Chuong_VIIIA may tu dong.pdf

7/23/2019 Chuong_VIIIA may tu dong.pdf

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MY T NG

- 2006 -


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AI CNG

V EM A Y T ONG


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CHNG VI I I

A I CNG V EM A Y T ONG

I . K hai NiemI .1. Vai tr o:

Cong cusan xuat luon c cai tien, thay oi dan tthos n gi anlen cong cuc kh hoa, cong cutong hoa.

Cach mang v econg cu san x uat gan l ien vi cac cuoc cach mangkhoa hoc kythuat, cuoc cach mang khoa hoc kythuat lan I vi noi dung chuyeulac kh hoa, bat au vao theky18.Cuoc cach mang k hoa hoc kythuat lan I I bat au vao au theky-21 vi noi dung

lat ong hoa v al inh hoat hoacac quatrnh san xuat, khoa hoc kythuat aaten trnh ocao.

H. VIII.1. M ay tien tong i eu khi en bang cam


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I .2. Tong hoa lag: ? C kh hoa lathay thesc lc cua con ngi bang may moc ethc

hi en nhanh, nhng cong viec t inh vi , phc tap, nang nhoc.Tong hoa l akhanang c kh hoa trnh ocao may moc thc hien

nhanh chong cac quatrnh san xuat makhong can sieu khien trc tiep cua con

ngi .- Hieu qualao ong cua may tong hoa:- Cong suat ln, lam viec l ien tuc 24/ 24.- Toc ocao, giam c thi gi an gi a cong.- Thay thecon ngi lam nhng cong viec nang nhoc, oc hai .- Ngi cong nhan cothetheo doi nhieu may cung mot luc.- M ay moc t ong athay thecon ngi eieu k hi en cac quatrnh sa n

xuat, phc tap tinh v i , vi nang suat cao vachat l ng tot nh: NC, CNC, FM S( flexibl e manufacturing system),

- Thay thecon ngi nhng i eu kien l am viec nang nhoc, oc hai nguy

hi em, gi am thi gi an lao ong vacothelam viec l ien tuc .

I I . Lythuyet venang suat cua may tong:Noi dung chuyeu: lagi am thi gi an chay k hong e tang nang suat l ao

ong.- Thi gi an gi a cong mot san pham, hay thi gi an 1 chu kygi a c ong- K hi eu: T, t nh theo cong thc sau:

(Phut)ay: lvt - thi gi an lam viec

T ck- thi gi an chay khong, gom thi gi an tien vao, lui ra ong mcac

c cau may.Nang suat cua may tong Q: lasosan pham may lam ra t rong mot n v

thi gi an.(Chi ec / Phut)

Neu t ck = 0, th nang suat bang:(1.2)

- K : goi lanang suat cong nghecua may, notng trng cho nang suat cuamot chiec may l tng t ong cat got l ien tuc, khong cohanh trnh chay

khong.Thay trso:

KTlv

1 , tcong thc (1.2) vao cong thc (1.1) , ta co:

(1.3)

cklv ttT

cklv ttTQ

11

KT

Qlv

1

..1

1.

.1

1K

tKK

tKQ

ckck


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Trong o;: goi lahesonang suat cua m ay,, noxac nh mc osdung may cohieu qua.

- Chuy: t(1.3) ta co:: oi khi con goi la mc ogi a cong l ien tuc cua quatrnh cong

nghe giatrcua notrung vi hesonang suat cua may tong.V du: Trong mot chu k gia cong t lv = 0.4 phut; t ck = 0.8 phut, nh vay

nang suat cong nghe K =4.0

1= 2.5 (chiec / phut) vahesonang suat:

-Tc thi gi an coch cua may chchiem 33% cua chu k gi a cong.-Theo cong thc (1.3) th nang suat cua may Q phu thuoc vao nang suat

cong ngheK vahesonang suat . M uon tang Q l ien tuc thi phai ong thi tangK va, tc giam ong thi, thigi an lam vie c(t lv ) vathi gi an chay khong (t ck).

Neu chcomot trong hai thanh phan nay gi am th gi a trQ seti en enmot gi a t rgii han nhat nh.

