-
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.