kerja pelat
TRANSCRIPT
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©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e
KERJA PELAT
(SHEET METALWORKING)
1. Cutting Operations/ Pemotongan
2. Bending Operations/penekukan
3. Drawing/ Penarikan
4. Pembentukan pelat yang lain
5. Dies and Presses untuk Pemrosesan Pelat
6. Operasi pelat tidak pada mesin pres.
7. Penarikan tabung
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©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e
Definisi Kerja Pelat
Pemotongan dan pembentukan terhadap
lembaran logam relatif tipis
Tebal lembaran logam = 0.4 mm (1/64 in) sd 6
mm (1/4 in)
Tebal pelat asal > 6 mm
Operasi bisanya dikategorikan sebagai kerja
dingin
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©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e
Produk Logam Lembaran dan pelat
Lembaran atau pelat untuk konsumen atau
produk industri, seperti:
Automobiles and trucks
Airplanes
Railway cars and locomotives
Farm and construction equipment
Small and large appliances
Office furniture
Computers and office equipment
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©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e
Keunggulan benda kerja berbahan pelat
logam
Kekuatan tinggi
Akurasi dimensi bagus
Permukaan akhir bagus
Biaya relatif murah
Ekonomis untuk produksi massal
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©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e
Terminologi Kerja Pelat
Punch-and-die – perkakas untuk
melakukan pemotongan, penekukan dan
penarikan
Stamping press – mesin perkakas yang
menjalankan kebanyakan operasi kerja
pelat
Stampings – produk kerja pelat
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©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e
Tipe Dasar Proses Kerja Pelat
1. Cutting /Pemotongan
Pengguntingan untuk memisahkan
lemabaran yang luas
Blanking untuk memotong sisi luar benda
kerja dari lembaran
Punching untuk membuat lubang pada
lembran pelat
2. Bending
Menekuk pelat terhadap satu sumbu lurus
3. Drawing
Pembentukan lembaran pelat menjadi
bentuk convex atau concave
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Pemotongan Pelat Logam
Figure 20.1 Pengguntingan logam lembaran diantara dua ujungpemotong: (1) sesaat sebelum pons menyentuh benda kerja; (2) ponsmulai menekan benda kerja, menyebabkan deformasi plastis. (3) pons menekan terhadap benda kerja menyebabkan permukaanterpotong halus; (4) retakan terjadi pada sisi lain dari pemotong yang memisahkan pelat.
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Pemotongan Pelat Logam
©2007 John Wiley & Sons, Inc. M P Groover,
Fundamentals of Modern Manufacturing 3/e
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©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e
Shearing, Blanking, and Punching
Tiga operasi dasar pemotongan pelat:
Shearing
Blanking
Punching
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©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e
Shearing
Operasi pemotongan sepanjang garis lurus di
antara dua pemotong
Umumnya untuk memotong pelat yang lebar
Figure 20.3 operasi pengguntingan; (a) pandangan
samping operasi pemotongan; (b) pandangan depan
gunting mesin yang dengan bilah pisau atas miring
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©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e
Blanking and Punching
Blanking – pemotongan pelat untuk memisahkanbenda kerja (disebut sbg blank) dari lembaransekelilingnya
Punching – mirip dg blanking kecuali yang terpotongadalah sekrap (disebut sbg slug)
Figure 20.4 (a) Blanking and (b) punching.
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Variabel penting pada Pemotongan
Parameter Proses:
Ukuran pons dan die
Kecepatan pemotongan, pelumasan dan celah
pemotongan©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e
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Skema ujung pelat yang digunting
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Tahapan pemotongan
dan penampang hasil potong
©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e
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©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e
Celah pada Pemotongan Pelat
Jarak antara ujung pons dan die
Umumnya antara 4% and 8% dari tebal pelat
Jika terlalu kecuali, garis retakan tidak
menyatu dan menyebabkan rambatan
retakan ganda dan gaya yang besar
Jika terlalu besar, logam terjepit di antara
dua pemotong dan hasilnya berduri (burr)
panjang seperti gantolan.
