H THNG LY SN PHM RA KHI KHUN

H THNG LY SN PHM RA KHI KHUN

trng H S PHM K THUT HCM

KHOA O TO CHT LNG CAO

THIT K V CH TO KHUN PHUN P NHA

H THNG LY SN PHM RA KHI KHUN

GVHD:Ths. TRN MINH TH UYN

SVTH: L VN TI MSSV:11144162

MC LC

CC PHNG PHP LY SN PHM RA KHI KHUN3

H THNG Y:4

1.Khi nim:4

2.Nguyn l chung:4

3.Gii thiu mt s loi thng dng:5

a.H thng y dng cht y5

b.H thng y dng li y7

c.H thng dng ng y8

d.H thng y s dng tm tho8

e.H thng y dng kh nn9

4.iu khin h thng y11

a.Gia tc thm cho mt cht y.11

b.Gia tc thm tm y12

c.Tm y c n by12

d.y kp13

5.Mt s im cn lu khi thit k h thng y13

6.Tnh ton h thng y v v d minh ha14

a.Khong y14

b.Cht y14

c.Tnh lc y15

d.Tnh ton l xo17

e.Tnh ton ng y v tm li17

f.Tnh ton bc v cht hi17

TI LIU THAM KHO18

CC PHNG PHP LY SN PHM RA KHI KHUN

Ngi cng nhn s ly sn phm ( sn phm ln, kh b tr h thng y, kim tra cht lng sn phm .

Dng h thng tay robot ( t ng ha cao nhng chi ph ban u cao).

Dng h thng y ly sn phm, cch ny hay dng.

H thng y.

H THNG Y:

1. Khi nim:

Sau khi sn phm trong khun c lm ngui, khun ly ra, sn phm cn dnh trn lng khun do s ht ca chn khng v sn phm co li nn cn h thng y ly sn phm ra.

Cu to ca h thng y:

n gin ha (nh, gn,nh v hiu qu).

cng cht y 40 45 HRC, c gia cng chnh xc, chng mi mn tt.

Tc tc ng ln sn phm nhanh, nhiu vng trn sn phm i vi sn phm ln, tc ng cc b i vi sn phm ngn

C khong y v lc y ph hp.

Ly sn phm ra d dn v khng lm bin dng sn phm, tnh thm m.

H thng y phi nm trn khun di ng.

2. Nguyn l chung:

Kt thc qu trnh in y nha trong khun v qu trnh lm mt, my p m khun v trc ca my p (ejector rod) s y 2 tm y (ejector plate) v thng qua cc chi tit y (cht y, li y, tm tho) y sn phm ra ngoi.

Trong qu trnh y th tm y lm l xo ca khun p nn li. Khi trc y ca my p tr v v tr ban u, lc tc ng ca ln tm y khng cn na, lc ny lc nn l xo s gip tm y tr v v tr ban u, qu trnh ny c s tham gia dn hng ca cht hi.

3. Gii thiu mt s loi thng dng:

a. H thng y dng cht y

y l h thng ph bin nht.

Vt liu T8A hoc T10A, c ti cng hn 50HRC, b nt nhm 0.8 lp chc H8/f8.

Cht y l chi tit tiu chun vi ng knh, chiu di, hnh dng khc nhau.

u im:

Nhng l trn d gia cng, nn h thng ny kh i gin d thc hin.

Nhc im:

Nhng l trn di v chnh xc th vn kh khn, do nn cn doa rng cc l cht y mt khong chiu di nht nh.

Lu :

Cht y phi tr v v tr ban u sau khi y sn phm ri ra ngoi.

Phn loi:

C 3 h thng hi ph bin:

S dng cht hi:

Mt chp ca cht hi phi ngang hng vi ng phn khun, tm khun c nh (4) iu khin cht hi (5) trong qu trnh khun ng. Khi khun ng, na khun cn li s tc ng ln chut hi nh lc ng khun a h thng v v tr ban u

S dng cht y ng thi cng l cht hi:

S dng l xo hi:

Mt s trng hp cht y trong cm y, hoc cm y kh mng hoc lc y khng cn bng, cht y c th b nghing. Kt qu l cht y b nt hoc cong, cn phi s dng h thng dn hng.

