PHAN 2 CONG NGHE GIA CONG BANG AP LC

Chng 1 Khai niem ve gia cong kim loai Chng 1. Khai niem ve gia cong kim loai bang ap lc .

Chng 2 N ng nong kim loai e gia cong Chng 2. Nung nong kim loai e gia cong ap lc.

Chng 3. Can va keo. Chng 4. Ren t do va ren khuon. Chng 5. Dap tam.

CHNG 1. KHAI NIEM VE GIA CONG KIM LOAI BANG AP LC

1 1 h h 1.1 nh ngha . 1.2 u nhc iem cua gia cong bang ap lc .

1 3 Ph l i h h i b l 1.3 Phan loai cac phng phap gia cong bang ap lc.1.4 S bien dang deo cua kim loai .1 5 Nh h t h h t h d ki l i 1.5 Nhng nhan to anh hng en tnh deo cua kim loai .

1.6 Anh hng cua bien dang deo en tnh chat va to chc cua kim loaichc cua kim loai .

1.7 S ket tinh lai .1 8 C h l t b d khi i 1.8 Cac nh luat c ban ap dung khi gia cong

bang ap lc.

1 1nh ngha1.1nh ngha.

Ph h h i d l bi Phng phap tao phoi da vao nguyen ly bien dang deo cua kim loai di tac dung cua ngoai lc lam thay oi hnh dang, kch thc theo y muon.

1.2 u nhc iem cua gia cong bang ap lc

So vi uc.* u iem:Kh c mot so khuyet tat nh ro kh ro co lam choKh c mot so khuyet tat nh ro kh, ro co lam cho

to chc kim loai mn, c tnh san pham cao.

Co kha nang bien to chc hat cua kim loai thanh to Co kha nang bien to chc hat cua kim loai thanh to chc th, co kha nang tao c cac to chc th uon, xoan khac nhau lam tang c tnh cua san pham.ac au a ta g c t cua sa p a .

o bong, o chnh xac cao hn cac chi tiet uc. De c kh hoa va t ong hoa nen nang suat cao, gia

thanh ha.

* Han che:

(Khong gia cong c cac chi tiet phc tap

( Khong ren dap c cac chi tiet qua ln.

( Khong gia cong c cac kim loai don.

*So vi cat got:So vi cat got:*u iem :G Nang suat cao, phe lieu t, gia thanh ha.G Ren, dap la nhng phng phap c ban e tao phoiG Ren, dap la nhng phng phap c ban e tao phoi

cho gia cong cat got.

*Nh i *Nhc iem :G o bong, o chnh xac thap hn so vi gia cong cat got.

1.3 Phan loai cac phng phap gia cong b lbang ap lc.

1.3.1 Phng phap can .

1.3.2 Phng phap keo kim loai .

1 3 3 Phng phap ep kim loai1.3.3 Phng phap ep kim loai .

1.3.4 Ren t do.

1.3.5 Ren khuon(Dap nong)

1.3.6 Dap tam(Dap nguoi)

1.3.1 Phng phap can .

Phng phap can la phng phap bien dang kim loai giaPhng phap can la phng phap bien dang kim loai gia hai truc can quay ngc chieu nhau e c san pham can co tiet dien giong nh lo hnh (khe h gia 2 truc can) va co chieu dai khong han che.

1.3.2 Phng phap keo kim loai :g p p La phng phap bien dang deo kim loai qua lo hnh cua khuon keo di tac dung cua lc keo, phoi c vuot dai ra, giam dien tch tiet dien p , g ngang, tang chieu dai.

1 3 3Phng phap ep kim loai :1.3.3Phng phap ep kim loai :

Kim loai sau khi nung nong cho vao buong ep,di tac dung cua chay ep kim loai chui qua lo khuon ep co hnh dang va kch thc cua chi tiet can che tao.

1.3.4 Phng phap ren t do : La phng phap bien dang t do kim loai di tac dung lc dap cua g g pbua hoac lc ep cua may ep.

1 3 5 Ph h kh L h h 1.3.5 Phng phap ren khuon : La phng phap bien dang deo kim loai trong long khuon ren di t d l d tac dung cua lc dap.

1.3.6 Dap tam : La phng phap bien dang deo p p g p p gphoi kim loai dang tam, trong khuon di tac dung cua ngoai lc e tao thanh san pham co hnh dang, g p g,kch thc theo yeu cau.

1.4. S bien dang deo cua kim loai1.4.1 Khai niem.

Ki l i khi h t d i l (Kim loai khi chu tac dung cua ngoai lc eu xay ra ba giai oan la bien dang an hoi,bien dang d h h deo, pha huy.

(Xet bien dang deo la bien dang ma sau khi a g gbo lc tac dung van con mot phan bien dang d c gi lai va tren cac phan t cua vat the khong nhan g p g thay co s pha huy.

Bi d d ki l i b bi d( Bien dang deo kim loai bao gom bien dang deo cua n tinh va a tinh.

.Bien dang deo cua n tinh the: La bien dang deo theo c che trt va song tinh.

Kim loai khac nhau th co tnh deo khac nhau.. Bien dang deo cua a tinh the.a tinh the la tap hp cua cac n tinh Biena tinh the la tap hp cua cac n tinh. Bien

dang cua a tinh gom 2 dang:

RBien dang trong noi bo hat : Gom s trt va song tinh. S trt xay ra oi vi cac hat co g y phng ket hp vi phng cua lc tac dung 450se trt trc roi en cac mat khac. S song tinh say ra g ykhi co lc tac dung ln ot ngot gay ra bien dang deo cua kim loai.

R Bien dang vung tinh gii : Tai ay cha hi t h t d h ti h th b i lnhieu tap chat de chay va mang tinh the b roi loan

cho nen s trt va bien dang thng nhiet o t0 9500Ct0>9500C.

Giai thch s trt.

* Theo thuyet lech, kim loai ket tinh khong sap xep y g p ptheo qui luat mot cach ly tng ma thc te co nhng cho lech, cac nguyen t v tr lech luon co xu g y hng tr ve v tr can bang. Khi co lc tac dung th au tien s di ong xay ra cac iem lech, cac vung g y glan can cung dch chuyen theo. Cuoi cung lai tao nen cho lech mi. Qua trnh c tiep tuc en khi khong Q p gcon lc tac dung na.

* Hien tng trt con c giai thch bang mot hien tng khac o la s khuyech tan khi nhiet o tang cao cac nguyen t di ong manh dan va dchtang cao, cac nguyen t di ong manh dan va dch chuyen sang mot v tr can bang khac, lam mang tinh the b bien dang di hnh thc trt. BDH latinh the b bien dang di hnh thc trt. BDH la bien dang ma khi thoi tac dung lc, kim loai se tr ve v tr ban au.

Giai thch hien tng song tinh.Di tac dung cua ng suat tiep , trong tinh the co s dch chuyen tng oi cua hang loat cac mat ngt

y g g g

nay so vi cac mat khac. Qua mot mat phang co nh nao o goi la mat song tinh. Hien tng song tinh g g g gxay ra rat nhanh va manh khi bien dang ot ngot, toc o bien dang lng

1.4.2 Cac hien tng xay ra khi bien dang deo.D S th i h h d h t S th i h h d h tD S thay oi hnh dang hat :S thay oi hnh dang hat

chu yeu la nh qua trnh trt . Hat khong nhng thay oi ve kch thc ma con co the v ra thanh nhieu khoi nho lamkch thc ma con co the v ra thanh nhieu khoi nho lam tang c tnh.

D S oi hng cua hat : Trc khi bien dang cac hat sapD S oi hng cua hat : Trc khi bien dang cac hat sap sep khong theo mot hng nhat nh nao.S hnh thanh to chc si dan en s sai khac ve c, l tnh cua kim loai theochc si dan en s sai khac ve c, l tnh cua kim loai theo nhng hng khac nhau, lam cho kim loai mat tnh ang hng .

D S tao thanh ng suat d : Khi gia cong ap lc do bien dang khong eu va khong cung mot lc nen trong noi bo vat g g g g g the sau khi bien dang con e lai ng suat goi la ng suat d.