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Celah pada Pemotongan Pelat
Efek dari celah, c terhadap zona deformasi pada pons
dan die. Jika celah meningkat bahan cenderung
tertarik ke die daripada tergunting©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e
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©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e
Celah pada Pemotongan Pelat
Celah direkomendasi dihitung dengan:
c = at
dengan c = celah; a = tetapan tambahan; dan
t = tebal pelat
Tetapan a ditentukan oleh tipe logam
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©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e
Tetapan “a” berdasarkan kelompok logam
Metal group a
1100S and 5052S aluminum alloys, all
tempers
0.045
2024ST and 6061ST aluminum alloys;
brass, soft cold rolled steel, soft
stainless steel
0.060
Cold rolled steel, half hard; stainless
steel, half hard and full hard
0.075
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©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e
Punch and Die Sizes
For a round blank of diameter Db:
Blanking punch diameter = Db - 2c
Blanking die diameter = Db
where c = clearance
For a round hole of diameter Dh:
Hole punch diameter = Dh
Hole die diameter = Dh + 2c
where c = clearance
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©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e
Figure 20.6 Die size
determines blank
size Db; punch size
determines hole
size Dh.; c =
clearance
Punch and Die Sizes
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©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e
Tujuan: memudahkan slug atau blank jatuh
melalui die
Sudut umumnya: 0.25 - 1.5 pada masing-
masing sisi
Figure 20.7
Angular
clearance.
Celah Anguler
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Perkakas pemotongBench Shear (Gunting tuas dan bagiannya)
Pandangan dekat rahangpemotong
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Perkakas pemotong
Gunting mesin yang mampumemotong pelat tebal sd 6mm Mesin Pemotong Guillotine
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©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e
Gaya Pemotongan
Penting untuk menentukan ukuran mesin press
(tonase)
F = S t L
dengan S = kekuatan geser logam; t = tebal
pelat; L = panjang pemotongan
Karena harga S jarang tersedia, maka diambil
dari harga kekuatan tarik maksimum (UTS)
material, sehingga
F = 0.7 (UTS) t L
Note: 1 Ton = 8.90 kN. 1kN = .112 Tons
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Contoh Properties untuk Baja
Properties of Steel
UNS Number
Processing Method
Yield Strength
kpsi
Tensile Strength
kpsi
Yield Strength
MPa
Tensile Strength
MPa
Elongation in 2 in.
Reduction in Area
BrinellHardness
% % H_b
G10100 Hot Rolled 26 47 179 324 28 50 95
G10100 Cold Drawn 44 53 303 365 20 40 105
G10150 Hot Rolled 27 50 186 345 28 50 101
G10150 Cold Drawn 47 56 324 386 18 40 111
G10180 Hot Rolled 32 58 220 400 25 50 116
G10180 Cold Drawn 54 64 372 441 15 40 126
G10350 Hot Rolled 39 72 269 496 18 40 143
G10350 Cold Drawn 67 80 462 551 12 35 163
G10350
Drawn 800
F 81 110 558 758 18 51 220
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Contoh Properties untuk Aluminum alloy (lakuran)
Properties of Aluminum Alloys
UNS Alloy Number Temper
Yield Strength
(kpsi)
Tensile Strength
(kpsi)
Shear Modulus of
Rupture (kpsi)
Fatigue Strength
(kpsi)Elongation in 2 in., %
BrinellHardness
