TRNG I HC BCH KHOA H NIVIN C KHB/M GIA CNG P LCCh 3---------------------------------------------------CN TO HNH SN PHMChng 3CN TO HNH SN PHM DNG KHI DNG KHIH ni, 26.8.2010NI DUNG3 1 Khi i b 3.1 Khi nim c bn3.1.1. Khi nim v phn loi3 1 2T h h h h khi 3.1.2. Trnh t cng ngh to hnh khi3.1.3. Ch nhit3 1 4 li 3.1.4. Vt liu3.2 Cc nguyn cng to hnh s b 3.2.1 Nguyn cng chn3.2.2 Nguyn cng rn trn u ba vn nng 3.2.3 Nguyn cng chun b khc3.3 Cc nguyn cng to hnh chnh2B/M GIA CNG P LC - ViN C KH - I HC BCH KHOA HN NI DUNG3 3 C t h h h h 3.3 Cc nguyn cng to hnh chnh3.3.1 Dp trong khun h3 3 2 D kh k 3.3.2 Dp trong khun kn3.3.3 p chy3 3 4 kh 3.3.4 Kt cu khun3.3.5 iu khin hng th theo yu cu lmi hi i vic ca chi tit3.4 V d tnh ton QTCN dp trc khuu 3.5 Cc trang thit b h tr thc hin CN3B/M GIA CNG P LC - ViN C KH - I HC BCH KHOA HN 3.1 KHI NIM V PHN LOI 3.1.1 KHI NIMC h d h h khi l 3.1.1 KHI NIMCng ngh dp to hnh khi l mtphng php dp to hnh sn phm dng p g p p p p gkhi bng cch tc dng lc lm binki l i dng do kim loi trong lng khun.4B/M GIA CNG P LC - ViN C KH - I HC BCH KHOA HN Cc dng sn phm dp khi5Dp khi sn phm ln6B/M GIA CNG P LC - ViN C KH - I HC BCH KHOA HN 3.1.2 Trnh t thc hin cng ngh S khi cng ngh rn dp khiS khi cng ngh rn, dp khiPhi NungphiRn t doSnphm X lsaudp7Dp khiPhn loi dp khi8B/M GIA CNG P LC - ViN C KH - I HC BCH KHOA HN i tng cn nghin cu3.1.2 Trnh t thc hin cng ngh g gPhiRn, Dp khiPhi dp- Phi c, g c - Chn - Bn thnh phm - Phi cn chu k, nh hnh - Vut, ko - Chi tit- Ch nhit - Un - Dung sai vt dp Ch nhitUn Dung sai vt dp- Vt liu, c tnh - Dt...- p chy - t l- Vn xon- Hn chy- Cht phi- Dp trong khun hD t kh k9- Dp trong khun knB/M GIA CNG P LC - ViN C KH - I HC BCH KHOA HN 3.1.3 CH NHIT KHI DP KHIKhi nim: Khi nim:- Khong nhit to hnh cho php (Tcp)khi rn v dp nngl khong nhit gii hn bi nhit bt u rn (T ) v l khong nhit gii hn bi nhit bt u rn (Tbd) vnhit kt thc rn (Tkt) m ti kim loi c tnh do cnthit bin dng v in y lng khun. i vi hp kim thp g y g p p- cc bon thng thng th khong nhit cho php nm tronggii hn t 12500C 750oC. g- Khong nhit to hnh cn thit (Tct) l khong nhit Khong nhit to hnh cn thit (Tct) l khong nhit nm trong khong nhit (Tcp) ph hp vi tng nguyn cng, thi gian gia cng v vt liu.10B/M GIA CNG P LC - ViN C KH - I HC BCH KHOA HN Y khi3.1.3 CH NHIT KHI DP KHIt hit Yu cu khi nung: t c nhit nung Nhit phn b ng u theo tit din ca thic hoc phi Hn ch oxy ha v thot cc bon b mt y Trnh nt t vi v ng sut d do nhit 11B/M GIA CNG P LC - ViN C KH - I HC BCH KHOA HN 3.1.3 CH NHIT KHI DP KHI+ Ch nung phn on cho phi c chiu dy ln:1. Nung ti nhit chuyn bin pha vi tc nung chophp; p p2. Gi nhit nhit chuyn bin pha;3. Tip tc nung n nhit nung cn thit vi tc nung cao nht c th;4. Gi nhit nhit ny ng u ha nhit theo titdin phi. din phi.123.1.3 CH NHIT KHI DP KHI+ Ch nung phn on cho phi nh:i vi a s thp kt cu khi phi c ng knh nhhn 100 mm hon ton c th cht ngay vo l c nhit caoKhi hi i t l hi di/ k hhn 