N TRUYN NG THY KH GVHD: TS.NGUYN TRNG THNH

NHN XT CA GIO VIN HNG DN. 000

TP HCM.Ngythng...nm 2012 Ch k GVHD:

Li Ni u Ngy nay, nghnh cng nghip pht trin mnh i hi quytrnh lm vic nhanh v hiu qu, trong cc nh my khng cn cc c cu lm vic th s hay km hiu qu na ,trong vic ct phi cng vy ,i hi phi c nhng my ct phi t ng nhm gim chi ph thu nhn cng v nng cao nng sut .Quy trnh cng ngh ct phi t dng m ti thc hin di y ch l mt phn rt nh trong thi i cng nghip ha hin i ha ngy nay. C nhiu cch thit k mt m hnh ct phi khc nhau, y ti thit k m hnh ct phi t ng iu khin bng h thng thun kh nn.Trong qu trnh thc hin n mc d ti c gng ht sc nhng chc chn s khng thiu nhng sai st. V vy, ti rt mong nhng kin ng gp ca qu thy c v cc bn. Nhn y xin gi li cm n chn thnh n thy Nguyn Trng Thnh gip ti hon thnh n ny Xin chn thnh cm n!

CHNG I GII THIU 1. Vi nt v s pht trin ca cng ngh thy lc - kh nn:

Khng kh xung quanh ta nhiu v k v n l mt ngun nng lng rt ln m con ngi bit s dng chng t trc Cng nguyn. Tuy nhin s pht trin v ng dng kh nn lc cn rt hn ch do cha c s phi hp gia cc ngnh vt l, c hc v.v..Mi cho n th k17, nh k s ch to ngi c Otto von Guerike, nh ton hc v trit hc ngi Php Blaise Pascal, cng nh nh vt l ngi Php Denis Papin xy dng nn nn tng c bn ng dng kh nn.Trong th k 19, cc my mc thit b s dng nng lng kh nn ln lt c pht minh nh: th vn chuyn trong ng bng kh nn (1835) ca Josef Ritter, phanh bng kh nn (1880), ba tn inh bng kh nn (1861)Vi s pht trin mnh m ca nng lng in, vai tr s dng nng lng bng kh nn b gim dn. Tuy nhin vic s dng nng lng bng kh nn vn ng mt vai tr ct yu trong nhiu lnh vc, m khi s dng nng lng in s nguy him; s dng nng lng kh nn nhng dng c nh, nhng truyn ng vi vn tc ln; s dng nng lng kh nn nhng thit b nh ba hi, dng c dp, phun sn, gi kp chi tit v nht l cc dng c, g kp cht trong cc my.Cng vi s pht trin khng ngng ca lnh vc t ng ha, ngy nay cc thit b truyn dn, iu khin bng thy lc kh nn s dng trong my mc tr nn rng ri hu ht cc lnh vc cng nghip nh my cng c CNC, phng tin vn chuyn, my dp, my un, my p phun, dy chuyn ch bin thc phm, do nhng thit b ny lm vic linh hot, iu khin ti u, m bo chnh xc cao, cng sut ln vi kch thc nh gn v lp t d dng nhng khng gian cht hp so vi cc thit b truyn ng v iu khin bng c kh hay in. u nhc im ca kh nn: u im: Do kh nng chu nn (n hi) ln ca khng kh, cho nn c th trch cha kh nn mt cch thun li. Nh vy c kh nng ng dng thnh lp cc trm trch cha kh nn. C kh nng truyn ti nng lng xa, bi v nht ng hc ca kh nn nh v tn tht p xut trn ng dn t. Khng gay nhim mi trng. Chi ph thp thit lp mt h thng truyn ng bng kh nn, bi v phn ln trong cc x nghip h thng ng dn kh nn c sn. H thng phng nga qu p sut gii hn c m bo. Nhc im: Lc truyn ti trng thp. Khi ti trng trong h thng thay i, th vn tc truyn cng thay i, bi v kh nng n hi ca kh nn ln, cho nn khng th thc hin nhng chuyn ng thng hoc quay u. Dng kh thot ra ng dn ra gy nn ting n. Hin nay, trong lnh vc iu khin, ngi ta thng kt hp h thng iu khin bng kh nn vi c, hoc vi in, in t. Cho nn rt kh xc nh mt cch chnh xc, r rng u, nhc im ca tng h thng iu khin.2. Yu cu ca ti Yu cu : Tnh ton v thit k h thng truyn ng ,cng nh kch thc ca cc xy lanh theo ng cc tiu chun ,cc bn v chi tit cng nh cc cch ghi kch thc phi tun th theo cc tiu chun k thut hc .

