NGHIEN c u i u KHOA HOC
\/XAC BjNH BO THONG SO DIEU KHIEN QUA TRINH HAN MIC/MAG A o
DETERMINATION OF PARAMETERS TO CONTROL VIRTUAL MIG/MAG WELDING PROCESS
Dinh Quang TuP, Nguyen Tien Diiang' 'TnJdng Trung cap nghi Giao thong Cong chinh Ha Npi
'Vien Co khi, TrUdng Dai hgc Bach Khoa Ha Noi
De nghien cdu, che tao he thdng thilt bi hdn MIG/MAG do phuc vu cho ddo too thUc hdnh hdn cdn thilt phdi nghien cdu phgm vi cho phep ciia cdc thdng sd ciia qud trinh hdn sao cho khi thiic hdnh tren thilt bi hdn do ngUdi hgc ren luyen dUdc cdc thag tdc nhu khi hdn MIG/MAG that DUa tren phgm vi cho phep cua cdc thong sd ndy ta cd thl xdy dung dUdc chUdng trinh cho phep ddnh gid ngudi hgc tren he thdng thilt bi hdn MIG/MAG do. Ddi vdi qud trinh hdn MIG/MAG do, cdc thdng so dieu khiln bao gdm ky thudt gdy ho quang, dieu khien gdc nghieng ciia simg hdn, cdc thao tdcdi chuyen sung hdn, duy tri tdm vdi dien cUc vd ky thudt kit thuc ho quang.
Tti Idioa; Hdn MIG/MAG do; Ky thudt hdn MIG/MAG; ThUc hdnh hdn do.
ABSTRACT
To study and fabricate virtual MIG/MAG welding equipment system for training welding practice, it is necessary to research on allowable range of parameters of welding process so that during practice on the virtual welding equipment the learners are exercised operations as during the real MIG/MAG welding. Based on the allowable range of parameters, we can develop a program thai allows learner evaluation on the virtual MIG/MAG welding equipment system. In the virtual MIG/
MAG welding process, the controlled parameters include technique of striking the arc, control of gun angle, move operations of the gun, electrode extension keeping and arc stopping technique.
Keywords: Virtual MIG/MAG welding; MIG/MAG welding technique; Virtual arc welding practice.
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1. TONG QUAN
Khi thuc h i n h han MIG/MAG tren he thdng thilt bi han that, ngoai chi phi d l dau tU may mde, trang thilt hi cdn phai ehi phi cho phdi ban, d i y ban, khi han, nang lUpng diln,...
Khi han, hd quang gay anh hudng d i n da va mat, khdi han do kim loai hda hdi gay ddc hai va nguy hiem vdi ca ngudi hpc va ngUdi day, giy d nhilm mdi trUdng khdng khi. He thdng ban MIG/MAG ao eho phep giam chi phi va khdng ddc hai ma van n i n g cao dUdc chat lUpng dao tao thUc hanh.
De khi thUe hanh t r i n he thdng han MIG/MAG ao, ngUdi hpc v i n ren luyen dUdc cac thao t i c nhii khi han MIG/MAG that, ta can phai nghien cdu de xae dinh cac thdng sd d l dieu khiln qua trinh h i n MIG/MAG ao raa khi thUc hanh ngUdi hpe se thUe hien eac thao tie trong pham vi cho phep eua eae thdng so dd.
dieu khien:
- Ky thuat giy hd quang: NgUdi thUc hanh han dilu ehinh dau sung han de day han vudng gde vdi be mat vat han sau do b i m edng tac hd quang se hinh thanh.
- Cac chuyen ddng cua sung han: Trong han hd quang cd 3 ehuyin ddng cd ban [1, 2]
dd la chuyen ddng doe theo dudng han, chuyen ddng dgc true que ban va dao ddng ngang. Tuy nhiln trong ban MIG/MAG do dUdc cap day tU ddng nen thUe t l ngUdi thUc hanh ban chi can thUc hiln 2 chuyen ddng, dd la ehuyin ddng dpe theo dUdng ban va thUc hien dao ddng ngang cua sung ban.
- Tam vdi cua dien cUc hay edn gpi la phan nhd eua diln eUc ban la khoang each gifla dau dien eUc (day han) va m l p dUdi cua dng tiep dien eho day han.