Co 3 loai ng suat d:Ong suat d loai 1 (1): La ng suat d sinh ra

do s bien dang khong ong eu gia cac bo phando s bien dang khong ong eu gia cac bo phan cua vat the.

O ng suat d loai 2 (2): La ng suat d sinh ra do s bien dang khong ong eu gia cac hat.

O ng suat d loai 3 (3): La ng suat d sinh ra do s bien dang khong ong eu trong noi bo hats bien dang khong ong eu trong noi bo hat.

AS thay oi the tch va the trong.AS thay oi the tch va the trong.Khi bien dang deo trong noi bo hat luon xay ra haiKhi bien dang deo trong noi bo hat luon xay ra hai

qua trnh:

Tao ra nhng vet nt, khe xop, lo ro te vi do s v nat cua mang tinh the khi trt va song tinh.

Qua trnh han gan nhng lo ro,vet nt khi ket tinh lai Do o khi gia cong ap lc t trong va thetinh lai. Do o khi gia cong ap lc, t trong va the tch cua kim loai b thay oi ang ke.

1.5 Nhng nhan to anh hng en tnh deo cua ki l ikim loai.

1 5 1 Trang thai ng suat1.5.1 Trang thai ng suat .

1.5.2 Toc o bien dang va nhiet o .g

1.5.3 Thanh phan va to chc kim loai .

1.5.1 Trang thai ng suat : g go zTrang thai ng suat keo cang t, nen cang nhieu th tnh deo kim loai cang cao.

z Trang thai ng suat nen khoi lam kim loai coz Trang thai ng suat nen khoi lam kim loai co tnh deo cao hn nen mat phang va ng thang con trang thai ng suat keo khoi th lai lam tnh deo kimtrang thai ng suat keo khoi th lai lam tnh deo kim loai kem i.

1.5.2 Toc o bien dang va nhiet o .

Toc o bien dang la lng bien dang dai tng oi trong mot n v thi gian.

W=d VW=

Gia cong nguoi t0 = TKTLdtV .

Neu tang toc o bien dang se lam giam tnh deo cua kim loai do co s bien cng cua kim loaikim loai do co s bien cng cua kim loai.

?Gi t0 > T?Gia cong nong t0 > TKTL nhiet o khong qua cao : g q

oi vi thep t0= 9000 C

Khi tang toc o bien dang(W) th lc ma sat lam tang nhiet o cua kim loai len 10000C 11000C nen g thep rat deo.

? Gia cong kim loai nhiet o qua cao : Neu tang? Gia cong kim loai nhiet o qua cao : Neu tang W th lc ma sat lam tang nhiet o cua kim loai en

ng q a nhiet lam o deo giam o cng tang lenvung qua nhiet lam o deo giam , o cng tang len.

1.5.3 Thanh phan va to chc kim loai.p

Thanh phan va to chc kim loai lien quan vi nhau.Thanh phan va to chc kim loai lien quan vi nhau. Kim loai trang thai nguyen chat hoac mot pha dung dch ran bao gi cung co tnh deo cao hn vadung dch ran bao gi cung co tnh deo cao hn va de bien dang hn so vi kim loai co cau tao hon hp c hoc hoac hp chat hoa hoc.c hoc hoac hp chat hoa hoc.

Vd : Thep % C thap deo hn thep %C cao.

1.6 Anh hng cua bien dang deo en tnh h t t h ki l ichat va to chc cua kim loai.

1.6.1 Anh hng cua bien dang deo en to chc va c tnh kim loaiva c tnh kim loai .

1.6.2 Anh hng cua bien dang deo ti ly tnh kim loai .

1 6 3 Anh hng cua bien dang deo ti hoa tnh1.6.3 Anh hng cua bien dang deo ti hoa tnh .

1.6.1 Anh hng cua bien dang deo en to h t h ki l ichc va c tnh kim loai.

JToc o bien dang cang tang th s v nat cua cac hat cang ln, o hat cang giam do o c tnh cang cao.

J Bien dang deo giup kh c cac khuyet tat nh xop co ro kh ro co lom co lam tang o mnnh xop co, ro kh, ro co, lom co lam tang o mn chat cua kim loai lam c tnh tang len.

JBien dang deo co the tao c cac th uon xoan khac nhau lam tang c tnh san phamxoan khac nhau lam tang c tnh san pham.

J Toc o bien dang cung co anh hng ln ti c tnh san pham : Neu toc o bien dang cang ln th s bien cng cang nhieu , s khong ong eu cua bien cng cang nghiem trong va s phan bo th cang khong eu do o c tnh kem.

1.6.2 Anh hng cua bien dang deo ti ly tnh kim loai.

Bien dang deo lam tang ien tr giam tnh dan ien va lamBien dang deo lam tang ien tr, giam tnh dan ien va lam thay oi t trng trong kim loai.

Tnh dan ien : Bien dang deo tao ra s sai lech trong mang tinh the lam tnh lien tuc cua ien trng trong i h h b h i h h tinh the b pha v, ngoai ra no con tao nhng mang chan can

tr s chuyen ong t do cua ien t. ay la nguyen nhan lam tang ien tr cua kim loailam tang ien tr cua kim loai.

Tnh dan nhiet : Bien dang deo lam giam tnh dan nhiet Do bien dang deo lam xo lech mang lam

.

dan nhiet. Do bien dang deo lam xo lech mang, lam xo lech vung tinh gii, lam giam bien o dao ong nhiet cua cac ien tnhiet cua cac ien t.

T tnh : Cac sai lech tao ra khi bien dang deo lam thay oi cach bo tr t trng c ban trong kim loai do o lam thay oi t tnh, o tham t,

1.6.3 Anh hng cua bien dang deo ti hoa tnh.

Sau khi bien dang deo nang lng t do cua cac kimSau khi bien dang deo nang lng t do cua cac kim loai tang do o hoat tnh hoa hoc cua kim loai cung tang lentang len.

1.7 S ket tinh lai.Kim loai trang thai ac co hien tng ket tinh (sinh ra

tam mam, phat trien mam ) goi la hien tng ket tinh lai .p g g

z Khi gia cong nguoi be mat kim loai b bien cng ( o cng tang, o deo giam ).cng tang, o deo giam ).

e kh bien cng ta nung kim loai len t0, gi nhiet,u ket tinh lai roi em gia cong tieptinh lai roi em gia cong tiep.

Hien tng ket tinh lai gom 3 giai oan :

6 Giai oan hoi phuc: t0 = (0.2 0.3)Tnc (0K )6 Giai oan ket tinh lai lan 1: t0 = 0 4 Tnc6 Giai oan ket tinh lai lan 1: t = 0.4 Tnc6 Giai oan ket tinh lai lan 2: t0 > 0.4 Tnc

Trong gia cong ap lc can tranh lng bien dang ti han v o o hat kim loai ln nhat lam c tnh kem.

z Gia cong nong t0> TKTL(0K )T 0 4 Tnc (0K )TKTL=0.4 Tnc (0K )

Gia cong nhiet o cao nen kim loai co o deo cao, b h l bi d kh l o ben ,o cng thap nen lc bien dang khong ln, cong suat thiet b khong ln, nhng o chnh xac, o bong cua be mat kim loai khong cao Thng gia cong phoi dang khoikim loai khong cao. Thng gia cong phoi dang khoi.

z Gia cong nguoi t0< TKTL (0K )Lc bien dang ln,oi hoi cong suat thiet b ln. o

chnh xac va o bong be mat cao. Thng gia cong phoi dang tam.

1.8 Cac nh luat c ban ap dung khi gia cong bang ap lc.

1 8 1 h l t bi d h i t t i1.8.1 nh luat bien dang an hoi ton tai

song song vi bien dang deo.g g g

1.8.2 nh luat ng suat d.

1.8.3 nh luat the tch khong oi .

1 8 4 h l t t l b h t1.8.4 nh luat tr lc be nhat.

