vehicle ConstructionTypes of Vehicle Construction

�A Typical Unibody Design.

Chapter 4

– Typical one piece body and frame assembly with bolt-on components.

PenyambunganPenyambungan tutuptutup kalengkaleng minumanminuman

Manufacturing, Engineering & Technology, Fifth Edition, by Serope Kalpakjian and Steven R.

Schmid.

Snap fit examplesSnap fit examples

� Toys

� Small Appliances

� Automotive

� Electronic Fields

Engine SystemsEngine Systems

�Exhaust system

– The exhaust system is designed to carry toxic exhaust fumes

Chapter 4

away from the passenger compartment, to quiet the exhaust pulses and burn or catalyze pollutants.

Engine SystemsEngine Systems

� Ignition system

– The ignition system must generate a spark to ignite the air/fuel mixture at the correct time.

– The coil transforms battery voltage into a

Chapter 4

– The coil transforms battery voltage into a spike of 30 000 to 100 000 volts to ignite the mixture.

– Ignition must occur before the piston completes its compression stroke.

Drivetrain ComponentsDrivetrain Components

�Clutch

– Used with manual transmissions and transaxles.

Chapter 4

– Mechanically connects the engine flywheel to the transmissions input shaft.

PenyambunganPenyambungan

� Proses-proses:– welding,– brazing,– soldering,– adhesive bonding, dan– adhesive bonding, dan– mechanical fastening.

� Proses-proses tersebut penting dan diperlukan pada proses manufakturing, dengan alasan sebagai berikut:

Manufacturing, Engineering & Technology, Fifth Edition, by Serope Kalpakjian and Steven R.

Schmid.

MengapaMengapa perluperlu prosesproses joining?joining?

a. Produknya tidak mungkin dibuat sebagai dalam “single piece”.

Sebagai contoh, rangka pipa seperti gambar di pipa seperti gambar di samping, masing-masing bagian panjangnya 5m, diameter Ø100 mm dan ketebalan pipa 1mm.


Struktur Raksasa tidak mungkin dibuat dalam “single piece”


b. Produk-produk seperti alat masak yang ada pemegangnya, akan lebih mudah dan lebih ekonomis jika dibuat per-komponen, dan kemudian dirakit.


c. Produk-produk seperti: automobile engines, hair dryers, printers dan soldered-joint electronic devices dapat dilepas komponen-komponennya untuk perawatan (maintenance).


d. Kadang suatu produk memerlukan sifat material yang berbeda dengan material induknya. Permukaan yang menerima beban gesek/aus, atau korosi dan lingkungan yang ekstrim.

Sebagai contohSebagai contohadalah ujung pahatyang terbuat darikarbida yang disambung ke pahatgurdi dengan prosesbrazing, juga sepaturem atau roda gerindayang sambung kestruktur logampenumpunya.


e. Pengangkutan produk per komponen individu dan merakitnya setelah sampai di tujuan bisa lebih mudah dan lebih murah. Beberapa sepeda danmainan, kebanyakan mesin perkakas, dan mesin pres hidrolik maupun mekanik diangkut secara per-komponen dan dirakit ditujuan.per-komponen dan dirakit ditujuan.

ProsesProses--prosesproses penyambunganpenyambungan

engine fasteners door

Mechanical ：：：：‧nuts/bolts ‧rivets ‧c-clips ‧pressure fits

Solid-liquid ：：：：

‧Adhesives ‧Soldering ‧Brazing

Solid ：：：：

‧Friction ‧Diffusion ‧Explosion ‧Ultrasound

Liquid ：：：：

Chemical ：：：：‧Oxyfuel ‧Thermit

ECUS emission controller windshield plastic fanswindshield

Body muffler

Resistance ：：：：

‧Spot ‧Seam ‧Flash

door hinges

Consumable electrode ：：：：

‧Shielded metal arc ‧Submerged arc ‧Gas metal arc

nonConsumable electrode ：：：：

‧Gas Tungsten Arc ‧Plasma ‧Electron Beam‧Laser Welding

Arc Welding

Adhesive bondingAdhesive bonding

Advantages� Sealing as well as

joining.� Better in fatigue loading.

Disadvantages• Disassembly is

difficult/impossible.• Surface preparation � Better in fatigue loading.

� Good damping. � Low weight penalty.

• Surface preparation required.

• Accurate assembly may be required.

• NDT difficult.• Possibly sensitive to

environment.

Mechanical fasteningMechanical fastening

Advantages� No surface preparation.� Disassembly possible� Simple inspection.

Disadvantages• High stress

concentration at hole.• Additional weight� Simple inspection.

� Better for thick sections.� No ‘chemistry’.

• Additional weight• Loss of smooth

surface.• Possible galvanic

corrosion.

Both types of joint result in Both types of joint result in stress concentrations:stress concentrations:

fasteners in shear; local stress concentrations around hole

peel in adherends: shear and through-thickness tension in adhesive - highest at joint edges

Mechanical FasteningMechanical Fastening�� Any shape and material almost�� Disassemblable (except Rivets, etc.)�� Least expensive for low volume (standardized)�� Problems: strength, seal, insertion, loosening

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Threaded Bolted Rivets Snap fit

Figures, B. Benhabib2.008-spring-2004 S.Kim

RivetsRivets

� Cheap, light weight, don’t get loose� Permanent, less strong than bolts� Rule of thumb

– Minimum spacing = 3 x d– Maximum spacing = 16 x thickness of the

outer plate

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outer plate

Rivets

2.008-spring-2004 S.Kim

Mechanical fasteningMechanical fastening

� Crimping� Embossed protrusions

– Plastic deformation/ interference

– Appliance– Automotive

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– Automotive

Lego assembly, elastic averaging

M. Culpepper, MIT2.008-spring-2004 S.Kim

Mechanical JoiningMechanical Joining

� Hemming, seaming– Bend edge of one component over

another– Automobile door stampings and

trunk lids

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Adhesive BondingAdhesive Bonding

� Quick and non-invasive� Most materials with high surface to volume ratio� Insulation (thermal, electrical), conducting

adhesives available� Good damping� Clean surface preparation

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� Clean surface preparation� Long curing, hold time, low service T� Reliability, quality?� Disassembly?

