TRNG I HC BCH KHOA H NI VIN C KH

BO CO THC HNH NHP MN C KH CH TO MY.

Sinh vin: M VN CHIN SHSV: 20109008 Lp: cn-cn ch to my.

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Gii thiu chung:Ngnh cng ngh c kh:Cng ngh c kh lun l mt trong nhng ngnh then cht i vi s pht trin kinh t x hi trn ton th gii. Ngy nay, tt c cc my mc t nh b tinh vi n to ln cng knh ang ngy m hot ng trong thi i cng nghip pht trin, chng vn hnh trong cc dy chuyn sn xut, hot ng mi ni (trn v di mt t, trn mt bin, di y bin, trn tri, ngoi v tr). Tt c u c s ng gp to ln ca cc nh khoa hc, cc tng cng trnh s, k s, cn b k thut v cc cng nhn c kh. Cng ngh c kh l ngnh ng dng cc nguyn l vt l to ra cc loi my mc v thit b vn hnh trong cc dy chuyn sn xut, hot ng mi ni hoc cc vt dng hu ch phc v i sng. C kh p dng cc nguyn l nhit ng lc hc, nh lut bo ton khi lng v nng lng phn tch cc h vt l tnh v ng, phc v cho cng tc thit k trong cc lnh vc nh t, my bay v cc phng tin giao thng khc, cc h thng gia nhit v lm lnh, dng gia nh, my mc v thit b sn xut, v kh ...

Hc vin theo hc chuyn ngnh cng ngh c kh c o to kin thc, k nng chuyn ngnh vng vng v c k nng thc hnh ngh thnh tho v lnh vc cng ngh ch to my. Sau khi tt nghip s c kh nng: T chc, iu hnh sn xut; tnh ton, kim tra v la chn cng ngh ph hp vi thit b v iu kin sn xut ca n v; Bit s dng, kim tra v bo dng thit b; pht hin v gii quyt nhng s c thng thng trong sn xut.

Phm cht, k nng yu cu: l ngi thnh cng trong lnh vc c kh, bn phi c kh nng tng tng tt, sng to, phn tch nhy bn, logic v nng ng, kin tr. Ngoi ra bn cng cn trang b nhng kin thc c bn v cc mn khoa hc t nhin c bit l ton hc ngay t khi cn hc ph thng, v chc chn khi A s chn lc bn vo trng. Ri nhng bc tp tnh lm mt chuyn vin c kh tht s, bn cn c tnh cn thn, tinh thn k lut v tc phong cng nghip. Nu khng yu thch cng vic tp th, khng cn thn, bn c th ph hng 2

thnh qu chung ca mi ngi. Thm vo mt tnh cch quan trng: s cp nht kin thc t sch bo, tp ch chuyn ngnh... lin tc v lin tc l iu nn lm. Cui cng, yu t sc khe gip bn gii thch ti sao ngnh c kh rt him k s l ph n. Thc t, ch ni v thi lng thc hnh trong trng hc, sinh vin c kh c dnh n 50% thi gian hc ti cc phng, xng thc hnh ca trng. Ngnh k thut c kh hin nay l ngnh x hi c nhu cu tuyn dng nhn lc ln, v vy nu hc ngnh ny khng phi lo v c hi tm vic lm trong tng lai, bn c th lm vic mi ni trn t nc v cc nc khc trn th gii trong mi ngnh cng nghip v kinh t khc nhau. Do vy, nu chuyn tm hc tp, bn s khng lo khng c cng vic ng chuyn mn. Bi v, mt vn quan trng l yu t con ngi. My mc d tinh vi n u m khng c cng nhn lnh ngh, kinh nghim v kho lo trong vic lp t, vn hnh, iu khin thit b s khng mang li hiu qu.

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Bi 1: Gia cng c kh (tin, phay, bo, ngui, lp rp).*Mc ch:Tm hiu v ngnh gia cng c kh ,cu to v nguyn tc hot ng ca cc my tin, phay, bo v cc cng on ngui Gip sinh vin ngnh c kh hiu thm v yu them ngnh hc ca mnh. * Thu hoch: + Nganh gia cng c kh:

Vi nhiu ngi, cng vic ca ngnh c kh lun lin quan n st thp, lin quan n cc cng vic gia cng bng tay nh tin, phay, hn, bo.... Tuy nhin, hin nay vi s pht trin ca cng ngh, cng vic ngnh c kh c chuyn mn ha, nhiu cng vic c kh m ngi lm vic gn nh khng tham gia vo tin, phay, bo, hn .Ngnh c kh - khng ch l tin, phay, bo, hn