1.8.1 nh luat bien dang an hoi ton tai song song vi bien dang deosong vi bien dang deo.z Khi gia cong ap lc neu trong kim loai xay ra bien dang d b i t l bi d h i k thdeo bao gi cung co mot lng bien dang an hoi kem theo (c xac nh bang goc an hoi , phu thuoc vao moduyn an hoi E cua vat lieu va chieu day tam kim loai)an hoi E cua vat lieu va chieu day tam kim loai)

N Gia cong nguoi : Kim loai dang tam se chu anh hng lnhng ln.

N Gia cong nong : Kim loai dang khoi , anh hng cua bi d h i h b bien dang an hoi co the bo qua.

Thng e ap dung khi thiet ke khuon dap, vat dap phai ke en lng bien dang d do bien dang an hoi gay ra.

1.8.2 nh luat ng suat d.N Khi gia cong ap lc do nung nong va lam nguoi khong eu lc bien dang lc ma sat phan bokhong eu, lc bien dang, lc ma sat phan bo khong eu lam phat sinh ra ng suat d ton tai can bang ben trong vat the kim loai Neu khong can bangbang ben trong vat the kim loai. Neu khong can bang th se co qua trnh tch, thoat ng suat lam cho vat the bien dang ngoai y muon e ng suat d ton taithe bien dang ngoai y muon e ng suat d ton tai can bang.

1.8.3 nh luat the tch khong oi . The tch cua vat the trc khi bien dang bang the tch vat

the sau khi bien dang

*Goi the tch vat trc khi gia cong la V0* Goi the tch vat sau khi gia cong la V.* Goi the tch vat sau khi gia cong la V.Vat the co chieu cao, rong, dai trc khi gia cong la:

h0 ; b0 ; l 0Vat the co chieu cao, rong, dai sau khi gia cong la: , g, g g

h ; b ; l

Theo ieu kien the tch khong oi ta co : h.b. l = h0.b0.l0

1= lbh

l l l 0

1000

lbh

h b l ln + ln + ln =0

0h 0b 0l

+ + =0 (*)1 2 3Phng trnh (*) goi la phng trnh ieu kien the tch khong oi.tch khong oi.

; ; : La cac ng bien chnh.1 2 3

Nhan xet : Khi gia cong bien dang neu ton tai ca ba ng bien chnh ngha la co s thay oi kch thc ca g g yba chieu th au cua mot ng bien phai trai dau vi hai ng bien kia va co gia tr tuyet oi bang tong cua g g y g ghai ng bien kia.

h

Khi co mot ng bien bang 0 th hai ng bienKhi co mot ng bien bang 0 th hai ng bien con lai phai ngc dau va co tr so tuyet oi bang nhaubang nhau.Dap khong lam mong thanh phoi :

S S 0 2 3S = S = 0 =F SP

1 2 3Ap dung e tnh toan kch thc, khoi lng phoi trc khi gia cong.p g g

1.8.4 nh luat tr lc be nhat.

R Khi bien dang kim loai, mot chat iem bat k tren vat the bien dang se di chuyen theo hng co tr lcvat the bien dang se di chuyen theo hng co tr lc be nhat hay di chuyen en ng vien co chu vi be nhatnhat.

Ap dung e thiet ke hnh dang cua phoi trc khi gia cong.

Chng 2NUNG NONG KIM LOAI ENUNG NONG KIM LOAI E

GIA CONG AP LC

2.1 Muc ch cua nung nong.

2.2 Nhng hien tng xay ra khi nung nong.

2.3 Che o nung.

2 4 Thiet b nung nong2.4 Thiet b nung nong.

2 5 Lam nguoi sau khi gia cong ap lc2.5 Lam nguoi sau khi gia cong ap lc.

2.1 Muc ch cua nung nong.

Nang cao tnh deo giam kha nang bien cng cua Nang cao tnh deo, giam kha nang bien cng cua kim loai, tao ieu kien thuan tien cho qua trnh bien dang nen giam c cong suat thiet bdang nen giam c cong suat thiet b.

nhiet o cao, dao ong nhiet cua cac nguyen t kim loai cang ln, qua trnh trt va song tinh thc hien de dang hn.

Co hien tng chuyen bien pha khi nung nong kim loai lam cho kha nang bien dang de hnloai lam cho kha nang bien dang de hn.

2.2 Nhng hien tng xay ra khi nung nong.

O Hien tng oxy hoa.O Hien tng thoat cacbonO Hien tng thoat cacbon .O Hien tng qua nhiet .O Hien tng chay kim loai .O Hien tng nt .

O Hien tng oxy hoa.

Khi nung nong nhiet o cao kim loai de b oxy hoa tao mot lp oxit kim loai, bong ra khoi be mat lam hao hut kch thc, khoi lng phoi.Do vay khi tnh toan phoi phai ke en lng oxy hoa.

O Hien tng thoat cacbon .

Khi nung thep cac chat kh nh O CO H H O co trongKhi nung thep cac chat kh nh O2,CO2,H2, H2O,...co trong moi trng kh lo de tac dung vi Fe3C cua thep lam cho ham lng cacbon tren be mat thep giam i, nhng khongham lng cacbon tren be mat thep giam i, nhng khong lam giam kch thc goi la hien tng thoat cacbon.

2 Lam anh hng ti c tnh cua be mat phoi (lam2 Lam anh hng ti c tnh cua be mat phoi (lam giam o ben, tang o cng)

2 Th b khi l b t b h d 2 Thep cacbon cao khi nung len be mat b chay dan en cng va chai nen khi gia cong cat got de b me dao.

O Hien tng qua nhiet . g q

Khi nung kim loai len gan nhiet o ng acKhi nung kim loai len gan nhiet o ng ac (t0 chay - 1500) lam cho o deo giam, o cng tang len gia cong de b nt v o o hat kim loai qualen, gia cong de b nt v o o hat kim loai qua ln.

e khac phuc hien tng nay ta thng u kim loai.

O Hien tng chay kim loai .La hien tng khi nung kim loai len nhiet o

tren vung qua nhiet (gan ng ac) phan kim loai bien gii hat se b chay phat ra hoa g y pla(thep) hoac sui bot(Cu+Al).

O Hien tng nt .

Khi nung thep cacbon cao,thep hp kim neu nung vi toc o nhanh th se lam nt phoi do hien tng truyen nhiet

cua kim loai kem, o dan nhiet va o deo kem.

Khi ket thuc gia cong nhiet o qua thap cung gay nt phoi do hien tng bien cng cua be mat kim loai.

oi vi thep cacbon thap ,kim loai va hp kim mau co the nung vi toc o bat k.

2.3 Che o nung.

Che o nung bao gom nhiet o nung, thi gian nung va toc o nung.

2.3.1 Nhiet o nung kim loai

(nhiet o bat au gia cong, nhiet o ket thuc gia cong).

2.3.2 Thi gian nung.

2.3.3 Toc o nung.

2.3.1 Nhiet o nung kim loai Ch hi t i b ki l i d h t h tChon nhiet o gia cong can bao am kim loai deo nhat, chat lng vat nung, kim loai bien dang tot nhat va hao ph t nhat Co 3 phng phap xac nh nhiet o nung:nhat. Co 3 phng phap xac nh nhiet o nung:

Da vao gian o trang thai. (H-167) Da vao cong thc kinh nghiem. Da vao mau sac phoi: Da vao mau sac phoi:

Thep mau sang trang phoi qua nhiet.

Thep mau vang rm t0BGC= t0nungThep mau tm hoa ca t0KTGCp KTGC

t0KTGC > 0.25 Tnc

2.3.2 Thi gian nung.

Che o nung hp l can bao am nung kim loai en nhiet o can thiet trong mot khoang thi gian cho phep nho nhat.can thiet trong mot khoang thi gian cho phep nho nhat.

tnung= . K . D . (gi). D:He so sap xep phoi trong lo.

:He so kch thc phoi L:He so kch thc phoi K :He so truyen nhiet kim loai. DD : ng knh phoi hoac chieu dai canh ngan nhat cua

phoi.

2.3.3 Toc o nung.Toc o nung anh hng ln en nang suat va chat lng

nungnung.

Co 2 giai oan e xac nh toc o nung:

F Giai oan nhiet o thap (thep t 800 0 8500): Giai oan nay kim loai co tnh deo thap, s nung nong phu thuoc

tnh truyen nhiet cua kim loai.

