cong nghe dk khi nen

8/2/2019 Cong Nghe Dk Khi Nen

1/20

Khoain - in t HTHNG KH NN, THU L C

Bin so n: ThS. Nguy n Phc o

48

Ch ng 4 CNG NGH I U KHI N IN KH NN4.1 Cc ph n t trong h th ng 4.1.1 C u trc h th ng i u khi n i n kh nn

Hth ng i u khi n bng in- Kh nn (hnh 4.1) so vi hth ng i u khi n honton bng kh nn ci m khc bit cbn l: tn hiu i u khi n l tn hiu in, theo cc ph n t a tn hiu, cc ph n t x l tn hiu v cc vano chi u lm victheo nguyn lin, in - t trng.

4.1.2 Cc ph n t a tn hi u 1. Nt n. Hnh 4.2 trnh by nguyn l c u to, k hiu ca mt s dng nt n trongmch in.

Hnh 4.1 H thng in kh nn

K hiu nt nthng ng(OFF/STOP)

K hiu nt nthng m (ON/START)

Hnh 4.2 : a) nt n t phc h i; b) nt n t gi

b)Nt n t gi

a)


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2. Cng tc hnh trnhin-c (hnh 4.3)

K hiu trn s mch i u khi n:

V dv nguyn tc tcng theo hnh trnh ca cng tc hnh trnhin c(hnh 4.4)

Hnh 4.5 trnh by mt h th ng vi mt xilanh kp

i u khi n bng in kh nn. Mch s dng haicng tc hnh trnhin- c ( 1S1 v 1S2);

Ti p i m thng ng Khic tc ng

Hnh 4.4

Hnh 4.5 Mch ng dng cng tc hnh trnh

Hnh 4.3

Khic tc ngTi p i m thng m


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3. Cng tc hnh trnh t tim cn (Magnetic proximity switch), (hnh 4.6)

B ti p i m c lm bng vt liu st t (Fe Ni) vc t trong ng ch akh tr. Khi tim cn vi t trng ca nam chm v nh c u (hoc nam chmin), ccti p i m c t ha v ht nhau (ti p xc) cho dngin c th chy qua.

V tr lp t thng gp (hnh 4.7)

Hnh 4.8 m tcch bi u din cng tc hnh trnh t tim cn trn k hiu caxilanh ( 1B1; 1B2) v cch n i cng tc trong mch in i u khi n hth ng. Cc r lein t KB1, KB2ng vai tr trung gian mang thng tin v trng thi ca cng tc1B1, 1B2 tng ng.

Hnh 4.7

K hiu

Hnh 4.6

Hnh 4.8 V d ng dng cng tc t tim cn


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4. Cc cm bi n tim cn ( proximity sensors) ( hnh 4.9)

a. C m bi n ti m c n c m ng t (Inductive proximity sensor) (hnh 4.10)

Ccc tr ng cbn ca mt cm bi n cm ng t :- i tng pht hin: Kim loi st t .- Khong cch pht hin: 0,8 10mm, ( loi cnhy cao nh t - max 250mm)- in p cung c p: 10-30 VDC- Dngin cung c p ra ti: 75 - 400mA

Nguyn l hot ng:Khi vt th bng kim loi c a vo vng tc dng ca sensor, dngin

xoy xu t hin trong vt th , n lm suy gim nng lng ca b to daong(Oscillator).i u dn n s thay i dngin tiu thca sensor. Nh vy,hai trng thi: suy gim v khng suy gim dngin tiu th ca sensor dn nchuy n trng thi c hay khng bng m c xungin p ra.

Xem s nguyn l mch in t ca cm bi n cm ng t (hnh 4.11)

sensor

Hnh 4.9 V dv v tr lm vic ca cm bi n tim cnv s mch in

K hiu

Hnh 4.10 Nguyn l hot ng v k hiutrn s mch in ca sensor cm ng t


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b. C m bi n ti m c n i n dung ( capacitive proximity sensor)

Nguyn l lm vic (hnh 4.12): - Cm bi n in dung pht hin c cc vt th lm bng vt liu b t k

( kim loi, , g , nc ...).- Khi vt th c dn vo vng tc dng ca cm bi n, in dung ca mt t in ( chnh thnh bi vt th v bn c c ca cm bi n) thayi. in dung ny tham gia trongmt mch cng hng RC ca cm bi n. Trang thi cng hng thayi dn n thayi dngin tiu th ca cm bi n v tng ng vi c hay khng c vt th trong vng pht hin ca cm bi n.