100 mm hon ton c th cht ngay vo l c nhit cao(1300 - 1400o C).Khi nung phi ngn vi t l chiu di/ ng knhL/D 2, thi gian nung c th gim 2%,L/D = 1,5 thi gian nung c th gim 8%,L/D = 1 th thi gian nung c th gim ti 29%.13B/M GIA CNG P LC - ViN C KH - I HC BCH KHOA HN 3.1.3 CH NHIT KHI DP KHI1. Phi b mt nhit trong khi to hnhQu trnh lm ngui gm 2 giai on: giai on ny phi c lm ngui l do- nhit truyn ra khng kh xung quanh- nhit truyn trc tip vo dng c gia cng.2. Lm ngui sau khi rny p g g g- i vi cc chi tit nh, lm ngui bng cch xp thnh ng ln trong l kn, trong l c cha vi bt, hoc trong l c nhit thp hn nhit ngng rn, tcl c gng lm ngui cng chm cng tt.- i vi cc chi tit ln (D = 500 1500 mm), ngi ta lm ngui ngoi khng ( ), g g g gkh, i khi cn lm o bao ly chi tit gim tc lm ngui kim loi. Cco cch nhit c lm bng amian v cch kim loi t 50 n 120 mm.143.1.3 CH NHIT KHI DP KHIPHNG PHP NUNG:a) Khi nung bng dng in tip xc ) g g g pb) Khi nung bng dng in cm ng b) u g b g d g c gc) Phng php nung bng dung dch in) g p p g g g phn15B/M GIA CNG P LC - ViN C KH - I HC BCH KHOA HN 3.1.4 Phi s dng trong rn v dp khi* Mi vt liu kim loi c tnh do u c th dp mt nhit nht nh* Vt liu rn v dp khi rt a dng, gm: - Cc loi thp cc bonCc loi thp hp kim - Cc loi thp hp kim- Kim loi mu v hp kim mu nh hp kim h i t h ki ik nhm, magi, ng v mt s hp kim niken, titan16CC DANG PHI CH YU CC DANG PHI CH YU PHI THEP DUCPHI THEP DUC PHI THEP CN DINH HNH PHI RN PHI THEP TM PHI QUA GIA CNG CO PHI DUCPHI DUC CC LOAI PHI KHC 1718Cc phng php ct phiS ct phi trn my ct19B/M GIA CNG P LC - ViN C KH - I HC BCH KHOA HN Cc phng php ct phiLi ct ct thp hnha ct phi trnb - ct phi vung b ct phi vungc - ct phi ch nht d - ct thp gce - ct tm e - ct tm20B/M GIA CNG P LC - ViN C KH - I HC BCH KHOA HN Cc phng php ct phiDng c trng ca u mt phi sau khi ct21B/M GIA CNG P LC - ViN C KH - I HC BCH KHOA HN V d tnh lc ct V d:Tnh lc ct phi tr 20 mm thp k hiu C30 trn my ct ?P = k . c. F 0,7 k . b. FTnh lc ct phi tr 20 mm thp k hiu C30 trn my ct ?Tra bng thng s vt liu ta c gii hn bn 480MpaF=pi*20*20/4=100pimm*mmb 480 M 480 N/ 2 b= 480 Mpa=480 N/mm2k = 1 1,6P=( 1 1,6 )*0,7*480*100pi = 105.557 168.892 N =10.516.8 T223.2 CC NGUYN CNG TO HNH S BCN DPTO HNH KHI CN DP TO HNH KHIRN T DODP KHIRN TH CNGRN MY23 Rn th cng:lccnguyncngnhmbin3.3.1 Khi nim v Phn loiRn th cng:lccnguyncngnhmbindngkimloimt phnhaytonbthtch nhit thch hp bng dng c bin dng n p g g ggin v s dng sc ngi l chnh. Rn my:ccnguyncngdptohnhkhi y gy g pn gin nhm bin dng mt phn hay ton bth tch c thc hin trn cc thit b to lc nhit thch hp.24Trong khun kh bi ging ny ch tp trung vo cng ngh rn my.B/M GIA CNG P LC - ViN C KH - I HC BCH KHOA HN 3.2 CC NGUYN CNG RNCN RNICN RNNTLANHNNGUIBCHAYUNN PHIPHIPHIG CHG VUQT LDAT VAN TRUC DAT TAO BHAN CHNG UM TRNPHIPHIRN PCT PCNGCNGCNG NG DT TRNNG DCNG TNG HYN CLI LMRN PCT PRCNG. NG. NG. CNG. CC VUTNG. CNG. CNG. CNGUYC TAO LRC25B/M GIA CNG P LC - ViN C KH - I HC