CHNG II

C S L THUYTA. NGUN KH NN

1. My nn kh:Khi nim: My nn kh l thit b to ra p sut kh, nng lng c hc ca ng c in hoc ng c t trong c chuyn i thnh nng lng kh nn v nhit nng.Phn loi:a. Theo p sut: My nn kh p sut thp: p 15 bar My nn kh p sut cao: p 15 bar My nn kh p sut rt cao: p 300barb. Theo nguyn l hot ng: My nn kh theo nguyn l thay i th tch: my nn kh kiu pittng, my nn kh kiu cch gt, my nn kh kiu root, my nn kh kiu trc vt. My nn kh tuabin: my nn kh ly tm v my nn kh theo chiu trc.

2. Bnh trch cha kh nn:Kh nn sau khi ra khi my nn kh v c x l th cn phi c mt b phn lu tr s dng. Bnh trch cha kh nn c nhim v cn bng p sut kh nn t my nn kh chuyn n trch cha, ngng t v tch nc.Kch thc bnh trch cha ph thuc vo cng sut ca my nn kh v cng sut tiu th ca cc thit b s dng, ngoi ra kch thc ny cn ph thuc vo phng php s dng: v d s dng lin tc hay gin on.K hiu :

B. CC PHN T TRONG H THNG IU KHIN

Mt s khi nim: Mt h thng iu khin bao gm t nht l mt mch iu khin vng h (Open loop Control System) vi cc phn t sau: Phn t a tn hiu : nhn nhng gi tr ca i lng vt l nh i lng vo, l phn t u tin ca mch iu khin. V d: van o chiu, rle p sut. Phn t x l tn hiu: X l tn hiu nhn vo theo mt quy tc logic nht nh, lm thay i trng thi ca phn t iu khin. V d: van o chiu, van tit lu, van logic OR hoc AND. C cu chp hnh: thay i trng thi ca i tng iu khin, l i lng ra ca mch iu khin. V d: xilanh, ng c kh nn.

1. Van o chiu Van o chiu c nhim v iu khin dng nng lng bng cch ng, m hay chuyn i v tr, thay i hng ca dng nng lng. Nguyn l hot ng:a) Van o chiu 3/2:Khi cha c tn hiu in tc ng vo ca (12), th ca (1) b chn v ca (2) ni vi ca (3). Khi c tn hiu in tc ng vo ca (12), nng van s dch chuyn v pha bn phi, ca (1) ni vi ca (2) v ca (3) b chn. Trng hp tn hiu tc ng vo ca (12) mt i, di tc ng ca l xo, nng van tr v v tr ban u. K hiu:

Mt s van o chiu 3/2 b) van o chiu 5/2 Khi cha c tn hiu in tc ng vo ca (14), th ca (3) b chn, ca (1) ni vi ca (2) v ca (4) ni vi ca (5). Khi c tn hiu in tc ng vo ca (14) th nng van s dch chuyn sang phi, ca (2) ni vi ca (3) v ca (1) ni vi ca (4) cn ca (5) b chn. Khi tn hiu tc ng vo ca (14) mt i th di tc ng ca l xo nng van tr v v tr ban u.

K hiu:

Mt s van o chiu 5/22. Van tit lu:Van tit lu c nhim v iu chnh lu lng dng chy, tc l iu chnh vn tc hoc thi gian chy ca c cu chp hnh. Ngoi ra van tit lu cng c nhim v iu chn thi gian chuyn i v tr ca van o chiu. Nguyn l lm vic ca van tit lu l lu lng dng chy qua van ph thuc vo s thay di tit din. Van tit lu mt chiu iu chnh bng tay.Nguyn l hot ng:Tit din chy Ax thay i bng iu chnh vt iu chnh bng tay. Khi dong kh nn t A qua B, l xo y mng ch xung v dng kh nn ch i qua tit din Ax. Khi dng kh nn i t B sang A, p sut kh nn thng lc l xo y mng chn ln v nh vy dong kh nn s i qua khong h gia mnh chn v mt ta mng chn, lu lng khng c iu chnhK hiu:

Van tit lu mt chiu

3. Cng tc hnh trnh

Cc cng tc hnh trnh hay cng tc gii hn ( limit switch) tc ng bng ckh ( Machanically actuated).Theo yu cu cng ngh iu khin h thng bng kh nn, ngi ta thng s dnghai loi cng tc hnh trnh, phn bit theo chiu tc ng: cng tc hnh trnh tcng c hai chiu v cng tc hnh trnh ch tc ng mt chiu hoc t tri sang phi hoc t phi sang tri. Nguyn l hot ng : khi m xy lanh i ra chm vo cng tc hnh trnh th lc xy lanh s b tc ng . k hiu :

Cng tc hnh trnh 2 chiu

Cng tc hnh trnh 1 chiu 4. Xy lanh kh nn Sau y l cu to ca mt s xylanh kh nn thng dng

1Ming m u trc .2 Nam chm.3 m ng ngoi .4 V ngoi .5ng dn thanh .6 Ming m .7 V bc mt trc .8 Mt dn kh .9 Cng tc t .10 Cn pittong .11 Vng chng mn .12 m pittong .Mt vi lai xy lanh thng dng : Xy lanh tc dng n bng l xo : Xylanh tc dng hai chiu, khng c b phn gim chn :

Xylanh tc dng hai chiu, c c b phn gim chn cui khoang chy .

Xylanh tc dng hai chiu, dng cng tc t . K hiu Xilanh kp c cn piston hai pha ( gi l xilanh ng b) ( hnh ), v din tch hai mt piston bng nhau nn lc tc dng sinh ra cng bng nhau . Xy lanh quay iu khin bng van 4/2; 5/2 hay 5/3

Hnh v v k hiu .

CHNG III THIT K V THI CNGA. Phn C Kh : 1.M hnh thit k :

2.Cc c cu trong m hnh:

C cu kp phi gm c 2 c cu: Pitton A bn trt: kp gi ko phi vo thc hin qu trnh ct Pitton C: kp gi phi lc ang ca v khi pitton B ko bn trt i v. C cu y phi: l pitton B mang theo bn trt pitton A C cu nng ca: pitton D v gi ca 3. Tnh ton c cu chn xylanh v my nn kh: Thng s ca phoi ct : Di : L=3500mm=3.5m. Rng: a=25mm=0.025m. Cao :b=2mm=210-3 m.Cht liu phi l nha PVC c :d=1380 (kg/m3).Ta c: mphi = a b L d=210-3 3.51380=0.2415(kg) Ta i tm ng knh xy lanh B : Ta c: phn lc tc dng ln bn trt l: Nbn trt = P bn trt Ta c : mphi =0.2415(kg) mc cu = 8 kg , m bn trt = 20kg . P bn trt =( mphi + mc cu + m bn trt ) 10 P bn trt = (20 + 8 + 0.2415) = 282.415 (N ) Ta c : Fma st = k Nbn trt ,ta chn k=0.3 l h s ma st ca bn trt iu kin piton B c th y c bn trt l FB Nbn trt k = 0.3 282.415 = 84.7245 (N) .M FB = P S B . Ta chn my nn kh c p sut l 10bar =10 10 5 (N/m2 ) .Ta c : S B = == 8.4725 10 -5 (m2 ) .M ta c : S B = =>> dB = 0.104m =10.4 (mm).Ta chn Pit tng B c dB = 16(mm). Ta i tm ng knh xi lanh A:Ta c : lc ma st gia ph v bn trt l Fms = k N . Phn lc tc dng ln bn trt l : N= Pphi + Fp . Fms phi = k (Pphi + Fp ). phi nm trn bn trt th khi pit tng B y bn trt th phi cng i theo bn trt th ta phi c : Fms F y ,m : F y = FB =84.725 (N) k (Pphi + Fp ) 84.725 (N) Fp - Pphi = 2.415 = 167.035 (N)Ta c : Fp = SA P SA = = = 1.67035 10 -4