Hnh 4.11S nguyn l ca cm bi n cm ng t

K hiu

Hnh 4.12K hiu v s nguyn l


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c. C m bi n ti m c n quang (Optical proximity sensors) (hnh 4.13)

Nguyn l lm vic :Bphn pht spht i tia h ng ngoi bng it pht quang, khi gp vt chn,

tia h ng ngoi sphn h i li bphn nhn. Nh vy bphn nhn, tia h ng ngoiphn h i l tn hiu kch thch to nn tn hiu ra.

Tu theo cch thi t lp v tr ca b phn pht v b phn nhn, ngi ta chiacm bi n quang thnh 2 loi chnh

- Cm bi n quang phn h i (hnh 4.14a)- Cm bi n quang mt chi u (hnh 4.14 b)

5. Bchuy n i tn hiu kh nn- tn hiu in (hnh 4.15)

K hiu

Hnh 4.13K hiu v s nguyn l

a.b.

Hnh 4.14s dng cm bi n quang

Hnh 4.15


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Hnh 4.17

Khi p su t kh nn vo c a 14 vt gi tr t, b ti p i m chuy n mch chuy ntrng thi mch in. Mch ng dung (hnh 4.16), ti p i m ca b chuy n i nyc g i vo mch in nh hnh v.

6. Bchuy n i p su t in vn nng(hnh 4.17)

Nguyn l lm vic:- Ch c nng chuy n i tn hiu kh nn ( p su t d ) in.Khi cng P1 c n i vi i m c p su t , cng P2 thng vi kh quy n. psu t P1 c a vo ng ln sng v gy ln l c tc dng cng vi l c n h i ca l

xo ln mt y ng khi n cho khong cch gy hiu ng in dung thayi. Nhim v ca cm bi n in dung l to ra tn hiu in dng tng t hoc nh phn a rangoi. C th t c gi tr tc ng theo mu n thng qua l c n h i ca l xo.Nguyn l lm vic ny cng c dng gii thch tng t cho hai ch c nng diy:

- Ch c nng chuy n i tn hiu kh nn ( p su t chn khng) in.Khi P2 n ivi i m c p su t chn khng, cng P1 thng vi kh quy n.

Hnh 4.16


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- Ch c nng chuy n i tn hiu kh nn (chnh lch p su t ) in.Khi c hai cng P1, P2 c n i vi haii m c p su t khc nhau, hiu P1-P2 s c ki msot.

V d ng dng b chuy n i p su t kh nn in FESTO ARL-2N-PEV,cc thngs k thut:P1 0.25/8barP2 -0.2/-0.8bar P= P1-P2 -0.95/8barT n s ng m70HzDngin 400mA

4.1.3 Ph n t x l tn hi u Cc ph n t x l tn hiu c dng trong h i u khi n in- kh nn r t a dng, v d nh cc mch in t , my tnh s tuy nhin trong nhi u trng hp n gin

chng ta dng R le in t (Relay)1. R le in t (hnh 4.19)

a.Mch kh nn b. Mch in

Hnh 4.18

Nguyn l c u to ca relay

S nguyn l ca relay

K hiu

Hnh 4.19


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2. R le thi gianR le thi gian cn gi l cc b nh thi (Timer) th c hin bng kh nn c trnhby chng 3. Trong c u trc h i u khi n bng in- kh nn, ngi ta c th s dng cc timer th c hin bng in t , in t hay k t hp cc linh kin in t virle in t , di y trnh by hai ki u rle thi gian loi ny:

Hnh 4.20 l rle tr ng ( Delay ON)

Hnh 4.21 bi u din rle trngt ( Delay OFF)

4.1.4 Ngu n cung c p Trong th c t , ph n ln cc ph n t in- kh nn trong h th ng c ch to vingu n cung c p l ngu n mt chi u cin p 24V (hnh 4.22)

Hnh 4.20

Hnh 4.22

Hnh 4.21


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4.2 M t s c u trc i u khi n i n kh nn 4.2.1 Cch bi u di n s h th ng (hnh 4.23)

Hnh 4.23 m t s h th ng i u khi n in kh nn. Trong, ph n mch l ckh nn: thng bao g m mch cung c p, o chi u v kh ng ch l u lng kh nncho c c u ch p hnh, c thi t k tng t nh h th ng i u khi n bng kh nn.Cn i vi mch i u khi n c quyc v t trn xu ng theo th t : lp a tnhiu vo; lp x l tn hiu v di cng l lp tn hiu ra ( cc cun dy in t cavano chi u).