(H_b)
A91100 -O 5 13 9.5 5 45 23
A91100 -H12 14 15.5 10 6 25 28
A91100 -H14 20 22 14 9 16 40
A91100 -H16 24 26 15 9.5 14 47
A91100 -H18 27 29 16 10 10 55
A93003 -O 6 16 11 7 40 28
A93003 -H12 17 19 12 8 20 35
A93003 -H14 20 22 14 9 16 40
A93003 -H16 24 26 15 9.5 14 47
A93003 -H18 27 29 16 10 10 55
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Contoh soal
1. Pelat aluminum A93003 tebal 3 mm yang telah mengalami temper H14 hendak dipotong dengan pisau guillotine. Dimensi pelat 1200 x 1000mm dan hendak dipotong sepanjang lebarnya. Tentukan gayapotong yang diperlukan jikaa) bilah pisau atas miring 3o
b) bilah pisau keduanya sejajar
2. Baja G10180 hasil pengerjaan dingin hendak dibuat ring berukuran diameter luar 10mm dan diameter dalam 6mm. a) Tentukan ukuran pons dan die
b) Berapakah gaya yang yang diperlukan untuk memotong saturing tersebut jika menggunakan
•
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Compound dies
• Beberapa operasi pada pelat yang sama dibuat dengan satulangkah pada satu stasiun kerja dibuat dengan compound dies
ilustrasi skema (a) sebelum dan (b) setelah operasi blanking untuk
membuat sebuah ring pada sebuah compound die. Perhatikan
gerakan pemisahan die (atau balnking) dan pons
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Progressive dies• Benda kerja dibuat dengan ulti operasi misalnya punching,
blanking dan notching dibuat pada laju produksi tinggi dalam
progressive dies.
(c) pembuatan ring dengan progressive die
(d) pembentukan tutup atas kaleng aerosol dengan sebuah progressive die.
Catatan bahwa benda kerja tetap menempel lembaran pelat sampai denganoperasi komplit
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©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e
Figure 20.11 (a) Penekukan lembaran logam
Penekukan lembaran Logam
Penekukan didefinisikan sebagai pembengkokan
logam terhadap sebuah sumbu lurus untuk
mendapatkan deformasi (perubahan bentuk)
permanen
α = sudut tekuk
w = lebar lembaran
R = radius tekuk
t = tebal lembaran
α′ = 180 - α, sudut “included”
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©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e
Ketika penekukan bagian dalam sumbu netral
mengalami tekan sementara bagian luar
mengalami tarik
Figure 20.11 (b)
elongasi tekan dan tarik
keduanya terjadi pada
penekukan.
Sheet Metal Bending
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©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e
Tipe Penekukan Lembaran Logam
V-bending – dilakukan dengan die berbentuk V
Edge bending – dibuat dengan sebuah wiping
die
Panah menujukkan arah pemberian gaya
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©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e
Untuk produksi rendah
Dibuat pada mesin press brake
Die V sederhana dan tidak mahal
Figure 20.12
(a) V-bending;
V-Bending
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©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e
Untuk laju produksi tinggi
Diperlukan bantalan penahan (Pressure pad)
Dies lebih kompleks dan mahal
Edge Bending
Figure 20.12
(b) edge
bending.
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Penarikan selama Penekukan
Jika radius tekuk relatif kecil dibanding tebal
pelat, logam cenderung tertarik selama
penekukan
Penting untuk memperkirakan jumlah
penarikan, sehingga panjang akhir = dimensi
yang ditentukan
Masalah: menentukan panjang sumbu netral
sebelum ditekuk.
