I-Precision Machining inqubo yokususa izinto kusuka ku-workpiece ngesikhathi sokubamba ukuphelela okubekezelelana eduze. Umshini wokunemba unezinhlobo eziningi, okuhlanganisa ukugaya, ukujika kanye nomshini wokukhipha ugesi. Umshini wokunemba namuhla uvame ukulawulwa kusetshenziswa i-Computer Numerical Controls (CNC).
Cishe yonke imikhiqizo yensimbi isebenzisa imishini yokulungisa ngokunemba, njengoba kunjalo nangezinye izinto eziningi ezifana nepulasitiki nokhuni. Le mishini iqhutshwa ochwepheshe bemishini abaqeqeshiwe nabaqeqeshiwe. Ukuze ithuluzi lokusika lenze umsebenzi walo, kumele lihanjiswe ngezindlela ezichazwe ukuze lenze ukusika okulungile. Lokhu kunyakaza okuyinhloko kubizwa ngokuthi "isivinini sokusika." Umsebenzi ungasuswa futhi, okwaziwa ngokuthi ukunyakaza kwesibili "kokuphakelayo." Ndawonye, lokhu kunyakaza kanye nokubukhali kwethuluzi lokusika kuvumela umshini wokulungisa ngokunemba ukuthi usebenze.
Umshini wokulungisa ngokunemba kwekhwalithi kudinga ikhono lokulandela amapulani akhethekile kakhulu enziwe yizinhlelo ze-CAD (umklamo osizwa yikhompyutha) noma ze-CAM (umshini wokukhiqiza osizwa yikhompyutha) njenge-AutoCAD ne-TurboCAD. Isofthiwe ingasiza ekukhiqizeni amadayagramu noma izinhlaka eziyinkimbinkimbi, ezinobukhulu obuthathu ezidingekayo ukuze kwenziwe ithuluzi, umshini noma into. Lawa mapulani kumele alandelwe ngemininingwane eminingi ukuqinisekisa ukuthi umkhiqizo ugcina ubuqotho bawo. Nakuba izinkampani eziningi zomshini wokulungisa ngokunemba zisebenza nohlobo oluthile lwezinhlelo ze-CAD/CAM, zisasebenza kaningi ngemidwebo edwetshwe ngesandla ezigabeni zokuqala zomklamo.
Umshini wokugaya ngokunembile usetshenziswa ezintweni eziningi ezihlanganisa insimbi, ithusi, i-graphite, ingilazi kanye nepulasitiki ukubala ezimbalwa. Kuye ngobukhulu bephrojekthi kanye nezinto ezizosetshenziswa, kuzosetshenziswa amathuluzi ahlukahlukene okugaya ngokunembile. Noma yikuphi ukuhlanganiswa kwama-lathe, imishini yokugaya, imishini yokubhoboza, ama-saw kanye nama-grinder, ngisho namarobhothi asheshayo kungasetshenziswa. Imboni yezindiza ingasebenzisa umshini wokugaya ngesivinini esikhulu, kanti imboni yokwenza amathuluzi okhuni ingasebenzisa izinqubo zokugaya nge-photo-chemical. Ukukhishwa komshini, noma inani elithile lanoma iyiphi into ethile, kungabalwa ngezinkulungwane, noma kube ezimbalwa nje. Umshini wokugaya ngokunembile uvame ukudinga ukuhlelwa kwamadivayisi e-CNC okusho ukuthi alawulwa ngezinombolo zekhompyutha. Idivayisi ye-CNC ivumela ukuthi kulandelwe ubukhulu obuqondile kulo lonke ukusebenza komkhiqizo.
Ukugaya kuyinqubo yokugaya esebenzisa izicucu ezijikelezayo ukususa izinto kusuka kumshini wokusebenza ngokuqhubekisela phambili (noma ngokuphakela) umshini wokusika endaweni yokusebenza ngendlela ethile. Umshini wokusika ungabanjwa nge-engeli ehlobene ne-axis yethuluzi. Ukugaya kuhlanganisa imisebenzi eminingi ehlukene kanye nemishini, kusukela ezingxenyeni ezincane kuya emisebenzini emikhulu, enzima yokugaya. Kungenye yezinqubo ezisetshenziswa kakhulu zokugaya izingxenye ezenziwe ngokwezifiso kuya ekubekezeleleni okunembile.
