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CHUYN CNC

Nhm 4

TRNG I HC GIAO THNG VN TIKHOA C KHB MN K THUT MY

g trn my CNC

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BO CO CHUYN CNCTM HIU G TRN MY CNCNhm sinh vin thc hin : Nhm 04 Nguyn Ngc Quyt o Duy Thanh Vng Khc Nht Lp : C in T - K46 Trng : i Hc Giao Thng Vn Ti GVHD : T.S Nguyn Hng Sn

H Ni 10/2009 GVHD : T.S Nguyn Hng Sn Trang 1

CHUYN CNC

Nhm 4

N

LI M U

g trn my CNC

h chng ta bit trn cc my cng c thng thng v c bit l trn my cng CNC th g l b phn quan trng v khng th thiu c. Cht lng sn phm c kh, nng sut lao ng v gi thnh l nhng ch tiu quan trng trong sn xut c kh. m bo cc ch tiu trn, trong qu trnh ch to cc sn phm c kh, ngoi my ct kim loi (my cng c) v dng c ct, chng ta cn cn c g v cc dng c ph (gi l trang b cng ngh). Trang b cng ngh ng vai tr rt quan trng, nh n sn xut c kh c th m bo nng sut v nng cao cht lng, tng nng sut v h gi thnh sn phm. c bit trong thi bui cng ngh ang pht trin, sn xut khng cn l c kh n thun na, n c tch hp iu khin, cc h thng truyn lc c iu khin m bo chnh xc gia cng cao, nng sut ln, chng ta c th d thy my cng c CNC (Computer Numerical Control). V vy g trn my CNC c ci tin c th iu khin t ng, d dng tho lp, t chnh xc cao, ph hp vi tc lm vic ln ca my v m bo tnh kinh t. Cng v l do nh vy nn nhm chng em cng nhau tm hiu v cc thit b g trn my CNC hiu r hn v n, nghin cu k v k thut cng nh nguyn l lm vic ca g.

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CHUYN CNC

Nhm 4

MC LCPHN I :GII THIU CHUNG V G TRN MY CNG C CNC.......................................................................................................................5 c im ca g trn my cng c CNC :.........................................5 Yu cu i vi chi tit gia cng trn cc my CNC :............................5 Phn loi g trn my CNC : .............................................................6 g vn nng khng iu chnh :....................................................6 g vn nng iu chnh :................................................................9 g chuyn dng iu chnh :..........................................................9 g vn nng lp ghp : .............................................................10 g lp ghp iu chnh :...............................................................11 g chuyn dng :..........................................................................12 PHN II: TM HIU V G TRN MY TIN............................14 2.1. g trn my tin CNC:..............................................................14 2.1.1. Mm cp:.................................................................................17 2.1.2. Kp rt : ..................................................................................19 2.1.3. Tc cp-Mi tm :...................................................................20 2.1.4. Trc g bung:...........................................................................22 2.1.5. Mn hoa :.................................................................................23 2.1.6. Luy-nt :...................................................................................24 PHN III : TM HIU V G TRN MY PHAY.....................25 3.1 Gii thiu chung .............................................................................25 3.2 g kp c kh ............................................................................27 3.2.1 Bn kp.....................................................................................27 3.2.2 u phn ..............................................................................28 3.2.3 -t...........................................................................................28 3.3 g kp thy lc v kh nn .......................................................31 3.3.1 -t kh nn ,thy lc...............................................................31 GVHD : T.S Nguyn Hng Sn Trang 3 g trn my CNC

CHUYN CNC

Nhm 4

2.2.3 g kp bng t tnh .............................................................36 PHN II : MT S LOI G C BIT:....................................37 g trn my CNC

2.1. g bn xoay:..............................................................................37 Phn loi :..............................................................................................37 Loi tiu chun :................................................................................37 2.1.2. Loi bn xoay c ng c lp pha sau :.................................38 2.1.3. Loi bn xoay c l trc chnh ln :.......................................39 2.1.4. Loi bn xoay c nhiu trc :................................................39 2.1.5. Loi bn xoay nghing :.........................................................40 ng dng :.............................................................................................41

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Nhm 4

PHN I :GII THIU CHUNG V G TRN MY CNG C CNCc im ca g trn my cng c CNC :Mt trong nhng c im chnh ca my cng c CNC l tnh chnh xc rt cao. g trn cc my nh hng rt ln ti chnh xc gia cng bi v sai s chun khi nh v chi tit trn g l mt trong nhng thnh phn sai s tng cng. g trn my CNC phi m bo chnh xc g t cao hn cc g trn my vn nng thng thng. m bo chnh xc g t phi chn chun sao cho sai s chun bng 0, sai s kp cht phi c gi tr nh nht, im t ca lc phi trnh gy bin dng cho chi tit gia cng. Cc my CNC c cng vng rt cao, do g trn cc my khng c lm gim cng vng ca h thng cng ngh khi s dng my vi cng sut ti a. iu c ngha l g trn cc my CNC phi c cng vng ln hn cc g thng thng khc. V vy, g trn cc my CNC phi c ch to t thp hp kim vi phng php ti b mt. Khi gia cng trn my CNC, cc dch chuyn ca my v dao c bt u t gc ta , do trong nhiu trng hp g phi m bo s nh hng hon ton ca chi tit gia cng, c ngha l phi hn ch tt c cc bc t do khi nh v g trn my (phi nh hng g trn c hai phng ngang v dc ca bn my). Trn cc my CNC ngi ta c gng gia cng c nhiu b mt chi tit vi mt ln g t, do cc c cu nh v v kp cht ca g khng c nh hng n dng c ct khi chuyn b mt dng c gia cng. Phng php kp cht c hiu qu nht l kp cht b mt i din vi b mt nh v.