Cohai trng hp nang suat tien en mot gi atrgi i han: ( chiec/ phut)

( chiec/ phut)

+ ng 1 ( hnh 1.3) chrang Q = K ( nang suat l tng), neu T ck= 0.+ Nhng v T ck 0 nen cong cong nang suat thc te2. trong trng hp nay

ducotang K ti au th nang suat Q van tien en gii hanck

T

1,chkhong tang t

levi K , v khi K tang th trso:cktK.1

1

lai giam.

cktK.1

1

T

t

tTT

Q lv

lv

1

:1

T

tlv

33.08,0.5,21

1

KtK

KQ

cktLim

ck

.10

max

ckcktK llK

KQ Lim

lv

1

.10

max

H. VI I I .2. Doth nang suat


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Cac ng cong t ren (hnh 1.4) cho thay moi quan hegi a K va.V du: Gi a cong chi ti et co: L =100 mm, S = 0,1 ( mm/ vong),

Tck= 1 ( phut), ( a dung cuvao vara, o, k iem tra,)Sovong quay truc chnh: n tc= 1000 (vong / phut).

Vay sovong quay can thiet egia cong phoi : 10001.0

100

S

Ln (vong)

Nang suat cua may: Q = k. (chiec / phut)

Nang suat cong ngheK : 11 n

n

TK

tc

lv

(chiec/ phut)

Hesonang suat : 5.01.11

1

.1

1

cktK

Nang suat cua may: Q = k. = 1.0,5 = 0,5 (chiec /phut)Gi ascothenang k = 50 ( chiec / phut) luc ohesonang suat vanang suatcua may Q = K .= 50.0,02 = 1 (chi ec /phut)

etang nang suat len 50 l an can nhng ph ton vekythuat rat l n, nhngnang suat thc techtang 2 lan.

Ket luan: muon tang nang suat Q cua may ong thi vi viec giam thigi an lam viec, etang nang suat cong ngheK, phai gi am thi gi an chay khong(T ck). L ch sphat trien cua mat t ong cothebi eudien bang othdi ay, Sau khi chetao loai may au tien ngi sanxuat cotan dung khanang cua chung bang cachtang cng ogi a cong ( tang K ),- Nhng en mot luc nao oK tang maQ sekhong

tang, econang suat cao hn na can comot loaimay mi vi thi gi an chay khong behn hoac v iqui trnh cong nghemi tot hn vanh thecac maymi dan dan xuat hien, cac ng cong nang suat ca o dan

02.01.501

1

H. VII I .3. oth hesonang suat

H. VI I I .4. Gian ophat tr ien nangsuat may tong


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Nang suat tang eu tren moi ng cong lado tang K hay giam thigi an lam viec ( T lv ).

Nang suat nhay vot tng cong nay len ng cong kia oi khi lanhcoqui trnh cong nghemi , T lv vaT ckeu giam, nhng chuyeu lagiam thigi an chay khong

Nen noi dung chuyeu cua tong hoa l agi am thi gian chay khong,giup tang nhanh nang suat lao ong.tren tnh ton that cua may cho tng chu k lam viec ( gi a cong xong

mot chi tiet) neu tnh cho mot thi gi an dai th nocao hn, v neu thi gi an dai sephat sinh ton that ngoai chu k , nh thay oi hay i eu chnh mot sodung cu amon, sa cha hay ieu chnh lai cac c cau may, a loat ph oi mi vao may,kiem tra san pham, ieu chnh may ., Cng ogia cong cang tang th ton thatngoai chu k cang ln.

Trong t rng hp nay ton that may tnh theo cong thc:

T tt = t tt1+ t tt2+ t tt3+, lathi gi an ton that ngoai chu k tnh cho mot san pham.tph= t ck+t tt latong sothi gi an phu( ton that t rong vangoai chu k ).

Trong thc tekhi tnh en nang suat phai tnh en cac ton that trong vangoaichu k.

I I I . Nhiem vu t ong egiam ton that va nang caonang suat:I I I .1 . Ton that loai 1 vaNhiem vutong hoa chu ky.

Ton that loai 1: L a ton that l ien quan en chuyen ong chay khong,

khong trung vi chu k ylam viec cua may, l ap phoi, thao phoi , oi vtr cua phoi,cac c cau ong m vv egiam ton that ngi ta tm cach gi am toi a thi gi an chay k hong

xuong mc thap nhat, hoac bang khongoi vi dang san xat hang loat ln ngi ta dung may tong nhieu truc

egia cong, phng phap nay conang suat gap 22 lan so vi khi gia cong trenmay van nang. v gi a cong tren may nay toc ocat cao, thi gi an gi a cong vathi gi an chay khong gi am.

phttcklv

tK

K

TTTQ

1

1


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Hnh 1 v ahnh 2: bi eu dien phng phap gia cong trungoai theo2 phng phap:

Hnh 1: gi a cong bang phng phap cat thL 1,L 2,L 3m Phng phap naygi am c thi gi an chay khong cho tng chu ky.