$ Toc o nung giai oan nay goi la: Toc o nung cho phep Vn.

>V h h ki l i b h bi d>Vn can cham e tranh kim loai b nt ne hoac bien dang.

F Giai oan nhiet o cao(> 8500C)F Giai oan nhiet o cao(> 850 C)$ Toc o nung giai oan nay goi la:

Toc o nung k thuat

> Giai oan nay can nung nhanh e giam s o xy hoa> Giai oan nay can nung nhanh e giam s o xy hoa, v nhiet o cao tnh deo cua kim loai tang nen khong s nt, nhng toc o oxi hoa manh. g

> Nhiet o nung phu thuoc vao vat lieu, kch thc vat nung.thc vat nung.

> Toc o nung giai oan nay co the tra trong bang cua so tay ren dapso tay ren dap.

2.4 Thiet b nung nong.

z Lo phan xa( lo buong) HNH /172

Nhien lieu s dung la than a.

z Lo ien : Co 3 loai:z Lo ien : Co 3 loai:

Lo ien tr . HNH /173 Lo ien cam ng . Lo dung nang lng ien phan .

2.5 Lam nguoi sau khi gia cong ap lc La mot cong viec rat quan trong e am bao chat lng

vat gia cong.g g Gom 2 giai oan: Lam nguoi trong khi ren dap: La qua trnh phoi truyen nhiet ra moi trng, dung cu gia cong Lam nguoi sau khi gia cong: Neu lam nguoi khong tot se lam giam chat lng san pham nh cong venh nt nese lam giam chat lng san pham,nh cong venh,nt neMoi vi chi tiet nho: Xep vao lo cha voi bot hay lo co

nhiet o thap hn e lam nguoi cham.nhiet o thap hn e lam nguoi cham.Moi vi chi tiet ln (D=500 1500mm) : at trong

khong kh, phu cat ao bao ve bang amiang, at cach vat 50 120 mm e lam nguoi cham.

CHNG 3.CAN VA KEOCAN VA KEO

3.1 Can.

3.1.1 Thc chat cua qua trnh can.

3.1.2 Cac san pham can.

3 1 3 Thiet b can3.1.3 Thiet b can.

3.2 Keo day.

3.2.1 Ban chat cua qua trnh keo day.

3.2.2 Dung cu va thiet b keo day.

3.1.1 Thc chat cua qua trnh can.

Kh i i Q h l h ki l i bi d i h iKhai niem:Qua trnh la cho kim loai bien dang gia hai truc can quay ngc chieu nhau, lam cho chieu cao giam, chieu dai va chieu rong tangchieu dai va chieu rong tang.

Cac thong so e bieu th khi can:l FHe so keo dai : = =

l F :Chieu dai dien tch phoi can

0

1

ll

1

0

FF

l0, F0 :Chieu dai ,dien tch phoi can.

l1, F1 :Chieu dai,dien tch tiet dien sau khi can.

Lng ep tuyet oi : ' h = h0 h1 =D(1- cos )D:ng knh truc can.:Goc an

Phan lc N

==

cos.sin.

NNNN

Y

X

Lc ma sat T

===

sin.cos..cos.

TTfNTT

Y

X

T = N.tg = N.f vi N: lc phap tuyen, : goc ma sat, f: he so ma sat

Y g

e can c th: Tx > NxN.f.cos > N.sin N.tg.cos > N.sin

tg > tg > Vay ieu kien can cla: >

h b hBien phap cong nghe tang he so ma sat bang cach:

N Khoet ranh , ha nhiet o au phoi.N Khoet ranh , ha nhiet o au phoi.N Boi cac chat tang ma sat.N Thay oi o h gia hai truc can.

3.1.2 Cac san pham can.Cong nghe can c s dung e can rat nhieu loai kim loai ( nh thep, nhom, hp kim nhom, ong) San pham can ratnh thep, nhom, hp kim nhom, ong) San pham can rat a dang va phong phu, co nhieu loai hnh.

Loai hnh: Co the chia lam 2 nhom:

Rn gian: La loai co tiet dien vuong tron tam giacRn gian: La loai co tiet dien vuong, tron, tam giac, ch nhat, bau duc, ban nguyet

R Phc tap: La loai co tiet dien hnh ch T L I U thepR Phc tap: La loai co tiet dien hnh ch T , L , I, U, thep goc, thep ng ray,

L i Loai tam:

Tam day: T 460 mm hoac ln hn, rong t 600mm en5000mm, dai t 4000mm en12000mm.

Tam mong: T 0.2mm en 3.75mm.gDai: La cac dai dai co chieu rong t 200mm en180m,

chieu dai t 100mm en 60000mm day t 0 2 en 2mmchieu dai t 100mm en 60000mm,day t 0.2 en 2mm.

+ L i C 2 l i+ Loai ong: Co 2 loai:O Ong khong co moi hang gO Ong co moi han+ Loai hnh dang ac biet: Nh cac chi tiet loai bi, cac chi tiet co hnh dang phc tap. g p p

3.1.3 Thiet b can.>Ga can: e lap truc can, co thiet b ieu chnh khoang

cach gia cac truc cancach gia cac truc can.

>Truc can: Gom truc can trn va truc can lo hnh.1.Banh can; 2.Co truc; 3.au ch thap

>Hop giam toc: Giam toc o t truc ong c a en truc>Hop giam toc: Giam toc o t truc ong c a en truc can

>Hop banh rang ch V: Nhan chuyen ong t hop giam>Hop banh rang ch V: Nhan chuyen ong t hop giam toc, qua cac banh rang ch V e phan phoi tren truc can.

T b h h Tat ca cac bo phan tren c co nh tren nen can

3.2.1 Ban chat cua qua trnh keo day.R La qua trnh keo phoi kim loai qua lo khuon keo lam cho tiet dien ngang cua phoi giam va chieu dai tang. Cac san pham co the at o chnh xac cap 2 en cap 4.

R o bong va o chnh xac thap hn san pham keo nguoinguoi.

RMoi lan keo qua khuon, tiet dien phoi giam t 15% en 35%.

K= =0

dd

( )f1

1+K 1d ( ) gf cot.1+

K: He so keo cho phep.

d0,d1: ng knh phoi trc va sau khi keo.0, 1 g p

: Gii han ben trung bnh cua kim loai(N/mm2).f : He so ma sat.

: Ap lc khuon keo len kim loai(N/mm2).H : Goc nghieng lo khuon.

Tnh so lan keo n. T ng knh ban au d en ng knh cuoi cung dn phai

keo qua cac khuon keo trung gian th:d d

Lan keo 1: K= d1 =

Lan keo 2: K= d2 =1

0

dd

Kd0

1

dd

20dLan keo 2: K d2

Lan keo n: K= dn=2d 2K

n

dd 1

nKd0

d0Kn=

n.lgK= (lgd0 - lgdn)

nd Knd

d0

g ( g 0 g n)

dd lglg n = K

dd nlg

lglg 0

Tnh lc keo day:Lc keo day co the c xac nh theo cong thc :

FP = .F.lg (1+f.cotg ) (N) Gii h b ki l i(N/ 2)1

0

FF

: Gii han ben cua kim loai(N/mm2)F0,F1: Tiet dien trc va sau khi keo (mm2)0, 1 ( )

f: He so ma sat gia kim loai va khuon.

3.2.2 Dung cu va thiet b keo day.

Khuon keo HNH 65/61

Kh k b Khuon keo gom cac vung c ban sau:1.Vung boi trn co goc 900 cha chat boi trn e phoi .V g g 90 p

i vao de dang

2 Vung bien dang goc 2H ( 2H = 60 180 )2. Vung bien dang, goc 2 H ( 2 H = 6 18 )3. Vung nh knh l3 =1/2 d

4. Vung thoat khuon, co goc bang 600 ,e phoi thoat khuon c de dang, tranh sc be mat san pham keo.

(Vat lieu e lam than khuon thng la hp kim cng vaVat lieu e lam than khuon thng la hp kim cng va thep dung cu thuoc nhom thep khuon dap nguoi ( CD80, CD120 ), hp kim cacbit W, thep hp kim Cr-Ni.p p p

( e khuon lam bang thep thng va han chat vao may keo.keo.

