TRNG I HC NHA TRANG KHOA C KH B MN CH TO MY

GVHD: Ts. Nguyn Vn Tng SVTH: Phan Vn Hiu Nguyn Trn Phi Hong Nguyn Xun Hong Phan Minh Hng Phm Tn Ha

13.1 Gii thiu chung. Nhng my phay hin i th c v ging nh cc loi c sn xut cch y 25 nm. Tuy nhin chng by gi phi ct c siu hp kim, titan, thp c bn ko cao dung sai gn hn, v tc nhanh hn trc y. x l cc yu cu ny, cc my phay cung cp m lc ln hn, cng cao hn v tc ln hn, lng chy dao rng hn. Thm vo vt dn chnh xc hn trc, iu khin s (CN) v iu khin trn my tnh (CNC) tt c cc kt qu trong cng vic nhanh hn, hon tt tt hn trc. Hnh 13.1 l 1 my phay ng CNC hin i. 13.2 Cc loi my phay. Nhiu loi my phay c s dng trong sn xut c nhm thnh 3 nhm chung. My phay cng-xn. My phay ging. My phay chuyn dng. Chng ta s bn v tng loi my di y. 13.2.1 My phay cng-xn. My phay cng-xn hot ng theo c hai chiu dc v ngang. Cc s ( hnh 13.2a v 13.2b) cho ta thy c hai kiu my ny. Tnh linh hot l tnh nng ch yu ca my phay cng-xn. Da vo my c bn ca loi ny, bn my, bn dao, gi c th xoay chuyn c. nhiu ph tng nh -t vn nng, bn xoay, chia, tng thm tnh linh hot cho loi my ny. Khng xt n loi my dc hay ngang, mt vi cu to ca my phay cng-xn tng t nhau. Ngoi tr l khc nhau v kch c, v mt vi im nh bi v s u tin ca nh sn xut. Nhng im tng ng c m t l hnh dng chung, mi quan h hnh hc vi phn cn li ca my, chc nng v vt liu m t cc thnh phn c thc hin. Hnh 13.3a l mt my phay dc tiu chun v hnh 13.3b l mt my phay dc CNC 3 trc. Tr my: thng c c lin vi b my, c c bng gang xm hoc gang do. Tr cc trc chnh, vng bi, v cc bnh rng cn thit, ly hp, trc, my bm, v c cu chuyn dch truyn nng lng t ng c in n trc chnh vi tc c chn. Cc bnh rng thng c chy trong du v c lm bng thp hp kim cacburizit cho bn cao. Mt s iu khin cn thit c gn vo kch thc ca tr. C s thng rng, v trong nhiu trng hp phc v nh thng ng nc thi cho cc cht lng ct. Mt ci bm , mt h thng lc c th c ci t trong c s. L trung tm ca cc c s h tr cho cc vt lm tng v gim gi cng-xn.