BCH KHOA HN NN.CNNNN.C3.2 CC NGUYN CNG TO HNH S BCc nguyn cng rn c chia thnh ccl i loi: nguyn cng s b, gy g nguyn cng ch yu, nguyn cng ph.26Bng tng hp cc nguyn cng rnTn nguyn cngNhim v Hnh v Ghi chI. Cc nguyn cng s b1. Rn phiBin g cthnh phi rn.Bao gmccnguyn cngp cnh v lmmt ring.2. Cht phi( xn, ct )Chia phi rn rathnhtngphnnh loi ct bh phn u vphn ui cag c.27II. Cc nguyn cng chnh3. Chn t do (1) Lmtng dintch tit dinbCc nguyn cng chncthlccnguynh b ( ( )Chn trong vng (2) v chn u (3)ngang bngcchgimtonb chiu di (1)Loi lmgimh hicngchunb (trckhi t l) loi nguyncng trung gian (chun b cho vut ).mt phnchiudi phi (2) vc th lmphnh to phn hi (3) u phi (3)4. VutLm tng chiudi phi bngh l iKhi vut phctpcth bao gmnhiub li t h cch lmgimdin tch titdinngangcan.bc p lin tc quanhtrc phi.285 T lt hi C th l5. t lToltrongphihoc trong chi tit.C th lnguyn cngs b, trckhi dt vnhloi m l.6. Dtng thi lmtng c ngNguyn cngphc tp baovnhtng c ngknh trong vngknhngoicaphi rng(cphc tp baogm nhiubc p cnhphi quaylinl sn). tc trong trcvubahp.297. Vut trn trcTng diphi rng.Khng thayi ng knhtrong trc nngtrong.8. Dt Lm tngchiu rngNhng nguyncngdt phc c u gphicgdt pctp bao gmnhiu qu trinhp theo titdin ngang.309. TobcDch chuyn mtphn kim loi lchkhi trc banuca phi ca phi.10.UnBin phi thngthnh phi congC th lnguyn cngUnthnh phi cong(hoc chi tit cong)theo gc un cnthit.nguyn cngchun b hocnguyn cngcui cng.11.ThtTo ngng trnphi (hocchi titC th lnguyn cngTht,tpphi (hocchi tit)nguyn cngchun b hocnguyn cngcui cng.3112. VT phi c nhiucnh lmthnhthanh trn ( ch b h th ton b hoccc b )13 VutVut mt hoc13. Vutcc bVut mt hoc hai u phi14. M lLmrnglc14. M l gsn vung gcvi bmt phiphng.32III. Cc nguyn cng ph15. hLm bin dng mtphn rt nh ca th tchCc nguyncng tip theo nnhdupphi nhm to thnhch li lm trn khun.g pthng l cncc b, vut ccb v.v16 VNhm gim cc nh Dng rn cc16. VcnhNhm gim cc nhhng xu ca victhot nhit ( gim nhit ) khng ng u hiDng rn ccphi bng thphp kim cao,khi b nt cnhkhi i ca phi. khi rn vi cccnh thngngui trc.3317. VnxonNhm quay ntb phn no ca phi i ca phi imt gc chotrc.18. HnNi hai phn Dng khichypphi li vinhau.grn bngmy ba.34C kh Cc nguyn cng khc19. CtbaviaCngcthlnhng nguyncng chuyn cng chuyntip.20. LLm mt nhng ch li lm, khng phng, cong, vnh ca phi.21. NnLmphng cc phi21. NnLmphng cc phicong khng tnh trc (congdothiust caquy trinh cng nghh khi i ) hoc khi gia cng).22.ngGhi li nhng k hiu,mcthp, shiuchitit b h 35dutit, bng cch c vochi tit hoc con du.Quy trnh rn g c1. Phi c (g)2 L 2. L nung3. Xe ch phi4. Chuyn phi5 M d 5. My dp6. Xe xoay phi7. Ph liu 8. Xe chuyn phi9. X l nhit10, 11. Kim tra 12. Kho thnh phm363.4 CC NGUYN C G O CNG DP TO HNH373.4 DP KHI TRN MY BACN DP TO HNH KHICN RN CN DP KHIDP KHI TRN KHUN HDP KHI TRN KHUN KNP CHY, KO DY*383.4 DP KHI TRN MY BA39CC CNG ON CA QU TRNH DP KHI403.4 DP KHI TRN MY BA41HNH NH THIT B DP KHIEquipmentVn tcm/sHydraulic press Mechanical press0.06 0.300 06 1 5 Mechanical press Screw