2. CAC T H 6 N G SO DIEU KHIEN QUA , ^ - Cac goc nghieng cua sung han: Duoc TRlNH HAN MIG/JMAG AO ' ' ' " ">>'" ° ™ !™°B P ' ' ^ " " "'^° P'^'P "^"^ ™ '
mdi loai hen ket h i n va mdi tU the ban.
- Ky thuit kit thuc hd quang: Bang each tha cdng tae ddng ngat ngudn han.
- Ky t h u i t mdi lai hd quang: Giy Iai hd quang d chd chUa ndng chay each mieng han 1 em rdi han ngUpc Iai de nung chay phan mieng han ndi hd quang vda tat, sau dd mdi tilp tuc han thed hUdng can thiet.
3. PHAM VI CHO PHEP CUA CAC THONG SO
3.1. Ky thuat gay va kit thiic hd quang
* Ky thudt gdy ho quang: '^
Cac thdng sd cua qua trinh han MIG/
MAG bad gdm cac thdng sd lien quan d i n che dp han va cac thdng sd lien quan den ky thuit ban. Cac thdng so cd ban eua ehe dd han MIG/
MAG bad gdm: Dudng kinh d i y han, cUdng dd ddng diln han, dien ap han, so ldp ban, toe dp ban va tam vdi diln cUc. Cae thdng so ca ban liln quan d i n ky thuat ban MIG/MAG gdm: Ky thuat gay ho quang, cac chuyen ddng cua sung han, cac gdc nghieng cua sung han va ky thuat kit thuc hd quang.
De ngUdi thUc hanh han tren h i thdng thiet bi han MIG/MAG ao ren luyen dUdc eac cae ky nang cd ban cua ngUdi thp han MIG/
MAG, cac thdng sd sau se dUde lUa chpn de
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NGHIEN cufu KHOA HOC
- Dieu chinh dau sung ban de diy ban vudng gde vdi b l mat vit han.
- DUa ea tay trai vad cam sung han, gifl cho khoang each diy han nhd ra va gdc dp sung ban khdng thay ddi, dau diy h i n each b l vat han 0,5-^1 mm.
- Giy hd quang bang each b i m edng tac sung han. Trong khi gay hd quang phai gifl cho khoang each diu nhd ra ciia day ban khdng ddi.
* Ky thuat ket thuc hS quang: Kit thuc hd quang bang each nha cdng tae ddng ngat ngudn ban trin sung han v i gifl nguyen vi tri sung ban tai cho kit thuc khoang 5s de khi h i o v l cudi dudng ban.
3.2. Cac gdc nghiing cua siing han Theo each p h i n loai thudng dung nhat, eac tu the ban dUde chia t h i n h 4 tU the: TU the han sap, tU the b i n ddng, tU t h l h i n ngang va tu t h l han tran. Han ddng ed 2 loai Ii h i n dUng tU dudi Iln va ban dUng tfl t r i n xudng. Ddi vdi ngUdi hpe thUc hanh ban vdi mong mudn chii yiu la lam quen vdi cae thao t i e ban n i n thUe te chu yeu la hpe thUc hanh h i n vdi cac tU the h i n sap, ban ddng va ban ngang cdn vdi tU the b i n tran la tU t h l khd ban n i n chi khi nao ban thanh thao cac tU t h l t r i n mdi hpc han tran.
Vl viy, trong he thdng ban MIG/MAG ao dUde thiet ke de thUe hiln 3 tU the ban: sip, ddng va ngang.
/ ) Tu the hdn sdp a) Mdi hdn gidp moi (1G)
Gde nghieng ciia sung ban so vdi phUdng thing ddng la 10 -^ 15° [2-5] hay la gde
nghiing cua sung h i n so vdi hUdng ban Ii a = 75 -^ 80° (hinh 1). Mat khac sung h i n phii nam trong mat phang vudng gdc vdi vat h i n va di qua dudng ban p = 90". Trong ban MIG/MAG ao, cic gdc nghiing eho phep cua sung ban nam trong khoang: a = 75" ^ 80°; p = 90° ± 2°.