Bn trt ng bng my trn mt trc ca tr my c th c hnh vung hoc kiu mng. Gi cng-xn di chuyn ln xung theo ng trt ny. Cc ng trt phi c gia cng mt goc 90o mt ca ct trong c hai loi my ngang v dc. Cc dung sai l rt nh v thng c biu din trong vi pht hoc vi giy ca cung. L ln khi kt hp vi tr c to thnh cc trc chnh. L rt chnh xc chn vung gc vi mt trc hai mt phng v song song vi vic trn trnh chiu. Trc chnh: trn mt my phay ngang, trc chnh l mt phn quan trng nht. N thng c gia cng hp kim rn v x l nhit chng mi mn, rung, lc y v ti un. Trc chnh ny thng c h tr ca s kt hp t qu bng v vng bi ln thng, hoc nhn c c hai ti xuyn tm v ht lc y. Nhng trc chnh rng mc ko c th c s dng gi an ton trong v tr trc gia. Mt trc trc chnh c ch to p ng tiu chun ca trc chnh. Hai cht ph hp vi khe cm tng ng trong cc trc gia to nn truyn ng thc t ca cc trc. Cc cn ni b, ci m ci t c s ng n v vy n ng tm vi trc chnh y, nh v cc trc. Gi cng-xn: gi cng-xn l mt vt c m c di chuyn ln hay xung cc ng trt trn mt trc ca ct bng vt nng cao. Hai khp nhau hay vung gc trt c gia cng 90o vi nhau. Cc ng cng trt theo chiu dc vi cc mt trc ca ct, v trt ngang mang bn trt. N bao gm cc thit b cn thit, c vt v cc c ch khc cung cp ngun in, cung cp d liu theo mi hng. Ngi thc hin c th la chn nhng tc khc nhau vi cc iu khin gn trn gi cng-xn. Bn trt: bn trt cho my phay l mt vt c vi hai ng trt c ch to gc 90o. Cc ng trt thp hn ph hp vi cc ng trt trn nh tr my v chp nhn trt trn cnh y ca bn my. Cc b mt ca ng trt lm cho lin h gia tr my vi bn my song song vi nhau. kha cho trt ngang v c hai bn c trang b cho yn xe, cng vi nhng ht m hot ng v s tin ngang v nhng bc tin ca bng vt. Trn mt my phay vn nng, bn trt c lm thnh tng mnh v phc tp hn v n phi cho php xoay c mt vng cung hn ch. Cc phn di c mt ng dn trt dng ui n ph hp vi phn trn ca gi cng-xn v mt bn trt trn trn n l bc chia cho mt phn nh ca vng ngoi vi ca n. Phn trn ca bn dao bao gm mt mt trn ph hp vi bn trt, mt mi trc trung tm, v mt ng dn trt dng ui n chp nhn bn my. Kha cht di chuyn trong mt khe trn ch T c cung cp hai phn ca bn dao c th v tr bt k. BN MY: bn my rt khc nhau v kch thc, nhng nhn chung chng c cng mt c im vt l. Phn di ca bn my c mt ng dn trt dng ui n trng hp vi s trt trn bn dao. N cng c vng bi 2 u mang vt dn hng bn my. u bn my c gia

cng song song vi bn trt pha di v c 1 s di ton b khe ch T cho lp -t hoc g lm vic khc. Mt mt chia trong phn nghn ca Inch c cung cp di chuyn chnh xc v v tr cuarbanf my. Vt dn hng bn my thng c mt ren Acme. My phay vi trc thng ng (hnh 13.3a)c mt lng ln cc chng loi v kch c.,trc chnh,ng c, v iu khin an dao,l hon ton vn nng v c th t mt gc y so vi b mt ca bn my. Ba thy ng , m ng u c c nh , c th c di chuyn v pha trc v tr li v b kho v tr bt k. Mt bn giao rvonve trn u tr my cho php lp v ba thy ng lp chiu ngang, tng bn knh nh hng i vi my. Mt s ba thy ng ca my phay c th s dng cho c phay dc v phay ngang. Trn loi my dc c ba thy ng c ng c trong tr my, lc c truyn ti trc chnh bng bnh rng v trc then hoa. Mt s my siu mnh thng ng c mt trc chnh v c cm trn c th duy chuyn ch theo chiu dc bng lc hp s t ng hoc bng tay. Chng thng c bit n nh la loi my phay c tay thng ng. 13.2.2 My phay ging. Sn xut nh cao ku gi ct mnh, v cng ca loi may phay cng-xn khng c lc ct cao. Mt loi my phay ging thng l tng cho loi cng vic nay. my ny, bn my c h tr trc tip trn mt ging ln, trong khi tr my t sau ging. Mt my phay ging CNC c th hin hnh 13.5, v mt thit lp hot ng hnh 13.6. C mt s li th ca my phay ging, c bit cho chy sn xut. Bc tin thy ng l c th c, cc thnh phn thy lc ang c t trong b my c. iu ny cho php lc ct rt ln, c th bin i t l bc dao trong khi ct, v t ng xoay vng bn my. Trc chnh c th nng ln hoc h xung bi c cu cam v mu sn xut ng nt c bit. Vic cu to nng n hn cho php nhiu lc hn cung cp cho cc trc chnh, cho php nng sut cao hn thng qua vic loi b kim loi nhanh hn. Loai my phay ging kp c hai tr my v trc chnh phay hai mt trn mt phn cng mt lc. Mt my phay ging ln CNC 5 trc c th hin hnh 13.7. Nhng bt li chnh ca loi my phay ging so vi mt trong cc loi cng-xn l n t linh hot cho cc b phn gia cng nh. Li th ca n nm nng sut cao hn, kh nng thch nghi ca n n cc my c kch thc ln, v n d dng thay i cc ng dng c bit.