Thiet b keo gom 2 loai:?May keo thang: Dung e keo day hoac ong co ng

knh ln, lc keo t 0.2 en 75 tan, toc o keo t 15 m/ph en 45 m/ph.

Dung bo phan truyen ong xch, truc vt, ecu, thanh rang g p y g , , , gva banh rang.

?May keo co tang cuon loai khong trt hoac co trt, dung day keo hoac thoi co ng knh 4.5 en 16mm. Dung

he thong rong roc lam cang day.

Hnh 2. :May keo co tang cuony g

1.Ong cuon; 2.Khuon keo; 3.Trong.

CHNG 4REN T DO VA REN KHUONREN T DO VA REN KHUON

4 1 Khai niem va phan loai cac phng phap4.1 Khai niem va phan loai cac phng phap ren, dap .

4.2 Thiet b ren dap .

4.3 Ren t do .

4 4 Thiet ke vat ren khuon va khuon ren4.4 Thiet ke vat ren khuon va khuon ren .

4.1 Khai niem va phan loai cac phng phap d ren, dap .

Ren dap: La phng phap gia cong kim loai bang ap p p g p p g g g plc nhiet o cao hoac nhiet o bnh thng e tao hnh dang va kch thc san pham theo yeu cau lc bien dang co

the la lc ong hay lc tnh.

Ren: La bien dang kim loai dang khoi di tac dung cua lc ong hay lc tnh co tnh chu ky hoac khong e c san pham co hnh dang va kch thc theo yeu cau.

Ren t do : Cac phng phap bien dang gom ren tay va Ren t do : Cac phng phap bien dang gom ren tay va ren may.

Ren khuon (dap khuon ) : Cac khuon bien dang b han Ren khuon (dap khuon ) : Cac khuon bien dang b han che trong long khuon.

D L bi d ki l i d d i Dap tam : La bien dang kim loai dang tam mong di tac dung cua lc tnh, khong co tnh chu ky : dap nguoi.

4.2 Thiet b ren dap .

OThiet b dap gom nhieu loai : may ren dap, thiet b nung, may nan thang, may cat phoi, thiet b van chuyen,nung, may nan thang, may cat phoi, thiet b van chuyen, thiet b lam sach c chia lam 4 nhom:

+ Nhom I : Nhom may bua+ Nhom I : Nhom may bua.+ Nhom II : Nhom may ep .+ Nhom III : Nhom may dap.+ Nhom IV : May co hnh dang va ket cau phc tap+ Nhom IV : May co hnh dang va ket cau phc tap.

+ Nhom I : Nhom may bua.Gom may bua van go, may bua hi, may bua lo xo, may

bua hi ncV 5 10 /Vmax = 5 10 m/stct > 0,01 s ( tct : thi gian cong tac )

Quan he gia van toc va thi gian cong tacQuan he gia van toc va thi gian cong tac cua nhom may bua.

+ Nhom II : Nhom may ep .

Nhom may ep gom may ep thuy lc may ep ma satNhom may ep gom may ep thuy lc, may ep ma sat.Vmax = 0,2 m/s

tct > 0 1 stct > 0,1 s

+ Nhom III : Nhom may dap.Nhom may dap gom may ren ngang, may dap truc khuyu.

Vmax = 5 m/s

tct > 0,01 s

+ Nhom IV : May co hnh dang va ket cau phc tap.

May co hnh dang va ket cau phc tap gom may ren lien tuc truc renren lien tuc, truc ren.

4 2 1 ac iem cac thiet b tao lc4.2.1 ac iem cac thiet b tao lcVe phng dien k thuat, ren t do co CX

khong cao, chat lng toan bo cua san pham phu thuoc nhieu vao trnh o tay nghe cua cong nhan. Thiet b va dung cu ren t do noi chung n gian, de s dung.

4.2.2 Cac loai may bua ( may nhom 1 )( may nhom 1 )

R May bua hi.R May bua lo xo.

R May bua kieu van go .R May bua hi nc - khong kh ep ren t doR May bua hi nc - khong kh ep ren t do.

R May bua hi.1.ong c; 2. Puli ; 3.Day ai ; 4. Puli; 5. Truc khuyu; 6. Tay bien; 7.Xilanh ep; 8. Pittong

9 V kh 10 Xiep; 9. Van kh; 10. Xi lanh bua; 11 .Pittong bua; 12 Can pittong; 13 e12. Can pittong; 13. e tren gan vi au bua; 14. e di ; 15. Than e; 16. Be ; 17. Bo phan ien khien may.

h 4 S l l Hnh 4..:S o nguyen ly lam viec cua may bua hi

R May bua lo xo.

1.Be e.

2.au bua.

3 R h d h 3.Ranh dan hng.

4.Nhp lo xo.

5.Tay bien.

6 B h l h t

Hnh 4..:S o nguyen ly lam

6.Banh xe lech tam.

viec cua may bua lo xo.

R May bua kieu van go .

1.e di; 2.e tren; 3.au bua; 4.Ga; 5.Ma

phanh; 6.Con lan truyen 7 V 8 Cong; 7.Van go; 8.Con lan; 9.Ma phanh; 10 on bay;11 Bang10.on bay;11.Bang ieu chnh chieu cao hanh trnh bua; 12.Can

H h 4 S l t

gat; 13.on bay; 14.Lo xo; 15.Chot; 16.Ban Hnh 4..:S o nguyen ly cau tao

cua may bua ma sat kieu van go.ap.

R May bua hi nc - khong kh ep ren t dodo.

1.Can ieu khien1.Can ieu khien

2.Ong dan

3.Con trt

4 V i khi 4.Van ieu khien

5.Xilanh cong tac

Hnh 4..:Bo phan phoi kh cua may b h i kh kh d

5.Xilanh cong tac

6.Pittong epbua hi nc-khong kh ep ren t do.

Hnh 4 :Nguyen ly chung cua cac ng truyen khHnh 4..:Nguyen ly chung cua cac ng truyen kh.

A:ng kh cao ap2: ng kh thoat

4.2.3 Cac loai may ep (may nhom 2 )GMay ep ma sat truc vt

ac iem :

Co lc ep t 40 60 tam, ren nhng chi tiet c nho va to ren trong khuon kn va hto, ren trong khuon kn va h.

GMay ep thuy lc i ac iem :

Dung e ren t do co lc ep t 100 700 tan. Dung e ren khuon co lc ep t 300 7000 tan. CX caoCX cao.

GMay ep ma sat truc vt

C t 1 P liCau tao : 1.Puli; 2,3.Banh ma sat; 4 on bay; 5 74.on bay; 5,7. C t; 6.Chot; 8. Can ieu khien; 9. au ep; 10.Truc vt; 11. E h 12

Hnh 4..:S o nguyen ly cua may ep kieu truc vt

Ecu co nh; 12. Banh ma sat

ep kieu truc vt.

GMay ep thuy lcCau tao : (H. * / tap ban ve )ve )1.Xilanh pittong nang ; 2. Xilanh pittong ep; p g p;3.au ep; 4. Cac chot nang noi vi san ngang;

5. Cac van dan chat long vao may ep; 6. Bo phan chnh lu; 7 Bm cao ap;chnh lu; 7. Bm cao ap; 8. Be ng chat long.

H h 4 B h kh h i tHnh 4..:Bo phan khuech ai ap suat

4.2.4 May nhom 3>May ep c kh ( may ren dap kieu truc khuyu )

ac iem :ac iem :

Lc ep ln ( 200 10.000 tan ). CX cao, nang suat lao ong tot. oi hoi viec tnh toan phoi khat khe, phai lam sach phoi oi hoi viec tnh toan phoi khat khe, phai lam sach phoi trc khi dap.

> May ep c kh( may ren dap kieu truc khuyu )( may ren dap kieu truc khuyu )

1.ong c; 2. Day ai; 3 B h h 43. Banh rang nho; 4. Banh rang ln long khong; 5 Li hp; 6 Taykhong; 5. Li hp; 6. Tay bien; 7. au trt bang au ep; 8. Be (ban pmay)9. Ma phanh; 10. Truc kh khuyu.