C kh l ngnh c lch s lu i, chim phn ln trong c cu hot ng kinh t x hi. Ngnh c kh tham gia vo mt di kh rng cc cng vic sn xut bao gm t khu khai khong, hnh thnh vt liu, gia cng cc thit b, ch to my mc, v iu hnh h thng sn xut cng nghip. Trc y gia cng mt sn phm, ngi th phi ly nguyn liu, gia cng bng tay trn cc my mc na th cng nh my tin, my phay, my bo, my hn... Hin nay cng vic gia cng c t ng ha bng cc my gia cng hin i (my CNC), cng vic ca ngi th ch cn l ng my nhn nt, lp trnh gia cng... Lp trnh gia cng l mt cng vic quan trng khi thc hin trn cc my gia cng t ng CNC, cc cng vic trc y nh ly vt liu (phi), tin, phay u c my t ng thc hin mt cch chnh xc theo chng trnh c lp trnh. Cng vic thit k trc y phi thc hin bng vic v cc bn v bng tay, ngy nay c s h tr ca my tnh vi cc chng trnh chuyn h tr cho vic thit k c kh. Vic thit k c kh trn my vi tnh vi s h tr ca phn mm c gi l CAD, CAM cho php xy dng c nhng bn v c phc tp cao. Ngi k s c kh hin nay lun phi bit v CAD. Mt bc tin cao hn trong ngnh c kh l cng ngh CAD/CAM/CNC, to thnh mt quy trnh khp kn t khu thit k n khu ch to sn phm bng cc my mc gia cng hin i. Vi nhng cng ngh nh trn, ngnh c kh ngy cng ng gp tch cc sn xut ra cc thit b, my mc, sn phm c kh c chnh xc cc cao, bn tt.

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My tin:

My tin l loi my ct kim loi, c dng rng ri nht gia cng cc mt trn xoay nh: mt tr, mt nh hnh, mt nn, mt ren vt, gia cng l ren, mt u ct t. C th khoan, khot, doa, ct ren bng tar bn ren trn my. Nu c g c th gia cng cc mt khng trn xoay, hnh nhiu cnh, ellp, cam

c im nguyn lMy tin l my ct kim loi c chuyn ng chnh l chuyn ng quay trn quanh tm ca phi to ra tc ct, chuyn ng chy dao l chuyn ng tnh tin ca dao gm hai loi: chy dao dc (dc theo hng trc ca chi tit), chy dao ngang (chy theo hng knh ca chi tit).

Phn loi+ V mt kt cu v cng dng, my tin c phn ra: 5

-My tin vn nng: c hai nhm: My tin trn v my tin ren vt. -My tin vn nng c ch to thnh nhiu c: C nh 500 kg); c trung 4 tn); c ln 15 tn); c nng 400 tn); v truyn ng kt cu my ny c loi c trc vt me, c loi khng c trc vt me. -My tin chp hnh: c trang b cc c cu chp hnh gia cng nhng chi tit c hnh dng c bit. Loi ny truyn ng ch c trc trn. -My tin chuyn dng : ch gia cng mt vi loi chi tit nht nh nh: my tin ren chnh xc, my tin ht lng, my tin trc khuu, my tin bnh xe la -My tin ct: gia cng cc chi tit nng c D > L. -My tin ng: c trc chnh thng ng: Gia cng cc chi tit nng phc tp. -My tin nhiu dao: l loi my tin c nhiu dao chuyn ng c lp, cng mt lc c th gia cng chi tit vi nhiu dao ct. -My tin revolver: dng gia cng hng lot nhng chi tit trn xoay vi nhiu nguyn cng khc nhau. Ton b dao ct cn thit c lp trn mt bn dao c bit gi l u revolver, c trc quay ng hoc nm ngang. -My tin t ng v na t ng. -My tin ren vt vn nng: L my tin thng dng nht trong nhm my tin c th tin trn v tin ren. Truyn ng cho bn dao thng dng hai trc : trc trn tin tr trn, trc vt me tin ren. Trn thc t c nhiu loi my tin ren vt vn nng.