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©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e
Rumus Kelonggaran Tekuk
Dengan Ab = kelonggaran tekuk (bend allowance);
= sudut tekuk; R= radius tekuk; t = tebal pelat; and
Kba = faktor untuk memerkirakan penarikan
Jika R < 2t, Kba = 0.33
Jika R 2t, Kba = 0.50
)tKR(A bab +360
2=α
π
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Springback
Penambahan sudut “include” (sudut dalam) hasil
penekukan dibandingkan terhadap sudut perkakas
tekuk setelah perkakas dilepas (beban ditiadakan)
Alasan terjadinya springback:
Jika tekanan tekuk dihilangkan, energi elastis
tersisa pada benda tertekuk, menyebabkan ianya
balik sebagian ke bentuk semula
Springback naik seiring turunnya modulus elastisitas,
E, dan naiknya kekuatan lulur (yield), Y dari bahan
Setelah springback:
Sudut tekuk akan turun (sudut dalam “include” akannaik
Radius tekuk akan naik
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Figure 20.13 Springback pada penekukan dapt dilihat sebagai sebuah
pengurangan sudut tekuk dan penambahan radius tekuk: (1) selama
penekukan, pelat dipaksa ke radius Rb dan sudut dalam b' mengikuti
perkakas penekuk, (2) setelah pons diangkat, pelat “springs back” ke
radius R dan sudut ‘.
Springback
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Springback in bending
Berikut ilustrasi springback pada penekukan:
Manufacturing processes by S. Kalpakjian and S. Schmid
αi: sudut tekuk sebelum springback
αf: sudut tekuk setelah springback
Ri: radius tekuk sebelum springback
Rf: radius tekuk sesudah springback
Catatan; Ri dan Rf adalah radius internal
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Springback in bending
Untuk memerkirakan springback, rumus berikut
dapat digunakan:
Manufacturing processes by S. Kalpakjian and S. Schmid
dengan:
Ri, Rf: radius mula dan radius tekuk akhir
Y: kekuatan luluh (Yield strength)
E: modulus Young’
t: tebal lembaran
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Kompensasi terhadap Springback
Banyak cara untuk mengompensasi springback. Dua cara yang
lazim:
Overbending/ penekukan berlebih
Bottoming (coining)
Tambahan:
Stretch bending – Pelat diberi beban tarik sambil ditekuk. Part is subjected to
tension while being bent.
Untuk mengurangi spring back, bending dapt dilakukan pada suhu yang
dinaikkan.
Jika penekukan berlebih diterapkan pada penekukan V (misalnya),
sudut dan radius pons dibuat sedikit lebih kecil daripada sudut dan
radius benda kahir. Dengan cara ini lembaran tertekuk akan
“springback” ke nilai yang diinginkan.
Bottoming melibatkan penekanan terhdap pelat pada langkah akhir,
sehingga mendeformasi plastis pelat pada daerah tekukan.
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©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e
Gaya Penekukan (Bending Force)
Gaya tekuk maksimum dapat diperkirakan sebagai:
dengan F = gaya tekuk;
TS = tensile strength lembar logam;
w = lebar pelat pada arah sumbu tekuk;
dan t = tebal pelat.
Untuk penekukan-V, Kbf = 1.33;
untuk penekukan ujung, Kbf = 0.33
Untuk (u-die) Kbf=0.7D= dimensi bukaan die
D
TSwtKF bf
2
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Khusus Penekuakan die-V
Max bending force, P = (UTS)Lt2
w
L=panjang penekukan
©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e
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©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e
Figure 20.14 Dimensi bukaan die: (a) V-die, (b) wiping die.
Dimensi Bukaan Die
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Variasi Flanging
Termasuk dalam operasi penekukan adalah:
Flanging adalah oprasi penekukan dengan
ujung pelat ditekuk 90o membentuk rim atau
flens. Hal ini sering dilakukan untuk memerkuat
pelat atau memerkakunya pelat. Flens dapat
lurus, ulur atau kerut.
(a) Straight flanging (lurus)
(b) Stretch flanging (ulur)
(c) Shrink flanging (kerut)
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Variasi Flanging
Pada flanging ulur (stretch) proyeksi garis tekuk adalah cekungdan pelat ditarik melingkar, yakniA>B. Flens mengalami pengurusanpada stretch flanging.
Pada flanging kerut garis proyeksitekukan adalah cembung (convex) dan bahan ditekan, yakni A<B. Pelat mengalami penggemukanpada shrink flanging.