4 3 Ren t do4.3 Ren t do

4.3.1 Cac nguyen cong ren.

4.3.2 Dung cu ren t do .

4.3.3 Thiet ke vat ren t do.

4.3.1 Cac nguyen cong renVuot : La nguyen cong lam giam tiet dien ngang va tang chieu dai cua phoi. Thng e ren cac chi tiet dang truc,chieu dai cua phoi. Thng e ren cac chi tiet dang truc, ong.Co 2 cach :N Sau moi nhat dap, lat phoi 90 va lat ngc tr lai.NVa dap va quay tron phoi. (H.89 /84)

Hnh 4..:Phng phap dch chuyen phoi khi vuot.

Chon : La nguyen cong lam giam chieu cao va tiet dien ngang cua phoi.

a. 2 : lc u ln.0

0

dh

b. < 2,5 : lc u ln.

0d

0

dh

Cac hien tng thng xay ra khi chon : c < 2 5 : lc khong u ln

0d

0h y(H.95 /86 ).

c. < 2,5 : lc khong u ln.0

0

d

hd. < 2,5 : lc qua nho, nhanh.

0

0

dh

e. > 2,5.0

0

dh

Khi chon tren may bua e bao am lc dap u ln th canKhi chon tren may bua e bao am lc dap u ln th can thoa man quan he :

ho 0,25 HH : Hanh trnh ln nhat cua au buaho :Chieu cao ban au cua phoi chon.

ot lo : Co 2 trng hp : ot lo thong suot ( H 99 / 87 )ot lo : Co 2 trng hp : ot lo thong suot ( H.99 / 87 )ot lo khong thong suot

N Xoan : La nguyen cong lam cho cac tiet dien tai N Xoan : La nguyen cong lam cho cac tiet dien tai cho xoan quay tng oi nhau mot goc nao o theo th t va quanh truc cua no. ( H.102 / 89 )

N Uon : Dung e thay oi hng cua truc hoac hng th cua vat ren. ( H.103/89).g ( )

Ngoai ra con co cac nguyen cong khac nh han ren, chat, dch trt, ep vet va cat vai, hieu chnh

S bien hnh tai tiet dien uon.

4 3 2 Dung cu ren t do4.3.2 Dung cu ren t do

. Dung cu ren t do c chia lam 3 nhom.a. Nhom th nhat : Gom nhng dung cu c ban nh : e, g g ,

bua, ban la, ban ban top, san, chat, mui otb. Nhom th 2 : Gom nhng dung cu kiem tra va o

lng nh eke, thc cap, compa, dng o (H.75 / 70)

4.3.3 Thiet ke vat ren t do4.3.3 Thiet ke vat ren t do

1. La chon ket cau va hnh dang hp ly cua vat ren.

2. Thiet ke ban ve vat ren.

3. Tnh khoi lng phoi ren.

4. Tnh kch thc phoi ren.

5. Tnh toan che o nung nong va lam nguoi.

6. Lap qui trnh cong nghe ren c ban.

7 Ch i h l 7. Chon may gia cong hp ly.

1. La chon ket cau va hnh dang hp ly t cua vat ren.

zNguyen tac chung cua viec la chon va thiet ke chi tiet la phai la chon sao cho ket cau va hnh dang chi tiet co thephai la chon sao cho ket cau va hnh dang chi tiet co the gia cong va gia cong c de dang. Khi la chon thiet ke nen :Nen tranh thiet ke vat ren hnh nem, mat con hoac

ng giao nhau bac hai hoac vat ren hnh bac hay mat cong phc tap, gan mong, thanh mong

Neu ket cau vat ren phc tap th nen chia thanh nhieu bo phan e ren sau o han lai vi nhauphan e ren sau o han lai vi nhau.

2.Thiet ke ban ve vat ren.

RDung sai, lng d gia cong c. (H.110 / 95) Lng d gia cong c : La lp kim loai se c tach ra

trong qua trnh gia cong cat got. D i L kh d h h k h Dung sai ren : La khoang dao ong cho phep cua kch

thc ren danh ngha.

S o bieu dien lng d gia cong c va dung sai ren tren mot kch thc.

: lng d da nh ngha: lng d da nh nghamin : lng d nho nhatmax : lng d ln nhat g : dung sai ren : sai lech di cua kch thc danh ngha vat ren. : sai lech tren cua kch thc danh ngha vat renthc danh ngha vat ren.(t so noi len dung sai hay lng d ve 1 pha. )hay lng d ve 1 pha. )

3.Tnh khoi lng phoi ren.

GF = GVR + Gch + Gl + GcbF VR ch l cbGVR = VVR .

G h = (1 5 2 5 % ) GF (Cho lan nung th nhat hoac chGch = (1,5 2,5 % ) GF (Cho lan nung th nhat hoac ch nung mot lan.) Gch = 1,5 % (cho cac lan nung th hai tr i.) Gch 1,5 % (cho cac lan nung th hai tr i.) Gcb = (10 15 %) GF (oi vi phoi can ).

GF : Khoi lng phoi ren.GVR : Khoi lng vat ren.Gch : Khoi lng chay hao.G Kh i l l Gl : Khoi lng ot lo .Gcb : Khoi lng cat bo .

4.Tnh kch thc phoi ren.IDa vao nguyen cong chu yeu trong qua trnh ren.

Neu nguyen cong chu yeu la vuot th ta chon: N g y g y v :FF = y.FmaxFF : Dien tch tiet dien phoi . Fmax : Dien tch ln nhat cua vat ren . y : He so ren 1,3 1,4

T F t h F h T FF ta se chon gan ung FF chuan. I Tnh chieu dai phoi.

VF / FF chuan = GF / 8.FF chuanKiem tra lai : LF / DF chuan 2,5 2,8

2 5 : oi vi ren tay2,5 : oi vi ren tay.

2,8 : oi vi ren may.

Nguyen cong chu yeu la chonNguyen cong chu yeu la chon{ Phoi tron : DF ( 0,8 1,0) (0,8 1)3 FV 3 F

G

{ Phoi vuong : aF (0,75 0,9) 3 FV

Tnh c DF aF ta se chon gan ung DF h Tnh c DF, aF ta se chon gan ung DF chuan

aF chuanLF = VF / DF chuan

Kiem tra lai : LF / DF chuan 2,5 2,8

5.Tnh toan che o nung nong va lam nguoi.

} Tuy thuoc vao tnh chat vat lieu, kch thc, dang san xuat ta can xac nh :

Nhiet o bat au gia cong. Nhiet o ket thuc. Thi gian nung lan 1,2. Cach xep phoi. Che o lam nguoi vat ren

6.Lap qui trnh cong nghe ren c ban.

Tuy thuoc vao ieu kien cu the (hnh dang vat ren dung cu thiet b ) ma ta la chon phng anren, dung cu, thiet b) ma ta la chon phng an toi u nhat.

7.Chon may gia cong hp ly.

D Tnh lc dap au bua (lc ep cua may ep )D Tnh lc dap au bua (lc ep cua may ep )G = P = k.Fmax

k : He so ap lc phu thuoc kim loai gia cong :

Thep thng k = 5Thep thng k = 5

Thep ac biet k = 7

Fmax : Dien tch tiep xuc ln nhat gia phoi va au ep (m)au ep (m ).

4.4 Thiet ke vat ren khuon va khuon ren .

4.4.1 Xac nh ket cau hp ly cua vat ren khuon .

4.4.2 Xac nh mat phan khuon.

4 4 3 Xac nh lng d va dung sai4.4.3 Xac nh lng d va dung sai.

4.4.4 Ranh vanh bien.

4.4.5 Goc nghieng va ban knh goc ln.

4.4.6 Lp ren cha thau cua lo.

4 4 7 Ban ve vat ren4.4.7 Ban ve vat ren.