4.2.2 i u khi n tr c ti p Khi n nt S1, dngin chy tr c ti p qua cun dy in t 1Y1 ca van, tc

dng in - t lm chuy n mch van kh nn 1V1, ngu n kh nn chy t 1 qua 2 cungc p cho Xilanh 1A. Khi thi n nt S1, dngin qua 1Y1 khng t n ti, van 1V1 trv

trng thi banu v n c (hnh 4.24)

4.2.3 i u khi n gin ti p Tcngi u khi n gin ti pthng qua rlein t K1

Hnh 4.24

Hnh 4.25i u khi n gin ti p

Hnh 4.23


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4.2.4 M ch t duy tr

4.2.5 i u khi n t ng theo hnh trnh (hnh 4.27)

n nt khing (START), rle K1 tcng v t duy tr bng ti p i m K1(ct 2); ti p i m thngmK1 ( ct 3)ng li c p ngu n cho cun dyin t 1Y1 mvano chi u 1V1 ( kh nn 14) y c n pistoni ra. Khi ra n vtr mong mu n (nit cng tc hnh trnh 1S2), 1S2 btcng, ti pi m 1S2 trong mchi u khi n ngt mch ca K1, van 1V1 trv trng thi banu ( 1 2), piston liv . Mchi u khi n cng cho php a c n piston li v t b t k vtr no khi n nt STOP.

4.2.6 i u khi n theo hnh trnh v p su t Mch i u khi n hnh 4.28ac thi t k vi cc ch sauy:- Do van 1V1 l van 5/2 xung nn khng c n thi t phi dng mch t duy tr;- 1B1 l cng tc chuy n i p su t-in: g m mch kh nn n i vong ng

cung c p kh nn cho xi lanh v mch in n i trong mch i u khi n;- Cng tc 1B2 l cng tc t tim cn;- Cc cng tc 1B1 v 1B2 hoc phi nh hai r le K2 v K3 lm trung gian ( nh

trong hnh 4.28a) hoc n i n i ti p qua K2 nh trong hnh 4.28b tha mn i ukin: piston ch c i u khi n li v khi tha mn ng thi hai y u t v a t psu t nn c n thi t ( quynh bi 1B1) v a t hnh trnh quynh bi 1B2.

Mch kh nn

Mch i u khi n t duy tr-khi to tri( Dominant set)

Mch i u khi n t duy tr-ngt tri( Dominant reset)

Hnh 4.26Mch t duy tr

Hnh 4.27


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4.2.7 i u khi n theo hnh trnh v th i gian

Hnh 4.29 trnh by s i u khi n h th ng, v dnh c yu c u khi c n piston rah t hnh trnh, c n thi t phi l u li mt thi gian no r i t ng li v . V trongtruy n ng kh nn, t c cc u ch p hnh thng ph thuc vo nhi u y u t v vvy kh duy trn nh nn thng p dngi u khi n theo thi gian ti cci m d ng

4.2.8 i u khi n theo c u trc t ng i n Phng php thi t k mch i u khi n in-kh nn theo t ng cng c xy

d ng d a trn nh ng nguyn tc nu nh i vi thi t k i u khi n bng kh nntheo t ng. C u trc mch h th ng c chia thnh hai ph n c bn : mch h th ngkh nn v mch i u khi n ( nh trnh by trn hnh 4.23). Thi t k c u trc i ukhi n theo t ng c th c hin trong mch in, v vy cc ph n t chuy n i t ng s

Hnh 4.28a

Hnh 4.28b

Hnh 4.29


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Hnh 4.31Mch i u khi n 3 t ng

l cc rle in t v cc tn hiu i u khi n dng s l nh ng tn hiu in p haydngin. Tuy nhin hon ton c th p dng cho cc cng c lp trnh khc nh PLChay vii u khi n.

Cth , c th tm tt li cc bc nh sau:Bc 1: Lp s hnh trnh bcBc 2: Phn chia t ngBc 3: Chn vano chi u v cc ph n t kh nn thi t k mch kh nn.Bc 4: Thi t k t ng i u khi n, g m cc ph n t chnh y u:

- Ph n t chuy n t ng l cc r le in t , s rle in t dnh cho chuy n t ngbng n-1 (n: s t ng).