Hnh 2: gi a cong tng lp mong L 1,L 2,L 3. Phng phap nay tieu ton nhieu

thi gi an chay khong, dao cat mau mon.Hnh 3 vahnh 4: bi eu dien phng phap k hoan loHnh 3: khoan l oat kch thc L 1trc, sau okhoan lokch thc L 2,

phng phap nay gi am c rat nhieu thi gi an chay khong, thng c ap dungtrong t rng hp vat l ieu cng khogia cong, nhng am bao phoi phai cng vngkhi khoan, gi c tuoi thocua mui khoan c l au hn.

Hnh 4: cach nay thng c ap dung egia cong vat l ieu mem, ton thigi an chay khong khoang L 2

I I I .2. Ton that loai 2 vaNhiem vu tong hoa thay the

ieu chnh dung cu. L aloai ton that l ien l ien quan en viec giao nh an mai sa, lap at,i euchnh dung cugi a cong.

ekhac phuc vagiam loai ton that nay can phai: Chon vat l ieu lam dao tot etang tuoi tho cua dao cat, gi am thi gi an

ieu chnh dung cat. Ngay nay ton that loai I I van con t ren may t ong,nhng c hien ai

hoa val inh hoat hoa hn, vi s ra i cua may i eu khi en theo chngtrnh so, tren may botr 1 odao quay c, thay dao nhvao hethongi eu khi en thuy lc hoac kh n en, nhanh vaan toan.

Ngi cong nhan cotheieu chnh, l ap ghep dao san ben ngoai , sau o

lap v ao odao emay tong thay dao. Ngoai ra egiam ton that ngi ta con sdung cac c cau ac bi et trong

gi adao, ogahay tren ban may eieu chnh dung cu chnh xac vanhanh chongvv..

H. VI I I .5. Cac phng phap cat tr ong chu kygi a cong


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Cac loai dao cat thong dung:

K ieu 1: lakieu l ap dao a dung, dedang thay oi kieu bang cach thayoi manh hp kim cng, khi chuy en sang mot cong oan khac

(1) than dao,(2) chot lap bophan cat,(3)bophan cat (mieng hp kim c gan lenno)(4) lovat; (5) vt ep ( conh bophan cat);(6) tiet di en vuong chong xoay.

K hi lam viec chxoay bophan cat en vtr can thi et vaxiet vt(5) laiK ieu 2: ay lakieu thong dung c dung phobi en.

Coket cau n gian nhng van bao am otin cay cao.(1)than dao, (2) mat nh chuan (2) va(3), 4) mieng cat (bang hp kim) , (5) ongkep coren evan v t (10) ong thi trong ong co3 ranh tao v i nhau 1 goc 90 o,vtr khi lam viec cac goc nay quay vepha mat (2) , (12) mieng em,gia miengcat (4) vamat chuan (3) , vt (10) coau con (1 1) .

K hi van vt 10 th cac canh 8 sebvan trc canh 9 vaep mieng cat 4vao mat nh chuan 2, neu tiep tuc van vt 10, canh 9, seep mieng cat xuong matnh chuan 3.

M ieng em 12) laeam bao cho mat nh chuan 3 cua dao khong bh khi mieng cat (4) bgay.

I I I .3. Ton that loai 3 vanhiem vunang cao otin cay cuacac hethong tong:

L aton that l ien quan en otin cay cua hethong, bao gom viec thayoi sa cha vaieu chnh cac c cau cua may M ay t ong lamay rat phc tap, nhieu bophan c k h nhanh chong

bmai mon, nen phai thc hien tot cong tac bao tr vasa cha may:+ Boi trn thng xuyen cho may.

K ieu1K ieu 2:

H. VI I I .6. cac loai dao galap nhanh


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+ Chuan bsan cac c cau mau mon ekp thi thay the.+ Chetao vat l ieu, nhiet l uy en tot, c cau ieu khi en hp l chnh xac,

egiam mai mon.+ nh kykiem tra cho may vathc hien tot cac thi et btong.

V Du: Cac c cau cam phai dei eu chnh vanhe nhan,may chay em khong b

rung. Ngay nay tren cac may t ong etruyen ong em vagi am masat

ngi ta dung v t me bi eieu k hien cac c cau,nham lam tang k hanang l amviec vanang suat cua may.