4.4.8 Khoi khuon ren.

4.4.1 Xac nh ket cau hp ly cua vat ren khuon .

Sa oi ket cau cua chi tiet cho n gian e gia congD Nh hi ti t h h d k h th i hD Nhng chi tiet co hnh dang va kch thc gan giong nhau th ch can dung mot loai chi tiet ien hnh.D Chia chi tiet thanh hai hay nhieu vat ren e de gia congD Chia chi tiet thanh hai hay nhieu vat ren e de gia cong sau o ket hp vi cac phng phap khac.D Dung nhng phoi co hnh dang kch thc gan giong vat ren e cong nghe ren c de dang.D Dung phng phap ep tinh hoac ep nghien e thay the

i i mot so cong viec gia cong cat got.

4.4.2 Xac nh mat phan khuon. p

OMat phan khuon la ranh gii cua hai na khuon tren va khuon di.zKhi xac nh mat phan khuon can am bao :

Lay c vat ren sau khi ren xong ra khoi khuon ren mot cach de dang (H.a,b)

Long khuon phai nong va rong nhat e kim loai deLong khuon phai nong va rong nhat e kim loai de ien ay khuon. (H.c,d)

Ch h kh h d h hi l h Chon mot phan khuon sao cho de phat hien s lech khuon khi rap khuon (tranh chon nhng be mat thay oi tiet dien ot ngot )dien ot ngot )

MPK h i th t h h b MPK phai thang tranh cong hay bac.

Phan phc tap cua vat ren, thanh mong, gan thng bo tr khuon tren v o chu lc tac dung ln hn, kim loai de ien ay hnde ien ay hn.

MPK h i h h h hi i b b i MPK phai thch hp e chi tiet am bao sc ben toi a.

4 4 3 Xac nh lng d va dung sai4.4.3 Xac nh lng d va dung sai.

OVat ren khuon co o bong va CX thap, do o can phai them lng d va gia cong c.

OViec xac nh lng d va dung sai ung se tiet kiem c kim loai am bao CX gia cong sautiet kiem c kim loai, am bao CX gia cong sau nay.

4.4.4 Ranh vanh bien.

4.4.5 Goc nghieng va ban knh goc ln.o nghieng cua thanh khuon:} e kim loai de ien ay khuon.

} Lay vat ren ra khoi khuon sau khi vat ren c de dang.Tr so o nghieng phu thuoc cac yeu to:} Phng phap ay kim loai vao long khuon ep phng} Phng phap ay kim loai vao long khuon ep, phng

phap thao vat ren ra khoi khuon.} Kch thc,hnh dang ben ngoai vat ren, tr so co rut kim} Kch thc,hnh dang ben ngoai vat ren, tr so co rut kim

loai.} Nhiet o khi hoan thanh ren khuon va toc o lam nguoi.} Thanh trong hay thanh ngoai:Thanh trong = 5 15Th h i 3 13Thanh ngoai = 3 13

Ban knh goc ln:

Hnh 4 :Ban knh goc ln trong R. Hnh 4..:Ban knh goc ln trong R va ban knh goc ln ngoai r cua chi

tiet.Tac dung : tiet.Tac dung : Lam cho kim loai di ong trong long khuon de dang. Tranh cho vat ren khoi nt, gap nep. g p p Nang cao sc ben, tuoi tho khuon.

4.4.6 Lp ren cha thau cua lo.

Hnh 4..:Hnh dang lp cha thauR Khi lam khuon, lo c lam di dang lo cha thau het e tang tuoi tho o ben cho khuon. Lp kim loai cha thau

khong c cat i cung vi cac lp bavia cua vat ren.R Cong thc kinh nghiem e tnh chieu day lp kim loai cha thau :cha thau :

S= 0,45 + 0,6 (mm)S:Chieu day cua lp cha thau ay bang (mm)

525.0 hd hy p y g ( )

h : Chieu cao mot pha lo (mm)d : ng knh lo (mm)

4.4.7 Ban ve vat ren.

Qui c :

1 Ban ve vat ren bang net am.g1 Chi tiet net t.1 Kch thc chi tiet ghi ben di kch thc vat ren.1 B h i l 1 11 Ban ve vat ren thng vi ty le 1 :1

neu qua ln ve t le 1 : 2

4.4.8 Khoi khuon ren.

a Bo tr long khuon tren khoi khuona. Bo tr long khuon tren khoi khuon.Co 2 loai :z Khuon mot long khuon (H 112/99)z Khuon mot long khuon (H.112/99)

z Kh hi l kh (136/120)z Khuon nhieu long khuon (136/120)

Yeu cau : Trung tam long khuon trung trung tam khoi khuon, va phai trung vi trong tam cua bua.

b. Chieu day thanh khuon va hnh dang, kch thc b. Chieu day thanh khuon va hnh dang, kch thc khoi khuon. (H.138 +139/121).

S, S1 10 mm (c tnh va tra trong so tay )Hmin = 0,9 Dmax + h1 (mm) Hmin : Kch thc chieu cao khuon.D k h l h t t t MPKDmax : ng knh ln nhat vat ren tren MPK.h1 : Chieu cao uoi en.

H h 4 H h d kh i kh b Hnh 4.: Hnh dang khoi khuon ren tren may bua.

CHNG 5DAP TAMDAP TAM.

5.1 Khai niem.

5 2 C t h i5.2 Cac nguyen cong cat phoi.

5.3 Dap khong lam mong thanh phoi.p g g p

5.4 Dap co lam mong thanh phoi (ep chay nguoi).

5.5 Cac cong nghe hoan chnh sau khi dap.

5 1 Kh i i 5.1 Khai niem:

E Dap tam la phng phap bien dang phoi dang h h h h h d h h htam thanh san pham co hnh dang phc tap, co thanh

mong (nh hnh hop, hnh tru) co vanh hay khong co h h kh vanh, co ay hoac khong co ay.

E Lc tac dung la lc tnh khong co chu ky.E Lc tac dung la lc tnh khong co chu ky.

ac iem : Tiet kiem vat lieu. San pham co hnh dang phc tap. Thiet b co hanh trnh n gian. S h d h l l kh i San pham dap co tnh lap lan tot, khong can gia cong c. Trnh o cong nhan khong can cao. Nang suat cao, gia thanh ha, c kh hoa, t ong hoa.

5.2 Cac nguyen cong cat phoi.

5 2 1 C t h i th th 5.2.1 Cat phoi theo ng thang.H Cat theo ng chu vi h.

Dung may cat li dao song song Dung may cat li dao song song.

Hnh 5 :May cat li dao song songHnh 5..:May cat li dao song song.

ac iem : E Tiep xuc ng nen lc rat ln, vet cat ep,thang.

P= K.S.B. catK H h h li d ki l i

K : He so phu thuoc vat lieu dao, kim loai cat.B : Chieu rong phoi cat.S : Chieu day phoi tamS : Chieu day phoi tam.

cat : Gii han ben cat cua phoi.Tcat = (0,8 0,9) b (N/mm)

( ) b ( )

b : Gi han ben cua phoi (N/mm)

May cat li dao nghieng mot gocQ = 20 60

Goc vat trc: = 50 150Goc vat sau: H 30 300Goc vat sau: H =30 300

Hnh 5..:May cat li dao nghieng.

P = K. . cat S 2.

z H li

tgz : He so vat lieuQ: Goc nghieng li dao tren

May cat li dao a

P=K tS 2 P=K. . cat

H : goc antg.2

Co the dung nhieu cap a e cat ong thi nhieu dai kim loai(HNH 149/129)

h 5 d Hnh 5..:May cat dao a

5.2.2 Dap cat va ot lo: Dap cat va ot lo la phng phap cat theo mot ng

cong khep kn.

Khi dap va ot lo s dung bo chay coi co canh sac.

H h 5 Q h bi d ki l i khi Hnh 5..:Qua trnh bien dang cua kim loai khi cat va ot.