press Gravity drop hammer Power drop hammer C t bl h0.06 1.50.6 1.23.6 4.83.0 9.04 5 9 042Counterblow hammer4.5 9.03.3.1 KHI NIM v PHN LOIDP KHI TRN KHUN H to ra cc phi pdp c vnh binDP KHI TRN KHUN KNtora snphm khng c vnh bin phm khng c vnh bin.43So snh dp trn khun kn v khun hSO SNH DP KHI TRN KHUN KN V H44Comparison of closed-die forging to precision or flashless forging of a cylindrical billet. Source: H. Takemasu, V. Vazquez, B. Painter, and T. Altan.3.3.2 DP KHI TRN KHUN Ha- Phib c Khun b, c- Khunkhng cgc nghing g g g(ly tng)d,e- Khun cgc nghingthnh lngkh ( hi khun (phitha)45KHUN DP TRN MY BAL kh h b1 B Lp khun h trn my ba1- B e2- Thanh chm b e3- B e ph/ tm ghp4- Thanh chm khun di5- Khun di6- Khun trn 6 Khun trn7- Thanh chm khun trn8- u ba trn9 C ht t 9- Con cht trn10- Con cht di46 - Dp khi trn my ba linh hot hn dp trnmypckhvmybachnhtrnhthay i, trnh c hin tng qu ti v kt my.-Kchthcchiungang c mbo, chiu g g ,caosnphmthngkhngchnhxc->dokch thc phi p- Vi khun dp khi h th vt dp lun c vnhbin -> cn thit c cc nguyn cng tinh chnh bin cn thit c cc nguyn cng tinh chnhv ct bin.47 MT PHN KHUNMt phn khun phn chia khun thnh 2 na Mt phn khun phn chia khun thnh 2 nakhun trn v khun di; thun li cho qu trnhin y kim loi, t phi v ly vt dp ra khi in y kim loi, t phi v ly vt dp ra khikhun. (xem hnh trang sau)Mt phn khun c th phng hoc gp khc. Mt phn khun c th phng hoc gp khc.Vt dp l hnh khi khng gian n gin th cth chn ti u: tho lp, hng th... th chn ti u: tho lp, hng th... Vt dp phc tp th c th thm lng thmkim loi c th ly vt dp. kim loi c th ly vt dp.Hnhdngvt dpphthucvomt phnkhun.48khun.MT PHN KHUN VI CC VT RN N GIN49S PHN B TH KL theo MT PHN KHUNChi tit dng con cht hay b ct t ti titdi h h kh h din a-a, nn chn mt phn khun I-I chot chc hng th lin tc.Phngnath gcnghinglngkhunnhtit kim kim loi50nh, tit kim kim loi. VNH BIN v RNH THOT BINVNH BIN l phn kim loi tha bao quanh vt dp.- Kha ca khun giai on cui qu trnh dp- Tng tr lc bin dng kim loi in y cc - Tng tr lc bin dng kim loi in y cc hc hp, rnh su trong lng khun.Vh bi t bi d - Vnh bin c ct bi cc nguyn cng sau dp51Kt cu khun ct bin v t mng ngn l52B. RNH THOT BIN RNH THOT BIN gm cu vnh bin a v ti cha kim loi bKch thc h ng vai tr quan trng trong vic in y kim loi v hnh thnh vnh bin. y53Cc loi rnh thot bin54Cc giai on hnh thnh vnh bin12355a)Vnh bin qu ln b)Vnh bin hp l GC NGHING THNH LNG KHUNMc ch:S khi d d l t i t d Sau khi dp do lc ma st gia vt dpv thnh lng khun ti cc mt tip xc, cho nn nu ta lm cc thnh lng khun ng thvt dp s dnh cht vo lng khun, khng p g gly ra c, hoc trong trng hp dng cny m lc ma st rt ln th lc cng ln. y m lc ma st rt ln th lc cng ln.56Xem gc nghingA. Cch chn gc nghing- Cc khun h dp trn my ba: lng khun vi mt gcnghing nht nh (khong 5100) - i vi cc khun dp c dng cn y ( kh nng ny rtkh thc hin trn my ba ) th c th gim gc nghingthh l kh i i b thnh lng khun i vi ba .- sutng i cacclngkhuncnglnth gcnghing thnh lng khun cng ln nghing thnh lng khun cng ln.