Ta c : SA = dA = 14.59 (mm)Ta chn dA = 16 (mm).Tng t ta c cho xy lanh C kp cht c chi tit th ng knh xy lanh cng l 16mm ( bng vi ng lnh xy lanh A ) . Ta i tm ng knh xy lanh D : y xy lanh D cha li ct vung gc vi phoi ct Ta c cng thc tnh lc ct nh sau :( y ta dng li ct c 2 li dao song song vi nhau ).Fct = k B S C (N).Trong K l h s nh hng ca dao mm ,vt liu kh ct ,khe h ln ,thng th k=1.1 1.3 . B l chiu rng ca tm phi . S l chiu dy ca tm phi . C l gii hn bn ca tm phi (C = 0.8 0.9 ) b (N/mm2 )(Sch cng ngh kim loi trng HSPKT trang 177 vi phi ct y th ta c (nha PVC ) ).Ta c : k=1.2 ,B=25 ,S=2 , C =50 80 MPa = 50 80 (N/mm2 ) .Chn C =55 (N/mm2 ) Ta c : Fct = 1.1 25 55 2 = 3025 (N).Ta c : Fct = 3025 (N) , m Fct = SD P SD== = 3,02510-4(m2)( y th ta chn my nn kh cho xy lanh D c p sut l 100bar )Ta c:SD =3,02510-4(m2) dD = =19,6(mmm),ta chn dD = 20(mm). Phn tnh ton sc bn cho cc dm g xy lanh nh sau : V phn dm g cho xy lanh A c l lp cht nh khng ng k nn ta khng tnh dm g ca n Ta i tnh ton sc bn cho 4 ct ca dm g 2 xy lanh C v xy lanh DTa chn dct = 8 mm Vt liu :thp C45. Gi s c ti tc dng u ln cc ct, ng sut tc dng ln cc ct s l: = + Mu/(0.1.d2) trong : F: tit din ct ngang ca ct. d:ng knh ct. N: lc tc dng ln cc ct N =( (1+) e: lch tm ca ct, chn e = 0.5(mm) l = .d3/32. Mu: momen un tc dng vo cc ct. Mu = Chn H = 50(mm), yH = 25(mm) h la chieu cao cua cot =>y+k = 1. T trn ta tnh c: N = (.0.0083/32 +) = 15.96(N) F = .0.0042 = 5.024.10-5(m2). Ta c : = 317675 (N/m2) Ta c : Mu = =49.876 (N). Ta c : = + Mu/(0.1d2) = 317675 + 7793125 = 8110800< = 320(MPa) ( l ng sut cho php ca thp CT45). Cc ct c nh vi cc x bng cc ai c v ren. Cc ai c c dng hnh tr c ch to t thp dc vi b = 450 MPa Ren ca ai c c tnh chu p sut ti 80Mpa,ng sut chu ct vng ren ti 55 Mpa, ng sut chu un vng ren ti 80 Mpa. Ta c hnh trnh ca cc xy lanh nh sau : Hnh trnh ca xy lanh A l : 50mm Hnh trnh ca xy lanh B l : 200mm Hnh trnh ca xy lanh C l : 50mm Hnh trnh ca xy lanh D l : 50mm CHNG IV THIT K MCH IN KH NN DNG PLCI. TNG QUAN V PLC S7-200 CPU 214 (SIEMENS)y l cng c iu khin hiu qu nht, c a chung cng nh ng dng rng ri nht trong thc t. N iu khin chnh xc, n gin, d thay i chu trnh lm vic bng cch thay i phn mm. H thng iu khin bng PLC tuy kh tn km nhng tnh n nh kh cao.PLC (programmable logic control): chng trnh iu khin logic. PLC l loi thit b cho php thc hin linh hot cc thut ton iu khin s thng qua mt ngn ng lp trnh, thay cho vic th hin thut ton bng mch s.

u im ca PLC: - Lp trnh vi PLC c th thay i thut ton mt cch d dng, chng trnh vit vi PLC th iu kin c d dng, chng trnh c lu trong b nh di dng cc khi v thc hin lnh theo chu k vng qut. - Lng I/o ln,tc hot ng nhanh.- Kch thc nh gn lp t n gin.- n nh tin cy cao.- C kh nng ni mng PLC-PLC,PC-PLC iu khin,gim st h thng. Nhc im: Gi thnh cao. i vi h thng phc tp i hi phi c chuyn gia ca hng. ng Dng: Cng nghip:iu khin thit b my mc,cc qu trnh sn xut:giy,xi mng,linh kin in t,xe hi. Gim st h thng iu khin qu trnh. Chiu sng giao thng cng cng. 1 .Gii thiu chung v PLC S7 200 (Siemens)