Cu to chung1: Thn my; 2: Hp tc ; 3: Mm cp; 4: ng; 5: Gi ; 6: Bn dao; 7: Hp xe dao; 8: Bn xe dao; 9: Trc vt me; 10: Trc trn; 11: Trc iu khin. a,b,d,e : Cc tay gt di ng cc khi bnh rng bn trong hp tc . ( c ): Tay gt dng ng m ly hp ,trn c s ng m my v o chiu trc chnh. 6

Bi 2: My CNC v rooboot, hn.My Tin CNC (CNC) l t vit tt cho Computer(ized) Numerical(ly) Control(led) (iu khin bng my tnh) cp n vic iu khin bng my tnh cc my mc khc vi mc ch sn xut (c tnh lp li) cc b phn kim kh (hay cc vt liu khc) phc tp, bng cch s dng cc chng trnh vit bng k hiu chuyn bit theo tiu chun EIA-274-D, thng gi l m G. CNC c pht trin vo khong u nhng nm 1950 phng th nghim Servomechanism ca Hc vin k thut Massachusetts Institute of Technology gi tt l M.I.T hc vin nghin cu v gio dc thnh ph Cambridge, Massachusetts Hoa K v nhanh chng ng dng vo vic ch to my mc.

My tin CNC xut hin nhanh chng thay i vic sn xut cng nghip. Vic tin hnh tin cc ng cong, hnh phc tp c thc hin d dng nh ng thng, cc cu trc phc tp 3 chiu cng d dng thc hin, v mt lng ln cc thao tc do con ngi thc hin c gim thiu. Vic gia tng t ng ha trong qu trnh sn xut vi my CNC to nn s pht trin ng k v chnh xc v cht lng. K thut t ng ca my tin CNC gim thiu ti a cc sai st v gip ngi thao tc c thi gian cho cc cng vic khc. Ngoi ra cn cho php linh hot trong thao tc cc sn phm v thi gian cn thit cho thay i my mc sn xut cc linh kin khc. Trong mi trng sn xut cc my tin CNC c th kt hp thnh mt t hp gi l cell, c th lm nhiu thao tc trn mt b phn. My tin CNC ngy nay c iu khin trc tip t cc bn v do phn mm CAM (computer - aided design). C th ni my tin CNC gn ging nht vi h thng robot cng nghip, tc l chng c thit k thc hin nhiu thao tc sn xut (trong tm gii hn). 7

Cng ngh hn h quang I. My hn in1. Gii thiu chung:

My hn in

- My hn l 1 dng ca my bin th bin i in p ngun (220 V) xung in p hn 80 (V) - Da trn hin tng phng in (chp mch) l hin tng chuyn ng khng ngng ca dng in t trong mi trng c ion ho gia hai in cc. ni c hin tng phn g in (h quang) sinh ra nhiu nhit, nhit lng ny t cho vt hn nng chy. + Phn loi: - Theo ngun in vo: my hn mt chiu my hn xoay chiu

2. Cu to

Khi nim v hn h quang

+Hn l mt trong nhng phng php lp ghp cc chi tit vi nhau. c im ca hn l phng php lp ghp m khng th tho di. +Hn h quang tay vi que hn c v bc l phng php hn h quang s dng nhit ca h quang c sinh ra gia in cc que hn vi kim loi hn. V bc dng n nh h quang v khng cho khng kh xm nhp vi mi hn lm nh hng ti cht lng mi hn, cn li que hn cung cp kim loi cho mi hn. +Khi hn th nng lng ca h quang in nung nng kim loi ch cn hn ti trng thi nng chy, nhit ca h quang in cc que hn c th t ti 50006000 lm nng chy in cc que hn v kim loi c bn to thnh vng nng chy hay cn gi l b hn, sau khi b hn kt tinh s to thnh mi hn ni cc chi tit thnh mt khi bn vng. 8

+H quang l hin tng phng in cc mnh v lin tc qua mi trng khi b ion ha gia cc in cc, h quang hn pht ra mt ngun nh sng v cung cp mt ngun nhit rt ln, ngun nhit c tp trung cao dng lm nng chy vt liu hn v kim loi c bn. +Trong qu trnh hn mi thao tc nh: iu chnh ngn la hn, gy h quang, dch chuyn que hn duy tr chiu di h quang, dao ng to chiu rng mi hn cng nh chuyn ng dc to chiu di mi hn u do ngi th thc hin bng tay cho nn cht lng mi hn ph thuc hon ton vo thao tc ca ngi th hn, bi vy tay ngh ca ngi th hn l iu rt quan trng.