46Figures courtesy of Engineering Research
Center for Net Shape Manufacturing
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Variasi Bending
Operasi bending yang lain, termasuk:
Hemming melibatkan penekukan ujung lembaran ke pelat semulapada tahap penekukan lebih dari sekali. Proses ini sering digunaknuntuk menghilangkan ujung tajam, meningkatkan kekakuan, danmemercantik penampilan; seperti ujung daun pintu mobil.
•Seaming operasi bending dengan dua lembar logam disatukan.
•Curling (pengeritingan atau beading) membentuk ujung benda kerjamenjadi sebuah roll. Pengeritinganjuga digunakan untuk keamana, kekuatan dan estetika.
47
(a) Hemming
(b) Seaming
(c) Curling
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Drawing
Kerja pelat membuat bentuk cup, kotak, atau
cekung kompleks dan benda kerja berlubang
Lembaran logam diletakkan di atas kawah die
kemudian pons menekan logam ke bukaan
yang tersedia.
Produk: kaleng minuman, selongsong peluru,
panel bodi mobil
Juga dikenal sebagai deep drawing (untuk
membedakan dari wire dan bar drawing)
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Figure 20.19 (a) Drawing
bentuk cangkir: (1)
sebelum pons
menyentuk benda
kerja, (2) hampir akhir
langkah drawing; (b)
benda kerja: (1)
lembaran awal, (2)
benda jadi.
Drawing
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Celah pada Penekukan
Sisi pons dan die dipisahkan oleh celah c
sebesar:
c = 1.1 t
dengan t = tebal pelat
Dengan kata lain, celah sekitar 10% lebih
besar daripada tebal pelat
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Uji Kelayakan Penekukan
Rasio penekukan
Reduksi
Rasio tebal terhadap diameter
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Rasio Penekukan (Drawing Ratio, DR)
dengan Db = diameter blank;
and Dp = diameter pons
Mengindikasikan batas aman operasi
penekukan:
Batas atas: DR 2.0
Paling mudah didefinisaikan untuk bentuk
silindris :
p
b
D
DDR
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Reduksi, r
Untuk bentuk silindris didefinisikan sebagai:
b
pb
D
DDr
Nilai r harus kurang dari 0.50
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Rasio Tebal terhadap Diamater, t/Db
Tebal pelat awal dibagi dengan diameter
Diinginkan rasio t/Db lebih dari 1%
Seiring penurunan t/Db, kecenderungan
terjadinya kerutan (wrinkle) naik.
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Penetuan Ukuran Blank
For final dimensions of drawn shape to be
correct, starting blank diameter Db must be
right
Solve for Db by setting starting sheet metal
blank volume = final product volume
To facilitate calculation, assume negligible
thinning of part wall
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Shapes other than Cylindrical Cups
Square or rectangular boxes (as in sinks),
Stepped cups
Cones
Cups with spherical rather than flat bases
Irregular curved forms (as in automobile body
panels)
Each of these shapes presents its own unique
technical problems in drawing
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Other Sheet Metal Forming on Presses
Other sheet metal forming operations performed
on conventional presses
Operations performed with metal tooling
Operations performed with flexible rubber
tooling
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Makes wall thickness of cylindrical cup more
uniform
Figure 20.25 Ironing to achieve more uniform wall thickness in a
drawn cup: (1) start of process; (2) during process. Note thinning
and elongation of walls.
Ironing
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Creates indentations in sheet, such as raised
(or indented) lettering or strengthening ribs
Figure 20.26 Embossing: (a) cross-section of punch and die
configuration during pressing; (b) finished part with embossed ribs.
Embossing
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Figure 20.28 Guerin process: (1) before and (2) after. Symbols v
and F indicate motion and applied force respectively.
Guerin Process
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Advantages of Guerin Process
Low tooling cost
Form block can be made of wood, plastic, or
other materials that are easy to shape
Rubber pad can be used with different form
blocks
Process attractive in small quantity production
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Dies for Sheet Metal Processes
Most pressworking operations performed with
conventional punch-and-die tooling
Custom-designed for particular part
The term stamping die sometimes used for
high production dies
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Figure 20.30 Components of a punch and die for a blanking operation.