- C nhiu loi PLC ca cc hng khc nhau nhng ta xt y l PLC S7-200 ca hng Simens. - Gm mt s loi nh:CPU214.CPU215,CPU216,CPU212,CPU221... - H thng iu khin vi PLC gm c: B ngun cung cp cho PLC c cc dng sau: ACV power supply, 24VDC input, 24VDC output Digital input/output : 4x DC 24VDC input, 4x Relay output Analog input/output: 3 analog input, 1 analog output 12bits Khi constact LSW 16 Khi relay Khi n Khi DC 24V My tnh , Cc dy ni vi cc mi ni hai u .

a) Cc tnh nng: H thng iu khin kiu Moudle nh gn cho cc ng dng trong phm vi hp C nhiu loi CPU C nhiu loi Moudle m rng C th m rng ti 7 Moudle Bus ni tch hp trong Moudle mt sau C th ni mng vi cng giao tip RS 485 hay Profius My tnh trung tm c th truy cp n cc Moudle Khng qui nh rnh cm Phn mm iu khin ring Tch hp CPU, I/O ngun cung cp vo mt Moudle Micro PLC vi nhiu chc nng tch hp b) Cc Moudle m rng: Moudle ng vo Digital: 24VDC, 120/230VAC Moudle ng ra Digital: 24VDC, ngt in t Moudle ng vo Analog: p, dng, in tr, cp nhit Moudle ng ra Analog: p, dng c) Cu trc b nh: B nh ca S7-200 c chia lm 4 vng: - Vng chng trnh - Vng tham s - Vng d liu - Vng i tng Trong hai vng nh d liu v i tng c vai tr quan trng trong vic thc hin mt chng trnh. Vng d liu: V - Variable memory : Vng nh bin. I - Input image register : Vng m ng vo. Q - Output image register : Vng m ng ra. M Internal memory bits : Vng nh trong. SM Special memory bits : Vng nh c bit. Cc vng nh ny u c th truy cp c theo bit, byte, word hay double word: + Truy sut theo bit: Mt ln mt bit. C php: Tn vng nh (+) a ch byte (+) . (+) a ch bit. V d: I0.0: ch bit 0 ca byte 0 ca vng I. + Truy sut theo byte: mi ln 1 byte. C php: Tn vng nh (+) B (+) a ch byte. V d: VB1: ch byte 1 ca vng V. + Truy sut theo word: C php: tn vng nh (+) W (+) a ch byte cao. V d:VW100:ch word 100 gm 2 byte 100 v 101 thuc vng V. + Truy sut theo Double word: C php: Tn vng nh (+) D (+) a ch byte cao. V d: VD150: ch double word gm 4 byte: 150, 151, 152, 153. Vng i tng: c phn chia nh sau: Timer: t T0 n T127. B m: t C0 n C127. B m cng vo tng t: t AW0 n AW30. B m cng ra tng t: t AQW0 n AQW30. Thanh ghi Acumulator: t AC0 n AC3, trong thanh ghi AC) khng c kh nng lm con tr. B m tc : t HSC0 n HSC2 d) Cch thc hin mt chng trnh: 1. Nhp d liu t ngoi vi vo b m o.2. Thc hin chng trnh.3. Truyn thng v t kim tra li.4. Chuyn d liu t b m o ra ngoi vi.PLC lm vic theo nguyn tc thc hin cc vng lp. Mi vng lp c gi l mt vng qut. Mi vng qut hon chnh gm cc bc nh sau