g trn my CNC

Yu cu i vi chi tit gia cng trn cc my CNC :Chi tit gia cng trn my CNC nh hng n kt cu ca g, do phi m bo c nhng yu cu sau y: + Chi tit gia cng phi c nhng b mt chun tt m bo chnh xc v n nh g t, ng thi chi tit phi c b mt thun tin cho vic kp cht, khng gy bin dng chi tit. GVHD : T.S Nguyn Hng Sn Trang 5

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+ khng phi dng g ph th chi tit khng nn c b mt nghing v gc nghing. + m bo chnh xc g t cao, chi tit phi c nh v theo 3 b mt. Trong trng hp ny c th dng cc b mt qua gia cng trn cc my vn nng nh v. + Nu chi tit gia cng khng cho php nh v theo 3 b mt th nh v theo mt b mt v hai l, khong cch cc l phi cch xa nhau v c bng cp 7. g trn my CNC

Phn loi g trn my CNC : g vn nng khng iu chnh g vn nng iu chnh g chuyn dng iu chnh g vn nng lp ghp g lp ghp iu chnh g chuyn dng g vn nng khng iu chnh : Loi g ny c cc chi tit c iu chnh c nh g nhiu loi chi tit gia cng khc nhau trong sn xut n chic v lot nh. l cc loi mm cp c dng truyn mmen xon cho chi tit gia cng. C 3 loi mm cp thng c dng trn cc my tin CNC (ngoi mm cp 3 v 4 chu thng dng).

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CHUYN CNC

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g trn my CNC

Hnh 1: Mm cp 3 chu

Hnh 2: Mn cp 4 chu

Mn cp ly tm (mm cp qun tnh): Loi mm cp ny c hai hoc ba chu kp. Cc chu l nhng chi tit c lp vi nhau, khi quay di tc dng ca lc ly tm chng kp cht chi tit v nh lc cn t hm m chi tit gia cng khng b x dch d b tc dng ca lc ct. Mm cp c chn mt u cng : Mm cp c chn mt u cng xc nh chnh xc mt u ca tt c cc chi tit gia cng theo truc Z. Lc kp chi tit sinh ra nh mi tm sau. Nu mt u ca chi tit khng vung gc vi tm ca n th cc mt u n vo chi tit gia cng khng u nhau, iu lm gim mmen xon c truyn t trc chnh ca my.

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CHUYN CNC

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g trn my CNC

Hnh 3: 1 Thn; 2 L xo; 3 Mi tm; 4 Chi tit t mt u 5 Chn mt u bng hp kim cng; 6 Chi tit gia cng

Mm cp c chn mt u ty ng : Cc mt u c dng trn xoay c lp vo l c cha cht do. Khi chi tit gia cng c kp cht t mi tm sau, mt u bn tri ca chi tit y cc chn mt u v bn tri v lm cho p lc ca cht do tng ln. Nh vy, tt c cc chn mt u u tip xc vi chn mt u chi tit cn gia cng v lc kp tc ng ln cc chn hu nh bng nhau. Mm cp mt u c chn ty ng to ra mmen xon ln hn so vi mm cp mt u cng. Loi mm cp ny c th dng kp chi tit gia cng th. S chn mt u c th l 8, 10, 12 v.v.

Hnh 4: 1 L xo; 2 Thn; 3 Cht do 4 Chn mt u; 5 Mi tm

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CHUYN CNC

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g vn nng iu chnh : Kt cu g vn nng iu chnh gm phn g c s v phn chi tit thay i iu chnh. Cc chi tit thay i iu chnh c kt cu n gin v gi thnh ch to khng cao. g vn nng iu chnh c s dng trong sn xut hng lot nh, c bit l khi thc hin gia cng nhm. Trn my tin CNC g vn nng iu chnh l cc mm cp 3 chu thay i iu chnh (thay i cc chu kp). g trn my CNC

Hnh 5: Mm cp 3 chu thay i hiu chnh

g chuyn dng iu chnh : g chuyn dng iu chnh cho php g t mt s loi chi tit in hnh c kch thc khc nhau. Kt cu ca g gm hai phn chnh: + Phn g c s + Phn chi tit thay i g ny cho php thay i chi tit gia cng ngoi vng lm vic ca my. Phm vi ng dng c hiu qu ca g l dng trong sn xut hng lot.

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CHUYN CNC

Nhm 4

g trn my CNC

Hnh 6: Cc dng chi tit gia cng: l kch thc iu chnh S g t: 1 Thn c s; 2,4 Trc g; 3,5 Chi tit nh v; 6 Rnh nh hng; 7 Cht

g trn (Hnh 6) c dng gia cng chi tit dng cng, dng chu kp, v.v g (Hnh 6) gm thn c s 1; cc chi tit thay i: trc g 2, trc g 4; cc chi tit nh v 3 v 5. g c nh v trn bn my bng u g 2 v cht 7. Chi tit gia cng c nh v bng mt phng trn cc chi tit nh v 3 v 5 vi cc mt l trn hai trc 2 v 4. Chi tit c kp cht bng hai m c. Cc chi tit thay i 4 v 5 c lp t v iu