I I I . 4 . Ton that loai 4 vanhiem vutong hoa khau tochc:

L akhau l ien quan en tochc san xuat, bao gom viec phan phoi , donphoi , thu thanh pham, oi ca vaieu chnh cong viec

egiam ton that phai tong hoa khau tochc , tong hoa khautiep l ieu,gaat phoi

T ong hoa k hau don phoi , v du: tren may t ong cocac c cau gatphoi , qua hethong ti nguoi vaa phoi ra ngoai , hoac dung c cau thu hoiphoi bang nam cham, ehut phoi vaa phoi ra ngoai .

V D u: Cac c cau don phoi trong quatrnh gia cong c kh c trnhbay trong hnh di ay:Cac c cau don phoi , a phoi ra ngoai bang truc xoan hoac ba ng bang tai.,thng c ap dung t rong cac may tong.

H. VI I I .6. Cac loai ai oc bi


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Dung may tnh i en ttrong v iec thi et kevatnh toan, am bao kehoach sanxuat kp tien o.ng dung cac bien phap kythuat hien ai trong cac xn g san xuat, dung maymoc thay thedan sc lao ong cua con ngi .Neu thi gian lam viec cua may ln hn nhieu so vt thi gian ban ron cua

ngi cong nhan th ngi cong nhan cotheng c nhieu may hn.- Goi Q: nang suat cua may+ tbr: tong thi gian ban ron+ T: thi gi an gi a cong mot chi tiet

Ta cohesoban ron:

TQtQT

tbr

br /1;.

Goi somay la: Z

brt

TZ

1

V du: Q = 5 (chi ti et / phut) , tbr= 0.1 (phut / 1 chi ti et)= 5. 0,1 = 0.5

Z = 1/ 0,5 = 2 (may), vay trong trng hp nay ngi cong nhan cotheng 2may.

Ngay nay etang nang suat tren may tong, ngi ta cap them cacpheu cap phoi t ong ( oi vi ph oi ri ), hoac ong kep an hoi t ong ieukhi en bang kh nen hoac thuy lc ( dang phoi thanh), ngi cong nhan conhiemvutheo doi shoat ong cua may vakiem tra chat lng san pham.

I I I .5. Ton that loai 5 vanh iem vu kiem tr a tong chatlng san pham:

L aloai ton that l ien quan en chat lng cua san pham:Do viec gia cong th, i eu chnh may, phoi h hong trong quatr nh

bao quan, van chuyen .ieu chnh vaxac nh sai socua may chon

1) ieu chnh:

H. VII I .7. C ac c cau don phoi


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ieu chnh may chon ay lai eu chnh au o vavtr cac tiep i em saucho tng ng vi cac thc mau ( hoac chi tiet mau) solng cac thc mau dosonhom chi tiet quyet nh, moi nhom cohai kch thc gi i han.

- ieu chnh cothelaieu chnh, tnh hoac ieu chnh ong: ieu chnh tnh l abat buoc vac t ien hanh luc may khong l am viec,

dung can mau hoac chi tiet mau eieu chnh khoang cach gia cac au o giacac tebao quang ien hoac ieu chnh cac tiep iem ien. Cam bien cothec ieu chnh xong mi lap vao may. ieu chnh ong: c t ien hanh trong trang thai lam viec cua may.

Dung chi tiet mau a vao may emay chon nhieu lan xem cac vtrmay can ieu chnh achnh xac cha.

Xac nh solan chon nham vatien hanh ieu chnh ve1 pha nao o.2.Xac nh sai socua may chon : Sai socua may chon do nhi eu yeu togay nen. trong oang kelasai so

cua bophan o vacac sai sovenh v, sai socua cac nhan totac ong.v.v.. V vay viec t nh toan cac sai son lekhong chnh xac bang khao sat

thc tecua k et quachia nhom. khao sat nen tien hanh vi tng gi han chianhom.

Cac phng phap khao sat, xac suat chia nhom sai : Giathuyet comot chi tiet mau, k ch thc cua nophan boeu t rong mien nao

o, mien oc vach ra vi hai gi i han t rai vaphai nh hnh ve:

Sau khi at hai gi i han ay vao may, ta cho nhom mau qua nochon, ket quachon cothela: mot somau b chon nham sang nhom hai ben. nguy en nh an ladomay cophan tan kch thc, neu biet c xac suat chon nham P

X et chi tiet mau nam cach gii han t rai 1 khoang X , sai sochon nham vixac suat S, ta co:

Trong ol aham lapl ace:oi vi canhom mau, xac suat bchon nham sang nhom trai la:

)(21)(21.2132

2

2

x x

xzdxeS

0

..2

1 dxxP

H. VII I.8.othphan bomi en dung sai


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Trong o:ladung sai cua nhom mau.khai trien phep tnh ta co:

khi >3th (/)1/2 vav vay:

Ta c: Biet dung sai cua nhom mau tien hanh th nghiem nhieu l an exac nh

P vatnh .