- Vt dpnhnhaunhit phi dpcngcaoth gcnghing thnh lng khun cng ln nghing thnh lng khun cng ln.- Nu dng cht bi trn tt th khng nhng lm gim h sma st m cn lm gim p lc php tuyn57ma st m cn lm gim p lc php tuyn.B. iu kin vt dp t thot ra khi lng khunSau nht p cui cng, trn b mt tipxc gia vt dp v lng khun tn ti cc xc gia vt dp v lng khun tn ti ccthnh phn lc:- P tc dng vung gc b mt vt dp.Gi ma st tip xc tng cng l T gc - Gi ma st tip xc tng cng l T, gcnghing thnh lng khun l, h s mast st58Coi tng hp cc lc tc dng ln vt dp l Q thPhn tch lc tc dng ln phiCoi tng hp cc lc tc dng ln vt dp l Q thQ = -Tcos + Psin = P(sin - cos)QT = .P ( theo nh lut Coulomb) t d t khi l kh th h l QPQ vt dp t y ra khi lng khun th hp lc Q phI ln hn khng (chiu dng)TQ > = 0(sin - cos) >=0tg >= 59Vng gi tr ca gc nghingIIIt > tg > Vng II m bo iu kin vt dp t y ra khi khun sau nht p thm60khun sau nht p thm+ Gc nghing ngoi: mt tip xc gia vt dp v lng khun m khi kim v lng khun m khi kim loi ngui i s to ra khe h.+ Gc nghing trong: l gc nghing cc mt ti khi ki l i tip xc m khi kim loi ngui i s to ra cng. g1< 261 BN KNH GC LN - L yutcngngh khngtrnhkhitronggiacngckh. Bnknhlncng gg g gnh mc gia cng cng kh.Bn knh ln ln hay nh s to thun li - Bn knh ln ln hay nh s to thun lihay kh khn khi in y kim loi. - Bn knh gc ln gim tp trung ng sut.- Bn knh ln trn dng c (chy ci) lun Bn knh ln trn dng c (chy,ci) lunnh hn hoc bng bn knh ln trn phi.62Cch chn bn knh gc ln Bn knh gc ln Bn knh gc ln- Bn knh gc ln trong RB k h l i - Bn knh gc ln ngoi rThng thng r = 1 6mmR = 3 15mmh/b < 2 0 05h + 0 5 R 2 5 + 0 5 h/b < 2 r = 0.05h + 0.5;R = 2.5r + 0.5 h/b = 2 4 r = 0.06h + 0.5;R = 3.0r + 0.5h/b > 4 r = 0.07h + 0.5;R = 3.5r + 0.563 L CHA THU V MNG NGN L L cha thu: thay hoc gimti cho n/c t l L cha thu: thay hoc gim ti cho n/c t l Mng ngn l: Phn kim loi cng ngh cn li trong l sau khi64Mng ngn l: Phn kim loi cng ngh cn li trong l sau khi dpChiu su ti a ca l cha thu Chiu su ti a hmax ca l cha thu c th dptrnmyba ctnhtheocngthckinhhi nghim sau:5 , 0 Dh =< 0 8D) (max75 , 2 ). 4 cos(t bh =< 0,8Db(t) Gii hn bn ca kim loi nhit bin dngD - ng knh l . g - Gc nghing thnh lng khun65Chiu dy mng ngn lKhi cn dp chi tit c mng ngn l th chiu dymng cng phi tnh ton sao cho hp l. Nu qa g g p p qdy th tn kim loi, tn lc t mng ngn l. Nuqu mng th d hng khun (du khun) tn nng q g g ( ) glng khi dp.C th tnh chiu dy mng ngn l theo cng thc C th tnh chiu dy mng ngn l theo cng thckinh nghim su y:mm h h D a 6 , 0 5 25 , 0 45 , 0 + =66LNG KHUN TINHLng khun tinh:- lng khun cui cng, - c hnh dng gn ht i t d nht vi vt dp.a) Bn v vt dp a) Bn v vt dpb) Hnh dng sau khi dui thng ca vt dpc) Cc bc dp c) Cc bc dpd) Khun die) Lng khun p t67CC NGUYN TC IN Y LNG KHUNa) Chnb c) Chn t b,c) Chn, tld) Chn phi ) pcaoe) p chyf) Chn, t, p chy68CC G QU TRNH IN Y LNG KHUNGiai on 1: Chn t do, t chiu cao ban u nkhi phi tip xc vo cc thnh