- S tn hiu chuy n t ng bng s t ng. - Cc tn hiu cn li khng tham gia chuy n

t ng snm trong t ng v dng i u khi ntr c ti p vano chi u trong bc th c hin.

Hnh 4.30 bi u din mch i u khi n 2 t ng (Line1, Line 2).

R le K1 lm nhim vchuy n t ng;Cc tn hiu chuy n t ng g m E1 thi t lpt ng 1; E2 dnh thi t lp t ng 2

Hnh 4.31 bi u din mch i u khi n 3t ng (Line 1, Line 2 v Line 3).Cc r le K1, K2 lm nhim vchuy nt ng;Cc tn hiu chuy n t ng: E1 thi t lpt ng 1; E2 thi t lp t ng 2 v E3 - t ng 3.

Hnh 3.30Mch i u khi n 2 t ng


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Tng t , to ra n t ng in th dng n-1 rle i u khi n (hnh 4.32)

Cc v d : 1. Thi t k theo t ng in- kh nn cho h th ng hai xi lanh hot ng theo bi u hnh trnh bc nh hnh v.

Hnh 4.33

Hnh 4.32Mch i u khi n n t ng


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Trong v dny, rle K 1 m nhim chuy n t ng. Cc tn hiu chuy n t ng c c p t cm (S1^1S1) v cng tc hnh trnh 2S2. Cc tn hiu c c p t 1S2 (thuc t ng I)v 2S1(thuc t ng II) dng choi u khi n tr c ti p Y3 v Y2 ( hnh 4.33).

2. Thi t k theo t ng in-kh nn cho h th ng c bi u hnh trnh bc cho tronghnh 4.34.Nhn th y rng hth ng kh nn hon ton tng t nh i vi v d1. Tuy nhin, nhn c bi u chuy n ng hon ton khng tng t , chc chn ph n mch i ukhi n sphi c thi t k theo c u trc khc. Mch i u khi n c thi t k theo 2t ng nh hnh 4.34. Tn hiu chuy n t ng g m: E1 = 1S2 ; E2=2S2. Cm tn hiu khing chu trnh: (S1^2S1) c t trong t ng II

4.2.9 i u khi n theo c u trc nh p Nguyn tc th c hin ca i u khi n theo nhp l cc bc th c hin lnh xy

ra tu n t . C ngh a l khi cc lnh trong mt nhp th c hin xong, th s thng bocho nhp ti p theo , ng thi sxo lnh nhp th c hin trc .

1. Chu n b cho nhp ti p theo;2. Xo cc lnh ca nhp trc ;3. Th c hin lnh ca tn hiu i u khi n;

Hnh 4.35 bi u din chui i u khi n g m 4 nhp th c hin theo nguyn tc trn. Cctn hi u i u khi n A1A4c thi t lp s m nhim 3 nhim v, v d nh A1:

Hnh 4.34


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i u khi n van o chi u no ; xa trng thi ca nhp th 4 bng tn hiu Z1;chu n b thi t lp nhp th 2 khi c tn hiu i u khi n X1.

V d ng d ng: Thi t b khoan c bi u hnh trnh bc cho trn hnh 4.36Bng m tcc bc th c hin:Nhp 1 2 3 4Xilanh A+ B+ B- A-Tn hiu i u khi n SET^1S1 1S2 2S2 2S1Tn hiu i u khi n van Y1 Y3 Y4 Y2

Hnh 4.36

Hnh 4.35


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4.3 Cc bi t p ng d ng

4.3.1 Thi t k hth ng i u khi n in-kh nntheo yu c u cho theo bi u hnh trnh bc

(hnh vbn)- Hth ng c th i u khi n bng tay M (Manual)hoc i u khi n t ng A ( Automation)- Gi tr p su t c n i u chnh v thi gian ttu chn theo yu c u cng ngh .Ty l a chn c u trci u khi n.

4.3.2 Thi t b phn ph i phi vt liu , s cng nghv bi u hnh trnh bc chotrn hnh v:

H i u kin:+ Thi gian t1 c hiu chnh cho hai kh i vt liu ln qua vng chn; thi gian t2 c hiu chnh theo yu c u v kch thc v s lng phi c n c p.+ Cci u kin khcc m ttrn bi u hnh trnh bc.+ C th lm vic t ng nhi u chu trnh khi dng mt cng tc

+ T c ra vo ca cc piston c n c i u chnh nh nhau.Nhim v:* Thi t k hth ng i u khi n bng in- kh nn ( Tm ra c u trci u khi n ph hpnh t)

Lp bng k cc ph n t c s dng trong s :

Ph n t Ch gii

4.3.3 Thi t b p ckh cho gia sc, s cng nghv bi u hnh trnh bc chotrn hnh trang sau.

H i u kin cho trn bi u Nhim v:* Thi t k hth ng i u khi n bng in- kh nn (ty chn c u trci u khi n).