Bc 1: Nhp d liu t thit b ngoi vi vo b m. Bc 2: Thc hin chng trnh. Bc 3: Truyn thng v t kim tra li. Bc 4: Chuyn d liu t b m o ra ngoi. e) Tp lnh ca S7 200 c biu din di 2 dng: LAD Ladder logic Gi l phng php hnh thang: l mt ngn ng vit di dng ha, d quan st, d kim tra. y chng ta dng tp lnh ny. STL Statement list Phng php lit k: Ngn ng th hin di dng nhng cu lnh. Phn ln nhng cu lnh di dng LAD u c th chuyn sang STL v ngc li. 2. M t PLC S7 - 200 CPU 214: Kch thc: 197x80x62mm Dung lng b nh chng trnh:2kword(4kbyte). Dung lng b nh d liu: 2kword(4kbyte). Loi b nh : EEFROM. C 14 ng vo: t I0.0 n I0.7 v t I1.0 n I1.5. C 10 ng ra : t Q0.0 n Q0.7 v t Q1.0 n Q1.1. C 14 led bo trng thi cc ng vo, 10 led bo trng thi cc ng ra. C 03 led bo trng thi ca CPU: Led SF : Bo trng thi CPU cn tt hay b hng. Led RUN: Bo trng thi CPU ang hot ng. Led STOP: Bo trng thi CPU ang ngng hot ng. Cc ng vo, ra u c mc in p tc ng l 24VDC. Tnh nng ca CPU-214 DC/DC/DC: Ngun nui: 24VDC. Mc logic ng vo : 24VDC = [1]. 0 VDC = [0]. Mc logic ng ra : 24VDC = [1], 0 VDC = [0]. Ti ng ra phi lm vic 24VDC v dng ti a l 50mA. C th m rng thm 7 Module Tc x l mt lnh logic:0.8us/lnh. C 3 b m tc cao :2Khz v 7Khz. C 2 b pht xung tc cao. C 2 b iu chnh Analog. ng h thi gian thc. Chng trnh c bo v bng pasword. Ton b dung lng nh khng b mt d liu 190 gi khi PLC mt in. C 128 timer, ty theo phn gii m chia lm 3 loi: + 04 timer 01ms. + 16 timer 10ms. + 108 timer 100ms. C 128 b m Counter, ty vo cch m m chia lm 2 loi: + m ln : Count up. + m ln xung : Count up-down. II.THIT K MCH IN - KH NN DNG PLC: 1.S hnh trnh bc :

2.s mch :

3.S mch in kh nn dng PLC :

4 .Chng trnh PLC :

5.Code chng trnh theo tp lnh LAD:

6 . Quy Trnh V Ch Lm Vic : a.Quy trnh thc hin: H thng gm 4 xylanh c b tr theo 2 phng. Phi dng thanh c np t ng nh xylanh A,B. Xylanh C kp phi v xylanh D i xunglm nhim v ct. Trnh t ct c thc hin nh sau : Xylanh A i xung kp phi. Xylanh B i ra y c cu mang xylanh A kp phi, a phi vo v tr ct. Xylanh C i xung kp phi. Xylanh A rt v ng thi xylanh D i xung ca ct phi v t ng rt v khi ct xong. Sau khi xylanh D rt v, xylanh B i v mang theo xy lanh A trong khi xylanh C vn kp gi phi. Sau cng xylanh C i v kt thc vic kp phi. Xylanh A i xung kp phi v xylanh B ti np phi chun b cho ln ct k tip. b. Ch lm vic : Trc khi hot ng h thng t Reset v trng thi ban u, hoc trong qu trnh hot ng c th Reset h thng bng cch nhn nt Reset trn bng iu khin.Nhn nt Start h thng bt u hot ng v lp li chu k hot ng.7 M Hnh Bn V 3D:

CHNG V KT LUN V NGHI KT QU THC HIN

Sau qu trnh thc hin vi nhiu c gng v n lc ca bn thn cng vi s tn tnh hng dn ca thy Nguyn Trng Thnh , tp n ny c hon thnh ng thi gian quy nh theo yu cu t ra l Thit k m hnh ct phi t ng.

thc hin c yu cu trn chng em nghin cu, tm hiu nhng vn v: Thit k mch iu khin bng in kh nn. M phng mch iu khin bng in kh nn bng phn mm chuyn dng Festo Fluidsim. M phng ha bng Autocad. Lp trnh ng dng PLC. Tnh ton lc, ti trng cng nh chn la thit b ph hp cho c cu. V cc vn khc c lin quan n ti.II HNG PHT TRIN TIDo gii hn ca thi gian thc hin n cng nh iu kin thit b khng cho php nn cha th pht trin n ca mnh ln mc cao hn. Mt s hn ch v hng pht trin ti: Hon thin h ct phi t ng v c th lm ra sn phm thc t . Do ch trn m hnh nn cc tnh ton v thit k cn c nhiu sai st khng th kim chng c . Cc chi tit ct phi ch mang tnh m phng do cha c thc t ha. M rng kh nng ct c th iu chnh kch thc ct ca phi mt cch linh hot hn.

--------------------------- MC LC-------------------------------NI DUNG TRANG Chng I : GII THIU ------------------------------------------------------------ 3 Chng II : C S L THUYT -------------------------------------------------- 4 Chng III : THIT K V THI CNG ------------------------------------------ 11 Chng IV: THIT K MCH IN KH NN DNG PLC---------------16 Chng V : KT LUN V NGH ------------------------------------------ 28

-M HNH MY CT PHI T NG --20-