� Weak to tensile loading, strong to shear and compressive� Organic

– epoxy, acrylic, etc..� Inorganic

Adhesive BondingAdhesive Bonding

� Inorganic– solder, cement, etc..

SolidSolid--Liquid: Brazing and SolderingLiquid: Brazing and Soldering

� In brazing, the filler material (silver, brass, bro nze) has a melting point above 425 ºC; and, in soldering, the filler m aterial (lead, tin) has a melting point well below 425 ºC.

� Capillary forces for the wetting and flow of the li quid metal into the gaps.

� Proper fluxes for lowering surface tension, remove oxides, and prevent oxidation.prevent oxidation.

Wave solderingWave soldering

� Exposed metal joints are passed over a wave in a continuous motion, where liquid solder penetrates into the joint by capillary forces:

Enlarged area

Circuitboard

Solder

Enlarged area

boardSolderfountain

Moltensolder

Heater Pump

OxyacetyleneOxyacetylene

Joining ProcessesJoining Processes

Types of Joints:1. Joints that allow relative motion (kinematic joints)2. Joints that disallow any relative motion (rigid joints)

Uses of Joints:1. To restrict some degrees of freedom of motion2. If complex part shape is impossible/expensive to manufacture3. To allow assembled product be disassembled for maintenance.4. Transporting a disassembled product is sometimes easier/feasible

Joining ProcessesJoining Processes

Fusion welding: joining metals by melting � solidification

Solid state welding: joining metals without melting

Brazing: joining metals with a lower mp metal

Soldering: joining metals with solder (very low mp)

Adhesive Bonding: joining with glue

Mechanical joining: screws, rivets etc.

Arc welding

Oxy-acetylenewelding

Flame: 3000°C

manual

robotic

Fusion weldingFusion welding

arc: 30,000°C

Gas shieldedarc welding Argon

MIG TIG

Al Ti, Mg,Thin sections

Plasma arc welding

Laser beam welding

Deep, narrow welds

Aerospace, medical, automobile body panels

Faster than TIW, slower than Laser

Nd:YAG and CO2 lasers, power ~ 100kW

Fusion welding..Fusion welding..

Electron beam welding

Laser beam weldingFast, high quality, deep, narrow welds

deep, narrow welds, expensive

Solid state weldingSolid state welding

Diffusion welds between very clean, smooth pieces of metal, at 0.3~0.5Tm

Cold welding (roll bonding)coins, bimetal strips

Solid state welding..Solid state welding..

Ultrasonic welding

25µm Al wire on IC Chip

Ultrasonic wire bonder

Medical, Packaging, IC chips, Toys

Materials: metal, plastic

- clean, fast, cheap

Resistance weldingResistance weldingWelding metal strips: clamp together, heat by current

Spot welds on a panSpot welding Robotic Spot welding on auto bodySpot welds on a panSpot welding Robotic Spot welding on auto body

Spot welding

Spot welding Robotic Spot welding on auto bodySpot welding Robotic Spot welding on auto body

Seam welding

resistance seam weldingresistance welded petrol tank

resistance seam weldingresistance welded petrol tank

BrazingBrazingTm of Filler material < Tm of the metals being joined

Torch brazing Furnace brazing

Common Filler materials: copper-alloys, e.g. bronze

Common applications: pipe joint seals, ship-construction

SolderingTin + Lead alloy, very low Tm (~ 200C)

Main application: electronic circuits

Adhesive Bonding/GluingAdhesive Bonding/GluingAdhesive type Notes Applications Acrylic two component thermoplastic; quick

setting; impact resistant, strong impact and peel strength

fiberglass, steel, plastics, motor magnets, tennis racquets

Anaerobic thermoset; slow, no-air curing – cures in presence of metal ions

sealing of nut-and-bolts, close-fitting holes and shafts, casting micro-porosities etc.

Epoxy strongest adhesive; thermoset; high tensile strength; low peel strength

metal parts (especially Nickel), ceramic parts, rigid plastics

Cyanoacrylate thermoplastic; high strength; rapid aerobic curing in presence of humidity

[common brand: Crazy glue™] plastics, rubber, ceramics, metals curing in presence of humidity plastics, rubber, ceramics, metals

Hot melt thermoplastic polymers; rigid or flexible; applied in molten state, cure on cooling

footwear, cartons and other packaging boxes, book-binding

Polyacrylate esters (PSA)

Pressure sensitive adhesives all types of tapes, labels, stickers, decals, envelops, etc.

Phenolic thermoset, oven curing, strong but brittle acoustic padding, brake lining, clutch pads, abrasive grain bonding

Silicone thermoset, slow curing, flexible gaskets and sealants Formaldehyde thermoset joining wood, making plywood Urethane thermoset, strong at large thickness fiberglass body parts, concrete gap

filling, mold repairs Water-based cheap, non-toxic, safe wood, paper, fabric, leather

Mechanical fastenersMechanical fasteners

(a) Screws (b) Bolts, nuts and washers (c) Rivets

(a) pneumatic carton stapler (b) Clips (c) A circlip in the gear drive of a kitchen mixer

Plastic wire clips

Wire �� conductor: crimping

Plastic snap-fasteners

Bab 27A Pengantar Proses Penyambungan.pdf

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