H THNG THOT KHGVHD:Ths. TRN MINH TH UYNSVTH: L VN TI MSSV:11144162KHOA O TO CHT LNG CAOTRNG H S PHM K THUT HCM

NI DUNGKHI QUTCC KIU THOT KHRnh thot kh trn mt phn khunH thng thot kh trn knh dnThot kh qua h thng y trong khunThot kh qua h thng ht chn khngThot kh qua h thng lm mt, slide, insertSo snh cc phng php v v d minh ha

KHI QUTNhng khuyt tt trn sn phm nha

m chyin khng y (Short Shot)Li h thng thot kh

KHI QUTNhng khuyt tt trn sn phm nhaLi h thng thot khng hn (weld line)L kh

KHI QUTH thng thot kh :

Lng khun cha khng kh, phi c thot ra trong qu trnh in y. Nhng khng cho nha nng chy i qua.Thit k khng tt th gy ra khuyt tt :ng hn, vt chy, chi tit khng in y,...

CC KIU THOT KHRnh thot kh trn mt phn khunH thng thot kh trn knh dnThot kh qua h thng y trong khunThot kh qua h thng ht chn khng4123Thot kh qua h thng lm mt, slide, insert5

1. Rnh thot kh trn mt phn khunCu to ca rnh thot gm hai phn chnh: rnh dn v rnh thotRnh thot kh c b tr mt phn khun v d gia cng v v sinh. Rnh lm nhim v nh mt cu ni gia lng khun v mi trng ngoi a khng kh ra khi lng khun.

Thot kh trn mt phn khunS rnh ty thuc vo lu lng v tc in y.Khi cn tng thot kh th c th tng thm rnh thot kh hay m rng cc rnh.

a. Rnh dnNm phn u ca rnh thot kh. Thit k khng cho vt liu chy vo cc l thng hi trong sut qu trnh in y.

Chiu su v tr u rnh dn rng ca rnh trong thc t n nm trong khong 3.175 12.7 mm.Chiu di rnh (l): 0.762mm 1 3.175mm

Loi nhaChiu su (INCHES)ABS 0.001-0.015ACETAL 0.0005-0.001ACRYLIC 0.0015-0.002CELLULOSE ACET, CAB 0.001-0.0015ETHYLENE VINYL ACET 0.001-0.0015IONOMER 0.0005 -0.001LCP 0.0005 - 0.0007NYLON 0.0003 - 0.0005POLYPROPYLENE 0.0005 - 0.00 2P C (RIGID) 0.0006 - 0.001PVC (FLEXIBLE) 0.0005-0.0007POLYETHYLENE 0.0005 - 0.0012PET, PBT, POLYESTERS 0.0005 - 0.0007POLYSULFONE 0.001 - 0.002

b.Rnh thot (relief slot)Cch b tr rnh thot khB tr nhng v tr c in y cui cng, l nhng khu vc xa cng vo nha nht.

Cch b trCch b tr rnh thot khThot kh thng qua l kh & knh dn hnh vnh khuyn

S lng rnh thot cn thit

2. H thng thot kh trn knh dnc imRnh thot kh c b tr thnh 1 vng khp kn quanh chu vi knh dn v dn ra ngoi bi cc rnh thot.

u im v nhc imu imNhc imD gia cngD b trnha khng chy ra khi lng khunKhng b tr chi tit qu mng, c gn,rnh ctPh thuc vo tc v lu lng dng chy

3. Thot kh qua h thng y trong khunB tr rnh thot kh trn ty yThit k cc rnh xon trn ty y, khng kh trong khun s theo cc rnh ny s i ra ngoi.

Cch b tr rnh thot trn ty yLp rp ca h thng y phi trt dc trc y chi tit ra ngoi l lp rp c h.Cn c thay th hay tho ra lm sch khi b tc.

u im v nhc imH thng y c gia tc thm cho cht yThit k chung vi h thng y nn c th tit kim chi ph.i hi chnh xc cao mi c th thot kh tt.i hi h thng y c bng caou im Nhc im

4. Thot kh qua h thng ht chn khngCch b tr h thng ht chn khngs dng rng ri trong ngnh cng nghip, thot kh trit v u vit so vi cc phng php c

Cu toCu to 3 phn :Cc rnh dnvng m bng cao suBm chn khngNguyn l hot ng: Bm chn khng c m a ton b lng khng kh ra ngoi khun khi khun ng, to cho th tch bn trong lng khun hon ton l chn khng

u im v nhc imu imNhc imHiu qu caou vitThit k phc tp, tn kmKh gia cng

5. Thot kh qua h thng lm mt, slide, insertThot kh qua h thng lm mtHnh di y cho thy lng khun c lp vo 1 mnh insert c lm t kim loi xp, c kh nng dn kh t lng khun vo knh lm mt.

Cht yu imNhc imGi rcho sn phm c gn Lng khun b tr phc tp

SO SNH CC PHNG PHP

Tiu chThot kh qua mt phn khunThot kh qua h thng yThot kh dng h thng ht chn khngThot kh qua h thng lm mt, insert, slideV trb trCh c th b tr ti mt phn khun ca chi tit.Ch b tr tch hp trong h thng y.B tr nhiu v tr trong lng k c nhng im cht (dead pockets).Thng b tr ti chi tit c gn khng th thot kh bng mt phn khun.Kh nng thot khThot kh tt ti v tr mt phn khun, khng thot kh c nhng im cht.Ch thot kh nhng v tr c t h thng y.Hu nh thot kh c ton b v tr trong lng khun.Thot kh c bit tt cho sp c gn, lng khun kiu insert.Kh nng gia cngNm trn mt phn khun nn d gia cng nhng phi m bo kch thc.Ch phi gia cng trn h thng y.Kh gia cng cch rnh dn v l thng ni my bm chn khng.Khng phi gia cng nhiu do li dng khe h trong khun dng insert.Tnh kinh tR tin.R tin.t do phi gia cng v s dng my bm chn khng.R tin.

V DChn loi hnh thot kh theo kiu thot kh qua mt phn khun. Tnh ton thit k knh thot kh khi sn phm l np chai nha PP ? su ca rnh dn: dChiu rng ca rnh dn : WChiu di rnh dn : l su ca rnh thot D = 20dS rnh thot kh cn thitDo sn phm lm bng nha PP 0.0005 d 0.0012 chn d = 0.001 (inch)Vy D = 20d = 0.02 (inch)Cc thng s W v l ly theo khong kch thc thc t:0.030" l 0.125" chn l = 0.1 (inch)1/8 W chn W = 0.25 (inch)Gii

Chu vi ca 1 rnh thot kh: a = 2 x (W + d) = 2 x (0.25 + 0.001) = 0.5002 inchChu vi ca sn phm: v d np chai nha c :D = 3 cm = 1,18 inch, Chiu cao ca np: h =1.5 cm = 0.59 inch

Chu vi gn ng ca sn phm: A = ((2 x 3.14 x 0.59) + 0.59)) x 2 = 8.5904 inchTa c: X.a = 0.3A M X = 0.3A/a = 0.3 x 8.5904/0.5002 = 5.15 Chn X = 6Cch b tr rnh thot kh: 6 rnh thot kh s c b tr trn mt phn khun mi rnh cch nhau 60.

TI LIU THAM KHOTHIT 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

CM N MI NGI THEO DI !

*