Khi nim v hn kh

1. Chai xy vi van gim p 2. Chai actylen vi van gim p 3. Thit b iu chnh trc 4. ng dn xy 5. ng dn kh actylen 6. M hn 7. Que hn 8. Ty hn 9. Chi tit hn 10. Ngn la hn +Hn kh l phng php hn m s dng nhit lng trong qu trnh phn ng chy ca hp cht chy nh C2H2, CH4, C3H8, C6H6,hoc H2 vi xy nung chy kim loi. +Phng php hn kh ch yu v c s dng rng nhiu l s dng phn ng chy ca kh t trong oxi v axetylen (C2H2) to ra ngn la nung nng chy c phn kim loi c hn ng thi que hn l cc thanh kim loi ng cht vi kim loi hn cng c nung nng chy cng vi kim loi hn v khi ngn la i qua s to thnh mi hn. +Ngoi chc nng nung nng chy vt liu hn v que hn ngn la hn cn c tc dng bo v vng hn trnh khi nhng nh hng xu ca mi trng xung quanh nhm nng cao cht lng mi hn. +Phng php hn kh c s dng hn cc tm mng v cc sn phm c thnh mng bng thp hoc hp kim mu. +Hn kh c phm vi s dng hp hn so vi hn h quang tay v nng sut lao ng thp nhng ngy nay n vn c s dng ph bin do thit b hn n gin v r, c th trang b v s dng ti nhng vng xa xi v xa ngun in. +Hn kh dng ch yu hn nhng chi tit mng, v sa cha nhng khuyt tt do vt c, hn vy, hn p gy ra. +Hn kh c s dng thng dng nht l hn v ct bng kh xy-

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Axtylen v nhit sinh ra do phn ng chy ca 2 kh ny ln v tp trng, to thnh ngn la c nhit cao v vng cao nht c th t ti 32000C bi vy ta c th s dng ngn la hn ct kim loi c chiu dy mng.

II. Dng in hn:- in th khng ti Uo ln gy ra h quang nhng phi khng gy nguy him khi s dng. Vi dng xoay chiu: Uo = 55 -80 (V) Vi dng mt chiu: Uo = 35 -55 (V) - Khi c ti (h quang chy) in th h xung tng ng: Dng xoay chiu: Uh = 25 - 40 (V) Dng mt chiu: Uh = 15 - 25 (V) - Cng dng in hn ph thuc vo ng knh que hn vt liu chi tit hn . ih = ( 30+ 5.d ).d ( A ) d : ng knh que hn - Cng thc kinh nghim cho mi hn sp, thp cacbon. ih = ( 20 + 6.d ).d

III. Que hn+ Li que d = (1 - 12 mm) tu theo cng dng ca que hn v thnh phn ho hc ca vt liu cn hn. Li que hn c th c lm t cc vt liu khc nhau nh thp, gang, ng, nhm,... + Lp thuc: - Lp thuc bc loi mng (chng vi phn mi mm): dn 1,2d lp thuc bc loi mng dng lm tng tnh n nh ca h quang. Thnh phn gm c vi, fenpat, bt tan.. ( 80 - 85 % khi lng), v thu tinh lng (15 - 20 % khi lng). Lp thuc bc loi ny dng hn cc cu trc khng quan trng. Mi hn bng que hn ny c c tnh km. - Lp thuc bc loi dy : dn 1,55d lm tng tnh n nh ca h quang v to quanh h quang 1 lp kh v x bo v kim loi khng b xy ho v khng b tc dng ca kh Nit. Trong trng hp cn thit ngi ta cho thm vo lp thuc bc nhng thnh phn hp kim (cc phero hp kim) nhng thnh phn ny s tham gia trong thnh phn mi hn v nng cao c tnh ca mi hn. Thnh phn ca lp bc ny gm c cc ion ha (phn), cht to x (cao lanh), cht to kh (tinh bt) cht kh (fero,mangan...), cc hp kim v cht dnh

IV. Tin trnh hnC 4 loi lin kt hn

a. Hn gip mi c. Hn ch T d. Hn chng

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Cc bc tin hnh+ Bc 1: chun b - Kim tra que hn, kim tra vt liu hn, tnh ra dng in hn v iu chnh trn my hn. - V sinh v tr hn (dng chi st qut sch bi bn, r st v tr hn) - nh v chi tit hn. - Cc dng (tay hn)kp que hn,cc m cho tip xc vi chi tit hn(tip mt) . Khi kp trnh kp vo phn thuc cho mch in hn l khp kn.. + Bc 2: ly la C 2 cch ly la to h quang. - M c:m nh nhng vo chi tit gy ra h quang Sau khi ly c h quang th a tay v v tr u mi hn. - Qut dim: qut que hn vo vi tr u mi hn qut dc theo vt hn ly la .Khi c h quang th li a tay v v tr u mi hn - Ly la bng cch qu dim d hn m c nhng gy ra khuyt tt trn sn phm. Ch ly la bng cch qut dim khi que hn b m, khi dng in thp hoc khi tay ngh ngi th cha cao. - Gc hn: Gc ca que hn hp vi trc Ox mt gc = (75 - 85) hp vi trc Oy mt gc = 90 + Bc 3 : Duy tr v thot que hn . duy tr c dng h quang n nh v lp y mi hn th que hn cn c hai chuyn ng. - Chuyn ng Sng t c b rng mi hn 6 - 8 mm - Chuyn ng Sd chy ht mi hn C th a que hn theo 2 cch: - Theo ng l xo (xon c) Theo ng rch rc + Thot que hn: Khi kt thc mi hn khung c rt que hn ra khi mi hn ngay nu rt que hn nh vy s lm thi thng vt hn. kt thc mi hn cn a que hn quay li mt on ri mi rt que hn.(on quay li ny c bc mt lp s bo v trn ln khng gy ra hin tng thi thng) - Sau khi hn xong cn g s kim tra mi hn.