bn. Chiu caophigimlngH1. plc nvthp, chyu l p lc p v p lc do lc ma st b mtgy ra m gy ra mp.Giai on 2:Chn+pchy, tkhi kimloi tipxc thnh bn n khi cu vnh bin bt u bng kn. Chiu cao phi gim i 1 lng H2.2Ngoi cc p lc p,mp cn c p lc trn thnhbn q v mqlc ma st do q gy ra.Giai on 3: Chn+p chy, kim loi in y cc l h h bi C thh gc ln v chy qua cu vnh bin. Cc thnhphn lc masat thnh bn mp, mq ko cn mc dvn c p lc bn q, do ko c s chuyn dchca lp kim loi b mt. Thm vo l p lc p p ti cu vnh bin c v ma st mc. Do lc dptng nhanh. H3 nh hn H1H2Giai on 4: y ntphn kim loitha ra vnhbi Thh h l i GDD3 t69bin. Thnh phn lc gn ging GDD3 v tngrt nhanh.M phng QU TRNH IN Y LNG KHUN70LNG KHUN TH- Lngkhunthcnhimvlmgimnhim v cng lm vic ca lng khun g gtinh, do tng tui th ca cc lng khuntinh tinh.- Phi dp qua lng khun th c hnh dng gn ging vt dp, c mt lp ba via cto ra t khe h gia hai mt bin71V tr cc lngkhunC IM LNG KHUN THCu to lng khun th gn ging lng khun tinhnhng c nhng im khc sau y. g g y1. Cc bn knh gc ln lng khun th ln hn lng khun tinh lng khun tinh.2. Lng khun th khng c rnh thot bin.3Chi l kh th hi l h hi 3. Chiu cao lng khun th phi ln hn chiu caovt dp khi dptrnlngkhuntinhcmtl bi d hi lng bin dng v chiu cao .72C IM LNG KHUN TH4. Chiurngcclngkhunthphi nhhnchiu rng lng khun tinh c th t bn thnh g g phm ( qua lng khun th) vo lng khun tinhc d dng . g5. Gcnghingthnhlngkhunthcthlnhn, bnghocnhhngcnghingthnhlng hn, bnghocnhhngcnghingthnhlngkhun tinh. Nu cn to gn hoc mt ch li caoth ta nn to hnh theo phng php p chy. th ta nn to hnh theo phng php p chy.73Vt dp trn lng khun th v tinh- Na tri: vt dp lng khun th74- Na phi: vt dp lng khun tinh CC NGUYN CNG CHUN B KHCCh b hi d b h d - Chun b phi dp bng my chuyn dng: my cn chu k, rn cn..h h h h h k - Phi cn nh hnh, chu k..- Phi c75- NGUYN CNG CHUN B VT DP DC-Vt dp dc l cc vt dp c dp theo chiudc trc phi. Thng l cc vt dp ngn , trn dc c p . g cc v dp g , xoay nh bnh rng , bnh , bnh ai...-Nguyn cng chun b ch yu cho vt dp dc -Nguyn cng chun b ch yu cho vt dp dcthng ch l chn76Khi khun ghp 2 lng khunLng khun chnLng khun tinhKhun dp phiRnh thot binKhun dp phi bnh rng77N/c chun b vt dp dca) Chnb) V t b) Vutc) p chy78- NGUYN CNG CHUN B VT DP DI -Vt dp di l cc vt dp c dp theo chiu vung gc trc phi.Cc nguyn cng chun b chnh gm:Vut: phi ngn hn vt dp - Vut: phi ngn hn vt dp- p t: di phi bng vt dp - Un: ng trc phi b un- Tht: to phnh nh p- Thnh hnh: phi dp khng i xng79CC LNG KHUN CHUN BVUT (a) - VUT (a)- P T (b) ( ) - UN (c)80CC LNG KHUN CHUN BUN THNH HNH81- TNH TH TCH PHI DPTh tch phi:V = k ( V + V ) VPh = k ( VVd+VPL) - k: h s kim loi chy khi nung k>1, k=1+(1%6%)- Vvd: Th tch vt dp trng thi ngui (theo bn v) - Vpl: Th tch ph liu82VT DP DC (NGN)- TNH TH TCH PHI DPVT DP DC (NGN)- i vi cc vt dp dc th phi phi tha mni ki khi h H 2 5 Dt h hi t iu kin khi chn: H0 < 2,5 D0 trnh hin tngmt n nh.- Lng bin dng khi chn chun b trc khi g g a vo dp nn trong khong: 25%50%.