13.2.3 my phay chuyn dng. Cc sn phm cng nghip tr nn phc tp hn, cc my phay mi v khc thng c pht trin. Mc tiu l ph hp vi cng vic ln hn, lm nhiu bn sao cc b phn, xc nh v tr cc l v cc b mt mt cch chnh xc hoc lm cng vic gia cng khc. My phay loi ging Cc chi tit chung ca loi my ny tng t nh my phay bo ( chng 7 ). Ngoi tr nhng v tr ca nhng mi khoan ring v u my phay c ci t trc. B mt ca my nng b phn iu khin vng quay u my ct. l b phn chy vi cng sut ring v c th chy vi tc khc nhau nu cn thit. c 4 my ct c s dng, 2 chic trn khung ( gi) trn thanh ngang v 2 chic trn tr thng. V d minh ha ca cc loi my phay c biu din trong hnh 13.8, 1 phn trong b phn ca cc loi my phay c biu din hnh 13.8b. My phay loi ging c s dng hu ht trong nhiu phn ca my ging nh bedways dng cho nhng cng c my ln v vt cha thnh phm khc. Chng yu cu tht chnh xc v nhm, b mt gc cnh v cc ng khe rnh. My phay chp hnh : 2 kch thc mt nghing c to ra bi s dng 1 khun ct kim loi hoc vi 1 my phay thng c iu khin bng s. Mt s mt nghing c nhiu mnh vn v mt s lng bn sao c sn xut trong mi chu k. Loi my chy bng hi nc c 1 kim nhn dc theo khun ct kim loi c a vo kt ni vi khun ct kim loi iu khin b iu hnh. Ngi iu khin my sau khi di chuyn mi kim dc theo kim ct kim loi to ra bi cht lng di 1 p sut theo sau nhng vng quay chnh xc. B mt di chuyn b phn iu khin my ct sao chp hnh dangh ca khun ct kim loi. mt b iu hnh mt nghing ca my s dng mt u mi my ct kim loi biu din hnh 13.9a. C 5 trc v cc loi trc quay ca my phay mt nghing c biu din hnh 13.9b. im cht chm v cc qu trnh lin quan n vic gia cng khc bao gm nhng khoang ca my c th dc lm trn 3 kch thc ca mt nghing. Mt m hnh chnh xc ca mt khoang c lm t g, nha hoc kim loi nh. u mi kim c i theo ng vin ca m hnh, hng my ct nh iu hnh ngoi khoang. Cc ch s iu khin trong my cng c s dng cch lm vic ca loi my ny.

13.3. H thng iu khin my. C nhiu tiu ch my c tho lun trong chng trc ca gio trnh, l s hot ng b iu hnh tt ca my v d nh 1 chic my tin c hot ng tt cu vng xoay, mi khoan

Tuy nhin, khi tng t l sn xut ln yu cu c 1 im ta ca 1 my b sung 1 cch hon ho. hiu qu kinh t v kh thi hn l im ta vo cc chc nng khc ca nhng my thay i nhanh cc my cng thi v nhng my gia cng t ng Cm t t ng ha c dng vo nhng nm 1920 v c ng dng pht minh cho cc b phn t ng np d liu hoc khng th np. hin nay t ny c chp nhn s dng rng hn. Hn na, b phn np d liu c chc nng ging nh quy trinh, tiu chun, kch thc nng vt cha thnh phm, iu chnh my duy tr kch thc v lp li cc chu k hot ng. H thng iu khin my c cp trong bi ny s c coi l trng tm ca my v nhng h thng my linh hot.