Hinhl: Hdn tu the IG
Hinh 2: Hdn tu thi IF b) Moi hdn goc (IF)
Sung han nam trong mat phang phan giic eua mdi ban gdc va gdc nghiing eua sung ban so vdi dUdng ban mdt gdc a = 80 -^ 85°
ve phia hUdng ban (hinh 2). Trong ban MIG/
MAG ao, cac gde nghiing cua sung ban cho phep nam trong khoang: a = 80° ^ 85°; |3 = 45°
+ 2°.
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2) Tu thi hdn ngang a) Moi hdn gidp mdi (2G)
Gdc nghieng ciia sung h i n so vdi phUdng vudng gdc vdi dUdng ban 0 ^ 5 " ve phia hudng han hay la gdc nghieng cua sung ban so vdi hudng ban la a = 90 ^ 95° [2-4]. Mat khac sung h i n phii nam trong mat phang di qua dddng ban va vudng gde b l mat vat ban. D l dilu khiln, cac gdc nghiing cua sung ban cho phip nam trong khoang (hinh 3): a = 90° ^ 95°;
6 = 90° ± 2°.
Hmh 3: Hdn tU thi20
Hinh4:HdntUthi2F b) Moi hdn goc (2F)
a) Moi hdn gidp moi (3G)
0
a) Tu thi hdn 3Gu b) Tu thi hdn 3Gd Hmh 5: Hdn tu thi 3G
Gdc nghiing cua sung ban so vdi
phUdng ngang la 45° va nghiing ve phia hddng b) Mdi hdn goc (3F) h i n mpt gde 10 ^ 15° [3, 4] (hinh 4). Cac gdc
nghiing cua sung ban nam trong khoang cho phep sau: a = 75-^80°; p = 45°+2°.
a) TU thi hdn 3Fu b) TU thihdn 3Fd Hmh 6: Hdn tu thi 3F
Gde nghiing cua sung h i n khi h i n ddng tfl dudi lln trong khoang 90 -^ 95° (hinh 5a) va gdc nghieng cua sung ban khi ban ddng tfl t r i n xudng trong khoang 70 ^ 75° (hinh 5b).
De dilu khiln, cac gdc nghieng cua sung ban cho phep nam trong khoang: a = 90° ^ 95° (tU the 3Gu); a = 70° ^ 75° (tU t h l 3Gd); Trong c i 2 trddng hdp p = 90° ± 2°.
3) TU thi hdn ddng
Gdc nghiing cua sung ban khi ban ddng td dudi lln (tU the 3Fu) trong khoang 80 -^ 90° (hinh 6a) va gdc nghiing cua sung ban khi han ddng tfl tren xudng (tU the 3Fd) trong khoang 70 •;• 75° (hinh 6b). De die'u khien, cae'^
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NGHIEN cufu KHOA HOC
gdc nghiing cua sung ban cho phep nam trong khoang: a = 90" ^ 100° (tU t h l 3Fu); a = 70" ^ 75°(tUthe3Fd);p=45° + 2°.
3.3. Chuyen dong dpc theo d d d n g h a n va dao dpng ngang cua siing ban
Chuyen ddng dpc theo dUdng ban dieu khien thdng qua van tdc ban. Cung gidng nhU khi han hd quang tay [1], de ngUdi hpc lam quen vdi cae van tdc ban Ung vdi eac mdc dd khae nhau, d day ta se dUa ra 3 mde van tdc ban: Tde dp thap la 10 [cm/phut], tde dp trung binh la 20 [cm/phut] va tdc dp cao la 35 [cm/
phut].
Khi h i n de mdi ban dat dUpe chilu rdng can thilt ddi khi phai cd dao ddng ngang, dd la dao ddng sang hai ben eua dUdng h i n . Khi dd ehuyin ddng cua siing han ed t h l thUc theo nhieu each la sU phdi hdp cua hai chuyin ddng cd ban la ehuyin ddng dpe theo dUdng ban va dao ddng ngang. Vdi thiet hi ban MIG/
MAG ao dung cho ngUdi mdi hpe ban n i n ta lUa chpn dao ddng ngang kieu ric rac [2], vi day la kilu dao ddng ngang ddn gian nhit de ngUdi hpc de dang thUe hiln.