Nhan xet: Phng phap t m xac suat chon l am chcongha trong v iec khao satmay chon at bi et lachtieu ochnh xac . Cha xac nh c sai soi eu

chnhx.Phng phap xac nh sai socu a may bang hai chi tiet mau:

- Chon lay chi tiet mau cokch thc l ax 1vax2nam gan gii han chia nhom X oa hai chi ti et qua hai may chon m 1vam2lan, gi athuyet chi tiet c chon

sang nhom m 1vi solan tng ng lan 1van2ta coxac suat chon:

Da vao ham laplace tra c:

Trong oG: laham ngc cua ham laplace :ta tm cvaX o.

em so sanh x o nay vi gii han X ocan at vao may ta tm c sai soieuchnh: oo xXX

Nhan xet: Phng phap nay ton t chi tiet mau, chon c sai sohnh dang be,thong thng lay m 1= m2>> 250, khi ocoi P n/m.

2

2

2

2

.2

0

2 1(.2

)(2

1...

..2

1)].(

2

1[

xx

edxexxx

P

12

2

2

e

4,0

.2P

..5,2..2 PP

1

1011 2

1

m

nxxP

2

2012 2

1

m

nxxP

)2

1(

1

101

m

nG

xx

)

2

1(

2

202

m

nG

xx

)

2

1()

2

1(

1

1

2

2

21

m

nG

m

nG

xx

)

2

1()

2

1(

)2

1(.)

2

1(.

1

1

2

2

1

12

2

21

m

nG

m

nG

m

nGx

m

nGx

Xo

H. VII I.9.Phon ha xac nh sai so ua oth


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egiam ton that can k iem tra enang cao cha t lng san pham.+ M ay moc, ocng vng+ Chat lng chi tiet gi a cong.+ Chat lng dung cucat vai eu chnh dung cucat.+ Chetao cac loai ogakiem tra vaogagi a cong chi tiet.

+Sdung cac loai may moc hien ai eam bao chat lng cua chi tietgi am bt sai sovathi gi a gia cong.+ Sdung cac dung cu o kiem coochnh xac cao, ekiem tra trc

ti ep trong quatr nh gi a cong nh: cal ip o lo, ong hovapanm e o lovao t rungoai .

I I I .6) Ton that loai 6 vanhiem vu linh hoat hoa san xuattong.

Ton that loai 4 l aloai ton that l ien quan en van ethay oi sanpham gi a cong, gom viec thay oi oga, dung cu cat c cau ieu khi en vachng trnh i eu khi en v.v

egi am c ton that loai nay, th cac c cau may phai c ieuchnh vac galap mot cach nhanh chong, khi can gia cong mot chi tiet mi ,khac vi chi tiet ban au..

M ay i eu khi en bang cam khong c ong vaton nhieu thi gi an eieu chnh may:

V Du: khi thay oi chi ti et gi a cong- Tr en may i eu k hi en bang cam, phai thay oi cam vatien hanh gi a

cong o k iem, ieu chnh l ai may nhieu l an.Ngay nay vi sxuat hi en cua may i eu k hi en theo chng trnh soth

viec ieu chnh may egia cong chi tiet mi c nhanh hn, khi thay oi san

pham chcan thay oi chng trnh hay cac thong soi eu k h ien cua chng t rnhtren may. ay lahnh thc i eu khi en cho phep ap dung t ong hoa vao trong

san xuat, ap dung c cho cac dang san xuat n chiec vahang loat nho, r at cohieu qua.

Gi ai quyet c cac van evekythat vaem lai hi eu quakinh tecaoV du: Gia cong c nhng bi en dang phc tap, cho obong vaochnh xaccao, giam thi gi an phuvathi gi an gia cong, em lai nang suat cao.

Nhc iem: Chgia cong c nhng chi tiet cokch thc gii han,khong gia cong c nhng chi tiet cochieu sau cat ln, vatieu ton rat nhieu thigian.

Do tnh c ong cua may nen thong thng may coocng vng kemhn may van nang vathng c ap dung trong nguyen cong gi a cong tinh vaban tinh.


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Ngoai ra enang cao nang suat lao ong vaochnh xac gia congngi ta cothesdung cac c cau tay may cong nghiep egalap v avan c huyenphoi thay thecon ngi :

H. VI II.10.Tay may cong nghiep phuc vusan xuat

Chuong_VIIIA may tu dong.pdf

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