- Tnh n mc phnh trng thun li chobin dng trong khun dp83bin dng trong khun dp.VT DP DI (DP NGANG)Ph liu trong cng thc trn gm: Ph liu trong cng thc trn gm:VPl= VVb+ Vch+ Vmn+ VmV Th h h bi VVb: Th tch vnh bin Vch: Th tch chui kp kmh h h h (d h ) Vmn: Th tch mch ni chi tit (dp chm) Vm: Th tch mng ngn l (nu c l cha thu)Khi c th tch phi th phi chn phi m bo yu cu:L0max = Lvd vD0max= Dghmax ng knh quy i ti tit din ngang ln nht ca 840max ghmaxg q y g gvt dp.GiN NG KNH VT DPB1: Xydnggin dintch ti cctit -B1: Xydnggin dintch, ti cctitdin ngang ca vt dp (Fgd).2 d i k h i -B2: Xydnggin ngknh i xngDgd= 1,13.Fgd1/2 tng ng vi cc tit dinngang.T h h h hi h bivb vd gdF F F 2 + =Tnh chnh xc phi gm c vnh bin:Fvd- Din tch tit din ngang ca vt dp Fvb - Din tch tit din ngang ca mt phavnh bin .vb vd gd85vb t c t t d gag ca t p av b .CC BC XY DNG G NG KNH86Cc phng n chn phi theo GDK Xy dng GDKGi k h l th h th i - Gin ng knh l th ph thuc gia di v cc gi tr Dg tng ng. -Nuphi cchunbtheo ngvigin ngknhth khi dpccphntkimloi ch phi bin dng theo chiu vung gc vi trc phi,ngha l kim loi c dch chuyn trong qu trnh dp theo cc ng vung gc ngn nht. Loi bhn cc thnh phn dch chuyn dc trc.873.3.3 DP KHI TRN KHUN KNa,b- Khun kn khnggc gc nghingc- Khun kn c gc h nghingd- Khun kn t trn my rn ngang88DP KHI KHUN KN TRN MY BA - Dp khi trn khun h to ra vnh bin chim5-15%tonbthtch. Cnthit ccnguyncng ct bin v gia cng c.- Dp khi trn khun kn cht lng vt dp cao Dp khi trn khun kn cht lng vt dp caohn, tit kim kim loi, khun phc tp hn, dgy qu ti my. gy qu ti my.- Kch thc v chiu cao khng m bo khi phikhng chnh xc khng chnh xc.- Thch hp cc vt dp dc thp89DP KHI KHUN KN TRN MY BAKhun kn gm c:L kh k Lng khun kn Kha khun90DP KHI KHUN KN TRN MY BALng khun su hn c b tr lng khun di91lng khun diDP KHI KHUN KN TRN MY BA92V D TNHTON V D TNH TON THIT K DP KHI THIT K DP KHI PHI BNH RNG PHI BNH RNG93Khun mt lng khunDp phi a xch Dp phi a xch94Kt cu khi khun hMt diMt trn95Lp khun96Animation of forging hammerQut h trnhdp pthchin hinnh thno?97no?3.5 DP KHI TRN MY P99DP KHI TRN MY P3.5.1 Dp khi trn my p trc khuu dp nng 3.5.2 Dp khi trn my p Vt ma st3.5.3 Dp khi trn my rn ngang p y g g3.5.4 Dp khi trn my p thy lc (p chy)3.5.5 Cc my chuyn dng1003.5.1 S my p trc khuu dp nng91 ui dn hng ph2 Bnh rng nh3 Bnh rng ln v ly hp ma st4 u trt5 Chm bn my6 Phanh7 B h 7 Bnh 8 Phanh bnh 9 C cu cn bng101My p trc khuu dp nng1023.5.1 Dp khi trn my p u im ca my p trc khuu so vi myba- c s dng rng ri trong sn xut hng lot ln v hng khi.-Thch hp cho t ng ho v c kh ho.- Chiu di hnh trnh my c nh, cho php thao tc lch tm nhng khng th dp nhiu ln mt vt dp trn mt lng khun.- Hiu sut lm vic cao (2 ln so vi my ba).- Nng sut lao ng cao ( v mi nht dp l mt chi tit trong khi vi my ba th mt sn phm phi dp trn nhiu lng khun). p p p g )- chnh xc vt dp cao hn so vi dp trn my ba. Dung sai ca vt dp c th t ti 0.2 0.5mm (i vi my ba l 0.8 1mm).H s s dng kim loi cao hn v c th gim lng thm v lng d do khun - H s s dng kim loi cao hn v c th gim lng thm v lng d do khun dp trn my p trc khuu c th s dng cn y.