Lp bng k cc ph n t c s dng trong s :

Ph n t Ch gii


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4.3.4 Thi t b np phi cho my ct laser m ttrn hnh v. Chi ti t c n gia cngc t vo gi k p ph i hp bi cc xilanh 2A, 1A vc a vo v tr gia cng.Thi gian t2 c n cho gia cng, khi gia cng xong, 1A rt v - chi ti t c vn chuy nra khi v tr gia cng bi mt khu khc. Khi 1A rt v v tr banu, 2A s c a ra v tr sn sng.

S dng cc cng tc t trng khng tim cn gn trn xilanh.Thi t k hth ng in- Kh nn (ty chn c u trci u khi n) Lp bng k cc ph n t c s dng trong s :

Ph n t Ch gii


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4.3.5i u khi n mt cylinder c bi u hnh trnh bc nh hnh v

H i u kin: Nh cho trn bi u ( Khi c p ngu n kh nn, trng thi ca pistontng ng m c 1 y cng l trng thi k t thc mt chu trnhi u khi n)

- Yu c u cng ngh:Hnh trnhi ra vi v c n ci u chnh t c . S hnh trnh qua li ca piston tu thuc vo khong thi giant.

- Nhim v:* Chn c u trci u khi n theo nhp thi t k hth ng i u khi n bng in - kh nnLp bng k cc ph n t c s dng trong s :

Ph n t Ch gii

4.3.6 S cng nghthi t b khoan cho trn hnh vbnH i u kin:

Sau khi chi ti t c n khoanc t ng v tr, pistondn ti n b u khoan rt ln v tr cao nh t (xcnhbng cm bi n 1S1) hnh trnh dn ti n khoan bt ukhi n nt 1S4. Khong cch dn nhanh (khng hn ch l u lng ) c xcnh bng 1S2.on hnh trnh khoan c n c khnng i u chnht c . Hnh trnh rt ln c n phi r t nhanh tng nng su t sn xu t.

Yu c u cng ngh:Hnh trnhi ra ca pistonc chia thnh hai giaion vi yu c u khc nhau v t chnh trnh.Hnh trnh rt v c n c t c ln nh t c th

Nhim v:* Thi t lp bi u hnh trnh bc ca Xilanh* Thi t k hth ng i u khi n bng in kh nn, s dng cc cng tc t trng

tim cn gn trn xilanh (tm c u trci u khi n ph hp nh t)Lp bng k cc ph n t c s dng trong s :

Ph n t Ch gii

4.3.7 Thi t b u n (hnh v trang sau). T m kim loi Xc a vo bng tay. Bngmt nt n START, xilanh 1A ra k p cht. L c k p c ki m sot bng ph n t psu t. Tn hiu do n cung c p dng i u khi n cho 2Ai ra u n s b t m kimloi cong mt gc 900 v t rt v . 2A v n v tr cu i cng, mt tn hiu t cmbi n v tr s i u khi n cho 3A th c hin


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cngon u n cu i cng. K t thc cngon u n, mt tn hiu t ph n t p su t n as i u khi n ng thi cho c3A v 1A rt v . Sn ph m c l y ra bng tay.

Nhim v:* Thi t lp bi u hnh trnh bc ca hth ng* Thi t k hth ng i u khi n bng in kh nn (t chn c u trci u khi n )

Lp bng k cc ph n t c s dng trong s :Ph n t Ch gii

4.3.8 Thi t b lm sch chi ti t sau gia cng. Chi ti t c n lm sch c vn chuy ntheo bng ti Wc xilanh 1A y vo gi vn chuy n X, xilanh 2A k p, xilanh 3A yvo bu ng lm sch Y, xi lanh 4A y ra bng ti vn chuy n i hng Z.Bi u hnh trnh bc nh hnh v.Hy chn c u trci u khi n in-kh nn thi t k hth ng.

Lp bng k cc ph n t c s dng trong s :Ph n t Ch gii

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