Ukugaya kungenziwa ngamathuluzi omshini ahlukahlukene. Uhlobo lokuqala lwamathuluzi omshini wokugaya kwakuyimishini yokugaya (evame ukubizwa ngokuthi umshini wokugaya). Ngemva kokufika kokulawulwa kwezinombolo zekhompyutha (i-CNC), imishini yokugaya yashintsha yaba izikhungo zokugaya: imishini yokugaya enwetshwe ngabashintshi bamathuluzi abazenzakalelayo, omagazini bamathuluzi noma ama-carousel, ikhono le-CNC, izinhlelo zokupholisa, kanye nezindawo zokuvala. Izikhungo zokugaya ngokuvamile zihlukaniswa njengezikhungo zokugaya eziqondile (ama-VMC) noma izikhungo zokugaya ezivundlile (ama-HMC).
Ukuhlanganiswa kokugaya ezindaweni zokujika, kanye nokuphikisana nalokho, kwaqala ngamathuluzi aphilayo okugaya kanye nokusetshenziswa ngezikhathi ezithile kwezigayo zokusebenza zokujika. Lokhu kwaholela ekilasini elisha lamathuluzi omshini, imishini yokwenza imisebenzi eminingi (ama-MTM), eyakhelwe ngenhloso yokwenza kube lula ukugaya nokujika ngaphakathi kwemvilophu yomsebenzi ofanayo.
Kwabanjiniyela bokuklama, amaqembu e-R&D, kanye nabakhiqizi abathembele ekutholeni izingxenye, ukushintshwa kwe-CNC ngokunemba kuvumela ukudalwa kwezingxenye eziyinkimbinkimbi ngaphandle kokucutshungulwa okwengeziwe. Eqinisweni, ukushintshwa kwe-CNC ngokunemba kuvame ukwenza kube nokwenzeka ukuthi izingxenye eziqediwe zenziwe emshinini owodwa.
Inqubo yokugaya isusa izinto bese isebenzisa amathuluzi amaningi okusika ukudala umklamo wokugcina, futhi ovame ukuba yinkimbinkimbi kakhulu, wengxenye. Izinga lokunemba liyathuthukiswa ngokusebenzisa i-computer numeral control (CNC), esetshenziselwa ukwenza ngokuzenzakalelayo ukulawulwa kwamathuluzi okugaya.
Indima ye-"CNC" ekusetshenzisweni kwemishini ngokunemba
Kusetshenziswa imiyalelo yokuhlela enekhodi, ukucutshungulwa kwe-CNC ngokunemba kuvumela ukuthi umsebenzi usikwe futhi ulolongwe ngokwezincazelo ngaphandle kokungenelela ngesandla komqhubi womshini.
Ngokusebenzisa imodeli yomklamo osizwa yikhompyutha (CAD) enikezwa yikhasimende, uchwepheshe wemishini usebenzisa isofthiwe yokukhiqiza esizwa yikhompyutha (CAM) ukudala imiyalelo yokulungisa ingxenye. Ngokusekelwe kumodeli ye-CAD, isofthiwe inquma ukuthi yiziphi izindlela zamathuluzi ezidingekayo futhi ikhiqize ikhodi yokuhlela etshela umshini:
■ Yimaphi ama-RPM afanele kanye namazinga okuphakelayo
■ Nini futhi kuphi lapho ithuluzi kanye/noma umsebenzi kufanele uthuthwe khona
■ Ukujula kangakanani ukusika
■ Nini ukufaka i-coolant
■ Noma yiziphi ezinye izinto ezihlobene nesivinini, izinga lokuphakelwa, kanye nokuxhumana
Isilawuli se-CNC sibe sesisebenzisa ikhodi yokuhlela ukulawula, ukwenza ngokuzenzakalelayo, nokuqapha ukunyakaza komshini.
Namuhla, i-CNC iyisici esakhelwe ngaphakathi semishini ehlukahlukene, kusukela kuma-lathe, ama-mill, nama-router kuya ku-wire EDM (electrical discharge machining), i-laser, kanye nemishini yokusika i-plasma. Ngaphezu kokwenza inqubo yokugaya ibe ngokuzenzakalela nokuthuthukisa ukunemba, i-CNC isusa imisebenzi eyenziwa ngesandla futhi ikhulule ochwepheshe bemishini ukuthi babheke imishini eminingi esebenza ngesikhathi esisodwa.