- iu kin lm vic ca cng nhn tt hn.103- Gi thnh sn phm h, do tit kim kim loi.- Nhc im khi dp trn my p trc khuu dp nng- Gi thnh u t ln.- My thng b kt im cht di.- Khng c rnh ui n g lp khun.H h t h h - Hnh trnh nh.- Bin dng n hi khung thn myTc chmhn my ba (0 5 1 5 m/s) - Tc chm hn my ba (0,5-1,5 m/s)104 th lin h gia hnh trnh u trt v thi gian l mt ng cong2. c im ca qu trnh dp trn my p trc khuu dp nng- th lin h gia hnh trnh u trt v thi gian l mt ng cong cng.- Vi mi lng khun, ch tn ti mt mc bin dng nht nh.- chnh xc ca vt dp trong khong 0.2 0.5mm- Tc bin dng thi im bin dng 0.5 0.8m/s, (vi my ban ng:5 6m/s) n ng:5 6m/s)- Tc bin dng thp to iu kin cho qu trnh in y lng khun tthn.105So snh tc u ba khi dp trn METK v MBM.BUAM E T K M.E.T.K106DP TRN MY PBN DANG AN H CUA MY P VA Y NGHA- Khi lm vic, do c im kt cu, cc chi tit ca my b bin dng n hi (trckhuu b un, tay bin v u trt b nn, thn my chu un v ko).- Lng bin dng n hi ph thuc vo tr lc bin dng trong lng khun nhit - Lng bin dng n hi ph thuc vo tr lc bin dng trong lng khun, nhit nung v th tch phi. C th xc nh bng cng thc sau:t = Hn+ at- HT trong :+ Hn: chiu cao vt dp sau khi ngui.+ at: lng co ngt kch thc sau khi ngui ca vt dp.+ HT: chiu cao vt dp theo thit k + HT: chiu cao vt dp theo thit k- Do , khi iu chnh khun lc khng c vt rn nu khong cch gia hai mtphn khun bng chiu cao vnh bin th s nhn c vp dp c chiu cao lnhn tnh ton. hn tnh ton.- Khi iu chnh khun, phi ch to dng c chiu cao bng chiu cao vnh binsau t ln cu vnh bin, h u trt i xung na khun trn v di cchnhau mt khong bng kch thc ca dng.107 g g gAC M KT CU KHUN- C th ch to t khi thp nguyn hoc s dng kt cu ghp.- Do bn my ca my p trc khuu dp nng khng c rnh mang c, phi thit Do bn my ca my p trc khuu dp nng khng c rnh mang c, phi thit k khun ph c rnh mang c g khun.- Trn my p c h thng y sn phm do gc nghing thnh lng khun trn METK nh hn gc nghing thnh lng khun trn my ba 1o 3o. C tht gc g g t g u t y ba 3 C t y ti mt hoc nhiu v tr tu thuc vo hnh dng v kch thc ca chi tit. Kt cu y c th b tr khun trn hoc khun di hoc ng thi c hai na khun.- Nu vt dp c chiu cao ln th phi dng c cu y kiu thu lc hoc kh nn.- Trn METK c th dng khun t hp (nhiu khun trn mt khi khun) g p ( )- Do METK c hnh trnh cng nn trong kt cu khun phi c c cu chng qu ti khun v my.108Rnh thot bin trn my pKhun trn METK dp nng(khng c mt gng)Khun trn my baKiu 1: thng dngKiu 2:Kiu 3Kiu 4109110Kch thc rnh thot binC cu y111Kt cu bn my112113Khun kn dp trn my p114V tr ti cha kim loi tha3.5.2 DP KHI TRN MY P VT MASATNguyn l hot ng nh my thc (63T) Vit cung in Stato115DP KHI TRN MY P VT MASAT c im gn ging my ba, kt cu bn my v phn ri my v phn ri. Hnh trnh dp khng c nh (mm), hnh trnh dp ln hn METK. Lc c nh do kt cu my (~1000T) Lc c nh do kt cu my (~1000T) Tc u ba 3- 4 m/s, chm hn my ba 2 ln, ln hn METK (