Khe h gia chay va coi (Z )Z=(Dcoi Dchay)/ 2

ot lo: Dap cat:

Z (Dcoi Dchay)/ 2

dchay =(dlo +')-Kchay' D i

Dcoi = (dchi tiet + ')+Kcoid (D 2Z ')-Kchay' : Dung sai

-Kchay : Dung sai chayd chay = (Dcoi 2Z- ')-KchayZ = (5 10%)S

Dcoi = (dchay+2Z+ ') S: Chieu day phoi

Lc cat:P=K L SLc cat:P=K.L.S. catL: Chieu dai ng cat

( h i t)

(chu vi cat)

5 3 Dap khong lam mong thanh phoi5.3 Dap khong lam mong thanh phoi

5.3.1 Thiet ke phoi dap.

5.3.2 Thiet ke cong nghe dap.

5.3.3 Thiet ke khuon dap.

5.3.1 Thiet ke phoi dap.

Hnh dang khai trien:Hnh dang khai trien: Hnh dang tam phoi phu thuoc vao hnh dang chi tiet:

L Neu chi tiet la hnh hop ,ay ch nhat th tam phoi co hnh bau duc hay elip.

L Neu chi tiet la hnh hop ,ay vuong hoac hnh tru ,ay tron th phoi la mieng cat tron.p g

z Tnh ng knh phoi (kch thc phoi)

Neu biet dien tch F (cm2) th:F4Dphoi= (cm)

Neu biet khoi lng kim loai chi tiet G(g) th:F4

Neu biet khoi lng kim loai chi tiet G(g) th:

Dphoi= =1.13 (cm)S

GV..

4 S

GV.

Neu biet the tch kim loai chi tiet (cm3) th :

Dphoi=1.13 (cm)

V

phoi ( )

: Khoilng rieng (g/cm3) cua vat lieu.S

S : Chieu day phoi (cm)

5.3.2 Thiet ke cong nghe dap.

He so dap m:

m = d chi tiet/ D phoi (m=0.55 0.95)

z Tnh so lan dap phoi co ng knh D thanh chi tiet co p p gng knh dn

n =1+ n Dmd ).lg(lg 1n 1+Vi (mtb )n-1 = m mn.

tbmlg

Nhan xet: Dap tam la mot qua trnh gia cong nguoi nen b bien cng be mat, do vay lan dap sau bien dang kho khan h l d D h d hn lan dap trc. Do o he so m tang dan.

Lc dap Pd : Pd = P + Q

P L bi d hi ti tP : Lc e bien dang chi tiet.

Q : Lc chan phoi chong nhan mieng san pham.

- Lc bien dang: Lc chan phoi:

Q p g g p

P = K1..d1.S. b (N)d1: ng knh chi tiet sau khi

Q = F. q (N)

F: Dien tch vanh chand1: ng knh chi tiet sau khi dap lan 1.

S : Chieu day phoi (mm)

F: Dien tch vanh chan tiep xuc chi tiet.

q: Ap suat chanS : Chieu day phoi (mm)

b: Gii han ben(N/mm2)q: Ap suat chan(N/mm2)

K : He so ieu chnh lan dap au, phu thuoc vao m.

5.3.3 Thiet ke khuon dap.

Khuon dap gom chay va coi.

Rch: Ban knh ln cua chay.

Rc : Ban knh ln cua coi.

Z: Khe h gia chay va coi dap..

Tnh khe h gia chay va coi dap (Z )Tnh khe h gia chay va coi dap (Z )Z = K.S + Smax

R Lan dap cuoi cung( dap nhieu lan) hoac ch dap 1 lan:Z S + ' + 0 1SZ = S + ' + 0.1S

S: Chieu day tam kim loai.

': Dung sai tam lim loai.R Dap nhieu lan tnh cho cac lan dap th hai tr i:R Dap nhieu lan,tnh cho cac lan dap th hai tr i:

Z = S + ' + 0.2S

O Chay va coi phai co goc ln e tranh rachO Chay va coi phai co goc ln e tranh rach, t phoi trong qua trnh dap.

O Neu ban knh goc ln qua ln bien dang cang de nhng san pham de tao nep nhan.cang de nhng san pham de tao nep nhan.

O Neu ban knh goc ln qua nho, phoi de b rach trong qua trnh dap.

& Ban knh goc ln cua coi c tnh theo cong thc:& Ban knh goc ln cua coi c tnh theo cong thc:Rc = 0.8 SdD )(

D: ng knh phoi trc khi dap (mm).

d: ng knh phoi sau khi dap (mm)d: ng knh phoi sau khi dap (mm).

S: Chieu day phoi (mm).

& Ban knh goc ln cua chay c tnh theo cong thc:Rch = ( 0.8 1.0 )RcRch ( 0.8 1.0 )Rc

Chu y: Lan dap cuoi cung Rch lay nho hn mot chut nhngRch 0 5RcRch 0.5Rc.

5.4 Dap co lam mong thanh phoi(ep chay nguoi)

5.4.1 Thiet ke phoi dap.

5.4.2 Thiet ke cong nghe dap.

5 4 3 Thi t k kh d 5.4.3 Thiet ke khuon dap.

5.4.1 Thiet ke phoi dap.p pO Chieu day phoi c tnh theo cong thc:

VS = (mm)

V : The tch chi tiet co tnh en lng d cat mep0FV

V : The tch chi tiet co tnh en lng d cat mep.

F0: Dien tch cua phoi (mm)

O Kch thc phoi:D D ( 0 1 0 5 ) ( )D0 = D - ( 0.1 0.5 ) (mm)

D0 : ng knh cua phoi.

D : ng knh ngoai cua san pham.

Chieu cao lng d cat mep:Chieu cao lng d cat mep:

'h=(0.5 0.8) h'h: chieu cao cua san pham theo kch thc ban ve.

5.4.2 Thiet ke cong nghe dap.He so bien dang K

SSK1 = .100%

0

10

SSS

Kn = .100%1

1

n

nn

SSS

K1: He so dap lan au khi co lam mong thanh phoi.

S0: Chieu day phoi ban au.

1n

0 y p

S1: Chieu day phoi sau lan dap au.

Sn,S n-1: Chieu day phoi sau, trc lan dap th n.

Tnh so lan dap theo cong thc:

n = .100%F : Dien tch tiet dien ngang chi tiet trc khi dap lan au

)1lg(lglg 0

tb

n

KFF

+

F0: Dien tch tiet dien ngang chi tiet trc khi dap lan au co lam mong thanh phoi.

i h i di hi i l d i Fn: Dien tch tiet dien ngang chi tiet sau lan dap cuoi cung.

Ktb: He so dap vuot trung bnh.

Khi tnh toan coi K=K= =Kn=Ktb

Nh t Th i l t ki l i b bi Nhan xet: Thng sau moi lan vuot kim loai b bien cng mot phan nen chon:

K> Ktb >Kn Chon he so K tuy thuoc vao vat lieu.

5 4 3 Thiet ke khuon dap5.4.3 Thiet ke khuon dap.

Khuon dap cung giong khuon dap cua dap khong lam mong thanh phoi nhng khe h gia chay va coi g p g g ytrong trng hp nay phai nho hn chieu day cua phoi.p

Z = ( 0.3 0.8 )S

5.5Cac cong nghe hoan chnh sau khi dap.Uon vanh: La phng phap tao cac chi tiet co g, co vanh

rong hoac chi tiet khong co ay.1 KHmax = D. + 0.43R (mm)

H : o cao uon vanh ln nhat2

1 nKHmax: o cao uon vanh ln nhat

Kn: He so uon vanh; Kn = ; Kn =0.62 0.72Dd

D: ng knh chi tiet; d: ng knh lo.

@ H < Hmax : Phoi tron hoac nh hnh, ot lo , dap bang

D

@ H < Hmax : Phoi tron hoac nh hnh, ot lo , dap bang chay coi.

@ H > H : Dap tao hnh ( Khong lam mong thanh@ H > Hmax : Dap tao hnh ( Khong lam mong thanh phoi) ot lo ay, uon vanh.

Gan phong: La nguyen cong lam to chi tiet phan di, mieng van gi nguyen.

Khuon thng lam hai na, pha chay co the gan vi khoi cao su e ep len thanh chi tiet vao trong khuon.

Chu y: Sau khi m khuon phai lay c chi tiet trong khuon.

Top mieng: La phng phap lam nho mieng chi tiet sau khi a dapkhi a dap.

In noi: Tang o cng vng cua chi tiet va tang tnh tham b h i h h h hi m bang cach in hnh gan, nhan hieu.