S dng cht hi c dn hng

b. H thng y dng li y

S dng:

y nhng chi tit c thnh mng v hnh dng phc tp.

H thng dng li y

c im:

S dng lc y ln hn, do cu to li y ln hn v din tch tip xc ca li y ln sn phm ln hn cht y.

c. H thng dng ng y

S dng:

Cc chi tit c dng trn xoay.

H thng dng ng y

c im:

Dng cc ng y gm c cht c nh, c nhim v dn hng ng y i trt tnh tin khi tm y b tc ng.

Cht c nh cn c nhim v lm li to hnh cho sn phm dng trn xoay.

d. H thng y s dng tm tho

S dng:

Dng cho nhng chi tit tr trn hay hnh hp ch nht c b dy thnh mng.

H thng dng ng tho

c im:

Sn phm lun t thm m cao, khng c vt cht y.

Nhc im:

S dng lc y ln hn cc phng php khc, do trng lng ln.

e. H thng y dng kh nn

S dng:

Dng cho cc sn phm c lng khun su nh: s, chu, bi v khi sn phm ngui th chn khng trong lng khun v li khun rt ln nn sn phm kh c th thot khun.

c im:

Cn mt lc y ln phn b u sn phm thot khun.

Kt hp s dng kh nn.

4. iu khin h thng y

a. Gia tc thm cho mt cht y.

Dng c cu thanh rang bnh rang gia tc thm cho cht y.

H thng c gia tc s gip sn phm ri khun nhanh hn.

H thng y c gia tc thm cho cht y

b. Gia tc thm tm y

Tng t h thng y c gia tc cho mt cht y chi khc ch h thng thanh rng s iu khin tm y pha trn.

Tm n by.

H thng tm y ca h thng ny s c lp trn on by tng chiu cao y v mt ph gip sn phm ri ra mt khun mt cc d dng.

H thng y c gia tc thm cho cht y

c. Tm y c n by

Tm y c n by

d. y kp

ng dng cho cc sn phm phc tp, cn phi y tun t, phi dng h thng y kp.

H thng y kp

5. Mt s im cn lu khi thit k h thng y

Lun c lp khun di ng, tr mt s trng hp c bit lp khun c nh.

B tr chc cht y hay li y ngay gn hoc cnh ca sn phm.

Hnh trnh y bng chiu su ln nht ca sn phm theo hng m khun cng thm 5 10 mm.

Cc cht y nn nm ngang so vi mt phn khun m bo khng li vt trn ca b mt sn phm.

t cht y ti nhng v tr khng yu cu thm m.

Lc y ht sc quang trng i vi thit k khun, lm cho sn phm ri ra m khng nh hng n sn phm cng nh khun.

6. Tnh ton h thng y v v d minh ha

a. Khong y

Khong y phi ln hn 5 10 mm so vi so vi chiu cao ca sn phm, sn phm c ly ra t khun sau theo chiu tc khun.

Khng nn lm khong y qu di s lm yu h thng y.

Sau khi y sn phm ly ra, h thng y phi tr v v tr ban u, trnh cht y lm hng lng khun. V th cn cht hi v (ty hi)

Cht y v tm y cng nm trn tm y, tm y chu p lc ln nn tm y phi c chiu di thch hp:

Kch thc ca cht y ph thuc vo kch thc ca sn phm, ng knh phi ln hn 3mm, tr khi khi iu cn thit cho sn phm.

Thit k h thng y khng lm yu khun.