Ngaphezu kwalokho, uma indlela yamathuluzi isiklanyiwe futhi umshini usuhlelwe, ungaqhuba ingxenye nganoma yisiphi isikhathi. Lokhu kunikeza izinga eliphezulu lokunemba nokuphindeka, okwenza inqubo ibe ngcono kakhulu futhi ikwazi ukukhuliswa.
Izinto ezisetshenziswa ngomshini
Ezinye izinsimbi ezivame ukwenziwa ngomshini zifaka phakathi i-aluminium, ithusi, ithusi, ithusi, insimbi, i-titanium, ne-zinc. Ngaphezu kwalokho, izinkuni, i-foam, i-fiberglass, kanye nepulasitiki njenge-polypropylene nazo zingakhiwa ngomshini.
Eqinisweni, cishe noma iyiphi into ingasetshenziswa ngokunemba kwe-CNC machining — vele, kuye ngokusetshenziswa kanye nezidingo zayo.
Ezinye izinzuzo zomshini wokulungisa i-CNC ngokunemba
Eziningi zezingxenye ezincane kanye nezingxenye ezisetshenziswa emikhiqizweni eminingi ekhiqizwe, ukushintshwa kwe-CNC ngokunemba ngokuvamile kuyindlela yokukhetha.
Njengoba kunjalo cishe kuzo zonke izindlela zokusika nokulungisa, izinto ezahlukene ziziphatha ngendlela ehlukile, futhi ubukhulu nesimo sengxenye nakho kunomthelela omkhulu enkambisweni. Kodwa-ke, ngokuvamile inqubo yokulungisa i-CNC ngokunemba inikeza izinzuzo kunezinye izindlela zokulungisa.
Lokho kungenxa yokuthi imishini ye-CNC iyakwazi ukuletha:
■ Izinga eliphezulu lobunzima bezingxenye
■ Ukubekezelelana okuqinile, ngokuvamile kusuka ku-±0.0002" (±0.00508 mm) kuya ku-±0.0005" (±0.0127 mm)
■ Ukuqeda okubushelelezi kakhulu, okuhlanganisa nokuqeda okwenziwe ngokwezifiso
■ Ukuphindaphindeka, ngisho noma kunomsindo omkhulu
Nakuba uchwepheshe wemishini angasebenzisa i-lathe yesandla ukwenza ingxenye esezingeni eliphezulu ngamanani ayi-10 noma ayi-100, kwenzekani uma udinga izingxenye eziyi-1,000, izingxenye eziyi-10,000, izingxenye eziyi-100,000 noma eziyisigidi?
Ngokusebenzisa imishini ye-CNC enembile, ungathola ukukhuliswa kanye nesivinini esidingekayo kulolu hlobo lokukhiqiza okuphezulu. Ngaphezu kwalokho, ukuphindaphindwa okuphezulu kokusebenzisa imishini ye-CNC enembile kukunikeza izingxenye ezifanayo kusukela ekuqaleni kuze kube sekupheleni, kungakhathaliseki ukuthi ukhiqiza izingxenye ezingaki.
Kunezindlela ezithile ezikhethekile kakhulu zomshini wokugaya we-CNC, okuhlanganisa i-wire EDM (umshini wokugaya ngogesi), umshini wokugaya owengeziwe, kanye nokuphrinta nge-laser ye-3D. Isibonelo, i-wire EDM isebenzisa izinto eziqhubayo — ngokuvamile izinsimbi — kanye nomshini wokugaya ngogesi ukuze igugule umsebenzi ube yizimo eziyinkimbinkimbi.
Kodwa-ke, lapha sizogxila ezinqubweni zokugaya nokujika — izindlela ezimbili zokususa ezitholakala kabanzi futhi ezisetshenziswa njalo ekushicileleni i-CNC ngokunemba.
Ukugaya vs. ukujika
Ukugaya kuyinqubo yokugaya esebenzisa ithuluzi lokusika elijikelezayo, eliyindilinga ukususa izinto bese kwakheka izimo. Imishini yokugaya, eyaziwa ngokuthi i-mill noma isikhungo sokugaya, igcwalisa indawo yonke ye-geometries yezingxenye eziyinkimbinkimbi kwezinye zezinto ezinkulu ezenziwe ngensimbi.