Punch and Die Components
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Figure 20.31 (a)
Progressive die;
(b) associated
strip development
Progressive Die
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Figure 20.32 Components of a typical mechanical drive stamping press
Stamping Press
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Types of Stamping Press Frame
Gap frame
Configuration of the letter C and often
referred to as a C-frame
Straight-sided frame
Box-like construction for higher tonnage
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Figure 20.33 Gap frame
press for sheet
metalworking (ohoto
courtesy of E. W. Bliss
Co.); capacity = 1350 kN
(150 tons)
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Figure 20.34 Press brake (photo courtesy of Niagara Machine & Tool Works); bed width = 9.15 m (30 ft) and capacity = 11,200 kN (1250 tons).
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Figure 20.35 Sheet metal parts produced on a turret press, showing
variety of hole shapes possible (photo courtesy of Strippet Inc.).
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Figure 20.36 Computer numerical control turret press (photo
courtesy of Strippet, Inc.).
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Figure 20.37
Straight-sided frame
press (photo courtesy of
Greenerd Press &
Machine Company,
Inc.).
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Power and Drive Systems
Hydraulic presses - use a large piston and
cylinder to drive the ram
Longer ram stroke than mechanical types
Suited to deep drawing
Slower than mechanical drives
Mechanical presses – convert rotation of motor
to linear motion of ram
High forces at bottom of stroke
Suited to blanking and punching
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Operations Not Performed on Presses
Stretch forming
Roll bending and forming
Spinning
High-energy-rate forming processes.
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Sheet metal is stretched and simultaneously
bent to achieve shape change
Figure 20.39 Stretch forming: (1) start of process; (2) form die is
pressed into the work with force Fdie, causing it to be stretched and
bent over the form. F = stretching force.
Stretch Forming
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Force Required in Stretch Forming
where F = stretching force; L = length of sheet in
direction perpendicular to stretching; t =
instantaneous stock thickness; and Yf = flow
stress of work metal
Die force Fdie can be determined by balancing
vertical force components
fLtYF
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Large metal sheets and plates are formed into
curved sections using rolls
Figure 20.40 Roll bending.
Roll Bending
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Continuous bending process in which opposing
rolls produce long sections of formed shapes
from coil or strip stock
Figure 20.41 Roll
forming of a
continuous
channel section:
(1) straight rolls,
(2) partial form,
(3) final form.
Roll Forming
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Spinning
Metal forming process in which an axially
symmetric part is gradually shaped over a
rotating mandrel using a rounded tool or roller
Three types:
1. Conventional spinning
2. Shear spinning
3. Tube spinning
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Figure 20.42 Conventional spinning: (1) setup at start of process;
(2) during spinning; and (3) completion of process.
Conventional Spinning
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High-Energy-Rate Forming (HERF)
Processes to form metals using large amounts of
energy over a very short time
HERF processes include:
Explosive forming
Electrohydraulic forming
Electromagnetic forming
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Explosive Forming
Use of explosive charge to form sheet (or plate)
metal into a die cavity
Explosive charge causes a shock wave whose
energy is transmitted to force part into cavity
Applications: large parts, typical of aerospace
industry
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Figure 20.45 Explosive forming: (1) setup, (2) explosive is
detonated, and (3) shock wave forms part and plume
escapes water surface.
Explosive Forming
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Electromagnetic Forming
Sheet metal is deformed by mechanical force of
an electromagnetic field induced in the
workpart by an energized coil
Presently the most widely used HERF process
Applications: tubular parts
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Figure 20.47 Electromagnetic forming: (1) setup in which coil is
inserted into tubular workpart surrounded by die; (2) formed part.
Electromagnetic Forming