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Bi 3 + 5: Cc phng php gia cng tin tin.TNG QUAN V CC PHNG PHP GIA CNG C BIT 1.1 NHU CU V CC PHNG PHP GIA CNG C BITGia cng c truyn thng (v d nh tin, khoan, phay) dng dng c dao ct tch phoi ra khi b mt gia cng nh bin dng ph hy. Ngoi cc phng php gia cng truyn thng ny, c mt h cc phng php gia cng s dng c ch khc tch vt liu. Thut ng "gia cng c bit" hay "gia cng khng truyn thng" lin quan n nhm cc phng php gia cng tch phn vt liu d bng cc k thut khc nhau lin quan n nng lng nhit, c, in, ha hoc kt hp cc dng nng lng ny. Nhng phng php ny khng s dng dao ct khi gia cng nh thng thng. Cc phng php gia cng khng truyn thng c pht trin t sau th chin th hai nhm p ng nhng nhu cu gia cng c bit v mi m cc phng php gia cng truyn thng khng th gii quyt c. Nhng nhu cu c tm quan trng v mt thng mi v cng ngh ca cc phng php gia cng c bit bao gm: - Nhu cu gia cng nhng vt liu kim loi v phi kim mi pht trin. Nhng vt liu mi ny thng c cc tnh cht c bit nh sc bn, cng v do cao, rt kh gia cng bng phng php ct gt thng thng. - Nhu cu gia cng nhng chi tit hnh hc phc tp, bt thng, kh hoc khng th gia cng c bng cc phng php truyn thng. - Nhu cu trnh lm hng b mt ca chi tit do s xut hin cc ng sut pht sinh trong gia cng truyn thng. i vi cc thit b, ngi ta dng cc loi vt liu c bn ring sb /g cao. Trong s c th k cc hp kim Titan, cc loi thp bn cao v siu bn, cc loi vt liu phi kim loi (composite, si thy tinh, vv.). Cc hp kim Titan cng c bn vi thp hp kim dng trong ch to my (sb = 60 -140 kg/mm2) nhng khi lng ring ch bng mt na (g = 4,8 g/cm3), ng thi li c tui th chng n mn cao trong hu ht cc mi trng khc nghit. Gia cng ct gt cc chi tit lm bng nhng vt liu mi thng rt kh khn v trong mt s trng hp l khng th c (hnh 1.1). V l do khi thit k my mi, i khi phi s dng cc loi vt liu c cc tnh cht s dng cha phi l hon thin nh mong mun nhng li c cc tnh cht cng ngh t yu cu. iu ny lm gim i cc c tnh lm vic v cc c trng cht lng ca my. V vy trn th gii hin nay tng ng vi cc vt liu mi c pht minh ngi ta phi tch cc tm kim cc phng php gia cng mi gia cng nhng vt liu ny.

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1.2 PHN LOI CC PHNG PHP GIA CNG C BIT 1.2.1 Cc c trng phn loi.Ngi ta phn loi cc phng php gia cng c bit theo cc c trng sau y: a. Loi nng lng a vo vng gia cng : c, in , ha v nhit. b. Phng php a nng lng vo: c xc nh bi v tr tng quan gia phi v cc b mt lm vic ca dng c trong khng gian v bi s thay v tr ny theo thi gian. V d: c th a nng lng dng in vo phn c bn ca b mt chi tit gia cng bng cch cho tip xc trc tip thng qua knh in tch hoc kt hp. - Trng hp th nht: tip xc c thc hin theo cc nhp nh t vi gia cc b mt dng c v phi. phng php ny c s dng khi gia cng in tip xc vi in p n 20 V. - Trng hp th hai: a dng in i theo mt knh in tch l c s ca gia cng tia la in . Trong trng hp ny ngi ta s dng in tch dng tia la hoc in tch dng cung h quang. c. nh tn gi ca phng php gia cng. Nhng qu trnh l ha c bn khi ly i vt liu l bin dng n hi km vi ph hy do hoc dn, nung chy, bay hi, ha tan anod, ph hy bng n mn.