3.4. Tam vdi cua d i l n cUc
Chuyen ddng cua diy ban dupe tU ddng hda thdng qua bp cip day tU ddng. Trong q u i trinh ban do mdt yeu tdc n i o dd l i m thay ddi khoang each tU dau siing ban den vat han thi thdng qua cUdng dp ddng dien ban se tU ddng hieu chinh tdc dp cap d i y va do dd chilu d i i hd quang dupe duy tri dn dinh. Tuy nhien, nhU vay lim cho tam vdi dien cUc hi thay ddi. Neu tam vdi diln cUc Idn se lam du kim loai ndng chay, Iang phi diy han va lam giam dp ngau, giam tinh on dinh cua hd quang. Neu tam vdi dien eUc nhd se gay ra sU ban tde, kim loai long
dinh vao chup khi lam c i n trd ddng Ichi bao v?, gay ra rd.
Khi h i n MAG tam vdi d i l n cdc (Lv) co the xac dinh theo cdng thde Lv = 5 + 5.d (mm) vdi d dudng kinh dien eUc. Khi ban MIG, do chilu dai hd quang ldn can tang tam vdi dien cue them 2-^3 mm. ThUdng khi han MIG/MAG dudng kinh eua d i y hay sii dung cd dUdng kinh 1-^1,2 mm [2]. NhU vay trong ban MIG/MAG khoing cho p h i p ciia tam vdi diln cdc la 10-^15 mm.
4. KET L U A N
Qua nghien cflu d t r i n ta rut ra cac thdng sd de dieu khien qua trinh h i n MIG/
MAG ao qua dd danh gia ngUdi thUc hanh ban.
Cung nhu khi ban MIG/MAG that, ngUdi thp ban dupc phep thUc hien cac thao tac dao ddng trong mdt pham vi nhat dinh. Vi vay, de danh gia ldi thi cin phai cho phep ngUdi thUc hinh han dupc phep dao ddng trong mdt pham vi nao dd, ngoai pham vi dd se bi danh gia la loi.
Khi dd se ed eac loai ldi sau:
- Ldi mdi hd quang va mdi lai hd quang:
Hd quang phii dUde mdi hoae mdi lai tai diem each dau dUdng ban 10±2 m m hoac each vi tri hd quang tat 10±2 m m ve phia chUa ban. Khi hd quang da hinh thanh thi di chuyen hd quang ngupc lai ve dau dUdng ban hoac v l phia hd quang tat trUdc dd de bat dau ban.
- Ldi bam dUdng han: NgUdi hpe dUpc phep lUa chpn bien dp ciia dao ddng ngang (b) [mm] va pham vi cho phep cua dao ddng ngang s e l i b ± l [mm].
- Loi tam vdi diln cUc: Trong ban MIG/
MAG ao, t i m vdi diln cUc eho phep nam trong khoang 10-^15 mm.
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- L6i gdc nghieng eua sung han: Khi gde nghiing cua sung h i n , cac gde a va p, dng vdi mdi Ioai mdi ban va tU t h l ban khdng nam trong pham vi cho phep nhU da trinh bay trong muc 3.2.
- Ldi van tde ban: Khi van tdc ban khdng nam trong pham vi eho phep nhU sau: Tdc dp thap l i 10+1 [cm/phut], tde dp trung binh la 20±2 [cm/phut] va tde dp cao la 35±2 [cm/phut].':*
Ngay n h i n bai: 25/8/2014 Ngay phan biln: 10/9/2014
Tai l i l u tham khao:
[1]. Nguyen Tien DUdng (2014), Nghien cdu xdc dmh pham vi cho phep doi vdi bd thdng sd diiu khien qud trinh hdn hd quang tay do. Tap chi Co khi Viet Nam; Sd 8 nam 2014, trang 64-69.
[2}. Ngo Le Thdng (2004), Cdng nghe hdn diin ndng chdy. Tap 1: Co sd ly thuyet, NXB. Khoa hpc va Ky thuat.
[3]. Larry Jeffus (2002), Welding: Principles and Applications, Fifth edition, Delmar Cengage Learning Publisher.
[4], A.C. Davies (1993), The science and practice of welding, Tenth edition. Volume 2: The practice of welding, Cambridge University Press.
[5]. Gower A. Kennedy (1982), Welding Technology, Second edition, Glencoe Publishing Company, Cali- fornia, USA.
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