Isici esibalulekile sokugaya ukuthi umsebenzi uhlala ungashintshi ngenkathi ithuluzi lokusika lijikeleza. Ngamanye amazwi, emshinini wokugaya, ithuluzi lokusika elijikelezayo lihambahamba endaweni yomsebenzi, elihlala liqinile embhedeni.
Ukujika kuyinqubo yokusika noma ukubumba i-workpiece emishinini ebizwa ngokuthi i-lathe. Ngokuvamile, i-lathe ijikeleza i-workpiece ku-axis eqondile noma evundlile kuyilapho ithuluzi lokusika eliqinile (elingase lijikeleze noma lingajikelezi) lihamba ku-axis ehleliwe.
Ithuluzi alikwazi ukuzungeza ingxenye ngokoqobo. Izinto ziyazungeza, okuvumela ithuluzi ukuthi lenze imisebenzi ehleliwe. (Kukhona isethi yama-lathe lapho amathuluzi ezungeza khona ucingo olufakwe i-spool, nokho, olungamboziwe lapha.)
Ngokujika, ngokungafani nokugaya, i-workpiece iyajikeleza. Ingxenye yesitokwe ijika ku-spindle ye-lathe bese ithuluzi lokusika lihlanganiswa ne-workpiece.
Umshini wokusebenza ngesandla vs. i-CNC
Nakuba kokubili imishini yokugaya kanye nemishini yokugaya kutholakala kumamodeli enziwe ngesandla, imishini ye-CNC ifaneleka kakhulu ngezinjongo zokukhiqiza izingxenye ezincane — inikeza ukukhuliswa kanye nokuphindaphindwa kwezicelo ezidinga ukukhiqizwa okuphezulu kwezingxenye ezibekezelelana ngokuqinile.
Ngaphezu kokunikeza imishini elula enama-axis amabili lapho ithuluzi lihamba khona kuma-axis e-X ne-Z, imishini ye-CNC enembile ifaka amamodeli anama-axis amaningi lapho umsebenzi ungahamba khona. Lokhu kuphambene ne-lathe lapho umsebenzi ukhawulelwe ekuphotheni futhi amathuluzi azohamba ukuze adale i-geometry oyifunayo.
Lokhu kulungiswa kwe-multi-axis kuvumela ukukhiqizwa kwamajiyometri ayinkimbinkimbi kakhulu ekusebenzeni okukodwa, ngaphandle kokudinga umsebenzi owengeziwe ngumqhubi womshini. Lokhu akugcini nje ngokwenza kube lula ukukhiqiza izingxenye eziyinkimbinkimbi, kodwa futhi kunciphisa noma kuqeda amathuba ephutha lomqhubi.
Ngaphezu kwalokho, ukusetshenziswa kwe-coolant enomfutho ophezulu kanye ne-CNC machining enembile kuqinisekisa ukuthi ama-chips awasebenzi, ngisho noma usebenzisa umshini one-spindle eqondiswe phezulu.
Izigayo ze-CNC
Imishini yokugaya ehlukene iyahlukahluka ngobukhulu bayo, ukwakheka kwe-axis, amazinga okuphakela, isivinini sokusika, isiqondiso sokuphakela kokugaya, kanye nezinye izici.
Kodwa-ke, ngokuvamile, izigayo ze-CNC zonke zisebenzisa i-spindle ejikelezayo ukusika izinto ezingafuneki. Zisetshenziselwa ukusika izinsimbi eziqinile njengensimbi ne-titanium kodwa zingasetshenziswa nezinto ezifana nepulasitiki ne-aluminium.
Izigayo ze-CNC zakhiwe ukuze ziphindeke futhi zingasetshenziswa kukho konke kusukela ekukhiqizeni ama-prototyping kuya ekukhiqizweni okuphezulu. Izigayo ze-CNC ezinembile kakhulu zivame ukusetshenziselwa umsebenzi wokubekezelelana okuqinile njengokugaya ama-fine dies kanye nezikhunta.
Nakuba ukugaya kwe-CNC kungaletha ushintsho olusheshayo, ukuqeda okugayiwe kudala izingxenye ezinezimpawu zamathuluzi ezibonakalayo. Kungase futhi kukhiqize izingxenye ezinemiphetho ebukhali nama-burrs, ngakho-ke kungadingeka izinqubo ezengeziwe uma imiphetho nama-burrs engamukeleki kulezo zici.