1.2.2 Phn loi theo nng lng a vo vng gia cng.a. Gia cng c. . Gia cng c bng ct gt, thng thng c tc ng c u n trn vt liu. Ct vi rung ng tn s thp c s dng b gy phoi. Ct vi rung ng tn s cao m bo ci thin kh nng gia cng ca vt liu. . Gia cng siu m s dng tc ng c c chu k ca cc ht mi xy ra vi tn s siu m. . Ct c nung nng s b vt liu lp ct nhm s dng tc dng nhit ph thm, ct c a dng in vo vng hnh thnh phoi l tn dng tc ng dng in b sung. . Cc phng php gia cng ct gt kt hp s dng ng thi mt s loi tc ng bc vt liu. Chng hn gia cng c - anod s dng ng thi cc tc ng in, ha v c. . Gia cng c khng truyn thng bao gm mt s phng php sau y: gia cng tia nc, gia cng tia nc c ht mi, gia cng dng ht mi. b. Gia cng ha. . Gia cng ha s dng trc tip nng lng ha cho cc mc ch cng ngh. Trong trng hp ny lp kim loi c bc i trong mt mi trng ha c tc ng tch cc. 13

Phng php gia cng ha ph bin nht hin nay l n mn su theo ng vin (phay ha). Phng php ny c th iu khin thi gian v v tr n mn kim loi trong mi trng axt v kim. Ngoi ra cn c mt s phng php khc nh: to phi ha, khc ha, quang ha, m ha, v.v. c. Gia cng in. . Gia cng in s dng trc tip nng lng in cho cc mc ch cng ngh bng cch a nng lng ny vo vng ct khng qua bin i trung gian sang cc dng nng lng khc. Nng lng in c chuyn trc tip sang dng nng lng khc nh nhit, ha, v.v. trong qu trnh bc i lp kim loi ca phi. Cc phng php gia cng in bao gm in ha (s dng tc ng ha ca dng in), tia la in (s dng tc ng n mn ca dng in), in nhit v in c (s dng tc ng nhit v c ca dng in). Gia cng tia la in: c thc hin bng in tch, lm pht sinh s ph hy v n mn kim loi. Gia cng in ha: c thc hin bng dng mt chiu c in p thp trong mi trng c cht lng dn in lu thng (cht in phn). Vt liu c bc i l do s ha tan anod, ngha l bin i nng lng in thnh nng lng ca cc lin kt ha hc. Kt qu l vt liu c chuyn thnh cc hp cht ha hc v c bc i d dng khi vng gia cng. Gia cng c in: s dng tc ng c ca dng in. Mt trong cc phng php loi ny l gia cng in thy lc, s dng tc ng ca cc sng va p pht sinh do kt qu ca s nh thng do xung ca mi trng cht lng v s to hnh in t ca vt dn in vi t trng cm ng trong phi. d. Gia cng nhit. . Gia cng nhit dng nng lng nhit ct hoc to hnh dng chi tit gia cng. Nng lng nhit thng c cung cp n mt phn rt nh ca chi tit gia cng, lm cho phn ny nng chy v bc hi tch ra khi b mt gia cng. Nng lng nhit c sinh ra bi s bin i nng lng in. . Gia cng chm tia: s dng tc ng ca chm tia tp trung vi mt nng lng rt cao kt qu l vt liu c ly i do s bin in nng trc tip sang nhit nng. Mt s phng php loi ny l gia cng tia in t, gia cng laser, gia cng tia la in, nh sng kt hp v ion.

1.2.3 Cc phng php gia cng kt hp.Con ng trin vng nht xy dng cc phng php gia cng mi c hiu qu l to ra cc phng php gia cng kt hp. Hin nay ngi ta a vo cc phng php mi nh : gia cng c anod vi rung ng tn s thp v siu m, khoan rung ng ng thi a dng in vo vng ct, gia cng c ha ng thi a vo ct thng v ct rung, gia cng tia la in v in ha vi dao ng siu m ca in cc, cc phng php to mu nhanh. a. Cc phng php gia cng trn c s ca tc ng ha v c ng thi: gia cng ng thi a vo vng ct cc dung dch trn ngui c hot tnh cao l gia cng ha c. Gia 14