B mt sn phm (cm2)

dy sn phm (mm)

5

12

10

15

25

20

50

30

100

50

Nhng sn phm c cht y di hoc nh, nn c cht dn hng trong h thng y.

b. Cht y

Sn phm c cc vch xung quanh cao, gn su th phn ny dnh chc trong khun (phn core), phi b tr ty y v tr ny

V tr y ti ny cng xa cc gn ny th lc tc dng ln n cng yu, v c nguy c lm thng b mt nha

Phn nh ca cht y v l thuyt nm ngang bng vi lng khun, nhng thc t, c th trn hoc di 0.05 0.1 mm. Tt nht t thp khong 0.02-0.04.

Gn tm kp sau cc con vt, m cao su va gim chn ng khi lo xo cht hi y h thng y v va c th iu chnh cc khong cch ca ty so vi khun bng cc vn cc con vt ny ln hay xung thay i cao.

c. Tnh lc y

Tnh lc y nh hnh:

Chi tit cn tnh lc y

Cng thc tnh lc y:

Ffriction=(N)

Feject= cos().Ffriction=cos().sFnormal(N)

Fnormal=

Trong :

Ffriction: lc ma st(N)

Feject: lc php tuyn (N)

Fnormal: lc y (N)

Daraft angle: gc thot

Cng thc tnh bin dng dos ca sn phm:

s =CTE(Tsoilddification-Tejection)

Trong :

Tsoilddification : nhit ha rn ca vt liu (oC)

Tejection :nhit khi ly sn phm ra khi khun (oC)

CTE: h s gin n v nhit ca vt liu nha (cm/oC)

ng xut ca mt ct ngang ca sn phm:

= E. s= E.CTE(Tsoilddification-Tejection)

Fnormal=.

Feject= cos().s .Fnormal = cos().s.E.CTE(Tsoilddification-Tejection)

Kim tra ng sut do ty y gy ra vi ng sut b ca vt liu lm sn phm, xem lc y c lm h sn phm hay khng nu c phi tng ng knh hoc tng s lng ty.

S phn b lc

Cc yu cu b tr ty li l :

t thp hn lng khun 0.02 0.1 mm.

B tr ty li tt nht cnh gn ca sn phm.

linh hot th gn trn tm kp sau ca con vt cc vng m gim chn ng khi l xo y h thng y v theo cht hi.

ng knh cht thng 1-25mm chiu di thng nm trong khong 150 -500mm

Thit k cho ty y:

Trong mt s trng hp h thng y cn c tc dng lm rnh thot kh (lp lng ln)

Ty li qu di th khi chu tc ng lc d b b cong. Khng tt cho khun v cht mao mn v yu

d. Tnh ton l xo

Kch thc l xo c xc nh theo tiu chun c sn

Tng chiu di ca l xo khng vt qu 35 % tng chiu di t don ca l xo.

Bng cch tnh ton ti trng ca h thng y, c th chn cng l xo ph hp. Nu cng qu kh lp rp, nu mm qu th khng lc n hi.

trnh trng hp b kt th l xo thng lp rp c nh vi tm , bao ly cht hi v hn ch ma st vi cht

.

e. Tnh ton ng y v tm li

Cng thc tnh lc y cho h thng ng li v tm li:

Feject= cos().s.Fnormal= cos().s.E..Aeff(N)

Vi sn phm nh trn th: =

Vi h s ma st: 0.5

Gc khun 0o

Da vo cng thc Aeject > . Tnh c din tch cn thit cho ng y hoc tm y.

f. Tnh ton bc v cht hi

C 2 loi cht hi:

Hi khun t ng: sau khi y sn phm ra khi khun th di lc n hi ca l xo th h thng s tr v trng thi ban u chun b chu k p tp theo.

Hi khun cng bc: sau khi y sn phm ra khi khun, h thng cht hi t vo mt tm khun a h thng y v v tr ban u.

Khi thit k cn phi b tr v tr cht hi i xng.

TI LIU THAM KHO

THIT K V CH TO KHUN PHUN P NHA( T.S PHM SN MINH THS TRN MINH TH UYN)

WEB THAM KHO : http://tai-lieu.com/tai-lieu/cong-nghe-che-tao-khuon-mau-khuon

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