Vele, amathuluzi okususa ukusha ahlelwe ngokulandelana azosusa ukusha, yize ngokuvamile efinyelela u-90% wesidingo esiqediwe okungenani, okushiya ezinye izici zokuqeda ngesandla kokugcina.
Ngokuphathelene nokuqeda ubuso, kunezindlela ezingeke zikhiqize kuphela ukuqeda ubuso okwamukelekayo, kodwa futhi nokuqeda okufana nesibuko ezingxenyeni zomkhiqizo womsebenzi.
Izinhlobo zemishini yokugaya i-CNC
Izinhlobo ezimbili eziyisisekelo zemishini yokugaya zaziwa ngokuthi izikhungo zokugaya eziqondile kanye nezikhungo zokugaya ezivundlile, lapho umehluko omkhulu usekuqondisweni kwe-spindle yomshini.
Isikhungo somshini oqondile siyisigayo lapho i-spindle axis iqondiswe khona ohlangothini lwe-Z-axis. Le mishini eqondile ingahlukaniswa ngezinhlobo ezimbili:
■Izigayo zokulala, lapho i-spindle ihamba khona ihambisana ne-axis yayo kuyilapho itafula lihamba liqonde ngqo ku-axis ye-spindle.
■Izigayo ze-Turret, lapho i-spindle imile khona futhi itafula lithuthwa ukuze lihlale liqonde futhi lihambisana ne-axis ye-spindle ngesikhathi sokusika.
Esikhungweni somshini ovundlile, i-spindle axis yesigayo iqondiswe ohlangothini lwe-Y-axis. Isakhiwo esivundlile sisho ukuthi lezi zigayo zivame ukuthatha isikhala esiningi phansi kwesitolo semishini; ngokuvamile zisinda futhi zinamandla kakhulu kunemishini eqondile.
Umshini wokugaya ovundlile uvame ukusetshenziswa uma kudingeka ukuqeda okungcono; lokho kungenxa yokuthi ukuqondiswa kwe-spindle kusho ukuthi ama-chips asikiwe ayawa ngokwemvelo futhi asuswe kalula. (Njengenzuzo eyengeziwe, ukususwa kwama-chip okuphumelelayo kusiza ukwandisa impilo yamathuluzi.)
Ngokuvamile, izikhungo zomshini eziqondile zivame kakhulu ngoba zingaba namandla njengezikhungo zomshini eziqondile futhi zingaphatha izingxenye ezincane kakhulu. Ngaphezu kwalokho, izikhungo eziqondile zinendawo encane kunezikhungo zomshini eziqondile.
Izigayo ze-CNC ezinama-axis amaningi
Izikhungo zokugaya ze-CNC eziqondile ziyatholakala ngama-axes amaningi. I-mill ene-axis ezintathu isebenzisa ama-axes e-X, Y, kanye ne-Z emisebenzini eyahlukahlukene. Nge-mill ene-axis ezine, umshini ungajikeleza ku-axis eqondile nevundlile bese uhambisa umsebenzi ukuze uvumele ukushintshwa okuqhubekayo.
Imishini yokugaya enezingqimba ezi-5 inama-axes amathathu endabuko kanye nama-axes amabili engeziwe ajikelezayo, okwenza ukuthi i-workpiece ijikelezwe njengoba ikhanda le-spindle lihamba nxazonke. Lokhu kwenza izinhlangothi ezinhlanu ze-workpiece zikwazi ukushintshwa ngaphandle kokususa i-workpiece bese kusethwa kabusha umshini.
Ama-lathe e-CNC
I-lathe — ebizwa nangokuthi isikhungo sokujika — ine-spindle eyodwa noma ngaphezulu, kanye ne-X kanye ne-Z axes. Umshini usetshenziselwa ukuzungezisa i-workpiece ku-axis yawo ukuze wenze imisebenzi ehlukahlukene yokusika nokubumba, usebenzisa amathuluzi ahlukahlukene ku-workpiece.