cng ha c l phng php ly kim loi nh cc phn ng ha hc gia b mt gia cng v mi trng cng ngh ng thi c tc ng c lm tng cng qu trnh. b. Cc phng php gia cng trn c s tc ng nhit c: ct c nung nng s b phi, ct c nung nng lin tc vt liu lp ct trong qu trnh chuyn ng ca dao v.v... c. Cc phng php gia cng trn c s kt hp cc tc ng c v rung ng vi cc dng tc ng c u n hoc cc tc ng vt l khc: ct c rung ng, ct va p gin on, ct c siu m, cc phng php gia cng c in ha, tia la in c b sung dao ng siu m trn dng c. d. Cc phng php gia cng trn c s kt hp tc ng in vi cc dng tc ng khc: gia cng in tip xc, c anod, ht mi anod, in n mn ha, cc phng php gia cng xung in, gia cng n (ly vt liu bng cch s dng cc xung nng lng cao), gia cng in thy lc, gia cng in t v.v. e. Cc phng php to mu nhanh: ng dng cng ngh CAD/ CAM c th ch to nhanh chng nhng chi tit mu c hnh dng ba chiu phc tp nhm to nhng sn phm c cht lng cao tung ra th trng trong khong thi gian ngn nht vi gi c cnh tranh. Cc phng php to mu nhanh bao gm mt s phng php nh: phng php to mu lp th (SLA), phng php x l trn c s khi (SGC), phng php ch to vt cn mng (LOM), phng php ct dy, phng php p, v.v.

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Bi 4:

K thut o lng c kh v cc dng c o c bnThc cp, banme ng h s:1. Thc cp ( caliper )L dng c c tnh a dng (o kch thc ngoi, kch thc trong, o chiu su) phm vi o rng, chnh xc tng i cao, d s dng, gi thnh r Cu to:

Phn loi: - Thc cp 1/10: o c kch thc chnh xc ti 0.1mm. - Thc cp 1/20: o c kch thc chnh xc ti 0.05mm. - Thc cp 1/50: o c kch thc chnh xc ti 0.02mm. Cch o: - Trc khi o cn kim tra xem thc c chnh xc khng. - Phi kim tra xem mt vt o c sch khng. - Khi o phi gi cho hai mt phng ca thc song song vi kch thc cn o. - Trng hp phi ly thc ra khi v tr o th vn c hm c nh hm ng vi thn thc chnh. Cch c tr s o: - Khi o xem vch 0 ca du xch v tr no ca thc chnh ta c c phn nguyn ca kch thc trn thc chnh. - Xem vch no c a du xch trng vi vch ca thc chnh ta c c phn l ca kch thc theo vch ca du xch (ti phn trng)

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+ c gi tr n 1.0mm: c trn thang o chnh v tr bn tri ca im 0 trn thanh trt. Nh hnh l 45mm. + c gi tr phn thp phn: c ti im m vch ca thc trt trng vi vch trn thang o chnh. Nh hnh l 25mm. + Cch tnh ton gi tr o: ly hai gi tr trn cng vo nhau (gi tr th hai nhn vi sai s ghi trn thn thc. v d: 0.02mm). G tr trn hnh l 45 + 25x0.02 = 45.5mm. - Hoc v d:

2. Panme ( micrometer )Panme l dng c o chnh xc, tnh vn nng km (phi ch to tng loi panme o ngoi, o trong, o su) phm vi o hp (trong khong 25mm). Panme c nhiu c: 0-25, 25-50, 50-75, 75-100, 100-125, Phn loi: - Theo bc ren - Theo cng dng Cu to:

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1. ng trt; 2. ng xoay; 3. du xch 1mm; 4. ng chun trn ng trt; 5. du xch 0.5mm

Cch o: - Trc khi o cn kim tra xem panme c chnh xc khng. - Khi o tay tri cm panme, tay phi vn cho u o n gn tip xc th vn nm vn cho u o tip xc vi vt ng p lc. - Phi gi cho ng tm ca hai m o trng vi kch thc cn o. - Trng hp phi ly panme ra khi v tr o th vn ai c hm ( cn hm ) c nh u o ng trc khi ly panme ra khi vt o. Cch c tr s: - Khi o da vo mp thc ng ta c c s mm v na mm ca kch thc trn thc chnh. - Da vo vch chun trn thc chnh ta c c phn trm mm trn thc ph ( gi tr mi vch l0.01 mm ). + c ti gi tr o n 0.5mm: c gi tr ln nht c th thy c trn thang o ca thc panme. Nh hnh trn l55.5mm. + c gi tr t 0.01mm n 0.5mm: c ti im m thang o trn ng xoay v ng chun trn thc panme trng nhau. Nh hnh v l0.45mm. + Tnh ton gi tr o: ly hai gi tr o c trn cng vi nhau: 55.5 + 0.45 = 55.95mm. 18

3. ng h s ( indicator )c im v cng dng: - L dng c o chnh xc ti 0.01, 0.001mm. ng h in t cn chnh xc hn. - ng h s dng nhiu trong vic kim tra sai lch hnh dng hnh hc v v tr ca chi tit nh cn, thng, song song, vung gc khng ng trc. - ng h s cn kim tra hng lot khi kim tra kch thc bng phng php so snh.

Cch s dng: - Khi s dng ng h so, trc ht phi g ln gi vn nng hoc ph kin ring. Sau chnh cho u o tip xc vi vt cn o. - iu chnh mt s ln cho kim ng v tr s 0. Di chuyn ng h tip xc sut trn b mt cn kim tra.

Bi 6:19

Cc sn phm do v ngnh c kh nghin cu cc sn phm do

Cht do

Hnh dng phn t PolymerCht do, hay cn gi l nha hoc polymer, l cc hp cht cao phn t, c dng lm vt liu sn xut nhiu loi vt dng trong i sng hng ngy cho n nhng sn phm cng nghip, gn vi i sng hin i ca con ngi. Chng l nhng vt liu c kh nng b bin dng khi chu tc dng ca nhit, p sut v vn gi c s bin dng khi thi tc dng.

Phn loiPhn loi theo hiu ng ca polyme vi nhit 1. Nha nhit do: L loi nha khi nung nng n nhit chy mm Tm th n chy mm ra v khi h nhit th n ng rn li. Thng tng hp bng phng php trng hp. Cc mch i phn t ca nha nhit do lin kt bng cc lin kt yu (lin kt hydro, vanderwall). Tnh cht c hc khng cao khi so snh vi nha nhit rn. Nha nhit do c kh nng ti sinh c nhiu ln, v d nh: polyetylen (PE), polypropylen (PP), polystyren (PS), poly metyl metacrylat (PMMA), poly butadien (PB), poly etylen tere phtalat (PET), ... 2. Nha nhit rn: l hp cht cao phn t c kh nng chuyn sang trng thi khng gian 3 chiu di tc dng ca nhit hoc phn ng ha hc v sau khng 20

nng chy hay ha tan tr li c na, khng c kh nng ti sinh. Mt s loi nha nhit rn: ure focmadehyt [UF], nha epoxy, phenol focmadehyt [PF], nha melamin, poly este khng no... 3. Vt liu n hi (elastome): l loi nha c tnh n hi nh cao su.

Phn loi theo ng dng1. Nha thng dng: l loi nha c s dng s lng ln, gi r, dng nhiu trong nhng vt dng thng ngy, nh: PP, PE, PS, PVC, PET, ABS,... 2. Nha k thut: L loi nha c tnh cht c l tri hn so vi cc loi nha thng dng, thng dng trong cc mt hng cng nghip, nh: PC, PA,... 3. Nha chuyn dng: L cc loi nha tng hp ch s dng ring bit cho tng trng hp.

Phn loi theo thnh phn ha hc mch chnh1. Polyme mch cacbon: polymer c mch chnh l cc phn t cacbon lin kt vi nhau: PE, PP, PS, PVC, PVAc, ... 2. Polyme d mch: polymer trong mch chnh ngoi nguyn t cacbon cn c cac nguyn t khc nh O, N, S... V d nh PET, POE, poly sunfua, poly amit, ... 3. Polyme v c nh poly dimetyl siloxan, si thy tinh, poly photphat,...

Kt lun chung21

- Qua t thc tp c s ny bn thn em nm c phn no kinh nghim gia cng trn cc my cng c. Nm c mt s c cu truyn lc, dn ng, c cu thay i tc , n khp...vv. c lm quen vi cc thut ng chuyn ngnh ca ngi lm c kh Trn my tin c mm cp ba chu nh tm, trn my khoan c b g to. - Qu trnh thc tp l qu trnh c gng hc tp tm ti ca cc bn sinh vin, l s ch bo tn tnh ca cc thy hng dn. Qua thy v tr hiu nhau hn, cc bn sinh vin trong lp thm gn kt.Qua ln thc tp em thy c nhng tng trong sn xut khng ch l ca nhng ngi i trc m c nhng bn trong t thc tp. Mt ln nhn li mnh so snh em cm thy mnh cn hc tp nhiu hn na, rn luyn nhiu hn na. - t thc tp c s ngnh ny cng vi nhng kin thc c bn t cc mn hc i cng nh hng ni dung, lnh vc chuyn ngnh s o to c c s chun b tt hn cho mn hc sau, to nim say m khi hc. t thc tp l iu kin hc tip v l cn thit hc tt cc mn hc chuyn nghnh tip theo . Em xin chn thnh cm n s hng dn tn tnh ca cc thy c!

..THE..END.

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