Ama-lathe e-CNC, abizwa nangokuthi ama-lathe asebenzayo asebenzayo, alungele ukudala izingxenye ezilinganayo zesilinda noma eziyindilinga. Njengezigayo ze-CNC, ama-lathe e-CNC angaphatha imisebenzi emincane efana ne-prototyping kodwa futhi angalungiselelwa ukuphindaphinda okuphezulu, asekele ukukhiqizwa kwevolumu ephezulu.
Ama-lathe e-CNC angaphinde asetshenziswe ukuze kukhiqizwe ngaphandle kwezandla, okwenza asetshenziswe kabanzi embonini yezimoto, ye-elekthronikhi, yezindiza, yerobhothi kanye neyamadivayisi ezokwelapha.
Indlela i-lathe ye-CNC esebenza ngayo
Nge-lathe ye-CNC, ibha engenalutho yezinto ezisetshenzisiwe ifakwa enqwabeni ye-spindle ye-lathe. Le chuck ibamba i-workpiece endaweni yayo ngenkathi i-spindle ijikeleza. Lapho i-spindle ifinyelela isivinini esidingekayo, ithuluzi lokusika elingaguquki lihlanganiswa ne-workpiece ukuze kususwe izinto futhi kufezwe i-geometry efanele.
I-lathe ye-CNC ingenza imisebenzi eminingana, njengokubhoboza, ukuthungela, ukubhoboza, ukulungisa kabusha, ukuqondisa, kanye nokujika kwe-taper. Imisebenzi ehlukene idinga ukuguqulwa kwamathuluzi futhi ingandisa izindleko nesikhathi sokusetha.
Uma yonke imisebenzi yokugaya edingekayo isiqediwe, ingxenye iyasikwa esitokweni ukuze iqhutshwe phambili, uma kudingeka. I-lathe ye-CNC isuke isilungele ukuphinda umsebenzi, isikhathi sokusetha esincane noma esingekho esidingekayo phakathi.
Ama-lathe e-CNC angaphinde afake izinhlobo ezahlukene ze-bar feeders ezizenzakalelayo, ezinciphisa inani lokuphathwa kwezinto zokusetshenziswa ngesandla futhi zinikeze izinzuzo ezifana nalezi ezilandelayo:
■ Nciphisa isikhathi nomzamo odingekayo kumqhubi womshini
■ Sekela i-barstock ukuze unciphise ukudlidliza okungathinta kabi ukunemba
■ Vumela ithuluzi lomshini ukuthi lisebenze ngesivinini esiphezulu se-spindle
■ Nciphisa izikhathi zokushintsha
■ Nciphisa imfucuza yezinto ezibonakalayo
Izinhlobo ze-CNC lathes
Kunezinhlobo eziningi ezahlukene zama-lathe, kodwa ezivame kakhulu ama-lathe e-CNC angu-2-axis kanye nama-lathe azenzakalelayo ase-China.
Iningi lama-lathe e-CNC e-China lisebenzisa i-spindle eyodwa noma ezimbili eziyinhloko kanye ne-spindle eyodwa noma ezimbili ezingemuva (noma zesibili), kanye nokudluliselwa okujikelezayo okunesibopho saleyo yokuqala. I-spindle eyinhloko yenza umsebenzi oyinhloko wokusebenza ngomshini, ngosizo lwe-guide bushing.
Ngaphezu kwalokho, amanye ama-lathe esitayela saseShayina afakwe ikhanda lesibili lamathuluzi elisebenza njengomshini wokugaya we-CNC.
Nge-lathe ezenzakalelayo yesitayela saseShayina se-CNC, izinto ezisetshenziswayo zifakwa nge-sliding head spindle zibe yi-guide bushing. Lokhu kuvumela ithuluzi ukuthi lisike izinto eduze nendawo lapho izinto ezisetshenziswa khona, okwenza umshini waseShayina ube wusizo kakhulu ezingxenyeni ezinde nezincane eziphendukile kanye nase-micromachining.
Izikhungo zokujika ze-CNC ezinama-axis amaningi kanye nama-lathe esitayela saseShayina zingafeza imisebenzi eminingi yokugaya kusetshenziswa umshini owodwa. Lokhu kuzenza zibe inketho engabizi kakhulu yejometri eziyinkimbinkimbi ebezingadinga imishini eminingi noma izinguquko zamathuluzi kusetshenziswa imishini efana nomshini wokugaya wendabuko we-CNC.